freebsd-dev/contrib/libpcap/pcap.c

288 lines
6.1 KiB
C

/*
* Copyright (c) 1993, 1994, 1995, 1996, 1997, 1998
* 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 the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the Computer Systems
* Engineering Group at Lawrence Berkeley Laboratory.
* 4. Neither the name of the University nor of the Laboratory may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static const char rcsid[] =
"@(#) $Header: /tcpdump/master/libpcap/pcap.c,v 1.38 2001/12/29 21:55:32 guy Exp $ (LBL)";
#endif
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#ifdef HAVE_OS_PROTO_H
#include "os-proto.h"
#endif
#include "pcap-int.h"
int
pcap_dispatch(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
if (p->sf.rfile != NULL)
return (pcap_offline_read(p, cnt, callback, user));
return (pcap_read(p, cnt, callback, user));
}
int
pcap_loop(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
register int n;
for (;;) {
if (p->sf.rfile != NULL)
n = pcap_offline_read(p, cnt, callback, user);
else {
/*
* XXX keep reading until we get something
* (or an error occurs)
*/
do {
n = pcap_read(p, cnt, callback, user);
} while (n == 0);
}
if (n <= 0)
return (n);
if (cnt > 0) {
cnt -= n;
if (cnt <= 0)
return (0);
}
}
}
struct singleton {
struct pcap_pkthdr *hdr;
const u_char *pkt;
};
static void
pcap_oneshot(u_char *userData, const struct pcap_pkthdr *h, const u_char *pkt)
{
struct singleton *sp = (struct singleton *)userData;
*sp->hdr = *h;
sp->pkt = pkt;
}
const u_char *
pcap_next(pcap_t *p, struct pcap_pkthdr *h)
{
struct singleton s;
s.hdr = h;
if (pcap_dispatch(p, 1, pcap_oneshot, (u_char*)&s) <= 0)
return (0);
return (s.pkt);
}
int
pcap_datalink(pcap_t *p)
{
return (p->linktype);
}
int
pcap_snapshot(pcap_t *p)
{
return (p->snapshot);
}
int
pcap_is_swapped(pcap_t *p)
{
return (p->sf.swapped);
}
int
pcap_major_version(pcap_t *p)
{
return (p->sf.version_major);
}
int
pcap_minor_version(pcap_t *p)
{
return (p->sf.version_minor);
}
FILE *
pcap_file(pcap_t *p)
{
return (p->sf.rfile);
}
int
pcap_fileno(pcap_t *p)
{
return (p->fd);
}
void
pcap_perror(pcap_t *p, char *prefix)
{
fprintf(stderr, "%s: %s\n", prefix, p->errbuf);
}
char *
pcap_geterr(pcap_t *p)
{
return (p->errbuf);
}
/*
* NOTE: in the future, these may need to call platform-dependent routines,
* e.g. on platforms with memory-mapped packet-capture mechanisms where
* "pcap_read()" uses "select()" or "poll()" to wait for packets to arrive.
*/
int
pcap_getnonblock(pcap_t *p, char *errbuf)
{
int fdflags;
if (p->sf.rfile != NULL) {
/*
* This is a savefile, not a live capture file, so
* never say it's in non-blocking mode.
*/
return (0);
}
fdflags = fcntl(p->fd, F_GETFL, 0);
if (fdflags == -1) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "F_GETFL: %s",
pcap_strerror(errno));
return (-1);
}
if (fdflags & O_NONBLOCK)
return (1);
else
return (0);
}
int
pcap_setnonblock(pcap_t *p, int nonblock, char *errbuf)
{
int fdflags;
if (p->sf.rfile != NULL) {
/*
* This is a savefile, not a live capture file, so
* ignore requests to put it in non-blocking mode.
*/
return (0);
}
fdflags = fcntl(p->fd, F_GETFL, 0);
if (fdflags == -1) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "F_GETFL: %s",
pcap_strerror(errno));
return (-1);
}
if (nonblock)
fdflags |= O_NONBLOCK;
else
fdflags &= ~O_NONBLOCK;
if (fcntl(p->fd, F_SETFL, fdflags) == -1) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "F_SETFL: %s",
pcap_strerror(errno));
return (-1);
}
return (0);
}
/*
* Not all systems have strerror().
*/
char *
pcap_strerror(int errnum)
{
#ifdef HAVE_STRERROR
return (strerror(errnum));
#else
extern int sys_nerr;
extern const char *const sys_errlist[];
static char ebuf[20];
if ((unsigned int)errnum < sys_nerr)
return ((char *)sys_errlist[errnum]);
(void)snprintf(ebuf, sizeof ebuf, "Unknown error: %d", errnum);
return(ebuf);
#endif
}
pcap_t *
pcap_open_dead(int linktype, int snaplen)
{
pcap_t *p;
p = malloc(sizeof(*p));
if (p == NULL)
return NULL;
memset (p, 0, sizeof(*p));
p->fd = -1;
p->snapshot = snaplen;
p->linktype = linktype;
return p;
}
void
pcap_close(pcap_t *p)
{
/*XXX*/
if (p->fd >= 0) {
#ifdef linux
pcap_close_linux(p);
#endif
close(p->fd);
}
if (p->sf.rfile != NULL) {
if (p->sf.rfile != stdin)
(void)fclose(p->sf.rfile);
if (p->sf.base != NULL)
free(p->sf.base);
} else if (p->buffer != NULL)
free(p->buffer);
pcap_freecode(&p->fcode);
free(p);
}