1
2 /*
3 * arp.c (C) 1995-1998 Darren Reed
4 *
5 * See the IPFILTER.LICENCE file for details on licencing.
6 */
7 #include <sys/types.h>
8 #include <sys/socket.h>
9 # include <sys/sockio.h>
10 #include <sys/ioctl.h>
11 #include <netinet/in_systm.h>
12 #include <netinet/in.h>
13 #include <net/if.h>
14 #include <netinet/if_ether.h>
15 # include <net/if_arp.h>
16 #include <netinet/in.h>
17 #include <netinet/ip.h>
18 #include <netinet/ip_var.h>
19 #include <netinet/tcp.h>
20 #include <stdio.h>
21 #include <errno.h>
22 #include <netdb.h>
23 #include "ipsend.h"
24 #include "iplang/iplang.h"
25
26
27 /*
28 * lookup host and return
29 * its IP address in address
30 * (4 bytes)
31 */
resolve(char * host,char * address)32 int resolve(char *host, char *address)
33 {
34 struct hostent *hp;
35 u_long add;
36
37 add = inet_addr(host);
38 if (add == -1)
39 {
40 if (!(hp = gethostbyname(host)))
41 {
42 fprintf(stderr, "unknown host: %s\n", host);
43 return (-1);
44 }
45 bcopy((char *)hp->h_addr, (char *)address, 4);
46 return (0);
47 }
48 bcopy((char*)&add, address, 4);
49 return (0);
50 }
51
52 /*
53 * ARP for the MAC address corresponding
54 * to the IP address. This taken from
55 * some BSD program, I cant remember which.
56 */
arp(ip,ether)57 int arp(ip, ether)
58 char *ip;
59 char *ether;
60 {
61 static int sfd = -1;
62 static char ethersave[6], ipsave[4];
63 struct arpreq ar;
64 struct sockaddr_in *sin, san;
65 struct hostent *hp;
66 int fd;
67
68 #ifdef IPSEND
69 if (arp_getipv4(ip, ether) == 0)
70 return (0);
71 #endif
72 if (!bcmp(ipsave, ip, 4)) {
73 bcopy(ethersave, ether, 6);
74 return (0);
75 }
76 fd = -1;
77 bzero((char *)&ar, sizeof(ar));
78 sin = (struct sockaddr_in *)&ar.arp_pa;
79 sin->sin_family = AF_INET;
80 bcopy(ip, (char *)&sin->sin_addr.s_addr, 4);
81 if ((hp = gethostbyaddr(ip, 4, AF_INET)))
82 # if SOLARIS && (SOLARIS2 >= 10)
83 if (!(ether_hostton(hp->h_name, (struct ether_addr *)ether)))
84 # else
85 if (!(ether_hostton(hp->h_name, ether)))
86 # endif
87 goto savearp;
88
89 if (sfd == -1)
90 if ((sfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
91 {
92 perror("arp: socket");
93 return (-1);
94 }
95 tryagain:
96 if (ioctl(sfd, SIOCGARP, (caddr_t)&ar) == -1)
97 {
98 if (fd == -1)
99 {
100 bzero((char *)&san, sizeof(san));
101 san.sin_family = AF_INET;
102 san.sin_port = htons(1);
103 bcopy(ip, &san.sin_addr.s_addr, 4);
104 fd = socket(AF_INET, SOCK_DGRAM, 0);
105 (void) sendto(fd, ip, 4, 0,
106 (struct sockaddr *)&san, sizeof(san));
107 sleep(1);
108 (void) close(fd);
109 goto tryagain;
110 }
111 fprintf(stderr, "(%s):", inet_ntoa(sin->sin_addr));
112 if (errno != ENXIO)
113 perror("SIOCGARP");
114 return (-1);
115 }
116
117 if ((ar.arp_ha.sa_data[0] == 0) && (ar.arp_ha.sa_data[1] == 0) &&
118 (ar.arp_ha.sa_data[2] == 0) && (ar.arp_ha.sa_data[3] == 0) &&
119 (ar.arp_ha.sa_data[4] == 0) && (ar.arp_ha.sa_data[5] == 0)) {
120 fprintf(stderr, "(%s):", inet_ntoa(sin->sin_addr));
121 return (-1);
122 }
123
124 bcopy(ar.arp_ha.sa_data, ether, 6);
125 savearp:
126 bcopy(ether, ethersave, 6);
127 bcopy(ip, ipsave, 4);
128 return (0);
129 }
130