blob: 5aa2b35d2a134ffa2e3fc54b8de6e40969ca6f5b [file] [log] [blame]
Erik Andersene49d5ec2000-02-08 19:58:47 +00001/* vi: set sw=4 ts=4: */
Denys Vlasenko0dd3be82018-04-14 14:05:45 +02002
Denys Vlasenko47367e12016-11-23 09:05:14 +01003//config:config NSLOOKUP
Denys Vlasenkob097a842018-12-28 03:20:17 +01004//config: bool "nslookup (9.7 kb)"
Denys Vlasenko47367e12016-11-23 09:05:14 +01005//config: default y
6//config: help
Denys Vlasenko72089cf2017-07-21 09:50:55 +02007//config: nslookup is a tool to query Internet name servers.
Denys Vlasenko0dd3be82018-04-14 14:05:45 +02008//config:
Denys Vlasenkod4461ef2018-04-15 12:01:46 +02009//config:config FEATURE_NSLOOKUP_BIG
Denys Vlasenko0dd3be82018-04-14 14:05:45 +020010//config: bool "Use internal resolver code instead of libc"
11//config: depends on NSLOOKUP
12//config: default y
13//config:
14//config:config FEATURE_NSLOOKUP_LONG_OPTIONS
15//config: bool "Enable long options"
16//config: default y
Denys Vlasenkod4461ef2018-04-15 12:01:46 +020017//config: depends on FEATURE_NSLOOKUP_BIG && LONG_OPTS
Denys Vlasenko47367e12016-11-23 09:05:14 +010018
19//applet:IF_NSLOOKUP(APPLET(nslookup, BB_DIR_USR_BIN, BB_SUID_DROP))
20
21//kbuild:lib-$(CONFIG_NSLOOKUP) += nslookup.o
John Beppub332e772000-01-29 12:59:01 +000022
Pere Orga5bc8c002011-04-11 03:29:49 +020023//usage:#define nslookup_trivial_usage
Denys Vlasenko6cdc3192018-04-15 12:49:11 +020024//usage: IF_FEATURE_NSLOOKUP_BIG("[-type=QUERY_TYPE] [-debug] ") "HOST [DNS_SERVER]"
Pere Orga5bc8c002011-04-11 03:29:49 +020025//usage:#define nslookup_full_usage "\n\n"
Denys Vlasenkod4461ef2018-04-15 12:01:46 +020026//usage: "Query DNS about HOST"
Denys Vlasenko4b6091f2018-04-15 12:57:32 +020027//usage: IF_FEATURE_NSLOOKUP_BIG("\n")
28//usage: IF_FEATURE_NSLOOKUP_BIG("\nQUERY_TYPE: soa,ns,a,"IF_FEATURE_IPV6("aaaa,")"cname,mx,txt,ptr,any")
Pere Orga5bc8c002011-04-11 03:29:49 +020029//usage:#define nslookup_example_usage
30//usage: "$ nslookup localhost\n"
31//usage: "Server: default\n"
32//usage: "Address: default\n"
33//usage: "\n"
34//usage: "Name: debian\n"
35//usage: "Address: 127.0.0.1\n"
36
Eric Andersendab3d462001-06-12 22:21:24 +000037#include <resolv.h>
Denys Vlasenko0dd3be82018-04-14 14:05:45 +020038#include <net/if.h> /* for IFNAMSIZ */
39//#include <arpa/inet.h>
40//#include <netdb.h>
Denis Vlasenkob6adbf12007-05-26 19:00:18 +000041#include "libbb.h"
Denys Vlasenko0dd3be82018-04-14 14:05:45 +020042#include "common_bufsiz.h"
43
44
Denys Vlasenkod4461ef2018-04-15 12:01:46 +020045#if !ENABLE_FEATURE_NSLOOKUP_BIG
Denys Vlasenko0dd3be82018-04-14 14:05:45 +020046
47/*
48 * Mini nslookup implementation for busybox
49 *
50 * Copyright (C) 1999,2000 by Lineo, inc. and John Beppu
51 * Copyright (C) 1999,2000,2001 by John Beppu <beppu@codepoet.org>
52 *
53 * Correct default name server display and explicit name server option
54 * added by Ben Zeckel <bzeckel@hmc.edu> June 2001
55 *
56 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
57 */
John Beppub332e772000-01-29 12:59:01 +000058
John Beppu50bc1012000-01-30 09:47:16 +000059/*
Denis Vlasenko391ffa12008-11-04 21:44:28 +000060 * I'm only implementing non-interactive mode;
61 * I totally forgot nslookup even had an interactive mode.
62 *
63 * This applet is the only user of res_init(). Without it,
64 * you may avoid pulling in _res global from libc.
John Beppu50bc1012000-01-30 09:47:16 +000065 */
John Beppub332e772000-01-29 12:59:01 +000066
Denis Vlasenkoebe578a2006-10-26 17:17:59 +000067/* Examples of 'standard' nslookup output
68 * $ nslookup yahoo.com
69 * Server: 128.193.0.10
70 * Address: 128.193.0.10#53
Denis Vlasenkof7996f32007-01-11 17:20:00 +000071 *
Denis Vlasenkoebe578a2006-10-26 17:17:59 +000072 * Non-authoritative answer:
73 * Name: yahoo.com
74 * Address: 216.109.112.135
75 * Name: yahoo.com
76 * Address: 66.94.234.13
77 *
78 * $ nslookup 204.152.191.37
79 * Server: 128.193.4.20
80 * Address: 128.193.4.20#53
Denis Vlasenkof7996f32007-01-11 17:20:00 +000081 *
Denis Vlasenkoebe578a2006-10-26 17:17:59 +000082 * Non-authoritative answer:
83 * 37.191.152.204.in-addr.arpa canonical name = 37.32-27.191.152.204.in-addr.arpa.
84 * 37.32-27.191.152.204.in-addr.arpa name = zeus-pub2.kernel.org.
Denis Vlasenkof7996f32007-01-11 17:20:00 +000085 *
Denis Vlasenkoebe578a2006-10-26 17:17:59 +000086 * Authoritative answers can be found from:
87 * 32-27.191.152.204.in-addr.arpa nameserver = ns1.kernel.org.
88 * 32-27.191.152.204.in-addr.arpa nameserver = ns2.kernel.org.
89 * 32-27.191.152.204.in-addr.arpa nameserver = ns3.kernel.org.
90 * ns1.kernel.org internet address = 140.211.167.34
91 * ns2.kernel.org internet address = 204.152.191.4
92 * ns3.kernel.org internet address = 204.152.191.36
93 */
John Beppub332e772000-01-29 12:59:01 +000094
Denis Vlasenkoebe578a2006-10-26 17:17:59 +000095static int print_host(const char *hostname, const char *header)
John Beppub332e772000-01-29 12:59:01 +000096{
Denis Vlasenko42823d52007-02-04 02:39:08 +000097 /* We can't use xhost2sockaddr() - we want to get ALL addresses,
Denis Vlasenko448f0242007-01-22 22:43:05 +000098 * not just one */
Denis Vlasenko448f0242007-01-22 22:43:05 +000099 struct addrinfo *result = NULL;
100 int rc;
101 struct addrinfo hint;
102
103 memset(&hint, 0 , sizeof(hint));
104 /* hint.ai_family = AF_UNSPEC; - zero anyway */
105 /* Needed. Or else we will get each address thrice (or more)
106 * for each possible socket type (tcp,udp,raw...): */
107 hint.ai_socktype = SOCK_STREAM;
108 // hint.ai_flags = AI_CANONNAME;
109 rc = getaddrinfo(hostname, NULL /*service*/, &hint, &result);
110
Vitaly Magerya7f4b7692011-03-22 20:14:26 +0100111 if (rc == 0) {
Denis Vlasenko448f0242007-01-22 22:43:05 +0000112 struct addrinfo *cur = result;
113 unsigned cnt = 0;
114
115 printf("%-10s %s\n", header, hostname);
Denis Vlasenkofeb7ae72007-10-01 12:05:12 +0000116 // puts(cur->ai_canonname); ?
Denis Vlasenko448f0242007-01-22 22:43:05 +0000117 while (cur) {
118 char *dotted, *revhost;
Denis Vlasenkoa27a11b2007-08-18 14:16:39 +0000119 dotted = xmalloc_sockaddr2dotted_noport(cur->ai_addr);
120 revhost = xmalloc_sockaddr2hostonly_noport(cur->ai_addr);
Denis Vlasenko448f0242007-01-22 22:43:05 +0000121
122 printf("Address %u: %s%c", ++cnt, dotted, revhost ? ' ' : '\n');
123 if (revhost) {
124 puts(revhost);
125 if (ENABLE_FEATURE_CLEAN_UP)
126 free(revhost);
127 }
128 if (ENABLE_FEATURE_CLEAN_UP)
129 free(dotted);
130 cur = cur->ai_next;
131 }
132 } else {
133#if ENABLE_VERBOSE_RESOLUTION_ERRORS
Denis Vlasenko5de9e9c2007-01-22 22:46:04 +0000134 bb_error_msg("can't resolve '%s': %s", hostname, gai_strerror(rc));
Denis Vlasenko448f0242007-01-22 22:43:05 +0000135#else
136 bb_error_msg("can't resolve '%s'", hostname);
137#endif
138 }
Vitaly Magerya7f4b7692011-03-22 20:14:26 +0100139 if (ENABLE_FEATURE_CLEAN_UP && result)
Denis Vlasenko448f0242007-01-22 22:43:05 +0000140 freeaddrinfo(result);
141 return (rc != 0);
Denis Vlasenko448f0242007-01-22 22:43:05 +0000142}
143
Denis Vlasenko448f0242007-01-22 22:43:05 +0000144/* lookup the default nameserver and display it */
145static void server_print(void)
146{
147 char *server;
Denis Vlasenko3f5f2462008-11-16 19:02:26 +0000148 struct sockaddr *sa;
Denis Vlasenko448f0242007-01-22 22:43:05 +0000149
Denis Vlasenko3f5f2462008-11-16 19:02:26 +0000150#if ENABLE_FEATURE_IPV6
151 sa = (struct sockaddr*)_res._u._ext.nsaddrs[0];
152 if (!sa)
153#endif
154 sa = (struct sockaddr*)&_res.nsaddr_list[0];
155 server = xmalloc_sockaddr2dotted_noport(sa);
156
Denis Vlasenko448f0242007-01-22 22:43:05 +0000157 print_host(server, "Server:");
158 if (ENABLE_FEATURE_CLEAN_UP)
159 free(server);
Denis Vlasenko4daad902007-09-27 10:20:47 +0000160 bb_putchar('\n');
John Beppub332e772000-01-29 12:59:01 +0000161}
162
Robert Griebl31a2e202002-07-24 00:56:56 +0000163/* alter the global _res nameserver structure to use
Denis Vlasenko391ffa12008-11-04 21:44:28 +0000164 an explicit dns server instead of what is in /etc/resolv.conf */
Denis Vlasenko3f5f2462008-11-16 19:02:26 +0000165static void set_default_dns(const char *server)
Robert Griebl31a2e202002-07-24 00:56:56 +0000166{
Denis Vlasenko3f5f2462008-11-16 19:02:26 +0000167 len_and_sockaddr *lsa;
Robert Griebl31a2e202002-07-24 00:56:56 +0000168
Denys Vlasenkod66eb902013-06-27 01:09:51 +0200169 if (!server)
170 return;
171
Denis Vlasenko3f5f2462008-11-16 19:02:26 +0000172 /* NB: this works even with, say, "[::1]:5353"! :) */
173 lsa = xhost2sockaddr(server, 53);
174
175 if (lsa->u.sa.sa_family == AF_INET) {
Robert Griebl31a2e202002-07-24 00:56:56 +0000176 _res.nscount = 1;
Denis Vlasenko3f5f2462008-11-16 19:02:26 +0000177 /* struct copy */
178 _res.nsaddr_list[0] = lsa->u.sin;
Robert Griebl31a2e202002-07-24 00:56:56 +0000179 }
Denis Vlasenko3f5f2462008-11-16 19:02:26 +0000180#if ENABLE_FEATURE_IPV6
Denis Vlasenko249d9482008-11-17 15:36:36 +0000181 /* Hoped libc can cope with IPv4 address there too.
182 * No such luck, glibc 2.4 segfaults even with IPv6,
183 * maybe I misunderstand how to make glibc use IPv6 addr?
184 * (uclibc 0.9.31+ should work) */
185 if (lsa->u.sa.sa_family == AF_INET6) {
186 // glibc neither SEGVs nor sends any dgrams with this
187 // (strace shows no socket ops):
188 //_res.nscount = 0;
Denis Vlasenko3f5f2462008-11-16 19:02:26 +0000189 _res._u._ext.nscount = 1;
190 /* store a pointer to part of malloc'ed lsa */
191 _res._u._ext.nsaddrs[0] = &lsa->u.sin6;
192 /* must not free(lsa)! */
Denis Vlasenko249d9482008-11-17 15:36:36 +0000193 }
Denis Vlasenko3f5f2462008-11-16 19:02:26 +0000194#endif
Eric Andersen39cdf4e2004-01-30 22:40:05 +0000195}
Robert Griebl31a2e202002-07-24 00:56:56 +0000196
Denis Vlasenko9b49a5e2007-10-11 10:05:36 +0000197int nslookup_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
Erik Andersene49d5ec2000-02-08 19:58:47 +0000198int nslookup_main(int argc, char **argv)
John Beppub332e772000-01-29 12:59:01 +0000199{
Denis Vlasenko448f0242007-01-22 22:43:05 +0000200 /* We allow 1 or 2 arguments.
201 * The first is the name to be looked up and the second is an
202 * optional DNS server with which to do the lookup.
203 * More than 3 arguments is an error to follow the pattern of the
204 * standard nslookup */
Denis Vlasenko391ffa12008-11-04 21:44:28 +0000205 if (!argv[1] || argv[1][0] == '-' || argc > 3)
Manuel Novoa III cad53642003-03-19 09:13:01 +0000206 bb_show_usage();
Denis Vlasenko448f0242007-01-22 22:43:05 +0000207
208 /* initialize DNS structure _res used in printing the default
209 * name server and in the explicit name server option feature. */
210 res_init();
211 /* rfc2133 says this enables IPv6 lookups */
Denis Vlasenko391ffa12008-11-04 21:44:28 +0000212 /* (but it also says "may be enabled in /etc/resolv.conf") */
Denis Vlasenko448f0242007-01-22 22:43:05 +0000213 /*_res.options |= RES_USE_INET6;*/
214
Denys Vlasenkod66eb902013-06-27 01:09:51 +0200215 set_default_dns(argv[2]);
Robert Griebl31a2e202002-07-24 00:56:56 +0000216
Eric Andersenfe9888a2001-01-20 21:51:21 +0000217 server_print();
Denys Vlasenkod66eb902013-06-27 01:09:51 +0200218
219 /* getaddrinfo and friends are free to request a resolver
220 * reinitialization. Just in case, set_default_dns() again
221 * after getaddrinfo (in server_print). This reportedly helps
222 * with bug 675 "nslookup does not properly use second argument"
223 * at least on Debian Wheezy and Openwrt AA (eglibc based).
224 */
225 set_default_dns(argv[2]);
226
Denis Vlasenko448f0242007-01-22 22:43:05 +0000227 return print_host(argv[1], "Name:");
John Beppub332e772000-01-29 12:59:01 +0000228}
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200229
230
231#else /****** A version from LEDE / OpenWRT ******/
232
233/*
234 * musl compatible nslookup
235 *
236 * Copyright (C) 2017 Jo-Philipp Wich <jo@mein.io>
237 *
238 * Permission to use, copy, modify, and/or distribute this software for any
239 * purpose with or without fee is hereby granted, provided that the above
240 * copyright notice and this permission notice appear in all copies.
241 *
242 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
243 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
244 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
245 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
246 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
247 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
248 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
249 */
250
251#if 0
252# define dbg(...) fprintf(stderr, __VA_ARGS__)
253#else
254# define dbg(...) ((void)0)
255#endif
256
257struct ns {
258 const char *name;
Denys Vlasenko55bc8e82018-04-14 17:54:24 +0200259 len_and_sockaddr *lsa;
Denys Vlasenko6ca8e342019-01-09 13:38:57 +0100260 //UNUSED: int failures;
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200261 int replies;
262};
263
264struct query {
265 const char *name;
Denys Vlasenko71e4b3f2018-04-15 19:51:42 +0200266 unsigned qlen;
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200267// unsigned latency;
268// uint8_t rcode;
269 unsigned char query[512];
270// unsigned char reply[512];
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200271};
272
273static const struct {
Denys Vlasenkoa9801092018-04-15 10:52:11 +0200274 unsigned char type;
275 char name[7];
Denys Vlasenko6cc49622020-11-30 14:58:02 +0100276} qtypes[] ALIGN1 = {
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200277 { ns_t_soa, "SOA" },
278 { ns_t_ns, "NS" },
279 { ns_t_a, "A" },
280#if ENABLE_FEATURE_IPV6
281 { ns_t_aaaa, "AAAA" },
282#endif
283 { ns_t_cname, "CNAME" },
284 { ns_t_mx, "MX" },
285 { ns_t_txt, "TXT" },
Jo-Philipp Wich6b496012019-06-27 17:27:29 +0200286 { ns_t_srv, "SRV" },
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200287 { ns_t_ptr, "PTR" },
288 { ns_t_any, "ANY" },
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200289};
290
Denys Vlasenko6cc49622020-11-30 14:58:02 +0100291static const char *const rcodes[] ALIGN_PTR = {
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200292 "NOERROR", // 0
293 "FORMERR", // 1
294 "SERVFAIL", // 2
295 "NXDOMAIN", // 3
296 "NOTIMP", // 4
297 "REFUSED", // 5
298 "YXDOMAIN", // 6
299 "YXRRSET", // 7
300 "NXRRSET", // 8
301 "NOTAUTH", // 9
302 "NOTZONE", // 10
303 "11", // 11 not assigned
304 "12", // 12 not assigned
305 "13", // 13 not assigned
306 "14", // 14 not assigned
307 "15", // 15 not assigned
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200308};
309
310#if ENABLE_FEATURE_IPV6
Denys Vlasenko6cdc3192018-04-15 12:49:11 +0200311static const char v4_mapped[12] = { 0,0,0,0, 0,0,0,0, 0,0,0xff,0xff };
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200312#endif
313
314struct globals {
315 unsigned default_port;
316 unsigned default_retry;
317 unsigned default_timeout;
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200318 unsigned query_count;
Denys Vlasenko55bc8e82018-04-14 17:54:24 +0200319 unsigned serv_count;
320 struct ns *server;
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200321 struct query *query;
Denys Vlasenko94089782018-08-01 19:42:46 +0200322 char *search;
323 smalluint have_search_directive;
Denys Vlasenko6ca8e342019-01-09 13:38:57 +0100324 smalluint exitcode;
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200325} FIX_ALIASING;
326#define G (*(struct globals*)bb_common_bufsiz1)
327#define INIT_G() do { \
328 setup_common_bufsiz(); \
329 G.default_port = 53; \
330 G.default_retry = 2; \
331 G.default_timeout = 5; \
332} while (0)
333
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200334enum {
Denys Vlasenko6cdc3192018-04-15 12:49:11 +0200335 OPT_debug = (1 << 0),
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200336};
337
338static int parse_reply(const unsigned char *msg, size_t len)
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200339{
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200340 HEADER *header;
341
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200342 ns_msg handle;
343 ns_rr rr;
344 int i, n, rdlen;
345 const char *format = NULL;
346 char astr[INET6_ADDRSTRLEN], dname[MAXDNAME];
347 const unsigned char *cp;
348
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200349 header = (HEADER *)msg;
350 if (!header->aa)
351 printf("Non-authoritative answer:\n");
352
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200353 if (ns_initparse(msg, len, &handle) != 0) {
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200354 //printf("Unable to parse reply: %s\n", strerror(errno));
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200355 return -1;
356 }
357
358 for (i = 0; i < ns_msg_count(handle, ns_s_an); i++) {
359 if (ns_parserr(&handle, ns_s_an, i, &rr) != 0) {
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200360 //printf("Unable to parse resource record: %s\n", strerror(errno));
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200361 return -1;
362 }
363
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200364 rdlen = ns_rr_rdlen(rr);
365
366 switch (ns_rr_type(rr))
367 {
368 case ns_t_a:
369 if (rdlen != 4) {
Denys Vlasenkocf950cd2018-04-14 23:08:23 +0200370 dbg("unexpected A record length %d\n", rdlen);
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200371 return -1;
372 }
373 inet_ntop(AF_INET, ns_rr_rdata(rr), astr, sizeof(astr));
Denys Vlasenkocf950cd2018-04-14 23:08:23 +0200374 printf("Name:\t%s\nAddress: %s\n", ns_rr_name(rr), astr);
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200375 break;
376
377#if ENABLE_FEATURE_IPV6
378 case ns_t_aaaa:
379 if (rdlen != 16) {
Denys Vlasenkocf950cd2018-04-14 23:08:23 +0200380 dbg("unexpected AAAA record length %d\n", rdlen);
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200381 return -1;
382 }
383 inet_ntop(AF_INET6, ns_rr_rdata(rr), astr, sizeof(astr));
Denys Vlasenkocf950cd2018-04-14 23:08:23 +0200384 /* bind-utils-9.11.3 uses the same format for A and AAAA answers */
385 printf("Name:\t%s\nAddress: %s\n", ns_rr_name(rr), astr);
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200386 break;
387#endif
388
389 case ns_t_ns:
390 if (!format)
391 format = "%s\tnameserver = %s\n";
392 /* fall through */
393
394 case ns_t_cname:
395 if (!format)
396 format = "%s\tcanonical name = %s\n";
397 /* fall through */
398
399 case ns_t_ptr:
400 if (!format)
401 format = "%s\tname = %s\n";
402 if (ns_name_uncompress(ns_msg_base(handle), ns_msg_end(handle),
Denys Vlasenkocf950cd2018-04-14 23:08:23 +0200403 ns_rr_rdata(rr), dname, sizeof(dname)) < 0
404 ) {
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200405 //printf("Unable to uncompress domain: %s\n", strerror(errno));
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200406 return -1;
407 }
408 printf(format, ns_rr_name(rr), dname);
409 break;
410
411 case ns_t_mx:
412 if (rdlen < 2) {
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200413 printf("MX record too short\n");
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200414 return -1;
415 }
416 n = ns_get16(ns_rr_rdata(rr));
417 if (ns_name_uncompress(ns_msg_base(handle), ns_msg_end(handle),
Denys Vlasenkocf950cd2018-04-14 23:08:23 +0200418 ns_rr_rdata(rr) + 2, dname, sizeof(dname)) < 0
419 ) {
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200420 //printf("Cannot uncompress MX domain: %s\n", strerror(errno));
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200421 return -1;
422 }
423 printf("%s\tmail exchanger = %d %s\n", ns_rr_name(rr), n, dname);
424 break;
425
426 case ns_t_txt:
427 if (rdlen < 1) {
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200428 //printf("TXT record too short\n");
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200429 return -1;
430 }
431 n = *(unsigned char *)ns_rr_rdata(rr);
432 if (n > 0) {
433 memset(dname, 0, sizeof(dname));
434 memcpy(dname, ns_rr_rdata(rr) + 1, n);
435 printf("%s\ttext = \"%s\"\n", ns_rr_name(rr), dname);
436 }
437 break;
438
Jo-Philipp Wich6b496012019-06-27 17:27:29 +0200439 case ns_t_srv:
440 if (rdlen < 6) {
441 //printf("SRV record too short\n");
442 return -1;
443 }
444
445 cp = ns_rr_rdata(rr);
446 n = ns_name_uncompress(ns_msg_base(handle), ns_msg_end(handle),
447 cp + 6, dname, sizeof(dname));
448
449 if (n < 0) {
450 //printf("Unable to uncompress domain: %s\n", strerror(errno));
451 return -1;
452 }
453
454 printf("%s\tservice = %u %u %u %s\n", ns_rr_name(rr),
455 ns_get16(cp), ns_get16(cp + 2), ns_get16(cp + 4), dname);
456 break;
457
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200458 case ns_t_soa:
459 if (rdlen < 20) {
Denys Vlasenkocf950cd2018-04-14 23:08:23 +0200460 dbg("SOA record too short:%d\n", rdlen);
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200461 return -1;
462 }
463
464 printf("%s\n", ns_rr_name(rr));
465
466 cp = ns_rr_rdata(rr);
467 n = ns_name_uncompress(ns_msg_base(handle), ns_msg_end(handle),
468 cp, dname, sizeof(dname));
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200469 if (n < 0) {
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200470 //printf("Unable to uncompress domain: %s\n", strerror(errno));
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200471 return -1;
472 }
473
474 printf("\torigin = %s\n", dname);
475 cp += n;
476
477 n = ns_name_uncompress(ns_msg_base(handle), ns_msg_end(handle),
478 cp, dname, sizeof(dname));
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200479 if (n < 0) {
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200480 //printf("Unable to uncompress domain: %s\n", strerror(errno));
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200481 return -1;
482 }
483
484 printf("\tmail addr = %s\n", dname);
485 cp += n;
486
487 printf("\tserial = %lu\n", ns_get32(cp));
488 cp += 4;
489
490 printf("\trefresh = %lu\n", ns_get32(cp));
491 cp += 4;
492
493 printf("\tretry = %lu\n", ns_get32(cp));
494 cp += 4;
495
496 printf("\texpire = %lu\n", ns_get32(cp));
497 cp += 4;
498
499 printf("\tminimum = %lu\n", ns_get32(cp));
500 break;
501
502 default:
503 break;
504 }
505 }
506
507 return i;
508}
509
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200510/*
511 * Function logic borrowed & modified from musl libc, res_msend.c
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200512 * G.query_count is always > 0.
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200513 */
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200514static int send_queries(struct ns *ns)
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200515{
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200516 unsigned char reply[512];
517 uint8_t rcode;
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200518 len_and_sockaddr *local_lsa;
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200519 struct pollfd pfd;
Denys Vlasenko55bc8e82018-04-14 17:54:24 +0200520 int servfail_retry = 0;
521 int n_replies = 0;
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200522// int save_idx = 0;
Denys Vlasenko55bc8e82018-04-14 17:54:24 +0200523 unsigned retry_interval;
524 unsigned timeout = G.default_timeout * 1000;
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200525 unsigned tstart, tsent, tcur;
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200526
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200527 pfd.events = POLLIN;
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200528 pfd.fd = xsocket_type(&local_lsa, ns->lsa->u.sa.sa_family, SOCK_DGRAM);
529 /*
530 * local_lsa has "null" address and port 0 now.
531 * bind() ensures we have a *particular port* selected by kernel
532 * and remembered in fd, thus later recv(fd)
533 * receives only packets sent to this port.
534 */
535 xbind(pfd.fd, &local_lsa->u.sa, local_lsa->len);
536 free(local_lsa);
537 /* Make read/writes know the destination */
538 xconnect(pfd.fd, &ns->lsa->u.sa, ns->lsa->len);
539 ndelay_on(pfd.fd);
Denys Vlasenko55bc8e82018-04-14 17:54:24 +0200540
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200541 retry_interval = timeout / G.default_retry;
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200542 tstart = tcur = monotonic_ms();
543 goto send;
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200544
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200545 while (tcur - tstart < timeout) {
546 int qn;
547 int recvlen;
548
549 if (tcur - tsent >= retry_interval) {
550 send:
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200551 for (qn = 0; qn < G.query_count; qn++) {
Denys Vlasenko71e4b3f2018-04-15 19:51:42 +0200552 if (G.query[qn].qlen == 0)
553 continue; /* this one was replied already */
554
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200555 if (write(pfd.fd, G.query[qn].query, G.query[qn].qlen) < 0) {
Denys Vlasenkodb93b212018-04-14 18:11:35 +0200556 bb_perror_msg("write to '%s'", ns->name);
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200557 n_replies = -1; /* "no go, try next server" */
558 goto ret;
Denys Vlasenkodb93b212018-04-14 18:11:35 +0200559 }
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200560 dbg("query %u sent\n", qn);
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200561 }
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200562 tsent = tcur;
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200563 servfail_retry = 2 * G.query_count;
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200564 }
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200565
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200566 /* Wait for a response, or until time to retry */
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200567 if (poll(&pfd, 1, retry_interval - (tcur - tsent)) <= 0)
568 goto next;
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200569
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200570 recvlen = read(pfd.fd, reply, sizeof(reply));
571 if (recvlen < 0) {
James Byrne69374872019-07-02 11:35:03 +0200572 bb_simple_perror_msg("read");
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200573 next:
574 tcur = monotonic_ms();
575 continue;
576 }
Denys Vlasenko55bc8e82018-04-14 17:54:24 +0200577
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200578 if (ns->replies++ == 0) {
579 printf("Server:\t\t%s\n", ns->name);
580 printf("Address:\t%s\n\n",
581 auto_string(xmalloc_sockaddr2dotted(&ns->lsa->u.sa))
582 );
583 /* In "Address", bind-utils-9.11.3 show port after a hash: "1.2.3.4#53" */
584 /* Should we do the same? */
585 }
586
587 /* Non-identifiable packet */
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200588 if (recvlen < 4) {
589 dbg("read is too short:%d\n", recvlen);
590 goto next;
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200591 }
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200592
593 /* Find which query this answer goes with, if any */
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200594// qn = save_idx;
595 qn = 0;
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200596 for (;;) {
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200597 if (memcmp(reply, G.query[qn].query, 2) == 0) {
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200598 dbg("response matches query %u\n", qn);
599 break;
600 }
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200601 if (++qn >= G.query_count) {
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200602 dbg("response does not match any query\n");
603 goto next;
604 }
605 }
606
Denys Vlasenko71e4b3f2018-04-15 19:51:42 +0200607 if (G.query[qn].qlen == 0) {
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200608 dbg("dropped duplicate response to query %u\n", qn);
609 goto next;
610 }
611
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200612 rcode = reply[3] & 0x0f;
613 dbg("query %u rcode:%s\n", qn, rcodes[rcode]);
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200614
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200615 /* Retry immediately on SERVFAIL */
616 if (rcode == 2) {
Denys Vlasenko6ca8e342019-01-09 13:38:57 +0100617 //UNUSED: ns->failures++;
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200618 if (servfail_retry) {
619 servfail_retry--;
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200620 write(pfd.fd, G.query[qn].query, G.query[qn].qlen);
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200621 dbg("query %u resent\n", qn);
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200622 goto next;
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200623 }
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200624 }
625
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200626 /* Process reply */
Denys Vlasenko71e4b3f2018-04-15 19:51:42 +0200627 G.query[qn].qlen = 0; /* flag: "reply received" */
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200628 tcur = monotonic_ms();
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200629#if 1
Denys Vlasenko6cdc3192018-04-15 12:49:11 +0200630 if (option_mask32 & OPT_debug) {
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200631 printf("Query #%d completed in %ums:\n", qn, tcur - tstart);
632 }
633 if (rcode != 0) {
634 printf("** server can't find %s: %s\n",
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200635 G.query[qn].name, rcodes[rcode]);
Denys Vlasenko6ca8e342019-01-09 13:38:57 +0100636 G.exitcode = EXIT_FAILURE;
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200637 } else {
Jo-Philipp Wich8c3b5202019-06-27 17:27:28 +0200638 switch (parse_reply(reply, recvlen)) {
639 case -1:
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200640 printf("*** Can't find %s: Parse error\n", G.query[qn].name);
Denys Vlasenko6ca8e342019-01-09 13:38:57 +0100641 G.exitcode = EXIT_FAILURE;
Jo-Philipp Wich8c3b5202019-06-27 17:27:28 +0200642 break;
643
644 case 0:
645 printf("*** Can't find %s: No answer\n", G.query[qn].name);
646 break;
Denys Vlasenko6ca8e342019-01-09 13:38:57 +0100647 }
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200648 }
649 bb_putchar('\n');
650 n_replies++;
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200651 if (n_replies >= G.query_count)
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200652 goto ret;
653#else
654//used to store replies and process them later
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200655 G.query[qn].latency = tcur - tstart;
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200656 n_replies++;
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200657 if (qn != save_idx) {
658 /* "wrong" receive buffer, move to correct one */
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200659 memcpy(G.query[qn].reply, G.query[save_idx].reply, recvlen);
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200660 continue;
661 }
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200662 /* G.query[0..save_idx] have replies, move to next one, if exists */
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200663 for (;;) {
664 save_idx++;
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200665 if (save_idx >= G.query_count)
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200666 goto ret; /* all are full: we have all results */
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200667 if (!G.query[save_idx].rlen)
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200668 break; /* this one is empty */
669 }
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200670#endif
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200671 } /* while() */
672
Denys Vlasenko55bc8e82018-04-14 17:54:24 +0200673 ret:
Denys Vlasenko71e016d2018-04-14 22:53:39 +0200674 close(pfd.fd);
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200675
676 return n_replies;
677}
678
Denys Vlasenko55bc8e82018-04-14 17:54:24 +0200679static void add_ns(const char *addr)
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200680{
Denys Vlasenko55bc8e82018-04-14 17:54:24 +0200681 struct ns *ns;
682 unsigned count;
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200683
684 dbg("%s: addr:'%s'\n", __func__, addr);
685
Denys Vlasenko55bc8e82018-04-14 17:54:24 +0200686 count = G.serv_count++;
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200687
Denys Vlasenko55bc8e82018-04-14 17:54:24 +0200688 G.server = xrealloc_vector(G.server, /*8=2^3:*/ 3, count);
689 ns = &G.server[count];
690 ns->name = addr;
Denys Vlasenkod4461ef2018-04-15 12:01:46 +0200691 ns->lsa = xhost2sockaddr(addr, G.default_port);
Denys Vlasenko55bc8e82018-04-14 17:54:24 +0200692 /*ns->replies = 0; - already is */
693 /*ns->failures = 0; - already is */
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200694}
695
Denys Vlasenko55bc8e82018-04-14 17:54:24 +0200696static void parse_resolvconf(void)
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200697{
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200698 FILE *resolv;
699
Denys Vlasenkob230ff92020-12-30 00:16:27 +0100700 resolv = fopen_for_read("/etc/resolv.conf");
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200701 if (resolv) {
Denys Vlasenko94089782018-08-01 19:42:46 +0200702 char line[512]; /* "search" is defined to be up to 256 chars */
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200703
704 while (fgets(line, sizeof(line), resolv)) {
Denys Vlasenko94089782018-08-01 19:42:46 +0200705 char *p, *arg;
Denys Vlasenko24966162020-10-06 02:36:47 +0200706 char *tokstate;
Denys Vlasenko94089782018-08-01 19:42:46 +0200707
Denys Vlasenko24966162020-10-06 02:36:47 +0200708 p = strtok_r(line, " \t\n", &tokstate);
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200709 if (!p)
710 continue;
Denys Vlasenko94089782018-08-01 19:42:46 +0200711 dbg("resolv_key:'%s'\n", p);
Denys Vlasenko24966162020-10-06 02:36:47 +0200712 arg = strtok_r(NULL, "\n", &tokstate);
Denys Vlasenko94089782018-08-01 19:42:46 +0200713 dbg("resolv_arg:'%s'\n", arg);
714 if (!arg)
715 continue;
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200716
Denys Vlasenko94089782018-08-01 19:42:46 +0200717 if (strcmp(p, "domain") == 0) {
718 /* domain DOM */
719 if (!G.have_search_directive)
720 goto set_search;
721 continue;
722 }
723 if (strcmp(p, "search") == 0) {
724 /* search DOM1 DOM2... */
725 G.have_search_directive = 1;
726 set_search:
727 free(G.search);
728 G.search = xstrdup(arg);
729 dbg("search='%s'\n", G.search);
730 continue;
731 }
732
733 if (strcmp(p, "nameserver") != 0)
734 continue;
735
736 /* nameserver DNS */
737 add_ns(xstrdup(arg));
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200738 }
739
740 fclose(resolv);
741 }
Denys Vlasenko94089782018-08-01 19:42:46 +0200742
743 if (!G.search) {
744 /* default search domain is domain part of hostname */
745 char *h = safe_gethostname();
746 char *d = strchr(h, '.');
747 if (d) {
748 G.search = d + 1;
749 dbg("search='%s' (from hostname)\n", G.search);
750 }
751 /* else free(h); */
752 }
753
754 /* Cater for case of "domain ." in resolv.conf */
755 if (G.search && LONE_CHAR(G.search, '.'))
756 G.search = NULL;
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200757}
758
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200759static void add_query(int type, const char *dname)
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200760{
761 struct query *new_q;
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200762 unsigned count;
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200763 ssize_t qlen;
764
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200765 count = G.query_count++;
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200766
Denys Vlasenko94089782018-08-01 19:42:46 +0200767 G.query = xrealloc_vector(G.query, /*4=2^2:*/ 2, count);
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200768 new_q = &G.query[count];
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200769
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200770 dbg("new query#%u type %u for '%s'\n", count, type, dname);
771 new_q->name = dname;
Denys Vlasenko71e4b3f2018-04-15 19:51:42 +0200772
773 qlen = res_mkquery(QUERY, dname, C_IN, type,
774 /*data:*/ NULL, /*datalen:*/ 0,
775 /*newrr:*/ NULL,
776 new_q->query, sizeof(new_q->query)
777 );
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200778 new_q->qlen = qlen;
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200779}
780
Denys Vlasenko94089782018-08-01 19:42:46 +0200781static void add_query_with_search(int type, const char *dname)
782{
783 char *s;
784
785 if (type == T_PTR || !G.search || strchr(dname, '.')) {
786 add_query(type, dname);
787 return;
788 }
789
790 s = G.search;
791 for (;;) {
792 char *fullname, *e;
793
794 e = skip_non_whitespace(s);
795 fullname = xasprintf("%s.%.*s", dname, (int)(e - s), s);
796 add_query(type, fullname);
797 s = skip_whitespace(e);
798 if (!*s)
799 break;
800 }
801}
802
Denys Vlasenkoc7249952018-04-15 20:04:57 +0200803static char *make_ptr(const char *addrstr)
804{
805 unsigned char addr[16];
Denys Vlasenkoc7249952018-04-15 20:04:57 +0200806
807#if ENABLE_FEATURE_IPV6
808 if (inet_pton(AF_INET6, addrstr, addr)) {
809 if (memcmp(addr, v4_mapped, 12) != 0) {
Denys Vlasenko2f7738e2018-06-27 14:44:35 +0200810 int i;
Denys Vlasenkoc7249952018-04-15 20:04:57 +0200811 char resbuf[80];
812 char *ptr = resbuf;
813 for (i = 0; i < 16; i++) {
814 *ptr++ = 0x20 | bb_hexdigits_upcase[(unsigned char)addr[15 - i] & 0xf];
815 *ptr++ = '.';
816 *ptr++ = 0x20 | bb_hexdigits_upcase[(unsigned char)addr[15 - i] >> 4];
817 *ptr++ = '.';
818 }
819 strcpy(ptr, "ip6.arpa");
820 return xstrdup(resbuf);
821 }
822 return xasprintf("%u.%u.%u.%u.in-addr.arpa",
823 addr[15], addr[14], addr[13], addr[12]);
824 }
825#endif
826
827 if (inet_pton(AF_INET, addrstr, addr)) {
828 return xasprintf("%u.%u.%u.%u.in-addr.arpa",
829 addr[3], addr[2], addr[1], addr[0]);
830 }
831
832 return NULL;
833}
834
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200835int nslookup_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
836int nslookup_main(int argc UNUSED_PARAM, char **argv)
837{
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200838 unsigned types;
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200839 int rc;
840 int err;
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200841
842 INIT_G();
843
Denys Vlasenkod4461ef2018-04-15 12:01:46 +0200844 /* manpage: "Options can also be specified on the command line
845 * if they precede the arguments and are prefixed with a hyphen."
846 */
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200847 types = 0;
Denys Vlasenkod4461ef2018-04-15 12:01:46 +0200848 argv++;
849 for (;;) {
850 const char *options =
851// bind-utils-9.11.3 accept these:
852// class= cl=
853// type= ty= querytype= query= qu= q=
854// domain= do=
855// port= po=
856// timeout= t=
857// retry= ret=
858// ndots=
859// recurse
860// norecurse
861// defname
862// nodefname
863// vc
864// novc
865// debug
866// nodebug
867// d2
868// nod2
869// search
870// nosearch
871// sil
872// fail
873// nofail
874// ver (prints version and exits)
875 "type\0" /* 0 */
876 "querytype\0" /* 1 */
877 "port\0" /* 2 */
878 "retry\0" /* 3 */
Denys Vlasenko6cdc3192018-04-15 12:49:11 +0200879 "debug\0" /* 4 */
Denys Vlasenkod4461ef2018-04-15 12:01:46 +0200880 "t\0" /* disambiguate with "type": else -t=2 fails */
881 "timeout\0" /* 6 */
882 "";
883 int i;
884 char *arg;
885 char *val;
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200886
Denys Vlasenkod4461ef2018-04-15 12:01:46 +0200887 if (!*argv)
888 bb_show_usage();
889 if (argv[0][0] != '-')
890 break;
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200891
Denys Vlasenkod4461ef2018-04-15 12:01:46 +0200892 /* Separate out "=val" part */
893 arg = (*argv++) + 1;
894 val = strchrnul(arg, '=');
895 if (*val)
896 *val++ = '\0';
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200897
Denys Vlasenkod4461ef2018-04-15 12:01:46 +0200898 i = index_in_substrings(options, arg);
899 //bb_error_msg("i:%d arg:'%s' val:'%s'", i, arg, val);
900 if (i < 0)
901 bb_show_usage();
902
903 if (i <= 1) {
904 for (i = 0;; i++) {
905 if (i == ARRAY_SIZE(qtypes))
906 bb_error_msg_and_die("invalid query type \"%s\"", val);
Denys Vlasenko4b6091f2018-04-15 12:57:32 +0200907 if (strcasecmp(qtypes[i].name, val) == 0)
Denys Vlasenkod4461ef2018-04-15 12:01:46 +0200908 break;
909 }
910 types |= (1 << i);
911 continue;
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200912 }
Denys Vlasenkod4461ef2018-04-15 12:01:46 +0200913 if (i == 2) {
914 G.default_port = xatou_range(val, 1, 0xffff);
915 }
916 if (i == 3) {
917 G.default_retry = xatou_range(val, 1, INT_MAX);
918 }
919 if (i == 4) {
Denys Vlasenko6cdc3192018-04-15 12:49:11 +0200920 option_mask32 |= OPT_debug;
Denys Vlasenkod4461ef2018-04-15 12:01:46 +0200921 }
922 if (i > 4) {
923 G.default_timeout = xatou_range(val, 1, INT_MAX / 1000);
924 }
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200925 }
926
Denys Vlasenko94089782018-08-01 19:42:46 +0200927 /* Use given DNS server if present */
928 if (argv[1]) {
929 if (argv[2])
930 bb_show_usage();
931 add_ns(argv[1]);
932 } else {
933 parse_resolvconf();
934 /* Fall back to localhost if we could not find NS in resolv.conf */
935 if (G.serv_count == 0)
936 add_ns("127.0.0.1");
937 }
938
Denys Vlasenkod4461ef2018-04-15 12:01:46 +0200939 if (types == 0) {
940 /* No explicit type given, guess query type.
941 * If we can convert the domain argument into a ptr (means that
942 * inet_pton() could read it) we assume a PTR request, else
943 * we issue A+AAAA queries and switch to an output format
944 * mimicking the one of the traditional nslookup applet.
945 */
946 char *ptr;
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200947
Denys Vlasenkoc7249952018-04-15 20:04:57 +0200948 ptr = make_ptr(argv[0]);
Denys Vlasenkod4461ef2018-04-15 12:01:46 +0200949 if (ptr) {
Denys Vlasenkoc7249952018-04-15 20:04:57 +0200950 add_query(T_PTR, ptr);
Denys Vlasenkoa9801092018-04-15 10:52:11 +0200951 } else {
Denys Vlasenko94089782018-08-01 19:42:46 +0200952 add_query_with_search(T_A, argv[0]);
Denys Vlasenkod4461ef2018-04-15 12:01:46 +0200953#if ENABLE_FEATURE_IPV6
Denys Vlasenko94089782018-08-01 19:42:46 +0200954 add_query_with_search(T_AAAA, argv[0]);
Denys Vlasenkod4461ef2018-04-15 12:01:46 +0200955#endif
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200956 }
Denys Vlasenkod4461ef2018-04-15 12:01:46 +0200957 } else {
958 int c;
959 for (c = 0; c < ARRAY_SIZE(qtypes); c++) {
960 if (types & (1 << c))
Denys Vlasenko94089782018-08-01 19:42:46 +0200961 add_query_with_search(qtypes[c].type, argv[0]);
Denys Vlasenkod4461ef2018-04-15 12:01:46 +0200962 }
963 }
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200964
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200965 for (rc = 0; rc < G.serv_count;) {
966 int c;
967
Denys Vlasenko58e43a42018-04-15 14:10:45 +0200968 c = send_queries(&G.server[rc]);
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200969 if (c > 0) {
970 /* more than zero replies received */
Denys Vlasenko6cdc3192018-04-15 12:49:11 +0200971#if 0 /* which version does this? */
972 if (option_mask32 & OPT_debug) {
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200973 printf("Replies:\t%d\n", G.server[rc].replies);
974 printf("Failures:\t%d\n\n", G.server[rc].failures);
975 }
Denys Vlasenko6cdc3192018-04-15 12:49:11 +0200976#endif
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200977 break;
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200978//FIXME: we "break" even though some queries may still be not answered, and other servers may know them?
979 }
Denys Vlasenkodb93b212018-04-14 18:11:35 +0200980 /* c = 0: timed out waiting for replies */
981 /* c < 0: error (message already printed) */
Denys Vlasenko0dd3be82018-04-14 14:05:45 +0200982 rc++;
Denys Vlasenko55bc8e82018-04-14 17:54:24 +0200983 if (rc >= G.serv_count) {
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200984//
985// NB: bind-utils-9.11.3 behavior (all to stdout, not stderr):
986//
987// $ nslookup gmail.com 8.8.8.8
988// ;; connection timed out; no servers could be reached
989//
Denys Vlasenko6cdc3192018-04-15 12:49:11 +0200990// Using TCP mode:
991// $ nslookup -vc gmail.com 8.8.8.8; echo EXITCODE:$?
Denys Vlasenko2cf75b32018-04-15 10:46:44 +0200992// <~10 sec>
993// ;; Connection to 8.8.8.8#53(8.8.8.8) for gmail.com failed: timed out.
994// <~10 sec>
995// ;; Connection to 8.8.8.8#53(8.8.8.8) for gmail.com failed: timed out.
996// <~10 sec>
997// ;; connection timed out; no servers could be reached
998// ;; Connection to 8.8.8.8#53(8.8.8.8) for gmail.com failed: timed out.
999// <empty line>
1000// EXITCODE:1
1001// $ _
1002 printf(";; connection timed out; no servers could be reached\n\n");
Denys Vlasenko0dd3be82018-04-14 14:05:45 +02001003 return EXIT_FAILURE;
1004 }
1005 }
1006
Denys Vlasenko2cf75b32018-04-15 10:46:44 +02001007 err = 0;
Denys Vlasenko58e43a42018-04-15 14:10:45 +02001008 for (rc = 0; rc < G.query_count; rc++) {
Denys Vlasenko71e4b3f2018-04-15 19:51:42 +02001009 if (G.query[rc].qlen) {
Denys Vlasenko58e43a42018-04-15 14:10:45 +02001010 printf("*** Can't find %s: No answer\n", G.query[rc].name);
Denys Vlasenko2cf75b32018-04-15 10:46:44 +02001011 err = 1;
1012 }
Denys Vlasenko0dd3be82018-04-14 14:05:45 +02001013 }
Denys Vlasenko71e4b3f2018-04-15 19:51:42 +02001014 if (err) /* should this affect exicode too? */
1015 bb_putchar('\n');
Denys Vlasenko0dd3be82018-04-14 14:05:45 +02001016
1017 if (ENABLE_FEATURE_CLEAN_UP) {
Denys Vlasenko58e43a42018-04-15 14:10:45 +02001018 free(G.server);
1019 free(G.query);
Denys Vlasenko0dd3be82018-04-14 14:05:45 +02001020 }
1021
Denys Vlasenko6ca8e342019-01-09 13:38:57 +01001022 return G.exitcode;
Denys Vlasenko0dd3be82018-04-14 14:05:45 +02001023}
1024
1025#endif