[backfire] merge r27666
[openwrt-10.03/.git] / package / resolveip / src / resolveip.c
1 /*
2  * Based on code found at https://dev.openwrt.org/ticket/4876 .
3  * Extended by Jo-Philipp Wich <jow@openwrt.org> for use in OpenWrt.
4  *
5  * You may use this program under the terms of the GPLv2 license.
6  */
7
8 #include <string.h>
9 #include <stdio.h>
10 #include <sys/types.h>
11 #include <sys/socket.h>
12 #include <netdb.h>
13 #include <arpa/inet.h>
14 #include <netinet/in.h>
15 #include <stdlib.h>
16 #include <unistd.h>
17 #include <signal.h>
18
19
20 static void abort_query(int sig)
21 {
22         exit(1);
23 }
24
25 static void show_usage(void)
26 {
27         printf("Usage:\n");
28         printf("        resolveip -h\n");
29         printf("        resolveip [-t timeout] hostname\n");
30         printf("        resolveip -4 [-t timeout] hostname\n");
31         printf("        resolveip -6 [-t timeout] hostname\n");
32         exit(255);
33 }
34
35 int main(int argc, char **argv)
36 {
37         int timeout = 3;
38         char opt;
39     char ipaddr[INET6_ADDRSTRLEN];
40     void *addr;
41     struct addrinfo *res, *rp;
42         struct sigaction sa = { .sa_handler = &abort_query };
43     struct addrinfo hints = {
44         .ai_family   = AF_UNSPEC,
45         .ai_socktype = SOCK_STREAM,
46         .ai_protocol = IPPROTO_TCP,
47         .ai_flags    = 0
48     };
49
50         while ((opt = getopt(argc, argv, "46t:h")) > -1)
51         {
52                 switch (opt)
53                 {
54                         case '4':
55                                 hints.ai_family = AF_INET;
56                                 break;
57
58                         case '6':
59                                 hints.ai_family = AF_INET6;
60                                 break;
61
62                         case 't':
63                                 timeout = atoi(optarg);
64                                 if (timeout <= 0)
65                                         show_usage();
66                                 break;
67
68                         case 'h':
69                                 show_usage();
70                                 break;
71                 }
72         }
73
74         if (!argv[optind])
75                 show_usage();
76
77         sigaction(SIGALRM, &sa, NULL);
78         alarm(timeout);
79
80         if (getaddrinfo(argv[optind], NULL, &hints, &res))
81                 exit(2);
82
83     for (rp = res; rp != NULL; rp = rp->ai_next)
84     {
85                 addr = (rp->ai_family == AF_INET)
86                         ? (void *)&((struct sockaddr_in *)rp->ai_addr)->sin_addr
87                         : (void *)&((struct sockaddr_in6 *)rp->ai_addr)->sin6_addr
88                 ;
89
90                 if (!inet_ntop(rp->ai_family, addr, ipaddr, INET6_ADDRSTRLEN - 1))
91                         exit(3);
92
93                 printf("%s\n", ipaddr);
94         }
95
96         freeaddrinfo(res);
97         exit(0);
98 }