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/* $OpenBSD: ipft_pc.c,v 1.18 2001/01/30 04:31:01 kjell Exp $ */
/*
* Copyright (C) 1993-2000 by Darren Reed.
*
* Redistribution and use in source and binary forms are permitted
* provided that this notice is preserved and due credit is given
* to the original author and the contributors.
*/
#include <stdio.h>
#include <string.h>
#if !defined(__SVR4) && !defined(__GNUC__)
#include <strings.h>
#endif
#include <sys/types.h>
#include <sys/time.h>
#include <stdlib.h>
#include <unistd.h>
#include <stddef.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/param.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#ifndef linux
#include <netinet/ip_var.h>
#endif
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <net/if.h>
#include <netinet/ip_fil_compat.h>
#include <netinet/tcpip.h>
#include "ipf.h"
#include "pcap.h"
#include "ipt.h"
#if !defined(lint)
static const char rcsid[] = "@(#)$IPFilter: ipft_pc.c,v 2.2 2000/03/13 22:10:24 darrenr Exp $";
#endif
struct llc {
int lc_sz; /* LLC header length */
int lc_to; /* LLC Type offset */
int lc_tl; /* LLC Type length */
};
/*
* While many of these maybe the same, some do have different header formats
* which make this useful.
*/
#define DLT_MAX 14
static struct llc llcs[DLT_MAX] = {
{ 0, 0, 0 }, /* DLT_NULL */
{ 14, 12, 2 }, /* DLT_E10MB */
{ 0, 0, 0 }, /* DLT_EN3MB */
{ 0, 0, 0 }, /* DLT_AX25 */
{ 0, 0, 0 }, /* DLT_PRONET */
{ 0, 0, 0 }, /* DLT_CHAOS */
{ 0, 0, 0 }, /* DLT_IEEE802 */
{ 0, 0, 0 }, /* DLT_ARCNET */
{ 0, 0, 0 }, /* DLT_SLIP */
{ 0, 0, 0 }, /* DLT_PPP */
{ 0, 0, 0 }, /* DLT_FDDI */
{ 0, 0, 0 }, /* DLT_ATMRFC1483 */
{ 0, 0, 0 }, /* DLT_LOOP */
{ 0, 0, 0 } /* DLT_ENC */
};
static int pcap_open __P((char *));
static int pcap_close __P((void));
static int pcap_readip __P((char *, int, char **, int *));
static void swap_hdr __P((pcaphdr_t *));
static int pcap_read_rec __P((struct pcap_pkthdr *));
static int pfd = -1, s_type = -1, swapped = 0;
struct ipread pcap = { pcap_open, pcap_close, pcap_readip };
#define SWAPLONG(y) \
((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff))
#define SWAPSHORT(y) \
( (((y)&0xff)<<8) | (((y)&0xff00)>>8) )
static void swap_hdr(p)
pcaphdr_t *p;
{
p->pc_v_maj = SWAPSHORT(p->pc_v_maj);
p->pc_v_min = SWAPSHORT(p->pc_v_min);
p->pc_zone = SWAPLONG(p->pc_zone);
p->pc_sigfigs = SWAPLONG(p->pc_sigfigs);
p->pc_slen = SWAPLONG(p->pc_slen);
p->pc_type = SWAPLONG(p->pc_type);
}
static int pcap_open(fname)
char *fname;
{
pcaphdr_t ph;
int fd;
if (pfd != -1)
return pfd;
if (!strcmp(fname, "-"))
fd = 0;
else if ((fd = open(fname, O_RDONLY)) == -1)
return -1;
if (read(fd, (char *)&ph, sizeof(ph)) != sizeof(ph))
return -2;
if (ph.pc_id != TCPDUMP_MAGIC) {
if (SWAPLONG(ph.pc_id) != TCPDUMP_MAGIC) {
(void) close(fd);
return -2;
}
swapped = 1;
swap_hdr(&ph);
}
if (ph.pc_v_maj != PCAP_VERSION_MAJ || ph.pc_type >= DLT_MAX) {
(void) close(fd);
return -2;
}
pfd = fd;
s_type = ph.pc_type;
printf("opened pcap file %s:\n", fname);
printf("\tid: %08x version: %d.%d type: %d snap %d\n",
ph.pc_id, ph.pc_v_maj, ph.pc_v_min, ph.pc_type, ph.pc_slen);
return fd;
}
static int pcap_close()
{
return close(pfd);
}
/*
* read in the header (and validate) which should be the first record
* in a pcap file.
*/
static int pcap_read_rec(rec)
struct pcap_pkthdr *rec;
{
int n, p;
if (read(pfd, (char *)rec, sizeof(*rec)) != sizeof(*rec))
return -2;
if (swapped) {
rec->ph_clen = SWAPLONG(rec->ph_clen);
rec->ph_len = SWAPLONG(rec->ph_len);
rec->ph_ts.tv_sec = SWAPLONG(rec->ph_ts.tv_sec);
rec->ph_ts.tv_usec = SWAPLONG(rec->ph_ts.tv_usec);
}
p = rec->ph_clen;
n = MIN(p, rec->ph_len);
if (!n || n < 0)
return -3;
return p;
}
#ifdef notyet
/*
* read an entire pcap packet record. only the data part is copied into
* the available buffer, with the number of bytes copied returned.
*/
static int pcap_read(buf, cnt)
char *buf;
int cnt;
{
struct pcap_pkthdr rec;
static char *bufp = NULL;
int i, n;
if ((i = pcap_read_rec(&rec)) <= 0)
return i;
if (!bufp)
bufp = malloc(i);
else
bufp = realloc(bufp, i);
if (read(pfd, bufp, i) != i)
return -2;
n = MIN(i, cnt);
bcopy(bufp, buf, n);
return n;
}
#endif
/*
* return only an IP packet read into buf
*/
static int pcap_readip(buf, cnt, ifn, dir)
char *buf, **ifn;
int cnt, *dir;
{
static char *bufp = NULL;
struct pcap_pkthdr rec;
struct llc *l;
char *s, ty[4];
int i, n;
do {
if ((i = pcap_read_rec(&rec)) <= 0)
return i;
if (!bufp)
bufp = malloc(i);
else
bufp = realloc(bufp, i);
s = bufp;
if (read(pfd, s, i) != i)
return -2;
l = &llcs[s_type];
i -= l->lc_sz;
s += l->lc_to;
bcopy(s, ty, l->lc_tl);
s += l->lc_tl;
} while (ty[0] != 0x8 && ty[1] != 0);
n = MIN(i, cnt);
bcopy(s, buf, n);
return n;
}
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