dist/ipf/ipsend/arp.c

   1 /*      $NetBSD$        */
   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: arp.c,v 2.8.2.2 2007/02/17 12:41:50 darrenr Exp";
  11 #endif
  12 #include <sys/types.h>
  13 #include <sys/socket.h>
  14 #if !defined(ultrix) && !defined(hpux) && !defined(__hpux) && !defined(__osf__) && !defined(_AIX51)
  15 # include <sys/sockio.h>
  16 #endif
  17 #include <sys/ioctl.h>
  18 #include <netinet/in_systm.h>
  19 #include <netinet/in.h>
  20 #ifdef __osf__
  21 # include "radix_ipf_local.h"
  22 #endif
  23 #include <net/if.h>
  24 #include <netinet/if_ether.h>
  25 #ifndef ultrix
  26 # include <net/if_arp.h>
  27 #endif
  28 #include <netinet/in.h>
  29 #include <netinet/ip.h>
  30 #include <netinet/ip_var.h>
  31 #include <netinet/tcp.h>
  32 #include <stdio.h>
  33 #include <errno.h>
  34 #include <netdb.h>
  35 #include "ipsend.h"
  36 #include "iplang/iplang.h"
  37
  38
  39 /*
  40  * lookup host and return
  41  * its IP address in address
  42  * (4 bytes)
  43  */
  44 int     resolve(host, address)
  45 char    *host, *address;
  46 {
  47         struct  hostent *hp;
  48         u_long  add;
  49
  50         add = inet_addr(host);
  51         if (add == -1)
  52             {
  53                 if (!(hp = gethostbyname(host)))
  54                     {
  55                         fprintf(stderr, "unknown host: %s\n", host);
  56                         return -1;
  57                     }
  58                 bcopy((char *)hp->h_addr, (char *)address, 4);
  59                 return 0;
  60         }
  61         bcopy((char*)&add, address, 4);
  62         return 0;
  63 }
  64
  65 /*
  66  * ARP for the MAC address corresponding
  67  * to the IP address.  This taken from
  68  * some BSD program, I cant remember which.
  69  */
  70 int     arp(ip, ether)
  71 char    *ip;
  72 char    *ether;
  73 {
  74         static  int     sfd = -1;
  75         static  char    ethersave[6], ipsave[4];
  76         struct  arpreq  ar;
  77         struct  sockaddr_in     *sin, san;
  78         struct  hostent *hp;
  79         int     fd;
  80
  81 #ifdef  IPSEND
  82         if (arp_getipv4(ip, ether) == 0)
  83                 return 0;
  84 #endif
  85         if (!bcmp(ipsave, ip, 4)) {
  86                 bcopy(ethersave, ether, 6);
  87                 return 0;
  88         }
  89         fd = -1;
  90         bzero((char *)&ar, sizeof(ar));
  91         sin = (struct sockaddr_in *)&ar.arp_pa;
  92         sin->sin_family = AF_INET;
  93         bcopy(ip, (char *)&sin->sin_addr.s_addr, 4);
  94 #ifndef hpux
  95         if ((hp = gethostbyaddr(ip, 4, AF_INET)))
  96 # if SOLARIS && (SOLARIS2 >= 10)
  97                 if (!(ether_hostton(hp->h_name, (struct ether_addr *)ether)))
  98 # else
  99                 if (!(ether_hostton(hp->h_name, ether)))
 100 # endif
 101                         goto savearp;
 102 #endif
 103
 104         if (sfd == -1)
 105                 if ((sfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
 106                     {
 107                         perror("arp: socket");
 108                         return -1;
 109                     }
 110 tryagain:
 111         if (ioctl(sfd, SIOCGARP, (caddr_t)&ar) == -1)
 112             {
 113                 if (fd == -1)
 114                     {
 115                         bzero((char *)&san, sizeof(san));
 116                         san.sin_family = AF_INET;
 117                         san.sin_port = htons(1);
 118                         bcopy(ip, &san.sin_addr.s_addr, 4);
 119                         fd = socket(AF_INET, SOCK_DGRAM, 0);
 120                         (void) sendto(fd, ip, 4, 0,
 121                                       (struct sockaddr *)&san, sizeof(san));
 122                         sleep(1);
 123                         (void) close(fd);
 124                         goto tryagain;
 125                     }
 126                 fprintf(stderr, "(%s):", inet_ntoa(sin->sin_addr));
 127                 if (errno != ENXIO)
 128                         perror("SIOCGARP");
 129                 return -1;
 130             }
 131
 132         if ((ar.arp_ha.sa_data[0] == 0) && (ar.arp_ha.sa_data[1] == 0) &&
 133             (ar.arp_ha.sa_data[2] == 0) && (ar.arp_ha.sa_data[3] == 0) &&
 134             (ar.arp_ha.sa_data[4] == 0) && (ar.arp_ha.sa_data[5] == 0)) {
 135                 fprintf(stderr, "(%s):", inet_ntoa(sin->sin_addr));
 136                 return -1;
 137         }
 138
 139         bcopy(ar.arp_ha.sa_data, ether, 6);
 140 savearp:
 141         bcopy(ether, ethersave, 6);
 142         bcopy(ip, ipsave, 4);
 143         return 0;
 144 }