NetBSD/dist/ipf/ipsd/sbpf.c

197 lines
4.1 KiB
C

/* $NetBSD: sbpf.c,v 1.2 2002/01/24 08:21:38 martti Exp $ */
/*
* (C)opyright 1995-1998 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/param.h>
#include <sys/mbuf.h>
#include <sys/time.h>
#include <sys/timeb.h>
#include <sys/socket.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#if BSD < 199103
#include <sys/fcntlcom.h>
#endif
#include <sys/dir.h>
#include <net/bpf.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>
#include "ip_compat.h"
#ifndef lint
static char sbpf[] = "@(#)sbpf.c 1.2 12/3/95 (C)1995 Darren Reed";
#endif
/*
(000) ldh [12]
(001) jeq #0x800 jt 2 jf 5
(002) ldb [23]
(003) jeq #0x6 jt 4 jf 5
(004) ret #68
(005) ret #0
*/
struct bpf_insn filter[] = {
/* 0. */ { BPF_LD|BPF_H|BPF_ABS, 0, 0, 12 },
/* 1. */ { BPF_JMP|BPF_JEQ, 0, 3, 0x0800 },
/* 2. */ { BPF_LD|BPF_B|BPF_ABS, 0, 0, 23 },
/* 3. */ { BPF_JMP|BPF_JEQ, 0, 1, 0x06 },
/* 4. */ { BPF_RET, 0, 0, 68 },
/* 5. */ { BPF_RET, 0, 0, 0 }
};
/*
* the code herein is dervied from libpcap.
*/
static u_char *buf = NULL;
static u_int bufsize = 32768, timeout = 1;
int ack_recv(ep)
char *ep;
{
struct tcpiphdr tip;
tcphdr_t *tcp;
ip_t *ip;
ip = (ip_t *)&tip;
tcp = (tcphdr_t *)(ip + 1);
bcopy(ep + 14, (char *)ip, sizeof(*ip));
bcopy(ep + 14 + (ip->ip_hl << 2), (char *)tcp, sizeof(*tcp));
if (ip->ip_p != IPPROTO_TCP && ip->ip_p != IPPROTO_UDP)
return -1;
if (ip->ip_p & 0x1fff != 0)
return 0;
if (0 == detect(ip, tcp))
return 1;
return 0;
}
int readloop(fd, port, dst)
int fd, port;
struct in_addr dst;
{
register u_char *bp, *cp, *bufend;
register struct bpf_hdr *bh;
register int cc;
time_t in = time(NULL);
int done = 0;
while ((cc = read(fd, buf, bufsize)) >= 0) {
if (!cc && (time(NULL) - in) > timeout)
return done;
bp = buf;
bufend = buf + cc;
/*
* loop through each snapshot in the chunk
*/
while (bp < bufend) {
bh = (struct bpf_hdr *)bp;
cp = bp + bh->bh_hdrlen;
done += ack_recv(cp);
bp += BPF_WORDALIGN(bh->bh_caplen + bh->bh_hdrlen);
}
return done;
}
perror("read");
exit(-1);
}
int initdevice(device, tout)
char *device;
int tout;
{
struct bpf_program prog;
struct bpf_version bv;
struct timeval to;
struct ifreq ifr;
char bpfname[16];
int fd, i;
for (i = 0; i < 16; i++)
{
(void) sprintf(bpfname, "/dev/bpf%d", i);
if ((fd = open(bpfname, O_RDWR)) >= 0)
break;
}
if (i == 16)
{
fprintf(stderr, "no bpf devices available as /dev/bpfxx\n");
return -1;
}
if (ioctl(fd, BIOCVERSION, (caddr_t)&bv) < 0)
{
perror("BIOCVERSION");
return -1;
}
if (bv.bv_major != BPF_MAJOR_VERSION ||
bv.bv_minor < BPF_MINOR_VERSION)
{
fprintf(stderr, "kernel bpf (v%d.%d) filter out of date:\n",
bv.bv_major, bv.bv_minor);
fprintf(stderr, "current version: %d.%d\n",
BPF_MAJOR_VERSION, BPF_MINOR_VERSION);
return -1;
}
(void) strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
if (ioctl(fd, BIOCSETIF, &ifr) == -1)
{
fprintf(stderr, "%s(%d):", ifr.ifr_name, fd);
perror("BIOCSETIF");
exit(1);
}
/*
* set the timeout
*/
timeout = tout;
to.tv_sec = 1;
to.tv_usec = 0;
if (ioctl(fd, BIOCSRTIMEOUT, (caddr_t)&to) == -1)
{
perror("BIOCSRTIMEOUT");
exit(-1);
}
/*
* get kernel buffer size
*/
if (ioctl(fd, BIOCSBLEN, &bufsize) == -1)
perror("BIOCSBLEN");
if (ioctl(fd, BIOCGBLEN, &bufsize) == -1)
{
perror("BIOCGBLEN");
exit(-1);
}
printf("BPF buffer size: %d\n", bufsize);
buf = (u_char*)malloc(bufsize);
prog.bf_len = sizeof(filter) / sizeof(struct bpf_insn);
prog.bf_insns = filter;
if (ioctl(fd, BIOCSETF, (caddr_t)&prog) == -1)
{
perror("BIOCSETF");
exit(-1);
}
(void) ioctl(fd, BIOCFLUSH, 0);
return fd;
}