/* pcapng.c
 *
 * $Id$
 *
 * Wiretap Library
 * Copyright (c) 1998 by Gilbert Ramirez <gram@alumni.rice.edu>
 *
 * File format support for pcap-ng file format
 * Copyright (c) 2007 by Ulf Lamping <ulf.lamping@web.de>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

/* File format reference:
 *   http://www.winpcap.org/ntar/draft/PCAP-DumpFileFormat.html
 * Related Wiki page:
 *   http://wiki.wireshark.org/Development/PcapNg
 */

#include "config.h"

#include <stdlib.h>
#include <string.h>
#include <errno.h>


#include "wtap-int.h"
#include <epan/addr_resolv.h>
#include "file_wrappers.h"
#include "buffer.h"
#include "libpcap.h"
#include "pcap-common.h"
#include "pcap-encap.h"
#include "pcapng.h"

#if 0
#define pcapng_debug0(str) g_warning(str)
#define pcapng_debug1(str,p1) g_warning(str,p1)
#define pcapng_debug2(str,p1,p2) g_warning(str,p1,p2)
#define pcapng_debug3(str,p1,p2,p3) g_warning(str,p1,p2,p3)
#else
#define pcapng_debug0(str)
#define pcapng_debug1(str,p1)
#define pcapng_debug2(str,p1,p2)
#define pcapng_debug3(str,p1,p2,p3)
#endif

static gboolean
pcapng_read(wtap *wth, int *err, gchar **err_info,
    gint64 *data_offset);
static gboolean
pcapng_seek_read(wtap *wth, gint64 seek_off,
    struct wtap_pkthdr *phdr, Buffer *buf, int length,
    int *err, gchar **err_info);
static void
pcapng_close(wtap *wth);


/* pcapng: common block header for every block type */
typedef struct pcapng_block_header_s {
        guint32 block_type;
        guint32 block_total_length;
        /* x bytes block_body */
        /* guint32 block_total_length */
} pcapng_block_header_t;

/*
 * Minimum block size = size of block header + size of block trailer.
 */
#define MIN_BLOCK_SIZE  ((guint32)(sizeof(pcapng_block_header_t) + sizeof(guint32)))

/*
 * In order to keep from trying to allocate large chunks of memory,
 * which could either fail or, even if it succeeds, chew up so much
 * address space or memory+backing store as not to leave room for
 * anything else, we impose an upper limit on the size of blocks
 * we're willing to handle.
 *
 * For now, we pick an arbitrary limit of 16MB (OK, fine, 16MiB, but
 * don't try saying that on Wikipedia :-) :-) :-)).
 */
#define MAX_BLOCK_SIZE	(16*1024*1024)

/* pcapng: section header block */
typedef struct pcapng_section_header_block_s {
        /* pcapng_block_header_t */
        guint32 magic;
        guint16 version_major;
        guint16 version_minor;
        guint64 section_length; /* might be -1 for unknown */
        /* ... Options ... */
} pcapng_section_header_block_t;

/*
 * Minimum SHB size = minimum block size + size of fixed length portion of SHB.
 */
#define MIN_SHB_SIZE    ((guint32)(MIN_BLOCK_SIZE + sizeof(pcapng_section_header_block_t)))

/* pcapng: interface description block */
typedef struct pcapng_interface_description_block_s {
        guint16 linktype;
        guint16 reserved;
        guint32 snaplen;
        /* ... Options ... */
} pcapng_interface_description_block_t;

/*
 * Minimum IDB size = minimum block size + size of fixed length portion of IDB.
 */
#define MIN_IDB_SIZE    ((guint32)(MIN_BLOCK_SIZE + sizeof(pcapng_interface_description_block_t)))

/* pcapng: packet block (obsolete) */
typedef struct pcapng_packet_block_s {
        guint16 interface_id;
        guint16 drops_count;
        guint32 timestamp_high;
        guint32 timestamp_low;
        guint32 captured_len;
        guint32 packet_len;
        /* ... Packet Data ... */
        /* ... Padding ... */
        /* ... Options ... */
} pcapng_packet_block_t;

/*
 * Minimum PB size = minimum block size + size of fixed length portion of PB.
 */
#define MIN_PB_SIZE     ((guint32)(MIN_BLOCK_SIZE + sizeof(pcapng_packet_block_t)))

/* pcapng: enhanced packet block */
typedef struct pcapng_enhanced_packet_block_s {
        guint32 interface_id;
        guint32 timestamp_high;
        guint32 timestamp_low;
        guint32 captured_len;
        guint32 packet_len;
        /* ... Packet Data ... */
        /* ... Padding ... */
        /* ... Options ... */
} pcapng_enhanced_packet_block_t;

/*
 * Minimum EPB size = minimum block size + size of fixed length portion of EPB.
 */
#define MIN_EPB_SIZE    ((guint32)(MIN_BLOCK_SIZE + sizeof(pcapng_enhanced_packet_block_t)))

/* pcapng: simple packet block */
typedef struct pcapng_simple_packet_block_s {
        guint32 packet_len;
        /* ... Packet Data ... */
        /* ... Padding ... */
} pcapng_simple_packet_block_t;

/*
 * Minimum SPB size = minimum block size + size of fixed length portion of SPB.
 */
#define MIN_SPB_SIZE    ((guint32)(MIN_BLOCK_SIZE + sizeof(pcapng_simple_packet_block_t)))

/* pcapng: name resolution block */
typedef struct pcapng_name_resolution_block_s {
        guint16 record_type;
        guint16 record_len;
        /* ... Record ... */
} pcapng_name_resolution_block_t;

/*
 * Minimum NRB size = minimum block size + size of smallest NRB record
 * (there must at least be an "end of records" record).
 */
#define MIN_NRB_SIZE    ((guint32)(MIN_BLOCK_SIZE + sizeof(pcapng_name_resolution_block_t)))

/* pcapng: interface statistics block */
typedef struct pcapng_interface_statistics_block_s {
        guint32 interface_id;
        guint32 timestamp_high;
        guint32 timestamp_low;
        /* ... Options ... */
} pcapng_interface_statistics_block_t;

/*
 * Minimum ISB size = minimum block size + size of fixed length portion of ISB.
 */
#define MIN_ISB_SIZE    ((guint32)(MIN_BLOCK_SIZE + sizeof(pcapng_interface_statistics_block_t)))

/* pcapng: common option header for every option type */
typedef struct pcapng_option_header_s {
        guint16 option_code;
        guint16 option_length;
        /* ... x bytes Option Body ... */
        /* ... Padding ... */
} pcapng_option_header_t;

struct option {
        guint16 type;
        guint16 value_length;
};

/* Block types */
#define BLOCK_TYPE_IDB 0x00000001 /* Interface Description Block */
#define BLOCK_TYPE_PB  0x00000002 /* Packet Block (obsolete) */
#define BLOCK_TYPE_SPB 0x00000003 /* Simple Packet Block */
#define BLOCK_TYPE_NRB 0x00000004 /* Name Resolution Block */
#define BLOCK_TYPE_ISB 0x00000005 /* Interface Statistics Block */
#define BLOCK_TYPE_EPB 0x00000006 /* Enhanced Packet Block */
#define BLOCK_TYPE_SHB 0x0A0D0D0A /* Section Header Block */

/* Options */
#define OPT_EOFOPT        0
#define OPT_COMMENT       1
#define OPT_SHB_HARDWARE  2
#define OPT_SHB_OS        3
#define OPT_SHB_USERAPPL  4
#define OPT_EPB_FLAGS     2
#define OPT_EPB_HASH      3
#define OPT_EPB_DROPCOUNT 4

/* Capture section */
#if 0
/* Moved to wtap.h */
typedef struct wtapng_section_s {
        /* mandatory */
        guint64                         section_length;
        /* options */
        gchar                           *opt_comment;   /* NULL if not available */
        gchar                           *shb_hardware;  /* NULL if not available */
        gchar                           *shb_os;                /* NULL if not available */
        gchar                           *shb_user_appl; /* NULL if not available */
} wtapng_section_t;
#endif

#if 0
/* Moved to wtap.h */

/* Interface Description
 *
 * Options:
 * if_name        2  A UTF-8 string containing the name of the device used to capture data. "eth0" / "\Device\NPF_{AD1CE675-96D0-47C5-ADD0-2504B9126B68}" / ...
 * if_description 3  A UTF-8 string containing the description of the device used to capture data. "Broadcom NetXtreme" / "First Ethernet Interface" / ...
 * if_IPv4addr    4  Interface network address and netmask. This option can be repeated multiple times within the same Interface Description Block when multiple IPv4 addresses are assigned to the interface. 192 168 1 1 255 255 255 0
 * if_IPv6addr    5  Interface network address and prefix length (stored in the last byte). This option can be repeated multiple times within the same Interface Description Block when multiple IPv6 addresses are assigned to the interface. 2001:0db8:85a3:08d3:1319:8a2e:0370:7344/64 is written (in hex) as "20 01 0d b8 85 a3 08 d3 13 19 8a 2e 03 70 73 44 40"
 * if_MACaddr     6  Interface Hardware MAC address (48 bits). 00 01 02 03 04 05
 * if_EUIaddr     7  Interface Hardware EUI address (64 bits), if available. TODO: give a good example
 * if_speed       8  Interface speed (in bps). 100000000 for 100Mbps
 * if_tsresol     9  Resolution of timestamps. If the Most Significant Bit is equal to zero, the remaining bits indicates the resolution of the timestamp as as a negative power of 10 (e.g. 6 means microsecond resolution, timestamps are the number of microseconds since 1/1/1970). If the Most Significant Bit is equal to one, the remaining bits indicates the resolution as as negative power of 2 (e.g. 10 means 1/1024 of second). If this option is not present, a resolution of 10^-6 is assumed (i.e. timestamps have the same resolution of the standard 'libpcap' timestamps). 6
 * if_tzone      10  Time zone for GMT support (TODO: specify better). TODO: give a good example
 * if_filter     11  The filter (e.g. "capture only TCP traffic") used to capture traffic. The first byte of the Option Data keeps a code of the filter used (e.g. if this is a libpcap string, or BPF bytecode, and more). More details about this format will be presented in Appendix XXX (TODO). (TODO: better use different options for different fields? e.g. if_filter_pcap, if_filter_bpf, ...) 00 "tcp port 23 and host 10.0.0.5"
 * if_os         12  A UTF-8 string containing the name of the operating system of the machine in which this interface is installed. This can be different from the same information that can be contained by the Section Header Block (Section 3.1 (Section Header Block (mandatory))) because the capture can have been done on a remote machine. "Windows XP SP2" / "openSUSE 10.2" / ...
 * if_fcslen     13  An integer value that specified the length of the Frame Check Sequence (in bits) for this interface. For link layers whose FCS length can change during time, the Packet Block Flags Word can be used (see Appendix A (Packet Block Flags Word)). 4
 * if_tsoffset   14  A 64 bits integer value that specifies an offset (in seconds) that must be added to the timestamp of each packet to obtain the absolute timestamp of a packet. If the option is missing, the timestamps stored in the packet must be considered absolute timestamps. The time zone of the offset can be specified with the option if_tzone. TODO: won't a if_tsoffset_low for fractional second offsets be useful for highly synchronized capture systems? 1234
 */

typedef struct wtapng_if_descr_s {
        /* mandatory */
        guint16                         link_type;
        guint                           encap;
        guint32                         snap_len;
        /* options */
        gchar                           *opt_comment;   /* NULL if not available */
        gchar                           *if_name;               /* NULL if not available, opt 2 A UTF-8 string containing the name of the device used to capture data. */
        gchar                           *if_description;/* NULL if not available, opt 3 A UTF-8 string containing the description of the device used to capture data. */
        /* XXX: if_IPv4addr opt 4  Interface network address and netmask.*/
        /* XXX: if_IPv6addr opt 5  Interface network address and prefix length (stored in the last byte).*/
        /* XXX: if_MACaddr  opt 6  Interface Hardware MAC address (48 bits).*/
        /* XXX: if_EUIaddr  opt 7  Interface Hardware EUI address (64 bits)*/
        guint64                         if_speed;       /* 0 if unknown, opt 8  Interface speed (in bps). 100000000 for 100Mbps */
        guint8                          if_tsresol;     /* default is 6 for microsecond resolution, opt 9  Resolution of timestamps.
                                                                         * If the Most Significant Bit is equal to zero, the remaining bits indicates the resolution of the timestamp as as a negative power of 10
                                                                         */
        /* XXX: if_tzone      10  Time zone for GMT support (TODO: specify better). */
        gchar                           *if_filter;     /* NULL if not available, opt 11  The filter (e.g. "capture only TCP traffic") used to capture traffic.
                                                                         * The first byte of the Option Data keeps a code of the filter used (e.g. if this is a libpcap string, or BPF bytecode, and more).
                                                                         */
        gchar                           *if_os;         /* NULL if not available, 12  A UTF-8 string containing the name of the operating system of the machine in which this interface is installed. */
        gint8                           if_fcslen;      /* -1 if unknown or changes between packets, opt 13  An integer value that specified the length of the Frame Check Sequence (in bits) for this interface. */
        /* XXX: guint64 if_tsoffset; opt 14  A 64 bits integer value that specifies an offset (in seconds)...*/
} wtapng_if_descr_t;
#endif

/* Packets */
typedef struct wtapng_packet_s {
        /* mandatory */
        guint32                         ts_high;        /* seconds since 1.1.1970 */
        guint32                         ts_low;         /* fraction of seconds, depends on if_tsresol */
        guint32                         cap_len;        /* data length in the file */
        guint32                         packet_len;     /* data length on the wire */
        guint32                         interface_id;   /* identifier of the interface. */
        guint16                         drops_count;    /* drops count, only valid for packet block */
                                                                                /* 0xffff if information no available */
        /* pack_hash */
        /* XXX - put the packet data / pseudo_header here as well? */
} wtapng_packet_t;

/* Simple Packets */
typedef struct wtapng_simple_packet_s {
        /* mandatory */
        guint32                         cap_len;        /* data length in the file */
        guint32                         packet_len;     /* data length on the wire */
        guint32                         pseudo_header_len;
        int                             wtap_encap;
        /* XXX - put the packet data / pseudo_header here as well? */
} wtapng_simple_packet_t;

/* Name Resolution */
typedef struct wtapng_name_res_s {
        /* options */
        gchar                           *opt_comment;   /* NULL if not available */
        /* XXX */
} wtapng_name_res_t;

#if 0
/* Interface Statistics moved to wtap.h*/
typedef struct wtapng_if_stats_s {
        /* mandatory */
        guint32                         interface_id;
        guint32                         ts_high;
        guint32                         ts_low;
        /* options */
        gchar                           *opt_comment;   /* NULL if not available */
        guint64                         isb_starttime;
        guint64                         isb_endtime;
        guint64                         isb_ifrecv;
        guint64                         isb_ifdrop;
        guint64                         isb_filteraccept;
        guint64                         isb_osdrop;
        guint64                         isb_usrdeliv;
} wtapng_if_stats_t;
#endif

typedef struct wtapng_block_s {
        guint32                                 type;           /* block_type as defined by pcapng */
        union {
                wtapng_section_t        section;
                wtapng_if_descr_t       if_descr;
                wtapng_name_res_t       name_res;
                wtapng_if_stats_t       if_stats;
        } data;

        /*
         * XXX - currently don't know how to handle these!
         *
         * For one thing, when we're reading a block, they must be
         * writable, i.e. not const, so that we can read into them,
         * but, when we're writing a block, they can be const, and,
         * in fact, they sometimes point to const values.
         */
        struct wtap_pkthdr *packet_header;
        Buffer *frame_buffer;
        int *file_encap;
} wtapng_block_t;

/* Interface data in private struct */
typedef struct interface_data_s {
        int wtap_encap;
        guint32 snap_len;
        guint64 time_units_per_second;
} interface_data_t;

typedef struct {
        gboolean shb_read;                                              /**< Set when first SHB read, second read will fail */
        gboolean byte_swapped;
        guint16 version_major;
        guint16 version_minor;
        GArray *interface_data;
        guint number_of_interfaces;
        gint8 if_fcslen;
        wtap_new_ipv4_callback_t add_new_ipv4;
        wtap_new_ipv6_callback_t add_new_ipv6;
} pcapng_t;

static int
pcapng_read_option(FILE_T fh, pcapng_t *pn, pcapng_option_header_t *oh,
                   char *content, guint len, guint to_read,
                   int *err, gchar **err_info)
{
        int     bytes_read;
        int     block_read;
        guint64 file_offset64;

        /* sanity check: don't run past the end of the block */
        if (to_read < sizeof (*oh)) {
                *err = WTAP_ERR_BAD_FILE;
                *err_info = g_strdup("pcapng_read_option: option goes past the end of the block");
                return -1;
        }

        /* read option header */
        errno = WTAP_ERR_CANT_READ;
        bytes_read = file_read(oh, sizeof (*oh), fh);
        if (bytes_read != sizeof (*oh)) {
                pcapng_debug0("pcapng_read_option: failed to read option");
                *err = file_error(fh, err_info);
                if (*err != 0)
                        return -1;
                return 0;
        }
        block_read = sizeof (*oh);
        if (pn->byte_swapped) {
                oh->option_code      = BSWAP16(oh->option_code);
                oh->option_length    = BSWAP16(oh->option_length);
        }

        /* sanity check: don't run past the end of the block */
        if (to_read < sizeof (*oh) + oh->option_length) {
                *err = WTAP_ERR_BAD_FILE;
                *err_info = g_strdup("pcapng_read_option: option goes past the end of the block");
                return -1;
        }

        /* sanity check: option length */
        if (oh->option_length > len) {
                pcapng_debug2("pcapng_read_option: option_length %u larger than buffer (%u)",
                              oh->option_length, len);
                return 0;
        }

        /* read option content */
        errno = WTAP_ERR_CANT_READ;
        bytes_read = file_read(content, oh->option_length, fh);
        if (bytes_read != oh->option_length) {
                pcapng_debug1("pcapng_read_option: failed to read content of option %u", oh->option_code);
                *err = file_error(fh, err_info);
                if (*err != 0)
                        return -1;
                return 0;
        }
        block_read += oh->option_length;

        /* jump over potential padding bytes at end of option */
        if ( (oh->option_length % 4) != 0) {
                file_offset64 = file_seek(fh, 4 - (oh->option_length % 4), SEEK_CUR, err);
                if (file_offset64 <= 0) {
                        if (*err != 0)
                                return -1;
                        return 0;
                }
                block_read += 4 - (oh->option_length % 4);
        }

        return block_read;
}


static int
pcapng_read_section_header_block(FILE_T fh, gboolean first_block,
                                 pcapng_block_header_t *bh, pcapng_t *pn,
                                 wtapng_block_t *wblock, int *err,
                                 gchar **err_info)
{
        int     bytes_read;
        guint   block_read;
        guint to_read, opt_cont_buf_len;
        pcapng_section_header_block_t shb;
        pcapng_option_header_t oh;
        char *option_content = NULL; /* Allocate as large as the options block */

        /*
         * Is this block long enough to be an SHB?
         */
        if (bh->block_total_length < MIN_SHB_SIZE) {
                /*
                 * No.
                 */
                if (first_block)
                        return 0;       /* probably not a pcap-ng file */
                *err = WTAP_ERR_BAD_FILE;
                *err_info = g_strdup_printf("pcapng_read_section_header_block: total block length %u of an SHB is less than the minimum SHB size %u",
                              bh->block_total_length, MIN_SHB_SIZE);
                return -1;
        }

        /* read block content */
        errno = WTAP_ERR_CANT_READ;
        bytes_read = file_read(&shb, sizeof shb, fh);
        if (bytes_read != sizeof shb) {
                *err = file_error(fh, err_info);
                if (*err == 0) {
                        if (first_block) {
                                /*
                                 * We're reading this as part of an open,
                                 * and this block is too short to be
                                 * an SHB, so the file is too short
                                 * to be a pcap-ng file.
                                 */
                                return 0;
                        }

                        /*
                         * Otherwise, just report this as an error.
                         */
                        *err = WTAP_ERR_SHORT_READ;
                }
                return -1;
        }
        block_read = bytes_read;

        /* is the magic number one we expect? */
        switch (shb.magic) {
            case(0x1A2B3C4D):
                /* this seems pcapng with correct byte order */
                pn->byte_swapped                = FALSE;
                pn->version_major               = shb.version_major;
                pn->version_minor               = shb.version_minor;

                pcapng_debug3("pcapng_read_section_header_block: SHB (little endian) V%u.%u, len %u",
                                pn->version_major, pn->version_minor, bh->block_total_length);
                break;
            case(0x4D3C2B1A):
                /* this seems pcapng with swapped byte order */
                pn->byte_swapped                = TRUE;
                pn->version_major               = BSWAP16(shb.version_major);
                pn->version_minor               = BSWAP16(shb.version_minor);

                /* tweak the block length to meet current swapping that we know now */
                bh->block_total_length  = BSWAP32(bh->block_total_length);

                pcapng_debug3("pcapng_read_section_header_block: SHB (big endian) V%u.%u, len %u",
                                pn->version_major, pn->version_minor, bh->block_total_length);
                break;
            default:
                /* Not a "pcapng" magic number we know about. */
                if (first_block) {
                        /* Not a pcap-ng file. */
                        return 0;
                }

                /* A bad block */
                *err = WTAP_ERR_BAD_FILE;
                *err_info = g_strdup_printf("pcapng_read_section_header_block: unknown byte-order magic number 0x%08x", shb.magic);
                return 0;
        }

        /* OK, at this point we assume it's a pcap-ng file.

           Don't try to allocate memory for a huge number of options, as
           that might fail and, even if it succeeds, it might not leave
           any address space or memory+backing store for anything else.

           We do that by imposing a maximum block size of MAX_BLOCK_SIZE.
           We check for this *after* checking the SHB for its byte
           order magic number, so that non-pcap-ng files are less
           likely to be treated as bad pcap-ng files. */
        if (bh->block_total_length > MAX_BLOCK_SIZE) {
                *err = WTAP_ERR_BAD_FILE;
                *err_info = g_strdup_printf("pcapng: total block length %u is too large (> %u)",
                              bh->block_total_length, MAX_BLOCK_SIZE);
                return -1;
        }

        /* We currently only suport one SHB */
        if (pn->shb_read == TRUE) {
                *err = WTAP_ERR_UNSUPPORTED;
                *err_info = g_strdup_printf("pcapng: multiple section header blocks not supported.");
                return 0;
        }

        /* we currently only understand SHB V1.0 */
        if (pn->version_major != 1 || pn->version_minor > 0) {
                *err = WTAP_ERR_UNSUPPORTED;
                *err_info = g_strdup_printf("pcapng_read_section_header_block: unknown SHB version %u.%u",
                              pn->version_major, pn->version_minor);
                return -1;
        }


        /* 64bit section_length (currently unused) */
        if (pn->byte_swapped) {
                wblock->data.section.section_length = BSWAP64(shb.section_length);
        } else {
                wblock->data.section.section_length = shb.section_length;
        }

        /* Option defaults */
        wblock->data.section.opt_comment        = NULL;
        wblock->data.section.shb_hardware       = NULL;
        wblock->data.section.shb_os                     = NULL;
        wblock->data.section.shb_user_appl      = NULL;

        /* Options */
        errno = WTAP_ERR_CANT_READ;
        to_read = bh->block_total_length - MIN_SHB_SIZE;

        /* Allocate enough memory to hold all options */
        opt_cont_buf_len = to_read;
        option_content = (char *)g_try_malloc(opt_cont_buf_len);
        if (opt_cont_buf_len != 0 && option_content == NULL) {
		*err = ENOMEM;	/* we assume we're out of memory */
		return -1;
	}
        pcapng_debug1("pcapng_read_section_header_block: Options %u bytes", to_read);
        while (to_read != 0) {
                /* read option */
                pcapng_debug1("pcapng_read_section_header_block: Options %u bytes remaining", to_read);
                bytes_read = pcapng_read_option(fh, pn, &oh, option_content, opt_cont_buf_len, to_read, err, err_info);
                if (bytes_read <= 0) {
                        pcapng_debug0("pcapng_read_section_header_block: failed to read option");
                        return bytes_read;
                }
                block_read += bytes_read;
                to_read -= bytes_read;

                /* handle option content */
                switch (oh.option_code) {
                    case(OPT_EOFOPT):
                        if (to_read != 0) {
                                pcapng_debug1("pcapng_read_section_header_block: %u bytes after opt_endofopt", to_read);
                        }
                        /* padding should be ok here, just get out of this */
                        to_read = 0;
                        break;
                    case(OPT_COMMENT):
                        if (oh.option_length > 0 && oh.option_length < opt_cont_buf_len) {
                                wblock->data.section.opt_comment = g_strndup(option_content, oh.option_length);
                                pcapng_debug1("pcapng_read_section_header_block: opt_comment %s", wblock->data.section.opt_comment);
                        } else {
                                pcapng_debug1("pcapng_read_section_header_block: opt_comment length %u seems strange", oh.option_length);
                        }
                        break;
                    case(OPT_SHB_HARDWARE):
                        if (oh.option_length > 0 && oh.option_length < opt_cont_buf_len) {
                                wblock->data.section.shb_hardware = g_strndup(option_content, oh.option_length);
                                pcapng_debug1("pcapng_read_section_header_block: shb_hardware %s", wblock->data.section.shb_hardware);
                        } else {
                                pcapng_debug1("pcapng_read_section_header_block: shb_hardware length %u seems strange", oh.option_length);
                        }
                        break;
                    case(OPT_SHB_OS):
                        if (oh.option_length > 0 && oh.option_length < opt_cont_buf_len) {
                                wblock->data.section.shb_os = g_strndup(option_content, oh.option_length);
                                pcapng_debug1("pcapng_read_section_header_block: shb_os %s", wblock->data.section.shb_os);
                        } else {
                                pcapng_debug2("pcapng_read_section_header_block: shb_os length %u seems strange, opt buffsize %u", oh.option_length,to_read);
                        }
                        break;
                    case(OPT_SHB_USERAPPL):
                        if (oh.option_length > 0 && oh.option_length < opt_cont_buf_len) {
                                wblock->data.section.shb_user_appl = g_strndup(option_content, oh.option_length);
                                pcapng_debug1("pcapng_read_section_header_block: shb_user_appl %s", wblock->data.section.shb_user_appl);
                        } else {
                                pcapng_debug1("pcapng_read_section_header_block: shb_user_appl length %u seems strange", oh.option_length);
                        }
                        break;
                    default:
                        pcapng_debug2("pcapng_read_section_header_block: unknown option %u - ignoring %u bytes",
                                      oh.option_code, oh.option_length);
                }
        }
        g_free(option_content);

        return block_read;
}


/* "Interface Description Block" */
static int
pcapng_read_if_descr_block(FILE_T fh, pcapng_block_header_t *bh, pcapng_t *pn,
                           wtapng_block_t *wblock, int *err, gchar **err_info)
{
        guint64 time_units_per_second = 1000000; /* default */
        int     bytes_read;
        guint   block_read;
        guint to_read, opt_cont_buf_len;
        pcapng_interface_description_block_t idb;
        pcapng_option_header_t oh;
        char *option_content = NULL; /* Allocate as large as the options block */

        /*
         * Is this block long enough to be an IDB?
         */
        if (bh->block_total_length < MIN_IDB_SIZE) {
                /*
                 * No.
                 */
                *err = WTAP_ERR_BAD_FILE;
                *err_info = g_strdup_printf("pcapng_read_if_descr_block: total block length %u of an IDB is less than the minimum IDB size %u",
                              bh->block_total_length, MIN_IDB_SIZE);
                return -1;
        }

        /* Don't try to allocate memory for a huge number of options, as
           that might fail and, even if it succeeds, it might not leave
           any address space or memory+backing store for anything else.

           We do that by imposing a maximum block size of MAX_BLOCK_SIZE.
           We check for this *after* checking the SHB for its byte
           order magic number, so that non-pcap-ng files are less
           likely to be treated as bad pcap-ng files. */
        if (bh->block_total_length > MAX_BLOCK_SIZE) {
                *err = WTAP_ERR_BAD_FILE;
                *err_info = g_strdup_printf("pcapng: total block length %u is too large (> %u)",
                              bh->block_total_length, MAX_BLOCK_SIZE);
                return -1;
        }

        /* read block content */
        errno = WTAP_ERR_CANT_READ;
        bytes_read = file_read(&idb, sizeof idb, fh);
        if (bytes_read != sizeof idb) {
                pcapng_debug0("pcapng_read_if_descr_block: failed to read IDB");
                *err = file_error(fh, err_info);
                if (*err != 0)
                        return -1;
                return 0;
        }
        block_read = bytes_read;

        /* mandatory values */
        if (pn->byte_swapped) {
                wblock->data.if_descr.link_type = BSWAP16(idb.linktype);
                wblock->data.if_descr.snap_len  = BSWAP32(idb.snaplen);
        } else {
                wblock->data.if_descr.link_type = idb.linktype;
                wblock->data.if_descr.snap_len  = idb.snaplen;
        }

        wblock->data.if_descr.wtap_encap = wtap_pcap_encap_to_wtap_encap(wblock->data.if_descr.link_type);
        wblock->data.if_descr.time_units_per_second = time_units_per_second;

        pcapng_debug3("pcapng_read_if_descr_block: IDB link_type %u (%s), snap %u",
                      wblock->data.if_descr.link_type,
                      wtap_encap_string(wblock->data.if_descr.wtap_encap),
                      wblock->data.if_descr.snap_len);

        if (wblock->data.if_descr.snap_len > WTAP_MAX_PACKET_SIZE) {
                /* This is unrealistic, but text2pcap currently uses 102400.
                 * We do not use this value, maybe we should check the
                 * snap_len of the packets against it. For now, only warn.
                 */
                pcapng_debug1("pcapng_read_if_descr_block: snapshot length %u unrealistic.",
                              wblock->data.if_descr.snap_len);
                /*wblock->data.if_descr.snap_len = WTAP_MAX_PACKET_SIZE;*/
        }

        /* Option defaults */
        wblock->data.if_descr.opt_comment = NULL;
        wblock->data.if_descr.if_name = NULL;
        wblock->data.if_descr.if_description = NULL;
        /* XXX: if_IPv4addr */
        /* XXX: if_IPv6addr */
        /* XXX: if_MACaddr */
        /* XXX: if_EUIaddr */
        wblock->data.if_descr.if_speed = 0;                     /* "unknown" */
        wblock->data.if_descr.if_tsresol = 6;                   /* default is 6 for microsecond resolution */
        wblock->data.if_descr.if_filter_str = NULL;
        wblock->data.if_descr.bpf_filter_len = 0;
        wblock->data.if_descr.if_filter_bpf_bytes = NULL;
        wblock->data.if_descr.if_os = NULL;
        wblock->data.if_descr.if_fcslen = -1;                   /* unknown or changes between packets */
        /* XXX: guint64 if_tsoffset; */


        /* Options */
        errno = WTAP_ERR_CANT_READ;
        to_read = bh->block_total_length - MIN_IDB_SIZE;

        /* Allocate enough memory to hold all options */
        opt_cont_buf_len = to_read;
        option_content = (char *)g_try_malloc(opt_cont_buf_len);
        if (opt_cont_buf_len != 0 && option_content == NULL) {
		*err = ENOMEM;	/* we assume we're out of memory */
		return -1;
	}

        while (to_read != 0) {
                /* read option */
                bytes_read = pcapng_read_option(fh, pn, &oh, option_content, opt_cont_buf_len, to_read, err, err_info);
                if (bytes_read <= 0) {
                        pcapng_debug0("pcapng_read_if_descr_block: failed to read option");
                        return bytes_read;
                }
                block_read += bytes_read;
                to_read -= bytes_read;

                /* handle option content */
                switch (oh.option_code) {
                    case(0): /* opt_endofopt */
                        if (to_read != 0) {
                                pcapng_debug1("pcapng_read_if_descr_block: %u bytes after opt_endofopt", to_read);
                        }
                        /* padding should be ok here, just get out of this */
                        to_read = 0;
                        break;
                    case(1): /* opt_comment */
                        if (oh.option_length > 0 && oh.option_length < opt_cont_buf_len) {
                                wblock->data.if_descr.opt_comment = g_strndup(option_content, oh.option_length);
                                pcapng_debug1("pcapng_read_if_descr_block: opt_comment %s", wblock->data.if_descr.opt_comment);
                        } else {
                                pcapng_debug1("pcapng_read_if_descr_block: opt_comment length %u seems strange", oh.option_length);
                        }
                        break;
                    case(2): /* if_name */
                        if (oh.option_length > 0 && oh.option_length < opt_cont_buf_len) {
                                wblock->data.if_descr.if_name = g_strndup(option_content, oh.option_length);
                                pcapng_debug1("pcapng_read_if_descr_block: if_name %s", wblock->data.if_descr.if_name);
                        } else {
                                pcapng_debug1("pcapng_read_if_descr_block: if_name length %u seems strange", oh.option_length);
                        }
                        break;
                    case(3): /* if_description */
                        if (oh.option_length > 0 && oh.option_length < opt_cont_buf_len) {
                            wblock->data.if_descr.if_description = g_strndup(option_content, oh.option_length);
                                pcapng_debug1("pcapng_read_if_descr_block: if_description %s", wblock->data.if_descr.if_description);
                        } else {
                                pcapng_debug1("pcapng_read_if_descr_block: if_description length %u seems strange", oh.option_length);
                        }
                        break;
                        /*
                         * if_IPv4addr    4  Interface network address and netmask. This option can be repeated multiple times within the same Interface Description Block when multiple IPv4 addresses are assigned to the interface. 192 168 1 1 255 255 255 0
                         * if_IPv6addr    5  Interface network address and prefix length (stored in the last byte). This option can be repeated multiple times within the same Interface Description Block when multiple IPv6 addresses are assigned to the interface. 2001:0db8:85a3:08d3:1319:8a2e:0370:7344/64 is written (in hex) as "20 01 0d b8 85 a3 08 d3 13 19 8a 2e 03 70 73 44 40"
                         * if_MACaddr     6  Interface Hardware MAC address (48 bits). 00 01 02 03 04 05
                         * if_EUIaddr     7  Interface Hardware EUI address (64 bits), if available. TODO: give a good example
                         */
                    case(8): /* if_speed */
                        if (oh.option_length == 8) {
                                /*  Don't cast a char[] into a guint64--the
                                 *  char[] may not be aligned correctly.
                                 */
                                memcpy(&wblock->data.if_descr.if_speed, option_content, sizeof(guint64));
                                if (pn->byte_swapped)
                                        wblock->data.if_descr.if_speed = BSWAP64(wblock->data.if_descr.if_speed);
                                pcapng_debug1("pcapng_read_if_descr_block: if_speed %" G_GINT64_MODIFIER "u (bps)", wblock->data.if_descr.if_speed);
                        } else {
                                    pcapng_debug1("pcapng_read_if_descr_block: if_speed length %u not 8 as expected", oh.option_length);
                        }
                        break;
                    case(9): /* if_tsresol */
                        if (oh.option_length == 1) {
                                guint64 base;
                                guint64 result;
                                guint8 i, exponent, if_tsresol;

                                if_tsresol = option_content[0];
                                if (if_tsresol & 0x80) {
                                        base = 2;
                                } else {
                                        base = 10;
                                }
                                exponent = (guint8)(if_tsresol & 0x7f);
                                if (((base == 2) && (exponent < 64)) || ((base == 10) && (exponent < 20))) {
                                        result = 1;
                                        for (i = 0; i < exponent; i++) {
                                                result *= base;
                                        }
                                        time_units_per_second = result;
                                } else {
                                        time_units_per_second = G_MAXUINT64;
                                }
                                if (time_units_per_second > (((guint64)1) << 32)) {
                                        pcapng_debug0("pcapng_open: time conversion might be inaccurate");
                                }
                                wblock->data.if_descr.time_units_per_second = time_units_per_second;
                                wblock->data.if_descr.if_tsresol = if_tsresol;
                                pcapng_debug2("pcapng_read_if_descr_block: if_tsresol %u, units/s %" G_GINT64_MODIFIER "u", wblock->data.if_descr.if_tsresol, wblock->data.if_descr.time_units_per_second);
                        } else {
                                pcapng_debug1("pcapng_read_if_descr_block: if_tsresol length %u not 1 as expected", oh.option_length);
                        }
                        break;
                        /*
                         * if_tzone      10  Time zone for GMT support (TODO: specify better). TODO: give a good example
                         */
                    case(11): /* if_filter */
                        if (oh.option_length > 0 && oh.option_length < opt_cont_buf_len) {
                                /* The first byte of the Option Data keeps a code of the filter used (e.g. if this is a libpcap string,
                                 * or BPF bytecode.
                                 */
                                if (option_content[0] == 0) {
                                        wblock->data.if_descr.if_filter_str = g_strndup(option_content+1, oh.option_length-1);
                                        pcapng_debug2("pcapng_read_if_descr_block: if_filter_str %s oh.option_length %u", wblock->data.if_descr.if_filter_str, oh.option_length);
                                } else if (option_content[0] == 1) {
                                        wblock->data.if_descr.bpf_filter_len = oh.option_length-1;
                                        wblock->data.if_descr.if_filter_bpf_bytes = (gchar *)g_malloc(oh.option_length-1);
                                        memcpy(&wblock->data.if_descr.if_filter_bpf_bytes, option_content+1, oh.option_length-1);
                                }
                        } else {
                                pcapng_debug1("pcapng_read_if_descr_block: if_filter length %u seems strange", oh.option_length);
                        }
                        break;
                    case(12): /* if_os */
                        /*
                         * if_os         12  A UTF-8 string containing the name of the operating system of the machine in which this interface is installed.
                         * This can be different from the same information that can be contained by the Section Header Block (Section 3.1 (Section Header Block (mandatory)))
                         * because the capture can have been done on a remote machine. "Windows XP SP2" / "openSUSE 10.2" / ...
                         */
                        if (oh.option_length > 0 && oh.option_length < opt_cont_buf_len) {
                            wblock->data.if_descr.if_os = g_strndup(option_content, oh.option_length);
                                pcapng_debug1("pcapng_read_if_descr_block: if_os %s", wblock->data.if_descr.if_os);
                        } else {
                                pcapng_debug1("pcapng_read_if_descr_block: if_os length %u seems strange", oh.option_length);
                        }
                        break;
                    case(13): /* if_fcslen */
                        if (oh.option_length == 1) {
                                wblock->data.if_descr.if_fcslen = option_content[0];
                                pn->if_fcslen = wblock->data.if_descr.if_fcslen;
                                pcapng_debug1("pcapng_read_if_descr_block: if_fcslen %u", wblock->data.if_descr.if_fcslen);
                                /* XXX - add sanity check */
                        } else {
                                pcapng_debug1("pcapng_read_if_descr_block: if_fcslen length %u not 1 as expected", oh.option_length);
                        }
                        break;
                        /*
                         * if_tsoffset   14  A 64 bits integer value that specifies an offset (in seconds) that must be added to the timestamp of each packet
                         * to obtain the absolute timestamp of a packet. If the option is missing, the timestamps stored in the packet must be considered absolute timestamps.
                         * The time zone of the offset can be specified with the option if_tzone.
                         * TODO: won't a if_tsoffset_low for fractional second offsets be useful for highly synchronized capture systems? 1234
                         */
                    default:
                        pcapng_debug2("pcapng_read_if_descr_block: unknown option %u - ignoring %u bytes",
                                      oh.option_code, oh.option_length);
                }
        }

        g_free(option_content);

        if (*wblock->file_encap == WTAP_ENCAP_UNKNOWN) {
                *wblock->file_encap = wblock->data.if_descr.wtap_encap;
        } else {
                if (*wblock->file_encap != wblock->data.if_descr.wtap_encap) {
                        *wblock->file_encap = WTAP_ENCAP_PER_PACKET;
                }
        }

        return block_read;
}


static int
pcapng_read_packet_block(FILE_T fh, pcapng_block_header_t *bh, pcapng_t *pn, wtapng_block_t *wblock, int *err, gchar **err_info, gboolean enhanced)
{
        int bytes_read;
        guint block_read;
        guint to_read, opt_cont_buf_len;
        guint64 file_offset64;
        pcapng_enhanced_packet_block_t epb;
        pcapng_packet_block_t pb;
        wtapng_packet_t packet;
        guint32 block_total_length;
        guint32 padding;
        interface_data_t int_data;
        guint64 ts;
        pcapng_option_header_t oh;
        int pseudo_header_len;
        char *option_content = NULL; /* Allocate as large as the options block */
        int fcslen;

        /* Don't try to allocate memory for a huge number of options, as
           that might fail and, even if it succeeds, it might not leave
           any address space or memory+backing store for anything else.

           We do that by imposing a maximum block size of MAX_BLOCK_SIZE.
           We check for this *after* checking the SHB for its byte
           order magic number, so that non-pcap-ng files are less
           likely to be treated as bad pcap-ng files. */
        if (bh->block_total_length > MAX_BLOCK_SIZE) {
                *err = WTAP_ERR_BAD_FILE;
                *err_info = g_strdup_printf("pcapng: total block length %u is too large (> %u)",
                              bh->block_total_length, MAX_BLOCK_SIZE);
                return -1;
        }

        /* "(Enhanced) Packet Block" read fixed part */
        errno = WTAP_ERR_CANT_READ;
        if (enhanced) {
                /*
                 * Is this block long enough to be an EPB?
                 */
                if (bh->block_total_length < MIN_EPB_SIZE) {
                        /*
                         * No.
                         */
                        *err = WTAP_ERR_BAD_FILE;
                        *err_info = g_strdup_printf("pcapng_read_packet_block: total block length %u of an EPB is less than the minimum EPB size %u",
                                      bh->block_total_length, MIN_EPB_SIZE);
                        return -1;
                }
                bytes_read = file_read(&epb, sizeof epb, fh);
                if (bytes_read != sizeof epb) {
                        pcapng_debug0("pcapng_read_packet_block: failed to read packet data");
                        *err = file_error(fh, err_info);
                        return 0;
                }
                block_read = bytes_read;

                if (pn->byte_swapped) {
                        packet.interface_id        = BSWAP32(epb.interface_id);
                        packet.drops_count         = -1; /* invalid */
                        packet.ts_high             = BSWAP32(epb.timestamp_high);
                        packet.ts_low              = BSWAP32(epb.timestamp_low);
                        packet.cap_len             = BSWAP32(epb.captured_len);
                        packet.packet_len          = BSWAP32(epb.packet_len);
                } else {
                        packet.interface_id        = epb.interface_id;
                        packet.drops_count         = -1; /* invalid */
                        packet.ts_high             = epb.timestamp_high;
                        packet.ts_low              = epb.timestamp_low;
                        packet.cap_len             = epb.captured_len;
                        packet.packet_len          = epb.packet_len;
                }
                pcapng_debug3("pcapng_read_packet_block: EPB on interface_id %d, cap_len %d, packet_len %d",
                              packet.interface_id, packet.cap_len, packet.packet_len);
        } else {
                /*
                 * Is this block long enough to be a PB?
                 */
                if (bh->block_total_length < MIN_PB_SIZE) {
                        /*
                         * No.
                         */
                        *err = WTAP_ERR_BAD_FILE;
                        *err_info = g_strdup_printf("pcapng_read_packet_block: total block length %u of a PB is less than the minimum PB size %u",
                                      bh->block_total_length, MIN_PB_SIZE);
                        return -1;
                }
                bytes_read = file_read(&pb, sizeof pb, fh);
                if (bytes_read != sizeof pb) {
                        pcapng_debug0("pcapng_read_packet_block: failed to read packet data");
                        *err = file_error(fh, err_info);
                        return 0;
                }
                block_read = bytes_read;

                if (pn->byte_swapped) {
                        packet.interface_id        = BSWAP16(pb.interface_id);
                        packet.drops_count         = BSWAP16(pb.drops_count);
                        packet.ts_high             = BSWAP32(pb.timestamp_high);
                        packet.ts_low              = BSWAP32(pb.timestamp_low);
                        packet.cap_len             = BSWAP32(pb.captured_len);
                        packet.packet_len          = BSWAP32(pb.packet_len);
                } else {
                        packet.interface_id        = pb.interface_id;
                        packet.drops_count         = pb.drops_count;
                        packet.ts_high             = pb.timestamp_high;
                        packet.ts_low              = pb.timestamp_low;
                        packet.cap_len             = pb.captured_len;
                        packet.packet_len          = pb.packet_len;
                }
                pcapng_debug3("pcapng_read_packet_block: PB on interface_id %d, cap_len %d, packet_len %d",
                              packet.interface_id, packet.cap_len, packet.packet_len);
        }

        /*
         * How much padding is there at the end of the packet data?
         */
        if ((packet.cap_len % 4) != 0)
                padding = 4 - (packet.cap_len % 4);
        else
                padding = 0;

        /* add padding bytes to "block total length" */
        /* (the "block total length" of some example files don't contain the packet data padding bytes!) */
        if (bh->block_total_length % 4) {
                block_total_length = bh->block_total_length + 4 - (bh->block_total_length % 4);
        } else {
                block_total_length = bh->block_total_length;
        }
        pcapng_debug1("pcapng_read_packet_block: block_total_length %d", block_total_length);

        /*
         * Is this block long enough to hold the packet data?
         */
        if (enhanced) {
                if (block_total_length <
                    MIN_EPB_SIZE + packet.cap_len + padding) {
                        /*
                         * No.
                         */
                        *err = WTAP_ERR_BAD_FILE;
                        *err_info = g_strdup_printf("pcapng_read_packet_block: total block length %u of EPB is too small for %u bytes of packet data",
                                      block_total_length, packet.cap_len);
                        return -1;
                }
        } else {
                if (block_total_length <
                    MIN_PB_SIZE + packet.cap_len + padding) {
                        /*
                         * No.
                         */
                        *err = WTAP_ERR_BAD_FILE;
                        *err_info = g_strdup_printf("pcapng_read_packet_block: total block length %u of PB is too small for %u bytes of packet data",
                                      block_total_length, packet.cap_len);
                        return -1;
                }
        }

        if (packet.cap_len > packet.packet_len) {
                *err = WTAP_ERR_BAD_FILE;
                *err_info = g_strdup_printf("pcapng_read_packet_block: cap_len %u is larger than packet_len %u.",
                    packet.cap_len, packet.packet_len);
                return 0;
        }
        if (packet.cap_len > WTAP_MAX_PACKET_SIZE) {
                *err = WTAP_ERR_BAD_FILE;
                *err_info = g_strdup_printf("pcapng_read_packet_block: cap_len %u is larger than WTAP_MAX_PACKET_SIZE %u.",
                    packet.cap_len, WTAP_MAX_PACKET_SIZE);
                return 0;
        }
        pcapng_debug3("pcapng_read_packet_block: packet data: packet_len %u captured_len %u interface_id %u",
                      packet.packet_len,
                      packet.cap_len,
                      packet.interface_id);

        if (packet.interface_id >= pn->number_of_interfaces) {
                *err = WTAP_ERR_BAD_FILE;
                *err_info = g_strdup_printf("pcapng: interface index %u is not less than interface count %u.",
                    packet.interface_id, pn->number_of_interfaces);
                return 0;
        }
        int_data = g_array_index(pn->interface_data, interface_data_t,
            packet.interface_id);

        wblock->packet_header->presence_flags = WTAP_HAS_TS|WTAP_HAS_CAP_LEN|WTAP_HAS_INTERFACE_ID;

        pcapng_debug3("pcapng_read_packet_block: encapsulation = %d (%s), pseudo header size = %d.",
                       int_data.wtap_encap,
                       wtap_encap_string(int_data.wtap_encap),
                       pcap_get_phdr_size(int_data.wtap_encap, &wblock->packet_header->pseudo_header));
        wblock->packet_header->interface_id = packet.interface_id;
        wblock->packet_header->pkt_encap = int_data.wtap_encap;

        memset((void *)&wblock->packet_header->pseudo_header, 0, sizeof(union wtap_pseudo_header));
        pseudo_header_len = pcap_process_pseudo_header(fh,
                                                       WTAP_FILE_TYPE_SUBTYPE_PCAPNG,
                                                       int_data.wtap_encap,
                                                       packet.cap_len,
                                                       TRUE,
                                                       wblock->packet_header,
                                                       err,
                                                       err_info);
        if (pseudo_header_len < 0) {
                return 0;
        }
        block_read += pseudo_header_len;
        if (pseudo_header_len != pcap_get_phdr_size(int_data.wtap_encap, &wblock->packet_header->pseudo_header)) {
                pcapng_debug1("pcapng_read_packet_block: Could only read %d bytes for pseudo header.",
                              pseudo_header_len);
        }
        wblock->packet_header->caplen = packet.cap_len - pseudo_header_len;
        wblock->packet_header->len = packet.packet_len - pseudo_header_len;

        /* Combine the two 32-bit pieces of the timestamp into one 64-bit value */
        ts = (((guint64)packet.ts_high) << 32) | ((guint64)packet.ts_low);
        wblock->packet_header->ts.secs = (time_t)(ts / int_data.time_units_per_second);
        wblock->packet_header->ts.nsecs = (int)(((ts % int_data.time_units_per_second) * 1000000000) / int_data.time_units_per_second);

        /* "(Enhanced) Packet Block" read capture data */
        errno = WTAP_ERR_CANT_READ;
	if (!wtap_read_packet_bytes(fh, wblock->frame_buffer,
	    packet.cap_len - pseudo_header_len, err, err_info))
		return 0;
        block_read += packet.cap_len - pseudo_header_len;

        /* jump over potential padding bytes at end of the packet data */
        if (padding != 0) {
                file_offset64 = file_seek(fh, padding, SEEK_CUR, err);
                if (file_offset64 <= 0) {
                        if (*err != 0)
                                return -1;
                        return 0;
                }
                block_read += padding;
        }

        /* Option defaults */
        wblock->packet_header->opt_comment = NULL;
        wblock->packet_header->drop_count  = -1;
        wblock->packet_header->pack_flags  = 0;

        /* FCS length default */
        fcslen = pn->if_fcslen;

        /* Options
         * opt_comment    1
         * epb_flags      2
         * epb_hash       3
         * epb_dropcount  4
         */
        errno = WTAP_ERR_CANT_READ;
        to_read = block_total_length -
                  (int)sizeof(pcapng_block_header_t) -
                  block_read -    /* fixed and variable part, including padding */
                  (int)sizeof(bh->block_total_length);

        /* Allocate enough memory to hold all options */
        opt_cont_buf_len = to_read;
        option_content = (char *)g_try_malloc(opt_cont_buf_len);
        if (opt_cont_buf_len != 0 && option_content == NULL) {
		*err = ENOMEM;	/* we assume we're out of memory */
		return -1;
	}

        while (to_read != 0) {
                /* read option */
                bytes_read = pcapng_read_option(fh, pn, &oh, option_content, opt_cont_buf_len, to_read, err, err_info);
                if (bytes_read <= 0) {
                        pcapng_debug0("pcapng_read_packet_block: failed to read option");
                        return bytes_read;
                }
                block_read += bytes_read;
                to_read -= bytes_read;

                /* handle option content */
                switch (oh.option_code) {
                    case(OPT_EOFOPT):
                        if (to_read != 0) {
                                pcapng_debug1("pcapng_read_packet_block: %u bytes after opt_endofopt", to_read);
                        }
                        /* padding should be ok here, just get out of this */
                        to_read = 0;
                        break;
                    case(OPT_COMMENT):
                        if (oh.option_length > 0 && oh.option_length < opt_cont_buf_len) {
                                wblock->packet_header->presence_flags |= WTAP_HAS_COMMENTS;
                                wblock->packet_header->opt_comment = g_strndup(option_content, oh.option_length);
                                pcapng_debug2("pcapng_read_packet_block: length %u opt_comment '%s'", oh.option_length, wblock->packet_header->opt_comment);
                        } else {
                                pcapng_debug1("pcapng_read_packet_block: opt_comment length %u seems strange", oh.option_length);
                        }
                        break;
                    case(OPT_EPB_FLAGS):
                        if (oh.option_length == 4) {
                                /*  Don't cast a char[] into a guint32--the
                                 *  char[] may not be aligned correctly.
                                 */
                                wblock->packet_header->presence_flags |= WTAP_HAS_PACK_FLAGS;
                                memcpy(&wblock->packet_header->pack_flags, option_content, sizeof(guint32));
                                if (pn->byte_swapped)
                                        wblock->packet_header->pack_flags = BSWAP32(wblock->packet_header->pack_flags);
                                if (wblock->packet_header->pack_flags & 0x000001E0) {
                                        /* The FCS length is present */
                                        fcslen = (wblock->packet_header->pack_flags & 0x000001E0) >> 5;
                                }
                                pcapng_debug1("pcapng_read_packet_block: pack_flags %u (ignored)", wblock->packet_header->pack_flags);
                        } else {
                                pcapng_debug1("pcapng_read_packet_block: pack_flags length %u not 4 as expected", oh.option_length);
                        }
                        break;
                    case(OPT_EPB_HASH):
                        pcapng_debug2("pcapng_read_packet_block: epb_hash %u currently not handled - ignoring %u bytes",
                                      oh.option_code, oh.option_length);
                        break;
                    case(OPT_EPB_DROPCOUNT):
                        if (oh.option_length == 8) {
                                /*  Don't cast a char[] into a guint32--the
                                 *  char[] may not be aligned correctly.
                                 */
                                wblock->packet_header->presence_flags |= WTAP_HAS_DROP_COUNT;
                                memcpy(&wblock->packet_header->drop_count, option_content, sizeof(guint64));
                                if (pn->byte_swapped)
                                        wblock->packet_header->drop_count = BSWAP64(wblock->packet_header->drop_count);

                                pcapng_debug1("pcapng_read_packet_block: drop_count %" G_GINT64_MODIFIER "u", wblock->packet_header->drop_count);
                        } else {
                                pcapng_debug1("pcapng_read_packet_block: drop_count length %u not 8 as expected", oh.option_length);
                        }
                        break;
                    default:
                        pcapng_debug2("pcapng_read_packet_block: unknown option %u - ignoring %u bytes",
                                      oh.option_code, oh.option_length);
                }
        }

        g_free(option_content);

        pcap_read_post_process(WTAP_FILE_TYPE_SUBTYPE_PCAPNG, int_data.wtap_encap,
            (union wtap_pseudo_header *)&wblock->packet_header->pseudo_header,
            buffer_start_ptr(wblock->frame_buffer),
            (int) (packet.cap_len - pseudo_header_len),
            pn->byte_swapped, fcslen);
        return block_read;
}


static int
pcapng_read_simple_packet_block(FILE_T fh, pcapng_block_header_t *bh, pcapng_t *pn, wtapng_block_t *wblock, int *err, gchar **err_info)
{
        int bytes_read;
        guint block_read;
        guint64 file_offset64;
        interface_data_t int_data;
        pcapng_simple_packet_block_t spb;
        wtapng_simple_packet_t simple_packet;
        guint32 block_total_length;
        guint32 padding;
        int pseudo_header_len;

        /*
         * Is this block long enough to be an SPB?
         */
        if (bh->block_total_length < MIN_SPB_SIZE) {
                /*
                 * No.
                 */
                *err = WTAP_ERR_BAD_FILE;
                *err_info = g_strdup_printf("pcapng_read_simple_packet_block: total block length %u of an SPB is less than the minimum SPB size %u",
                              bh->block_total_length, MIN_SPB_SIZE);
                return -1;
        }

        /* Don't try to allocate memory for a huge number of options, as
           that might fail and, even if it succeeds, it might not leave
           any address space or memory+backing store for anything else.

           We do that by imposing a maximum block size of MAX_BLOCK_SIZE.
           We check for this *after* checking the SHB for its byte
           order magic number, so that non-pcap-ng files are less
           likely to be treated as bad pcap-ng files. */
        if (bh->block_total_length > MAX_BLOCK_SIZE) {
                *err = WTAP_ERR_BAD_FILE;
                *err_info = g_strdup_printf("pcapng: total block length %u is too large (> %u)",
                              bh->block_total_length, MAX_BLOCK_SIZE);
                return -1;
        }

        /* "Simple Packet Block" read fixed part */
        errno = WTAP_ERR_CANT_READ;
        bytes_read = file_read(&spb, sizeof spb, fh);
        if (bytes_read != sizeof spb) {
                pcapng_debug0("pcapng_read_simple_packet_block: failed to read packet data");
                *err = file_error(fh, err_info);
                return 0;
        }
        block_read = bytes_read;

        if (0 >= pn->number_of_interfaces) {
                *err = WTAP_ERR_BAD_FILE;
                *err_info = g_strdup_printf("pcapng: SPB appeared before any IDBs");
                return 0;
        }
        int_data = g_array_index(pn->interface_data, interface_data_t, 0);

        if (pn->byte_swapped) {
                simple_packet.packet_len   = BSWAP32(spb.packet_len);
        } else {
                simple_packet.packet_len   = spb.packet_len;
        }

        /*
         * The captured length is not a field in the SPB; it can be
         * calculated as the minimum of the snapshot length from the
	 * IDB and the packet length, as per the pcap-ng spec.
         */
        simple_packet.cap_len = simple_packet.packet_len;
        if (simple_packet.cap_len > int_data.snap_len)
                simple_packet.cap_len = int_data.snap_len;

        /*
         * How much padding is there at the end of the packet data?
         */
        if ((simple_packet.cap_len % 4) != 0)
                padding = 4 - (simple_packet.cap_len % 4);
        else
                padding = 0;

        /* add padding bytes to "block total length" */
        /* (the "block total length" of some example files don't contain the packet data padding bytes!) */
        if (bh->block_total_length % 4) {
                block_total_length = bh->block_total_length + 4 - (bh->block_total_length % 4);
        } else {
                block_total_length = bh->block_total_length;
        }
        pcapng_debug1("pcapng_read_simple_packet_block: block_total_length %d", block_total_length);

        /*
         * Is this block long enough to hold the packet data?
         */
        if (block_total_length < MIN_SPB_SIZE + simple_packet.cap_len + padding) {
                /*
                 * No.  That means that the problem is with the packet
                 * length; the snapshot length can be bigger than the amount
                 * of packet data in the block, as it's a *maximum* length,
                 * not a *minimum* length.
                 */
                *err = WTAP_ERR_BAD_FILE;
                *err_info = g_strdup_printf("pcapng_read_simple_packet_block: total block length %u of PB is too small for %u bytes of packet data",
                              block_total_length, simple_packet.packet_len);
                return -1;
        }

        if (simple_packet.cap_len > WTAP_MAX_PACKET_SIZE) {
                *err = WTAP_ERR_BAD_FILE;
                *err_info = g_strdup_printf("pcapng_read_simple_packet_block: cap_len %u is larger than WTAP_MAX_PACKET_SIZE %u.",
                    simple_packet.cap_len, WTAP_MAX_PACKET_SIZE);
                return 0;
        }
        pcapng_debug1("pcapng_read_simple_packet_block: packet data: packet_len %u",
                       simple_packet.packet_len);

        pcapng_debug1("pcapng_read_simple_packet_block: Need to read pseudo header of size %d",
                      pcap_get_phdr_size(int_data.wtap_encap, &wblock->packet_header->pseudo_header));

        /* No time stamp in a simple packet block; no options, either */
        wblock->packet_header->presence_flags = WTAP_HAS_CAP_LEN|WTAP_HAS_INTERFACE_ID;
        wblock->packet_header->interface_id = 0;
        wblock->packet_header->pkt_encap = int_data.wtap_encap;
        wblock->packet_header->ts.secs = 0;
        wblock->packet_header->ts.nsecs = 0;
        wblock->packet_header->interface_id = 0;
        wblock->packet_header->opt_comment = NULL;
        wblock->packet_header->drop_count = 0;
        wblock->packet_header->pack_flags = 0;

        memset((void *)&wblock->packet_header->pseudo_header, 0, sizeof(union wtap_pseudo_header));
        pseudo_header_len = pcap_process_pseudo_header(fh,
                                                       WTAP_FILE_TYPE_SUBTYPE_PCAPNG,
                                                       int_data.wtap_encap,
                                                       simple_packet.cap_len,
                                                       TRUE,
                                                       wblock->packet_header,
                                                       err,
                                                       err_info);
        if (pseudo_header_len < 0) {
                return 0;
        }
        wblock->packet_header->caplen = simple_packet.cap_len - pseudo_header_len;
        wblock->packet_header->len = simple_packet.packet_len - pseudo_header_len;
        block_read += pseudo_header_len;
        if (pseudo_header_len != pcap_get_phdr_size(int_data.wtap_encap, &wblock->packet_header->pseudo_header)) {
                pcapng_debug1("pcapng_read_simple_packet_block: Could only read %d bytes for pseudo header.",
                              pseudo_header_len);
        }

        memset((void *)&wblock->packet_header->pseudo_header, 0, sizeof(union wtap_pseudo_header));

        /* "Simple Packet Block" read capture data */
        errno = WTAP_ERR_CANT_READ;
	if (!wtap_read_packet_bytes(fh, wblock->frame_buffer,
	    simple_packet.cap_len, err, err_info))
		return 0;
        block_read += simple_packet.cap_len;

        /* jump over potential padding bytes at end of the packet data */
        if ((simple_packet.cap_len % 4) != 0) {
                file_offset64 = file_seek(fh, 4 - (simple_packet.cap_len % 4), SEEK_CUR, err);
                if (file_offset64 <= 0) {
                        if (*err != 0)
                                return -1;
                        return 0;
                }
                block_read += 4 - (simple_packet.cap_len % 4);
        }

        pcap_read_post_process(WTAP_FILE_TYPE_SUBTYPE_PCAPNG, int_data.wtap_encap,
            (union wtap_pseudo_header *)&wblock->packet_header->pseudo_header,
            buffer_start_ptr(wblock->frame_buffer),
            (int) simple_packet.cap_len,
            pn->byte_swapped, pn->if_fcslen);
        return block_read;
}

#define NRES_ENDOFRECORD 0
#define NRES_IP4RECORD 1
#define NRES_IP6RECORD 2
#define PADDING4(x) ((((x + 3) >> 2) << 2) - x)
/* IPv6 + MAXNAMELEN */
#define INITIAL_NRB_REC_SIZE (16 + 64)

/*
 * Find the end of the NUL-terminated name the beginning of which is pointed
 * to by p; record_len is the number of bytes remaining in the record.
 *
 * Return the length of the name, including the terminating NUL.
 *
 * If we don't find a terminating NUL, return -1 and set *err and
 * *err_info appropriately.
 */
static int
name_resolution_block_find_name_end(const char *p, guint record_len, int *err,
    gchar **err_info)
{
        int namelen;

        namelen = 0;
        for (;;) {
                if (record_len == 0) {
                        /*
                         * We ran out of bytes in the record without
                         * finding a NUL.
                         */
                        *err = WTAP_ERR_BAD_FILE;
                        *err_info = g_strdup("pcapng_read_name_resolution_block: NRB record has non-null-terminated host name");
                        return -1;
                }
                if (*p == '\0')
                        break;  /* that's the terminating NUL */
                p++;
                record_len--;
                namelen++;      /* count this byte */
        }

        /* Include the NUL in the name length. */
        return namelen + 1;
}

static int
pcapng_read_name_resolution_block(FILE_T fh, pcapng_block_header_t *bh, pcapng_t *pn, wtapng_block_t *wblock _U_,int *err, gchar **err_info)
{
        int bytes_read = 0;
        int block_read = 0;
        int to_read;
        guint64 file_offset64;
        pcapng_name_resolution_block_t nrb;
        Buffer nrb_rec;
        guint32 v4_addr;
        guint record_len;
        char *namep;
        int namelen;

        /*
         * Is this block long enough to be an NRB?
         */
        if (bh->block_total_length < MIN_NRB_SIZE) {
                /*
                 * No.
                 */
                *err = WTAP_ERR_BAD_FILE;
                *err_info = g_strdup_printf("pcapng_read_name_resolution_block: total block length %u of an NRB is less than the minimum NRB size %u",
                              bh->block_total_length, MIN_NRB_SIZE);
                return -1;
        }

        /* Don't try to allocate memory for a huge number of options, as
           that might fail and, even if it succeeds, it might not leave
           any address space or memory+backing store for anything else.

           We do that by imposing a maximum block size of MAX_BLOCK_SIZE.
           We check for this *after* checking the SHB for its byte
           order magic number, so that non-pcap-ng files are less
           likely to be treated as bad pcap-ng files. */
        if (bh->block_total_length > MAX_BLOCK_SIZE) {
                *err = WTAP_ERR_BAD_FILE;
                *err_info = g_strdup_printf("pcapng: total block length %u is too large (> %u)",
                              bh->block_total_length, MAX_BLOCK_SIZE);
                return -1;
        }

        errno = WTAP_ERR_CANT_READ;
        to_read = bh->block_total_length - 8 - 4; /* We have read the header adn should not read the final block_total_length */

        pcapng_debug1("pcapng_read_name_resolution_block, total %d bytes", bh->block_total_length);

        /*
         * Start out with a buffer big enough for an IPv6 address and one
         * 64-byte name; we'll make the buffer bigger if necessary.
         */
        buffer_init(&nrb_rec, INITIAL_NRB_REC_SIZE);
        while (block_read < to_read) {
                /*
                 * There must be at least one record's worth of data
                 * here.
                 */
                if ((size_t)(to_read - block_read) < sizeof nrb) {
                        buffer_free(&nrb_rec);
                        *err = WTAP_ERR_BAD_FILE;
                        *err_info = g_strdup_printf("pcapng_read_name_resolution_block: %d bytes left in the block < NRB record header size %u",
                                      to_read - block_read,
                                      (guint)sizeof nrb);
                        return -1;
                }
                bytes_read = file_read(&nrb, sizeof nrb, fh);
                if (bytes_read != sizeof nrb) {
                        buffer_free(&nrb_rec);
                        pcapng_debug0("pcapng_read_name_resolution_block: failed to read record header");
                        *err = file_error(fh, err_info);
                        return 0;
                }
                block_read += bytes_read;

                if (pn->byte_swapped) {
                        nrb.record_type = BSWAP16(nrb.record_type);
                        nrb.record_len  = BSWAP16(nrb.record_len);
                }

                if (to_read - block_read < nrb.record_len + PADDING4(nrb.record_len)) {
                        buffer_free(&nrb_rec);
                        *err = WTAP_ERR_BAD_FILE;
                        *err_info = g_strdup_printf("pcapng_read_name_resolution_block: %d bytes left in the block < NRB record length + padding %u",
                                      to_read - block_read,
                                      nrb.record_len + PADDING4(nrb.record_len));
                        return -1;
                }
                switch (nrb.record_type) {
                        case NRES_ENDOFRECORD:
                                /* There shouldn't be any more data */
                                to_read = 0;
                                break;
                        case NRES_IP4RECORD:
                                /*
                                 * The smallest possible record must have
                                 * a 4-byte IPv4 address, hence a minimum
                                 * of 4 bytes.
                                 *
                                 * (The pcap-NG spec really indicates
                                 * that it must be at least 5 bytes,
                                 * as there must be at least one name,
                                 * and it really must be at least 6
                                 * bytes, as the name mustn't be null,
                                 * but there's no need to fail if there
                                 * aren't any names at all, and we
                                 * should report a null name as such.)
                                 */
                                if (nrb.record_len < 4) {
                                        buffer_free(&nrb_rec);
                                        *err = WTAP_ERR_BAD_FILE;
                                        *err_info = g_strdup_printf("pcapng_read_name_resolution_block: NRB record length for IPv4 record %u < minimum length 4",
                                                      nrb.record_len);
                                        return -1;
                                }
                                buffer_assure_space(&nrb_rec, nrb.record_len);
                                bytes_read = file_read(buffer_start_ptr(&nrb_rec),
                                    nrb.record_len, fh);
                                if (bytes_read != nrb.record_len) {
                                        buffer_free(&nrb_rec);
                                        pcapng_debug0("pcapng_read_name_resolution_block: failed to read IPv4 record data");
                                        *err = file_error(fh, err_info);
                                        return 0;
                                }
                                block_read += bytes_read;

                                if (pn->add_new_ipv4) {
                                        /*
                                         * Scan through all the names in
                                         * the record and add them.
                                         */
                                        memcpy(&v4_addr,
                                            buffer_start_ptr(&nrb_rec), 4);
                                        if (pn->byte_swapped)
                                                v4_addr = BSWAP32(v4_addr);
                                        for (namep = (char *)buffer_start_ptr(&nrb_rec) + 4, record_len = nrb.record_len - 4;
                                            record_len != 0;
                                            namep += namelen, record_len -= namelen) {
                                                /*
                                                 * Scan forward for a null
                                                 * byte.
                                                 */
                                                namelen = name_resolution_block_find_name_end(namep, record_len, err, err_info);
                                                if (namelen == -1) {
                                                        buffer_free(&nrb_rec);
                                                        return -1;      /* fail */
                                                }
                                                pn->add_new_ipv4(v4_addr, namep);
                                        }
                                }

                                file_offset64 = file_seek(fh, PADDING4(nrb.record_len), SEEK_CUR, err);
                                if (file_offset64 <= 0) {
                                        buffer_free(&nrb_rec);
                                        if (*err != 0)
                                                return -1;
                                        return 0;
                                }
                                block_read += PADDING4(nrb.record_len);
                                break;
                        case NRES_IP6RECORD:
                                /*
                                 * The smallest possible record must have
                                 * a 16-byte IPv6 address, hence a minimum
                                 * of 16 bytes.
                                 *
                                 * (The pcap-NG spec really indicates
                                 * that it must be at least 17 bytes,
                                 * as there must be at least one name,
                                 * and it really must be at least 18
                                 * bytes, as the name mustn't be null,
                                 * but there's no need to fail if there
                                 * aren't any names at all, and we
                                 * should report a null name as such.)
                                 */
                                if (nrb.record_len < 16) {
                                        buffer_free(&nrb_rec);
                                        *err = WTAP_ERR_BAD_FILE;
                                        *err_info = g_strdup_printf("pcapng_read_name_resolution_block: NRB record length for IPv6 record %u < minimum length 16",
                                                      nrb.record_len);
                                        return -1;
                                }
                                if (to_read < nrb.record_len) {
                                        buffer_free(&nrb_rec);
                                        pcapng_debug0("pcapng_read_name_resolution_block: insufficient data for IPv6 record");
                                        return 0;
                                }
                                buffer_assure_space(&nrb_rec, nrb.record_len);
                                bytes_read = file_read(buffer_start_ptr(&nrb_rec),
                                    nrb.record_len, fh);
                                if (bytes_read != nrb.record_len) {
                                        buffer_free(&nrb_rec);
                                        pcapng_debug0("pcapng_read_name_resolution_block: failed to read IPv6 record data");
                                        *err = file_error(fh, err_info);
                                        return 0;
                                }
                                block_read += bytes_read;

                                if (pn->add_new_ipv6) {
                                        for (namep = (char *)buffer_start_ptr(&nrb_rec) + 16, record_len = nrb.record_len - 16;
                                            record_len != 0;
                                            namep += namelen, record_len -= namelen) {
                                                /*
                                                 * Scan forward for a null
                                                 * byte.
                                                 */
                                                namelen = name_resolution_block_find_name_end(namep, record_len, err, err_info);
                                                if (namelen == -1) {
                                                        buffer_free(&nrb_rec);
                                                        return -1;      /* fail */
                                                }
                                                pn->add_new_ipv6(buffer_start_ptr(&nrb_rec),
                                                    namep);
                                        }
                                }

                                file_offset64 = file_seek(fh, PADDING4(nrb.record_len), SEEK_CUR, err);
                                if (file_offset64 <= 0) {
                                        buffer_free(&nrb_rec);
                                        if (*err != 0)
                                                return -1;
                                        return 0;
                                }
                                block_read += PADDING4(nrb.record_len);
                                break;
                        default:
                                pcapng_debug1("pcapng_read_name_resolution_block: unknown record type 0x%x", nrb.record_type);
                                file_offset64 = file_seek(fh, nrb.record_len + PADDING4(nrb.record_len), SEEK_CUR, err);
                                if (file_offset64 <= 0) {
                                        buffer_free(&nrb_rec);
                                        if (*err != 0)
                                                return -1;
                                        return 0;
                                }
                                block_read += nrb.record_len + PADDING4(nrb.record_len);
                                break;
                }
        }

        buffer_free(&nrb_rec);
        return block_read;
}

static int
pcapng_read_interface_statistics_block(FILE_T fh, pcapng_block_header_t *bh, pcapng_t *pn, wtapng_block_t *wblock,int *err, gchar **err_info)
{
        int bytes_read;
        guint block_read;
        guint to_read, opt_cont_buf_len;
        pcapng_interface_statistics_block_t isb;
        pcapng_option_header_t oh;
        char *option_content = NULL; /* Allocate as large as the options block */

        /*
         * Is this block long enough to be an ISB?
         */
        if (bh->block_total_length < MIN_ISB_SIZE) {
                /*
                 * No.
                 */
                *err = WTAP_ERR_BAD_FILE;
                *err_info = g_strdup_printf("pcapng_read_interface_statistics_block: total block length %u is too small (< %u)",
                              bh->block_total_length, MIN_ISB_SIZE);
                return -1;
        }

        /* Don't try to allocate memory for a huge number of options, as
           that might fail and, even if it succeeds, it might not leave
           any address space or memory+backing store for anything else.

           We do that by imposing a maximum block size of MAX_BLOCK_SIZE.
           We check for this *after* checking the SHB for its byte
           order magic number, so that non-pcap-ng files are less
           likely to be treated as bad pcap-ng files. */
        if (bh->block_total_length > MAX_BLOCK_SIZE) {
                *err = WTAP_ERR_BAD_FILE;
                *err_info = g_strdup_printf("pcapng: total block length %u is too large (> %u)",
                              bh->block_total_length, MAX_BLOCK_SIZE);
                return -1;
        }

        /* "Interface Statistics Block" read fixed part */
        errno = WTAP_ERR_CANT_READ;
        bytes_read = file_read(&isb, sizeof isb, fh);
        if (bytes_read != sizeof isb) {
                pcapng_debug0("pcapng_read_interface_statistics_block: failed to read packet data");
                *err = file_error(fh, err_info);
                return 0;
        }
        block_read = bytes_read;

        if (pn->byte_swapped) {
                wblock->data.if_stats.interface_id = BSWAP32(isb.interface_id);
                wblock->data.if_stats.ts_high      = BSWAP32(isb.timestamp_high);
                wblock->data.if_stats.ts_low       = BSWAP32(isb.timestamp_low);
        } else {
                wblock->data.if_stats.interface_id = isb.interface_id;
                wblock->data.if_stats.ts_high      = isb.timestamp_high;
                wblock->data.if_stats.ts_low       = isb.timestamp_low;
        }
        pcapng_debug1("pcapng_read_interface_statistics_block: interface_id %u", wblock->data.if_stats.interface_id);

        /* Option defaults */
        wblock->data.if_stats.opt_comment          = NULL;
        wblock->data.if_stats.isb_ifrecv           = -1;
        wblock->data.if_stats.isb_ifdrop           = -1;
        wblock->data.if_stats.isb_filteraccept     = -1;
        wblock->data.if_stats.isb_osdrop           = -1;
        wblock->data.if_stats.isb_usrdeliv         = -1;

        /* Options */
        errno = WTAP_ERR_CANT_READ;
        to_read = bh->block_total_length -
                  (MIN_BLOCK_SIZE + block_read);    /* fixed and variable part, including padding */

        /* Allocate enough memory to hold all options */
        opt_cont_buf_len = to_read;
        option_content = (char *)g_try_malloc(opt_cont_buf_len);
        if (opt_cont_buf_len != 0 && option_content == NULL) {
		*err = ENOMEM;	/* we assume we're out of memory */
		return -1;
	}

        while (to_read != 0) {
                /* read option */
                bytes_read = pcapng_read_option(fh, pn, &oh, option_content, opt_cont_buf_len, to_read, err, err_info);
                if (bytes_read <= 0) {
                        pcapng_debug0("pcapng_read_interface_statistics_block: failed to read option");
                        return bytes_read;
                }
                block_read += bytes_read;
                to_read -= bytes_read;

                /* handle option content */
                switch (oh.option_code) {
                    case(0): /* opt_endofopt */
                        if (to_read != 0) {
                                pcapng_debug1("pcapng_read_interface_statistics_block: %u bytes after opt_endofopt", to_read);
                        }
                        /* padding should be ok here, just get out of this */
                        to_read = 0;
                        break;
                    case(1): /* opt_comment */
                        if (oh.option_length > 0 && oh.option_length < opt_cont_buf_len) {
                                wblock->data.if_stats.opt_comment = g_strndup(option_content, oh.option_length);
                                pcapng_debug1("pcapng_read_interface_statistics_block: opt_comment %s", wblock->data.if_stats.opt_comment);
                        } else {
                                pcapng_debug1("pcapng_read_interface_statistics_block: opt_comment length %u seems strange", oh.option_length);
                        }
                        break;
                    case(2): /* isb_starttime */
                        if (oh.option_length == 8) {
                                guint32 high, low;

                                /*  Don't cast a char[] into a guint32--the
                                 *  char[] may not be aligned correctly.
                                 */
                                memcpy(&high, option_content, sizeof(guint32));
                                memcpy(&low, option_content + sizeof(guint32), sizeof(guint32));
                                if (pn->byte_swapped) {
                                        high = BSWAP32(high);
                                        low = BSWAP32(low);
                                }
                                wblock->data.if_stats.isb_starttime = (guint64)high;
                                wblock->data.if_stats.isb_starttime <<= 32;
                                wblock->data.if_stats.isb_starttime += (guint64)low;
                                pcapng_debug1("pcapng_read_interface_statistics_block: isb_starttime %" G_GINT64_MODIFIER "u", wblock->data.if_stats.isb_starttime);
                        } else {
                                pcapng_debug1("pcapng_read_interface_statistics_block: isb_starttime length %u not 8 as expected", oh.option_length);
                        }
                        break;
                    case(3): /* isb_endtime */
                        if (oh.option_length == 8) {
                                guint32 high, low;

                                /*  Don't cast a char[] into a guint32--the
                                 *  char[] may not be aligned correctly.
                                 */
                                memcpy(&high, option_content, sizeof(guint32));
                                memcpy(&low, option_content + sizeof(guint32), sizeof(guint32));
                                if (pn->byte_swapped) {
                                        high = BSWAP32(high);
                                        low = BSWAP32(low);
                                }
                                wblock->data.if_stats.isb_endtime = (guint64)high;
                                wblock->data.if_stats.isb_endtime <<= 32;
                                wblock->data.if_stats.isb_endtime += (guint64)low;
                                pcapng_debug1("pcapng_read_interface_statistics_block: isb_endtime %" G_GINT64_MODIFIER "u", wblock->data.if_stats.isb_endtime);
                        } else {
                                pcapng_debug1("pcapng_read_interface_statistics_block: isb_starttime length %u not 8 as expected", oh.option_length);
                        }
                        break;
                    case(4): /* isb_ifrecv */
                        if (oh.option_length == 8) {
                                /*  Don't cast a char[] into a guint32--the
                                 *  char[] may not be aligned correctly.
                                 */
                                memcpy(&wblock->data.if_stats.isb_ifrecv, option_content, sizeof(guint64));
                                if (pn->byte_swapped)
                                        wblock->data.if_stats.isb_ifrecv = BSWAP64(wblock->data.if_stats.isb_ifrecv);
                                pcapng_debug1("pcapng_read_interface_statistics_block: isb_ifrecv %" G_GINT64_MODIFIER "u", wblock->data.if_stats.isb_ifrecv);
                        } else {
                                pcapng_debug1("pcapng_read_interface_statistics_block: isb_ifrecv length %u not 8 as expected", oh.option_length);
                        }
                        break;
                    case(5): /* isb_ifdrop */
                        if (oh.option_length == 8) {
                                /*  Don't cast a char[] into a guint32--the
                                 *  char[] may not be aligned correctly.
                                 */
                                memcpy(&wblock->data.if_stats.isb_ifdrop, option_content, sizeof(guint64));
                                if (pn->byte_swapped)
                                        wblock->data.if_stats.isb_ifdrop = BSWAP64(wblock->data.if_stats.isb_ifdrop);
                                pcapng_debug1("pcapng_read_interface_statistics_block: isb_ifdrop %" G_GINT64_MODIFIER "u", wblock->data.if_stats.isb_ifdrop);
                        } else {
                                pcapng_debug1("pcapng_read_interface_statistics_block: isb_ifdrop length %u not 8 as expected", oh.option_length);
                        }
                        break;
                    case(6): /* isb_filteraccept 6 */
                        if (oh.option_length == 8) {
                                /*  Don't cast a char[] into a guint32--the
                                 *  char[] may not be aligned correctly.
                                 */
                                memcpy(&wblock->data.if_stats.isb_filteraccept, option_content, sizeof(guint64));
                                if (pn->byte_swapped)
                                        wblock->data.if_stats.isb_ifdrop = BSWAP64(wblock->data.if_stats.isb_filteraccept);
                                pcapng_debug1("pcapng_read_interface_statistics_block: isb_filteraccept %" G_GINT64_MODIFIER "u", wblock->data.if_stats.isb_filteraccept);
                        } else {
                                pcapng_debug1("pcapng_read_interface_statistics_block: isb_filteraccept length %u not 8 as expected", oh.option_length);
                        }
                        break;
                    case(7): /* isb_osdrop 7 */
                        if (oh.option_length == 8) {
                                /*  Don't cast a char[] into a guint32--the
                                 *  char[] may not be aligned correctly.
                                 */
                                memcpy(&wblock->data.if_stats.isb_osdrop, option_content, sizeof(guint64));
                                if (pn->byte_swapped)
                                        wblock->data.if_stats.isb_osdrop = BSWAP64(wblock->data.if_stats.isb_osdrop);
                                pcapng_debug1("pcapng_read_interface_statistics_block: isb_osdrop %" G_GINT64_MODIFIER "u", wblock->data.if_stats.isb_osdrop);
                        } else {
                                pcapng_debug1("pcapng_read_interface_statistics_block: isb_osdrop length %u not 8 as expected", oh.option_length);
                        }
                        break;
                    case(8): /* isb_usrdeliv 8  */
                        if (oh.option_length == 8) {
                                /*  Don't cast a char[] into a guint32--the
                                 *  char[] may not be aligned correctly.
                                 */
                                memcpy(&wblock->data.if_stats.isb_usrdeliv, option_content, sizeof(guint64));
                                if (pn->byte_swapped)
                                        wblock->data.if_stats.isb_usrdeliv = BSWAP64(wblock->data.if_stats.isb_osdrop);
                                pcapng_debug1("pcapng_read_interface_statistics_block: isb_usrdeliv %" G_GINT64_MODIFIER "u", wblock->data.if_stats.isb_usrdeliv);
                        } else {
                                pcapng_debug1("pcapng_read_interface_statistics_block: isb_usrdeliv length %u not 8 as expected", oh.option_length);
                        }
                        break;
                    default:
                        pcapng_debug2("pcapng_read_interface_statistics_block: unknown option %u - ignoring %u bytes",
                                      oh.option_code, oh.option_length);
                }
        }

        g_free(option_content);

        return block_read;
}


static int
pcapng_read_unknown_block(FILE_T fh, pcapng_block_header_t *bh, pcapng_t *pn _U_, wtapng_block_t *wblock _U_, int *err, gchar **err_info)
{
        int block_read;
        guint64 file_offset64;
        guint32 block_total_length;

        if (bh->block_total_length < MIN_BLOCK_SIZE) {
                *err = WTAP_ERR_BAD_FILE;
                *err_info = g_strdup_printf("pcapng_read_unknown_block: total block length %u of an unknown block type is less than the minimum block size %u",
                              bh->block_total_length, MIN_BLOCK_SIZE);
                return -1;
        }

        /* add padding bytes to "block total length" */
        /* (the "block total length" of some example files don't contain any padding bytes!) */
        if (bh->block_total_length % 4) {
                block_total_length = bh->block_total_length + 4 - (bh->block_total_length % 4);
        } else {
                block_total_length = bh->block_total_length;
        }

        block_read = block_total_length - MIN_BLOCK_SIZE;

        /* jump over this unknown block */
        file_offset64 = file_seek(fh, block_read, SEEK_CUR, err);
        if (file_offset64 <= 0) {
                if (*err != 0)
                        return -1;
                return 0;
        }

        return block_read;
}


static int
pcapng_read_block(FILE_T fh, gboolean first_block, pcapng_t *pn, wtapng_block_t *wblock, int *err, gchar **err_info)
{
        int block_read;
        int bytes_read;
        pcapng_block_header_t bh;
        guint32 block_total_length;


        /* Try to read the (next) block header */
        errno = WTAP_ERR_CANT_READ;
        bytes_read = file_read(&bh, sizeof bh, fh);
        if (bytes_read != sizeof bh) {
                *err = file_error(fh, err_info);
                pcapng_debug3("pcapng_read_block: file_read() returned %d instead of %u, err = %d.", bytes_read, (unsigned int)sizeof bh, *err);
                if (*err != 0)
                        return -1;
                return 0;
        }

        block_read = bytes_read;
        if (pn->byte_swapped) {
                bh.block_type         = BSWAP32(bh.block_type);
                bh.block_total_length = BSWAP32(bh.block_total_length);
        }

        wblock->type = bh.block_type;

        pcapng_debug1("pcapng_read_block: block_type 0x%x", bh.block_type);

        if (first_block) {
                /*
                 * This is being read in by pcapng_open(), so this block
                 * must be an SHB.  If it's not, this is not a pcap-ng
                 * file.
                 *
                 * XXX - check for various forms of Windows <-> UN*X
                 * mangling, and suggest that the file might be a
                 * pcap-ng file that was damaged in transit?
                 */
                if (bh.block_type != BLOCK_TYPE_SHB)
                        return 0;       /* not a pcap-ng file */
        }

        switch (bh.block_type) {
                case(BLOCK_TYPE_SHB):
                        bytes_read = pcapng_read_section_header_block(fh, first_block, &bh, pn, wblock, err, err_info);
                        break;
                case(BLOCK_TYPE_IDB):
                        bytes_read = pcapng_read_if_descr_block(fh, &bh, pn, wblock, err, err_info);
                        break;
                case(BLOCK_TYPE_PB):
                        bytes_read = pcapng_read_packet_block(fh, &bh, pn, wblock, err, err_info, FALSE);
                        break;
                case(BLOCK_TYPE_SPB):
                        bytes_read = pcapng_read_simple_packet_block(fh, &bh, pn, wblock, err, err_info);
                        break;
                case(BLOCK_TYPE_EPB):
                        bytes_read = pcapng_read_packet_block(fh, &bh, pn, wblock, err, err_info, TRUE);
                        break;
                case(BLOCK_TYPE_NRB):
                        bytes_read = pcapng_read_name_resolution_block(fh, &bh, pn, wblock, err, err_info);
                        break;
                case(BLOCK_TYPE_ISB):
                        bytes_read = pcapng_read_interface_statistics_block(fh, &bh, pn, wblock, err, err_info);
                        break;
                default:
                        pcapng_debug2("pcapng_read_block: Unknown block_type: 0x%x (block ignored), block total length %d", bh.block_type, bh.block_total_length);
                        bytes_read = pcapng_read_unknown_block(fh, &bh, pn, wblock, err, err_info);
        }

        if (bytes_read <= 0) {
                return bytes_read;
        }
        block_read += bytes_read;

        /* sanity check: first and second block lengths must match */
        errno = WTAP_ERR_CANT_READ;
        bytes_read = file_read(&block_total_length, sizeof block_total_length, fh);
        if (bytes_read != sizeof block_total_length) {
                pcapng_debug0("pcapng_read_block: couldn't read second block length");
                *err = file_error(fh, err_info);
                if (*err == 0)
                        *err = WTAP_ERR_SHORT_READ;
                return -1;
        }
        block_read += bytes_read;

        if (pn->byte_swapped)
                block_total_length = BSWAP32(block_total_length);

        if (!(block_total_length == bh.block_total_length)) {
                *err = WTAP_ERR_BAD_FILE;
                *err_info = g_strdup_printf("pcapng_read_block: total block lengths (first %u and second %u) don't match",
                              bh.block_total_length, block_total_length);
                return -1;
        }

        return block_read;
}

/* Process an IDB that we've just read. */
static void
pcapng_process_idb(wtap *wth, pcapng_t *pcapng, wtapng_block_t *wblock)
{
        wtapng_if_descr_t int_data;
        interface_data_t interface_data;

        int_data.wtap_encap = wblock->data.if_descr.wtap_encap;
        int_data.time_units_per_second = wblock->data.if_descr.time_units_per_second;
        int_data.link_type = wblock->data.if_descr.link_type;
        int_data.snap_len = wblock->data.if_descr.snap_len;
        /* Options */
        int_data.opt_comment = wblock->data.if_descr.opt_comment;
        int_data.if_name = wblock->data.if_descr.if_name;
        int_data.if_description = wblock->data.if_descr.if_description;
        /* XXX: if_IPv4addr opt 4  Interface network address and netmask.*/
        /* XXX: if_IPv6addr opt 5  Interface network address and prefix length (stored in the last byte).*/
        /* XXX: if_MACaddr  opt 6  Interface Hardware MAC address (48 bits).*/
        /* XXX: if_EUIaddr  opt 7  Interface Hardware EUI address (64 bits)*/
        int_data.if_speed = wblock->data.if_descr.if_speed;
        int_data.if_tsresol = wblock->data.if_descr.if_tsresol;
        /* XXX: if_tzone      10  Time zone for GMT support (TODO: specify better). */
        int_data.if_filter_str = wblock->data.if_descr.if_filter_str;
        int_data.bpf_filter_len = wblock->data.if_descr.bpf_filter_len;
        int_data.if_filter_bpf_bytes = wblock->data.if_descr.if_filter_bpf_bytes;
        int_data.if_os = wblock->data.if_descr.if_os;
        int_data.if_fcslen = wblock->data.if_descr.if_fcslen;
        /* XXX if_tsoffset; opt 14  A 64 bits integer value that specifies an offset (in seconds)...*/
        /* Interface statistics */
        int_data.num_stat_entries = 0;
        int_data.interface_statistics = NULL;

        g_array_append_val(wth->interface_data, int_data);
        wth->number_of_interfaces++;

        interface_data.wtap_encap = wblock->data.if_descr.wtap_encap;
        interface_data.snap_len = wblock->data.if_descr.snap_len;
        interface_data.time_units_per_second = wblock->data.if_descr.time_units_per_second;

        g_array_append_val(pcapng->interface_data, interface_data);
        pcapng->number_of_interfaces++;
}

/* classic wtap: open capture file */
int
pcapng_open(wtap *wth, int *err, gchar **err_info)
{
        int bytes_read;
        pcapng_t pn;
        wtapng_block_t wblock;
        pcapng_t *pcapng;
        pcapng_block_header_t bh;
        gint64 saved_offset;

        pn.shb_read = FALSE;
        /* we don't know the byte swapping of the file yet */
        pn.byte_swapped = FALSE;
        pn.if_fcslen = -1;
        pn.version_major = -1;
        pn.version_minor = -1;
        pn.interface_data = g_array_new(FALSE, FALSE, sizeof(interface_data_t));
        pn.number_of_interfaces = 0;


        /* we don't expect any packet blocks yet */
        wblock.frame_buffer = NULL;
        wblock.packet_header = NULL;
        wblock.file_encap = &wth->file_encap;

        pcapng_debug0("pcapng_open: opening file");
        /* read first block */
        bytes_read = pcapng_read_block(wth->fh, TRUE, &pn, &wblock, err, err_info);
        if (bytes_read <= 0) {
                pcapng_debug0("pcapng_open: couldn't read first SHB");
                *err = file_error(wth->fh, err_info);
                if (*err != 0 && *err != WTAP_ERR_SHORT_READ)
                        return -1;
                return 0;
        }

        /* first block must be a "Section Header Block" */
        if (wblock.type != BLOCK_TYPE_SHB) {
                /*
                 * XXX - check for damage from transferring a file
                 * between Windows and UN*X as text rather than
                 * binary data?
                 */
                pcapng_debug1("pcapng_open: first block type %u not SHB", wblock.type);
                return 0;
        }
        pn.shb_read = TRUE;

        /*
         * At this point, we've decided this is a pcap-NG file, not
         * some other type of file, so we can't return 0, as that
         * means "this isn't a pcap-NG file, try some other file
         * type".
         */
        wth->shb_hdr.opt_comment = wblock.data.section.opt_comment;
        wth->shb_hdr.shb_hardware = wblock.data.section.shb_hardware;
        wth->shb_hdr.shb_os = wblock.data.section.shb_os;
        wth->shb_hdr.shb_user_appl = wblock.data.section.shb_user_appl;

        wth->file_encap = WTAP_ENCAP_UNKNOWN;
        wth->snapshot_length = 0;
        wth->tsprecision = WTAP_FILE_TSPREC_NSEC;
        pcapng = (pcapng_t *)g_malloc(sizeof(pcapng_t));
        wth->priv = (void *)pcapng;
        *pcapng = pn;

        wth->subtype_read = pcapng_read;
        wth->subtype_seek_read = pcapng_seek_read;
        wth->subtype_close = pcapng_close;
        wth->file_type_subtype = WTAP_FILE_TYPE_SUBTYPE_PCAPNG;

        /* Read IDBs */
        wth->interface_data = g_array_new(FALSE, FALSE, sizeof(wtapng_if_descr_t));
        wth->number_of_interfaces = 0;

        /* Loop over all IDB:s that appear before any packets */
        while (1) {
                /* peek at next block */
                /* Try to read the (next) block header */
                saved_offset = file_tell(wth->fh);
                errno = WTAP_ERR_CANT_READ;
                bytes_read = file_read(&bh, sizeof bh, wth->fh);
                if (bytes_read == 0) {
                        pcapng_debug0("No more IDBs available...");
                        break;
                }
                if (bytes_read != sizeof bh) {
                        *err = file_error(wth->fh, err_info);
                        pcapng_debug3("pcapng_open:  Check for more IDB:s, file_read() returned %d instead of %u, err = %d.", bytes_read, (unsigned int)sizeof bh, *err);
                        if (*err == 0)
                                *err = WTAP_ERR_SHORT_READ;
                        return -1;
                }

                /* go back to where we were */
                file_seek(wth->fh, saved_offset, SEEK_SET, err);

                if (pn.byte_swapped) {
                        bh.block_type         = BSWAP32(bh.block_type);
                }

                pcapng_debug1("pcapng_open: Check for more IDB:s block_type 0x%x", bh.block_type);

                if (bh.block_type != BLOCK_TYPE_IDB) {
                        break;  /* No more IDB:s */
                }
                bytes_read = pcapng_read_block(wth->fh, FALSE, &pn, &wblock, err, err_info);
                if (bytes_read == 0) {
                        pcapng_debug0("No more IDBs available...");
                        break;
                }
                if (bytes_read <= 0) {
                        pcapng_debug0("pcapng_open: couldn't read IDB");
                        *err = file_error(wth->fh, err_info);
                        if (*err == 0)
                                *err = WTAP_ERR_SHORT_READ;
                        return -1;
                }
                pcapng_process_idb(wth, pcapng, &wblock);
                pcapng_debug2("pcapng_open: Read IDB number_of_interfaces %u, wtap_encap %i", wth->number_of_interfaces, *wblock.file_encap);
        }
        return 1;
}


/* classic wtap: read packet */
static gboolean
pcapng_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset)
{
        pcapng_t *pcapng = (pcapng_t *)wth->priv;
        int bytes_read;
        wtapng_block_t wblock;
        wtapng_if_descr_t *wtapng_if_descr;
        wtapng_if_stats_t if_stats;

        *data_offset = file_tell(wth->fh);
        pcapng_debug1("pcapng_read: data_offset is initially %" G_GINT64_MODIFIER "d", *data_offset);

        wblock.frame_buffer  = wth->frame_buffer;
        wblock.packet_header = &wth->phdr;
        wblock.file_encap    = &wth->file_encap;

        pcapng->add_new_ipv4 = wth->add_new_ipv4;
        pcapng->add_new_ipv6 = wth->add_new_ipv6;

        /* read next block */
        while (1) {
                bytes_read = pcapng_read_block(wth->fh, FALSE, pcapng, &wblock, err, err_info);
                if (bytes_read <= 0) {
                        pcapng_debug1("pcapng_read: data_offset is finally %" G_GINT64_MODIFIER "d", *data_offset);
                        pcapng_debug0("pcapng_read: couldn't read packet block");
                        return FALSE;
                }

                switch (wblock.type) {

                case(BLOCK_TYPE_SHB):
                        /* We don't currently support multi-section files. */
                        wth->phdr.pkt_encap = WTAP_ENCAP_UNKNOWN;
                        *err = WTAP_ERR_UNSUPPORTED;
                        *err_info = g_strdup_printf("pcapng: multi-section files not currently supported.");
                        return FALSE;

                case(BLOCK_TYPE_PB):
                case(BLOCK_TYPE_SPB):
                case(BLOCK_TYPE_EPB):
                        /* packet block - we've found a packet */
                        goto got_packet;

                case(BLOCK_TYPE_IDB):
                        /* A new interface */
                        pcapng_debug0("pcapng_read: block type BLOCK_TYPE_IDB");
                        *data_offset += bytes_read;
                        pcapng_process_idb(wth, pcapng, &wblock);
                        break;

                case(BLOCK_TYPE_NRB):
                        /* More name resolution entries */
                        pcapng_debug0("pcapng_read: block type BLOCK_TYPE_NRB");
                        *data_offset += bytes_read;
                        break;

                case(BLOCK_TYPE_ISB):
                        /* Another interface statistics report */
                        pcapng_debug0("pcapng_read: block type BLOCK_TYPE_ISB");
                        *data_offset += bytes_read;
                        pcapng_debug1("pcapng_read: *data_offset is updated to %" G_GINT64_MODIFIER "d", *data_offset);
                        if (wth->number_of_interfaces < wblock.data.if_stats.interface_id) {
                                pcapng_debug1("pcapng_read: BLOCK_TYPE_ISB wblock.if_stats.interface_id %u > number_of_interfaces", wblock.data.if_stats.interface_id);
                        } else {
                                /* Get the interface description */
                                wtapng_if_descr = &g_array_index(wth->interface_data, wtapng_if_descr_t, wblock.data.if_stats.interface_id);
                                if (wtapng_if_descr->num_stat_entries == 0) {
                                    /* First ISB found, no previous entry */
                                    pcapng_debug0("pcapng_read: block type BLOCK_TYPE_ISB. First ISB found, no previous entry");
                                    wtapng_if_descr->interface_statistics = g_array_new(FALSE, FALSE, sizeof(wtapng_if_stats_t));
                                }

                                if_stats.interface_id       = wblock.data.if_stats.interface_id;
                                if_stats.ts_high            = wblock.data.if_stats.ts_high;
                                if_stats.ts_low             = wblock.data.if_stats.ts_low;
                                /* options */
                                if_stats.opt_comment        = wblock.data.if_stats.opt_comment;	/* NULL if not available */
                                if_stats.isb_starttime      = wblock.data.if_stats.isb_starttime;
                                if_stats.isb_endtime        = wblock.data.if_stats.isb_endtime;
                                if_stats.isb_ifrecv         = wblock.data.if_stats.isb_ifrecv;
                                if_stats.isb_ifdrop         = wblock.data.if_stats.isb_ifdrop;
                                if_stats.isb_filteraccept   = wblock.data.if_stats.isb_filteraccept;
                                if_stats.isb_osdrop         = wblock.data.if_stats.isb_osdrop;
                                if_stats.isb_usrdeliv       = wblock.data.if_stats.isb_usrdeliv;

                                g_array_append_val(wtapng_if_descr->interface_statistics, if_stats);
                                wtapng_if_descr->num_stat_entries++;
                        }
                        break;

                default:
                        /* XXX - improve handling of "unknown" blocks */
                        pcapng_debug1("pcapng_read: Unknown block type 0x%08x", wblock.type);
                        *data_offset += bytes_read;
                        pcapng_debug1("pcapng_read: *data_offset is updated to %" G_GINT64_MODIFIER "d", *data_offset);
                        break;
                }
        }

got_packet:

        /*pcapng_debug2("Read length: %u Packet length: %u", bytes_read, wth->phdr.caplen);*/
        pcapng_debug1("pcapng_read: data_offset is finally %" G_GINT64_MODIFIER "d", *data_offset + bytes_read);

        return TRUE;
}


/* classic wtap: seek to file position and read packet */
static gboolean
pcapng_seek_read(wtap *wth, gint64 seek_off,
    struct wtap_pkthdr *phdr, Buffer *buf, int length _U_,
    int *err, gchar **err_info)
{
        pcapng_t *pcapng = (pcapng_t *)wth->priv;
        guint64 bytes_read64;
        int bytes_read;
        wtapng_block_t wblock;


        /* seek to the right file position */
        bytes_read64 = file_seek(wth->random_fh, seek_off, SEEK_SET, err);
        if (bytes_read64 <= 0) {
                return FALSE;   /* Seek error */
        }
        pcapng_debug1("pcapng_seek_read: reading at offset %" G_GINT64_MODIFIER "u", seek_off);

        wblock.frame_buffer = buf;
        wblock.packet_header = phdr;
        wblock.file_encap = &wth->file_encap;

        /* read the block */
        bytes_read = pcapng_read_block(wth->random_fh, FALSE, pcapng, &wblock, err, err_info);
        if (bytes_read <= 0) {
                pcapng_debug3("pcapng_seek_read: couldn't read packet block (err=%d, errno=%d, bytes_read=%d).",
                              *err, errno, bytes_read);
                return FALSE;
        }

        /* block must be a "Packet Block", an "Enhanced Packet Block",
           or a "Simple Packet Block" */
        if (wblock.type != BLOCK_TYPE_PB && wblock.type != BLOCK_TYPE_EPB &&
            wblock.type != BLOCK_TYPE_SPB) {
                pcapng_debug1("pcapng_seek_read: block type %u not PB/EPB/SPB", wblock.type);
                return FALSE;
        }

        return TRUE;
}


/* classic wtap: close capture file */
static void
pcapng_close(wtap *wth)
{
        pcapng_t *pcapng = (pcapng_t *)wth->priv;

        pcapng_debug0("pcapng_close: closing file");
        if (pcapng->interface_data != NULL) {
                g_array_free(pcapng->interface_data, TRUE);
        }
}



typedef struct {
        GArray *interface_data;
        guint number_of_interfaces;
} pcapng_dump_t;

static gboolean
pcapng_write_section_header_block(wtap_dumper *wdh, int *err)
{
        pcapng_block_header_t bh;
        pcapng_section_header_block_t shb;
        const guint32 zero_pad = 0;
        gboolean have_options = FALSE;
        struct option option_hdr;                   /* guint16 type, guint16 value_length; */
        guint32 options_total_length = 0;
        guint32 comment_len = 0, shb_hardware_len = 0, shb_os_len = 0, shb_user_appl_len = 0;
        guint32 comment_pad_len = 0, shb_hardware_pad_len = 0, shb_os_pad_len = 0, shb_user_appl_pad_len = 0;

        if (wdh->shb_hdr) {
                pcapng_debug0("pcapng_write_section_header_block: Have shb_hdr");
                /* Check if we should write comment option */
                if (wdh->shb_hdr->opt_comment) {
                        have_options = TRUE;
                        comment_len = (guint32)strlen(wdh->shb_hdr->opt_comment) & 0xffff;
                        if ((comment_len % 4)) {
                                comment_pad_len = 4 - (comment_len % 4);
                        } else {
                                comment_pad_len = 0;
                        }
                        options_total_length = options_total_length + comment_len + comment_pad_len + 4 /* comment options tag */ ;
                }

                /* Check if we should write shb_hardware option */
                if (wdh->shb_hdr->shb_hardware) {
                        have_options = TRUE;
                        shb_hardware_len = (guint32)strlen(wdh->shb_hdr->shb_hardware) & 0xffff;
                        if ((shb_hardware_len % 4)) {
                                shb_hardware_pad_len = 4 - (shb_hardware_len % 4);
                        } else {
                                shb_hardware_pad_len = 0;
                        }
                        options_total_length = options_total_length + shb_hardware_len + shb_hardware_pad_len + 4 /* options tag */ ;
                }

                /* Check if we should write shb_os option */
                if (wdh->shb_hdr->shb_os) {
                        have_options = TRUE;
                        shb_os_len = (guint32)strlen(wdh->shb_hdr->shb_os) & 0xffff;
                        if ((shb_os_len % 4)) {
                                shb_os_pad_len = 4 - (shb_os_len % 4);
                        } else {
                                shb_os_pad_len = 0;
                        }
                        options_total_length = options_total_length + shb_os_len + shb_os_pad_len + 4 /* options tag */ ;
                }

                /* Check if we should write shb_user_appl option */
                if (wdh->shb_hdr->shb_user_appl) {
                        have_options = TRUE;
                        shb_user_appl_len = (guint32)strlen(wdh->shb_hdr->shb_user_appl) & 0xffff;
                        if ((shb_user_appl_len % 4)) {
                                shb_user_appl_pad_len = 4 - (shb_user_appl_len % 4);
                        } else {
                                shb_user_appl_pad_len = 0;
                        }
                        options_total_length = options_total_length + shb_user_appl_len + shb_user_appl_pad_len + 4 /* options tag */ ;
                }
                if (have_options) {
                        /* End-of-options tag */
                        options_total_length += 4;
                }
        }

        /* write block header */
        bh.block_type = BLOCK_TYPE_SHB;
        bh.block_total_length = (guint32)(sizeof(bh) + sizeof(shb) + options_total_length + 4);
        pcapng_debug2("pcapng_write_section_header_block: Total len %u, Options total len %u",bh.block_total_length, options_total_length);

        if (!wtap_dump_file_write(wdh, &bh, sizeof bh, err))
                return FALSE;
        wdh->bytes_dumped += sizeof bh;

        /* write block fixed content */
        /* XXX - get these values from wblock? */
        shb.magic = 0x1A2B3C4D;
        shb.version_major = 1;
        shb.version_minor = 0;
        shb.section_length = -1;

        if (!wtap_dump_file_write(wdh, &shb, sizeof shb, err))
                return FALSE;
        wdh->bytes_dumped += sizeof shb;

        /* XXX - write (optional) block options
         * opt_comment  1
         * shb_hardware 2
         * shb_os       3
         * shb_user_appl 4
         */

        if (comment_len) {
                option_hdr.type          = OPT_COMMENT;
                option_hdr.value_length = comment_len;
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;

                /* Write the comments string */
                pcapng_debug3("pcapng_write_section_header_block, comment:'%s' comment_len %u comment_pad_len %u" , wdh->shb_hdr->opt_comment, comment_len, comment_pad_len);
                if (!wtap_dump_file_write(wdh, wdh->shb_hdr->opt_comment, comment_len, err))
                        return FALSE;
                wdh->bytes_dumped += comment_len;

                /* write padding (if any) */
                if (comment_pad_len != 0) {
                        if (!wtap_dump_file_write(wdh, &zero_pad, comment_pad_len, err))
                                return FALSE;
                        wdh->bytes_dumped += comment_pad_len;
                }
        }

        if (shb_hardware_len) {
                option_hdr.type          = OPT_SHB_HARDWARE;
                option_hdr.value_length = shb_hardware_len;
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;

                /* Write the string */
                pcapng_debug3("pcapng_write_section_header_block, shb_hardware:'%s' shb_hardware_len %u shb_hardware_pad_len %u" , wdh->shb_hdr->shb_hardware, shb_hardware_len, shb_hardware_pad_len);
                if (!wtap_dump_file_write(wdh, wdh->shb_hdr->shb_hardware, shb_hardware_len, err))
                        return FALSE;
                wdh->bytes_dumped += shb_hardware_len;

                /* write padding (if any) */
                if (shb_hardware_pad_len != 0) {
                        if (!wtap_dump_file_write(wdh, &zero_pad, shb_hardware_pad_len, err))
                                return FALSE;
                        wdh->bytes_dumped += shb_hardware_pad_len;
                }
        }

        if (shb_os_len) {
                option_hdr.type          = OPT_SHB_OS;
                option_hdr.value_length = shb_os_len;
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;

                /* Write the string */
                pcapng_debug3("pcapng_write_section_header_block, shb_os:'%s' shb_os_len %u shb_os_pad_len %u" , wdh->shb_hdr->shb_os, shb_os_len, shb_os_pad_len);
                if (!wtap_dump_file_write(wdh, wdh->shb_hdr->shb_os, shb_os_len, err))
                        return FALSE;
                wdh->bytes_dumped += shb_os_len;

                /* write padding (if any) */
                if (shb_os_pad_len != 0) {
                        if (!wtap_dump_file_write(wdh, &zero_pad, shb_os_pad_len, err))
                                return FALSE;
                        wdh->bytes_dumped += shb_os_pad_len;
                }
        }

        if (shb_user_appl_len) {
                option_hdr.type          = OPT_SHB_USERAPPL;
                option_hdr.value_length = shb_user_appl_len;
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;

                /* Write the comments string */
                pcapng_debug3("pcapng_write_section_header_block, shb_user_appl:'%s' shb_user_appl_len %u shb_user_appl_pad_len %u" , wdh->shb_hdr->shb_user_appl, shb_user_appl_len, shb_user_appl_pad_len);
                if (!wtap_dump_file_write(wdh, wdh->shb_hdr->shb_user_appl, shb_user_appl_len, err))
                        return FALSE;
                wdh->bytes_dumped += shb_user_appl_len;

                /* write padding (if any) */
                if (shb_user_appl_pad_len != 0) {
                        if (!wtap_dump_file_write(wdh, &zero_pad, shb_user_appl_pad_len, err))
                                return FALSE;
                        wdh->bytes_dumped += shb_user_appl_pad_len;
                }
        }

        /* Write end of options if we have otions */
        if (have_options) {
                option_hdr.type = OPT_EOFOPT;
                option_hdr.value_length = 0;
                if (!wtap_dump_file_write(wdh, &zero_pad, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;
        }

        /* write block footer */
        if (!wtap_dump_file_write(wdh, &bh.block_total_length,
            sizeof bh.block_total_length, err))
                return FALSE;
        wdh->bytes_dumped += sizeof bh.block_total_length;

        return TRUE;
}

#define IDB_OPT_IF_NAME         2
#define IDB_OPT_IF_DESCR        3
#define IDB_OPT_IF_SPEED        8
#define IDB_OPT_IF_TSRESOL      9
#define IDB_OPT_IF_FILTER       11
#define IDB_OPT_IF_OS           12

static gboolean
pcapng_write_if_descr_block(wtap_dumper *wdh, wtapng_if_descr_t *int_data, int *err)
{
        pcapng_block_header_t bh;
        pcapng_interface_description_block_t idb;
        const guint32 zero_pad = 0;
        gboolean have_options = FALSE;
        struct option option_hdr;                   /* guint16 type, guint16 value_length; */
        guint32 options_total_length = 0;
        guint32 comment_len = 0, if_name_len = 0, if_description_len = 0 , if_os_len = 0, if_filter_str_len = 0;
        guint32 comment_pad_len = 0, if_name_pad_len = 0, if_description_pad_len = 0, if_os_pad_len = 0, if_filter_str_pad_len = 0;


        pcapng_debug3("pcapng_write_if_descr_block: encap = %d (%s), snaplen = %d",
                      int_data->link_type,
                      wtap_encap_string(wtap_pcap_encap_to_wtap_encap(int_data->link_type)),
                      int_data->snap_len);

        if (int_data->link_type == (guint16)-1) {
                *err = WTAP_ERR_UNSUPPORTED_ENCAP;
                return FALSE;
        }

        /* Calculate options length */
        if (int_data->opt_comment) {
                have_options = TRUE;
                comment_len = (guint32)strlen(int_data->opt_comment) & 0xffff;
                if ((comment_len % 4)) {
                        comment_pad_len = 4 - (comment_len % 4);
                } else {
                        comment_pad_len = 0;
                }
                options_total_length = options_total_length + comment_len + comment_pad_len + 4 /* comment options tag */ ;
        }

        /*
         * if_name        2  A UTF-8 string containing the name of the device used to capture data.
         */
        if (int_data->if_name) {
                have_options = TRUE;
                if_name_len = (guint32)strlen(int_data->if_name) & 0xffff;
                if ((if_name_len % 4)) {
                        if_name_pad_len = 4 - (if_name_len % 4);
                } else {
                        if_name_pad_len = 0;
                }
                options_total_length = options_total_length + if_name_len + if_name_pad_len + 4 /* comment options tag */ ;
        }

        /*
         * if_description 3  A UTF-8 string containing the description of the device used to capture data.
         */
        if (int_data->if_description) {
                have_options = TRUE;
                if_description_len = (guint32)strlen(int_data->if_description) & 0xffff;
                if ((if_description_len % 4)) {
                        if_description_pad_len = 4 - (if_description_len % 4);
                } else {
                        if_description_pad_len = 0;
                }
                options_total_length = options_total_length + if_description_len + if_description_pad_len + 4 /* comment options tag */ ;
        }
        /* Currently not handled
         * if_IPv4addr    4  Interface network address and netmask.
         * if_IPv6addr    5  Interface network address and prefix length (stored in the last byte).
         * if_MACaddr     6  Interface Hardware MAC address (48 bits). 00 01 02 03 04 05
         * if_EUIaddr     7  Interface Hardware EUI address (64 bits), if available. TODO: give a good example
         */
        /*
         * if_speed       8  Interface speed (in bps). 100000000 for 100Mbps
         */
        if (int_data->if_speed != 0) {
                have_options = TRUE;
                options_total_length = options_total_length + 8 + 4;
        }
        /*
         * if_tsresol     9  Resolution of timestamps.
         */
        if (int_data->if_tsresol != 0) {
                have_options = TRUE;
                options_total_length = options_total_length + 4 + 4;
        }
        /* Not used
         * if_tzone      10  Time zone for GMT support (TODO: specify better). TODO: give a good example
         */
        /*
         * if_filter     11  The filter (e.g. "capture only TCP traffic") used to capture traffic.
         * The first byte of the Option Data keeps a code of the filter used (e.g. if this is a libpcap string, or BPF bytecode, and more).
         */
        if (int_data->if_filter_str) {
                have_options = TRUE;
                if_filter_str_len = (guint32)(strlen(int_data->if_filter_str) + 1) & 0xffff;
                if ((if_filter_str_len % 4)) {
                        if_filter_str_pad_len = 4 - (if_filter_str_len % 4);
                } else {
                        if_filter_str_pad_len = 0;
                }
                options_total_length = options_total_length + if_filter_str_len + if_filter_str_pad_len + 4 /* comment options tag */ ;
        }
        /*
         * if_os         12  A UTF-8 string containing the name of the operating system of the machine in which this interface is installed.
         */
        if (int_data->if_os) {
                have_options = TRUE;
                if_os_len = (guint32)strlen(int_data->if_os) & 0xffff;
                if ((if_os_len % 4)) {
                        if_os_pad_len = 4 - (if_os_len % 4);
                } else {
                        if_os_pad_len = 0;
                }
                options_total_length = options_total_length + if_os_len + if_os_pad_len + 4 /* comment options tag */ ;
        }
        /*
         * if_fcslen     13  An integer value that specified the length of the Frame Check Sequence (in bits) for this interface.
         * -1 if unknown or changes between packets, opt 13  An integer value that specified the length of the Frame Check Sequence (in bits) for this interface.
         */
        if (int_data->if_fcslen != 0) {
        }
        /* Not used
         * if_tsoffset   14  A 64 bits integer value that specifies an offset (in seconds) that must be added to the timestamp of each packet
         * to obtain the absolute timestamp of a packet. If the option is missing, the timestamps stored in the packet must be considered absolute timestamps.
         */

        if (have_options) {
                /* End-of-options tag */
                options_total_length += 4;
        }

        /* write block header */
        bh.block_type = BLOCK_TYPE_IDB;
        bh.block_total_length = (guint32)(sizeof(bh) + sizeof(idb) + options_total_length + 4);

        if (!wtap_dump_file_write(wdh, &bh, sizeof bh, err))
                return FALSE;
        wdh->bytes_dumped += sizeof bh;

        /* write block fixed content */
        idb.linktype    = int_data->link_type;
        idb.reserved    = 0;
        idb.snaplen     = int_data->snap_len;

        if (!wtap_dump_file_write(wdh, &idb, sizeof idb, err))
                return FALSE;
        wdh->bytes_dumped += sizeof idb;

        /* XXX - write (optional) block options */
        if (comment_len != 0) {
                option_hdr.type         = OPT_COMMENT;
                option_hdr.value_length = comment_len;
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;

                /* Write the comments string */
                pcapng_debug3("pcapng_write_if_descr_block, comment:'%s' comment_len %u comment_pad_len %u" , int_data->opt_comment, comment_len, comment_pad_len);
                if (!wtap_dump_file_write(wdh, int_data->opt_comment, comment_len, err))
                        return FALSE;
                wdh->bytes_dumped += comment_len;

                /* write padding (if any) */
                if (comment_pad_len != 0) {
                        if (!wtap_dump_file_write(wdh, &zero_pad, comment_pad_len, err))
                                return FALSE;
                        wdh->bytes_dumped += comment_pad_len;
                }
        }
        /*
         * if_name        2  A UTF-8 string containing the name of the device used to capture data.
         */
        if (if_name_len !=0) {
                option_hdr.type = IDB_OPT_IF_NAME;
                option_hdr.value_length = if_name_len;
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;

                /* Write the comments string */
                pcapng_debug3("pcapng_write_if_descr_block, if_name:'%s' if_name_len %u if_name_pad_len %u" , int_data->if_name, if_name_len, if_name_pad_len);
                if (!wtap_dump_file_write(wdh, int_data->if_name, if_name_len, err))
                        return FALSE;
                wdh->bytes_dumped += if_name_len;

                /* write padding (if any) */
                if (if_name_pad_len != 0) {
                        if (!wtap_dump_file_write(wdh, &zero_pad, if_name_pad_len, err))
                                return FALSE;
                        wdh->bytes_dumped += if_name_pad_len;
                }
        }
        /*
         * if_description 3  A UTF-8 string containing the description of the device used to capture data.
         */
        if (if_description_len != 0) {
                option_hdr.type          = IDB_OPT_IF_NAME;
                option_hdr.value_length = if_description_len;
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;

                /* Write the comments string */
                pcapng_debug3("pcapng_write_if_descr_block, if_description:'%s' if_description_len %u if_description_pad_len %u" , int_data->if_description, if_description_len, if_description_pad_len);
                if (!wtap_dump_file_write(wdh, int_data->if_description, if_description_len, err))
                        return FALSE;
                wdh->bytes_dumped += if_description_len;

                /* write padding (if any) */
                if (if_description_pad_len != 0) {
                        if (!wtap_dump_file_write(wdh, &zero_pad, if_description_pad_len, err))
                                return FALSE;
                        wdh->bytes_dumped += if_description_pad_len;
                }
        }
        /* Currently not handled
         * if_IPv4addr    4  Interface network address and netmask.
         * if_IPv6addr    5  Interface network address and prefix length (stored in the last byte).
         * if_MACaddr     6  Interface Hardware MAC address (48 bits). 00 01 02 03 04 05
         * if_EUIaddr     7  Interface Hardware EUI address (64 bits), if available. TODO: give a good example
         */
        /*
         * if_speed       8  Interface speed (in bps). 100000000 for 100Mbps
         */
        if (int_data->if_speed != 0) {
                option_hdr.type          = IDB_OPT_IF_SPEED;
                option_hdr.value_length = 8;
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;

                /* Write the comments string */
                pcapng_debug1("pcapng_write_if_descr_block: if_speed %" G_GINT64_MODIFIER "u (bps)", int_data->if_speed);
                if (!wtap_dump_file_write(wdh, &int_data->if_speed, sizeof(guint64), err))
                        return FALSE;
                wdh->bytes_dumped += 8;
        }
        /*
         * if_tsresol     9  Resolution of timestamps.
         * default is 6 for microsecond resolution, opt 9  Resolution of timestamps.
         * If the Most Significant Bit is equal to zero, the remaining bits indicates
         * the resolution of the timestamp as as a negative power of 10
         */
        if (int_data->if_tsresol != 0) {
                option_hdr.type          = IDB_OPT_IF_TSRESOL;
                option_hdr.value_length = 1;
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;

                /* Write the time stamp resolution */
                pcapng_debug1("pcapng_write_if_descr_block: if_tsresol %u", int_data->if_tsresol);
                if (!wtap_dump_file_write(wdh, &int_data->if_tsresol, 1, err))
                        return FALSE;
                wdh->bytes_dumped += 1;
                if (!wtap_dump_file_write(wdh, &zero_pad, 3, err))
                        return FALSE;
                wdh->bytes_dumped += 3;
        }
        /* not used
         * if_tzone      10  Time zone for GMT support (TODO: specify better). TODO: give a good example
         */
        /*
         * if_filter     11  The filter (e.g. "capture only TCP traffic") used to capture traffic.
         */
        /* Libpcap string variant */
        if (if_filter_str_len !=0) {
                option_hdr.type          = IDB_OPT_IF_FILTER;
                option_hdr.value_length = if_filter_str_len;
                /* if_filter_str_len includes the leading byte indicating filter type (libpcap str or BPF code) */
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;

                /* Write the zero indicating libpcap filter variant */
                if (!wtap_dump_file_write(wdh, &zero_pad, 1, err))
                        return FALSE;
                wdh->bytes_dumped += 1;

                /* Write the comments string */
                pcapng_debug3("pcapng_write_if_descr_block, if_filter_str:'%s' if_filter_str_len %u if_filter_str_pad_len %u" , int_data->if_filter_str, if_filter_str_len, if_filter_str_pad_len);
                /* if_filter_str_len includes the leading byte indicating filter type (libpcap str or BPF code) */
                if (!wtap_dump_file_write(wdh, int_data->if_filter_str, if_filter_str_len-1, err))
                        return FALSE;
                wdh->bytes_dumped += if_filter_str_len - 1;

                /* write padding (if any) */
                if (if_filter_str_pad_len != 0) {
                        if (!wtap_dump_file_write(wdh, &zero_pad, if_filter_str_pad_len, err))
                                return FALSE;
                        wdh->bytes_dumped += if_filter_str_pad_len;
                }
        }
        /*
         * if_os         12  A UTF-8 string containing the name of the operating system of the machine in which this interface is installed.
         */
        if (if_os_len != 0) {
                option_hdr.type          = IDB_OPT_IF_OS;
                option_hdr.value_length = if_os_len;
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;

                /* Write the comments string */
                pcapng_debug3("pcapng_write_if_descr_block, if_os:'%s' if_os_len %u if_os_pad_len %u" , int_data->if_os, if_os_len, if_os_pad_len);
                if (!wtap_dump_file_write(wdh, int_data->if_os, if_os_len, err))
                        return FALSE;
                wdh->bytes_dumped += if_os_len;

                /* write padding (if any) */
                if (if_os_pad_len != 0) {
                        if (!wtap_dump_file_write(wdh, &zero_pad, if_os_pad_len, err))
                                return FALSE;
                        wdh->bytes_dumped += if_os_pad_len;
                }
        }

        if (have_options) {
                option_hdr.type = OPT_EOFOPT;
                option_hdr.value_length = 0;
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;
        }

        /*
         * if_fcslen     13  An integer value that specified the length of the Frame Check Sequence (in bits) for this interface.
         */
        /*
         * if_tsoffset   14  A 64 bits integer value that specifies an offset (in seconds) that must be added to the timestamp of each packet
         * to obtain the absolute timestamp of a packet. If the option is missing, the timestamps stored in the packet must be considered absolute timestamps.
         */

        /* write block footer */
        if (!wtap_dump_file_write(wdh, &bh.block_total_length,
            sizeof bh.block_total_length, err))
                return FALSE;
        wdh->bytes_dumped += sizeof bh.block_total_length;

        return TRUE;
}

#define ISB_STARTTIME     2
#define ISB_ENDTIME       3
#define ISB_IFRECV        4
#define ISB_IFDROP        5
#define ISB_FILTERACCEPT  6
#define ISB_OSDROP        7
#define ISB_USRDELIV      8

static gboolean
pcapng_write_interface_statistics_block(wtap_dumper *wdh, wtapng_if_stats_t *if_stats, int *err)
{

        pcapng_block_header_t bh;
        pcapng_interface_statistics_block_t isb;
        const guint32 zero_pad = 0;
        gboolean have_options = FALSE;
        struct option option_hdr;                   /* guint16 type, guint16 value_length; */
        guint32 options_total_length = 0;
        guint32 comment_len = 0;
        guint32 comment_pad_len = 0;

        pcapng_debug0("pcapng_write_interface_statistics_block");


        /* Calculate options length */
        if (if_stats->opt_comment) {
                have_options = TRUE;
                comment_len = (guint32)strlen(if_stats->opt_comment) & 0xffff;
                if ((comment_len % 4)) {
                        comment_pad_len = 4 - (comment_len % 4);
                } else {
                        comment_pad_len = 0;
                }
                options_total_length = options_total_length + comment_len + comment_pad_len + 4 /* comment options tag */ ;
        }
        /*guint64				isb_starttime */
        if (if_stats->isb_starttime != 0) {
                have_options = TRUE;
                options_total_length = options_total_length + 8 + 4 /* options tag */ ;
        }
        /*guint64				isb_endtime */
        if (if_stats->isb_endtime != 0) {
                have_options = TRUE;
                options_total_length = options_total_length + 8 + 4 /* options tag */ ;
        }
        /*guint64				isb_ifrecv */
        if (if_stats->isb_ifrecv != G_GUINT64_CONSTANT(0xFFFFFFFFFFFFFFFF)) {
                have_options = TRUE;
                options_total_length = options_total_length + 8 + 4 /* options tag */ ;
        }
        /*guint64				isb_ifdrop */
        if (if_stats->isb_ifdrop != G_GUINT64_CONSTANT(0xFFFFFFFFFFFFFFFF)) {
                have_options = TRUE;
                options_total_length = options_total_length + 8 + 4 /* options tag */ ;
        }
        /*guint64				isb_filteraccept */
        if (if_stats->isb_filteraccept != G_GUINT64_CONSTANT(0xFFFFFFFFFFFFFFFF)) {
                have_options = TRUE;
                options_total_length = options_total_length + 8 + 4 /* options tag */ ;
        }
        /*guint64				isb_osdrop */
        if (if_stats->isb_osdrop != G_GUINT64_CONSTANT(0xFFFFFFFFFFFFFFFF)) {
                have_options = TRUE;
                options_total_length = options_total_length + 8 + 4 /* options tag */ ;
        }
        /*guint64				isb_usrdeliv */
        if (if_stats->isb_usrdeliv != G_GUINT64_CONSTANT(0xFFFFFFFFFFFFFFFF)) {
                have_options = TRUE;
                options_total_length = options_total_length + 8 + 4 /* options tag */ ;
        }

        /* write block header */
        if (have_options) {
                /* End-of-optios tag */
                options_total_length += 4;
        }

        /* write block header */
        bh.block_type = BLOCK_TYPE_ISB;
        bh.block_total_length = (guint32)(sizeof(bh) + sizeof(isb) + options_total_length + 4);

        if (!wtap_dump_file_write(wdh, &bh, sizeof bh, err))
                return FALSE;
        wdh->bytes_dumped += sizeof bh;

        /* write block fixed content */
        isb.interface_id                = if_stats->interface_id;
        isb.timestamp_high              = if_stats->ts_high;
        isb.timestamp_low               = if_stats->ts_low;


        if (!wtap_dump_file_write(wdh, &isb, sizeof isb, err))
                return FALSE;
        wdh->bytes_dumped += sizeof isb;

        /* write (optional) block options */
        if (comment_len) {
                option_hdr.type          = OPT_COMMENT;
                option_hdr.value_length  = comment_len;
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;

                /* Write the comments string */
                pcapng_debug3("pcapng_write_interface_statistics_block, comment:'%s' comment_len %u comment_pad_len %u" , if_stats->opt_comment, comment_len, comment_pad_len);
                if (!wtap_dump_file_write(wdh, if_stats->opt_comment, comment_len, err))
                        return FALSE;
                wdh->bytes_dumped += comment_len;

                /* write padding (if any) */
                if (comment_pad_len != 0) {
                        if (!wtap_dump_file_write(wdh, &zero_pad, comment_pad_len, err))
                                return FALSE;
                        wdh->bytes_dumped += comment_pad_len;
                }
        }
        /*guint64               isb_starttime */
        if (if_stats->isb_starttime != 0) {
                guint32 high, low;

                option_hdr.type = ISB_STARTTIME;
                option_hdr.value_length = 8;
                high = (guint32)((if_stats->isb_starttime>>32) & 0xffffffff);
                low = (guint32)(if_stats->isb_starttime & 0xffffffff);
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;

                /* Write isb_starttime */
                pcapng_debug1("pcapng_write_interface_statistics_block, isb_starttime: %" G_GINT64_MODIFIER "u" , if_stats->isb_starttime);
                if (!wtap_dump_file_write(wdh, &high, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;
                if (!wtap_dump_file_write(wdh, &low, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;
        }
        /*guint64               isb_endtime */
        if (if_stats->isb_endtime != 0) {
                guint32 high, low;

                option_hdr.type = ISB_ENDTIME;
                option_hdr.value_length = 8;
                high = (guint32)((if_stats->isb_endtime>>32) & 0xffffffff);
                low = (guint32)(if_stats->isb_endtime & 0xffffffff);
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;

                /* Write isb_endtime */
                pcapng_debug1("pcapng_write_interface_statistics_block, isb_starttime: %" G_GINT64_MODIFIER "u" , if_stats->isb_endtime);
                if (!wtap_dump_file_write(wdh, &high, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;
                if (!wtap_dump_file_write(wdh, &low, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;
        }
        /*guint64               isb_ifrecv;*/
        if (if_stats->isb_ifrecv != G_GUINT64_CONSTANT(0xFFFFFFFFFFFFFFFF)) {
                option_hdr.type          = ISB_IFRECV;
                option_hdr.value_length  = 8;
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;

                /* Write isb_ifrecv */
                pcapng_debug1("pcapng_write_interface_statistics_block, isb_ifrecv: %" G_GINT64_MODIFIER "u" , if_stats->isb_ifrecv);
                if (!wtap_dump_file_write(wdh, &if_stats->isb_ifrecv, 8, err))
                        return FALSE;
                wdh->bytes_dumped += 8;
        }
        /*guint64               isb_ifdrop;*/
        if (if_stats->isb_ifdrop != G_GUINT64_CONSTANT(0xFFFFFFFFFFFFFFFF)) {
                option_hdr.type          = ISB_IFDROP;
                option_hdr.value_length  = 8;
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;

                /* Write isb_ifdrop */
                pcapng_debug1("pcapng_write_interface_statistics_block, isb_ifdrop: %" G_GINT64_MODIFIER "u" , if_stats->isb_ifdrop);
                if (!wtap_dump_file_write(wdh, &if_stats->isb_ifdrop, 8, err))
                        return FALSE;
                wdh->bytes_dumped += 8;
        }
        /*guint64               isb_filteraccept;*/
        if (if_stats->isb_filteraccept != G_GUINT64_CONSTANT(0xFFFFFFFFFFFFFFFF)) {
                option_hdr.type          = ISB_FILTERACCEPT;
                option_hdr.value_length  = 8;
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;

                /* Write isb_filteraccept */
                pcapng_debug1("pcapng_write_interface_statistics_block, isb_filteraccept: %" G_GINT64_MODIFIER "u" , if_stats->isb_filteraccept);
                if (!wtap_dump_file_write(wdh, &if_stats->isb_filteraccept, 8, err))
                        return FALSE;
                wdh->bytes_dumped += 8;
        }
        /*guint64               isb_osdrop;*/
        if (if_stats->isb_osdrop != G_GUINT64_CONSTANT(0xFFFFFFFFFFFFFFFF)) {
                option_hdr.type          = ISB_OSDROP;
                option_hdr.value_length  = 8;
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;

                /* Write isb_osdrop */
                pcapng_debug1("pcapng_write_interface_statistics_block, isb_osdrop: %" G_GINT64_MODIFIER "u" , if_stats->isb_osdrop);
                if (!wtap_dump_file_write(wdh, &if_stats->isb_osdrop, 8, err))
                        return FALSE;
                wdh->bytes_dumped += 8;
        }
        /*guint64               isb_usrdeliv;*/
        if (if_stats->isb_usrdeliv != G_GUINT64_CONSTANT(0xFFFFFFFFFFFFFFFF)) {
                option_hdr.type          = ISB_USRDELIV;
                option_hdr.value_length  = 8;
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;

                /* Write isb_usrdeliv */
                pcapng_debug1("pcapng_write_interface_statistics_block, isb_usrdeliv: %" G_GINT64_MODIFIER "u" , if_stats->isb_usrdeliv);
                if (!wtap_dump_file_write(wdh, &if_stats->isb_usrdeliv, 8, err))
                        return FALSE;
                wdh->bytes_dumped += 8;
        }

        if (have_options) {
                option_hdr.type = OPT_EOFOPT;
                option_hdr.value_length = 0;
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;
        }

        /* write block footer */
        if (!wtap_dump_file_write(wdh, &bh.block_total_length,
            sizeof bh.block_total_length, err))
                return FALSE;
        wdh->bytes_dumped += sizeof bh.block_total_length;

        return TRUE;

}


static gboolean
pcapng_write_enhanced_packet_block(wtap_dumper *wdh,
    const struct wtap_pkthdr *phdr,
    const union wtap_pseudo_header *pseudo_header, const guint8 *pd, int *err)
{
        pcapng_block_header_t bh;
        pcapng_enhanced_packet_block_t epb;
        guint64 ts;
        const guint32 zero_pad = 0;
        guint32 pad_len;
        guint32 phdr_len;
        gboolean have_options = FALSE;
        guint32 options_total_length = 0;
        struct option option_hdr;
        guint32 comment_len = 0, comment_pad_len = 0;
        wtapng_if_descr_t int_data;

        phdr_len = (guint32)pcap_get_phdr_size(phdr->pkt_encap, pseudo_header);
        if ((phdr_len + phdr->caplen) % 4) {
                pad_len = 4 - ((phdr_len + phdr->caplen) % 4);
        } else {
                pad_len = 0;
        }

        /* Check if we should write comment option */
        if (phdr->opt_comment) {
                have_options = TRUE;
                comment_len = (guint32)strlen(phdr->opt_comment) & 0xffff;
                if ((comment_len % 4)) {
                        comment_pad_len = 4 - (comment_len % 4);
                } else {
                        comment_pad_len = 0;
                }
                options_total_length = options_total_length + comment_len + comment_pad_len + 4 /* comment options tag */ ;
        }
        if (phdr->presence_flags & WTAP_HAS_PACK_FLAGS) {
                have_options = TRUE;
                options_total_length = options_total_length + 8;
        }
        if (have_options) {
                /* End-of optios tag */
                options_total_length += 4;
        }

        /* write (enhanced) packet block header */
        bh.block_type = BLOCK_TYPE_EPB;
        bh.block_total_length = (guint32)sizeof(bh) + (guint32)sizeof(epb) + phdr_len + phdr->caplen + pad_len + options_total_length + 4;

        if (!wtap_dump_file_write(wdh, &bh, sizeof bh, err))
                return FALSE;
        wdh->bytes_dumped += sizeof bh;

        /* write block fixed content */
        if (phdr->presence_flags & WTAP_HAS_INTERFACE_ID)
                epb.interface_id        = phdr->interface_id;
        else {
                /*
                 * XXX - we should support writing WTAP_ENCAP_PER_PACKET
                 * data to pcap-NG files even if we *don't* have interface
                 * IDs.
                 */
                epb.interface_id        = 0;
        }
        /*
         * Split the 64-bit timestamp into two 32-bit pieces, using
         * the time stamp resolution for the interface.
         */
        if (epb.interface_id >= wdh->number_of_interfaces) {
                /*
                 * Our caller is doing something bad.
                 */
                *err = WTAP_ERR_INTERNAL;
                return FALSE;
        }
        int_data = g_array_index(wdh->interface_data, wtapng_if_descr_t,
            epb.interface_id);
        ts = ((guint64)phdr->ts.secs) * int_data.time_units_per_second +
             (((guint64)phdr->ts.nsecs) * int_data.time_units_per_second) / 1000000000;
        epb.timestamp_high      = (guint32)(ts >> 32);
        epb.timestamp_low       = (guint32)ts;
        epb.captured_len        = phdr->caplen + phdr_len;
        epb.packet_len          = phdr->len + phdr_len;

        if (!wtap_dump_file_write(wdh, &epb, sizeof epb, err))
                return FALSE;
        wdh->bytes_dumped += sizeof epb;

        /* write pseudo header */
        if (!pcap_write_phdr(wdh, phdr->pkt_encap, pseudo_header, err)) {
                return FALSE;
        }
        wdh->bytes_dumped += phdr_len;

        /* write packet data */
        if (!wtap_dump_file_write(wdh, pd, phdr->caplen, err))
                return FALSE;
        wdh->bytes_dumped += phdr->caplen;

        /* write padding (if any) */
        if (pad_len != 0) {
                if (!wtap_dump_file_write(wdh, &zero_pad, pad_len, err))
                        return FALSE;
                wdh->bytes_dumped += pad_len;
        }

        /* XXX - write (optional) block options */
        /* options defined in Section 2.5 (Options)
         * Name           Code Length     Description
         * opt_comment    1    variable   A UTF-8 string containing a comment that is associated to the current block.
         *
         * Enhanced Packet Block options
         * epb_flags      2    4          A flags word containing link-layer information. A complete specification of
         *                                the allowed flags can be found in Appendix A (Packet Block Flags Word).
         * epb_hash       3    variable   This option contains a hash of the packet. The first byte specifies the hashing algorithm,
         *                                while the following bytes contain the actual hash, whose size depends on the hashing algorithm,
         *                                                                and hence from the value in the first bit. The hashing algorithm can be: 2s complement
         *                                                                (algorithm byte = 0, size=XXX), XOR (algorithm byte = 1, size=XXX), CRC32 (algorithm byte = 2, size = 4),
         *                                                                MD-5 (algorithm byte = 3, size=XXX), SHA-1 (algorithm byte = 4, size=XXX).
         *                                                                The hash covers only the packet, not the header added by the capture driver:
         *                                                                this gives the possibility to calculate it inside the network card.
         *                                                                The hash allows easier comparison/merging of different capture files, and reliable data transfer between the
         *                                                                data acquisition system and the capture library.
         * epb_dropcount   4   8          A 64bit integer value specifying the number of packets lost (by the interface and the operating system)
         *                                between this packet and the preceding one.
         * opt_endofopt    0   0          It delimits the end of the optional fields. This block cannot be repeated within a given list of options.
         */
        if (phdr->opt_comment) {
                option_hdr.type         = OPT_COMMENT;
                option_hdr.value_length = comment_len;
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;

                /* Write the comments string */
                pcapng_debug3("pcapng_write_enhanced_packet_block, comment:'%s' comment_len %u comment_pad_len %u" , phdr->opt_comment, comment_len, comment_pad_len);
                if (!wtap_dump_file_write(wdh, phdr->opt_comment, comment_len, err))
                        return FALSE;
                wdh->bytes_dumped += comment_len;

                /* write padding (if any) */
                if (comment_pad_len != 0) {
                        if (!wtap_dump_file_write(wdh, &zero_pad, comment_pad_len, err))
                                return FALSE;
                        wdh->bytes_dumped += comment_pad_len;
                }

                pcapng_debug2("pcapng_write_enhanced_packet_block: Wrote Options comments: comment_len %u, comment_pad_len %u",
                        comment_len,
                        comment_pad_len);
        }
        if (phdr->presence_flags & WTAP_HAS_PACK_FLAGS) {
                option_hdr.type         = OPT_EPB_FLAGS;
                option_hdr.value_length = 4;
                if (!wtap_dump_file_write(wdh, &option_hdr, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;
                if (!wtap_dump_file_write(wdh, &phdr->pack_flags, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;
                pcapng_debug1("pcapng_write_enhanced_packet_block: Wrote Options packet flags: %x", phdr->pack_flags);
        }
        /* Write end of options if we have otions */
        if (have_options) {
                if (!wtap_dump_file_write(wdh, &zero_pad, 4, err))
                        return FALSE;
                wdh->bytes_dumped += 4;
        }

        /* write block footer */
        if (!wtap_dump_file_write(wdh, &bh.block_total_length,
            sizeof bh.block_total_length, err))
                return FALSE;
        wdh->bytes_dumped += sizeof bh.block_total_length;

        return TRUE;
}

/* Arbitrary. */
#define NRES_REC_MAX_SIZE ((WTAP_MAX_PACKET_SIZE * 4) + 16)
static gboolean
pcapng_write_name_resolution_block(wtap_dumper *wdh, int *err)
{
    pcapng_block_header_t bh;
    pcapng_name_resolution_block_t nrb;
    guint8 *rec_data;
    gint rec_off, namelen, tot_rec_len;
    hashipv4_t *ipv4_hash_list_entry;
    hashipv6_t *ipv6_hash_list_entry;
    int i;

    if ((!wdh->addrinfo_lists) || ((!wdh->addrinfo_lists->ipv4_addr_list)&&(!wdh->addrinfo_lists->ipv6_addr_list))) {
        return TRUE;
    }

    rec_off = 8; /* block type + block total length */
    bh.block_type = BLOCK_TYPE_NRB;
    bh.block_total_length = rec_off + 8; /* end-of-record + block total length */
    rec_data = (guint8 *)g_malloc(NRES_REC_MAX_SIZE);

    if (wdh->addrinfo_lists->ipv4_addr_list){
        i = 0;
        ipv4_hash_list_entry = (hashipv4_t *)g_list_nth_data(wdh->addrinfo_lists->ipv4_addr_list, i);
        while(ipv4_hash_list_entry != NULL){

            nrb.record_type = NRES_IP4RECORD;
            namelen = (gint)strlen(ipv4_hash_list_entry->name) + 1;
            nrb.record_len = 4 + namelen;
            tot_rec_len = 4 + nrb.record_len + PADDING4(nrb.record_len);

            if (rec_off + tot_rec_len > NRES_REC_MAX_SIZE){
                /* We know the total length now; copy the block header. */
                memcpy(rec_data, &bh, sizeof(bh));

                /* End of record */
                memset(rec_data + rec_off, 0, 4);
                rec_off += 4;

                memcpy(rec_data + rec_off, &bh.block_total_length, sizeof(bh.block_total_length));

                pcapng_debug2("pcapng_write_name_resolution_block: Write bh.block_total_length bytes %d, rec_off %u", bh.block_total_length, rec_off);

                if (!wtap_dump_file_write(wdh, rec_data, bh.block_total_length, err)) {
                    g_free(rec_data);
                    return FALSE;
                }
                wdh->bytes_dumped += bh.block_total_length;

                /*Start a new NRB */
                rec_off = 8; /* block type + block total length */
                bh.block_type = BLOCK_TYPE_NRB;
                bh.block_total_length = rec_off + 8; /* end-of-record + block total length */

            }

            bh.block_total_length += tot_rec_len;
            memcpy(rec_data + rec_off, &nrb, sizeof(nrb));
            rec_off += 4;
            memcpy(rec_data + rec_off, &(ipv4_hash_list_entry->addr), 4);
            rec_off += 4;
            memcpy(rec_data + rec_off, ipv4_hash_list_entry->name, namelen);
            rec_off += namelen;
            memset(rec_data + rec_off, 0, PADDING4(namelen));
            rec_off += PADDING4(namelen);
            pcapng_debug1("NRB: added IPv4 record for %s", ipv4_hash_list_entry->name);

            i++;
            ipv4_hash_list_entry = (hashipv4_t *)g_list_nth_data(wdh->addrinfo_lists->ipv4_addr_list, i);
        }
        g_list_free(wdh->addrinfo_lists->ipv4_addr_list);
        wdh->addrinfo_lists->ipv4_addr_list = NULL;
    }

    if (wdh->addrinfo_lists->ipv6_addr_list){
        i = 0;
        ipv6_hash_list_entry = (hashipv6_t *)g_list_nth_data(wdh->addrinfo_lists->ipv6_addr_list, i);
        while(ipv6_hash_list_entry != NULL){

            nrb.record_type = NRES_IP6RECORD;
            namelen = (gint)strlen(ipv6_hash_list_entry->name) + 1;
            nrb.record_len = 16 + namelen;
            tot_rec_len = 16 + nrb.record_len + PADDING4(nrb.record_len);

            if (rec_off + tot_rec_len > NRES_REC_MAX_SIZE){
                /* We know the total length now; copy the block header. */
                memcpy(rec_data, &bh, sizeof(bh));

                /* End of record */
                memset(rec_data + rec_off, 0, 4);
                rec_off += 4;

                memcpy(rec_data + rec_off, &bh.block_total_length, sizeof(bh.block_total_length));

                pcapng_debug2("pcapng_write_name_resolution_block: Write bh.block_total_length bytes %d, rec_off %u", bh.block_total_length, rec_off);

                if (!wtap_dump_file_write(wdh, rec_data, bh.block_total_length, err)) {
                    g_free(rec_data);
                    return FALSE;
                }
                wdh->bytes_dumped += bh.block_total_length;

                /*Start a new NRB */
                rec_off = 8; /* block type + block total length */
                bh.block_type = BLOCK_TYPE_NRB;
                bh.block_total_length = rec_off + 8; /* end-of-record + block total length */

            }

            bh.block_total_length += tot_rec_len;
            memcpy(rec_data + rec_off, &nrb, sizeof(nrb));
            rec_off += 4;
            memcpy(rec_data + rec_off, &(ipv6_hash_list_entry->addr), 16);
            rec_off += 16;
            memcpy(rec_data + rec_off, ipv6_hash_list_entry->name, namelen);
            rec_off += namelen;
            memset(rec_data + rec_off, 0, PADDING4(namelen));
            rec_off += PADDING4(namelen);
            pcapng_debug1("NRB: added IPv6 record for %s", ipv6_hash_list_entry->name);

            i++;
            ipv6_hash_list_entry = (hashipv6_t *)g_list_nth_data(wdh->addrinfo_lists->ipv6_addr_list, i);
        }
        g_list_free(wdh->addrinfo_lists->ipv6_addr_list);
        wdh->addrinfo_lists->ipv6_addr_list = NULL;
    }

    /* We know the total length now; copy the block header. */
    memcpy(rec_data, &bh, sizeof(bh));

    /* End of record */
    memset(rec_data + rec_off, 0, 4);
    rec_off += 4;

    memcpy(rec_data + rec_off, &bh.block_total_length, sizeof(bh.block_total_length));

    pcapng_debug2("pcapng_write_name_resolution_block: Write bh.block_total_length bytes %d, rec_off %u", bh.block_total_length, rec_off);

    if (!wtap_dump_file_write(wdh, rec_data, bh.block_total_length, err)) {
        g_free(rec_data);
        return FALSE;
    }

    g_free(rec_data);
    wdh->bytes_dumped += bh.block_total_length;
    return TRUE;
}

#if 0
static guint32
pcapng_lookup_interface_id_by_encap(int wtap_encap, wtap_dumper *wdh)
{
        gint i;
        interface_data_t int_data;
        pcapng_dump_t *pcapng = (pcapng_dump_t *)wdh->priv;

        for(i = 0; i < (gint)pcapng->number_of_interfaces; i++) {
                int_data = g_array_index(pcapng->interface_data, interface_data_t, i);
                if (wtap_encap == int_data.wtap_encap) {
                        return (guint32)i;
                }
        }
        return G_MAXUINT32;
}
#endif

static gboolean pcapng_dump(wtap_dumper *wdh,
        const struct wtap_pkthdr *phdr,
        const guint8 *pd, int *err)
{
        const union wtap_pseudo_header *pseudo_header = &phdr->pseudo_header;
        /*interface_data_t int_data;*/
        /* pcapng_dump_t *pcapng = (pcapng_dump_t *)wdh->priv; */
        /*int pcap_encap;*/

        pcapng_debug2("pcapng_dump: encap = %d (%s)",
                      phdr->pkt_encap,
                      wtap_encap_string(phdr->pkt_encap));

        /* Flush any hostname resolution info we may have */
        pcapng_write_name_resolution_block(wdh, err);

        if (!pcapng_write_enhanced_packet_block(wdh, phdr, pseudo_header, pd, err)) {
                return FALSE;
        }

        return TRUE;
}


/* Finish writing to a dump file.
   Returns TRUE on success, FALSE on failure. */
static gboolean pcapng_dump_close(wtap_dumper *wdh, int *err _U_)
{
        int i, j;
        pcapng_dump_t *pcapng = (pcapng_dump_t *)wdh->priv;

        if ((wdh->number_of_interfaces > 0) && (wdh->interface_data != NULL)) {
                for (i = 0; i < (int)wdh->number_of_interfaces; i++) {

                        /* Get the interface description */
                        wtapng_if_descr_t int_data;

                        int_data = g_array_index(wdh->interface_data, wtapng_if_descr_t, i);
                        for (j = 0; j < (int)int_data.num_stat_entries; j++) {
                                wtapng_if_stats_t if_stats;

                                if_stats = g_array_index(int_data.interface_statistics, wtapng_if_stats_t, j);
                                pcapng_debug1("pcapng_dump_close: write ISB for interface %u",if_stats.interface_id);
                                if (!pcapng_write_interface_statistics_block(wdh, &if_stats, err)) {
                                        return FALSE;
                                }
                        }
                }
        }

        pcapng_debug0("pcapng_dump_close");
        g_array_free(pcapng->interface_data, TRUE);
        pcapng->number_of_interfaces = 0;
        return TRUE;
}


/* Returns TRUE on success, FALSE on failure; sets "*err" to an error code on
   failure */
gboolean
pcapng_dump_open(wtap_dumper *wdh, int *err)
{
        pcapng_dump_t *pcapng;
        int i;
        interface_data_t interface_data;

        pcapng_debug0("pcapng_dump_open");
        /* This is a pcapng file */
        wdh->subtype_write = pcapng_dump;
        wdh->subtype_close = pcapng_dump_close;
        pcapng = (pcapng_dump_t *)g_malloc0(sizeof(pcapng_dump_t));
        wdh->priv = (void *)pcapng;
        pcapng->interface_data = g_array_new(FALSE, FALSE, sizeof(wtapng_if_descr_t));

        if ((wdh->number_of_interfaces == 0) || (wdh->interface_data == NULL)) {
                pcapng_debug0("There are no interfaces. Can't handle that...");
                *err = WTAP_ERR_INTERNAL;
                return FALSE;
        }

        /* write the section header block */
        if (!pcapng_write_section_header_block(wdh, err)) {
                return FALSE;
        }
        pcapng_debug0("pcapng_dump_open: wrote section header block.");

        /* Write the Interface description blocks */
        pcapng_debug1("pcapng_dump_open: Number of IDB:s to write (number of interfaces) %u", wdh->number_of_interfaces);

        for (i = 0; i < (int)wdh->number_of_interfaces; i++) {

                /* Get the interface description */
                wtapng_if_descr_t int_data;

                int_data = g_array_index(wdh->interface_data, wtapng_if_descr_t, i);

                interface_data.wtap_encap = int_data.wtap_encap;
                interface_data.time_units_per_second = int_data.time_units_per_second;

                g_array_append_val(pcapng->interface_data, interface_data);
                pcapng->number_of_interfaces++;

                if (!pcapng_write_if_descr_block(wdh, &int_data, err)) {
                        return FALSE;
                }

        }
#if 0
        interface_id = pcapng_lookup_interface_id_by_encap(phdr->pkt_encap, wdh);
        if (interface_id == G_MAXUINT32) {
                /*
                 * We haven't yet written out an interface description
                 * block for an interface with this encapsulation.
                 *
                 * Is this encapsulation even supported in pcap-ng?
                 */
                pcap_encap = wtap_wtap_encap_to_pcap_encap(phdr->pkt_encap);
                if (pcap_encap == -1) {
                        /*
                         * No.  Fail.
                         */
                        *err = WTAP_ERR_UNSUPPORTED_ENCAP;
                        return FALSE;
                }

                /* write the interface description block */
                wblock.frame_buffer            = NULL;
                wblock.pseudo_header           = NULL;
                wblock.packet_header           = NULL;
                wblock.file_encap              = NULL;
                wblock.type                    = BLOCK_TYPE_IDB;
                wblock.data.if_descr.link_type = pcap_encap;
                wblock.data.if_descr.snap_len = (wdh->snaplen != 0) ? wdh->snaplen :
                                                                      WTAP_MAX_PACKET_SIZE; /* XXX */

                /* XXX - options unused */
                wblock.data.if_descr.if_speed   = -1;
                /*wblock.data.if_descr.if_tsresol = 6;*/    /* default: usec */
                wblock.data.if_descr.if_os      = NULL;
                wblock.data.if_descr.if_fcslen  = -1;

                if (!pcapng_write_if_descr_block(wdh, &wblock, err)) {
                        return FALSE;
                }

                interface_id = pcapng->number_of_interfaces;
                int_data.wtap_encap = phdr->pkt_encap;
                int_data.time_units_per_second = 0;
                g_array_append_val(pcapng->interface_data, int_data);
                pcapng->number_of_interfaces++;

                pcapng_debug3("pcapng_dump: added interface description block with index %u for encap = %d (%s).",
                              interface_id,
                              phdr->pkt_encap,
                              wtap_encap_string(phdr->pkt_encap));
        }
#endif

        return TRUE;
}


/* Returns 0 if we could write the specified encapsulation type,
   an error indication otherwise. */
int pcapng_dump_can_write_encap(int wtap_encap)
{
        pcapng_debug2("pcapng_dump_can_write_encap: encap = %d (%s)",
                      wtap_encap,
                      wtap_encap_string(wtap_encap));

        /* Per-packet encapsulation is supported. */
        if (wtap_encap == WTAP_ENCAP_PER_PACKET)
                return 0;

        /* Make sure we can figure out this DLT type */
        if (wtap_wtap_encap_to_pcap_encap(wtap_encap) == -1)
                return WTAP_ERR_UNSUPPORTED_ENCAP;

        return 0;
}

/*
 * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
 *
 * Local variables:
 * c-basic-offset: 4
 * tab-width: 8
 * indent-tabs-mode: nil
 * End:
 *
 * vi: set shiftwidth=4 tabstop=8 expandtab:
 * :indentSize=4:tabSize=8:noTabs=true:
 */
