xref: /freebsd/contrib/libpcap/pcap-septel.c (revision 730cecb05aaf016ac52ef7cfc691ccec3a0408cd)
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 #ifdef HAVE_SEPTEL_API
42 #include <msg.h>
43 #include <ss7_inc.h>
44 #include <sysgct.h>
45 #include <pack.h>
46 #include <system.h>
47 #endif /* HAVE_SEPTEL_API */
48 
49 #ifdef SEPTEL_ONLY
50 /* This code is required when compiling for a Septel device only. */
51 #include "pcap-septel.h"
52 
53 /* Replace septel function names with pcap equivalent. */
54 #define septel_create pcap_create
55 #define septel_platform_finddevs pcap_platform_finddevs
56 #endif /* SEPTEL_ONLY */
57 
58 static int septel_setfilter(pcap_t *p, struct bpf_program *fp);
59 static int septel_stats(pcap_t *p, struct pcap_stat *ps);
60 static int septel_setnonblock(pcap_t *p, int nonblock, char *errbuf);
61 
62 /*
63  *  Read at most max_packets from the capture queue and call the callback
64  *  for each of them. Returns the number of packets handled, -1 if an
65  *  error occured, or -2 if we were told to break out of the loop.
66  */
67 static int septel_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user) {
68 
69   HDR *h;
70   MSG *m;
71   int processed = 0 ;
72   int t = 0 ;
73 
74   /* identifier for the message queue of the module(upe) from which we are capturing
75    * packets.These IDs are defined in system.txt . By default it is set to 0x2d
76    * so change it to 0xdd for technical reason and therefore the module id for upe becomes:
77    * LOCAL        0xdd           * upe - Example user part task */
78   unsigned int id = 0xdd;
79 
80   /* process the packets */
81   do  {
82 
83     unsigned short packet_len = 0;
84     int caplen = 0;
85     int counter = 0;
86     struct pcap_pkthdr   pcap_header;
87     u_char *dp ;
88 
89     /*
90      * Has "pcap_breakloop()" been called?
91      */
92 loop:
93     if (p->break_loop) {
94       /*
95        * Yes - clear the flag that indicates that
96        * it has, and return -2 to indicate that
97        * we were told to break out of the loop.
98        */
99       p->break_loop = 0;
100       return -2;
101     }
102 
103     /*repeat until a packet is read
104      *a NULL message means :
105      * when no packet is in queue or all packets in queue already read */
106     do  {
107       /* receive packet in non-blocking mode
108        * GCT_grab is defined in the septel library software */
109       h = GCT_grab(id);
110 
111       m = (MSG*)h;
112       /* a couter is added here to avoid an infinite loop
113        * that will cause our capture program GUI to freeze while waiting
114        * for a packet*/
115       counter++ ;
116 
117     }
118     while  ((m == NULL)&& (counter< 100)) ;
119 
120     if (m != NULL) {
121 
122       t = h->type ;
123 
124       /* catch only messages with type = 0xcf00 or 0x8f01 corrsponding to ss7 messages*/
125       /* XXX = why not use API_MSG_TX_REQ for 0xcf00 and API_MSG_RX_IND
126        * for 0x8f01? */
127       if ((t != 0xcf00) && (t != 0x8f01)) {
128         relm(h);
129         goto loop ;
130       }
131 
132       /* XXX - is API_MSG_RX_IND for an MTP2 or MTP3 message? */
133       dp = get_param(m);/* get pointer to MSG parameter area (m->param) */
134       packet_len = m->len;
135       caplen =  p->snapshot ;
136 
137 
138       if (caplen > packet_len) {
139 
140         caplen = packet_len;
141       }
142       /* Run the packet filter if there is one. */
143       if ((p->fcode.bf_insns == NULL) || bpf_filter(p->fcode.bf_insns, dp, packet_len, caplen)) {
144 
145 
146         /*  get a time stamp , consisting of :
147          *
148          *  pcap_header.ts.tv_sec:
149          *  ----------------------
150          *   a UNIX format time-in-seconds when he packet was captured,
151          *   i.e. the number of seconds since Epoch time (January 1,1970, 00:00:00 GMT)
152          *
153          *  pcap_header.ts.tv_usec :
154          *  ------------------------
155          *   the number of microseconds since that second
156          *   when the packet was captured
157          */
158 
159         (void)gettimeofday(&pcap_header.ts, NULL);
160 
161         /* Fill in our own header data */
162         pcap_header.caplen = caplen;
163         pcap_header.len = packet_len;
164 
165         /* Count the packet. */
166         p->md.stat.ps_recv++;
167 
168         /* Call the user supplied callback function */
169         callback(user, &pcap_header, dp);
170 
171         processed++ ;
172 
173       }
174       /* after being processed the packet must be
175        *released in order to receive another one */
176       relm(h);
177     }else
178       processed++;
179 
180   }
181   while (processed < cnt) ;
182 
183   return processed ;
184 }
185 
186 
187 static int
188 septel_inject(pcap_t *handle, const void *buf _U_, size_t size _U_)
189 {
190   strlcpy(handle->errbuf, "Sending packets isn't supported on Septel cards",
191           PCAP_ERRBUF_SIZE);
192   return (-1);
193 }
194 
195 /*
196  *  Activate a handle for a live capture from the given Septel device.  Always pass a NULL device
197  *  The promisc flag is ignored because Septel cards have built-in tracing.
198  *  The timeout is also ignored as it is not supported in hardware.
199  *
200  *  See also pcap(3).
201  */
202 static pcap_t *septel_activate(pcap_t* handle) {
203   /* Initialize some components of the pcap structure. */
204   handle->linktype = DLT_MTP2;
205 
206   handle->bufsize = 0;
207 
208   /*
209    * "select()" and "poll()" don't work on Septel queues
210    */
211   handle->selectable_fd = -1;
212 
213   handle->read_op = septel_read;
214   handle->inject_op = septel_inject;
215   handle->setfilter_op = septel_setfilter;
216   handle->set_datalink_op = NULL; /* can't change data link type */
217   handle->getnonblock_op = pcap_getnonblock_fd;
218   handle->setnonblock_op = septel_setnonblock;
219   handle->stats_op = septel_stats;
220 
221   return 0;
222 }
223 
224 pcap_t *septel_create(const char *device, char *ebuf) {
225 	pcap_t *p;
226 
227 	p = pcap_create_common(device, ebuf);
228 	if (p == NULL)
229 		return NULL;
230 
231 	p->activate_op = septel_activate;
232 	return p;
233 }
234 
235 static int septel_stats(pcap_t *p, struct pcap_stat *ps) {
236   /*p->md.stat.ps_recv = 0;*/
237   /*p->md.stat.ps_drop = 0;*/
238 
239   *ps = p->md.stat;
240 
241   return 0;
242 }
243 
244 
245 int
246 septel_platform_finddevs(pcap_if_t **devlistp, char *errbuf)
247 {
248 unsigned char *p;
249   const char description[512]= "Intel/Septel device";
250   char name[512]="septel" ;
251   int ret = 0;
252   pcap_add_if(devlistp,name,0,description,errbuf);
253 
254   return (ret);
255 }
256 
257 
258 /*
259  * Installs the given bpf filter program in the given pcap structure.  There is
260  * no attempt to store the filter in kernel memory as that is not supported
261  * with Septel cards.
262  */
263 static int septel_setfilter(pcap_t *p, struct bpf_program *fp) {
264   if (!p)
265     return -1;
266   if (!fp) {
267     strncpy(p->errbuf, "setfilter: No filter specified",
268 	    sizeof(p->errbuf));
269     return -1;
270   }
271 
272   /* Make our private copy of the filter */
273 
274   if (install_bpf_program(p, fp) < 0) {
275     snprintf(p->errbuf, sizeof(p->errbuf),
276 	     "malloc: %s", pcap_strerror(errno));
277     return -1;
278   }
279 
280   p->md.use_bpf = 0;
281 
282   return (0);
283 }
284 
285 
286 static int
287 septel_setnonblock(pcap_t *p, int nonblock, char *errbuf)
288 {
289   return (0);
290 }
291