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_setnonblock(pcap_t *p, int nonblock, char *errbuf);
47
48 /*
49 * Private data for capturing on Septel devices.
50 */
51 struct pcap_septel {
52 struct pcap_stat stat;
53 }
54
55 /*
56 * Read at most max_packets from the capture queue and call the callback
57 * for each of them. Returns the number of packets handled, -1 if an
58 * error occured, or -2 if we were told to break out of the loop.
59 */
septel_read(pcap_t * p,int cnt,pcap_handler callback,u_char * user)60 static int septel_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user) {
61
62 struct pcap_septel *ps = p->priv;
63 HDR *h;
64 MSG *m;
65 int processed = 0 ;
66 int t = 0 ;
67
68 /* identifier for the message queue of the module(upe) from which we are capturing
69 * packets.These IDs are defined in system.txt . By default it is set to 0x2d
70 * so change it to 0xdd for technical reason and therefore the module id for upe becomes:
71 * LOCAL 0xdd * upe - Example user part task */
72 unsigned int id = 0xdd;
73
74 /* process the packets */
75 do {
76
77 unsigned short packet_len = 0;
78 int caplen = 0;
79 int counter = 0;
80 struct pcap_pkthdr pcap_header;
81 u_char *dp ;
82
83 /*
84 * Has "pcap_breakloop()" been called?
85 */
86 loop:
87 if (p->break_loop) {
88 /*
89 * Yes - clear the flag that indicates that
90 * it has, and return -2 to indicate that
91 * we were told to break out of the loop.
92 */
93 p->break_loop = 0;
94 return -2;
95 }
96
97 /*repeat until a packet is read
98 *a NULL message means :
99 * when no packet is in queue or all packets in queue already read */
100 do {
101 /* receive packet in non-blocking mode
102 * GCT_grab is defined in the septel library software */
103 h = GCT_grab(id);
104
105 m = (MSG*)h;
106 /* a couter is added here to avoid an infinite loop
107 * that will cause our capture program GUI to freeze while waiting
108 * for a packet*/
109 counter++ ;
110
111 }
112 while ((m == NULL)&& (counter< 100)) ;
113
114 if (m != NULL) {
115
116 t = h->type ;
117
118 /* catch only messages with type = 0xcf00 or 0x8f01 corrsponding to ss7 messages*/
119 /* XXX = why not use API_MSG_TX_REQ for 0xcf00 and API_MSG_RX_IND
120 * for 0x8f01? */
121 if ((t != 0xcf00) && (t != 0x8f01)) {
122 relm(h);
123 goto loop ;
124 }
125
126 /* XXX - is API_MSG_RX_IND for an MTP2 or MTP3 message? */
127 dp = get_param(m);/* get pointer to MSG parameter area (m->param) */
128 packet_len = m->len;
129 caplen = p->snapshot ;
130
131
132 if (caplen > packet_len) {
133
134 caplen = packet_len;
135 }
136 /* Run the packet filter if there is one. */
137 if ((p->fcode.bf_insns == NULL) || bpf_filter(p->fcode.bf_insns, dp, packet_len, caplen)) {
138
139
140 /* get a time stamp , consisting of :
141 *
142 * pcap_header.ts.tv_sec:
143 * ----------------------
144 * a UNIX format time-in-seconds when he packet was captured,
145 * i.e. the number of seconds since Epoch time (January 1,1970, 00:00:00 GMT)
146 *
147 * pcap_header.ts.tv_usec :
148 * ------------------------
149 * the number of microseconds since that second
150 * when the packet was captured
151 */
152
153 (void)gettimeofday(&pcap_header.ts, NULL);
154
155 /* Fill in our own header data */
156 pcap_header.caplen = caplen;
157 pcap_header.len = packet_len;
158
159 /* Count the packet. */
160 ps->stat.ps_recv++;
161
162 /* Call the user supplied callback function */
163 callback(user, &pcap_header, dp);
164
165 processed++ ;
166
167 }
168 /* after being processed the packet must be
169 *released in order to receive another one */
170 relm(h);
171 }else
172 processed++;
173
174 }
175 while (processed < cnt) ;
176
177 return processed ;
178 }
179
180
181 static int
septel_inject(pcap_t * handle,const void * buf _U_,size_t size _U_)182 septel_inject(pcap_t *handle, const void *buf _U_, size_t size _U_)
183 {
184 strlcpy(handle->errbuf, "Sending packets isn't supported on Septel cards",
185 PCAP_ERRBUF_SIZE);
186 return (-1);
187 }
188
189 /*
190 * Activate a handle for a live capture from the given Septel device. Always pass a NULL device
191 * The promisc flag is ignored because Septel cards have built-in tracing.
192 * The timeout is also ignored as it is not supported in hardware.
193 *
194 * See also pcap(3).
195 */
septel_activate(pcap_t * handle)196 static pcap_t *septel_activate(pcap_t* handle) {
197 /* Initialize some components of the pcap structure. */
198 handle->linktype = DLT_MTP2;
199
200 handle->bufsize = 0;
201
202 /*
203 * "select()" and "poll()" don't work on Septel queues
204 */
205 handle->selectable_fd = -1;
206
207 handle->read_op = septel_read;
208 handle->inject_op = septel_inject;
209 handle->setfilter_op = septel_setfilter;
210 handle->set_datalink_op = NULL; /* can't change data link type */
211 handle->getnonblock_op = pcap_getnonblock_fd;
212 handle->setnonblock_op = septel_setnonblock;
213 handle->stats_op = septel_stats;
214
215 return 0;
216 }
217
septel_create(const char * device,char * ebuf,int * is_ours)218 pcap_t *septel_create(const char *device, char *ebuf, int *is_ours) {
219 const char *cp;
220 pcap_t *p;
221
222 /* Does this look like the Septel device? */
223 cp = strrchr(device, '/');
224 if (cp == NULL)
225 cp = device;
226 if (strcmp(cp, "septel") != 0) {
227 /* Nope, it's not "septel" */
228 *is_ours = 0;
229 return NULL;
230 }
231
232 /* OK, it's probably ours. */
233 *is_ours = 1;
234
235 p = pcap_create_common(ebuf, sizeof (struct pcap_septel));
236 if (p == NULL)
237 return NULL;
238
239 p->activate_op = septel_activate;
240 return p;
241 }
242
septel_stats(pcap_t * p,struct pcap_stat * ps)243 static int septel_stats(pcap_t *p, struct pcap_stat *ps) {
244 struct pcap_septel *handlep = p->priv;
245 /*handlep->stat.ps_recv = 0;*/
246 /*handlep->stat.ps_drop = 0;*/
247
248 *ps = handlep->stat;
249
250 return 0;
251 }
252
253
254 int
septel_findalldevs(pcap_if_t ** devlistp,char * errbuf)255 septel_findalldevs(pcap_if_t **devlistp, char *errbuf)
256 {
257 return (pcap_add_if(devlistp,"septel",0,
258 "Intel/Septel device",errbuf));
259 }
260
261
262 /*
263 * Installs the given bpf filter program in the given pcap structure. There is
264 * no attempt to store the filter in kernel memory as that is not supported
265 * with Septel cards.
266 */
septel_setfilter(pcap_t * p,struct bpf_program * fp)267 static int septel_setfilter(pcap_t *p, struct bpf_program *fp) {
268 if (!p)
269 return -1;
270 if (!fp) {
271 strncpy(p->errbuf, "setfilter: No filter specified",
272 sizeof(p->errbuf));
273 return -1;
274 }
275
276 /* Make our private copy of the filter */
277
278 if (install_bpf_program(p, fp) < 0) {
279 pcap_snprintf(p->errbuf, sizeof(p->errbuf),
280 "malloc: %s", pcap_strerror(errno));
281 return -1;
282 }
283
284 return (0);
285 }
286
287
288 static int
septel_setnonblock(pcap_t * p,int nonblock,char * errbuf)289 septel_setnonblock(pcap_t *p, int nonblock, char *errbuf)
290 {
291 fprintf(errbuf, PCAP_ERRBUF_SIZE, "Non-blocking mode not supported on Septel devices");
292 return (-1);
293 }
294
295 #ifdef SEPTEL_ONLY
296 /*
297 * This libpcap build supports only Septel cards, not regular network
298 * interfaces.
299 */
300
301 /*
302 * There are no regular interfaces, just Septel interfaces.
303 */
304 int
pcap_platform_finddevs(pcap_if_t ** alldevsp,char * errbuf)305 pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf)
306 {
307 *alldevsp = NULL;
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 pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
318 "This version of libpcap only supports Septel cards");
319 return (NULL);
320 }
321 #endif
322