Contents of /tags/mkinitrd-6_0_5/mkinitrd-magellan/busybox/networking/nslookup.c
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This commit was manufactured by cvs2svn to create tag 'mkinitrd-6_0_5'.
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * Mini nslookup implementation for busybox |
4 | * |
5 | * Copyright (C) 1999,2000 by Lineo, inc. and John Beppu |
6 | * Copyright (C) 1999,2000,2001 by John Beppu <beppu@codepoet.org> |
7 | * |
8 | * Correct default name server display and explicit name server option |
9 | * added by Ben Zeckel <bzeckel@hmc.edu> June 2001 |
10 | * |
11 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. |
12 | */ |
13 | |
14 | #include <resolv.h> |
15 | #include "busybox.h" |
16 | |
17 | /* |
18 | * I'm only implementing non-interactive mode; |
19 | * I totally forgot nslookup even had an interactive mode. |
20 | */ |
21 | |
22 | /* Examples of 'standard' nslookup output |
23 | * $ nslookup yahoo.com |
24 | * Server: 128.193.0.10 |
25 | * Address: 128.193.0.10#53 |
26 | * |
27 | * Non-authoritative answer: |
28 | * Name: yahoo.com |
29 | * Address: 216.109.112.135 |
30 | * Name: yahoo.com |
31 | * Address: 66.94.234.13 |
32 | * |
33 | * $ nslookup 204.152.191.37 |
34 | * Server: 128.193.4.20 |
35 | * Address: 128.193.4.20#53 |
36 | * |
37 | * Non-authoritative answer: |
38 | * 37.191.152.204.in-addr.arpa canonical name = 37.32-27.191.152.204.in-addr.arpa. |
39 | * 37.32-27.191.152.204.in-addr.arpa name = zeus-pub2.kernel.org. |
40 | * |
41 | * Authoritative answers can be found from: |
42 | * 32-27.191.152.204.in-addr.arpa nameserver = ns1.kernel.org. |
43 | * 32-27.191.152.204.in-addr.arpa nameserver = ns2.kernel.org. |
44 | * 32-27.191.152.204.in-addr.arpa nameserver = ns3.kernel.org. |
45 | * ns1.kernel.org internet address = 140.211.167.34 |
46 | * ns2.kernel.org internet address = 204.152.191.4 |
47 | * ns3.kernel.org internet address = 204.152.191.36 |
48 | */ |
49 | |
50 | static int sockaddr_to_dotted(struct sockaddr *saddr, char *buf, int buflen) |
51 | { |
52 | if (buflen <= 0) return -1; |
53 | buf[0] = '\0'; |
54 | if (saddr->sa_family == AF_INET) { |
55 | inet_ntop(AF_INET, &((struct sockaddr_in*)saddr)->sin_addr, buf, buflen); |
56 | return 0; |
57 | } |
58 | if (saddr->sa_family == AF_INET6) { |
59 | inet_ntop(AF_INET6, &((struct sockaddr_in6*)saddr)->sin6_addr, buf, buflen); |
60 | return 0; |
61 | } |
62 | return -1; |
63 | } |
64 | |
65 | static int print_host(const char *hostname, const char *header) |
66 | { |
67 | char str[128]; /* IPv6 address will fit, hostnames hopefully too */ |
68 | struct addrinfo *result = NULL; |
69 | int rc; |
70 | struct addrinfo hint; |
71 | |
72 | memset(&hint, 0 , sizeof(hint)); |
73 | /* hint.ai_family = AF_UNSPEC; - zero anyway */ |
74 | /* Needed. Or else we will get each address thrice (or more) |
75 | * for each possible socket type (tcp,udp,raw...): */ |
76 | hint.ai_socktype = SOCK_STREAM; |
77 | // hint.ai_flags = AI_CANONNAME; |
78 | rc = getaddrinfo(hostname, NULL /*service*/, &hint, &result); |
79 | if (!rc) { |
80 | struct addrinfo *cur = result; |
81 | // printf("%s\n", cur->ai_canonname); ? |
82 | while (cur) { |
83 | sockaddr_to_dotted(cur->ai_addr, str, sizeof(str)); |
84 | printf("%s %s\nAddress: %s", header, hostname, str); |
85 | str[0] = ' '; |
86 | if (getnameinfo(cur->ai_addr, cur->ai_addrlen, str+1, sizeof(str)-1, NULL, 0, NI_NAMEREQD)) |
87 | str[0] = '\0'; |
88 | puts(str); |
89 | cur = cur->ai_next; |
90 | } |
91 | } else { |
92 | bb_error_msg("getaddrinfo('%s') failed: %s", hostname, gai_strerror(rc)); |
93 | } |
94 | freeaddrinfo(result); |
95 | return (rc != 0); |
96 | } |
97 | |
98 | |
99 | /* alter the global _res nameserver structure to use |
100 | an explicit dns server instead of what is in /etc/resolv.h */ |
101 | static void set_default_dns(char *server) |
102 | { |
103 | struct in_addr server_in_addr; |
104 | |
105 | if (inet_pton(AF_INET, server, &server_in_addr) > 0) { |
106 | _res.nscount = 1; |
107 | _res.nsaddr_list[0].sin_addr = server_in_addr; |
108 | } |
109 | } |
110 | |
111 | |
112 | /* lookup the default nameserver and display it */ |
113 | static void server_print(void) |
114 | { |
115 | char str[INET6_ADDRSTRLEN]; |
116 | |
117 | sockaddr_to_dotted((struct sockaddr*)&_res.nsaddr_list[0], str, sizeof(str)); |
118 | print_host(str, "Server:"); |
119 | puts(""); |
120 | } |
121 | |
122 | |
123 | int nslookup_main(int argc, char **argv) |
124 | { |
125 | /* |
126 | * initialize DNS structure _res used in printing the default |
127 | * name server and in the explicit name server option feature. |
128 | */ |
129 | |
130 | res_init(); |
131 | |
132 | /* |
133 | * We allow 1 or 2 arguments. |
134 | * The first is the name to be looked up and the second is an |
135 | * optional DNS server with which to do the lookup. |
136 | * More than 3 arguments is an error to follow the pattern of the |
137 | * standard nslookup |
138 | */ |
139 | |
140 | if (argc < 2 || *argv[1] == '-' || argc > 3) |
141 | bb_show_usage(); |
142 | else if(argc == 3) |
143 | set_default_dns(argv[2]); |
144 | |
145 | server_print(); |
146 | return print_host(argv[1], "Name: "); |
147 | } |
148 | |
149 | /* $Id: nslookup.c,v 1.1 2007-09-01 22:43:53 niro Exp $ */ |