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 */
septel_read(pcap_t * p,int cnt,pcap_handler callback,u_char * user)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
septel_inject(pcap_t * handle,const void * buf _U_,int size _U_)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 */
septel_activate(pcap_t * handle)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 = 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
septel_create(const char * device,char * ebuf,int * is_ours)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
septel_stats(pcap_t * p,struct pcap_stat * ps)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
septel_findalldevs(pcap_if_list_t * devlistp,char * errbuf)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 (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
septel_getnonblock(pcap_t * p)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
septel_setnonblock(pcap_t * p,int nonblock _U_)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
pcap_platform_finddevs(pcap_if_list_t * devlistp,char * errbuf)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 *
pcap_create_interface(const char * device,char * errbuf)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 *
pcap_lib_version(void)326 pcap_lib_version(void)
327 {
328 return (PCAP_VERSION_STRING " (Septel-only)");
329 }
330 #endif
331