1 /* $FreeBSD$ */ 2 3 /* 4 * arp.c (C) 1995-1998 Darren Reed 5 * 6 * See the IPFILTER.LICENCE file for details on licencing. 7 */ 8 #if !defined(lint) 9 static const char sccsid[] = "@(#)arp.c 1.4 1/11/96 (C)1995 Darren Reed"; 10 static const char rcsid[] = "@(#)$Id$"; 11 #endif 12 #include <sys/types.h> 13 #include <sys/socket.h> 14 # include <sys/sockio.h> 15 #include <sys/ioctl.h> 16 #include <netinet/in_systm.h> 17 #include <netinet/in.h> 18 #include <net/if.h> 19 #include <netinet/if_ether.h> 20 # include <net/if_arp.h> 21 #include <netinet/in.h> 22 #include <netinet/ip.h> 23 #include <netinet/ip_var.h> 24 #include <netinet/tcp.h> 25 #include <stdio.h> 26 #include <errno.h> 27 #include <netdb.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 */ 37 int resolve(host, address) 38 char *host, *address; 39 { 40 struct hostent *hp; 41 u_long add; 42 43 add = inet_addr(host); 44 if (add == -1) 45 { 46 if (!(hp = gethostbyname(host))) 47 { 48 fprintf(stderr, "unknown host: %s\n", host); 49 return -1; 50 } 51 bcopy((char *)hp->h_addr, (char *)address, 4); 52 return 0; 53 } 54 bcopy((char*)&add, address, 4); 55 return 0; 56 } 57 58 /* 59 * ARP for the MAC address corresponding 60 * to the IP address. This taken from 61 * some BSD program, I cant remember which. 62 */ 63 int arp(ip, ether) 64 char *ip; 65 char *ether; 66 { 67 static int sfd = -1; 68 static char ethersave[6], ipsave[4]; 69 struct arpreq ar; 70 struct sockaddr_in *sin, san; 71 struct hostent *hp; 72 int fd; 73 74 #ifdef IPSEND 75 if (arp_getipv4(ip, ether) == 0) 76 return 0; 77 #endif 78 if (!bcmp(ipsave, ip, 4)) { 79 bcopy(ethersave, ether, 6); 80 return 0; 81 } 82 fd = -1; 83 bzero((char *)&ar, sizeof(ar)); 84 sin = (struct sockaddr_in *)&ar.arp_pa; 85 sin->sin_family = AF_INET; 86 bcopy(ip, (char *)&sin->sin_addr.s_addr, 4); 87 if ((hp = gethostbyaddr(ip, 4, AF_INET))) 88 # if SOLARIS && (SOLARIS2 >= 10) 89 if (!(ether_hostton(hp->h_name, (struct ether_addr *)ether))) 90 # else 91 if (!(ether_hostton(hp->h_name, ether))) 92 # endif 93 goto savearp; 94 95 if (sfd == -1) 96 if ((sfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) 97 { 98 perror("arp: socket"); 99 return -1; 100 } 101 tryagain: 102 if (ioctl(sfd, SIOCGARP, (caddr_t)&ar) == -1) 103 { 104 if (fd == -1) 105 { 106 bzero((char *)&san, sizeof(san)); 107 san.sin_family = AF_INET; 108 san.sin_port = htons(1); 109 bcopy(ip, &san.sin_addr.s_addr, 4); 110 fd = socket(AF_INET, SOCK_DGRAM, 0); 111 (void) sendto(fd, ip, 4, 0, 112 (struct sockaddr *)&san, sizeof(san)); 113 sleep(1); 114 (void) close(fd); 115 goto tryagain; 116 } 117 fprintf(stderr, "(%s):", inet_ntoa(sin->sin_addr)); 118 if (errno != ENXIO) 119 perror("SIOCGARP"); 120 return -1; 121 } 122 123 if ((ar.arp_ha.sa_data[0] == 0) && (ar.arp_ha.sa_data[1] == 0) && 124 (ar.arp_ha.sa_data[2] == 0) && (ar.arp_ha.sa_data[3] == 0) && 125 (ar.arp_ha.sa_data[4] == 0) && (ar.arp_ha.sa_data[5] == 0)) { 126 fprintf(stderr, "(%s):", inet_ntoa(sin->sin_addr)); 127 return -1; 128 } 129 130 bcopy(ar.arp_ha.sa_data, ether, 6); 131 savearp: 132 bcopy(ether, ethersave, 6); 133 bcopy(ip, ipsave, 4); 134 return 0; 135 } 136