message.h
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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 has_dname : 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. */ bool dns_message_hasdname(dns_message_t *msg); /*%< * Return whether a DNAME was detected in the ANSWER section of a QUERY * message when it was parsed. */ ISC_LANG_ENDDECLS #endif /* DNS_MESSAGE_H */
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