mirror of
https://git.wownero.com/wownero/wownero.git
synced 2024-08-15 01:03:23 +00:00
302 lines
10 KiB
C
302 lines
10 KiB
C
/*
|
|
* util/data/msgparse.h - parse wireformat DNS messages.
|
|
*
|
|
* 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
|
|
* Contains message parsing data structures.
|
|
* These point back into the packet buffer.
|
|
*
|
|
* During parsing RRSIGS are put together with the rrsets they (claim to) sign.
|
|
* This process works as follows:
|
|
* o if RRSIG follows the data rrset, it is added to the rrset rrsig list.
|
|
* o if no matching data rrset is found, the RRSIG becomes a new rrset.
|
|
* o If the data rrset later follows the RRSIG
|
|
* o See if the RRSIG rrset contains multiple types, and needs to
|
|
* have the rrsig(s) for that data type split off.
|
|
* o Put the data rr as data type in the rrset and rrsig in list.
|
|
* o RRSIGs are allowed to move to a different section. The section of
|
|
* the data item is used for the final rrset.
|
|
* o multiple signatures over an RRset are possible.
|
|
*
|
|
* For queries of qtype=RRSIG, some special handling is needed, to avoid
|
|
* splitting the RRSIG in the answer section.
|
|
* o duplicate, not split, RRSIGs from the answer section, if qtype=RRSIG.
|
|
* o check for doubles in the rrsig list when adding an RRSIG to data,
|
|
* so that a data rrset is signed by RRSIGs with different rdata.
|
|
* when qtype=RRSIG.
|
|
* This will move the RRSIG from the answer section to sign the data further
|
|
* in the packet (if possible). If then after that, more RRSIGs are found
|
|
* that sign the data as well, doubles are removed.
|
|
*/
|
|
|
|
#ifndef UTIL_DATA_MSGPARSE_H
|
|
#define UTIL_DATA_MSGPARSE_H
|
|
#include "util/storage/lruhash.h"
|
|
#include "ldns/pkthdr.h"
|
|
#include "ldns/rrdef.h"
|
|
struct sldns_buffer;
|
|
struct rrset_parse;
|
|
struct rr_parse;
|
|
struct regional;
|
|
|
|
/** number of buckets in parse rrset hash table. Must be power of 2. */
|
|
#define PARSE_TABLE_SIZE 32
|
|
/** Maximum TTL that is allowed. */
|
|
extern time_t MAX_TTL;
|
|
/** Minimum TTL that is allowed. */
|
|
extern time_t MIN_TTL;
|
|
/** Negative cache time (for entries without any RRs.) */
|
|
#define NORR_TTL 5 /* seconds */
|
|
|
|
/**
|
|
* Data stored in scratch pad memory during parsing.
|
|
* Stores the data that will enter into the msgreply and packet result.
|
|
*/
|
|
struct msg_parse {
|
|
/** id from message, network format. */
|
|
uint16_t id;
|
|
/** flags from message, host format. */
|
|
uint16_t flags;
|
|
/** count of RRs, host format */
|
|
uint16_t qdcount;
|
|
/** count of RRs, host format */
|
|
uint16_t ancount;
|
|
/** count of RRs, host format */
|
|
uint16_t nscount;
|
|
/** count of RRs, host format */
|
|
uint16_t arcount;
|
|
/** count of RRsets per section. */
|
|
size_t an_rrsets;
|
|
/** count of RRsets per section. */
|
|
size_t ns_rrsets;
|
|
/** count of RRsets per section. */
|
|
size_t ar_rrsets;
|
|
/** total number of rrsets found. */
|
|
size_t rrset_count;
|
|
|
|
/** query dname (pointer to start location in packet, NULL if none */
|
|
uint8_t* qname;
|
|
/** length of query dname in octets, 0 if none */
|
|
size_t qname_len;
|
|
/** query type, host order. 0 if qdcount=0 */
|
|
uint16_t qtype;
|
|
/** query class, host order. 0 if qdcount=0 */
|
|
uint16_t qclass;
|
|
|
|
/**
|
|
* Hash table array used during parsing to lookup rrset types.
|
|
* Based on name, type, class. Same hash value as in rrset cache.
|
|
*/
|
|
struct rrset_parse* hashtable[PARSE_TABLE_SIZE];
|
|
|
|
/** linked list of rrsets that have been found (in order). */
|
|
struct rrset_parse* rrset_first;
|
|
/** last element of rrset list. */
|
|
struct rrset_parse* rrset_last;
|
|
};
|
|
|
|
/**
|
|
* Data stored for an rrset during parsing.
|
|
*/
|
|
struct rrset_parse {
|
|
/** next in hash bucket */
|
|
struct rrset_parse* rrset_bucket_next;
|
|
/** next in list of all rrsets */
|
|
struct rrset_parse* rrset_all_next;
|
|
/** hash value of rrset */
|
|
hashvalue_t hash;
|
|
/** which section was it found in: one of
|
|
* LDNS_SECTION_ANSWER, LDNS_SECTION_AUTHORITY, LDNS_SECTION_ADDITIONAL
|
|
*/
|
|
sldns_pkt_section section;
|
|
/** start of (possibly compressed) dname in packet */
|
|
uint8_t* dname;
|
|
/** length of the dname uncompressed wireformat */
|
|
size_t dname_len;
|
|
/** type, host order. */
|
|
uint16_t type;
|
|
/** class, network order. var name so that it is not a c++ keyword. */
|
|
uint16_t rrset_class;
|
|
/** the flags for the rrset, like for packedrrset */
|
|
uint32_t flags;
|
|
/** number of RRs in the rr list */
|
|
size_t rr_count;
|
|
/** sum of RR rdata sizes */
|
|
size_t size;
|
|
/** linked list of RRs in this rrset. */
|
|
struct rr_parse* rr_first;
|
|
/** last in list of RRs in this rrset. */
|
|
struct rr_parse* rr_last;
|
|
/** number of RRSIGs over this rrset. */
|
|
size_t rrsig_count;
|
|
/** linked list of RRsig RRs over this rrset. */
|
|
struct rr_parse* rrsig_first;
|
|
/** last in list of RRSIG RRs over this rrset. */
|
|
struct rr_parse* rrsig_last;
|
|
};
|
|
|
|
/**
|
|
* Data stored for an RR during parsing.
|
|
*/
|
|
struct rr_parse {
|
|
/**
|
|
* Pointer to the RR. Points to start of TTL value in the packet.
|
|
* Rdata length and rdata follow it.
|
|
* its dname, type and class are the same and stored for the rrset.
|
|
*/
|
|
uint8_t* ttl_data;
|
|
/** true if ttl_data is not part of the packet, but elsewhere in mem.
|
|
* Set for generated CNAMEs for DNAMEs. */
|
|
int outside_packet;
|
|
/** the length of the rdata if allocated (with no dname compression)*/
|
|
size_t size;
|
|
/** next in list of RRs. */
|
|
struct rr_parse* next;
|
|
};
|
|
|
|
/** Check if label length is first octet of a compression pointer, pass u8. */
|
|
#define LABEL_IS_PTR(x) ( ((x)&0xc0) == 0xc0 )
|
|
/** Calculate destination offset of a compression pointer. pass first and
|
|
* second octets of the compression pointer. */
|
|
#define PTR_OFFSET(x, y) ( ((x)&0x3f)<<8 | (y) )
|
|
/** create a compression pointer to the given offset. */
|
|
#define PTR_CREATE(offset) ((uint16_t)(0xc000 | (offset)))
|
|
|
|
/** error codes, extended with EDNS, so > 15. */
|
|
#define EDNS_RCODE_BADVERS 16 /** bad EDNS version */
|
|
/** largest valid compression offset */
|
|
#define PTR_MAX_OFFSET 0x3fff
|
|
|
|
/**
|
|
* EDNS data storage
|
|
* EDNS rdata is ignored.
|
|
*/
|
|
struct edns_data {
|
|
/** if EDNS OPT record was present */
|
|
int edns_present;
|
|
/** Extended RCODE */
|
|
uint8_t ext_rcode;
|
|
/** The EDNS version number */
|
|
uint8_t edns_version;
|
|
/** the EDNS bits field from ttl (host order): Z */
|
|
uint16_t bits;
|
|
/** UDP reassembly size. */
|
|
uint16_t udp_size;
|
|
};
|
|
|
|
/**
|
|
* Obtain size in the packet of an rr type, that is before dname type.
|
|
* Do TYPE_DNAME, and type STR, yourself. Gives size for most regular types.
|
|
* @param rdf: the rdf type from the descriptor.
|
|
* @return: size in octets. 0 on failure.
|
|
*/
|
|
size_t get_rdf_size(sldns_rdf_type rdf);
|
|
|
|
/**
|
|
* Parse the packet.
|
|
* @param pkt: packet, position at call must be at start of packet.
|
|
* at end position is after packet.
|
|
* @param msg: where to store results.
|
|
* @param region: how to alloc results.
|
|
* @return: 0 if OK, or rcode on error.
|
|
*/
|
|
int parse_packet(struct sldns_buffer* pkt, struct msg_parse* msg,
|
|
struct regional* region);
|
|
|
|
/**
|
|
* After parsing the packet, extract EDNS data from packet.
|
|
* If not present this is noted in the data structure.
|
|
* If a parse error happens, an error code is returned.
|
|
*
|
|
* Quirks:
|
|
* o ignores OPT rdata.
|
|
* o ignores OPT owner name.
|
|
* o ignores extra OPT records, except the last one in the packet.
|
|
*
|
|
* @param msg: parsed message structure. Modified on exit, if EDNS was present
|
|
* it is removed from the additional section.
|
|
* @param edns: the edns data is stored here. Does not have to be initialised.
|
|
* @return: 0 on success. or an RCODE on an error.
|
|
* RCODE formerr if OPT in wrong section, and so on.
|
|
*/
|
|
int parse_extract_edns(struct msg_parse* msg, struct edns_data* edns);
|
|
|
|
/**
|
|
* If EDNS data follows a query section, extract it and initialize edns struct.
|
|
* @param pkt: the packet. position at start must be right after the query
|
|
* section. At end, right after EDNS data or no movement if failed.
|
|
* @param edns: the edns data allocated by the caller. Does not have to be
|
|
* initialised.
|
|
* @return: 0 on success, or an RCODE on error.
|
|
* RCODE formerr if OPT is badly formatted and so on.
|
|
*/
|
|
int parse_edns_from_pkt(struct sldns_buffer* pkt, struct edns_data* edns);
|
|
|
|
/**
|
|
* Calculate hash value for rrset in packet.
|
|
* @param pkt: the packet.
|
|
* @param dname: pointer to uncompressed dname, or compressed dname in packet.
|
|
* @param type: rrset type in host order.
|
|
* @param dclass: rrset class in network order.
|
|
* @param rrset_flags: rrset flags (same as packed_rrset flags).
|
|
* @return hash value
|
|
*/
|
|
hashvalue_t pkt_hash_rrset(struct sldns_buffer* pkt, uint8_t* dname, uint16_t type,
|
|
uint16_t dclass, uint32_t rrset_flags);
|
|
|
|
/**
|
|
* Lookup in msg hashtable to find a rrset.
|
|
* @param msg: with the hashtable.
|
|
* @param pkt: packet for compressed names.
|
|
* @param h: hash value
|
|
* @param rrset_flags: flags of rrset sought for.
|
|
* @param dname: name of rrset sought for.
|
|
* @param dnamelen: len of dname.
|
|
* @param type: rrset type, host order.
|
|
* @param dclass: rrset class, network order.
|
|
* @return NULL or the rrset_parse if found.
|
|
*/
|
|
struct rrset_parse* msgparse_hashtable_lookup(struct msg_parse* msg,
|
|
struct sldns_buffer* pkt, hashvalue_t h, uint32_t rrset_flags,
|
|
uint8_t* dname, size_t dnamelen, uint16_t type, uint16_t dclass);
|
|
|
|
/**
|
|
* Remove rrset from hash table.
|
|
* @param msg: with hashtable.
|
|
* @param rrset: with hash value and id info.
|
|
*/
|
|
void msgparse_bucket_remove(struct msg_parse* msg, struct rrset_parse* rrset);
|
|
|
|
#endif /* UTIL_DATA_MSGPARSE_H */
|