1 /* $NetBSD: pcap-nit.c,v 1.3 2015/03/31 21:39:42 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 24 #include <sys/cdefs.h> 25 __RCSID("$NetBSD: pcap-nit.c,v 1.3 2015/03/31 21:39:42 christos Exp $"); 26 27 #ifdef HAVE_CONFIG_H 28 #include "config.h" 29 #endif 30 31 #include <sys/types.h> 32 #include <sys/time.h> 33 #include <sys/timeb.h> 34 #include <sys/file.h> 35 #include <sys/ioctl.h> 36 #include <sys/socket.h> 37 38 #include <net/if.h> 39 #include <net/nit.h> 40 41 #include <netinet/in.h> 42 #include <netinet/in_systm.h> 43 #include <netinet/ip.h> 44 #include <netinet/if_ether.h> 45 #include <netinet/ip_var.h> 46 #include <netinet/udp.h> 47 #include <netinet/udp_var.h> 48 #include <netinet/tcp.h> 49 #include <netinet/tcpip.h> 50 51 #include <ctype.h> 52 #include <errno.h> 53 #include <stdio.h> 54 55 #include "pcap-int.h" 56 57 #ifdef HAVE_OS_PROTO_H 58 #include "os-proto.h" 59 #endif 60 61 /* 62 * The chunk size for NIT. This is the amount of buffering 63 * done for read calls. 64 */ 65 #define CHUNKSIZE (2*1024) 66 67 /* 68 * The total buffer space used by NIT. 69 */ 70 #define BUFSPACE (4*CHUNKSIZE) 71 72 /* Forwards */ 73 static int nit_setflags(int, int, int, char *); 74 75 /* 76 * Private data for capturing on NIT devices. 77 */ 78 struct pcap_nit { 79 struct pcap_stat stat; 80 }; 81 82 static int 83 pcap_stats_nit(pcap_t *p, struct pcap_stat *ps) 84 { 85 struct pcap_nit *pn = p->priv; 86 87 /* 88 * "ps_recv" counts packets handed to the filter, not packets 89 * that passed the filter. As filtering is done in userland, 90 * this does not include packets dropped because we ran out 91 * of buffer space. 92 * 93 * "ps_drop" presumably counts packets dropped by the socket 94 * because of flow control requirements or resource exhaustion; 95 * it doesn't count packets dropped by the interface driver. 96 * As filtering is done in userland, it counts packets regardless 97 * of whether they would've passed the filter. 98 * 99 * These statistics don't include packets not yet read from the 100 * kernel by libpcap or packets not yet read from libpcap by the 101 * application. 102 */ 103 *ps = pn->stat; 104 return (0); 105 } 106 107 static int 108 pcap_read_nit(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 109 { 110 struct pcap_nit *pn = p->priv; 111 register int cc, n; 112 register u_char *bp, *cp, *ep; 113 register struct nit_hdr *nh; 114 register int caplen; 115 116 cc = p->cc; 117 if (cc == 0) { 118 cc = read(p->fd, (char *)p->buffer, p->bufsize); 119 if (cc < 0) { 120 if (errno == EWOULDBLOCK) 121 return (0); 122 snprintf(p->errbuf, sizeof(p->errbuf), "pcap_read: %s", 123 pcap_strerror(errno)); 124 return (-1); 125 } 126 bp = p->buffer; 127 } else 128 bp = p->bp; 129 130 /* 131 * Loop through each packet. The increment expression 132 * rounds up to the next int boundary past the end of 133 * the previous packet. 134 */ 135 n = 0; 136 ep = bp + cc; 137 while (bp < ep) { 138 /* 139 * Has "pcap_breakloop()" been called? 140 * If so, return immediately - if we haven't read any 141 * packets, clear the flag and return -2 to indicate 142 * that we were told to break out of the loop, otherwise 143 * leave the flag set, so that the *next* call will break 144 * out of the loop without having read any packets, and 145 * return the number of packets we've processed so far. 146 */ 147 if (p->break_loop) { 148 if (n == 0) { 149 p->break_loop = 0; 150 return (-2); 151 } else { 152 p->cc = ep - bp; 153 p->bp = bp; 154 return (n); 155 } 156 } 157 158 nh = (struct nit_hdr *)bp; 159 cp = bp + sizeof(*nh); 160 161 switch (nh->nh_state) { 162 163 case NIT_CATCH: 164 break; 165 166 case NIT_NOMBUF: 167 case NIT_NOCLUSTER: 168 case NIT_NOSPACE: 169 pn->stat.ps_drop = nh->nh_dropped; 170 continue; 171 172 case NIT_SEQNO: 173 continue; 174 175 default: 176 snprintf(p->errbuf, sizeof(p->errbuf), 177 "bad nit state %d", nh->nh_state); 178 return (-1); 179 } 180 ++pn->stat.ps_recv; 181 bp += ((sizeof(struct nit_hdr) + nh->nh_datalen + 182 sizeof(int) - 1) & ~(sizeof(int) - 1)); 183 184 caplen = nh->nh_wirelen; 185 if (caplen > p->snapshot) 186 caplen = p->snapshot; 187 if (bpf_filter(p->fcode.bf_insns, cp, nh->nh_wirelen, caplen)) { 188 struct pcap_pkthdr h; 189 h.ts = nh->nh_timestamp; 190 h.len = nh->nh_wirelen; 191 h.caplen = caplen; 192 (*callback)(user, &h, cp); 193 if (++n >= cnt && !PACKET_COUNT_IS_UNLIMITED(cnt)) { 194 p->cc = ep - bp; 195 p->bp = bp; 196 return (n); 197 } 198 } 199 } 200 p->cc = 0; 201 return (n); 202 } 203 204 static int 205 pcap_inject_nit(pcap_t *p, const void *buf, size_t size) 206 { 207 struct sockaddr sa; 208 int ret; 209 210 memset(&sa, 0, sizeof(sa)); 211 strncpy(sa.sa_data, device, sizeof(sa.sa_data)); 212 ret = sendto(p->fd, buf, size, 0, &sa, sizeof(sa)); 213 if (ret == -1) { 214 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s", 215 pcap_strerror(errno)); 216 return (-1); 217 } 218 return (ret); 219 } 220 221 static int 222 nit_setflags(pcap_t *p) 223 { 224 struct nit_ioc nioc; 225 226 memset(&nioc, 0, sizeof(nioc)); 227 nioc.nioc_typetomatch = NT_ALLTYPES; 228 nioc.nioc_snaplen = p->snapshot; 229 nioc.nioc_bufalign = sizeof(int); 230 nioc.nioc_bufoffset = 0; 231 232 if (p->opt.buffer_size != 0) 233 nioc.nioc_bufspace = p->opt.buffer_size; 234 else { 235 /* Default buffer size */ 236 nioc.nioc_bufspace = BUFSPACE; 237 } 238 239 if (p->opt.immediate) { 240 /* 241 * XXX - will this cause packets to be delivered immediately? 242 * XXX - given that this is for SunOS prior to 4.0, do 243 * we care? 244 */ 245 nioc.nioc_chunksize = 0; 246 } else 247 nioc.nioc_chunksize = CHUNKSIZE; 248 if (p->opt.timeout != 0) { 249 nioc.nioc_flags |= NF_TIMEOUT; 250 nioc.nioc_timeout.tv_sec = p->opt.timeout / 1000; 251 nioc.nioc_timeout.tv_usec = (p->opt.timeout * 1000) % 1000000; 252 } 253 if (p->opt.promisc) 254 nioc.nioc_flags |= NF_PROMISC; 255 256 if (ioctl(p->fd, SIOCSNIT, &nioc) < 0) { 257 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "SIOCSNIT: %s", 258 pcap_strerror(errno)); 259 return (-1); 260 } 261 return (0); 262 } 263 264 static int 265 pcap_activate_nit(pcap_t *p) 266 { 267 int fd; 268 struct sockaddr_nit snit; 269 270 if (p->opt.rfmon) { 271 /* 272 * No monitor mode on SunOS 3.x or earlier (no 273 * Wi-Fi *devices* for the hardware that supported 274 * them!). 275 */ 276 return (PCAP_ERROR_RFMON_NOTSUP); 277 } 278 279 if (p->snapshot < 96) 280 /* 281 * NIT requires a snapshot length of at least 96. 282 */ 283 p->snapshot = 96; 284 285 memset(p, 0, sizeof(*p)); 286 p->fd = fd = socket(AF_NIT, SOCK_RAW, NITPROTO_RAW); 287 if (fd < 0) { 288 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 289 "socket: %s", pcap_strerror(errno)); 290 goto bad; 291 } 292 snit.snit_family = AF_NIT; 293 (void)strncpy(snit.snit_ifname, p->opt.source, NITIFSIZ); 294 295 if (bind(fd, (struct sockaddr *)&snit, sizeof(snit))) { 296 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 297 "bind: %s: %s", snit.snit_ifname, pcap_strerror(errno)); 298 goto bad; 299 } 300 if (nit_setflags(p) < 0) 301 goto bad; 302 303 /* 304 * NIT supports only ethernets. 305 */ 306 p->linktype = DLT_EN10MB; 307 308 p->bufsize = BUFSPACE; 309 p->buffer = (u_char *)malloc(p->bufsize); 310 if (p->buffer == NULL) { 311 strlcpy(p->errbuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE); 312 goto bad; 313 } 314 315 /* 316 * "p->fd" is a socket, so "select()" should work on it. 317 */ 318 p->selectable_fd = p->fd; 319 320 /* 321 * This is (presumably) a real Ethernet capture; give it a 322 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so 323 * that an application can let you choose it, in case you're 324 * capturing DOCSIS traffic that a Cisco Cable Modem 325 * Termination System is putting out onto an Ethernet (it 326 * doesn't put an Ethernet header onto the wire, it puts raw 327 * DOCSIS frames out on the wire inside the low-level 328 * Ethernet framing). 329 */ 330 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2); 331 /* 332 * If that fails, just leave the list empty. 333 */ 334 if (p->dlt_list != NULL) { 335 p->dlt_list[0] = DLT_EN10MB; 336 p->dlt_list[1] = DLT_DOCSIS; 337 p->dlt_count = 2; 338 } 339 340 p->read_op = pcap_read_nit; 341 p->inject_op = pcap_inject_nit; 342 p->setfilter_op = install_bpf_program; /* no kernel filtering */ 343 p->setdirection_op = NULL; /* Not implemented. */ 344 p->set_datalink_op = NULL; /* can't change data link type */ 345 p->getnonblock_op = pcap_getnonblock_fd; 346 p->setnonblock_op = pcap_setnonblock_fd; 347 p->stats_op = pcap_stats_nit; 348 349 return (0); 350 bad: 351 pcap_cleanup_live_common(p); 352 return (PCAP_ERROR); 353 } 354 355 pcap_t * 356 pcap_create_interface(const char *device, char *ebuf) 357 { 358 pcap_t *p; 359 360 p = pcap_create_common(device, ebuf, sizeof (struct pcap_nit)); 361 if (p == NULL) 362 return (NULL); 363 364 p->activate_op = pcap_activate_nit; 365 return (p); 366 } 367 368 int 369 pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf) 370 { 371 return (0); 372 } 373