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 (at) 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 */ 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 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 */ 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 } 217 218 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 } 242 243 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 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 */ 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 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 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 * 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
