| 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 | } |
| 99 | |
