pcapreport.c

/* 
 * Report on a pcap (.pcap) file.
 *
 * <rrw@kynesim.co.uk> 2008-09-05
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is the MPEG TS, PS and ES tools.
 *
 * The Initial Developer of the Original Code is Amino Communications Ltd.
 * Portions created by the Initial Developer are Copyright (C) 2008
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Richard Watts, Kynesim <rrw@kynesim.co.uk>
 *
 * ***** END LICENSE BLOCK *****
 */

#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <limits.h>
#include <time.h>
#ifdef _WIN32
#include <stddef.h>
#else // _WIN32
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#endif // _WIN32

#include "compat.h"
#include "pcap.h"
#include "ethernet.h"
#include "ipv4.h"
#include "version.h"
#include "misc_fns.h"
#include "ts_fns.h"
#include "fmtx.h"

typedef struct pcapreport_stream_struct pcapreport_stream_t;

#define JITTER_BUF_SIZE 1024

typedef struct jitter_el_struct {
  uint32_t t;
  int delta;
} jitter_el_t;

typedef struct jitter_env_struct {
  int min_val;
  int max_val;
  int in_n;
  int out_n;
  int len;
  jitter_el_t buf[JITTER_BUF_SIZE];
} jitter_env_t;

typedef struct pcapreport_section_struct pcapreport_section_t;
struct pcapreport_section_struct {
  pcapreport_section_t * next;
  unsigned int section_no;
  unsigned int pcr_count;
  unsigned int jitter_max;
  uint32_t pkt_start;
  uint32_t pkt_final;
  uint64_t time_start;  // 90kHz
  uint64_t time_first;  // time @ first PCR
  uint64_t time_last;   // time @ last PCR
  uint64_t time_final;
  uint64_t pcr_start;   // 90kHz
  uint64_t pcr_last;
  int64_t skew_last;
  int64_t skew_min;
  int64_t skew_max;
  uint64_t ts_byte_start;
  uint64_t ts_byte_final;
  int32_t rtp_skew_min;
  int32_t rtp_skew_max;
};

typedef struct pcapreport_vlan_info_s
{
  uint16_t vid;
  uint16_t cfimap;
  uint16_t pcpmap;
} pcapreport_vlan_info_t;

typedef struct pcapreport_rtp_info_s
{
  uint16_t last_seq;
  uint32_t n;
  uint32_t ssrc;
  int multiple_ssrc;
} pcapreport_rtp_info_t;

// RTP info (if any) in a packet
typedef struct rtp_header_s
{
  int is_rtp_ts;
  int is_rtp_raw;
  int marker;
  uint8_t payload_type;
  uint16_t sequence_number;
  uint32_t timestamp;
  uint32_t ssrc;
  uint32_t header_len;
  uint32_t pad_len;
  // CSRC ignored
  // Extension ignored
} rtp_header_t;

struct pcapreport_stream_struct {
  pcapreport_stream_t * hash_next;

  const char *output_name;
  FILE *output_file;
  uint32_t output_dest_addr;
  uint32_t output_dest_port;

  FILE * csv_file;
  const char * csv_name;

  int stream_no;
  int force;  // We have an explicit filter - try harder
  int ts_good;  // Not a boolean -ve is bad, +ve is good
  int seen_good;  // Includes those seen_dodgy
  int seen_bad;
  int seen_dodgy;  // Count of packets that we aren't completely happy with but have declared good
  int multiple_pcr_pids;

  TS_reader_p ts_r;

  uint32_t pcr_pid;

  // The temporary read buffer used by our ts reader.
  byte    *tmp_buf;
  uint32_t tmp_len;

  // ts packet counter for error reporting.
  uint32_t ts_counter;

  // Count overlength packets
  uint32_t pkts_overlength;

  /*! How far do we need to skew (in 90kHz units) to signal a discontinuity? */
  int64_t skew_discontinuity_threshold;

  int64_t last_time_offset;

  uint64_t ts_bytes;

  pcapreport_section_t * section_first;
  pcapreport_section_t * section_last;

  int vlan_count;
  pcapreport_vlan_info_t vlans[ETHERNET_VLANS_MAX];
  pcapreport_rtp_info_t rtp_info;

  jitter_env_t jitter;
};


typedef struct pcapreport_fragment_struct
{
  int in_use;
  uint16_t ident;
  uint16_t current_len;
  byte pkt[65536];
} pcapreport_fragment_t;

typedef struct pcapreport_reassembly_struct
{
  pcapreport_fragment_t frag;
} pcapreport_reassembly_t;



typedef struct pcapreport_ctx_struct
{
  int use_stdin;
  char *input_name;
  const char * base_name;
  int had_input_name;
  int extract_data;
  int dump_data;
  int dump_extra;
  int time_report;
  int verbose;
  int analyse;
  int extract;
  int stream_count;
  int csv_gen;
  int good_ts_only;  // Only keep good pkts
  int keep_bad;        // Keep all packets (inc bad)
  int file_split_section;
  PCAP_reader_p pcreader;
  pcap_hdr_t pcap_hdr;

  unsigned int tfmt;

  // packet counter.
  uint32_t pkt_counter;

  uint32_t filter_dest_addr;
  uint32_t filter_dest_port;

  const char * output_name_base;

  int64_t opt_skew_discontinuity_threshold;

  uint64_t time_start; // 90kHz
  uint32_t time_usec;
  time_t time_sec;

  uint8_t rtp_raw_wanted[256];

  pcapreport_stream_t * stream_hash[256];
  pcapreport_reassembly_t reassembly_env;
} pcapreport_ctx_t;


static unsigned int
jitter_value(const jitter_env_t * const je)
{
  return je->max_val - je->min_val;
}

static unsigned int
jitter_add(jitter_env_t * const je, const int delta, const uint32_t time, const uint32_t range)
{
  jitter_el_t * const eob = je->buf + JITTER_BUF_SIZE;
  jitter_el_t * const in_el = je->buf + je->in_n;
  jitter_el_t * out_el = je->buf + je->out_n;
  jitter_el_t * const next_el = (je->in_n == JITTER_BUF_SIZE - 1) ? je->buf : in_el + 1;
  int needs_scan = FALSE;

  // 1st expire anything we no longer want - in any case expire one if
  // we are about to overflow.
  while (in_el != out_el && (time - out_el->t > range || out_el == next_el))
  {
    if (out_el->delta == je->min_val || out_el->delta == je->max_val)
      needs_scan = TRUE;

    // Inc with wrap
    if (++out_el >= eob)
      out_el = je->buf;
  }

  if (needs_scan || in_el == out_el)
  {
    // Only recalc max & min for the buffer if we have expired a previous one
    // also if empty then must force both to delta which this code will do

    const jitter_el_t * el = out_el;
    int min_val = delta;
    int max_val = delta;

    while (el != in_el)
    {
      if (el->delta > max_val)
        max_val = el->delta;
      if (el->delta < min_val)
        min_val = el->delta;

      if (++el >= eob)
        el = je->buf;
    }

    je->max_val = max_val;
    je->min_val = min_val;
  }
  else
  {
    // Otherwise check to see if this is a new max/min based on old values

    if (delta > je->max_val)
      je->max_val = delta;
    if (delta < je->min_val)
      je->min_val = delta;
  }

  // Now add to the end
  in_el->t = time;
  in_el->delta = delta;

  // and update the environment
  je->in_n = next_el - je->buf;
  je->out_n = out_el - je->buf;

  return jitter_value(je);
}

static void
jitter_clear(jitter_env_t * const je)
{
  je->in_n = 0;
  je->out_n = 0;
  je->max_val = 0;
  je->min_val = 0;
}

static uint64_t
pkt_time(const pcaprec_hdr_t * const pcap_pkt_hdr)
{
  return (((int64_t)pcap_pkt_hdr->ts_usec*9)/100) +
    ((int64_t)pcap_pkt_hdr->ts_sec * 90000);
}


static char *
vlan_name(const char * prefix, const pcapreport_stream_t * const st, const size_t blen, char * const buf)
{
  if (st->vlan_count == 0)
  {
    buf[0] = '\0';
  }
  else
  {
    int i;
    size_t n = strlen(prefix);
    char * p = buf;
    char * const eob = buf + blen;

    memcpy(p, prefix, n);
    p += n;

    for (i = 0; i < st->vlan_count && eob - p > 2; ++i)
    {
      const pcapreport_vlan_info_t * const vi = st->vlans + i;
      if (i != 0)
        *p++ = '.';
      p += snprintf(p, eob - p, "%d", vi->vid);
    }
  }
  return buf;
}


static char *
section_name(const pcapreport_ctx_t * const ctx, const pcapreport_stream_t * const st, char * const pbuf, const size_t pbuf_len)
{
  if (!ctx->file_split_section)
  {
    *pbuf = '\0';
    return pbuf;
  }

  snprintf(pbuf, pbuf_len, "_S%d", st->section_last == NULL ? 0 : st->section_last->section_no);
  return pbuf;
}

static void
stream_gen_names2(const pcapreport_ctx_t * const ctx, pcapreport_stream_t * const st,
    const rtp_header_t * const rtp_header)
{
  const uint32_t dest_addr = st->output_dest_addr;
  const uint32_t dest_port = st->output_dest_port;
  char pbuf[32], pbuf2[32];
  char identifier[64];
  const char * const base_name = ctx->output_name_base != NULL ? ctx->output_name_base : ctx->base_name;
  const size_t base_len = strlen(base_name);
  int fixed_extract_name = FALSE;

  if (ctx->filter_dest_addr == 0 || ctx->filter_dest_port == 0)
  {
    snprintf(identifier, 64, "%s_%u.%u.%u.%u_%u%s",
      vlan_name("_V", st, sizeof(pbuf), pbuf),
      dest_addr >> 24, (dest_addr >> 16) & 0xff,
      (dest_addr >> 8) & 0xff, dest_addr & 0xff,
      dest_port,
      section_name(ctx, st, pbuf2, sizeof(pbuf2)));
  }
  else
  {
    identifier[0] = '\0';
    // If we have been given a unique filter and a name then assume they
    // actually want that name!
    fixed_extract_name = (ctx->output_name_base != NULL);
  }

  if (ctx->extract)
  {
    char * name = malloc(base_len + 64);
    memcpy(name, base_name, base_len + 1);

    if (!fixed_extract_name)
      snprintf(name + base_len, 64, "%s.%s", identifier,
          (rtp_header != NULL && rtp_header->is_rtp_raw) ? "rtp" : "ts");
    st->output_name = name;
  }

  if (ctx->csv_gen)
  {
    char * name = malloc(base_len + 64);
    memcpy(name, ctx->base_name, base_len);
    snprintf(name + base_len, 64, "%s.csv", identifier);
    st->csv_name = name;
  }
}

static void
stream_gen_names(const pcapreport_ctx_t * const ctx, pcapreport_stream_t * const st,
    const rtp_header_t * const rtp_header)
{
  // Only bother if there is some reason
  if (ctx->extract || ctx->csv_gen)
    stream_gen_names2(ctx, st, rtp_header);
}

static void
stream_close_files(const pcapreport_ctx_t * const ctx, pcapreport_stream_t * const st)
{
  if (st->output_file != NULL)
  {
    if (st->seen_dodgy != 0)
    {
      fprint_msg(">%d> WARNING: %d dodgy packet%s written to: %s\n",
                 st->stream_no,
                 st->seen_dodgy, st->seen_dodgy == 1 ? "" : "s", st->output_name);
    }
    if (st->seen_bad != 0)
    {
      fprint_msg(">%d> WARNING: %d bad packet%s excluded from: %s\n",
                 st->stream_no,
                 st->seen_bad, st->seen_bad == 1 ? "" : "s", st->output_name);
    }
    fclose(st->output_file);
    st->output_file = NULL;
  }
  if (st->csv_file != NULL)
  {
    fclose(st->csv_file);
    st->csv_file = NULL;
  }
}



static pcapreport_section_t *
section_create(const pcapreport_ctx_t * const ctx, pcapreport_stream_t * const st, const pcaprec_hdr_t * const pcap_pkt_hdr)
{
  pcapreport_section_t * const tsect = calloc(1, sizeof(*tsect));
  pcapreport_section_t * const last = st->section_last;

  if (ctx->file_split_section)
    stream_close_files(ctx, st);

  if (tsect == NULL)
    return NULL;

  // Bind into stream

  if (last == NULL)
  {
    // Empty chain - add as first el
    st->section_first = tsect;
  }
  else
  {
    // Add to end
    tsect->section_no = last->section_no + 1;
    last->next = tsect;
  }
  st->section_last = tsect;

  // Init "obvious" non-zero stuff
  tsect->rtp_skew_max = -0x7fffffff;
  tsect->rtp_skew_min = 0x7fffffff;
  tsect->skew_max = -0x7fffffff;
  tsect->skew_min = 0x7fffffff;

  tsect->time_final =
  tsect->time_start = pkt_time(pcap_pkt_hdr);
  tsect->pkt_final =
  tsect->pkt_start = ctx->pkt_counter;
  tsect->ts_byte_start =
  tsect->ts_byte_final = st->ts_bytes;

  if (ctx->file_split_section || last == NULL)
    stream_gen_names(ctx, st, NULL);

  return tsect;
}

// Discontinuity threshold is 6s.
#define SKEW_DISCONTINUITY_THRESHOLD (6*90000)

static int digest_times_read(void *handle, byte *out_buf, size_t len)
{
  pcapreport_stream_t * const st = handle;
  int nr_bytes = (len < st->tmp_len ? len : st->tmp_len);
  int new_tmp_len = st->tmp_len - nr_bytes;

  memcpy(out_buf, st->tmp_buf, nr_bytes);
  memmove(st->tmp_buf, &st->tmp_buf[nr_bytes], 
          new_tmp_len);
  st->tmp_len = new_tmp_len;
  //   fprint_msg(">> read %d bytes from intermediate buffer. \n", nr_bytes);

  return nr_bytes;
}


static int digest_times_seek(void *handle, offset_t val)
{
  // Cannot seek in a ts stream.
  return 1;
}

// 33 bit comparison
static int64_t
pts_diff(const uint64_t a, const uint64_t b)
{
  return ((int64_t)(a - b) << 31) >> 31;
}

static int64_t
pts_diff_abs(const uint64_t a, const uint64_t b)
{
  const int64_t t = pts_diff(a, b);
  return t < 0 ? -t : t;
}


static int digest_times(pcapreport_ctx_t * const ctx, 
                        pcapreport_stream_t * const st,
                        const pcaprec_hdr_t * const pcap_pkt_hdr,
                        const ethernet_packet_t * const epkt,
                        const ipv4_header_t * const ipv4_header, 
                        const ipv4_udp_header_t * const udp_header,
                        const rtp_header_t * const rtp_header,
                        const byte * const data,
                        const uint32_t len)
{
  int rv;
  unsigned int rtp_seq_delta = 0;

  // Deal with RTP contents - currently held with stream but could be moved to section
  // especially if we do more timestamp analysis
  if (rtp_header->is_rtp_ts)
  {
    pcapreport_rtp_info_t * const ri = &st->rtp_info;

    if (ri->ssrc != rtp_header->ssrc && ri->n != 0 && !ri->multiple_ssrc)
    {
      fprint_msg("!%d! Multiple SSRCs detected: SSRCs: %u,%u,...\n", st->stream_no,
                 ri->ssrc, rtp_header->ssrc);
      ri->multiple_ssrc = TRUE;
    }

    rtp_seq_delta = ri->n == 0 ? 0 :
      (rtp_header->sequence_number - (ri->last_seq + 1)) & 0xffffU;

    if (rtp_seq_delta != 0)
    {
      fprint_msg("!%d! @%u: RTP seq delta (%u->%u) != 1\n", st->stream_no, ctx->pkt_counter,
          ri->last_seq, rtp_header->sequence_number);
    }

    ++ri->n;
    ri->ssrc = rtp_header->ssrc;
    ri->last_seq = rtp_header->sequence_number;
  }


  if (st->ts_r == NULL)
  {
    rv = build_TS_reader_with_fns(st,
                                  digest_times_read, 
                                  digest_times_seek, 
                                  &st->ts_r);
    if (rv)
    {
      print_err( "### pcapreport: Cannot create ts reader.\n");
      return 1;
    }
  }

  // Add all our data to the pool.
  {
    unsigned int pkts = len / TS_PACKET_SIZE;
    unsigned int pktlen = pkts * TS_PACKET_SIZE;

    if (pktlen != len)
      ++st->pkts_overlength;

    st->tmp_buf = (byte *)realloc(st->tmp_buf, st->tmp_len + pktlen);
    memcpy(&st->tmp_buf[st->tmp_len], data, pktlen);
    st->tmp_len += pktlen;
  }

  // Now read out all the ts packets we can.
  while (1)
  {
    byte *pkt;
    int rv;

    rv = read_next_TS_packet(st->ts_r, &pkt);
    if (rv == EOF)
    {
      // Got to EOF - return for more data
      return 0;
    }


    // Right. Split it ..
    {
      const uint64_t t_pcr = pkt_time(pcap_pkt_hdr);
      uint32_t pid;
      int pusi;
      byte *adapt;
      int adapt_len;
      byte *payload;
      int payload_len;

      rv = split_TS_packet(pkt, &pid, &pusi, &adapt, &adapt_len,
                           &payload, &payload_len);
      if (rv)
      {
        fprint_msg(">%d> WARNING: TS packet %d [ packet %d @ %d.%d s ] cannot be split.\n",
                   st->stream_no,
                   st->ts_counter, ctx->pkt_counter, 
                   pcap_pkt_hdr->ts_sec, pcap_pkt_hdr->ts_usec);
      }
      else
      {
        //int cc;

        // PCR ?
        if (adapt && adapt_len)
        {
          int has_pcr;
          uint64_t pcr;
          int64_t pcr_time_offset;

          get_PCR_from_adaptation_field(adapt, adapt_len, &has_pcr,
                                        &pcr);

          if (has_pcr)
          {
            int64_t skew;

            if (ctx->time_report)
            {
              fprint_msg(">%d> Found PCR %lld at %d.%d s \n", st->stream_no,
                         pcr, pcap_pkt_hdr->ts_sec, pcap_pkt_hdr->ts_usec);
            }

            if (st->pcr_pid == 0)
              st->pcr_pid = pid;

            if (pid != st->pcr_pid)
            {
              // *** If this happens often then fix to track each Pid
              if (!st->multiple_pcr_pids)
              {
                fprint_msg("!%d! Multiple PCR pids detected: pids: %d,%d,...\n",
                  st->stream_no, st->pcr_pid, pid);
              }
              st->multiple_pcr_pids = TRUE;
            }
            else
            {
              pcapreport_section_t * tsect = st->section_last;
              unsigned int cur_jitter;

              // PCR pops out in 27MHz units. Let's do all our comparisons
              // in 90kHz.
              pcr /= 300;

              // fprint_msg("pcr = %lld t_pcr = %lld diff = %lld\n", 
              //            pcr, t_pcr, t_pcr - pcr);

              pcr_time_offset = pts_diff(t_pcr, pcr);

              skew = tsect->pcr_count == 0 ? 0LL :
                pcr_time_offset - pts_diff(tsect->time_first, tsect->pcr_start);

              // Change section if discontinuity too big
              if (st->skew_discontinuity_threshold > 0 && tsect->pcr_count != 0)
              {
                const int64_t pcr_delta = pts_diff_abs(pcr, tsect->pcr_last);
                const int64_t time_delta = pts_diff_abs(t_pcr, tsect->time_last);
                const int64_t skew_delta = skew - tsect->skew_last;

                if (pcr_delta > st->skew_discontinuity_threshold ||
                    time_delta > st->skew_discontinuity_threshold ||
                    skew_delta > st->skew_discontinuity_threshold)
                {
                  section_create(ctx, st, pcap_pkt_hdr);
                  tsect = st->section_last;
                }
              }

              if (tsect->pcr_count == 0)
              {
                if (tsect->section_no != 0)
                {
                  fprint_msg(">%d> Skew discontinuity! Skew = %lld (> %lld) at"
                             " ts = %d network = %d (PCR %lld Time %d.%d)\n", 
                             st->stream_no,
                             skew, st->skew_discontinuity_threshold, 
                             st->ts_counter, ctx->pkt_counter,
                             pcr, pcap_pkt_hdr->ts_sec,
                             pcap_pkt_hdr->ts_usec);
                }

                tsect->pkt_final = ctx->pkt_counter;
                tsect->pcr_last =
                tsect->pcr_start = pcr;
                tsect->time_last =
                tsect->time_first = t_pcr;

                jitter_clear(&st->jitter);
                skew = 0;
                st->last_time_offset = 0;
              }

              // Extract jitter over up to the last 10s.  skew will be within
              // an int by now
              cur_jitter = jitter_add(&st->jitter, (int)skew,
                (uint32_t)(t_pcr & 0xffffffffU), 90000 * 10);

              if (tsect->skew_max < skew)
                tsect->skew_max = skew;
              if (tsect->skew_min > skew)
                tsect->skew_min = skew;

              if (tsect->jitter_max < cur_jitter)
                tsect->jitter_max = cur_jitter;

              if (rtp_header->is_rtp_ts)
              {
                // We have both PCR & RTP times - look for min & max
                int32_t rtp_skew = (int32_t)(rtp_header->timestamp - (uint32_t)(t_pcr & 0xffffffffU));
                if (tsect->rtp_skew_max < rtp_skew)
                  tsect->rtp_skew_max = rtp_skew;
                if (tsect->rtp_skew_min > rtp_skew)
                  tsect->rtp_skew_min = rtp_skew;
              }

              if (ctx->time_report)
              {
                int64_t rel_tim = t_pcr - tsect->time_first; // 90kHz
                double skew_rate = (rel_tim == 0) ? 0.0 :
                  (double)skew / ((double)((double)rel_tim / (60*90000)));

                fprint_msg(">%d> [ts %d net %d ] PCR %lld Time %d.%d [rel %d.%d]  - skew = %lld (delta = %lld, rate = %.4g PTS/min) - jitter=%u\n",
                           st->stream_no,
                           st->ts_counter, ctx->pkt_counter,
                           pcr,
                           pcap_pkt_hdr->ts_sec, pcap_pkt_hdr->ts_usec,
                           (int)(rel_tim / (int64_t)1000000),
                           (int)rel_tim%1000000,
                           skew, pcr_time_offset - st->last_time_offset,
                           skew_rate, cur_jitter);
              }

              if (st->csv_name != NULL)  // We should be outputting to file
              {
                if (st->csv_file == NULL)
                {
                  if ((st->csv_file = fopen(st->csv_name, "wt")) == NULL)
                  {
                    fprint_err("### pcapreport: Cannot open %s .\n",
                               st->csv_name);
                    exit(1);
                  }
                  fprintf(st->csv_file, "\"PKT\",\"Time\",\"PCR\",\"Skew\",\"Jitter\"\n");
                }
                fprintf(st->csv_file, "%d," LLU_FORMAT "," LLU_FORMAT "," LLD_FORMAT ",%u\n", ctx->pkt_counter,
                  t_pcr - ctx->time_start, pcr, skew, cur_jitter);
              }

              // Remember where we are for posterity
              tsect->pcr_last = pcr;
              tsect->time_last = t_pcr;
              tsect->skew_last = skew;

              st->last_time_offset = pcr_time_offset;
              ++tsect->pcr_count;
            }
          }
        }
      }

      // Actions at end of TS packet
      ++st->ts_counter;
      st->ts_bytes += TS_PACKET_SIZE;

      {
        pcapreport_section_t * const tsect = st->section_last;
        if (tsect != NULL)
        {
          tsect->time_final = t_pcr;
          tsect->ts_byte_final = st->ts_bytes;
          tsect->pkt_final = ctx->pkt_counter;
        }
      }

    }
  }
}

static int write_out_packet(pcapreport_ctx_t * const ctx,
                            pcapreport_stream_t * const st,
                            const byte *data, 
                            const uint32_t len)
{
  int rv;
  unsigned int pkts = len / 188;

  if (st->output_name)
  {
    if (st->output_file == NULL)
    {
      fprint_msg("pcapreport: Dumping %s packets for %s:%d to %s\n",
                 ctx->good_ts_only ? "good ts" : ctx->keep_bad ? "all" : "ts",
                 ipv4_addr_to_string(st->output_dest_addr),
                 st->output_dest_port,
                 st->output_name);
      st->output_file = fopen(st->output_name, "wb");
      if (!st->output_file)
      {
        fprint_err("### pcapreport: Cannot open %s .\n", 
                   st->output_name);
        return 1;
      }
    }

    if (ctx->verbose)
    {
      fprint_msg("++   Dumping %d bytes to output file.\n", len);
    }
    rv = fwrite(data, 188, pkts, st->output_file);
    if (rv != pkts)
    {
      fprint_err( "### pcapreport: Couldn't write %d bytes"
                  " to %s (error = %d).\n", 
                  len, st->output_name, 
                  ferror(st->output_file));
      return 1;
    }
  }
  return 0;
}

static int
stream_ts_check(const pcapreport_ctx_t * const ctx, pcapreport_stream_t * const st,
                            const byte * const data,
                            const uint32_t len)
{
  const byte * ptr;
  int good = 0;
  int bad = 0;

  if (st->force)
    st->ts_good = 10;  

  if (len % 188 != 0)
    ++bad;
  else
    ++good;

  for (ptr = data; ptr < data + len; ptr += 188)
  {
    if (*ptr != 0x47)
      ++bad;
    else
      ++good;
  }

  st->ts_good += good - bad;

  if (st->ts_good > 10)
    st->ts_good = 10;
  if (st->ts_good < -10)
    st->ts_good = -10;

  if (st->ts_good <= 0 || (bad != 0 && ctx->good_ts_only))
  {
    ++st->seen_bad;
    return FALSE;
  }

  if (bad != 0)
    ++st->seen_dodgy;
  ++st->seen_good;
  return TRUE;
}

// RTP - RFC 3550
// RTP payload types - RFC 3551
// M2TS - RFC 2250

static int write_rtp_raw_packet(pcapreport_ctx_t * const ctx,
                            pcapreport_stream_t * const st,
                            const byte *data,
                            const uint32_t len)
{
  if (st->output_name)
  {
    int rv;

    if (st->output_file == NULL)
    {
      fprint_msg("pcapreport: Dumping raw RTP packets for %s:%d to %s\n",
                 ipv4_addr_to_string(st->output_dest_addr),
                 st->output_dest_port,
                 st->output_name);
      st->output_file = fopen(st->output_name, "wb");
      if (!st->output_file)
      {
        fprint_err("### pcapreport: Cannot open %s .\n",
                   st->output_name);
        return 1;
      }
    }

    if (ctx->verbose)
    {
      fprint_msg("++   Dumping %d bytes to output file.\n", len);
    }

    // need header
    {
      byte hdr[8];
      hdr[0] = 'R';
      hdr[1] = 'T';
      hdr[2] = 'P';
      hdr[3] = ' ';
      hdr[4] = (len >> 24) & 0xff;
      hdr[5] = (len >> 16) & 0xff;
      hdr[6] = (len >> 8) & 0xff;
      hdr[7] = len & 0xff;
      rv = fwrite(hdr, sizeof(hdr), 1, st->output_file);
      if (rv != 1)
      {
        fprint_err( "### pcapreport: Couldn't write RTP hdr bytes"
                    " to %s (error = %d).\n",
                    st->output_name,
                    ferror(st->output_file));
        return 1;
      }
    }

    rv = fwrite(data, 1, len, st->output_file);
    if (rv != len)
    {
      fprint_err( "### pcapreport: Couldn't write %d bytes"
                  " to %s (error = %d).\n",
                  len, st->output_name,
                  ferror(st->output_file));
      return 1;
    }
  }
  return 0;

}

static int
stream_rtp_check(const pcapreport_ctx_t * const ctx, pcapreport_stream_t * const st,
                const byte * const data, 
                const uint32_t len,
                rtp_header_t * const rh)
{
  uint32_t offset;
  uint32_t padlen = 0;
  unsigned int payload_type;
  int is_raw = FALSE;

  // Flatten output
  memset(rh, 0, sizeof(*rh));

  // Must contain at least the header!
  if (len < 12)
    return FALSE;

  // Check version - must be 2
  // Incidentally this will reject 0x47 which is good :-)
  if ((data[0] & 0xc0) != 0x80)
    return FALSE;
  // We only deal with TS in RTP so check for that alone
  payload_type = data[1] & 0x7f;
  if (ctx->rtp_raw_wanted[payload_type] != 0)
    is_raw = TRUE;
  else if ((data[1] & 0x7f) != 33)  // PT bits
    return FALSE;

  // ??Check sequence??

  // offset = start of extension or payload
  offset = 12 + (data[0] & 0xf) * 4;

  // Check for padding
  if ((data[0] & 0x20) != 0)  // P bit
  {
    padlen = data[len - 1];
    // Padlen of zero makes no sense as padding len includes this byte
    if (padlen == 0)
      return FALSE;
  }

  // Check for extension
  if ((data[0] & 0x10) != 0)  // X bit
  {
    if (offset + 4 + padlen > len)
      return FALSE;
    // Skip extension header
    offset += 4 + uint_16_be(data + offset + 2);
  }

  // trivial check for TS in payload if not raw extraction
  if (!is_raw && (offset + 188 + padlen > len || data[offset] != 0x47))
    return FALSE;

  rh->is_rtp_raw = is_raw;
  rh->is_rtp_ts = !is_raw;
  rh->marker = ((data[1] & 0x80) != 0);
  rh->payload_type = (uint8_t)payload_type;
  rh->sequence_number = uint_16_be(data + 2);
  rh->timestamp = uint_32_be(data + 4);
  rh->ssrc = uint_32_be(data + 8);
  rh->header_len = offset;
  rh->pad_len = padlen;

  return TRUE;
}

static void
stream_merge_vlan_info(pcapreport_stream_t * const st, const ethernet_packet_t * const epkt)
{
  int i;
  for (i = 0; i < epkt->vlan_count; ++i)
  {
    st->vlans[i].cfimap |= (1 << epkt->vlans[i].cfi);
    st->vlans[i].pcpmap |= (1 << epkt->vlans[i].pcp);
  }
}

// Close the stream
// Closes any extraction file(s) & frees associated memory
// Replaces contents of passed stream pointer with next in hash chain
void
stream_close(pcapreport_ctx_t * const ctx, pcapreport_stream_t ** pst)
{
  pcapreport_stream_t * const st = *pst;

  // Set pointer to next in chain
  *pst = st->hash_next;

  {
    // Free off all our section data
    pcapreport_section_t * p = st->section_first;
    while (p != NULL)
    {
      pcapreport_section_t * np = p->next;
      free(p);
      p = np;
    }
  }
  stream_close_files(ctx, st);

  if (st->csv_name != NULL)
    free((void *)st->csv_name);
  if (st->output_name != NULL)
    free((void *)st->output_name);
  free(st);
}


static pcapreport_stream_t *
stream_create(pcapreport_ctx_t * const ctx, const pcaprec_hdr_t * const pcap_pkt_hdr,
  const ethernet_packet_t * const epkt, uint32_t const dest_addr, const uint32_t dest_port)
{
  int i;
  pcapreport_stream_t * st = calloc(1, sizeof(*st));
  st->stream_no = ctx->stream_count++;
  st->output_dest_addr = dest_addr;
  st->output_dest_port = dest_port;
  st->vlan_count = epkt->vlan_count;
  for (i = 0; i < epkt->vlan_count; ++i)
  {
    st->vlans[i].vid = epkt->vlans[i].vid;
    // Maps are zero - will be filled in by merge_vlan_info
  }

  st->skew_discontinuity_threshold = ctx->opt_skew_discontinuity_threshold;
  st->force = ctx->keep_bad;

  // Even if we don't need sections it won't hurt to have one
  // Also generates output names
  if (section_create(ctx, st, pcap_pkt_hdr) == NULL)
  {
    stream_close(ctx, &st);
    return NULL;
  }

  return st;
}

static char *
map_to_string(unsigned int n, const size_t blen, char * const buf)
{
  int i = 0;
  char * p = buf;
  char * const eob = buf + blen;
  int first = TRUE;

  while (n != 0 && eob - p > 2)
  {
    if ((n & 1) != 0)
    {
      if (!first)
        *p++ = ',';
      p += snprintf(p, eob - p, "%d", i);
      first = FALSE;
    }
    n >>= 1;
    ++i;
  }
  return buf;
}

static void
stream_analysis(const pcapreport_ctx_t * const ctx, const pcapreport_stream_t * const st)
{
  uint32_t dest_addr = st->output_dest_addr;
  char pbuf[32];

  if (ctx->verbose < 1 && st->seen_good == 0)
    return;

  fprint_msg("Stream %d: Dest:%s %u.%u.%u.%u:%u\n",
    st->stream_no,
    vlan_name(" VLAN:", st, sizeof(pbuf), pbuf),
    dest_addr >> 24, (dest_addr >> 16) & 0xff,
    (dest_addr >> 8) & 0xff, dest_addr & 0xff,
    st->output_dest_port);
  if (st->vlan_count != 0)
  {
    int i;

    for (i = 0; i < st->vlan_count; ++i)
    {
      const pcapreport_vlan_info_t * const vi = st->vlans + i;
      char pbuf1[64], pbuf2[64];

      fprint_msg("  VLAN %d: cfi:[%s], pcp[%s]\n", vi->vid,
        map_to_string(vi->cfimap, sizeof(pbuf1), pbuf1), map_to_string(vi->pcpmap, sizeof(pbuf2), pbuf2));
    }
  }

  if (st->seen_good == 0)
  {
    // Cut the rest of the stats short if they are meaningless
    fprint_msg("  No TS detected: Pkts=%u\n", st->seen_bad);
  }
  else
  {
    const pcapreport_section_t * tsect;

    fprint_msg("  Pkts: Good=%d, Dodgy=%d, Bad=%d, Overlength=%u\n",
      st->seen_good - st->seen_dodgy, st->seen_dodgy, st->seen_bad, st->pkts_overlength);

    if (st->rtp_info.n != 0)
    {
      const pcapreport_rtp_info_t * const ri = &st->rtp_info;
      fprint_msg("  RTP TS packets: %d, SSRC: %u%s\n", ri->n, ri->ssrc, ri->multiple_ssrc ? "..." : "");
    }

    fprint_msg("  PCR PID: %d (%#x)%s\n", st->pcr_pid, st->pcr_pid,
      !st->multiple_pcr_pids ? "" : " ### Other PCR PIDs in stream - not tracked");

    for (tsect = st->section_first; tsect != NULL; tsect = tsect->next)
    {
      uint64_t time_offset = ctx->time_start;
      int64_t time_len = tsect->time_last - tsect->time_first;  // PCR duration
      int64_t time_len2 = tsect->time_final - tsect->time_start;  // Stream duration
      int64_t pcr_len = pts_diff(tsect->pcr_last, tsect->pcr_start);
      int64_t drift = time_len - pcr_len;
      fprint_msg("  Section %d:\n", tsect->section_no);
      fprint_msg("    Pkts: %u->%u\n", tsect->pkt_start, tsect->pkt_final);
      fprint_msg("    TS Bytes: %llu (%llu bits/sec)\n", tsect->ts_byte_final - tsect->ts_byte_start,
        time_len2 == 0LL ? 0LL : (tsect->ts_byte_final - tsect->ts_byte_start) * 8ULL * 90000ULL / time_len2);
      fprint_msg("    Time (Total): %s->%s (%s)\n",
        fmtx_timestamp(tsect->time_start - time_offset, ctx->tfmt),
        fmtx_timestamp(tsect->time_final - time_offset, ctx->tfmt),
        fmtx_timestamp(time_len2, ctx->tfmt));
      if (tsect->pcr_count == 0)
      {
        fprint_msg("    No PCRs seen\n");
      }
      else
      {
        fprint_msg("    Time (PCRs): %s->%s (%s)\n",
          fmtx_timestamp(tsect->time_first - time_offset, ctx->tfmt),
          fmtx_timestamp(tsect->time_last - time_offset, ctx->tfmt),
          fmtx_timestamp(time_len, ctx->tfmt));
        fprint_msg("    PCR[count=%u]: %s->%s (%s)\n",
          tsect->pcr_count,
          fmtx_timestamp(tsect->pcr_start, ctx->tfmt),
          fmtx_timestamp(tsect->pcr_last, ctx->tfmt),
          fmtx_timestamp(pcr_len, ctx->tfmt));
        fprint_msg("    Drift: diff=%s; rate=%s/min; 1s per %llds%s\n",
          fmtx_timestamp(time_len - pcr_len, ctx->tfmt),
          fmtx_timestamp(time_len == 0 ? 0LL : drift * 60LL * 90000LL / time_len, ctx->tfmt),
          drift == 0 ? 0LL : time_len / drift,
          drift == 0 ? "" : drift < 0 ? " (fast)" : " (slow)");
        fprint_msg("    Max jitter: %s; Skew min: %s, max: %s\n", fmtx_timestamp(tsect->jitter_max, ctx->tfmt),
          fmtx_timestamp(tsect->skew_min, ctx->tfmt),
          fmtx_timestamp(tsect->skew_max, ctx->tfmt));
      }
      if (st->rtp_info.n != 0)
      {
        fprint_msg("    PCR/RTP skew: min=%s max=%s (diff=%s)\n",
          fmtx_timestamp(tsect->rtp_skew_min, ctx->tfmt),
          fmtx_timestamp(tsect->rtp_skew_max, ctx->tfmt),
          fmtx_timestamp(tsect->rtp_skew_max - tsect->rtp_skew_min, ctx->tfmt));
      }
    }
  }

  fprint_msg("\n");
}


unsigned int
stream_hash(uint32_t const dest_addr, const uint32_t dest_port)
{
  uint32_t x = dest_addr ^ dest_port;
  x ^= x >> 16;
  return (x ^ (x >> 8)) & 0xff;
}

static int
stream_vlan_match(const pcapreport_stream_t * const st, const ethernet_packet_t * const epkt)
{
  int i;

  if (epkt->vlan_count != st->vlan_count)
    return FALSE;

  for (i = 0; i < epkt->vlan_count; ++i)
  {
    if (epkt->vlans[i].vid != st->vlans[i].vid)
      return FALSE;
  }
  return TRUE;
}

pcapreport_stream_t *
stream_find(pcapreport_ctx_t * const ctx,
    const pcaprec_hdr_t * const pcap_pkt_hdr, const ethernet_packet_t * const epkt,
    uint32_t const dest_addr, const uint32_t dest_port)
{
  const unsigned int h = stream_hash(dest_addr, dest_port);
  pcapreport_stream_t ** pst = ctx->stream_hash + h;
  pcapreport_stream_t * st;

  while ((st = *pst) != NULL)
  {
    if (st->output_dest_addr == dest_addr && st->output_dest_port == dest_port &&
        stream_vlan_match(st, epkt))
    {
      return st;
    }
    pst = &st->hash_next;
  }

  if ((st = stream_create(ctx, pcap_pkt_hdr, epkt, dest_addr, dest_port)) == NULL)
    return NULL;

  *pst = st;
  return st;
}

static int
stream_sort_fn(const void *va, const void * vb)
{
  const pcapreport_stream_t * const * const pa = va;
  const pcapreport_stream_t * const * const pb = vb;
  return (*pa)->stream_no - (*pb)->stream_no;
}

static int
ip_reassemble(pcapreport_reassembly_t * const reas, const ipv4_header_t * const ip, byte * const in_data,
  byte ** const out_pdata, uint32_t * const out_plen)
{
  uint32_t frag_len = ip->length - ip->hdr_length * 4;
  uint32_t frag_offset = ip->frag_offset * 8;  // bytes
  int frag_final = (ip->flags & 1) == 0;

  // Discard unless we succeed
  *out_pdata = (void *)NULL;
  *out_plen = 0;

  if (frag_final && frag_offset == 0)
  {
    // Normal case - no fragmentation
    *out_pdata = in_data;
    *out_plen = frag_len;
    return 0;
  }

  if ((frag_len & 7) != 0 && !frag_final)
  {
    // Only final fragment may have length that is not a multiple of 8
    fprint_err("### Non-final fragment with bad length: %d\n", frag_len);
    return -1;
  }

  if (frag_len + frag_offset >= 0x10000)
  {
    // I can't find this explicitly prohibited in RFC791 but it can't be good
    // and the limit should probably be a little less if we were being pedantic
    fprint_err("### Fragment end >= 64k: %d+%d\n", frag_offset, frag_len);
    return -1;
  }

  // Very limited reassembly
  {
    pcapreport_fragment_t * frag = &reas->frag;

    if (frag->in_use && frag->ident != ip->ident)
    {
      fprint_err("### Multi-packet fragment reassembly NIF - previous packet discarded\n");
      frag->in_use = 0;
    }

    // If previously idle then reset stuff
    if (!frag->in_use)
    {
      frag->in_use = 1;
      frag->current_len = 0;
      frag->ident = ip->ident;
    }

    if (frag->current_len != frag_offset)
    {
      fprint_err("### Reordering fragment reassembly NIF - packet discarded\n");
      frag->in_use = 0;
      return -1;
    }

    frag->current_len = frag_offset + frag_len;

    memcpy(frag->pkt + ip->frag_offset * 8, in_data, frag_len);

    if (!frag_final)
      return 1;

    *out_pdata = frag->pkt;
    *out_plen = frag->current_len;
    frag->in_use = 0;
    return 0;
  }
}

static int
ip_reassembly_init(pcapreport_reassembly_t * const reas)
{
  memset(reas, 0, sizeof(*reas));
  return 0;
}


static void print_usage()
{
  print_msg(
    "Usage: pcapreport [switches] <infile>\n"
    "\n"
    );
  REPORT_VERSION("pcapreport");
  print_msg(
    "\n"
    "Report on a pcap capture file.\n"
    "\n"
    "  -h                 This help\n"
    "  -h detail          More detail on what some terms used by pcapreport mean\n"
    "  --name <file>\n"
    "  -n <file>          Set the default base name for output files; by default\n"
    "                     this will be the input name without any .pcap suffix\n"
    "  -x, --extract      Extract TS(s) to files of the default name\n"
    "  -c, --csvgen       Create a .csv file for each stream containing timing info\n"
    "  -output <file>\n"
    "  -o <file>,         Dump selected UDP payloads to output file(s)\n"
    "                     Uses given filename if <ip>:<port> specified,\n"
    "                     otherwise appends <ip>_<port> to filename per TS\n"
    "                     Is much the same as -x -n <name>\n"
    "  -a                 Analyse.  Produces summary info on every TS in the pcap\n"
    "  -d <dest ip>:<port>\n"
    "  -d <dest ip>       Select data with the given destination IP and port.\n"
    "                     If the <port> is not specified, it defaults to 0\n"
    "                     (see below).\n"
    "  -g, --good-ts-only Only extract/analyse packets that seem entirely good.\n"
    "                     By default there is a bit of slack in determining if a\n"
    "                     packet is good and some dodgy packets are let through\n"
    "                     This switch ensures that all packets pass simple testing\n"
    "  -keep-bad          Extract all packets including bad ones.  Is implied if\n"
    "                     an ip & port filter is set.  Overriden by --good-ts-only.\n"
    "  -tfmt 32|90|ms|hms Set time format in report [default = 90kHz units]\n"
    "  -dump-data, -D     Dump any data in the input file to stdout.\n"
    "  -extra-dump, -e    Dump only data which isn't being sent to the -o file.\n"
    "  -times,  -t        Report continuously on PCR vs PCAP timing for the\n"
    "                     destination specified in -d.\n"
    "  -verbose, -v       Output metadata about every packet.\n"
    "  -skew-discontinuity-threshold <number>\n"
    "  -skew <number>     Gives the skew discontinuity threshold in 90kHz units.\n"
    "                     A value of 0 disables this. [default = 6*90000]\n"
    "  -split-section     Split extracted streams into multiple files on section\n"
    "                     (discontinutity) boundries\n"
    "\n"
    "  -err stdout        Write error messages to standard output (the default)\n"
    "  -err stderr        Write error messages to standard error (Unix traditional)\n"
    "\n"
    "Specifying 0.0.0.0 for destination IP will capture all hosts, specifying 0\n"
    "as a destination port will capture all ports on the destination host.\n"
    "\n"
    "Network packet numbers start at 1 (like wireshark)\n"
    "TS packet numbers start at 0.\n"
    "\n"
    "Positive skew means that we received too low a PCR for this timestamp.\n"
    "\n"
    );
}

static char manpage[] =
"Times (packet and PCR)\n"
"----------------------\n"
"\n"
"The times associated with packets and PCR are held internally in 90kHz units\n"
"and are displayed in those units by default\n"
"\n"
"Stream\n"
"------\n"
"\n"
"A set of packets to the same IP & Port.  TS streams are detected by looking\n"
"for 0x47s at appropriate places in the packets\n"
"\n"
"Section\n"
"-------\n"
"A part of a stream which appears to have a continuous TS embedded in it.  If\n"
"the PCR jumps then a new section should be started (though this will not\n"
"generate a separate .ts file if the extraction option is in effect, nor will\n"
"it generate a new .csv file.)\n"
"\n"
"As it stands pcapreport will only report on a single PCR pid within a TS. If\n"
"multiple pids with PCRs are detected then this will be reported but the other\n"
"PCRs will be ignored\n"
"\n"
"Skew\n"
"----\n"
"\n"
"This is the difference between the time in the pcap for a UDP packet and any\n"
"PCR found in the TS contained within that packet.  The accuracy of this figure\n"
"obviously depends on how good the clock was in the capture process.  Skew is\n"
"arbitrarily set to zero at the start of a section.  A skew of >6s is assumed\n"
"to be a discontinuity and will start a new section.\n"
"\n"
"Drift\n"
"-----\n"
"\n"
"This is skew over time and (assuming that the playout process is good)\n"
"represents the difference in speed between the transmitters clock and the\n"
"receivers clock.  The algorithm for determining this isn't very sophisticated\n"
"so if you have a large maximum jitter or a short sample this should be taken\n"
"with a pinch of salt.  Beware also that PC clocks (like the one in the m/c\n"
"doing the tcpdump) are not always amongst the most stable or accurate; however\n"
"they should be good enough to detect gross errors\n"
"\n"
"Jitter\n"
"------\n"
"\n"
"This is measured as the difference between the maximum and minimum skews over\n"
"a 10sec (max 1024 samples) period.  This should be long enough to capture a\n"
"good baseline but short enough that drift has a negligible effect\n"
"\n"
"Max Jitter\n"
"----------\n"
"\n"
"The maximum value of jitter (see above) found in a section\n"
"";


const char *onechararg[26] =
{
  "analyse", // a
  "", // b
  "csvgen", // c
  "destip", // d
  "", // e
  "", // f
  "good-ts-only", // g
  "help", // h
  "", // i
  "", // j
  "", // k
  "", // l
  "", // m
  "name", // n
  "output", // o
  "", // p
  "", // q
  "", // r
  "", // s
  "times", // t
  "", // u
  "verbose", // v
  "", // w
  "extract", // x
  "", // y
  ""  // z
};


int main(int argc, char **argv)
{
  int err = 0;
  int ii = 1;
  pcapreport_ctx_t sctx = {0};
  pcapreport_ctx_t  * const ctx = &sctx;

  ctx->opt_skew_discontinuity_threshold = SKEW_DISCONTINUITY_THRESHOLD;
  ctx->tfmt = FMTX_TS_DISPLAY_90kHz_RAW;
  ctx->rtp_raw_wanted[96] = 1;

  ip_reassembly_init(&ctx->reassembly_env);

  if (argc < 2)
  {
    print_usage();
    return 0;
  }

  while (ii < argc)
  {
    if (argv[ii][0] == '-')
    {
      // remove double dashes
      const char c = argv[ii][1];
      const char * const arg = c >= 'a' && c <= 'z' && argv[ii][2] == 0 ? onechararg[c - 'a'] :
        argv[ii][1] == '-' ? argv[ii] + 2 : argv[ii] + 1;

      if (strcmp("help", arg) == 0)
      {
        if (ii + 1 < argc && strcmp("detail", argv[ii + 1]) == 0)
        {
          fwrite(manpage, sizeof(manpage), 1, stdout);
          exit(0);
        }
        print_usage();
        return 0;
      }
      else if (!strcmp("err",arg))
      {
        CHECKARG("pcapreport",ii);
        if (!strcmp(argv[ii+1],"stderr"))
          redirect_output_stderr();
        else if (!strcmp(argv[ii+1],"stdout"))
          redirect_output_stdout();
        else
        {
          fprint_err("### pcapreport: "
                     "Unrecognised option '%s' to -err (not 'stdout' or"
                     " 'stderr')\n",argv[ii+1]);
          return 1;
        }
        ii++;
      }
      else if (!strcmp("output", arg))
      {
        CHECKARG("pcapreport",ii);
        ctx->output_name_base = argv[++ii];
        ctx->extract_data = TRUE;
      }
      else if (!strcmp("times", arg))
      {
        ++ctx->time_report;
      }
      else if (!strcmp("analyse", arg))
      {
        ctx->analyse = TRUE;
      }
      else if (!strcmp("verbose", arg))
      {
        ++ctx->verbose;
      }
      else if (!strcmp("destip", arg))
      {
        char *hostname;
        int port = 0;

        CHECKARG("pcapreport",ii);
        err = host_value("pcapreport", argv[ii], argv[ii+1], &hostname, &port);
        if (err) return 1;
        ++ii;

        ctx->filter_dest_port = port;
        if (ipv4_string_to_addr(&ctx->filter_dest_addr, hostname))
        {
          fprint_err( "### pcapreport: '%s' is not a host IP address (names are not allowed!)\n",
                      hostname);
          return 1;
        }
      }
      else if (!strcmp("dump-data", arg) || !strcmp("D", arg))
      {
        ++ctx->dump_data;
      }
      else if (!strcmp("extra-dump", arg) || !strcmp("E", arg))
      {
        ++ctx->dump_extra;
      }
      else if (!strcmp("skew-discontinuity-threshold", arg) ||
               !strcmp("skew", arg))
      {
        int val;
        CHECKARG("pcapreport",ii);
        err = int_value("pcapreport", argv[ii], argv[ii+1], TRUE, 0, &val); 
        if (err) return 1;
        ctx->opt_skew_discontinuity_threshold = val;
        ++ii;
      }
      else if (strcmp("name", arg) == 0)
      {
        CHECKARG("pcapreport",ii);
        ctx->base_name = strdup(argv[++ii]);  // So we know it is always malloced
      }
      else if (strcmp("extract", arg) == 0)
      {
        ctx->extract = TRUE;
      }
      else if (strcmp("csvgen", arg) == 0)
      {
        ctx->csv_gen = TRUE;
      }
      else if (strcmp("good-ts-only", arg) == 0)
      {
        ctx->good_ts_only = TRUE;
      }
      else if (strcmp("keep-bad", arg) == 0)
      {
        ctx->keep_bad = TRUE;
      }
      else if (strcmp("split-section", arg) == 0)
      {
        ctx->file_split_section = TRUE;
      }
      else if (strcmp("tfmt", arg) == 0)
      {
        int tfmt;
        CHECKARG("pcapreport",ii);
        if ((tfmt = fmtx_str_to_timestamp_flags(argv[ii + 1])) < 0)
        {
          fprint_err("### Bad timeformat: %s\n", argv[ii + 1]);
          exit(1);
        }
        ctx->tfmt = tfmt;
        ++ii;
      }
      else
      {
        fprint_err( "### pcapreport: "
                    "Unrecognised command line switch '%s'\n", argv[ii]);
        return 1;
      }
    }
    else
    {
      if (ctx->had_input_name)
      {
        fprint_err( "### pcapreport: Unexpected '%s'\n", argv[ii]);
        return 1;
      }
      else
      {
        ctx->input_name = argv[ii];
        ctx->had_input_name = TRUE;
      }
    }
    ++ii;
  }

  if (!ctx->had_input_name)
  {
    print_err("### pcapreport: No input file specified\n");
    return 1;
  }

  // If the dest:port is fully specified then avoid guesswork
  if (ctx->filter_dest_addr != 0 && ctx->filter_dest_port != 0)
    ctx->keep_bad = TRUE;

  // Good only overrides keep bad
  if (ctx->good_ts_only)
    ctx->keep_bad  = FALSE;

  if (ctx->base_name == NULL)
  {
    // If we have no default name then use the input name as a base after
    // stripping off any likely pcap extension
    static const char * const strip_exts[] = {
      ".cap", ".pcap", ".pcapng"
    };

    const char * const input_name = ctx->input_name == NULL ? "pcap" : ctx->input_name;
    char * const buf = strdup(ctx->input_name);
    const size_t len = strlen(input_name);
    int i;

    for (i = 0; i != sizeof(strip_exts)/sizeof(strip_exts[0]); ++i)
    {
      const size_t extlen = strlen(strip_exts[i]);
      if (len > extlen && strcmp(strip_exts[i], buf + len - extlen) == 0)
      {
        buf[len - extlen] = 0;
        break;
      }
    }
    ctx->base_name = buf;
  }

  fprint_msg("%s\n",ctx->input_name);

  err = pcap_open(&ctx->pcreader, &ctx->pcap_hdr, ctx->input_name);
  if (err)
  {
    fprint_err("### pcapreport: Unable to open input file %s for reading "
               "PCAP (code %d)\n", 
               ctx->had_input_name?ctx->input_name:"<stdin>", err);
    // Just an error code isn't much use - let's look at the source
    // and report something more helpful...
    fprint_err("                %s\n",
               (err==-1?"Unable to open file":
                err==-2?"Unable to allocate PCAP reader datastructure":
                err==-4?"Unable to read PCAP header - is it a PCAP file?":
                "<unrecogised error code>"));
    return 1;
  }

  fprint_msg("Capture made by version %u.%u local_tz_correction "
             "%d sigfigs %u snaplen %d network %u\n", 
             ctx->pcap_hdr.version_major, ctx->pcap_hdr.version_minor,
             ctx->pcap_hdr.thiszone,
             ctx->pcap_hdr.sigfigs,
             ctx->pcap_hdr.snaplen,
             ctx->pcap_hdr.network);

  if (ctx->pcap_hdr.snaplen < 65535)
  {
    fprint_err("### pcapreport: WARNING snaplen is %d, not >= 65535 - "
               "not all data may have been captured.\n", 
               ctx->pcap_hdr.snaplen);
  }


  {
    int done = 0;

    while (!done)
    {
      pcaprec_hdr_t rec_hdr;
      byte *data = NULL;
      uint32_t len = 0;
      int sent_to_output = 0;

      err = pcap_read_next(ctx->pcreader, &rec_hdr, &data, &len);
      switch (err)
      {
      case 0: // EOF.
        ++done;
        break;
      case 1: // Got a packet.
        {
          byte *allocated = data;

          // Wireshark numbers packets from 1 so we shall do the same
          if (ctx->pkt_counter++ == 0)
          {
            // Note time of 1st packet
            ctx->time_usec = rec_hdr.ts_usec;
            ctx->time_sec = rec_hdr.ts_sec;
            ctx->time_start = pkt_time(&rec_hdr);
          }

          if (ctx->verbose)
          {
            fprint_msg("pkt: Time = %d.%d orig_len = %d \n", 
                       rec_hdr.ts_sec, rec_hdr.ts_usec, 
                       rec_hdr.orig_len);
          }

          if (!(ctx->pcap_hdr.network == PCAP_NETWORK_TYPE_ETHERNET))
          {
            goto dump_out;
          }

          {
            ethernet_packet_t epkt;
            uint32_t out_st, out_len;
            int rv;
            ipv4_header_t ipv4_hdr;
            ipv4_udp_header_t udp_hdr;

            rv = ethernet_packet_from_pcap(&rec_hdr, 
                                           data, len, 
                                           &epkt,
                                           &out_st,
                                           &out_len);

            if (rv)
            {
              goto dump_out;
            }


            if (ctx->verbose)
            {
              fprint_msg("++ 802.11: src %02x:%02x:%02x:%02x:%02x:%02x "
                         " dst %02x:%02x:%02x:%02x:%02x:%02x "
                         "typeorlen 0x%04x\n",
                         epkt.src_addr[0], epkt.src_addr[1], 
                         epkt.src_addr[2], epkt.src_addr[3], 
                         epkt.src_addr[4], epkt.src_addr[5],
                         epkt.dst_addr[0], epkt.dst_addr[1], 
                         epkt.dst_addr[2], epkt.dst_addr[3],
                         epkt.dst_addr[4], epkt.dst_addr[5], 
                         epkt.typeorlen);
            }

            data = &data[out_st];
            len = out_len;

            // Is it IP?
            if (epkt.typeorlen != 0x800)
            {
              goto dump_out;
            }


            rv = ipv4_from_payload(data, len, 
                                   &ipv4_hdr, 
                                   &out_st, 
                                   &out_len);
            if (rv)
            {
              goto dump_out;
            }

            if (ctx->verbose)
            {		    
              fprint_msg("++ IPv4: src = %s", 
                         ipv4_addr_to_string(ipv4_hdr.src_addr));
              fprint_msg(" dest = %s \n", 
                         ipv4_addr_to_string(ipv4_hdr.dest_addr));

              fprint_msg("++ IPv4: version = 0x%x hdr_length = 0x%x"
                         " serv_type = 0x%08x length = 0x%04x\n"
                         "++ IPv4: ident = 0x%04x flags = 0x%02x"
                         " frag_offset = 0x%04x ttl = %d\n"
                         "++ IPv4: proto = %d csum = 0x%04x\n",
                         ipv4_hdr.version,
                         ipv4_hdr.hdr_length,
                         ipv4_hdr.serv_type,
                         ipv4_hdr.length,
                         ipv4_hdr.ident,
                         ipv4_hdr.flags,
                         ipv4_hdr.frag_offset,
                         ipv4_hdr.ttl,
                         ipv4_hdr.proto,
                         ipv4_hdr.csum);
            }

            data = &data[out_st];
            len = out_len;

            if (ip_reassemble(&ctx->reassembly_env, &ipv4_hdr, data, &data, &len) != 0)
            {
              goto dump_out;
            }

            if (!(IPV4_HDR_IS_UDP(&ipv4_hdr)))
            {
              goto dump_out;
            }


            rv = ipv4_udp_from_payload(data, len,
                                       &udp_hdr,
                                       &out_st,
                                       &out_len);
            if (rv) 
            {
              goto dump_out;
            }

            if (ctx->verbose)
            {
              fprint_msg("++ udp: src port = %d "
                         "dest port = %d len = %d \n",
                         udp_hdr.source_port,
                         udp_hdr.dest_port,
                         udp_hdr.length);
            }

            data = &data[out_st];
            len = out_len;

            if (
              (ctx->filter_dest_addr == 0 || (ipv4_hdr.dest_addr == ctx->filter_dest_addr)) && 
              (ctx->filter_dest_port == 0 || (udp_hdr.dest_port == ctx->filter_dest_port)))
            {
              pcapreport_stream_t * const st = stream_find(ctx, &rec_hdr, &epkt,
                  ipv4_hdr.dest_addr, udp_hdr.dest_port);
              rtp_header_t rtp_hdr;

              stream_merge_vlan_info(st, &epkt);

              if (stream_rtp_check(ctx, st, data, len, &rtp_hdr))
              {
                if (ctx->extract && rtp_hdr.is_rtp_raw)
                {
                  stream_gen_names(ctx, st, &rtp_hdr);
                  write_rtp_raw_packet(ctx, st, data, len);
                }

                data += rtp_hdr.header_len;
                len -= rtp_hdr.header_len + rtp_hdr.pad_len;
              }

              if (stream_ts_check(ctx, st, data, len))
              {
                ++sent_to_output;
  
                if (ctx->time_report || ctx->analyse || ctx->csv_gen || (ctx->extract && ctx->file_split_section))
                {
                  rv = digest_times(ctx, 
                                   st,
                                   &rec_hdr,
                                   &epkt,
                                   &ipv4_hdr,
                                   &udp_hdr,
                                   &rtp_hdr,
                                   data, len);
                  if (rv) { return rv; }
                }
                if (ctx->extract)
                {
                  rv = write_out_packet(ctx, st, data, len);
                  if (rv) { return rv; }
                }
              }
            }
          }

          // Adjust 
dump_out:
          if (ctx->dump_data || (ctx->dump_extra && !sent_to_output))
          {
            print_data(TRUE, "data", data, len, len);
          }
          free(allocated); allocated = data = NULL;
        }
        break;
      default:
        // Some other error.
        fprint_err( "### pcapreport: Can't read packet %d - code %d\n",
                    ctx->pkt_counter, err);
        ++done;
        break;
      }
    }
  }

  pcap_close(&ctx->pcreader);

  // Analyse data if requested
  if (ctx->analyse)
  {
    // Spit out pcap part of the report
    //
    const struct tm * const t = gmtime(&ctx->time_sec);

    fprint_msg("Pcap start time: %llu (%d-%02d-%02d %d:%02d:%02d.%06d)\n", ctx->time_start,
      t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
      t->tm_hour, t->tm_min, t->tm_sec, ctx->time_usec);
    fprint_msg("Pcap pkts: %u\n", ctx->pkt_counter);
    fprint_msg("\n");

    // Spit out the per stream info
    if (ctx->stream_count != 0)
    {
      unsigned int i;
      unsigned int j = 0;
      pcapreport_stream_t ** const streams = malloc(sizeof(pcapreport_stream_t *) * ctx->stream_count);

      // Add to array for sorting
      for (i = 0; i != 256; ++i)
      {
        pcapreport_stream_t * st = ctx->stream_hash[i];
        while (st != NULL)
        {
          streams[j++] = st;
          st = st->hash_next;
        }
      }

      // Sort into stream_no order
      qsort(streams, ctx->stream_count, sizeof(pcapreport_stream_t *), stream_sort_fn);

      // Display
      for (i = 0; i != ctx->stream_count; ++i)
        stream_analysis(ctx, streams[i]);

      free(streams);
    }
  }

  // Kill it
  {
    unsigned int i;
    for (i = 0; i != 256; ++i)
    {
      while (ctx->stream_hash[i] != NULL)
        stream_close(ctx, ctx->stream_hash + i);
    }
  }

  return 0;
}

// Local Variables:
// tab-width: 8
// indent-tabs-mode: nil
// c-basic-offset: 2
// End:
// vim: set tabstop=8 shiftwidth=2 expandtab: