pcap-septel.c 9.21 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
/*
 * pcap-septel.c: Packet capture interface for Intel/Septel card.
 *
 * The functionality of this code attempts to mimic that of pcap-linux as much
 * as possible.  This code is compiled in several different ways depending on
 * whether SEPTEL_ONLY and HAVE_SEPTEL_API are defined.  If HAVE_SEPTEL_API is
 * not defined it should not get compiled in, otherwise if SEPTEL_ONLY is
 * defined then the 'septel_' function calls are renamed to 'pcap_'
 * equivalents.  If SEPTEL_ONLY is not defined then nothing is altered - the
 * septel_ functions will be called as required from their
 * pcap-linux/equivalents.
 *
 * Authors: Gilbert HOYEK (gil_hoyek@hotmail.com), Elias M. KHOURY
 * (+961 3 485243)
 */

#ifdef HAVE_CONFIG_H
18
#include <config.h>
19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
#endif

#include <sys/param.h>

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

#include "pcap-int.h"

#include <ctype.h>
#include <netinet/in.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>

#include <msg.h>
#include <ss7_inc.h>
#include <sysgct.h>
#include <pack.h>
#include <system.h>

#include "pcap-septel.h"

static int septel_setfilter(pcap_t *p, struct bpf_program *fp);
static int septel_stats(pcap_t *p, struct pcap_stat *ps);
46 47
static int septel_getnonblock(pcap_t *p);
static int septel_setnonblock(pcap_t *p, int nonblock);
48

49 50 51 52 53 54 55
/*
 * Private data for capturing on Septel devices.
 */
struct pcap_septel {
	struct pcap_stat stat;
}

56 57 58 59 60 61 62
/*
 *  Read at most max_packets from the capture queue and call the callback
 *  for each of them. Returns the number of packets handled, -1 if an
 *  error occured, or -2 if we were told to break out of the loop.
 */
static int septel_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user) {

63
  struct pcap_septel *ps = p->priv;
64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160
  HDR *h;
  MSG *m;
  int processed = 0 ;
  int t = 0 ;

  /* identifier for the message queue of the module(upe) from which we are capturing
   * packets.These IDs are defined in system.txt . By default it is set to 0x2d
   * so change it to 0xdd for technical reason and therefore the module id for upe becomes:
   * LOCAL        0xdd           * upe - Example user part task */
  unsigned int id = 0xdd;

  /* process the packets */
  do  {

    unsigned short packet_len = 0;
    int caplen = 0;
    int counter = 0;
    struct pcap_pkthdr   pcap_header;
    u_char *dp ;

    /*
     * Has "pcap_breakloop()" been called?
     */
loop:
    if (p->break_loop) {
      /*
       * Yes - clear the flag that indicates that
       * it has, and return -2 to indicate that
       * we were told to break out of the loop.
       */
      p->break_loop = 0;
      return -2;
    }

    /*repeat until a packet is read
     *a NULL message means :
     * when no packet is in queue or all packets in queue already read */
    do  {
      /* receive packet in non-blocking mode
       * GCT_grab is defined in the septel library software */
      h = GCT_grab(id);

      m = (MSG*)h;
      /* a couter is added here to avoid an infinite loop
       * that will cause our capture program GUI to freeze while waiting
       * for a packet*/
      counter++ ;

    }
    while  ((m == NULL)&& (counter< 100)) ;

    if (m != NULL) {

      t = h->type ;

      /* catch only messages with type = 0xcf00 or 0x8f01 corrsponding to ss7 messages*/
      /* XXX = why not use API_MSG_TX_REQ for 0xcf00 and API_MSG_RX_IND
       * for 0x8f01? */
      if ((t != 0xcf00) && (t != 0x8f01)) {
        relm(h);
        goto loop ;
      }

      /* XXX - is API_MSG_RX_IND for an MTP2 or MTP3 message? */
      dp = get_param(m);/* get pointer to MSG parameter area (m->param) */
      packet_len = m->len;
      caplen =  p->snapshot ;


      if (caplen > packet_len) {

        caplen = packet_len;
      }
      /* Run the packet filter if there is one. */
      if ((p->fcode.bf_insns == NULL) || bpf_filter(p->fcode.bf_insns, dp, packet_len, caplen)) {


        /*  get a time stamp , consisting of :
         *
         *  pcap_header.ts.tv_sec:
         *  ----------------------
         *   a UNIX format time-in-seconds when he packet was captured,
         *   i.e. the number of seconds since Epoch time (January 1,1970, 00:00:00 GMT)
         *
         *  pcap_header.ts.tv_usec :
         *  ------------------------
         *   the number of microseconds since that second
         *   when the packet was captured
         */

        (void)gettimeofday(&pcap_header.ts, NULL);

        /* Fill in our own header data */
        pcap_header.caplen = caplen;
        pcap_header.len = packet_len;

        /* Count the packet. */
161
        ps->stat.ps_recv++;
162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190

        /* Call the user supplied callback function */
        callback(user, &pcap_header, dp);

        processed++ ;

      }
      /* after being processed the packet must be
       *released in order to receive another one */
      relm(h);
    }else
      processed++;

  }
  while (processed < cnt) ;

  return processed ;
}


static int
septel_inject(pcap_t *handle, const void *buf _U_, size_t size _U_)
{
  strlcpy(handle->errbuf, "Sending packets isn't supported on Septel cards",
          PCAP_ERRBUF_SIZE);
  return (-1);
}

/*
191
 *  Activate a handle for a live capture from the given Septel device.  Always pass a NULL device
192
 *  The promisc flag is ignored because Septel cards have built-in tracing.
193
 *  The timeout is also ignored as it is not supported in hardware.
194 195 196
 *
 *  See also pcap(3).
 */
197
static pcap_t *septel_activate(pcap_t* handle) {
198
  /* Initialize some components of the pcap structure. */
199
  handle->linktype = DLT_MTP2;
200

201 202 203 204 205 206 207 208 209 210 211
  /*
   * Turn a negative snapshot value (invalid), a snapshot value of
   * 0 (unspecified), or a value bigger than the normal maximum
   * value, into the maximum allowed value.
   *
   * If some application really *needs* a bigger snapshot
   * length, we should just increase MAXIMUM_SNAPLEN.
   */
  if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN)
    handle->snapshot = MAXIMUM_SNAPLEN;

212 213 214 215 216 217 218 219 220 221 222
  handle->bufsize = 0;

  /*
   * "select()" and "poll()" don't work on Septel queues
   */
  handle->selectable_fd = -1;

  handle->read_op = septel_read;
  handle->inject_op = septel_inject;
  handle->setfilter_op = septel_setfilter;
  handle->set_datalink_op = NULL; /* can't change data link type */
223
  handle->getnonblock_op = septel_getnonblock;
224 225 226
  handle->setnonblock_op = septel_setnonblock;
  handle->stats_op = septel_stats;

227 228
  return 0;
}
229

230 231
pcap_t *septel_create(const char *device, char *ebuf, int *is_ours) {
	const char *cp;
232 233
	pcap_t *p;

234 235 236 237 238 239 240 241 242 243 244 245 246
	/* Does this look like the Septel device? */
	cp = strrchr(device, '/');
	if (cp == NULL)
		cp = device;
	if (strcmp(cp, "septel") != 0) {
		/* Nope, it's not "septel" */
		*is_ours = 0;
		return NULL;
	}

	/* OK, it's probably ours. */
	*is_ours = 1;

247
	p = pcap_create_common(ebuf, sizeof (struct pcap_septel));
248 249
	if (p == NULL)
		return NULL;
250

251
	p->activate_op = septel_activate;
252 253 254 255 256 257 258 259 260
	/*
	 * Set these up front, so that, even if our client tries
	 * to set non-blocking mode before we're activated, or
	 * query the state of non-blocking mode, they get an error,
	 * rather than having the non-blocking mode option set
	 * for use later.
	 */
	p->getnonblock_op = septel_getnonblock;
	p->setnonblock_op = septel_setnonblock;
261
	return p;
262 263 264
}

static int septel_stats(pcap_t *p, struct pcap_stat *ps) {
265 266 267
  struct pcap_septel *handlep = p->priv;
  /*handlep->stat.ps_recv = 0;*/
  /*handlep->stat.ps_drop = 0;*/
268

269
  *ps = handlep->stat;
270

271 272 273 274 275
  return 0;
}


int
276
septel_findalldevs(pcap_if_list_t *devlistp, char *errbuf)
277
{
278 279 280 281 282 283
  /*
   * XXX - do the notions of "up", "running", or "connected" apply here?
   */
  if (add_dev(devlistp,"septel",0,"Intel/Septel device",errbuf) == NULL)
    return -1;
  return 0;
284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302
}


/*
 * Installs the given bpf filter program in the given pcap structure.  There is
 * no attempt to store the filter in kernel memory as that is not supported
 * with Septel cards.
 */
static int septel_setfilter(pcap_t *p, struct bpf_program *fp) {
  if (!p)
    return -1;
  if (!fp) {
    strncpy(p->errbuf, "setfilter: No filter specified",
	    sizeof(p->errbuf));
    return -1;
  }

  /* Make our private copy of the filter */

303
  if (install_bpf_program(p, fp) < 0)
304 305 306 307 308
    return -1;

  return (0);
}

309 310 311 312 313 314 315 316 317 318 319 320
/*
 * We don't support non-blocking mode.  I'm not sure what we'd
 * do to support it and, given that we don't support select()/
 * poll()/epoll_wait()/kevent() etc., it probably doesn't
 * matter.
 */
static int
septel_getnonblock(pcap_t *p)
{
  fprintf(p->errbuf, PCAP_ERRBUF_SIZE, "Non-blocking mode not supported on Septel devices");
  return (-1);
}
321 322

static int
323
septel_setnonblock(pcap_t *p, int nonblock _U_)
324
{
325
  fprintf(p->errbuf, PCAP_ERRBUF_SIZE, "Non-blocking mode not supported on Septel devices");
326
  return (-1);
327
}
328 329 330 331 332 333 334 335 336 337 338

#ifdef SEPTEL_ONLY
/*
 * This libpcap build supports only Septel cards, not regular network
 * interfaces.
 */

/*
 * There are no regular interfaces, just Septel interfaces.
 */
int
339
pcap_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf)
340 341 342 343 344 345 346 347 348 349 350 351 352 353
{
  return (0);
}

/*
 * Attempts to open a regular interface fail.
 */
pcap_t *
pcap_create_interface(const char *device, char *errbuf)
{
  pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
                "This version of libpcap only supports Septel cards");
  return (NULL);
}
354 355 356 357 358 359 360 361 362

/*
 * Libpcap version string.
 */
const char *
pcap_lib_version(void)
{
  return (PCAP_VERSION_STRING " (Septel-only)");
}
363
#endif