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   1 /*
   2  * pcap-septel.c: Packet capture interface for Intel/Septel card.
   3  *
   4  *  The functionality of this code attempts to mimic that of pcap-linux as much
   5  * as possible.  This code is compiled in several different ways depending on
   6  * whether SEPTEL_ONLY and HAVE_SEPTEL_API are defined.  If HAVE_SEPTEL_API is
   7  * not defined it should not get compiled in, otherwise if SEPTEL_ONLY is
   8  * defined then the 'septel_' function calls are renamed to 'pcap_'
   9  * equivalents.  If SEPTEL_ONLY is not defined then nothing is altered - the
  10  * septel_ functions will be called as required from their
  11  * pcap-linux/equivalents.
  12  *
  13  * Authors: Gilbert HOYEK (gil_hoyek@hotmail.com), Elias M. KHOURY
  14  * (+961 3 485243)
  15  */
  16
  17 #ifndef lint
  18 static const char rcsid[] _U_ =
  19     "@(#) $Header: /tcpdump/master/libpcap/pcap-septel.c,v 1.1 2005-06-20 21:27:10 guy Exp $";
  20 #endif
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include "config.h"
  24 #endif
  25
  26 #include <sys/param.h>
  27
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <errno.h>
  31
  32 #include "pcap-int.h"
  33
  34 #include <ctype.h>
  35 #include <netinet/in.h>
  36 #include <sys/mman.h>
  37 #include <sys/socket.h>
  38 #include <sys/types.h>
  39 #include <unistd.h>
  40
  41 #ifdef HAVE_SEPTEL_API
  42 #include <msg.h>
  43 #include <ss7_inc.h>
  44 #include <sysgct.h>
  45 #include <pack.h>
  46 #include <system.h>
  47 #endif /* HAVE_SEPTEL_API */
  48
  49 #ifdef SEPTEL_ONLY
  50 /* This code is required when compiling for a DAG device only. */
  51 #include "pcap-septel.h"
  52
  53 /* Replace dag function names with pcap equivalent. */
  54 #define septel_open_live pcap_open_live
  55 #define septel_platform_finddevs pcap_platform_finddevs
  56 #endif /* SEPTEL_ONLY */
  57
  58 static int septel_setfilter(pcap_t *p, struct bpf_program *fp);
  59 static int septel_stats(pcap_t *p, struct pcap_stat *ps);
  60 static int septel_set_datalink(pcap_t *p, int dlt);
  61 static int septel_get_datalink(pcap_t *p);
  62 static int septel_setnonblock(pcap_t *p, int nonblock, char *errbuf);
  63
  64 static void septel_platform_close(pcap_t *p) {
  65
  66 }
  67
  68
  69
  70 /*
  71  *  Read at most max_packets from the capture queue and call the callback
  72  *  for each of them. Returns the number of packets handled, -1 if an
  73  *  error occured, or -2 if we were told to break out of the loop.
  74  */
  75 static int septel_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user) {
  76
  77     HDR *h;
  78     MSG *m;
  79     int processed = 0 ;
  80     int t = 0 ;
  81
  82     /* identifier for the message queue of the module(upe) from which we are capturing
  83      * packets.These IDs are defined in system.txt . By default it is set to 0x2d
  84      * so change it to 0xdd for technical reason and therefore the module id for upe becomes:
  85      * LOCAL        0xdd           * upe - Example user part task */
  86     unsigned int id = 0xdd;
  87
  88        /* process the packets */
  89     do  {
  90
  91       unsigned short packet_len = 0;
  92       int caplen = 0;
  93       int counter = 0;
  94       struct pcap_pkthdr   pcap_header;
  95
  96       u_char *dp ;
  97       dp = malloc(320); /* 320 = size of param area */
  98
  99         /*
 100          * Has "pcap_breakloop()" been called?
 101          */
 102       loop:
 103          if (p->break_loop) {
 104           /*
 105            * Yes - clear the flag that indicates that
 106            * it has, and return -2 to indicate that
 107            * we were told to break out of the loop.
 108            */
 109                 p->break_loop = 0;
 110                 return -2;
 111                 }
 112
 113           /*repeat until a packet is read
 114           *a NULL message means :
 115           * when no packet is in queue or all packets in queue already read */
 116       do  {
 117          /* receive packet in non-blocking mode
 118           * GCT_grab is defined in the septel library software */
 119          h = GCT_grab(id);
 120
 121          m = (MSG*)h;
 122          /* a couter is added here to avoid an infinite loop
 123           * that will cause our capture program GUI to freeze while waiting for a packet*/
 124          counter++ ;
 125
 126       }
 127       while  ((m == NULL)&& (counter< 100)) ;
 128
 129       if (m != NULL) {
 130
 131           t = h->type ;
 132
 133          /* catch only messages with type = 0xcf00 or 0x8f01 corrsponding to ss7 messages*/
 134           if ((t != 0xcf00) && (t != 0x8f01)) {
 135                relm(h);
 136                goto loop ;
 137           }
 138
 139
 140           dp = get_param(m);/* get pointer to MSG parameter area (m->param) */
 141           packet_len = m->len;
 142           caplen =  p->snapshot ;
 143
 144
 145           if (caplen > packet_len) {
 146
 147                 caplen = packet_len;
 148           }
 149           /* Run the packet filter if there is one. */
 150           if ((p->fcode.bf_insns == NULL) || bpf_filter(p->fcode.bf_insns, dp, packet_len, caplen)) {
 151
 152
 153                 /*  get a time stamp , consisting of :
 154                  *
 155                  *  pcap_header.ts.tv_sec:
 156                  *  ----------------------
 157                  *   a UNIX format time-in-seconds when he packet was captured,
 158                  *   i.e. the number of seconds since Epoch time (January 1,1970, 00:00:00 GMT)
 159                  *
 160                  *  pcap_header.ts.tv_usec :
 161                  *  ------------------------
 162                  *   the number of microseconds since that second
 163                  *   when the packet was captured
 164                  */
 165
 166                  (void)gettimeofday(&pcap_header.ts, NULL);
 167
 168                  /* Fill in our own header data */
 169                  pcap_header.caplen = caplen;
 170                  pcap_header.len = packet_len;
 171
 172                  /* Count the packet. */
 173                  p->md.stat.ps_recv++;
 174
 175                  /* Call the user supplied callback function */
 176                  callback(user, &pcap_header, dp);
 177
 178                  processed++ ;
 179
 180           }
 181          /* after being processed the packet must be
 182           *released in order to receive another one */
 183           relm(h);
 184       }else
 185        processed++;
 186
 187     }
 188
 189     while (processed < cnt ) ;
 190
 191     return processed ;
 192 }
 193
 194 /*
 195  *  Get a handle for a live capture from the given Septel device.  Always pass a NULL device
 196  *  The promisc flag is ignored because Septel cards have built-in tracing.
 197  *  The to_ms parameter is also ignored as it is
 198  *  not supported in hardware.
 199  *
 200  *  See also pcap(3).
 201  */
 202 pcap_t *septel_open_live(const char *device, int snaplen, int promisc, int to_ms, char *ebuf) {
 203   pcap_t *handle;
 204
 205   handle = malloc(sizeof(*handle));
 206   if (handle == NULL) {
 207     snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc %s: %s", device, pcap_strerror(errno));
 208     return NULL;
 209   }
 210
 211   /* Initialize some components of the pcap structure. */
 212
 213   memset(handle, 0, sizeof(*handle));
 214
 215   handle->snapshot = snaplen;
 216
 217   if ((handle->linktype = septel_get_datalink(handle)) < 0) {
 218     snprintf(ebuf, PCAP_ERRBUF_SIZE, "septel_get_linktype %s: unknown linktype\n", device);
 219   goto fail;
 220   }
 221
 222   handle->bufsize = 0;
 223
 224
 225   /*
 226    * "select()" and "poll()" don't  work on Septel queues
 227    */
 228   handle->selectable_fd = -1;
 229
 230   handle->read_op = septel_read;
 231   handle->setfilter_op = septel_setfilter;
 232   handle->set_datalink_op = septel_set_datalink;
 233   handle->getnonblock_op = pcap_getnonblock_fd;
 234   handle->setnonblock_op = septel_setnonblock;
 235   handle->stats_op = septel_stats;
 236   handle->close_op = septel_platform_close;
 237
 238   return handle;
 239
 240 fail:
 241   if (handle != NULL) {
 242       free(handle);
 243       }
 244
 245   return NULL;
 246 }
 247
 248 static int septel_stats(pcap_t *p, struct pcap_stat *ps) {
 249   /*p->md.stat.ps_recv = 0;*/
 250   /*p->md.stat.ps_drop = 0;*/
 251
 252   *ps = p->md.stat;
 253
 254   return 0;
 255 }
 256
 257
 258 int
 259 septel_platform_finddevs(pcap_if_t **devlistp, char *errbuf)
 260 {
 261 unsigned char *p;
 262   const char description[512]= "Intel/Septel device";
 263   char name[512]="septel" ;
 264   int ret = 0;
 265   pcap_add_if(devlistp,name,0,description,errbuf);
 266
 267   return (ret);
 268 }
 269
 270
 271 /*
 272  * Installs the given bpf filter program in the given pcap structure.  There is
 273  * no attempt to store the filter in kernel memory as that is not supported
 274  * with SEPTEL cards.
 275  */
 276 static int septel_setfilter(pcap_t *p, struct bpf_program *fp) {
 277 if (!p)
 278     return -1;
 279   if (!fp) {
 280     strncpy(p->errbuf, "setfilter: No filter specified",
 281             sizeof(p->errbuf));
 282     return -1;
 283   }
 284
 285   /* Make our private copy of the filter */
 286
 287   if (install_bpf_program(p, fp) < 0) {
 288     snprintf(p->errbuf, sizeof(p->errbuf),
 289              "malloc: %s", pcap_strerror(errno));
 290     return -1;
 291   }
 292
 293   p->md.use_bpf = 0;
 294
 295
 296
 297     return (0);
 298 }
 299
 300
 301 static int
 302 septel_set_datalink(pcap_t *p, int dlt)
 303 {
 304         return (0);
 305 }
 306
 307 static int
 308 septel_setnonblock(pcap_t *p, int nonblock, char *errbuf)
 309 {
 310         return (0);
 311 }
 312
 313 static int
 314 septel_get_datalink(pcap_t *p)
 315 {
 316   int linktype = -1;
 317   return DLT_MTP2;
 318 }