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/* $FreeBSD: src/contrib/ipfilter/ipsd/snit.c,v 1.2.22.1.6.1 2010/12/21 17:09:25 kensmith Exp $ */
/*
* (C)opyright 1992-1998 Darren Reed. (from tcplog)
*
* See the IPFILTER.LICENCE file for details on licencing.
*
*/
#include <stdio.h>
#include <netdb.h>
#include <ctype.h>
#include <signal.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/timeb.h>
#include <sys/socket.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <net/nit.h>
#include <sys/fcntlcom.h>
#include <sys/dir.h>
#include <net/nit_if.h>
#include <net/nit_pf.h>
#include <net/nit_buf.h>
#include <net/packetfilt.h>
#include <sys/stropts.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/if_ether.h>
#include <netinet/ip_var.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netinet/tcp.h>
#include <netinet/tcpip.h>
#ifndef lint
static char snitid[] = "@(#)snit.c 1.2 12/3/95 (C)1995 Darren Reed";
#endif
#define BUFSPACE 32768
/*
* Be careful to only include those defined in the flags option for the
* interface are included in the header size.
*/
#define BUFHDR_SIZE (sizeof(struct nit_bufhdr))
#define NIT_HDRSIZE (BUFHDR_SIZE)
static int timeout;
int ack_recv(ep)
char *ep;
{
struct tcpiphdr tip;
struct tcphdr *tcp;
struct ip *ip;
ip = (struct ip *)&tip;
tcp = (struct tcphdr *)(ip + 1);
bcopy(ep + 14, (char *)ip, sizeof(*ip));
bcopy(ep + 14 + (ip->ip_hl << 2), (char *)tcp, sizeof(*tcp));
if (ip->ip_off & 0x1fff != 0)
return 0;
if (0 == detect(ip, tcp))
return 1;
return 0;
}
int readloop(fd, dst)
int fd;
struct in_addr dst;
{
static u_char buf[BUFSPACE];
register u_char *bp, *cp, *bufend;
register struct nit_bufhdr *hp;
register int cc;
time_t now = time(NULL);
int done = 0;
while ((cc = read(fd, buf, BUFSPACE-1)) >= 0) {
if (!cc)
if ((time(NULL) - now) > timeout)
return done;
else
continue;
bp = buf;
bufend = buf + cc;
/*
* loop through each snapshot in the chunk
*/
while (bp < bufend) {
cp = (u_char *)((char *)bp + NIT_HDRSIZE);
/*
* get past NIT buffer
*/
hp = (struct nit_bufhdr *)bp;
/*
* next snapshot
*/
bp += hp->nhb_totlen;
done += ack_recv(cp);
}
return done;
}
perror("read");
exit(-1);
}
int initdevice(device, tout)
char *device;
int tout;
{
struct strioctl si;
struct timeval to;
struct ifreq ifr;
struct packetfilt pfil;
u_long if_flags;
u_short *fwp = pfil.Pf_Filter;
int ret, offset, fd, snaplen= 76, chunksize = BUFSPACE;
if ((fd = open("/dev/nit", O_RDWR)) < 0)
{
perror("/dev/nit");
exit(-1);
}
/*
* Create some filter rules for our TCP watcher. We only want ethernet
* pacets which are IP protocol and only the TCP packets from IP.
*/
offset = 6;
*fwp++ = ENF_PUSHWORD + offset;
*fwp++ = ENF_PUSHLIT | ENF_CAND;
*fwp++ = htons(ETHERTYPE_IP);
*fwp++ = ENF_PUSHWORD + sizeof(struct ether_header)/sizeof(short)+4;
*fwp++ = ENF_PUSHLIT | ENF_AND;
*fwp++ = htons(0x00ff);
*fwp++ = ENF_PUSHLIT | ENF_COR;
*fwp++ = htons(IPPROTO_TCP);
*fwp++ = ENF_PUSHWORD + sizeof(struct ether_header)/sizeof(short)+4;
*fwp++ = ENF_PUSHLIT | ENF_AND;
*fwp++ = htons(0x00ff);
*fwp++ = ENF_PUSHLIT | ENF_CAND;
*fwp++ = htons(IPPROTO_UDP);
pfil.Pf_FilterLen = fwp - &pfil.Pf_Filter[0];
/*
* put filter in place.
*/
if (ioctl(fd, I_PUSH, "pf") == -1)
{
perror("ioctl: I_PUSH pf");
exit(1);
}
if (ioctl(fd, NIOCSETF, &pfil) == -1)
{
perror("ioctl: NIOCSETF");
exit(1);
}
/*
* arrange to get messages from the NIT STREAM and use NIT_BUF option
*/
ioctl(fd, I_SRDOPT, (char*)RMSGD);
ioctl(fd, I_PUSH, "nbuf");
/*
* set the timeout
*/
timeout = tout;
si.ic_timout = 1;
to.tv_sec = 1;
to.tv_usec = 0;
si.ic_cmd = NIOCSTIME;
si.ic_len = sizeof(to);
si.ic_dp = (char*)&to;
if (ioctl(fd, I_STR, (char*)&si) == -1)
{
perror("ioctl: NIT timeout");
exit(-1);
}
/*
* set the chunksize
*/
si.ic_cmd = NIOCSCHUNK;
si.ic_len = sizeof(chunksize);
si.ic_dp = (char*)&chunksize;
if (ioctl(fd, I_STR, (char*)&si) == -1)
perror("ioctl: NIT chunksize");
if (ioctl(fd, NIOCGCHUNK, (char*)&chunksize) == -1)
{
perror("ioctl: NIT chunksize");
exit(-1);
}
printf("NIT buffer size: %d\n", chunksize);
/*
* request the interface
*/
strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = ' ';
si.ic_cmd = NIOCBIND;
si.ic_len = sizeof(ifr);
si.ic_dp = (char*)𝔦
if (ioctl(fd, I_STR, (char*)&si) == -1)
{
perror(ifr.ifr_name);
exit(1);
}
/*
* set the snapshot length
*/
si.ic_cmd = NIOCSSNAP;
si.ic_len = sizeof(snaplen);
si.ic_dp = (char*)&snaplen;
if (ioctl(fd, I_STR, (char*)&si) == -1)
{
perror("ioctl: NIT snaplen");
exit(1);
}
(void) ioctl(fd, I_FLUSH, (char*)FLUSHR);
return fd;
}
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