Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Name server resolution |
| 3 | * |
| 4 | * Copyright 2014 Baptiste Assmann <bedis9@gmail.com> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License |
| 8 | * as published by the Free Software Foundation; either version |
| 9 | * 2 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | */ |
| 12 | |
| 13 | #include <errno.h> |
| 14 | #include <fcntl.h> |
| 15 | #include <stdio.h> |
| 16 | #include <stdlib.h> |
| 17 | #include <string.h> |
| 18 | #include <unistd.h> |
| 19 | |
| 20 | #include <sys/types.h> |
| 21 | |
| 22 | #include <common/time.h> |
| 23 | #include <common/ticks.h> |
| 24 | |
Baptiste Assmann | fa4a663 | 2017-05-04 09:05:00 +0200 | [diff] [blame] | 25 | #include <import/lru.h> |
| 26 | #include <import/xxhash.h> |
| 27 | |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 28 | #include <types/applet.h> |
| 29 | #include <types/cli.h> |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 30 | #include <types/global.h> |
| 31 | #include <types/dns.h> |
| 32 | #include <types/proto_udp.h> |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 33 | #include <types/stats.h> |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 34 | |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 35 | #include <proto/channel.h> |
| 36 | #include <proto/cli.h> |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 37 | #include <proto/checks.h> |
| 38 | #include <proto/dns.h> |
| 39 | #include <proto/fd.h> |
| 40 | #include <proto/log.h> |
| 41 | #include <proto/server.h> |
| 42 | #include <proto/task.h> |
| 43 | #include <proto/proto_udp.h> |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 44 | #include <proto/stream_interface.h> |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 45 | |
| 46 | struct list dns_resolvers = LIST_HEAD_INIT(dns_resolvers); |
| 47 | struct dns_resolution *resolution = NULL; |
| 48 | |
| 49 | static int64_t dns_query_id_seed; /* random seed */ |
| 50 | |
Baptiste Assmann | fa4a663 | 2017-05-04 09:05:00 +0200 | [diff] [blame] | 51 | static struct lru64_head *dns_lru_tree; |
| 52 | static int dns_cache_size = 1024; /* arbitrary DNS cache size */ |
| 53 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 54 | /* proto_udp callback functions for a DNS resolution */ |
| 55 | struct dgram_data_cb resolve_dgram_cb = { |
| 56 | .recv = dns_resolve_recv, |
| 57 | .send = dns_resolve_send, |
| 58 | }; |
| 59 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 60 | /* local function prototypes */ |
| 61 | static int dns_run_resolution(struct dns_requester *requester); |
| 62 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 63 | #if DEBUG |
| 64 | /* |
| 65 | * go through the resolutions associated to a resolvers section and print the ID and hostname in |
| 66 | * domain name format |
| 67 | * should be used for debug purpose only |
| 68 | */ |
| 69 | void dns_print_current_resolutions(struct dns_resolvers *resolvers) |
| 70 | { |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 71 | list_for_each_entry(resolution, &resolvers->resolution.curr, list) { |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 72 | printf(" resolution %d for %s\n", resolution->query_id, resolution->hostname_dn); |
| 73 | } |
| 74 | } |
| 75 | #endif |
| 76 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 77 | void dump_dns_config() |
| 78 | { |
| 79 | struct dns_resolvers *curr_resolvers = NULL; |
| 80 | struct dns_nameserver *curr_nameserver = NULL; |
| 81 | struct dns_resolution *curr_resolution = NULL; |
| 82 | struct dns_requester *curr_requester = NULL; |
| 83 | |
| 84 | printf("===============\n"); |
| 85 | list_for_each_entry(curr_resolvers, &dns_resolvers, list) { |
| 86 | printf("Resolvers: %s\n", curr_resolvers->id); |
| 87 | |
| 88 | printf(" nameservers:\n"); |
| 89 | list_for_each_entry(curr_nameserver, &curr_resolvers->nameserver_list, list) { |
| 90 | printf(" %s\n", curr_nameserver->id); |
| 91 | } |
| 92 | |
| 93 | /* |
| 94 | printf(" resolution.pool list:\n"); |
| 95 | list_for_each_entry(curr_resolution, &curr_resolvers->resolution.pool, list) { |
| 96 | printf(" %p\n", curr_resolution); |
| 97 | } |
| 98 | */ |
| 99 | |
| 100 | printf(" resolution.wait list:\n"); |
| 101 | list_for_each_entry(curr_resolution, &curr_resolvers->resolution.wait, list) { |
| 102 | printf(" %p %s\n", curr_resolution, curr_resolution->hostname_dn); |
| 103 | printf(" requester.wait list:\n"); |
| 104 | list_for_each_entry(curr_requester, &curr_resolution->requester.wait, list) { |
| 105 | printf(" %p %s %d\n", curr_requester, objt_server(curr_requester->requester)->id, curr_requester->prefered_query_type); |
| 106 | } |
| 107 | printf(" requester.curr list:\n"); |
| 108 | list_for_each_entry(curr_requester, &curr_resolution->requester.curr, list) { |
| 109 | printf(" %p %s %d\n", curr_requester, objt_server(curr_requester->requester)->id, curr_requester->prefered_query_type); |
| 110 | } |
| 111 | } |
| 112 | printf(" resolution.curr list:\n"); |
| 113 | list_for_each_entry(curr_resolution, &curr_resolvers->resolution.curr, list) { |
| 114 | printf(" %p %s\n", curr_resolution, curr_resolution->hostname_dn); |
| 115 | printf(" requester.wait list:\n"); |
| 116 | list_for_each_entry(curr_requester, &curr_resolution->requester.wait, list) { |
| 117 | printf(" %p %s %d\n", curr_requester, objt_server(curr_requester->requester)->id, curr_requester->prefered_query_type); |
| 118 | } |
| 119 | printf(" requester.curr list:\n"); |
| 120 | list_for_each_entry(curr_requester, &curr_resolution->requester.curr, list) { |
| 121 | printf(" %p %s %d\n", curr_requester, objt_server(curr_requester->requester)->id, curr_requester->prefered_query_type); |
| 122 | } |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | printf("===============\n"); |
| 127 | } |
| 128 | |
| 129 | /* |
| 130 | * Initiates a new name resolution: |
| 131 | * - generates a query id |
| 132 | * - configure the resolution structure |
| 133 | * - startup the resolvers task if required |
| 134 | * |
| 135 | * returns: |
| 136 | * - 0 if everything started properly |
| 137 | * - -1 in case of error or if resolution already running |
| 138 | */ |
| 139 | int dns_trigger_resolution(struct dns_resolution *resolution) |
| 140 | { |
| 141 | struct dns_requester *requester = NULL, *tmprequester; |
| 142 | struct dns_resolvers *resolvers = NULL; |
| 143 | int inter; |
| 144 | |
| 145 | /* process the element of the wait queue */ |
| 146 | list_for_each_entry_safe(requester, tmprequester, &resolution->requester.wait, list) { |
| 147 | inter = 0; |
| 148 | |
| 149 | switch (obj_type(requester->requester)) { |
| 150 | case OBJ_TYPE_SERVER: |
| 151 | inter = objt_server(requester->requester)->check.inter; |
| 152 | resolvers = objt_server(requester->requester)->resolvers; |
| 153 | break; |
| 154 | case OBJ_TYPE_NONE: |
| 155 | default: |
| 156 | return -1; |
| 157 | } |
| 158 | |
| 159 | /* if data is fresh enough, let's use it */ |
| 160 | if (!tick_is_expired(tick_add(resolution->last_resolution, inter), now_ms)) { |
| 161 | /* we only use cache if the response there is valid. |
| 162 | * If not valid, we run the resolution and move the requester to |
| 163 | * the run queue. */ |
| 164 | if (resolution->status != RSLV_STATUS_VALID) { |
| 165 | LIST_DEL(&requester->list); |
| 166 | LIST_ADDQ(&resolution->requester.curr, &requester->list); |
| 167 | dns_run_resolution(requester); |
| 168 | continue; |
| 169 | } |
| 170 | |
| 171 | requester->requester_cb(requester, NULL); |
| 172 | } |
| 173 | else { |
| 174 | LIST_DEL(&requester->list); |
| 175 | LIST_ADDQ(&resolution->requester.curr, &requester->list); |
| 176 | dns_run_resolution(requester); |
| 177 | } |
| 178 | } |
| 179 | |
| 180 | if (resolvers) |
| 181 | dns_update_resolvers_timeout(resolvers); |
| 182 | |
| 183 | return 0; |
| 184 | } |
| 185 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 186 | /* |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 187 | * Prepare and send a DNS resolution. |
| 188 | * |
| 189 | * Return code: |
| 190 | * - 0 if no error occured |
| 191 | * - -1 in case of error |
| 192 | */ |
| 193 | static int |
| 194 | dns_run_resolution(struct dns_requester *requester) |
| 195 | { |
| 196 | struct dns_resolution *resolution; |
| 197 | struct dns_resolvers *resolvers; |
| 198 | int query_id, query_type, i; |
| 199 | struct proxy *proxy; |
| 200 | |
| 201 | resolution = NULL; |
| 202 | resolvers = NULL; |
| 203 | proxy = NULL; |
| 204 | query_type = -1; |
| 205 | switch (obj_type(requester->requester)) { |
| 206 | case OBJ_TYPE_SERVER: |
| 207 | resolution = objt_server(requester->requester)->resolution; |
| 208 | resolvers = objt_server(requester->requester)->resolvers; |
| 209 | proxy = objt_server(requester->requester)->proxy; |
| 210 | query_type = requester->prefered_query_type; |
| 211 | break; |
| 212 | case OBJ_TYPE_NONE: |
| 213 | default: |
| 214 | return -1; |
| 215 | } |
| 216 | |
| 217 | /* |
| 218 | * check if a resolution has already been started for this server |
| 219 | * return directly to avoid resolution pill up. |
| 220 | */ |
| 221 | if (resolution->step != RSLV_STEP_NONE) |
| 222 | return 0; |
| 223 | |
| 224 | /* generates a query id */ |
| 225 | i = 0; |
| 226 | do { |
| 227 | query_id = dns_rnd16(); |
| 228 | /* we do try only 100 times to find a free query id */ |
| 229 | if (i++ > 100) { |
| 230 | chunk_printf(&trash, "could not generate a query id for %s, in resolvers %s", |
| 231 | resolution->hostname_dn, resolvers->id); |
| 232 | |
| 233 | if (proxy) |
| 234 | send_log(proxy, LOG_NOTICE, "%s.\n", trash.str); |
| 235 | return -1; |
| 236 | } |
| 237 | } while (eb32_lookup(&resolvers->query_ids, query_id)); |
| 238 | |
| 239 | /* move the resolution into the run queue */ |
| 240 | LIST_DEL(&resolution->list); |
| 241 | LIST_ADDQ(&resolvers->resolution.curr, &resolution->list); |
| 242 | |
| 243 | /* now update resolution parameters */ |
| 244 | resolution->query_id = query_id; |
| 245 | resolution->qid.key = query_id; |
| 246 | resolution->step = RSLV_STEP_RUNNING; |
| 247 | resolution->query_type = query_type; |
| 248 | resolution->try = resolvers->resolve_retries; |
| 249 | resolution->try_cname = 0; |
| 250 | resolution->nb_responses = 0; |
| 251 | eb32_insert(&resolvers->query_ids, &resolution->qid); |
| 252 | |
| 253 | dns_send_query(resolution); |
| 254 | resolution->try -= 1; |
| 255 | |
| 256 | /* update wakeup date if this resolution is the only one in the FIFO list */ |
| 257 | if (dns_check_resolution_queue(resolvers) == 1) { |
| 258 | /* update task timeout */ |
| 259 | dns_update_resolvers_timeout(resolvers); |
| 260 | task_queue(resolvers->t); |
| 261 | } |
| 262 | |
| 263 | return 0; |
| 264 | } |
| 265 | |
| 266 | /* |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 267 | * check if there is more than 1 resolution in the resolver's resolution list |
| 268 | * return value: |
| 269 | * 0: empty list |
| 270 | * 1: exactly one entry in the list |
| 271 | * 2: more than one entry in the list |
| 272 | */ |
| 273 | int dns_check_resolution_queue(struct dns_resolvers *resolvers) |
| 274 | { |
| 275 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 276 | if (LIST_ISEMPTY(&resolvers->resolution.curr)) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 277 | return 0; |
| 278 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 279 | if ((resolvers->resolution.curr.n) && (resolvers->resolution.curr.n == resolvers->resolution.curr.p)) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 280 | return 1; |
| 281 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 282 | if (! ((resolvers->resolution.curr.n == resolvers->resolution.curr.p) |
| 283 | && (&resolvers->resolution.curr != resolvers->resolution.curr.n))) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 284 | return 2; |
| 285 | |
| 286 | return 0; |
| 287 | } |
| 288 | |
| 289 | /* |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 290 | * reset some resolution parameters to initial values and also delete the |
| 291 | * query ID from the resolver's tree. |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 292 | */ |
| 293 | void dns_reset_resolution(struct dns_resolution *resolution) |
| 294 | { |
| 295 | /* update resolution status */ |
| 296 | resolution->step = RSLV_STEP_NONE; |
| 297 | |
| 298 | resolution->try = 0; |
| 299 | resolution->try_cname = 0; |
| 300 | resolution->last_resolution = now_ms; |
| 301 | resolution->nb_responses = 0; |
| 302 | |
| 303 | /* clean up query id */ |
| 304 | eb32_delete(&resolution->qid); |
| 305 | resolution->query_id = 0; |
| 306 | resolution->qid.key = 0; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 307 | } |
| 308 | |
| 309 | /* |
| 310 | * function called when a network IO is generated on a name server socket for an incoming packet |
| 311 | * It performs the following actions: |
| 312 | * - check if the packet requires processing (not outdated resolution) |
| 313 | * - ensure the DNS packet received is valid and call requester's callback |
| 314 | * - call requester's error callback if invalid response |
Baptiste Assmann | 3cf7f98 | 2016-04-17 22:43:26 +0200 | [diff] [blame] | 315 | * - check the dn_name in the packet against the one sent |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 316 | */ |
| 317 | void dns_resolve_recv(struct dgram_conn *dgram) |
| 318 | { |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 319 | struct dns_nameserver *nameserver, *tmpnameserver; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 320 | struct dns_resolvers *resolvers; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 321 | struct dns_resolution *resolution = NULL; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 322 | struct dns_query_item *query; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 323 | unsigned char buf[DNS_MAX_UDP_MESSAGE + 1]; |
| 324 | unsigned char *bufend; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 325 | int fd, buflen, dns_resp, need_resend; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 326 | unsigned short query_id; |
| 327 | struct eb32_node *eb; |
Baptiste Assmann | fa4a663 | 2017-05-04 09:05:00 +0200 | [diff] [blame] | 328 | struct lru64 *lru = NULL; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 329 | struct dns_requester *requester = NULL, *tmprequester = NULL; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 330 | |
| 331 | fd = dgram->t.sock.fd; |
| 332 | |
| 333 | /* check if ready for reading */ |
| 334 | if (!fd_recv_ready(fd)) |
| 335 | return; |
| 336 | |
| 337 | /* no need to go further if we can't retrieve the nameserver */ |
Vincent Bernat | 3c2f2f2 | 2016-04-03 13:48:42 +0200 | [diff] [blame] | 338 | if ((nameserver = dgram->owner) == NULL) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 339 | return; |
| 340 | |
| 341 | resolvers = nameserver->resolvers; |
| 342 | |
| 343 | /* process all pending input messages */ |
| 344 | while (1) { |
| 345 | /* read message received */ |
| 346 | memset(buf, '\0', DNS_MAX_UDP_MESSAGE + 1); |
| 347 | if ((buflen = recv(fd, (char*)buf , DNS_MAX_UDP_MESSAGE, 0)) < 0) { |
| 348 | /* FIXME : for now we consider EAGAIN only */ |
| 349 | fd_cant_recv(fd); |
| 350 | break; |
| 351 | } |
| 352 | |
| 353 | /* message too big */ |
| 354 | if (buflen > DNS_MAX_UDP_MESSAGE) { |
| 355 | nameserver->counters.too_big += 1; |
| 356 | continue; |
| 357 | } |
| 358 | |
| 359 | /* initializing variables */ |
| 360 | bufend = buf + buflen; /* pointer to mark the end of the buffer */ |
| 361 | |
| 362 | /* read the query id from the packet (16 bits) */ |
| 363 | if (buf + 2 > bufend) { |
| 364 | nameserver->counters.invalid += 1; |
| 365 | continue; |
| 366 | } |
| 367 | query_id = dns_response_get_query_id(buf); |
| 368 | |
| 369 | /* search the query_id in the pending resolution tree */ |
Baptiste Assmann | 01daef3 | 2015-09-02 22:05:24 +0200 | [diff] [blame] | 370 | eb = eb32_lookup(&resolvers->query_ids, query_id); |
| 371 | if (eb == NULL) { |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 372 | /* unknown query id means an outdated response and can be safely ignored */ |
| 373 | nameserver->counters.outdated += 1; |
| 374 | continue; |
| 375 | } |
| 376 | |
| 377 | /* known query id means a resolution in prgress */ |
| 378 | resolution = eb32_entry(eb, struct dns_resolution, qid); |
| 379 | |
| 380 | if (!resolution) { |
| 381 | nameserver->counters.outdated += 1; |
| 382 | continue; |
| 383 | } |
| 384 | |
| 385 | /* number of responses received */ |
| 386 | resolution->nb_responses += 1; |
| 387 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 388 | dns_resp = dns_validate_dns_response(buf, bufend, resolution); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 389 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 390 | /* treat errors first |
| 391 | * need_resend flag could be set to 0 by default before the 'switch' and then |
| 392 | * set to 1 only where needed, but I think it's better this way to make people |
| 393 | * aware they have to think twice how to set this flag when updating this portion |
| 394 | * of the code |
| 395 | */ |
| 396 | switch (dns_resp) { |
| 397 | case DNS_RESP_VALID: |
| 398 | need_resend = 0; |
| 399 | break; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 400 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 401 | case DNS_RESP_INVALID: |
| 402 | case DNS_RESP_QUERY_COUNT_ERROR: |
| 403 | case DNS_RESP_WRONG_NAME: |
| 404 | if (resolution->status != RSLV_STATUS_INVALID) { |
| 405 | resolution->status = RSLV_STATUS_INVALID; |
| 406 | resolution->last_status_change = now_ms; |
| 407 | } |
| 408 | nameserver->counters.invalid += 1; |
| 409 | need_resend = 0; |
| 410 | break; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 411 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 412 | case DNS_RESP_ANCOUNT_ZERO: |
| 413 | if (resolution->status != RSLV_STATUS_OTHER) { |
| 414 | resolution->status = RSLV_STATUS_OTHER; |
| 415 | resolution->last_status_change = now_ms; |
| 416 | } |
| 417 | nameserver->counters.any_err += 1; |
| 418 | need_resend = 1; |
| 419 | break; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 420 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 421 | case DNS_RESP_NX_DOMAIN: |
| 422 | if (resolution->status != RSLV_STATUS_NX) { |
| 423 | resolution->status = RSLV_STATUS_NX; |
| 424 | resolution->last_status_change = now_ms; |
| 425 | } |
| 426 | nameserver->counters.nx += 1; |
| 427 | need_resend = 0; |
| 428 | break; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 429 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 430 | case DNS_RESP_REFUSED: |
| 431 | if (resolution->status != RSLV_STATUS_REFUSED) { |
| 432 | resolution->status = RSLV_STATUS_REFUSED; |
| 433 | resolution->last_status_change = now_ms; |
| 434 | } |
| 435 | nameserver->counters.refused += 1; |
| 436 | need_resend = 0; |
| 437 | break; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 438 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 439 | case DNS_RESP_CNAME_ERROR: |
| 440 | if (resolution->status != RSLV_STATUS_OTHER) { |
| 441 | resolution->status = RSLV_STATUS_OTHER; |
| 442 | resolution->last_status_change = now_ms; |
| 443 | } |
| 444 | nameserver->counters.cname_error += 1; |
| 445 | need_resend = 1; |
| 446 | break; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 447 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 448 | case DNS_RESP_TRUNCATED: |
| 449 | if (resolution->status != RSLV_STATUS_OTHER) { |
| 450 | resolution->status = RSLV_STATUS_OTHER; |
| 451 | resolution->last_status_change = now_ms; |
| 452 | } |
| 453 | nameserver->counters.truncated += 1; |
| 454 | need_resend = 1; |
| 455 | break; |
Baptiste Assmann | 96972bc | 2015-09-09 00:46:58 +0200 | [diff] [blame] | 456 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 457 | case DNS_RESP_NO_EXPECTED_RECORD: |
| 458 | if (resolution->status != RSLV_STATUS_OTHER) { |
| 459 | resolution->status = RSLV_STATUS_OTHER; |
| 460 | resolution->last_status_change = now_ms; |
| 461 | } |
| 462 | nameserver->counters.other += 1; |
| 463 | need_resend = 1; |
| 464 | break; |
| 465 | |
| 466 | case DNS_RESP_ERROR: |
| 467 | case DNS_RESP_INTERNAL: |
| 468 | if (resolution->status != RSLV_STATUS_OTHER) { |
| 469 | resolution->status = RSLV_STATUS_OTHER; |
| 470 | resolution->last_status_change = now_ms; |
| 471 | } |
| 472 | nameserver->counters.other += 1; |
| 473 | need_resend = 1; |
| 474 | break; |
| 475 | } |
| 476 | |
| 477 | /* some error codes trigger a re-send of the query, but switching the |
| 478 | * query type. |
| 479 | * This is the case for the following error codes: |
| 480 | * DNS_RESP_ANCOUNT_ZERO |
| 481 | * DNS_RESP_TRUNCATED |
| 482 | * DNS_RESP_ERROR |
| 483 | * DNS_RESP_INTERNAL |
| 484 | * DNS_RESP_NO_EXPECTED_RECORD |
| 485 | * DNS_RESP_CNAME_ERROR |
| 486 | */ |
| 487 | if (need_resend) { |
| 488 | int family_prio; |
| 489 | int res_preferred_afinet, res_preferred_afinet6; |
| 490 | |
| 491 | requester = LIST_NEXT(&resolution->requester.curr, struct dns_requester *, list); |
| 492 | switch (obj_type(requester->requester)) { |
| 493 | case OBJ_TYPE_SERVER: |
| 494 | family_prio = objt_server(requester->requester)->dns_opts.family_prio; |
| 495 | break; |
| 496 | case OBJ_TYPE_NONE: |
| 497 | default: |
| 498 | family_prio = AF_INET6; |
| 499 | } |
| 500 | res_preferred_afinet = family_prio == AF_INET && resolution->query_type == DNS_RTYPE_A; |
| 501 | res_preferred_afinet6 = family_prio == AF_INET6 && resolution->query_type == DNS_RTYPE_AAAA; |
| 502 | if ((res_preferred_afinet || res_preferred_afinet6) |
| 503 | || (resolution->try > 0)) { |
| 504 | /* let's change the query type */ |
| 505 | if (res_preferred_afinet6) { |
| 506 | /* fallback from AAAA to A */ |
| 507 | resolution->query_type = DNS_RTYPE_A; |
| 508 | } |
| 509 | else if (res_preferred_afinet) { |
| 510 | /* fallback from A to AAAA */ |
| 511 | resolution->query_type = DNS_RTYPE_AAAA; |
| 512 | } |
| 513 | else { |
| 514 | resolution->try -= 1; |
| 515 | if (family_prio == AF_INET) { |
| 516 | resolution->query_type = DNS_RTYPE_A; |
| 517 | } else { |
| 518 | resolution->query_type = DNS_RTYPE_AAAA; |
| 519 | } |
| 520 | } |
| 521 | |
| 522 | dns_send_query(resolution); |
| 523 | /* |
| 524 | * move the resolution to the last element of the FIFO queue |
| 525 | * and update timeout wakeup based on the new first entry |
| 526 | */ |
| 527 | if (dns_check_resolution_queue(resolvers) > 1) { |
| 528 | /* second resolution becomes first one */ |
| 529 | LIST_DEL(&resolution->list); |
| 530 | /* ex first resolution goes to the end of the queue */ |
| 531 | LIST_ADDQ(&resolvers->resolution.curr, &resolution->list); |
| 532 | } |
| 533 | |
| 534 | dns_update_resolvers_timeout(resolvers); |
| 535 | goto next_packet; |
| 536 | } |
| 537 | |
| 538 | /* if we're there, this means that we already ran out of chances to re-send |
| 539 | * the query */ |
| 540 | list_for_each_entry_safe(requester, tmprequester, &resolution->requester.curr, list) { |
| 541 | requester->requester_error_cb(requester, dns_resp); |
| 542 | } |
| 543 | goto next_packet; |
| 544 | } |
| 545 | |
| 546 | /* now processing those error codes only: |
| 547 | * DNS_RESP_NX_DOMAIN |
| 548 | * DNS_RESP_REFUSED |
| 549 | */ |
| 550 | if (dns_resp != DNS_RESP_VALID) { |
| 551 | /* now parse list of requesters currently waiting for this resolution */ |
| 552 | list_for_each_entry_safe(requester, tmprequester, &resolution->requester.curr, list) { |
| 553 | requester->requester_error_cb(requester, dns_resp); |
| 554 | |
| 555 | /* we can move the requester the wait queue */ |
| 556 | LIST_DEL(&requester->list); |
| 557 | LIST_ADDQ(&resolution->requester.wait, &requester->list); |
| 558 | } |
| 559 | goto next_packet; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 560 | } |
| 561 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 562 | /* Now let's check the query's dname corresponds to the one we sent. |
| 563 | * We can check only the first query of the list. We send one query at a time |
| 564 | * so we get one query in the response */ |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 565 | query = LIST_NEXT(&resolution->response.query_list, struct dns_query_item *, list); |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 566 | if (query && memcmp(query->name, resolution->hostname_dn, resolution->hostname_dn_len) != 0) { |
| 567 | nameserver->counters.other += 1; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 568 | /* now parse list of requesters currently waiting for this resolution */ |
| 569 | list_for_each_entry_safe(requester, tmprequester, &resolution->requester.curr, list) { |
| 570 | requester->requester_error_cb(requester, DNS_RESP_WRONG_NAME); |
| 571 | /* we can move the requester the wait queue */ |
| 572 | LIST_DEL(&requester->list); |
| 573 | LIST_ADDQ(&resolution->requester.wait, &requester->list); |
| 574 | } |
| 575 | goto next_packet; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 576 | } |
| 577 | |
Baptiste Assmann | fa4a663 | 2017-05-04 09:05:00 +0200 | [diff] [blame] | 578 | /* no errors, we can save the response in the cache */ |
| 579 | if (dns_lru_tree) { |
| 580 | unsigned long long seed = 1; |
| 581 | struct chunk *buf = get_trash_chunk(); |
| 582 | struct chunk *tmp = NULL; |
| 583 | |
| 584 | chunk_reset(buf); |
| 585 | tmp = dns_cache_key(resolution->query_type, resolution->hostname_dn, |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 586 | resolution->hostname_dn_len, buf); |
Baptiste Assmann | fa4a663 | 2017-05-04 09:05:00 +0200 | [diff] [blame] | 587 | if (!tmp) { |
| 588 | nameserver->counters.other += 1; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 589 | /* now parse list of requesters currently waiting for this resolution */ |
| 590 | list_for_each_entry_safe(requester, tmprequester, &resolution->requester.curr, list) { |
| 591 | requester->requester_error_cb(requester, DNS_RESP_ERROR); |
| 592 | /* we can move the requester the wait queue */ |
| 593 | LIST_DEL(&requester->list); |
| 594 | LIST_ADDQ(&resolution->requester.wait, &requester->list); |
| 595 | } |
| 596 | goto next_packet; |
Baptiste Assmann | fa4a663 | 2017-05-04 09:05:00 +0200 | [diff] [blame] | 597 | } |
| 598 | |
| 599 | lru = lru64_get(XXH64(buf->str, buf->len, seed), |
| 600 | dns_lru_tree, nameserver->resolvers, 1); |
| 601 | |
| 602 | lru64_commit(lru, resolution, nameserver->resolvers, 1, NULL); |
| 603 | } |
| 604 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 605 | if (resolution->status != RSLV_STATUS_VALID) { |
| 606 | resolution->status = RSLV_STATUS_VALID; |
| 607 | resolution->last_status_change = now_ms; |
| 608 | } |
| 609 | |
Baptiste Assmann | 37bb372 | 2015-08-07 10:18:32 +0200 | [diff] [blame] | 610 | nameserver->counters.valid += 1; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 611 | /* now parse list of requesters currently waiting for this resolution */ |
| 612 | tmpnameserver = nameserver; |
| 613 | list_for_each_entry_safe(requester, tmprequester, &resolution->requester.curr, list) { |
| 614 | requester->requester_cb(requester, tmpnameserver); |
| 615 | /* we can move the requester the wait queue */ |
| 616 | LIST_DEL(&requester->list); |
| 617 | LIST_ADDQ(&resolution->requester.wait, &requester->list); |
| 618 | /* first response is managed by the server, others are from the cache */ |
| 619 | tmpnameserver = NULL; |
| 620 | } |
| 621 | |
| 622 | next_packet: |
| 623 | /* resolution may be NULL when we receive an ICMP unreachable packet */ |
| 624 | if (resolution && LIST_ISEMPTY(&resolution->requester.curr)) { |
| 625 | /* move the resolution into the wait queue */ |
| 626 | LIST_DEL(&resolution->list); |
| 627 | LIST_ADDQ(&resolvers->resolution.wait, &resolution->list); |
| 628 | /* update last resolution date and time */ |
| 629 | resolution->last_resolution = now_ms; |
| 630 | /* reset current status flag */ |
| 631 | resolution->step = RSLV_STEP_NONE; |
| 632 | /* reset values */ |
| 633 | dns_reset_resolution(resolution); |
| 634 | } |
| 635 | |
| 636 | } // end of while "packets" loop |
| 637 | |
| 638 | dns_update_resolvers_timeout(nameserver->resolvers); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 639 | } |
| 640 | |
| 641 | /* |
| 642 | * function called when a resolvers network socket is ready to send data |
| 643 | * It performs the following actions: |
| 644 | */ |
| 645 | void dns_resolve_send(struct dgram_conn *dgram) |
| 646 | { |
| 647 | int fd; |
| 648 | struct dns_nameserver *nameserver; |
| 649 | struct dns_resolvers *resolvers; |
| 650 | struct dns_resolution *resolution; |
| 651 | |
| 652 | fd = dgram->t.sock.fd; |
| 653 | |
| 654 | /* check if ready for sending */ |
| 655 | if (!fd_send_ready(fd)) |
| 656 | return; |
| 657 | |
| 658 | /* we don't want/need to be waked up any more for sending */ |
| 659 | fd_stop_send(fd); |
| 660 | |
| 661 | /* no need to go further if we can't retrieve the nameserver */ |
Vincent Bernat | 3c2f2f2 | 2016-04-03 13:48:42 +0200 | [diff] [blame] | 662 | if ((nameserver = dgram->owner) == NULL) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 663 | return; |
| 664 | |
| 665 | resolvers = nameserver->resolvers; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 666 | resolution = LIST_NEXT(&resolvers->resolution.curr, struct dns_resolution *, list); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 667 | |
| 668 | dns_send_query(resolution); |
| 669 | dns_update_resolvers_timeout(resolvers); |
| 670 | } |
| 671 | |
| 672 | /* |
| 673 | * forge and send a DNS query to resolvers associated to a resolution |
| 674 | * It performs the following actions: |
| 675 | * returns: |
| 676 | * 0 in case of error or safe ignorance |
| 677 | * 1 if no error |
| 678 | */ |
| 679 | int dns_send_query(struct dns_resolution *resolution) |
| 680 | { |
Baptiste Assmann | 4274637 | 2017-05-03 12:12:02 +0200 | [diff] [blame] | 681 | struct dns_resolvers *resolvers = NULL; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 682 | struct dns_nameserver *nameserver; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 683 | struct dns_requester *requester = NULL; |
Erwan Velu | 5457eb4 | 2015-10-15 15:07:26 +0200 | [diff] [blame] | 684 | int ret, bufsize, fd; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 685 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 686 | /* nothing to do */ |
| 687 | if (LIST_ISEMPTY(&resolution->requester.curr)) |
| 688 | return 0; |
| 689 | |
| 690 | requester = LIST_NEXT(&resolution->requester.curr, struct dns_requester *, list); |
| 691 | |
| 692 | switch (obj_type(requester->requester)) { |
| 693 | case OBJ_TYPE_SERVER: |
| 694 | resolvers = objt_server(requester->requester)->resolvers; |
| 695 | break; |
| 696 | case OBJ_TYPE_NONE: |
| 697 | default: |
| 698 | return 0; |
| 699 | } |
Baptiste Assmann | 4274637 | 2017-05-03 12:12:02 +0200 | [diff] [blame] | 700 | |
| 701 | if (!resolvers) |
| 702 | return 0; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 703 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 704 | bufsize = dns_build_query(resolution->query_id, resolution->query_type, resolution->hostname_dn, |
| 705 | resolution->hostname_dn_len, trash.str, trash.size); |
| 706 | |
| 707 | if (bufsize == -1) |
| 708 | return 0; |
| 709 | |
| 710 | list_for_each_entry(nameserver, &resolvers->nameserver_list, list) { |
| 711 | fd = nameserver->dgram->t.sock.fd; |
| 712 | errno = 0; |
| 713 | |
| 714 | ret = send(fd, trash.str, bufsize, 0); |
| 715 | |
| 716 | if (ret > 0) |
| 717 | nameserver->counters.sent += 1; |
| 718 | |
| 719 | if (ret == 0 || errno == EAGAIN) { |
| 720 | /* nothing written, let's update the poller that we wanted to send |
| 721 | * but we were not able to */ |
| 722 | fd_want_send(fd); |
| 723 | fd_cant_send(fd); |
| 724 | } |
| 725 | } |
| 726 | |
| 727 | /* update resolution */ |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 728 | resolution->nb_responses = 0; |
| 729 | resolution->last_sent_packet = now_ms; |
| 730 | |
| 731 | return 1; |
| 732 | } |
| 733 | |
| 734 | /* |
| 735 | * update a resolvers' task timeout for next wake up |
| 736 | */ |
| 737 | void dns_update_resolvers_timeout(struct dns_resolvers *resolvers) |
| 738 | { |
| 739 | struct dns_resolution *resolution; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 740 | struct dns_requester *requester; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 741 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 742 | if ((LIST_ISEMPTY(&resolvers->resolution.curr)) && (LIST_ISEMPTY(&resolvers->resolution.wait))) { |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 743 | resolvers->t->expire = TICK_ETERNITY; |
| 744 | } |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 745 | else if (!LIST_ISEMPTY(&resolvers->resolution.curr)) { |
| 746 | resolution = LIST_NEXT(&resolvers->resolution.curr, struct dns_resolution *, list); |
| 747 | if (!resolvers->t->expire || tick_is_le(resolvers->t->expire, tick_add(resolution->last_sent_packet, resolvers->timeout.retry))) { |
| 748 | resolvers->t->expire = tick_add(resolution->last_sent_packet, resolvers->timeout.retry); |
| 749 | } |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 750 | } |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 751 | else if (!LIST_ISEMPTY(&resolvers->resolution.wait)) { |
| 752 | int valid_period, inter, need_wakeup; |
| 753 | struct dns_resolution *res_back; |
| 754 | need_wakeup = 0; |
| 755 | list_for_each_entry_safe(resolution, res_back, &resolvers->resolution.wait, list) { |
| 756 | valid_period = 0; |
| 757 | inter = 0; |
| 758 | |
| 759 | requester = LIST_NEXT(&resolution->requester.wait, struct dns_requester *, list); |
| 760 | |
| 761 | switch (obj_type(requester->requester)) { |
| 762 | case OBJ_TYPE_SERVER: |
| 763 | valid_period = objt_server(requester->requester)->check.inter; |
| 764 | break; |
| 765 | case OBJ_TYPE_NONE: |
| 766 | default: |
| 767 | continue; |
| 768 | } |
| 769 | |
| 770 | if (resolvers->hold.valid < valid_period) |
| 771 | inter = resolvers->hold.valid; |
| 772 | else |
| 773 | inter = valid_period; |
| 774 | |
| 775 | if (tick_is_expired(tick_add(resolution->last_resolution, inter), now_ms)) { |
| 776 | switch (obj_type(requester->requester)) { |
| 777 | case OBJ_TYPE_SERVER: |
| 778 | dns_trigger_resolution(objt_server(requester->requester)->resolution); |
| 779 | break; |
| 780 | case OBJ_TYPE_NONE: |
| 781 | default: |
| 782 | ;; |
| 783 | } |
| 784 | } |
| 785 | else { |
| 786 | need_wakeup = 1; |
| 787 | } |
| 788 | } |
| 789 | /* in such case, we wake up in 1s */ |
| 790 | if (need_wakeup) { |
| 791 | int r = 1000; |
| 792 | |
| 793 | resolution = LIST_NEXT(&resolvers->resolution.wait, struct dns_resolution *, list); |
| 794 | if (tick_is_le(resolvers->t->expire, tick_add(now_ms, r))) |
| 795 | resolvers->t->expire = tick_add(now_ms, r); |
| 796 | resolvers->t->expire = tick_add(now_ms, 1000); |
| 797 | } |
| 798 | } |
| 799 | |
| 800 | task_queue(resolvers->t); |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 801 | } |
| 802 | |
| 803 | /* |
| 804 | * Analyse, re-build and copy the name <name> from the DNS response packet <buffer>. |
| 805 | * <name> must point to the 'data_len' information or pointer 'c0' for compressed data. |
| 806 | * The result is copied into <dest>, ensuring we don't overflow using <dest_len> |
| 807 | * Returns the number of bytes the caller can move forward. If 0 it means an error occured |
| 808 | * while parsing the name. |
| 809 | * <offset> is the number of bytes the caller could move forward. |
| 810 | */ |
| 811 | int dns_read_name(unsigned char *buffer, unsigned char *bufend, unsigned char *name, char *destination, int dest_len, int *offset) |
| 812 | { |
| 813 | int nb_bytes = 0, n = 0; |
| 814 | int label_len; |
| 815 | unsigned char *reader = name; |
| 816 | char *dest = destination; |
| 817 | |
| 818 | while (1) { |
| 819 | /* name compression is in use */ |
| 820 | if ((*reader & 0xc0) == 0xc0) { |
| 821 | /* a pointer must point BEFORE current position */ |
| 822 | if ((buffer + reader[1]) > reader) { |
| 823 | goto out_error; |
| 824 | } |
| 825 | |
| 826 | n = dns_read_name(buffer, bufend, buffer + reader[1], dest, dest_len - nb_bytes, offset); |
| 827 | if (n == 0) |
| 828 | goto out_error; |
| 829 | |
| 830 | dest += n; |
| 831 | nb_bytes += n; |
| 832 | goto out; |
| 833 | } |
| 834 | |
| 835 | label_len = *reader; |
| 836 | if (label_len == 0) |
| 837 | goto out; |
| 838 | /* Check if: |
| 839 | * - we won't read outside the buffer |
| 840 | * - there is enough place in the destination |
| 841 | */ |
| 842 | if ((reader + label_len >= bufend) || (nb_bytes + label_len >= dest_len)) |
| 843 | goto out_error; |
| 844 | |
| 845 | /* +1 to take label len + label string */ |
| 846 | label_len += 1; |
| 847 | |
| 848 | memcpy(dest, reader, label_len); |
| 849 | |
| 850 | dest += label_len; |
| 851 | nb_bytes += label_len; |
| 852 | reader += label_len; |
| 853 | } |
| 854 | |
| 855 | out: |
| 856 | /* offset computation: |
| 857 | * parse from <name> until finding either NULL or a pointer "c0xx" |
| 858 | */ |
| 859 | reader = name; |
| 860 | *offset = 0; |
| 861 | while (reader < bufend) { |
| 862 | if ((reader[0] & 0xc0) == 0xc0) { |
| 863 | *offset += 2; |
| 864 | break; |
| 865 | } |
| 866 | else if (*reader == 0) { |
| 867 | *offset += 1; |
| 868 | break; |
| 869 | } |
| 870 | *offset += 1; |
| 871 | ++reader; |
| 872 | } |
| 873 | |
| 874 | return nb_bytes; |
| 875 | |
| 876 | out_error: |
| 877 | return 0; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 878 | } |
| 879 | |
| 880 | /* |
| 881 | * Function to validate that the buffer DNS response provided in <resp> and |
| 882 | * finishing before <bufend> is valid from a DNS protocol point of view. |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 883 | * |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 884 | * The result is stored in <resolution>' response, buf_response, response_query_records |
| 885 | * and response_answer_records members. |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 886 | * |
| 887 | * This function returns one of the DNS_RESP_* code to indicate the type of |
| 888 | * error found. |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 889 | */ |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 890 | int dns_validate_dns_response(unsigned char *resp, unsigned char *bufend, struct dns_resolution *resolution) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 891 | { |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 892 | unsigned char *reader; |
| 893 | char *previous_dname, tmpname[DNS_MAX_NAME_SIZE]; |
| 894 | int len, flags, offset, ret; |
| 895 | int dns_query_record_id, dns_answer_record_id; |
Baptiste Assmann | 69fce67 | 2017-05-04 08:37:45 +0200 | [diff] [blame] | 896 | int nb_saved_records; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 897 | struct dns_query_item *dns_query; |
| 898 | struct dns_answer_item *dns_answer_record; |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 899 | struct dns_response_packet *dns_p; |
| 900 | struct chunk *dns_response_buffer; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 901 | |
| 902 | reader = resp; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 903 | len = 0; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 904 | previous_dname = NULL; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 905 | |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 906 | /* initialization of response buffer and structure */ |
| 907 | dns_p = &resolution->response; |
| 908 | dns_response_buffer = &resolution->response_buffer; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 909 | memset(dns_p, '\0', sizeof(struct dns_response_packet)); |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 910 | chunk_reset(dns_response_buffer); |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 911 | |
| 912 | /* query id */ |
| 913 | if (reader + 2 >= bufend) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 914 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 915 | dns_p->header.id = reader[0] * 256 + reader[1]; |
| 916 | reader += 2; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 917 | |
| 918 | /* |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 919 | * flags and rcode are stored over 2 bytes |
Baptiste Assmann | 3440f0d | 2015-09-02 22:08:38 +0200 | [diff] [blame] | 920 | * First byte contains: |
| 921 | * - response flag (1 bit) |
| 922 | * - opcode (4 bits) |
| 923 | * - authoritative (1 bit) |
| 924 | * - truncated (1 bit) |
| 925 | * - recursion desired (1 bit) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 926 | */ |
Baptiste Assmann | 3440f0d | 2015-09-02 22:08:38 +0200 | [diff] [blame] | 927 | if (reader + 2 >= bufend) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 928 | return DNS_RESP_INVALID; |
| 929 | |
Baptiste Assmann | 3440f0d | 2015-09-02 22:08:38 +0200 | [diff] [blame] | 930 | flags = reader[0] * 256 + reader[1]; |
| 931 | |
| 932 | if (flags & DNS_FLAG_TRUNCATED) |
| 933 | return DNS_RESP_TRUNCATED; |
| 934 | |
| 935 | if ((flags & DNS_FLAG_REPLYCODE) != DNS_RCODE_NO_ERROR) { |
| 936 | if ((flags & DNS_FLAG_REPLYCODE) == DNS_RCODE_NX_DOMAIN) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 937 | return DNS_RESP_NX_DOMAIN; |
Baptiste Assmann | 3440f0d | 2015-09-02 22:08:38 +0200 | [diff] [blame] | 938 | else if ((flags & DNS_FLAG_REPLYCODE) == DNS_RCODE_REFUSED) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 939 | return DNS_RESP_REFUSED; |
| 940 | |
| 941 | return DNS_RESP_ERROR; |
| 942 | } |
| 943 | |
Baptiste Assmann | 3440f0d | 2015-09-02 22:08:38 +0200 | [diff] [blame] | 944 | /* move forward 2 bytes for flags */ |
| 945 | reader += 2; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 946 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 947 | /* 2 bytes for question count */ |
| 948 | if (reader + 2 >= bufend) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 949 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 950 | dns_p->header.qdcount = reader[0] * 256 + reader[1]; |
| 951 | /* (for now) we send one query only, so we expect only one in the response too */ |
| 952 | if (dns_p->header.qdcount != 1) |
| 953 | return DNS_RESP_QUERY_COUNT_ERROR; |
| 954 | if (dns_p->header.qdcount > DNS_MAX_QUERY_RECORDS) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 955 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 956 | reader += 2; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 957 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 958 | /* 2 bytes for answer count */ |
| 959 | if (reader + 2 >= bufend) |
| 960 | return DNS_RESP_INVALID; |
| 961 | dns_p->header.ancount = reader[0] * 256 + reader[1]; |
| 962 | if (dns_p->header.ancount == 0) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 963 | return DNS_RESP_ANCOUNT_ZERO; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 964 | /* check if too many records are announced */ |
| 965 | if (dns_p->header.ancount > DNS_MAX_ANSWER_RECORDS) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 966 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 967 | reader += 2; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 968 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 969 | /* 2 bytes authority count */ |
| 970 | if (reader + 2 >= bufend) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 971 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 972 | dns_p->header.nscount = reader[0] * 256 + reader[1]; |
| 973 | reader += 2; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 974 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 975 | /* 2 bytes additional count */ |
| 976 | if (reader + 2 >= bufend) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 977 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 978 | dns_p->header.arcount = reader[0] * 256 + reader[1]; |
| 979 | reader += 2; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 980 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 981 | /* parsing dns queries */ |
| 982 | LIST_INIT(&dns_p->query_list); |
| 983 | for (dns_query_record_id = 0; dns_query_record_id < dns_p->header.qdcount; dns_query_record_id++) { |
| 984 | /* use next pre-allocated dns_query_item after ensuring there is |
| 985 | * still one available. |
| 986 | * It's then added to our packet query list. |
| 987 | */ |
| 988 | if (dns_query_record_id > DNS_MAX_QUERY_RECORDS) |
| 989 | return DNS_RESP_INVALID; |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 990 | dns_query = &resolution->response_query_records[dns_query_record_id]; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 991 | LIST_ADDQ(&dns_p->query_list, &dns_query->list); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 992 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 993 | /* name is a NULL terminated string in our case, since we have |
| 994 | * one query per response and the first one can't be compressed |
| 995 | * (using the 0x0c format) |
| 996 | */ |
| 997 | offset = 0; |
| 998 | len = dns_read_name(resp, bufend, reader, dns_query->name, DNS_MAX_NAME_SIZE, &offset); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 999 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1000 | if (len == 0) |
| 1001 | return DNS_RESP_INVALID; |
| 1002 | |
| 1003 | reader += offset; |
| 1004 | previous_dname = dns_query->name; |
| 1005 | |
| 1006 | /* move forward 2 bytes for question type */ |
| 1007 | if (reader + 2 >= bufend) |
| 1008 | return DNS_RESP_INVALID; |
| 1009 | dns_query->type = reader[0] * 256 + reader[1]; |
| 1010 | reader += 2; |
| 1011 | |
| 1012 | /* move forward 2 bytes for question class */ |
| 1013 | if (reader + 2 >= bufend) |
| 1014 | return DNS_RESP_INVALID; |
| 1015 | dns_query->class = reader[0] * 256 + reader[1]; |
| 1016 | reader += 2; |
| 1017 | } |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1018 | |
| 1019 | /* now parsing response records */ |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1020 | LIST_INIT(&dns_p->answer_list); |
Baptiste Assmann | 69fce67 | 2017-05-04 08:37:45 +0200 | [diff] [blame] | 1021 | nb_saved_records = 0; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1022 | for (dns_answer_record_id = 0; dns_answer_record_id < dns_p->header.ancount; dns_answer_record_id++) { |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1023 | if (reader >= bufend) |
| 1024 | return DNS_RESP_INVALID; |
| 1025 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1026 | /* pull next response record from the list, if still one available, then add it |
| 1027 | * to the record list */ |
| 1028 | if (dns_answer_record_id > DNS_MAX_ANSWER_RECORDS) |
| 1029 | return DNS_RESP_INVALID; |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 1030 | dns_answer_record = &resolution->response_answer_records[dns_answer_record_id]; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1031 | LIST_ADDQ(&dns_p->answer_list, &dns_answer_record->list); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1032 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1033 | offset = 0; |
| 1034 | len = dns_read_name(resp, bufend, reader, tmpname, DNS_MAX_NAME_SIZE, &offset); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1035 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1036 | if (len == 0) |
| 1037 | return DNS_RESP_INVALID; |
| 1038 | |
| 1039 | /* check if the current record dname is valid. |
| 1040 | * previous_dname points either to queried dname or last CNAME target |
| 1041 | */ |
| 1042 | if (memcmp(previous_dname, tmpname, len) != 0) { |
| 1043 | if (dns_answer_record_id == 0) { |
| 1044 | /* first record, means a mismatch issue between queried dname |
| 1045 | * and dname found in the first record */ |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1046 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1047 | } else { |
| 1048 | /* if not the first record, this means we have a CNAME resolution |
| 1049 | * error */ |
| 1050 | return DNS_RESP_CNAME_ERROR; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1051 | } |
| 1052 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1053 | } |
| 1054 | |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 1055 | dns_answer_record->name = chunk_newstr(dns_response_buffer); |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1056 | if (dns_answer_record->name == NULL) |
| 1057 | return DNS_RESP_INVALID; |
Baptiste Assmann | 5d681ba | 2015-10-15 15:23:28 +0200 | [diff] [blame] | 1058 | |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 1059 | ret = chunk_strncat(dns_response_buffer, tmpname, len); |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1060 | if (ret == 0) |
| 1061 | return DNS_RESP_INVALID; |
Baptiste Assmann | 2359ff1 | 2015-08-07 11:24:05 +0200 | [diff] [blame] | 1062 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1063 | reader += offset; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1064 | if (reader >= bufend) |
| 1065 | return DNS_RESP_INVALID; |
| 1066 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1067 | if (reader >= bufend) |
| 1068 | return DNS_RESP_INVALID; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1069 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1070 | /* 2 bytes for record type (A, AAAA, CNAME, etc...) */ |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1071 | if (reader + 2 > bufend) |
| 1072 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1073 | dns_answer_record->type = reader[0] * 256 + reader[1]; |
| 1074 | reader += 2; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1075 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1076 | /* 2 bytes for class (2) */ |
| 1077 | if (reader + 2 > bufend) |
| 1078 | return DNS_RESP_INVALID; |
| 1079 | dns_answer_record->class = reader[0] * 256 + reader[1]; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1080 | reader += 2; |
| 1081 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1082 | /* 4 bytes for ttl (4) */ |
| 1083 | if (reader + 4 > bufend) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1084 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1085 | dns_answer_record->ttl = reader[0] * 16777216 + reader[1] * 65536 |
| 1086 | + reader[2] * 256 + reader[3]; |
| 1087 | reader += 4; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1088 | |
| 1089 | /* now reading data len */ |
| 1090 | if (reader + 2 > bufend) |
| 1091 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1092 | dns_answer_record->data_len = reader[0] * 256 + reader[1]; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1093 | |
| 1094 | /* move forward 2 bytes for data len */ |
| 1095 | reader += 2; |
| 1096 | |
| 1097 | /* analyzing record content */ |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1098 | switch (dns_answer_record->type) { |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1099 | case DNS_RTYPE_A: |
| 1100 | /* ipv4 is stored on 4 bytes */ |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1101 | if (dns_answer_record->data_len != 4) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1102 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1103 | dns_answer_record->address.sa_family = AF_INET; |
| 1104 | memcpy(&(((struct sockaddr_in *)&dns_answer_record->address)->sin_addr), |
| 1105 | reader, dns_answer_record->data_len); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1106 | break; |
| 1107 | |
| 1108 | case DNS_RTYPE_CNAME: |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1109 | /* check if this is the last record and update the caller about the status: |
| 1110 | * no IP could be found and last record was a CNAME. Could be triggered |
| 1111 | * by a wrong query type |
| 1112 | * |
| 1113 | * + 1 because dns_answer_record_id starts at 0 while number of answers |
| 1114 | * is an integer and starts at 1. |
| 1115 | */ |
| 1116 | if (dns_answer_record_id + 1 == dns_p->header.ancount) |
| 1117 | return DNS_RESP_CNAME_ERROR; |
| 1118 | |
| 1119 | offset = 0; |
| 1120 | len = dns_read_name(resp, bufend, reader, tmpname, DNS_MAX_NAME_SIZE, &offset); |
| 1121 | |
| 1122 | if (len == 0) |
| 1123 | return DNS_RESP_INVALID; |
| 1124 | |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 1125 | dns_answer_record->target = chunk_newstr(dns_response_buffer); |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1126 | if (dns_answer_record->target == NULL) |
| 1127 | return DNS_RESP_INVALID; |
| 1128 | |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 1129 | ret = chunk_strncat(dns_response_buffer, tmpname, len); |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1130 | if (ret == 0) |
| 1131 | return DNS_RESP_INVALID; |
| 1132 | |
| 1133 | previous_dname = dns_answer_record->target; |
| 1134 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1135 | break; |
| 1136 | |
| 1137 | case DNS_RTYPE_AAAA: |
| 1138 | /* ipv6 is stored on 16 bytes */ |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1139 | if (dns_answer_record->data_len != 16) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1140 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1141 | dns_answer_record->address.sa_family = AF_INET6; |
| 1142 | memcpy(&(((struct sockaddr_in6 *)&dns_answer_record->address)->sin6_addr), |
| 1143 | reader, dns_answer_record->data_len); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1144 | break; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1145 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1146 | } /* switch (record type) */ |
| 1147 | |
Baptiste Assmann | 69fce67 | 2017-05-04 08:37:45 +0200 | [diff] [blame] | 1148 | /* increment the counter for number of records saved into our local response */ |
| 1149 | nb_saved_records += 1; |
| 1150 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1151 | /* move forward dns_answer_record->data_len for analyzing next record in the response */ |
| 1152 | reader += dns_answer_record->data_len; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1153 | } /* for i 0 to ancount */ |
| 1154 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1155 | /* let's add a last \0 to close our last string */ |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 1156 | ret = chunk_strncat(dns_response_buffer, "\0", 1); |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1157 | if (ret == 0) |
| 1158 | return DNS_RESP_INVALID; |
Baptiste Assmann | 96972bc | 2015-09-09 00:46:58 +0200 | [diff] [blame] | 1159 | |
Baptiste Assmann | 69fce67 | 2017-05-04 08:37:45 +0200 | [diff] [blame] | 1160 | /* save the number of records we really own */ |
| 1161 | dns_p->header.ancount = nb_saved_records; |
| 1162 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1163 | return DNS_RESP_VALID; |
| 1164 | } |
| 1165 | |
| 1166 | /* |
| 1167 | * search dn_name resolution in resp. |
| 1168 | * If existing IP not found, return the first IP matching family_priority, |
| 1169 | * otherwise, first ip found |
| 1170 | * The following tasks are the responsibility of the caller: |
Baptiste Assmann | 3cf7f98 | 2016-04-17 22:43:26 +0200 | [diff] [blame] | 1171 | * - <dns_p> contains an error free DNS response |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1172 | * For both cases above, dns_validate_dns_response is required |
| 1173 | * returns one of the DNS_UPD_* code |
| 1174 | */ |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1175 | #define DNS_MAX_IP_REC 20 |
Baptiste Assmann | fb7091e | 2017-05-03 15:43:12 +0200 | [diff] [blame] | 1176 | int dns_get_ip_from_response(struct dns_response_packet *dns_p, |
Baptiste Assmann | 4274637 | 2017-05-03 12:12:02 +0200 | [diff] [blame] | 1177 | struct dns_options *dns_opts, void *currentip, |
Thierry Fournier | ada3484 | 2016-02-17 21:25:09 +0100 | [diff] [blame] | 1178 | short currentip_sin_family, |
Baptiste Assmann | fb7091e | 2017-05-03 15:43:12 +0200 | [diff] [blame] | 1179 | void **newip, short *newip_sin_family, |
| 1180 | void *owner) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1181 | { |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1182 | struct dns_answer_item *record; |
Thierry Fournier | ada3484 | 2016-02-17 21:25:09 +0100 | [diff] [blame] | 1183 | int family_priority; |
Baptiste Assmann | 3cf7f98 | 2016-04-17 22:43:26 +0200 | [diff] [blame] | 1184 | int i, currentip_found; |
| 1185 | unsigned char *newip4, *newip6; |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1186 | struct { |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1187 | void *ip; |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1188 | unsigned char type; |
| 1189 | } rec[DNS_MAX_IP_REC]; |
| 1190 | int currentip_sel; |
| 1191 | int j; |
| 1192 | int rec_nb = 0; |
| 1193 | int score, max_score; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1194 | |
Baptiste Assmann | 4274637 | 2017-05-03 12:12:02 +0200 | [diff] [blame] | 1195 | family_priority = dns_opts->family_prio; |
Baptiste Assmann | 3cf7f98 | 2016-04-17 22:43:26 +0200 | [diff] [blame] | 1196 | *newip = newip4 = newip6 = NULL; |
| 1197 | currentip_found = 0; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1198 | *newip_sin_family = AF_UNSPEC; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1199 | |
| 1200 | /* now parsing response records */ |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 1201 | list_for_each_entry(record, &dns_p->answer_list, list) { |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1202 | /* analyzing record content */ |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1203 | switch (record->type) { |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1204 | case DNS_RTYPE_A: |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1205 | /* Store IPv4, only if some room is avalaible. */ |
| 1206 | if (rec_nb < DNS_MAX_IP_REC) { |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1207 | rec[rec_nb].ip = &(((struct sockaddr_in *)&record->address)->sin_addr); |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1208 | rec[rec_nb].type = AF_INET; |
| 1209 | rec_nb++; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1210 | } |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1211 | break; |
| 1212 | |
Baptiste Assmann | 3cf7f98 | 2016-04-17 22:43:26 +0200 | [diff] [blame] | 1213 | /* we're looking for IPs only. CNAME validation is done when |
| 1214 | * parsing the response buffer for the first time */ |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1215 | case DNS_RTYPE_CNAME: |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1216 | break; |
| 1217 | |
| 1218 | case DNS_RTYPE_AAAA: |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1219 | /* Store IPv6, only if some room is avalaible. */ |
| 1220 | if (rec_nb < DNS_MAX_IP_REC) { |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1221 | rec[rec_nb].ip = &(((struct sockaddr_in6 *)&record->address)->sin6_addr); |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1222 | rec[rec_nb].type = AF_INET6; |
| 1223 | rec_nb++; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1224 | } |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1225 | break; |
| 1226 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1227 | } /* switch (record type) */ |
Baptiste Assmann | bcbd491 | 2016-04-18 19:42:57 +0200 | [diff] [blame] | 1228 | } /* list for each record entries */ |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1229 | |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1230 | /* Select an IP regarding configuration preference. |
| 1231 | * Top priority is the prefered network ip version, |
| 1232 | * second priority is the prefered network. |
| 1233 | * the last priority is the currently used IP, |
| 1234 | * |
| 1235 | * For these three priorities, a score is calculated. The |
| 1236 | * weight are: |
Baptiste | fc72590 | 2016-12-26 23:21:08 +0100 | [diff] [blame] | 1237 | * 8 - prefered netwok ip version. |
| 1238 | * 4 - prefered network. |
| 1239 | * 2 - if the ip in the record is not affected to any other server in the same backend (duplication) |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1240 | * 1 - current ip. |
| 1241 | * The result with the biggest score is returned. |
| 1242 | */ |
| 1243 | max_score = -1; |
| 1244 | for (i = 0; i < rec_nb; i++) { |
Baptiste | fc72590 | 2016-12-26 23:21:08 +0100 | [diff] [blame] | 1245 | int record_ip_already_affected = 0; |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1246 | |
| 1247 | score = 0; |
| 1248 | |
| 1249 | /* Check for prefered ip protocol. */ |
| 1250 | if (rec[i].type == family_priority) |
Baptiste | fc72590 | 2016-12-26 23:21:08 +0100 | [diff] [blame] | 1251 | score += 8; |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1252 | |
| 1253 | /* Check for prefered network. */ |
Baptiste Assmann | 4274637 | 2017-05-03 12:12:02 +0200 | [diff] [blame] | 1254 | for (j = 0; j < dns_opts->pref_net_nb; j++) { |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1255 | |
| 1256 | /* Compare only the same adresses class. */ |
Baptiste Assmann | 4274637 | 2017-05-03 12:12:02 +0200 | [diff] [blame] | 1257 | if (dns_opts->pref_net[j].family != rec[i].type) |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1258 | continue; |
| 1259 | |
| 1260 | if ((rec[i].type == AF_INET && |
Willy Tarreau | eec1d38 | 2016-07-13 11:59:39 +0200 | [diff] [blame] | 1261 | in_net_ipv4(rec[i].ip, |
Baptiste Assmann | 4274637 | 2017-05-03 12:12:02 +0200 | [diff] [blame] | 1262 | &dns_opts->pref_net[j].mask.in4, |
| 1263 | &dns_opts->pref_net[j].addr.in4)) || |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1264 | (rec[i].type == AF_INET6 && |
Willy Tarreau | eec1d38 | 2016-07-13 11:59:39 +0200 | [diff] [blame] | 1265 | in_net_ipv6(rec[i].ip, |
Baptiste Assmann | 4274637 | 2017-05-03 12:12:02 +0200 | [diff] [blame] | 1266 | &dns_opts->pref_net[j].mask.in6, |
| 1267 | &dns_opts->pref_net[j].addr.in6))) { |
Baptiste | fc72590 | 2016-12-26 23:21:08 +0100 | [diff] [blame] | 1268 | score += 4; |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1269 | break; |
| 1270 | } |
| 1271 | } |
| 1272 | |
Baptiste Assmann | fb7091e | 2017-05-03 15:43:12 +0200 | [diff] [blame] | 1273 | /* Check if the IP found in the record is already affected to a member of a group. |
| 1274 | * If yes, the score should be incremented by 2. |
| 1275 | */ |
| 1276 | if (owner) { |
| 1277 | if (snr_check_ip_callback(owner, rec[i].ip, &rec[i].type)) |
Baptiste | fc72590 | 2016-12-26 23:21:08 +0100 | [diff] [blame] | 1278 | record_ip_already_affected = 1; |
Baptiste | fc72590 | 2016-12-26 23:21:08 +0100 | [diff] [blame] | 1279 | } |
Baptiste Assmann | fb7091e | 2017-05-03 15:43:12 +0200 | [diff] [blame] | 1280 | if (record_ip_already_affected == 0) |
Baptiste | fc72590 | 2016-12-26 23:21:08 +0100 | [diff] [blame] | 1281 | score += 2; |
| 1282 | |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1283 | /* Check for current ip matching. */ |
| 1284 | if (rec[i].type == currentip_sin_family && |
| 1285 | ((currentip_sin_family == AF_INET && |
Willy Tarreau | eec1d38 | 2016-07-13 11:59:39 +0200 | [diff] [blame] | 1286 | memcmp(rec[i].ip, currentip, 4) == 0) || |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1287 | (currentip_sin_family == AF_INET6 && |
| 1288 | memcmp(rec[i].ip, currentip, 16) == 0))) { |
| 1289 | score += 1; |
| 1290 | currentip_sel = 1; |
| 1291 | } else |
| 1292 | currentip_sel = 0; |
| 1293 | |
Baptiste | fc72590 | 2016-12-26 23:21:08 +0100 | [diff] [blame] | 1294 | |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1295 | /* Keep the address if the score is better than the previous |
Baptiste | fc72590 | 2016-12-26 23:21:08 +0100 | [diff] [blame] | 1296 | * score. The maximum score is 15, if this value is reached, |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1297 | * we break the parsing. Implicitly, this score is reached |
| 1298 | * the ip selected is the current ip. |
| 1299 | */ |
| 1300 | if (score > max_score) { |
| 1301 | if (rec[i].type == AF_INET) |
| 1302 | newip4 = rec[i].ip; |
| 1303 | else |
| 1304 | newip6 = rec[i].ip; |
| 1305 | currentip_found = currentip_sel; |
Baptiste | fc72590 | 2016-12-26 23:21:08 +0100 | [diff] [blame] | 1306 | if (score == 15) |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1307 | return DNS_UPD_NO; |
| 1308 | max_score = score; |
| 1309 | } |
| 1310 | } |
| 1311 | |
Baptiste Assmann | 0453a1d | 2015-09-09 00:51:08 +0200 | [diff] [blame] | 1312 | /* no IP found in the response */ |
| 1313 | if (!newip4 && !newip6) { |
| 1314 | return DNS_UPD_NO_IP_FOUND; |
| 1315 | } |
| 1316 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1317 | /* case when the caller looks first for an IPv4 address */ |
| 1318 | if (family_priority == AF_INET) { |
| 1319 | if (newip4) { |
| 1320 | *newip = newip4; |
| 1321 | *newip_sin_family = AF_INET; |
| 1322 | if (currentip_found == 1) |
| 1323 | return DNS_UPD_NO; |
Baptiste Assmann | 8ea0bcc | 2017-05-04 08:24:11 +0200 | [diff] [blame] | 1324 | goto return_DNS_UPD_SRVIP_NOT_FOUND; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1325 | } |
| 1326 | else if (newip6) { |
| 1327 | *newip = newip6; |
| 1328 | *newip_sin_family = AF_INET6; |
| 1329 | if (currentip_found == 1) |
| 1330 | return DNS_UPD_NO; |
Baptiste Assmann | 8ea0bcc | 2017-05-04 08:24:11 +0200 | [diff] [blame] | 1331 | goto return_DNS_UPD_SRVIP_NOT_FOUND; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1332 | } |
| 1333 | } |
| 1334 | /* case when the caller looks first for an IPv6 address */ |
| 1335 | else if (family_priority == AF_INET6) { |
| 1336 | if (newip6) { |
| 1337 | *newip = newip6; |
| 1338 | *newip_sin_family = AF_INET6; |
| 1339 | if (currentip_found == 1) |
| 1340 | return DNS_UPD_NO; |
Baptiste Assmann | 8ea0bcc | 2017-05-04 08:24:11 +0200 | [diff] [blame] | 1341 | goto return_DNS_UPD_SRVIP_NOT_FOUND; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1342 | } |
| 1343 | else if (newip4) { |
| 1344 | *newip = newip4; |
| 1345 | *newip_sin_family = AF_INET; |
| 1346 | if (currentip_found == 1) |
| 1347 | return DNS_UPD_NO; |
Baptiste Assmann | 8ea0bcc | 2017-05-04 08:24:11 +0200 | [diff] [blame] | 1348 | goto return_DNS_UPD_SRVIP_NOT_FOUND; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1349 | } |
| 1350 | } |
| 1351 | /* case when the caller have no preference (we prefer IPv6) */ |
| 1352 | else if (family_priority == AF_UNSPEC) { |
| 1353 | if (newip6) { |
| 1354 | *newip = newip6; |
| 1355 | *newip_sin_family = AF_INET6; |
| 1356 | if (currentip_found == 1) |
| 1357 | return DNS_UPD_NO; |
Baptiste Assmann | 8ea0bcc | 2017-05-04 08:24:11 +0200 | [diff] [blame] | 1358 | goto return_DNS_UPD_SRVIP_NOT_FOUND; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1359 | } |
| 1360 | else if (newip4) { |
| 1361 | *newip = newip4; |
| 1362 | *newip_sin_family = AF_INET; |
| 1363 | if (currentip_found == 1) |
| 1364 | return DNS_UPD_NO; |
Baptiste Assmann | 8ea0bcc | 2017-05-04 08:24:11 +0200 | [diff] [blame] | 1365 | goto return_DNS_UPD_SRVIP_NOT_FOUND; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1366 | } |
| 1367 | } |
| 1368 | |
| 1369 | /* no reason why we should change the server's IP address */ |
| 1370 | return DNS_UPD_NO; |
Baptiste Assmann | 8ea0bcc | 2017-05-04 08:24:11 +0200 | [diff] [blame] | 1371 | |
| 1372 | return_DNS_UPD_SRVIP_NOT_FOUND: |
| 1373 | list_for_each_entry(record, &dns_p->answer_list, list) { |
| 1374 | /* move the first record to the end of the list, for internal round robin */ |
| 1375 | if (record) { |
| 1376 | LIST_DEL(&record->list); |
| 1377 | LIST_ADDQ(&dns_p->answer_list, &record->list); |
| 1378 | break; |
| 1379 | } |
| 1380 | } |
| 1381 | return DNS_UPD_SRVIP_NOT_FOUND; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1382 | } |
| 1383 | |
| 1384 | /* |
| 1385 | * returns the query id contained in a DNS response |
| 1386 | */ |
Thiago Farina | b1af23e | 2016-01-20 23:46:34 +0100 | [diff] [blame] | 1387 | unsigned short dns_response_get_query_id(unsigned char *resp) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1388 | { |
| 1389 | /* read the query id from the response */ |
| 1390 | return resp[0] * 256 + resp[1]; |
| 1391 | } |
| 1392 | |
| 1393 | /* |
| 1394 | * used during haproxy's init phase |
| 1395 | * parses resolvers sections and initializes: |
| 1396 | * - task (time events) for each resolvers section |
| 1397 | * - the datagram layer (network IO events) for each nameserver |
Baptiste Assmann | 5cd1b92 | 2017-02-02 22:44:15 +0100 | [diff] [blame] | 1398 | * It takes one argument: |
| 1399 | * - close_first takes 2 values: 0 or 1. If 1, the connection is closed first. |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1400 | * returns: |
| 1401 | * 0 in case of error |
| 1402 | * 1 when no error |
| 1403 | */ |
Baptiste Assmann | 5cd1b92 | 2017-02-02 22:44:15 +0100 | [diff] [blame] | 1404 | int dns_init_resolvers(int close_socket) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1405 | { |
| 1406 | struct dns_resolvers *curr_resolvers; |
| 1407 | struct dns_nameserver *curnameserver; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1408 | struct dns_resolution *resolution, *res_back; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1409 | struct dgram_conn *dgram; |
| 1410 | struct task *t; |
| 1411 | int fd; |
| 1412 | |
Baptiste Assmann | fa4a663 | 2017-05-04 09:05:00 +0200 | [diff] [blame] | 1413 | /* initialize our DNS resolution cache */ |
| 1414 | dns_lru_tree = lru64_new(dns_cache_size); |
| 1415 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1416 | /* give a first random value to our dns query_id seed */ |
| 1417 | dns_query_id_seed = random(); |
| 1418 | |
| 1419 | /* run through the resolvers section list */ |
| 1420 | list_for_each_entry(curr_resolvers, &dns_resolvers, list) { |
| 1421 | /* create the task associated to the resolvers section */ |
| 1422 | if ((t = task_new()) == NULL) { |
| 1423 | Alert("Starting [%s] resolvers: out of memory.\n", curr_resolvers->id); |
| 1424 | return 0; |
| 1425 | } |
| 1426 | |
| 1427 | /* update task's parameters */ |
| 1428 | t->process = dns_process_resolve; |
| 1429 | t->context = curr_resolvers; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1430 | t->expire = 0; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1431 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1432 | /* no need to keep the new task if one is already affected to our resolvers |
| 1433 | * section */ |
| 1434 | if (!curr_resolvers->t) |
| 1435 | curr_resolvers->t = t; |
| 1436 | else |
| 1437 | task_free(t); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1438 | |
| 1439 | list_for_each_entry(curnameserver, &curr_resolvers->nameserver_list, list) { |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1440 | dgram = NULL; |
Baptiste Assmann | 5cd1b92 | 2017-02-02 22:44:15 +0100 | [diff] [blame] | 1441 | |
| 1442 | if (close_socket == 1) { |
| 1443 | if (curnameserver->dgram) { |
Frédéric Lécaille | 6492053 | 2017-05-12 09:57:15 +0200 | [diff] [blame] | 1444 | fd_delete(curnameserver->dgram->t.sock.fd); |
Baptiste Assmann | 5cd1b92 | 2017-02-02 22:44:15 +0100 | [diff] [blame] | 1445 | memset(curnameserver->dgram, '\0', sizeof(*dgram)); |
| 1446 | dgram = curnameserver->dgram; |
| 1447 | } |
| 1448 | } |
| 1449 | |
| 1450 | /* allocate memory only if it has not already been allocated |
| 1451 | * by a previous call to this function */ |
| 1452 | if (!dgram && (dgram = calloc(1, sizeof(*dgram))) == NULL) { |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1453 | Alert("Starting [%s/%s] nameserver: out of memory.\n", curr_resolvers->id, |
| 1454 | curnameserver->id); |
| 1455 | return 0; |
| 1456 | } |
| 1457 | /* update datagram's parameters */ |
| 1458 | dgram->owner = (void *)curnameserver; |
| 1459 | dgram->data = &resolve_dgram_cb; |
| 1460 | |
| 1461 | /* create network UDP socket for this nameserver */ |
Frédéric Lécaille | 5e5bc9f | 2017-04-11 08:46:37 +0200 | [diff] [blame] | 1462 | if ((fd = socket(curnameserver->addr.ss_family, SOCK_DGRAM, IPPROTO_UDP)) == -1) { |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1463 | Alert("Starting [%s/%s] nameserver: can't create socket.\n", curr_resolvers->id, |
| 1464 | curnameserver->id); |
| 1465 | free(dgram); |
| 1466 | dgram = NULL; |
| 1467 | return 0; |
| 1468 | } |
| 1469 | |
| 1470 | /* "connect" the UDP socket to the name server IP */ |
Baptiste Assmann | 8c62c47 | 2015-09-21 20:55:08 +0200 | [diff] [blame] | 1471 | if (connect(fd, (struct sockaddr*)&curnameserver->addr, get_addr_len(&curnameserver->addr)) == -1) { |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1472 | Alert("Starting [%s/%s] nameserver: can't connect socket.\n", curr_resolvers->id, |
| 1473 | curnameserver->id); |
| 1474 | close(fd); |
| 1475 | free(dgram); |
| 1476 | dgram = NULL; |
| 1477 | return 0; |
| 1478 | } |
| 1479 | |
| 1480 | /* make the socket non blocking */ |
| 1481 | fcntl(fd, F_SETFL, O_NONBLOCK); |
| 1482 | |
| 1483 | /* add the fd in the fd list and update its parameters */ |
| 1484 | fd_insert(fd); |
| 1485 | fdtab[fd].owner = dgram; |
| 1486 | fdtab[fd].iocb = dgram_fd_handler; |
| 1487 | fd_want_recv(fd); |
| 1488 | dgram->t.sock.fd = fd; |
| 1489 | |
| 1490 | /* update nameserver's datagram property */ |
| 1491 | curnameserver->dgram = dgram; |
| 1492 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1493 | continue; |
| 1494 | } |
| 1495 | |
| 1496 | if (close_socket == 0) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1497 | continue; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1498 | |
| 1499 | /* now, we can trigger DNS resolution */ |
| 1500 | list_for_each_entry_safe(resolution, res_back, &curr_resolvers->resolution.wait, list) { |
| 1501 | /* if there is no requester in the wait queue, no need to trigger the resolution */ |
| 1502 | if (LIST_ISEMPTY(&resolution->requester.wait)) |
| 1503 | continue; |
| 1504 | |
| 1505 | dns_trigger_resolution(resolution); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1506 | } |
| 1507 | |
| 1508 | /* task can be queued */ |
| 1509 | task_queue(t); |
| 1510 | } |
| 1511 | |
| 1512 | return 1; |
| 1513 | } |
| 1514 | |
| 1515 | /* |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1516 | * Allocate a pool of resolution to a resolvers section. |
| 1517 | * Each resolution is associated with a UUID. |
| 1518 | * |
| 1519 | * Return code: |
| 1520 | * - 0 if everything went smoothly |
| 1521 | * - -1 if an error occured |
| 1522 | */ |
| 1523 | int dns_alloc_resolution_pool(struct dns_resolvers *resolvers) |
| 1524 | { |
| 1525 | int i; |
| 1526 | struct dns_resolution *resolution; |
| 1527 | |
| 1528 | /* return if a pool has already been set for this resolvers */ |
| 1529 | if (!LIST_ISEMPTY(&resolvers->resolution.pool)) { |
| 1530 | return 0; |
| 1531 | } |
| 1532 | |
| 1533 | for (i = 0; i < resolvers->resolution_pool_size; i++) { |
| 1534 | resolution = dns_alloc_resolution(); |
| 1535 | if (!resolution) { |
| 1536 | Alert("Starting [%s] resolvers: can't allocate memory for DNS resolution pool.\n", resolvers->id); |
| 1537 | return -1; |
| 1538 | } |
| 1539 | resolution->uuid = i; |
| 1540 | LIST_ADDQ(&resolvers->resolution.pool, &resolution->list); |
| 1541 | } |
| 1542 | |
| 1543 | return 0; |
| 1544 | } |
| 1545 | |
| 1546 | /* |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1547 | * Forge a DNS query. It needs the following information from the caller: |
| 1548 | * - <query_id>: the DNS query id corresponding to this query |
| 1549 | * - <query_type>: DNS_RTYPE_* request DNS record type (A, AAAA, ANY, etc...) |
| 1550 | * - <hostname_dn>: hostname in domain name format |
| 1551 | * - <hostname_dn_len>: length of <hostname_dn> |
| 1552 | * To store the query, the caller must pass a buffer <buf> and its size <bufsize> |
| 1553 | * |
| 1554 | * the DNS query is stored in <buf> |
| 1555 | * returns: |
| 1556 | * -1 if <buf> is too short |
| 1557 | */ |
| 1558 | int dns_build_query(int query_id, int query_type, char *hostname_dn, int hostname_dn_len, char *buf, int bufsize) |
| 1559 | { |
| 1560 | struct dns_header *dns; |
Vincent Bernat | 9b7125c | 2016-04-08 22:17:45 +0200 | [diff] [blame] | 1561 | struct dns_question qinfo; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1562 | char *ptr, *bufend; |
| 1563 | |
| 1564 | memset(buf, '\0', bufsize); |
| 1565 | ptr = buf; |
| 1566 | bufend = buf + bufsize; |
| 1567 | |
| 1568 | /* check if there is enough room for DNS headers */ |
| 1569 | if (ptr + sizeof(struct dns_header) >= bufend) |
| 1570 | return -1; |
| 1571 | |
| 1572 | /* set dns query headers */ |
| 1573 | dns = (struct dns_header *)ptr; |
| 1574 | dns->id = (unsigned short) htons(query_id); |
Nenad Merdanovic | 8ab7942 | 2016-07-13 14:03:43 +0200 | [diff] [blame] | 1575 | dns->flags = htons(0x0100); /* qr=0, opcode=0, aa=0, tc=0, rd=1, ra=0, z=0, rcode=0 */ |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1576 | dns->qdcount = htons(1); /* 1 question */ |
| 1577 | dns->ancount = 0; |
| 1578 | dns->nscount = 0; |
| 1579 | dns->arcount = 0; |
| 1580 | |
| 1581 | /* move forward ptr */ |
| 1582 | ptr += sizeof(struct dns_header); |
| 1583 | |
| 1584 | /* check if there is enough room for query hostname */ |
| 1585 | if ((ptr + hostname_dn_len) >= bufend) |
| 1586 | return -1; |
| 1587 | |
| 1588 | /* set up query hostname */ |
| 1589 | memcpy(ptr, hostname_dn, hostname_dn_len); |
| 1590 | ptr[hostname_dn_len + 1] = '\0'; |
| 1591 | |
| 1592 | /* move forward ptr */ |
| 1593 | ptr += (hostname_dn_len + 1); |
| 1594 | |
| 1595 | /* check if there is enough room for query hostname*/ |
| 1596 | if (ptr + sizeof(struct dns_question) >= bufend) |
| 1597 | return -1; |
| 1598 | |
| 1599 | /* set up query info (type and class) */ |
Vincent Bernat | 9b7125c | 2016-04-08 22:17:45 +0200 | [diff] [blame] | 1600 | qinfo.qtype = htons(query_type); |
| 1601 | qinfo.qclass = htons(DNS_RCLASS_IN); |
| 1602 | memcpy(ptr, &qinfo, sizeof(qinfo)); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1603 | |
| 1604 | ptr += sizeof(struct dns_question); |
| 1605 | |
| 1606 | return ptr - buf; |
| 1607 | } |
| 1608 | |
| 1609 | /* |
| 1610 | * turn a string into domain name label: |
| 1611 | * www.haproxy.org into 3www7haproxy3org |
| 1612 | * if dn memory is pre-allocated, you must provide its size in dn_len |
| 1613 | * if dn memory isn't allocated, dn_len must be set to 0. |
| 1614 | * In the second case, memory will be allocated. |
| 1615 | * in case of error, -1 is returned, otherwise, number of bytes copied in dn |
| 1616 | */ |
Willy Tarreau | 2100b49 | 2015-07-22 16:42:43 +0200 | [diff] [blame] | 1617 | char *dns_str_to_dn_label(const char *string, char *dn, int dn_len) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1618 | { |
| 1619 | char *c, *d; |
| 1620 | int i, offset; |
| 1621 | |
| 1622 | /* offset between string size and theorical dn size */ |
| 1623 | offset = 1; |
| 1624 | |
| 1625 | /* |
| 1626 | * first, get the size of the string turned into its domain name version |
| 1627 | * This function also validates the string respect the RFC |
| 1628 | */ |
| 1629 | if ((i = dns_str_to_dn_label_len(string)) == -1) |
| 1630 | return NULL; |
| 1631 | |
| 1632 | /* yes, so let's check there is enough memory */ |
| 1633 | if (dn_len < i + offset) |
| 1634 | return NULL; |
| 1635 | |
Willy Tarreau | d69d6f3 | 2015-07-22 16:45:36 +0200 | [diff] [blame] | 1636 | i = strlen(string); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1637 | memcpy(dn + offset, string, i); |
| 1638 | dn[i + offset] = '\0'; |
| 1639 | /* avoid a '\0' at the beginning of dn string which may prevent the for loop |
| 1640 | * below from working. |
| 1641 | * Actually, this is the reason of the offset. */ |
| 1642 | dn[0] = '0'; |
| 1643 | |
| 1644 | for (c = dn; *c ; ++c) { |
| 1645 | /* c points to the first '0' char or a dot, which we don't want to read */ |
| 1646 | d = c + offset; |
| 1647 | i = 0; |
| 1648 | while (*d != '.' && *d) { |
| 1649 | i++; |
| 1650 | d++; |
| 1651 | } |
| 1652 | *c = i; |
| 1653 | |
| 1654 | c = d - 1; /* because of c++ of the for loop */ |
| 1655 | } |
| 1656 | |
| 1657 | return dn; |
| 1658 | } |
| 1659 | |
| 1660 | /* |
| 1661 | * compute and return the length of <string> it it were translated into domain name |
| 1662 | * label: |
| 1663 | * www.haproxy.org into 3www7haproxy3org would return 16 |
| 1664 | * NOTE: add +1 for '\0' when allocating memory ;) |
| 1665 | */ |
| 1666 | int dns_str_to_dn_label_len(const char *string) |
| 1667 | { |
| 1668 | return strlen(string) + 1; |
| 1669 | } |
| 1670 | |
| 1671 | /* |
| 1672 | * validates host name: |
| 1673 | * - total size |
| 1674 | * - each label size individually |
| 1675 | * returns: |
| 1676 | * 0 in case of error. If <err> is not NULL, an error message is stored there. |
| 1677 | * 1 when no error. <err> is left unaffected. |
| 1678 | */ |
| 1679 | int dns_hostname_validation(const char *string, char **err) |
| 1680 | { |
| 1681 | const char *c, *d; |
| 1682 | int i; |
| 1683 | |
| 1684 | if (strlen(string) > DNS_MAX_NAME_SIZE) { |
| 1685 | if (err) |
| 1686 | *err = DNS_TOO_LONG_FQDN; |
| 1687 | return 0; |
| 1688 | } |
| 1689 | |
| 1690 | c = string; |
| 1691 | while (*c) { |
| 1692 | d = c; |
| 1693 | |
| 1694 | i = 0; |
| 1695 | while (*d != '.' && *d && i <= DNS_MAX_LABEL_SIZE) { |
| 1696 | i++; |
| 1697 | if (!((*d == '-') || (*d == '_') || |
| 1698 | ((*d >= 'a') && (*d <= 'z')) || |
| 1699 | ((*d >= 'A') && (*d <= 'Z')) || |
| 1700 | ((*d >= '0') && (*d <= '9')))) { |
| 1701 | if (err) |
| 1702 | *err = DNS_INVALID_CHARACTER; |
| 1703 | return 0; |
| 1704 | } |
| 1705 | d++; |
| 1706 | } |
| 1707 | |
| 1708 | if ((i >= DNS_MAX_LABEL_SIZE) && (d[i] != '.')) { |
| 1709 | if (err) |
| 1710 | *err = DNS_LABEL_TOO_LONG; |
| 1711 | return 0; |
| 1712 | } |
| 1713 | |
| 1714 | if (*d == '\0') |
| 1715 | goto out; |
| 1716 | |
| 1717 | c = ++d; |
| 1718 | } |
| 1719 | out: |
| 1720 | return 1; |
| 1721 | } |
| 1722 | |
| 1723 | /* |
| 1724 | * 2 bytes random generator to generate DNS query ID |
| 1725 | */ |
| 1726 | uint16_t dns_rnd16(void) |
| 1727 | { |
| 1728 | dns_query_id_seed ^= dns_query_id_seed << 13; |
| 1729 | dns_query_id_seed ^= dns_query_id_seed >> 7; |
| 1730 | dns_query_id_seed ^= dns_query_id_seed << 17; |
| 1731 | return dns_query_id_seed; |
| 1732 | } |
| 1733 | |
| 1734 | |
| 1735 | /* |
| 1736 | * function called when a timeout occurs during name resolution process |
| 1737 | * if max number of tries is reached, then stop, otherwise, retry. |
| 1738 | */ |
| 1739 | struct task *dns_process_resolve(struct task *t) |
| 1740 | { |
| 1741 | struct dns_resolvers *resolvers = t->context; |
| 1742 | struct dns_resolution *resolution, *res_back; |
Baptiste Assmann | 060e573 | 2016-01-06 02:01:59 +0100 | [diff] [blame] | 1743 | int res_preferred_afinet, res_preferred_afinet6; |
Baptiste Assmann | 4274637 | 2017-05-03 12:12:02 +0200 | [diff] [blame] | 1744 | struct dns_options *dns_opts = NULL; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1745 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1746 | /* if both there is no resolution in the run queue, we can re-schedule a wake up */ |
| 1747 | if (LIST_ISEMPTY(&resolvers->resolution.curr)) { |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1748 | /* no first entry, so wake up was useless */ |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1749 | dns_update_resolvers_timeout(resolvers); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1750 | return t; |
| 1751 | } |
| 1752 | |
| 1753 | /* look for the first resolution which is not expired */ |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1754 | list_for_each_entry_safe(resolution, res_back, &resolvers->resolution.curr, list) { |
| 1755 | struct dns_requester *requester = NULL; |
| 1756 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1757 | /* when we find the first resolution in the future, then we can stop here */ |
| 1758 | if (tick_is_le(now_ms, resolution->last_sent_packet)) |
| 1759 | goto out; |
| 1760 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1761 | if (LIST_ISEMPTY(&resolution->requester.curr)) |
| 1762 | goto out; |
| 1763 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1764 | /* |
| 1765 | * if current resolution has been tried too many times and finishes in timeout |
| 1766 | * we update its status and remove it from the list |
| 1767 | */ |
Baptiste Assmann | f778bb4 | 2015-09-09 00:54:38 +0200 | [diff] [blame] | 1768 | if (resolution->try <= 0) { |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1769 | struct dns_requester *tmprequester; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1770 | /* clean up resolution information and remove from the list */ |
| 1771 | dns_reset_resolution(resolution); |
| 1772 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1773 | LIST_DEL(&resolution->list); |
| 1774 | LIST_ADDQ(&resolvers->resolution.wait, &resolution->list); |
| 1775 | |
| 1776 | if (resolution->status != RSLV_STATUS_TIMEOUT) { |
| 1777 | resolution->status = RSLV_STATUS_TIMEOUT; |
| 1778 | resolution->last_status_change = now_ms; |
| 1779 | } |
| 1780 | |
| 1781 | /* notify the result to the requesters */ |
| 1782 | list_for_each_entry_safe(requester, tmprequester, &resolution->requester.curr, list) { |
| 1783 | requester->requester_error_cb(requester, DNS_RESP_TIMEOUT); |
| 1784 | LIST_DEL(&requester->list); |
| 1785 | LIST_ADDQ(&resolution->requester.wait, &requester->list); |
| 1786 | } |
Baptiste Assmann | 382824c | 2016-01-06 01:53:46 +0100 | [diff] [blame] | 1787 | goto out; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1788 | } |
| 1789 | |
Baptiste Assmann | f778bb4 | 2015-09-09 00:54:38 +0200 | [diff] [blame] | 1790 | resolution->try -= 1; |
| 1791 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1792 | /* running queue is empty, nothing to do but wait */ |
| 1793 | if (LIST_ISEMPTY(&resolution->requester.curr)) |
| 1794 | goto out; |
| 1795 | |
| 1796 | requester = LIST_NEXT(&resolution->requester.curr, struct dns_requester *, list); |
| 1797 | |
| 1798 | switch (obj_type(requester->requester)) { |
| 1799 | case OBJ_TYPE_SERVER: |
| 1800 | dns_opts = &(objt_server(requester->requester)->dns_opts); |
| 1801 | break; |
| 1802 | |
| 1803 | case OBJ_TYPE_NONE: |
| 1804 | default: |
| 1805 | /* clean up resolution information and remove from the list */ |
| 1806 | dns_reset_resolution(resolution); |
| 1807 | |
| 1808 | LIST_DEL(&resolution->list); |
| 1809 | LIST_ADDQ(&resolvers->resolution.wait, &resolution->list); |
| 1810 | |
| 1811 | /* notify the result to the requester */ |
| 1812 | requester->requester_error_cb(requester, DNS_RESP_INTERNAL); |
| 1813 | goto out; |
| 1814 | } |
Baptiste Assmann | 4274637 | 2017-05-03 12:12:02 +0200 | [diff] [blame] | 1815 | |
| 1816 | res_preferred_afinet = dns_opts->family_prio == AF_INET && resolution->query_type == DNS_RTYPE_A; |
| 1817 | res_preferred_afinet6 = dns_opts->family_prio == AF_INET6 && resolution->query_type == DNS_RTYPE_AAAA; |
Baptiste Assmann | 060e573 | 2016-01-06 02:01:59 +0100 | [diff] [blame] | 1818 | |
| 1819 | /* let's change the query type if needed */ |
| 1820 | if (res_preferred_afinet6) { |
| 1821 | /* fallback from AAAA to A */ |
| 1822 | resolution->query_type = DNS_RTYPE_A; |
| 1823 | } |
| 1824 | else if (res_preferred_afinet) { |
| 1825 | /* fallback from A to AAAA */ |
| 1826 | resolution->query_type = DNS_RTYPE_AAAA; |
| 1827 | } |
| 1828 | |
Baptiste Assmann | 382824c | 2016-01-06 01:53:46 +0100 | [diff] [blame] | 1829 | /* resend the DNS query */ |
| 1830 | dns_send_query(resolution); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1831 | |
Baptiste Assmann | 382824c | 2016-01-06 01:53:46 +0100 | [diff] [blame] | 1832 | /* check if we have more than one resolution in the list */ |
| 1833 | if (dns_check_resolution_queue(resolvers) > 1) { |
| 1834 | /* move the rsolution to the end of the list */ |
| 1835 | LIST_DEL(&resolution->list); |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1836 | LIST_ADDQ(&resolvers->resolution.curr, &resolution->list); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1837 | } |
| 1838 | } |
| 1839 | |
| 1840 | out: |
| 1841 | dns_update_resolvers_timeout(resolvers); |
| 1842 | return t; |
| 1843 | } |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 1844 | |
Baptiste Assmann | fa4a663 | 2017-05-04 09:05:00 +0200 | [diff] [blame] | 1845 | /* |
| 1846 | * build a dns cache key composed as follow: |
| 1847 | * <query type>#<hostname in domain name format> |
| 1848 | * and store it into <str>. |
| 1849 | * It's up to the caller to allocate <buf> and to reset it. |
| 1850 | * The function returns NULL in case of error (IE <buf> too small) or a pointer |
| 1851 | * to buf if successful |
| 1852 | */ |
| 1853 | struct chunk * |
| 1854 | dns_cache_key(int query_type, char *hostname_dn, int hostname_dn_len, struct chunk *buf) |
| 1855 | { |
| 1856 | int len, size; |
| 1857 | char *str; |
| 1858 | |
| 1859 | str = buf->str; |
| 1860 | len = buf->len; |
| 1861 | size = buf->size; |
| 1862 | |
| 1863 | switch (query_type) { |
| 1864 | case DNS_RTYPE_A: |
| 1865 | if (len + 1 > size) |
| 1866 | return NULL; |
| 1867 | memcpy(&str[len], "A", 1); |
| 1868 | len += 1; |
| 1869 | break; |
| 1870 | case DNS_RTYPE_AAAA: |
| 1871 | if (len + 4 > size) |
| 1872 | return NULL; |
| 1873 | memcpy(&str[len], "AAAA", 4); |
| 1874 | len += 4; |
| 1875 | break; |
| 1876 | default: |
| 1877 | return NULL; |
| 1878 | } |
| 1879 | |
| 1880 | if (len + 1 > size) |
| 1881 | return NULL; |
| 1882 | memcpy(&str[len], "#", 1); |
| 1883 | len += 1; |
| 1884 | |
| 1885 | if (len + hostname_dn_len + 1 > size) // +1 for trailing zero |
| 1886 | return NULL; |
| 1887 | memcpy(&str[len], hostname_dn, hostname_dn_len); |
| 1888 | len += hostname_dn_len; |
| 1889 | str[len] = '\0'; |
| 1890 | |
| 1891 | return buf; |
| 1892 | } |
| 1893 | |
| 1894 | /* |
| 1895 | * returns a pointer to a cache entry which may still be considered as up to date |
| 1896 | * by the caller. |
| 1897 | * returns NULL if no entry can be found or if the data found is outdated. |
| 1898 | */ |
| 1899 | struct lru64 * |
| 1900 | dns_cache_lookup(int query_type, char *hostname_dn, int hostname_dn_len, int valid_period, void *cache_domain) { |
| 1901 | struct lru64 *elem = NULL; |
| 1902 | struct dns_resolution *resolution = NULL; |
| 1903 | struct dns_resolvers *resolvers = NULL; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1904 | struct dns_requester *requester = NULL; |
Baptiste Assmann | fa4a663 | 2017-05-04 09:05:00 +0200 | [diff] [blame] | 1905 | int inter = 0; |
| 1906 | struct chunk *buf = get_trash_chunk(); |
| 1907 | struct chunk *tmp = NULL; |
| 1908 | |
| 1909 | if (!dns_lru_tree) |
| 1910 | return NULL; |
| 1911 | |
| 1912 | chunk_reset(buf); |
| 1913 | tmp = dns_cache_key(query_type, hostname_dn, hostname_dn_len, buf); |
| 1914 | if (tmp == NULL) |
| 1915 | return NULL; |
| 1916 | |
| 1917 | elem = lru64_lookup(XXH64(buf->str, buf->len, 1), dns_lru_tree, cache_domain, 1); |
| 1918 | |
| 1919 | if (!elem || !elem->data) |
| 1920 | return NULL; |
| 1921 | |
| 1922 | resolution = elem->data; |
| 1923 | |
| 1924 | /* since we can change the fqdn of a server at run time, it may happen that |
| 1925 | * we got an innacurate elem. |
| 1926 | * This is because resolution->hostname_dn points to (owner)->hostname_dn (which |
| 1927 | * may be changed at run time) |
| 1928 | */ |
| 1929 | if ((hostname_dn_len == resolution->hostname_dn_len) && |
| 1930 | (memcmp(hostname_dn, resolution->hostname_dn, hostname_dn_len) != 0)) { |
| 1931 | return NULL; |
| 1932 | } |
| 1933 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1934 | requester = LIST_NEXT(&resolution->requester.wait, struct dns_requester *, list); |
| 1935 | |
| 1936 | switch (obj_type(requester->requester)) { |
| 1937 | case OBJ_TYPE_SERVER: |
| 1938 | resolvers = objt_server(requester->requester)->resolvers; |
| 1939 | break; |
| 1940 | case OBJ_TYPE_NONE: |
| 1941 | default: |
| 1942 | return NULL; |
| 1943 | } |
Baptiste Assmann | fa4a663 | 2017-05-04 09:05:00 +0200 | [diff] [blame] | 1944 | |
| 1945 | if (!resolvers) |
| 1946 | return NULL; |
| 1947 | |
| 1948 | if (resolvers->hold.valid < valid_period) |
| 1949 | inter = resolvers->hold.valid; |
| 1950 | else |
| 1951 | inter = valid_period; |
| 1952 | |
| 1953 | if (!tick_is_expired(tick_add(resolution->last_resolution, inter), now_ms)) |
| 1954 | return elem; |
| 1955 | |
| 1956 | return NULL; |
| 1957 | } |
| 1958 | |
Willy Tarreau | 777b560 | 2016-12-16 18:06:26 +0100 | [diff] [blame] | 1959 | /* if an arg is found, it sets the resolvers section pointer into cli.p0 */ |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 1960 | static int cli_parse_stat_resolvers(char **args, struct appctx *appctx, void *private) |
| 1961 | { |
| 1962 | struct dns_resolvers *presolvers; |
| 1963 | |
| 1964 | if (*args[3]) { |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 1965 | list_for_each_entry(presolvers, &dns_resolvers, list) { |
| 1966 | if (strcmp(presolvers->id, args[3]) == 0) { |
Willy Tarreau | 777b560 | 2016-12-16 18:06:26 +0100 | [diff] [blame] | 1967 | appctx->ctx.cli.p0 = presolvers; |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 1968 | break; |
| 1969 | } |
| 1970 | } |
Willy Tarreau | 777b560 | 2016-12-16 18:06:26 +0100 | [diff] [blame] | 1971 | if (appctx->ctx.cli.p0 == NULL) { |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 1972 | appctx->ctx.cli.msg = "Can't find that resolvers section\n"; |
Willy Tarreau | 3b6e547 | 2016-11-24 15:53:53 +0100 | [diff] [blame] | 1973 | appctx->st0 = CLI_ST_PRINT; |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 1974 | return 1; |
| 1975 | } |
| 1976 | } |
Willy Tarreau | 3067bfa | 2016-12-05 14:50:15 +0100 | [diff] [blame] | 1977 | return 0; |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 1978 | } |
| 1979 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1980 | /* |
| 1981 | * if <resolution> is provided, then the function skips the memory allocation part. |
| 1982 | * It does the linking only. |
| 1983 | * |
| 1984 | * if <resolution> is NULL, the function links a dns resolution to a requester: |
| 1985 | * - it allocates memory for the struct requester used to link |
| 1986 | * the resolution to the requester |
| 1987 | * - it configures the resolution if this is the first requester to be linked to it |
| 1988 | * - it updates the requester with a pointer to the resolution |
| 1989 | * |
| 1990 | * Return code: |
| 1991 | * - 0 if everything happened smoothly |
| 1992 | * - -1 if an error occured. Of course, no resolution is linked to the requester |
| 1993 | */ |
| 1994 | int dns_link_resolution(void *requester, int requester_type, struct dns_resolution *resolution) |
| 1995 | { |
| 1996 | struct dns_resolution *tmpresolution = NULL; |
| 1997 | struct dns_requester *tmprequester = NULL; |
| 1998 | struct dns_resolvers *resolvers = NULL; |
| 1999 | char *hostname_dn = NULL; |
| 2000 | int new_resolution; |
| 2001 | |
| 2002 | if (!resolution) { |
| 2003 | tmprequester = calloc(1, sizeof(*tmprequester)); |
| 2004 | if (!tmprequester) |
| 2005 | return -1; |
| 2006 | |
| 2007 | switch (requester_type) { |
| 2008 | case OBJ_TYPE_SERVER: |
| 2009 | tmprequester->requester = &((struct server *)requester)->obj_type; |
| 2010 | hostname_dn = objt_server(tmprequester->requester)->hostname_dn; |
| 2011 | resolvers = objt_server(tmprequester->requester)->resolvers; |
| 2012 | switch (objt_server(tmprequester->requester)->dns_opts.family_prio) { |
| 2013 | case AF_INET: |
| 2014 | tmprequester->prefered_query_type = DNS_RTYPE_A; |
| 2015 | break; |
| 2016 | default: |
| 2017 | tmprequester->prefered_query_type = DNS_RTYPE_AAAA; |
| 2018 | } |
| 2019 | |
| 2020 | break; |
| 2021 | case OBJ_TYPE_NONE: |
| 2022 | default: |
| 2023 | free(tmprequester); |
| 2024 | return -1; |
| 2025 | } |
| 2026 | |
| 2027 | /* get a resolution from the resolvers' wait queue or pool */ |
| 2028 | tmpresolution = dns_resolution_list_get(resolvers, hostname_dn, tmprequester->prefered_query_type); |
| 2029 | if (!tmpresolution) { |
| 2030 | free(tmprequester); |
| 2031 | return -1; |
| 2032 | } |
| 2033 | } |
| 2034 | else { |
| 2035 | tmpresolution = resolution; |
| 2036 | |
| 2037 | switch (requester_type) { |
| 2038 | case OBJ_TYPE_SERVER: |
| 2039 | tmprequester = ((struct server *)requester)->dns_requester; |
| 2040 | resolvers = ((struct server *)requester)->resolvers; |
| 2041 | break; |
| 2042 | case OBJ_TYPE_NONE: |
| 2043 | default: |
| 2044 | return -1; |
| 2045 | } |
| 2046 | } |
| 2047 | |
| 2048 | /* flag this resolution as NEW if applicable (not already linked to any requester). |
| 2049 | * this is required to decide which parameters we have to update on the resolution. |
| 2050 | * If new, it means we pulled up the resolution from the resolvers' pool. |
| 2051 | */ |
| 2052 | if (LIST_ISEMPTY(&tmpresolution->requester.wait)) { |
| 2053 | new_resolution = 1; |
| 2054 | } |
| 2055 | else |
| 2056 | new_resolution = 0; |
| 2057 | |
| 2058 | /* those parameters are related to the requester type */ |
| 2059 | switch (obj_type(tmprequester->requester)) { |
| 2060 | case OBJ_TYPE_SERVER: |
| 2061 | /* some parameters should be set only if the resolution is brand new */ |
| 2062 | if (new_resolution) { |
| 2063 | tmpresolution->query_type = tmprequester->prefered_query_type; |
| 2064 | tmpresolution->hostname_dn = objt_server(tmprequester->requester)->hostname_dn; |
| 2065 | tmpresolution->hostname_dn_len = objt_server(tmprequester->requester)->hostname_dn_len; |
| 2066 | } |
| 2067 | |
| 2068 | /* update requester as well, only if we just allocated it */ |
| 2069 | objt_server(tmprequester->requester)->resolution = tmpresolution; |
| 2070 | if (!resolution) { |
| 2071 | tmprequester->requester_cb = snr_resolution_cb; |
| 2072 | tmprequester->requester_error_cb = snr_resolution_error_cb; |
| 2073 | objt_server(tmprequester->requester)->dns_requester = tmprequester; |
| 2074 | } |
| 2075 | break; |
| 2076 | case OBJ_TYPE_NONE: |
| 2077 | default: |
| 2078 | free(tmprequester); |
| 2079 | return -1; |
| 2080 | } |
| 2081 | |
| 2082 | /* update some parameters only if this is a brand new resolution */ |
| 2083 | if (new_resolution) { |
| 2084 | /* move the resolution to the requesters' wait queue */ |
| 2085 | LIST_DEL(&tmpresolution->list); |
| 2086 | LIST_ADDQ(&resolvers->resolution.wait, &tmpresolution->list); |
| 2087 | |
| 2088 | tmpresolution->status = RSLV_STATUS_NONE; |
| 2089 | tmpresolution->step = RSLV_STEP_NONE; |
| 2090 | tmpresolution->revision = 1; |
| 2091 | } |
| 2092 | |
| 2093 | /* add the requester to the resolution's wait queue */ |
| 2094 | if (resolution) |
| 2095 | LIST_DEL(&tmprequester->list); |
| 2096 | LIST_ADDQ(&tmpresolution->requester.wait, &tmprequester->list); |
| 2097 | |
| 2098 | return 0; |
| 2099 | } |
| 2100 | |
| 2101 | /* |
| 2102 | * pick up an available resolution from the different resolution list associated to a resolvers section, |
| 2103 | * in this order: |
| 2104 | * 1. check in resolution.curr for the same hostname and query_type |
| 2105 | * 2. check in resolution.wait for the same hostname and query_type |
| 2106 | * 3. take an available resolution from resolution.pool |
| 2107 | * |
| 2108 | * return an available resolution, NULL if none found. |
| 2109 | */ |
| 2110 | struct dns_resolution *dns_resolution_list_get(struct dns_resolvers *resolvers, char *hostname_dn, int query_type) |
| 2111 | { |
| 2112 | struct dns_resolution *resolution, *tmpresolution; |
| 2113 | struct dns_requester *requester; |
| 2114 | |
| 2115 | /* search for same hostname and query type in resolution.curr */ |
| 2116 | list_for_each_entry_safe(resolution, tmpresolution, &resolvers->resolution.curr, list) { |
| 2117 | requester = NULL; |
| 2118 | |
| 2119 | if (!LIST_ISEMPTY(&resolution->requester.wait)) |
| 2120 | requester = LIST_NEXT(&resolution->requester.wait, struct dns_requester *, list); |
| 2121 | else if (!LIST_ISEMPTY(&resolution->requester.curr)) |
| 2122 | requester = LIST_NEXT(&resolution->requester.curr, struct dns_requester *, list); |
| 2123 | |
| 2124 | if (!requester) |
| 2125 | continue; |
| 2126 | |
| 2127 | if ((query_type == requester->prefered_query_type) && |
| 2128 | (strcmp(hostname_dn, resolution->hostname_dn) == 0)) { |
| 2129 | return resolution; |
| 2130 | } |
| 2131 | } |
| 2132 | |
| 2133 | /* search for same hostname and query type in resolution.wait */ |
| 2134 | list_for_each_entry_safe(resolution, tmpresolution, &resolvers->resolution.wait, list) { |
| 2135 | requester = NULL; |
| 2136 | |
| 2137 | if (!LIST_ISEMPTY(&resolution->requester.wait)) |
| 2138 | requester = LIST_NEXT(&resolution->requester.wait, struct dns_requester *, list); |
| 2139 | else if (!LIST_ISEMPTY(&resolution->requester.curr)) |
| 2140 | requester = LIST_NEXT(&resolution->requester.curr, struct dns_requester *, list); |
| 2141 | |
| 2142 | if (!requester) |
| 2143 | continue; |
| 2144 | |
| 2145 | if ((query_type == requester->prefered_query_type) && |
| 2146 | (strcmp(hostname_dn, resolution->hostname_dn) == 0)) { |
| 2147 | return resolution; |
| 2148 | } |
| 2149 | } |
| 2150 | |
| 2151 | /* take the first one (hopefully) from the pool */ |
| 2152 | list_for_each_entry_safe(resolution, tmpresolution, &resolvers->resolution.pool, list) { |
| 2153 | if (LIST_ISEMPTY(&resolution->requester.wait)) { |
| 2154 | return resolution; |
| 2155 | } |
| 2156 | } |
| 2157 | |
| 2158 | return NULL; |
| 2159 | } |
| 2160 | |
Baptiste Assmann | 81ed1a0 | 2017-05-03 10:11:44 +0200 | [diff] [blame] | 2161 | /* This function allocates memory for a DNS resolution structure. |
| 2162 | * It's up to the caller to set the parameters |
| 2163 | * Returns a pointer to the structure resolution or NULL if memory could |
| 2164 | * not be allocated. |
| 2165 | */ |
| 2166 | struct dns_resolution *dns_alloc_resolution(void) |
| 2167 | { |
| 2168 | struct dns_resolution *resolution = NULL; |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 2169 | char *buffer = NULL; |
Baptiste Assmann | 81ed1a0 | 2017-05-03 10:11:44 +0200 | [diff] [blame] | 2170 | |
| 2171 | resolution = calloc(1, sizeof(*resolution)); |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 2172 | buffer = calloc(1, global.tune.bufsize); |
Baptiste Assmann | 81ed1a0 | 2017-05-03 10:11:44 +0200 | [diff] [blame] | 2173 | |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 2174 | if (!resolution || !buffer) { |
| 2175 | free(buffer); |
Baptiste Assmann | 81ed1a0 | 2017-05-03 10:11:44 +0200 | [diff] [blame] | 2176 | free(resolution); |
| 2177 | return NULL; |
| 2178 | } |
| 2179 | |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 2180 | chunk_init(&resolution->response_buffer, buffer, global.tune.bufsize); |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 2181 | LIST_INIT(&resolution->requester.wait); |
| 2182 | LIST_INIT(&resolution->requester.curr); |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 2183 | |
Baptiste Assmann | 81ed1a0 | 2017-05-03 10:11:44 +0200 | [diff] [blame] | 2184 | return resolution; |
| 2185 | } |
| 2186 | |
| 2187 | /* This function free the memory allocated to a DNS resolution */ |
| 2188 | void dns_free_resolution(struct dns_resolution *resolution) |
| 2189 | { |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 2190 | chunk_destroy(&resolution->response_buffer); |
Baptiste Assmann | 81ed1a0 | 2017-05-03 10:11:44 +0200 | [diff] [blame] | 2191 | free(resolution); |
| 2192 | |
| 2193 | return; |
| 2194 | } |
| 2195 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 2196 | /* this function free a resolution from its requester(s) and move it back to the pool */ |
| 2197 | void dns_resolution_free(struct dns_resolvers *resolvers, struct dns_resolution *resolution) |
| 2198 | { |
| 2199 | struct dns_requester *requester, *tmprequester; |
| 2200 | |
| 2201 | /* clean up configuration */ |
| 2202 | dns_reset_resolution(resolution); |
| 2203 | resolution->hostname_dn = NULL; |
| 2204 | resolution->hostname_dn_len = 0; |
| 2205 | |
| 2206 | list_for_each_entry_safe(requester, tmprequester, &resolution->requester.wait, list) { |
| 2207 | LIST_DEL(&requester->list); |
| 2208 | } |
| 2209 | list_for_each_entry_safe(requester, tmprequester, &resolution->requester.curr, list) { |
| 2210 | LIST_DEL(&requester->list); |
| 2211 | } |
| 2212 | |
| 2213 | LIST_DEL(&resolution->list); |
| 2214 | LIST_ADDQ(&resolvers->resolution.pool, &resolution->list); |
| 2215 | |
| 2216 | return; |
| 2217 | } |
| 2218 | |
| 2219 | /* |
| 2220 | * this function remove a requester from a resolution |
| 2221 | * and takes care of all the consequences. |
| 2222 | * It also cleans up some parameters from the requester |
| 2223 | */ |
| 2224 | void dns_rm_requester_from_resolution(struct dns_requester *requester, struct dns_resolution *resolution) |
| 2225 | { |
| 2226 | char *hostname_dn; |
| 2227 | struct dns_requester *tmprequester; |
| 2228 | |
| 2229 | /* resolution is still used by other requesters, we need to move |
| 2230 | * some pointers to an other requester if needed |
| 2231 | */ |
| 2232 | switch (obj_type(requester->requester)) { |
| 2233 | case OBJ_TYPE_SERVER: |
| 2234 | hostname_dn = objt_server(requester->requester)->hostname_dn; |
| 2235 | break; |
| 2236 | case OBJ_TYPE_NONE: |
| 2237 | default: |
| 2238 | hostname_dn = NULL; |
| 2239 | break; |
| 2240 | } |
| 2241 | |
| 2242 | if (resolution->hostname_dn != hostname_dn) |
| 2243 | return; |
| 2244 | |
| 2245 | /* First, we need to find this other requester */ |
| 2246 | tmprequester = NULL; |
| 2247 | list_for_each_entry(tmprequester, &resolution->requester.wait, list) { |
| 2248 | if (tmprequester != requester) |
| 2249 | break; |
| 2250 | } |
| 2251 | if (!tmprequester) { |
| 2252 | /* if we can't find it in wait queue, let's get one in run queue */ |
| 2253 | list_for_each_entry(tmprequester, &resolution->requester.curr, list) { |
| 2254 | if (tmprequester != requester) |
| 2255 | break; |
| 2256 | } |
| 2257 | } |
| 2258 | |
| 2259 | /* move hostname_dn related pointers to the next requester */ |
| 2260 | switch (obj_type(tmprequester->requester)) { |
| 2261 | case OBJ_TYPE_SERVER: |
| 2262 | resolution->hostname_dn = objt_server(tmprequester->requester)->hostname_dn; |
| 2263 | resolution->hostname_dn_len = objt_server(tmprequester->requester)->hostname_dn_len; |
| 2264 | break; |
| 2265 | case OBJ_TYPE_NONE: |
| 2266 | default: |
| 2267 | ;; |
| 2268 | } |
| 2269 | |
| 2270 | |
| 2271 | /* clean up the requester */ |
| 2272 | LIST_DEL(&requester->list); |
| 2273 | switch (obj_type(requester->requester)) { |
| 2274 | case OBJ_TYPE_SERVER: |
| 2275 | objt_server(requester->requester)->resolution = NULL; |
| 2276 | break; |
| 2277 | case OBJ_TYPE_NONE: |
| 2278 | default: |
| 2279 | ;; |
| 2280 | } |
| 2281 | } |
| 2282 | |
Willy Tarreau | 777b560 | 2016-12-16 18:06:26 +0100 | [diff] [blame] | 2283 | /* This function dumps counters from all resolvers section and associated name |
| 2284 | * servers. It returns 0 if the output buffer is full and it needs to be called |
| 2285 | * again, otherwise non-zero. It may limit itself to the resolver pointed to by |
| 2286 | * <cli.p0> if it's not null. |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 2287 | */ |
| 2288 | static int cli_io_handler_dump_resolvers_to_buffer(struct appctx *appctx) |
| 2289 | { |
| 2290 | struct stream_interface *si = appctx->owner; |
| 2291 | struct dns_resolvers *presolvers; |
| 2292 | struct dns_nameserver *pnameserver; |
| 2293 | |
| 2294 | chunk_reset(&trash); |
| 2295 | |
| 2296 | switch (appctx->st2) { |
| 2297 | case STAT_ST_INIT: |
| 2298 | appctx->st2 = STAT_ST_LIST; /* let's start producing data */ |
| 2299 | /* fall through */ |
| 2300 | |
| 2301 | case STAT_ST_LIST: |
| 2302 | if (LIST_ISEMPTY(&dns_resolvers)) { |
| 2303 | chunk_appendf(&trash, "No resolvers found\n"); |
| 2304 | } |
| 2305 | else { |
| 2306 | list_for_each_entry(presolvers, &dns_resolvers, list) { |
Willy Tarreau | 777b560 | 2016-12-16 18:06:26 +0100 | [diff] [blame] | 2307 | if (appctx->ctx.cli.p0 != NULL && appctx->ctx.cli.p0 != presolvers) |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 2308 | continue; |
| 2309 | |
| 2310 | chunk_appendf(&trash, "Resolvers section %s\n", presolvers->id); |
| 2311 | list_for_each_entry(pnameserver, &presolvers->nameserver_list, list) { |
| 2312 | chunk_appendf(&trash, " nameserver %s:\n", pnameserver->id); |
| 2313 | chunk_appendf(&trash, " sent: %ld\n", pnameserver->counters.sent); |
| 2314 | chunk_appendf(&trash, " valid: %ld\n", pnameserver->counters.valid); |
| 2315 | chunk_appendf(&trash, " update: %ld\n", pnameserver->counters.update); |
| 2316 | chunk_appendf(&trash, " cname: %ld\n", pnameserver->counters.cname); |
| 2317 | chunk_appendf(&trash, " cname_error: %ld\n", pnameserver->counters.cname_error); |
| 2318 | chunk_appendf(&trash, " any_err: %ld\n", pnameserver->counters.any_err); |
| 2319 | chunk_appendf(&trash, " nx: %ld\n", pnameserver->counters.nx); |
| 2320 | chunk_appendf(&trash, " timeout: %ld\n", pnameserver->counters.timeout); |
| 2321 | chunk_appendf(&trash, " refused: %ld\n", pnameserver->counters.refused); |
| 2322 | chunk_appendf(&trash, " other: %ld\n", pnameserver->counters.other); |
| 2323 | chunk_appendf(&trash, " invalid: %ld\n", pnameserver->counters.invalid); |
| 2324 | chunk_appendf(&trash, " too_big: %ld\n", pnameserver->counters.too_big); |
| 2325 | chunk_appendf(&trash, " truncated: %ld\n", pnameserver->counters.truncated); |
| 2326 | chunk_appendf(&trash, " outdated: %ld\n", pnameserver->counters.outdated); |
| 2327 | } |
| 2328 | } |
| 2329 | } |
| 2330 | |
| 2331 | /* display response */ |
| 2332 | if (bi_putchk(si_ic(si), &trash) == -1) { |
| 2333 | /* let's try again later from this session. We add ourselves into |
| 2334 | * this session's users so that it can remove us upon termination. |
| 2335 | */ |
| 2336 | si->flags |= SI_FL_WAIT_ROOM; |
| 2337 | return 0; |
| 2338 | } |
| 2339 | |
| 2340 | appctx->st2 = STAT_ST_FIN; |
| 2341 | /* fall through */ |
| 2342 | |
| 2343 | default: |
| 2344 | appctx->st2 = STAT_ST_FIN; |
| 2345 | return 1; |
| 2346 | } |
| 2347 | } |
| 2348 | |
| 2349 | /* register cli keywords */ |
| 2350 | static struct cli_kw_list cli_kws = {{ },{ |
| 2351 | { { "show", "stat", "resolvers", NULL }, "show stat resolvers [id]: dumps counters from all resolvers section and\n" |
| 2352 | " associated name servers", |
| 2353 | cli_parse_stat_resolvers, cli_io_handler_dump_resolvers_to_buffer }, |
| 2354 | {{},} |
| 2355 | }}; |
| 2356 | |
| 2357 | |
| 2358 | __attribute__((constructor)) |
| 2359 | static void __dns_init(void) |
| 2360 | { |
| 2361 | cli_register_kw(&cli_kws); |
| 2362 | } |
| 2363 | |