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[] = 28 "@(#) $Header: /tcpdump/master/libpcap/pcap-snit.c,v 1.56 2001/12/10 07:14:20 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 int 88 pcap_stats(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 int 113 pcap_read(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 ++p->md.stat.ps_recv; 145 cp = bp; 146 147 /* get past NIT buffer */ 148 hdrp = (struct nit_bufhdr *)cp; 149 cp += sizeof(*hdrp); 150 151 /* get past NIT timer */ 152 ntp = (struct nit_iftime *)cp; 153 cp += sizeof(*ntp); 154 155 ndp = (struct nit_ifdrops *)cp; 156 p->md.stat.ps_drop = ndp->nh_drops; 157 cp += sizeof *ndp; 158 159 /* get past packet len */ 160 nlp = (struct nit_iflen *)cp; 161 cp += sizeof(*nlp); 162 163 /* next snapshot */ 164 bp += hdrp->nhb_totlen; 165 166 caplen = nlp->nh_pktlen; 167 if (caplen > p->snapshot) 168 caplen = p->snapshot; 169 170 if (bpf_filter(fcode, cp, nlp->nh_pktlen, caplen)) { 171 struct pcap_pkthdr h; 172 h.ts = ntp->nh_timestamp; 173 h.len = nlp->nh_pktlen; 174 h.caplen = caplen; 175 (*callback)(user, &h, cp); 176 if (++n >= cnt && cnt >= 0) { 177 p->cc = ep - bp; 178 p->bp = bp; 179 return (n); 180 } 181 } 182 } 183 p->cc = 0; 184 return (n); 185 } 186 187 static int 188 nit_setflags(int fd, int promisc, int to_ms, char *ebuf) 189 { 190 bpf_u_int32 flags; 191 struct strioctl si; 192 struct timeval timeout; 193 194 si.ic_timout = INFTIM; 195 if (to_ms != 0) { 196 timeout.tv_sec = to_ms / 1000; 197 timeout.tv_usec = (to_ms * 1000) % 1000000; 198 si.ic_cmd = NIOCSTIME; 199 si.ic_len = sizeof(timeout); 200 si.ic_dp = (char *)&timeout; 201 if (ioctl(fd, I_STR, (char *)&si) < 0) { 202 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSTIME: %s", 203 pcap_strerror(errno)); 204 return (-1); 205 } 206 } 207 flags = NI_TIMESTAMP | NI_LEN | NI_DROPS; 208 if (promisc) 209 flags |= NI_PROMISC; 210 si.ic_cmd = NIOCSFLAGS; 211 si.ic_len = sizeof(flags); 212 si.ic_dp = (char *)&flags; 213 if (ioctl(fd, I_STR, (char *)&si) < 0) { 214 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSFLAGS: %s", 215 pcap_strerror(errno)); 216 return (-1); 217 } 218 return (0); 219 } 220 221 pcap_t * 222 pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf) 223 { 224 struct strioctl si; /* struct for ioctl() */ 225 struct ifreq ifr; /* interface request struct */ 226 int chunksize = CHUNKSIZE; 227 int fd; 228 static char dev[] = "/dev/nit"; 229 register pcap_t *p; 230 231 p = (pcap_t *)malloc(sizeof(*p)); 232 if (p == NULL) { 233 strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE); 234 return (NULL); 235 } 236 237 if (snaplen < 96) 238 /* 239 * NIT requires a snapshot length of at least 96. 240 */ 241 snaplen = 96; 242 243 memset(p, 0, sizeof(*p)); 244 p->fd = fd = open(dev, O_RDONLY); 245 if (fd < 0) { 246 snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s: %s", dev, 247 pcap_strerror(errno)); 248 goto bad; 249 } 250 251 /* arrange to get discrete messages from the STREAM and use NIT_BUF */ 252 if (ioctl(fd, I_SRDOPT, (char *)RMSGD) < 0) { 253 snprintf(ebuf, PCAP_ERRBUF_SIZE, "I_SRDOPT: %s", 254 pcap_strerror(errno)); 255 goto bad; 256 } 257 if (ioctl(fd, I_PUSH, "nbuf") < 0) { 258 snprintf(ebuf, PCAP_ERRBUF_SIZE, "push nbuf: %s", 259 pcap_strerror(errno)); 260 goto bad; 261 } 262 /* set the chunksize */ 263 si.ic_cmd = NIOCSCHUNK; 264 si.ic_timout = INFTIM; 265 si.ic_len = sizeof(chunksize); 266 si.ic_dp = (char *)&chunksize; 267 if (ioctl(fd, I_STR, (char *)&si) < 0) { 268 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSCHUNK: %s", 269 pcap_strerror(errno)); 270 goto bad; 271 } 272 273 /* request the interface */ 274 strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name)); 275 ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = ' '; 276 si.ic_cmd = NIOCBIND; 277 si.ic_len = sizeof(ifr); 278 si.ic_dp = (char *)𝔦 279 if (ioctl(fd, I_STR, (char *)&si) < 0) { 280 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCBIND: %s: %s", 281 ifr.ifr_name, pcap_strerror(errno)); 282 goto bad; 283 } 284 285 /* set the snapshot length */ 286 si.ic_cmd = NIOCSSNAP; 287 si.ic_len = sizeof(snaplen); 288 si.ic_dp = (char *)&snaplen; 289 if (ioctl(fd, I_STR, (char *)&si) < 0) { 290 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSSNAP: %s", 291 pcap_strerror(errno)); 292 goto bad; 293 } 294 p->snapshot = snaplen; 295 if (nit_setflags(p->fd, promisc, to_ms, ebuf) < 0) 296 goto bad; 297 298 (void)ioctl(fd, I_FLUSH, (char *)FLUSHR); 299 /* 300 * NIT supports only ethernets. 301 */ 302 p->linktype = DLT_EN10MB; 303 304 p->bufsize = BUFSPACE; 305 p->buffer = (u_char *)malloc(p->bufsize); 306 if (p->buffer == NULL) { 307 strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE); 308 goto bad; 309 } 310 return (p); 311 bad: 312 if (fd >= 0) 313 close(fd); 314 free(p); 315 return (NULL); 316 } 317 318 int 319 pcap_setfilter(pcap_t *p, struct bpf_program *fp) 320 { 321 322 if (install_bpf_program(p, fp) < 0) 323 return (-1); 324 return (0); 325 } 326