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 #ifdef HAVE_CONFIG_H
18 #include <config.h>
19 #endif
20
21 #include <sys/param.h>
22
23 #include <stdlib.h>
24 #include <string.h>
25 #include <errno.h>
26
27 #include "pcap-int.h"
28
29 #include <ctype.h>
30 #include <netinet/in.h>
31 #include <sys/mman.h>
32 #include <sys/socket.h>
33 #include <sys/types.h>
34 #include <unistd.h>
35
36 #include <msg.h>
37 #include <ss7_inc.h>
38 #include <sysgct.h>
39 #include <pack.h>
40 #include <system.h>
41
42 #include "pcap-septel.h"
43
44 static int septel_setfilter(pcap_t *p, struct bpf_program *fp);
45 static int septel_stats(pcap_t *p, struct pcap_stat *ps);
46 static int septel_getnonblock(pcap_t *p);
47 static int septel_setnonblock(pcap_t *p, int nonblock);
48
49 /*
50 * Private data for capturing on Septel devices.
51 */
52 struct pcap_septel {
53 struct pcap_stat stat;
54 }
55
56 /*
57 * Read at most max_packets from the capture queue and call the callback
58 * for each of them. Returns the number of packets handled, -1 if an
59 * error occured, or -2 if we were told to break out of the loop.
60 */
septel_read(pcap_t * p,int cnt,pcap_handler callback,u_char * user)61 static int septel_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user) {
62
63 struct pcap_septel *ps = p->priv;
64 HDR *h;
65 MSG *m;
66 int processed = 0 ;
67 int t = 0 ;
68
69 /* identifier for the message queue of the module(upe) from which we are capturing
70 * packets.These IDs are defined in system.txt . By default it is set to 0x2d
71 * so change it to 0xdd for technical reason and therefore the module id for upe becomes:
72 * LOCAL 0xdd * upe - Example user part task */
73 unsigned int id = 0xdd;
74
75 /* process the packets */
76 do {
77
78 unsigned short packet_len = 0;
79 int caplen = 0;
80 int counter = 0;
81 struct pcap_pkthdr pcap_header;
82 u_char *dp ;
83
84 /*
85 * Has "pcap_breakloop()" been called?
86 */
87 loop:
88 if (p->break_loop) {
89 /*
90 * Yes - clear the flag that indicates that
91 * it has, and return -2 to indicate that
92 * we were told to break out of the loop.
93 */
94 p->break_loop = 0;
95 return -2;
96 }
97
98 /*repeat until a packet is read
99 *a NULL message means :
100 * when no packet is in queue or all packets in queue already read */
101 do {
102 /* receive packet in non-blocking mode
103 * GCT_grab is defined in the septel library software */
104 h = GCT_grab(id);
105
106 m = (MSG*)h;
107 /* a couter is added here to avoid an infinite loop
108 * that will cause our capture program GUI to freeze while waiting
109 * for a packet*/
110 counter++ ;
111
112 }
113 while ((m == NULL)&& (counter< 100)) ;
114
115 if (m != NULL) {
116
117 t = h->type ;
118
119 /* catch only messages with type = 0xcf00 or 0x8f01 corrsponding to ss7 messages*/
120 /* XXX = why not use API_MSG_TX_REQ for 0xcf00 and API_MSG_RX_IND
121 * for 0x8f01? */
122 if ((t != 0xcf00) && (t != 0x8f01)) {
123 relm(h);
124 goto loop ;
125 }
126
127 /* XXX - is API_MSG_RX_IND for an MTP2 or MTP3 message? */
128 dp = get_param(m);/* get pointer to MSG parameter area (m->param) */
129 packet_len = m->len;
130 caplen = p->snapshot ;
131
132
133 if (caplen > packet_len) {
134
135 caplen = packet_len;
136 }
137 /* Run the packet filter if there is one. */
138 if ((p->fcode.bf_insns == NULL) || bpf_filter(p->fcode.bf_insns, dp, packet_len, caplen)) {
139
140
141 /* get a time stamp , consisting of :
142 *
143 * pcap_header.ts.tv_sec:
144 * ----------------------
145 * a UNIX format time-in-seconds when he packet was captured,
146 * i.e. the number of seconds since Epoch time (January 1,1970, 00:00:00 GMT)
147 *
148 * pcap_header.ts.tv_usec :
149 * ------------------------
150 * the number of microseconds since that second
151 * when the packet was captured
152 */
153
154 (void)gettimeofday(&pcap_header.ts, NULL);
155
156 /* Fill in our own header data */
157 pcap_header.caplen = caplen;
158 pcap_header.len = packet_len;
159
160 /* Count the packet. */
161 ps->stat.ps_recv++;
162
163 /* Call the user supplied callback function */
164 callback(user, &pcap_header, dp);
165
166 processed++ ;
167
168 }
169 /* after being processed the packet must be
170 *released in order to receive another one */
171 relm(h);
172 }else
173 processed++;
174
175 }
176 while (processed < cnt) ;
177
178 return processed ;
179 }
180
181
182 static int
septel_inject(pcap_t * handle,const void * buf _U_,size_t size _U_)183 septel_inject(pcap_t *handle, const void *buf _U_, size_t size _U_)
184 {
185 strlcpy(handle->errbuf, "Sending packets isn't supported on Septel cards",
186 PCAP_ERRBUF_SIZE);
187 return (-1);
188 }
189
190 /*
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 * See also pcap(3).
196 */
septel_activate(pcap_t * handle)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 * Turn a negative snapshot value (invalid), a snapshot value of
203 * 0 (unspecified), or a value bigger than the normal maximum
204 * value, into the maximum allowed value.
205 *
206 * If some application really *needs* a bigger snapshot
207 * length, we should just increase MAXIMUM_SNAPLEN.
208 */
209 if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN)
210 handle->snapshot = MAXIMUM_SNAPLEN;
211
212 handle->bufsize = 0;
213
214 /*
215 * "select()" and "poll()" don't work on Septel queues
216 */
217 handle->selectable_fd = -1;
218
219 handle->read_op = septel_read;
220 handle->inject_op = septel_inject;
221 handle->setfilter_op = septel_setfilter;
222 handle->set_datalink_op = NULL; /* can't change data link type */
223 handle->getnonblock_op = septel_getnonblock;
224 handle->setnonblock_op = septel_setnonblock;
225 handle->stats_op = septel_stats;
226
227 return 0;
228 }
229
septel_create(const char * device,char * ebuf,int * is_ours)230 pcap_t *septel_create(const char *device, char *ebuf, int *is_ours) {
231 const char *cp;
232 pcap_t *p;
233
234 /* Does this look like the Septel device? */
235 cp = strrchr(device, '/');
236 if (cp == NULL)
237 cp = device;
238 if (strcmp(cp, "septel") != 0) {
239 /* Nope, it's not "septel" */
240 *is_ours = 0;
241 return NULL;
242 }
243
244 /* OK, it's probably ours. */
245 *is_ours = 1;
246
247 p = pcap_create_common(ebuf, sizeof (struct pcap_septel));
248 if (p == NULL)
249 return NULL;
250
251 p->activate_op = septel_activate;
252 /*
253 * Set these up front, so that, even if our client tries
254 * to set non-blocking mode before we're activated, or
255 * query the state of non-blocking mode, they get an error,
256 * rather than having the non-blocking mode option set
257 * for use later.
258 */
259 p->getnonblock_op = septel_getnonblock;
260 p->setnonblock_op = septel_setnonblock;
261 return p;
262 }
263
septel_stats(pcap_t * p,struct pcap_stat * ps)264 static int septel_stats(pcap_t *p, struct pcap_stat *ps) {
265 struct pcap_septel *handlep = p->priv;
266 /*handlep->stat.ps_recv = 0;*/
267 /*handlep->stat.ps_drop = 0;*/
268
269 *ps = handlep->stat;
270
271 return 0;
272 }
273
274
275 int
septel_findalldevs(pcap_if_list_t * devlistp,char * errbuf)276 septel_findalldevs(pcap_if_list_t *devlistp, char *errbuf)
277 {
278 /*
279 * XXX - do the notions of "up", "running", or "connected" apply here?
280 */
281 if (add_dev(devlistp,"septel",0,"Intel/Septel device",errbuf) == NULL)
282 return -1;
283 return 0;
284 }
285
286
287 /*
288 * Installs the given bpf filter program in the given pcap structure. There is
289 * no attempt to store the filter in kernel memory as that is not supported
290 * with Septel cards.
291 */
septel_setfilter(pcap_t * p,struct bpf_program * fp)292 static int septel_setfilter(pcap_t *p, struct bpf_program *fp) {
293 if (!p)
294 return -1;
295 if (!fp) {
296 strncpy(p->errbuf, "setfilter: No filter specified",
297 sizeof(p->errbuf));
298 return -1;
299 }
300
301 /* Make our private copy of the filter */
302
303 if (install_bpf_program(p, fp) < 0)
304 return -1;
305
306 return (0);
307 }
308
309 /*
310 * We don't support non-blocking mode. I'm not sure what we'd
311 * do to support it and, given that we don't support select()/
312 * poll()/epoll_wait()/kevent() etc., it probably doesn't
313 * matter.
314 */
315 static int
septel_getnonblock(pcap_t * p)316 septel_getnonblock(pcap_t *p)
317 {
318 fprintf(p->errbuf, PCAP_ERRBUF_SIZE, "Non-blocking mode not supported on Septel devices");
319 return (-1);
320 }
321
322 static int
septel_setnonblock(pcap_t * p,int nonblock _U_)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 #ifdef SEPTEL_ONLY
330 /*
331 * This libpcap build supports only Septel cards, not regular network
332 * interfaces.
333 */
334
335 /*
336 * There are no regular interfaces, just Septel interfaces.
337 */
338 int
pcap_platform_finddevs(pcap_if_list_t * devlistp,char * errbuf)339 pcap_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf)
340 {
341 return (0);
342 }
343
344 /*
345 * Attempts to open a regular interface fail.
346 */
347 pcap_t *
pcap_create_interface(const char * device,char * errbuf)348 pcap_create_interface(const char *device, char *errbuf)
349 {
350 pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
351 "This version of libpcap only supports Septel cards");
352 return (NULL);
353 }
354
355 /*
356 * Libpcap version string.
357 */
358 const char *
pcap_lib_version(void)359 pcap_lib_version(void)
360 {
361 return (PCAP_VERSION_STRING " (Septel-only)");
362 }
363 #endif
364