1 /* $NetBSD: pcap-nit.c,v 1.1.1.4 2013/12/31 16:57:19 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that: (1) source code distributions 9 * retain the above copyright notice and this paragraph in its entirety, (2) 10 * distributions including binary code include the above copyright notice and 11 * this paragraph in its entirety in the documentation or other materials 12 * provided with the distribution, and (3) all advertising materials mentioning 13 * features or use of this software display the following acknowledgement: 14 * ``This product includes software developed by the University of California, 15 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of 16 * the University nor the names of its contributors may be used to endorse 17 * or promote products derived from this software without specific prior 18 * written permission. 19 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED 20 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF 21 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 22 */ 23 #ifndef lint 24 static const char rcsid[] _U_ = 25 "@(#) Header: /tcpdump/master/libpcap/pcap-nit.c,v 1.62 2008-04-14 20:40:58 guy Exp (LBL)"; 26 #endif 27 28 #ifdef HAVE_CONFIG_H 29 #include "config.h" 30 #endif 31 32 #include <sys/types.h> 33 #include <sys/time.h> 34 #include <sys/timeb.h> 35 #include <sys/file.h> 36 #include <sys/ioctl.h> 37 #include <sys/socket.h> 38 39 #include <net/if.h> 40 #include <net/nit.h> 41 42 #include <netinet/in.h> 43 #include <netinet/in_systm.h> 44 #include <netinet/ip.h> 45 #include <netinet/if_ether.h> 46 #include <netinet/ip_var.h> 47 #include <netinet/udp.h> 48 #include <netinet/udp_var.h> 49 #include <netinet/tcp.h> 50 #include <netinet/tcpip.h> 51 52 #include <ctype.h> 53 #include <errno.h> 54 #include <stdio.h> 55 56 #include "pcap-int.h" 57 58 #ifdef HAVE_OS_PROTO_H 59 #include "os-proto.h" 60 #endif 61 62 /* 63 * The chunk size for NIT. This is the amount of buffering 64 * done for read calls. 65 */ 66 #define CHUNKSIZE (2*1024) 67 68 /* 69 * The total buffer space used by NIT. 70 */ 71 #define BUFSPACE (4*CHUNKSIZE) 72 73 /* Forwards */ 74 static int nit_setflags(int, int, int, char *); 75 76 /* 77 * Private data for capturing on NIT devices. 78 */ 79 struct pcap_nit { 80 struct pcap_stat stat; 81 }; 82 83 static int 84 pcap_stats_nit(pcap_t *p, struct pcap_stat *ps) 85 { 86 struct pcap_nit *pn = p->priv; 87 88 /* 89 * "ps_recv" counts packets handed to the filter, not packets 90 * that passed the filter. As filtering is done in userland, 91 * this does not include packets dropped because we ran out 92 * of buffer space. 93 * 94 * "ps_drop" presumably counts packets dropped by the socket 95 * because of flow control requirements or resource exhaustion; 96 * it doesn't count packets dropped by the interface driver. 97 * As filtering is done in userland, it counts packets regardless 98 * of whether they would've passed the filter. 99 * 100 * These statistics don't include packets not yet read from the 101 * kernel by libpcap or packets not yet read from libpcap by the 102 * application. 103 */ 104 *ps = pn->stat; 105 return (0); 106 } 107 108 static int 109 pcap_read_nit(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 110 { 111 struct pcap_nit *pn = p->priv; 112 register int cc, n; 113 register u_char *bp, *cp, *ep; 114 register struct nit_hdr *nh; 115 register int caplen; 116 117 cc = p->cc; 118 if (cc == 0) { 119 cc = read(p->fd, (char *)p->buffer, p->bufsize); 120 if (cc < 0) { 121 if (errno == EWOULDBLOCK) 122 return (0); 123 snprintf(p->errbuf, sizeof(p->errbuf), "pcap_read: %s", 124 pcap_strerror(errno)); 125 return (-1); 126 } 127 bp = p->buffer; 128 } else 129 bp = p->bp; 130 131 /* 132 * Loop through each packet. The increment expression 133 * rounds up to the next int boundary past the end of 134 * the previous packet. 135 */ 136 n = 0; 137 ep = bp + cc; 138 while (bp < ep) { 139 /* 140 * Has "pcap_breakloop()" been called? 141 * If so, return immediately - if we haven't read any 142 * packets, clear the flag and return -2 to indicate 143 * that we were told to break out of the loop, otherwise 144 * leave the flag set, so that the *next* call will break 145 * out of the loop without having read any packets, and 146 * return the number of packets we've processed so far. 147 */ 148 if (p->break_loop) { 149 if (n == 0) { 150 p->break_loop = 0; 151 return (-2); 152 } else { 153 p->cc = ep - bp; 154 p->bp = bp; 155 return (n); 156 } 157 } 158 159 nh = (struct nit_hdr *)bp; 160 cp = bp + sizeof(*nh); 161 162 switch (nh->nh_state) { 163 164 case NIT_CATCH: 165 break; 166 167 case NIT_NOMBUF: 168 case NIT_NOCLUSTER: 169 case NIT_NOSPACE: 170 pn->stat.ps_drop = nh->nh_dropped; 171 continue; 172 173 case NIT_SEQNO: 174 continue; 175 176 default: 177 snprintf(p->errbuf, sizeof(p->errbuf), 178 "bad nit state %d", nh->nh_state); 179 return (-1); 180 } 181 ++pn->stat.ps_recv; 182 bp += ((sizeof(struct nit_hdr) + nh->nh_datalen + 183 sizeof(int) - 1) & ~(sizeof(int) - 1)); 184 185 caplen = nh->nh_wirelen; 186 if (caplen > p->snapshot) 187 caplen = p->snapshot; 188 if (bpf_filter(p->fcode.bf_insns, cp, nh->nh_wirelen, caplen)) { 189 struct pcap_pkthdr h; 190 h.ts = nh->nh_timestamp; 191 h.len = nh->nh_wirelen; 192 h.caplen = caplen; 193 (*callback)(user, &h, cp); 194 if (++n >= cnt && cnt > 0) { 195 p->cc = ep - bp; 196 p->bp = bp; 197 return (n); 198 } 199 } 200 } 201 p->cc = 0; 202 return (n); 203 } 204 205 static int 206 pcap_inject_nit(pcap_t *p, const void *buf, size_t size) 207 { 208 struct sockaddr sa; 209 int ret; 210 211 memset(&sa, 0, sizeof(sa)); 212 strncpy(sa.sa_data, device, sizeof(sa.sa_data)); 213 ret = sendto(p->fd, buf, size, 0, &sa, sizeof(sa)); 214 if (ret == -1) { 215 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s", 216 pcap_strerror(errno)); 217 return (-1); 218 } 219 return (ret); 220 } 221 222 static int 223 nit_setflags(pcap_t *p) 224 { 225 struct nit_ioc nioc; 226 227 memset(&nioc, 0, sizeof(nioc)); 228 nioc.nioc_typetomatch = NT_ALLTYPES; 229 nioc.nioc_snaplen = p->snapshot; 230 nioc.nioc_bufalign = sizeof(int); 231 nioc.nioc_bufoffset = 0; 232 233 if (p->opt.buffer_size != 0) 234 nioc.nioc_bufspace = p->opt.buffer_size; 235 else { 236 /* Default buffer size */ 237 nioc.nioc_bufspace = BUFSPACE; 238 } 239 240 if (p->opt.immediate) { 241 /* 242 * XXX - will this cause packets to be delivered immediately? 243 * XXX - given that this is for SunOS prior to 4.0, do 244 * we care? 245 */ 246 nioc.nioc_chunksize = 0; 247 } else 248 nioc.nioc_chunksize = CHUNKSIZE; 249 if (p->opt.timeout != 0) { 250 nioc.nioc_flags |= NF_TIMEOUT; 251 nioc.nioc_timeout.tv_sec = p->opt.timeout / 1000; 252 nioc.nioc_timeout.tv_usec = (p->opt.timeout * 1000) % 1000000; 253 } 254 if (p->opt.promisc) 255 nioc.nioc_flags |= NF_PROMISC; 256 257 if (ioctl(p->fd, SIOCSNIT, &nioc) < 0) { 258 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "SIOCSNIT: %s", 259 pcap_strerror(errno)); 260 return (-1); 261 } 262 return (0); 263 } 264 265 static int 266 pcap_activate_nit(pcap_t *p) 267 { 268 int fd; 269 struct sockaddr_nit snit; 270 271 if (p->opt.rfmon) { 272 /* 273 * No monitor mode on SunOS 3.x or earlier (no 274 * Wi-Fi *devices* for the hardware that supported 275 * them!). 276 */ 277 return (PCAP_ERROR_RFMON_NOTSUP); 278 } 279 280 if (p->snapshot < 96) 281 /* 282 * NIT requires a snapshot length of at least 96. 283 */ 284 p->snapshot = 96; 285 286 memset(p, 0, sizeof(*p)); 287 p->fd = fd = socket(AF_NIT, SOCK_RAW, NITPROTO_RAW); 288 if (fd < 0) { 289 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 290 "socket: %s", pcap_strerror(errno)); 291 goto bad; 292 } 293 snit.snit_family = AF_NIT; 294 (void)strncpy(snit.snit_ifname, p->opt.source, NITIFSIZ); 295 296 if (bind(fd, (struct sockaddr *)&snit, sizeof(snit))) { 297 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 298 "bind: %s: %s", snit.snit_ifname, pcap_strerror(errno)); 299 goto bad; 300 } 301 if (nit_setflags(p) < 0) 302 goto bad; 303 304 /* 305 * NIT supports only ethernets. 306 */ 307 p->linktype = DLT_EN10MB; 308 309 p->bufsize = BUFSPACE; 310 p->buffer = (u_char *)malloc(p->bufsize); 311 if (p->buffer == NULL) { 312 strlcpy(p->errbuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE); 313 goto bad; 314 } 315 316 /* 317 * "p->fd" is a socket, so "select()" should work on it. 318 */ 319 p->selectable_fd = p->fd; 320 321 /* 322 * This is (presumably) a real Ethernet capture; give it a 323 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so 324 * that an application can let you choose it, in case you're 325 * capturing DOCSIS traffic that a Cisco Cable Modem 326 * Termination System is putting out onto an Ethernet (it 327 * doesn't put an Ethernet header onto the wire, it puts raw 328 * DOCSIS frames out on the wire inside the low-level 329 * Ethernet framing). 330 */ 331 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2); 332 /* 333 * If that fails, just leave the list empty. 334 */ 335 if (p->dlt_list != NULL) { 336 p->dlt_list[0] = DLT_EN10MB; 337 p->dlt_list[1] = DLT_DOCSIS; 338 p->dlt_count = 2; 339 } 340 341 p->read_op = pcap_read_nit; 342 p->inject_op = pcap_inject_nit; 343 p->setfilter_op = install_bpf_program; /* no kernel filtering */ 344 p->setdirection_op = NULL; /* Not implemented. */ 345 p->set_datalink_op = NULL; /* can't change data link type */ 346 p->getnonblock_op = pcap_getnonblock_fd; 347 p->setnonblock_op = pcap_setnonblock_fd; 348 p->stats_op = pcap_stats_nit; 349 350 return (0); 351 bad: 352 pcap_cleanup_live_common(p); 353 return (PCAP_ERROR); 354 } 355 356 pcap_t * 357 pcap_create_interface(const char *device, char *ebuf) 358 { 359 pcap_t *p; 360 361 p = pcap_create_common(device, ebuf, sizeof (struct pcap_nit)); 362 if (p == NULL) 363 return (NULL); 364 365 p->activate_op = pcap_activate_nit; 366 return (p); 367 } 368 369 int 370 pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf) 371 { 372 return (0); 373 } 374