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/* $OpenBSD: pf.c,v 1.11 2004/05/08 20:23:21 canacar Exp $ */
/*
* Copyright (c) 1993-95 Mats O Jansson. All rights reserved.
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is partly derived from rarpd.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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[] =
"$OpenBSD: pf.c,v 1.11 2004/05/08 20:23:21 canacar Exp $";
#endif
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#include <sys/file.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <net/if.h>
#include <net/bpf.h>
#include <sys/errno.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <netdb.h>
#include <ctype.h>
#include <string.h>
#include <err.h>
#include <syslog.h>
#include "common/mopdef.h"
/*
* Variables
*/
extern int promisc;
/*
* Return information to device.c how to open device.
* In this case the driver can handle both Ethernet type II and
* IEEE 802.3 frames (SNAP) in a single pfOpen.
*/
int
pfTrans(char *interface)
{
return (TRANS_ETHER + TRANS_8023 + TRANS_AND);
}
/*
* Open and initialize packet filter.
*/
int
pfInit(char *interface, int mode, u_short protocol, int typ)
{
int fd;
int n = 0;
char device[sizeof "/dev/bpf000"];
struct ifreq ifr;
u_int dlt;
int immediate;
static struct bpf_insn insns[] = {
BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 12),
BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0x4711, 4, 0),
BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 20),
BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0x4711, 0, 3),
BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 14),
BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0xaaaa, 0, 1),
BPF_STMT(BPF_RET | BPF_K, 1520),
BPF_STMT(BPF_RET | BPF_K, 0),
};
static struct bpf_program filter = {
sizeof insns / sizeof(insns[0]),
insns
};
/* Go through all the minors and find one that isn't in use. */
do {
snprintf(device, sizeof device, "/dev/bpf%d", n++);
fd = open(device, mode);
} while (fd < 0 && errno == EBUSY);
if (fd < 0) {
syslog(LOG_ERR,"pfInit: open bpf %m");
return (-1);
}
/* Set immediate mode so packets are processed as they arrive. */
immediate = 1;
if (ioctl(fd, BIOCIMMEDIATE, &immediate) < 0) {
syslog(LOG_ERR,"pfInit: BIOCIMMEDIATE: %m");
return (-1);
}
strncpy(ifr.ifr_name, interface, sizeof ifr.ifr_name);
if (ioctl(fd, BIOCSETIF, (caddr_t) & ifr) < 0) {
syslog(LOG_ERR,"pfInit: BIOCSETIF: %m");
return (-1);
}
/* Check that the data link layer is an Ethernet; this code won't work
* with anything else. */
if (ioctl(fd, BIOCGDLT, (caddr_t)&dlt) < 0) {
syslog(LOG_ERR,"pfInit: BIOCGDLT: %m");
return (-1);
}
if (dlt != DLT_EN10MB) {
syslog(LOG_ERR,"pfInit: %s is not ethernet", device);
return (-1);
}
if (promisc)
/* Set promiscuous mode. */
if (ioctl(fd, BIOCPROMISC, (caddr_t)0) < 0) {
syslog(LOG_ERR,"pfInit: BIOCPROMISC: %m");
return (-1);
}
/* Set filter program. */
insns[1].k = protocol;
insns[3].k = protocol;
if (ioctl(fd, BIOCSETF, (caddr_t) & filter) < 0) {
syslog(LOG_ERR,"pfInit: BIOCSETF: %m");
return (-1);
}
/* XXX set the same write filter (for protocol only) */
if (ioctl(fd, BIOCSETWF, (caddr_t) & filter) < 0) {
syslog(LOG_ERR,"pfInit: BIOCSETWF: %m");
return (-1);
}
/* Lock the interface to prevent further changes */
if (ioctl(fd, BIOCLOCK) < 0) {
syslog(LOG_ERR,"pfInit: BIOCLOCK: %m");
return (-1);
}
return (fd);
}
/*
* Add a Multicast address to the interface
*/
int
pfAddMulti(int s, char *interface, char *addr)
{
struct ifreq ifr;
int fd;
strncpy(ifr.ifr_name, interface, sizeof(ifr.ifr_name) - 1);
ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = 0;
ifr.ifr_addr.sa_family = AF_UNSPEC;
bcopy(addr, ifr.ifr_addr.sa_data, 6);
/*
* open a socket, temporarily, to use for SIOC* ioctls
*/
if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
syslog(LOG_ERR, "pfAddMulti: socket: %m");
return (-1);
}
if (ioctl(fd, SIOCADDMULTI, (caddr_t)&ifr) < 0) {
syslog(LOG_ERR, "pfAddMulti: SIOCADDMULTI: %m");
close(fd);
return (-1);
}
close(fd);
return (0);
}
/*
* Delete a Multicast address from the interface
*/
int
pfDelMulti(int s, char *interface, char *addr)
{
struct ifreq ifr;
int fd;
strncpy(ifr.ifr_name, interface, sizeof (ifr.ifr_name) - 1);
ifr.ifr_name[sizeof(ifr.ifr_name)-1] = 0;
ifr.ifr_addr.sa_family = AF_UNSPEC;
bcopy(addr, ifr.ifr_addr.sa_data, 6);
/*
* open a socket, temporarily, to use for SIOC* ioctls
*
*/
if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
syslog(LOG_ERR, "pfDelMulti: socket: %m");
return (-1);
}
if (ioctl(fd, SIOCDELMULTI, (caddr_t)&ifr) < 0) {
syslog(LOG_ERR, "pfAddMulti: SIOCDELMULTI: %m");
close(fd);
return (-1);
}
close(fd);
return (0);
}
/*
* read a packet
*/
int
pfRead(int fd, u_char *buf, int len)
{
return (read(fd, buf, len));
}
/*
* write a packet
*/
int
pfWrite(int fd, u_char *buf, int len, int trans)
{
struct iovec iov[2];
/* XXX */
switch (trans) {
case TRANS_8023:
iov[0].iov_base = buf;
iov[0].iov_len = 22;
iov[1].iov_base = buf + 22;
iov[1].iov_len = len - 22;
break;
default:
iov[0].iov_base = buf;
iov[0].iov_len = 14;
iov[1].iov_base = buf + 14;
iov[1].iov_len = len - 14;
break;
}
if (writev(fd, iov, 2) == len)
return (len);
return (-1);
}
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