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 static int 75 pcap_stats_nit(pcap_t *p, struct pcap_stat *ps) 76 { 77 78 /* 79 * "ps_recv" counts packets handed to the filter, not packets 80 * that passed the filter. As filtering is done in userland, 81 * this does not include packets dropped because we ran out 82 * of buffer space. 83 * 84 * "ps_drop" presumably counts packets dropped by the socket 85 * because of flow control requirements or resource exhaustion; 86 * it doesn't count packets dropped by the interface driver. 87 * As filtering is done in userland, it counts packets regardless 88 * of whether they would've passed the filter. 89 * 90 * These statistics don't include packets not yet read from the 91 * kernel by libpcap or packets not yet read from libpcap by the 92 * application. 93 */ 94 *ps = p->md.stat; 95 return (0); 96 } 97 98 static int 99 pcap_read_nit(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 100 { 101 register int cc, n; 102 register u_char *bp, *cp, *ep; 103 register struct nit_hdr *nh; 104 register int caplen; 105 106 cc = p->cc; 107 if (cc == 0) { 108 cc = read(p->fd, (char *)p->buffer, p->bufsize); 109 if (cc < 0) { 110 if (errno == EWOULDBLOCK) 111 return (0); 112 snprintf(p->errbuf, sizeof(p->errbuf), "pcap_read: %s", 113 pcap_strerror(errno)); 114 return (-1); 115 } 116 bp = p->buffer; 117 } else 118 bp = p->bp; 119 120 /* 121 * Loop through each packet. The increment expression 122 * rounds up to the next int boundary past the end of 123 * the previous packet. 124 */ 125 n = 0; 126 ep = bp + cc; 127 while (bp < ep) { 128 /* 129 * Has "pcap_breakloop()" been called? 130 * If so, return immediately - if we haven't read any 131 * packets, clear the flag and return -2 to indicate 132 * that we were told to break out of the loop, otherwise 133 * leave the flag set, so that the *next* call will break 134 * out of the loop without having read any packets, and 135 * return the number of packets we've processed so far. 136 */ 137 if (p->break_loop) { 138 if (n == 0) { 139 p->break_loop = 0; 140 return (-2); 141 } else { 142 p->cc = ep - bp; 143 p->bp = bp; 144 return (n); 145 } 146 } 147 148 nh = (struct nit_hdr *)bp; 149 cp = bp + sizeof(*nh); 150 151 switch (nh->nh_state) { 152 153 case NIT_CATCH: 154 break; 155 156 case NIT_NOMBUF: 157 case NIT_NOCLUSTER: 158 case NIT_NOSPACE: 159 p->md.stat.ps_drop = nh->nh_dropped; 160 continue; 161 162 case NIT_SEQNO: 163 continue; 164 165 default: 166 snprintf(p->errbuf, sizeof(p->errbuf), 167 "bad nit state %d", nh->nh_state); 168 return (-1); 169 } 170 ++p->md.stat.ps_recv; 171 bp += ((sizeof(struct nit_hdr) + nh->nh_datalen + 172 sizeof(int) - 1) & ~(sizeof(int) - 1)); 173 174 caplen = nh->nh_wirelen; 175 if (caplen > p->snapshot) 176 caplen = p->snapshot; 177 if (bpf_filter(p->fcode.bf_insns, cp, nh->nh_wirelen, caplen)) { 178 struct pcap_pkthdr h; 179 h.ts = nh->nh_timestamp; 180 h.len = nh->nh_wirelen; 181 h.caplen = caplen; 182 (*callback)(user, &h, cp); 183 if (++n >= cnt && cnt > 0) { 184 p->cc = ep - bp; 185 p->bp = bp; 186 return (n); 187 } 188 } 189 } 190 p->cc = 0; 191 return (n); 192 } 193 194 static int 195 pcap_inject_nit(pcap_t *p, const void *buf, size_t size) 196 { 197 struct sockaddr sa; 198 int ret; 199 200 memset(&sa, 0, sizeof(sa)); 201 strncpy(sa.sa_data, device, sizeof(sa.sa_data)); 202 ret = sendto(p->fd, buf, size, 0, &sa, sizeof(sa)); 203 if (ret == -1) { 204 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s", 205 pcap_strerror(errno)); 206 return (-1); 207 } 208 return (ret); 209 } 210 211 static int 212 nit_setflags(int fd, int promisc, int to_ms, char *ebuf) 213 { 214 struct nit_ioc nioc; 215 216 memset(&nioc, 0, sizeof(nioc)); 217 nioc.nioc_bufspace = BUFSPACE; 218 nioc.nioc_chunksize = CHUNKSIZE; 219 nioc.nioc_typetomatch = NT_ALLTYPES; 220 nioc.nioc_snaplen = p->snapshot; 221 nioc.nioc_bufalign = sizeof(int); 222 nioc.nioc_bufoffset = 0; 223 224 if (to_ms != 0) { 225 nioc.nioc_flags |= NF_TIMEOUT; 226 nioc.nioc_timeout.tv_sec = to_ms / 1000; 227 nioc.nioc_timeout.tv_usec = (to_ms * 1000) % 1000000; 228 } 229 if (promisc) 230 nioc.nioc_flags |= NF_PROMISC; 231 232 if (ioctl(fd, SIOCSNIT, &nioc) < 0) { 233 snprintf(ebuf, PCAP_ERRBUF_SIZE, "SIOCSNIT: %s", 234 pcap_strerror(errno)); 235 return (-1); 236 } 237 return (0); 238 } 239 240 static int 241 pcap_activate_nit(pcap_t *p) 242 { 243 int fd; 244 struct sockaddr_nit snit; 245 246 if (p->opt.rfmon) { 247 /* 248 * No monitor mode on SunOS 3.x or earlier (no 249 * Wi-Fi *devices* for the hardware that supported 250 * them!). 251 */ 252 return (PCAP_ERROR_RFMON_NOTSUP); 253 } 254 255 if (p->snapshot < 96) 256 /* 257 * NIT requires a snapshot length of at least 96. 258 */ 259 p->snapshot = 96; 260 261 memset(p, 0, sizeof(*p)); 262 p->fd = fd = socket(AF_NIT, SOCK_RAW, NITPROTO_RAW); 263 if (fd < 0) { 264 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 265 "socket: %s", pcap_strerror(errno)); 266 goto bad; 267 } 268 snit.snit_family = AF_NIT; 269 (void)strncpy(snit.snit_ifname, p->opt.source, NITIFSIZ); 270 271 if (bind(fd, (struct sockaddr *)&snit, sizeof(snit))) { 272 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 273 "bind: %s: %s", snit.snit_ifname, pcap_strerror(errno)); 274 goto bad; 275 } 276 nit_setflags(p->fd, p->opt.promisc, p->md.timeout, p->errbuf); 277 278 /* 279 * NIT supports only ethernets. 280 */ 281 p->linktype = DLT_EN10MB; 282 283 p->bufsize = BUFSPACE; 284 p->buffer = (u_char *)malloc(p->bufsize); 285 if (p->buffer == NULL) { 286 strlcpy(p->errbuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE); 287 goto bad; 288 } 289 290 /* 291 * "p->fd" is a socket, so "select()" should work on it. 292 */ 293 p->selectable_fd = p->fd; 294 295 /* 296 * This is (presumably) a real Ethernet capture; give it a 297 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so 298 * that an application can let you choose it, in case you're 299 * capturing DOCSIS traffic that a Cisco Cable Modem 300 * Termination System is putting out onto an Ethernet (it 301 * doesn't put an Ethernet header onto the wire, it puts raw 302 * DOCSIS frames out on the wire inside the low-level 303 * Ethernet framing). 304 */ 305 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2); 306 /* 307 * If that fails, just leave the list empty. 308 */ 309 if (p->dlt_list != NULL) { 310 p->dlt_list[0] = DLT_EN10MB; 311 p->dlt_list[1] = DLT_DOCSIS; 312 p->dlt_count = 2; 313 } 314 315 p->read_op = pcap_read_nit; 316 p->inject_op = pcap_inject_nit; 317 p->setfilter_op = install_bpf_program; /* no kernel filtering */ 318 p->setdirection_op = NULL; /* Not implemented. */ 319 p->set_datalink_op = NULL; /* can't change data link type */ 320 p->getnonblock_op = pcap_getnonblock_fd; 321 p->setnonblock_op = pcap_setnonblock_fd; 322 p->stats_op = pcap_stats_nit; 323 324 return (0); 325 bad: 326 pcap_cleanup_live_common(p); 327 return (PCAP_ERROR); 328 } 329 330 pcap_t * 331 pcap_create_interface(const char *device, char *ebuf) 332 { 333 pcap_t *p; 334 335 p = pcap_create_common(device, ebuf); 336 if (p == NULL) 337 return (NULL); 338 339 p->activate_op = pcap_activate_nit; 340 return (p); 341 } 342 343 int 344 pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf) 345 { 346 return (0); 347 } 348