2 * util/data/msgreply.h - store message and reply data.
4 * Copyright (c) 2007, NLnet Labs. All rights reserved.
6 * This software is open source.
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9 * modification, are permitted provided that the following conditions
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39 * This file contains a data structure to store a message and its reply.
42 #ifndef UTIL_DATA_MSGREPLY_H
43 #define UTIL_DATA_MSGREPLY_H
44 #include "util/storage/lruhash.h"
45 #include "util/data/packed_rrset.h"
54 /** calculate the prefetch TTL as 90% of original. Calculation
55 * without numerical overflow (uin32_t) */
56 #define PREFETCH_TTL_CALC(ttl) ((ttl) - (ttl)/10)
59 * Structure to store query information that makes answers to queries
64 * Salient data on the query: qname, in wireformat.
65 * can be allocated or a pointer to outside buffer.
66 * User has to keep track on the status of this.
69 /** length of qname (including last 0 octet) */
71 /** qtype, host byte order */
73 /** qclass, host byte order */
78 * Information to reference an rrset
81 /** the key with lock, and ptr to packed data. */
82 struct ub_packed_rrset_key* key;
88 * Structure to store DNS query and the reply packet.
89 * To use it, copy over the flags from reply and modify using flags from
90 * the query (RD,CD if not AA). prepend ID.
95 * o packed_rrset_key* array.
97 * Memory layout is sometimes not packed, when the message is synthesized,
98 * for easy of the generation. It is allocated packed when it is copied
99 * from the region allocation to the malloc allocation.
102 /** the flags for the answer, host byte order. */
106 * This flag informs unbound the answer is authoritative and
107 * the AA flag should be preserved.
109 uint8_t authoritative;
112 * Number of RRs in the query section.
113 * If qdcount is not 0, then it is 1, and the data that appears
114 * in the reply is the same as the query_info.
120 * TTL of the entire reply (for negative caching).
121 * only for use when there are 0 RRsets in this message.
122 * if there are RRsets, check those instead.
127 * TTL for prefetch. After it has expired, a prefetch is suitable.
128 * Smaller than the TTL, otherwise the prefetch would not happen.
130 uint32_t prefetch_ttl;
132 /** 32 bit padding to pad struct member alignment to 64 bits. */
136 * The security status from DNSSEC validation of this message.
138 enum sec_status security;
141 * Number of RRsets in each section.
142 * The answer section. Add up the RRs in every RRset to calculate
143 * the number of RRs, and the count for the dns packet.
144 * The number of RRs in RRsets can change due to RRset updates.
148 /** Count of authority section RRsets */
150 /** Count of additional section RRsets */
153 /** number of RRsets: an_numrrsets + ns_numrrsets + ar_numrrsets */
157 * List of pointers (only) to the rrsets in the order in which
158 * they appear in the reply message.
159 * Number of elements is ancount+nscount+arcount RRsets.
160 * This is a pointer to that array.
161 * Use the accessor function for access.
163 struct ub_packed_rrset_key** rrsets;
166 * Packed array of ids (see counts) and pointers to packed_rrset_key.
167 * The number equals ancount+nscount+arcount RRsets.
168 * These are sorted in ascending pointer, the locking order. So
169 * this list can be locked (and id, ttl checked), to see if
170 * all the data is available and recent enough.
172 * This is defined as an array of size 1, so that the compiler
173 * associates the identifier with this position in the structure.
174 * Array bound overflow on this array then gives access to the further
175 * elements of the array, which are allocated after the main structure.
177 * It could be more pure to define as array of size 0, ref[0].
178 * But ref[1] may be less confusing for compilers.
179 * Use the accessor function for access.
181 struct rrset_ref ref[1];
185 * Structure to keep hash table entry for message replies.
187 struct msgreply_entry {
188 /** the hash table key */
189 struct query_info key;
190 /** the hash table entry, data is struct reply_info* */
191 struct lruhash_entry entry;
195 * Parse wire query into a queryinfo structure, return 0 on parse error.
196 * initialises the (prealloced) queryinfo structure as well.
197 * This query structure contains a pointer back info the buffer!
198 * This pointer avoids memory allocation. allocqname does memory allocation.
199 * @param m: the prealloced queryinfo structure to put query into.
200 * must be unused, or _clear()ed.
201 * @param query: the wireformat packet query. starts with ID.
202 * @return: 0 on format error.
204 int query_info_parse(struct query_info* m, ldns_buffer* query);
208 * Fills in preallocated query_info structure (with ptr into buffer).
209 * Allocates reply_info and packed_rrsets. These are not yet added to any
210 * caches or anything, this is only parsing. Returns formerror on qdcount > 1.
211 * @param pkt: the packet buffer. Must be positioned after the query section.
212 * @param alloc: creates packed rrset key structures.
213 * @param rep: allocated reply_info is returned (only on no error).
214 * @param qinf: query_info is returned (only on no error).
215 * @param region: where to store temporary data (for parsing).
216 * @param edns: where to store edns information, does not need to be inited.
217 * @return: zero is OK, or DNS error code in case of error
218 * o FORMERR for parse errors.
219 * o SERVFAIL for memory allocation errors.
221 int reply_info_parse(ldns_buffer* pkt, struct alloc_cache* alloc,
222 struct query_info* qinf, struct reply_info** rep,
223 struct regional* region, struct edns_data* edns);
226 * Allocate and decompress parsed message and rrsets.
227 * @param pkt: for name decompression.
228 * @param msg: parsed message in scratch region.
229 * @param alloc: alloc cache for special rrset key structures.
230 * Not used if region!=NULL, it can be NULL in that case.
231 * @param qinf: where to store query info.
232 * qinf itself is allocated by the caller.
233 * @param rep: reply info is allocated and returned.
234 * @param region: if this parameter is NULL then malloc and the alloc is used.
235 * otherwise, everything is allocated in this region.
236 * In a region, no special rrset key structures are needed (not shared),
237 * and no rrset_ref array in the reply is built up.
238 * @return 0 if allocation failed.
240 int parse_create_msg(ldns_buffer* pkt, struct msg_parse* msg,
241 struct alloc_cache* alloc, struct query_info* qinf,
242 struct reply_info** rep, struct regional* region);
245 * Sorts the ref array.
246 * @param rep: reply info. rrsets must be filled in.
248 void reply_info_sortref(struct reply_info* rep);
251 * Set TTLs inside the replyinfo to absolute values.
252 * @param rep: reply info. rrsets must be filled in.
253 * Also refs must be filled in.
254 * @param timenow: the current time.
256 void reply_info_set_ttls(struct reply_info* rep, uint32_t timenow);
259 * Delete reply_info and packed_rrsets (while they are not yet added to the
260 * hashtables.). Returns rrsets to the alloc cache.
261 * @param rep: reply_info to delete.
262 * @param alloc: where to return rrset structures to.
264 void reply_info_parsedelete(struct reply_info* rep, struct alloc_cache* alloc);
267 * Compare two queryinfo structures, on query and type, class.
268 * It is _not_ sorted in canonical ordering.
269 * @param m1: struct query_info* , void* here to ease use as function pointer.
270 * @param m2: struct query_info* , void* here to ease use as function pointer.
271 * @return: 0 = same, -1 m1 is smaller, +1 m1 is larger.
273 int query_info_compare(void* m1, void* m2);
275 /** clear out query info structure */
276 void query_info_clear(struct query_info* m);
278 /** calculate size of struct query_info + reply_info */
279 size_t msgreply_sizefunc(void* k, void* d);
281 /** delete msgreply_entry key structure */
282 void query_entry_delete(void *q, void* arg);
284 /** delete reply_info data structure */
285 void reply_info_delete(void* d, void* arg);
287 /** calculate hash value of query_info, lowercases the qname */
288 hashvalue_t query_info_hash(struct query_info *q);
291 * Setup query info entry
292 * @param q: query info to copy. Emptied as if clear is called.
293 * @param r: reply to init data.
294 * @param h: hash value.
295 * @return: newly allocated message reply cache item.
297 struct msgreply_entry* query_info_entrysetup(struct query_info* q,
298 struct reply_info* r, hashvalue_t h);
301 * Copy reply_info and all rrsets in it and allocate.
302 * @param rep: what to copy, probably inside region, no ref[] array in it.
303 * @param alloc: how to allocate rrset keys.
304 * Not used if region!=NULL, it can be NULL in that case.
305 * @param region: if this parameter is NULL then malloc and the alloc is used.
306 * otherwise, everything is allocated in this region.
307 * In a region, no special rrset key structures are needed (not shared),
308 * and no rrset_ref array in the reply is built up.
309 * @return new reply info or NULL on memory error.
311 struct reply_info* reply_info_copy(struct reply_info* rep,
312 struct alloc_cache* alloc, struct regional* region);
315 * Copy a parsed rrset into given key, decompressing and allocating rdata.
316 * @param pkt: packet for decompression
317 * @param msg: the parser message (for flags for trust).
318 * @param pset: the parsed rrset to copy.
319 * @param region: if NULL - malloc, else data is allocated in this region.
320 * @param pk: a freshly obtained rrsetkey structure. No dname is set yet,
321 * will be set on return.
322 * Note that TTL will still be relative on return.
323 * @return false on alloc failure.
325 int parse_copy_decompress_rrset(ldns_buffer* pkt, struct msg_parse* msg,
326 struct rrset_parse *pset, struct regional* region,
327 struct ub_packed_rrset_key* pk);
330 * Find final cname target in reply, the one matching qinfo. Follows CNAMEs.
331 * @param qinfo: what to start with.
332 * @param rep: looks in answer section of this message.
333 * @return: pointer dname, or NULL if not found.
335 uint8_t* reply_find_final_cname_target(struct query_info* qinfo,
336 struct reply_info* rep);
339 * Check if cname chain in cached reply is still valid.
340 * @param rep: reply to check.
341 * @return: true if valid, false if invalid.
343 int reply_check_cname_chain(struct reply_info* rep);
346 * Check security status of all RRs in the message.
347 * @param rep: reply to check
348 * @return: true if all RRs are secure. False if not.
349 * True if there are zero RRs.
351 int reply_all_rrsets_secure(struct reply_info* rep);
354 * Find answer rrset in reply, the one matching qinfo. Follows CNAMEs, so the
355 * result may have a different owner name.
356 * @param qinfo: what to look for.
357 * @param rep: looks in answer section of this message.
358 * @return: pointer to rrset, or NULL if not found.
360 struct ub_packed_rrset_key* reply_find_answer_rrset(struct query_info* qinfo,
361 struct reply_info* rep);
364 * Find rrset in reply, inside the answer section. Does not follow CNAMEs.
365 * @param rep: looks in answer section of this message.
366 * @param name: what to look for.
367 * @param namelen: length of name.
368 * @param type: looks for (host order).
369 * @param dclass: looks for (host order).
370 * @return: pointer to rrset, or NULL if not found.
372 struct ub_packed_rrset_key* reply_find_rrset_section_an(struct reply_info* rep,
373 uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass);
376 * Find rrset in reply, inside the authority section. Does not follow CNAMEs.
377 * @param rep: looks in authority section of this message.
378 * @param name: what to look for.
379 * @param namelen: length of name.
380 * @param type: looks for (host order).
381 * @param dclass: looks for (host order).
382 * @return: pointer to rrset, or NULL if not found.
384 struct ub_packed_rrset_key* reply_find_rrset_section_ns(struct reply_info* rep,
385 uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass);
388 * Find rrset in reply, inside any section. Does not follow CNAMEs.
389 * @param rep: looks in answer,authority and additional section of this message.
390 * @param name: what to look for.
391 * @param namelen: length of name.
392 * @param type: looks for (host order).
393 * @param dclass: looks for (host order).
394 * @return: pointer to rrset, or NULL if not found.
396 struct ub_packed_rrset_key* reply_find_rrset(struct reply_info* rep,
397 uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass);
400 * Debug send the query info and reply info to the log in readable form.
401 * @param str: descriptive string printed with packet content.
402 * @param qinfo: query section.
403 * @param rep: rest of message.
405 void log_dns_msg(const char* str, struct query_info* qinfo,
406 struct reply_info* rep);
409 * Print string with neat domain name, type, class from query info.
410 * @param v: at what verbosity level to print this.
411 * @param str: string of message.
412 * @param qinf: query info structure with name, type and class.
414 void log_query_info(enum verbosity_value v, const char* str,
415 struct query_info* qinf);
417 #endif /* UTIL_DATA_MSGREPLY_H */