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