Home | History | Annotate | Line # | Download | only in util 
      1 /*	$NetBSD: inet_addr_host.c,v 1.3 2022/10/08 16:12:50 christos Exp $	*/
      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 /*	Wietse Venema
     39 /*	Google, Inc.
     40 /*	111 8th Avenue
     41 /*	New York, NY 10011, USA
     42 /*--*/
     43 
     44 /* System library. */
     45 
     46 #include <sys_defs.h>
     47 #include <netinet/in.h>
     48 #include <arpa/inet.h>
     49 #include <sys/socket.h>
     50 #include <netdb.h>
     51 #include <stdlib.h>
     52 #include <string.h>
     53 #include <unistd.h>
     54 
     55 /* Utility library. */
     56 
     57 #include <mymalloc.h>
     58 #include <inet_addr_list.h>
     59 #include <inet_addr_host.h>
     60 #include <myaddrinfo.h>
     61 #include <sock_addr.h>
     62 #include <inet_proto.h>
     63 #include <msg.h>
     64 
     65 /* inet_addr_host - look up address list for host */
     66 
     67 int     inet_addr_host(INET_ADDR_LIST *addr_list, const char *hostname)
     68 {
     69     const char *myname = "inet_addr_host";
     70     int     sock;
     71     struct addrinfo *res0;
     72     struct addrinfo *res;
     73     int     aierr;
     74     ssize_t hostnamelen;
     75     const char *hname;
     76     const char *serv;
     77     int     initial_count = addr_list->used;
     78     const INET_PROTO_INFO *proto_info;
     79 
     80     /*
     81      * The use of square brackets around an IPv6 addresses is required, even
     82      * though we don't enforce it as it'd make the code unnecessarily
     83      * complicated.
     84      *
     85      * XXX AIX 5.1 getaddrinfo() does not allow "0" as service, regardless of
     86      * whether or not a host is specified.
     87      */
     88     if (*hostname == 0) {
     89 	hname = 0;
     90 	serv = "1";
     91     } else if (*hostname == '['
     92 	       && hostname[(hostnamelen = strlen(hostname)) - 1] == ']') {
     93 	hname = mystrndup(hostname + 1, hostnamelen - 2);
     94 	serv = 0;
     95     } else {
     96 	hname = hostname;
     97 	serv = 0;
     98     }
     99 
    100     proto_info = inet_proto_info();
    101     if ((aierr = hostname_to_sockaddr(hname, serv, SOCK_STREAM, &res0)) == 0) {
    102 	for (res = res0; res; res = res->ai_next) {
    103 
    104 	    /*
    105 	     * Safety net.
    106 	     */
    107 	    if (strchr((char *) proto_info->sa_family_list, res->ai_family) == 0) {
    108 		msg_info("%s: skipping address family %d for host \"%s\"",
    109 			 myname, res->ai_family, hostname);
    110 		continue;
    111 	    }
    112 
    113 	    /*
    114 	     * On Linux systems it is not unusual for user-land to be out of
    115 	     * sync with kernel-land. When this is the case we try to be
    116 	     * helpful and filter out address families that the library
    117 	     * claims to understand but that are not supported by the kernel.
    118 	     */
    119 	    if ((sock = socket(res->ai_family, SOCK_STREAM, 0)) < 0) {
    120 		msg_warn("%s: skipping address family %d: %m",
    121 			 myname, res->ai_family);
    122 		continue;
    123 	    }
    124 	    if (close(sock))
    125 		msg_warn("%s: close socket: %m", myname);
    126 
    127 	    inet_addr_list_append(addr_list, res->ai_addr);
    128 	}
    129 	freeaddrinfo(res0);
    130     }
    131     if (hname && hname != hostname)
    132 	myfree((void *) hname);
    133 
    134     return (addr_list->used - initial_count);
    135 }
    136 
    137 #ifdef TEST
    138 
    139 #include <msg.h>
    140 #include <vstream.h>
    141 #include <msg_vstream.h>
    142 #include <sock_addr.h>
    143 
    144 int     main(int argc, char **argv)
    145 {
    146     INET_ADDR_LIST list;
    147     struct sockaddr_storage *sa;
    148     MAI_HOSTADDR_STR hostaddr;
    149     INET_PROTO_INFO *proto_info;
    150 
    151     msg_vstream_init(argv[0], VSTREAM_ERR);
    152 
    153     if (argc < 3)
    154 	msg_fatal("usage: %s protocols hostname...", argv[0]);
    155 
    156     proto_info = inet_proto_init(argv[0], argv[1]);
    157     argv += 1;
    158 
    159     while (--argc && *++argv) {
    160 	inet_addr_list_init(&list);
    161 	if (inet_addr_host(&list, *argv) == 0)
    162 	    msg_fatal("not found: %s", *argv);
    163 
    164 	for (sa = list.addrs; sa < list.addrs + list.used; sa++) {
    165 	    SOCKADDR_TO_HOSTADDR(SOCK_ADDR_PTR(sa), SOCK_ADDR_LEN(sa),
    166 				 &hostaddr, (MAI_SERVPORT_STR *) 0, 0);
    167 	    vstream_printf("%s\t%s\n", *argv, hostaddr.buf);
    168 	}
    169 	vstream_fflush(VSTREAM_OUT);
    170 	inet_addr_list_free(&list);
    171     }
    172     return (0);
    173 }
    174 
    175 #endif
    176