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
34static int septel_stats(pcap_t *p, struct pcap_stat *ps);
35static int septel_getnonblock(pcap_t *p);
36static int septel_setnonblock(pcap_t *p, int nonblock);
37
38/*
39 * Private data for capturing on Septel devices.
40 */
41struct 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 */
50static 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     */
76loop:
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
171static int
172septel_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 */
186static 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 = 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
219pcap_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
253static 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
264int
265septel_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 (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 */
282static int
283septel_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
289static int
290septel_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 */
305int
306pcap_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 */
314pcap_t *
315pcap_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 */
325const char *
326pcap_lib_version(void)
327{
328  return (PCAP_VERSION_STRING " (Septel-only)");
329}
330#endif
331