1 /* 2 * Copyright (c) 1993, 1994, 1995, 1996, 1997 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[] = 23 "@(#) $Header: /tcpdump/master/libpcap/pcap-snoop.c,v 1.33 2001/12/10 07:14:21 guy Exp $ (LBL)"; 24 #endif 25 26 #ifdef HAVE_CONFIG_H 27 #include "config.h" 28 #endif 29 30 #include <sys/param.h> 31 #include <sys/file.h> 32 #include <sys/ioctl.h> 33 #include <sys/socket.h> 34 #include <sys/time.h> 35 36 #include <net/raw.h> 37 #include <net/if.h> 38 39 #include <netinet/in.h> 40 #include <netinet/in_systm.h> 41 #include <netinet/ip.h> 42 #include <netinet/if_ether.h> 43 #include <netinet/ip_var.h> 44 #include <netinet/udp.h> 45 #include <netinet/udp_var.h> 46 #include <netinet/tcp.h> 47 #include <netinet/tcpip.h> 48 49 #include <errno.h> 50 #include <stdio.h> 51 #include <stdlib.h> 52 #include <string.h> 53 #include <unistd.h> 54 55 #include "pcap-int.h" 56 57 #ifdef HAVE_OS_PROTO_H 58 #include "os-proto.h" 59 #endif 60 61 int 62 pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 63 { 64 int cc; 65 register struct snoopheader *sh; 66 register int datalen; 67 register int caplen; 68 register u_char *cp; 69 70 again: 71 cc = read(p->fd, (char *)p->buffer, p->bufsize); 72 if (cc < 0) { 73 /* Don't choke when we get ptraced */ 74 switch (errno) { 75 76 case EINTR: 77 goto again; 78 79 case EWOULDBLOCK: 80 return (0); /* XXX */ 81 } 82 snprintf(p->errbuf, sizeof(p->errbuf), 83 "read: %s", pcap_strerror(errno)); 84 return (-1); 85 } 86 sh = (struct snoopheader *)p->buffer; 87 datalen = sh->snoop_packetlen; 88 caplen = (datalen < p->snapshot) ? datalen : p->snapshot; 89 cp = (u_char *)(sh + 1) + p->offset; /* XXX */ 90 91 if (p->fcode.bf_insns == NULL || 92 bpf_filter(p->fcode.bf_insns, cp, datalen, caplen)) { 93 struct pcap_pkthdr h; 94 ++p->md.stat.ps_recv; 95 h.ts = sh->snoop_timestamp; 96 h.len = datalen; 97 h.caplen = caplen; 98 (*callback)(user, &h, cp); 99 return (1); 100 } 101 return (0); 102 } 103 104 int 105 pcap_stats(pcap_t *p, struct pcap_stat *ps) 106 { 107 register struct rawstats *rs; 108 struct rawstats rawstats; 109 110 rs = &rawstats; 111 memset(rs, 0, sizeof(*rs)); 112 if (ioctl(p->fd, SIOCRAWSTATS, (char *)rs) < 0) { 113 snprintf(p->errbuf, sizeof(p->errbuf), 114 "SIOCRAWSTATS: %s", pcap_strerror(errno)); 115 return (-1); 116 } 117 118 /* 119 * "ifdrops" are those dropped by the network interface 120 * due to resource shortages or hardware errors. 121 * 122 * "sbdrops" are those dropped due to socket buffer limits. 123 * 124 * As filter is done in userland, "sbdrops" counts packets 125 * regardless of whether they would've passed the filter. 126 * 127 * XXX - does this count *all* Snoop or Drain sockets, 128 * rather than just this socket? If not, why does it have 129 * both Snoop and Drain statistics? 130 */ 131 p->md.stat.ps_drop = 132 rs->rs_snoop.ss_ifdrops + rs->rs_snoop.ss_sbdrops + 133 rs->rs_drain.ds_ifdrops + rs->rs_drain.ds_sbdrops; 134 135 /* 136 * "ps_recv" counts only packets that passed the filter. 137 * As filtering is done in userland, this does not include 138 * packets dropped because we ran out of buffer space. 139 */ 140 *ps = p->md.stat; 141 return (0); 142 } 143 144 /* XXX can't disable promiscuous */ 145 pcap_t * 146 pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf) 147 { 148 int fd; 149 struct sockaddr_raw sr; 150 struct snoopfilter sf; 151 u_int v; 152 int ll_hdrlen; 153 int snooplen; 154 pcap_t *p; 155 struct ifreq ifr; 156 157 p = (pcap_t *)malloc(sizeof(*p)); 158 if (p == NULL) { 159 snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s", 160 pcap_strerror(errno)); 161 return (NULL); 162 } 163 memset(p, 0, sizeof(*p)); 164 fd = socket(PF_RAW, SOCK_RAW, RAWPROTO_SNOOP); 165 if (fd < 0) { 166 snprintf(ebuf, PCAP_ERRBUF_SIZE, "snoop socket: %s", 167 pcap_strerror(errno)); 168 goto bad; 169 } 170 p->fd = fd; 171 memset(&sr, 0, sizeof(sr)); 172 sr.sr_family = AF_RAW; 173 (void)strncpy(sr.sr_ifname, device, sizeof(sr.sr_ifname)); 174 if (bind(fd, (struct sockaddr *)&sr, sizeof(sr))) { 175 snprintf(ebuf, PCAP_ERRBUF_SIZE, "snoop bind: %s", 176 pcap_strerror(errno)); 177 goto bad; 178 } 179 memset(&sf, 0, sizeof(sf)); 180 if (ioctl(fd, SIOCADDSNOOP, &sf) < 0) { 181 snprintf(ebuf, PCAP_ERRBUF_SIZE, "SIOCADDSNOOP: %s", 182 pcap_strerror(errno)); 183 goto bad; 184 } 185 v = 64 * 1024; 186 (void)setsockopt(fd, SOL_SOCKET, SO_RCVBUF, (char *)&v, sizeof(v)); 187 /* 188 * XXX hack - map device name to link layer type 189 */ 190 if (strncmp("et", device, 2) == 0 || /* Challenge 10 Mbit */ 191 strncmp("ec", device, 2) == 0 || /* Indigo/Indy 10 Mbit, 192 O2 10/100 */ 193 strncmp("ef", device, 2) == 0 || /* O200/2000 10/100 Mbit */ 194 strncmp("gfe", device, 3) == 0 || /* GIO 100 Mbit */ 195 strncmp("fxp", device, 3) == 0 || /* Challenge VME Enet */ 196 strncmp("ep", device, 2) == 0 || /* Challenge 8x10 Mbit EPLEX */ 197 strncmp("vfe", device, 3) == 0 || /* Challenge VME 100Mbit */ 198 strncmp("fa", device, 2) == 0 || 199 strncmp("qaa", device, 3) == 0 || 200 strncmp("cip", device, 3) == 0 || 201 strncmp("el", device, 2) == 0) { 202 p->linktype = DLT_EN10MB; 203 p->offset = RAW_HDRPAD(sizeof(struct ether_header)); 204 ll_hdrlen = sizeof(struct ether_header); 205 } else if (strncmp("ipg", device, 3) == 0 || 206 strncmp("rns", device, 3) == 0 || /* O2/200/2000 FDDI */ 207 strncmp("xpi", device, 3) == 0) { 208 p->linktype = DLT_FDDI; 209 p->offset = 3; /* XXX yeah? */ 210 ll_hdrlen = 13; 211 } else if (strncmp("ppp", device, 3) == 0) { 212 p->linktype = DLT_RAW; 213 ll_hdrlen = 0; /* DLT_RAW meaning "no PPP header, just the IP packet"? */ 214 } else if (strncmp("lo", device, 2) == 0) { 215 p->linktype = DLT_NULL; 216 ll_hdrlen = 4; /* is this just like BSD's loopback device? */ 217 } else { 218 snprintf(ebuf, PCAP_ERRBUF_SIZE, 219 "snoop: unknown physical layer type"); 220 goto bad; 221 } 222 #ifdef SIOCGIFMTU 223 /* 224 * XXX - IRIX appears to give you an error if you try to set the 225 * capture length to be greater than the MTU, so let's try to get 226 * the MTU first and, if that succeeds, trim the snap length 227 * to be no greater than the MTU. 228 */ 229 (void)strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name)); 230 if (ioctl(fd, SIOCGIFMTU, (char *)&ifr) < 0) { 231 snprintf(ebuf, PCAP_ERRBUF_SIZE, "SIOCGIFMTU: %s", 232 pcap_strerror(errno)); 233 goto bad; 234 } 235 /* 236 * OK, we got it. 237 * 238 * XXX - some versions of IRIX 6.5 define "ifr_mtu" and have an 239 * "ifru_metric" member of the "ifr_ifru" union in an "ifreq" 240 * structure, others don't. 241 * 242 * I've no idea what's going on, so, if "ifr_mtu" isn't defined, 243 * we define it as "ifr_metric", as using that field appears to 244 * work on the versions that lack "ifr_mtu" (and, on those that 245 * don't lack it, "ifru_metric" and "ifru_mtu" are both "int" 246 * members of the "ifr_ifru" union, which suggests that they 247 * may be interchangeable in this case). 248 */ 249 #ifndef ifr_mtu 250 #define ifr_mtu ifr_metric 251 #endif 252 if (snaplen > ifr.ifr_mtu) 253 snaplen = ifr.ifr_mtu; 254 #endif 255 256 /* 257 * The argument to SIOCSNOOPLEN is the number of link-layer 258 * payload bytes to capture - it doesn't count link-layer 259 * header bytes. 260 */ 261 snooplen = snaplen - ll_hdrlen; 262 if (snooplen < 0) 263 snooplen = 0; 264 if (ioctl(fd, SIOCSNOOPLEN, &snooplen) < 0) { 265 snprintf(ebuf, PCAP_ERRBUF_SIZE, "SIOCSNOOPLEN: %s", 266 pcap_strerror(errno)); 267 goto bad; 268 } 269 p->snapshot = snaplen; 270 v = 1; 271 if (ioctl(fd, SIOCSNOOPING, &v) < 0) { 272 snprintf(ebuf, PCAP_ERRBUF_SIZE, "SIOCSNOOPING: %s", 273 pcap_strerror(errno)); 274 goto bad; 275 } 276 277 p->bufsize = 4096; /* XXX */ 278 p->buffer = (u_char *)malloc(p->bufsize); 279 if (p->buffer == NULL) { 280 snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s", 281 pcap_strerror(errno)); 282 goto bad; 283 } 284 285 return (p); 286 bad: 287 (void)close(fd); 288 free(p); 289 return (NULL); 290 } 291 292 int 293 pcap_setfilter(pcap_t *p, struct bpf_program *fp) 294 { 295 296 if (install_bpf_program(p, fp) < 0) 297 return (-1); 298 return (0); 299 } 300