2 Unix SMB/CIFS implementation.
4 read a file containing DNS names, types and IP addresses
6 Copyright (C) Andrew Tridgell 1994-1998
7 Copyright (C) Jeremy Allison 2007
8 Copyright (C) Andrew Bartlett 2009-2011
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3 of the License, or
13 (at your option) any later version.
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with this program. If not, see <http://www.gnu.org/licenses/>.
24 /* The purpose of this file is to read the file generated by the samba_dnsupdate script */
27 #include "lib/util/xfile.h"
28 #include "lib/util/util_net.h"
29 #include "system/filesys.h"
30 #include "system/network.h"
31 #include "libcli/nbt/libnbt.h"
32 #include "libcli/dns/dns.h"
38 /********************************************************
39 Start parsing the dns_hosts_file file.
40 *********************************************************/
42 static XFILE *startdns_hosts_file(const char *fname)
44 XFILE *fp = x_fopen(fname,O_RDONLY, 0);
46 DEBUG(4,("startdns_hosts_file: Can't open dns_hosts_file file %s. "
48 fname, strerror(errno)));
54 /********************************************************
55 Parse the next line in the dns_hosts_file file.
56 *********************************************************/
58 static bool getdns_hosts_fileent(TALLOC_CTX *ctx, XFILE *fp, char **pp_name, char **pp_name_type,
60 struct sockaddr_storage *pss, uint32_t *p_port)
69 while(!x_feof(fp) && !x_ferror(fp)) {
70 char *name_type = NULL;
72 char *next_name = NULL;
79 if (!fgets_slash(line,sizeof(line),fp)) {
89 if (next_token_talloc(ctx, &ptr, &name_type, NULL))
94 if (next_token_talloc(ctx, &ptr, &name, NULL))
96 if ((strcasecmp(name_type, "A") == 0) ||
97 (strcasecmp(name_type, "AAAA") == 0))
99 if (next_token_talloc(ctx, &ptr, &ip, NULL))
101 } else if (name_type && strcasecmp(name_type, "SRV") == 0) {
102 if (next_token_talloc(ctx, &ptr, &next_name, NULL))
104 if (next_token_talloc(ctx, &ptr, &port, NULL))
106 } else if (name_type && strcasecmp(name_type, "CNAME") == 0) {
107 if (next_token_talloc(ctx, &ptr, &next_name, NULL))
109 } else if (name_type && strcasecmp(name_type, "NS") == 0) {
110 if (next_token_talloc(ctx, &ptr, &next_name, NULL))
114 if ((strcasecmp(name_type, "A") == 0) ||
115 (strcasecmp(name_type, "AAAA") == 0))
118 DEBUG(0,("getdns_hosts_fileent: Ill formed hosts A[AAA] record [%s]\n",
122 DEBUG(4, ("getdns_hosts_fileent: host entry: %s %s %s\n",
123 name_type, name, ip));
124 if (!interpret_string_addr(pss, ip, AI_NUMERICHOST)) {
125 DEBUG(0,("getdns_hosts_fileent: invalid address "
129 } else if (strcasecmp(name_type, "SRV") == 0) {
131 DEBUG(0,("getdns_hosts_fileent: Ill formed hosts SRV record [%s]\n",
135 *p_port = strtoul(port, NULL, 10);
136 if (*p_port == UINT32_MAX) {
137 DEBUG(0, ("getdns_hosts_fileent: Ill formed hosts SRV record [%s] (invalid port: %s)\n",
141 DEBUG(4, ("getdns_hosts_fileent: host entry: %s %s %s %u\n",
142 name_type, name, next_name, (unsigned int)*p_port));
143 *pp_next_name = talloc_strdup(ctx, next_name);
144 if (!*pp_next_name) {
147 } else if (strcasecmp(name_type, "CNAME") == 0) {
149 DEBUG(0,("getdns_hosts_fileent: Ill formed hosts CNAME record [%s]\n",
153 DEBUG(4, ("getdns_hosts_fileent: host entry: %s %s %s\n",
154 name_type, name, next_name));
155 *pp_next_name = talloc_strdup(ctx, next_name);
156 if (!*pp_next_name) {
159 } else if (strcasecmp(name_type, "NS") == 0) {
161 DEBUG(0,("getdns_hosts_fileent: Ill formed hosts NS record [%s]\n",
165 DEBUG(4, ("getdns_hosts_fileent: NS entry: %s %s %s\n",
166 name_type, name, next_name));
169 DEBUG(0,("getdns_hosts_fileent: unknown type %s\n", name_type));
173 *pp_name = talloc_strdup(ctx, name);
178 *pp_name_type = talloc_strdup(ctx, name_type);
179 if (!*pp_name_type) {
188 /********************************************************
189 Finish parsing the dns_hosts_file file.
190 *********************************************************/
192 static void enddns_hosts_file(XFILE *fp)
197 /********************************************************
198 Resolve via "dns_hosts" method.
199 *********************************************************/
201 static NTSTATUS resolve_dns_hosts_file_as_dns_rr_recurse(const char *dns_hosts_file,
202 const char *name, bool srv_lookup,
203 int level, uint32_t port,
205 struct dns_rr_srv **return_rr,
209 * "dns_hosts" means parse the local dns_hosts file.
213 char *host_name = NULL;
214 char *name_type = NULL;
215 char *next_name = NULL;
216 struct sockaddr_storage return_ss;
218 NTSTATUS status = NT_STATUS_OBJECT_NAME_NOT_FOUND;
219 TALLOC_CTX *ctx = NULL;
220 TALLOC_CTX *ip_list_ctx = NULL;
221 struct dns_rr_srv *rr = NULL;
225 /* Don't recurse forever, even on our own flat files */
227 DEBUG(0, ("resolve_dns_hosts_file recursion limit reached looking up %s!\n", name));
233 DEBUG(3,("resolve_dns_hosts: (%d) "
234 "Attempting %s dns_hosts lookup for name %s\n",
235 level, srv_lookup ? "SRV" : "A[AAA]", name));
237 fp = startdns_hosts_file(dns_hosts_file);
240 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
242 ip_list_ctx = talloc_new(mem_ctx);
244 enddns_hosts_file(fp);
245 return NT_STATUS_NO_MEMORY;
248 ctx = talloc_new(ip_list_ctx);
250 talloc_free(ip_list_ctx);
251 enddns_hosts_file(fp);
252 return NT_STATUS_NO_MEMORY;
255 while (getdns_hosts_fileent(ctx, fp, &host_name, &name_type, &next_name, &return_ss, &srv_port)) {
256 if (!strequal(name, host_name)) {
257 /* continue at the bottom of the loop */
258 } else if (srv_lookup) {
259 if (strcasecmp(name_type, "SRV") == 0) {
260 NTSTATUS status_recurse;
261 struct dns_rr_srv *tmp_rr;
263 /* we only accept one host name per SRV entry */
265 = resolve_dns_hosts_file_as_dns_rr_recurse(dns_hosts_file, next_name,
268 ip_list_ctx, &tmp_rr,
270 if (NT_STATUS_EQUAL(status_recurse, NT_STATUS_OBJECT_NAME_NOT_FOUND)) {
271 /* Don't fail on a dangling SRV record */
272 } else if (!NT_STATUS_IS_OK(status_recurse)) {
273 enddns_hosts_file(fp);
274 talloc_free(ip_list_ctx);
275 return status_recurse;
276 } else if (tmp_count != 1) {
277 status = NT_STATUS_OBJECT_NAME_NOT_FOUND;
279 status = status_recurse;
280 rr = talloc_realloc(ip_list_ctx, rr, struct dns_rr_srv, (*return_count) + 1);
282 enddns_hosts_file(fp);
283 return NT_STATUS_NO_MEMORY;
285 talloc_steal(rr, tmp_rr);
286 rr[*return_count] = *tmp_rr;
287 *return_count = (*return_count) + 1;
290 } else if (strcasecmp(name_type, "CNAME") == 0) {
291 /* we only accept one host name per CNAME */
292 enddns_hosts_file(fp);
293 status = resolve_dns_hosts_file_as_dns_rr_recurse(dns_hosts_file, next_name, false,
295 mem_ctx, return_rr, return_count);
296 talloc_free(ip_list_ctx);
298 } else if ((strcasecmp(name_type, "A") == 0) ||
299 (strcasecmp(name_type, "AAAA") == 0))
301 if (*return_count == 0) {
302 /* We are happy to keep looking for other possible A record matches */
303 rr = talloc_zero(ip_list_ctx,
308 enddns_hosts_file(fp);
309 DEBUG(3,("resolve_dns_hosts: talloc_realloc fail !\n"));
310 return NT_STATUS_NO_MEMORY;
313 rr->hostname = talloc_strdup(rr, host_name);
315 if (rr->hostname == NULL) {
317 enddns_hosts_file(fp);
318 DEBUG(3,("resolve_dns_hosts: talloc_realloc fail !\n"));
319 return NT_STATUS_NO_MEMORY;
326 /* Set the specified port (possibly from a SRV lookup) into the structure we return */
327 set_sockaddr_port((struct sockaddr *)&return_ss, port);
329 /* We are happy to keep looking for other possible A record matches */
330 rr->ss_s = talloc_realloc(rr, rr->ss_s,
331 struct sockaddr_storage,
334 if (rr->ss_s == NULL) {
336 enddns_hosts_file(fp);
337 DEBUG(3,("resolve_dns_hosts: talloc_realloc fail !\n"));
338 return NT_STATUS_NO_MEMORY;
341 rr->ss_s[rr->num_ips] = return_ss;
344 /* we found something */
345 status = NT_STATUS_OK;
349 ctx = talloc_new(mem_ctx);
351 enddns_hosts_file(fp);
352 return NT_STATUS_NO_MEMORY;
356 *return_rr = talloc_steal(mem_ctx, rr);
357 TALLOC_FREE(ip_list_ctx);
358 enddns_hosts_file(fp);
362 /********************************************************
363 Resolve via "dns_hosts_file" method, returning a list of sockaddr_storage values
364 *********************************************************/
366 NTSTATUS resolve_dns_hosts_file_as_sockaddr(const char *dns_hosts_file,
367 const char *name, bool srv_lookup,
369 struct sockaddr_storage **return_iplist,
373 struct dns_rr_srv *dns_rr = NULL;
374 int i, j, rr_count = 0;
376 *return_iplist = NULL;
379 status = resolve_dns_hosts_file_as_dns_rr_recurse(dns_hosts_file, name, srv_lookup,
381 mem_ctx, &dns_rr, &rr_count);
382 if (!NT_STATUS_IS_OK(status)) {
383 DEBUG(3,("resolve_dns_hosts (sockaddr): "
384 "failed to obtain %s result records for for name %s: %s\n",
385 srv_lookup ? "SRV" : "A", name, nt_errstr(status)));
389 for (i=0; i < rr_count; i++) {
390 *return_iplist = talloc_realloc(mem_ctx, *return_iplist, struct sockaddr_storage, *return_count + dns_rr[i].num_ips);
391 if (!*return_iplist) {
392 return NT_STATUS_NO_MEMORY;
394 for (j=0; j < dns_rr[i].num_ips; j++) {
395 (*return_iplist)[*return_count] = dns_rr[i].ss_s[j];
396 *return_count = *return_count + 1;
399 DEBUG(3,("resolve_dns_hosts (sockaddr): "
400 "Found %d results for for name %s\n",
401 *return_count, name));
406 /********************************************************
407 Resolve via "dns_hosts_file" method, returning struct dns_rr_srv
408 *********************************************************/
410 NTSTATUS resolve_dns_hosts_file_as_dns_rr(const char *dns_hosts_file,
411 const char *name, bool srv_lookup,
413 struct dns_rr_srv **return_rr,
420 status = resolve_dns_hosts_file_as_dns_rr_recurse(dns_hosts_file, name, srv_lookup,
422 mem_ctx, return_rr, return_count);
424 if (NT_STATUS_IS_OK(status)) {
425 DEBUG(3,("resolve_dns_hosts (dns_rr): "
426 "Found %d %s result records for for name %s\n",
427 *return_count, srv_lookup ? "SRV" : "A[AAA]", name));
429 DEBUG(3,("resolve_dns_hosts (dns_rr): "
430 "failed to obtain %s result records for for name %s: %s\n",
431 srv_lookup ? "SRV" : "A[AAA]", name, nt_errstr(status)));