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start of EDNS work; TC truncation of message encoding.

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git-svn-id: file:///svn/unbound/trunk@276 be551aaa-1e26-0410-a405-d3ace91eadb9
This commit is contained in:
Wouter Wijngaards 2007-05-02 15:31:32 +00:00
parent 9d3e09b838
commit d86f444442
4 changed files with 143 additions and 72 deletions
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2
doc/Changelog
View file

@ -1,6 +1,8 @@
2 May 2007: Wouter
- dname unit tests in own file and spread out neatly in functions.
- more dname unit tests.
- message encoding creates truncated TC flagged messages if they do
not fit, and will leave out (whole)rrsets from additional if needed.
1 May 2007: Wouter
- decompress query section, extremely lenient acceptance.

2
util/data/msgparse.h
View file

@ -180,6 +180,8 @@ struct rr_parse {
/** Calculate destination offset of a compression pointer. pass first and
* second octets of the compression pointer. */
#define PTR_OFFSET(x, y) ( ((x)&0x3f)<<8 | (y) )
/** create a compression pointer to the given offset. */
#define PTR_CREATE(offset) ((uint16_t)(0xc000 | (offset)))
/** error codes, extended with EDNS, so > 15. */
#define EDNS_RCODE_BADVERS 16 /** bad EDNS version */

206
util/data/msgreply.c
View file

@ -50,6 +50,14 @@
#include "util/region-allocator.h"
#include "util/data/msgparse.h"
/** return code that means the function ran out of memory. negative so it does
* not conflict with DNS rcodes. */
#define RETVAL_OUTMEM -2
/** return code that means the data did not fit (completely) in the packet */
#define RETVAL_TRUNC -4
/** return code that means all is peachy keen. Equal to DNS rcode NOERROR */
#define RETVAL_OK 0
/** allocate qinfo, return 0 on error. */
static int
parse_create_qinfo(ldns_buffer* pkt, struct msg_parse* msg,
@ -668,7 +676,7 @@ compress_tree_store(struct compress_tree_node** tree, uint8_t* dname,
}
/** compress a domain name */
static void
static int
write_compressed_dname(ldns_buffer* pkt, uint8_t* dname, int labs,
struct compress_tree_node* p)
{
@ -680,16 +688,21 @@ write_compressed_dname(ldns_buffer* pkt, uint8_t* dname, int labs,
/* copy the first couple of labels */
while(labcopy--) {
lablen = *dname++;
if(ldns_buffer_remaining(pkt) < (size_t)lablen+1)
return 0;
ldns_buffer_write_u8(pkt, lablen);
ldns_buffer_write(pkt, dname, lablen);
dname += lablen;
}
/* insert compression ptr */
ptr = (uint16_t)(0xc000 | p->offset);
if(ldns_buffer_remaining(pkt) < 2)
return 0;
ptr = PTR_CREATE(p->offset);
ldns_buffer_write_u16(pkt, ptr);
return 1;
}
/** compress owner name of RR */
/** compress owner name of RR, return RETVAL_OUTMEM RETVAL_TRUNC */
static int
compress_owner(struct ub_packed_rrset_key* key, ldns_buffer* pkt,
region_type* region, struct compress_tree_node** tree,
@ -703,39 +716,38 @@ compress_owner(struct ub_packed_rrset_key* key, ldns_buffer* pkt,
if(p->labs == owner_labs)
/* avoid ptr chains, since some software is
* not capable of decoding ptr after a ptr. */
*owner_ptr = htons((uint16_t)(0xc000 |
p->offset));
/* check if ptr + tc+4 ttl + rdatalen is available */
if(ldns_buffer_remaining(pkt) < 2+4+4+2)
return 0;
write_compressed_dname(pkt, key->rk.dname,
owner_labs, p);
*owner_ptr = htons(PTR_CREATE(p->offset));
if(!write_compressed_dname(pkt, key->rk.dname,
owner_labs, p))
return RETVAL_TRUNC;
/* check if typeclass+4 ttl + rdatalen is available */
if(ldns_buffer_remaining(pkt) < 4+4+2)
return RETVAL_TRUNC;
ldns_buffer_write(pkt, &key->rk.dname[
key->rk.dname_len], 4);
} else {
/* no compress */
if(ldns_buffer_remaining(pkt) < key->rk.dname_len+4+4+2)
return 0;
return RETVAL_TRUNC;
ldns_buffer_write(pkt, key->rk.dname,
key->rk.dname_len+4);
if(owner_pos <= PTR_MAX_OFFSET)
*owner_ptr = htons((uint16_t)(0xc000 |
owner_pos));
*owner_ptr = htons(PTR_CREATE(owner_pos));
}
if(!compress_tree_store(tree, key->rk.dname,
owner_labs, owner_pos, region, p))
return 0;
return RETVAL_OUTMEM;
} else {
/* always compress 2nd-further RRs in RRset */
if(ldns_buffer_remaining(pkt) < 2+4+4+2)
return 0;
return RETVAL_TRUNC;
ldns_buffer_write(pkt, owner_ptr, 2);
ldns_buffer_write(pkt, &key->rk.dname[key->rk.dname_len], 4);
}
return 1;
return RETVAL_OK;
}
/** compress any domain name to the packet */
/** compress any domain name to the packet, return RETVAL_* */
static int
compress_any_dname(uint8_t* dname, ldns_buffer* pkt, int labs,
region_type* region, struct compress_tree_node** tree)
@ -743,13 +755,15 @@ compress_any_dname(uint8_t* dname, ldns_buffer* pkt, int labs,
struct compress_tree_node* p;
size_t pos = ldns_buffer_position(pkt);
if((p = compress_tree_lookup(*tree, dname, labs))) {
if(ldns_buffer_remaining(pkt) < 2)
return 0;
write_compressed_dname(pkt, dname, labs, p);
if(!write_compressed_dname(pkt, dname, labs, p))
return RETVAL_TRUNC;
} else {
dname_buffer_write(pkt, dname);
if(!dname_buffer_write(pkt, dname))
return RETVAL_TRUNC;
}
return compress_tree_store(tree, dname, labs, pos, region, p);
if(!compress_tree_store(tree, dname, labs, pos, region, p))
return RETVAL_OUTMEM;
return RETVAL_OK;
}
/** return true if type needs domain name compression in rdata */
@ -765,13 +779,13 @@ type_rdata_compressable(struct ub_packed_rrset_key* key)
return 0;
}
/** compress domain names in rdata */
/** compress domain names in rdata, return RETVAL_* */
static int
compress_rdata(ldns_buffer* pkt, uint8_t* rdata, size_t todolen,
region_type* region, struct compress_tree_node** tree,
const ldns_rr_descriptor* desc)
{
int labs, rdf = 0;
int labs, r, rdf = 0;
size_t dname_len, len, pos = ldns_buffer_position(pkt);
uint8_t count = desc->_dname_count;
@ -783,8 +797,9 @@ compress_rdata(ldns_buffer* pkt, uint8_t* rdata, size_t todolen,
switch(desc->_wireformat[rdf]) {
case LDNS_RDF_TYPE_DNAME:
labs = dname_count_size_labels(rdata, &dname_len);
if(!compress_any_dname(rdata, pkt, labs, region, tree))
return 0;
if((r=compress_any_dname(rdata, pkt, labs, region,
tree)) != RETVAL_OK)
return r;
rdata += dname_len;
todolen -= dname_len;
count--;
@ -799,7 +814,7 @@ compress_rdata(ldns_buffer* pkt, uint8_t* rdata, size_t todolen,
if(len) {
/* copy over */
if(ldns_buffer_remaining(pkt) < len)
return 0;
return RETVAL_TRUNC;
ldns_buffer_write(pkt, rdata, len);
todolen -= len;
rdata += len;
@ -809,23 +824,23 @@ compress_rdata(ldns_buffer* pkt, uint8_t* rdata, size_t todolen,
/* copy remainder */
if(todolen > 0) {
if(ldns_buffer_remaining(pkt) < todolen)
return 0;
return RETVAL_TRUNC;
ldns_buffer_write(pkt, rdata, todolen);
}
/* set rdata len */
ldns_buffer_write_u16_at(pkt, pos, ldns_buffer_position(pkt)-pos-2);
return 1;
return RETVAL_OK;
}
/** store rrset in iov vector */
/** store rrset in buffer in wireformat, return RETVAL_* */
static int
packed_rrset_iov(struct ub_packed_rrset_key* key, ldns_buffer* pkt,
packed_rrset_encode(struct ub_packed_rrset_key* key, ldns_buffer* pkt,
uint16_t* num_rrs, uint32_t timenow, region_type* region,
int do_data, int do_sig, struct compress_tree_node** tree)
{
size_t i, owner_pos;
int owner_labs;
int r, owner_labs;
uint16_t owner_ptr = 0;
struct packed_rrset_data* data = (struct packed_rrset_data*)
key->entry.data;
@ -835,27 +850,29 @@ packed_rrset_iov(struct ub_packed_rrset_key* key, ldns_buffer* pkt,
if(do_data) {
const ldns_rr_descriptor* c = type_rdata_compressable(key);
*num_rrs += data->count;
for(i=0; i<data->count; i++) {
if(1) { /* compression */
if(!compress_owner(key, pkt, region, tree,
if((r=compress_owner(key, pkt, region, tree,
owner_pos, &owner_ptr, owner_labs))
return 0;
!= RETVAL_OK)
return r;
} else {
/* no compression */
if(ldns_buffer_remaining(pkt) <
key->rk.dname_len + 4+4+2) return 0;
key->rk.dname_len + 4+4+2)
return RETVAL_TRUNC;
ldns_buffer_write(pkt, key->rk.dname,
key->rk.dname_len + 4);
}
ldns_buffer_write_u32(pkt, data->rr_ttl[i]-timenow);
if(c) {
if(!compress_rdata(pkt, data->rr_data[i],
if((r=compress_rdata(pkt, data->rr_data[i],
data->rr_len[i], region, tree, c))
return 0;
!= RETVAL_OK)
return r;
} else {
if(ldns_buffer_remaining(pkt) < data->rr_len[i])
return 0;
return RETVAL_TRUNC;
ldns_buffer_write(pkt, data->rr_data[i],
data->rr_len[i]);
}
@ -864,24 +881,27 @@ packed_rrset_iov(struct ub_packed_rrset_key* key, ldns_buffer* pkt,
/* insert rrsigs */
if(do_sig) {
size_t total = data->count+data->rrsig_count;
*num_rrs += data->rrsig_count;
for(i=data->count; i<total; i++) {
if(1) { /* compression */
if(owner_ptr) {
if(ldns_buffer_remaining(pkt) <
2+4+4+data->rr_len[i])
return 0;
return RETVAL_TRUNC;
ldns_buffer_write(pkt, &owner_ptr, 2);
} else {
if(!compress_any_dname(key->rk.dname,
if((r=compress_any_dname(key->rk.dname,
pkt, owner_labs, region, tree))
return 0;
!= RETVAL_OK)
return r;
if(ldns_buffer_remaining(pkt) <
4+4+data->rr_len[i])
return RETVAL_TRUNC;
}
} else {
/* no compression */
if(ldns_buffer_remaining(pkt) <
key->rk.dname_len+4+4+data->rr_len[i])
return 0;
return RETVAL_TRUNC;
ldns_buffer_write(pkt, key->rk.dname,
key->rk.dname_len);
}
@ -895,36 +915,57 @@ packed_rrset_iov(struct ub_packed_rrset_key* key, ldns_buffer* pkt,
data->rr_len[i]);
}
}
/* change rrnum only after we are sure it fits */
if(do_data)
*num_rrs += data->count;
if(do_sig)
*num_rrs += data->rrsig_count;
return 1;
return RETVAL_OK;
}
/** store msg section in iov vector */
/** store msg section in wireformat buffer, return RETVAL_* */
static int
insert_section(struct reply_info* rep, size_t num_rrsets, uint16_t* num_rrs,
ldns_buffer* pkt, size_t rrsets_before, uint32_t timenow,
region_type* region, int addit, struct compress_tree_node** tree)
{
size_t i;
int r;
size_t i, setstart;
*num_rrs = 0;
if(!addit) {
for(i=0; i<num_rrsets; i++)
if(!packed_rrset_iov(rep->rrsets[rrsets_before+i], pkt,
num_rrs, timenow, region, 1, 1, tree))
/* Bad, but if due to size must set TC bit */
return 0;
for(i=0; i<num_rrsets; i++) {
setstart = ldns_buffer_position(pkt);
if((r=packed_rrset_encode(rep->rrsets[rrsets_before+i],
pkt, num_rrs, timenow, region, 1, 1, tree))
!= RETVAL_OK) {
/* Bad, but if due to size must set TC bit */
/* trim off the rrset neatly. */
ldns_buffer_set_position(pkt, setstart);
return r;
}
}
} else {
/* might be OKAY to discard rrsets at end */
for(i=0; i<num_rrsets; i++)
if(!packed_rrset_iov(rep->rrsets[rrsets_before+i], pkt,
num_rrs, timenow, region, 1, 0, tree))
return 0;
for(i=0; i<num_rrsets; i++)
if(!packed_rrset_iov(rep->rrsets[rrsets_before+i], pkt,
num_rrs, timenow, region, 0, 1, tree))
return 0;
for(i=0; i<num_rrsets; i++) {
setstart = ldns_buffer_position(pkt);
if((r=packed_rrset_encode(rep->rrsets[rrsets_before+i],
pkt, num_rrs, timenow, region, 1, 0, tree))
!= RETVAL_OK) {
ldns_buffer_set_position(pkt, setstart);
return r;
}
}
for(i=0; i<num_rrsets; i++) {
setstart = ldns_buffer_position(pkt);
if((r=packed_rrset_encode(rep->rrsets[rrsets_before+i],
pkt, num_rrs, timenow, region, 0, 1, tree))
!= RETVAL_OK) {
ldns_buffer_set_position(pkt, setstart);
return r;
}
}
}
return 1;
return RETVAL_OK;
}
int reply_info_encode(struct query_info* qinfo, struct reply_info* rep,
@ -933,6 +974,7 @@ int reply_info_encode(struct query_info* qinfo, struct reply_info* rep,
{
uint16_t ancount=0, nscount=0, arcount=0;
struct compress_tree_node* tree = 0;
int r;
ldns_buffer_clear(buffer);
if(ldns_buffer_remaining(buffer) < LDNS_HEADER_SIZE)
@ -941,8 +983,8 @@ int reply_info_encode(struct query_info* qinfo, struct reply_info* rep,
ldns_buffer_write(buffer, &id, sizeof(uint16_t));
ldns_buffer_write_u16(buffer, flags);
ldns_buffer_write_u16(buffer, rep->qdcount);
/* skip an, ns, ar counts */
ldns_buffer_set_position(buffer, LDNS_HEADER_SIZE);
/* set an, ns, ar counts to zero in case of small packets */
ldns_buffer_write(buffer, "\000\000\000\000\000\000", 6);
/* insert query section */
if(rep->qdcount) {
@ -959,25 +1001,47 @@ int reply_info_encode(struct query_info* qinfo, struct reply_info* rep,
}
/* insert answer section */
if(!insert_section(rep, rep->an_numrrsets, &ancount, buffer,
0, timenow, region, 0, &tree))
if((r=insert_section(rep, rep->an_numrrsets, &ancount, buffer,
0, timenow, region, 0, &tree)) != RETVAL_OK) {
if(r == RETVAL_TRUNC) {
/* create truncated message */
ldns_buffer_write_u16_at(buffer, 6, ancount);
LDNS_TC_SET(ldns_buffer_begin(buffer));
ldns_buffer_flip(buffer);
return 1;
}
return 0;
}
ldns_buffer_write_u16_at(buffer, 6, ancount);
/* insert auth section */
if(!insert_section(rep, rep->ns_numrrsets, &nscount, buffer,
rep->an_numrrsets, timenow, region, 0, &tree))
if((r=insert_section(rep, rep->ns_numrrsets, &nscount, buffer,
rep->an_numrrsets, timenow, region, 0, &tree)) != RETVAL_OK) {
if(r == RETVAL_TRUNC) {
/* create truncated message */
ldns_buffer_write_u16_at(buffer, 8, nscount);
LDNS_TC_SET(ldns_buffer_begin(buffer));
ldns_buffer_flip(buffer);
return 1;
}
return 0;
}
ldns_buffer_write_u16_at(buffer, 8, nscount);
/* insert add section */
if(!insert_section(rep, rep->ar_numrrsets, &arcount, buffer,
if((r=insert_section(rep, rep->ar_numrrsets, &arcount, buffer,
rep->an_numrrsets + rep->ns_numrrsets, timenow, region,
1, &tree))
1, &tree)) != RETVAL_OK) {
if(r == RETVAL_TRUNC) {
/* no need to set TC bit, this is the additional */
ldns_buffer_write_u16_at(buffer, 10, arcount);
ldns_buffer_flip(buffer);
return 1;
}
return 0;
}
ldns_buffer_write_u16_at(buffer, 10, arcount);
ldns_buffer_flip(buffer);
return 1;
}

5
util/data/msgreply.h
View file

@ -252,6 +252,9 @@ void reply_info_answer(struct reply_info* rep, uint16_t qflags,
/**
* Regenerate the wireformat from the stored msg reply.
* If the buffer is too small then the message is truncated at a whole
* rrset and the TC bit set, or whole rrsets are left out of the additional
* and the TC bit is not set.
* @param qinfo: query info to store.
* @param rep: reply to store.
* @param id: id value to store, network order.
@ -260,7 +263,7 @@ void reply_info_answer(struct reply_info* rep, uint16_t qflags,
* @param timenow: time now, to adjust ttl values.
* @param region: to store temporary data in.
* @return: nonzero is success, or
* 0 on error: malloc failure or buffer too small.
* 0 on error: malloc failure (no log_err has been done).
*/
int reply_info_encode(struct query_info* qinfo, struct reply_info* rep,
uint16_t id, uint16_t flags, ldns_buffer* buffer, uint32_t timenow,