| /* |
| * 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 1.18 2000-04-27 14:24:12 itojun Exp $ (LBL)"; |
| #endif |
| |
| #include <sys/param.h> |
| #include <sys/ioctl.h> |
| #include <sys/socket.h> |
| #include <sys/time.h> |
| |
| #include <net/if.h> |
| #ifdef HAVE_NET_IF_ARP_H |
| #include <net/if_arp.h> |
| #else |
| #include <linux/if_arp.h> |
| #endif |
| #include <linux/if_ether.h> |
| |
| #include <netinet/in.h> |
| |
| #include <errno.h> |
| #include <malloc.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <unistd.h> |
| |
| 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 */ |
| } |
| snprintf(p->errbuf, sizeof(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) { |
| snprintf(p->errbuf, sizeof(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) { |
| snprint(ebuf, PCAP_ERRBUF_SIZE, PCAP_ERRBUF_SIZE, |
| "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) { |
| snprint(ebuf, PCAP_ERRBUF_SIZE, "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))) { |
| snprint(ebuf, PCAP_ERRBUF_SIZE, "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 ) { |
| snprint(ebuf, PCAP_ERRBUF_SIZE, "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: |
| snprint(ebuf, PCAP_ERRBUF_SIZE, |
| "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 ) { |
| snprint(ebuf, PCAP_ERRBUF_SIZE, "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) { |
| snprint(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s", |
| pcap_strerror(errno)); |
| goto bad; |
| } |
| |
| /* XXX */ |
| if (promisc && broadcast) { |
| memset(&ifr, 0, sizeof(ifr)); |
| strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name)); |
| if (ioctl(p->fd, SIOCGIFFLAGS, &ifr) < 0 ) { |
| snprint(ebuf, PCAP_ERRBUF_SIZE, "SIOCGIFFLAGS: %s", |
| pcap_strerror(errno)); |
| goto bad; |
| } |
| saved_ifr = ifr; |
| ifr.ifr_flags |= IFF_PROMISC; |
| if (ioctl(p->fd, SIOCSIFFLAGS, &ifr) < 0 ) { |
| snprint(ebuf, PCAP_ERRBUF_SIZE, "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) { |
| snprint(ebuf, PCAP_ERRBUF_SIZE, "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)); |
| } |