xref: /freebsd/sbin/ipf/ipsend/sbpf.c (revision 2b8331622f0b212cf3bb4fc4914a501e5321d506)
1 /* $FreeBSD$ */
2 /*
3  * (C)opyright 1995-1998 Darren Reed. (from tcplog)
4  *
5  * See the IPFILTER.LICENCE file for details on licencing.
6  *
7  */
8 #include <sys/param.h>
9 #include <sys/types.h>
10 #include <sys/mbuf.h>
11 #include <sys/time.h>
12 #include <sys/socket.h>
13 #include <sys/file.h>
14 #include <sys/ioctl.h>
15 #ifdef __FreeBSD__
16 # include <sys/dirent.h>
17 #else
18 # include <sys/dir.h>
19 #endif
20 #include <net/bpf.h>
21 
22 #include <net/if.h>
23 #include <netinet/in.h>
24 #include <netinet/in_systm.h>
25 #include <netinet/ip.h>
26 #include <netinet/udp.h>
27 #include <netinet/tcp.h>
28 
29 #include <stdio.h>
30 #include <netdb.h>
31 #include <string.h>
32 #include <unistd.h>
33 #include <stdlib.h>
34 #ifdef __NetBSD__
35 # include <paths.h>
36 #endif
37 #include <ctype.h>
38 #include <signal.h>
39 #include <errno.h>
40 
41 #include "ipsend.h"
42 
43 #if !defined(lint)
44 static const char sccsid[] = "@(#)sbpf.c	1.3 8/25/95 (C)1995 Darren Reed";
45 static const char rcsid[] = "@(#)$Id$";
46 #endif
47 
48 /*
49  * the code herein is dervied from libpcap.
50  */
51 static	u_char	*buf = NULL;
52 static	int	bufsize = 0, timeout = 1;
53 
54 
55 int
56 initdevice(char *device, int tout)
57 {
58 	struct	bpf_version bv;
59 	struct	timeval to;
60 	struct	ifreq ifr;
61 #ifdef _PATH_BPF
62 	char	*bpfname = _PATH_BPF;
63 	int	fd;
64 
65 	if ((fd = open(bpfname, O_RDWR)) < 0)
66 	    {
67 		fprintf(stderr, "no bpf devices available as /dev/bpfxx\n");
68 		return (-1);
69 	    }
70 #else
71 	char	bpfname[16];
72 	int	fd = 0, i;
73 
74 	for (i = 0; i < 16; i++)
75 	    {
76 		(void) snprintf(bpfname, sizeof(bpfname), "/dev/bpf%d", i);
77 		if ((fd = open(bpfname, O_RDWR)) >= 0)
78 			break;
79 	    }
80 	if (i == 16)
81 	    {
82 		fprintf(stderr, "no bpf devices available as /dev/bpfxx\n");
83 		return (-1);
84 	    }
85 #endif
86 
87 	if (ioctl(fd, BIOCVERSION, (caddr_t)&bv) < 0)
88 	    {
89 		perror("BIOCVERSION");
90 		return (-1);
91 	    }
92 	if (bv.bv_major != BPF_MAJOR_VERSION ||
93 	    bv.bv_minor < BPF_MINOR_VERSION)
94 	    {
95 		fprintf(stderr, "kernel bpf (v%d.%d) filter out of date:\n",
96 			bv.bv_major, bv.bv_minor);
97 		fprintf(stderr, "current version: %d.%d\n",
98 			BPF_MAJOR_VERSION, BPF_MINOR_VERSION);
99 		return (-1);
100 	    }
101 
102 	(void) strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
103 	if (ioctl(fd, BIOCSETIF, &ifr) == -1)
104 	    {
105 		fprintf(stderr, "%s(%d):", ifr.ifr_name, fd);
106 		perror("BIOCSETIF");
107 		exit(1);
108 	    }
109 	/*
110 	 * get kernel buffer size
111 	 */
112 	if (ioctl(fd, BIOCGBLEN, &bufsize) == -1)
113 	    {
114 		perror("BIOCSBLEN");
115 		exit(-1);
116 	    }
117 	buf = (u_char*)malloc(bufsize);
118 	/*
119 	 * set the timeout
120 	 */
121 	timeout = tout;
122 	to.tv_sec = 1;
123 	to.tv_usec = 0;
124 	if (ioctl(fd, BIOCSRTIMEOUT, (caddr_t)&to) == -1)
125 	    {
126 		perror("BIOCSRTIMEOUT");
127 		exit(-1);
128 	    }
129 
130 	(void) ioctl(fd, BIOCFLUSH, 0);
131 	return (fd);
132 }
133 
134 
135 /*
136  * output an IP packet onto a fd opened for /dev/bpf
137  */
138 int
139 sendip(int fd, char *pkt, int len)
140 {
141 	if (write(fd, pkt, len) == -1)
142 	    {
143 		perror("send");
144 		return (-1);
145 	    }
146 
147 	return (len);
148 }
149