/* * util/data/msgreply.h - store message and reply data. * * Copyright (c) 2007, NLnet Labs. All rights reserved. * * This software is open source. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * Neither the name of the NLNET LABS nor the names of its contributors may * be used to endorse or promote products derived from this software without * specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /** * \file * * This file contains a data structure to store a message and its reply. */ #ifndef UTIL_DATA_MSGREPLY_H #define UTIL_DATA_MSGREPLY_H #include "util/storage/lruhash.h" #include "util/data/packed_rrset.h" struct sldns_buffer; struct comm_reply; struct alloc_cache; struct iovec; struct regional; struct edns_data; struct msg_parse; struct rrset_parse; /** calculate the prefetch TTL as 90% of original. Calculation * without numerical overflow (uin32_t) */ #define PREFETCH_TTL_CALC(ttl) ((ttl) - (ttl)/10) /** * Structure to store query information that makes answers to queries * different. */ struct query_info { /** * Salient data on the query: qname, in wireformat. * can be allocated or a pointer to outside buffer. * User has to keep track on the status of this. */ uint8_t* qname; /** length of qname (including last 0 octet) */ size_t qname_len; /** qtype, host byte order */ uint16_t qtype; /** qclass, host byte order */ uint16_t qclass; }; /** * Information to reference an rrset */ struct rrset_ref { /** the key with lock, and ptr to packed data. */ struct ub_packed_rrset_key* key; /** id needed */ rrset_id_t id; }; /** * Structure to store DNS query and the reply packet. * To use it, copy over the flags from reply and modify using flags from * the query (RD,CD if not AA). prepend ID. * * Memory layout is: * o struct * o rrset_ref array * o packed_rrset_key* array. * * Memory layout is sometimes not packed, when the message is synthesized, * for easy of the generation. It is allocated packed when it is copied * from the region allocation to the malloc allocation. */ struct reply_info { /** the flags for the answer, host byte order. */ uint16_t flags; /** * This flag informs unbound the answer is authoritative and * the AA flag should be preserved. */ uint8_t authoritative; /** * Number of RRs in the query section. * If qdcount is not 0, then it is 1, and the data that appears * in the reply is the same as the query_info. * Host byte order. */ uint8_t qdcount; /** 32 bit padding to pad struct member alignment to 64 bits. */ uint32_t padding; /** * TTL of the entire reply (for negative caching). * only for use when there are 0 RRsets in this message. * if there are RRsets, check those instead. */ time_t ttl; /** * TTL for prefetch. After it has expired, a prefetch is suitable. * Smaller than the TTL, otherwise the prefetch would not happen. */ time_t prefetch_ttl; /** * The security status from DNSSEC validation of this message. */ enum sec_status security; /** * Number of RRsets in each section. * The answer section. Add up the RRs in every RRset to calculate * the number of RRs, and the count for the dns packet. * The number of RRs in RRsets can change due to RRset updates. */ size_t an_numrrsets; /** Count of authority section RRsets */ size_t ns_numrrsets; /** Count of additional section RRsets */ size_t ar_numrrsets; /** number of RRsets: an_numrrsets + ns_numrrsets + ar_numrrsets */ size_t rrset_count; /** * List of pointers (only) to the rrsets in the order in which * they appear in the reply message. * Number of elements is ancount+nscount+arcount RRsets. * This is a pointer to that array. * Use the accessor function for access. */ struct ub_packed_rrset_key** rrsets; /** * Packed array of ids (see counts) and pointers to packed_rrset_key. * The number equals ancount+nscount+arcount RRsets. * These are sorted in ascending pointer, the locking order. So * this list can be locked (and id, ttl checked), to see if * all the data is available and recent enough. * * This is defined as an array of size 1, so that the compiler * associates the identifier with this position in the structure. * Array bound overflow on this array then gives access to the further * elements of the array, which are allocated after the main structure. * * It could be more pure to define as array of size 0, ref[0]. * But ref[1] may be less confusing for compilers. * Use the accessor function for access. */ struct rrset_ref ref[1]; }; /** * Structure to keep hash table entry for message replies. */ struct msgreply_entry { /** the hash table key */ struct query_info key; /** the hash table entry, data is struct reply_info* */ struct lruhash_entry entry; }; /** * Constructor for replyinfo. * @param region: where to allocate the results, pass NULL to use malloc. * @param flags: flags for the replyinfo. * @param qd: qd count * @param ttl: TTL of replyinfo * @param prettl: prefetch ttl * @param an: an count * @param ns: ns count * @param ar: ar count * @param total: total rrset count (presumably an+ns+ar). * @param sec: security status of the reply info. * @return the reply_info base struct with the array for putting the rrsets * in. The array has been zeroed. Returns NULL on malloc failure. */ struct reply_info* construct_reply_info_base(struct regional* region, uint16_t flags, size_t qd, time_t ttl, time_t prettl, size_t an, size_t ns, size_t ar, size_t total, enum sec_status sec); /** * Parse wire query into a queryinfo structure, return 0 on parse error. * initialises the (prealloced) queryinfo structure as well. * This query structure contains a pointer back info the buffer! * This pointer avoids memory allocation. allocqname does memory allocation. * @param m: the prealloced queryinfo structure to put query into. * must be unused, or _clear()ed. * @param query: the wireformat packet query. starts with ID. * @return: 0 on format error. */ int query_info_parse(struct query_info* m, struct sldns_buffer* query); /** * Parse query reply. * Fills in preallocated query_info structure (with ptr into buffer). * Allocates reply_info and packed_rrsets. These are not yet added to any * caches or anything, this is only parsing. Returns formerror on qdcount > 1. * @param pkt: the packet buffer. Must be positioned after the query section. * @param alloc: creates packed rrset key structures. * @param rep: allocated reply_info is returned (only on no error). * @param qinf: query_info is returned (only on no error). * @param region: where to store temporary data (for parsing). * @param edns: where to store edns information, does not need to be inited. * @return: zero is OK, or DNS error code in case of error * o FORMERR for parse errors. * o SERVFAIL for memory allocation errors. */ int reply_info_parse(struct sldns_buffer* pkt, struct alloc_cache* alloc, struct query_info* qinf, struct reply_info** rep, struct regional* region, struct edns_data* edns); /** * Allocate and decompress parsed message and rrsets. * @param pkt: for name decompression. * @param msg: parsed message in scratch region. * @param alloc: alloc cache for special rrset key structures. * Not used if region!=NULL, it can be NULL in that case. * @param qinf: where to store query info. * qinf itself is allocated by the caller. * @param rep: reply info is allocated and returned. * @param region: if this parameter is NULL then malloc and the alloc is used. * otherwise, everything is allocated in this region. * In a region, no special rrset key structures are needed (not shared), * and no rrset_ref array in the reply is built up. * @return 0 if allocation failed. */ int parse_create_msg(struct sldns_buffer* pkt, struct msg_parse* msg, struct alloc_cache* alloc, struct query_info* qinf, struct reply_info** rep, struct regional* region); /** * Sorts the ref array. * @param rep: reply info. rrsets must be filled in. */ void reply_info_sortref(struct reply_info* rep); /** * Set TTLs inside the replyinfo to absolute values. * @param rep: reply info. rrsets must be filled in. * Also refs must be filled in. * @param timenow: the current time. */ void reply_info_set_ttls(struct reply_info* rep, time_t timenow); /** * Delete reply_info and packed_rrsets (while they are not yet added to the * hashtables.). Returns rrsets to the alloc cache. * @param rep: reply_info to delete. * @param alloc: where to return rrset structures to. */ void reply_info_parsedelete(struct reply_info* rep, struct alloc_cache* alloc); /** * Compare two queryinfo structures, on query and type, class. * It is _not_ sorted in canonical ordering. * @param m1: struct query_info* , void* here to ease use as function pointer. * @param m2: struct query_info* , void* here to ease use as function pointer. * @return: 0 = same, -1 m1 is smaller, +1 m1 is larger. */ int query_info_compare(void* m1, void* m2); /** clear out query info structure */ void query_info_clear(struct query_info* m); /** calculate size of struct query_info + reply_info */ size_t msgreply_sizefunc(void* k, void* d); /** delete msgreply_entry key structure */ void query_entry_delete(void *q, void* arg); /** delete reply_info data structure */ void reply_info_delete(void* d, void* arg); /** calculate hash value of query_info, lowercases the qname, * uses CD flag for AAAA qtype */ hashvalue_t query_info_hash(struct query_info *q, uint16_t flags); /** * Setup query info entry * @param q: query info to copy. Emptied as if clear is called. * @param r: reply to init data. * @param h: hash value. * @return: newly allocated message reply cache item. */ struct msgreply_entry* query_info_entrysetup(struct query_info* q, struct reply_info* r, hashvalue_t h); /** * Copy reply_info and all rrsets in it and allocate. * @param rep: what to copy, probably inside region, no ref[] array in it. * @param alloc: how to allocate rrset keys. * Not used if region!=NULL, it can be NULL in that case. * @param region: if this parameter is NULL then malloc and the alloc is used. * otherwise, everything is allocated in this region. * In a region, no special rrset key structures are needed (not shared), * and no rrset_ref array in the reply is built up. * @return new reply info or NULL on memory error. */ struct reply_info* reply_info_copy(struct reply_info* rep, struct alloc_cache* alloc, struct regional* region); /** * Copy a parsed rrset into given key, decompressing and allocating rdata. * @param pkt: packet for decompression * @param msg: the parser message (for flags for trust). * @param pset: the parsed rrset to copy. * @param region: if NULL - malloc, else data is allocated in this region. * @param pk: a freshly obtained rrsetkey structure. No dname is set yet, * will be set on return. * Note that TTL will still be relative on return. * @return false on alloc failure. */ int parse_copy_decompress_rrset(struct sldns_buffer* pkt, struct msg_parse* msg, struct rrset_parse *pset, struct regional* region, struct ub_packed_rrset_key* pk); /** * Find final cname target in reply, the one matching qinfo. Follows CNAMEs. * @param qinfo: what to start with. * @param rep: looks in answer section of this message. * @return: pointer dname, or NULL if not found. */ uint8_t* reply_find_final_cname_target(struct query_info* qinfo, struct reply_info* rep); /** * Check if cname chain in cached reply is still valid. * @param rep: reply to check. * @return: true if valid, false if invalid. */ int reply_check_cname_chain(struct reply_info* rep); /** * Check security status of all RRs in the message. * @param rep: reply to check * @return: true if all RRs are secure. False if not. * True if there are zero RRs. */ int reply_all_rrsets_secure(struct reply_info* rep); /** * Find answer rrset in reply, the one matching qinfo. Follows CNAMEs, so the * result may have a different owner name. * @param qinfo: what to look for. * @param rep: looks in answer section of this message. * @return: pointer to rrset, or NULL if not found. */ struct ub_packed_rrset_key* reply_find_answer_rrset(struct query_info* qinfo, struct reply_info* rep); /** * Find rrset in reply, inside the answer section. Does not follow CNAMEs. * @param rep: looks in answer section of this message. * @param name: what to look for. * @param namelen: length of name. * @param type: looks for (host order). * @param dclass: looks for (host order). * @return: pointer to rrset, or NULL if not found. */ struct ub_packed_rrset_key* reply_find_rrset_section_an(struct reply_info* rep, uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass); /** * Find rrset in reply, inside the authority section. Does not follow CNAMEs. * @param rep: looks in authority section of this message. * @param name: what to look for. * @param namelen: length of name. * @param type: looks for (host order). * @param dclass: looks for (host order). * @return: pointer to rrset, or NULL if not found. */ struct ub_packed_rrset_key* reply_find_rrset_section_ns(struct reply_info* rep, uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass); /** * Find rrset in reply, inside any section. Does not follow CNAMEs. * @param rep: looks in answer,authority and additional section of this message. * @param name: what to look for. * @param namelen: length of name. * @param type: looks for (host order). * @param dclass: looks for (host order). * @return: pointer to rrset, or NULL if not found. */ struct ub_packed_rrset_key* reply_find_rrset(struct reply_info* rep, uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass); /** * Debug send the query info and reply info to the log in readable form. * @param str: descriptive string printed with packet content. * @param qinfo: query section. * @param rep: rest of message. */ void log_dns_msg(const char* str, struct query_info* qinfo, struct reply_info* rep); /** * Print string with neat domain name, type, class from query info. * @param v: at what verbosity level to print this. * @param str: string of message. * @param qinf: query info structure with name, type and class. */ void log_query_info(enum verbosity_value v, const char* str, struct query_info* qinf); #endif /* UTIL_DATA_MSGREPLY_H */