2 * services/outside_network.h - listen to answers from the network
4 * Copyright (c) 2007, NLnet Labs. All rights reserved.
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39 * This file has functions to send queries to authoritative servers,
40 * and wait for the pending answer, with timeouts.
43 #ifndef OUTSIDE_NETWORK_H
44 #define OUTSIDE_NETWORK_H
46 #include "util/rbtree.h"
47 #include "util/netevent.h"
48 #include "dnstap/dnstap_config.h"
50 struct pending_timeout;
59 struct serviced_query;
64 * Send queries to outside servers and wait for answers from servers.
65 * Contains answer-listen sockets.
67 struct outside_network {
68 /** Base for select calls */
69 struct comm_base* base;
70 /** pointer to time in seconds */
72 /** pointer to time in microseconds */
73 struct timeval* now_tv;
75 /** buffer shared by UDP connections, since there is only one
76 datagram at any time. */
77 struct sldns_buffer* udp_buff;
78 /** serviced_callbacks malloc overhead when processing multiple
79 * identical serviced queries to the same server. */
81 /** use x20 bits to encode additional ID random bits */
83 /** outside network wants to quit. Stop queued msgs from sent. */
86 /** number of unwanted replies received (for statistics) */
87 size_t unwanted_replies;
88 /** cumulative total of unwanted replies (for defense) */
89 size_t unwanted_total;
90 /** threshold when to take defensive action. If 0 then never. */
91 size_t unwanted_threshold;
92 /** what action to take, called when defensive action is needed */
93 void (*unwanted_action)(void*);
94 /** user param for action */
97 /** linked list of available commpoints, unused file descriptors,
98 * for use as outgoing UDP ports. cp.fd=-1 in them. */
99 struct port_comm* unused_fds;
100 /** if udp is done */
102 /** if udp is delay-closed (delayed answers do not meet closed port)*/
104 /** timeout for delayclose */
105 struct timeval delay_tv;
107 /** array of outgoing IP4 interfaces */
108 struct port_if* ip4_ifs;
109 /** number of outgoing IP4 interfaces */
112 /** array of outgoing IP6 interfaces */
113 struct port_if* ip6_ifs;
114 /** number of outgoing IP6 interfaces */
117 /** pending udp queries waiting to be sent out, waiting for fd */
118 struct pending* udp_wait_first;
119 /** last pending udp query in list */
120 struct pending* udp_wait_last;
122 /** pending udp answers. sorted by id, addr */
124 /** serviced queries, sorted by qbuf, addr, dnssec */
126 /** host cache, pointer but not owned by outnet. */
127 struct infra_cache* infra;
128 /** where to get random numbers */
129 struct ub_randstate* rnd;
130 /** ssl context to create ssl wrapped TCP with DNS connections */
133 /** dnstap environment */
134 struct dt_env* dtenv;
136 /** maximum segment size of tcp socket */
140 * Array of tcp pending used for outgoing TCP connections.
141 * Each can be used to establish a TCP connection with a server.
142 * The file descriptors are -1 if they are free, and need to be
143 * opened for the tcp connection. Can be used for ip4 and ip6.
145 struct pending_tcp **tcp_conns;
146 /** number of tcp communication points. */
148 /** number of tcp communication points in use. */
149 size_t num_tcp_outgoing;
150 /** list of tcp comm points that are free for use */
151 struct pending_tcp* tcp_free;
152 /** list of tcp queries waiting for a buffer */
153 struct waiting_tcp* tcp_wait_first;
154 /** last of waiting query list */
155 struct waiting_tcp* tcp_wait_last;
159 * Outgoing interface. Ports available and currently used are tracked
163 /** address ready to allocate new socket (except port no). */
164 struct sockaddr_storage addr;
165 /** length of addr field */
168 /** prefix length of network address (in bits), for randomisation.
169 * if 0, no randomisation. */
172 /** the available ports array. These are unused.
173 * Only the first total-inuse part is filled. */
175 /** the total number of available ports (size of the array) */
178 /** array of the commpoints currently in use.
179 * allocated for max number of fds, first part in use. */
180 struct port_comm** out;
181 /** max number of fds, size of out array */
183 /** number of commpoints (and thus also ports) in use */
188 * Outgoing commpoint for UDP port.
191 /** next in free list */
192 struct port_comm* next;
193 /** which port number (when in use) */
195 /** interface it is used in */
197 /** index in the out array of the interface */
199 /** number of outstanding queries on this port */
201 /** UDP commpoint, fd=-1 if not in use */
202 struct comm_point* cp;
206 * A query that has an answer pending for it.
209 /** redblacktree entry, key is the pending struct(id, addr). */
211 /** the ID for the query. int so that a value out of range can
212 * be used to signify a pending that is for certain not present in
213 * the rbtree. (and for which deletion is safe). */
215 /** remote address. */
216 struct sockaddr_storage addr;
217 /** length of addr field in use. */
219 /** comm point it was sent on (and reply must come back on). */
220 struct port_comm* pc;
222 struct comm_timer* timer;
223 /** callback for the timeout, error or reply to the message */
224 comm_point_callback_t* cb;
225 /** callback user argument */
227 /** the outside network it is part of */
228 struct outside_network* outnet;
229 /** the corresponding serviced_query */
230 struct serviced_query* sq;
232 /*---- filled if udp pending is waiting -----*/
233 /** next in waiting list. */
234 struct pending* next_waiting;
235 /** timeout in msec */
237 /** The query itself, the query packet to send. */
239 /** length of query packet. */
244 * Pending TCP query to server.
247 /** next in list of free tcp comm points, or NULL. */
248 struct pending_tcp* next_free;
249 /** the ID for the query; checked in reply */
251 /** tcp comm point it was sent on (and reply must come back on). */
252 struct comm_point* c;
253 /** the query being serviced, NULL if the pending_tcp is unused. */
254 struct waiting_tcp* query;
258 * Query waiting for TCP buffer.
262 * next in waiting list.
263 * if pkt==0, this points to the pending_tcp structure.
265 struct waiting_tcp* next_waiting;
266 /** timeout event; timer keeps running whether the query is
267 * waiting for a buffer or the tcp reply is pending */
268 struct comm_timer* timer;
269 /** the outside network it is part of */
270 struct outside_network* outnet;
271 /** remote address. */
272 struct sockaddr_storage addr;
273 /** length of addr field in use. */
276 * The query itself, the query packet to send.
277 * allocated after the waiting_tcp structure.
278 * set to NULL when the query is serviced and it part of pending_tcp.
279 * if this is NULL, the next_waiting points to the pending_tcp.
282 /** length of query packet. */
284 /** callback for the timeout, error or reply to the message */
285 comm_point_callback_t* cb;
286 /** callback user argument */
288 /** if it uses ssl upstream */
293 * Callback to party interested in serviced query results.
295 struct service_callback {
296 /** next in callback list */
297 struct service_callback* next;
298 /** callback function */
299 comm_point_callback_t* cb;
300 /** user argument for callback function */
304 /** fallback size for fragmentation for EDNS in IPv4 */
305 #define EDNS_FRAG_SIZE_IP4 1472
306 /** fallback size for EDNS in IPv6, fits one fragment with ip6-tunnel-ids */
307 #define EDNS_FRAG_SIZE_IP6 1232
310 * Query service record.
311 * Contains query and destination. UDP, TCP, EDNS are all tried.
312 * complete with retries and timeouts. A number of interested parties can
313 * receive a callback.
315 struct serviced_query {
316 /** The rbtree node, key is this record */
318 /** The query that needs to be answered. Starts with flags u16,
319 * then qdcount, ..., including qname, qtype, qclass. Does not include
322 /** length of qbuf. */
324 /** If an EDNS section is included, the DO/CD bit will be turned on. */
326 /** We want signatures, or else the answer is likely useless */
328 /** ignore capsforid */
330 /** tcp upstream used, use tcp, or ssl_upstream for SSL */
331 int tcp_upstream, ssl_upstream;
332 /** where to send it */
333 struct sockaddr_storage addr;
334 /** length of addr field in use. */
336 /** zone name, uncompressed domain name in wireformat */
338 /** length of zone name */
342 /** current status */
343 enum serviced_query_status {
344 /** initial status */
346 /** UDP with EDNS sent */
347 serviced_query_UDP_EDNS,
348 /** UDP without EDNS sent */
350 /** TCP with EDNS sent */
351 serviced_query_TCP_EDNS,
352 /** TCP without EDNS sent */
354 /** probe to test EDNS lameness (EDNS is dropped) */
355 serviced_query_PROBE_EDNS,
356 /** probe to test noEDNS0 (EDNS gives FORMERRorNOTIMP) */
357 serviced_query_UDP_EDNS_fallback,
358 /** probe to test TCP noEDNS0 (EDNS gives FORMERRorNOTIMP) */
359 serviced_query_TCP_EDNS_fallback,
360 /** send UDP query with EDNS1480 (or 1280) */
361 serviced_query_UDP_EDNS_FRAG
363 /** variable with current status */
365 /** true if serviced_query is scheduled for deletion already */
367 /** number of UDP retries */
369 /** time last UDP was sent */
370 struct timeval last_sent_time;
371 /** rtt of last (UDP) message */
373 /** do we know edns probe status already, for UDP_EDNS queries */
375 /** edns options to use for sending upstream packet */
376 struct edns_option* opt_list;
377 /** outside network this is part of */
378 struct outside_network* outnet;
379 /** list of interested parties that need callback on results. */
380 struct service_callback* cblist;
381 /** the UDP or TCP query that is pending, see status which */
386 * Create outside_network structure with N udp ports.
387 * @param base: the communication base to use for event handling.
388 * @param bufsize: size for network buffers.
389 * @param num_ports: number of udp ports to open per interface.
390 * @param ifs: interface names (or NULL for default interface).
391 * These interfaces must be able to access all authoritative servers.
392 * @param num_ifs: number of names in array ifs.
393 * @param do_ip4: service IP4.
394 * @param do_ip6: service IP6.
395 * @param num_tcp: number of outgoing tcp buffers to preallocate.
396 * @param infra: pointer to infra cached used for serviced queries.
397 * @param rnd: stored to create random numbers for serviced queries.
398 * @param use_caps_for_id: enable to use 0x20 bits to encode id randomness.
399 * @param availports: array of available ports.
400 * @param numavailports: number of available ports in array.
401 * @param unwanted_threshold: when to take defensive action.
402 * @param unwanted_action: the action to take.
403 * @param unwanted_param: user parameter to action.
404 * @param tcp_mss: maximum segment size of tcp socket.
405 * @param do_udp: if udp is done.
406 * @param sslctx: context to create outgoing connections with (if enabled).
407 * @param delayclose: if not 0, udp sockets are delayed before timeout closure.
408 * msec to wait on timeouted udp sockets.
409 * @param dtenv: environment to send dnstap events with (if enabled).
410 * @return: the new structure (with no pending answers) or NULL on error.
412 struct outside_network* outside_network_create(struct comm_base* base,
413 size_t bufsize, size_t num_ports, char** ifs, int num_ifs,
414 int do_ip4, int do_ip6, size_t num_tcp, struct infra_cache* infra,
415 struct ub_randstate* rnd, int use_caps_for_id, int* availports,
416 int numavailports, size_t unwanted_threshold, int tcp_mss,
417 void (*unwanted_action)(void*), void* unwanted_param, int do_udp,
418 void* sslctx, int delayclose, struct dt_env *dtenv);
421 * Delete outside_network structure.
422 * @param outnet: object to delete.
424 void outside_network_delete(struct outside_network* outnet);
427 * Prepare for quit. Sends no more queries, even if queued up.
428 * @param outnet: object to prepare for removal
430 void outside_network_quit_prepare(struct outside_network* outnet);
433 * Send UDP query, create pending answer.
434 * Changes the ID for the query to be random and unique for that destination.
435 * @param sq: serviced query.
436 * @param packet: wireformat query to send to destination.
437 * @param timeout: in milliseconds from now.
438 * @param callback: function to call on error, timeout or reply.
439 * @param callback_arg: user argument for callback function.
440 * @return: NULL on error for malloc or socket. Else the pending query object.
442 struct pending* pending_udp_query(struct serviced_query* sq,
443 struct sldns_buffer* packet, int timeout, comm_point_callback_t* callback,
447 * Send TCP query. May wait for TCP buffer. Selects ID to be random, and
449 * @param sq: serviced query.
450 * @param packet: wireformat query to send to destination. copied from.
451 * @param timeout: in seconds from now.
452 * Timer starts running now. Timer may expire if all buffers are used,
453 * without any query been sent to the server yet.
454 * @param callback: function to call on error, timeout or reply.
455 * @param callback_arg: user argument for callback function.
456 * @return: false on error for malloc or socket. Else the pending TCP object.
458 struct waiting_tcp* pending_tcp_query(struct serviced_query* sq,
459 struct sldns_buffer* packet, int timeout, comm_point_callback_t* callback,
463 * Delete pending answer.
464 * @param outnet: outside network the pending query is part of.
465 * Internal feature: if outnet is NULL, p is not unlinked from rbtree.
468 void pending_delete(struct outside_network* outnet, struct pending* p);
471 * Perform a serviced query to the authoritative servers.
472 * Duplicate efforts are detected, and EDNS, TCP and UDP retry is performed.
473 * @param outnet: outside network, with rbtree of serviced queries.
474 * @param qname: what qname to query.
475 * @param qnamelen: length of qname in octets including 0 root label.
476 * @param qtype: rrset type to query (host format)
477 * @param qclass: query class. (host format)
478 * @param flags: flags u16 (host format), includes opcode, CD bit.
479 * @param dnssec: if set, DO bit is set in EDNS queries.
480 * If the value includes BIT_CD, CD bit is set when in EDNS queries.
481 * If the value includes BIT_DO, DO bit is set when in EDNS queries.
482 * @param want_dnssec: signatures are needed, without EDNS the answer is
483 * likely to be useless.
484 * @param nocaps: ignore use_caps_for_id and use unperturbed qname.
485 * @param tcp_upstream: use TCP for upstream queries.
486 * @param ssl_upstream: use SSL for upstream queries.
487 * @param opt_list: pass edns option list (deep copied into serviced query)
488 * these options are set on the outgoing packets.
489 * @param callback: callback function.
490 * @param callback_arg: user argument to callback function.
491 * @param addr: to which server to send the query.
492 * @param addrlen: length of addr.
493 * @param zone: name of the zone of the delegation point. wireformat dname.
494 This is the delegation point name for which the server is deemed
496 * @param zonelen: length of zone.
497 * @param buff: scratch buffer to create query contents in. Empty on exit.
498 * @return 0 on error, or pointer to serviced query that is used to answer
499 * this serviced query may be shared with other callbacks as well.
501 struct serviced_query* outnet_serviced_query(struct outside_network* outnet,
502 uint8_t* qname, size_t qnamelen, uint16_t qtype, uint16_t qclass,
503 uint16_t flags, int dnssec, int want_dnssec, int nocaps,
504 int tcp_upstream, int ssl_upstream, struct edns_option* opt_list,
505 struct sockaddr_storage* addr, socklen_t addrlen, uint8_t* zone,
506 size_t zonelen, comm_point_callback_t* callback, void* callback_arg,
507 struct sldns_buffer* buff);
510 * Remove service query callback.
511 * If that leads to zero callbacks, the query is completely cancelled.
512 * @param sq: serviced query to adjust.
513 * @param cb_arg: callback argument of callback that needs removal.
514 * same as the callback_arg to outnet_serviced_query().
516 void outnet_serviced_query_stop(struct serviced_query* sq, void* cb_arg);
519 * Get memory size in use by outside network.
520 * Counts buffers and outstanding query (serviced queries) malloced data.
521 * @param outnet: outside network structure.
522 * @return size in bytes.
524 size_t outnet_get_mem(struct outside_network* outnet);
527 * Get memory size in use by serviced query while it is servicing callbacks.
528 * This takes into account the pre-deleted status of it; it will be deleted
529 * when the callbacks are done.
530 * @param sq: serviced query.
531 * @return size in bytes.
533 size_t serviced_get_mem(struct serviced_query* sq);
535 /** callback for incoming udp answers from the network */
536 int outnet_udp_cb(struct comm_point* c, void* arg, int error,
537 struct comm_reply *reply_info);
539 /** callback for pending tcp connections */
540 int outnet_tcp_cb(struct comm_point* c, void* arg, int error,
541 struct comm_reply *reply_info);
543 /** callback for udp timeout */
544 void pending_udp_timer_cb(void *arg);
546 /** callback for udp delay for timeout */
547 void pending_udp_timer_delay_cb(void *arg);
549 /** callback for outgoing TCP timer event */
550 void outnet_tcptimer(void* arg);
552 /** callback for serviced query UDP answers */
553 int serviced_udp_callback(struct comm_point* c, void* arg, int error,
554 struct comm_reply* rep);
556 /** TCP reply or error callback for serviced queries */
557 int serviced_tcp_callback(struct comm_point* c, void* arg, int error,
558 struct comm_reply* rep);
560 /** compare function of pending rbtree */
561 int pending_cmp(const void* key1, const void* key2);
563 /** compare function of serviced query rbtree */
564 int serviced_cmp(const void* key1, const void* key2);
566 #endif /* OUTSIDE_NETWORK_H */