1 /* 2 * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that: (1) source code distributions 7 * retain the above copyright notice and this paragraph in its entirety, (2) 8 * distributions including binary code include the above copyright notice and 9 * this paragraph in its entirety in the documentation or other materials 10 * provided with the distribution, and (3) all advertising materials mentioning 11 * features or use of this software display the following acknowledgement: 12 * ``This product includes software developed by the University of California, 13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of 14 * the University nor the names of its contributors may be used to endorse 15 * or promote products derived from this software without specific prior 16 * written permission. 17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED 18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF 19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 20 */ 21 #ifndef lint 22 static const char rcsid[] _U_ = 23 "@(#) $Header: /tcpdump/master/libpcap/pcap-nit.c,v 1.62 2008-04-14 20:40:58 guy Exp $ (LBL)"; 24 #endif 25 26 #ifdef HAVE_CONFIG_H 27 #include "config.h" 28 #endif 29 30 #include <sys/types.h> 31 #include <sys/time.h> 32 #include <sys/timeb.h> 33 #include <sys/file.h> 34 #include <sys/ioctl.h> 35 #include <sys/socket.h> 36 37 #include <net/if.h> 38 #include <net/nit.h> 39 40 #include <netinet/in.h> 41 #include <netinet/in_systm.h> 42 #include <netinet/ip.h> 43 #include <netinet/if_ether.h> 44 #include <netinet/ip_var.h> 45 #include <netinet/udp.h> 46 #include <netinet/udp_var.h> 47 #include <netinet/tcp.h> 48 #include <netinet/tcpip.h> 49 50 #include <ctype.h> 51 #include <errno.h> 52 #include <stdio.h> 53 54 #include "pcap-int.h" 55 56 #ifdef HAVE_OS_PROTO_H 57 #include "os-proto.h" 58 #endif 59 60 /* 61 * The chunk size for NIT. This is the amount of buffering 62 * done for read calls. 63 */ 64 #define CHUNKSIZE (2*1024) 65 66 /* 67 * The total buffer space used by NIT. 68 */ 69 #define BUFSPACE (4*CHUNKSIZE) 70 71 /* Forwards */ 72 static int nit_setflags(int, int, int, char *); 73 74 /* 75 * Private data for capturing on NIT devices. 76 */ 77 struct pcap_nit { 78 struct pcap_stat stat; 79 }; 80 81 static int 82 pcap_stats_nit(pcap_t *p, struct pcap_stat *ps) 83 { 84 struct pcap_nit *pn = p->priv; 85 86 /* 87 * "ps_recv" counts packets handed to the filter, not packets 88 * that passed the filter. As filtering is done in userland, 89 * this does not include packets dropped because we ran out 90 * of buffer space. 91 * 92 * "ps_drop" presumably counts packets dropped by the socket 93 * because of flow control requirements or resource exhaustion; 94 * it doesn't count packets dropped by the interface driver. 95 * As filtering is done in userland, it counts packets regardless 96 * of whether they would've passed the filter. 97 * 98 * These statistics don't include packets not yet read from the 99 * kernel by libpcap or packets not yet read from libpcap by the 100 * application. 101 */ 102 *ps = pn->stat; 103 return (0); 104 } 105 106 static int 107 pcap_read_nit(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 108 { 109 struct pcap_nit *pn = p->priv; 110 register int cc, n; 111 register u_char *bp, *cp, *ep; 112 register struct nit_hdr *nh; 113 register int caplen; 114 115 cc = p->cc; 116 if (cc == 0) { 117 cc = read(p->fd, (char *)p->buffer, p->bufsize); 118 if (cc < 0) { 119 if (errno == EWOULDBLOCK) 120 return (0); 121 snprintf(p->errbuf, sizeof(p->errbuf), "pcap_read: %s", 122 pcap_strerror(errno)); 123 return (-1); 124 } 125 bp = p->buffer; 126 } else 127 bp = p->bp; 128 129 /* 130 * Loop through each packet. The increment expression 131 * rounds up to the next int boundary past the end of 132 * the previous packet. 133 */ 134 n = 0; 135 ep = bp + cc; 136 while (bp < ep) { 137 /* 138 * Has "pcap_breakloop()" been called? 139 * If so, return immediately - if we haven't read any 140 * packets, clear the flag and return -2 to indicate 141 * that we were told to break out of the loop, otherwise 142 * leave the flag set, so that the *next* call will break 143 * out of the loop without having read any packets, and 144 * return the number of packets we've processed so far. 145 */ 146 if (p->break_loop) { 147 if (n == 0) { 148 p->break_loop = 0; 149 return (-2); 150 } else { 151 p->cc = ep - bp; 152 p->bp = bp; 153 return (n); 154 } 155 } 156 157 nh = (struct nit_hdr *)bp; 158 cp = bp + sizeof(*nh); 159 160 switch (nh->nh_state) { 161 162 case NIT_CATCH: 163 break; 164 165 case NIT_NOMBUF: 166 case NIT_NOCLUSTER: 167 case NIT_NOSPACE: 168 pn->stat.ps_drop = nh->nh_dropped; 169 continue; 170 171 case NIT_SEQNO: 172 continue; 173 174 default: 175 snprintf(p->errbuf, sizeof(p->errbuf), 176 "bad nit state %d", nh->nh_state); 177 return (-1); 178 } 179 ++pn->stat.ps_recv; 180 bp += ((sizeof(struct nit_hdr) + nh->nh_datalen + 181 sizeof(int) - 1) & ~(sizeof(int) - 1)); 182 183 caplen = nh->nh_wirelen; 184 if (caplen > p->snapshot) 185 caplen = p->snapshot; 186 if (bpf_filter(p->fcode.bf_insns, cp, nh->nh_wirelen, caplen)) { 187 struct pcap_pkthdr h; 188 h.ts = nh->nh_timestamp; 189 h.len = nh->nh_wirelen; 190 h.caplen = caplen; 191 (*callback)(user, &h, cp); 192 if (++n >= cnt && !PACKET_COUNT_IS_UNLIMITED(cnt)) { 193 p->cc = ep - bp; 194 p->bp = bp; 195 return (n); 196 } 197 } 198 } 199 p->cc = 0; 200 return (n); 201 } 202 203 static int 204 pcap_inject_nit(pcap_t *p, const void *buf, size_t size) 205 { 206 struct sockaddr sa; 207 int ret; 208 209 memset(&sa, 0, sizeof(sa)); 210 strncpy(sa.sa_data, device, sizeof(sa.sa_data)); 211 ret = sendto(p->fd, buf, size, 0, &sa, sizeof(sa)); 212 if (ret == -1) { 213 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s", 214 pcap_strerror(errno)); 215 return (-1); 216 } 217 return (ret); 218 } 219 220 static int 221 nit_setflags(pcap_t *p) 222 { 223 struct nit_ioc nioc; 224 225 memset(&nioc, 0, sizeof(nioc)); 226 nioc.nioc_typetomatch = NT_ALLTYPES; 227 nioc.nioc_snaplen = p->snapshot; 228 nioc.nioc_bufalign = sizeof(int); 229 nioc.nioc_bufoffset = 0; 230 231 if (p->opt.buffer_size != 0) 232 nioc.nioc_bufspace = p->opt.buffer_size; 233 else { 234 /* Default buffer size */ 235 nioc.nioc_bufspace = BUFSPACE; 236 } 237 238 if (p->opt.immediate) { 239 /* 240 * XXX - will this cause packets to be delivered immediately? 241 * XXX - given that this is for SunOS prior to 4.0, do 242 * we care? 243 */ 244 nioc.nioc_chunksize = 0; 245 } else 246 nioc.nioc_chunksize = CHUNKSIZE; 247 if (p->opt.timeout != 0) { 248 nioc.nioc_flags |= NF_TIMEOUT; 249 nioc.nioc_timeout.tv_sec = p->opt.timeout / 1000; 250 nioc.nioc_timeout.tv_usec = (p->opt.timeout * 1000) % 1000000; 251 } 252 if (p->opt.promisc) 253 nioc.nioc_flags |= NF_PROMISC; 254 255 if (ioctl(p->fd, SIOCSNIT, &nioc) < 0) { 256 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "SIOCSNIT: %s", 257 pcap_strerror(errno)); 258 return (-1); 259 } 260 return (0); 261 } 262 263 static int 264 pcap_activate_nit(pcap_t *p) 265 { 266 int fd; 267 struct sockaddr_nit snit; 268 269 if (p->opt.rfmon) { 270 /* 271 * No monitor mode on SunOS 3.x or earlier (no 272 * Wi-Fi *devices* for the hardware that supported 273 * them!). 274 */ 275 return (PCAP_ERROR_RFMON_NOTSUP); 276 } 277 278 if (p->snapshot < 96) 279 /* 280 * NIT requires a snapshot length of at least 96. 281 */ 282 p->snapshot = 96; 283 284 memset(p, 0, sizeof(*p)); 285 p->fd = fd = socket(AF_NIT, SOCK_RAW, NITPROTO_RAW); 286 if (fd < 0) { 287 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 288 "socket: %s", pcap_strerror(errno)); 289 goto bad; 290 } 291 snit.snit_family = AF_NIT; 292 (void)strncpy(snit.snit_ifname, p->opt.source, NITIFSIZ); 293 294 if (bind(fd, (struct sockaddr *)&snit, sizeof(snit))) { 295 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 296 "bind: %s: %s", snit.snit_ifname, pcap_strerror(errno)); 297 goto bad; 298 } 299 if (nit_setflags(p) < 0) 300 goto bad; 301 302 /* 303 * NIT supports only ethernets. 304 */ 305 p->linktype = DLT_EN10MB; 306 307 p->bufsize = BUFSPACE; 308 p->buffer = (u_char *)malloc(p->bufsize); 309 if (p->buffer == NULL) { 310 strlcpy(p->errbuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE); 311 goto bad; 312 } 313 314 /* 315 * "p->fd" is a socket, so "select()" should work on it. 316 */ 317 p->selectable_fd = p->fd; 318 319 /* 320 * This is (presumably) a real Ethernet capture; give it a 321 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so 322 * that an application can let you choose it, in case you're 323 * capturing DOCSIS traffic that a Cisco Cable Modem 324 * Termination System is putting out onto an Ethernet (it 325 * doesn't put an Ethernet header onto the wire, it puts raw 326 * DOCSIS frames out on the wire inside the low-level 327 * Ethernet framing). 328 */ 329 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2); 330 /* 331 * If that fails, just leave the list empty. 332 */ 333 if (p->dlt_list != NULL) { 334 p->dlt_list[0] = DLT_EN10MB; 335 p->dlt_list[1] = DLT_DOCSIS; 336 p->dlt_count = 2; 337 } 338 339 p->read_op = pcap_read_nit; 340 p->inject_op = pcap_inject_nit; 341 p->setfilter_op = install_bpf_program; /* no kernel filtering */ 342 p->setdirection_op = NULL; /* Not implemented. */ 343 p->set_datalink_op = NULL; /* can't change data link type */ 344 p->getnonblock_op = pcap_getnonblock_fd; 345 p->setnonblock_op = pcap_setnonblock_fd; 346 p->stats_op = pcap_stats_nit; 347 348 return (0); 349 bad: 350 pcap_cleanup_live_common(p); 351 return (PCAP_ERROR); 352 } 353 354 pcap_t * 355 pcap_create_interface(const char *device, char *ebuf) 356 { 357 pcap_t *p; 358 359 p = pcap_create_common(device, ebuf, sizeof (struct pcap_nit)); 360 if (p == NULL) 361 return (NULL); 362 363 p->activate_op = pcap_activate_nit; 364 return (p); 365 } 366 367 int 368 pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf) 369 { 370 return (0); 371 } 372
