unbound/services/outside_network.c

/*
 * services/outside_network.c - implement sending of queries and wait answer.
 *
 * 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 REGENTS 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 has functions to send queries to authoritative servers and
 * wait for the pending answer events.
 */
#include "config.h"
#include <ctype.h>
#ifdef HAVE_SYS_TYPES_H
#  include <sys/types.h>
#endif
#include <sys/time.h>
#include "ldns/wire2host.h"
#include "services/outside_network.h"
#include "services/listen_dnsport.h"
#include "services/cache/infra.h"
#include "util/data/msgparse.h"
#include "util/data/msgreply.h"
#include "util/data/msgencode.h"
#include "util/data/dname.h"
#include "util/netevent.h"
#include "util/log.h"
#include "util/net_help.h"
#include "util/random.h"
#include "util/fptr_wlist.h"

#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#include <fcntl.h>

/** number of times to retry making a random ID that is unique. */
#define MAX_ID_RETRY 1000
/** number of times to retry finding interface, port that can be opened. */
#define MAX_PORT_RETRY 10000
/** number of retries on outgoing UDP queries */
#define OUTBOUND_UDP_RETRY 1

/** initiate TCP transaction for serviced query */
static void serviced_tcp_initiate(struct outside_network* outnet, 
	struct serviced_query* sq, ldns_buffer* buff);
/** with a fd available, randomize and send UDP */
static int randomize_and_send_udp(struct outside_network* outnet, 
	struct pending* pend, ldns_buffer* packet, int timeout);

int 
pending_cmp(const void* key1, const void* key2)
{
	struct pending *p1 = (struct pending*)key1;
	struct pending *p2 = (struct pending*)key2;
	if(p1->id < p2->id)
		return -1;
	if(p1->id > p2->id)
		return 1;
	log_assert(p1->id == p2->id);
	return sockaddr_cmp(&p1->addr, p1->addrlen, &p2->addr, p2->addrlen);
}

int 
serviced_cmp(const void* key1, const void* key2)
{
	struct serviced_query* q1 = (struct serviced_query*)key1;
	struct serviced_query* q2 = (struct serviced_query*)key2;
	int r;
	if(q1->qbuflen < q2->qbuflen)
		return -1;
	if(q1->qbuflen > q2->qbuflen)
		return 1;
	log_assert(q1->qbuflen == q2->qbuflen);
	log_assert(q1->qbuflen >= 15 /* 10 header, root, type, class */);
	/* alternate casing of qname is still the same query */
	if((r = memcmp(q1->qbuf, q2->qbuf, 10)) != 0)
		return r;
	if((r = memcmp(q1->qbuf+q1->qbuflen-4, q2->qbuf+q2->qbuflen-4, 4)) != 0)
		return r;
	if(q1->dnssec != q2->dnssec) {
		if(q1->dnssec < q2->dnssec)
			return -1;
		return 1;
	}
	if((r = query_dname_compare(q1->qbuf+10, q2->qbuf+10)) != 0)
		return r;
	return sockaddr_cmp(&q1->addr, q1->addrlen, &q2->addr, q2->addrlen);
}

/** delete waiting_tcp entry. Does not unlink from waiting list. 
 * @param w: to delete.
 */
static void
waiting_tcp_delete(struct waiting_tcp* w)
{
	if(!w) return;
	if(w->timer)
		comm_timer_delete(w->timer);
	free(w);
}

/** 
 * Pick random outgoing-interface of that family, and bind it.
 * port set to 0 so OS picks a port number for us.
 * if it is the ANY address, do not bind.
 * @param w: tcp structure with destination address.
 * @param s: socket fd.
 * @return false on error, socket closed.
 */
static int
pick_outgoing_tcp(struct waiting_tcp* w, int s)
{
	struct port_if* pi = NULL;
	int num;
#ifdef INET6
	if(addr_is_ip6(&w->addr, w->addrlen))
		num = w->outnet->num_ip6;
	else
#endif
		num = w->outnet->num_ip4;
	if(num == 0) {
		log_err("no TCP outgoing interfaces of family");
		log_addr(VERB_OPS, "for addr", &w->addr, w->addrlen);
#ifndef USE_WINSOCK
		close(s);
#else
		closesocket(s);
#endif
		return 0;
	}
#ifdef INET6
	if(addr_is_ip6(&w->addr, w->addrlen))
		pi = &w->outnet->ip6_ifs[ub_random_max(w->outnet->rnd, num)];
	else
#endif
		pi = &w->outnet->ip4_ifs[ub_random_max(w->outnet->rnd, num)];
	log_assert(pi);
	if(addr_is_any(&pi->addr, pi->addrlen)) {
		/* binding to the ANY interface is for listening sockets */
		return 1;
	}
	/* set port to 0 */
	if(addr_is_ip6(&pi->addr, pi->addrlen))
		((struct sockaddr_in6*)&pi->addr)->sin6_port = 0;
	else	((struct sockaddr_in*)&pi->addr)->sin_port = 0;
	if(bind(s, (struct sockaddr*)&pi->addr, pi->addrlen) != 0) {
#ifndef USE_WINSOCK
		log_err("outgoing tcp: bind: %s", strerror(errno));
		close(s);
#else
		log_err("outgoing tcp: bind: %s", 
			wsa_strerror(WSAGetLastError()));
		closesocket(s);
#endif
		return 0;
	}
	log_addr(VERB_ALGO, "tcp bound to src", &pi->addr, pi->addrlen);
	return 1;
}

/** use next free buffer to service a tcp query */
static int
outnet_tcp_take_into_use(struct waiting_tcp* w, uint8_t* pkt, size_t pkt_len)
{
	struct pending_tcp* pend = w->outnet->tcp_free;
	int s;
	log_assert(pend);
	log_assert(pkt);
	log_assert(w->addrlen > 0);
	/* open socket */
#ifdef INET6
	if(addr_is_ip6(&w->addr, w->addrlen))
		s = socket(PF_INET6, SOCK_STREAM, IPPROTO_TCP);
	else
#endif
		s = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
	if(s == -1) {
#ifndef USE_WINSOCK
		log_err("outgoing tcp: socket: %s", strerror(errno));
#else
		log_err("outgoing tcp: socket: %s", 
			wsa_strerror(WSAGetLastError()));
#endif
		log_addr(0, "failed address", &w->addr, w->addrlen);
		return 0;
	}
	if(!pick_outgoing_tcp(w, s))
		return 0;

	fd_set_nonblock(s);
	if(connect(s, (struct sockaddr*)&w->addr, w->addrlen) == -1) {
#ifndef USE_WINSOCK
#ifdef EINPROGRESS
		if(errno != EINPROGRESS) {
#else
		if(1) {
#endif
			log_err("outgoing tcp: connect: %s", strerror(errno));
			close(s);
#else /* USE_WINSOCK */
		if(WSAGetLastError() != WSAEINPROGRESS &&
			WSAGetLastError() != WSAEWOULDBLOCK) {
			closesocket(s);
#endif
			log_addr(0, "failed address", &w->addr, w->addrlen);
			return 0;
		}
	}
	w->pkt = NULL;
	w->next_waiting = (void*)pend;
	pend->id = LDNS_ID_WIRE(pkt);
	w->outnet->tcp_free = pend->next_free;
	pend->next_free = NULL;
	pend->query = w;
	pend->c->repinfo.addrlen = w->addrlen;
	memcpy(&pend->c->repinfo.addr, &w->addr, w->addrlen);
	ldns_buffer_clear(pend->c->buffer);
	ldns_buffer_write(pend->c->buffer, pkt, pkt_len);
	ldns_buffer_flip(pend->c->buffer);
	pend->c->tcp_is_reading = 0;
	pend->c->tcp_byte_count = 0;
	comm_point_start_listening(pend->c, s, -1);
	return 1;
}

/** see if buffers can be used to service TCP queries */
static void
use_free_buffer(struct outside_network* outnet)
{
	struct waiting_tcp* w;
	while(outnet->tcp_free && outnet->tcp_wait_first 
		&& !outnet->want_to_quit) {
		w = outnet->tcp_wait_first;
		outnet->tcp_wait_first = w->next_waiting;
		if(outnet->tcp_wait_last == w)
			outnet->tcp_wait_last = NULL;
		if(!outnet_tcp_take_into_use(w, w->pkt, w->pkt_len)) {
			comm_point_callback_t* cb = w->cb;
			void* cb_arg = w->cb_arg;
			waiting_tcp_delete(w);
			fptr_ok(fptr_whitelist_pending_tcp(cb));
			(void)(*cb)(NULL, cb_arg, NETEVENT_CLOSED, NULL);
		}
	}
}

/** decomission a tcp buffer, closes commpoint and frees waiting_tcp entry */
static void
decomission_pending_tcp(struct outside_network* outnet, 
	struct pending_tcp* pend)
{
	comm_point_close(pend->c);
	pend->next_free = outnet->tcp_free;
	outnet->tcp_free = pend;
	waiting_tcp_delete(pend->query);
	pend->query = NULL;
	use_free_buffer(outnet);
}

int 
outnet_tcp_cb(struct comm_point* c, void* arg, int error,
	struct comm_reply *reply_info)
{
	struct pending_tcp* pend = (struct pending_tcp*)arg;
	struct outside_network* outnet = pend->query->outnet;
	verbose(VERB_ALGO, "outnettcp cb");
	if(error != NETEVENT_NOERROR) {
		verbose(VERB_QUERY, "outnettcp got tcp error %d", error);
		/* pass error below and exit */
	} else {
		/* check ID */
		if(ldns_buffer_limit(c->buffer) < sizeof(uint16_t) ||
			LDNS_ID_WIRE(ldns_buffer_begin(c->buffer))!=pend->id) {
			log_addr(VERB_QUERY, 
				"outnettcp: bad ID in reply, from:",
				&pend->query->addr, pend->query->addrlen);
			error = NETEVENT_CLOSED;
		}
	}
	fptr_ok(fptr_whitelist_pending_tcp(pend->query->cb));
	(void)(*pend->query->cb)(c, pend->query->cb_arg, error, reply_info);
	decomission_pending_tcp(outnet, pend);
	return 0;
}

/** lower use count on pc, see if it can be closed */
static void
portcomm_loweruse(struct outside_network* outnet, struct port_comm* pc)
{
	struct port_if* pif;
	pc->num_outstanding--;
	if(pc->num_outstanding > 0) {
		return;
	}
	/* close it and replace in unused list */
	verbose(VERB_ALGO, "close of port %d", pc->number);
	comm_point_close(pc->cp);
	pif = pc->pif;
	log_assert(pif->inuse > 0);
	pif->avail_ports[pif->avail_total - pif->inuse] = pc->number;
	pif->inuse--;
	pif->out[pc->index] = pif->out[pif->inuse];
	pif->out[pc->index]->index = pc->index;
	pc->next = outnet->unused_fds;
	outnet->unused_fds = pc;
}

/** try to send waiting UDP queries */
static void
outnet_send_wait_udp(struct outside_network* outnet)
{
	struct pending* pend;
	/* process waiting queries */
	while(outnet->udp_wait_first && outnet->unused_fds 
		&& !outnet->want_to_quit) {
		pend = outnet->udp_wait_first;
		outnet->udp_wait_first = pend->next_waiting;
		if(!pend->next_waiting) outnet->udp_wait_last = NULL;
		ldns_buffer_clear(outnet->udp_buff);
		ldns_buffer_write(outnet->udp_buff, pend->pkt, pend->pkt_len);
		ldns_buffer_flip(outnet->udp_buff);
		free(pend->pkt); /* freeing now makes get_mem correct */
		pend->pkt = NULL; 
		pend->pkt_len = 0;
		if(!randomize_and_send_udp(outnet, pend, outnet->udp_buff, 
			pend->timeout)) {
			/* callback error on pending */
			fptr_ok(fptr_whitelist_pending_udp(pend->cb));
			(void)(*pend->cb)(outnet->unused_fds->cp, pend->cb_arg, 
				NETEVENT_CLOSED, NULL);
			pending_delete(outnet, pend);
		}
	}
}

int 
outnet_udp_cb(struct comm_point* c, void* arg, int error,
	struct comm_reply *reply_info)
{
	struct outside_network* outnet = (struct outside_network*)arg;
	struct pending key;
	struct pending* p;
	verbose(VERB_ALGO, "answer cb");

	if(error != NETEVENT_NOERROR) {
		verbose(VERB_QUERY, "outnetudp got udp error %d", error);
		return 0;
	}
	if(ldns_buffer_limit(c->buffer) < LDNS_HEADER_SIZE) {
		verbose(VERB_QUERY, "outnetudp udp too short");
		return 0;
	}
	log_assert(reply_info);

	/* setup lookup key */
	key.id = (unsigned)LDNS_ID_WIRE(ldns_buffer_begin(c->buffer));
	memcpy(&key.addr, &reply_info->addr, reply_info->addrlen);
	key.addrlen = reply_info->addrlen;
	verbose(VERB_ALGO, "Incoming reply id = %4.4x", key.id);
	log_addr(VERB_ALGO, "Incoming reply addr =", 
		&reply_info->addr, reply_info->addrlen);

	/* find it, see if this thing is a valid query response */
	verbose(VERB_ALGO, "lookup size is %d entries", (int)outnet->pending->count);
	p = (struct pending*)rbtree_search(outnet->pending, &key);
	if(!p) {
		verbose(VERB_QUERY, "received unwanted or unsolicited udp reply dropped.");
		log_buf(VERB_ALGO, "dropped message", c->buffer);
		outnet->unwanted_replies++;
		if(outnet->unwanted_threshold && ++outnet->unwanted_total 
			>= outnet->unwanted_threshold) {
			log_warn("unwanted reply total reached threshold (%u)"
				" you may be under attack."
				" defensive action: clearing the cache",
				(unsigned)outnet->unwanted_threshold);
			fptr_ok(fptr_whitelist_alloc_cleanup(
				outnet->unwanted_action));
			(*outnet->unwanted_action)(outnet->unwanted_param);
			outnet->unwanted_total = 0;
		}
		return 0;
	}

	verbose(VERB_ALGO, "received udp reply.");
	log_buf(VERB_ALGO, "udp message", c->buffer);
	if(p->pc->cp != c) {
		verbose(VERB_QUERY, "received reply id,addr on wrong port. "
			"dropped.");
		outnet->unwanted_replies++;
		if(outnet->unwanted_threshold && ++outnet->unwanted_total 
			>= outnet->unwanted_threshold) {
			log_warn("unwanted reply total reached threshold (%u)"
				" you may be under attack."
				" defensive action: clearing the cache",
				(unsigned)outnet->unwanted_threshold);
			fptr_ok(fptr_whitelist_alloc_cleanup(
				outnet->unwanted_action));
			(*outnet->unwanted_action)(outnet->unwanted_param);
			outnet->unwanted_total = 0;
		}
		return 0;
	}
	comm_timer_disable(p->timer);
	verbose(VERB_ALGO, "outnet handle udp reply");
	/* delete from tree first in case callback creates a retry */
	(void)rbtree_delete(outnet->pending, p->node.key);
	fptr_ok(fptr_whitelist_pending_udp(p->cb));
	(void)(*p->cb)(p->pc->cp, p->cb_arg, NETEVENT_NOERROR, reply_info);
	portcomm_loweruse(outnet, p->pc);
	pending_delete(NULL, p);
	outnet_send_wait_udp(outnet);
	return 0;
}

/** calculate number of ip4 and ip6 interfaces*/
static void 
calc_num46(char** ifs, int num_ifs, int do_ip4, int do_ip6, 
	int* num_ip4, int* num_ip6)
{
	int i;
	*num_ip4 = 0;
	*num_ip6 = 0;
	if(num_ifs <= 0) {
		if(do_ip4)
			*num_ip4 = 1;
		if(do_ip6)
			*num_ip6 = 1;
		return;
	}
	for(i=0; i<num_ifs; i++)
	{
		if(str_is_ip6(ifs[i])) {
			if(do_ip6)
				(*num_ip6)++;
		} else {
			if(do_ip4)
				(*num_ip4)++;
		}
	}

}

void 
pending_udp_timer_cb(void *arg)
{
	struct pending* p = (struct pending*)arg;
	struct outside_network* outnet = p->outnet;
	/* it timed out */
	verbose(VERB_ALGO, "timeout udp");
	fptr_ok(fptr_whitelist_pending_udp(p->cb));
	(void)(*p->cb)(p->pc->cp, p->cb_arg, NETEVENT_TIMEOUT, NULL);
	portcomm_loweruse(outnet, p->pc);
	pending_delete(outnet, p);
	outnet_send_wait_udp(outnet);
}

/** create pending_tcp buffers */
static int
create_pending_tcp(struct outside_network* outnet, size_t bufsize)
{
	size_t i;
	if(outnet->num_tcp == 0)
		return 1; /* no tcp needed, nothing to do */
	if(!(outnet->tcp_conns = (struct pending_tcp **)calloc(
			outnet->num_tcp, sizeof(struct pending_tcp*))))
		return 0;
	for(i=0; i<outnet->num_tcp; i++) {
		if(!(outnet->tcp_conns[i] = (struct pending_tcp*)calloc(1, 
			sizeof(struct pending_tcp))))
			return 0;
		outnet->tcp_conns[i]->next_free = outnet->tcp_free;
		outnet->tcp_free = outnet->tcp_conns[i];
		outnet->tcp_conns[i]->c = comm_point_create_tcp_out(
			outnet->base, bufsize, outnet_tcp_cb, 
			outnet->tcp_conns[i]);
		if(!outnet->tcp_conns[i]->c)
			return 0;
	}
	return 1;
}

/** setup an outgoing interface, ready address */
static int setup_if(struct port_if* pif, const char* addrstr, 
	int* avail, int numavail, size_t numfd)
{
	pif->avail_total = numavail;
	pif->avail_ports = (int*)memdup(avail, (size_t)numavail*sizeof(int));
	if(!pif->avail_ports)
		return 0;
	if(!ipstrtoaddr(addrstr, UNBOUND_DNS_PORT, &pif->addr, &pif->addrlen))
		return 0;
	pif->maxout = (int)numfd;
	pif->inuse = 0;
	pif->out = (struct port_comm**)calloc(numfd, 
		sizeof(struct port_comm*));
	if(!pif->out)
		return 0;
	return 1;
}

struct outside_network* 
outside_network_create(struct comm_base *base, size_t bufsize, 
	size_t num_ports, char** ifs, int num_ifs, int do_ip4, 
	int do_ip6, size_t num_tcp, struct infra_cache* infra,
	struct ub_randstate* rnd, int use_caps_for_id, int* availports, 
	int numavailports, size_t unwanted_threshold,
	void (*unwanted_action)(void*), void* unwanted_param, int do_udp)
{
	struct outside_network* outnet = (struct outside_network*)
		calloc(1, sizeof(struct outside_network));
	size_t k;
	if(!outnet) {
		log_err("malloc failed");
		return NULL;
	}
	comm_base_timept(base, &outnet->now_secs, &outnet->now_tv);
	outnet->base = base;
	outnet->num_tcp = num_tcp;
	outnet->infra = infra;
	outnet->rnd = rnd;
	outnet->svcd_overhead = 0;
	outnet->want_to_quit = 0;
	outnet->unwanted_threshold = unwanted_threshold;
	outnet->unwanted_action = unwanted_action;
	outnet->unwanted_param = unwanted_param;
	outnet->use_caps_for_id = use_caps_for_id;
	outnet->do_udp = do_udp;
	if(numavailports == 0) {
		log_err("no outgoing ports available");
		outside_network_delete(outnet);
		return NULL;
	}
#ifndef INET6
	do_ip6 = 0;
#endif
	calc_num46(ifs, num_ifs, do_ip4, do_ip6, 
		&outnet->num_ip4, &outnet->num_ip6);
	if(outnet->num_ip4 != 0) {
		if(!(outnet->ip4_ifs = (struct port_if*)calloc(
			(size_t)outnet->num_ip4, sizeof(struct port_if)))) {
			log_err("malloc failed");
			outside_network_delete(outnet);
			return NULL;
		}
	}
	if(outnet->num_ip6 != 0) {
		if(!(outnet->ip6_ifs = (struct port_if*)calloc(
			(size_t)outnet->num_ip6, sizeof(struct port_if)))) {
			log_err("malloc failed");
			outside_network_delete(outnet);
			return NULL;
		}
	}
	if(	!(outnet->udp_buff = ldns_buffer_new(bufsize)) ||
		!(outnet->pending = rbtree_create(pending_cmp)) ||
		!(outnet->serviced = rbtree_create(serviced_cmp)) ||
		!create_pending_tcp(outnet, bufsize)) {
		log_err("malloc failed");
		outside_network_delete(outnet);
		return NULL;
	}

	/* allocate commpoints */
	for(k=0; k<num_ports; k++) {
		struct port_comm* pc;
		pc = (struct port_comm*)calloc(1, sizeof(*pc));
		if(!pc) {
			log_err("malloc failed");
			outside_network_delete(outnet);
			return NULL;
		}
		pc->cp = comm_point_create_udp(outnet->base, -1, 
			outnet->udp_buff, outnet_udp_cb, outnet);
		if(!pc->cp) {
			log_err("malloc failed");
			free(pc);
			outside_network_delete(outnet);
			return NULL;
		}
		pc->next = outnet->unused_fds;
		outnet->unused_fds = pc;
	}

	/* allocate interfaces */
	if(num_ifs == 0) {
		if(do_ip4 && !setup_if(&outnet->ip4_ifs[0], "0.0.0.0", 
			availports, numavailports, num_ports)) {
			log_err("malloc failed");
			outside_network_delete(outnet);
			return NULL;
		}
		if(do_ip6 && !setup_if(&outnet->ip6_ifs[0], "::", 
			availports, numavailports, num_ports)) {
			log_err("malloc failed");
			outside_network_delete(outnet);
			return NULL;
		}
	} else {
		size_t done_4 = 0, done_6 = 0;
		int i;
		for(i=0; i<num_ifs; i++) {
			if(str_is_ip6(ifs[i]) && do_ip6) {
				if(!setup_if(&outnet->ip6_ifs[done_6], ifs[i],
					availports, numavailports, num_ports)){
					log_err("malloc failed");
					outside_network_delete(outnet);
					return NULL;
				}
				done_6++;
			}
			if(!str_is_ip6(ifs[i]) && do_ip4) {
				if(!setup_if(&outnet->ip4_ifs[done_4], ifs[i],
					availports, numavailports, num_ports)){
					log_err("malloc failed");
					outside_network_delete(outnet);
					return NULL;
				}
				done_4++;
			}
		}
	}
	return outnet;
}

/** helper pending delete */
static void
pending_node_del(rbnode_t* node, void* arg)
{
	struct pending* pend = (struct pending*)node;
	struct outside_network* outnet = (struct outside_network*)arg;
	pending_delete(outnet, pend);
}

/** helper serviced delete */
static void
serviced_node_del(rbnode_t* node, void* ATTR_UNUSED(arg))
{
	struct serviced_query* sq = (struct serviced_query*)node;
	struct service_callback* p = sq->cblist, *np;
	free(sq->qbuf);
	while(p) {
		np = p->next;
		free(p);
		p = np;
	}
	free(sq);
}

void 
outside_network_quit_prepare(struct outside_network* outnet)
{
	if(!outnet)
		return;
	/* prevent queued items from being sent */
	outnet->want_to_quit = 1; 
}

void 
outside_network_delete(struct outside_network* outnet)
{
	if(!outnet)
		return;
	outnet->want_to_quit = 1;
	/* check every element, since we can be called on malloc error */
	if(outnet->pending) {
		/* free pending elements, but do no unlink from tree. */
		traverse_postorder(outnet->pending, pending_node_del, NULL);
		free(outnet->pending);
	}
	if(outnet->serviced) {
		traverse_postorder(outnet->serviced, serviced_node_del, NULL);
		free(outnet->serviced);
	}
	if(outnet->udp_buff)
		ldns_buffer_free(outnet->udp_buff);
	if(outnet->unused_fds) {
		struct port_comm* p = outnet->unused_fds, *np;
		while(p) {
			np = p->next;
			comm_point_delete(p->cp);
			free(p);
			p = np;
		}
		outnet->unused_fds = NULL;
	}
	if(outnet->ip4_ifs) {
		int i, k;
		for(i=0; i<outnet->num_ip4; i++) {
			for(k=0; k<outnet->ip4_ifs[i].inuse; k++) {
				struct port_comm* pc = outnet->ip4_ifs[i].
					out[k];
				comm_point_delete(pc->cp);
				free(pc);
			}
			free(outnet->ip4_ifs[i].avail_ports);
			free(outnet->ip4_ifs[i].out);
		}
		free(outnet->ip4_ifs);
	}
	if(outnet->ip6_ifs) {
		int i, k;
		for(i=0; i<outnet->num_ip6; i++) {
			for(k=0; k<outnet->ip6_ifs[i].inuse; k++) {
				struct port_comm* pc = outnet->ip6_ifs[i].
					out[k];
				comm_point_delete(pc->cp);
				free(pc);
			}
			free(outnet->ip6_ifs[i].avail_ports);
			free(outnet->ip6_ifs[i].out);
		}
		free(outnet->ip6_ifs);
	}
	if(outnet->tcp_conns) {
		size_t i;
		for(i=0; i<outnet->num_tcp; i++)
			if(outnet->tcp_conns[i]) {
				comm_point_delete(outnet->tcp_conns[i]->c);
				waiting_tcp_delete(outnet->tcp_conns[i]->query);
				free(outnet->tcp_conns[i]);
			}
		free(outnet->tcp_conns);
	}
	if(outnet->tcp_wait_first) {
		struct waiting_tcp* p = outnet->tcp_wait_first, *np;
		while(p) {
			np = p->next_waiting;
			waiting_tcp_delete(p);
			p = np;
		}
	}
	if(outnet->udp_wait_first) {
		struct pending* p = outnet->udp_wait_first, *np;
		while(p) {
			np = p->next_waiting;
			pending_delete(NULL, p);
			p = np;
		}
	}
	free(outnet);
}

void 
pending_delete(struct outside_network* outnet, struct pending* p)
{
	if(!p)
		return;
	if(outnet && outnet->udp_wait_first &&
		(p->next_waiting || p == outnet->udp_wait_last) ) {
		/* delete from waiting list, if it is in the waiting list */
		struct pending* prev = NULL, *x = outnet->udp_wait_first;
		while(x && x != p) {
			prev = x;
			x = x->next_waiting;
		}
		if(x) {
			log_assert(x == p);
			if(prev)
				prev->next_waiting = p->next_waiting;
			else	outnet->udp_wait_first = p->next_waiting;
			if(outnet->udp_wait_last == p)
				outnet->udp_wait_last = prev;
		}
	}
	if(outnet) {
		(void)rbtree_delete(outnet->pending, p->node.key);
	}
	if(p->timer)
		comm_timer_delete(p->timer);
	free(p->pkt);
	free(p);
}

/**
 * Try to open a UDP socket for outgoing communication.
 * Sets sockets options as needed.
 * @param addr: socket address.
 * @param addrlen: length of address.
 * @param port: port override for addr.
 * @param inuse: if -1 is returned, this bool means the port was in use.
 * @return fd or -1
 */
static int
udp_sockport(struct sockaddr_storage* addr, socklen_t addrlen, int port, 
	int* inuse)
{
	int fd, noproto;
	if(addr_is_ip6(addr, addrlen)) {
		struct sockaddr_in6* sa = (struct sockaddr_in6*)addr;
		sa->sin6_port = (in_port_t)htons((uint16_t)port);
		fd = create_udp_sock(AF_INET6, SOCK_DGRAM, 
			(struct sockaddr*)addr, addrlen, 1, inuse, &noproto,
			0, 0);
	} else {
		struct sockaddr_in* sa = (struct sockaddr_in*)addr;
		sa->sin_port = (in_port_t)htons((uint16_t)port);
		fd = create_udp_sock(AF_INET, SOCK_DGRAM, 
			(struct sockaddr*)addr, addrlen, 1, inuse, &noproto,
			0, 0);
	}
	return fd;
}

/** Select random ID */
static int
select_id(struct outside_network* outnet, struct pending* pend,
	ldns_buffer* packet)
{
	int id_tries = 0;
	pend->id = ((unsigned)ub_random(outnet->rnd)>>8) & 0xffff;
	LDNS_ID_SET(ldns_buffer_begin(packet), pend->id);

	/* insert in tree */
	pend->node.key = pend;
	while(!rbtree_insert(outnet->pending, &pend->node)) {
		/* change ID to avoid collision */
		pend->id = ((unsigned)ub_random(outnet->rnd)>>8) & 0xffff;
		LDNS_ID_SET(ldns_buffer_begin(packet), pend->id);
		id_tries++;
		if(id_tries == MAX_ID_RETRY) {
			pend->id=99999; /* non existant ID */
			log_err("failed to generate unique ID, drop msg");
			return 0;
		}
	}
	verbose(VERB_ALGO, "inserted new pending reply id=%4.4x", pend->id);
	return 1;
}

/** Select random interface and port */
static int
select_ifport(struct outside_network* outnet, struct pending* pend,
	int num_if, struct port_if* ifs)
{
	int my_if, my_port, fd, portno, inuse, tries=0;
	struct port_if* pif;
	/* randomly select interface and port */
	if(num_if == 0) {
		verbose(VERB_QUERY, "Need to send query but have no "
			"outgoing interfaces of that family");
		return 0;
	}
	log_assert(outnet->unused_fds);
	tries = 0;
	while(1) {
		my_if = ub_random_max(outnet->rnd, num_if);
		pif = &ifs[my_if];
		my_port = ub_random_max(outnet->rnd, pif->avail_total);
		if(my_port < pif->inuse) {
			/* port already open */
			pend->pc = pif->out[my_port];
			verbose(VERB_ALGO, "using UDP if=%d port=%d", 
				my_if, pend->pc->number);
			break;
		}
		/* try to open new port, if fails, loop to try again */
		log_assert(pif->inuse < pif->maxout);
		portno = pif->avail_ports[my_port - pif->inuse];
		fd = udp_sockport(&pif->addr, pif->addrlen, portno, &inuse);
		if(fd == -1 && !inuse) {
			/* nonrecoverable error making socket */
			return 0;
		}
		if(fd != -1) {
			verbose(VERB_ALGO, "opened UDP if=%d port=%d", 
				my_if, portno);
			/* grab fd */
			pend->pc = outnet->unused_fds;
			outnet->unused_fds = pend->pc->next;

			/* setup portcomm */
			pend->pc->next = NULL;
			pend->pc->number = portno;
			pend->pc->pif = pif;
			pend->pc->index = pif->inuse;
			pend->pc->num_outstanding = 0;
			comm_point_start_listening(pend->pc->cp, fd, -1);

			/* grab port in interface */
			pif->out[pif->inuse] = pend->pc;
			pif->avail_ports[my_port - pif->inuse] =
				pif->avail_ports[pif->avail_total-pif->inuse-1];
			pif->inuse++;
			break;
		}
		/* failed, already in use */
		verbose(VERB_QUERY, "port %d in use, trying another", portno);
		tries++;
		if(tries == MAX_PORT_RETRY) {
			log_err("failed to find an open port, drop msg");
			return 0;
		}
	}
	log_assert(pend->pc);
	pend->pc->num_outstanding++;

	return 1;
}

static int
randomize_and_send_udp(struct outside_network* outnet, struct pending* pend,
	ldns_buffer* packet, int timeout)
{
	struct timeval tv;

	/* select id */
	if(!select_id(outnet, pend, packet)) {
		return 0;
	}

	/* select src_if, port */
	if(addr_is_ip6(&pend->addr, pend->addrlen)) {
		if(!select_ifport(outnet, pend, 
			outnet->num_ip6, outnet->ip6_ifs))
			return 0;
	} else {
		if(!select_ifport(outnet, pend, 
			outnet->num_ip4, outnet->ip4_ifs))
			return 0;
	}
	log_assert(pend->pc && pend->pc->cp);

	/* send it over the commlink */
	if(!comm_point_send_udp_msg(pend->pc->cp, packet, 
		(struct sockaddr*)&pend->addr, pend->addrlen)) {
		portcomm_loweruse(outnet, pend->pc);
		return 0;
	}

	/* system calls to set timeout after sending UDP to make roundtrip
	   smaller. */
#ifndef S_SPLINT_S
	tv.tv_sec = timeout/1000;
	tv.tv_usec = (timeout%1000)*1000;
#endif
	comm_timer_set(pend->timer, &tv);
	return 1;
}

struct pending* 
pending_udp_query(struct outside_network* outnet, ldns_buffer* packet, 
	struct sockaddr_storage* addr, socklen_t addrlen, int timeout,
	comm_point_callback_t* cb, void* cb_arg)
{
	struct pending* pend = (struct pending*)calloc(1, sizeof(*pend));
	if(!pend) return NULL;
	pend->outnet = outnet;
	pend->addrlen = addrlen;
	memmove(&pend->addr, addr, addrlen);
	pend->cb = cb;
	pend->cb_arg = cb_arg;
	pend->node.key = pend;
	pend->timer = comm_timer_create(outnet->base, pending_udp_timer_cb, 
		pend);
	if(!pend->timer) {
		free(pend);
		return NULL;
	}

	if(outnet->unused_fds == NULL) {
		/* no unused fd, cannot create a new port (randomly) */
		verbose(VERB_ALGO, "no fds available, udp query waiting");
		pend->timeout = timeout;
		pend->pkt_len = ldns_buffer_limit(packet);
		pend->pkt = (uint8_t*)memdup(ldns_buffer_begin(packet),
			pend->pkt_len);
		if(!pend->pkt) {
			comm_timer_delete(pend->timer);
			free(pend);
			return NULL;
		}
		/* put at end of waiting list */
		if(outnet->udp_wait_last)
			outnet->udp_wait_last->next_waiting = pend;
		else 
			outnet->udp_wait_first = pend;
		outnet->udp_wait_last = pend;
		return pend;
	}
	if(!randomize_and_send_udp(outnet, pend, packet, timeout)) {
		pending_delete(outnet, pend);
		return NULL;
	}
	return pend;
}

void
outnet_tcptimer(void* arg)
{
	struct waiting_tcp* w = (struct waiting_tcp*)arg;
	struct outside_network* outnet = w->outnet;
	comm_point_callback_t* cb;
	void* cb_arg;
	if(w->pkt) {
		/* it is on the waiting list */
		struct waiting_tcp* p=outnet->tcp_wait_first, *prev=NULL;
		while(p) {
			if(p == w) {
				if(prev) prev->next_waiting = w->next_waiting;
				else	outnet->tcp_wait_first=w->next_waiting;
				outnet->tcp_wait_last = prev;
				break;
			}
			prev = p;
			p=p->next_waiting;
		}
	} else {
		/* it was in use */
		struct pending_tcp* pend=(struct pending_tcp*)w->next_waiting;
		comm_point_close(pend->c);
		pend->query = NULL;
		pend->next_free = outnet->tcp_free;
		outnet->tcp_free = pend;
	}
	cb = w->cb;
	cb_arg = w->cb_arg;
	waiting_tcp_delete(w);
	fptr_ok(fptr_whitelist_pending_tcp(cb));
	(void)(*cb)(NULL, cb_arg, NETEVENT_TIMEOUT, NULL);
	use_free_buffer(outnet);
}

struct waiting_tcp* 
pending_tcp_query(struct outside_network* outnet, ldns_buffer* packet, 
	struct sockaddr_storage* addr, socklen_t addrlen, int timeout,
	comm_point_callback_t* callback, void* callback_arg)
{
	struct pending_tcp* pend = outnet->tcp_free;
	struct waiting_tcp* w;
	struct timeval tv;
	uint16_t id;
	/* if no buffer is free allocate space to store query */
	w = (struct waiting_tcp*)malloc(sizeof(struct waiting_tcp) 
		+ (pend?0:ldns_buffer_limit(packet)));
	if(!w) {
		return NULL;
	}
	if(!(w->timer = comm_timer_create(outnet->base, outnet_tcptimer, w))) {
		free(w);
		return NULL;
	}
	w->pkt = NULL;
	w->pkt_len = 0;
	id = ((unsigned)ub_random(outnet->rnd)>>8) & 0xffff;
	LDNS_ID_SET(ldns_buffer_begin(packet), id);
	memcpy(&w->addr, addr, addrlen);
	w->addrlen = addrlen;
	w->outnet = outnet;
	w->cb = callback;
	w->cb_arg = callback_arg;
#ifndef S_SPLINT_S
	tv.tv_sec = timeout;
	tv.tv_usec = 0;
#endif
	comm_timer_set(w->timer, &tv);
	if(pend) {
		/* we have a buffer available right now */
		if(!outnet_tcp_take_into_use(w, ldns_buffer_begin(packet),
			ldns_buffer_limit(packet))) {
			waiting_tcp_delete(w);
			return NULL;
		}
	} else {
		/* queue up */
		w->pkt = (uint8_t*)w + sizeof(struct waiting_tcp);
		w->pkt_len = ldns_buffer_limit(packet);
		memmove(w->pkt, ldns_buffer_begin(packet), w->pkt_len);
		w->next_waiting = NULL;
		if(outnet->tcp_wait_last)
			outnet->tcp_wait_last->next_waiting = w;
		else	outnet->tcp_wait_first = w;
		outnet->tcp_wait_last = w;
	}
	return w;
}

/** create query for serviced queries */
static void
serviced_gen_query(ldns_buffer* buff, uint8_t* qname, size_t qnamelen, 
	uint16_t qtype, uint16_t qclass, uint16_t flags)
{
	ldns_buffer_clear(buff);
	/* skip id */
	ldns_buffer_write_u16(buff, flags);
	ldns_buffer_write_u16(buff, 1); /* qdcount */
	ldns_buffer_write_u16(buff, 0); /* ancount */
	ldns_buffer_write_u16(buff, 0); /* nscount */
	ldns_buffer_write_u16(buff, 0); /* arcount */
	ldns_buffer_write(buff, qname, qnamelen);
	ldns_buffer_write_u16(buff, qtype);
	ldns_buffer_write_u16(buff, qclass);
	ldns_buffer_flip(buff);
}

/** lookup serviced query in serviced query rbtree */
static struct serviced_query*
lookup_serviced(struct outside_network* outnet, ldns_buffer* buff, int dnssec,
	struct sockaddr_storage* addr, socklen_t addrlen)
{
	struct serviced_query key;
	key.node.key = &key;
	key.qbuf = ldns_buffer_begin(buff);
	key.qbuflen = ldns_buffer_limit(buff);
	key.dnssec = dnssec;
	memcpy(&key.addr, addr, addrlen);
	key.addrlen = addrlen;
	key.outnet = outnet;
	return (struct serviced_query*)rbtree_search(outnet->serviced, &key);
}

/** Create new serviced entry */
static struct serviced_query*
serviced_create(struct outside_network* outnet, ldns_buffer* buff, int dnssec,
	int want_dnssec, struct sockaddr_storage* addr, socklen_t addrlen)
{
	struct serviced_query* sq = (struct serviced_query*)malloc(sizeof(*sq));
#ifdef UNBOUND_DEBUG
	rbnode_t* ins;
#endif
	if(!sq) 
		return NULL;
	sq->node.key = sq;
	sq->qbuf = memdup(ldns_buffer_begin(buff), ldns_buffer_limit(buff));
	if(!sq->qbuf) {
		free(sq);
		return NULL;
	}
	sq->qbuflen = ldns_buffer_limit(buff);
	sq->dnssec = dnssec;
	sq->want_dnssec = want_dnssec;
	memcpy(&sq->addr, addr, addrlen);
	sq->addrlen = addrlen;
	sq->outnet = outnet;
	sq->cblist = NULL;
	sq->pending = NULL;
	sq->status = serviced_initial;
	sq->retry = 0;
	sq->to_be_deleted = 0;
#ifdef UNBOUND_DEBUG
	ins = 
#endif
	rbtree_insert(outnet->serviced, &sq->node);
	log_assert(ins != NULL); /* must not be already present */
	return sq;
}

/** remove waiting tcp from the outnet waiting list */
static void
waiting_list_remove(struct outside_network* outnet, struct waiting_tcp* w)
{
	struct waiting_tcp* p = outnet->tcp_wait_first, *prev = NULL;
	while(p) {
		if(p == w) {
			/* remove w */
			if(prev)
				prev->next_waiting = w->next_waiting;
			else	outnet->tcp_wait_first = w->next_waiting;
			if(outnet->tcp_wait_last == w)
				outnet->tcp_wait_last = prev;
			return;
		}
		prev = p;
		p = p->next_waiting;
	}
}

/** cleanup serviced query entry */
static void
serviced_delete(struct serviced_query* sq)
{
	if(sq->pending) {
		/* clear up the pending query */
		if(sq->status == serviced_query_UDP_EDNS ||
			sq->status == serviced_query_UDP ||
			sq->status == serviced_query_PROBE_EDNS ||
			sq->status == serviced_query_UDP_EDNS_FRAG ||
			sq->status == serviced_query_UDP_EDNS_fallback) {
			struct pending* p = (struct pending*)sq->pending;
			if(p->pc)
				portcomm_loweruse(sq->outnet, p->pc);
			pending_delete(sq->outnet, p);
			/* this call can cause reentrant calls back into the
			 * mesh */
			outnet_send_wait_udp(sq->outnet);
		} else {
			struct waiting_tcp* p = (struct waiting_tcp*)
				sq->pending;
			if(p->pkt == NULL) {
				decomission_pending_tcp(sq->outnet, 
					(struct pending_tcp*)p->next_waiting);
			} else {
				waiting_list_remove(sq->outnet, p);
				waiting_tcp_delete(p);
			}
		}
	}
	/* does not delete from tree, caller has to do that */
	serviced_node_del(&sq->node, NULL);
}

/** perturb a dname capitalization randomly */
static void
serviced_perturb_qname(struct ub_randstate* rnd, uint8_t* qbuf, size_t len)
{
	uint8_t lablen;
	uint8_t* d = qbuf + 10;
	long int random = 0;
	int bits = 0;
	log_assert(len >= 10 + 5 /* offset qname, root, qtype, qclass */);
	lablen = *d++;
	while(lablen) {
		while(lablen--) {
			/* only perturb A-Z, a-z */
			if(isalpha((int)*d)) {
				/* get a random bit */	
				if(bits == 0) {
					random = ub_random(rnd);
					bits = 30;
				}
				if(random & 0x1) {
					*d = (uint8_t)toupper((int)*d);
				} else {
					*d = (uint8_t)tolower((int)*d);
				}
				random >>= 1;
				bits--;
			}
			d++;
		}
		lablen = *d++;
	}
	if(verbosity >= VERB_ALGO) {
		char buf[LDNS_MAX_DOMAINLEN+1];
		dname_str(qbuf+10, buf);
		verbose(VERB_ALGO, "qname perturbed to %s", buf);
	}
}

/** put serviced query into a buffer */
static void
serviced_encode(struct serviced_query* sq, ldns_buffer* buff, int with_edns)
{
	/* if we are using 0x20 bits for ID randomness, perturb them */
	if(sq->outnet->use_caps_for_id) {
		serviced_perturb_qname(sq->outnet->rnd, sq->qbuf, sq->qbuflen);
	}
	/* generate query */
	ldns_buffer_clear(buff);
	ldns_buffer_write_u16(buff, 0); /* id placeholder */
	ldns_buffer_write(buff, sq->qbuf, sq->qbuflen);
	ldns_buffer_flip(buff);
	if(with_edns) {
		/* add edns section */
		struct edns_data edns;
		edns.edns_present = 1;
		edns.ext_rcode = 0;
		edns.edns_version = EDNS_ADVERTISED_VERSION;
		if(sq->status == serviced_query_UDP_EDNS_FRAG) {
			if(addr_is_ip6(&sq->addr, sq->addrlen)) {
				if(EDNS_FRAG_SIZE_IP6 < EDNS_ADVERTISED_SIZE)
					edns.udp_size = EDNS_FRAG_SIZE_IP6;
				else	edns.udp_size = EDNS_ADVERTISED_SIZE;
			} else {
				if(EDNS_FRAG_SIZE_IP4 < EDNS_ADVERTISED_SIZE)
					edns.udp_size = EDNS_FRAG_SIZE_IP4;
				else	edns.udp_size = EDNS_ADVERTISED_SIZE;
			}
		} else {
			edns.udp_size = EDNS_ADVERTISED_SIZE;
		}
		edns.bits = 0;
		if(sq->dnssec & EDNS_DO)
			edns.bits = EDNS_DO;
		if(sq->dnssec & BIT_CD)
			LDNS_CD_SET(ldns_buffer_begin(buff));
		attach_edns_record(buff, &edns);
	}
}

/**
 * Perform serviced query UDP sending operation.
 * Sends UDP with EDNS, unless infra host marked non EDNS.
 * @param sq: query to send.
 * @param buff: buffer scratch space.
 * @return 0 on error.
 */
static int
serviced_udp_send(struct serviced_query* sq, ldns_buffer* buff)
{
	int rtt, vs;
	uint8_t edns_lame_known;
	uint32_t now = *sq->outnet->now_secs;

	if(!infra_host(sq->outnet->infra, &sq->addr, sq->addrlen, now, &vs,
		&edns_lame_known, &rtt))
		return 0;
	sq->last_rtt = rtt;
	verbose(VERB_ALGO, "EDNS lookup known=%d vs=%d", edns_lame_known, vs);
	if(sq->status == serviced_initial) {
		if(edns_lame_known == 0 && rtt > 5000 && rtt < 10001) {
			/* perform EDNS lame probe - check if server is
			 * EDNS lame (EDNS queries to it are dropped) */
			verbose(VERB_ALGO, "serviced query: send probe to see "
				" if use of EDNS causes timeouts");
			/* even 700 msec may be too small */
			rtt = 1000;
			sq->status = serviced_query_PROBE_EDNS;
		} else if(vs != -1) {
			sq->status = serviced_query_UDP_EDNS;
		} else { 	
			sq->status = serviced_query_UDP; 
		}
	}
	serviced_encode(sq, buff, (sq->status == serviced_query_UDP_EDNS) ||
		(sq->status == serviced_query_UDP_EDNS_FRAG));
	sq->last_sent_time = *sq->outnet->now_tv;
	sq->edns_lame_known = (int)edns_lame_known;
	verbose(VERB_ALGO, "serviced query UDP timeout=%d msec", rtt);
	sq->pending = pending_udp_query(sq->outnet, buff, &sq->addr, 
		sq->addrlen, rtt, serviced_udp_callback, sq);
	if(!sq->pending)
		return 0;
	return 1;
}

/** check that perturbed qname is identical */
static int
serviced_check_qname(ldns_buffer* pkt, uint8_t* qbuf, size_t qbuflen)
{
	uint8_t* d1 = ldns_buffer_at(pkt, 12);
	uint8_t* d2 = qbuf+10;
	uint8_t len1, len2;
	int count = 0;
	log_assert(qbuflen >= 15 /* 10 header, root, type, class */);
	len1 = *d1++;
	len2 = *d2++;
	if(ldns_buffer_limit(pkt) < 12+1+4) /* packet too small for qname */
		return 0;
	while(len1 != 0 || len2 != 0) {
		if(LABEL_IS_PTR(len1)) {
			d1 = ldns_buffer_at(pkt, PTR_OFFSET(len1, *d1));
			if(d1 >= ldns_buffer_at(pkt, ldns_buffer_limit(pkt)))
				return 0;
			len1 = *d1++;
			if(count++ > MAX_COMPRESS_PTRS)
				return 0;
			continue;
		}
		if(d2 > qbuf+qbuflen)
			return 0;
		if(len1 != len2)
			return 0;
		if(len1 > LDNS_MAX_LABELLEN)
			return 0;
		log_assert(len1 <= LDNS_MAX_LABELLEN);
		log_assert(len2 <= LDNS_MAX_LABELLEN);
		log_assert(len1 == len2 && len1 != 0);
		/* compare the labels - bitwise identical */
		if(memcmp(d1, d2, len1) != 0)
			return 0;
		d1 += len1;
		d2 += len2;
		len1 = *d1++;
		len2 = *d2++;
	}
	return 1;
}

/** call the callbacks for a serviced query */
static void
serviced_callbacks(struct serviced_query* sq, int error, struct comm_point* c,
	struct comm_reply* rep)
{
	struct service_callback* p = sq->cblist, *n;
	int dobackup = (sq->cblist && sq->cblist->next); /* >1 cb*/
	uint8_t *backup_p = NULL;
	size_t backlen = 0;
#ifdef UNBOUND_DEBUG
	rbnode_t* rem =
#endif
	/* remove from tree, and schedule for deletion, so that callbacks
	 * can safely deregister themselves and even create new serviced
	 * queries that are identical to this one. */
	rbtree_delete(sq->outnet->serviced, sq);
	log_assert(rem); /* should have been present */
	sq->to_be_deleted = 1; 
	verbose(VERB_ALGO, "svcd callbacks start");
	if(sq->outnet->use_caps_for_id && error == NETEVENT_NOERROR && c) {
		/* noerror and nxdomain must have a qname in reply */
		if(ldns_buffer_read_u16_at(c->buffer, 4) == 0 &&
			(LDNS_RCODE_WIRE(ldns_buffer_begin(c->buffer))
				== LDNS_RCODE_NOERROR || 
			 LDNS_RCODE_WIRE(ldns_buffer_begin(c->buffer))
				== LDNS_RCODE_NXDOMAIN)) {
			verbose(VERB_DETAIL, "no qname in reply to check 0x20ID");
			log_addr(VERB_DETAIL, "from server", 
				&sq->addr, sq->addrlen);
			log_buf(VERB_DETAIL, "for packet", c->buffer);
			error = NETEVENT_CLOSED;
			c = NULL;
		} else if(ldns_buffer_read_u16_at(c->buffer, 4) > 0 &&
			!serviced_check_qname(c->buffer, sq->qbuf, 
			sq->qbuflen)) {
			verbose(VERB_DETAIL, "wrong 0x20-ID in reply qname");
			log_addr(VERB_DETAIL, "from server", 
				&sq->addr, sq->addrlen);
			log_buf(VERB_DETAIL, "for packet", c->buffer);
			error = NETEVENT_CAPSFAIL;
			/* and cleanup too */
			pkt_dname_tolower(c->buffer, 
				ldns_buffer_at(c->buffer, 12));
		} else {
			verbose(VERB_ALGO, "good 0x20-ID in reply qname");
			/* cleanup caps, prettier cache contents. */
			pkt_dname_tolower(c->buffer, 
				ldns_buffer_at(c->buffer, 12));
		}
	}
	if(dobackup && c) {
		/* make a backup of the query, since the querystate processing
		 * may send outgoing queries that overwrite the buffer.
		 * use secondary buffer to store the query.
		 * This is a data copy, but faster than packet to server */
		backlen = ldns_buffer_limit(c->buffer);
		backup_p = memdup(ldns_buffer_begin(c->buffer), backlen);
		if(!backup_p) {
			log_err("malloc failure in serviced query callbacks");
			error = NETEVENT_CLOSED;
			c = NULL;
		}
		sq->outnet->svcd_overhead = backlen;
	}
	while(p) {
		n = p->next;
		if(dobackup && c) {
			ldns_buffer_clear(c->buffer);
			ldns_buffer_write(c->buffer, backup_p, backlen);
			ldns_buffer_flip(c->buffer);
		}
		fptr_ok(fptr_whitelist_serviced_query(p->cb));
		(void)(*p->cb)(c, p->cb_arg, error, rep);
		p = n;
	}
	if(backup_p) {
		free(backup_p);
		sq->outnet->svcd_overhead = 0;
	}
	verbose(VERB_ALGO, "svcd callbacks end");
	log_assert(sq->cblist == NULL);
	serviced_delete(sq);
}

int 
serviced_tcp_callback(struct comm_point* c, void* arg, int error,
        struct comm_reply* rep)
{
	struct serviced_query* sq = (struct serviced_query*)arg;
	struct comm_reply r2;
	sq->pending = NULL; /* removed after this callback */
	if(error != NETEVENT_NOERROR)
		log_addr(VERB_QUERY, "tcp error for address", 
			&sq->addr, sq->addrlen);
	if(error==NETEVENT_NOERROR)
		infra_update_tcp_works(sq->outnet->infra, &sq->addr,
			sq->addrlen);
	if(error==NETEVENT_NOERROR && sq->status == serviced_query_TCP_EDNS &&
		(LDNS_RCODE_WIRE(ldns_buffer_begin(c->buffer)) == 
		LDNS_RCODE_FORMERR || LDNS_RCODE_WIRE(ldns_buffer_begin(
		c->buffer)) == LDNS_RCODE_NOTIMPL) ) {
		/* attempt to fallback to nonEDNS */
		sq->status = serviced_query_TCP_EDNS_fallback;
		serviced_tcp_initiate(sq->outnet, sq, c->buffer);
		return 0;
	} else if(error==NETEVENT_NOERROR && 
		sq->status == serviced_query_TCP_EDNS_fallback &&
			(LDNS_RCODE_WIRE(ldns_buffer_begin(c->buffer)) == 
			LDNS_RCODE_NOERROR || LDNS_RCODE_WIRE(
			ldns_buffer_begin(c->buffer)) == LDNS_RCODE_NXDOMAIN 
			|| LDNS_RCODE_WIRE(ldns_buffer_begin(c->buffer)) 
			== LDNS_RCODE_YXDOMAIN)) {
		/* the fallback produced a result that looks promising, note
		 * that this server should be approached without EDNS */
		/* only store noEDNS in cache if domain is noDNSSEC */
		if(!sq->want_dnssec)
		  if(!infra_edns_update(sq->outnet->infra, &sq->addr, 
			sq->addrlen, -1, *sq->outnet->now_secs))
			log_err("Out of memory caching no edns for host");
		sq->status = serviced_query_TCP;
	}
	/* insert address into reply info */
	if(!rep) {
		/* create one if there isn't (on errors) */
		rep = &r2;
		r2.c = c;
	}
	memcpy(&rep->addr, &sq->addr, sq->addrlen);
	rep->addrlen = sq->addrlen;
	serviced_callbacks(sq, error, c, rep);
	return 0;
}

static void
serviced_tcp_initiate(struct outside_network* outnet, 
	struct serviced_query* sq, ldns_buffer* buff)
{
	verbose(VERB_ALGO, "initiate TCP query %s", 
		sq->status==serviced_query_TCP_EDNS?"EDNS":"");
	serviced_encode(sq, buff, sq->status == serviced_query_TCP_EDNS);
	sq->pending = pending_tcp_query(outnet, buff, &sq->addr,
		sq->addrlen, TCP_AUTH_QUERY_TIMEOUT, serviced_tcp_callback, 
		sq);
	if(!sq->pending) {
		/* delete from tree so that a retry by above layer does not
		 * clash with this entry */
		log_err("serviced_tcp_initiate: failed to send tcp query");
		serviced_callbacks(sq, NETEVENT_CLOSED, NULL, NULL);
	}
}

/** Send serviced query over TCP return false on initial failure */
static int
serviced_tcp_send(struct serviced_query* sq, ldns_buffer* buff)
{
	int vs, rtt;
	uint8_t edns_lame_known;
	if(!infra_host(sq->outnet->infra, &sq->addr, sq->addrlen, 
		*sq->outnet->now_secs, &vs, &edns_lame_known, &rtt))
		return 0;
	if(vs != -1)
		sq->status = serviced_query_TCP_EDNS;
	else 	sq->status = serviced_query_TCP;
	serviced_encode(sq, buff, sq->status == serviced_query_TCP_EDNS);
	sq->pending = pending_tcp_query(sq->outnet, buff, &sq->addr,
		sq->addrlen, TCP_AUTH_QUERY_TIMEOUT, serviced_tcp_callback, 
		sq);
	return sq->pending != NULL;
}

int 
serviced_udp_callback(struct comm_point* c, void* arg, int error,
        struct comm_reply* rep)
{
	struct serviced_query* sq = (struct serviced_query*)arg;
	struct outside_network* outnet = sq->outnet;
	struct timeval now = *sq->outnet->now_tv;
	int fallback_tcp = 0;

	sq->pending = NULL; /* removed after callback */
	if(error == NETEVENT_TIMEOUT) {
		int rto = 0;
		if(sq->status == serviced_query_PROBE_EDNS) {
			/* non-EDNS probe failed; we do not know its status,
			 * keep trying with EDNS, timeout may not be caused
			 * by EDNS. */
			sq->status = serviced_query_UDP_EDNS;
		}
		if(sq->status == serviced_query_UDP_EDNS && sq->last_rtt < 5000) {
			/* fallback to 1480/1280 */
			sq->status = serviced_query_UDP_EDNS_FRAG;
			log_name_addr(VERB_ALGO, "try edns1xx0", sq->qbuf+10,
				&sq->addr, sq->addrlen);
			if(!serviced_udp_send(sq, c->buffer)) {
				serviced_callbacks(sq, NETEVENT_CLOSED, c, rep);
			}
			return 0;
		}
		if(sq->status == serviced_query_UDP_EDNS_FRAG) {
			/* fragmentation size did not fix it */
			sq->status = serviced_query_UDP_EDNS;
		}
		sq->retry++;
		if(!(rto=infra_rtt_update(outnet->infra, &sq->addr, sq->addrlen,
			-1, sq->last_rtt, (uint32_t)now.tv_sec)))
			log_err("out of memory in UDP exponential backoff");
		if(sq->retry < OUTBOUND_UDP_RETRY) {
			log_name_addr(VERB_ALGO, "retry query", sq->qbuf+10,
				&sq->addr, sq->addrlen);
			if(!serviced_udp_send(sq, c->buffer)) {
				serviced_callbacks(sq, NETEVENT_CLOSED, c, rep);
			}
			return 0;
		}
		if(rto >= RTT_MAX_TIMEOUT) {
			fallback_tcp = 1;
			/* UDP does not work, fallback to TCP below */
		} else {
			serviced_callbacks(sq, NETEVENT_TIMEOUT, c, rep);
			return 0;
		}
	} else if(error != NETEVENT_NOERROR) {
		/* udp returns error (due to no ID or interface available) */
		serviced_callbacks(sq, error, c, rep);
		return 0;
	}
	if(!fallback_tcp) {
	    if( (sq->status == serviced_query_UDP_EDNS 
	        ||sq->status == serviced_query_UDP_EDNS_FRAG)
		&& (LDNS_RCODE_WIRE(ldns_buffer_begin(c->buffer)) 
			== LDNS_RCODE_FORMERR || LDNS_RCODE_WIRE(
			ldns_buffer_begin(c->buffer)) == LDNS_RCODE_NOTIMPL)) {
		/* try to get an answer by falling back without EDNS */
		verbose(VERB_ALGO, "serviced query: attempt without EDNS");
		sq->status = serviced_query_UDP_EDNS_fallback;
		sq->retry = 0;
		if(!serviced_udp_send(sq, c->buffer)) {
			serviced_callbacks(sq, NETEVENT_CLOSED, c, rep);
		}
		return 0;
	    } else if(sq->status == serviced_query_PROBE_EDNS) {
		/* probe without EDNS succeeds, so we conclude that this
		 * host likely has EDNS packets dropped */
		log_addr(VERB_DETAIL, "timeouts, concluded that connection to "
			"host drops EDNS packets", &sq->addr, sq->addrlen);
		/* only store noEDNS in cache if domain is noDNSSEC */
		if(!sq->want_dnssec)
		  if(!infra_edns_update(outnet->infra, &sq->addr, sq->addrlen,
			-1, (uint32_t)now.tv_sec)) {
			log_err("Out of memory caching no edns for host");
		  }
		sq->status = serviced_query_UDP;
	    } else if(sq->status == serviced_query_UDP_EDNS && 
		!sq->edns_lame_known) {
		/* now we know that edns queries received answers store that */
		log_addr(VERB_ALGO, "serviced query: EDNS works for",
			&sq->addr, sq->addrlen);
		if(!infra_edns_update(outnet->infra, &sq->addr, sq->addrlen, 
			0, (uint32_t)now.tv_sec)) {
			log_err("Out of memory caching edns works");
		}
		sq->edns_lame_known = 1;
	    } else if(sq->status == serviced_query_UDP_EDNS_fallback &&
		!sq->edns_lame_known && (LDNS_RCODE_WIRE(
		ldns_buffer_begin(c->buffer)) == LDNS_RCODE_NOERROR || 
		LDNS_RCODE_WIRE(ldns_buffer_begin(c->buffer)) == 
		LDNS_RCODE_NXDOMAIN || LDNS_RCODE_WIRE(ldns_buffer_begin(
		c->buffer)) == LDNS_RCODE_YXDOMAIN)) {
		/* the fallback produced a result that looks promising, note
		 * that this server should be approached without EDNS */
		/* only store noEDNS in cache if domain is noDNSSEC */
		if(!sq->want_dnssec) {
		  log_addr(VERB_ALGO, "serviced query: EDNS fails for",
			&sq->addr, sq->addrlen);
		  if(!infra_edns_update(outnet->infra, &sq->addr, sq->addrlen,
			-1, (uint32_t)now.tv_sec)) {
			log_err("Out of memory caching no edns for host");
		  }
		} else {
		  log_addr(VERB_ALGO, "serviced query: EDNS fails, but "
		  	"not stored because need DNSSEC for", &sq->addr,
			sq->addrlen);
		}
		sq->status = serviced_query_UDP;
	    }
	    if(now.tv_sec > sq->last_sent_time.tv_sec ||
		(now.tv_sec == sq->last_sent_time.tv_sec &&
		now.tv_usec > sq->last_sent_time.tv_usec)) {
		/* convert from microseconds to milliseconds */
		int roundtime = ((int)now.tv_sec - (int)sq->last_sent_time.tv_sec)*1000
		  + ((int)now.tv_usec - (int)sq->last_sent_time.tv_usec)/1000;
		verbose(VERB_ALGO, "measured roundtrip at %d msec", roundtime);
		log_assert(roundtime >= 0);
		if(!infra_rtt_update(outnet->infra, &sq->addr, sq->addrlen, 
			roundtime, sq->last_rtt, (uint32_t)now.tv_sec))
			log_err("out of memory noting rtt.");
	    }
	} /* end of if_!fallback_tcp */
	/* perform TC flag check and TCP fallback after updating our
	 * cache entries for EDNS status and RTT times */
	if(LDNS_TC_WIRE(ldns_buffer_begin(c->buffer)) || fallback_tcp) {
		/* fallback to TCP */
		/* this discards partial UDP contents */
		if(sq->status == serviced_query_UDP_EDNS ||
			sq->status == serviced_query_UDP_EDNS_FRAG ||
			sq->status == serviced_query_UDP_EDNS_fallback)
			/* if we have unfinished EDNS_fallback, start again */
			sq->status = serviced_query_TCP_EDNS;
		else	sq->status = serviced_query_TCP;
		serviced_tcp_initiate(outnet, sq, c->buffer);
		return 0;
	}
	/* yay! an answer */
	serviced_callbacks(sq, error, c, rep);
	return 0;
}

/** find callback in list */
static struct service_callback*
callback_list_find(struct serviced_query* sq, void* cb_arg, 
	int (*arg_compare)(void*,void*))
{
	struct service_callback* p;
	for(p = sq->cblist; p; p = p->next) {
		if(arg_compare(p->cb_arg, cb_arg))
			return p;
	}
	return NULL;
}

struct serviced_query* 
outnet_serviced_query(struct outside_network* outnet,
	uint8_t* qname, size_t qnamelen, uint16_t qtype, uint16_t qclass,
	uint16_t flags, int dnssec, int want_dnssec, int tcp_upstream,
	struct sockaddr_storage* addr, socklen_t addrlen, 
	comm_point_callback_t* callback, void* callback_arg, 
	ldns_buffer* buff, int (*arg_compare)(void*,void*))
{
	struct serviced_query* sq;
	struct service_callback* cb;
	serviced_gen_query(buff, qname, qnamelen, qtype, qclass, flags);
	sq = lookup_serviced(outnet, buff, dnssec, addr, addrlen);
	if(sq) {
		/* see if it is a duplicate notification request for cb_arg */
		if(callback_list_find(sq, callback_arg, arg_compare)) {
			return sq;
		}
	}
	if(!(cb = (struct service_callback*)malloc(sizeof(*cb))))
		return NULL;
	if(!sq) {
		/* make new serviced query entry */
		sq = serviced_create(outnet, buff, dnssec, want_dnssec,
			addr, addrlen);
		if(!sq) {
			free(cb);
			return NULL;
		}
		/* perform first network action */
		if(outnet->do_udp && !tcp_upstream) {
			if(!serviced_udp_send(sq, buff)) {
				(void)rbtree_delete(outnet->serviced, sq);
				free(sq->qbuf);
				free(sq);
				free(cb);
				return NULL;
			}
		} else {
			if(!serviced_tcp_send(sq, buff)) {
				(void)rbtree_delete(outnet->serviced, sq);
				free(sq->qbuf);
				free(sq);
				free(cb);
				return NULL;
			}
		}
	}
	/* add callback to list of callbacks */
	cb->cb = callback;
	cb->cb_arg = callback_arg;
	cb->next = sq->cblist;
	sq->cblist = cb;
	return sq;
}

/** remove callback from list */
static void
callback_list_remove(struct serviced_query* sq, void* cb_arg)
{
	struct service_callback** pp = &sq->cblist;
	while(*pp) {
		if((*pp)->cb_arg == cb_arg) {
			struct service_callback* del = *pp;
			*pp = del->next;
			free(del);
			return;
		}
		pp = &(*pp)->next;
	}
}

void outnet_serviced_query_stop(struct serviced_query* sq, void* cb_arg)
{
	if(!sq) 
		return;
	callback_list_remove(sq, cb_arg);
	/* if callbacks() routine scheduled deletion, let it do that */
	if(!sq->cblist && !sq->to_be_deleted) {
#ifdef UNBOUND_DEBUG
		rbnode_t* rem =
#endif
		rbtree_delete(sq->outnet->serviced, sq);
		log_assert(rem); /* should be present */
		serviced_delete(sq); 
	}
}

/** get memory used by waiting tcp entry (in use or not) */
static size_t
waiting_tcp_get_mem(struct waiting_tcp* w)
{
	size_t s;
	if(!w) return 0;
	s = sizeof(*w) + w->pkt_len;
	if(w->timer)
		s += comm_timer_get_mem(w->timer);
	return s;
}

/** get memory used by port if */
static size_t
if_get_mem(struct port_if* pif)
{
	size_t s;
	int i;
	s = sizeof(*pif) + sizeof(int)*pif->avail_total +
		sizeof(struct port_comm*)*pif->maxout;
	for(i=0; i<pif->inuse; i++)
		s += sizeof(*pif->out[i]) + 
			comm_point_get_mem(pif->out[i]->cp);
	return s;
}

/** get memory used by waiting udp */
static size_t
waiting_udp_get_mem(struct pending* w)
{
	size_t s;
	s = sizeof(*w) + comm_timer_get_mem(w->timer) + w->pkt_len;
	return s;
}

size_t outnet_get_mem(struct outside_network* outnet)
{
	size_t i;
	int k;
	struct waiting_tcp* w;
	struct pending* u;
	struct serviced_query* sq;
	struct service_callback* sb;
	struct port_comm* pc;
	size_t s = sizeof(*outnet) + sizeof(*outnet->base) + 
		sizeof(*outnet->udp_buff) + 
		ldns_buffer_capacity(outnet->udp_buff);
	/* second buffer is not ours */
	for(pc = outnet->unused_fds; pc; pc = pc->next) {
		s += sizeof(*pc) + comm_point_get_mem(pc->cp);
	}
	for(k=0; k<outnet->num_ip4; k++)
		s += if_get_mem(&outnet->ip4_ifs[k]);
	for(k=0; k<outnet->num_ip6; k++)
		s += if_get_mem(&outnet->ip6_ifs[k]);
	for(u=outnet->udp_wait_first; u; u=u->next_waiting)
		s += waiting_udp_get_mem(u);
	
	s += sizeof(struct pending_tcp*)*outnet->num_tcp;
	for(i=0; i<outnet->num_tcp; i++) {
		s += sizeof(struct pending_tcp);
		s += comm_point_get_mem(outnet->tcp_conns[i]->c);
		if(outnet->tcp_conns[i]->query)
			s += waiting_tcp_get_mem(outnet->tcp_conns[i]->query);
	}
	for(w=outnet->tcp_wait_first; w; w = w->next_waiting)
		s += waiting_tcp_get_mem(w);
	s += sizeof(*outnet->pending);
	s += (sizeof(struct pending) + comm_timer_get_mem(NULL)) * 
		outnet->pending->count;
	s += sizeof(*outnet->serviced);
	s += outnet->svcd_overhead;
	RBTREE_FOR(sq, struct serviced_query*, outnet->serviced) {
		s += sizeof(*sq) + sq->qbuflen;
		for(sb = sq->cblist; sb; sb = sb->next)
			s += sizeof(*sb);
	}
	return s;
}

size_t 
serviced_get_mem(struct serviced_query* sq)
{
	struct service_callback* sb;
	size_t s;
	s = sizeof(*sq) + sq->qbuflen;
	for(sb = sq->cblist; sb; sb = sb->next)
		s += sizeof(*sb);
	if(sq->status == serviced_query_UDP_EDNS ||
		sq->status == serviced_query_UDP ||
		sq->status == serviced_query_PROBE_EDNS ||
		sq->status == serviced_query_UDP_EDNS_FRAG ||
		sq->status == serviced_query_UDP_EDNS_fallback) {
		s += sizeof(struct pending);
		s += comm_timer_get_mem(NULL);
	} else {
		/* does not have size of the pkt pointer */
		/* always has a timer except on malloc failures */

		/* these sizes are part of the main outside network mem */
		/*
		s += sizeof(struct waiting_tcp);
		s += comm_timer_get_mem(NULL);
		*/
	}
	return s;
}