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 #ifndef lint
18 static const char rcsid[] _U_ =
19 "@(#) $Header: /tcpdump/master/libpcap/pcap-septel.c,v 1.4 2008-04-14 20:40:58 guy Exp $";
20 #endif
21
22 #ifdef HAVE_CONFIG_H
23 #include "config.h"
24 #endif
25
26 #include <sys/param.h>
27
28 #include <stdlib.h>
29 #include <string.h>
30 #include <errno.h>
31
32 #include "pcap-int.h"
33
34 #include <ctype.h>
35 #include <netinet/in.h>
36 #include <sys/mman.h>
37 #include <sys/socket.h>
38 #include <sys/types.h>
39 #include <unistd.h>
40
41 #include <msg.h>
42 #include <ss7_inc.h>
43 #include <sysgct.h>
44 #include <pack.h>
45 #include <system.h>
46
47 #include "pcap-septel.h"
48
49 static int septel_setfilter(pcap_t *p, struct bpf_program *fp);
50 static int septel_stats(pcap_t *p, struct pcap_stat *ps);
51 static int septel_setnonblock(pcap_t *p, int nonblock, char *errbuf);
52
53 /*
54 * Private data for capturing on Septel devices.
55 */
56 struct pcap_septel {
57 struct pcap_stat stat;
58 }
59
60 /*
61 * Read at most max_packets from the capture queue and call the callback
62 * for each of them. Returns the number of packets handled, -1 if an
63 * error occured, or -2 if we were told to break out of the loop.
64 */
septel_read(pcap_t * p,int cnt,pcap_handler callback,u_char * user)65 static int septel_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user) {
66
67 struct pcap_septel *ps = p->priv;
68 HDR *h;
69 MSG *m;
70 int processed = 0 ;
71 int t = 0 ;
72
73 /* identifier for the message queue of the module(upe) from which we are capturing
74 * packets.These IDs are defined in system.txt . By default it is set to 0x2d
75 * so change it to 0xdd for technical reason and therefore the module id for upe becomes:
76 * LOCAL 0xdd * upe - Example user part task */
77 unsigned int id = 0xdd;
78
79 /* process the packets */
80 do {
81
82 unsigned short packet_len = 0;
83 int caplen = 0;
84 int counter = 0;
85 struct pcap_pkthdr pcap_header;
86 u_char *dp ;
87
88 /*
89 * Has "pcap_breakloop()" been called?
90 */
91 loop:
92 if (p->break_loop) {
93 /*
94 * Yes - clear the flag that indicates that
95 * it has, and return -2 to indicate that
96 * we were told to break out of the loop.
97 */
98 p->break_loop = 0;
99 return -2;
100 }
101
102 /*repeat until a packet is read
103 *a NULL message means :
104 * when no packet is in queue or all packets in queue already read */
105 do {
106 /* receive packet in non-blocking mode
107 * GCT_grab is defined in the septel library software */
108 h = GCT_grab(id);
109
110 m = (MSG*)h;
111 /* a couter is added here to avoid an infinite loop
112 * that will cause our capture program GUI to freeze while waiting
113 * for a packet*/
114 counter++ ;
115
116 }
117 while ((m == NULL)&& (counter< 100)) ;
118
119 if (m != NULL) {
120
121 t = h->type ;
122
123 /* catch only messages with type = 0xcf00 or 0x8f01 corrsponding to ss7 messages*/
124 /* XXX = why not use API_MSG_TX_REQ for 0xcf00 and API_MSG_RX_IND
125 * for 0x8f01? */
126 if ((t != 0xcf00) && (t != 0x8f01)) {
127 relm(h);
128 goto loop ;
129 }
130
131 /* XXX - is API_MSG_RX_IND for an MTP2 or MTP3 message? */
132 dp = get_param(m);/* get pointer to MSG parameter area (m->param) */
133 packet_len = m->len;
134 caplen = p->snapshot ;
135
136
137 if (caplen > packet_len) {
138
139 caplen = packet_len;
140 }
141 /* Run the packet filter if there is one. */
142 if ((p->fcode.bf_insns == NULL) || bpf_filter(p->fcode.bf_insns, dp, packet_len, caplen)) {
143
144
145 /* get a time stamp , consisting of :
146 *
147 * pcap_header.ts.tv_sec:
148 * ----------------------
149 * a UNIX format time-in-seconds when he packet was captured,
150 * i.e. the number of seconds since Epoch time (January 1,1970, 00:00:00 GMT)
151 *
152 * pcap_header.ts.tv_usec :
153 * ------------------------
154 * the number of microseconds since that second
155 * when the packet was captured
156 */
157
158 (void)gettimeofday(&pcap_header.ts, NULL);
159
160 /* Fill in our own header data */
161 pcap_header.caplen = caplen;
162 pcap_header.len = packet_len;
163
164 /* Count the packet. */
165 ps->stat.ps_recv++;
166
167 /* Call the user supplied callback function */
168 callback(user, &pcap_header, dp);
169
170 processed++ ;
171
172 }
173 /* after being processed the packet must be
174 *released in order to receive another one */
175 relm(h);
176 }else
177 processed++;
178
179 }
180 while (processed < cnt) ;
181
182 return processed ;
183 }
184
185
186 static int
septel_inject(pcap_t * handle,const void * buf _U_,size_t size _U_)187 septel_inject(pcap_t *handle, const void *buf _U_, size_t size _U_)
188 {
189 strlcpy(handle->errbuf, "Sending packets isn't supported on Septel cards",
190 PCAP_ERRBUF_SIZE);
191 return (-1);
192 }
193
194 /*
195 * Activate a handle for a live capture from the given Septel device. Always pass a NULL device
196 * The promisc flag is ignored because Septel cards have built-in tracing.
197 * The timeout is also ignored as it is not supported in hardware.
198 *
199 * See also pcap(3).
200 */
septel_activate(pcap_t * handle)201 static pcap_t *septel_activate(pcap_t* handle) {
202 /* Initialize some components of the pcap structure. */
203 handle->linktype = DLT_MTP2;
204
205 handle->bufsize = 0;
206
207 /*
208 * "select()" and "poll()" don't work on Septel queues
209 */
210 handle->selectable_fd = -1;
211
212 handle->read_op = septel_read;
213 handle->inject_op = septel_inject;
214 handle->setfilter_op = septel_setfilter;
215 handle->set_datalink_op = NULL; /* can't change data link type */
216 handle->getnonblock_op = pcap_getnonblock_fd;
217 handle->setnonblock_op = septel_setnonblock;
218 handle->stats_op = septel_stats;
219
220 return 0;
221 }
222
septel_create(const char * device,char * ebuf,int * is_ours)223 pcap_t *septel_create(const char *device, char *ebuf, int *is_ours) {
224 const char *cp;
225 pcap_t *p;
226
227 /* Does this look like the Septel device? */
228 cp = strrchr(device, '/');
229 if (cp == NULL)
230 cp = device;
231 if (strcmp(cp, "septel") != 0) {
232 /* Nope, it's not "septel" */
233 *is_ours = 0;
234 return NULL;
235 }
236
237 /* OK, it's probably ours. */
238 *is_ours = 1;
239
240 p = pcap_create_common(device, ebuf, sizeof (struct pcap_septel));
241 if (p == NULL)
242 return NULL;
243
244 p->activate_op = septel_activate;
245 return p;
246 }
247
septel_stats(pcap_t * p,struct pcap_stat * ps)248 static int septel_stats(pcap_t *p, struct pcap_stat *ps) {
249 struct pcap_septel *handlep = p->priv;
250 /*handlep->stat.ps_recv = 0;*/
251 /*handlep->stat.ps_drop = 0;*/
252
253 *ps = handlep->stat;
254
255 return 0;
256 }
257
258
259 int
septel_findalldevs(pcap_if_t ** devlistp,char * errbuf)260 septel_findalldevs(pcap_if_t **devlistp, char *errbuf)
261 {
262 unsigned char *p;
263 const char description[512]= "Intel/Septel device";
264 char name[512]="septel" ;
265 int ret = 0;
266 pcap_add_if(devlistp,name,0,description,errbuf);
267
268 return (ret);
269 }
270
271
272 /*
273 * Installs the given bpf filter program in the given pcap structure. There is
274 * no attempt to store the filter in kernel memory as that is not supported
275 * with Septel cards.
276 */
septel_setfilter(pcap_t * p,struct bpf_program * fp)277 static int septel_setfilter(pcap_t *p, struct bpf_program *fp) {
278 if (!p)
279 return -1;
280 if (!fp) {
281 strncpy(p->errbuf, "setfilter: No filter specified",
282 sizeof(p->errbuf));
283 return -1;
284 }
285
286 /* Make our private copy of the filter */
287
288 if (install_bpf_program(p, fp) < 0) {
289 snprintf(p->errbuf, sizeof(p->errbuf),
290 "malloc: %s", pcap_strerror(errno));
291 return -1;
292 }
293
294 return (0);
295 }
296
297
298 static int
septel_setnonblock(pcap_t * p,int nonblock,char * errbuf)299 septel_setnonblock(pcap_t *p, int nonblock, char *errbuf)
300 {
301 fprintf(errbuf, PCAP_ERRBUF_SIZE, "Non-blocking mode not supported on Septel devices");
302 return (-1);
303 }
304