Routines for message parsing a packet buffer to a descriptive structure. More...

#include "config.h"
#include "util/config_file.h"
#include "util/data/msgparse.h"
#include "util/data/msgreply.h"
#include "util/data/dname.h"
#include "util/data/packed_rrset.h"
#include "util/netevent.h"
#include "util/storage/lookup3.h"
#include "util/regional.h"
#include "util/rfc_1982.h"
#include "util/edns.h"
#include "util/net_help.h"
#include "sldns/rrdef.h"
#include "sldns/sbuffer.h"
#include "sldns/parseutil.h"
#include "sldns/wire2str.h"

Functions
static int	smart_compare (sldns_buffer pkt, uint8_t dnow, uint8_t dprfirst, uint8_t dprlast)
	smart comparison of (compressed, valid) dnames from packet

static struct rrset_parse *	new_rrset (struct msg_parse msg, uint8_t dname, size_t dnamelen, uint16_t type, uint16_t dclass, hashvalue_type hash, uint32_t rrset_flags, sldns_pkt_section section, struct regional *region)
	Allocate new rrset in region, fill with data.

static int	nsec_at_apex (sldns_buffer *pkt)
	See if next rrset is nsec at zone apex.

static uint32_t	pkt_rrset_flags (sldns_buffer *pkt, uint16_t type, sldns_pkt_section sec)
	Calculate rrset flags.

hashvalue_type	pkt_hash_rrset (sldns_buffer pkt, uint8_t dname, uint16_t type, uint16_t dclass, uint32_t rrset_flags)
	Calculate hash value for rrset in packet.

static hashvalue_type	pkt_hash_rrset_first (sldns_buffer pkt, uint8_t dname)
	create partial dname hash for rrset hash

static hashvalue_type	pkt_hash_rrset_rest (hashvalue_type dname_h, uint16_t type, uint16_t dclass, uint32_t rrset_flags)
	create a rrset hash from a partial dname hash

static int	rrset_parse_equals (struct rrset_parse p, sldns_buffer pkt, hashvalue_type h, uint32_t rrset_flags, uint8_t *dname, size_t dnamelen, uint16_t type, uint16_t dclass)
	compare rrset_parse with data

struct rrset_parse *	msgparse_hashtable_lookup (struct msg_parse msg, sldns_buffer pkt, hashvalue_type h, uint32_t rrset_flags, uint8_t *dname, size_t dnamelen, uint16_t type, uint16_t dclass)
	Lookup in msg hashtable to find a rrset.

static int	pkt_rrsig_covered (sldns_buffer pkt, uint8_t here, uint16_t *type)
	return type networkformat that rrsig in packet covers

static int	pkt_rrsig_covered_equals (sldns_buffer pkt, uint8_t here, uint16_t type)
	true if covered type equals prevtype

void	msgparse_bucket_remove (struct msg_parse msg, struct rrset_parse rrset)
	Remove rrset from hash table.

static void	change_section (struct msg_parse msg, struct rrset_parse rrset, sldns_pkt_section section)
	change section of rrset from previous to current section

static int	rrset_has_sigover (sldns_buffer pkt, struct rrset_parse rrset, uint16_t type, int *hasother)
	see if rrset of type RRSIG contains sig over given type

static int	moveover_rrsigs (sldns_buffer pkt, struct regional region, struct rrset_parse sigset, struct rrset_parse dataset, int duplicate)
	move rrsigs from sigset to dataset

static struct rrset_parse *	change_rrsig_rrset (struct rrset_parse sigset, struct msg_parse msg, sldns_buffer pkt, uint16_t datatype, uint32_t rrset_flags, int hasother, sldns_pkt_section section, struct regional region)
	change an rrsig rrset for use as data rrset

static int	find_rrset (struct msg_parse msg, sldns_buffer pkt, uint8_t dname, size_t dnamelen, uint16_t type, uint16_t dclass, hashvalue_type hash, uint32_t rrset_flags, uint8_t prev_dname_first, uint8_t prev_dname_last, size_t prev_dnamelen, uint16_t prev_type, uint16_t prev_dclass, struct rrset_parse *rrset_prev, sldns_pkt_section section, struct regional region)
	Find rrset.

static int	parse_query_section (sldns_buffer pkt, struct msg_parse msg)
	Parse query section.

size_t	get_rdf_size (sldns_rdf_type rdf)
	Obtain size in the packet of an rr type, that is before dname type.

static int	calc_size (sldns_buffer pkt, uint16_t type, struct rr_parse rr)
	calculate the size of one rr

static int	skip_ttl_rdata (sldns_buffer *pkt)
	skip rr ttl and rdata

static int	sig_is_double (sldns_buffer pkt, struct rrset_parse rrset, uint8_t *ttldata)
	see if RRSIG is a duplicate of another

static int	add_rr_to_rrset (struct rrset_parse rrset, sldns_buffer pkt, struct msg_parse msg, struct regional region, sldns_pkt_section section, uint16_t type)
	Add rr (from packet here) to rrset, skips rr.

static int	parse_section (sldns_buffer pkt, struct msg_parse msg, struct regional region, sldns_pkt_section section, uint16_t num_rrs, size_t num_rrsets)
	Parse packet RR section, for answer, authority and additional sections.

int	parse_packet (sldns_buffer pkt, struct msg_parse msg, struct regional *region)
	Parse the packet.

static int	parse_edns_options_from_query (uint8_t rdata_ptr, size_t rdata_len, struct edns_data edns, struct config_file cfg, struct comm_point c, struct comm_reply repinfo, uint32_t now, struct regional region, struct cookie_secrets *cookie_secrets)
	parse EDNS options from EDNS wireformat rdata

int	parse_extract_edns_from_response_msg (struct msg_parse msg, struct edns_data edns, struct regional *region)
	After parsing the packet, extract EDNS data from packet.

static int	skip_pkt_rr (sldns_buffer *pkt)
	skip RR in packet

int	skip_pkt_rrs (sldns_buffer *pkt, int num)
	skip RRs from packet

int	parse_edns_from_query_pkt (sldns_buffer pkt, struct edns_data edns, struct config_file cfg, struct comm_point c, struct comm_reply repinfo, time_t now, struct regional region, struct cookie_secrets *cookie_secrets)
	If EDNS data follows a query section, extract it and initialize edns struct.

void	log_edns_opt_list (enum verbosity_value level, const char info_str, struct edns_option list)
	Log the edns options in the edns option list.

int	msgparse_rrset_remove_rr (const char str, sldns_buffer pkt, struct rrset_parse rrset, struct rr_parse prev, struct rr_parse rr, struct sockaddr_storage addr, socklen_t addrlen)
	remove RR from msgparse RRset, return true if rrset is entirely bad

Detailed Description

Routines for message parsing a packet buffer to a descriptive structure.

Function Documentation

◆ pkt_hash_rrset()

hashvalue_type pkt_hash_rrset	(	struct sldns_buffer *	pkt,
		uint8_t *	dname,
		uint16_t	type,
		uint16_t	dclass,
		uint32_t	rrset_flags
	)

Calculate hash value for rrset in packet.

Parameters

pkt	the packet.
dname	pointer to uncompressed dname, or compressed dname in packet.
type	rrset type in host order.
dclass	rrset class in network order.
rrset_flags	rrset flags (same as packed_rrset flags).

Returns: hash value

References rrset_parse::dname, dname_pkt_hash(), and rrset_parse::type.

Referenced by change_rrsig_rrset(), mark_additional_rrset(), scrub_sanitize(), and synth_cname_rrset().

◆ msgparse_hashtable_lookup()

struct rrset_parse * msgparse_hashtable_lookup	(	struct msg_parse *	msg,
		struct sldns_buffer *	pkt,
		hashvalue_type	h,
		uint32_t	rrset_flags,
		uint8_t *	dname,
		size_t	dnamelen,
		uint16_t	type,
		uint16_t	dclass
	)

Lookup in msg hashtable to find a rrset.

Parameters

msg	with the hashtable.
pkt	packet for compressed names.
h	hash value
rrset_flags	flags of rrset sought for.
dname	name of rrset sought for.
dnamelen	len of dname.
type	rrset type, host order.
dclass	rrset class, network order.

Returns: NULL or the rrset_parse if found.

References rrset_parse::dname, msg_parse::hashtable, PARSE_TABLE_SIZE, rrset_parse::rrset_bucket_next, rrset_parse_equals(), and rrset_parse::type.

Referenced by find_rrset(), and mark_additional_rrset().

◆ msgparse_bucket_remove()

void msgparse_bucket_remove	(	struct msg_parse *	msg,
		struct rrset_parse *	rrset
	)

Remove rrset from hash table.

Parameters

msg	with hashtable.
rrset	with hash value and id info.

References rrset_parse::hash, msg_parse::hashtable, PARSE_TABLE_SIZE, and rrset_parse::rrset_bucket_next.

Referenced by change_rrsig_rrset(), and remove_rrset().

◆ find_rrset()

static int find_rrset	(	struct msg_parse *	msg,
		sldns_buffer *	pkt,
		uint8_t *	dname,
		size_t	dnamelen,
		uint16_t	type,
		uint16_t	dclass,
		hashvalue_type *	hash,
		uint32_t *	rrset_flags,
		uint8_t **	prev_dname_first,
		uint8_t **	prev_dname_last,
		size_t *	prev_dnamelen,
		uint16_t *	prev_type,
		uint16_t *	prev_dclass,
		struct rrset_parse **	rrset_prev,
		sldns_pkt_section	section,
		struct regional *	region
	)

static

Find rrset.

If equal to previous it is fast. hash if not so.

Parameters

msg	the message with hash table.
pkt	the packet in wireformat (needed for compression ptrs).
dname	pointer to start of dname (compressed) in packet.
dnamelen	uncompressed wirefmt length of dname.
type	type of current rr.
dclass	class of current rr.
hash	hash value is returned if the rrset could not be found.
rrset_flags	is returned if the rrset could not be found.
prev_dname_first	dname of last seen RR. First seen dname.
prev_dname_last	dname of last seen RR. Last seen dname.
prev_dnamelen	dname len of last seen RR.
prev_type	type of last seen RR.
prev_dclass	class of last seen RR.
rrset_prev	last seen RRset.
section	the current section in the packet.
region	used to allocate temporary parsing data.

Returns: 0 on out of memory.

References change_rrsig_rrset(), rrset_parse::dname, rrset_parse::hash, LDNS_RR_TYPE_RRSIG, LDNS_RR_TYPE_SOA, msgparse_hashtable_lookup(), PACKED_RRSET_NSEC_AT_APEX, PACKED_RRSET_SOA_NEG, pkt_hash_rrset_first(), pkt_hash_rrset_rest(), pkt_rrset_flags(), pkt_rrsig_covered(), pkt_rrsig_covered_equals(), rrset_has_sigover(), rrset_parse::section, sldns_buffer_current(), smart_compare(), and rrset_parse::type.

Referenced by parse_section().

◆ parse_query_section()

static int parse_query_section	(	sldns_buffer *	pkt,
		struct msg_parse *	msg
	)

static

Parse query section.

Parameters

pkt	packet, position at call must be at start of query section. at end position is after query section.
msg	store results here.

Returns: : 0 if OK, or rcode on error.

References log_assert, pkt_dname_len(), msg_parse::qclass, msg_parse::qdcount, msg_parse::qname, msg_parse::qname_len, msg_parse::qtype, sldns_buffer_current(), sldns_buffer_read_u16(), and sldns_buffer_remaining().

Referenced by parse_packet().

◆ get_rdf_size()

size_t get_rdf_size ( sldns_rdf_type rdf )

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.

Parameters

rdf	the rdf type from the descriptor.

Returns: : size in octets. 0 on failure.

References LDNS_RDF_TYPE_A, LDNS_RDF_TYPE_AAAA, LDNS_RDF_TYPE_ALG, LDNS_RDF_TYPE_CERT_ALG, LDNS_RDF_TYPE_CLASS, LDNS_RDF_TYPE_INT16, LDNS_RDF_TYPE_INT32, LDNS_RDF_TYPE_INT8, LDNS_RDF_TYPE_PERIOD, LDNS_RDF_TYPE_TIME, LDNS_RDF_TYPE_TSIGTIME, LDNS_RDF_TYPE_TYPE, and log_assert.

Referenced by analyze_rdata(), calc_size(), canonical_compare_byfield(), compress_rdata(), decompress_rr_into_buffer(), and rdata_copy().

◆ parse_section()

static int parse_section	(	sldns_buffer *	pkt,
		struct msg_parse *	msg,
		struct regional *	region,
		sldns_pkt_section	section,
		uint16_t	num_rrs,
		size_t *	num_rrsets
	)

static

Parse packet RR section, for answer, authority and additional sections.

Parameters

pkt	packet, position at call must be at start of section. at end position is after section.
msg	store results here.
region	how to alloc results.
section	section enum.
num_rrs	how many rrs are in the section.
num_rrsets	returns number of rrsets in the section.

Returns: : 0 if OK, or rcode on error.

References sldns_struct_rr_descriptor::_name, add_rr_to_rrset(), rrset_parse::dname, dname_print(), find_rrset(), rrset_parse::hash, LDNS_RR_TYPE_RRSIG, new_rrset(), pkt_dname_len(), pkt_rrsig_covered(), rrset_parse::section, sldns_buffer_current(), sldns_buffer_read(), sldns_buffer_read_u16(), sldns_buffer_remaining(), sldns_rr_classes, sldns_rr_descript(), and rrset_parse::type.

Referenced by parse_packet().

◆ parse_packet()

int parse_packet	(	struct sldns_buffer *	pkt,
		struct msg_parse *	msg,
		struct regional *	region
	)

Parse the packet.

Parameters

pkt	packet, position at call must be at start of packet. at end position is after packet.
msg	where to store results.
region	how to alloc results.

Returns: : 0 if OK, or rcode on error.

References msg_parse::an_rrsets, msg_parse::ancount, msg_parse::ar_rrsets, msg_parse::arcount, msg_parse::flags, msg_parse::id, msg_parse::ns_rrsets, msg_parse::nscount, parse_query_section(), parse_section(), msg_parse::qdcount, msg_parse::rrset_count, sldns_buffer_read(), sldns_buffer_read_u16(), and sldns_buffer_remaining().

Referenced by createResponse(), parse_reply_in_temp_region(), process_response(), and reply_info_parse().

◆ parse_extract_edns_from_response_msg()

int parse_extract_edns_from_response_msg	(	struct msg_parse *	msg,
		struct edns_data *	edns,
		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.

Parameters

msg	parsed message structure. Modified on exit, if EDNS was present it is removed from the additional section.
edns	the edns data is stored here. Does not have to be initialised.
region	region to alloc results in (edns option contents)

Returns: : 0 on success. or an RCODE on an error. RCODE formerr if OPT in wrong section, and so on.

References msg_parse::ar_rrsets, msg_parse::arcount, edns_data::bits, edns_data::cookie_present, edns_data::cookie_valid, rrset_parse::dname, rrset_parse::dname_len, edns_opt_list_append(), edns_data::edns_present, edns_data::edns_version, edns_data::ext_rcode, LDNS_RR_TYPE_OPT, log_assert, log_err(), edns_data::opt_list_in, edns_data::opt_list_inplace_cb_out, edns_data::opt_list_out, edns_data::padding_block_size, rrset_parse::rr_count, rrset_parse::rr_first, rrset_parse::rr_last, rrset_parse::rrset_all_next, rrset_parse::rrset_class, msg_parse::rrset_count, msg_parse::rrset_first, msg_parse::rrset_last, rrset_parse::section, rr_parse::size, rr_parse::ttl_data, rrset_parse::type, and edns_data::udp_size.

Referenced by createResponse(), process_response(), and reply_info_parse().

◆ skip_pkt_rrs()

int skip_pkt_rrs	(	sldns_buffer *	pkt,
		int	num
	)

skip RRs from packet

Skip RRs from packet.

References skip_pkt_rr().

Referenced by parse_edns_from_query_pkt().

◆ parse_edns_from_query_pkt()

int parse_edns_from_query_pkt	(	struct sldns_buffer *	pkt,
		struct edns_data *	edns,
		struct config_file *	cfg,
		struct comm_point *	c,
		struct comm_reply *	repinfo,
		time_t	now,
		struct regional *	region,
		struct cookie_secrets *	cookie_secrets
	)

If EDNS data follows a query section, extract it and initialize edns struct.

Parameters

pkt	the packet. position at start must be right after the query section. At end, right after EDNS data or partial movement if failed.
edns	the edns data allocated by the caller. Does not have to be initialised.
cfg	the configuration (with nsid value etc.)
c	commpoint to determine transport (if needed)
repinfo	commreply to determine the client address
now	current time
region	region to alloc results in (edns option contents)
cookie_secrets	the cookie secrets for EDNS COOKIE validation.

Returns: : 0 on success, or an RCODE on error. RCODE formerr if OPT is badly formatted and so on.

References edns_data::bits, edns_data::cookie_present, edns_data::cookie_valid, edns_data::edns_present, edns_data::edns_version, edns_data::ext_rcode, LDNS_RR_TYPE_OPT, log_assert, edns_data::opt_list_in, edns_data::opt_list_inplace_cb_out, edns_data::opt_list_out, edns_data::padding_block_size, parse_edns_options_from_query(), pkt_dname_len(), skip_pkt_rrs(), sldns_buffer_begin(), sldns_buffer_current(), sldns_buffer_read_u16(), sldns_buffer_read_u8(), sldns_buffer_remaining(), and edns_data::udp_size.

Referenced by worker_handle_request().

◆ log_edns_opt_list()

void log_edns_opt_list	(	enum verbosity_value	level,
		const char *	info_str,
		struct edns_option *	list
	)

Log the edns options in the edns option list.

Parameters

level	the verbosity level.
info_str	the informational string to be printed before the options.
list	the edns option list.

References edns_option::next, edns_option::opt_code, edns_option::opt_data, edns_option::opt_len, sldns_wire2str_edns_option_print(), verbose(), and verbosity.

◆ msgparse_rrset_remove_rr()

int msgparse_rrset_remove_rr	(	const char *	str,
		sldns_buffer *	pkt,
		struct rrset_parse *	rrset,
		struct rr_parse *	prev,
		struct rr_parse *	rr,
		struct sockaddr_storage *	addr,
		socklen_t	addrlen
	)

remove RR from msgparse RRset, return true if rrset is entirely bad

Remove RR from msgparse RRset.

References rrset_parse::dname, rrset_parse::dname_len, dname_pkt_copy(), LDNS_MAX_DOMAINLEN, log_name_addr(), log_nametypeclass(), rr_parse::next, rrset_parse::rr_count, rrset_parse::rr_first, rrset_parse::rr_last, rrset_parse::rrset_class, rrset_parse::size, rr_parse::size, rrset_parse::type, VERB_QUERY, and verbosity.

Referenced by priv_rrset_bad(), and scrub_sanitize_rr_length().

Functions

Detailed Description

Function Documentation

◆ pkt_hash_rrset()

◆ msgparse_hashtable_lookup()

◆ msgparse_bucket_remove()

◆ find_rrset()

◆ parse_query_section()

◆ get_rdf_size()

◆ parse_section()

◆ parse_packet()

◆ parse_extract_edns_from_response_msg()

◆ skip_pkt_rrs()

◆ parse_edns_from_query_pkt()

◆ log_edns_opt_list()

◆ msgparse_rrset_remove_rr()