unbound/services/cache/infra.h

   1 /*
   2  * services/cache/infra.h - infrastructure cache, server rtt and capabilities
   3  *
   4  * Copyright (c) 2007, NLnet Labs. All rights reserved.
   5  *
   6  * This software is open source.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * Redistributions of source code must retain the above copyright notice,
  13  * this list of conditions and the following disclaimer.
  14  *
  15  * Redistributions in binary form must reproduce the above copyright notice,
  16  * this list of conditions and the following disclaimer in the documentation
  17  * and/or other materials provided with the distribution.
  18  *
  19  * Neither the name of the NLNET LABS nor the names of its contributors may
  20  * be used to endorse or promote products derived from this software without
  21  * specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  24  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  26  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  27  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
  29  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  30  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  31  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  32  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  33  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  34  */
  35
  36 /**
  37  * \file
  38  *
  39  * This file contains the infrastructure cache.
  40  */
  41
  42 #ifndef SERVICES_CACHE_INFRA_H
  43 #define SERVICES_CACHE_INFRA_H
  44 #include "util/storage/lruhash.h"
  45 #include "util/rtt.h"
  46 struct slabhash;
  47 struct config_file;
  48
  49 /**
  50  * Host information kept for every server, per zone.
  51  */
  52 struct infra_key {
  53         /** the host address. */
  54         struct sockaddr_storage addr;
  55         /** length of addr. */
  56         socklen_t addrlen;
  57         /** zone name in wireformat */
  58         uint8_t* zonename;
  59         /** length of zonename */
  60         size_t namelen;
  61         /** hash table entry, data of type infra_data. */
  62         struct lruhash_entry entry;
  63 };
  64
  65 /**
  66  * Host information encompasses host capabilities and retransmission timeouts.
  67  * And lameness information (notAuthoritative, noEDNS, Recursive)
  68  */
  69 struct infra_data {
  70         /** TTL value for this entry. absolute time. */
  71         time_t ttl;
  72
  73         /** time in seconds (absolute) when probing re-commences, 0 disabled */
  74         time_t probedelay;
  75         /** round trip times for timeout calculation */
  76         struct rtt_info rtt;
  77
  78         /** edns version that the host supports, -1 means no EDNS */
  79         int edns_version;
  80         /** if the EDNS lameness is already known or not.
  81          * EDNS lame is when EDNS queries or replies are dropped,
  82          * and cause a timeout */
  83         uint8_t edns_lame_known;
  84
  85         /** is the host lame (does not serve the zone authoritatively),
  86          * or is the host dnssec lame (does not serve DNSSEC data) */
  87         uint8_t isdnsseclame;
  88         /** is the host recursion lame (not AA, but RA) */
  89         uint8_t rec_lame;
  90         /** the host is lame (not authoritative) for A records */
  91         uint8_t lame_type_A;
  92         /** the host is lame (not authoritative) for other query types */
  93         uint8_t lame_other;
  94
  95         /** timeouts counter for type A */
  96         uint8_t timeout_A;
  97         /** timeouts counter for type AAAA */
  98         uint8_t timeout_AAAA;
  99         /** timeouts counter for others */
 100         uint8_t timeout_other;
 101 };
 102
 103 /**
 104  * Infra cache
 105  */
 106 struct infra_cache {
 107         /** The hash table with hosts */
 108         struct slabhash* hosts;
 109         /** TTL value for host information, in seconds */
 110         int host_ttl;
 111 };
 112
 113 /** infra host cache default hash lookup size */
 114 #define INFRA_HOST_STARTSIZE 32
 115 /** bytes per zonename reserved in the hostcache, dnamelen(zonename.com.) */
 116 #define INFRA_BYTES_NAME 14
 117
 118 /**
 119  * Create infra cache.
 120  * @param cfg: config parameters or NULL for defaults.
 121  * @return: new infra cache, or NULL.
 122  */
 123 struct infra_cache* infra_create(struct config_file* cfg);
 124
 125 /**
 126  * Delete infra cache.
 127  * @param infra: infrastructure cache to delete.
 128  */
 129 void infra_delete(struct infra_cache* infra);
 130
 131 /**
 132  * Adjust infra cache to use updated configuration settings.
 133  * This may clean the cache. Operates a bit like realloc.
 134  * There may be no threading or use by other threads.
 135  * @param infra: existing cache. If NULL a new infra cache is returned.
 136  * @param cfg: config options.
 137  * @return the new infra cache pointer or NULL on error.
 138  */
 139 struct infra_cache* infra_adjust(struct infra_cache* infra,
 140         struct config_file* cfg);
 141
 142 /**
 143  * Plain find infra data function (used by the the other functions)
 144  * @param infra: infrastructure cache.
 145  * @param addr: host address.
 146  * @param addrlen: length of addr.
 147  * @param name: domain name of zone.
 148  * @param namelen: length of domain name.
 149  * @param wr: if true, writelock, else readlock.
 150  * @return the entry, could be expired (this is not checked) or NULL.
 151  */
 152 struct lruhash_entry* infra_lookup_nottl(struct infra_cache* infra,
 153         struct sockaddr_storage* addr, socklen_t addrlen, uint8_t* name,
 154         size_t namelen, int wr);
 155
 156 /**
 157  * Find host information to send a packet. Creates new entry if not found.
 158  * Lameness is empty. EDNS is 0 (try with first), and rtt is returned for
 159  * the first message to it.
 160  * Use this to send a packet only, because it also locks out others when
 161  * probing is restricted.
 162  * @param infra: infrastructure cache.
 163  * @param addr: host address.
 164  * @param addrlen: length of addr.
 165  * @param name: domain name of zone.
 166  * @param namelen: length of domain name.
 167  * @param timenow: what time it is now.
 168  * @param edns_vs: edns version it supports, is returned.
 169  * @param edns_lame_known: if EDNS lame (EDNS is dropped in transit) has
 170  *      already been probed, is returned.
 171  * @param to: timeout to use, is returned.
 172  * @return: 0 on error.
 173  */
 174 int infra_host(struct infra_cache* infra, struct sockaddr_storage* addr,
 175         socklen_t addrlen, uint8_t* name, size_t namelen,
 176         time_t timenow, int* edns_vs, uint8_t* edns_lame_known, int* to);
 177
 178 /**
 179  * Set a host to be lame for the given zone.
 180  * @param infra: infrastructure cache.
 181  * @param addr: host address.
 182  * @param addrlen: length of addr.
 183  * @param name: domain name of zone apex.
 184  * @param namelen: length of domain name.
 185  * @param timenow: what time it is now.
 186  * @param dnsseclame: if true the host is set dnssec lame.
 187  *      if false, the host is marked lame (not serving the zone).
 188  * @param reclame: if true host is a recursor not AA server.
 189  *      if false, dnsseclame or marked lame.
 190  * @param qtype: the query type for which it is lame.
 191  * @return: 0 on error.
 192  */
 193 int infra_set_lame(struct infra_cache* infra,
 194         struct sockaddr_storage* addr, socklen_t addrlen,
 195         uint8_t* name, size_t namelen, time_t timenow, int dnsseclame,
 196         int reclame, uint16_t qtype);
 197
 198 /**
 199  * Update rtt information for the host.
 200  * @param infra: infrastructure cache.
 201  * @param addr: host address.
 202  * @param addrlen: length of addr.
 203  * @param name: zone name
 204  * @param namelen: zone name length
 205  * @param qtype: query type.
 206  * @param roundtrip: estimate of roundtrip time in milliseconds or -1 for
 207  *      timeout.
 208  * @param orig_rtt: original rtt for the query that timed out (roundtrip==-1).
 209  *      ignored if roundtrip != -1.
 210  * @param timenow: what time it is now.
 211  * @return: 0 on error. new rto otherwise.
 212  */
 213 int infra_rtt_update(struct infra_cache* infra, struct sockaddr_storage* addr,
 214         socklen_t addrlen, uint8_t* name, size_t namelen, int qtype,
 215         int roundtrip, int orig_rtt, time_t timenow);
 216
 217 /**
 218  * Update information for the host, store that a TCP transaction works.
 219  * @param infra: infrastructure cache.
 220  * @param addr: host address.
 221  * @param addrlen: length of addr.
 222  * @param name: name of zone
 223  * @param namelen: length of name
 224  */
 225 void infra_update_tcp_works(struct infra_cache* infra,
 226         struct sockaddr_storage* addr, socklen_t addrlen,
 227         uint8_t* name, size_t namelen);
 228
 229 /**
 230  * Update edns information for the host.
 231  * @param infra: infrastructure cache.
 232  * @param addr: host address.
 233  * @param addrlen: length of addr.
 234  * @param name: name of zone
 235  * @param namelen: length of name
 236  * @param edns_version: the version that it publishes.
 237  *      If it is known to support EDNS then no-EDNS is not stored over it.
 238  * @param timenow: what time it is now.
 239  * @return: 0 on error.
 240  */
 241 int infra_edns_update(struct infra_cache* infra,
 242         struct sockaddr_storage* addr, socklen_t addrlen,
 243         uint8_t* name, size_t namelen, int edns_version, time_t timenow);
 244
 245 /**
 246  * Get Lameness information and average RTT if host is in the cache.
 247  * This information is to be used for server selection.
 248  * @param infra: infrastructure cache.
 249  * @param addr: host address.
 250  * @param addrlen: length of addr.
 251  * @param name: zone name.
 252  * @param namelen: zone name length.
 253  * @param qtype: the query to be made.
 254  * @param lame: if function returns true, this returns lameness of the zone.
 255  * @param dnsseclame: if function returns true, this returns if the zone
 256  *      is dnssec-lame.
 257  * @param reclame: if function returns true, this is if it is recursion lame.
 258  * @param rtt: if function returns true, this returns avg rtt of the server.
 259  *      The rtt value is unclamped and reflects recent timeouts.
 260  * @param timenow: what time it is now.
 261  * @return if found in cache, or false if not (or TTL bad).
 262  */
 263 int infra_get_lame_rtt(struct infra_cache* infra,
 264         struct sockaddr_storage* addr, socklen_t addrlen,
 265         uint8_t* name, size_t namelen, uint16_t qtype,
 266         int* lame, int* dnsseclame, int* reclame, int* rtt, time_t timenow);
 267
 268 /**
 269  * Get additional (debug) info on timing.
 270  * @param infra: infra cache.
 271  * @param addr: host address.
 272  * @param addrlen: length of addr.
 273  * @param name: zone name
 274  * @param namelen: zone name length
 275  * @param rtt: the rtt_info is copied into here (caller alloced return struct).
 276  * @param delay: probe delay (if any).
 277  * @param timenow: what time it is now.
 278  * @param tA: timeout counter on type A.
 279  * @param tAAAA: timeout counter on type AAAA.
 280  * @param tother: timeout counter on type other.
 281  * @return TTL the infra host element is valid for. If -1: not found in cache.
 282  *      TTL -2: found but expired.
 283  */
 284 long long infra_get_host_rto(struct infra_cache* infra,
 285         struct sockaddr_storage* addr, socklen_t addrlen, uint8_t* name,
 286         size_t namelen, struct rtt_info* rtt, int* delay, time_t timenow,
 287         int* tA, int* tAAAA, int* tother);
 288
 289 /**
 290  * Get memory used by the infra cache.
 291  * @param infra: infrastructure cache.
 292  * @return memory in use in bytes.
 293  */
 294 size_t infra_get_mem(struct infra_cache* infra);
 295
 296 /** calculate size for the hashtable, does not count size of lameness,
 297  * so the hashtable is a fixed number of items */
 298 size_t infra_sizefunc(void* k, void* d);
 299
 300 /** compare two addresses, returns -1, 0, or +1 */
 301 int infra_compfunc(void* key1, void* key2);
 302
 303 /** delete key, and destroy the lock */
 304 void infra_delkeyfunc(void* k, void* arg);
 305
 306 /** delete data and destroy the lameness hashtable */
 307 void infra_deldatafunc(void* d, void* arg);
 308
 309 #endif /* SERVICES_CACHE_INFRA_H */