/* * Copyright (c) 1996, 1997 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that: (1) source code distributions * retain the above copyright notice and this paragraph in its entirety, (2) * distributions including binary code include the above copyright notice and * this paragraph in its entirety in the documentation or other materials * provided with the distribution, and (3) all advertising materials mentioning * features or use of this software display the following acknowledgement: * ``This product includes software developed by the University of California, * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of * the University nor the names of its contributors may be used to endorse * or promote products derived from this software without specific prior * written permission. * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. */ #ifndef lint static const char rcsid[] = "@(#) $Header: /tcpdump/master/libpcap/pcap-linux.c,v 1.15.1.1 1999/10/07 23:46:40 mcr Exp $ (LBL)"; #endif #include #include #include #include #include #ifdef HAVE_NET_IF_ARP_H #include #else #include #endif #include #include #include #include #include #include #include #include static struct ifreq saved_ifr; #include "pcap-int.h" #include "gnuc.h" #ifdef HAVE_OS_PROTO_H #include "os-proto.h" #endif void linux_restore_ifr(void); int pcap_stats(pcap_t *p, struct pcap_stat *ps) { *ps = p->md.stat; return (0); } int pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user) { register int cc; register int bufsize; register int caplen; register u_char *bp; struct sockaddr from; int fromlen; bp = p->buffer + p->offset; bufsize = p->bufsize; if (p->md.pad > 0) { memset(bp, 0, p->md.pad); bp += p->md.pad; bufsize -= p->md.pad; } again: do { fromlen = sizeof(from); cc = recvfrom(p->fd, bp, bufsize, 0, &from, &fromlen); if (cc < 0) { /* Don't choke when we get ptraced */ switch (errno) { case EINTR: goto again; case EWOULDBLOCK: return (0); /* XXX */ } sprintf(p->errbuf, "read: %s", pcap_strerror(errno)); return (-1); } } while (strcmp(p->md.device, from.sa_data)); /* If we need have leading zero bytes, adjust count */ cc += p->md.pad; bp = p->buffer + p->offset; /* If we need to step over leading junk, adjust count and pointer */ cc -= p->md.skip; bp += p->md.skip; /* Captured length can't exceed our read buffer size */ caplen = cc; if (caplen > bufsize) caplen = bufsize; /* Captured length can't exceed the snapshot length */ if (caplen > p->snapshot) caplen = p->snapshot; if (p->fcode.bf_insns == NULL || bpf_filter(p->fcode.bf_insns, bp, cc, caplen)) { struct pcap_pkthdr h; ++p->md.stat.ps_recv; /* Get timestamp */ if (ioctl(p->fd, SIOCGSTAMP, &h.ts) < 0) { sprintf(p->errbuf, "SIOCGSTAMP: %s", pcap_strerror(errno)); return (-1); } h.len = cc; h.caplen = caplen; (*callback)(user, &h, bp); return (1); } return (0); } pcap_t * pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf) { register int fd, broadcast; register pcap_t *p; struct ifreq ifr; struct sockaddr sa; p = (pcap_t *)malloc(sizeof(*p)); if (p == NULL) { sprintf(ebuf, "malloc: %s", pcap_strerror(errno)); return (NULL); } memset(p, 0, sizeof(*p)); fd = -1; fd = socket(PF_INET, SOCK_PACKET, htons(ETH_P_ALL)); if (fd < 0) { sprintf(ebuf, "socket: %s", pcap_strerror(errno)); goto bad; } p->fd = fd; /* Bind to the interface name */ memset(&sa, 0, sizeof(sa)); sa.sa_family = AF_INET; (void)strncpy(sa.sa_data, device, sizeof(sa.sa_data)); if (bind(p->fd, &sa, sizeof(sa))) { sprintf(ebuf, "bind: %s: %s", device, pcap_strerror(errno)); goto bad; } memset(&ifr, 0, sizeof(ifr)); strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name)); if (ioctl(p->fd, SIOCGIFHWADDR, &ifr) < 0 ) { sprintf(ebuf, "SIOCGIFHWADDR: %s", pcap_strerror(errno)); goto bad; } broadcast = 0; switch (ifr.ifr_hwaddr.sa_family) { case ARPHRD_ETHER: case ARPHRD_METRICOM: p->linktype = DLT_EN10MB; p->offset = 2; ++broadcast; break; case ARPHRD_EETHER: p->linktype = DLT_EN3MB; ++broadcast; break; case ARPHRD_AX25: p->linktype = DLT_AX25; ++broadcast; break; case ARPHRD_PRONET: p->linktype = DLT_PRONET; break; case ARPHRD_CHAOS: p->linktype = DLT_CHAOS; break; case ARPHRD_IEEE802: p->linktype = DLT_IEEE802; ++broadcast; break; case ARPHRD_ARCNET: p->linktype = DLT_ARCNET; ++broadcast; break; case ARPHRD_SLIP: case ARPHRD_CSLIP: case ARPHRD_SLIP6: case ARPHRD_CSLIP6: case ARPHRD_PPP: p->linktype = DLT_RAW; break; case ARPHRD_LOOPBACK: p->linktype = DLT_NULL; p->md.pad = 2; p->md.skip = 12; break; #ifdef ARPHRD_FDDI /* Not all versions of the kernel has this define */ case ARPHRD_FDDI: p->linktype = DLT_FDDI; ++broadcast; break; #endif #ifdef notdef case ARPHRD_LOCALTLK: case ARPHRD_NETROM: case ARPHRD_APPLETLK: case ARPHRD_DLCI: case ARPHRD_RSRVD: case ARPHRD_ADAPT: case ARPHRD_TUNNEL: case ARPHRD_TUNNEL6: case ARPHRD_FRAD: case ARPHRD_SKIP: /* XXX currently do not know what to do with these... */ abort(); #endif default: sprintf(ebuf, "unknown physical layer type 0x%x", ifr.ifr_hwaddr.sa_family); goto bad; } /* Base the buffer size on the interface MTU */ memset(&ifr, 0, sizeof(ifr)); strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name)); if (ioctl(p->fd, SIOCGIFMTU, &ifr) < 0 ) { sprintf(ebuf, "SIOCGIFMTU: %s", pcap_strerror(errno)); goto bad; } /* Leave room for link header (which is never large under linux...) */ p->bufsize = ifr.ifr_mtu + 64; p->buffer = (u_char *)malloc(p->bufsize + p->offset); if (p->buffer == NULL) { sprintf(ebuf, "malloc: %s", pcap_strerror(errno)); goto bad; } /* XXX */ if (promisc && broadcast) { memset(&ifr, 0, sizeof(ifr)); strcpy(ifr.ifr_name, device); if (ioctl(p->fd, SIOCGIFFLAGS, &ifr) < 0 ) { sprintf(ebuf, "SIOCGIFFLAGS: %s", pcap_strerror(errno)); goto bad; } saved_ifr = ifr; ifr.ifr_flags |= IFF_PROMISC; if (ioctl(p->fd, SIOCSIFFLAGS, &ifr) < 0 ) { sprintf(ebuf, "SIOCSIFFLAGS: %s", pcap_strerror(errno)); goto bad; } ifr.ifr_flags &= ~IFF_PROMISC; atexit(linux_restore_ifr); } p->md.device = strdup(device); if (p->md.device == NULL) { sprintf(ebuf, "malloc: %s", pcap_strerror(errno)); goto bad; } p->snapshot = snaplen; return (p); bad: if (fd >= 0) (void)close(fd); if (p->buffer != NULL) free(p->buffer); if (p->md.device != NULL) free(p->md.device); free(p); return (NULL); } int pcap_setfilter(pcap_t *p, struct bpf_program *fp) { p->fcode = *fp; return (0); } void linux_restore_ifr(void) { register int fd; fd = socket(PF_INET, SOCK_PACKET, htons(0x0003)); if (fd < 0) fprintf(stderr, "linux socket: %s", pcap_strerror(errno)); else if (ioctl(fd, SIOCSIFFLAGS, &saved_ifr) < 0) fprintf(stderr, "linux SIOCSIFFLAGS: %s", pcap_strerror(errno)); }