pcap-linux.c
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上传日期:2021-02-23
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- /*
- * 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: /usr/local/cvs/nessus-libraries/libpcap-nessus/pcap-linux.c,v 1.5 2003/03/07 00:57:40 renaud 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
- #define TIMEVAL_SUBTRACT(a,b) ((a.tv_sec - b.tv_sec) * 1000000 + a.tv_usec - b.tv_usec)
- static int timeout;
- 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;
- fd_set fd_r;
- struct timeval select_time, start, now, tmp;
- int res;
- fromlen = sizeof(from);
- select_time.tv_sec = timeout / 1000;
- select_time.tv_usec = (timeout % 1000) * 1000;
- gettimeofday(&start, NULL);
- do {
- FD_ZERO(&fd_r);
- FD_SET(p->fd, &fd_r );
- bp = p->buffer + p->offset;
- bufsize = p->bufsize - p->offset;
- if (p->md.pad > 0) {
- memset(bp, 0, p->md.pad);
- bp += p->md.pad;
- bufsize -= p->md.pad;
- }
- tmp = select_time; /* Because linux mucks with the timeout in select() */
- res = select(p->fd+1, &fd_r, NULL, NULL, &tmp);
- if (res < 0) {
- sprintf(p->errbuf, "select: %s", pcap_strerror(errno));
- return (-1);
- } else if (res > 0) {
- fromlen = sizeof(from);
- while ((cc = recvfrom(p->fd, bp, bufsize, 0, &from, &fromlen)) < 0) {
- /* Don't choke when we get ptraced */
- if (errno != EINTR && errno != EAGAIN) {
- sprintf(p->errbuf, "read: %s", pcap_strerror(errno));
- return (-1);
- }
- }
-
- if (!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);
- }
- }
- }
- gettimeofday(&now, NULL);
- } while((timeout == 0 && res) || (TIMEVAL_SUBTRACT(now,start) < timeout * 1000));
- 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;
- timeout = to_ms;
- 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;
-
- #if defined(ARPHRD_IEEE802_TR) && defined(DLT_IEEE802)
- case ARPHRD_IEEE802_TR:
- p->linktype = DLT_IEEE802;
- ++broadcast;
- break;
- #endif
- 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));
- }