message.c revision 7153a32ae99388656620b200e6f4ba6e170a208c
/*
* Copyright (C) 1999 Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
* SOFTWARE.
*/
/***
*** Imports
***/
#include <config.h>
#include <stddef.h>
#include <string.h>
#include <isc/assertions.h>
#include <isc/boolean.h>
#include <isc/region.h>
#include <isc/types.h>
#include <dns/message.h>
#include <dns/rdataset.h>
#include <dns/rdata.h>
#include <dns/rdataclass.h>
#include <dns/rdatatype.h>
#include <dns/rdatalist.h>
#include <dns/compress.h>
#include <dns/tsig.h>
#define DNS_MESSAGE_OPCODE_MASK 0x7800U
#define DNS_MESSAGE_OPCODE_SHIFT 11
#define DNS_MESSAGE_RCODE_MASK 0x000fU
#define DNS_MESSAGE_FLAG_MASK 0x8ff0U
#define DNS_MESSAGE_EDNSRCODE_MASK 0xff000000U
#define DNS_MESSAGE_EDNSRCODE_SHIFT 24
#define DNS_MESSAGE_EDNSVERSION_MASK 0x00ff0000U
#define DNS_MESSAGE_EDNSVERSION_SHIFT 16
#define VALID_NAMED_SECTION(s) (((s) > DNS_SECTION_ANY) \
&& ((s) < DNS_SECTION_MAX))
#define VALID_SECTION(s) (((s) >= DNS_SECTION_ANY) \
&& ((s) < DNS_SECTION_MAX))
/*
* This is the size of each individual scratchpad buffer, and the numbers
* of various block allocations used within the server.
* XXXMLG These should come from a config setting.
*/
#define SCRATCHPAD_SIZE 512
#define NAME_COUNT 8
#define RDATA_COUNT 8
#define RDATALIST_COUNT 8
#define RDATASET_COUNT RDATALIST_COUNT
/*
* "helper" type, which consists of a block of some type, and is linkable.
* For it to work, sizeof(dns_msgblock_t) must be a multiple of the pointer
* size, or the allocated elements will not be alligned correctly.
*/
struct dns_msgblock {
unsigned int count;
unsigned int remaining;
ISC_LINK(dns_msgblock_t) link;
}; /* dynamically sized */
static inline dns_msgblock_t *
msgblock_allocate(isc_mem_t *, unsigned int, unsigned int);
#define msgblock_get(block, type) \
((type *)msgblock_internalget(block, sizeof(type)))
static inline void *
msgblock_internalget(dns_msgblock_t *, unsigned int);
static inline void
msgblock_reset(dns_msgblock_t *);
static inline void
msgblock_free(isc_mem_t *, dns_msgblock_t *, unsigned int);
/*
* Allocate a new dns_msgblock_t, and return a pointer to it. If no memory
* is free, return NULL.
*/
static inline dns_msgblock_t *
msgblock_allocate(isc_mem_t *mctx, unsigned int sizeof_type,
unsigned int count)
{
dns_msgblock_t *block;
unsigned int length;
length = sizeof(dns_msgblock_t) + (sizeof_type * count);
block = isc_mem_get(mctx, length);
if (block == NULL)
return (NULL);
block->count = count;
block->remaining = count;
ISC_LINK_INIT(block, link);
return (block);
}
/*
* Return an element from the msgblock. If no more are available, return
* NULL.
*/
static inline void *
msgblock_internalget(dns_msgblock_t *block, unsigned int sizeof_type)
{
void *ptr;
if (block == NULL || block->remaining == 0)
return (NULL);
block->remaining--;
ptr = (((unsigned char *)block)
+ sizeof(dns_msgblock_t)
+ (sizeof_type * block->remaining));
return (ptr);
}
static inline void
msgblock_reset(dns_msgblock_t *block)
{
block->remaining = block->count;
}
/*
* Release memory associated with a message block.
*/
static inline void
msgblock_free(isc_mem_t *mctx, dns_msgblock_t *block,
unsigned int sizeof_type)
{
unsigned int length;
length = sizeof(dns_msgblock_t) + (sizeof_type * block->count);
isc_mem_put(mctx, block, length);
}
/*
* Allocate a new dynamic buffer, and attach it to this message as the
* "current" buffer. (which is always the last on the list, for our
* uses)
*/
static inline dns_result_t
newbuffer(dns_message_t *msg, unsigned int size)
{
isc_result_t result;
isc_buffer_t *dynbuf;
dynbuf = NULL;
result = isc_buffer_allocate(msg->mctx, &dynbuf, size,
ISC_BUFFERTYPE_BINARY);
if (result != ISC_R_SUCCESS)
return (DNS_R_NOMEMORY);
ISC_LIST_APPEND(msg->scratchpad, dynbuf, link);
return (DNS_R_SUCCESS);
}
static inline isc_buffer_t *
currentbuffer(dns_message_t *msg)
{
isc_buffer_t *dynbuf;
dynbuf = ISC_LIST_TAIL(msg->scratchpad);
INSIST(dynbuf != NULL);
return (dynbuf);
}
static inline void
releaserdata(dns_message_t *msg, dns_rdata_t *rdata)
{
ISC_LIST_PREPEND(msg->freerdata, rdata, link);
}
static inline dns_rdata_t *
newrdata(dns_message_t *msg)
{
dns_msgblock_t *msgblock;
dns_rdata_t *rdata;
rdata = ISC_LIST_HEAD(msg->freerdata);
if (rdata != NULL) {
ISC_LIST_UNLINK(msg->freerdata, rdata, link);
return (rdata);
}
msgblock = ISC_LIST_TAIL(msg->rdatas);
rdata = msgblock_get(msgblock, dns_rdata_t);
if (rdata == NULL) {
msgblock = msgblock_allocate(msg->mctx, sizeof(dns_rdata_t),
RDATA_COUNT);
if (msgblock == NULL)
return (NULL);
ISC_LIST_APPEND(msg->rdatas, msgblock, link);
rdata = msgblock_get(msgblock, dns_rdata_t);
}
return (rdata);
}
static inline void
releaserdatalist(dns_message_t *msg, dns_rdatalist_t *rdatalist)
{
ISC_LIST_PREPEND(msg->freerdatalist, rdatalist, link);
}
static inline dns_rdatalist_t *
newrdatalist(dns_message_t *msg)
{
dns_msgblock_t *msgblock;
dns_rdatalist_t *rdatalist;
rdatalist = ISC_LIST_HEAD(msg->freerdatalist);
if (rdatalist != NULL) {
ISC_LIST_UNLINK(msg->freerdatalist, rdatalist, link);
return (rdatalist);
}
msgblock = ISC_LIST_TAIL(msg->rdatalists);
rdatalist = msgblock_get(msgblock, dns_rdatalist_t);
if (rdatalist == NULL) {
msgblock = msgblock_allocate(msg->mctx,
sizeof(dns_rdatalist_t),
RDATALIST_COUNT);
if (msgblock == NULL)
return (NULL);
ISC_LIST_APPEND(msg->rdatalists, msgblock, link);
rdatalist = msgblock_get(msgblock, dns_rdatalist_t);
}
return (rdatalist);
}
static inline void
msginitheader(dns_message_t *m)
{
m->id = 0;
m->flags = 0;
m->rcode = 0;
m->opcode = 0;
m->rdclass = 0;
}
static inline void
msginitprivate(dns_message_t *m)
{
unsigned int i;
for (i = 0; i < DNS_SECTION_MAX; i++) {
m->cursors[i] = NULL;
m->counts[i] = 0;
}
m->opt = NULL;
m->state = DNS_SECTION_ANY; /* indicate nothing parsed or rendered */
m->reserved = 0;
m->buffer = NULL;
m->need_cctx_cleanup = 0;
}
static inline void
msginittsig(dns_message_t *m)
{
m->tsigstatus = m->querytsigstatus = dns_rcode_noerror;
m->tsig = m->querytsig = NULL;
m->tsigkey = NULL;
m->tsigctx = NULL;
m->tsigstart = -1;
}
/*
* Init elements to default state. Used both when allocating a new element
* and when resetting one.
*/
static inline void
msginit(dns_message_t *m)
{
msginitheader(m);
msginitprivate(m);
msginittsig(m);
m->header_ok = 0;
m->question_ok = 0;
m->tcp_continuation = 0;
}
static inline void
msgresetnames(dns_message_t *msg, unsigned int first_section) {
unsigned int i;
dns_name_t *name, *next_name;
dns_rdataset_t *rds, *next_rds;
/*
* Clean up name lists by calling the rdataset disassociate function.
*/
for (i = first_section; i < DNS_SECTION_MAX; i++) {
name = ISC_LIST_HEAD(msg->sections[i]);
while (name != NULL) {
next_name = ISC_LIST_NEXT(name, link);
ISC_LIST_UNLINK(msg->sections[i], name, link);
rds = ISC_LIST_HEAD(name->list);
while (rds != NULL) {
next_rds = ISC_LIST_NEXT(rds, link);
ISC_LIST_UNLINK(name->list, rds, link);
dns_rdataset_disassociate(rds);
isc_mempool_put(msg->rdspool, rds);
rds = next_rds;
}
isc_mempool_put(msg->namepool, name);
name = next_name;
}
}
}
/*
* Free all but one (or everything) for this message. This is used by
* both dns_message_reset() and dns_message_parse().
*/
static void
msgreset(dns_message_t *msg, isc_boolean_t everything)
{
dns_msgblock_t *msgblock, *next_msgblock;
isc_buffer_t *dynbuf, *next_dynbuf;
dns_rdata_t *rdata;
dns_rdatalist_t *rdatalist;
msgresetnames(msg, 0);
if (msg->opt != NULL) {
dns_rdataset_disassociate(msg->opt);
isc_mempool_put(msg->rdspool, msg->opt);
msg->opt = NULL;
}
/*
* Clean up linked lists.
*/
/*
* Run through the free lists, and just unlink anything found there.
* The memory isn't lost since these are part of message blocks we
* have allocated.
*/
rdata = ISC_LIST_HEAD(msg->freerdata);
while (rdata != NULL) {
ISC_LIST_UNLINK(msg->freerdata, rdata, link);
rdata = ISC_LIST_HEAD(msg->freerdata);
}
rdatalist = ISC_LIST_HEAD(msg->freerdatalist);
while (rdatalist != NULL) {
ISC_LIST_UNLINK(msg->freerdatalist, rdatalist, link);
rdatalist = ISC_LIST_HEAD(msg->freerdatalist);
}
dynbuf = ISC_LIST_HEAD(msg->scratchpad);
INSIST(dynbuf != NULL);
if (!everything) {
isc_buffer_clear(dynbuf);
dynbuf = ISC_LIST_NEXT(dynbuf, link);
}
while (dynbuf != NULL) {
next_dynbuf = ISC_LIST_NEXT(dynbuf, link);
ISC_LIST_UNLINK(msg->scratchpad, dynbuf, link);
isc_buffer_free(&dynbuf);
dynbuf = next_dynbuf;
}
msgblock = ISC_LIST_HEAD(msg->rdatas);
INSIST(msgblock != NULL);
if (!everything) {
msgblock_reset(msgblock);
msgblock = ISC_LIST_NEXT(msgblock, link);
}
while (msgblock != NULL) {
next_msgblock = ISC_LIST_NEXT(msgblock, link);
ISC_LIST_UNLINK(msg->rdatas, msgblock, link);
msgblock_free(msg->mctx, msgblock, sizeof(dns_rdata_t));
msgblock = next_msgblock;
}
/*
* rdatalists could be empty.
*/
msgblock = ISC_LIST_HEAD(msg->rdatalists);
if (!everything && msgblock != NULL) {
msgblock_reset(msgblock);
msgblock = ISC_LIST_NEXT(msgblock, link);
}
while (msgblock != NULL) {
next_msgblock = ISC_LIST_NEXT(msgblock, link);
ISC_LIST_UNLINK(msg->rdatalists, msgblock, link);
msgblock_free(msg->mctx, msgblock, sizeof(dns_rdatalist_t));
msgblock = next_msgblock;
}
if (msg->need_cctx_cleanup == 1)
dns_compress_invalidate(&msg->cctx);
if (msg->tsig != NULL) {
dns_rdata_freestruct(msg->tsig);
isc_mem_put(msg->mctx, msg->tsig,
sizeof(dns_rdata_any_tsig_t));
}
if (msg->querytsig != NULL) {
dns_rdata_freestruct(msg->querytsig);
isc_mem_put(msg->mctx, msg->querytsig,
sizeof(dns_rdata_any_tsig_t));
}
if (msg->tsigkey != NULL && dns_tsig_emptykey(msg->tsigkey))
dns_tsig_key_free(&msg->tsigkey);
/*
* cleanup the buffer cleanup list
*/
dynbuf = ISC_LIST_HEAD(msg->cleanup);
while (dynbuf != NULL) {
next_dynbuf = ISC_LIST_NEXT(dynbuf, link);
ISC_LIST_UNLINK(msg->scratchpad, dynbuf, link);
isc_buffer_free(&dynbuf);
dynbuf = next_dynbuf;
}
/*
* Set other bits to normal default values.
*/
if (!everything)
msginit(msg);
}
dns_result_t
dns_message_create(isc_mem_t *mctx, unsigned int intent, dns_message_t **msgp)
{
dns_message_t *m;
isc_result_t result;
dns_msgblock_t *msgblock;
isc_buffer_t *dynbuf;
unsigned int i;
REQUIRE(mctx != NULL);
REQUIRE(msgp != NULL);
REQUIRE(*msgp == NULL);
REQUIRE(intent == DNS_MESSAGE_INTENTPARSE
|| intent == DNS_MESSAGE_INTENTRENDER);
m = isc_mem_get(mctx, sizeof(dns_message_t));
if (m == NULL)
return(DNS_R_NOMEMORY);
/*
* No allocations until further notice. Just initialize all lists
* and other members that are freed in the cleanup phase here.
*/
m->magic = DNS_MESSAGE_MAGIC;
m->from_to_wire = intent;
msginit(m);
for (i = 0 ; i < DNS_SECTION_MAX ; i++)
ISC_LIST_INIT(m->sections[i]);
m->mctx = mctx;
ISC_LIST_INIT(m->scratchpad);
ISC_LIST_INIT(m->cleanup);
m->namepool = NULL;
m->rdspool = NULL;
ISC_LIST_INIT(m->rdatas);
ISC_LIST_INIT(m->rdatalists);
ISC_LIST_INIT(m->freerdata);
ISC_LIST_INIT(m->freerdatalist);
/*
* Ok, it is safe to allocate (and then "goto cleanup" if failure)
*/
result = isc_mempool_create(m->mctx, sizeof(dns_name_t), &m->namepool);
if (result != ISC_R_SUCCESS)
goto cleanup;
isc_mempool_setfreemax(m->namepool, NAME_COUNT);
isc_mempool_setfillcount(m->namepool, NAME_COUNT);
result = isc_mempool_create(m->mctx, sizeof(dns_rdataset_t),
&m->rdspool);
if (result != ISC_R_SUCCESS)
goto cleanup;
isc_mempool_setfreemax(m->rdspool, NAME_COUNT);
isc_mempool_setfillcount(m->rdspool, NAME_COUNT);
dynbuf = NULL;
result = isc_buffer_allocate(mctx, &dynbuf, SCRATCHPAD_SIZE,
ISC_BUFFERTYPE_BINARY);
if (result != ISC_R_SUCCESS)
goto cleanup;
ISC_LIST_APPEND(m->scratchpad, dynbuf, link);
msgblock = msgblock_allocate(mctx, sizeof(dns_rdata_t),
RDATA_COUNT);
if (msgblock == NULL)
goto cleanup;
ISC_LIST_APPEND(m->rdatas, msgblock, link);
if (intent == DNS_MESSAGE_INTENTPARSE) {
msgblock = msgblock_allocate(mctx, sizeof(dns_rdatalist_t),
RDATALIST_COUNT);
if (msgblock == NULL)
goto cleanup;
ISC_LIST_APPEND(m->rdatalists, msgblock, link);
}
*msgp = m;
return (DNS_R_SUCCESS);
/*
* Cleanup for error returns.
*/
cleanup:
msgblock = ISC_LIST_HEAD(m->rdatas);
if (msgblock != NULL)
msgblock_free(mctx, msgblock, sizeof(dns_rdata_t));
dynbuf = ISC_LIST_HEAD(m->scratchpad);
if (dynbuf != NULL)
isc_buffer_free(&dynbuf);
if (m->namepool != NULL)
isc_mempool_destroy(&m->namepool);
if (m->rdspool != NULL)
isc_mempool_destroy(&m->rdspool);
m->magic = 0;
isc_mem_put(mctx, m, sizeof(dns_message_t));
return (DNS_R_NOMEMORY);
}
void
dns_message_reset(dns_message_t *msg, unsigned int intent)
{
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE(intent == DNS_MESSAGE_INTENTPARSE
|| intent == DNS_MESSAGE_INTENTRENDER);
msg->from_to_wire = intent;
msgreset(msg, ISC_FALSE);
}
void
dns_message_destroy(dns_message_t **msgp)
{
dns_message_t *msg;
REQUIRE(msgp != NULL);
REQUIRE(DNS_MESSAGE_VALID(*msgp));
msg = *msgp;
*msgp = NULL;
msgreset(msg, ISC_TRUE);
isc_mempool_destroy(&msg->namepool);
isc_mempool_destroy(&msg->rdspool);
msg->magic = 0;
isc_mem_put(msg->mctx, msg, sizeof(dns_message_t));
}
static dns_result_t
findname(dns_name_t **foundname, dns_name_t *target, dns_namelist_t *section)
{
dns_name_t *curr;
for (curr = ISC_LIST_TAIL(*section) ;
curr != NULL ;
curr = ISC_LIST_PREV(curr, link)) {
if (dns_name_equal(curr, target)) {
if (foundname != NULL)
*foundname = curr;
return (DNS_R_SUCCESS);
}
}
return (DNS_R_NOTFOUND);
}
dns_result_t
dns_message_findtype(dns_name_t *name, dns_rdatatype_t type,
dns_rdatatype_t covers, dns_rdataset_t **rdataset)
{
dns_rdataset_t *curr;
if (rdataset != NULL) {
REQUIRE(*rdataset == NULL);
}
for (curr = ISC_LIST_TAIL(name->list) ;
curr != NULL ;
curr = ISC_LIST_PREV(curr, link)) {
if (curr->type == type && curr->covers == covers) {
if (rdataset != NULL)
*rdataset = curr;
return (DNS_R_SUCCESS);
}
}
return (DNS_R_NOTFOUND);
}
/*
* Read a name from buffer "source".
*/
static dns_result_t
getname(dns_name_t *name, isc_buffer_t *source, dns_message_t *msg,
dns_decompress_t *dctx)
{
isc_buffer_t *scratch;
dns_result_t result;
unsigned int tries;
scratch = currentbuffer(msg);
/*
* First try: use current buffer.
* Second try: allocate a new buffer and use that.
*/
tries = 0;
while (tries < 2) {
dns_name_init(name, NULL);
result = dns_name_fromwire(name, source, dctx, ISC_FALSE,
scratch);
if (result == DNS_R_NOSPACE) {
tries++;
result = newbuffer(msg, SCRATCHPAD_SIZE);
if (result != DNS_R_SUCCESS)
return (result);
scratch = currentbuffer(msg);
} else {
return (result);
}
}
INSIST(0); /* Cannot get here... */
return (DNS_R_UNEXPECTED);
}
static dns_result_t
getrdata(dns_name_t *name, isc_buffer_t *source, dns_message_t *msg,
dns_decompress_t *dctx, dns_rdataclass_t rdclass,
dns_rdatatype_t rdtype, unsigned int rdatalen, dns_rdata_t *rdata)
{
isc_buffer_t *scratch;
dns_result_t result;
unsigned int tries;
unsigned int trysize;
/*
* In dynamic update messages, the rdata can be empty.
*/
if (msg->opcode == dns_opcode_update && rdatalen == 0) {
/*
* When the rdata is empty, the data pointer is never
* dereferenced, but it must still be non-NULL.
*/
rdata->data = (unsigned char *)"";
rdata->length = 0;
rdata->rdclass = rdclass;
rdata->type = rdtype;
return DNS_R_SUCCESS;
}
scratch = currentbuffer(msg);
isc_buffer_setactive(source, rdatalen);
dns_decompress_localinit(dctx, name, source);
/*
* First try: use current buffer.
* Second try: allocate a new buffer of size
* max(SCRATCHPAD_SIZE, 2 * compressed_rdatalen)
* (the data will fit if it was not more than 50% compressed)
* Subsequent tries: double buffer size on each try.
*/
tries = 0;
trysize = 0;
for (;;) {
result = dns_rdata_fromwire(rdata, rdclass, rdtype,
source, dctx, ISC_FALSE,
scratch);
if (result == DNS_R_NOSPACE) {
if (tries == 0) {
trysize = 2 * rdatalen;
if (trysize < SCRATCHPAD_SIZE)
trysize = SCRATCHPAD_SIZE;
} else {
INSIST(trysize != 0);
if (trysize >= 65535)
return (ISC_R_NOSPACE);
/* XXX DNS_R_RRTOOLONG? */
trysize *= 2;
}
tries++;
result = newbuffer(msg, trysize);
if (result != DNS_R_SUCCESS)
return (result);
scratch = currentbuffer(msg);
} else {
return (result);
}
}
}
static dns_result_t
getquestions(isc_buffer_t *source, dns_message_t *msg, dns_decompress_t *dctx)
{
isc_region_t r;
unsigned int count;
dns_name_t *name;
dns_name_t *name2;
dns_rdataset_t *rdataset;
dns_rdatalist_t *rdatalist;
dns_result_t result;
dns_rdatatype_t rdtype;
dns_rdataclass_t rdclass;
dns_namelist_t *section;
isc_boolean_t free_name;
section = &msg->sections[DNS_SECTION_QUESTION];
name = NULL;
rdataset = NULL;
rdatalist = NULL;
for (count = 0 ; count < msg->counts[DNS_SECTION_QUESTION] ; count++) {
name = isc_mempool_get(msg->namepool);
if (name == NULL)
return (DNS_R_NOMEMORY);
free_name = ISC_TRUE;
/*
* Parse the name out of this packet.
*/
isc_buffer_remaining(source, &r);
isc_buffer_setactive(source, r.length);
result = getname(name, source, msg, dctx);
if (result != DNS_R_SUCCESS)
goto cleanup;
/*
* Run through the section, looking to see if this name
* is already there. If it is found, put back the allocated
* name since we no longer need it, and set our name pointer
* to point to the name we found.
*/
result = findname(&name2, name, section);
/*
* If it is the first name in the section, accept it.
*
* If it is not, but is not the same as the name already
* in the question section, append to the section. Note that
* here in the question section this is illegal, so return
* FORMERR. In the future, check the opcode to see if
* this should be legal or not. In either case we no longer
* need this name pointer.
*/
if (result != DNS_R_SUCCESS) {
if (ISC_LIST_EMPTY(*section)) {
ISC_LIST_APPEND(*section, name, link);
free_name = ISC_FALSE;
} else {
result = DNS_R_FORMERR;
goto cleanup;
}
} else {
isc_mempool_put(msg->namepool, name);
name = name2;
name2 = NULL;
free_name = ISC_FALSE;
}
/*
* Get type and class.
*/
isc_buffer_remaining(source, &r);
if (r.length < 4) {
result = DNS_R_UNEXPECTEDEND;
goto cleanup;
}
rdtype = isc_buffer_getuint16(source);
rdclass = isc_buffer_getuint16(source);
/*
* If this class is different than the one we already read,
* this is an error.
*/
if (msg->state == DNS_SECTION_ANY) {
msg->state = DNS_SECTION_QUESTION;
msg->rdclass = rdclass;
msg->state = DNS_SECTION_QUESTION;
} else if (msg->rdclass != rdclass) {
result = DNS_R_FORMERR;
goto cleanup;
}
/*
* Can't ask the same question twice.
*/
result = dns_message_findtype(name, rdtype, 0, NULL);
if (result == DNS_R_SUCCESS) {
result = DNS_R_FORMERR;
goto cleanup;
}
/*
* Allocate a new rdatalist.
*/
rdatalist = newrdatalist(msg);
if (rdatalist == NULL) {
result = DNS_R_NOMEMORY;
goto cleanup;
}
rdataset = isc_mempool_get(msg->rdspool);
if (rdataset == NULL) {
result = DNS_R_NOMEMORY;
goto cleanup;
}
/*
* Convert rdatalist to rdataset, and attach the latter to
* the name.
*/
rdatalist->type = rdtype;
rdatalist->rdclass = rdclass;
rdatalist->ttl = 0;
ISC_LIST_INIT(rdatalist->rdata);
dns_rdataset_init(rdataset);
result = dns_rdatalist_tordataset(rdatalist, rdataset);
if (result != DNS_R_SUCCESS)
goto cleanup;
rdataset->attributes |= DNS_RDATASETATTR_QUESTION;
ISC_LIST_APPEND(name->list, rdataset, link);
}
return (DNS_R_SUCCESS);
cleanup:
if (rdataset != NULL)
isc_mempool_put(msg->rdspool, rdataset);
#if 0
if (rdatalist != NULL)
isc_mempool_put(msg->rdlpool, rdatalist);
#endif
if (free_name)
isc_mempool_put(msg->namepool, name);
return (result);
}
static dns_result_t
getsection(isc_buffer_t *source, dns_message_t *msg, dns_decompress_t *dctx,
dns_section_t sectionid, isc_boolean_t preserve_order)
{
isc_region_t r;
unsigned int count;
unsigned int rdatalen;
dns_name_t *name;
dns_name_t *name2;
dns_rdataset_t *rdataset;
dns_rdatalist_t *rdatalist;
dns_result_t result;
dns_rdatatype_t rdtype, covers;
dns_rdataclass_t rdclass;
dns_rdata_t *rdata;
dns_ttl_t ttl;
dns_namelist_t *section;
for (count = 0 ; count < msg->counts[sectionid] ; count++) {
int recstart = source->current;
isc_boolean_t skip_search;
section = &msg->sections[sectionid];
skip_search = ISC_FALSE;
name = isc_mempool_get(msg->namepool);
if (name == NULL)
return (DNS_R_NOMEMORY);
/*
* Parse the name out of this packet.
*/
isc_buffer_remaining(source, &r);
isc_buffer_setactive(source, r.length);
result = getname(name, source, msg, dctx);
if (result != DNS_R_SUCCESS)
return (result);
/*
* Get type, class, ttl, and rdatalen. Verify that at least
* rdatalen bytes remain. (Some of this is deferred to
* later.)
*/
isc_buffer_remaining(source, &r);
if (r.length < 2 + 2 + 4 + 2)
return (DNS_R_UNEXPECTEDEND);
rdtype = isc_buffer_getuint16(source);
rdclass = isc_buffer_getuint16(source);
/*
* If there was no question section, we may not yet have
* established a class. Do so now.
*/
if (msg->state == DNS_SECTION_ANY) {
if (rdclass == 0 || rdclass == dns_rdataclass_any)
return (DNS_R_FORMERR);
msg->rdclass = rdclass;
msg->state = DNS_SECTION_QUESTION;
}
/*
* If this class is different than the one in the question
* section, bail.
*/
if (msg->opcode != dns_opcode_update
&& rdtype != dns_rdatatype_tsig
&& rdtype != dns_rdatatype_opt
&& msg->rdclass != rdclass)
return (DNS_R_FORMERR);
/*
* Special type handling for TSIG and OPT.
*/
if (rdtype == dns_rdatatype_tsig) {
/*
* If it is a tsig, verify that it is in the
* additional data section, and switch sections for
* the rest of this rdata.
*/
if (sectionid != DNS_SECTION_ADDITIONAL)
return (DNS_R_FORMERR);
if (rdclass != dns_rdataclass_any)
return (DNS_R_FORMERR);
section = &msg->sections[DNS_SECTION_TSIG];
msg->tsigstart = recstart;
skip_search = ISC_TRUE;
} else if (rdtype == dns_rdatatype_opt) {
/*
* The name of an OPT record must be ".", it
* must be in the additional data section, and
* it must be the first OPT we've seen.
*/
if (!dns_name_equal(dns_rootname, name) ||
sectionid != DNS_SECTION_ADDITIONAL ||
msg->opt != NULL)
return (DNS_R_FORMERR);
skip_search = ISC_TRUE;
}
/*
* ... now get ttl and rdatalen, and check buffer.
*/
ttl = isc_buffer_getuint32(source);
rdatalen = isc_buffer_getuint16(source);
r.length -= (2 + 2 + 4 + 2);
if (r.length < rdatalen)
return (DNS_R_UNEXPECTEDEND);
/*
* If we are doing a dynamic update don't bother searching
* for a name, just append this one to the end of the message.
*/
if (preserve_order || msg->opcode == dns_opcode_update ||
skip_search) {
if (rdtype != dns_rdatatype_opt)
ISC_LIST_APPEND(*section, name, link);
} else {
/*
* Run through the section, looking to see if this name
* is already there. If it is found, put back the
* allocated name since we no longer need it, and set
* our name pointer to point to the name we found.
*/
result = findname(&name2, name, section);
/*
* If it is a new name, append to the section.
*/
if (result == DNS_R_SUCCESS) {
isc_mempool_put(msg->namepool, name);
name = name2;
} else {
ISC_LIST_APPEND(*section, name, link);
}
}
/*
* Read the rdata from the wire format. Interpret the
* rdata according to its actual class, even if it had a
* DynDNS meta-class in the packet (unless this is a TSIG).
* Then put the meta-class back into the finished rdata.
*/
rdata = newrdata(msg);
if (rdata == NULL)
return (DNS_R_NOMEMORY);
if (rdtype != dns_rdatatype_tsig)
result = getrdata(name, source, msg, dctx,
msg->rdclass, rdtype,
rdatalen, rdata);
else
result = getrdata(name, source, msg, dctx,
rdclass, rdtype, rdatalen, rdata);
if (result != DNS_R_SUCCESS)
return (result);
rdata->rdclass = rdclass;
if (rdtype == dns_rdatatype_sig && rdata->length > 0)
covers = dns_rdata_covers(rdata);
else
covers = 0;
/*
* Search name for the particular type and class.
* Skip this stage if in update mode, or this is a TSIG.
*/
if (preserve_order || msg->opcode == dns_opcode_update ||
skip_search)
result = DNS_R_NOTFOUND;
else {
rdataset = NULL;
result = dns_message_findtype(name, rdtype, covers,
&rdataset);
}
/*
* If we found an rdataset that matches, we need to
* append this rdata to that set. If we did not, we need
* to create a new rdatalist, store the important bits there,
* convert it to an rdataset, and link the latter to the name.
* Yuck.
*/
if (result == DNS_R_NOTFOUND) {
rdataset = isc_mempool_get(msg->rdspool);
if (rdataset == NULL)
return (DNS_R_NOMEMORY);
rdatalist = newrdatalist(msg);
if (rdatalist == NULL)
return (DNS_R_NOMEMORY);
rdatalist->type = rdtype;
rdatalist->covers = covers;
rdatalist->rdclass = rdclass;
rdatalist->ttl = ttl;
ISC_LIST_INIT(rdatalist->rdata);
dns_rdataset_init(rdataset);
dns_rdatalist_tordataset(rdatalist, rdataset);
if (rdtype != dns_rdatatype_opt)
ISC_LIST_APPEND(name->list, rdataset, link);
}
/*
* XXXRTH Normalize TTLs.
*/
/*
* XXXMLG Perform a totally ugly hack here to pull
* the rdatalist out of the private field in the rdataset,
* and append this rdata to the rdatalist's linked list
* of rdata.
*/
rdatalist = (dns_rdatalist_t *)(rdataset->private1);
ISC_LIST_APPEND(rdatalist->rdata, rdata, link);
/*
* If this is an OPT record, remember it. Also, set
* the extended rcode.
*/
if (rdtype == dns_rdatatype_opt) {
unsigned int ercode;
msg->opt = rdataset;
ercode = (msg->opt->ttl & DNS_MESSAGE_EDNSRCODE_MASK)
>> 20;
msg->rcode |= ercode;
isc_mempool_put(msg->namepool, name);
}
}
return (DNS_R_SUCCESS);
}
dns_result_t
dns_message_parse(dns_message_t *msg, isc_buffer_t *source,
isc_boolean_t preserve_order)
{
isc_region_t r;
dns_decompress_t dctx;
dns_result_t ret;
isc_uint16_t tmpflags;
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE(source != NULL);
REQUIRE(msg->from_to_wire == DNS_MESSAGE_INTENTPARSE);
msg->header_ok = 0;
msg->question_ok = 0;
isc_buffer_remaining(source, &r);
if (r.length < DNS_MESSAGE_HEADERLEN)
return (DNS_R_UNEXPECTEDEND);
msg->id = isc_buffer_getuint16(source);
tmpflags = isc_buffer_getuint16(source);
msg->opcode = ((tmpflags & DNS_MESSAGE_OPCODE_MASK)
>> DNS_MESSAGE_OPCODE_SHIFT);
msg->rcode = (tmpflags & DNS_MESSAGE_RCODE_MASK);
msg->flags = (tmpflags & DNS_MESSAGE_FLAG_MASK);
msg->counts[DNS_SECTION_QUESTION] = isc_buffer_getuint16(source);
msg->counts[DNS_SECTION_ANSWER] = isc_buffer_getuint16(source);
msg->counts[DNS_SECTION_AUTHORITY] = isc_buffer_getuint16(source);
msg->counts[DNS_SECTION_ADDITIONAL] = isc_buffer_getuint16(source);
msg->header_ok = 1;
/*
* -1 means no EDNS.
*/
dns_decompress_init(&dctx, -1, ISC_FALSE);
if (dns_decompress_edns(&dctx) > 1 || !dns_decompress_strict(&dctx))
dns_decompress_setmethods(&dctx, DNS_COMPRESS_GLOBAL);
else
dns_decompress_setmethods(&dctx, DNS_COMPRESS_GLOBAL14);
ret = getquestions(source, msg, &dctx);
if (ret != DNS_R_SUCCESS)
return (ret);
msg->question_ok = 1;
ret = getsection(source, msg, &dctx, DNS_SECTION_ANSWER,
preserve_order);
if (ret != DNS_R_SUCCESS)
return (ret);
ret = getsection(source, msg, &dctx, DNS_SECTION_AUTHORITY,
preserve_order);
if (ret != DNS_R_SUCCESS)
return (ret);
ret = getsection(source, msg, &dctx, DNS_SECTION_ADDITIONAL,
preserve_order);
if (ret != DNS_R_SUCCESS)
return (ret);
isc_buffer_remaining(source, &r);
if (r.length != 0)
return (DNS_R_FORMERR);
if (msg->tsigkey != NULL ||
!ISC_LIST_EMPTY(msg->sections[DNS_SECTION_TSIG]))
{
if (!msg->tcp_continuation)
ret = dns_tsig_verify(source, msg);
else
ret = dns_tsig_verify_tcp(source, msg);
if (ret != DNS_R_SUCCESS)
return ret;
}
return (DNS_R_SUCCESS);
}
dns_result_t
dns_message_renderbegin(dns_message_t *msg, isc_buffer_t *buffer)
{
isc_region_t r;
dns_result_t result;
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE(buffer != NULL);
REQUIRE(msg->buffer == NULL);
REQUIRE(msg->from_to_wire == DNS_MESSAGE_INTENTRENDER);
/*
* Erase the contents of this buffer.
*/
isc_buffer_clear(buffer);
/*
* Make certain there is enough for at least the header in this
* buffer.
*/
isc_buffer_available(buffer, &r);
REQUIRE(r.length >= DNS_MESSAGE_HEADERLEN);
result = dns_compress_init(&msg->cctx, -1, msg->mctx);
if (result != DNS_R_SUCCESS)
return (result);
msg->need_cctx_cleanup = 1;
/*
* Reserve enough space for the header in this buffer.
*/
isc_buffer_add(buffer, DNS_MESSAGE_HEADERLEN);
msg->buffer = buffer;
return (DNS_R_SUCCESS);
}
dns_result_t
dns_message_renderchangebuffer(dns_message_t *msg, isc_buffer_t *buffer)
{
isc_region_t r, rn;
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE(buffer != NULL);
REQUIRE(msg->buffer != NULL);
/*
* ensure that the new buffer is empty, and has enough space to
* hold the current contents.
*/
isc_buffer_clear(buffer);
isc_buffer_available(buffer, &rn);
isc_buffer_used(msg->buffer, &r);
REQUIRE(rn.length > r.length);
/*
* Copy the contents from the old to the new buffer.
*/
isc_buffer_add(buffer, r.length);
memcpy(rn.base, r.base, r.length);
msg->buffer = buffer;
return (DNS_R_SUCCESS);
}
dns_result_t
dns_message_renderrelease(dns_message_t *msg, unsigned int space)
{
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE(msg->buffer != NULL);
if (msg->reserved < space)
return (DNS_R_NOSPACE);
msg->reserved -= space;
return (DNS_R_SUCCESS);
}
dns_result_t
dns_message_renderreserve(dns_message_t *msg, unsigned int space)
{
isc_region_t r;
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE(msg->buffer != NULL);
isc_buffer_available(msg->buffer, &r);
if (r.length < (space + msg->reserved))
return (DNS_R_NOSPACE);
msg->reserved += space;
return (DNS_R_SUCCESS);
}
dns_result_t
dns_message_rendersection(dns_message_t *msg, dns_section_t sectionid,
unsigned int priority, unsigned int options)
{
dns_namelist_t *section;
dns_name_t *name, *next_name;
dns_rdataset_t *rdataset, *next_rdataset;
unsigned int count, total;
dns_result_t result;
isc_buffer_t st; /* for rollbacks */
(void)priority; /* XXXMLG implement */
(void)options; /* XXXMLG implement */
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE(msg->buffer != NULL);
REQUIRE(VALID_NAMED_SECTION(sectionid));
section = &msg->sections[sectionid];
name = ISC_LIST_HEAD(*section);
if (name == NULL)
return (DNS_R_SUCCESS);
/*
* Shrink the space in the buffer by the reserved amount.
*/
msg->buffer->length -= msg->reserved;
total = 0;
while (name != NULL) {
next_name = ISC_LIST_NEXT(name, link);
rdataset = ISC_LIST_HEAD(name->list);
while (rdataset != NULL) {
next_rdataset = ISC_LIST_NEXT(rdataset, link);
if (rdataset->attributes & DNS_RDATASETATTR_RENDERED) {
rdataset = next_rdataset;
continue;
}
st = *(msg->buffer);
count = 0;
result = dns_rdataset_towire(rdataset, name,
&msg->cctx,
msg->buffer, &count);
total += count;
/*
* If out of space, record stats on what we rendered
* so far, and return that status.
*
* XXXMLG Need to change this when
* dns_rdataset_towire() can render partial
* sets starting at some arbitary point in the set.
* This will include setting a bit in the
* rdataset to indicate that a partial rendering
* was done, and some state saved somewhere
* (probably in the message struct)
* to indicate where to continue from.
*/
if (result != DNS_R_SUCCESS) {
dns_compress_rollback(&msg->cctx, st.used);
*(msg->buffer) = st; /* rollback */
msg->buffer->length += msg->reserved;
msg->counts[sectionid] += total;
return (result);
}
rdataset->attributes |= DNS_RDATASETATTR_RENDERED;
rdataset = next_rdataset;
}
name = next_name;
}
msg->buffer->length += msg->reserved;
msg->counts[sectionid] += total;
return (DNS_R_SUCCESS);
}
void
dns_message_renderheader(dns_message_t *msg, isc_buffer_t *target)
{
isc_uint16_t tmp;
isc_region_t r;
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE(target != NULL);
isc_buffer_available(target, &r);
REQUIRE(r.length >= DNS_MESSAGE_HEADERLEN);
isc_buffer_putuint16(target, msg->id);
tmp = ((msg->opcode << DNS_MESSAGE_OPCODE_SHIFT)
& DNS_MESSAGE_OPCODE_MASK);
tmp |= (msg->rcode & DNS_MESSAGE_RCODE_MASK);
tmp |= (msg->flags & DNS_MESSAGE_FLAG_MASK);
isc_buffer_putuint16(target, tmp);
isc_buffer_putuint16(target, msg->counts[DNS_SECTION_QUESTION]);
isc_buffer_putuint16(target, msg->counts[DNS_SECTION_ANSWER]);
isc_buffer_putuint16(target, msg->counts[DNS_SECTION_AUTHORITY]);
tmp = msg->counts[DNS_SECTION_ADDITIONAL]
+ msg->counts[DNS_SECTION_TSIG];
isc_buffer_putuint16(target, tmp);
}
dns_result_t
dns_message_renderend(dns_message_t *msg)
{
isc_buffer_t tmpbuf;
isc_region_t r;
int result;
dns_rdata_t rdata;
unsigned int count;
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE(msg->buffer != NULL);
if ((msg->rcode & ~DNS_MESSAGE_RCODE_MASK) != 0 && msg->opt == NULL) {
/*
* We have an extended rcode but are not using EDNS.
*/
return (DNS_R_FORMERR);
}
/*
* If we've got an OPT record, render it.
*/
if (msg->opt != NULL) {
result = dns_rdataset_first(msg->opt);
if (result != ISC_R_SUCCESS)
return (result);
dns_rdataset_current(msg->opt, &rdata);
result = dns_message_renderrelease(msg, 11 + rdata.length);
if (result != ISC_R_SUCCESS)
return (result);
/*
* Set the extended rcode.
*/
msg->opt->ttl &= ~DNS_MESSAGE_EDNSRCODE_MASK;
msg->opt->ttl |= ((msg->rcode << 20) &
DNS_MESSAGE_EDNSRCODE_MASK);
/*
* Render.
*/
count = 0;
result = dns_rdataset_towire(msg->opt, dns_rootname,
&msg->cctx, msg->buffer, &count);
msg->counts[DNS_SECTION_ADDITIONAL] += count;
if (result != ISC_R_SUCCESS)
return (result);
}
if (msg->tsigkey != NULL ||
((msg->flags & DNS_MESSAGEFLAG_QR) != 0 &&
msg->querytsigstatus != dns_rcode_noerror))
{
result = dns_tsig_sign(msg);
if (result != DNS_R_SUCCESS)
return (result);
result = dns_message_rendersection(msg, DNS_SECTION_TSIG, 0,
0);
if (result != DNS_R_SUCCESS)
return (result);
}
isc_buffer_used(msg->buffer, &r);
isc_buffer_init(&tmpbuf, r.base, r.length, ISC_BUFFERTYPE_BINARY);
dns_message_renderheader(msg, &tmpbuf);
msg->buffer = NULL; /* forget about this buffer only on success XXX */
dns_compress_invalidate(&msg->cctx);
msg->need_cctx_cleanup = 0;
return (DNS_R_SUCCESS);
}
dns_result_t
dns_message_firstname(dns_message_t *msg, dns_section_t section)
{
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE(VALID_NAMED_SECTION(section));
msg->cursors[section] = ISC_LIST_HEAD(msg->sections[section]);
if (msg->cursors[section] == NULL)
return (DNS_R_NOMORE);
return (DNS_R_SUCCESS);
}
dns_result_t
dns_message_nextname(dns_message_t *msg, dns_section_t section)
{
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE(VALID_NAMED_SECTION(section));
REQUIRE(msg->cursors[section] != NULL);
msg->cursors[section] = ISC_LIST_NEXT(msg->cursors[section], link);
if (msg->cursors[section] == NULL)
return (DNS_R_NOMORE);
return (DNS_R_SUCCESS);
}
void
dns_message_currentname(dns_message_t *msg, dns_section_t section,
dns_name_t **name)
{
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE(VALID_NAMED_SECTION(section));
REQUIRE(name != NULL && *name == NULL);
REQUIRE(msg->cursors[section] != NULL);
*name = msg->cursors[section];
}
dns_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 **name,
dns_rdataset_t **rdataset)
{
dns_name_t *foundname;
dns_result_t result;
/*
* XXX These requirements are probably too intensive, especially
* where things can be NULL, but as they are they ensure that if
* something is NON-NULL, indicating that the caller expects it
* to be filled in, that we can in fact fill it in.
*/
REQUIRE(msg != NULL);
REQUIRE(VALID_SECTION(section));
REQUIRE(target != NULL);
if (name != NULL)
REQUIRE(*name == NULL);
if (type == dns_rdatatype_any) {
REQUIRE(rdataset == NULL);
} else {
if (rdataset != NULL)
REQUIRE(*rdataset == NULL);
}
/*
* Search through, looking for the name.
*/
result = findname(&foundname, target, &msg->sections[section]);
if (result == DNS_R_NOTFOUND)
return (DNS_R_NXDOMAIN);
else if (result != DNS_R_SUCCESS)
return (result);
if (name != NULL)
*name = foundname;
/*
* And now look for the type.
*/
if (type == dns_rdatatype_any)
return (DNS_R_SUCCESS);
result = dns_message_findtype(foundname, type, covers, rdataset);
if (result == DNS_R_NOTFOUND)
return (DNS_R_NXRDATASET);
return (result);
}
void
dns_message_movename(dns_message_t *msg, dns_name_t *name,
dns_section_t fromsection,
dns_section_t tosection)
{
REQUIRE(msg != NULL);
REQUIRE(msg->from_to_wire == DNS_MESSAGE_INTENTRENDER);
REQUIRE(name != NULL);
REQUIRE(VALID_NAMED_SECTION(fromsection));
REQUIRE(VALID_NAMED_SECTION(tosection));
/*
* Unlink the name from the old section
*/
ISC_LIST_UNLINK(msg->sections[fromsection], name, link);
ISC_LIST_APPEND(msg->sections[tosection], name, link);
}
void
dns_message_addname(dns_message_t *msg, dns_name_t *name,
dns_section_t section)
{
REQUIRE(msg != NULL);
REQUIRE(msg->from_to_wire == DNS_MESSAGE_INTENTRENDER);
REQUIRE(name != NULL);
REQUIRE(VALID_NAMED_SECTION(section));
ISC_LIST_APPEND(msg->sections[section], name, link);
}
dns_result_t
dns_message_gettempname(dns_message_t *msg, dns_name_t **item)
{
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE(item != NULL && *item == NULL);
*item = isc_mempool_get(msg->namepool);
if (*item == NULL)
return (DNS_R_NOMEMORY);
return (DNS_R_SUCCESS);
}
void
dns_message_puttempname(dns_message_t *msg, dns_name_t **item)
{
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE(item != NULL && *item != NULL);
isc_mempool_put(msg->namepool, *item);
*item = NULL;
}
dns_result_t
dns_message_gettemprdata(dns_message_t *msg, dns_rdata_t **item)
{
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE(item != NULL && *item == NULL);
*item = newrdata(msg);
if (*item == NULL)
return (DNS_R_NOMEMORY);
return (DNS_R_SUCCESS);
}
dns_result_t
dns_message_gettemprdataset(dns_message_t *msg, dns_rdataset_t **item)
{
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE(item != NULL && *item == NULL);
*item = isc_mempool_get(msg->rdspool);
if (*item == NULL)
return (DNS_R_NOMEMORY);
return (DNS_R_SUCCESS);
}
dns_result_t
dns_message_gettemprdatalist(dns_message_t *msg, dns_rdatalist_t **item)
{
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE(item != NULL && *item == NULL);
*item = newrdatalist(msg);
if (*item == NULL)
return (DNS_R_NOMEMORY);
return (DNS_R_SUCCESS);
}
void
dns_message_puttemprdata(dns_message_t *msg, dns_rdata_t **item)
{
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE(item != NULL && *item != NULL);
releaserdata(msg, *item);
*item = NULL;
}
void
dns_message_puttemprdataset(dns_message_t *msg, dns_rdataset_t **item)
{
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE(item != NULL && *item != NULL);
isc_mempool_put(msg->rdspool, *item);
*item = NULL;
}
void
dns_message_puttemprdatalist(dns_message_t *msg, dns_rdatalist_t **item)
{
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE(item != NULL && *item != NULL);
releaserdatalist(msg, *item);
*item = NULL;
}
dns_result_t
dns_message_peekheader(isc_buffer_t *source, dns_messageid_t *idp,
unsigned int *flagsp)
{
isc_region_t r;
isc_buffer_t buffer;
dns_messageid_t id;
unsigned int flags;
REQUIRE(source != NULL);
buffer = *source;
isc_buffer_remaining(&buffer, &r);
if (r.length < DNS_MESSAGE_HEADERLEN)
return (DNS_R_UNEXPECTEDEND);
id = isc_buffer_getuint16(&buffer);
flags = isc_buffer_getuint16(&buffer);
flags &= DNS_MESSAGE_FLAG_MASK;
if (flagsp != NULL)
*flagsp = flags;
if (idp != NULL)
*idp = id;
return (DNS_R_SUCCESS);
}
dns_result_t
dns_message_reply(dns_message_t *msg, isc_boolean_t want_question_section) {
unsigned int first_section;
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE((msg->flags & DNS_MESSAGEFLAG_QR) == 0);
if (!msg->header_ok)
return (DNS_R_FORMERR);
if (msg->opcode != dns_opcode_query)
want_question_section = ISC_FALSE;
if (want_question_section) {
if (!msg->question_ok)
return (DNS_R_FORMERR);
first_section = DNS_SECTION_ANSWER;
} else
first_section = DNS_SECTION_QUESTION;
msg->from_to_wire = DNS_MESSAGE_INTENTRENDER;
msgresetnames(msg, first_section);
msginitprivate(msg);
/*
* We now clear most flags and then set QR, ensuring that the
* reply's flags will be in a reasonable state.
*/
msg->flags &= DNS_MESSAGE_REPLYPRESERVE;
msg->flags |= DNS_MESSAGEFLAG_QR;
/*
* This saves the query TSIG information for later use, if there is
* any. This only happens once - that is, if dns_message_reply
* has already moved the variables, this has no effect.
*/
if (msg->tsig != NULL) {
msg->querytsig = msg->tsig;
msg->tsig = NULL;
msg->querytsigstatus = msg->tsigstatus;
msg->tsigstatus = dns_rcode_noerror;
}
return (DNS_R_SUCCESS);
}
dns_rdataset_t *
dns_message_getopt(dns_message_t *msg) {
/*
* Get the OPT record for 'msg'.
*/
REQUIRE(DNS_MESSAGE_VALID(msg));
return (msg->opt);
}
dns_result_t
dns_message_setopt(dns_message_t *msg, dns_rdataset_t *opt) {
dns_result_t result;
dns_rdata_t rdata;
/*
* Set the OPT record for 'msg'.
*/
/*
* The space required for an OPT record is:
*
* 1 byte for the name
* 2 bytes for the type
* 2 bytes for the class
* 4 bytes for the ttl
* 2 bytes for the rdata length
* ---------------------------------
* 11 bytes
*
* plus the length of the rdata.
*/
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE(opt->type == dns_rdatatype_opt);
REQUIRE(msg->from_to_wire == DNS_MESSAGE_INTENTRENDER);
REQUIRE(msg->buffer != NULL);
REQUIRE(msg->state == DNS_SECTION_ANY);
if (msg->opt != NULL) {
result = dns_rdataset_first(msg->opt);
if (result != ISC_R_SUCCESS)
return (result);
dns_rdataset_current(msg->opt, &rdata);
result = dns_message_renderrelease(msg, 11 + rdata.length);
dns_rdataset_disassociate(msg->opt);
isc_mempool_put(msg->rdspool, msg->opt);
msg->opt = NULL;
}
result = dns_rdataset_first(opt);
if (result != ISC_R_SUCCESS)
return (result);
dns_rdataset_current(opt, &rdata);
result = dns_message_renderreserve(msg, 11 + rdata.length);
if (result != ISC_R_SUCCESS)
return (result);
msg->opt = opt;
return (DNS_R_SUCCESS);
}
void
dns_message_takebuffer(dns_message_t *msg, isc_buffer_t **buffer)
{
REQUIRE(DNS_MESSAGE_VALID(msg));
REQUIRE(buffer != NULL);
REQUIRE(ISC_BUFFER_VALID(*buffer));
ISC_LIST_APPEND(msg->cleanup, *buffer, link);
*buffer = NULL;
}