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ixfr.c
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ixfr.c
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/*
* ixfr.c -- generating IXFR responses.
*
* Copyright (c) 2021, NLnet Labs. All rights reserved.
*
* See LICENSE for the license.
*
*/
#include "config.h"
#include <errno.h>
#include <string.h>
#include <ctype.h>
#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
#ifdef HAVE_SYS_STAT_H
# include <sys/stat.h>
#endif
#include <unistd.h>
#include "ixfr.h"
#include "packet.h"
#include "rdata.h"
#include "axfr.h"
#include "options.h"
#include "zonec.h"
#include "zone.h"
/*
* For optimal compression IXFR response packets are limited in size
* to MAX_COMPRESSION_OFFSET.
*/
#define IXFR_MAX_MESSAGE_LEN MAX_COMPRESSION_OFFSET
/* draft-ietf-dnsop-rfc2845bis-06, section 5.3.1 says to sign every packet */
#define IXFR_TSIG_SIGN_EVERY_NTH 0 /* tsig sign every N packets. */
/* initial space in rrs data for storing records */
#define IXFR_STORE_INITIAL_SIZE 4096
/* store compression for one name */
struct rrcompress_entry {
/* rbtree node, key is this struct */
struct rbnode node;
/* the uncompressed domain name */
const uint8_t* dname;
/* the length of the dname, includes terminating 0 label */
uint16_t len;
/* the offset of the dname in the packet */
uint16_t offset;
};
/* structure to store compression data for the packet */
struct pktcompression {
/* rbtree of rrcompress_entry. sorted by dname */
struct rbtree tree;
/* allocation information, how many bytes allocated now */
size_t alloc_now;
/* allocation information, total size in block */
size_t alloc_max;
/* region to use if block full, this is NULL if unused */
struct region* region;
/* block of temp data for allocation */
uint8_t block[sizeof(struct rrcompress_entry)*1024];
};
/* compare two elements in the compression tree. Returns -1, 0, or 1. */
static int compression_cmp(const void* a, const void* b)
{
struct rrcompress_entry* rra = (struct rrcompress_entry*)a;
struct rrcompress_entry* rrb = (struct rrcompress_entry*)b;
if(rra->len != rrb->len) {
if(rra->len < rrb->len)
return -1;
return 1;
}
return memcmp(rra->dname, rrb->dname, rra->len);
}
/* init the pktcompression to a new packet */
static void pktcompression_init(struct pktcompression* pcomp)
{
pcomp->alloc_now = 0;
pcomp->alloc_max = sizeof(pcomp->block);
pcomp->region = NULL;
pcomp->tree.root = RBTREE_NULL;
pcomp->tree.count = 0;
pcomp->tree.region = NULL;
pcomp->tree.cmp = &compression_cmp;
}
/* freeup the pktcompression data */
static void pktcompression_freeup(struct pktcompression* pcomp)
{
if(pcomp->region) {
region_destroy(pcomp->region);
pcomp->region = NULL;
}
pcomp->alloc_now = 0;
pcomp->tree.root = RBTREE_NULL;
pcomp->tree.count = 0;
}
/* alloc data in pktcompression */
static void* pktcompression_alloc(struct pktcompression* pcomp, size_t s)
{
/* first attempt to allocate in the fixed block,
* that is very fast and on the stack in the pcomp struct */
if(pcomp->alloc_now + s <= pcomp->alloc_max) {
void* ret = pcomp->block + pcomp->alloc_now;
pcomp->alloc_now += s;
return ret;
}
/* if that fails, create a region to allocate in,
* it is freed in the freeup */
if(!pcomp->region) {
pcomp->region = region_create(xalloc, free);
if(!pcomp->region)
return NULL;
}
return region_alloc(pcomp->region, s);
}
/* find a pktcompression name, return offset if found */
static uint16_t pktcompression_find(struct pktcompression* pcomp,
const uint8_t* dname, size_t len)
{
struct rrcompress_entry key, *found;
key.node.key = &key;
key.dname = dname;
key.len = len;
found = (struct rrcompress_entry*)rbtree_search(&pcomp->tree, &key);
if(found) return found->offset;
return 0;
}
/* insert a new domain name into the compression tree.
* it fails silently, no need to compress then. */
static void pktcompression_insert(struct pktcompression* pcomp,
const uint8_t* dname, size_t len, uint16_t offset)
{
struct rrcompress_entry* entry;
if(len > 65535)
return;
if(offset > MAX_COMPRESSION_OFFSET)
return; /* too far for a compression pointer */
entry = pktcompression_alloc(pcomp, sizeof(*entry));
if(!entry)
return;
memset(&entry->node, 0, sizeof(entry->node));
entry->node.key = entry;
entry->dname = dname;
entry->len = len;
entry->offset = offset;
(void)rbtree_insert(&pcomp->tree, &entry->node);
}
/* insert all the labels of a domain name */
static void pktcompression_insert_with_labels(struct pktcompression* pcomp,
uint8_t* dname, size_t len, uint16_t offset)
{
if(!dname)
return;
if(offset > MAX_COMPRESSION_OFFSET)
return;
/* while we have not seen the end root label */
while(len > 0 && dname[0] != 0) {
size_t lablen;
pktcompression_insert(pcomp, dname, len, offset);
lablen = (size_t)(dname[0]);
if( (lablen&0xc0) )
return; /* the dname should be uncompressed */
if(lablen+1 > len)
return; /* len should be uncompressed wireformat len */
if(offset > MAX_COMPRESSION_OFFSET - lablen - 1)
return; /* offset moves too far for compression */
/* skip label */
len -= lablen+1;
dname += lablen+1;
offset += lablen+1;
}
}
/* calculate length of dname in uncompressed wireformat in buffer */
static size_t dname_length(const uint8_t* buf, size_t len)
{
size_t l = 0;
if(!buf || len == 0)
return l;
while(len > 0 && buf[0] != 0) {
size_t lablen = (size_t)(buf[0]);
if( (lablen&0xc0) )
return 0; /* the name should be uncompressed */
if(lablen+1 > len)
return 0; /* should fit in the buffer */
l += lablen+1;
len -= lablen+1;
buf += lablen+1;
}
if(len == 0)
return 0; /* end label should fit in buffer */
if(buf[0] != 0)
return 0; /* must end in root label */
l += 1; /* for the end root label */
return l;
}
/* write a compressed domain name into the packet,
* returns uncompressed wireformat length,
* 0 if it does not fit and -1 on failure, bad dname. */
static int pktcompression_write_dname(struct buffer* packet,
struct pktcompression* pcomp, const uint8_t* rr, size_t rrlen)
{
size_t wirelen = 0;
size_t dname_len = dname_length(rr, rrlen);
if(!rr || rrlen == 0 || dname_len == 0)
return 0;
while(rrlen > 0 && rr[0] != 0) {
size_t lablen = (size_t)(rr[0]);
uint16_t offset;
if( (lablen&0xc0) )
return -1; /* name should be uncompressed */
if(lablen+1 > rrlen)
return -1; /* name should fit */
/* see if the domain name has a compression pointer */
if((offset=pktcompression_find(pcomp, rr, dname_len))!=0) {
if(!buffer_available(packet, 2))
return 0;
buffer_write_u16(packet, (uint16_t)(0xc000 | offset));
wirelen += dname_len;
return wirelen;
} else {
if(!buffer_available(packet, lablen+1))
return 0;
/* insert the domain name at this position */
pktcompression_insert(pcomp, rr, dname_len,
buffer_position(packet));
/* write it */
buffer_write(packet, rr, lablen+1);
}
wirelen += lablen+1;
rr += lablen+1;
rrlen -= lablen+1;
dname_len -= lablen+1;
}
if(rrlen > 0 && rr[0] == 0) {
/* write end root label */
if(!buffer_available(packet, 1))
return 0;
buffer_write_u8(packet, 0);
wirelen += 1;
}
return wirelen;
}
/* write an RR into the packet with compression for domain names,
* return 0 and resets position if it does not fit in the packet. */
static int ixfr_write_rr_pkt(struct query* query, struct buffer* packet,
struct pktcompression* pcomp, const uint8_t* rr, size_t rrlen,
uint16_t total_added)
{
size_t oldpos = buffer_position(packet);
size_t rdpos;
uint16_t tp;
int dname_len;
size_t rdlen;
size_t i;
rrtype_descriptor_type* descriptor;
if(total_added == 0) {
size_t oldmaxlen = query->maxlen;
/* RR > 16K can be first RR */
query->maxlen = (query->tcp?TCP_MAX_MESSAGE_LEN:UDP_MAX_MESSAGE_LEN);
if(query_overflow(query)) {
query->maxlen = oldmaxlen;
return 0;
}
query->maxlen = oldmaxlen;
} else {
if(buffer_position(packet) > MAX_COMPRESSION_OFFSET
|| query_overflow(query)) {
/* we are past the maximum length */
return 0;
}
}
/* write owner */
dname_len = pktcompression_write_dname(packet, pcomp, rr, rrlen);
if(dname_len == -1)
return 1; /* attempt to skip this malformed rr, could assert */
if(dname_len == 0) {
buffer_set_position(packet, oldpos);
return 0;
}
rr += dname_len;
rrlen -= dname_len;
/* type, class, ttl, rdatalen */
if(!buffer_available(packet, 10)) {
buffer_set_position(packet, oldpos);
return 0;
}
if(10 > rrlen)
return 1; /* attempt to skip this malformed rr, could assert */
tp = read_uint16(rr);
buffer_write(packet, rr, 8);
rr += 8;
rrlen -= 8;
rdlen = read_uint16(rr);
rr += 2;
rrlen -= 2;
rdpos = buffer_position(packet);
buffer_write_u16(packet, 0);
if(rdlen > rrlen)
return 1; /* attempt to skip this malformed rr, could assert */
/* rdata */
descriptor = rrtype_descriptor_by_type(tp);
for(i=0; i<descriptor->maximum; i++) {
size_t copy_len = 0;
if(rdlen == 0)
break;
switch(rdata_atom_wireformat_type(tp, i)) {
case RDATA_WF_COMPRESSED_DNAME:
dname_len = pktcompression_write_dname(packet, pcomp,
rr, rdlen);
if(dname_len == -1)
return 1; /* attempt to skip malformed rr */
if(dname_len == 0) {
buffer_set_position(packet, oldpos);
return 0;
}
rr += dname_len;
rdlen -= dname_len;
break;
case RDATA_WF_UNCOMPRESSED_DNAME:
case RDATA_WF_LITERAL_DNAME:
copy_len = rdlen;
break;
case RDATA_WF_BYTE:
copy_len = 1;
break;
case RDATA_WF_SHORT:
copy_len = 2;
break;
case RDATA_WF_LONG:
copy_len = 4;
break;
case RDATA_WF_TEXTS:
case RDATA_WF_LONG_TEXT:
copy_len = rdlen;
break;
case RDATA_WF_TEXT:
case RDATA_WF_BINARYWITHLENGTH:
copy_len = 1;
if(rdlen > copy_len)
copy_len += rr[0];
break;
case RDATA_WF_A:
copy_len = 4;
break;
case RDATA_WF_AAAA:
copy_len = 16;
break;
case RDATA_WF_ILNP64:
copy_len = 8;
break;
case RDATA_WF_EUI48:
copy_len = EUI48ADDRLEN;
break;
case RDATA_WF_EUI64:
copy_len = EUI64ADDRLEN;
break;
case RDATA_WF_BINARY:
copy_len = rdlen;
break;
case RDATA_WF_APL:
copy_len = (sizeof(uint16_t) /* address family */
+ sizeof(uint8_t) /* prefix */
+ sizeof(uint8_t)); /* length */
if(copy_len <= rdlen)
copy_len += (rr[copy_len-1]&APL_LENGTH_MASK);
break;
case RDATA_WF_IPSECGATEWAY:
copy_len = rdlen;
break;
case RDATA_WF_SVCPARAM:
copy_len = 4;
if(copy_len <= rdlen)
copy_len += read_uint16(rr+2);
break;
default:
copy_len = rdlen;
break;
}
if(copy_len) {
if(!buffer_available(packet, copy_len)) {
buffer_set_position(packet, oldpos);
return 0;
}
if(copy_len > rdlen)
return 1; /* assert of skip malformed */
buffer_write(packet, rr, copy_len);
rr += copy_len;
rdlen -= copy_len;
}
}
/* write compressed rdata length */
buffer_write_u16_at(packet, rdpos, buffer_position(packet)-rdpos-2);
if(total_added == 0) {
size_t oldmaxlen = query->maxlen;
query->maxlen = (query->tcp?TCP_MAX_MESSAGE_LEN:UDP_MAX_MESSAGE_LEN);
if(query_overflow(query)) {
query->maxlen = oldmaxlen;
buffer_set_position(packet, oldpos);
return 0;
}
query->maxlen = oldmaxlen;
} else {
if(query_overflow(query)) {
/* we are past the maximum length */
buffer_set_position(packet, oldpos);
return 0;
}
}
return 1;
}
/* parse the serial number from the IXFR query */
static int parse_qserial(struct buffer* packet, uint32_t* qserial,
size_t* snip_pos)
{
unsigned int i;
uint16_t type, rdlen;
/* we must have a SOA in the authority section */
if(NSCOUNT(packet) == 0)
return 0;
/* skip over the question section, we want only one */
buffer_set_position(packet, QHEADERSZ);
if(QDCOUNT(packet) != 1)
return 0;
if(!packet_skip_rr(packet, 1))
return 0;
/* set position to snip off the authority section */
*snip_pos = buffer_position(packet);
/* skip over the authority section RRs until we find the SOA */
for(i=0; i<NSCOUNT(packet); i++) {
/* is this the SOA record? */
if(!packet_skip_dname(packet))
return 0; /* malformed name */
if(!buffer_available(packet, 10))
return 0; /* no type,class,ttl,rdatalen */
type = buffer_read_u16(packet);
buffer_skip(packet, 6);
rdlen = buffer_read_u16(packet);
if(!buffer_available(packet, rdlen))
return 0;
if(type == TYPE_SOA) {
/* read serial from rdata, skip two dnames, then
* read the 32bit value */
if(!packet_skip_dname(packet))
return 0; /* malformed nsname */
if(!packet_skip_dname(packet))
return 0; /* malformed rname */
if(!buffer_available(packet, 4))
return 0;
*qserial = buffer_read_u32(packet);
return 1;
}
buffer_skip(packet, rdlen);
}
return 0;
}
/* get serial from SOA RR */
static uint32_t soa_rr_get_serial(struct rr* rr)
{
if(rr->rdata_count < 3)
return 0;
if(rr->rdatas[2].data[0] < 4)
return 0;
return read_uint32(&rr->rdatas[2].data[1]);
}
/* get the current serial from the zone */
uint32_t zone_get_current_serial(struct zone* zone)
{
if(!zone || !zone->soa_rrset)
return 0;
if(zone->soa_rrset->rr_count == 0)
return 0;
if(zone->soa_rrset->rrs[0].rdata_count < 3)
return 0;
if(zone->soa_rrset->rrs[0].rdatas[2].data[0] < 4)
return 0;
return read_uint32(&zone->soa_rrset->rrs[0].rdatas[2].data[1]);
}
/* iterator over ixfr data. find first element, eg. oldest zone version
* change.
* The iterator can be started with the ixfr_data_first, but also with
* ixfr_data_last, or with an existing ixfr_data element to start from.
* Continue by using ixfr_data_next or ixfr_data_prev to ask for more elements
* until that returns NULL. NULL because end of list or loop was detected.
* The ixfr_data_prev uses a counter, start it at 0, it returns NULL when
* a loop is detected.
*/
static struct ixfr_data* ixfr_data_first(struct zone_ixfr* ixfr)
{
struct ixfr_data* n;
if(!ixfr || !ixfr->data || ixfr->data->count==0)
return NULL;
n = (struct ixfr_data*)rbtree_search(ixfr->data, &ixfr->oldest_serial);
if(!n || n == (struct ixfr_data*)RBTREE_NULL)
return NULL;
return n;
}
/* iterator over ixfr data. find last element, eg. newest zone version
* change. */
static struct ixfr_data* ixfr_data_last(struct zone_ixfr* ixfr)
{
struct ixfr_data* n;
if(!ixfr || !ixfr->data || ixfr->data->count==0)
return NULL;
n = (struct ixfr_data*)rbtree_search(ixfr->data, &ixfr->newest_serial);
if(!n || n == (struct ixfr_data*)RBTREE_NULL)
return NULL;
return n;
}
/* iterator over ixfr data. fetch next item. If loop or nothing, NULL */
static struct ixfr_data* ixfr_data_next(struct zone_ixfr* ixfr,
struct ixfr_data* cur)
{
struct ixfr_data* n;
if(!cur || cur == (struct ixfr_data*)RBTREE_NULL)
return NULL;
if(cur->oldserial == ixfr->newest_serial)
return NULL; /* that was the last element */
n = (struct ixfr_data*)rbtree_next(&cur->node);
if(n && n != (struct ixfr_data*)RBTREE_NULL &&
cur->newserial == n->oldserial) {
/* the next rbtree item is the next ixfr data item */
return n;
}
/* If the next item is last of tree, and we have to loop around,
* the search performs the lookup for the next item we need.
* If the next item exists, but also is not connected, the search
* finds the correct connected ixfr in the sorted tree. */
/* try searching for the correct ixfr data item */
n = (struct ixfr_data*)rbtree_search(ixfr->data, &cur->newserial);
if(!n || n == (struct ixfr_data*)RBTREE_NULL)
return NULL;
return n;
}
/* iterator over ixfr data. fetch the previous item. If loop or nothing NULL.*/
static struct ixfr_data* ixfr_data_prev(struct zone_ixfr* ixfr,
struct ixfr_data* cur, size_t* prevcount)
{
struct ixfr_data* prev;
if(!cur || cur == (struct ixfr_data*)RBTREE_NULL)
return NULL;
if(cur->oldserial == ixfr->oldest_serial)
return NULL; /* this was the first element */
prev = (struct ixfr_data*)rbtree_previous(&cur->node);
if(!prev || prev == (struct ixfr_data*)RBTREE_NULL) {
/* We hit the first element in the tree, go again
* at the last one. Wrap around. */
prev = (struct ixfr_data*)rbtree_last(ixfr->data);
}
while(prev && prev != (struct ixfr_data*)RBTREE_NULL) {
if(prev->newserial == cur->oldserial) {
/* This is the correct matching previous ixfr data */
/* Increase the prevcounter every time the routine
* returns an item, and if that becomes too large, we
* are in a loop. in that case, stop. */
if(prevcount) {
(*prevcount)++;
if(*prevcount > ixfr->data->count + 12) {
/* Larger than the max number of items
* plus a small margin. The longest
* chain is all the ixfr elements in
* the tree. It loops. */
return NULL;
}
}
return prev;
}
prev = (struct ixfr_data*)rbtree_previous(&prev->node);
if(!prev || prev == (struct ixfr_data*)RBTREE_NULL) {
/* We hit the first element in the tree, go again
* at the last one. Wrap around. */
prev = (struct ixfr_data*)rbtree_last(ixfr->data);
}
}
/* no elements in list */
return NULL;
}
/* connect IXFRs, return true if connected, false if not. Return last serial */
static int connect_ixfrs(struct zone_ixfr* ixfr, struct ixfr_data* data,
uint32_t* end_serial)
{
struct ixfr_data* p = data;
while(p != NULL) {
struct ixfr_data* next = ixfr_data_next(ixfr, p);
if(next) {
if(p->newserial != next->oldserial) {
/* These ixfrs are not connected,
* during IXFR processing that could already
* have been deleted, but we check here
* in any case */
return 0;
}
} else {
/* the chain of IXFRs ends in this serial number */
*end_serial = p->newserial;
}
p = next;
}
return 1;
}
/* Count length of next record in data */
static size_t count_rr_length(const uint8_t* data, size_t data_len,
size_t current)
{
uint8_t label_size;
uint16_t rdlen;
size_t i = current;
if(current >= data_len)
return 0;
/* pass the owner dname */
while(1) {
if(i+1 > data_len)
return 0;
label_size = data[i++];
if(label_size == 0) {
break;
} else if((label_size &0xc0) != 0) {
return 0; /* uncompressed dnames in IXFR store */
} else if(i+label_size > data_len) {
return 0;
} else {
i += label_size;
}
}
/* after dname, we pass type, class, ttl, rdatalen */
if(i+10 > data_len)
return 0;
i += 8;
rdlen = read_uint16(data+i);
i += 2;
/* pass over the rdata */
if(i+((size_t)rdlen) > data_len)
return 0;
i += ((size_t)rdlen);
return i-current;
}
/* Copy RRs into packet until packet full, return number RRs added */
static uint16_t ixfr_copy_rrs_into_packet(struct query* query,
struct pktcompression* pcomp)
{
uint16_t total_added = 0;
/* Copy RRs into the packet until the answer is full,
* when an RR does not fit, we return and add no more. */
/* Add first SOA */
if(query->ixfr_count_newsoa < query->ixfr_end_data->newsoa_len) {
/* the new SOA is added from the end_data segment, it is
* the final SOA of the result of the IXFR */
if(ixfr_write_rr_pkt(query, query->packet, pcomp,
query->ixfr_end_data->newsoa,
query->ixfr_end_data->newsoa_len, total_added)) {
query->ixfr_count_newsoa = query->ixfr_end_data->newsoa_len;
total_added++;
query->ixfr_pos_of_newsoa = buffer_position(query->packet);
} else {
/* cannot add another RR, so return */
return total_added;
}
}
/* Add second SOA */
if(query->ixfr_count_oldsoa < query->ixfr_data->oldsoa_len) {
if(ixfr_write_rr_pkt(query, query->packet, pcomp,
query->ixfr_data->oldsoa,
query->ixfr_data->oldsoa_len, total_added)) {
query->ixfr_count_oldsoa = query->ixfr_data->oldsoa_len;
total_added++;
} else {
/* cannot add another RR, so return */
return total_added;
}
}
/* Add del data, with deleted RRs and a SOA */
while(query->ixfr_count_del < query->ixfr_data->del_len) {
size_t rrlen = count_rr_length(query->ixfr_data->del,
query->ixfr_data->del_len, query->ixfr_count_del);
if(rrlen && ixfr_write_rr_pkt(query, query->packet, pcomp,
query->ixfr_data->del + query->ixfr_count_del,
rrlen, total_added)) {
query->ixfr_count_del += rrlen;
total_added++;
} else {
/* the next record does not fit in the remaining
* space of the packet */
return total_added;
}
}
/* Add add data, with added RRs and a SOA */
while(query->ixfr_count_add < query->ixfr_data->add_len) {
size_t rrlen = count_rr_length(query->ixfr_data->add,
query->ixfr_data->add_len, query->ixfr_count_add);
if(rrlen && ixfr_write_rr_pkt(query, query->packet, pcomp,
query->ixfr_data->add + query->ixfr_count_add,
rrlen, total_added)) {
query->ixfr_count_add += rrlen;
total_added++;
} else {
/* the next record does not fit in the remaining
* space of the packet */
return total_added;
}
}
return total_added;
}
query_state_type query_ixfr(struct nsd *nsd, struct query *query)
{
uint16_t total_added = 0;
struct pktcompression pcomp;
if (query->ixfr_is_done)
return QUERY_PROCESSED;
pktcompression_init(&pcomp);
if (query->maxlen > IXFR_MAX_MESSAGE_LEN)
query->maxlen = IXFR_MAX_MESSAGE_LEN;
assert(!query_overflow(query));
/* only keep running values for most packets */
query->tsig_prepare_it = 0;
query->tsig_update_it = 1;
if(query->tsig_sign_it) {
/* prepare for next updates */
query->tsig_prepare_it = 1;
query->tsig_sign_it = 0;
}
if (query->ixfr_data == NULL) {
/* This is the first packet, process the query further */
uint32_t qserial = 0, current_serial = 0, end_serial = 0;
struct zone* zone;
struct ixfr_data* ixfr_data;
size_t oldpos;
STATUP(nsd, rixfr);
/* parse the serial number from the IXFR request */
oldpos = QHEADERSZ;
if(!parse_qserial(query->packet, &qserial, &oldpos)) {
NSCOUNT_SET(query->packet, 0);
ARCOUNT_SET(query->packet, 0);
buffer_set_position(query->packet, oldpos);
RCODE_SET(query->packet, RCODE_FORMAT);
return QUERY_PROCESSED;
}
NSCOUNT_SET(query->packet, 0);
ARCOUNT_SET(query->packet, 0);
buffer_set_position(query->packet, oldpos);
DEBUG(DEBUG_XFRD,1, (LOG_INFO, "ixfr query routine, %s IXFR=%u",
dname_to_string(query->qname, NULL), (unsigned)qserial));
/* do we have an IXFR with this serial number? If not, serve AXFR */
zone = namedb_find_zone(nsd->db, query->qname);
if(!zone) {
/* no zone is present */
RCODE_SET(query->packet, RCODE_NOTAUTH);
return QUERY_PROCESSED;
}
ZTATUP(nsd, zone, rixfr);
/* if the query is for same or newer serial than our current
* serial, then serve a single SOA with our current serial */
current_serial = zone_get_current_serial(zone);
if(compare_serial(qserial, current_serial) >= 0) {
if(!zone->soa_rrset || zone->soa_rrset->rr_count != 1){
RCODE_SET(query->packet, RCODE_SERVFAIL);
return QUERY_PROCESSED;
}
query_add_compression_domain(query, zone->apex,
QHEADERSZ);
if(packet_encode_rr(query, zone->apex,
&zone->soa_rrset->rrs[0],
zone->soa_rrset->rrs[0].ttl)) {
ANCOUNT_SET(query->packet, 1);
} else {
RCODE_SET(query->packet, RCODE_SERVFAIL);
}
AA_SET(query->packet);
query_clear_compression_tables(query);
if(query->tsig.status == TSIG_OK)
query->tsig_sign_it = 1;
return QUERY_PROCESSED;
}
if(!zone->ixfr) {
/* we have no ixfr information for the zone, make an AXFR */
if(query->tsig_prepare_it)
query->tsig_sign_it = 1;
VERBOSITY(2, (LOG_INFO, "ixfr fallback to axfr, no ixfr info for zone: %s",
dname_to_string(query->qname, NULL)));
return query_axfr(nsd, query, 0);
}
ixfr_data = zone_ixfr_find_serial(zone->ixfr, qserial);
if(!ixfr_data) {
/* the specific version is not available, make an AXFR */
if(query->tsig_prepare_it)
query->tsig_sign_it = 1;
VERBOSITY(2, (LOG_INFO, "ixfr fallback to axfr, no history for serial for zone: %s",
dname_to_string(query->qname, NULL)));
return query_axfr(nsd, query, 0);
}
/* see if the IXFRs connect to the next IXFR, and if it ends
* at the current served zone, if not, AXFR */
if(!connect_ixfrs(zone->ixfr, ixfr_data, &end_serial) ||
end_serial != current_serial) {
if(query->tsig_prepare_it)
query->tsig_sign_it = 1;
VERBOSITY(2, (LOG_INFO, "ixfr fallback to axfr, incomplete history from this serial for zone: %s",
dname_to_string(query->qname, NULL)));
return query_axfr(nsd, query, 0);
}
query->zone = zone;
query->ixfr_data = ixfr_data;
query->ixfr_is_done = 0;
/* set up to copy the last version's SOA as first SOA */
query->ixfr_end_data = ixfr_data_last(zone->ixfr);
query->ixfr_count_newsoa = 0;
query->ixfr_count_oldsoa = 0;
query->ixfr_count_del = 0;
query->ixfr_count_add = 0;
query->ixfr_pos_of_newsoa = 0;
/* the query name can be compressed to */
pktcompression_insert_with_labels(&pcomp,
buffer_at(query->packet, QHEADERSZ),
query->qname->name_size, QHEADERSZ);
if(query->tsig.status == TSIG_OK) {
query->tsig_sign_it = 1; /* sign first packet in stream */
}
} else {
/*
* Query name need not be repeated after the
* first response packet.
*/
buffer_set_limit(query->packet, QHEADERSZ);
QDCOUNT_SET(query->packet, 0);
query_prepare_response(query);
}
total_added = ixfr_copy_rrs_into_packet(query, &pcomp);
while(query->ixfr_count_add >= query->ixfr_data->add_len) {
struct ixfr_data* next = ixfr_data_next(query->zone->ixfr,
query->ixfr_data);
/* finished the ixfr_data */
if(next) {
/* move to the next IXFR */
query->ixfr_data = next;
/* we need to skip the SOA records, set len to done*/
/* the newsoa count is already done, at end_data len */
query->ixfr_count_oldsoa = next->oldsoa_len;
/* and then set up to copy the del and add sections */
query->ixfr_count_del = 0;
query->ixfr_count_add = 0;
total_added += ixfr_copy_rrs_into_packet(query, &pcomp);
} else {
/* we finished the IXFR */
/* sign the last packet */
query->tsig_sign_it = 1;
query->ixfr_is_done = 1;
break;
}
}
/* return the answer */
AA_SET(query->packet);
ANCOUNT_SET(query->packet, total_added);
NSCOUNT_SET(query->packet, 0);
ARCOUNT_SET(query->packet, 0);
if(!query->tcp && !query->ixfr_is_done) {
TC_SET(query->packet);
if(query->ixfr_pos_of_newsoa) {
/* if we recorded the newsoa in the result, snip off
* the rest of the response, the RFC1995 response for
* when it does not fit is only the latest SOA */
buffer_set_position(query->packet, query->ixfr_pos_of_newsoa);
ANCOUNT_SET(query->packet, 1);
}
query->ixfr_is_done = 1;
}
/* check if it needs tsig signatures */
if(query->tsig.status == TSIG_OK) {
#if IXFR_TSIG_SIGN_EVERY_NTH > 0
if(query->tsig.updates_since_last_prepare >= IXFR_TSIG_SIGN_EVERY_NTH) {
#endif
query->tsig_sign_it = 1;
#if IXFR_TSIG_SIGN_EVERY_NTH > 0
}
#endif
}
pktcompression_freeup(&pcomp);
return QUERY_IN_IXFR;
}
/* free ixfr_data structure */
static void ixfr_data_free(struct ixfr_data* data)
{
if(!data)
return;
free(data->newsoa);
free(data->oldsoa);
free(data->del);
free(data->add);
free(data->log_str);
free(data);
}
size_t ixfr_data_size(struct ixfr_data* data)
{
return sizeof(struct ixfr_data) + data->newsoa_len + data->oldsoa_len
+ data->del_len + data->add_len;
}
struct ixfr_store* ixfr_store_start(struct zone* zone,
struct ixfr_store* ixfr_store_mem)
{
struct ixfr_store* ixfr_store = ixfr_store_mem;
memset(ixfr_store, 0, sizeof(*ixfr_store));
ixfr_store->zone = zone;
ixfr_store->data = xalloc_zero(sizeof(*ixfr_store->data));
return ixfr_store;
}
void ixfr_store_cancel(struct ixfr_store* ixfr_store)
{
ixfr_store->cancelled = 1;
ixfr_data_free(ixfr_store->data);
ixfr_store->data = NULL;
}
void ixfr_store_free(struct ixfr_store* ixfr_store)
{
if(!ixfr_store)
return;
ixfr_data_free(ixfr_store->data);
}
/* make space in record data for the new size, grows the allocation */
static void ixfr_rrs_make_space(uint8_t** rrs, size_t* len, size_t* capacity,
size_t added)
{
size_t newsize = 0;
if(*rrs == NULL) {
newsize = IXFR_STORE_INITIAL_SIZE;
} else {
if(*len + added <= *capacity)
return; /* already enough space */
newsize = (*capacity)*2;
}
if(*len + added > newsize)
newsize = *len + added;
if(*rrs == NULL) {
*rrs = xalloc(newsize);
} else {
*rrs = xrealloc(*rrs, newsize);
}
*capacity = newsize;
}
/* put new SOA record after delrrs and addrrs */
static void ixfr_put_newsoa(struct ixfr_store* ixfr_store, uint8_t** rrs,
size_t* len, size_t* capacity)
{