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   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 }