freebsd-dev/contrib/libpcap/pcap-snoop.c

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/*
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* Copyright (c) 1993, 1994, 1995, 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
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static const char rcsid[] =
"@(#) $Header: /tcpdump/master/libpcap/pcap-snoop.c,v 1.33 2001/12/10 07:14:21 guy Exp $ (LBL)";
#endif
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <sys/param.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <net/raw.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/if_ether.h>
#include <netinet/ip_var.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netinet/tcp.h>
#include <netinet/tcpip.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "pcap-int.h"
#ifdef HAVE_OS_PROTO_H
#include "os-proto.h"
#endif
int
pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
int cc;
register struct snoopheader *sh;
register int datalen;
register int caplen;
register u_char *cp;
again:
cc = read(p->fd, (char *)p->buffer, p->bufsize);
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);
}
sh = (struct snoopheader *)p->buffer;
datalen = sh->snoop_packetlen;
caplen = (datalen < p->snapshot) ? datalen : p->snapshot;
cp = (u_char *)(sh + 1) + p->offset; /* XXX */
if (p->fcode.bf_insns == NULL ||
bpf_filter(p->fcode.bf_insns, cp, datalen, caplen)) {
struct pcap_pkthdr h;
++p->md.stat.ps_recv;
h.ts = sh->snoop_timestamp;
h.len = datalen;
h.caplen = caplen;
(*callback)(user, &h, cp);
return (1);
}
return (0);
}
int
pcap_stats(pcap_t *p, struct pcap_stat *ps)
{
register struct rawstats *rs;
struct rawstats rawstats;
rs = &rawstats;
memset(rs, 0, sizeof(*rs));
if (ioctl(p->fd, SIOCRAWSTATS, (char *)rs) < 0) {
snprintf(p->errbuf, sizeof(p->errbuf),
"SIOCRAWSTATS: %s", pcap_strerror(errno));
return (-1);
}
/*
* "ifdrops" are those dropped by the network interface
* due to resource shortages or hardware errors.
*
* "sbdrops" are those dropped due to socket buffer limits.
*
* As filter is done in userland, "sbdrops" counts packets
* regardless of whether they would've passed the filter.
*
* XXX - does this count *all* Snoop or Drain sockets,
* rather than just this socket? If not, why does it have
* both Snoop and Drain statistics?
*/
p->md.stat.ps_drop =
rs->rs_snoop.ss_ifdrops + rs->rs_snoop.ss_sbdrops +
rs->rs_drain.ds_ifdrops + rs->rs_drain.ds_sbdrops;
/*
* "ps_recv" counts only packets that passed the filter.
* As filtering is done in userland, this does not include
* packets dropped because we ran out of buffer space.
*/
*ps = p->md.stat;
return (0);
}
/* XXX can't disable promiscuous */
pcap_t *
pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf)
{
int fd;
struct sockaddr_raw sr;
struct snoopfilter sf;
u_int v;
int ll_hdrlen;
int snooplen;
pcap_t *p;
struct ifreq ifr;
p = (pcap_t *)malloc(sizeof(*p));
if (p == NULL) {
snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s",
pcap_strerror(errno));
return (NULL);
}
memset(p, 0, sizeof(*p));
fd = socket(PF_RAW, SOCK_RAW, RAWPROTO_SNOOP);
if (fd < 0) {
snprintf(ebuf, PCAP_ERRBUF_SIZE, "snoop socket: %s",
pcap_strerror(errno));
goto bad;
}
p->fd = fd;
memset(&sr, 0, sizeof(sr));
sr.sr_family = AF_RAW;
(void)strncpy(sr.sr_ifname, device, sizeof(sr.sr_ifname));
if (bind(fd, (struct sockaddr *)&sr, sizeof(sr))) {
snprintf(ebuf, PCAP_ERRBUF_SIZE, "snoop bind: %s",
pcap_strerror(errno));
goto bad;
}
memset(&sf, 0, sizeof(sf));
if (ioctl(fd, SIOCADDSNOOP, &sf) < 0) {
snprintf(ebuf, PCAP_ERRBUF_SIZE, "SIOCADDSNOOP: %s",
pcap_strerror(errno));
goto bad;
}
v = 64 * 1024;
(void)setsockopt(fd, SOL_SOCKET, SO_RCVBUF, (char *)&v, sizeof(v));
/*
* XXX hack - map device name to link layer type
*/
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if (strncmp("et", device, 2) == 0 || /* Challenge 10 Mbit */
strncmp("ec", device, 2) == 0 || /* Indigo/Indy 10 Mbit,
O2 10/100 */
strncmp("ef", device, 2) == 0 || /* O200/2000 10/100 Mbit */
strncmp("gfe", device, 3) == 0 || /* GIO 100 Mbit */
strncmp("fxp", device, 3) == 0 || /* Challenge VME Enet */
strncmp("ep", device, 2) == 0 || /* Challenge 8x10 Mbit EPLEX */
strncmp("vfe", device, 3) == 0 || /* Challenge VME 100Mbit */
strncmp("fa", device, 2) == 0 ||
strncmp("qaa", device, 3) == 0 ||
strncmp("cip", device, 3) == 0 ||
strncmp("el", device, 2) == 0) {
p->linktype = DLT_EN10MB;
p->offset = RAW_HDRPAD(sizeof(struct ether_header));
ll_hdrlen = sizeof(struct ether_header);
} else if (strncmp("ipg", device, 3) == 0 ||
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strncmp("rns", device, 3) == 0 || /* O2/200/2000 FDDI */
strncmp("xpi", device, 3) == 0) {
p->linktype = DLT_FDDI;
p->offset = 3; /* XXX yeah? */
ll_hdrlen = 13;
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} else if (strncmp("ppp", device, 3) == 0) {
p->linktype = DLT_RAW;
ll_hdrlen = 0; /* DLT_RAW meaning "no PPP header, just the IP packet"? */
} else if (strncmp("lo", device, 2) == 0) {
p->linktype = DLT_NULL;
ll_hdrlen = 4; /* is this just like BSD's loopback device? */
} else {
snprintf(ebuf, PCAP_ERRBUF_SIZE,
"snoop: unknown physical layer type");
goto bad;
}
#ifdef SIOCGIFMTU
/*
* XXX - IRIX appears to give you an error if you try to set the
* capture length to be greater than the MTU, so let's try to get
* the MTU first and, if that succeeds, trim the snap length
* to be no greater than the MTU.
*/
(void)strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
if (ioctl(fd, SIOCGIFMTU, (char *)&ifr) < 0) {
snprintf(ebuf, PCAP_ERRBUF_SIZE, "SIOCGIFMTU: %s",
pcap_strerror(errno));
goto bad;
}
/*
* OK, we got it.
*
* XXX - some versions of IRIX 6.5 define "ifr_mtu" and have an
* "ifru_metric" member of the "ifr_ifru" union in an "ifreq"
* structure, others don't.
*
* I've no idea what's going on, so, if "ifr_mtu" isn't defined,
* we define it as "ifr_metric", as using that field appears to
* work on the versions that lack "ifr_mtu" (and, on those that
* don't lack it, "ifru_metric" and "ifru_mtu" are both "int"
* members of the "ifr_ifru" union, which suggests that they
* may be interchangeable in this case).
*/
#ifndef ifr_mtu
#define ifr_mtu ifr_metric
#endif
if (snaplen > ifr.ifr_mtu)
snaplen = ifr.ifr_mtu;
#endif
/*
* The argument to SIOCSNOOPLEN is the number of link-layer
* payload bytes to capture - it doesn't count link-layer
* header bytes.
*/
snooplen = snaplen - ll_hdrlen;
if (snooplen < 0)
snooplen = 0;
if (ioctl(fd, SIOCSNOOPLEN, &snooplen) < 0) {
snprintf(ebuf, PCAP_ERRBUF_SIZE, "SIOCSNOOPLEN: %s",
pcap_strerror(errno));
goto bad;
}
p->snapshot = snaplen;
v = 1;
if (ioctl(fd, SIOCSNOOPING, &v) < 0) {
snprintf(ebuf, PCAP_ERRBUF_SIZE, "SIOCSNOOPING: %s",
pcap_strerror(errno));
goto bad;
}
p->bufsize = 4096; /* XXX */
p->buffer = (u_char *)malloc(p->bufsize);
if (p->buffer == NULL) {
snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s",
pcap_strerror(errno));
goto bad;
}
return (p);
bad:
(void)close(fd);
free(p);
return (NULL);
}
int
pcap_setfilter(pcap_t *p, struct bpf_program *fp)
{
if (install_bpf_program(p, fp) < 0)
return (-1);
return (0);
}