The Tcpdump Group git mirrors - libpcap/blob - pcap-snit.c

   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 1.49 2000-07-01 03:35:07 assar Exp $ (LBL)";
  29 #endif
  30
  31 #include <sys/types.h>
  32 #include <sys/time.h>
  33 #include <sys/timeb.h>
  34 #include <sys/dir.h>
  35 #include <sys/fcntlcom.h>
  36 #include <sys/file.h>
  37 #include <sys/ioctl.h>
  38 #include <sys/socket.h>
  39 #include <sys/stropts.h>
  40
  41 #include <net/if.h>
  42 #include <net/nit.h>
  43 #include <net/nit_if.h>
  44 #include <net/nit_pf.h>
  45 #include <net/nit_buf.h>
  46
  47 #include <netinet/in.h>
  48 #include <netinet/in_systm.h>
  49 #include <netinet/ip.h>
  50 #include <netinet/if_ether.h>
  51 #include <netinet/ip_var.h>
  52 #include <netinet/udp.h>
  53 #include <netinet/udp_var.h>
  54 #include <netinet/tcp.h>
  55 #include <netinet/tcpip.h>
  56
  57 #include <ctype.h>
  58 #include <errno.h>
  59 #include <stdio.h>
  60 #include <string.h>
  61 #include <unistd.h>
  62
  63 #include "pcap-int.h"
  64
  65 #include "gnuc.h"
  66 #ifdef HAVE_OS_PROTO_H
  67 #include "os-proto.h"
  68 #endif
  69
  70 /*
  71  * The chunk size for NIT.  This is the amount of buffering
  72  * done for read calls.
  73  */
  74 #define CHUNKSIZE (2*1024)
  75
  76 /*
  77  * The total buffer space used by NIT.
  78  */
  79 #define BUFSPACE (4*CHUNKSIZE)
  80
  81 /* Forwards */
  82 static int nit_setflags(int, int, int, char *);
  83
  84 int
  85 pcap_stats(pcap_t *p, struct pcap_stat *ps)
  86 {
  87
  88         *ps = p->md.stat;
  89         return (0);
  90 }
  91
  92 int
  93 pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
  94 {
  95         register int cc, n;
  96         register struct bpf_insn *fcode = p->fcode.bf_insns;
  97         register u_char *bp, *cp, *ep;
  98         register struct nit_bufhdr *hdrp;
  99         register struct nit_iftime *ntp;
 100         register struct nit_iflen *nlp;
 101         register struct nit_ifdrops *ndp;
 102         register int caplen;
 103
 104         cc = p->cc;
 105         if (cc == 0) {
 106                 cc = read(p->fd, (char *)p->buffer, p->bufsize);
 107                 if (cc < 0) {
 108                         if (errno == EWOULDBLOCK)
 109                                 return (0);
 110                         snprintf(p->errbuf, sizeof(p->errbuf), "pcap_read: %s",
 111                                 pcap_strerror(errno));
 112                         return (-1);
 113                 }
 114                 bp = p->buffer;
 115         } else
 116                 bp = p->bp;
 117
 118         /*
 119          * loop through each snapshot in the chunk
 120          */
 121         n = 0;
 122         ep = bp + cc;
 123         while (bp < ep) {
 124                 ++p->md.stat.ps_recv;
 125                 cp = bp;
 126
 127                 /* get past NIT buffer  */
 128                 hdrp = (struct nit_bufhdr *)cp;
 129                 cp += sizeof(*hdrp);
 130
 131                 /* get past NIT timer   */
 132                 ntp = (struct nit_iftime *)cp;
 133                 cp += sizeof(*ntp);
 134
 135                 ndp = (struct nit_ifdrops *)cp;
 136                 p->md.stat.ps_drop = ndp->nh_drops;
 137                 cp += sizeof *ndp;
 138
 139                 /* get past packet len  */
 140                 nlp = (struct nit_iflen *)cp;
 141                 cp += sizeof(*nlp);
 142
 143                 /* next snapshot        */
 144                 bp += hdrp->nhb_totlen;
 145
 146                 caplen = nlp->nh_pktlen;
 147                 if (caplen > p->snapshot)
 148                         caplen = p->snapshot;
 149
 150                 if (bpf_filter(fcode, cp, nlp->nh_pktlen, caplen)) {
 151                         struct pcap_pkthdr h;
 152                         h.ts = ntp->nh_timestamp;
 153                         h.len = nlp->nh_pktlen;
 154                         h.caplen = caplen;
 155                         (*callback)(user, &h, cp);
 156                         if (++n >= cnt && cnt >= 0) {
 157                                 p->cc = ep - bp;
 158                                 p->bp = bp;
 159                                 return (n);
 160                         }
 161                 }
 162         }
 163         p->cc = 0;
 164         return (n);
 165 }
 166
 167 static int
 168 nit_setflags(int fd, int promisc, int to_ms, char *ebuf)
 169 {
 170         bpf_u_int32 flags;
 171         struct strioctl si;
 172         struct timeval timeout;
 173
 174         si.ic_timout = INFTIM;
 175         if (to_ms != 0) {
 176                 timeout.tv_sec = to_ms / 1000;
 177                 timeout.tv_usec = (to_ms * 1000) % 1000000;
 178                 si.ic_cmd = NIOCSTIME;
 179                 si.ic_len = sizeof(timeout);
 180                 si.ic_dp = (char *)&timeout;
 181                 if (ioctl(fd, I_STR, (char *)&si) < 0) {
 182                         snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSTIME: %s",
 183                             pcap_strerror(errno));
 184                         return (-1);
 185                 }
 186         }
 187         flags = NI_TIMESTAMP | NI_LEN | NI_DROPS;
 188         if (promisc)
 189                 flags |= NI_PROMISC;
 190         si.ic_cmd = NIOCSFLAGS;
 191         si.ic_len = sizeof(flags);
 192         si.ic_dp = (char *)&flags;
 193         if (ioctl(fd, I_STR, (char *)&si) < 0) {
 194                 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSFLAGS: %s",
 195                     pcap_strerror(errno));
 196                 return (-1);
 197         }
 198         return (0);
 199 }
 200
 201 pcap_t *
 202 pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf)
 203 {
 204         struct strioctl si;             /* struct for ioctl() */
 205         struct ifreq ifr;               /* interface request struct */
 206         int chunksize = CHUNKSIZE;
 207         int fd;
 208         static char dev[] = "/dev/nit";
 209         register pcap_t *p;
 210
 211         p = (pcap_t *)malloc(sizeof(*p));
 212         if (p == NULL) {
 213                 strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
 214                 return (NULL);
 215         }
 216
 217         if (snaplen < 96)
 218                 /*
 219                  * NIT requires a snapshot length of at least 96.
 220                  */
 221                 snaplen = 96;
 222
 223         bzero(p, sizeof(*p));
 224         p->fd = fd = open(dev, O_RDONLY);
 225         if (fd < 0) {
 226                 snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s: %s", dev,
 227                     pcap_strerror(errno));
 228                 goto bad;
 229         }
 230
 231         /* arrange to get discrete messages from the STREAM and use NIT_BUF */
 232         if (ioctl(fd, I_SRDOPT, (char *)RMSGD) < 0) {
 233                 snprintf(ebuf, PCAP_ERRBUF_SIZE, "I_SRDOPT: %s",
 234                     pcap_strerror(errno));
 235                 goto bad;
 236         }
 237         if (ioctl(fd, I_PUSH, "nbuf") < 0) {
 238                 snprintf(ebuf, PCAP_ERRBUF_SIZE, "push nbuf: %s",
 239                     pcap_strerror(errno));
 240                 goto bad;
 241         }
 242         /* set the chunksize */
 243         si.ic_cmd = NIOCSCHUNK;
 244         si.ic_timout = INFTIM;
 245         si.ic_len = sizeof(chunksize);
 246         si.ic_dp = (char *)&chunksize;
 247         if (ioctl(fd, I_STR, (char *)&si) < 0) {
 248                 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSCHUNK: %s",
 249                     pcap_strerror(errno));
 250                 goto bad;
 251         }
 252
 253         /* request the interface */
 254         strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
 255         ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = ' ';
 256         si.ic_cmd = NIOCBIND;
 257         si.ic_len = sizeof(ifr);
 258         si.ic_dp = (char *)&ifr;
 259         if (ioctl(fd, I_STR, (char *)&si) < 0) {
 260                 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCBIND: %s: %s",
 261                         ifr.ifr_name, pcap_strerror(errno));
 262                 goto bad;
 263         }
 264
 265         /* set the snapshot length */
 266         si.ic_cmd = NIOCSSNAP;
 267         si.ic_len = sizeof(snaplen);
 268         si.ic_dp = (char *)&snaplen;
 269         if (ioctl(fd, I_STR, (char *)&si) < 0) {
 270                 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSSNAP: %s",
 271                     pcap_strerror(errno));
 272                 goto bad;
 273         }
 274         p->snapshot = snaplen;
 275         if (nit_setflags(p->fd, promisc, to_ms, ebuf) < 0)
 276                 goto bad;
 277
 278         (void)ioctl(fd, I_FLUSH, (char *)FLUSHR);
 279         /*
 280          * NIT supports only ethernets.
 281          */
 282         p->linktype = DLT_EN10MB;
 283
 284         p->bufsize = BUFSPACE;
 285         p->buffer = (u_char *)malloc(p->bufsize);
 286         if (p->buffer == NULL) {
 287                 strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
 288                 goto bad;
 289         }
 290         return (p);
 291  bad:
 292         if (fd >= 0)
 293                 close(fd);
 294         free(p);
 295         return (NULL);
 296 }
 297
 298 int
 299 pcap_setfilter(pcap_t *p, struct bpf_program *fp)
 300 {
 301
 302         p->fcode = *fp;
 303         return (0);
 304 }