xref: /freebsd/sbin/ipf/ipsend/44arp.c (revision b3d14eaccc5f606690d99b1998bfdf32a22404f6)
1 /*	$FreeBSD$	*/
2 
3 /*
4  * Based upon 4.4BSD's /usr/sbin/arp
5  */
6 #include <sys/param.h>
7 #include <sys/file.h>
8 #include <sys/socket.h>
9 #include <sys/sysctl.h>
10 #include <net/if.h>
11 #include <net/if_dl.h>
12 #include <net/if_types.h>
13 # include <net/route.h>
14 #include <netinet/in.h>
15 #include <netinet/if_ether.h>
16 #include <arpa/inet.h>
17 #include <netinet/in.h>
18 #include <netinet/in_systm.h>
19 #include <netinet/ip.h>
20 #include <netinet/ip_var.h>
21 #include <netinet/tcp.h>
22 #include <unistd.h>
23 #include <string.h>
24 #include <stdlib.h>
25 #include <netdb.h>
26 #include <errno.h>
27 #include <nlist.h>
28 #include <stdio.h>
29 #include "ipsend.h"
30 #include "iplang/iplang.h"
31 
32 
33 /*
34  * lookup host and return
35  * its IP address in address
36  * (4 bytes)
37  */
38 int	resolve(host, address)
39 	char	*host, *address;
40 {
41         struct	hostent	*hp;
42         u_long	add;
43 
44 	add = inet_addr(host);
45 	if (add == -1)
46 	    {
47 		if (!(hp = gethostbyname(host)))
48 		    {
49 			fprintf(stderr, "unknown host: %s\n", host);
50 			return -1;
51 		    }
52 		bcopy((char *)hp->h_addr, (char *)address, 4);
53 		return 0;
54 	}
55 	bcopy((char*)&add, address, 4);
56 	return 0;
57 }
58 
59 
60 int	arp(addr, eaddr)
61 	char	*addr, *eaddr;
62 {
63 	int	mib[6];
64 	size_t	needed;
65 	char	*lim, *buf, *next;
66 	struct	rt_msghdr	*rtm;
67 	struct	sockaddr_in	*sin;
68 	struct	sockaddr_dl	*sdl;
69 
70 #ifdef	IPSEND
71 	if (arp_getipv4(addr, ether) == 0)
72 		return 0;
73 #endif
74 
75 	if (!addr)
76 		return -1;
77 
78 	mib[0] = CTL_NET;
79 	mib[1] = PF_ROUTE;
80 	mib[2] = 0;
81 	mib[3] = AF_INET;
82 	mib[4] = NET_RT_FLAGS;
83 #ifdef RTF_LLINFO
84 	mib[5] = RTF_LLINFO;
85 #else
86 	mib[5] = 0;
87 #endif
88 
89 	if (sysctl(mib, 6, NULL, &needed, NULL, 0) == -1)
90 	    {
91 		perror("route-sysctl-estimate");
92 		exit(-1);
93 	    }
94 	if ((buf = malloc(needed)) == NULL)
95 	    {
96 		perror("malloc");
97 		exit(-1);
98 	    }
99 	if (sysctl(mib, 6, buf, &needed, NULL, 0) == -1)
100 	    {
101 		perror("actual retrieval of routing table");
102 		exit(-1);
103 	    }
104 	lim = buf + needed;
105 	for (next = buf; next < lim; next += rtm->rtm_msglen)
106 	    {
107 		rtm = (struct rt_msghdr *)next;
108 		sin = (struct sockaddr_in *)(rtm + 1);
109 		sdl = (struct sockaddr_dl *)(sin + 1);
110 		if (!bcmp(addr, (char *)&sin->sin_addr,
111 			  sizeof(struct in_addr)))
112 		    {
113 			bcopy(LLADDR(sdl), eaddr, sdl->sdl_alen);
114 			return 0;
115 		    }
116 	    }
117 	return -1;
118 }
119