2 * services/cache/infra.h - infrastructure cache, server rtt and capabilities
4 * Copyright (c) 2007, NLnet Labs. All rights reserved.
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39 * This file contains the infrastructure cache, as well as rate limiting.
40 * Note that there are two sorts of rate-limiting here:
41 * - Pre-cache, per-query rate limiting (query ratelimits)
42 * - Post-cache, per-domain name rate limiting (infra-ratelimits)
45 #ifndef SERVICES_CACHE_INFRA_H
46 #define SERVICES_CACHE_INFRA_H
47 #include "util/storage/lruhash.h"
48 #include "util/storage/dnstree.h"
50 #include "util/netevent.h"
51 #include "util/data/msgreply.h"
56 * Host information kept for every server, per zone.
59 /** the host address. */
60 struct sockaddr_storage addr;
61 /** length of addr. */
63 /** zone name in wireformat */
65 /** length of zonename */
67 /** hash table entry, data of type infra_data. */
68 struct lruhash_entry entry;
72 * Host information encompasses host capabilities and retransmission timeouts.
73 * And lameness information (notAuthoritative, noEDNS, Recursive)
76 /** TTL value for this entry. absolute time. */
79 /** time in seconds (absolute) when probing re-commences, 0 disabled */
81 /** round trip times for timeout calculation */
84 /** edns version that the host supports, -1 means no EDNS */
86 /** if the EDNS lameness is already known or not.
87 * EDNS lame is when EDNS queries or replies are dropped,
88 * and cause a timeout */
89 uint8_t edns_lame_known;
91 /** is the host lame (does not serve the zone authoritatively),
92 * or is the host dnssec lame (does not serve DNSSEC data) */
94 /** is the host recursion lame (not AA, but RA) */
96 /** the host is lame (not authoritative) for A records */
98 /** the host is lame (not authoritative) for other query types */
101 /** timeouts counter for type A */
103 /** timeouts counter for type AAAA */
104 uint8_t timeout_AAAA;
105 /** timeouts counter for others */
106 uint8_t timeout_other;
113 /** The hash table with hosts */
114 struct slabhash* hosts;
115 /** TTL value for host information, in seconds */
117 /** the hosts that are down are kept probed for recovery */
118 int infra_keep_probing;
119 /** hash table with query rates per name: rate_key, rate_data */
120 struct slabhash* domain_rates;
121 /** ratelimit settings for domains, struct domain_limit_data */
122 rbtree_type domain_limits;
123 /** hash table with query rates per client ip: ip_rate_key, ip_rate_data */
124 struct slabhash* client_ip_rates;
127 /** ratelimit, unless overridden by domain_limits, 0 is off */
128 extern int infra_dp_ratelimit;
131 * ratelimit settings for domains
133 struct domain_limit_data {
134 /** key for rbtree, must be first in struct, name of domain */
135 struct name_tree_node node;
136 /** ratelimit for exact match with this name, -1 if not set */
138 /** ratelimit for names below this name, -1 if not set */
143 * key for ratelimit lookups, a domain name
146 /** lruhash key entry */
147 struct lruhash_entry entry;
148 /** domain name in uncompressed wireformat */
150 /** length of name */
154 /** ip ratelimit, 0 is off */
155 extern int infra_ip_ratelimit;
158 * key for ip_ratelimit lookups, a source IP.
161 /** lruhash key entry */
162 struct lruhash_entry entry;
163 /** client ip information */
164 struct sockaddr_storage addr;
165 /** length of address */
169 /** number of seconds to track qps rate */
170 #define RATE_WINDOW 2
173 * Data for ratelimits per domain name
174 * It is incremented when a non-cache-lookup happens for that domain name.
175 * The name is the delegation point we have for the name.
176 * If a new delegation point is found (a referral reply), the previous
177 * delegation point is decremented, and the new one is charged with the query.
180 /** queries counted, for that second. 0 if not in use. */
181 int qps[RATE_WINDOW];
182 /** what the timestamp is of the qps array members, counter is
183 * valid for that timestamp. Usually now and now-1. */
184 time_t timestamp[RATE_WINDOW];
187 #define ip_rate_data rate_data
189 /** infra host cache default hash lookup size */
190 #define INFRA_HOST_STARTSIZE 32
191 /** bytes per zonename reserved in the hostcache, dnamelen(zonename.com.) */
192 #define INFRA_BYTES_NAME 14
195 * Create infra cache.
196 * @param cfg: config parameters or NULL for defaults.
197 * @return: new infra cache, or NULL.
199 struct infra_cache* infra_create(struct config_file* cfg);
202 * Delete infra cache.
203 * @param infra: infrastructure cache to delete.
205 void infra_delete(struct infra_cache* infra);
208 * Adjust infra cache to use updated configuration settings.
209 * This may clean the cache. Operates a bit like realloc.
210 * There may be no threading or use by other threads.
211 * @param infra: existing cache. If NULL a new infra cache is returned.
212 * @param cfg: config options.
213 * @return the new infra cache pointer or NULL on error.
215 struct infra_cache* infra_adjust(struct infra_cache* infra,
216 struct config_file* cfg);
219 * Plain find infra data function (used by the the other functions)
220 * @param infra: infrastructure cache.
221 * @param addr: host address.
222 * @param addrlen: length of addr.
223 * @param name: domain name of zone.
224 * @param namelen: length of domain name.
225 * @param wr: if true, writelock, else readlock.
226 * @return the entry, could be expired (this is not checked) or NULL.
228 struct lruhash_entry* infra_lookup_nottl(struct infra_cache* infra,
229 struct sockaddr_storage* addr, socklen_t addrlen, uint8_t* name,
230 size_t namelen, int wr);
233 * Find host information to send a packet. Creates new entry if not found.
234 * Lameness is empty. EDNS is 0 (try with first), and rtt is returned for
235 * the first message to it.
236 * Use this to send a packet only, because it also locks out others when
237 * probing is restricted.
238 * @param infra: infrastructure cache.
239 * @param addr: host address.
240 * @param addrlen: length of addr.
241 * @param name: domain name of zone.
242 * @param namelen: length of domain name.
243 * @param timenow: what time it is now.
244 * @param edns_vs: edns version it supports, is returned.
245 * @param edns_lame_known: if EDNS lame (EDNS is dropped in transit) has
246 * already been probed, is returned.
247 * @param to: timeout to use, is returned.
248 * @return: 0 on error.
250 int infra_host(struct infra_cache* infra, struct sockaddr_storage* addr,
251 socklen_t addrlen, uint8_t* name, size_t namelen,
252 time_t timenow, int* edns_vs, uint8_t* edns_lame_known, int* to);
255 * Set a host to be lame for the given zone.
256 * @param infra: infrastructure cache.
257 * @param addr: host address.
258 * @param addrlen: length of addr.
259 * @param name: domain name of zone apex.
260 * @param namelen: length of domain name.
261 * @param timenow: what time it is now.
262 * @param dnsseclame: if true the host is set dnssec lame.
263 * if false, the host is marked lame (not serving the zone).
264 * @param reclame: if true host is a recursor not AA server.
265 * if false, dnsseclame or marked lame.
266 * @param qtype: the query type for which it is lame.
267 * @return: 0 on error.
269 int infra_set_lame(struct infra_cache* infra,
270 struct sockaddr_storage* addr, socklen_t addrlen,
271 uint8_t* name, size_t namelen, time_t timenow, int dnsseclame,
272 int reclame, uint16_t qtype);
275 * Update rtt information for the host.
276 * @param infra: infrastructure cache.
277 * @param addr: host address.
278 * @param addrlen: length of addr.
279 * @param name: zone name
280 * @param namelen: zone name length
281 * @param qtype: query type.
282 * @param roundtrip: estimate of roundtrip time in milliseconds or -1 for
284 * @param orig_rtt: original rtt for the query that timed out (roundtrip==-1).
285 * ignored if roundtrip != -1.
286 * @param timenow: what time it is now.
287 * @return: 0 on error. new rto otherwise.
289 int infra_rtt_update(struct infra_cache* infra, struct sockaddr_storage* addr,
290 socklen_t addrlen, uint8_t* name, size_t namelen, int qtype,
291 int roundtrip, int orig_rtt, time_t timenow);
294 * Update information for the host, store that a TCP transaction works.
295 * @param infra: infrastructure cache.
296 * @param addr: host address.
297 * @param addrlen: length of addr.
298 * @param name: name of zone
299 * @param namelen: length of name
301 void infra_update_tcp_works(struct infra_cache* infra,
302 struct sockaddr_storage* addr, socklen_t addrlen,
303 uint8_t* name, size_t namelen);
306 * Update edns information for the host.
307 * @param infra: infrastructure cache.
308 * @param addr: host address.
309 * @param addrlen: length of addr.
310 * @param name: name of zone
311 * @param namelen: length of name
312 * @param edns_version: the version that it publishes.
313 * If it is known to support EDNS then no-EDNS is not stored over it.
314 * @param timenow: what time it is now.
315 * @return: 0 on error.
317 int infra_edns_update(struct infra_cache* infra,
318 struct sockaddr_storage* addr, socklen_t addrlen,
319 uint8_t* name, size_t namelen, int edns_version, time_t timenow);
322 * Get Lameness information and average RTT if host is in the cache.
323 * This information is to be used for server selection.
324 * @param infra: infrastructure cache.
325 * @param addr: host address.
326 * @param addrlen: length of addr.
327 * @param name: zone name.
328 * @param namelen: zone name length.
329 * @param qtype: the query to be made.
330 * @param lame: if function returns true, this returns lameness of the zone.
331 * @param dnsseclame: if function returns true, this returns if the zone
333 * @param reclame: if function returns true, this is if it is recursion lame.
334 * @param rtt: if function returns true, this returns avg rtt of the server.
335 * The rtt value is unclamped and reflects recent timeouts.
336 * @param timenow: what time it is now.
337 * @return if found in cache, or false if not (or TTL bad).
339 int infra_get_lame_rtt(struct infra_cache* infra,
340 struct sockaddr_storage* addr, socklen_t addrlen,
341 uint8_t* name, size_t namelen, uint16_t qtype,
342 int* lame, int* dnsseclame, int* reclame, int* rtt, time_t timenow);
345 * Get additional (debug) info on timing.
346 * @param infra: infra cache.
347 * @param addr: host address.
348 * @param addrlen: length of addr.
349 * @param name: zone name
350 * @param namelen: zone name length
351 * @param rtt: the rtt_info is copied into here (caller alloced return struct).
352 * @param delay: probe delay (if any).
353 * @param timenow: what time it is now.
354 * @param tA: timeout counter on type A.
355 * @param tAAAA: timeout counter on type AAAA.
356 * @param tother: timeout counter on type other.
357 * @return TTL the infra host element is valid for. If -1: not found in cache.
358 * TTL -2: found but expired.
360 long long infra_get_host_rto(struct infra_cache* infra,
361 struct sockaddr_storage* addr, socklen_t addrlen, uint8_t* name,
362 size_t namelen, struct rtt_info* rtt, int* delay, time_t timenow,
363 int* tA, int* tAAAA, int* tother);
366 * Increment the query rate counter for a delegation point.
367 * @param infra: infra cache.
368 * @param name: zone name
369 * @param namelen: zone name length
370 * @param timenow: what time it is now.
371 * @param qinfo: for logging, query name.
372 * @param replylist: for logging, querier's address (if any).
373 * @return 1 if it could be incremented. 0 if the increment overshot the
374 * ratelimit or if in the previous second the ratelimit was exceeded.
375 * Failures like alloc failures are not returned (probably as 1).
377 int infra_ratelimit_inc(struct infra_cache* infra, uint8_t* name,
378 size_t namelen, time_t timenow, struct query_info* qinfo,
379 struct comm_reply* replylist);
382 * Decrement the query rate counter for a delegation point.
383 * Because the reply received for the delegation point was pleasant,
384 * we do not charge this delegation point with it (i.e. it was a referral).
385 * Should call it with same second as when inc() was called.
386 * @param infra: infra cache.
387 * @param name: zone name
388 * @param namelen: zone name length
389 * @param timenow: what time it is now.
391 void infra_ratelimit_dec(struct infra_cache* infra, uint8_t* name,
392 size_t namelen, time_t timenow);
395 * See if the query rate counter for a delegation point is exceeded.
396 * So, no queries are going to be allowed.
397 * @param infra: infra cache.
398 * @param name: zone name
399 * @param namelen: zone name length
400 * @param timenow: what time it is now.
401 * @return true if exceeded.
403 int infra_ratelimit_exceeded(struct infra_cache* infra, uint8_t* name,
404 size_t namelen, time_t timenow);
406 /** find the maximum rate stored, not too old. 0 if no information. */
407 int infra_rate_max(void* data, time_t now);
409 /** find the ratelimit in qps for a domain. 0 if no limit for domain. */
410 int infra_find_ratelimit(struct infra_cache* infra, uint8_t* name,
413 /** Update query ratelimit hash and decide
414 * whether or not a query should be dropped.
415 * @param infra: infra cache
416 * @param repinfo: information about client
417 * @param timenow: what time it is now.
418 * @param buffer: with query for logging.
419 * @return 1 if it could be incremented. 0 if the increment overshot the
420 * ratelimit and the query should be dropped. */
421 int infra_ip_ratelimit_inc(struct infra_cache* infra,
422 struct comm_reply* repinfo, time_t timenow,
423 struct sldns_buffer* buffer);
426 * Get memory used by the infra cache.
427 * @param infra: infrastructure cache.
428 * @return memory in use in bytes.
430 size_t infra_get_mem(struct infra_cache* infra);
432 /** calculate size for the hashtable, does not count size of lameness,
433 * so the hashtable is a fixed number of items */
434 size_t infra_sizefunc(void* k, void* d);
436 /** compare two addresses, returns -1, 0, or +1 */
437 int infra_compfunc(void* key1, void* key2);
439 /** delete key, and destroy the lock */
440 void infra_delkeyfunc(void* k, void* arg);
442 /** delete data and destroy the lameness hashtable */
443 void infra_deldatafunc(void* d, void* arg);
445 /** calculate size for the hashtable */
446 size_t rate_sizefunc(void* k, void* d);
448 /** compare two names, returns -1, 0, or +1 */
449 int rate_compfunc(void* key1, void* key2);
451 /** delete key, and destroy the lock */
452 void rate_delkeyfunc(void* k, void* arg);
455 void rate_deldatafunc(void* d, void* arg);
457 /* calculate size for the client ip hashtable */
458 size_t ip_rate_sizefunc(void* k, void* d);
460 /* compare two addresses */
461 int ip_rate_compfunc(void* key1, void* key2);
463 /* delete key, and destroy the lock */
464 void ip_rate_delkeyfunc(void* d, void* arg);
467 #define ip_rate_deldatafunc rate_deldatafunc
469 #endif /* SERVICES_CACHE_INFRA_H */