1 /* $NetBSD: pcap-snit.c,v 1.1.1.3 2013/04/06 15:57:46 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 * Modifications made to accommodate the new SunOS4.0 NIT facility by 24 * Micky Liu, micky@cunixc.cc.columbia.edu, Columbia University in May, 1989. 25 * This module now handles the STREAMS based NIT. 26 */ 27 28 #ifndef lint 29 static const char rcsid[] _U_ = 30 "@(#) Header: /tcpdump/master/libpcap/pcap-snit.c,v 1.77 2008-04-14 20:40:58 guy Exp (LBL)"; 31 #endif 32 33 #ifdef HAVE_CONFIG_H 34 #include "config.h" 35 #endif 36 37 #include <sys/types.h> 38 #include <sys/time.h> 39 #include <sys/timeb.h> 40 #include <sys/dir.h> 41 #include <sys/fcntlcom.h> 42 #include <sys/file.h> 43 #include <sys/ioctl.h> 44 #include <sys/socket.h> 45 #include <sys/stropts.h> 46 47 #include <net/if.h> 48 #include <net/nit.h> 49 #include <net/nit_if.h> 50 #include <net/nit_pf.h> 51 #include <net/nit_buf.h> 52 53 #include <netinet/in.h> 54 #include <netinet/in_systm.h> 55 #include <netinet/ip.h> 56 #include <netinet/if_ether.h> 57 #include <netinet/ip_var.h> 58 #include <netinet/udp.h> 59 #include <netinet/udp_var.h> 60 #include <netinet/tcp.h> 61 #include <netinet/tcpip.h> 62 63 #include <ctype.h> 64 #include <errno.h> 65 #include <stdio.h> 66 #include <string.h> 67 #include <unistd.h> 68 69 #include "pcap-int.h" 70 71 #ifdef HAVE_OS_PROTO_H 72 #include "os-proto.h" 73 #endif 74 75 /* 76 * The chunk size for NIT. This is the amount of buffering 77 * done for read calls. 78 */ 79 #define CHUNKSIZE (2*1024) 80 81 /* 82 * The total buffer space used by NIT. 83 */ 84 #define BUFSPACE (4*CHUNKSIZE) 85 86 /* Forwards */ 87 static int nit_setflags(int, int, int, char *); 88 89 static int 90 pcap_stats_snit(pcap_t *p, struct pcap_stat *ps) 91 { 92 93 /* 94 * "ps_recv" counts packets handed to the filter, not packets 95 * that passed the filter. As filtering is done in userland, 96 * this does not include packets dropped because we ran out 97 * of buffer space. 98 * 99 * "ps_drop" counts packets dropped inside the "/dev/nit" 100 * device because of flow control requirements or resource 101 * exhaustion; it doesn't count packets dropped by the 102 * interface driver, or packets dropped upstream. As filtering 103 * is done in userland, it counts packets regardless of whether 104 * they would've passed the filter. 105 * 106 * These statistics don't include packets not yet read from the 107 * kernel by libpcap or packets not yet read from libpcap by the 108 * application. 109 */ 110 *ps = p->md.stat; 111 return (0); 112 } 113 114 static int 115 pcap_read_snit(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 116 { 117 register int cc, n; 118 register u_char *bp, *cp, *ep; 119 register struct nit_bufhdr *hdrp; 120 register struct nit_iftime *ntp; 121 register struct nit_iflen *nlp; 122 register struct nit_ifdrops *ndp; 123 register int caplen; 124 125 cc = p->cc; 126 if (cc == 0) { 127 cc = read(p->fd, (char *)p->buffer, p->bufsize); 128 if (cc < 0) { 129 if (errno == EWOULDBLOCK) 130 return (0); 131 snprintf(p->errbuf, sizeof(p->errbuf), "pcap_read: %s", 132 pcap_strerror(errno)); 133 return (-1); 134 } 135 bp = p->buffer; 136 } else 137 bp = p->bp; 138 139 /* 140 * loop through each snapshot in the chunk 141 */ 142 n = 0; 143 ep = bp + cc; 144 while (bp < ep) { 145 /* 146 * Has "pcap_breakloop()" been called? 147 * If so, return immediately - if we haven't read any 148 * packets, clear the flag and return -2 to indicate 149 * that we were told to break out of the loop, otherwise 150 * leave the flag set, so that the *next* call will break 151 * out of the loop without having read any packets, and 152 * return the number of packets we've processed so far. 153 */ 154 if (p->break_loop) { 155 if (n == 0) { 156 p->break_loop = 0; 157 return (-2); 158 } else { 159 p->bp = bp; 160 p->cc = ep - bp; 161 return (n); 162 } 163 } 164 165 ++p->md.stat.ps_recv; 166 cp = bp; 167 168 /* get past NIT buffer */ 169 hdrp = (struct nit_bufhdr *)cp; 170 cp += sizeof(*hdrp); 171 172 /* get past NIT timer */ 173 ntp = (struct nit_iftime *)cp; 174 cp += sizeof(*ntp); 175 176 ndp = (struct nit_ifdrops *)cp; 177 p->md.stat.ps_drop = ndp->nh_drops; 178 cp += sizeof *ndp; 179 180 /* get past packet len */ 181 nlp = (struct nit_iflen *)cp; 182 cp += sizeof(*nlp); 183 184 /* next snapshot */ 185 bp += hdrp->nhb_totlen; 186 187 caplen = nlp->nh_pktlen; 188 if (caplen > p->snapshot) 189 caplen = p->snapshot; 190 191 if (bpf_filter(p->fcode.bf_insns, cp, nlp->nh_pktlen, caplen)) { 192 struct pcap_pkthdr h; 193 h.ts = ntp->nh_timestamp; 194 h.len = nlp->nh_pktlen; 195 h.caplen = caplen; 196 (*callback)(user, &h, cp); 197 if (++n >= cnt && cnt > 0) { 198 p->cc = ep - bp; 199 p->bp = bp; 200 return (n); 201 } 202 } 203 } 204 p->cc = 0; 205 return (n); 206 } 207 208 static int 209 pcap_inject_snit(pcap_t *p, const void *buf, size_t size) 210 { 211 struct strbuf ctl, data; 212 213 /* 214 * XXX - can we just do 215 * 216 ret = write(pd->f, buf, size); 217 */ 218 ctl.len = sizeof(*sa); /* XXX - what was this? */ 219 ctl.buf = (char *)sa; 220 data.buf = buf; 221 data.len = size; 222 ret = putmsg(p->fd, &ctl, &data); 223 if (ret == -1) { 224 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s", 225 pcap_strerror(errno)); 226 return (-1); 227 } 228 return (ret); 229 } 230 231 static int 232 nit_setflags(int fd, int promisc, int to_ms, char *ebuf) 233 { 234 bpf_u_int32 flags; 235 struct strioctl si; 236 struct timeval timeout; 237 238 si.ic_timout = INFTIM; 239 if (to_ms != 0) { 240 timeout.tv_sec = to_ms / 1000; 241 timeout.tv_usec = (to_ms * 1000) % 1000000; 242 si.ic_cmd = NIOCSTIME; 243 si.ic_len = sizeof(timeout); 244 si.ic_dp = (char *)&timeout; 245 if (ioctl(fd, I_STR, (char *)&si) < 0) { 246 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSTIME: %s", 247 pcap_strerror(errno)); 248 return (-1); 249 } 250 } 251 flags = NI_TIMESTAMP | NI_LEN | NI_DROPS; 252 if (promisc) 253 flags |= NI_PROMISC; 254 si.ic_cmd = NIOCSFLAGS; 255 si.ic_len = sizeof(flags); 256 si.ic_dp = (char *)&flags; 257 if (ioctl(fd, I_STR, (char *)&si) < 0) { 258 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSFLAGS: %s", 259 pcap_strerror(errno)); 260 return (-1); 261 } 262 return (0); 263 } 264 265 static int 266 pcap_activate_snit(pcap_t *p) 267 { 268 struct strioctl si; /* struct for ioctl() */ 269 struct ifreq ifr; /* interface request struct */ 270 int chunksize = CHUNKSIZE; 271 int fd; 272 static char dev[] = "/dev/nit"; 273 274 if (p->opt.rfmon) { 275 /* 276 * No monitor mode on SunOS 4.x (no Wi-Fi devices on 277 * hardware supported by SunOS 4.x). 278 */ 279 return (PCAP_ERROR_RFMON_NOTSUP); 280 } 281 282 if (p->snapshot < 96) 283 /* 284 * NIT requires a snapshot length of at least 96. 285 */ 286 p->snapshot = 96; 287 288 /* 289 * Initially try a read/write open (to allow the inject 290 * method to work). If that fails due to permission 291 * issues, fall back to read-only. This allows a 292 * non-root user to be granted specific access to pcap 293 * capabilities via file permissions. 294 * 295 * XXX - we should have an API that has a flag that 296 * controls whether to open read-only or read-write, 297 * so that denial of permission to send (or inability 298 * to send, if sending packets isn't supported on 299 * the device in question) can be indicated at open 300 * time. 301 */ 302 p->fd = fd = open(dev, O_RDWR); 303 if (fd < 0 && errno == EACCES) 304 p->fd = fd = open(dev, O_RDONLY); 305 if (fd < 0) { 306 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "%s: %s", dev, 307 pcap_strerror(errno)); 308 goto bad; 309 } 310 311 /* arrange to get discrete messages from the STREAM and use NIT_BUF */ 312 if (ioctl(fd, I_SRDOPT, (char *)RMSGD) < 0) { 313 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "I_SRDOPT: %s", 314 pcap_strerror(errno)); 315 goto bad; 316 } 317 if (ioctl(fd, I_PUSH, "nbuf") < 0) { 318 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "push nbuf: %s", 319 pcap_strerror(errno)); 320 goto bad; 321 } 322 /* set the chunksize */ 323 si.ic_cmd = NIOCSCHUNK; 324 si.ic_timout = INFTIM; 325 si.ic_len = sizeof(chunksize); 326 si.ic_dp = (char *)&chunksize; 327 if (ioctl(fd, I_STR, (char *)&si) < 0) { 328 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "NIOCSCHUNK: %s", 329 pcap_strerror(errno)); 330 goto bad; 331 } 332 333 /* request the interface */ 334 strncpy(ifr.ifr_name, p->opt.source, sizeof(ifr.ifr_name)); 335 ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = '\0'; 336 si.ic_cmd = NIOCBIND; 337 si.ic_len = sizeof(ifr); 338 si.ic_dp = (char *)𝔦 339 if (ioctl(fd, I_STR, (char *)&si) < 0) { 340 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "NIOCBIND: %s: %s", 341 ifr.ifr_name, pcap_strerror(errno)); 342 goto bad; 343 } 344 345 /* set the snapshot length */ 346 si.ic_cmd = NIOCSSNAP; 347 si.ic_len = sizeof(p->snapshot); 348 si.ic_dp = (char *)&p->snapshot; 349 if (ioctl(fd, I_STR, (char *)&si) < 0) { 350 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "NIOCSSNAP: %s", 351 pcap_strerror(errno)); 352 goto bad; 353 } 354 if (nit_setflags(p->fd, p->opt.promisc, p->md.timeout, p->errbuf) < 0) 355 goto bad; 356 357 (void)ioctl(fd, I_FLUSH, (char *)FLUSHR); 358 /* 359 * NIT supports only ethernets. 360 */ 361 p->linktype = DLT_EN10MB; 362 363 p->bufsize = BUFSPACE; 364 p->buffer = (u_char *)malloc(p->bufsize); 365 if (p->buffer == NULL) { 366 strlcpy(p->errbuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE); 367 goto bad; 368 } 369 370 /* 371 * "p->fd" is an FD for a STREAMS device, so "select()" and 372 * "poll()" should work on it. 373 */ 374 p->selectable_fd = p->fd; 375 376 /* 377 * This is (presumably) a real Ethernet capture; give it a 378 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so 379 * that an application can let you choose it, in case you're 380 * capturing DOCSIS traffic that a Cisco Cable Modem 381 * Termination System is putting out onto an Ethernet (it 382 * doesn't put an Ethernet header onto the wire, it puts raw 383 * DOCSIS frames out on the wire inside the low-level 384 * Ethernet framing). 385 */ 386 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2); 387 /* 388 * If that fails, just leave the list empty. 389 */ 390 if (p->dlt_list != NULL) { 391 p->dlt_list[0] = DLT_EN10MB; 392 p->dlt_list[1] = DLT_DOCSIS; 393 p->dlt_count = 2; 394 } 395 396 p->read_op = pcap_read_snit; 397 p->inject_op = pcap_inject_snit; 398 p->setfilter_op = install_bpf_program; /* no kernel filtering */ 399 p->setdirection_op = NULL; /* Not implemented. */ 400 p->set_datalink_op = NULL; /* can't change data link type */ 401 p->getnonblock_op = pcap_getnonblock_fd; 402 p->setnonblock_op = pcap_setnonblock_fd; 403 p->stats_op = pcap_stats_snit; 404 405 return (0); 406 bad: 407 pcap_cleanup_live_common(p); 408 return (PCAP_ERROR); 409 } 410 411 pcap_t * 412 pcap_create(const char *device, char *ebuf) 413 { 414 pcap_t *p; 415 416 p = pcap_create_common(device, ebuf); 417 if (p == NULL) 418 return (NULL); 419 420 p->activate_op = pcap_activate_snit; 421 return (p); 422 } 423 424 int 425 pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf) 426 { 427 return (0); 428 } 429