monero/external/unbound/util/data/msgreply.h

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2014-10-05 21:44:31 +00:00
/*
* 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 */
hashvalue_t query_info_hash(struct query_info *q);
/**
* 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 */