text: /*
   * daemon/worker.c - worker that handles a pending list of requests.
   *
   * 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 implements the worker that handles callbacks on events, for
   * pending requests.
   */
  #include "config.h"
  #include "util/log.h"
  #include "util/net_help.h"
  #include "util/random.h"
  #include "daemon/worker.h"
  #include "daemon/daemon.h"
  #include "daemon/remote.h"
  #include "daemon/acl_list.h"
  #include "util/netevent.h"
  #include "util/config_file.h"
  #include "util/module.h"
  #include "util/regional.h"
  #include "util/storage/slabhash.h"
  #include "services/listen_dnsport.h"
  #include "services/outside_network.h"
  #include "services/outbound_list.h"
  #include "services/cache/rrset.h"
  #include "services/cache/infra.h"
  #include "services/cache/dns.h"
  #include "services/authzone.h"
  #include "services/mesh.h"
  #include "services/localzone.h"
  #include "util/data/msgparse.h"
  #include "util/data/msgencode.h"
  #include "util/data/dname.h"
  #include "util/fptr_wlist.h"
  #include "util/tube.h"
  #include "iterator/iter_fwd.h"
  #include "iterator/iter_hints.h"
  #include "validator/autotrust.h"
  #include "validator/val_anchor.h"
  #include "respip/respip.h"
  #include "libunbound/context.h"
  #include "libunbound/libworker.h"
  #include "sldns/sbuffer.h"
  #include "sldns/wire2str.h"
  #include "util/shm_side/shm_main.h"
  #include "dnscrypt/dnscrypt.h"
  
  #ifdef HAVE_SYS_TYPES_H
  #  include <sys/types.h>
  #endif
  #ifdef HAVE_NETDB_H
  #include <netdb.h>
  #endif
  #include <signal.h>
  #ifdef UB_ON_WINDOWS
  #include "winrc/win_svc.h"
  #endif
  
  /** Size of an UDP datagram */
  #define NORMAL_UDP_SIZE	512 /* bytes */
  /** ratelimit for error responses */
  #define ERROR_RATELIMIT 100 /* qps */
  
  /** 
   * seconds to add to prefetch leeway.  This is a TTL that expires old rrsets
   * earlier than they should in order to put the new update into the cache.
   * This additional value is to make sure that if not all TTLs are equal in
   * the message to be updated(and replaced), that rrsets with up to this much
   * extra TTL are also replaced.  This means that the resulting new message
   * will have (most likely) this TTL at least, avoiding very small 'split
   * second' TTLs due to operators choosing relative primes for TTLs (or so).
   * Also has to be at least one to break ties (and overwrite cached entry).
   */
  #define PREFETCH_EXPIRY_ADD 60
  
  /** Report on memory usage by this thread and global */
  static void
  worker_mem_report(struct worker* ATTR_UNUSED(worker), 
  	struct serviced_query* ATTR_UNUSED(cur_serv))
  {
  #ifdef UNBOUND_ALLOC_STATS
  	/* measure memory leakage */
  	extern size_t unbound_mem_alloc, unbound_mem_freed;
  	/* debug func in validator module */
  	size_t total, front, back, mesh, msg, rrset, infra, ac, superac;
  	size_t me, iter, val, anch;
  	int i;
  #ifdef CLIENT_SUBNET
  	size_t subnet = 0;
  #endif /* CLIENT_SUBNET */
  	if(verbosity < VERB_ALGO) 
  		return;
  	front = listen_get_mem(worker->front);
  	back = outnet_get_mem(worker->back);
  	msg = slabhash_get_mem(worker->env.msg_cache);
  	rrset = slabhash_get_mem(&worker->env.rrset_cache->table);
  	infra = infra_get_mem(worker->env.infra_cache);
  	mesh = mesh_get_mem(worker->env.mesh);
  	ac = alloc_get_mem(&worker->alloc);
  	superac = alloc_get_mem(&worker->daemon->superalloc);
  	anch = anchors_get_mem(worker->env.anchors);
  	iter = 0;
  	val = 0;
  	for(i=0; i<worker->env.mesh->mods.num; i++) {
  		fptr_ok(fptr_whitelist_mod_get_mem(worker->env.mesh->
  			mods.mod[i]->get_mem));
  		if(strcmp(worker->env.mesh->mods.mod[i]->name, "validator")==0)
  			val += (*worker->env.mesh->mods.mod[i]->get_mem)
  				(&worker->env, i);
  #ifdef CLIENT_SUBNET
  		else if(strcmp(worker->env.mesh->mods.mod[i]->name,
  			"subnet")==0)
  			subnet += (*worker->env.mesh->mods.mod[i]->get_mem)
  				(&worker->env, i);
  #endif /* CLIENT_SUBNET */
  		else	iter += (*worker->env.mesh->mods.mod[i]->get_mem)
  				(&worker->env, i);
  	}
  	me = sizeof(*worker) + sizeof(*worker->base) + sizeof(*worker->comsig)
  		+ comm_point_get_mem(worker->cmd_com) 
  		+ sizeof(worker->rndstate) 
  		+ regional_get_mem(worker->scratchpad) 
  		+ sizeof(*worker->env.scratch_buffer) 
  		+ sldns_buffer_capacity(worker->env.scratch_buffer)
  		+ forwards_get_mem(worker->env.fwds)
  		+ hints_get_mem(worker->env.hints);
  	if(worker->thread_num == 0)
  		me += acl_list_get_mem(worker->daemon->acl);
  	if(cur_serv) {
  		me += serviced_get_mem(cur_serv);
  	}
  	total = front+back+mesh+msg+rrset+infra+iter+val+ac+superac+me;
  #ifdef CLIENT_SUBNET
  	total += subnet;
  	log_info("Memory conditions: %u front=%u back=%u mesh=%u msg=%u "
  		"rrset=%u infra=%u iter=%u val=%u subnet=%u anchors=%u "
  		"alloccache=%u globalalloccache=%u me=%u",
  		(unsigned)total, (unsigned)front, (unsigned)back, 
  		(unsigned)mesh, (unsigned)msg, (unsigned)rrset, (unsigned)infra,
  		(unsigned)iter, (unsigned)val,
  		(unsigned)subnet, (unsigned)anch, (unsigned)ac,
  		(unsigned)superac, (unsigned)me);
  #else /* no CLIENT_SUBNET */
  	log_info("Memory conditions: %u front=%u back=%u mesh=%u msg=%u "
  		"rrset=%u infra=%u iter=%u val=%u anchors=%u "
  		"alloccache=%u globalalloccache=%u me=%u",
  		(unsigned)total, (unsigned)front, (unsigned)back, 
  		(unsigned)mesh, (unsigned)msg, (unsigned)rrset, 
  		(unsigned)infra, (unsigned)iter, (unsigned)val, (unsigned)anch,
  		(unsigned)ac, (unsigned)superac, (unsigned)me);
  #endif /* CLIENT_SUBNET */
  	log_info("Total heap memory estimate: %u  total-alloc: %u  "
  		"total-free: %u", (unsigned)total, 
  		(unsigned)unbound_mem_alloc, (unsigned)unbound_mem_freed);
  #else /* no UNBOUND_ALLOC_STATS */
  	size_t val = 0;
  #ifdef CLIENT_SUBNET
  	size_t subnet = 0;
  #endif /* CLIENT_SUBNET */
  	int i;
  	if(verbosity < VERB_QUERY)
  		return;
  	for(i=0; i<worker->env.mesh->mods.num; i++) {
  		fptr_ok(fptr_whitelist_mod_get_mem(worker->env.mesh->
  			mods.mod[i]->get_mem));
  		if(strcmp(worker->env.mesh->mods.mod[i]->name, "validator")==0)
  			val += (*worker->env.mesh->mods.mod[i]->get_mem)
  				(&worker->env, i);
  #ifdef CLIENT_SUBNET
  		else if(strcmp(worker->env.mesh->mods.mod[i]->name,
  			"subnet")==0)
  			subnet += (*worker->env.mesh->mods.mod[i]->get_mem)
  				(&worker->env, i);
  #endif /* CLIENT_SUBNET */
  	}
  #ifdef CLIENT_SUBNET
  	verbose(VERB_QUERY, "cache memory msg=%u rrset=%u infra=%u val=%u "
  		"subnet=%u",
  		(unsigned)slabhash_get_mem(worker->env.msg_cache),
  		(unsigned)slabhash_get_mem(&worker->env.rrset_cache->table),
  		(unsigned)infra_get_mem(worker->env.infra_cache),
  		(unsigned)val, (unsigned)subnet);
  #else /* no CLIENT_SUBNET */
  	verbose(VERB_QUERY, "cache memory msg=%u rrset=%u infra=%u val=%u",
  		(unsigned)slabhash_get_mem(worker->env.msg_cache),
  		(unsigned)slabhash_get_mem(&worker->env.rrset_cache->table),
  		(unsigned)infra_get_mem(worker->env.infra_cache),
  		(unsigned)val);
  #endif /* CLIENT_SUBNET */
  #endif /* UNBOUND_ALLOC_STATS */
  }
  
  void 
  worker_send_cmd(struct worker* worker, enum worker_commands cmd)
  {
  	uint32_t c = (uint32_t)htonl(cmd);
  	if(!tube_write_msg(worker->cmd, (uint8_t*)&c, sizeof(c), 0)) {
  		log_err("worker send cmd %d failed", (int)cmd);
  	}
  }
  
  int 
  worker_handle_reply(struct comm_point* c, void* arg, int error, 
  	struct comm_reply* reply_info)
  {
  	struct module_qstate* q = (struct module_qstate*)arg;
  	struct worker* worker = q->env->worker;
  	struct outbound_entry e;
  	e.qstate = q;
  	e.qsent = NULL;
  
  	if(error != 0) {
  		mesh_report_reply(worker->env.mesh, &e, reply_info, error);
  		worker_mem_report(worker, NULL);
  		return 0;
  	}
  	/* sanity check. */
  	if(!LDNS_QR_WIRE(sldns_buffer_begin(c->buffer))
  		|| LDNS_OPCODE_WIRE(sldns_buffer_begin(c->buffer)) != 
  			LDNS_PACKET_QUERY
  		|| LDNS_QDCOUNT(sldns_buffer_begin(c->buffer)) > 1) {
  		/* error becomes timeout for the module as if this reply
  		 * never arrived. */
  		mesh_report_reply(worker->env.mesh, &e, reply_info, 
  			NETEVENT_TIMEOUT);
  		worker_mem_report(worker, NULL);
  		return 0;
  	}
  	mesh_report_reply(worker->env.mesh, &e, reply_info, NETEVENT_NOERROR);
  	worker_mem_report(worker, NULL);
  	return 0;
  }
  
  int 
  worker_handle_service_reply(struct comm_point* c, void* arg, int error, 
  	struct comm_reply* reply_info)
  {
  	struct outbound_entry* e = (struct outbound_entry*)arg;
  	struct worker* worker = e->qstate->env->worker;
  	struct serviced_query *sq = e->qsent;
  
  	verbose(VERB_ALGO, "worker svcd callback for qstate %p", e->qstate);
  	if(error != 0) {
  		mesh_report_reply(worker->env.mesh, e, reply_info, error);
  		worker_mem_report(worker, sq);
  		return 0;
  	}
  	/* sanity check. */
  	if(!LDNS_QR_WIRE(sldns_buffer_begin(c->buffer))
  		|| LDNS_OPCODE_WIRE(sldns_buffer_begin(c->buffer)) != 
  			LDNS_PACKET_QUERY
  		|| LDNS_QDCOUNT(sldns_buffer_begin(c->buffer)) > 1) {
  		/* error becomes timeout for the module as if this reply
  		 * never arrived. */
  		verbose(VERB_ALGO, "worker: bad reply handled as timeout");
  		mesh_report_reply(worker->env.mesh, e, reply_info, 
  			NETEVENT_TIMEOUT);
  		worker_mem_report(worker, sq);
  		return 0;
  	}
  	mesh_report_reply(worker->env.mesh, e, reply_info, NETEVENT_NOERROR);
  	worker_mem_report(worker, sq);
  	return 0;
  }
  
  /** ratelimit error replies
   * @param worker: the worker struct with ratelimit counter
   * @param err: error code that would be wanted.
   * @return value of err if okay, or -1 if it should be discarded instead.
   */
  static int
  worker_err_ratelimit(struct worker* worker, int err)
  {
  	if(worker->err_limit_time == *worker->env.now) {
  		/* see if limit is exceeded for this second */
  		if(worker->err_limit_count++ > ERROR_RATELIMIT)
  			return -1;
  	} else {
  		/* new second, new limits */
  		worker->err_limit_time = *worker->env.now;
  		worker->err_limit_count = 1;
  	}
  	return err;
  }
  
  /** check request sanity.
   * @param pkt: the wire packet to examine for sanity.
   * @param worker: parameters for checking.
   * @return error code, 0 OK, or -1 discard.
  */
  static int 
  worker_check_request(sldns_buffer* pkt, struct worker* worker)
  {
  	if(sldns_buffer_limit(pkt) < LDNS_HEADER_SIZE) {
  		verbose(VERB_QUERY, "request too short, discarded");
  		return -1;
  	}
  	if(sldns_buffer_limit(pkt) > NORMAL_UDP_SIZE && 
  		worker->daemon->cfg->harden_large_queries) {
  		verbose(VERB_QUERY, "request too large, discarded");
  		return -1;
  	}
  	if(LDNS_QR_WIRE(sldns_buffer_begin(pkt))) {
  		verbose(VERB_QUERY, "request has QR bit on, discarded");
  		return -1;
  	}
  	if(LDNS_TC_WIRE(sldns_buffer_begin(pkt))) {
  		LDNS_TC_CLR(sldns_buffer_begin(pkt));
  		verbose(VERB_QUERY, "request bad, has TC bit on");
  		return worker_err_ratelimit(worker, LDNS_RCODE_FORMERR);
  	}
  	if(LDNS_OPCODE_WIRE(sldns_buffer_begin(pkt)) != LDNS_PACKET_QUERY &&
  		LDNS_OPCODE_WIRE(sldns_buffer_begin(pkt)) != LDNS_PACKET_NOTIFY) {
  		verbose(VERB_QUERY, "request unknown opcode %d", 
  			LDNS_OPCODE_WIRE(sldns_buffer_begin(pkt)));
  		return worker_err_ratelimit(worker, LDNS_RCODE_NOTIMPL);
  	}
  	if(LDNS_QDCOUNT(sldns_buffer_begin(pkt)) != 1) {
  		verbose(VERB_QUERY, "request wrong nr qd=%d", 
  			LDNS_QDCOUNT(sldns_buffer_begin(pkt)));
  		return worker_err_ratelimit(worker, LDNS_RCODE_FORMERR);
  	}
  	if(LDNS_ANCOUNT(sldns_buffer_begin(pkt)) != 0 && 
  		(LDNS_ANCOUNT(sldns_buffer_begin(pkt)) != 1 ||
  		LDNS_OPCODE_WIRE(sldns_buffer_begin(pkt)) != LDNS_PACKET_NOTIFY)) {
  		verbose(VERB_QUERY, "request wrong nr an=%d", 
  			LDNS_ANCOUNT(sldns_buffer_begin(pkt)));
  		return worker_err_ratelimit(worker, LDNS_RCODE_FORMERR);
  	}
  	if(LDNS_NSCOUNT(sldns_buffer_begin(pkt)) != 0) {
  		verbose(VERB_QUERY, "request wrong nr ns=%d", 
  			LDNS_NSCOUNT(sldns_buffer_begin(pkt)));
  		return worker_err_ratelimit(worker, LDNS_RCODE_FORMERR);
  	}
  	if(LDNS_ARCOUNT(sldns_buffer_begin(pkt)) > 1) {
  		verbose(VERB_QUERY, "request wrong nr ar=%d", 
  			LDNS_ARCOUNT(sldns_buffer_begin(pkt)));
  		return worker_err_ratelimit(worker, LDNS_RCODE_FORMERR);
  	}
  	return 0;
  }
  
  void 
  worker_handle_control_cmd(struct tube* ATTR_UNUSED(tube), uint8_t* msg,
  	size_t len, int error, void* arg)
  {
  	struct worker* worker = (struct worker*)arg;
  	enum worker_commands cmd;
  	if(error != NETEVENT_NOERROR) {
  		free(msg);
  		if(error == NETEVENT_CLOSED)
  			comm_base_exit(worker->base);
  		else	log_info("control event: %d", error);
  		return;
  	}
  	if(len != sizeof(uint32_t)) {
  		fatal_exit("bad control msg length %d", (int)len);
  	}
  	cmd = sldns_read_uint32(msg);
  	free(msg);
  	switch(cmd) {
  	case worker_cmd_quit:
  		verbose(VERB_ALGO, "got control cmd quit");
  		comm_base_exit(worker->base);
  		break;
  	case worker_cmd_stats:
  		verbose(VERB_ALGO, "got control cmd stats");
  		server_stats_reply(worker, 1);
  		break;
  	case worker_cmd_stats_noreset:
  		verbose(VERB_ALGO, "got control cmd stats_noreset");
  		server_stats_reply(worker, 0);
  		break;
  	case worker_cmd_remote:
  		verbose(VERB_ALGO, "got control cmd remote");
  		daemon_remote_exec(worker);
  		break;
  	default:
  		log_err("bad command %d", (int)cmd);
  		break;
  	}
  }
  
  /** check if a delegation is secure */
  static enum sec_status
  check_delegation_secure(struct reply_info *rep) 
  {
  	/* return smallest security status */
  	size_t i;
  	enum sec_status sec = sec_status_secure;
  	enum sec_status s;
  	size_t num = rep->an_numrrsets + rep->ns_numrrsets;
  	/* check if answer and authority are OK */
  	for(i=0; i<num; i++) {
  		s = ((struct packed_rrset_data*)rep->rrsets[i]->entry.data)
  			->security;
  		if(s < sec)
  			sec = s;
  	}
  	/* in additional, only unchecked triggers revalidation */
  	for(i=num; i<rep->rrset_count; i++) {
  		s = ((struct packed_rrset_data*)rep->rrsets[i]->entry.data)
  			->security;
  		if(s == sec_status_unchecked)
  			return s;
  	}
  	return sec;
  }
  
  /** remove nonsecure from a delegation referral additional section */
  static void
  deleg_remove_nonsecure_additional(struct reply_info* rep)
  {
  	/* we can simply edit it, since we are working in the scratch region */
  	size_t i;
  	enum sec_status s;
  
  	for(i = rep->an_numrrsets+rep->ns_numrrsets; i<rep->rrset_count; i++) {
  		s = ((struct packed_rrset_data*)rep->rrsets[i]->entry.data)
  			->security;
  		if(s != sec_status_secure) {
  			memmove(rep->rrsets+i, rep->rrsets+i+1, 
  				sizeof(struct ub_packed_rrset_key*)* 
  				(rep->rrset_count - i - 1));
  			rep->ar_numrrsets--; 
  			rep->rrset_count--;
  			i--;
  		}
  	}
  }
  
  /** answer nonrecursive query from the cache */
  static int
  answer_norec_from_cache(struct worker* worker, struct query_info* qinfo,
  	uint16_t id, uint16_t flags, struct comm_reply* repinfo, 
  	struct edns_data* edns)
  {
  	/* for a nonrecursive query return either:
  	 * 	o an error (servfail; we try to avoid this)
  	 * 	o a delegation (closest we have; this routine tries that)
  	 * 	o the answer (checked by answer_from_cache) 
  	 *
  	 * So, grab a delegation from the rrset cache. 
  	 * Then check if it needs validation, if so, this routine fails,
  	 * so that iterator can prime and validator can verify rrsets.
  	 */
  	uint16_t udpsize = edns->udp_size;
  	int secure = 0;
  	time_t timenow = *worker->env.now;
  	int must_validate = (!(flags&BIT_CD) || worker->env.cfg->ignore_cd)
  		&& worker->env.need_to_validate;
  	struct dns_msg *msg = NULL;
  	struct delegpt *dp;
  
  	dp = dns_cache_find_delegation(&worker->env, qinfo->qname, 
  		qinfo->qname_len, qinfo->qtype, qinfo->qclass,
  		worker->scratchpad, &msg, timenow);
  	if(!dp) { /* no delegation, need to reprime */
  		return 0;
  	}
  	/* In case we have a local alias, copy it into the delegation message.
  	 * Shallow copy should be fine, as we'll be done with msg in this
  	 * function. */
  	msg->qinfo.local_alias = qinfo->local_alias;
  	if(must_validate) {
  		switch(check_delegation_secure(msg->rep)) {
  		case sec_status_unchecked:
  			/* some rrsets have not been verified yet, go and 
  			 * let validator do that */
  			return 0;
  		case sec_status_bogus:
  		case sec_status_secure_sentinel_fail:
  			/* some rrsets are bogus, reply servfail */
  			edns->edns_version = EDNS_ADVERTISED_VERSION;
  			edns->udp_size = EDNS_ADVERTISED_SIZE;
  			edns->ext_rcode = 0;
  			edns->bits &= EDNS_DO;
  			if(!inplace_cb_reply_servfail_call(&worker->env, qinfo, NULL,
  				msg->rep, LDNS_RCODE_SERVFAIL, edns, worker->scratchpad))
  					return 0;
  			error_encode(repinfo->c->buffer, LDNS_RCODE_SERVFAIL, 
  				&msg->qinfo, id, flags, edns);
  			if(worker->stats.extended) {
  				worker->stats.ans_bogus++;
  				worker->stats.ans_rcode[LDNS_RCODE_SERVFAIL]++;
  			}
  			return 1;
  		case sec_status_secure:
  			/* all rrsets are secure */
  			/* remove non-secure rrsets from the add. section*/
  			if(worker->env.cfg->val_clean_additional)
  				deleg_remove_nonsecure_additional(msg->rep);
  			secure = 1;
  			break;
  		case sec_status_indeterminate:
  		case sec_status_insecure:
  		default:
  			/* not secure */
  			secure = 0;
  			break;
  		}
  	}
  	/* return this delegation from the cache */
  	edns->edns_version = EDNS_ADVERTISED_VERSION;
  	edns->udp_size = EDNS_ADVERTISED_SIZE;
  	edns->ext_rcode = 0;
  	edns->bits &= EDNS_DO;
  	if(!inplace_cb_reply_cache_call(&worker->env, qinfo, NULL, msg->rep,
  		(int)(flags&LDNS_RCODE_MASK), edns, worker->scratchpad))
  			return 0;
  	msg->rep->flags |= BIT_QR|BIT_RA;
  	if(!reply_info_answer_encode(&msg->qinfo, msg->rep, id, flags, 
  		repinfo->c->buffer, 0, 1, worker->scratchpad,
  		udpsize, edns, (int)(edns->bits & EDNS_DO), secure)) {
  		if(!inplace_cb_reply_servfail_call(&worker->env, qinfo, NULL, NULL,
  			LDNS_RCODE_SERVFAIL, edns, worker->scratchpad))
  				edns->opt_list = NULL;
  		error_encode(repinfo->c->buffer, LDNS_RCODE_SERVFAIL, 
  			&msg->qinfo, id, flags, edns);
  	}
  	if(worker->stats.extended) {
  		if(secure) worker->stats.ans_secure++;
  		server_stats_insrcode(&worker->stats, repinfo->c->buffer);
  	}
  	return 1;
  }
  
  /** Apply, if applicable, a response IP action to a cached answer.
   * If the answer is rewritten as a result of an action, '*encode_repp' will
   * point to the reply info containing the modified answer.  '*encode_repp' will
   * be intact otherwise.
   * It returns 1 on success, 0 otherwise. */
  static int
  apply_respip_action(struct worker* worker, const struct query_info* qinfo,
  	struct respip_client_info* cinfo, struct reply_info* rep,
  	struct comm_reply* repinfo, struct ub_packed_rrset_key** alias_rrset,
  	struct reply_info** encode_repp)
  {
  	struct respip_action_info actinfo = {respip_none, NULL};
  
  	if(qinfo->qtype != LDNS_RR_TYPE_A &&
  		qinfo->qtype != LDNS_RR_TYPE_AAAA &&
  		qinfo->qtype != LDNS_RR_TYPE_ANY)
  		return 1;
  
  	if(!respip_rewrite_reply(qinfo, cinfo, rep, encode_repp, &actinfo,
  		alias_rrset, 0, worker->scratchpad))
  		return 0;
  
  	/* xxx_deny actions mean dropping the reply, unless the original reply
  	 * was redirected to response-ip data. */
  	if((actinfo.action == respip_deny ||
  		actinfo.action == respip_inform_deny) &&
  		*encode_repp == rep)
  		*encode_repp = NULL;
  
  	/* If address info is returned, it means the action should be an
  	 * 'inform' variant and the information should be logged. */
  	if(actinfo.addrinfo) {
  		respip_inform_print(actinfo.addrinfo, qinfo->qname,
  			qinfo->qtype, qinfo->qclass, qinfo->local_alias,
  			repinfo);
  	}
  
  	return 1;
  }
  
  /** answer query from the cache.
   * Normally, the answer message will be built in repinfo->c->buffer; if the
   * answer is supposed to be suppressed or the answer is supposed to be an
   * incomplete CNAME chain, the buffer is explicitly cleared to signal the
   * caller as such.  In the latter case *partial_rep will point to the incomplete
   * reply, and this function is (possibly) supposed to be called again with that
   * *partial_rep value to complete the chain.  In addition, if the query should
   * be completely dropped, '*need_drop' will be set to 1. */
  static int
  answer_from_cache(struct worker* worker, struct query_info* qinfo,
  	struct respip_client_info* cinfo, int* need_drop,
  	struct ub_packed_rrset_key** alias_rrset,
  	struct reply_info** partial_repp,
  	struct reply_info* rep, uint16_t id, uint16_t flags, 
  	struct comm_reply* repinfo, struct edns_data* edns)
  {
  	time_t timenow = *worker->env.now;
  	uint16_t udpsize = edns->udp_size;
  	struct reply_info* encode_rep = rep;
  	struct reply_info* partial_rep = *partial_repp;
  	int secure;
  	int must_validate = (!(flags&BIT_CD) || worker->env.cfg->ignore_cd)
  		&& worker->env.need_to_validate;
  	*partial_repp = NULL;	/* avoid accidental further pass */
  	if(worker->env.cfg->serve_expired) {
  		/* always lock rrsets, rep->ttl is ignored */
  		if(!rrset_array_lock(rep->ref, rep->rrset_count, 0))
  			return 0;
  		/* below, rrsets with ttl before timenow become TTL 0 in
  		 * the response */
  		/* This response was served with zero TTL */
  		if (timenow >= rep->ttl) {
  			worker->stats.zero_ttl_responses++;
  		}
  	} else {
  		/* see if it is possible */
  		if(rep->ttl < timenow) {
  			/* the rrsets may have been updated in the meantime.
  			 * we will refetch the message format from the
  			 * authoritative server 
  			 */
  			return 0;
  		}
  		if(!rrset_array_lock(rep->ref, rep->rrset_count, timenow))
  			return 0;
  		/* locked and ids and ttls are OK. */
  	}
  	/* check CNAME chain (if any) */
  	if(rep->an_numrrsets > 0 && (rep->rrsets[0]->rk.type == 
  		htons(LDNS_RR_TYPE_CNAME) || rep->rrsets[0]->rk.type == 
  		htons(LDNS_RR_TYPE_DNAME))) {
  		if(!reply_check_cname_chain(qinfo, rep)) {
  			/* cname chain invalid, redo iterator steps */
  			verbose(VERB_ALGO, "Cache reply: cname chain broken");
  		bail_out:
  			rrset_array_unlock_touch(worker->env.rrset_cache, 
  				worker->scratchpad, rep->ref, rep->rrset_count);
  			return 0;
  		}
  	}
  	/* check security status of the cached answer */
  	if(must_validate && (rep->security == sec_status_bogus ||
  		rep->security == sec_status_secure_sentinel_fail)) {
  		/* BAD cached */
  		edns->edns_version = EDNS_ADVERTISED_VERSION;
  		edns->udp_size = EDNS_ADVERTISED_SIZE;
  		edns->ext_rcode = 0;
  		edns->bits &= EDNS_DO;
  		if(!inplace_cb_reply_servfail_call(&worker->env, qinfo, NULL, rep,
  			LDNS_RCODE_SERVFAIL, edns, worker->scratchpad))
  			goto bail_out;
  		error_encode(repinfo->c->buffer, LDNS_RCODE_SERVFAIL, 
  			qinfo, id, flags, edns);
  		rrset_array_unlock_touch(worker->env.rrset_cache, 
  			worker->scratchpad, rep->ref, rep->rrset_count);
  		if(worker->stats.extended) {
  			worker->stats.ans_bogus ++;
  			worker->stats.ans_rcode[LDNS_RCODE_SERVFAIL] ++;
  		}
  		return 1;
  	} else if( rep->security == sec_status_unchecked && must_validate) {
  		verbose(VERB_ALGO, "Cache reply: unchecked entry needs "
  			"validation");
  		goto bail_out; /* need to validate cache entry first */
  	} else if(rep->security == sec_status_secure) {
  		if(reply_all_rrsets_secure(rep))
  			secure = 1;
  		else	{
  			if(must_validate) {
  				verbose(VERB_ALGO, "Cache reply: secure entry"
  					" changed status");
  				goto bail_out; /* rrset changed, re-verify */
  			}
  			secure = 0;
  		}
  	} else	secure = 0;
  
  	edns->edns_version = EDNS_ADVERTISED_VERSION;
  	edns->udp_size = EDNS_ADVERTISED_SIZE;
  	edns->ext_rcode = 0;
  	edns->bits &= EDNS_DO;
  	if(!inplace_cb_reply_cache_call(&worker->env, qinfo, NULL, rep,
  		(int)(flags&LDNS_RCODE_MASK), edns, worker->scratchpad))
  		goto bail_out;
  	*alias_rrset = NULL; /* avoid confusion if caller set it to non-NULL */
  	if(worker->daemon->use_response_ip && !partial_rep &&
  	   !apply_respip_action(worker, qinfo, cinfo, rep, repinfo, alias_rrset,
  			&encode_rep)) {
  		goto bail_out;
  	} else if(partial_rep &&
  		!respip_merge_cname(partial_rep, qinfo, rep, cinfo,
  		must_validate, &encode_rep, worker->scratchpad)) {
  		goto bail_out;
  	}
  	if(encode_rep != rep)
  		secure = 0; /* if rewritten, it can't be considered "secure" */
  	if(!encode_rep || *alias_rrset) {
  		sldns_buffer_clear(repinfo->c->buffer);
  		sldns_buffer_flip(repinfo->c->buffer);
  		if(!encode_rep)
  			*need_drop = 1;
  		else {
  			/* If a partial CNAME chain is found, we first need to
  			 * make a copy of the reply in the scratchpad so we
  			 * can release the locks and lookup the cache again. */
  			*partial_repp = reply_info_copy(encode_rep, NULL,
  				worker->scratchpad);
  			if(!*partial_repp)
  				goto bail_out;
  		}
  	} else if(!reply_info_answer_encode(qinfo, encode_rep, id, flags,
  		repinfo->c->buffer, timenow, 1, worker->scratchpad,
  		udpsize, edns, (int)(edns->bits & EDNS_DO), secure)) {
  		if(!inplace_cb_reply_servfail_call(&worker->env, qinfo, NULL, NULL,
  			LDNS_RCODE_SERVFAIL, edns, worker->scratchpad))
  				edns->opt_list = NULL;
  		error_encode(repinfo->c->buffer, LDNS_RCODE_SERVFAIL, 
  			qinfo, id, flags, edns);
  	}
  	/* cannot send the reply right now, because blocking network syscall
  	 * is bad while holding locks. */
  	rrset_array_unlock_touch(worker->env.rrset_cache, worker->scratchpad,
  		rep->ref, rep->rrset_count);
  	if(worker->stats.extended) {
  		if(secure) worker->stats.ans_secure++;
  		server_stats_insrcode(&worker->stats, repinfo->c->buffer);
  	}
  	/* go and return this buffer to the client */
  	return 1;
  }
  
  /** Reply to client and perform prefetch to keep cache up to date.
   * If the buffer for the reply is empty, it indicates that only prefetch is
   * necessary and the reply should be suppressed (because it's dropped or
   * being deferred). */
  static void
  reply_and_prefetch(struct worker* worker, struct query_info* qinfo, 
  	uint16_t flags, struct comm_reply* repinfo, time_t leeway)
  {
  	/* first send answer to client to keep its latency 
  	 * as small as a cachereply */
  	if(sldns_buffer_limit(repinfo->c->buffer) != 0)
  		comm_point_send_reply(repinfo);
  	server_stats_prefetch(&worker->stats, worker);
  	
  	/* create the prefetch in the mesh as a normal lookup without
  	 * client addrs waiting, which has the cache blacklisted (to bypass
  	 * the cache and go to the network for the data). */
  	/* this (potentially) runs the mesh for the new query */
  	mesh_new_prefetch(worker->env.mesh, qinfo, flags, leeway + 
  		PREFETCH_EXPIRY_ADD);
  }
  
  /**
   * Fill CH class answer into buffer. Keeps query.
   * @param pkt: buffer
   * @param str: string to put into text record (<255).
   * 	array of strings, every string becomes a text record.
   * @param num: number of strings in array.
   * @param edns: edns reply information.
   * @param worker: worker with scratch region.
   */
  static void
  chaos_replystr(sldns_buffer* pkt, char** str, int num, struct edns_data* edns,
  	struct worker* worker)
  {
  	int i;
  	unsigned int rd = LDNS_RD_WIRE(sldns_buffer_begin(pkt));
  	unsigned int cd = LDNS_CD_WIRE(sldns_buffer_begin(pkt));
  	sldns_buffer_clear(pkt);
  	sldns_buffer_skip(pkt, (ssize_t)sizeof(uint16_t)); /* skip id */
  	sldns_buffer_write_u16(pkt, (uint16_t)(BIT_QR|BIT_RA));
  	if(rd) LDNS_RD_SET(sldns_buffer_begin(pkt));
  	if(cd) LDNS_CD_SET(sldns_buffer_begin(pkt));
  	sldns_buffer_write_u16(pkt, 1); /* qdcount */
  	sldns_buffer_write_u16(pkt, (uint16_t)num); /* ancount */
  	sldns_buffer_write_u16(pkt, 0); /* nscount */
  	sldns_buffer_write_u16(pkt, 0); /* arcount */
  	(void)query_dname_len(pkt); /* skip qname */
  	sldns_buffer_skip(pkt, (ssize_t)sizeof(uint16_t)); /* skip qtype */
  	sldns_buffer_skip(pkt, (ssize_t)sizeof(uint16_t)); /* skip qclass */
  	for(i=0; i<num; i++) {
  		size_t len = strlen(str[i]);
  		if(len>255) len=255; /* cap size of TXT record */
  		sldns_buffer_write_u16(pkt, 0xc00c); /* compr ptr to query */
  		sldns_buffer_write_u16(pkt, LDNS_RR_TYPE_TXT);
  		sldns_buffer_write_u16(pkt, LDNS_RR_CLASS_CH);
  		sldns_buffer_write_u32(pkt, 0); /* TTL */
  		sldns_buffer_write_u16(pkt, sizeof(uint8_t) + len);
  		sldns_buffer_write_u8(pkt, len);
  		sldns_buffer_write(pkt, str[i], len);
  	}
  	sldns_buffer_flip(pkt);
  	edns->edns_version = EDNS_ADVERTISED_VERSION;
  	edns->udp_size = EDNS_ADVERTISED_SIZE;
  	edns->bits &= EDNS_DO;
  	if(!inplace_cb_reply_local_call(&worker->env, NULL, NULL, NULL,
  		LDNS_RCODE_NOERROR, edns, worker->scratchpad))
  			edns->opt_list = NULL;
  	if(sldns_buffer_capacity(pkt) >=
  		sldns_buffer_limit(pkt)+calc_edns_field_size(edns))
  		attach_edns_record(pkt, edns);
  }
  
  /** Reply with one string */
  static void
  chaos_replyonestr(sldns_buffer* pkt, const char* str, struct edns_data* edns,
  	struct worker* worker)
  {
  	chaos_replystr(pkt, (char**)&str, 1, edns, worker);
  }
  
  /**
   * Create CH class trustanchor answer.
   * @param pkt: buffer
   * @param edns: edns reply information.
   * @param w: worker with scratch region.
   */
  static void
  chaos_trustanchor(sldns_buffer* pkt, struct edns_data* edns, struct worker* w)
  {
  #define TA_RESPONSE_MAX_TXT 16 /* max number of TXT records */
  #define TA_RESPONSE_MAX_TAGS 32 /* max number of tags printed per zone */
  	char* str_array[TA_RESPONSE_MAX_TXT];
  	uint16_t tags[TA_RESPONSE_MAX_TAGS];
  	int num = 0;
  	struct trust_anchor* ta;
  
  	if(!w->env.need_to_validate) {
  		/* no validator module, reply no trustanchors */
  		chaos_replystr(pkt, NULL, 0, edns, w);
  		return;
  	}
  
  	/* fill the string with contents */
  	lock_basic_lock(&w->env.anchors->lock);
  	RBTREE_FOR(ta, struct trust_anchor*, w->env.anchors->tree) {
  		char* str;
  		size_t i, numtag, str_len = 255;
  		if(num == TA_RESPONSE_MAX_TXT) continue;
  		str = (char*)regional_alloc(w->scratchpad, str_len);
  		if(!str) continue;
  		lock_basic_lock(&ta->lock);
  		numtag = anchor_list_keytags(ta, tags, TA_RESPONSE_MAX_TAGS);
  		if(numtag == 0) {
  			/* empty, insecure point */
  			lock_basic_unlock(&ta->lock);
  			continue;
  		}
  		str_array[num] = str;
  		num++;
  
  		/* spool name of anchor */
  		(void)sldns_wire2str_dname_buf(ta->name, ta->namelen, str, str_len);
  		str_len -= strlen(str); str += strlen(str);
  		/* spool tags */
  		for(i=0; i<numtag; i++) {
  			snprintf(str, str_len, " %u", (unsigned)tags[i]);
  			str_len -= strlen(str); str += strlen(str);
  		}
  		lock_basic_unlock(&ta->lock);
  	}
  	lock_basic_unlock(&w->env.anchors->lock);
  
  	chaos_replystr(pkt, str_array, num, edns, w);
  	regional_free_all(w->scratchpad);
  }
  
  /**
   * Answer CH class queries.
   * @param w: worker
   * @param qinfo: query info. Pointer into packet buffer.
   * @param edns: edns info from query.
   * @param pkt: packet buffer.
   * @return: true if a reply is to be sent.
   */
  static int
  answer_chaos(struct worker* w, struct query_info* qinfo, 
  	struct edns_data* edns, sldns_buffer* pkt)
  {
  	struct config_file* cfg = w->env.cfg;
  	if(qinfo->qtype != LDNS_RR_TYPE_ANY && qinfo->qtype != LDNS_RR_TYPE_TXT)
  		return 0;
  	if(query_dname_compare(qinfo->qname, 
  		(uint8_t*)"\002id\006server") == 0 ||
  		query_dname_compare(qinfo->qname, 
  		(uint8_t*)"\010hostname\004bind") == 0)
  	{
  		if(cfg->hide_identity) 
  			return 0;
  		if(cfg->identity==NULL || cfg->identity[0]==0) {
  			char buf[MAXHOSTNAMELEN+1];
  			if (gethostname(buf, MAXHOSTNAMELEN) == 0) {
  				buf[MAXHOSTNAMELEN] = 0;
  				chaos_replyonestr(pkt, buf, edns, w);
  			} else 	{
  				log_err("gethostname: %s", strerror(errno));
  				chaos_replyonestr(pkt, "no hostname", edns, w);
  			}
  		}
  		else 	chaos_replyonestr(pkt, cfg->identity, edns, w);
  		return 1;
  	}
  	if(query_dname_compare(qinfo->qname, 
  		(uint8_t*)"\007version\006server") == 0 ||
  		query_dname_compare(qinfo->qname, 
  		(uint8_t*)"\007version\004bind") == 0)
  	{
  		if(cfg->hide_version) 
  			return 0;
  		if(cfg->version==NULL || cfg->version[0]==0)
  			chaos_replyonestr(pkt, PACKAGE_STRING, edns, w);
  		else 	chaos_replyonestr(pkt, cfg->version, edns, w);
  		return 1;
  	}
  	if(query_dname_compare(qinfo->qname,
  		(uint8_t*)"\013trustanchor\007unbound") == 0)
  	{
  		if(cfg->hide_trustanchor)
  			return 0;
  		chaos_trustanchor(pkt, edns, w);
  		return 1;
  	}
  
  	return 0;
  }
  
  /**
   * Answer notify queries.  These are notifies for authoritative zones,
   * the reply is an ack that the notify has been received.  We need to check
   * access permission here.
   * @param w: worker
   * @param qinfo: query info. Pointer into packet buffer.
   * @param edns: edns info from query.
   * @param repinfo: reply info with source address.
   * @param pkt: packet buffer.
   */
  static void
  answer_notify(struct worker* w, struct query_info* qinfo, 
  	struct edns_data* edns, sldns_buffer* pkt, struct comm_reply* repinfo)
  {
  	int refused = 0;
  	int rcode = LDNS_RCODE_NOERROR;
  	uint32_t serial = 0;
  	int has_serial;
  	if(!w->env.auth_zones) return;
  	has_serial = auth_zone_parse_notify_serial(pkt, &serial);
  	if(auth_zones_notify(w->env.auth_zones, &w->env, qinfo->qname,
  		qinfo->qname_len, qinfo->qclass, &repinfo->addr,
  		repinfo->addrlen, has_serial, serial, &refused)) {
  		rcode = LDNS_RCODE_NOERROR;
  	} else {
  		if(refused)
  			rcode = LDNS_RCODE_REFUSED;
  		else	rcode = LDNS_RCODE_SERVFAIL;
  	}
  
  	if(verbosity >= VERB_DETAIL) {
  		char buf[380];
  		char zname[255+1];
  		char sr[25];
  		dname_str(qinfo->qname, zname);
  		sr[0]=0;
  		if(has_serial)
  			snprintf(sr, sizeof(sr), "serial %u ",
  				(unsigned)serial);
  		if(rcode == LDNS_RCODE_REFUSED)
  			snprintf(buf, sizeof(buf),
  				"refused NOTIFY %sfor %s from", sr, zname);
  		else if(rcode == LDNS_RCODE_SERVFAIL)
  			snprintf(buf, sizeof(buf),
  				"servfail for NOTIFY %sfor %s from", sr, zname);
  		else	snprintf(buf, sizeof(buf),
  				"received NOTIFY %sfor %s from", sr, zname);
  		log_addr(VERB_DETAIL, buf, &repinfo->addr, repinfo->addrlen);
  	}
  	edns->edns_version = EDNS_ADVERTISED_VERSION;
  	edns->udp_size = EDNS_ADVERTISED_SIZE;
  	edns->ext_rcode = 0;
  	edns->bits &= EDNS_DO;
  	edns->opt_list = NULL;
  	error_encode(pkt, rcode, qinfo,
  		*(uint16_t*)(void *)sldns_buffer_begin(pkt),
  		sldns_buffer_read_u16_at(pkt, 2), edns);
  	LDNS_OPCODE_SET(sldns_buffer_begin(pkt), LDNS_PACKET_NOTIFY);
  }
  
  static int
  deny_refuse(struct comm_point* c, enum acl_access acl,
  	enum acl_access deny, enum acl_access refuse,
  	struct worker* worker, struct comm_reply* repinfo)
  {
  	if(acl == deny) {
  		comm_point_drop_reply(repinfo);
  		if(worker->stats.extended)
  			worker->stats.unwanted_queries++;
  		return 0;
  	} else if(acl == refuse) {
  		log_addr(VERB_ALGO, "refused query from",
  			&repinfo->addr, repinfo->addrlen);
  		log_buf(VERB_ALGO, "refuse", c->buffer);
  		if(worker->stats.extended)
  			worker->stats.unwanted_queries++;
  		if(worker_check_request(c->buffer, worker) == -1) {
  			comm_point_drop_reply(repinfo);
  			return 0; /* discard this */
  		}
  		sldns_buffer_set_limit(c->buffer, LDNS_HEADER_SIZE);
  		sldns_buffer_write_at(c->buffer, 4, 
  			(uint8_t*)"\0\0\0\0\0\0\0\0", 8);
  		LDNS_QR_SET(sldns_buffer_begin(c->buffer));
  		LDNS_RCODE_SET(sldns_buffer_begin(c->buffer), 
  			LDNS_RCODE_REFUSED);
  		sldns_buffer_set_position(c->buffer, LDNS_HEADER_SIZE);
  		sldns_buffer_flip(c->buffer);
  		return 1;
  	}
  
  	return -1;
  }
  
  static int
  deny_refuse_all(struct comm_point* c, enum acl_access acl,
  	struct worker* worker, struct comm_reply* repinfo)
  {
  	return deny_refuse(c, acl, acl_deny, acl_refuse, worker, repinfo);
  }
  
  static int
  deny_refuse_non_local(struct comm_point* c, enum acl_access acl,
  	struct worker* worker, struct comm_reply* repinfo)
  {
  	return deny_refuse(c, acl, acl_deny_non_local, acl_refuse_non_local, worker, repinfo);
  }
  
  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_type h;
  	struct lruhash_entry* e;
  	struct query_info qinfo;
  	struct edns_data edns;
  	enum acl_access acl;
  	struct acl_addr* acladdr;
  	int rc = 0;
  	int need_drop = 0;
  	/* We might have to chase a CNAME chain internally, in which case
  	 * we'll have up to two replies and combine them to build a complete
  	 * answer.  These variables control this case. */
  	struct ub_packed_rrset_key* alias_rrset = NULL;
  	struct reply_info* partial_rep = NULL;
  	struct query_info* lookup_qinfo = &qinfo;
  	struct query_info qinfo_tmp; /* placeholdoer for lookup_qinfo */
  	struct respip_client_info* cinfo = NULL, cinfo_tmp;
  	memset(&qinfo, 0, sizeof(qinfo));
  
  	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_DNSCRYPT
  	repinfo->max_udp_size = worker->daemon->cfg->max_udp_size;
  	if(!dnsc_handle_curved_request(worker->daemon->dnscenv, repinfo)) {
  		worker->stats.num_query_dnscrypt_crypted_malformed++;
  		return 0;
  	}
  	if(c->dnscrypt && !repinfo->is_dnscrypted) {
  		char buf[LDNS_MAX_DOMAINLEN+1];
  		/* Check if this is unencrypted and asking for certs */
  		if(worker_check_request(c->buffer, worker) != 0) {
  			verbose(VERB_ALGO,
  				"dnscrypt: worker check request: bad query.");
  			log_addr(VERB_CLIENT,"from",&repinfo->addr,
  				repinfo->addrlen);
  			comm_point_drop_reply(repinfo);
  			return 0;
  		}
  		if(!query_info_parse(&qinfo, c->buffer)) {
  			verbose(VERB_ALGO,
  				"dnscrypt: worker parse request: formerror.");
  			log_addr(VERB_CLIENT, "from", &repinfo->addr,
  				repinfo->addrlen);
  			comm_point_drop_reply(repinfo);
  			return 0;
  		}
  		dname_str(qinfo.qname, buf);
  		if(!(qinfo.qtype == LDNS_RR_TYPE_TXT &&
  			strcasecmp(buf,
  			worker->daemon->dnscenv->provider_name) == 0)) {
  			verbose(VERB_ALGO,
  				"dnscrypt: not TXT \"%s\". Received: %s \"%s\"",
  				worker->daemon->dnscenv->provider_name,
  				sldns_rr_descript(qinfo.qtype)->_name,
  				buf);
  			comm_point_drop_reply(repinfo);
  			worker->stats.num_query_dnscrypt_cleartext++;
  			return 0;
  		}
  		worker->stats.num_query_dnscrypt_cert++;
  		sldns_buffer_rewind(c->buffer);
  	} else if(c->dnscrypt && repinfo->is_dnscrypted) {
  		worker->stats.num_query_dnscrypt_crypted++;
  	}
  #endif
  #ifdef USE_DNSTAP
  	if(worker->dtenv.log_client_query_messages)
  		dt_msg_send_client_query(&worker->dtenv, &repinfo->addr, c->type,
  			c->buffer);
  #endif
  	acladdr = acl_addr_lookup(worker->daemon->acl, &repinfo->addr, 
  		repinfo->addrlen);
  	acl = acl_get_control(acladdr);
  	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++;
  
  	/* check if this query should be dropped based on source ip rate limiting */
  	if(!infra_ip_ratelimit_inc(worker->env.infra_cache, repinfo,
  			*worker->env.now)) {
  		/* See if we are passed through with slip factor */
  		if(worker->env.cfg->ip_ratelimit_factor != 0 &&
  			ub_random_max(worker->env.rnd,
  						  worker->env.cfg->ip_ratelimit_factor) == 1) {
  
  			char addrbuf[128];
  			addr_to_str(&repinfo->addr, repinfo->addrlen,
  						addrbuf, sizeof(addrbuf));
  		  verbose(VERB_OPS, "ip_ratelimit allowed through for ip address %s ",
  				  addrbuf);
  		} else {
  			worker->stats.num_queries_ip_ratelimited++;
  			comm_point_drop_reply(repinfo);
  			return 0;
  		}
  	}
  
  	/* 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);
  		memset(&qinfo, 0, sizeof(qinfo)); /* zero qinfo.qname */
  		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(qinfo.qtype == LDNS_RR_TYPE_OPT || 
  		qinfo.qtype == LDNS_RR_TYPE_TSIG ||
  		qinfo.qtype == LDNS_RR_TYPE_TKEY ||
  		qinfo.qtype == LDNS_RR_TYPE_MAILA ||
  		qinfo.qtype == LDNS_RR_TYPE_MAILB ||
  		(qinfo.qtype >= 128 && qinfo.qtype <= 248)) {
  		verbose(VERB_ALGO, "worker request: formerror for meta-type.");
  		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);
  		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);
  		if(sldns_buffer_capacity(c->buffer) >=
  			sldns_buffer_limit(c->buffer)+calc_edns_field_size(&edns))
  			attach_edns_record(c->buffer, &edns);
  		regional_free_all(worker->scratchpad);
  		goto send_reply;
  	}
  	if(edns.edns_present && edns.udp_size < NORMAL_UDP_SIZE &&
  		worker->daemon->cfg->harden_short_bufsize) {
  		verbose(VERB_QUERY, "worker request: EDNS bufsize %d ignored",
  			(int)edns.udp_size);
  		log_addr(VERB_CLIENT,"from",&repinfo->addr, repinfo->addrlen);
  		edns.udp_size = NORMAL_UDP_SIZE;
  	}
  	if(edns.udp_size > worker->daemon->cfg->max_udp_size &&
  		c->type == comm_udp) {
  		verbose(VERB_QUERY,
  			"worker request: max UDP reply size modified"
  			" (%d to max-udp-size)", (int)edns.udp_size);
  		log_addr(VERB_CLIENT,"from",&repinfo->addr, repinfo->addrlen);
  		edns.udp_size = worker->daemon->cfg->max_udp_size;
  	}
  	if(edns.udp_size < LDNS_HEADER_SIZE) {
  		verbose(VERB_ALGO, "worker request: edns is too small.");
  		log_addr(VERB_CLIENT, "from", &repinfo->addr, repinfo->addrlen);
  		LDNS_QR_SET(sldns_buffer_begin(c->buffer));
  		LDNS_TC_SET(sldns_buffer_begin(c->buffer));
  		LDNS_RCODE_SET(sldns_buffer_begin(c->buffer), 
  			LDNS_RCODE_SERVFAIL);
  		sldns_buffer_set_position(c->buffer, LDNS_HEADER_SIZE);
  		sldns_buffer_write_at(c->buffer, 4, 
  			(uint8_t*)"\0\0\0\0\0\0\0\0", 8);
  		sldns_buffer_flip(c->buffer);
  		regional_free_all(worker->scratchpad);
  		goto send_reply;
  	}
  	if(worker->stats.extended)
  		server_stats_insquery(&worker->stats, c, qinfo.qtype,
  			qinfo.qclass, &edns, repinfo);
  	if(c->type != comm_udp)
  		edns.udp_size = 65535; /* max size for TCP replies */
  	if(qinfo.qclass == LDNS_RR_CLASS_CH && answer_chaos(worker, &qinfo,
  		&edns, c->buffer)) {
  		server_stats_insrcode(&worker->stats, c->buffer);
  		regional_free_all(worker->scratchpad);
  		goto send_reply;
  	}
  	if(LDNS_OPCODE_WIRE(sldns_buffer_begin(c->buffer)) ==
  		LDNS_PACKET_NOTIFY) {
  		answer_notify(worker, &qinfo, &edns, c->buffer, repinfo);
  		regional_free_all(worker->scratchpad);
  		goto send_reply;
  	}
  	if(local_zones_answer(worker->daemon->local_zones, &worker->env, &qinfo,
  		&edns, c->buffer, worker->scratchpad, repinfo, acladdr->taglist,
  		acladdr->taglen, acladdr->tag_actions,
  		acladdr->tag_actions_size, acladdr->tag_datas,
  		acladdr->tag_datas_size, worker->daemon->cfg->tagname,
  		worker->daemon->cfg->num_tags, acladdr->view)) {
  		regional_free_all(worker->scratchpad);
  		if(sldns_buffer_limit(c->buffer) == 0) {
  			comm_point_drop_reply(repinfo);
  			return 0;
  		}
  		server_stats_insrcode(&worker->stats, c->buffer);
  		goto send_reply;
  	}
  	if(worker->env.auth_zones &&
  		auth_zones_answer(worker->env.auth_zones, &worker->env,
  		&qinfo, &edns, c->buffer, worker->scratchpad)) {
  		regional_free_all(worker->scratchpad);
  		if(sldns_buffer_limit(c->buffer) == 0) {
  			comm_point_drop_reply(repinfo);
  			return 0;
  		}
  		/* set RA for everyone that can have recursion (based on
  		 * access control list) */
  		if(LDNS_RD_WIRE(sldns_buffer_begin(c->buffer)) &&
  		   acl != acl_deny_non_local && acl != acl_refuse_non_local)
  			LDNS_RA_SET(sldns_buffer_begin(c->buffer));
  		server_stats_insrcode(&worker->stats, c->buffer);
  		goto send_reply;
  	}
  
  	/* We've looked in our local zones. If the answer isn't there, we
  	 * might need to bail out based on ACLs now. */
  	if((ret=deny_refuse_non_local(c, acl, worker, repinfo)) != -1)
  	{
  		regional_free_all(worker->scratchpad);
  		if(ret == 1)
  			goto send_reply;
  		return ret;
  	}
  
  	/* If this request does not have the recursion bit set, verify
  	 * ACLs allow the recursion bit to be treated as set. */
  	if(!(LDNS_RD_WIRE(sldns_buffer_begin(c->buffer))) &&
  		acl == acl_allow_setrd ) {
  		LDNS_RD_SET(sldns_buffer_begin(c->buffer));
  	}
  
  	/* If this request does not have the recursion bit set, verify
  	 * ACLs allow the snooping. */
  	if(!(LDNS_RD_WIRE(sldns_buffer_begin(c->buffer))) &&
  		acl != acl_allow_snoop ) {
  		error_encode(c->buffer, LDNS_RCODE_REFUSED, &qinfo,
  			*(uint16_t*)(void *)sldns_buffer_begin(c->buffer),
  			sldns_buffer_read_u16_at(c->buffer, 2), NULL);
  		regional_free_all(worker->scratchpad);
  		server_stats_insrcode(&worker->stats, c->buffer);
  		log_addr(VERB_ALGO, "refused nonrec (cache snoop) query from",
  			&repinfo->addr, repinfo->addrlen);
  		goto send_reply;
  	}
  
  	/* If we've found a local alias, replace the qname with the alias
  	 * target before resolving it. */
  	if(qinfo.local_alias) {
  		struct ub_packed_rrset_key* rrset = qinfo.local_alias->rrset;
  		struct packed_rrset_data* d = rrset->entry.data;
  
  		/* Sanity check: our current implementation only supports
  		 * a single CNAME RRset as a local alias. */
  		if(qinfo.local_alias->next ||
  			rrset->rk.type != htons(LDNS_RR_TYPE_CNAME) ||
  			d->count != 1) {
  			log_err("assumption failure: unexpected local alias");
  			regional_free_all(worker->scratchpad);
  			return 0; /* drop it */
  		}
  		qinfo.qname = d->rr_data[0] + 2;
  		qinfo.qname_len = d->rr_len[0] - 2;
  	}
  
  	/* If we may apply IP-based actions to the answer, build the client
  	 * information.  As this can be expensive, skip it if there is
  	 * absolutely no possibility of it. */
  	if(worker->daemon->use_response_ip &&
  		(qinfo.qtype == LDNS_RR_TYPE_A ||
  		qinfo.qtype == LDNS_RR_TYPE_AAAA ||
  		qinfo.qtype == LDNS_RR_TYPE_ANY)) {
  		cinfo_tmp.taglist = acladdr->taglist;
  		cinfo_tmp.taglen = acladdr->taglen;
  		cinfo_tmp.tag_actions = acladdr->tag_actions;
  		cinfo_tmp.tag_actions_size = acladdr->tag_actions_size;
  		cinfo_tmp.tag_datas = acladdr->tag_datas;
  		cinfo_tmp.tag_datas_size = acladdr->tag_datas_size;
  		cinfo_tmp.view = acladdr->view;
  		cinfo_tmp.respip_set = worker->daemon->respip_set;
  		cinfo = &cinfo_tmp;
  	}
  
  lookup_cache:
  	/* Lookup the cache.  In case we chase an intermediate CNAME chain
  	 * this is a two-pass operation, and lookup_qinfo is different for
  	 * each pass.  We should still pass the original qinfo to
  	 * answer_from_cache(), however, since it's used to build the reply. */
  	if(!edns_bypass_cache_stage(edns.opt_list, &worker->env)) {
  		h = query_info_hash(lookup_qinfo, sldns_buffer_read_u16_at(c->buffer, 2));
  		if((e=slabhash_lookup(worker->env.msg_cache, h, lookup_qinfo, 0))) {
  			/* answer from cache - we have acquired a readlock on it */
  			if(answer_from_cache(worker, &qinfo,
  				cinfo, &need_drop, &alias_rrset, &partial_rep,
  				(struct reply_info*)e->data,
  				*(uint16_t*)(void *)sldns_buffer_begin(c->buffer),
  				sldns_buffer_read_u16_at(c->buffer, 2), repinfo,
  				&edns)) {
  				/* prefetch it if the prefetch TTL expired.
  				 * Note that if there is more than one pass
  				 * its qname must be that used for cache
  				 * lookup. */
  				if((worker->env.cfg->prefetch || worker->env.cfg->serve_expired)
  					&& *worker->env.now >=
  					((struct reply_info*)e->data)->prefetch_ttl) {
  					time_t leeway = ((struct reply_info*)e->
  						data)->ttl - *worker->env.now;
  					if(((struct reply_info*)e->data)->ttl
  						< *worker->env.now)
  						leeway = 0;
  					lock_rw_unlock(&e->lock);
  					reply_and_prefetch(worker, lookup_qinfo,
  						sldns_buffer_read_u16_at(c->buffer, 2),
  						repinfo, leeway);
  					if(!partial_rep) {
  						rc = 0;
  						regional_free_all(worker->scratchpad);
  						goto send_reply_rc;
  					}
  				} else if(!partial_rep) {
  					lock_rw_unlock(&e->lock);
  					regional_free_all(worker->scratchpad);
  					goto send_reply;
  				} else {
  					/* Note that we've already released the
  					 * lock if we're here after prefetch. */
  					lock_rw_unlock(&e->lock);
  				}
  				/* We've found a partial reply ending with an
  				 * alias.  Replace the lookup qinfo for the
  				 * alias target and lookup the cache again to
  				 * (possibly) complete the reply.  As we're
  				 * passing the "base" reply, there will be no
  				 * more alias chasing. */
  				memset(&qinfo_tmp, 0, sizeof(qinfo_tmp));
  				get_cname_target(alias_rrset, &qinfo_tmp.qname,
  					&qinfo_tmp.qname_len);
  				if(!qinfo_tmp.qname) {
  					log_err("unexpected: invalid answer alias");
  					regional_free_all(worker->scratchpad);
  					return 0; /* drop query */
  				}
  				qinfo_tmp.qtype = qinfo.qtype;
  				qinfo_tmp.qclass = qinfo.qclass;
  				lookup_qinfo = &qinfo_tmp;
  				goto lookup_cache;
  			}
  			verbose(VERB_ALGO, "answer from the cache failed");
  			lock_rw_unlock(&e->lock);
  		}
  		if(!LDNS_RD_WIRE(sldns_buffer_begin(c->buffer))) {
  			if(answer_norec_from_cache(worker, &qinfo,
  				*(uint16_t*)(void *)sldns_buffer_begin(c->buffer), 
  				sldns_buffer_read_u16_at(c->buffer, 2), repinfo, 
  				&edns)) {
  				regional_free_all(worker->scratchpad);
  				goto send_reply;
  			}
  			verbose(VERB_ALGO, "answer norec from cache -- "
  				"need to validate or not primed");
  		}
  	}
  	sldns_buffer_rewind(c->buffer);
  	server_stats_querymiss(&worker->stats, worker);
  
  	if(verbosity >= VERB_CLIENT) {
  		if(c->type == comm_udp)
  			log_addr(VERB_CLIENT, "udp request from",
  				&repinfo->addr, repinfo->addrlen);
  		else	log_addr(VERB_CLIENT, "tcp request from",
  				&repinfo->addr, repinfo->addrlen);
  	}
  
  	/* grab a work request structure for this new request */
  	mesh_new_client(worker->env.mesh, &qinfo, cinfo,
  		sldns_buffer_read_u16_at(c->buffer, 2),
  		&edns, repinfo, *(uint16_t*)(void *)sldns_buffer_begin(c->buffer));
  	regional_free_all(worker->scratchpad);
  	worker_mem_report(worker, NULL);
  	return 0;
  
  send_reply:
  	rc = 1;
  send_reply_rc:
  	if(need_drop) {
  		comm_point_drop_reply(repinfo);
  		return 0;
  	}
  #ifdef USE_DNSTAP
  	if(worker->dtenv.log_client_response_messages)
  		dt_msg_send_client_response(&worker->dtenv, &repinfo->addr,
  			c->type, c->buffer);
  #endif
  	if(worker->env.cfg->log_replies)
  	{
  		struct timeval tv = {0, 0};
  		log_reply_info(0, &qinfo, &repinfo->addr, repinfo->addrlen,
  			tv, 1, c->buffer);
  	}
  #ifdef USE_DNSCRYPT
  	if(!dnsc_handle_uncurved_request(repinfo)) {
  		return 0;
  	}
  #endif
  	return rc;
  }
  
  void 
  worker_sighandler(int sig, void* arg)
  {
  	/* note that log, print, syscalls here give race conditions. 
  	 * And cause hangups if the log-lock is held by the application. */
  	struct worker* worker = (struct worker*)arg;
  	switch(sig) {
  #ifdef SIGHUP
  		case SIGHUP:
  			comm_base_exit(worker->base);
  			break;
  #endif
  		case SIGINT:
  			worker->need_to_exit = 1;
  			comm_base_exit(worker->base);
  			break;
  #ifdef SIGQUIT
  		case SIGQUIT:
  			worker->need_to_exit = 1;
  			comm_base_exit(worker->base);
  			break;
  #endif
  		case SIGTERM:
  			worker->need_to_exit = 1;
  			comm_base_exit(worker->base);
  			break;
  		default:
  			/* unknown signal, ignored */
  			break;
  	}
  }
  
  /** restart statistics timer for worker, if enabled */
  static void
  worker_restart_timer(struct worker* worker)
  {
  	if(worker->env.cfg->stat_interval > 0) {
  		struct timeval tv;
  #ifndef S_SPLINT_S
  		tv.tv_sec = worker->env.cfg->stat_interval;
  		tv.tv_usec = 0;
  #endif
  		comm_timer_set(worker->stat_timer, &tv);
  	}
  }
  
  void worker_stat_timer_cb(void* arg)
  {
  	struct worker* worker = (struct worker*)arg;
  	server_stats_log(&worker->stats, worker, worker->thread_num);
  	mesh_stats(worker->env.mesh, "mesh has");
  	worker_mem_report(worker, NULL);
  	/* SHM is enabled, process data to SHM */
  	if (worker->daemon->cfg->shm_enable) {
  		shm_main_run(worker);
  	}
  	if(!worker->daemon->cfg->stat_cumulative) {
  		worker_stats_clear(worker);
  	}
  	/* start next timer */
  	worker_restart_timer(worker);
  }
  
  void worker_probe_timer_cb(void* arg)
  {
  	struct worker* worker = (struct worker*)arg;
  	struct timeval tv;
  #ifndef S_SPLINT_S
  	tv.tv_sec = (time_t)autr_probe_timer(&worker->env);
  	tv.tv_usec = 0;
  #endif
  	if(tv.tv_sec != 0)
  		comm_timer_set(worker->env.probe_timer, &tv);
  }
  
  struct worker* 
  worker_create(struct daemon* daemon, int id, int* ports, int n)
  {
  	unsigned int seed;
  	struct worker* worker = (struct worker*)calloc(1, 
  		sizeof(struct worker));
  	if(!worker) 
  		return NULL;
  	worker->numports = n;
  	worker->ports = (int*)memdup(ports, sizeof(int)*n);
  	if(!worker->ports) {
  		free(worker);
  		return NULL;
  	}
  	worker->daemon = daemon;
  	worker->thread_num = id;
  	if(!(worker->cmd = tube_create())) {
  		free(worker->ports);
  		free(worker);
  		return NULL;
  	}
  	/* create random state here to avoid locking trouble in RAND_bytes */
  	seed = (unsigned int)time(NULL) ^ (unsigned int)getpid() ^
  		(((unsigned int)worker->thread_num)<<17);
  		/* shift thread_num so it does not match out pid bits */
  	if(!(worker->rndstate = ub_initstate(seed, daemon->rand))) {
  		seed = 0;
  		log_err("could not init random numbers.");
  		tube_delete(worker->cmd);
  		free(worker->ports);
  		free(worker);
  		return NULL;
  	}
  	seed = 0;
  #ifdef USE_DNSTAP
  	if(daemon->cfg->dnstap) {
  		log_assert(daemon->dtenv != NULL);
  		memcpy(&worker->dtenv, daemon->dtenv, sizeof(struct dt_env));
  		if(!dt_init(&worker->dtenv))
  			fatal_exit("dt_init failed");
  	}
  #endif
  	return worker;
  }
  
  int
  worker_init(struct worker* worker, struct config_file *cfg, 
  	struct listen_port* ports, int do_sigs)
  {
  #ifdef USE_DNSTAP
  	struct dt_env* dtenv = &worker->dtenv;
  #else
  	void* dtenv = NULL;
  #endif
  	worker->need_to_exit = 0;
  	worker->base = comm_base_create(do_sigs);
  	if(!worker->base) {
  		log_err("could not create event handling base");
  		worker_delete(worker);
  		return 0;
  	}
  	comm_base_set_slow_accept_handlers(worker->base, &worker_stop_accept,
  		&worker_start_accept, worker);
  	if(do_sigs) {
  #ifdef SIGHUP
  		ub_thread_sig_unblock(SIGHUP);
  #endif
  		ub_thread_sig_unblock(SIGINT);
  #ifdef SIGQUIT
  		ub_thread_sig_unblock(SIGQUIT);
  #endif
  		ub_thread_sig_unblock(SIGTERM);
  #ifndef LIBEVENT_SIGNAL_PROBLEM
  		worker->comsig = comm_signal_create(worker->base, 
  			worker_sighandler, worker);
  		if(!worker->comsig 
  #ifdef SIGHUP
  			|| !comm_signal_bind(worker->comsig, SIGHUP)
  #endif
  #ifdef SIGQUIT
  			|| !comm_signal_bind(worker->comsig, SIGQUIT)
  #endif
  			|| !comm_signal_bind(worker->comsig, SIGTERM)
  			|| !comm_signal_bind(worker->comsig, SIGINT)) {
  			log_err("could not create signal handlers");
  			worker_delete(worker);
  			return 0;
  		}
  #endif /* LIBEVENT_SIGNAL_PROBLEM */
  		if(!daemon_remote_open_accept(worker->daemon->rc, 
  			worker->daemon->rc_ports, worker)) {
  			worker_delete(worker);
  			return 0;
  		}
  #ifdef UB_ON_WINDOWS
  		wsvc_setup_worker(worker);
  #endif /* UB_ON_WINDOWS */
  	} else { /* !do_sigs */
  		worker->comsig = NULL;
  	}
  	worker->front = listen_create(worker->base, ports,
  		cfg->msg_buffer_size, (int)cfg->incoming_num_tcp, 
  		worker->daemon->listen_sslctx, dtenv, worker_handle_request,
  		worker);
  	if(!worker->front) {
  		log_err("could not create listening sockets");
  		worker_delete(worker);
  		return 0;
  	}
  	worker->back = outside_network_create(worker->base,
  		cfg->msg_buffer_size, (size_t)cfg->outgoing_num_ports, 
  		cfg->out_ifs, cfg->num_out_ifs, cfg->do_ip4, cfg->do_ip6, 
  		cfg->do_tcp?cfg->outgoing_num_tcp:0, 
  		worker->daemon->env->infra_cache, worker->rndstate,
  		cfg->use_caps_bits_for_id, worker->ports, worker->numports,
  		cfg->unwanted_threshold, cfg->outgoing_tcp_mss,
  		&worker_alloc_cleanup, worker,
  		cfg->do_udp || cfg->udp_upstream_without_downstream,
  		worker->daemon->connect_sslctx, cfg->delay_close,
  		dtenv);
  	if(!worker->back) {
  		log_err("could not create outgoing sockets");
  		worker_delete(worker);
  		return 0;
  	}
  	/* start listening to commands */
  	if(!tube_setup_bg_listen(worker->cmd, worker->base,
  		&worker_handle_control_cmd, worker)) {
  		log_err("could not create control compt.");
  		worker_delete(worker);
  		return 0;
  	}
  	worker->stat_timer = comm_timer_create(worker->base, 
  		worker_stat_timer_cb, worker);
  	if(!worker->stat_timer) {
  		log_err("could not create statistics timer");
  	}
  
  	/* we use the msg_buffer_size as a good estimate for what the 
  	 * user wants for memory usage sizes */
  	worker->scratchpad = regional_create_custom(cfg->msg_buffer_size);
  	if(!worker->scratchpad) {
  		log_err("malloc failure");
  		worker_delete(worker);
  		return 0;
  	}
  
  	server_stats_init(&worker->stats, cfg);
  	alloc_init(&worker->alloc, &worker->daemon->superalloc, 
  		worker->thread_num);
  	alloc_set_id_cleanup(&worker->alloc, &worker_alloc_cleanup, worker);
  	worker->env = *worker->daemon->env;
  	comm_base_timept(worker->base, &worker->env.now, &worker->env.now_tv);
  	if(worker->thread_num == 0)
  		log_set_time(worker->env.now);
  	worker->env.worker = worker;
  	worker->env.worker_base = worker->base;
  	worker->env.send_query = &worker_send_query;
  	worker->env.alloc = &worker->alloc;
  	worker->env.outnet = worker->back;
  	worker->env.rnd = worker->rndstate;
  	/* If case prefetch is triggered, the corresponding mesh will clear
  	 * the scratchpad for the module env in the middle of request handling.
  	 * It would be prone to a use-after-free kind of bug, so we avoid
  	 * sharing it with worker's own scratchpad at the cost of having
  	 * one more pad per worker. */
  	worker->env.scratch = regional_create_custom(cfg->msg_buffer_size);
  	if(!worker->env.scratch) {
  		log_err("malloc failure");
  		worker_delete(worker);
  		return 0;
  	}
  	worker->env.mesh = mesh_create(&worker->daemon->mods, &worker->env);
  	worker->env.detach_subs = &mesh_detach_subs;
  	worker->env.attach_sub = &mesh_attach_sub;
  	worker->env.add_sub = &mesh_add_sub;
  	worker->env.kill_sub = &mesh_state_delete;
  	worker->env.detect_cycle = &mesh_detect_cycle;
  	worker->env.scratch_buffer = sldns_buffer_new(cfg->msg_buffer_size);
  	if(!(worker->env.fwds = forwards_create()) ||
  		!forwards_apply_cfg(worker->env.fwds, cfg)) {
  		log_err("Could not set forward zones");
  		worker_delete(worker);
  		return 0;
  	}
  	if(!(worker->env.hints = hints_create()) ||
  		!hints_apply_cfg(worker->env.hints, cfg)) {
  		log_err("Could not set root or stub hints");
  		worker_delete(worker);
  		return 0;
  	}
  	/* one probe timer per process -- if we have 5011 anchors */
  	if(autr_get_num_anchors(worker->env.anchors) > 0
  #ifndef THREADS_DISABLED
  		&& worker->thread_num == 0
  #endif
  		) {
  		struct timeval tv;
  		tv.tv_sec = 0;
  		tv.tv_usec = 0;
  		worker->env.probe_timer = comm_timer_create(worker->base,
  			worker_probe_timer_cb, worker);
  		if(!worker->env.probe_timer) {
  			log_err("could not create 5011-probe timer");
  		} else {
  			/* let timer fire, then it can reset itself */
  			comm_timer_set(worker->env.probe_timer, &tv);
  		}
  	}
  	/* zone transfer tasks, setup once per process, if any */
  	if(worker->env.auth_zones
  #ifndef THREADS_DISABLED
  		&& worker->thread_num == 0
  #endif
  		) {
  		auth_xfer_pickup_initial(worker->env.auth_zones, &worker->env);
  	}
  	if(!worker->env.mesh || !worker->env.scratch_buffer) {
  		worker_delete(worker);
  		return 0;
  	}
  	worker_mem_report(worker, NULL);
  	/* if statistics enabled start timer */
  	if(worker->env.cfg->stat_interval > 0) {
  		verbose(VERB_ALGO, "set statistics interval %d secs", 
  			worker->env.cfg->stat_interval);
  		worker_restart_timer(worker);
  	}
  	return 1;
  }
  
  void 
  worker_work(struct worker* worker)
  {
  	comm_base_dispatch(worker->base);
  }
  
  void 
  worker_delete(struct worker* worker)
  {
  	if(!worker) 
  		return;
  	if(worker->env.mesh && verbosity >= VERB_OPS) {
  		server_stats_log(&worker->stats, worker, worker->thread_num);
  		mesh_stats(worker->env.mesh, "mesh has");
  		worker_mem_report(worker, NULL);
  	}
  	outside_network_quit_prepare(worker->back);
  	mesh_delete(worker->env.mesh);
  	sldns_buffer_free(worker->env.scratch_buffer);
  	forwards_delete(worker->env.fwds);
  	hints_delete(worker->env.hints);
  	listen_delete(worker->front);
  	outside_network_delete(worker->back);
  	comm_signal_delete(worker->comsig);
  	tube_delete(worker->cmd);
  	comm_timer_delete(worker->stat_timer);
  	comm_timer_delete(worker->env.probe_timer);
  	free(worker->ports);
  	if(worker->thread_num == 0) {
  		log_set_time(NULL);
  #ifdef UB_ON_WINDOWS
  		wsvc_desetup_worker(worker);
  #endif /* UB_ON_WINDOWS */
  	}
  	comm_base_delete(worker->base);
  	ub_randfree(worker->rndstate);
  	alloc_clear(&worker->alloc);
  	regional_destroy(worker->env.scratch);
  	regional_destroy(worker->scratchpad);
  	free(worker);
  }
  
  struct outbound_entry*
  worker_send_query(struct query_info* qinfo, uint16_t flags, int dnssec,
  	int want_dnssec, int nocaps, struct sockaddr_storage* addr,
  	socklen_t addrlen, uint8_t* zone, size_t zonelen, int ssl_upstream,
  	char* tls_auth_name, struct module_qstate* q)
  {
  	struct worker* worker = q->env->worker;
  	struct outbound_entry* e = (struct outbound_entry*)regional_alloc(
  		q->region, sizeof(*e));
  	if(!e) 
  		return NULL;
  	e->qstate = q;
  	e->qsent = outnet_serviced_query(worker->back, qinfo, flags, dnssec,
  		want_dnssec, nocaps, q->env->cfg->tcp_upstream,
  		ssl_upstream, tls_auth_name, addr, addrlen, zone, zonelen, q,
  		worker_handle_service_reply, e, worker->back->udp_buff, q->env);
  	if(!e->qsent) {
  		return NULL;
  	}
  	return e;
  }
  
  void 
  worker_alloc_cleanup(void* arg)
  {
  	struct worker* worker = (struct worker*)arg;
  	slabhash_clear(&worker->env.rrset_cache->table);
  	slabhash_clear(worker->env.msg_cache);
  }
  
  void worker_stats_clear(struct worker* worker)
  {
  	server_stats_init(&worker->stats, worker->env.cfg);
  	mesh_stats_clear(worker->env.mesh);
  	worker->back->unwanted_replies = 0;
  	worker->back->num_tcp_outgoing = 0;
  }
  
  void worker_start_accept(void* arg)
  {
  	struct worker* worker = (struct worker*)arg;
  	listen_start_accept(worker->front);
  	if(worker->thread_num == 0)
  		daemon_remote_start_accept(worker->daemon->rc);
  }
  
  void worker_stop_accept(void* arg)
  {
  	struct worker* worker = (struct worker*)arg;
  	listen_stop_accept(worker->front);
  	if(worker->thread_num == 0)
  		daemon_remote_stop_accept(worker->daemon->rc);
  }
  
  /* --- fake callbacks for fptr_wlist to work --- */
  struct outbound_entry* libworker_send_query(
  	struct query_info* ATTR_UNUSED(qinfo),
  	uint16_t ATTR_UNUSED(flags), int ATTR_UNUSED(dnssec),
  	int ATTR_UNUSED(want_dnssec), int ATTR_UNUSED(nocaps),
  	struct sockaddr_storage* ATTR_UNUSED(addr), socklen_t ATTR_UNUSED(addrlen),
  	uint8_t* ATTR_UNUSED(zone), size_t ATTR_UNUSED(zonelen),
  	int ATTR_UNUSED(ssl_upstream), char* ATTR_UNUSED(tls_auth_name),
  	struct module_qstate* ATTR_UNUSED(q))
  {
  	log_assert(0);
  	return 0;
  }
  
  int libworker_handle_reply(struct comm_point* ATTR_UNUSED(c), 
  	void* ATTR_UNUSED(arg), int ATTR_UNUSED(error),
          struct comm_reply* ATTR_UNUSED(reply_info))
  {
  	log_assert(0);
  	return 0;
  }
  
  int libworker_handle_service_reply(struct comm_point* ATTR_UNUSED(c), 
  	void* ATTR_UNUSED(arg), int ATTR_UNUSED(error),
          struct comm_reply* ATTR_UNUSED(reply_info))
  {
  	log_assert(0);
  	return 0;
  }
  
  void libworker_handle_control_cmd(struct tube* ATTR_UNUSED(tube),
          uint8_t* ATTR_UNUSED(buffer), size_t ATTR_UNUSED(len),
          int ATTR_UNUSED(error), void* ATTR_UNUSED(arg))
  {
  	log_assert(0);
  }
  
  void libworker_fg_done_cb(void* ATTR_UNUSED(arg), int ATTR_UNUSED(rcode),
          sldns_buffer* ATTR_UNUSED(buf), enum sec_status ATTR_UNUSED(s),
  	char* ATTR_UNUSED(why_bogus))
  {
  	log_assert(0);
  }
  
  void libworker_bg_done_cb(void* ATTR_UNUSED(arg), int ATTR_UNUSED(rcode),
          sldns_buffer* ATTR_UNUSED(buf), enum sec_status ATTR_UNUSED(s),
  	char* ATTR_UNUSED(why_bogus))
  {
  	log_assert(0);
  }
  
  void libworker_event_done_cb(void* ATTR_UNUSED(arg), int ATTR_UNUSED(rcode),
          sldns_buffer* ATTR_UNUSED(buf), enum sec_status ATTR_UNUSED(s),
  	char* ATTR_UNUSED(why_bogus))
  {
  	log_assert(0);
  }
  
  int context_query_cmp(const void* ATTR_UNUSED(a), const void* ATTR_UNUSED(b))
  {
  	log_assert(0);
  	return 0;
  }
  
  int order_lock_cmp(const void* ATTR_UNUSED(e1), const void* ATTR_UNUSED(e2))
  {
          log_assert(0);
          return 0;
  }
  
  int codeline_cmp(const void* ATTR_UNUSED(a), const void* ATTR_UNUSED(b))
  {
          log_assert(0);
          return 0;
  }
  
  