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