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   1 /*
   2  * pcap-septel.c: Packet capture interface for Intel/Septel card.
   3  *
   4  * Authors: Gilbert HOYEK (gil_hoyek@hotmail.com), Elias M. KHOURY
   5  * (+961 3 485243)
   6  */
   7
   8 #ifdef HAVE_CONFIG_H
   9 #include <config.h>
  10 #endif
  11
  12 #include <sys/param.h>
  13
  14 #include <stdlib.h>
  15 #include <string.h>
  16 #include <errno.h>
  17
  18 #include "pcap-int.h"
  19
  20 #include <netinet/in.h>
  21 #include <sys/mman.h>
  22 #include <sys/socket.h>
  23 #include <sys/types.h>
  24 #include <unistd.h>
  25
  26 #include <msg.h>
  27 #include <ss7_inc.h>
  28 #include <sysgct.h>
  29 #include <pack.h>
  30 #include <system.h>
  31
  32 #include "pcap-septel.h"
  33
  34 static int septel_stats(pcap_t *p, struct pcap_stat *ps);
  35 static int septel_getnonblock(pcap_t *p);
  36 static int septel_setnonblock(pcap_t *p, int nonblock);
  37
  38 /*
  39  * Private data for capturing on Septel devices.
  40  */
  41 struct pcap_septel {
  42         struct pcap_stat stat;
  43 }
  44
  45 /*
  46  *  Read at most max_packets from the capture queue and call the callback
  47  *  for each of them. Returns the number of packets handled, -1 if an
  48  *  error occurred, or -2 if we were told to break out of the loop.
  49  */
  50 static int septel_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user) {
  51
  52   struct pcap_septel *ps = p->priv;
  53   HDR *h;
  54   MSG *m;
  55   int processed = 0 ;
  56   int t = 0 ;
  57
  58   /* identifier for the message queue of the module(upe) from which we are capturing
  59    * packets.These IDs are defined in system.txt . By default it is set to 0x2d
  60    * so change it to 0xdd for technical reason and therefore the module id for upe becomes:
  61    * LOCAL        0xdd           * upe - Example user part task */
  62   unsigned int id = 0xdd;
  63
  64   /* process the packets */
  65   do  {
  66
  67     unsigned short packet_len = 0;
  68     int caplen = 0;
  69     int counter = 0;
  70     struct pcap_pkthdr   pcap_header;
  71     u_char *dp ;
  72
  73     /*
  74      * Has "pcap_breakloop()" been called?
  75      */
  76 loop:
  77     if (p->break_loop) {
  78       /*
  79        * Yes - clear the flag that indicates that
  80        * it has, and return -2 to indicate that
  81        * we were told to break out of the loop.
  82        */
  83       p->break_loop = 0;
  84       return -2;
  85     }
  86
  87     /*repeat until a packet is read
  88      *a NULL message means :
  89      * when no packet is in queue or all packets in queue already read */
  90     do  {
  91       /* receive packet in non-blocking mode
  92        * GCT_grab is defined in the septel library software */
  93       h = GCT_grab(id);
  94
  95       m = (MSG*)h;
  96       /* a counter is added here to avoid an infinite loop
  97        * that will cause our capture program GUI to freeze while waiting
  98        * for a packet*/
  99       counter++ ;
 100
 101     }
 102     while  ((m == NULL)&& (counter< 100)) ;
 103
 104     if (m != NULL) {
 105
 106       t = h->type ;
 107
 108       /* catch only messages with type = 0xcf00 or 0x8f01 corresponding to ss7 messages*/
 109       /* XXX = why not use API_MSG_TX_REQ for 0xcf00 and API_MSG_RX_IND
 110        * for 0x8f01? */
 111       if ((t != 0xcf00) && (t != 0x8f01)) {
 112         relm(h);
 113         goto loop ;
 114       }
 115
 116       /* XXX - is API_MSG_RX_IND for an MTP2 or MTP3 message? */
 117       dp = get_param(m);/* get pointer to MSG parameter area (m->param) */
 118       packet_len = m->len;
 119       caplen =  p->snapshot ;
 120
 121
 122       if (caplen > packet_len) {
 123
 124         caplen = packet_len;
 125       }
 126       /* Run the packet filter if there is one. */
 127       if ((p->fcode.bf_insns == NULL) || pcap_filter(p->fcode.bf_insns, dp, packet_len, caplen)) {
 128
 129
 130         /*  get a time stamp , consisting of :
 131          *
 132          *  pcap_header.ts.tv_sec:
 133          *  ----------------------
 134          *   a UNIX format time-in-seconds when he packet was captured,
 135          *   i.e. the number of seconds since Epoch time (January 1,1970, 00:00:00 GMT)
 136          *
 137          *  pcap_header.ts.tv_usec :
 138          *  ------------------------
 139          *   the number of microseconds since that second
 140          *   when the packet was captured
 141          */
 142
 143         (void)gettimeofday(&pcap_header.ts, NULL);
 144
 145         /* Fill in our own header data */
 146         pcap_header.caplen = caplen;
 147         pcap_header.len = packet_len;
 148
 149         /* Count the packet. */
 150         ps->stat.ps_recv++;
 151
 152         /* Call the user supplied callback function */
 153         callback(user, &pcap_header, dp);
 154
 155         processed++ ;
 156
 157       }
 158       /* after being processed the packet must be
 159        *released in order to receive another one */
 160       relm(h);
 161     }else
 162       processed++;
 163
 164   }
 165   while (processed < cnt) ;
 166
 167   return processed ;
 168 }
 169
 170
 171 static int
 172 septel_inject(pcap_t *handle, const void *buf _U_, int size _U_)
 173 {
 174   pcap_strlcpy(handle->errbuf, "Sending packets isn't supported on Septel cards",
 175           PCAP_ERRBUF_SIZE);
 176   return (-1);
 177 }
 178
 179 /*
 180  *  Activate a handle for a live capture from the given Septel device.  Always pass a NULL device
 181  *  The promisc flag is ignored because Septel cards have built-in tracing.
 182  *  The timeout is also ignored as it is not supported in hardware.
 183  *
 184  *  See also pcap(3).
 185  */
 186 static pcap_t *septel_activate(pcap_t* handle) {
 187   /* Initialize some components of the pcap structure. */
 188   handle->linktype = DLT_MTP2;
 189
 190   /*
 191    * Turn a negative snapshot value (invalid), a snapshot value of
 192    * 0 (unspecified), or a value bigger than the normal maximum
 193    * value, into the maximum allowed value.
 194    *
 195    * If some application really *needs* a bigger snapshot
 196    * length, we should just increase MAXIMUM_SNAPLEN.
 197    */
 198   if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN)
 199     handle->snapshot = MAXIMUM_SNAPLEN;
 200
 201   handle->bufsize = 0;
 202
 203   /*
 204    * "select()" and "poll()" don't work on Septel queues
 205    */
 206   handle->selectable_fd = -1;
 207
 208   handle->read_op = septel_read;
 209   handle->inject_op = septel_inject;
 210   handle->setfilter_op = pcap_install_bpf_program;
 211   handle->set_datalink_op = NULL; /* can't change data link type */
 212   handle->getnonblock_op = septel_getnonblock;
 213   handle->setnonblock_op = septel_setnonblock;
 214   handle->stats_op = septel_stats;
 215
 216   return 0;
 217 }
 218
 219 pcap_t *septel_create(const char *device, char *ebuf, int *is_ours) {
 220         const char *cp;
 221         pcap_t *p;
 222
 223         /* Does this look like the Septel device? */
 224         cp = strrchr(device, '/');
 225         if (cp == NULL)
 226                 cp = device;
 227         if (strcmp(cp, "septel") != 0) {
 228                 /* Nope, it's not "septel" */
 229                 *is_ours = 0;
 230                 return NULL;
 231         }
 232
 233         /* OK, it's probably ours. */
 234         *is_ours = 1;
 235
 236         p = PCAP_CREATE_COMMON(ebuf, struct pcap_septel);
 237         if (p == NULL)
 238                 return NULL;
 239
 240         p->activate_op = septel_activate;
 241         /*
 242          * Set these up front, so that, even if our client tries
 243          * to set non-blocking mode before we're activated, or
 244          * query the state of non-blocking mode, they get an error,
 245          * rather than having the non-blocking mode option set
 246          * for use later.
 247          */
 248         p->getnonblock_op = septel_getnonblock;
 249         p->setnonblock_op = septel_setnonblock;
 250         return p;
 251 }
 252
 253 static int septel_stats(pcap_t *p, struct pcap_stat *ps) {
 254   struct pcap_septel *handlep = p->priv;
 255   /*handlep->stat.ps_recv = 0;*/
 256   /*handlep->stat.ps_drop = 0;*/
 257
 258   *ps = handlep->stat;
 259
 260   return 0;
 261 }
 262
 263
 264 int
 265 septel_findalldevs(pcap_if_list_t *devlistp, char *errbuf)
 266 {
 267   /*
 268    * XXX - do the notions of "up", "running", or "connected" apply here?
 269    */
 270   if (pcap_add_dev(devlistp,"septel",0,"Intel/Septel device",errbuf) == NULL)
 271     return -1;
 272   return 0;
 273 }
 274
 275
 276 /*
 277  * We don't support non-blocking mode.  I'm not sure what we'd
 278  * do to support it and, given that we don't support select()/
 279  * poll()/epoll_wait()/kevent() etc., it probably doesn't
 280  * matter.
 281  */
 282 static int
 283 septel_getnonblock(pcap_t *p)
 284 {
 285   fprintf(p->errbuf, PCAP_ERRBUF_SIZE, "Non-blocking mode not supported on Septel devices");
 286   return (-1);
 287 }
 288
 289 static int
 290 septel_setnonblock(pcap_t *p, int nonblock _U_)
 291 {
 292   fprintf(p->errbuf, PCAP_ERRBUF_SIZE, "Non-blocking mode not supported on Septel devices");
 293   return (-1);
 294 }
 295
 296 #ifdef SEPTEL_ONLY
 297 /*
 298  * This libpcap build supports only Septel cards, not regular network
 299  * interfaces.
 300  */
 301
 302 /*
 303  * There are no regular interfaces, just Septel interfaces.
 304  */
 305 int
 306 pcap_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf)
 307 {
 308   return (0);
 309 }
 310
 311 /*
 312  * Attempts to open a regular interface fail.
 313  */
 314 pcap_t *
 315 pcap_create_interface(const char *device, char *errbuf)
 316 {
 317   snprintf(errbuf, PCAP_ERRBUF_SIZE,
 318                 "This version of libpcap only supports Septel cards");
 319   return (NULL);
 320 }
 321
 322 /*
 323  * Libpcap version string.
 324  */
 325 const char *
 326 pcap_lib_version(void)
 327 {
 328   return (PCAP_VERSION_STRING " (Septel-only)");
 329 }
 330 #endif