contrib/ipfilter/ipsend/arp.c

   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 }