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/* $OpenBSD: pf-snit.c,v 1.7 2006/04/17 16:23:01 deraadt Exp $ */
/*
* Copyright (c) 1993-96 Mats O Jansson. 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.
*
* 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-snit.c,v 1.7 2006/04/17 16:23:01 deraadt Exp $";
#endif
#include <stdio.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>
#define DEV_NIT "/dev/nit"
#include <net/nit.h>
#include <net/nit_if.h>
#include <net/nit_pf.h>
#include <net/nit_buf.h>
#include <net/packetfilt.h>
#include <stropts.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <netdb.h>
#include <ctype.h>
#include <syslog.h>
#include "common/mopdef.h"
/*
* Variables
*/
/* struct ifreq ifr; */
extern int errno;
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(interface)
char *interface;
{
return TRANS_ETHER+TRANS_8023+TRANS_AND;
}
/*
* Open and initialize packet filter.
*/
int
pfInit(interface, mode, protocol, trans)
char *interface;
u_short protocol;
int trans, mode;
{
int fd;
int ioarg;
char device[64];
unsigned long if_flags;
struct ifreq ifr;
struct strioctl si;
/* get clone */
if ((fd = open(DEV_NIT, mode)) < 0) {
syslog(LOG_ERR,"pfInit: open nit %m");
return(-1);
}
/*
* set filter for protocol
*/
if (setup_pf(fd, protocol, trans) < 0)
return(-1);
/*
* set options, bind to underlying interface
*/
strncpy(ifr.ifr_name, interface, sizeof(ifr.ifr_name));
/* bind */
si.ic_cmd = NIOCBIND; /* bind to underlying interface */
si.ic_timout = 10;
si.ic_len = sizeof(ifr);
si.ic_dp = (caddr_t)𝔦
if (ioctl(fd, I_STR, (caddr_t)&si) < 0) {
syslog(LOG_ERR,"pfinit: I_STR %m");
return(-1);
}
if (promisc) {
if_flags = NI_PROMISC;
si.ic_cmd = NIOCSFLAGS;
si.ic_timout = 10;
si.ic_len = sizeof(if_flags);
si.ic_dp = (caddr_t)&if_flags;
if (ioctl(fd, I_STR, (caddr_t)&si) < 0) {
syslog(LOG_ERR,"pfInit: I_STR (promisc) %m");
return(-1);
}
}
/* set up messages */
if (ioctl(fd, I_SRDOPT, (char *)RMSGD) < 0) { /* want messages */
syslog(LOG_ERR,"pfInit: I_SRDOPT %m");
return(-1);
}
/* flush read queue */
if (ioctl(fd, I_FLUSH, (char *)FLUSHR) < 0) {
syslog(LOG_ERR,"pfInit: I_FLUSH %m");
return(-1);
}
return(fd);
}
/*
* establish protocol filter
*/
int
setup_pf(s, prot, trans)
int s, trans;
u_short prot;
{
int ioarg;
u_short offset;
struct packetfilt pf;
u_short *fwp = pf.Pf_Filter;
struct strioctl si;
#define s_offset(structp, element) (&(((structp)0)->element))
bzero(&pf, sizeof(pf));
pf.Pf_Priority = 128;
offset = ((int)s_offset(struct ether_header *, ether_type))/sizeof(u_short);
*fwp++ = ENF_PUSHWORD + offset; /* Check Ethernet type II */
*fwp++ = ENF_PUSHLIT | ENF_EQ; /* protocol prot */
*fwp++ = htons(prot);
*fwp++ = ENF_PUSHWORD + offset + 4; /* Check 802.3 protocol prot */
*fwp++ = ENF_PUSHLIT | ENF_EQ;
*fwp++ = htons(prot);
*fwp++ = ENF_PUSHWORD + offset + 1; /* Check for SSAP and DSAP */
*fwp++ = ENF_PUSHLIT | ENF_EQ;
*fwp++ = htons(0xaaaa);
*fwp++ = ENF_AND;
*fwp++ = ENF_OR;
pf.Pf_FilterLen = 11;
si.ic_cmd = NIOCSETF;
si.ic_timout = 10;
si.ic_len = sizeof(pf);
si.ic_dp = (char *)&pf;
if (ioctl(s, I_PUSH, "pf") < 0) {
syslog(LOG_ERR,"setup_pf: I_PUSH %m");
return(-1);
}
if (ioctl(s, I_STR, (char *)&si) < 0) {
syslog(LOG_ERR,"setup_pf: I_STR %m");
return(-1);
}
return(0);
}
/*
* Get the interface ethernet address
*/
int
pfEthAddr(fd, addr)
int fd;
u_char *addr;
{
struct ifreq ifr;
struct sockaddr *sa;
if (ioctl(fd, SIOCGIFADDR, &ifr) < 0) {
syslog(LOG_ERR,"pfEthAddr: SIOCGIFADDR %m");
return(-1);
}
sa = (struct sockaddr *)ifr.ifr_data;
bcopy((char *)sa->sa_data, (char *)addr, 6);
return(0);
}
/*
* Add a Multicast address to the interface
*/
int
pfAddMulti(s, interface, addr)
int s;
char *interface, *addr;
{
struct ifreq ifr;
int fd;
strncpy(ifr.ifr_name, interface, sizeof (ifr.ifr_name) -1);
ifr.ifr_name[sizeof(ifr.ifr_name)] = 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(s, interface, addr)
int s;
char *interface, *addr;
{
struct ifreq ifr;
int fd;
strncpy(ifr.ifr_name, interface, sizeof (ifr.ifr_name) -1);
ifr.ifr_name[sizeof(ifr.ifr_name)] = 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,"pfDelMulti: SIOCDELMULTI %m");
close(fd);
return(-1);
}
close(fd);
return(0);
}
/*
* read a packet
*/
int
pfRead(fd, buf, len)
int fd, len;
u_char *buf;
{
return(read(fd, buf, len));
}
/*
* write a packet
*/
int
pfWrite(fd, buf, len, trans)
int fd, len, trans;
u_char *buf;
{
struct sockaddr sa;
struct strbuf pbuf, dbuf;
sa.sa_family = AF_UNSPEC;
bcopy(buf, sa.sa_data, sizeof(sa.sa_data));
switch (trans) {
default:
pbuf.len = sizeof(struct sockaddr);
pbuf.buf = (char *) &sa;
dbuf.len = len-14;
dbuf.buf = (char *)buf+14;
break;
}
if (putmsg(fd, &pbuf, &dbuf, 0) == 0)
return(len);
return(-1);
}
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