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
inet_addr_host(INET_ADDR_LIST * addr_list,const char * hostname)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
main(int argc,char ** argv)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