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mirror of https://git.FreeBSD.org/src.git synced 2024-12-24 11:29:10 +00:00
freebsd/lib/libpcap/pcap-bpf.c
1995-01-20 04:13:07 +00:00

234 lines
5.5 KiB
C

/*
* Copyright (c) 1993, 1994
* 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 char rcsid[] =
"@(#)$Header: pcap-bpf.c,v 1.14 94/06/03 19:58:49 leres Exp $ (LBL)";
#endif
#include <stdio.h>
#include <netdb.h>
#include <ctype.h>
#include <signal.h>
#include <errno.h>
#include <sys/param.h> /* optionally get BSD define */
#include <sys/time.h>
#include <sys/timeb.h>
#include <sys/socket.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <net/bpf.h>
#include <net/if.h>
#include <string.h>
#include "pcap-int.h"
int
pcap_stats(pcap_t *p, struct pcap_stat *ps)
{
struct bpf_stat s;
if (ioctl(p->fd, BIOCGSTATS, &s) < 0) {
sprintf(p->errbuf, "BIOCGSTATS: %s", pcap_strerror(errno));
return (-1);
}
ps->ps_recv = s.bs_recv;
ps->ps_drop = s.bs_drop;
return (0);
}
int
pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
int cc;
int n = 0;
register u_char *bp, *ep;
again:
cc = p->cc;
if (p->cc == 0) {
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);
#if defined(sun) && !defined(BSD)
/*
* Due to a SunOS bug, after 2^31 bytes, the kernel
* file offset overflows and read fails with EINVAL.
* The lseek() to 0 will fix things.
*/
case EINVAL:
if ((long)(tell(p->fd) + p->bufsize) < 0) {
(void)lseek(p->fd, 0, 0);
goto again;
}
/* fall through */
#endif
}
sprintf(p->errbuf, "read: %s", pcap_strerror(errno));
return (-1);
}
bp = p->buffer;
} else
bp = p->bp;
/*
* Loop through each packet.
*/
#define bhp ((struct bpf_hdr *)bp)
ep = bp + cc;
while (bp < ep) {
register int caplen, hdrlen;
caplen = bhp->bh_caplen;
hdrlen = bhp->bh_hdrlen;
/*
* XXX A bpf_hdr matches a pcap_pkthdr.
*/
(*callback)(user, (struct pcap_pkthdr*)bp, bp + hdrlen);
bp += BPF_WORDALIGN(caplen + hdrlen);
if (++n >= cnt && cnt > 0) {
p->bp = bp;
p->cc = ep - bp;
return (n);
}
}
#undef bhp
p->cc = 0;
return (n);
}
static inline int
bpf_open(pcap_t *p, char *errbuf)
{
int fd;
int n = 0;
char device[sizeof "/dev/bpf000"];
/*
* Go through all the minors and find one that isn't in use.
*/
do {
(void)sprintf(device, "/dev/bpf%d", n++);
fd = open(device, O_RDONLY);
} while (fd < 0 && errno == EBUSY);
/*
* XXX better message for all minors used
*/
if (fd < 0)
sprintf(errbuf, "%s: %s", device, pcap_strerror(errno));
return (fd);
}
pcap_t *
pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf)
{
int fd;
struct ifreq ifr;
struct bpf_version bv;
u_int v;
pcap_t *p;
p = (pcap_t *)malloc(sizeof(*p));
if (p == NULL) {
sprintf(ebuf, "malloc: %s", pcap_strerror(errno));
return (NULL);
}
bzero(p, sizeof(*p));
fd = bpf_open(p, ebuf);
if (fd < 0)
goto bad;
p->fd = fd;
p->snapshot = snaplen;
if (ioctl(fd, BIOCVERSION, (caddr_t)&bv) < 0) {
sprintf(ebuf, "BIOCVERSION: %s", pcap_strerror(errno));
goto bad;
}
if (bv.bv_major != BPF_MAJOR_VERSION ||
bv.bv_minor < BPF_MINOR_VERSION) {
sprintf(ebuf, "kernel bpf filter out of date");
goto bad;
}
(void)strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) {
sprintf(ebuf, "%s: %s", device, pcap_strerror(errno));
goto bad;
}
/* Get the data link layer type. */
if (ioctl(fd, BIOCGDLT, (caddr_t)&v) < 0) {
sprintf(ebuf, "BIOCGDLT: %s", pcap_strerror(errno));
goto bad;
}
p->linktype = v;
/* set timeout */
if (to_ms != 0) {
struct timeval to;
to.tv_sec = to_ms / 1000;
to.tv_usec = (to_ms * 1000) % 1000000;
if (ioctl(p->fd, BIOCSRTIMEOUT, (caddr_t)&to) < 0) {
sprintf(ebuf, "BIOCSRTIMEOUT: %s",
pcap_strerror(errno));
goto bad;
}
}
if (promisc)
/* set promiscuous mode, okay if it fails */
(void)ioctl(p->fd, BIOCPROMISC, NULL);
if (ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) {
sprintf(ebuf, "BIOCGBLEN: %s", pcap_strerror(errno));
goto bad;
}
p->bufsize = v;
p->buffer = (u_char*)malloc(p->bufsize);
if (p->buffer == NULL) {
sprintf(ebuf, "malloc: %s", pcap_strerror(errno));
goto bad;
}
return (p);
bad:
free(p);
return (NULL);
}
int
pcap_setfilter(pcap_t *p, struct bpf_program *fp)
{
if (p->sf.rfile != NULL)
p->fcode = *fp;
else if (ioctl(p->fd, BIOCSETF, (caddr_t)fp) < 0) {
sprintf(p->errbuf, "BIOCSETF: %s", pcap_strerror(errno));
return (-1);
}
return (0);
}