unbound/util/data/msgreply.c
Yorgos Thessalonikefs 2e398d51ba
Fix cache update when serve expired is used (#1143)
- Fix cache update when serve expired is used in order to not evict
  still usable expired records. Modules are forbidden to update the
  cache if their answer is DNSSEC unchecked or bogus and a valid
  (expired) entry already exists. Bogus replies from the validator are
  also discarded in favor of existing (expired) valid replies.

- serve-expired-ttl-reset should try to keep expired records in the
  cache in case they are reset.
2024-09-24 16:47:04 +02:00

1473 lines
42 KiB
C

/*
* util/data/msgreply.c - store message and reply data.
*
* Copyright (c) 2007, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* \file
*
* This file contains a data structure to store a message and its reply.
*/
#include "config.h"
#include "util/data/msgreply.h"
#include "util/storage/lookup3.h"
#include "util/log.h"
#include "util/alloc.h"
#include "util/netevent.h"
#include "util/net_help.h"
#include "util/data/dname.h"
#include "util/regional.h"
#include "util/data/msgparse.h"
#include "util/data/msgencode.h"
#include "sldns/sbuffer.h"
#include "sldns/wire2str.h"
#include "util/module.h"
#include "util/fptr_wlist.h"
/** MAX TTL default for messages and rrsets */
time_t MAX_TTL = 3600 * 24 * 10; /* ten days */
/** MIN TTL default for messages and rrsets */
time_t MIN_TTL = 0;
/** MAX Negative TTL, for SOA records in authority section */
time_t MAX_NEG_TTL = 3600; /* one hour */
/** MIN Negative TTL, for SOA records in authority section */
time_t MIN_NEG_TTL = 0;
/** If we serve expired entries and prefetch them */
int SERVE_EXPIRED = 0;
/** Time to serve records after expiration */
time_t SERVE_EXPIRED_TTL = 0;
/** Reset serve expired TTL after failed update attempt */
time_t SERVE_EXPIRED_TTL_RESET = 0;
/** TTL to use for expired records */
time_t SERVE_EXPIRED_REPLY_TTL = 30;
/** If we serve the original TTL or decrementing TTLs */
int SERVE_ORIGINAL_TTL = 0;
/** allocate qinfo, return 0 on error */
static int
parse_create_qinfo(sldns_buffer* pkt, struct msg_parse* msg,
struct query_info* qinf, struct regional* region)
{
if(msg->qname) {
if(region)
qinf->qname = (uint8_t*)regional_alloc(region,
msg->qname_len);
else qinf->qname = (uint8_t*)malloc(msg->qname_len);
if(!qinf->qname) return 0;
dname_pkt_copy(pkt, qinf->qname, msg->qname);
} else qinf->qname = 0;
qinf->qname_len = msg->qname_len;
qinf->qtype = msg->qtype;
qinf->qclass = msg->qclass;
qinf->local_alias = NULL;
return 1;
}
/** constructor for replyinfo */
struct reply_info*
construct_reply_info_base(struct regional* region, uint16_t flags, size_t qd,
time_t ttl, time_t prettl, time_t expttl, time_t norecttl, size_t an,
size_t ns, size_t ar, size_t total, enum sec_status sec,
sldns_ede_code reason_bogus)
{
struct reply_info* rep;
/* rrset_count-1 because the first ref is part of the struct. */
size_t s = sizeof(struct reply_info) - sizeof(struct rrset_ref) +
sizeof(struct ub_packed_rrset_key*) * total;
if(total >= RR_COUNT_MAX) return NULL; /* sanity check on numRRS*/
if(region)
rep = (struct reply_info*)regional_alloc(region, s);
else rep = (struct reply_info*)malloc(s +
sizeof(struct rrset_ref) * (total));
if(!rep)
return NULL;
rep->flags = flags;
rep->qdcount = qd;
rep->ttl = ttl;
rep->prefetch_ttl = prettl;
rep->serve_expired_ttl = expttl;
rep->serve_expired_norec_ttl = norecttl;
rep->an_numrrsets = an;
rep->ns_numrrsets = ns;
rep->ar_numrrsets = ar;
rep->rrset_count = total;
rep->security = sec;
rep->reason_bogus = reason_bogus;
/* this is only allocated and used for caching on copy */
rep->reason_bogus_str = NULL;
rep->authoritative = 0;
/* array starts after the refs */
if(region)
rep->rrsets = (struct ub_packed_rrset_key**)&(rep->ref[0]);
else rep->rrsets = (struct ub_packed_rrset_key**)&(rep->ref[total]);
/* zero the arrays to assist cleanup in case of malloc failure */
memset( rep->rrsets, 0, sizeof(struct ub_packed_rrset_key*) * total);
if(!region)
memset( &rep->ref[0], 0, sizeof(struct rrset_ref) * total);
return rep;
}
/** allocate replyinfo, return 0 on error */
static int
parse_create_repinfo(struct msg_parse* msg, struct reply_info** rep,
struct regional* region)
{
*rep = construct_reply_info_base(region, msg->flags, msg->qdcount, 0,
0, 0, 0, msg->an_rrsets, msg->ns_rrsets, msg->ar_rrsets,
msg->rrset_count, sec_status_unchecked, LDNS_EDE_NONE);
if(!*rep)
return 0;
return 1;
}
int
reply_info_alloc_rrset_keys(struct reply_info* rep, struct alloc_cache* alloc,
struct regional* region)
{
size_t i;
for(i=0; i<rep->rrset_count; i++) {
if(region) {
rep->rrsets[i] = (struct ub_packed_rrset_key*)
regional_alloc(region,
sizeof(struct ub_packed_rrset_key));
if(rep->rrsets[i]) {
memset(rep->rrsets[i], 0,
sizeof(struct ub_packed_rrset_key));
rep->rrsets[i]->entry.key = rep->rrsets[i];
}
}
else rep->rrsets[i] = alloc_special_obtain(alloc);
if(!rep->rrsets[i])
return 0;
rep->rrsets[i]->entry.data = NULL;
}
return 1;
}
int
reply_info_can_answer_expired(struct reply_info* rep, time_t timenow)
{
log_assert(rep->ttl < timenow);
/* Really expired */
if(SERVE_EXPIRED_TTL && rep->serve_expired_ttl < timenow) return 0;
/* Ignore expired failure answers */
if(FLAGS_GET_RCODE(rep->flags) != LDNS_RCODE_NOERROR &&
FLAGS_GET_RCODE(rep->flags) != LDNS_RCODE_NXDOMAIN &&
FLAGS_GET_RCODE(rep->flags) != LDNS_RCODE_YXDOMAIN) return 0;
return 1;
}
int reply_info_could_use_expired(struct reply_info* rep, time_t timenow)
{
log_assert(rep->ttl < timenow);
/* Really expired */
if(SERVE_EXPIRED_TTL && rep->serve_expired_ttl < timenow &&
!SERVE_EXPIRED_TTL_RESET) return 0;
/* Ignore expired failure answers */
if(FLAGS_GET_RCODE(rep->flags) != LDNS_RCODE_NOERROR &&
FLAGS_GET_RCODE(rep->flags) != LDNS_RCODE_NXDOMAIN &&
FLAGS_GET_RCODE(rep->flags) != LDNS_RCODE_YXDOMAIN) return 0;
return 1;
}
struct reply_info *
make_new_reply_info(const struct reply_info* rep, struct regional* region,
size_t an_numrrsets, size_t copy_rrsets)
{
struct reply_info* new_rep;
size_t i;
/* create a base struct. we specify 'insecure' security status as
* the modified response won't be DNSSEC-valid. In our faked response
* the authority and additional sections will be empty (except possible
* EDNS0 OPT RR in the additional section appended on sending it out),
* so the total number of RRsets is an_numrrsets. */
new_rep = construct_reply_info_base(region, rep->flags,
rep->qdcount, rep->ttl, rep->prefetch_ttl,
rep->serve_expired_ttl, rep->serve_expired_norec_ttl,
an_numrrsets, 0, 0, an_numrrsets,
sec_status_insecure, LDNS_EDE_NONE);
if(!new_rep)
return NULL;
if(!reply_info_alloc_rrset_keys(new_rep, NULL, region))
return NULL;
for(i=0; i<copy_rrsets; i++)
new_rep->rrsets[i] = rep->rrsets[i];
return new_rep;
}
/** find the minimumttl in the rdata of SOA record */
static time_t
soa_find_minttl(struct rr_parse* rr)
{
uint16_t rlen = sldns_read_uint16(rr->ttl_data+4);
if(rlen < 20)
return 0; /* rdata too small for SOA (dname, dname, 5*32bit) */
/* minimum TTL is the last 32bit value in the rdata of the record */
/* at position ttl_data + 4(ttl) + 2(rdatalen) + rdatalen - 4(timeval)*/
return (time_t)sldns_read_uint32(rr->ttl_data+6+rlen-4);
}
/** do the rdata copy */
static int
rdata_copy(sldns_buffer* pkt, struct packed_rrset_data* data, uint8_t* to,
struct rr_parse* rr, time_t* rr_ttl, uint16_t type,
sldns_pkt_section section)
{
uint16_t pkt_len;
const sldns_rr_descriptor* desc;
*rr_ttl = sldns_read_uint32(rr->ttl_data);
/* RFC 2181 Section 8. if msb of ttl is set treat as if zero. */
if(*rr_ttl & 0x80000000U)
*rr_ttl = 0;
if(type == LDNS_RR_TYPE_SOA && section == LDNS_SECTION_AUTHORITY) {
/* negative response. see if TTL of SOA record larger than the
* minimum-ttl in the rdata of the SOA record */
if(*rr_ttl > soa_find_minttl(rr)) *rr_ttl = soa_find_minttl(rr);
if(!SERVE_ORIGINAL_TTL) {
/* If MIN_NEG_TTL is configured skip setting MIN_TTL */
if(MIN_NEG_TTL <= 0 && *rr_ttl < MIN_TTL) {
*rr_ttl = MIN_TTL;
}
if(*rr_ttl > MAX_TTL) *rr_ttl = MAX_TTL;
}
/* MAX_NEG_TTL overrides the min and max ttl of everything
* else; it is for a more specific record */
if(*rr_ttl > MAX_NEG_TTL) *rr_ttl = MAX_NEG_TTL;
/* MIN_NEG_TTL overrides the min and max ttl of everything
* else if configured; it is for a more specific record */
if(MIN_NEG_TTL > 0 && *rr_ttl < MIN_NEG_TTL) {
*rr_ttl = MIN_NEG_TTL;
}
} else if(!SERVE_ORIGINAL_TTL) {
if(*rr_ttl < MIN_TTL) *rr_ttl = MIN_TTL;
if(*rr_ttl > MAX_TTL) *rr_ttl = MAX_TTL;
}
if(*rr_ttl < data->ttl)
data->ttl = *rr_ttl;
if(rr->outside_packet) {
/* uncompressed already, only needs copy */
memmove(to, rr->ttl_data+sizeof(uint32_t), rr->size);
return 1;
}
sldns_buffer_set_position(pkt, (size_t)
(rr->ttl_data - sldns_buffer_begin(pkt) + sizeof(uint32_t)));
/* insert decompressed size into rdata len stored in memory */
/* -2 because rdatalen bytes are not included. */
pkt_len = htons(rr->size - 2);
memmove(to, &pkt_len, sizeof(uint16_t));
to += 2;
/* read packet rdata len */
pkt_len = sldns_buffer_read_u16(pkt);
if(sldns_buffer_remaining(pkt) < pkt_len)
return 0;
desc = sldns_rr_descript(type);
if(pkt_len > 0 && desc && desc->_dname_count > 0) {
int count = (int)desc->_dname_count;
int rdf = 0;
size_t len;
size_t oldpos;
/* decompress dnames. */
while(pkt_len > 0 && count) {
switch(desc->_wireformat[rdf]) {
case LDNS_RDF_TYPE_DNAME:
oldpos = sldns_buffer_position(pkt);
dname_pkt_copy(pkt, to,
sldns_buffer_current(pkt));
to += pkt_dname_len(pkt);
pkt_len -= sldns_buffer_position(pkt)-oldpos;
count--;
len = 0;
break;
case LDNS_RDF_TYPE_STR:
len = sldns_buffer_current(pkt)[0] + 1;
break;
default:
len = get_rdf_size(desc->_wireformat[rdf]);
break;
}
if(len) {
log_assert(len <= pkt_len);
memmove(to, sldns_buffer_current(pkt), len);
to += len;
sldns_buffer_skip(pkt, (ssize_t)len);
pkt_len -= len;
}
rdf++;
}
}
/* copy remaining rdata */
if(pkt_len > 0)
memmove(to, sldns_buffer_current(pkt), pkt_len);
return 1;
}
/** copy over the data into packed rrset */
static int
parse_rr_copy(sldns_buffer* pkt, struct rrset_parse* pset,
struct packed_rrset_data* data)
{
size_t i;
struct rr_parse* rr = pset->rr_first;
uint8_t* nextrdata;
size_t total = pset->rr_count + pset->rrsig_count;
data->ttl = MAX_TTL;
data->count = pset->rr_count;
data->rrsig_count = pset->rrsig_count;
data->trust = rrset_trust_none;
data->security = sec_status_unchecked;
/* layout: struct - rr_len - rr_data - rr_ttl - rdata - rrsig */
data->rr_len = (size_t*)((uint8_t*)data +
sizeof(struct packed_rrset_data));
data->rr_data = (uint8_t**)&(data->rr_len[total]);
data->rr_ttl = (time_t*)&(data->rr_data[total]);
nextrdata = (uint8_t*)&(data->rr_ttl[total]);
for(i=0; i<data->count; i++) {
data->rr_len[i] = rr->size;
data->rr_data[i] = nextrdata;
nextrdata += rr->size;
if(!rdata_copy(pkt, data, data->rr_data[i], rr,
&data->rr_ttl[i], pset->type, pset->section))
return 0;
rr = rr->next;
}
/* if rrsig, its rdata is at nextrdata */
rr = pset->rrsig_first;
for(i=data->count; i<total; i++) {
data->rr_len[i] = rr->size;
data->rr_data[i] = nextrdata;
nextrdata += rr->size;
if(!rdata_copy(pkt, data, data->rr_data[i], rr,
&data->rr_ttl[i], LDNS_RR_TYPE_RRSIG, pset->section))
return 0;
rr = rr->next;
}
return 1;
}
/** create rrset return 0 on failure */
static int
parse_create_rrset(sldns_buffer* pkt, struct rrset_parse* pset,
struct packed_rrset_data** data, struct regional* region)
{
/* allocate */
size_t s;
if(pset->rr_count > RR_COUNT_MAX || pset->rrsig_count > RR_COUNT_MAX ||
pset->size > RR_COUNT_MAX)
return 0; /* protect against integer overflow */
s = sizeof(struct packed_rrset_data) +
(pset->rr_count + pset->rrsig_count) *
(sizeof(size_t)+sizeof(uint8_t*)+sizeof(time_t)) +
pset->size;
if(region)
*data = regional_alloc_zero(region, s);
else *data = calloc(1, s);
if(!*data)
return 0;
/* copy & decompress */
if(!parse_rr_copy(pkt, pset, *data)) {
if(!region) {
free(*data);
*data = NULL;
}
return 0;
}
return 1;
}
/** get trust value for rrset */
static enum rrset_trust
get_rrset_trust(struct msg_parse* msg, struct rrset_parse* rrset)
{
uint16_t AA = msg->flags & BIT_AA;
if(rrset->section == LDNS_SECTION_ANSWER) {
if(AA) {
/* RFC2181 says remainder of CNAME chain is nonauth*/
if(msg->rrset_first &&
msg->rrset_first->section==LDNS_SECTION_ANSWER
&& msg->rrset_first->type==LDNS_RR_TYPE_CNAME){
if(rrset == msg->rrset_first)
return rrset_trust_ans_AA;
else return rrset_trust_ans_noAA;
}
if(msg->rrset_first &&
msg->rrset_first->section==LDNS_SECTION_ANSWER
&& msg->rrset_first->type==LDNS_RR_TYPE_DNAME){
if(rrset == msg->rrset_first ||
rrset == msg->rrset_first->rrset_all_next)
return rrset_trust_ans_AA;
else return rrset_trust_ans_noAA;
}
return rrset_trust_ans_AA;
}
else return rrset_trust_ans_noAA;
} else if(rrset->section == LDNS_SECTION_AUTHORITY) {
if(AA) return rrset_trust_auth_AA;
else return rrset_trust_auth_noAA;
} else {
/* addit section */
if(AA) return rrset_trust_add_AA;
else return rrset_trust_add_noAA;
}
/* NOTREACHED */
return rrset_trust_none;
}
int
parse_copy_decompress_rrset(sldns_buffer* pkt, struct msg_parse* msg,
struct rrset_parse *pset, struct regional* region,
struct ub_packed_rrset_key* pk)
{
struct packed_rrset_data* data;
pk->rk.flags = pset->flags;
pk->rk.dname_len = pset->dname_len;
if(region)
pk->rk.dname = (uint8_t*)regional_alloc(
region, pset->dname_len);
else pk->rk.dname =
(uint8_t*)malloc(pset->dname_len);
if(!pk->rk.dname)
return 0;
/** copy & decompress dname */
dname_pkt_copy(pkt, pk->rk.dname, pset->dname);
/** copy over type and class */
pk->rk.type = htons(pset->type);
pk->rk.rrset_class = pset->rrset_class;
/** read data part. */
if(!parse_create_rrset(pkt, pset, &data, region)) {
if(!region) {
free(pk->rk.dname);
pk->rk.dname = NULL;
}
return 0;
}
pk->entry.data = (void*)data;
pk->entry.key = (void*)pk;
pk->entry.hash = pset->hash;
data->trust = get_rrset_trust(msg, pset);
return 1;
}
/**
* Copy and decompress rrs
* @param pkt: the packet for compression pointer resolution.
* @param msg: the parsed message
* @param rep: reply info to put rrs into.
* @param region: if not NULL, used for allocation.
* @return 0 on failure.
*/
static int
parse_copy_decompress(sldns_buffer* pkt, struct msg_parse* msg,
struct reply_info* rep, struct regional* region)
{
size_t i;
struct rrset_parse *pset = msg->rrset_first;
struct packed_rrset_data* data;
log_assert(rep);
rep->ttl = MAX_TTL;
rep->security = sec_status_unchecked;
if(rep->rrset_count == 0)
rep->ttl = NORR_TTL;
for(i=0; i<rep->rrset_count; i++) {
if(!parse_copy_decompress_rrset(pkt, msg, pset, region,
rep->rrsets[i]))
return 0;
data = (struct packed_rrset_data*)rep->rrsets[i]->entry.data;
if(data->ttl < rep->ttl)
rep->ttl = data->ttl;
pset = pset->rrset_all_next;
}
rep->prefetch_ttl = PREFETCH_TTL_CALC(rep->ttl);
rep->serve_expired_ttl = rep->ttl + SERVE_EXPIRED_TTL;
/* rep->serve_expired_norec_ttl should stay at 0 */
log_assert(rep->serve_expired_norec_ttl == 0);
return 1;
}
int
parse_create_msg(sldns_buffer* pkt, struct msg_parse* msg,
struct alloc_cache* alloc, struct query_info* qinf,
struct reply_info** rep, struct regional* region)
{
log_assert(pkt && msg);
if(!parse_create_qinfo(pkt, msg, qinf, region))
return 0;
if(!parse_create_repinfo(msg, rep, region))
return 0;
if(!reply_info_alloc_rrset_keys(*rep, alloc, region)) {
if(!region) reply_info_parsedelete(*rep, alloc);
return 0;
}
if(!parse_copy_decompress(pkt, msg, *rep, region)) {
if(!region) reply_info_parsedelete(*rep, alloc);
return 0;
}
return 1;
}
int reply_info_parse(sldns_buffer* pkt, struct alloc_cache* alloc,
struct query_info* qinf, struct reply_info** rep,
struct regional* region, struct edns_data* edns)
{
/* use scratch pad region-allocator during parsing. */
struct msg_parse* msg;
int ret;
qinf->qname = NULL;
qinf->local_alias = NULL;
*rep = NULL;
if(!(msg = regional_alloc(region, sizeof(*msg)))) {
return LDNS_RCODE_SERVFAIL;
}
memset(msg, 0, sizeof(*msg));
sldns_buffer_set_position(pkt, 0);
if((ret = parse_packet(pkt, msg, region)) != 0) {
return ret;
}
if((ret = parse_extract_edns_from_response_msg(msg, edns, region)) != 0)
return ret;
/* parse OK, allocate return structures */
/* this also performs dname decompression */
if(!parse_create_msg(pkt, msg, alloc, qinf, rep, NULL)) {
query_info_clear(qinf);
*rep = NULL;
return LDNS_RCODE_SERVFAIL;
}
return 0;
}
/** helper compare function to sort in lock order */
static int
reply_info_sortref_cmp(const void* a, const void* b)
{
struct rrset_ref* x = (struct rrset_ref*)a;
struct rrset_ref* y = (struct rrset_ref*)b;
if(x->key < y->key) return -1;
if(x->key > y->key) return 1;
return 0;
}
void
reply_info_sortref(struct reply_info* rep)
{
qsort(&rep->ref[0], rep->rrset_count, sizeof(struct rrset_ref),
reply_info_sortref_cmp);
}
void
reply_info_set_ttls(struct reply_info* rep, time_t timenow)
{
size_t i, j;
rep->ttl += timenow;
rep->prefetch_ttl += timenow;
rep->serve_expired_ttl += timenow;
/* Don't set rep->serve_expired_norec_ttl; this should only be set
* on cached records when encountering an error */
log_assert(rep->serve_expired_norec_ttl == 0);
for(i=0; i<rep->rrset_count; i++) {
struct packed_rrset_data* data = (struct packed_rrset_data*)
rep->ref[i].key->entry.data;
if(i>0 && rep->ref[i].key == rep->ref[i-1].key)
continue;
data->ttl += timenow;
for(j=0; j<data->count + data->rrsig_count; j++) {
data->rr_ttl[j] += timenow;
}
data->ttl_add = timenow;
}
}
void
reply_info_parsedelete(struct reply_info* rep, struct alloc_cache* alloc)
{
size_t i;
if(!rep)
return;
/* no need to lock, since not shared in hashtables. */
for(i=0; i<rep->rrset_count; i++) {
ub_packed_rrset_parsedelete(rep->rrsets[i], alloc);
}
if(rep->reason_bogus_str) {
free(rep->reason_bogus_str);
rep->reason_bogus_str = NULL;
}
free(rep);
}
int
query_info_parse(struct query_info* m, sldns_buffer* query)
{
uint8_t* q = sldns_buffer_begin(query);
/* minimum size: header + \0 + qtype + qclass */
if(sldns_buffer_limit(query) < LDNS_HEADER_SIZE + 5)
return 0;
if((LDNS_OPCODE_WIRE(q) != LDNS_PACKET_QUERY && LDNS_OPCODE_WIRE(q) !=
LDNS_PACKET_NOTIFY) || LDNS_QDCOUNT(q) != 1 ||
sldns_buffer_position(query) != 0)
return 0;
sldns_buffer_skip(query, LDNS_HEADER_SIZE);
m->qname = sldns_buffer_current(query);
if((m->qname_len = query_dname_len(query)) == 0)
return 0; /* parse error */
if(sldns_buffer_remaining(query) < 4)
return 0; /* need qtype, qclass */
m->qtype = sldns_buffer_read_u16(query);
m->qclass = sldns_buffer_read_u16(query);
m->local_alias = NULL;
return 1;
}
/** tiny subroutine for msgreply_compare */
#define COMPARE_IT(x, y) \
if( (x) < (y) ) return -1; \
else if( (x) > (y) ) return +1; \
log_assert( (x) == (y) );
int
query_info_compare(void* m1, void* m2)
{
struct query_info* msg1 = (struct query_info*)m1;
struct query_info* msg2 = (struct query_info*)m2;
int mc;
/* from most different to least different for speed */
COMPARE_IT(msg1->qtype, msg2->qtype);
if((mc = query_dname_compare(msg1->qname, msg2->qname)) != 0)
return mc;
log_assert(msg1->qname_len == msg2->qname_len);
COMPARE_IT(msg1->qclass, msg2->qclass);
return 0;
#undef COMPARE_IT
}
void
query_info_clear(struct query_info* m)
{
free(m->qname);
m->qname = NULL;
}
size_t
msgreply_sizefunc(void* k, void* d)
{
struct msgreply_entry* q = (struct msgreply_entry*)k;
struct reply_info* r = (struct reply_info*)d;
size_t s = sizeof(struct msgreply_entry) + sizeof(struct reply_info)
+ q->key.qname_len + lock_get_mem(&q->entry.lock)
- sizeof(struct rrset_ref);
s += r->rrset_count * sizeof(struct rrset_ref);
s += r->rrset_count * sizeof(struct ub_packed_rrset_key*);
return s;
}
void
query_entry_delete(void *k, void* ATTR_UNUSED(arg))
{
struct msgreply_entry* q = (struct msgreply_entry*)k;
lock_rw_destroy(&q->entry.lock);
query_info_clear(&q->key);
free(q);
}
void
reply_info_delete(void* d, void* ATTR_UNUSED(arg))
{
struct reply_info* r = (struct reply_info*)d;
if(r->reason_bogus_str) {
free(r->reason_bogus_str);
r->reason_bogus_str = NULL;
}
free(r);
}
hashvalue_type
query_info_hash(struct query_info *q, uint16_t flags)
{
hashvalue_type h = 0xab;
h = hashlittle(&q->qtype, sizeof(q->qtype), h);
if(q->qtype == LDNS_RR_TYPE_AAAA && (flags&BIT_CD))
h++;
h = hashlittle(&q->qclass, sizeof(q->qclass), h);
h = dname_query_hash(q->qname, h);
return h;
}
struct msgreply_entry*
query_info_entrysetup(struct query_info* q, struct reply_info* r,
hashvalue_type h)
{
struct msgreply_entry* e = (struct msgreply_entry*)malloc(
sizeof(struct msgreply_entry));
if(!e) return NULL;
memcpy(&e->key, q, sizeof(*q));
e->entry.hash = h;
e->entry.key = e;
e->entry.data = r;
lock_rw_init(&e->entry.lock);
lock_protect(&e->entry.lock, &e->key.qname, sizeof(e->key.qname));
lock_protect(&e->entry.lock, &e->key.qname_len, sizeof(e->key.qname_len));
lock_protect(&e->entry.lock, &e->key.qtype, sizeof(e->key.qtype));
lock_protect(&e->entry.lock, &e->key.qclass, sizeof(e->key.qclass));
lock_protect(&e->entry.lock, &e->key.local_alias, sizeof(e->key.local_alias));
lock_protect(&e->entry.lock, &e->entry.hash, sizeof(e->entry.hash));
lock_protect(&e->entry.lock, &e->entry.key, sizeof(e->entry.key));
lock_protect(&e->entry.lock, &e->entry.data, sizeof(e->entry.data));
lock_protect(&e->entry.lock, e->key.qname, e->key.qname_len);
q->qname = NULL;
return e;
}
/** copy rrsets from replyinfo to dest replyinfo */
static int
repinfo_copy_rrsets(struct reply_info* dest, struct reply_info* from,
struct regional* region)
{
size_t i, s;
struct packed_rrset_data* fd, *dd;
struct ub_packed_rrset_key* fk, *dk;
for(i=0; i<dest->rrset_count; i++) {
fk = from->rrsets[i];
dk = dest->rrsets[i];
fd = (struct packed_rrset_data*)fk->entry.data;
dk->entry.hash = fk->entry.hash;
dk->rk = fk->rk;
if(region) {
dk->id = fk->id;
dk->rk.dname = (uint8_t*)regional_alloc_init(region,
fk->rk.dname, fk->rk.dname_len);
} else
dk->rk.dname = (uint8_t*)memdup(fk->rk.dname,
fk->rk.dname_len);
if(!dk->rk.dname)
return 0;
s = packed_rrset_sizeof(fd);
if(region)
dd = (struct packed_rrset_data*)regional_alloc_init(
region, fd, s);
else dd = (struct packed_rrset_data*)memdup(fd, s);
if(!dd)
return 0;
packed_rrset_ptr_fixup(dd);
dk->entry.data = (void*)dd;
}
return 1;
}
struct reply_info*
reply_info_copy(struct reply_info* rep, struct alloc_cache* alloc,
struct regional* region)
{
struct reply_info* cp;
cp = construct_reply_info_base(region, rep->flags, rep->qdcount,
rep->ttl, rep->prefetch_ttl, rep->serve_expired_ttl,
rep->serve_expired_norec_ttl,
rep->an_numrrsets, rep->ns_numrrsets, rep->ar_numrrsets,
rep->rrset_count, rep->security, rep->reason_bogus);
if(!cp)
return NULL;
if(rep->reason_bogus_str && *rep->reason_bogus_str != 0) {
if(region) {
cp->reason_bogus_str = (char*)regional_alloc(region,
sizeof(char)
* (strlen(rep->reason_bogus_str)+1));
} else {
cp->reason_bogus_str = malloc(sizeof(char)
* (strlen(rep->reason_bogus_str)+1));
}
if(!cp->reason_bogus_str) {
if(!region)
reply_info_parsedelete(cp, alloc);
return NULL;
}
memcpy(cp->reason_bogus_str, rep->reason_bogus_str,
strlen(rep->reason_bogus_str)+1);
}
/* allocate ub_key structures special or not */
if(!reply_info_alloc_rrset_keys(cp, alloc, region)) {
if(!region)
reply_info_parsedelete(cp, alloc);
return NULL;
}
if(!repinfo_copy_rrsets(cp, rep, region)) {
if(!region)
reply_info_parsedelete(cp, alloc);
return NULL;
}
return cp;
}
uint8_t*
reply_find_final_cname_target(struct query_info* qinfo, struct reply_info* rep)
{
uint8_t* sname = qinfo->qname;
size_t snamelen = qinfo->qname_len;
size_t i;
for(i=0; i<rep->an_numrrsets; i++) {
struct ub_packed_rrset_key* s = rep->rrsets[i];
/* follow CNAME chain (if any) */
if(ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME &&
ntohs(s->rk.rrset_class) == qinfo->qclass &&
snamelen == s->rk.dname_len &&
query_dname_compare(sname, s->rk.dname) == 0) {
get_cname_target(s, &sname, &snamelen);
}
}
if(sname != qinfo->qname)
return sname;
return NULL;
}
struct ub_packed_rrset_key*
reply_find_answer_rrset(struct query_info* qinfo, struct reply_info* rep)
{
uint8_t* sname = qinfo->qname;
size_t snamelen = qinfo->qname_len;
size_t i;
for(i=0; i<rep->an_numrrsets; i++) {
struct ub_packed_rrset_key* s = rep->rrsets[i];
/* first match type, for query of qtype cname */
if(ntohs(s->rk.type) == qinfo->qtype &&
ntohs(s->rk.rrset_class) == qinfo->qclass &&
snamelen == s->rk.dname_len &&
query_dname_compare(sname, s->rk.dname) == 0) {
return s;
}
/* follow CNAME chain (if any) */
if(ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME &&
ntohs(s->rk.rrset_class) == qinfo->qclass &&
snamelen == s->rk.dname_len &&
query_dname_compare(sname, s->rk.dname) == 0) {
get_cname_target(s, &sname, &snamelen);
}
}
return NULL;
}
struct ub_packed_rrset_key* reply_find_rrset_section_an(struct reply_info* rep,
uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass)
{
size_t i;
for(i=0; i<rep->an_numrrsets; i++) {
struct ub_packed_rrset_key* s = rep->rrsets[i];
if(ntohs(s->rk.type) == type &&
ntohs(s->rk.rrset_class) == dclass &&
namelen == s->rk.dname_len &&
query_dname_compare(name, s->rk.dname) == 0) {
return s;
}
}
return NULL;
}
struct ub_packed_rrset_key* reply_find_rrset_section_ns(struct reply_info* rep,
uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass)
{
size_t i;
for(i=rep->an_numrrsets; i<rep->an_numrrsets+rep->ns_numrrsets; i++) {
struct ub_packed_rrset_key* s = rep->rrsets[i];
if(ntohs(s->rk.type) == type &&
ntohs(s->rk.rrset_class) == dclass &&
namelen == s->rk.dname_len &&
query_dname_compare(name, s->rk.dname) == 0) {
return s;
}
}
return NULL;
}
struct ub_packed_rrset_key* reply_find_rrset(struct reply_info* rep,
uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass)
{
size_t i;
for(i=0; i<rep->rrset_count; i++) {
struct ub_packed_rrset_key* s = rep->rrsets[i];
if(ntohs(s->rk.type) == type &&
ntohs(s->rk.rrset_class) == dclass &&
namelen == s->rk.dname_len &&
query_dname_compare(name, s->rk.dname) == 0) {
return s;
}
}
return NULL;
}
void
log_dns_msg(const char* str, struct query_info* qinfo, struct reply_info* rep)
{
/* not particularly fast but flexible, make wireformat and print */
sldns_buffer* buf = sldns_buffer_new(65535);
struct regional* region = regional_create();
if(!(buf && region)) {
log_err("%s: log_dns_msg: out of memory", str);
sldns_buffer_free(buf);
regional_destroy(region);
return;
}
if(!reply_info_encode(qinfo, rep, 0, rep->flags, buf, 0,
region, 65535, 1, 0)) {
log_err("%s: log_dns_msg: out of memory", str);
} else {
char* s = sldns_wire2str_pkt(sldns_buffer_begin(buf),
sldns_buffer_limit(buf));
if(!s) {
log_info("%s: log_dns_msg: ldns tostr failed", str);
} else {
log_info("%s %s", str, s);
}
free(s);
}
sldns_buffer_free(buf);
regional_destroy(region);
}
void
log_reply_info(enum verbosity_value v, struct query_info *qinf,
struct sockaddr_storage *addr, socklen_t addrlen, struct timeval dur,
int cached, struct sldns_buffer *rmsg, struct sockaddr_storage* daddr,
enum comm_point_type tp)
{
char qname_buf[LDNS_MAX_DOMAINLEN+1];
char clientip_buf[128];
char rcode_buf[16];
char type_buf[16];
char class_buf[16];
char dest_buf[160];
size_t pktlen;
uint16_t rcode = FLAGS_GET_RCODE(sldns_buffer_read_u16_at(rmsg, 2));
if(verbosity < v)
return;
sldns_wire2str_rcode_buf((int)rcode, rcode_buf, sizeof(rcode_buf));
addr_to_str(addr, addrlen, clientip_buf, sizeof(clientip_buf));
if(daddr) {
char da[128];
int port = 0;
char* comm;
if(daddr->ss_family == AF_INET6) {
struct sockaddr_in6 *d = (struct sockaddr_in6 *)daddr;
if(inet_ntop(d->sin6_family, &d->sin6_addr, da,
sizeof(*d)) == 0)
snprintf(dest_buf, sizeof(dest_buf),
"(inet_ntop_error)");
port = ntohs(d->sin6_port);
} else if(daddr->ss_family == AF_INET) {
struct sockaddr_in *d = (struct sockaddr_in *)daddr;
if(inet_ntop(d->sin_family, &d->sin_addr, da,
sizeof(*d)) == 0)
snprintf(dest_buf, sizeof(dest_buf),
"(inet_ntop_error)");
port = ntohs(d->sin_port);
} else {
snprintf(da, sizeof(da), "socket%d",
(int)daddr->ss_family);
}
comm = "udp";
if(tp == comm_tcp) comm = "tcp";
else if(tp == comm_tcp_accept) comm = "tcp";
else if(tp == comm_http) comm = "dot";
else if(tp == comm_local) comm = "unix";
else if(tp == comm_raw) comm = "raw";
snprintf(dest_buf, sizeof(dest_buf), " on %s %s %d",
comm, da, port);
} else {
dest_buf[0]=0;
}
if(rcode == LDNS_RCODE_FORMERR)
{
if(LOG_TAG_QUERYREPLY)
log_reply("%s - - - %s - - -%s", clientip_buf,
rcode_buf, dest_buf);
else log_info("%s - - - %s - - -%s", clientip_buf,
rcode_buf, dest_buf);
} else {
if(qinf->qname)
dname_str(qinf->qname, qname_buf);
else snprintf(qname_buf, sizeof(qname_buf), "null");
pktlen = sldns_buffer_limit(rmsg);
sldns_wire2str_type_buf(qinf->qtype, type_buf, sizeof(type_buf));
sldns_wire2str_class_buf(qinf->qclass, class_buf, sizeof(class_buf));
if(LOG_TAG_QUERYREPLY)
log_reply("%s %s %s %s %s " ARG_LL "d.%6.6d %d %d%s",
clientip_buf, qname_buf, type_buf, class_buf,
rcode_buf, (long long)dur.tv_sec, (int)dur.tv_usec,
cached, (int)pktlen, dest_buf);
else log_info("%s %s %s %s %s " ARG_LL "d.%6.6d %d %d%s",
clientip_buf, qname_buf, type_buf, class_buf,
rcode_buf, (long long)dur.tv_sec, (int)dur.tv_usec,
cached, (int)pktlen, dest_buf);
}
}
void
log_query_info(enum verbosity_value v, const char* str,
struct query_info* qinf)
{
log_nametypeclass(v, str, qinf->qname, qinf->qtype, qinf->qclass);
}
int
reply_check_cname_chain(struct query_info* qinfo, struct reply_info* rep)
{
/* check only answer section rrs for matching cname chain.
* the cache may return changed rdata, but owner names are untouched.*/
size_t i;
uint8_t* sname = qinfo->qname;
size_t snamelen = qinfo->qname_len;
for(i=0; i<rep->an_numrrsets; i++) {
uint16_t t = ntohs(rep->rrsets[i]->rk.type);
if(t == LDNS_RR_TYPE_DNAME)
continue; /* skip dnames; note TTL 0 not cached */
/* verify that owner matches current sname */
if(query_dname_compare(sname, rep->rrsets[i]->rk.dname) != 0){
/* cname chain broken */
return 0;
}
/* if this is a cname; move on */
if(t == LDNS_RR_TYPE_CNAME) {
get_cname_target(rep->rrsets[i], &sname, &snamelen);
}
}
return 1;
}
int
reply_all_rrsets_secure(struct reply_info* rep)
{
size_t i;
for(i=0; i<rep->rrset_count; i++) {
if( ((struct packed_rrset_data*)rep->rrsets[i]->entry.data)
->security != sec_status_secure )
return 0;
}
return 1;
}
struct reply_info*
parse_reply_in_temp_region(sldns_buffer* pkt, struct regional* region,
struct query_info* qi)
{
struct reply_info* rep;
struct msg_parse* msg;
if(!(msg = regional_alloc(region, sizeof(*msg)))) {
return NULL;
}
memset(msg, 0, sizeof(*msg));
sldns_buffer_set_position(pkt, 0);
if(parse_packet(pkt, msg, region) != 0){
return 0;
}
if(!parse_create_msg(pkt, msg, NULL, qi, &rep, region)) {
return 0;
}
return rep;
}
int edns_opt_list_append_ede(struct edns_option** list, struct regional* region,
sldns_ede_code code, const char *txt)
{
struct edns_option** prevp;
struct edns_option* opt;
size_t txt_len = txt ? strlen(txt) : 0;
/* allocate new element */
opt = (struct edns_option*)regional_alloc(region, sizeof(*opt));
if(!opt)
return 0;
opt->next = NULL;
opt->opt_code = LDNS_EDNS_EDE;
opt->opt_len = txt_len + sizeof(uint16_t);
opt->opt_data = regional_alloc(region, txt_len + sizeof(uint16_t));
if(!opt->opt_data)
return 0;
sldns_write_uint16(opt->opt_data, (uint16_t)code);
if (txt_len)
memmove(opt->opt_data + 2, txt, txt_len);
/* append at end of list */
prevp = list;
while(*prevp != NULL)
prevp = &((*prevp)->next);
verbose(VERB_ALGO, "attached EDE code: %d with message: %s", code, (txt?txt:"\"\""));
*prevp = opt;
return 1;
}
int edns_opt_list_append_keepalive(struct edns_option** list, int msec,
struct regional* region)
{
uint8_t data[2]; /* For keepalive value */
data[0] = (uint8_t)((msec >> 8) & 0xff);
data[1] = (uint8_t)(msec & 0xff);
return edns_opt_list_append(list, LDNS_EDNS_KEEPALIVE, sizeof(data),
data, region);
}
int edns_opt_list_append(struct edns_option** list, uint16_t code, size_t len,
uint8_t* data, struct regional* region)
{
struct edns_option** prevp;
struct edns_option* opt;
/* allocate new element */
opt = (struct edns_option*)regional_alloc(region, sizeof(*opt));
if(!opt)
return 0;
opt->next = NULL;
opt->opt_code = code;
opt->opt_len = len;
opt->opt_data = NULL;
if(len > 0) {
opt->opt_data = regional_alloc_init(region, data, len);
if(!opt->opt_data)
return 0;
}
/* append at end of list */
prevp = list;
while(*prevp != NULL) {
prevp = &((*prevp)->next);
}
*prevp = opt;
return 1;
}
int edns_opt_list_remove(struct edns_option** list, uint16_t code)
{
/* The list should already be allocated in a region. Freeing the
* allocated space in a region is not possible. We just unlink the
* required elements and they will be freed together with the region. */
struct edns_option* prev;
struct edns_option* curr;
if(!list || !(*list)) return 0;
/* Unlink and repoint if the element(s) are first in list */
while(list && *list && (*list)->opt_code == code) {
*list = (*list)->next;
}
if(!list || !(*list)) return 1;
/* Unlink elements and reattach the list */
prev = *list;
curr = (*list)->next;
while(curr != NULL) {
if(curr->opt_code == code) {
prev->next = curr->next;
curr = curr->next;
} else {
prev = curr;
curr = curr->next;
}
}
return 1;
}
static int inplace_cb_reply_call_generic(
struct inplace_cb* callback_list, enum inplace_cb_list_type type,
struct query_info* qinfo, struct module_qstate* qstate,
struct reply_info* rep, int rcode, struct edns_data* edns,
struct comm_reply* repinfo, struct regional* region,
struct timeval* start_time)
{
struct inplace_cb* cb;
struct edns_option* opt_list_out = NULL;
#if defined(EXPORT_ALL_SYMBOLS)
(void)type; /* param not used when fptr_ok disabled */
#endif
if(qstate)
opt_list_out = qstate->edns_opts_front_out;
for(cb=callback_list; cb; cb=cb->next) {
fptr_ok(fptr_whitelist_inplace_cb_reply_generic(
(inplace_cb_reply_func_type*)cb->cb, type));
(void)(*(inplace_cb_reply_func_type*)cb->cb)(qinfo, qstate, rep,
rcode, edns, &opt_list_out, repinfo, region, start_time, cb->id, cb->cb_arg);
}
edns->opt_list_inplace_cb_out = opt_list_out;
return 1;
}
int inplace_cb_reply_call(struct module_env* env, struct query_info* qinfo,
struct module_qstate* qstate, struct reply_info* rep, int rcode,
struct edns_data* edns, struct comm_reply* repinfo, struct regional* region,
struct timeval* start_time)
{
return inplace_cb_reply_call_generic(
env->inplace_cb_lists[inplace_cb_reply], inplace_cb_reply, qinfo,
qstate, rep, rcode, edns, repinfo, region, start_time);
}
int inplace_cb_reply_cache_call(struct module_env* env,
struct query_info* qinfo, struct module_qstate* qstate,
struct reply_info* rep, int rcode, struct edns_data* edns,
struct comm_reply* repinfo, struct regional* region,
struct timeval* start_time)
{
return inplace_cb_reply_call_generic(
env->inplace_cb_lists[inplace_cb_reply_cache], inplace_cb_reply_cache,
qinfo, qstate, rep, rcode, edns, repinfo, region, start_time);
}
int inplace_cb_reply_local_call(struct module_env* env,
struct query_info* qinfo, struct module_qstate* qstate,
struct reply_info* rep, int rcode, struct edns_data* edns,
struct comm_reply* repinfo, struct regional* region,
struct timeval* start_time)
{
return inplace_cb_reply_call_generic(
env->inplace_cb_lists[inplace_cb_reply_local], inplace_cb_reply_local,
qinfo, qstate, rep, rcode, edns, repinfo, region, start_time);
}
int inplace_cb_reply_servfail_call(struct module_env* env,
struct query_info* qinfo, struct module_qstate* qstate,
struct reply_info* rep, int rcode, struct edns_data* edns,
struct comm_reply* repinfo, struct regional* region,
struct timeval* start_time)
{
/* We are going to servfail. Remove any potential edns options. */
if(qstate)
qstate->edns_opts_front_out = NULL;
return inplace_cb_reply_call_generic(
env->inplace_cb_lists[inplace_cb_reply_servfail],
inplace_cb_reply_servfail, qinfo, qstate, rep, rcode, edns, repinfo,
region, start_time);
}
int inplace_cb_query_call(struct module_env* env, struct query_info* qinfo,
uint16_t flags, struct sockaddr_storage* addr, socklen_t addrlen,
uint8_t* zone, size_t zonelen, struct module_qstate* qstate,
struct regional* region)
{
struct inplace_cb* cb = env->inplace_cb_lists[inplace_cb_query];
for(; cb; cb=cb->next) {
fptr_ok(fptr_whitelist_inplace_cb_query(
(inplace_cb_query_func_type*)cb->cb));
(void)(*(inplace_cb_query_func_type*)cb->cb)(qinfo, flags,
qstate, addr, addrlen, zone, zonelen, region,
cb->id, cb->cb_arg);
}
return 1;
}
int inplace_cb_edns_back_parsed_call(struct module_env* env,
struct module_qstate* qstate)
{
struct inplace_cb* cb =
env->inplace_cb_lists[inplace_cb_edns_back_parsed];
for(; cb; cb=cb->next) {
fptr_ok(fptr_whitelist_inplace_cb_edns_back_parsed(
(inplace_cb_edns_back_parsed_func_type*)cb->cb));
(void)(*(inplace_cb_edns_back_parsed_func_type*)cb->cb)(qstate,
cb->id, cb->cb_arg);
}
return 1;
}
int inplace_cb_query_response_call(struct module_env* env,
struct module_qstate* qstate, struct dns_msg* response) {
struct inplace_cb* cb =
env->inplace_cb_lists[inplace_cb_query_response];
for(; cb; cb=cb->next) {
fptr_ok(fptr_whitelist_inplace_cb_query_response(
(inplace_cb_query_response_func_type*)cb->cb));
(void)(*(inplace_cb_query_response_func_type*)cb->cb)(qstate,
response, cb->id, cb->cb_arg);
}
return 1;
}
struct edns_option* edns_opt_copy_region(struct edns_option* list,
struct regional* region)
{
struct edns_option* result = NULL, *cur = NULL, *s;
while(list) {
/* copy edns option structure */
s = regional_alloc_init(region, list, sizeof(*list));
if(!s) return NULL;
s->next = NULL;
/* copy option data */
if(s->opt_data) {
s->opt_data = regional_alloc_init(region, s->opt_data,
s->opt_len);
if(!s->opt_data)
return NULL;
}
/* link into list */
if(cur)
cur->next = s;
else result = s;
cur = s;
/* examine next element */
list = list->next;
}
return result;
}
struct edns_option* edns_opt_copy_filter_region(struct edns_option* list,
uint16_t* filter_list, size_t filter_list_len, struct regional* region)
{
struct edns_option* result = NULL, *cur = NULL, *s;
size_t i;
while(list) {
for(i=0; i<filter_list_len; i++)
if(filter_list[i] == list->opt_code) goto found;
if(i == filter_list_len) goto next;
found:
/* copy edns option structure */
s = regional_alloc_init(region, list, sizeof(*list));
if(!s) return NULL;
s->next = NULL;
/* copy option data */
if(s->opt_data) {
s->opt_data = regional_alloc_init(region, s->opt_data,
s->opt_len);
if(!s->opt_data)
return NULL;
}
/* link into list */
if(cur)
cur->next = s;
else result = s;
cur = s;
next:
/* examine next element */
list = list->next;
}
return result;
}
int edns_opt_compare(struct edns_option* p, struct edns_option* q)
{
if(!p && !q) return 0;
if(!p) return -1;
if(!q) return 1;
log_assert(p && q);
if(p->opt_code != q->opt_code)
return (int)q->opt_code - (int)p->opt_code;
if(p->opt_len != q->opt_len)
return (int)q->opt_len - (int)p->opt_len;
if(p->opt_len != 0)
return memcmp(p->opt_data, q->opt_data, p->opt_len);
return 0;
}
int edns_opt_list_compare(struct edns_option* p, struct edns_option* q)
{
int r;
while(p && q) {
r = edns_opt_compare(p, q);
if(r != 0)
return r;
p = p->next;
q = q->next;
}
if(p || q) {
/* uneven length lists */
if(p) return 1;
if(q) return -1;
}
return 0;
}
void edns_opt_list_free(struct edns_option* list)
{
struct edns_option* n;
while(list) {
free(list->opt_data);
n = list->next;
free(list);
list = n;
}
}
struct edns_option* edns_opt_copy_alloc(struct edns_option* list)
{
struct edns_option* result = NULL, *cur = NULL, *s;
while(list) {
/* copy edns option structure */
s = memdup(list, sizeof(*list));
if(!s) {
edns_opt_list_free(result);
return NULL;
}
s->next = NULL;
/* copy option data */
if(s->opt_data) {
s->opt_data = memdup(s->opt_data, s->opt_len);
if(!s->opt_data) {
free(s);
edns_opt_list_free(result);
return NULL;
}
}
/* link into list */
if(cur)
cur->next = s;
else result = s;
cur = s;
/* examine next element */
list = list->next;
}
return result;
}
struct edns_option* edns_opt_list_find(struct edns_option* list, uint16_t code)
{
struct edns_option* p;
for(p=list; p; p=p->next) {
if(p->opt_code == code)
return p;
}
return NULL;
}