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
67int     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
144int     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