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/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, you can obtain one at https://mozilla.org/MPL/2.0/.
*
* See the COPYRIGHT file distributed with this work for additional
* information regarding copyright ownership.
*/
#ifndef DNS_MESSAGE_H
#define DNS_MESSAGE_H 1
/***
*** Imports
***/
#include <inttypes.h>
#include <stdbool.h>
#include <isc/lang.h>
#include <isc/magic.h>
#include <isc/refcount.h>
#include <dns/compress.h>
#include <dns/masterdump.h>
#include <dns/types.h>
#include <dst/dst.h>
/*! \file dns/message.h
* \brief Message Handling Module
*
* How this beast works:
*
* When a dns message is received in a buffer, dns_message_parse() is called
* on the memory region. Various items are checked including the format
* of the message (if counts are right, if counts consume the entire sections,
* and if sections consume the entire message) and known pseudo-RRs in the
* additional data section are analyzed and removed.
*
* TSIG checking is also done at this layer, and any DNSSEC transaction
* signatures should also be checked here.
*
* Notes on using the gettemp*() and puttemp*() functions:
*
* These functions return items (names, rdatasets, etc) allocated from some
* internal state of the dns_message_t.
*
* Names and rdatasets must be put back into the dns_message_t in
* one of two ways. Assume a name was allocated via
* dns_message_gettempname():
*
*\li (1) insert it into a section, using dns_message_addname().
*
*\li (2) return it to the message using dns_message_puttempname().
*
* The same applies to rdatasets.
*
* On the other hand, offsets, rdatalists and rdatas allocated using
* dns_message_gettemp*() will always be freed automatically
* when the message is reset or destroyed; calling dns_message_puttemp*()
* on rdatalists and rdatas is optional and serves only to enable the item
* to be reused multiple times during the lifetime of the message; offsets
* cannot be reused.
*
* Buffers allocated using isc_buffer_allocate() can be automatically freed
* as well by giving the buffer to the message using dns_message_takebuffer().
* Doing this will cause the buffer to be freed using isc_buffer_free()
* when the section lists are cleared, such as in a reset or in a destroy.
* Since the buffer itself exists until the message is destroyed, this sort
* of code can be written:
*
* \code
* buffer = isc_buffer_allocate(mctx, 512);
* name = NULL;
* name = dns_message_gettempname(message, &name);
* dns_name_init(name, NULL);
* result = dns_name_fromtext(name, &source, dns_rootname, 0, buffer);
* dns_message_takebuffer(message, &buffer);
* \endcode
*
*
* TODO:
*
* XXX Needed: ways to set and retrieve EDNS information, add rdata to a
* section, move rdata from one section to another, remove rdata, etc.
*/
#define DNS_MESSAGEFLAG_QR 0x8000U
#define DNS_MESSAGEFLAG_AA 0x0400U
#define DNS_MESSAGEFLAG_TC 0x0200U
#define DNS_MESSAGEFLAG_RD 0x0100U
#define DNS_MESSAGEFLAG_RA 0x0080U
#define DNS_MESSAGEFLAG_AD 0x0020U
#define DNS_MESSAGEFLAG_CD 0x0010U
/*%< EDNS0 extended message flags */
#define DNS_MESSAGEEXTFLAG_DO 0x8000U
/*%< EDNS0 extended OPT codes */
#define DNS_OPT_LLQ 1 /*%< LLQ opt code */
#define DNS_OPT_NSID 3 /*%< NSID opt code */
#define DNS_OPT_CLIENT_SUBNET 8 /*%< client subnet opt code */
#define DNS_OPT_EXPIRE 9 /*%< EXPIRE opt code */
#define DNS_OPT_COOKIE 10 /*%< COOKIE opt code */
#define DNS_OPT_TCP_KEEPALIVE 11 /*%< TCP keepalive opt code */
#define DNS_OPT_PAD 12 /*%< PAD opt code */
#define DNS_OPT_KEY_TAG 14 /*%< Key tag opt code */
#define DNS_OPT_EDE 15 /*%< Extended DNS Error opt code */
#define DNS_OPT_CLIENT_TAG 16 /*%< Client tag opt code */
#define DNS_OPT_SERVER_TAG 17 /*%< Server tag opt code */
/*%< Experimental options [65001...65534] as per RFC6891 */
/*%< The number of EDNS options we know about. */
#define DNS_EDNSOPTIONS 5
#define DNS_MESSAGE_REPLYPRESERVE (DNS_MESSAGEFLAG_RD|DNS_MESSAGEFLAG_CD)
#define DNS_MESSAGEEXTFLAG_REPLYPRESERVE (DNS_MESSAGEEXTFLAG_DO)
#define DNS_MESSAGE_HEADERLEN 12 /*%< 6 uint16_t's */
#define DNS_MESSAGE_MAGIC ISC_MAGIC('M','S','G','@')
#define DNS_MESSAGE_VALID(msg) ISC_MAGIC_VALID(msg, DNS_MESSAGE_MAGIC)
/*
* Ordering here matters. DNS_SECTION_ANY must be the lowest and negative,
* and DNS_SECTION_MAX must be one greater than the last used section.
*/
typedef int dns_section_t;
#define DNS_SECTION_ANY (-1)
#define DNS_SECTION_QUESTION 0
#define DNS_SECTION_ANSWER 1
#define DNS_SECTION_AUTHORITY 2
#define DNS_SECTION_ADDITIONAL 3
#define DNS_SECTION_MAX 4
typedef int dns_pseudosection_t;
#define DNS_PSEUDOSECTION_ANY (-1)
#define DNS_PSEUDOSECTION_OPT 0
#define DNS_PSEUDOSECTION_TSIG 1
#define DNS_PSEUDOSECTION_SIG0 2
#define DNS_PSEUDOSECTION_MAX 3
typedef int dns_messagetextflag_t;
#define DNS_MESSAGETEXTFLAG_NOCOMMENTS 0x0001
#define DNS_MESSAGETEXTFLAG_NOHEADERS 0x0002
#define DNS_MESSAGETEXTFLAG_ONESOA 0x0004
#define DNS_MESSAGETEXTFLAG_OMITSOA 0x0008
/*
* Dynamic update names for these sections.
*/
#define DNS_SECTION_ZONE DNS_SECTION_QUESTION
#define DNS_SECTION_PREREQUISITE DNS_SECTION_ANSWER
#define DNS_SECTION_UPDATE DNS_SECTION_AUTHORITY
/*
* These tell the message library how the created dns_message_t will be used.
*/
#define DNS_MESSAGE_INTENTUNKNOWN 0 /*%< internal use only */
#define DNS_MESSAGE_INTENTPARSE 1 /*%< parsing messages */
#define DNS_MESSAGE_INTENTRENDER 2 /*%< rendering */
/*
* Control behavior of parsing
*/
#define DNS_MESSAGEPARSE_PRESERVEORDER 0x0001 /*%< preserve rdata order */
#define DNS_MESSAGEPARSE_BESTEFFORT 0x0002 /*%< return a message if a
recoverable parse error
occurs */
#define DNS_MESSAGEPARSE_CLONEBUFFER 0x0004 /*%< save a copy of the
source buffer */
#define DNS_MESSAGEPARSE_IGNORETRUNCATION 0x0008 /*%< truncation errors are
* not fatal. */
/*
* Control behavior of rendering
*/
#define DNS_MESSAGERENDER_ORDERED 0x0001 /*%< don't change order */
#define DNS_MESSAGERENDER_PARTIAL 0x0002 /*%< allow a partial rdataset */
#define DNS_MESSAGERENDER_OMITDNSSEC 0x0004 /*%< omit DNSSEC records */
#define DNS_MESSAGERENDER_PREFER_A 0x0008 /*%< prefer A records in
additional section. */
#define DNS_MESSAGERENDER_PREFER_AAAA 0x0010 /*%< prefer AAAA records in
additional section. */
#ifdef ALLOW_FILTER_AAAA
#define DNS_MESSAGERENDER_FILTER_AAAA 0x0020 /*%< filter AAAA records */
#endif
typedef struct dns_msgblock dns_msgblock_t;
struct dns_message {
/* public from here down */
unsigned int magic;
isc_refcount_t refcount;
dns_messageid_t id;
unsigned int flags;
dns_rcode_t rcode;
dns_opcode_t opcode;
dns_rdataclass_t rdclass;
/* 4 real, 1 pseudo */
unsigned int counts[DNS_SECTION_MAX];
/* private from here down */
dns_namelist_t sections[DNS_SECTION_MAX];
dns_name_t *cursors[DNS_SECTION_MAX];
dns_rdataset_t *opt;
dns_rdataset_t *sig0;
dns_rdataset_t *tsig;
int state;
unsigned int from_to_wire : 2;
unsigned int header_ok : 1;
unsigned int question_ok : 1;
unsigned int tcp_continuation : 1;
unsigned int verified_sig : 1;
unsigned int verify_attempted : 1;
unsigned int free_query : 1;
unsigned int free_saved : 1;
unsigned int cc_ok : 1;
unsigned int cc_bad : 1;
unsigned int tkey : 1;
unsigned int rdclass_set : 1;
unsigned int opt_reserved;
unsigned int sig_reserved;
unsigned int reserved; /* reserved space (render) */
isc_buffer_t *buffer;
dns_compress_t *cctx;
isc_mem_t *mctx;
isc_mempool_t *namepool;
isc_mempool_t *rdspool;
isc_bufferlist_t scratchpad;
isc_bufferlist_t cleanup;
ISC_LIST(dns_msgblock_t) rdatas;
ISC_LIST(dns_msgblock_t) rdatalists;
ISC_LIST(dns_msgblock_t) offsets;
ISC_LIST(dns_rdata_t) freerdata;
ISC_LIST(dns_rdatalist_t) freerdatalist;
dns_rcode_t tsigstatus;
dns_rcode_t querytsigstatus;
dns_name_t *tsigname; /* Owner name of TSIG, if any */
dns_rdataset_t *querytsig;
dns_tsigkey_t *tsigkey;
dst_context_t *tsigctx;
int sigstart;
int timeadjust;
dns_name_t *sig0name; /* Owner name of SIG0, if any */
dst_key_t *sig0key;
dns_rcode_t sig0status;
isc_region_t query;
isc_region_t saved;
dns_rdatasetorderfunc_t order;
const void * order_arg;
dns_indent_t indent;
};
struct dns_ednsopt {
uint16_t code;
uint16_t length;
unsigned char *value;
};
/***
*** Functions
***/
ISC_LANG_BEGINDECLS
isc_result_t
dns_message_create(isc_mem_t *mctx, unsigned int intent, dns_message_t **msgp);
/*%<
* Create msg structure.
*
* This function will allocate some internal blocks of memory that are
* expected to be needed for parsing or rendering nearly any type of message.
*
* Requires:
*\li 'mctx' be a valid memory context.
*
*\li 'msgp' be non-null and '*msg' be NULL.
*
*\li 'intent' must be one of DNS_MESSAGE_INTENTPARSE or
* #DNS_MESSAGE_INTENTRENDER.
*
* Ensures:
*\li The data in "*msg" is set to indicate an unused and empty msg
* structure.
*
* Returns:
*\li #ISC_R_NOMEMORY -- out of memory
*\li #ISC_R_SUCCESS -- success
*/
void
dns_message_reset(dns_message_t *msg, unsigned int intent);
/*%<
* Reset a message structure to default state. All internal lists are freed
* or reset to a default state as well. This is simply a more efficient
* way to call dns_message_detach() (assuming last reference is hold),
* followed by dns_message_create(), since it avoid many memory allocations.
*
* If any data loanouts (buffers, names, rdatas, etc) were requested,
* the caller must no longer use them after this call.
*
* The intended next use of the message will be 'intent'.
*
* Requires:
*
*\li 'msg' be valid.
*
*\li 'intent' is DNS_MESSAGE_INTENTPARSE or DNS_MESSAGE_INTENTRENDER
*/
void
dns_message_attach(dns_message_t *source, dns_message_t **target);
/*%<
* Attach to message 'source'.
*
* Requires:
*\li 'source' to be a valid message.
*\li 'target' to be non NULL and '*target' to be NULL.
*/
void
dns_message_detach(dns_message_t **messagep);
/*%<
* Detach *messagep from its message.
* list.
*
* Requires:
*\li '*messagep' to be a valid message.
*/
isc_result_t
dns_message_sectiontotext(dns_message_t *msg, dns_section_t section,
const dns_master_style_t *style,
dns_messagetextflag_t flags,
isc_buffer_t *target);
isc_result_t
dns_message_pseudosectiontotext(dns_message_t *msg,
dns_pseudosection_t section,
const dns_master_style_t *style,
dns_messagetextflag_t flags,
isc_buffer_t *target);
/*%<
* Convert section 'section' or 'pseudosection' of message 'msg' to
* a cleartext representation
*
* Notes:
* \li See dns_message_totext for meanings of flags.
*
* Requires:
*
*\li 'msg' is a valid message.
*
*\li 'style' is a valid master dump style.
*
*\li 'target' is a valid buffer.
*
*\li 'section' is a valid section label.
*
* Ensures:
*
*\li If the result is success:
* The used space in 'target' is updated.
*
* Returns:
*
*\li #ISC_R_SUCCESS
*\li #ISC_R_NOSPACE
*\li #ISC_R_NOMORE
*
*\li Note: On error return, *target may be partially filled with data.
*/
isc_result_t
dns_message_totext(dns_message_t *msg, const dns_master_style_t *style,
dns_messagetextflag_t flags, isc_buffer_t *target);
/*%<
* Convert all sections of message 'msg' to a cleartext representation
*
* Notes on flags:
*\li If #DNS_MESSAGETEXTFLAG_NOCOMMENTS is cleared, lines beginning with
* ";;" will be emitted indicating section name.
*\li If #DNS_MESSAGETEXTFLAG_NOHEADERS is cleared, header lines will be
* emitted.
*\li If #DNS_MESSAGETEXTFLAG_ONESOA is set then only print the first
* SOA record in the answer section.
*\li If *#DNS_MESSAGETEXTFLAG_OMITSOA is set don't print any SOA records
* in the answer section.
*
* The SOA flags are useful for suppressing the display of the second
* SOA record in an AXFR by setting #DNS_MESSAGETEXTFLAG_ONESOA on the
* first message in an AXFR stream and #DNS_MESSAGETEXTFLAG_OMITSOA on
* subsequent messages.
*
* Requires:
*
*\li 'msg' is a valid message.
*
*\li 'style' is a valid master dump style.
*
*\li 'target' is a valid buffer.
*
* Ensures:
*
*\li If the result is success:
* The used space in 'target' is updated.
*
* Returns:
*
*\li #ISC_R_SUCCESS
*\li #ISC_R_NOSPACE
*\li #ISC_R_NOMORE
*
*\li Note: On error return, *target may be partially filled with data.
*/
isc_result_t
dns_message_parse(dns_message_t *msg, isc_buffer_t *source,
unsigned int options);
/*%<
* Parse raw wire data in 'source' as a DNS message.
*
* OPT records are detected and stored in the pseudo-section "opt".
* TSIGs are detected and stored in the pseudo-section "tsig".
*
* If #DNS_MESSAGEPARSE_PRESERVEORDER is set, or if the opcode of the message
* is UPDATE, a separate dns_name_t object will be created for each RR in the
* message. Each such dns_name_t will have a single rdataset containing the
* single RR, and the order of the RRs in the message is preserved.
* Otherwise, only one dns_name_t object will be created for each unique
* owner name in the section, and each such dns_name_t will have a list
* of rdatasets. To access the names and their data, use
* dns_message_firstname() and dns_message_nextname().
*
* If #DNS_MESSAGEPARSE_BESTEFFORT is set, errors in message content will
* not be considered FORMERRs. If the entire message can be parsed, it
* will be returned and DNS_R_RECOVERABLE will be returned.
*
* If #DNS_MESSAGEPARSE_IGNORETRUNCATION is set then return as many complete
* RR's as possible, DNS_R_RECOVERABLE will be returned.
*
* OPT and TSIG records are always handled specially, regardless of the
* 'preserve_order' setting.
*
* Requires:
*\li "msg" be valid.
*
*\li "buffer" be a wire format buffer.
*
* Ensures:
*\li The buffer's data format is correct.
*
*\li The buffer's contents verify as correct regarding header bits, buffer
* and rdata sizes, etc.
*
* Returns:
*\li #ISC_R_SUCCESS -- all is well
*\li #ISC_R_NOMEMORY -- no memory
*\li #DNS_R_RECOVERABLE -- the message parsed properly, but contained
* errors.
*\li Many other errors possible XXXMLG
*/
isc_result_t
dns_message_renderbegin(dns_message_t *msg, dns_compress_t *cctx,
isc_buffer_t *buffer);
/*%<
* Begin rendering on a message. Only one call can be made to this function
* per message.
*
* The compression context is "owned" by the message library until
* dns_message_renderend() is called. It must be invalidated by the caller.
*
* The buffer is "owned" by the message library until dns_message_renderend()
* is called.
*
* Requires:
*
*\li 'msg' be valid.
*
*\li 'cctx' be valid.
*
*\li 'buffer' is a valid buffer.
*
* Side Effects:
*
*\li The buffer is cleared before it is used.
*
* Returns:
*\li #ISC_R_SUCCESS -- all is well
*\li #ISC_R_NOSPACE -- output buffer is too small
*/
isc_result_t
dns_message_renderchangebuffer(dns_message_t *msg, isc_buffer_t *buffer);
/*%<
* Reset the buffer. This can be used after growing the old buffer
* on a ISC_R_NOSPACE return from most of the render functions.
*
* On successful completion, the old buffer is no longer used by the
* library. The new buffer is owned by the library until
* dns_message_renderend() is called.
*
* Requires:
*
*\li 'msg' be valid.
*
*\li dns_message_renderbegin() was called.
*
*\li buffer != NULL.
*
* Returns:
*\li #ISC_R_NOSPACE -- new buffer is too small
*\li #ISC_R_SUCCESS -- all is well.
*/
isc_result_t
dns_message_renderreserve(dns_message_t *msg, unsigned int space);
/*%<
* XXXMLG should use size_t rather than unsigned int once the buffer
* API is cleaned up
*
* Reserve "space" bytes in the given buffer.
*
* Requires:
*
*\li 'msg' be valid.
*
*\li dns_message_renderbegin() was called.
*
* Returns:
*\li #ISC_R_SUCCESS -- all is well.
*\li #ISC_R_NOSPACE -- not enough free space in the buffer.
*/
void
dns_message_renderrelease(dns_message_t *msg, unsigned int space);
/*%<
* XXXMLG should use size_t rather than unsigned int once the buffer
* API is cleaned up
*
* Release "space" bytes in the given buffer that was previously reserved.
*
* Requires:
*
*\li 'msg' be valid.
*
*\li 'space' is less than or equal to the total amount of space reserved
* via prior calls to dns_message_renderreserve().
*
*\li dns_message_renderbegin() was called.
*/
isc_result_t
dns_message_rendersection(dns_message_t *msg, dns_section_t section,
unsigned int options);
/*%<
* Render all names, rdatalists, etc from the given section at the
* specified priority or higher.
*
* Requires:
*\li 'msg' be valid.
*
*\li 'section' be a valid section.
*
*\li dns_message_renderbegin() was called.
*
* Returns:
*\li #ISC_R_SUCCESS -- all records were written, and there are
* no more records for this section.
*\li #ISC_R_NOSPACE -- Not enough room in the buffer to write
* all records requested.
*\li #DNS_R_MOREDATA -- All requested records written, and there
* are records remaining for this section.
*/
void
dns_message_renderheader(dns_message_t *msg, isc_buffer_t *target);
/*%<
* Render the message header. This is implicitly called by
* dns_message_renderend().
*
* Requires:
*
*\li 'msg' be a valid message.
*
*\li dns_message_renderbegin() was called.
*
*\li 'target' is a valid buffer with enough space to hold a message header
*/
isc_result_t
dns_message_renderend(dns_message_t *msg);
/*%<
* Finish rendering to the buffer. Note that more data can be in the
* 'msg' structure. Destroying the structure will free this, or in a multi-
* part EDNS1 message this data can be rendered to another buffer later.
*
* Requires:
*
*\li 'msg' be a valid message.
*
*\li dns_message_renderbegin() was called.
*
* Returns:
*\li #ISC_R_SUCCESS -- all is well.
*/
void
dns_message_renderreset(dns_message_t *msg);
/*%<
* Reset the message so that it may be rendered again.
*
* Notes:
*
*\li If dns_message_renderbegin() has been called, dns_message_renderend()
* must be called before calling this function.
*
* Requires:
*
*\li 'msg' be a valid message with rendering intent.
*/
isc_result_t
dns_message_firstname(dns_message_t *msg, dns_section_t section);
/*%<
* Set internal per-section name pointer to the beginning of the section.
*
* The functions dns_message_firstname() and dns_message_nextname() may
* be used for iterating over the owner names in a section.
*
* Requires:
*
*\li 'msg' be valid.
*
*\li 'section' be a valid section.
*
* Returns:
*\li #ISC_R_SUCCESS -- All is well.
*\li #ISC_R_NOMORE -- No names on given section.
*/
isc_result_t
dns_message_nextname(dns_message_t *msg, dns_section_t section);
/*%<
* Sets the internal per-section name pointer to point to the next name
* in that section.
*
* Requires:
*
* \li 'msg' be valid.
*
*\li 'section' be a valid section.
*
*\li dns_message_firstname() must have been called on this section,
* and the result was ISC_R_SUCCESS.
*
* Returns:
*\li #ISC_R_SUCCESS -- All is well.
*\li #ISC_R_NOMORE -- No more names in given section.
*/
void
dns_message_currentname(dns_message_t *msg, dns_section_t section,
dns_name_t **name);
/*%<
* Sets 'name' to point to the name where the per-section internal name
* pointer is currently set.
*
* This function returns the name in the database, so any data associated
* with it (via the name's "list" member) contains the actual rdatasets.
*
* Requires:
*
*\li 'msg' be valid.
*
*\li 'name' be non-NULL, and *name be NULL.
*
*\li 'section' be a valid section.
*
*\li dns_message_firstname() must have been called on this section,
* and the result of it and any dns_message_nextname() calls was
* #ISC_R_SUCCESS.
*/
isc_result_t
dns_message_findname(dns_message_t *msg, dns_section_t section,
dns_name_t *target, dns_rdatatype_t type,
dns_rdatatype_t covers, dns_name_t **foundname,
dns_rdataset_t **rdataset);
/*%<
* Search for a name in the specified section. If it is found, *name is
* set to point to the name, and *rdataset is set to point to the found
* rdataset (if type is specified as other than dns_rdatatype_any).
*
* Requires:
*\li 'msg' be valid.
*
*\li 'section' be a valid section.
*
*\li If a pointer to the name is desired, 'foundname' should be non-NULL.
* If it is non-NULL, '*foundname' MUST be NULL.
*
*\li If a type other than dns_datatype_any is searched for, 'rdataset'
* may be non-NULL, '*rdataset' be NULL, and will point at the found
* rdataset. If the type is dns_datatype_any, 'rdataset' must be NULL.
*
*\li 'target' be a valid name.
*
*\li 'type' be a valid type.
*
*\li If 'type' is dns_rdatatype_rrsig, 'covers' must be a valid type.
* Otherwise it should be 0.
*
* Returns:
*\li #ISC_R_SUCCESS -- all is well.
*\li #DNS_R_NXDOMAIN -- name does not exist in that section.
*\li #DNS_R_NXRRSET -- The name does exist, but the desired
* type does not.
*/
isc_result_t
dns_message_findtype(dns_name_t *name, dns_rdatatype_t type,
dns_rdatatype_t covers, dns_rdataset_t **rdataset);
/*%<
* Search the name for the specified type. If it is found, *rdataset is
* filled in with a pointer to that rdataset.
*
* Requires:
*\li if '**rdataset' is non-NULL, *rdataset needs to be NULL.
*
*\li 'type' be a valid type, and NOT dns_rdatatype_any.
*
*\li If 'type' is dns_rdatatype_rrsig, 'covers' must be a valid type.
* Otherwise it should be 0.
*
* Returns:
*\li #ISC_R_SUCCESS -- all is well.
*\li #ISC_R_NOTFOUND -- the desired type does not exist.
*/
void
dns_message_addname(dns_message_t *msg, dns_name_t *name,
dns_section_t section);
/*%<
* Adds the name to the given section.
*
* It is the caller's responsibility to enforce any unique name requirements
* in a section.
*
* Requires:
*
*\li 'msg' be valid, and be a renderable message.
*
*\li 'name' be a valid absolute name.
*
*\li 'section' be a named section.
*/
void
dns_message_removename(dns_message_t *msg, dns_name_t *name,
dns_section_t section);
/*%<
* Remove a existing name from a given section.
*
* It is the caller's responsibility to ensure the name is part of the
* given section.
*
* Requires:
*
*\li 'msg' be valid, and be a renderable message.
*
*\li 'name' be a valid absolute name.
*
*\li 'section' be a named section.
*/
/*
* LOANOUT FUNCTIONS
*
* Each of these functions loan a particular type of data to the caller.
* The storage for these will vanish when the message is destroyed or
* reset, and must NOT be used after these operations.
*/
isc_result_t
dns_message_gettempname(dns_message_t *msg, dns_name_t **item);
/*%<
* Return a name that can be used for any temporary purpose, including
* inserting into the message's linked lists. The name must be returned
* to the message code using dns_message_puttempname() or inserted into
* one of the message's sections before the message is destroyed.
*
* It is the caller's responsibility to initialize this name.
*
* Requires:
*\li msg be a valid message
*
*\li item != NULL && *item == NULL
*
* Returns:
*\li #ISC_R_SUCCESS -- All is well.
*\li #ISC_R_NOMEMORY -- No item can be allocated.
*/
isc_result_t
dns_message_gettempoffsets(dns_message_t *msg, dns_offsets_t **item);
/*%<
* Return an offsets array that can be used for any temporary purpose,
* such as attaching to a temporary name. The offsets will be freed
* when the message is destroyed or reset.
*
* Requires:
*\li msg be a valid message
*
*\li item != NULL && *item == NULL
*
* Returns:
*\li #ISC_R_SUCCESS -- All is well.
*\li #ISC_R_NOMEMORY -- No item can be allocated.
*/
isc_result_t
dns_message_gettemprdata(dns_message_t *msg, dns_rdata_t **item);
/*%<
* Return a rdata that can be used for any temporary purpose, including
* inserting into the message's linked lists. The rdata will be freed
* when the message is destroyed or reset.
*
* Requires:
*\li msg be a valid message
*
*\li item != NULL && *item == NULL
*
* Returns:
*\li #ISC_R_SUCCESS -- All is well.
*\li #ISC_R_NOMEMORY -- No item can be allocated.
*/
isc_result_t
dns_message_gettemprdataset(dns_message_t *msg, dns_rdataset_t **item);
/*%<
* Return a rdataset that can be used for any temporary purpose, including
* inserting into the message's linked lists. The name must be returned
* to the message code using dns_message_puttempname() or inserted into
* one of the message's sections before the message is destroyed.
*
* Requires:
*\li msg be a valid message
*
*\li item != NULL && *item == NULL
*
* Returns:
*\li #ISC_R_SUCCESS -- All is well.
*\li #ISC_R_NOMEMORY -- No item can be allocated.
*/
isc_result_t
dns_message_gettemprdatalist(dns_message_t *msg, dns_rdatalist_t **item);
/*%<
* Return a rdatalist that can be used for any temporary purpose, including
* inserting into the message's linked lists. The rdatalist will be
* destroyed when the message is destroyed or reset.
*
* Requires:
*\li msg be a valid message
*
*\li item != NULL && *item == NULL
*
* Returns:
*\li #ISC_R_SUCCESS -- All is well.
*\li #ISC_R_NOMEMORY -- No item can be allocated.
*/
void
dns_message_puttempname(dns_message_t *msg, dns_name_t **item);
/*%<
* Return a borrowed name to the message's name free list.
*
* Requires:
*\li msg be a valid message
*
*\li item != NULL && *item point to a name returned by
* dns_message_gettempname()
*
* Ensures:
*\li *item == NULL
*/
void
dns_message_puttemprdata(dns_message_t *msg, dns_rdata_t **item);
/*%<
* Return a borrowed rdata to the message's rdata free list.
*
* Requires:
*\li msg be a valid message
*
*\li item != NULL && *item point to a rdata returned by
* dns_message_gettemprdata()
*
* Ensures:
*\li *item == NULL
*/
void
dns_message_puttemprdataset(dns_message_t *msg, dns_rdataset_t **item);
/*%<
* Return a borrowed rdataset to the message's rdataset free list.
*
* Requires:
*\li msg be a valid message
*
*\li item != NULL && *item point to a rdataset returned by
* dns_message_gettemprdataset()
*
* Ensures:
*\li *item == NULL
*/
void
dns_message_puttemprdatalist(dns_message_t *msg, dns_rdatalist_t **item);
/*%<
* Return a borrowed rdatalist to the message's rdatalist free list.
*
* Requires:
*\li msg be a valid message
*
*\li item != NULL && *item point to a rdatalist returned by
* dns_message_gettemprdatalist()
*
* Ensures:
*\li *item == NULL
*/
isc_result_t
dns_message_peekheader(isc_buffer_t *source, dns_messageid_t *idp,
unsigned int *flagsp);
/*%<
* Assume the remaining region of "source" is a DNS message. Peek into
* it and fill in "*idp" with the message id, and "*flagsp" with the flags.
*
* Requires:
*
*\li source != NULL
*
* Ensures:
*
*\li if (idp != NULL) *idp == message id.
*
*\li if (flagsp != NULL) *flagsp == message flags.
*
* Returns:
*
*\li #ISC_R_SUCCESS -- all is well.
*
*\li #ISC_R_UNEXPECTEDEND -- buffer doesn't contain enough for a header.
*/
isc_result_t
dns_message_reply(dns_message_t *msg, bool want_question_section);
/*%<
* Start formatting a reply to the query in 'msg'.
*
* Requires:
*
*\li 'msg' is a valid message with parsing intent, and contains a query.
*
* Ensures:
*
*\li The message will have a rendering intent. If 'want_question_section'
* is true, the message opcode is query or notify, and the question
* section is present and properly formatted, then the question section
* will be included in the reply. All other sections will be cleared.
* The QR flag will be set, the RD flag will be preserved, and all other
* flags will be cleared.
*
* Returns:
*
*\li #ISC_R_SUCCESS -- all is well.
*
*\li #DNS_R_FORMERR -- the header or question section of the
* message is invalid, replying is impossible.
* If DNS_R_FORMERR is returned when
* want_question_section is false, then
* it's the header section that's bad;
* otherwise either of the header or question
* sections may be bad.
*/
dns_rdataset_t *
dns_message_getopt(dns_message_t *msg);
/*%<
* Get the OPT record for 'msg'.
*
* Requires:
*
*\li 'msg' is a valid message.
*
* Returns:
*
*\li The OPT rdataset of 'msg', or NULL if there isn't one.
*/
isc_result_t
dns_message_setopt(dns_message_t *msg, dns_rdataset_t *opt);
/*%<
* Set the OPT record for 'msg'.
*
* Requires:
*
*\li 'msg' is a valid message with rendering intent
* and no sections have been rendered.
*
*\li 'opt' is a valid OPT record.
*
* Ensures:
*
*\li The OPT record has either been freed or ownership of it has
* been transferred to the message.
*
*\li If ISC_R_SUCCESS was returned, the OPT record will be rendered
* when dns_message_renderend() is called.
*
* Returns:
*
*\li #ISC_R_SUCCESS -- all is well.
*
*\li #ISC_R_NOSPACE -- there is no space for the OPT record.
*/
dns_rdataset_t *
dns_message_gettsig(dns_message_t *msg, dns_name_t **owner);
/*%<
* Get the TSIG record and owner for 'msg'.
*
* Requires:
*
*\li 'msg' is a valid message.
*\li 'owner' is NULL or *owner is NULL.
*
* Returns:
*
*\li The TSIG rdataset of 'msg', or NULL if there isn't one.
*
* Ensures:
*
* \li If 'owner' is not NULL, it will point to the owner name.
*/
isc_result_t
dns_message_settsigkey(dns_message_t *msg, dns_tsigkey_t *key);
/*%<
* Set the tsig key for 'msg'. This is only necessary for when rendering a
* query or parsing a response. The key (if non-NULL) is attached to, and
* will be detached when the message is destroyed.
*
* Requires:
*
*\li 'msg' is a valid message with rendering intent,
* dns_message_renderbegin() has been called, and no sections have been
* rendered.
*\li 'key' is a valid tsig key or NULL.
*
* Returns:
*
*\li #ISC_R_SUCCESS -- all is well.
*
*\li #ISC_R_NOSPACE -- there is no space for the TSIG record.
*/
dns_tsigkey_t *
dns_message_gettsigkey(dns_message_t *msg);
/*%<
* Gets the tsig key for 'msg'.
*
* Requires:
*
*\li 'msg' is a valid message
*/
isc_result_t
dns_message_setquerytsig(dns_message_t *msg, isc_buffer_t *querytsig);
/*%<
* Indicates that 'querytsig' is the TSIG from the signed query for which
* 'msg' is the response. This is also used for chained TSIGs in TCP
* responses.
*
* Requires:
*
*\li 'querytsig' is a valid buffer as returned by dns_message_getquerytsig()
* or NULL
*
*\li 'msg' is a valid message
*
* Returns:
*
*\li #ISC_R_SUCCESS
*\li #ISC_R_NOMEMORY
*/
isc_result_t
dns_message_getquerytsig(dns_message_t *msg, isc_mem_t *mctx,
isc_buffer_t **querytsig);
/*%<
* Gets the tsig from the TSIG from the signed query 'msg'. This is also used
* for chained TSIGs in TCP responses. Unlike dns_message_gettsig, this makes
* a copy of the data, so can be used if the message is destroyed.
*
* Requires:
*
*\li 'msg' is a valid signed message
*\li 'mctx' is a valid memory context
*\li querytsig != NULL && *querytsig == NULL
*
* Returns:
*
*\li #ISC_R_SUCCESS
*\li #ISC_R_NOMEMORY
*
* Ensures:
*\li 'tsig' points to NULL or an allocated buffer which must be freed
* by the caller.
*/
dns_rdataset_t *
dns_message_getsig0(dns_message_t *msg, dns_name_t **owner);
/*%<
* Get the SIG(0) record and owner for 'msg'.
*
* Requires:
*
*\li 'msg' is a valid message.
*\li 'owner' is NULL or *owner is NULL.
*
* Returns:
*
*\li The SIG(0) rdataset of 'msg', or NULL if there isn't one.
*
* Ensures:
*
* \li If 'owner' is not NULL, it will point to the owner name.
*/
isc_result_t
dns_message_setsig0key(dns_message_t *msg, dst_key_t *key);
/*%<
* Set the SIG(0) key for 'msg'.
*
* Requires:
*
*\li 'msg' is a valid message with rendering intent,
* dns_message_renderbegin() has been called, and no sections have been
* rendered.
*\li 'key' is a valid sig key or NULL.
*
* Returns:
*
*\li #ISC_R_SUCCESS -- all is well.
*
*\li #ISC_R_NOSPACE -- there is no space for the SIG(0) record.
*/
dst_key_t *
dns_message_getsig0key(dns_message_t *msg);
/*%<
* Gets the SIG(0) key for 'msg'.
*
* Requires:
*
*\li 'msg' is a valid message
*/
void
dns_message_takebuffer(dns_message_t *msg, isc_buffer_t **buffer);
/*%<
* Give the *buffer to the message code to clean up when it is no
* longer needed. This is usually when the message is reset or
* destroyed.
*
* Requires:
*
*\li msg be a valid message.
*
*\li buffer != NULL && *buffer is a valid isc_buffer_t, which was
* dynamically allocated via isc_buffer_allocate().
*/
isc_result_t
dns_message_signer(dns_message_t *msg, dns_name_t *signer);
/*%<
* If this message was signed, return the identity of the signer.
* Unless ISC_R_NOTFOUND is returned, signer will reflect the name of the
* key that signed the message.
*
* Requires:
*
*\li msg is a valid parsed message.
*\li signer is a valid name
*
* Returns:
*
*\li #ISC_R_SUCCESS - the message was signed, and *signer
* contains the signing identity
*
*\li #ISC_R_NOTFOUND - no TSIG or SIG(0) record is present in the
* message
*
*\li #DNS_R_TSIGVERIFYFAILURE - the message was signed by a TSIG, but the
* signature failed to verify
*
*\li #DNS_R_TSIGERRORSET - the message was signed by a TSIG and
* verified, but the query was rejected by
* the server
*
*\li #DNS_R_NOIDENTITY - the message was signed by a TSIG and
* verified, but the key has no identity since
* it was generated by an unsigned TKEY process
*
*\li #DNS_R_SIGINVALID - the message was signed by a SIG(0), but
* the signature failed to verify
*
*\li #DNS_R_NOTVERIFIEDYET - the message was signed by a TSIG or SIG(0),
* but the signature has not been verified yet
*/
isc_result_t
dns_message_checksig(dns_message_t *msg, dns_view_t *view);
/*%<
* If this message was signed, verify the signature.
*
* Requires:
*
*\li msg is a valid parsed message.
*\li view is a valid view or NULL
*
* Returns:
*
*\li #ISC_R_SUCCESS - the message was unsigned, or the message
* was signed correctly.
*
*\li #DNS_R_EXPECTEDTSIG - A TSIG was expected, but not seen
*\li #DNS_R_UNEXPECTEDTSIG - A TSIG was seen but not expected
*\li #DNS_R_TSIGVERIFYFAILURE - The TSIG failed to verify
*/
isc_result_t
dns_message_rechecksig(dns_message_t *msg, dns_view_t *view);
/*%<
* Reset the signature state and then if the message was signed,
* verify the message.
*
* Requires:
*
*\li msg is a valid parsed message.
*\li view is a valid view or NULL
*
* Returns:
*
*\li #ISC_R_SUCCESS - the message was unsigned, or the message
* was signed correctly.
*
*\li #DNS_R_EXPECTEDTSIG - A TSIG was expected, but not seen
*\li #DNS_R_UNEXPECTEDTSIG - A TSIG was seen but not expected
*\li #DNS_R_TSIGVERIFYFAILURE - The TSIG failed to verify
*/
void
dns_message_resetsig(dns_message_t *msg);
/*%<
* Reset the signature state.
*
* Requires:
*\li 'msg' is a valid parsed message.
*/
isc_region_t *
dns_message_getrawmessage(dns_message_t *msg);
/*%<
* Retrieve the raw message in compressed wire format. The message must
* have been successfully parsed for it to have been saved.
*
* Requires:
*\li msg is a valid parsed message.
*
* Returns:
*\li NULL if there is no saved message.
* a pointer to a region which refers the dns message.
*/
void
dns_message_setsortorder(dns_message_t *msg, dns_rdatasetorderfunc_t order,
const void *order_arg);
/*%<
* Define the order in which RR sets get rendered by
* dns_message_rendersection() to be the ascending order
* defined by the integer value returned by 'order' when
* given each RR and 'arg' as arguments. If 'order' and
* 'order_arg' are NULL, a default order is used.
*
* Requires:
*\li msg be a valid message.
*\li order_arg is NULL if and only if order is NULL.
*/
void
dns_message_settimeadjust(dns_message_t *msg, int timeadjust);
/*%<
* Adjust the time used to sign/verify a message by timeadjust.
* Currently only TSIG.
*
* Requires:
*\li msg be a valid message.
*/
int
dns_message_gettimeadjust(dns_message_t *msg);
/*%<
* Return the current time adjustment.
*
* Requires:
*\li msg be a valid message.
*/
void
dns_message_logpacket(dns_message_t *message, const char *description,
isc_logcategory_t *category, isc_logmodule_t *module,
int level, isc_mem_t *mctx);
void
dns_message_logpacket2(dns_message_t *message,
const char *description, isc_sockaddr_t *address,
isc_logcategory_t *category, isc_logmodule_t *module,
int level, isc_mem_t *mctx);
void
dns_message_logfmtpacket(dns_message_t *message, const char *description,
isc_logcategory_t *category, isc_logmodule_t *module,
const dns_master_style_t *style, int level,
isc_mem_t *mctx);
void
dns_message_logfmtpacket2(dns_message_t *message,
const char *description, isc_sockaddr_t *address,
isc_logcategory_t *category, isc_logmodule_t *module,
const dns_master_style_t *style, int level,
isc_mem_t *mctx);
/*%<
* Log 'message' at the specified logging parameters.
*
* For dns_message_logpacket and dns_message_logfmtpacket expect the
* 'description' to end in a newline.
*
* For dns_message_logpacket2 and dns_message_logfmtpacket2
* 'description' will be emitted at the start of the message followed
* by the formatted address and a newline.
*
* Requires:
* \li message be a valid.
* \li description to be non NULL.
* \li address to be non NULL.
* \li category to be valid.
* \li module to be valid.
* \li style to be valid.
* \li mctx to be a valid.
*/
isc_result_t
dns_message_buildopt(dns_message_t *msg, dns_rdataset_t **opt,
unsigned int version, uint16_t udpsize,
unsigned int flags, dns_ednsopt_t *ednsopts, size_t count);
/*%<
* Built a opt record.
*
* Requires:
* \li msg be a valid message.
* \li opt to be a non NULL and *opt to be NULL.
*
* Returns:
* \li ISC_R_SUCCESS on success.
* \li ISC_R_NOMEMORY
* \li ISC_R_NOSPACE
* \li other.
*/
void
dns_message_setclass(dns_message_t *msg, dns_rdataclass_t rdclass);
/*%<
* Set the expected class of records in the response.
*
* Requires:
* \li msg be a valid message with parsing intent.
*/
ISC_LANG_ENDDECLS
#endif /* DNS_MESSAGE_H */