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
18static 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
58static int septel_setfilter(pcap_t *p, struct bpf_program *fp);
59static int septel_stats(pcap_t *p, struct pcap_stat *ps);
60static 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 */
67static 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     */
92loop:
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
187static int
188septel_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 */
202static 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
224pcap_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
235static 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
245int
246septel_platform_finddevs(pcap_if_t **devlistp, char *errbuf)
247{
248unsigned 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 */
263static 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
286static int
287septel_setnonblock(pcap_t *p, int nonblock, char *errbuf)
288{
289  return (0);
290}
291