external/ibm-public/postfix/dist/src/util/inet_addr_host.c

   1 /*      $NetBSD$        */
   2
   3 /*++
   4 /* NAME
   5 /*      inet_addr_host 3
   6 /* SUMMARY
   7 /*      determine all host internet interface addresses
   8 /* SYNOPSIS
   9 /*      #include <inet_addr_host.h>
  10 /*
  11 /*      int     inet_addr_host(addr_list, hostname)
  12 /*      INET_ADDR_LIST *addr_list;
  13 /*      const char *hostname;
  14 /* DESCRIPTION
  15 /*      inet_addr_host() determines all interface addresses of the
  16 /*      named host. The host may be specified as a symbolic name,
  17 /*      or as a numerical address. An empty host expands as the
  18 /*      wild-card address.  Address results are appended to
  19 /*      the specified address list. The result value is the number
  20 /*      of addresses appended to the list.
  21 /* DIAGNOSTICS
  22 /*      Fatal errors: out of memory.
  23 /* BUGS
  24 /*      This code uses the name service, so it talks to the network,
  25 /*      and that may not be desirable.
  26 /* SEE ALSO
  27 /*      inet_addr_list(3) address list management
  28 /* LICENSE
  29 /* .ad
  30 /* .fi
  31 /*      The Secure Mailer license must be distributed with this software.
  32 /* AUTHOR(S)
  33 /*      Wietse Venema
  34 /*      IBM T.J. Watson Research
  35 /*      P.O. Box 704
  36 /*      Yorktown Heights, NY 10598, USA
  37 /*--*/
  38
  39 /* System library. */
  40
  41 #include <sys_defs.h>
  42 #include <netinet/in.h>
  43 #include <arpa/inet.h>
  44 #include <sys/socket.h>
  45 #include <netdb.h>
  46 #include <stdlib.h>
  47 #include <string.h>
  48 #include <unistd.h>
  49
  50 /* Utility library. */
  51
  52 #include <mymalloc.h>
  53 #include <inet_addr_list.h>
  54 #include <inet_addr_host.h>
  55 #include <myaddrinfo.h>
  56 #include <sock_addr.h>
  57 #include <inet_proto.h>
  58 #include <msg.h>
  59
  60 /* inet_addr_host - look up address list for host */
  61
  62 int     inet_addr_host(INET_ADDR_LIST *addr_list, const char *hostname)
  63 {
  64     const char *myname = "inet_addr_host";
  65     int     sock;
  66     struct addrinfo *res0;
  67     struct addrinfo *res;
  68     int     aierr;
  69     ssize_t hostnamelen;
  70     const char *hname;
  71     const char *serv;
  72     int     initial_count = addr_list->used;
  73     INET_PROTO_INFO *proto_info;
  74
  75     /*
  76      * The use of square brackets around an IPv6 addresses is required, even
  77      * though we don't enforce it as it'd make the code unnecessarily
  78      * complicated.
  79      *
  80      * XXX AIX 5.1 getaddrinfo() does not allow "0" as service, regardless of
  81      * whether or not a host is specified.
  82      */
  83     if (*hostname == 0) {
  84         hname = 0;
  85         serv = "1";
  86     } else if (*hostname == '['
  87                && hostname[(hostnamelen = strlen(hostname)) - 1] == ']') {
  88         hname = mystrndup(hostname + 1, hostnamelen - 2);
  89         serv = 0;
  90     } else {
  91         hname = hostname;
  92         serv = 0;
  93     }
  94
  95     proto_info = inet_proto_info();
  96     if ((aierr = hostname_to_sockaddr(hname, serv, SOCK_STREAM, &res0)) == 0) {
  97         for (res = res0; res; res = res->ai_next) {
  98
  99             /*
 100              * Safety net.
 101              */
 102             if (strchr((char *) proto_info->sa_family_list, res->ai_family) == 0) {
 103                 msg_info("%s: skipping address family %d for host \"%s\"",
 104                          myname, res->ai_family, hostname);
 105                 continue;
 106             }
 107
 108             /*
 109              * On Linux systems it is not unusual for user-land to be out of
 110              * sync with kernel-land. When this is the case we try to be
 111              * helpful and filter out address families that the library
 112              * claims to understand but that are not supported by the kernel.
 113              */
 114             if ((sock = socket(res->ai_family, SOCK_STREAM, 0)) < 0) {
 115                 msg_warn("%s: skipping address family %d: %m",
 116                          myname, res->ai_family);
 117                 continue;
 118             }
 119             if (close(sock))
 120                 msg_warn("%s: close socket: %m", myname);
 121
 122             inet_addr_list_append(addr_list, res->ai_addr);
 123         }
 124         freeaddrinfo(res0);
 125     }
 126     if (hname && hname != hostname)
 127         myfree((char *) hname);
 128
 129     return (addr_list->used - initial_count);
 130 }
 131
 132 #ifdef TEST
 133
 134 #include <msg.h>
 135 #include <vstream.h>
 136 #include <msg_vstream.h>
 137 #include <sock_addr.h>
 138
 139 int     main(int argc, char **argv)
 140 {
 141     INET_ADDR_LIST list;
 142     struct sockaddr_storage *sa;
 143     MAI_HOSTADDR_STR hostaddr;
 144     INET_PROTO_INFO *proto_info;
 145
 146     msg_vstream_init(argv[0], VSTREAM_ERR);
 147
 148     if (argc < 3)
 149         msg_fatal("usage: %s protocols hostname...", argv[0]);
 150
 151     proto_info = inet_proto_init(argv[0], argv[1]);
 152     argv += 1;
 153
 154     while (--argc && *++argv) {
 155         inet_addr_list_init(&list);
 156         if (inet_addr_host(&list, *argv) == 0)
 157             msg_fatal("not found: %s", *argv);
 158
 159         for (sa = list.addrs; sa < list.addrs + list.used; sa++) {
 160             SOCKADDR_TO_HOSTADDR(SOCK_ADDR_PTR(sa), SOCK_ADDR_LEN(sa),
 161                                  &hostaddr, (MAI_SERVPORT_STR *) 0, 0);
 162             vstream_printf("%s\t%s\n", *argv, hostaddr.buf);
 163         }
 164         vstream_fflush(VSTREAM_OUT);
 165         inet_addr_list_free(&list);
 166     }
 167     return (0);
 168 }
 169
 170 #endif