/**
   pcap-snoop.c


   Copyright (C) 1999-2001 RTFM, Inc.
   All Rights Reserved

   This package is a SSLv3/TLS protocol analyzer written by Eric
   Rescorla <ekr@rtfm.com> and licensed by RTFM, Inc.

   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions
   are met:
   1. Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
   2. Redistributions in binary form must reproduce the above
      copyright notice, this list of conditions and the following
      disclaimer in the documentation and/or other materials provided
      with the distribution.
   3. All advertising materials mentioning features or use of this
      software must display the following acknowledgement:

      This product includes software developed by Eric Rescorla for
      RTFM, Inc.

   4. Neither the name of RTFM, Inc. nor the name of Eric Rescorla may
      be used to endorse or promote products derived from this
      software without specific prior written permission.

   THIS SOFTWARE IS PROVIDED BY ERIC RESCORLA AND RTFM, INC. ``AS IS''
   AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
   TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
   PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR
   CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
   USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
   SUCH DAMAGE.

   $Id: pcap-snoop.c,v 1.14 2002/09/09 21:02:58 ekr Exp $


   ekr@rtfm.com  Tue Dec 29 10:17:41 1998
 */

#include <pcap.h>
#include <unistd.h>
#ifndef __OpenBSD__
#include <pcap-bpf.h>
#endif
#ifndef _WIN32
#include <sys/param.h>
#endif
#include <sys/types.h>
#ifndef _WIN32
#include <sys/socket.h>
#include <netinet/in.h>
#else
#include <winsock2.h>
#include <bittypes.h>
#endif
#include <signal.h>

#include <net/if.h>
#include <netinet/if_ether.h>
#include "network.h"
#include <r_common.h>
#include <r_time.h>
#include "null_analyze.h"
#include "ssl_analyze.h"
#ifdef ENABLE_RECORD
#include "record_analyze.h"
#endif
#include "pcap_logger.h"
#include "tcpconn.h"

#ifndef ETHERTYPE_8021Q
#define ETHERTYPE_8021Q 0x8100
#endif

char *collapse_args PROTO_LIST((int argc, char **argv));
static int pcap_if_type = DLT_NULL;
int err_exit PROTO_LIST((char *str, int num));
int usage PROTO_LIST((void));
int print_version PROTO_LIST((void));
void sig_handler_quit PROTO_LIST((int sig));
void sig_handler_usr PROTO_LIST((int sig));
void pcap_cb PROTO_LIST((u_char * ptr,
                         const struct pcap_pkthdr *hdr,
                         const u_char *data));
int main PROTO_LIST((int argc, char **argv));

int packet_cnt = 0;   // Packet counter used for connection pool cleaning
int conn_freq = 100;  // Number of packets after which a connection pool
                      // cleaning is performed
int conn_ttl = 100;   // TTL of inactive connections in connection pool
struct timeval last_packet_seen_time =  // Timestamp of the last packet of the
    (struct timeval){0};                // last block of conn_freq packets seen

logger_mod *logger = NULL;

int err_exit(char *str, int num) {
  fprintf(stderr, "ERROR: %s\n", str);
  sig_handler_quit(SIGQUIT);
  exit(num);
}

int usage(void) {
  fprintf(stderr,
          "Usage: ssldump [-r dumpfile] [-i interface] [-l sslkeylogfile] [-w "
          "outpcapfile]\n");
  fprintf(stderr,
          "               [-k keyfile] [-p password] [-vtaTznsAxVNde]\n");
  fprintf(stderr, "               [filter]\n");
  exit(0);
}

int print_version(void) {
  printf("Version: @ssldump_VERSION@ (@ssldump_DESCRIPTION@)\n");
  printf(
      "Maintained by a bunch of volunteers, see "
      "https://github.com/adulau/ssldump/blob/master/CREDITS\n");
  printf("Copyright (C) 2015-2023 the aforementioned volunteers\n");
  printf("Copyright (C) 1998-2001 RTFM, Inc.\n");
  printf("All rights reserved.\n");
#ifdef OPENSSL
  printf("Compiled with OpenSSL: decryption enabled\n");
#endif
  exit(0);
}

pcap_t *p;
proto_mod *mod = &ssl_mod;
n_handler *n;
char *interface_name = 0;
char *file = 0;
char *filter = 0;
void sig_handler_quit(int sig) {
  int freed_conn = 0;
  fflush(stdout);
  if(logger)
    logger->vtbl->deinit();

  freed_conn = destroy_all_conn();
  if(freed_conn && !(NET_print_flags & NET_PRINT_JSON))
    fprintf(stderr, "Cleaned %d remaining connection(s) from connection pool\n",
            freed_conn);

  network_handler_destroy(mod, &n);

  if(p)
    pcap_close(p);
  if(interface_name)
    free(interface_name);
  if(filter)
    free(filter);
  if(file)
    free(file);

  exit(sig);
}

void sig_handler_usr(int sig) {
  int freed_conn = 0;

  if(sig == SIGUSR1) {
    if(!first_conn) {
      fprintf(stderr,
              "Received SIGUSR1, connection pool empty, nothing to list.\n");
    } else {
      fprintf(
          stderr,
          "Received SIGUSR1, listing currently tracked connection(s) ...\n");
      list_all_conn();
    }
  } else if(sig == SIGUSR2) {
    if(!first_conn) {
      fprintf(stderr,
              "Received SIGUSR2, connection pool empty, nothing to purge.\n");
    } else {
      fprintf(stderr, "Received SIGUSR2, purging connection pool ...\n");
      freed_conn = destroy_all_conn();
      if(freed_conn && !(NET_print_flags & NET_PRINT_JSON))
        fprintf(stderr, "Purged %d connection(s) from connection pool\n",
                freed_conn);
    }
  }
}

void pcap_cb(u_char *ptr, const struct pcap_pkthdr *hdr, const u_char *data) {
  n_handler *n;
  int len;
  struct ether_header *e_hdr = (struct ether_header *)data;
  int type = ETHERTYPE_IP;
  int cleaned_conn;

  n = (n_handler *)ptr;
  if(hdr->caplen != hdr->len)
    err_exit("Length mismatch", -1);

  len = hdr->len;

  switch(pcap_if_type) {
    case DLT_RAW:
      switch(((u_int8_t)*data) >> 4) {
        case 4:
          type = ETHERTYPE_IP;
          break;
        case 6:
          type = ETHERTYPE_IPV6;
          break;
        default:
          fprintf(stderr, "Unknown packet type, skipping ...\n");
          return;
      }
      break;
#ifdef DLT_LOOP
    case DLT_LOOP:
#endif
    case DLT_NULL:
      data += 4;
      len -= 4;
      break;
    case DLT_EN10MB:
      if(len < sizeof(struct ether_header)) {
        if(!(NET_print_flags & NET_PRINT_JSON))
          fprintf(stderr,
                  "Frame size too small to contain Ethernet header, skipping "
                  "...\n");
        return;
      }

      type = ntohs(e_hdr->ether_type);

      data += sizeof(struct ether_header);
      len -= sizeof(struct ether_header);

      /* if vlans, push past VLAN header (4 bytes) */
      if(type == ETHERTYPE_8021Q) {
        type = ntohs(*(u_int16_t *)(data + 2));

        data += 4;
        len += 4;
      }

      if(type != ETHERTYPE_IP && type != ETHERTYPE_IPV6)
        return;

      break;
    case DLT_IEEE802:
      data += 22;
      len -= 22;
      break;
    case DLT_FDDI:
      data += 21;
      len -= 21;
      break;
#ifdef __amigaos__
    case DLT_MIAMI:
      data += 16;
      len -= 16;
      break;
#endif
    case DLT_SLIP:
#ifdef DLT_SLIP_BSDOS
    case DLT_SLIP_BSDOS:
#endif
#if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) || \
    defined(__bsdi__) || defined(__APPLE__)
      data += 16;
      len -= 16;
#else
      data += 24;
      len -= 24;
#endif
      break;
    case DLT_PPP:
#ifdef DLT_PPP_BSDOS
    case DLT_PPP_BSDOS:
#endif
#ifdef DLT_PPP_SERIAL
    case DLT_PPP_SERIAL:
#endif
#ifdef DLT_PPP_ETHER
    case DLT_PPP_ETHER:
#endif
#if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) || \
    defined(__bsdi__) || defined(__APPLE__)
      data += 4;
      len -= 4;
#else
#if defined(sun) || defined(__sun)
      data += 8;
      len -= 8;
#else
      data += 24;
      len -= 24;
#endif
#endif
      break;
#ifdef DLT_ENC
    case DLT_ENC:
      data += 12;
      len -= 12;
      break;
#endif
#ifdef DLT_LINUX_SLL
    case DLT_LINUX_SLL:
      data += 16;
      len -= 16;
      break;
#endif
#ifdef DLT_IPNET
    case DLT_IPNET:
      data += 24;
      len -= 24;
      break;
#endif
  }

  if(type == ETHERTYPE_IPV6)
    network_process_packet(n, (struct timeval *)&hdr->ts, (u_char *)data, len,
                           AF_INET6);
  else
    network_process_packet(n, (struct timeval *)&hdr->ts, (u_char *)data, len,
                           AF_INET);

  if(packet_cnt == conn_freq) {
    packet_cnt = 0;
    memcpy(&last_packet_seen_time, &hdr->ts, sizeof(struct timeval));
    if((cleaned_conn = clean_old_conn()) && !(NET_print_flags & NET_PRINT_JSON))
      fprintf(stderr,
              "%d inactive connection(s) cleaned from connection pool\n",
              cleaned_conn);
  } else {
    packet_cnt++;
  }
}

typedef struct module_def_ {
  char *name;
  proto_mod *mod;
} module_def;

static module_def modules[] = {{"SSL", &ssl_mod},
                               {"NULL", &null_mod},
#ifdef ENABLE_RECORD
                               {"RECORD", &record_mod},
#endif
                               {0, 0}};

int parse_ssl_flag PROTO_LIST((int c));

int main(int argc, char **argv) {
  int r;
#ifdef _WIN32
  __declspec(dllimport) char *optarg;
  __declspec(dllimport) int optind;
#else
  extern char *optarg;
  extern int optind;
#endif
  pcap_if_t *interfaces;
  bpf_u_int32 localnet, netmask;
  int c;
  module_def *m = 0;
  int no_promiscuous = 0;
  int freed_conn = 0;

  char errbuf[PCAP_ERRBUF_SIZE];

  signal(SIGINT, sig_handler_quit);
  signal(SIGUSR1, sig_handler_usr);
  signal(SIGUSR2, sig_handler_usr);

  while((c = getopt(argc, argv, "vr:F:f:S:jyTt:ai:k:l:w:p:znsAxXhHVNdqem:P")) !=
        EOF) {
    switch(c) {
      case 'v':
        print_version();
        break;
      case 'f':
        fprintf(stderr, "-f option replaced by -r. Use that in the future\n");
      case 'r':
        file = strdup(optarg);
        break;
      case 'S':
        ssl_mod.vtbl->parse_flags(optarg);
        break;
      case 'y':
        NET_print_flags |= NET_PRINT_TYPESET;
        /*Kludge*/
        SSL_print_flags |= SSL_PRINT_NROFF;
        break;
      case 'j':
        NET_print_flags |= NET_PRINT_JSON;
        SSL_print_flags |= SSL_PRINT_JSON;
        break;
      case 'z':
        NET_print_flags |= NET_PRINT_TS;
        break;
      case 'a':
        NET_print_flags |= NET_PRINT_ACKS;
        break;
      case 'A':
        SSL_print_flags |= SSL_PRINT_ALL_FIELDS;
        break;
      case 'T':
        NET_print_flags |= NET_PRINT_TCP_HDR;
        break;
      case 'i':
        interface_name = strdup(optarg);
        break;
      case 'k':
        SSL_keyfile = strdup(optarg);
        break;
      case 'l':
        SSL_keylogfile = strdup(optarg);
        break;
      case 'w':
        logger = &pcap_mod;
        if(logger->vtbl->init(optarg) != 0) {
          fprintf(stderr, "Can not open/create out pcap %s\n", optarg);
          exit(1);
        }
        break;
      case 'p':
        SSL_password = strdup(optarg);
        break;
      case 'P':
        ++no_promiscuous;
        break;
      case 'n':
        NET_print_flags |= NET_PRINT_NO_RESOLVE;
        break;
      case 't':
        conn_ttl = atoi(optarg);
        break;
      case 'F':
        conn_freq = atoi(optarg);
        break;
      case 'm':
        for(m = modules; m->name != 0; m++) {
          if(!strcmp(m->name, optarg)) {
            mod = m->mod;
            break;
          }
        }
        if(!m->name) {
          fprintf(stderr, "Request analysis module %s not found\n", optarg);
          exit(1);
        }
        break;
      case 'h':
        usage();
        printf("Do 'man ssldump' for documentation\n");
        exit(1);

      case '?':
        usage();
        exit(1);

        /* must be an SSL flag. This is kind of a gross
           special case */
      default:
        parse_ssl_flag(c);
        break;
    }
  }

  argv += optind;
  argc -= optind;

  if(!file) {
    if(!interface_name) {
      if(pcap_findalldevs(&interfaces, errbuf) == -1) {
        fprintf(stderr, "PCAP: %s\n", errbuf);
        err_exit("Aborting", -1);
      }
      interface_name = interfaces->name;
      if(!interface_name) {
        fprintf(stderr, "PCAP: %s\n", errbuf);
        err_exit("Aborting", -1);
      }
    }
    fprintf(stderr, "ssldump: listening on %s\n", interface_name);
    if(!(p = pcap_open_live(interface_name, 65535, !no_promiscuous, 1000,
                            errbuf))) {
      fprintf(stderr, "PCAP: %s\n", errbuf);
      err_exit("Aborting", -1);
    }

    if(pcap_lookupnet(interface_name, &localnet, &netmask, errbuf) < 0)
      fprintf(stderr, "PCAP: %s\n", errbuf);
  } else {
    if(!(p = pcap_open_offline(file, errbuf))) {
      fprintf(stderr, "PCAP: %s\n", errbuf);
      err_exit("Aborting", -1);
    }

    netmask = 0;
    localnet = 0;
  }

  if(argc != 0)
    filter = collapse_args(argc, argv);

  if(filter) {
    struct bpf_program fp;

    /* (F5 patch)
     * reformat filter to include traffic with or without the 802.1q
     * vlan header. for example, "port 80" becomes:
     * "( port 80 ) or ( vlan and port 80 )".
     * note that if the filter includes the literals vlan, tagged, or
     * untagged, then it is assumed that the user knows what she is
     * doing, and the filter is not reformatted.
     */
    if((pcap_datalink(p) == DLT_EN10MB) && (filter != NULL) &&
       (strstr(filter, "vlan") == NULL)) {
      char *tmp_filter;
      char *fmt = "( (not ether proto 0x8100) and (%s) ) or ( vlan and (%s) )";

      tmp_filter = (char *)malloc((strlen(filter) * 2) + strlen(fmt) + 1);
      if(tmp_filter == NULL) {
        fprintf(stderr, "PCAP: malloc failed\n");
        err_exit("Aborting", -1);
      }

      sprintf(tmp_filter, fmt, filter, filter);
      free(filter);
      filter = tmp_filter;
    }

    if(pcap_compile(p, &fp, filter, 0, netmask) < 0)
      verr_exit("PCAP: %s\n", pcap_geterr(p));

    if(pcap_setfilter(p, &fp) < 0)
      verr_exit("PCAP: %s\n", pcap_geterr(p));
  }

  pcap_if_type = pcap_datalink(p);

  if(!(NET_print_flags & NET_PRINT_JSON))
    if(NET_print_flags & NET_PRINT_TYPESET)
      printf("\n.nf\n.ps -2\n");

  if((r = network_handler_create(mod, &n)))
    err_exit("Couldn't create network handler", r);

  pcap_loop(p, -1, pcap_cb, (u_char *)n);

  if(!(NET_print_flags & NET_PRINT_JSON))
    if(NET_print_flags & NET_PRINT_TYPESET)
      printf("\n.ps\n.fi\n");

  freed_conn = destroy_all_conn();
  if(freed_conn && !(NET_print_flags & NET_PRINT_JSON))
    fprintf(stderr, "Cleaned %d remaining connection(s) from connection pool\n",
            freed_conn);

  network_handler_destroy(mod, &n);
  pcap_close(p);

  free(n);

  if(filter)
    free(filter);
  if(file)
    free(file);
  if(interface_name)
    free(interface_name);
  if(SSL_keyfile)
    free(SSL_keyfile);
  if(SSL_keylogfile)
    free(SSL_keylogfile);
  if(SSL_password)
    free(SSL_password);
  if(logger) {
    logger->vtbl->deinit();
  }

  exit(0);
}

char *collapse_args(int argc, char **argv) {
  int i, len = 0;
  char *ret;

  if(!argc)
    return 0;

  for(i = 0; i < argc; i++) {
    len += strlen(argv[i]) + 1;
  }

  if(!(ret = (char *)malloc(len)))
    err_exit("Out of memory", 1);

  len = 0;
  for(i = 0; i < argc; i++) {
    strcpy(ret + len, argv[i]);
    len += strlen(argv[i]);

    if(i != (argc - 1))
      ret[len++] = ' ';
  }

  return ret;
}
