/** encode answer consisting of 1 rrset */
static int
local_encode(struct query_info* qinfo, struct edns_data* edns,
sldns_buffer* buf, struct regional* temp,
struct ub_packed_rrset_key* rrset, int ansec, int rcode)
{
struct reply_info rep;
uint16_t udpsize;
/* make answer with time=0 for fixed TTL values */
memset(&rep, 0, sizeof(rep));
rep.flags = (uint16_t)((BIT_QR | BIT_AA | BIT_RA) | rcode);
rep.qdcount = 1;
if(ansec)
rep.an_numrrsets = 1;
else rep.ns_numrrsets = 1;
rep.rrset_count = 1;
rep.rrsets = &rrset;
udpsize = edns->udp_size;
edns->edns_version = EDNS_ADVERTISED_VERSION;
edns->udp_size = EDNS_ADVERTISED_SIZE;
edns->ext_rcode = 0;
edns->bits &= EDNS_DO;
if(!edns_opt_inplace_reply(edns, temp) ||
!reply_info_answer_encode(qinfo, &rep,
*(uint16_t*)sldns_buffer_begin(buf),
sldns_buffer_read_u16_at(buf, 2),
buf, 0, 0, temp, udpsize, edns,
(int)(edns->bits&EDNS_DO), 0))
error_encode(buf, (LDNS_RCODE_SERVFAIL|BIT_AA), qinfo,
*(uint16_t*)sldns_buffer_begin(buf),
sldns_buffer_read_u16_at(buf, 2), edns);
return 1;
}
/**
* answer in case where no exact match is found
* @param z: zone for query
* @param qinfo: query
* @param edns: edns from query
* @param buf: buffer for answer.
* @param temp: temp region for encoding
* @param ld: local data, if NULL, no such name exists in localdata.
* @param lz_type: type of the local zone
* @return 1 if a reply is to be sent, 0 if not.
*/
static int
lz_zone_answer(struct local_zone* z, struct query_info* qinfo,
struct edns_data* edns, sldns_buffer* buf, struct regional* temp,
struct local_data* ld, enum localzone_type lz_type)
{
if(lz_type == local_zone_deny || lz_type == local_zone_inform_deny) {
/** no reply at all, signal caller by clearing buffer. */
sldns_buffer_clear(buf);
sldns_buffer_flip(buf);
return 1;
} else if(lz_type == local_zone_refuse
|| lz_type == local_zone_always_refuse) {
error_encode(buf, (LDNS_RCODE_REFUSED|BIT_AA), qinfo,
*(uint16_t*)sldns_buffer_begin(buf),
sldns_buffer_read_u16_at(buf, 2), edns);
return 1;
} else if(lz_type == local_zone_static ||
lz_type == local_zone_redirect ||
lz_type == local_zone_always_nxdomain) {
/* for static, reply nodata or nxdomain
* for redirect, reply nodata */
/* no additional section processing,
* cname, dname or wildcard processing,
* or using closest match for NSEC.
* or using closest match for returning delegation downwards
*/
int rcode = (ld || lz_type == local_zone_redirect)?
LDNS_RCODE_NOERROR:LDNS_RCODE_NXDOMAIN;
if(z->soa)
return local_encode(qinfo, edns, buf, temp,
z->soa, 0, rcode);
error_encode(buf, (rcode|BIT_AA), qinfo,
*(uint16_t*)sldns_buffer_begin(buf),
sldns_buffer_read_u16_at(buf, 2), edns);
return 1;
} else if(lz_type == local_zone_typetransparent
|| lz_type == local_zone_always_transparent) {
/* no NODATA or NXDOMAINS for this zone type */
return 0;
}
/* else lz_type == local_zone_transparent */
/* if the zone is transparent and the name exists, but the type
* does not, then we should make this noerror/nodata */
if(ld && ld->rrsets) {
int rcode = LDNS_RCODE_NOERROR;
if(z->soa)
return local_encode(qinfo, edns, buf, temp,
z->soa, 0, rcode);
error_encode(buf, (rcode|BIT_AA), qinfo,
*(uint16_t*)sldns_buffer_begin(buf),
sldns_buffer_read_u16_at(buf, 2), edns);
return 1;
}
/* stop here, and resolve further on */
return 0;
}
void
attach_edns_record(sldns_buffer* pkt, struct edns_data* edns)
{
size_t len;
size_t rdatapos;
struct edns_option* opt;
if(!edns || !edns->edns_present)
return;
/* inc additional count */
sldns_buffer_write_u16_at(pkt, 10,
sldns_buffer_read_u16_at(pkt, 10) + 1);
len = sldns_buffer_limit(pkt);
sldns_buffer_clear(pkt);
sldns_buffer_set_position(pkt, len);
/* write EDNS record */
sldns_buffer_write_u8(pkt, 0); /* '.' label */
sldns_buffer_write_u16(pkt, LDNS_RR_TYPE_OPT); /* type */
sldns_buffer_write_u16(pkt, edns->udp_size); /* class */
sldns_buffer_write_u8(pkt, edns->ext_rcode); /* ttl */
sldns_buffer_write_u8(pkt, edns->edns_version);
sldns_buffer_write_u16(pkt, edns->bits);
rdatapos = sldns_buffer_position(pkt);
sldns_buffer_write_u16(pkt, 0); /* rdatalen */
/* write rdata */
for(opt=edns->opt_list; opt; opt=opt->next) {
sldns_buffer_write_u16(pkt, opt->opt_code);
sldns_buffer_write_u16(pkt, opt->opt_len);
if(opt->opt_len != 0)
sldns_buffer_write(pkt, opt->opt_data, opt->opt_len);
}
if(edns->opt_list)
sldns_buffer_write_u16_at(pkt, rdatapos,
sldns_buffer_position(pkt)-rdatapos-2);
sldns_buffer_flip(pkt);
}
void
dt_msg_send_outside_query(dt_env_t *env,
struct sockaddr_storage *rsock,
enum comm_point_type cptype,
uint8_t *zone, size_t zone_len,
sldns_buffer *qmsg)
{
dt_msg_t dm;
struct timeval qtime;
uint16_t qflags;
gettimeofday(&qtime, NULL);
qflags = sldns_buffer_read_u16_at(qmsg, 2);
/* type */
if (qflags & BIT_RD) {
if (!env->log_forwarder_query_messages)
return;
dt_msg_init(env, &dm, DNSTAP__MESSAGE__TYPE__FORWARDER_QUERY);
} else {
if (!env->log_resolver_query_messages)
return;
dt_msg_init(env, &dm, DNSTAP__MESSAGE__TYPE__RESOLVER_QUERY);
}
/* query_zone */
dm.m.query_zone.data = zone;
dm.m.query_zone.len = zone_len;
dm.m.has_query_zone = 1;
/* query_time_sec, query_time_nsec */
dt_fill_timeval(&qtime,
&dm.m.query_time_sec, &dm.m.has_query_time_sec,
&dm.m.query_time_nsec, &dm.m.has_query_time_nsec);
/* query_message */
dt_fill_buffer(qmsg, &dm.m.query_message, &dm.m.has_query_message);
/* socket_family, socket_protocol, response_address, response_port */
log_assert(cptype == comm_udp || cptype == comm_tcp);
dt_msg_fill_net(&dm, rsock, cptype,
&dm.m.response_address, &dm.m.has_response_address,
&dm.m.response_port, &dm.m.has_response_port);
if (dt_pack(&dm.d, &dm.buf, &dm.len_buf))
dt_send(env, dm.buf, dm.len_buf);
}
void
attach_edns_record(sldns_buffer* pkt, struct edns_data* edns)
{
size_t len;
if(!edns || !edns->edns_present)
return;
/* inc additional count */
sldns_buffer_write_u16_at(pkt, 10,
sldns_buffer_read_u16_at(pkt, 10) + 1);
len = sldns_buffer_limit(pkt);
sldns_buffer_clear(pkt);
sldns_buffer_set_position(pkt, len);
/* write EDNS record */
sldns_buffer_write_u8(pkt, 0); /* '.' label */
sldns_buffer_write_u16(pkt, LDNS_RR_TYPE_OPT); /* type */
sldns_buffer_write_u16(pkt, edns->udp_size); /* class */
sldns_buffer_write_u8(pkt, edns->ext_rcode); /* ttl */
sldns_buffer_write_u8(pkt, edns->edns_version);
sldns_buffer_write_u16(pkt, edns->bits);
sldns_buffer_write_u16(pkt, 0); /* rdatalen */
sldns_buffer_flip(pkt);
}
void server_stats_insquery(struct ub_server_stats* stats, struct comm_point* c,
uint16_t qtype, uint16_t qclass, struct edns_data* edns,
struct comm_reply* repinfo)
{
uint16_t flags = sldns_buffer_read_u16_at(c->buffer, 2);
if(qtype < UB_STATS_QTYPE_NUM)
stats->qtype[qtype]++;
else stats->qtype_big++;
if(qclass < UB_STATS_QCLASS_NUM)
stats->qclass[qclass]++;
else stats->qclass_big++;
stats->qopcode[ LDNS_OPCODE_WIRE(sldns_buffer_begin(c->buffer)) ]++;
if(c->type != comm_udp)
stats->qtcp++;
if(repinfo && addr_is_ip6(&repinfo->addr, repinfo->addrlen))
stats->qipv6++;
if( (flags&BIT_QR) )
stats->qbit_QR++;
if( (flags&BIT_AA) )
stats->qbit_AA++;
if( (flags&BIT_TC) )
stats->qbit_TC++;
if( (flags&BIT_RD) )
stats->qbit_RD++;
if( (flags&BIT_RA) )
stats->qbit_RA++;
if( (flags&BIT_Z) )
stats->qbit_Z++;
if( (flags&BIT_AD) )
stats->qbit_AD++;
if( (flags&BIT_CD) )
stats->qbit_CD++;
if(edns->edns_present) {
stats->qEDNS++;
if( (edns->bits & EDNS_DO) )
stats->qEDNS_DO++;
}
}
int
worker_handle_request(struct comm_point* c, void* arg, int error,
struct comm_reply* repinfo)
{
struct worker* worker = (struct worker*)arg;
int ret;
hashvalue_t h;
struct lruhash_entry* e;
struct query_info qinfo;
struct edns_data edns;
enum acl_access acl;
int rc = 0;
if(error != NETEVENT_NOERROR) {
/* some bad tcp query DNS formats give these error calls */
verbose(VERB_ALGO, "handle request called with err=%d", error);
return 0;
}
#ifdef USE_DNSTAP
if(worker->dtenv.log_client_query_messages)
dt_msg_send_client_query(&worker->dtenv, &repinfo->addr, c->type,
c->buffer);
#endif
acl = acl_list_lookup(worker->daemon->acl, &repinfo->addr,
repinfo->addrlen);
if((ret=deny_refuse_all(c, acl, worker, repinfo)) != -1)
{
if(ret == 1)
goto send_reply;
return ret;
}
if((ret=worker_check_request(c->buffer, worker)) != 0) {
verbose(VERB_ALGO, "worker check request: bad query.");
log_addr(VERB_CLIENT,"from",&repinfo->addr, repinfo->addrlen);
if(ret != -1) {
LDNS_QR_SET(sldns_buffer_begin(c->buffer));
LDNS_RCODE_SET(sldns_buffer_begin(c->buffer), ret);
return 1;
}
comm_point_drop_reply(repinfo);
return 0;
}
worker->stats.num_queries++;
/* see if query is in the cache */
if(!query_info_parse(&qinfo, c->buffer)) {
verbose(VERB_ALGO, "worker parse request: formerror.");
log_addr(VERB_CLIENT,"from",&repinfo->addr, repinfo->addrlen);
if(worker_err_ratelimit(worker, LDNS_RCODE_FORMERR) == -1) {
comm_point_drop_reply(repinfo);
return 0;
}
sldns_buffer_rewind(c->buffer);
LDNS_QR_SET(sldns_buffer_begin(c->buffer));
LDNS_RCODE_SET(sldns_buffer_begin(c->buffer),
LDNS_RCODE_FORMERR);
server_stats_insrcode(&worker->stats, c->buffer);
goto send_reply;
}
if(worker->env.cfg->log_queries) {
char ip[128];
addr_to_str(&repinfo->addr, repinfo->addrlen, ip, sizeof(ip));
log_nametypeclass(0, ip, qinfo.qname, qinfo.qtype, qinfo.qclass);
}
if(qinfo.qtype == LDNS_RR_TYPE_AXFR ||
qinfo.qtype == LDNS_RR_TYPE_IXFR) {
verbose(VERB_ALGO, "worker request: refused zone transfer.");
log_addr(VERB_CLIENT,"from",&repinfo->addr, repinfo->addrlen);
sldns_buffer_rewind(c->buffer);
LDNS_QR_SET(sldns_buffer_begin(c->buffer));
LDNS_RCODE_SET(sldns_buffer_begin(c->buffer),
LDNS_RCODE_REFUSED);
if(worker->stats.extended) {
worker->stats.qtype[qinfo.qtype]++;
server_stats_insrcode(&worker->stats, c->buffer);
}
goto send_reply;
}
if((ret=parse_edns_from_pkt(c->buffer, &edns, worker->scratchpad)) != 0) {
struct edns_data reply_edns;
verbose(VERB_ALGO, "worker parse edns: formerror.");
log_addr(VERB_CLIENT,"from",&repinfo->addr, repinfo->addrlen);
memset(&reply_edns, 0, sizeof(reply_edns));
reply_edns.edns_present = 1;
reply_edns.udp_size = EDNS_ADVERTISED_SIZE;
LDNS_RCODE_SET(sldns_buffer_begin(c->buffer), ret);
error_encode(c->buffer, ret, &qinfo,
*(uint16_t*)(void *)sldns_buffer_begin(c->buffer),
sldns_buffer_read_u16_at(c->buffer, 2), &reply_edns);
regional_free_all(worker->scratchpad);
server_stats_insrcode(&worker->stats, c->buffer);
goto send_reply;
}
if(edns.edns_present && edns.edns_version != 0) {
edns.ext_rcode = (uint8_t)(EDNS_RCODE_BADVERS>>4);
edns.edns_version = EDNS_ADVERTISED_VERSION;
edns.udp_size = EDNS_ADVERTISED_SIZE;
edns.bits &= EDNS_DO;
edns.opt_list = NULL;
verbose(VERB_ALGO, "query with bad edns version.");
log_addr(VERB_CLIENT,"from",&repinfo->addr, repinfo->addrlen);
error_encode(c->buffer, EDNS_RCODE_BADVERS&0xf, &qinfo,
*(uint16_t*)(void *)sldns_buffer_begin(c->buffer),
sldns_buffer_read_u16_at(c->buffer, 2), NULL);
attach_edns_record(c->buffer, &edns);
regional_free_all(worker->scratchpad);
goto send_reply;
}
