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 * Modifications made to accommodate the new SunOS4.0 NIT facility by 22 * Micky Liu, micky@cunixc.cc.columbia.edu, Columbia University in May, 1989. 23 * This module now handles the STREAMS based NIT. 24 */ 25 26 #ifndef lint 27 static const char rcsid[] _U_ = 28 "@(#) $Header: /tcpdump/master/libpcap/pcap-snit.c,v 1.66.2.3 2003/11/21 10:20:48 guy Exp $ (LBL)"; 29 #endif 30 31 #ifdef HAVE_CONFIG_H 32 #include "config.h" 33 #endif 34 35 #include <sys/types.h> 36 #include <sys/time.h> 37 #include <sys/timeb.h> 38 #include <sys/dir.h> 39 #include <sys/fcntlcom.h> 40 #include <sys/file.h> 41 #include <sys/ioctl.h> 42 #include <sys/socket.h> 43 #include <sys/stropts.h> 44 45 #include <net/if.h> 46 #include <net/nit.h> 47 #include <net/nit_if.h> 48 #include <net/nit_pf.h> 49 #include <net/nit_buf.h> 50 51 #include <netinet/in.h> 52 #include <netinet/in_systm.h> 53 #include <netinet/ip.h> 54 #include <netinet/if_ether.h> 55 #include <netinet/ip_var.h> 56 #include <netinet/udp.h> 57 #include <netinet/udp_var.h> 58 #include <netinet/tcp.h> 59 #include <netinet/tcpip.h> 60 61 #include <ctype.h> 62 #include <errno.h> 63 #include <stdio.h> 64 #include <string.h> 65 #include <unistd.h> 66 67 #include "pcap-int.h" 68 69 #ifdef HAVE_OS_PROTO_H 70 #include "os-proto.h" 71 #endif 72 73 /* 74 * The chunk size for NIT. This is the amount of buffering 75 * done for read calls. 76 */ 77 #define CHUNKSIZE (2*1024) 78 79 /* 80 * The total buffer space used by NIT. 81 */ 82 #define BUFSPACE (4*CHUNKSIZE) 83 84 /* Forwards */ 85 static int nit_setflags(int, int, int, char *); 86 87 static int 88 pcap_stats_snit(pcap_t *p, struct pcap_stat *ps) 89 { 90 91 /* 92 * "ps_recv" counts packets handed to the filter, not packets 93 * that passed the filter. As filtering is done in userland, 94 * this does not include packets dropped because we ran out 95 * of buffer space. 96 * 97 * "ps_drop" counts packets dropped inside the "/dev/nit" 98 * device because of flow control requirements or resource 99 * exhaustion; it doesn't count packets dropped by the 100 * interface driver, or packets dropped upstream. As filtering 101 * is done in userland, it counts packets regardless of whether 102 * they would've passed the filter. 103 * 104 * These statistics don't include packets not yet read from the 105 * kernel by libpcap or packets not yet read from libpcap by the 106 * application. 107 */ 108 *ps = p->md.stat; 109 return (0); 110 } 111 112 static int 113 pcap_read_snit(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 114 { 115 register int cc, n; 116 register struct bpf_insn *fcode = p->fcode.bf_insns; 117 register u_char *bp, *cp, *ep; 118 register struct nit_bufhdr *hdrp; 119 register struct nit_iftime *ntp; 120 register struct nit_iflen *nlp; 121 register struct nit_ifdrops *ndp; 122 register int caplen; 123 124 cc = p->cc; 125 if (cc == 0) { 126 cc = read(p->fd, (char *)p->buffer, p->bufsize); 127 if (cc < 0) { 128 if (errno == EWOULDBLOCK) 129 return (0); 130 snprintf(p->errbuf, sizeof(p->errbuf), "pcap_read: %s", 131 pcap_strerror(errno)); 132 return (-1); 133 } 134 bp = p->buffer; 135 } else 136 bp = p->bp; 137 138 /* 139 * loop through each snapshot in the chunk 140 */ 141 n = 0; 142 ep = bp + cc; 143 while (bp < ep) { 144 /* 145 * Has "pcap_breakloop()" been called? 146 * If so, return immediately - if we haven't read any 147 * packets, clear the flag and return -2 to indicate 148 * that we were told to break out of the loop, otherwise 149 * leave the flag set, so that the *next* call will break 150 * out of the loop without having read any packets, and 151 * return the number of packets we've processed so far. 152 */ 153 if (p->break_loop) { 154 if (n == 0) { 155 p->break_loop = 0; 156 return (-2); 157 } else { 158 p->bp = bp; 159 p->cc = ep - bp; 160 return (n); 161 } 162 } 163 164 ++p->md.stat.ps_recv; 165 cp = bp; 166 167 /* get past NIT buffer */ 168 hdrp = (struct nit_bufhdr *)cp; 169 cp += sizeof(*hdrp); 170 171 /* get past NIT timer */ 172 ntp = (struct nit_iftime *)cp; 173 cp += sizeof(*ntp); 174 175 ndp = (struct nit_ifdrops *)cp; 176 p->md.stat.ps_drop = ndp->nh_drops; 177 cp += sizeof *ndp; 178 179 /* get past packet len */ 180 nlp = (struct nit_iflen *)cp; 181 cp += sizeof(*nlp); 182 183 /* next snapshot */ 184 bp += hdrp->nhb_totlen; 185 186 caplen = nlp->nh_pktlen; 187 if (caplen > p->snapshot) 188 caplen = p->snapshot; 189 190 if (bpf_filter(fcode, cp, nlp->nh_pktlen, caplen)) { 191 struct pcap_pkthdr h; 192 h.ts = ntp->nh_timestamp; 193 h.len = nlp->nh_pktlen; 194 h.caplen = caplen; 195 (*callback)(user, &h, cp); 196 if (++n >= cnt && cnt >= 0) { 197 p->cc = ep - bp; 198 p->bp = bp; 199 return (n); 200 } 201 } 202 } 203 p->cc = 0; 204 return (n); 205 } 206 207 static int 208 nit_setflags(int fd, int promisc, int to_ms, char *ebuf) 209 { 210 bpf_u_int32 flags; 211 struct strioctl si; 212 struct timeval timeout; 213 214 si.ic_timout = INFTIM; 215 if (to_ms != 0) { 216 timeout.tv_sec = to_ms / 1000; 217 timeout.tv_usec = (to_ms * 1000) % 1000000; 218 si.ic_cmd = NIOCSTIME; 219 si.ic_len = sizeof(timeout); 220 si.ic_dp = (char *)&timeout; 221 if (ioctl(fd, I_STR, (char *)&si) < 0) { 222 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSTIME: %s", 223 pcap_strerror(errno)); 224 return (-1); 225 } 226 } 227 flags = NI_TIMESTAMP | NI_LEN | NI_DROPS; 228 if (promisc) 229 flags |= NI_PROMISC; 230 si.ic_cmd = NIOCSFLAGS; 231 si.ic_len = sizeof(flags); 232 si.ic_dp = (char *)&flags; 233 if (ioctl(fd, I_STR, (char *)&si) < 0) { 234 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSFLAGS: %s", 235 pcap_strerror(errno)); 236 return (-1); 237 } 238 return (0); 239 } 240 241 static void 242 pcap_close_snit(pcap_t *p) 243 { 244 if (p->buffer != NULL) 245 free(p->buffer); 246 if (p->fd >= 0) 247 close(p->fd); 248 } 249 250 pcap_t * 251 pcap_open_live(const char *device, int snaplen, int promisc, int to_ms, 252 char *ebuf) 253 { 254 struct strioctl si; /* struct for ioctl() */ 255 struct ifreq ifr; /* interface request struct */ 256 int chunksize = CHUNKSIZE; 257 int fd; 258 static char dev[] = "/dev/nit"; 259 register pcap_t *p; 260 261 p = (pcap_t *)malloc(sizeof(*p)); 262 if (p == NULL) { 263 strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE); 264 return (NULL); 265 } 266 267 if (snaplen < 96) 268 /* 269 * NIT requires a snapshot length of at least 96. 270 */ 271 snaplen = 96; 272 273 memset(p, 0, sizeof(*p)); 274 p->fd = fd = open(dev, O_RDONLY); 275 if (fd < 0) { 276 snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s: %s", dev, 277 pcap_strerror(errno)); 278 goto bad; 279 } 280 281 /* arrange to get discrete messages from the STREAM and use NIT_BUF */ 282 if (ioctl(fd, I_SRDOPT, (char *)RMSGD) < 0) { 283 snprintf(ebuf, PCAP_ERRBUF_SIZE, "I_SRDOPT: %s", 284 pcap_strerror(errno)); 285 goto bad; 286 } 287 if (ioctl(fd, I_PUSH, "nbuf") < 0) { 288 snprintf(ebuf, PCAP_ERRBUF_SIZE, "push nbuf: %s", 289 pcap_strerror(errno)); 290 goto bad; 291 } 292 /* set the chunksize */ 293 si.ic_cmd = NIOCSCHUNK; 294 si.ic_timout = INFTIM; 295 si.ic_len = sizeof(chunksize); 296 si.ic_dp = (char *)&chunksize; 297 if (ioctl(fd, I_STR, (char *)&si) < 0) { 298 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSCHUNK: %s", 299 pcap_strerror(errno)); 300 goto bad; 301 } 302 303 /* request the interface */ 304 strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name)); 305 ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = '\0'; 306 si.ic_cmd = NIOCBIND; 307 si.ic_len = sizeof(ifr); 308 si.ic_dp = (char *)𝔦 309 if (ioctl(fd, I_STR, (char *)&si) < 0) { 310 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCBIND: %s: %s", 311 ifr.ifr_name, pcap_strerror(errno)); 312 goto bad; 313 } 314 315 /* set the snapshot length */ 316 si.ic_cmd = NIOCSSNAP; 317 si.ic_len = sizeof(snaplen); 318 si.ic_dp = (char *)&snaplen; 319 if (ioctl(fd, I_STR, (char *)&si) < 0) { 320 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSSNAP: %s", 321 pcap_strerror(errno)); 322 goto bad; 323 } 324 p->snapshot = snaplen; 325 if (nit_setflags(p->fd, promisc, to_ms, ebuf) < 0) 326 goto bad; 327 328 (void)ioctl(fd, I_FLUSH, (char *)FLUSHR); 329 /* 330 * NIT supports only ethernets. 331 */ 332 p->linktype = DLT_EN10MB; 333 334 p->bufsize = BUFSPACE; 335 p->buffer = (u_char *)malloc(p->bufsize); 336 if (p->buffer == NULL) { 337 strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE); 338 goto bad; 339 } 340 341 /* 342 * "p->fd" is an FD for a STREAMS device, so "select()" and 343 * "poll()" should work on it. 344 */ 345 p->selectable_fd = p->fd; 346 347 p->read_op = pcap_read_snit; 348 p->setfilter_op = install_bpf_program; /* no kernel filtering */ 349 p->set_datalink_op = NULL; /* can't change data link type */ 350 p->getnonblock_op = pcap_getnonblock_fd; 351 p->setnonblock_op = pcap_setnonblock_fd; 352 p->stats_op = pcap_stats_snit; 353 p->close_op = pcap_close_snit; 354 355 return (p); 356 bad: 357 if (fd >= 0) 358 close(fd); 359 free(p); 360 return (NULL); 361 } 362 363 int 364 pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf) 365 { 366 return (0); 367 } 368