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	diff --git a/libknet/threads_pmtud.c b/libknet/threads_pmtud.c
	index 9e433290..02945791 100644
	--- a/libknet/threads_pmtud.c
	+++ b/libknet/threads_pmtud.c
	@@ -1,804 +1,895 @@
	/*
	* Copyright (C) 2015-2020 Red Hat, Inc. All rights reserved.
	*
	* Authors: Fabio M. Di Nitto <fabbione@kronosnet.org>
	* Federico Simoncelli <fsimon@kronosnet.org>
	*
	* This software licensed under LGPL-2.0+
	*/

	#include "config.h"

	#include <unistd.h>
	#include <string.h>
	#include <errno.h>
	#include <pthread.h>

	#include "crypto.h"
	#include "links.h"
	#include "host.h"
	#include "logging.h"
	#include "transports.h"
	#include "threads_common.h"
	#include "threads_pmtud.h"

	static int _calculate_manual_mtu(knet_handle_t knet_h, struct knet_link *dst_link)
	{
	size_t ipproto_overhead_len; /* onwire packet overhead (protocol based) */

	switch (dst_link->dst_addr.ss_family) {
	case AF_INET6:
	ipproto_overhead_len = KNET_PMTUD_OVERHEAD_V6 + dst_link->proto_overhead;
	break;
	case AF_INET:
	ipproto_overhead_len = KNET_PMTUD_OVERHEAD_V4 + dst_link->proto_overhead;
	break;
	default:
	log_debug(knet_h, KNET_SUB_PMTUD, "unknown protocol");
	return 0;
	break;
	}

	dst_link->status.mtu = calc_max_data_outlen(knet_h, knet_h->manual_mtu - ipproto_overhead_len);

	return 1;
	}

	static int _handle_check_link_pmtud(knet_handle_t knet_h, struct knet_host dst_host, struct knet_link dst_link)
	{
	int err, ret, savederrno, mutex_retry_limit, failsafe, use_kernel_mtu, warn_once;
	uint32_t kernel_mtu; /* record kernel_mtu from EMSGSIZE */
	size_t onwire_len; /* current packet onwire size */
	size_t ipproto_overhead_len; /* onwire packet overhead (protocol based) */
	size_t max_mtu_len; /* max mtu for protocol */
	size_t data_len; /* how much data we can send in the packet
	* generally would be onwire_len - ipproto_overhead_len
	* needs to be adjusted for crypto
	*/
	size_t app_mtu_len; /* real data that we can send onwire */
	ssize_t len; /* len of what we were able to sendto onwire */

	struct timespec ts, pmtud_crypto_start_ts, pmtud_crypto_stop_ts;
	unsigned long long pong_timeout_adj_tmp, timediff;
	int pmtud_crypto_reduce = 1;
	unsigned char outbuf = (unsigned char )knet_h->pmtudbuf;

	warn_once = 0;

	mutex_retry_limit = 0;
	failsafe = 0;

	knet_h->pmtudbuf->khp_pmtud_link = dst_link->link_id;

	switch (dst_link->dst_addr.ss_family) {
	case AF_INET6:
	max_mtu_len = KNET_PMTUD_SIZE_V6;
	ipproto_overhead_len = KNET_PMTUD_OVERHEAD_V6 + dst_link->proto_overhead;
	break;
	case AF_INET:
	max_mtu_len = KNET_PMTUD_SIZE_V4;
	ipproto_overhead_len = KNET_PMTUD_OVERHEAD_V4 + dst_link->proto_overhead;
	break;
	default:
	log_debug(knet_h, KNET_SUB_PMTUD, "PMTUD aborted, unknown protocol");
	return -1;
	break;
	}

	dst_link->last_bad_mtu = 0;
	dst_link->last_good_mtu = dst_link->last_ping_size + ipproto_overhead_len;

	/*
	* discovery starts from the top because kernel will
	* refuse to send packets > current iface mtu.
	* this saves us some time and network bw.
	*/
	onwire_len = max_mtu_len;

	restart:

	/*
	* prevent a race when interface mtu is changed _exactly_ during
	* the discovery process and it's complex to detect. Easier
	* to wait the next loop.
	* 30 is not an arbitrary value. To bisect from 576 to 128000 doesn't
	* take more than 18/19 steps.
	*/

	if (failsafe == 30) {
	log_err(knet_h, KNET_SUB_PMTUD,
	"Aborting PMTUD process: Too many attempts. MTU might have changed during discovery.");
	return -1;
	} else {
	failsafe++;
	}

	/*
	* common to all packets
	*/

	/*
	* calculate the application MTU based on current onwire_len minus ipproto_overhead_len
	*/

	app_mtu_len = calc_max_data_outlen(knet_h, onwire_len - ipproto_overhead_len);

	/*
	* recalculate onwire len back that might be different based
	* on data padding from crypto layer.
	*/

	onwire_len = calc_data_outlen(knet_h, app_mtu_len + KNET_HEADER_ALL_SIZE) + ipproto_overhead_len;

	/*
	* calculate the size of what we need to send to sendto(2).
	* see also onwire.c for packet format explanation.
	*/
	data_len = app_mtu_len + knet_h->sec_hash_size + knet_h->sec_salt_size + KNET_HEADER_ALL_SIZE;

	if (knet_h->crypto_in_use_config) {
	if (data_len < (knet_h->sec_hash_size + knet_h->sec_salt_size) + 1) {
	log_debug(knet_h, KNET_SUB_PMTUD, "Aborting PMTUD process: link mtu smaller than crypto header detected (link might have been disconnected)");
	return -1;
	}

	knet_h->pmtudbuf->khp_pmtud_size = onwire_len;

	if (crypto_encrypt_and_sign(knet_h,
	(const unsigned char *)knet_h->pmtudbuf,
	data_len - (knet_h->sec_hash_size + knet_h->sec_salt_size),
	knet_h->pmtudbuf_crypt,
	(ssize_t *)&data_len) < 0) {
	log_debug(knet_h, KNET_SUB_PMTUD, "Unable to crypto pmtud packet");
	return -1;
	}

	outbuf = knet_h->pmtudbuf_crypt;
	if (pthread_mutex_lock(&knet_h->handle_stats_mutex) < 0) {
	log_err(knet_h, KNET_SUB_PMTUD, "Unable to get mutex lock");
	return -1;
	}
	knet_h->stats_extra.tx_crypt_pmtu_packets++;
	pthread_mutex_unlock(&knet_h->handle_stats_mutex);
	} else {
	knet_h->pmtudbuf->khp_pmtud_size = onwire_len;
	}

	/* link has gone down, aborting pmtud */
	if (dst_link->status.connected != 1) {
	log_debug(knet_h, KNET_SUB_PMTUD, "PMTUD detected host (%u) link (%u) has been disconnected", dst_host->host_id, dst_link->link_id);
	return -1;
	}

	if (dst_link->transport_connected != 1) {
	log_debug(knet_h, KNET_SUB_PMTUD, "PMTUD detected host (%u) link (%u) has been disconnected", dst_host->host_id, dst_link->link_id);
	return -1;
	}

	if (pthread_mutex_lock(&knet_h->pmtud_mutex) != 0) {
	log_debug(knet_h, KNET_SUB_PMTUD, "Unable to get mutex lock");
	return -1;
	}

	if (knet_h->pmtud_abort) {
	pthread_mutex_unlock(&knet_h->pmtud_mutex);
	errno = EDEADLK;
	return -1;
	}

	savederrno = pthread_mutex_lock(&knet_h->tx_mutex);
	if (savederrno) {
	pthread_mutex_unlock(&knet_h->pmtud_mutex);
	log_err(knet_h, KNET_SUB_PMTUD, "Unable to get TX mutex lock: %s", strerror(savederrno));
	return -1;
	}

	savederrno = pthread_mutex_lock(&dst_link->link_stats_mutex);
	if (savederrno) {
	pthread_mutex_unlock(&knet_h->pmtud_mutex);
	pthread_mutex_unlock(&knet_h->tx_mutex);
	log_err(knet_h, KNET_SUB_PMTUD, "Unable to get stats mutex lock for host %u link %u: %s",
	dst_host->host_id, dst_link->link_id, strerror(savederrno));
	return -1;
	}

	retry:
	if (transport_get_connection_oriented(knet_h, dst_link->transport) == TRANSPORT_PROTO_NOT_CONNECTION_ORIENTED) {
	len = sendto(dst_link->outsock, outbuf, data_len, MSG_DONTWAIT \| MSG_NOSIGNAL,
	(struct sockaddr *) &dst_link->dst_addr, sizeof(struct sockaddr_storage));
	} else {
	len = sendto(dst_link->outsock, outbuf, data_len, MSG_DONTWAIT \| MSG_NOSIGNAL, NULL, 0);
	}
	savederrno = errno;

	/*
	* we cannot hold a lock on kmtu_mutex between resetting
	* knet_h->kernel_mtu here and below where it's used.
	* use_kernel_mtu tells us if the knet_h->kernel_mtu was
	* set to 0 and we can trust its value later.
	*/
	use_kernel_mtu = 0;

	if (pthread_mutex_lock(&knet_h->kmtu_mutex) == 0) {
	use_kernel_mtu = 1;
	knet_h->kernel_mtu = 0;
	pthread_mutex_unlock(&knet_h->kmtu_mutex);
	}

	kernel_mtu = 0;

	err = transport_tx_sock_error(knet_h, dst_link->transport, dst_link->outsock, len, savederrno);
	switch(err) {
	case -1: /* unrecoverable error */
	log_debug(knet_h, KNET_SUB_PMTUD, "Unable to send pmtu packet (sendto): %d %s", savederrno, strerror(savederrno));
	pthread_mutex_unlock(&knet_h->tx_mutex);
	pthread_mutex_unlock(&knet_h->pmtud_mutex);
	dst_link->status.stats.tx_pmtu_errors++;
	pthread_mutex_unlock(&dst_link->link_stats_mutex);
	return -1;
	case 0: /* ignore error and continue */
	break;
	case 1: /* retry to send those same data */
	dst_link->status.stats.tx_pmtu_retries++;
	goto retry;
	break;
	}

	pthread_mutex_unlock(&knet_h->tx_mutex);

	if (len != (ssize_t )data_len) {
	pthread_mutex_unlock(&dst_link->link_stats_mutex);
	if (savederrno == EMSGSIZE) {
	/*
	* we cannot hold a lock on kmtu_mutex between resetting
	* knet_h->kernel_mtu and here.
	* use_kernel_mtu tells us if the knet_h->kernel_mtu was
	* set to 0 previously and we can trust its value now.
	*/
	if (use_kernel_mtu) {
	use_kernel_mtu = 0;
	if (pthread_mutex_lock(&knet_h->kmtu_mutex) == 0) {
	kernel_mtu = knet_h->kernel_mtu;
	pthread_mutex_unlock(&knet_h->kmtu_mutex);
	}
	}
	if (kernel_mtu > 0) {
	dst_link->last_bad_mtu = kernel_mtu + 1;
	} else {
	dst_link->last_bad_mtu = onwire_len;
	}
	} else {
	log_debug(knet_h, KNET_SUB_PMTUD, "Unable to send pmtu packet len: %zu err: %s", onwire_len, strerror(savederrno));
	}

	} else {
	dst_link->last_sent_mtu = onwire_len;
	dst_link->last_recv_mtu = 0;
	dst_link->status.stats.tx_pmtu_packets++;
	dst_link->status.stats.tx_pmtu_bytes += data_len;
	pthread_mutex_unlock(&dst_link->link_stats_mutex);

	if (clock_gettime(CLOCK_REALTIME, &ts) < 0) {
	log_debug(knet_h, KNET_SUB_PMTUD, "Unable to get current time: %s", strerror(errno));
	pthread_mutex_unlock(&knet_h->pmtud_mutex);
	return -1;
	}

	/*
	* non fatal, we can wait the next round to reduce the
	* multiplier
	*/
	if (clock_gettime(CLOCK_MONOTONIC, &pmtud_crypto_start_ts) < 0) {
	log_debug(knet_h, KNET_SUB_PMTUD, "Unable to get current time: %s", strerror(errno));
	pmtud_crypto_reduce = 0;
	}

	/*
	* set PMTUd reply timeout to match pong_timeout on a given link
	*
	* math: internally pong_timeout is expressed in microseconds, while
	* the public API exports milliseconds. So careful with the 0's here.
	* the loop is necessary because we are grabbing the current time just above
	* and add values to it that could overflow into seconds.
	*/

	if (pthread_mutex_lock(&knet_h->backoff_mutex)) {
	log_debug(knet_h, KNET_SUB_PMTUD, "Unable to get backoff_mutex");
	pthread_mutex_unlock(&knet_h->pmtud_mutex);
	return -1;
	}

	if (knet_h->crypto_in_use_config) {
	/*
	* crypto, under pressure, is a royal PITA
	*/
	pong_timeout_adj_tmp = dst_link->pong_timeout_adj * dst_link->pmtud_crypto_timeout_multiplier;
	} else {
	pong_timeout_adj_tmp = dst_link->pong_timeout_adj;
	}

	ts.tv_sec += pong_timeout_adj_tmp / 1000000;
	ts.tv_nsec += (((pong_timeout_adj_tmp) % 1000000) * 1000);
	while (ts.tv_nsec > 1000000000) {
	ts.tv_sec += 1;
	ts.tv_nsec -= 1000000000;
	}

	pthread_mutex_unlock(&knet_h->backoff_mutex);

	knet_h->pmtud_waiting = 1;

	ret = pthread_cond_timedwait(&knet_h->pmtud_cond, &knet_h->pmtud_mutex, &ts);

	knet_h->pmtud_waiting = 0;

	if (knet_h->pmtud_abort) {
	pthread_mutex_unlock(&knet_h->pmtud_mutex);
	errno = EDEADLK;
	return -1;
	}

	/*
	* we cannot use shutdown_in_progress in here because
	* we already hold the read lock
	*/
	if (knet_h->fini_in_progress) {
	pthread_mutex_unlock(&knet_h->pmtud_mutex);
	log_debug(knet_h, KNET_SUB_PMTUD, "PMTUD aborted. shutdown in progress");
	return -1;
	}

	if (ret) {
	if (ret == ETIMEDOUT) {
	if ((knet_h->crypto_in_use_config) && (dst_link->pmtud_crypto_timeout_multiplier < KNET_LINK_PMTUD_CRYPTO_TIMEOUT_MULTIPLIER_MAX)) {
	dst_link->pmtud_crypto_timeout_multiplier = dst_link->pmtud_crypto_timeout_multiplier * 2;
	pmtud_crypto_reduce = 0;
	log_debug(knet_h, KNET_SUB_PMTUD,
	"Increasing PMTUd response timeout multiplier to (%u) for host %u link: %u",
	dst_link->pmtud_crypto_timeout_multiplier,
	dst_host->host_id,
	dst_link->link_id);
	pthread_mutex_unlock(&knet_h->pmtud_mutex);
	goto restart;
	}
	if (!warn_once) {
	log_warn(knet_h, KNET_SUB_PMTUD,
	"possible MTU misconfiguration detected. "
	"kernel is reporting MTU: %u bytes for "
	"host %u link %u but the other node is "
	"not acknowledging packets of this size. ",
	dst_link->last_sent_mtu,
	dst_host->host_id,
	dst_link->link_id);
	log_warn(knet_h, KNET_SUB_PMTUD,
	"This can be caused by this node interface MTU "
	"too big or a network device that does not "
	"support or has been misconfigured to manage MTU "
	"of this size, or packet loss. knet will continue "
	"to run but performances might be affected.");
	warn_once = 1;
	}
	} else {
	pthread_mutex_unlock(&knet_h->pmtud_mutex);
	if (mutex_retry_limit == 3) {
	log_debug(knet_h, KNET_SUB_PMTUD, "PMTUD aborted, unable to get mutex lock");
	return -1;
	}
	mutex_retry_limit++;
	goto restart;
	}
	}

	if ((knet_h->crypto_in_use_config) && (pmtud_crypto_reduce == 1) &&
	(dst_link->pmtud_crypto_timeout_multiplier > KNET_LINK_PMTUD_CRYPTO_TIMEOUT_MULTIPLIER_MIN)) {
	if (!clock_gettime(CLOCK_MONOTONIC, &pmtud_crypto_stop_ts)) {
	timespec_diff(pmtud_crypto_start_ts, pmtud_crypto_stop_ts, &timediff);
	if (((pong_timeout_adj_tmp * 1000) / 2) > timediff) {
	dst_link->pmtud_crypto_timeout_multiplier = dst_link->pmtud_crypto_timeout_multiplier / 2;
	log_debug(knet_h, KNET_SUB_PMTUD,
	"Decreasing PMTUd response timeout multiplier to (%u) for host %u link: %u",
	dst_link->pmtud_crypto_timeout_multiplier,
	dst_host->host_id,
	dst_link->link_id);
	}
	} else {
	log_debug(knet_h, KNET_SUB_PMTUD, "Unable to get current time: %s", strerror(errno));
	}
	}

	if ((dst_link->last_recv_mtu != onwire_len) \|\| (ret)) {
	dst_link->last_bad_mtu = onwire_len;
	} else {
	int found_mtu = 0;

	if (knet_h->sec_block_size) {
	if ((onwire_len + knet_h->sec_block_size >= max_mtu_len) \|\|
	((dst_link->last_bad_mtu) && (dst_link->last_bad_mtu <= (onwire_len + knet_h->sec_block_size)))) {
	found_mtu = 1;
	}
	} else {
	if ((onwire_len == max_mtu_len) \|\|
	((dst_link->last_bad_mtu) && (dst_link->last_bad_mtu == (onwire_len + 1))) \|\|
	(dst_link->last_bad_mtu == dst_link->last_good_mtu)) {
	found_mtu = 1;
	}
	}

	if (found_mtu) {
	/*
	* account for IP overhead, knet headers and crypto in PMTU calculation
	*/
	dst_link->status.mtu = calc_max_data_outlen(knet_h, onwire_len - ipproto_overhead_len);
	pthread_mutex_unlock(&knet_h->pmtud_mutex);
	return 0;
	}

	dst_link->last_good_mtu = onwire_len;
	}
	}

	if (kernel_mtu) {
	onwire_len = kernel_mtu;
	} else {
	onwire_len = (dst_link->last_good_mtu + dst_link->last_bad_mtu) / 2;
	}

	pthread_mutex_unlock(&knet_h->pmtud_mutex);

	goto restart;
	}

	static int _handle_check_pmtud(knet_handle_t knet_h, struct knet_host dst_host, struct knet_link dst_link, int force_run)
	{
	uint8_t saved_valid_pmtud;
	unsigned int saved_pmtud;
	struct timespec clock_now;
	unsigned long long diff_pmtud, interval;

	if (clock_gettime(CLOCK_MONOTONIC, &clock_now) != 0) {
	log_debug(knet_h, KNET_SUB_PMTUD, "Unable to get monotonic clock");
	return 0;
	}

	if (!force_run) {
	interval = knet_h->pmtud_interval * 1000000000llu; /* nanoseconds */

	timespec_diff(dst_link->pmtud_last, clock_now, &diff_pmtud);

	if (diff_pmtud < interval) {
	return dst_link->has_valid_mtu;
	}
	}

	/*
	* status.proto_overhead should include all IP/(UDP\|SCTP)/knet headers
	*
	* please note that it is not the same as link->proto_overhead that
	* includes only either UDP or SCTP (at the moment) overhead.
	*/
	switch (dst_link->dst_addr.ss_family) {
	case AF_INET6:
	dst_link->status.proto_overhead = KNET_PMTUD_OVERHEAD_V6 + dst_link->proto_overhead + KNET_HEADER_ALL_SIZE + knet_h->sec_hash_size + knet_h->sec_salt_size;
	break;
	case AF_INET:
	dst_link->status.proto_overhead = KNET_PMTUD_OVERHEAD_V4 + dst_link->proto_overhead + KNET_HEADER_ALL_SIZE + knet_h->sec_hash_size + knet_h->sec_salt_size;
	break;
	}

	saved_pmtud = dst_link->status.mtu;
	saved_valid_pmtud = dst_link->has_valid_mtu;

	log_debug(knet_h, KNET_SUB_PMTUD, "Starting PMTUD for host: %u link: %u", dst_host->host_id, dst_link->link_id);

	errno = 0;
	if (_handle_check_link_pmtud(knet_h, dst_host, dst_link) < 0) {
	if (errno == EDEADLK) {
	log_debug(knet_h, KNET_SUB_PMTUD, "PMTUD for host: %u link: %u has been rescheduled", dst_host->host_id, dst_link->link_id);
	dst_link->status.mtu = saved_pmtud;
	dst_link->has_valid_mtu = saved_valid_pmtud;
	errno = EDEADLK;
	return dst_link->has_valid_mtu;
	}
	dst_link->has_valid_mtu = 0;
	} else {
	if (dst_link->status.mtu < calc_min_mtu(knet_h)) {
	log_info(knet_h, KNET_SUB_PMTUD,
	"Invalid MTU detected for host: %u link: %u mtu: %u",
	dst_host->host_id, dst_link->link_id, dst_link->status.mtu);
	dst_link->has_valid_mtu = 0;
	} else {
	dst_link->has_valid_mtu = 1;
	}
	if (dst_link->has_valid_mtu) {
	if ((saved_pmtud) && (saved_pmtud != dst_link->status.mtu)) {
	log_info(knet_h, KNET_SUB_PMTUD, "PMTUD link change for host: %u link: %u from %u to %u",
	dst_host->host_id, dst_link->link_id, saved_pmtud, dst_link->status.mtu);
	}
	log_debug(knet_h, KNET_SUB_PMTUD, "PMTUD completed for host: %u link: %u current link mtu: %u",
	dst_host->host_id, dst_link->link_id, dst_link->status.mtu);

	/*
	* set pmtud_last, if we can, after we are done with the PMTUd process
	* because it can take a very long time.
	*/
	dst_link->pmtud_last = clock_now;
	if (!clock_gettime(CLOCK_MONOTONIC, &clock_now)) {
	dst_link->pmtud_last = clock_now;
	}
	}
	}

	if (saved_valid_pmtud != dst_link->has_valid_mtu) {
	_host_dstcache_update_async(knet_h, dst_host);
	}

	return dst_link->has_valid_mtu;
	}

	void _handle_pmtud_link_thread(void data)
	{
	knet_handle_t knet_h = (knet_handle_t) data;
	struct knet_host *dst_host;
	struct knet_link *dst_link;
	int link_idx;
	unsigned int have_mtu;
	unsigned int lower_mtu;
	int link_has_mtu;
	int force_run = 0;

	set_thread_status(knet_h, KNET_THREAD_PMTUD, KNET_THREAD_STARTED);

	knet_h->data_mtu = calc_min_mtu(knet_h);

	/* preparing pmtu buffer */
	knet_h->pmtudbuf->kh_version = KNET_HEADER_VERSION;
	knet_h->pmtudbuf->kh_type = KNET_HEADER_TYPE_PMTUD;
	knet_h->pmtudbuf->kh_node = htons(knet_h->host_id);

	while (!shutdown_in_progress(knet_h)) {
	usleep(knet_h->threads_timer_res);

	if (pthread_mutex_lock(&knet_h->pmtud_mutex) != 0) {
	log_debug(knet_h, KNET_SUB_PMTUD, "Unable to get mutex lock");
	continue;
	}
	knet_h->pmtud_abort = 0;
	knet_h->pmtud_running = 1;
	force_run = knet_h->pmtud_forcerun;
	knet_h->pmtud_forcerun = 0;
	pthread_mutex_unlock(&knet_h->pmtud_mutex);

	if (force_run) {
	log_debug(knet_h, KNET_SUB_PMTUD, "PMTUd request to rerun has been received");
	}

	if (pthread_rwlock_rdlock(&knet_h->global_rwlock) != 0) {
	log_debug(knet_h, KNET_SUB_PMTUD, "Unable to get read lock");
	continue;
	}

	lower_mtu = KNET_PMTUD_SIZE_V4;
	have_mtu = 0;

	for (dst_host = knet_h->host_head; dst_host != NULL; dst_host = dst_host->next) {
	for (link_idx = 0; link_idx < KNET_MAX_LINK; link_idx++) {
	dst_link = &dst_host->link[link_idx];

	if ((dst_link->status.enabled != 1) \|\|
	(dst_link->status.connected != 1) \|\|
	(dst_host->link[link_idx].transport == KNET_TRANSPORT_LOOPBACK) \|\|
	(!dst_link->last_ping_size) \|\|
	((dst_link->dynamic == KNET_LINK_DYNIP) &&
	(dst_link->status.dynconnected != 1)))
	continue;

	if (!knet_h->manual_mtu) {
	link_has_mtu = _handle_check_pmtud(knet_h, dst_host, dst_link, force_run);
	if (errno == EDEADLK) {
	goto out_unlock;
	}
	if (link_has_mtu) {
	have_mtu = 1;
	if (dst_link->status.mtu < lower_mtu) {
	lower_mtu = dst_link->status.mtu;
	}
	}
	} else {
	link_has_mtu = _calculate_manual_mtu(knet_h, dst_link);
	if (link_has_mtu) {
	have_mtu = 1;
	if (dst_link->status.mtu < lower_mtu) {
	lower_mtu = dst_link->status.mtu;
	}
	}
	}
	}
	}

	if (have_mtu) {
	if (knet_h->data_mtu != lower_mtu) {
	knet_h->data_mtu = lower_mtu;
	log_info(knet_h, KNET_SUB_PMTUD, "Global data MTU changed to: %u", knet_h->data_mtu);

	if (knet_h->pmtud_notify_fn) {
	knet_h->pmtud_notify_fn(knet_h->pmtud_notify_fn_private_data,
	knet_h->data_mtu);
	}
	}
	}
	out_unlock:
	pthread_rwlock_unlock(&knet_h->global_rwlock);
	if (pthread_mutex_lock(&knet_h->pmtud_mutex) != 0) {
	log_debug(knet_h, KNET_SUB_PMTUD, "Unable to get mutex lock");
	} else {
	knet_h->pmtud_running = 0;
	pthread_mutex_unlock(&knet_h->pmtud_mutex);
	}
	}

	set_thread_status(knet_h, KNET_THREAD_PMTUD, KNET_THREAD_STOPPED);

	return NULL;
	}

	+static void send_pmtud_reply(knet_handle_t knet_h, struct knet_link src_link, struct knet_header inbuf)
	+{
	+ int err = 0, savederrno = 0, stats_err = 0;
	+ unsigned char outbuf = (unsigned char )inbuf;
	+ ssize_t len, outlen;
	+
	+ outlen = KNET_HEADER_PMTUD_SIZE;
	+ inbuf->kh_type = KNET_HEADER_TYPE_PMTUD_REPLY;
	+ inbuf->kh_node = htons(knet_h->host_id);
	+
	+ if (knet_h->crypto_in_use_config) {
	+ if (crypto_encrypt_and_sign(knet_h,
	+ (const unsigned char *)inbuf,
	+ outlen,
	+ knet_h->recv_from_links_buf_crypt,
	+ &outlen) < 0) {
	+ log_debug(knet_h, KNET_SUB_RX, "Unable to encrypt PMTUd reply packet");
	+ return;
	+ }
	+ outbuf = knet_h->recv_from_links_buf_crypt;
	+ stats_err = pthread_mutex_lock(&knet_h->handle_stats_mutex);
	+ if (stats_err < 0) {
	+ log_err(knet_h, KNET_SUB_RX, "Unable to get mutex lock: %s", strerror(stats_err));
	+ return;
	+ }
	+ knet_h->stats_extra.tx_crypt_pmtu_reply_packets++;
	+ pthread_mutex_unlock(&knet_h->handle_stats_mutex);
	+ }
	+
	+ savederrno = pthread_mutex_lock(&knet_h->tx_mutex);
	+ if (savederrno) {
	+ log_err(knet_h, KNET_SUB_RX, "Unable to get TX mutex lock: %s", strerror(savederrno));
	+ return;
	+ }
	+retry_pmtud:
	+ if (src_link->transport_connected) {
	+ if (transport_get_connection_oriented(knet_h, src_link->transport) == TRANSPORT_PROTO_NOT_CONNECTION_ORIENTED) {
	+ len = sendto(src_link->outsock, outbuf, outlen, MSG_DONTWAIT \| MSG_NOSIGNAL,
	+ (struct sockaddr *) &src_link->dst_addr, sizeof(struct sockaddr_storage));
	+ } else {
	+ len = sendto(src_link->outsock, outbuf, outlen, MSG_DONTWAIT \| MSG_NOSIGNAL, NULL, 0);
	+ }
	+ savederrno = errno;
	+ if (len != outlen) {
	+ err = transport_tx_sock_error(knet_h, src_link->transport, src_link->outsock, len, savederrno);
	+ stats_err = pthread_mutex_lock(&src_link->link_stats_mutex);
	+ if (stats_err < 0) {
	+ log_err(knet_h, KNET_SUB_RX, "Unable to get mutex lock: %s", strerror(stats_err));
	+ return;
	+ }
	+ switch(err) {
	+ case -1: /* unrecoverable error */
	+ log_debug(knet_h, KNET_SUB_RX,
	+ "Unable to send PMTUd reply (sock: %d) packet (sendto): %d %s. recorded src ip: %s src port: %s dst ip: %s dst port: %s",
	+ src_link->outsock, errno, strerror(errno),
	+ src_link->status.src_ipaddr, src_link->status.src_port,
	+ src_link->status.dst_ipaddr, src_link->status.dst_port);
	+
	+ src_link->status.stats.tx_pmtu_errors++;
	+ break;
	+ case 0: /* ignore error and continue */
	+ src_link->status.stats.tx_pmtu_errors++;
	+ break;
	+ case 1: /* retry to send those same data */
	+ src_link->status.stats.tx_pmtu_retries++;
	+ pthread_mutex_unlock(&src_link->link_stats_mutex);
	+ goto retry_pmtud;
	+ break;
	+ }
	+ pthread_mutex_unlock(&src_link->link_stats_mutex);
	+ }
	+ }
	+ pthread_mutex_unlock(&knet_h->tx_mutex);
	+}
	+
	+void process_pmtud(knet_handle_t knet_h, struct knet_link src_link, struct knet_header inbuf)
	+{
	+ send_pmtud_reply(knet_h, src_link, inbuf);
	+}
	+
	+void process_pmtud_reply(knet_handle_t knet_h, struct knet_link src_link, struct knet_header inbuf)
	+{
	+ if (pthread_mutex_lock(&knet_h->pmtud_mutex) != 0) {
	+ log_debug(knet_h, KNET_SUB_RX, "Unable to get mutex lock");
	+ return;
	+ }
	+ src_link->last_recv_mtu = inbuf->khp_pmtud_size;
	+ pthread_cond_signal(&knet_h->pmtud_cond);
	+ pthread_mutex_unlock(&knet_h->pmtud_mutex);
	+}
	+
	int knet_handle_pmtud_getfreq(knet_handle_t knet_h, unsigned int *interval)
	{
	int savederrno = 0;

	if (!knet_h) {
	errno = EINVAL;
	return -1;
	}

	if (!interval) {
	errno = EINVAL;
	return -1;
	}

	savederrno = pthread_rwlock_rdlock(&knet_h->global_rwlock);
	if (savederrno) {
	log_err(knet_h, KNET_SUB_HANDLE, "Unable to get read lock: %s",
	strerror(savederrno));
	errno = savederrno;
	return -1;
	}

	*interval = knet_h->pmtud_interval;

	pthread_rwlock_unlock(&knet_h->global_rwlock);

	errno = 0;
	return 0;
	}

	int knet_handle_pmtud_setfreq(knet_handle_t knet_h, unsigned int interval)
	{
	int savederrno = 0;

	if (!knet_h) {
	errno = EINVAL;
	return -1;
	}

	if ((!interval) \|\| (interval > 86400)) {
	errno = EINVAL;
	return -1;
	}

	savederrno = get_global_wrlock(knet_h);
	if (savederrno) {
	log_err(knet_h, KNET_SUB_HANDLE, "Unable to get write lock: %s",
	strerror(savederrno));
	errno = savederrno;
	return -1;
	}

	knet_h->pmtud_interval = interval;
	log_debug(knet_h, KNET_SUB_HANDLE, "PMTUd interval set to: %u seconds", interval);

	pthread_rwlock_unlock(&knet_h->global_rwlock);

	errno = 0;
	return 0;
	}

	int knet_handle_enable_pmtud_notify(knet_handle_t knet_h,
	void *pmtud_notify_fn_private_data,
	void (*pmtud_notify_fn) (
	void *private_data,
	unsigned int data_mtu))
	{
	int savederrno = 0;

	if (!knet_h) {
	errno = EINVAL;
	return -1;
	}

	savederrno = get_global_wrlock(knet_h);
	if (savederrno) {
	log_err(knet_h, KNET_SUB_HANDLE, "Unable to get write lock: %s",
	strerror(savederrno));
	errno = savederrno;
	return -1;
	}

	knet_h->pmtud_notify_fn_private_data = pmtud_notify_fn_private_data;
	knet_h->pmtud_notify_fn = pmtud_notify_fn;
	if (knet_h->pmtud_notify_fn) {
	log_debug(knet_h, KNET_SUB_HANDLE, "pmtud_notify_fn enabled");
	} else {
	log_debug(knet_h, KNET_SUB_HANDLE, "pmtud_notify_fn disabled");
	}

	pthread_rwlock_unlock(&knet_h->global_rwlock);

	errno = 0;
	return 0;
	}

	int knet_handle_pmtud_set(knet_handle_t knet_h,
	unsigned int iface_mtu)
	{
	int savederrno = 0;

	if (!knet_h) {
	errno = EINVAL;
	return -1;
	}

	if (iface_mtu > KNET_PMTUD_SIZE_V4) {
	errno = EINVAL;
	return -1;
	}

	savederrno = pthread_rwlock_rdlock(&knet_h->global_rwlock);
	if (savederrno) {
	log_err(knet_h, KNET_SUB_PMTUD, "Unable to get read lock: %s",
	strerror(savederrno));
	errno = savederrno;
	return -1;
	}

	log_info(knet_h, KNET_SUB_PMTUD, "MTU manually set to: %u", iface_mtu);

	knet_h->manual_mtu = iface_mtu;

	force_pmtud_run(knet_h, KNET_SUB_PMTUD, 0);

	pthread_rwlock_unlock(&knet_h->global_rwlock);

	errno = 0;
	return 0;
	}

	int knet_handle_pmtud_get(knet_handle_t knet_h,
	unsigned int *data_mtu)
	{
	int savederrno = 0;

	if (!knet_h) {
	errno = EINVAL;
	return -1;
	}

	if (!data_mtu) {
	errno = EINVAL;
	return -1;
	}

	savederrno = pthread_rwlock_rdlock(&knet_h->global_rwlock);
	if (savederrno) {
	log_err(knet_h, KNET_SUB_HANDLE, "Unable to get read lock: %s",
	strerror(savederrno));
	errno = savederrno;
	return -1;
	}

	*data_mtu = knet_h->data_mtu;

	pthread_rwlock_unlock(&knet_h->global_rwlock);

	errno = 0;
	return 0;
	}
	diff --git a/libknet/threads_pmtud.h b/libknet/threads_pmtud.h
	index c2c2c7b7..de12ea33 100644
	--- a/libknet/threads_pmtud.h
	+++ b/libknet/threads_pmtud.h
	@@ -1,15 +1,18 @@
	/*
	* Copyright (C) 2012-2020 Red Hat, Inc. All rights reserved.
	*
	* Authors: Fabio M. Di Nitto <fabbione@kronosnet.org>
	* Federico Simoncelli <fsimon@kronosnet.org>
	*
	* This software licensed under LGPL-2.0+
	*/

	#ifndef __KNET_THREADS_PMTUD_H__
	#define __KNET_THREADS_PMTUD_H__

	void _handle_pmtud_link_thread(void data);

	+void process_pmtud(knet_handle_t knet_h, struct knet_link src_link, struct knet_header inbuf);
	+void process_pmtud_reply(knet_handle_t knet_h, struct knet_link src_link, struct knet_header inbuf);
	+
	#endif
	diff --git a/libknet/threads_rx.c b/libknet/threads_rx.c
	index 0467b4dd..b43ca14e 100644
	--- a/libknet/threads_rx.c
	+++ b/libknet/threads_rx.c
	@@ -1,892 +1,816 @@
	/*
	* Copyright (C) 2012-2020 Red Hat, Inc. All rights reserved.
	*
	* Authors: Fabio M. Di Nitto <fabbione@kronosnet.org>
	* Federico Simoncelli <fsimon@kronosnet.org>
	*
	* This software licensed under LGPL-2.0+
	*/

	#include "config.h"

	#include <stdio.h>
	#include <string.h>
	#include <errno.h>
	#include <sys/uio.h>
	#include <pthread.h>

	#include "compat.h"
	#include "compress.h"
	#include "crypto.h"
	#include "host.h"
	#include "links.h"
	#include "links_acl.h"
	#include "logging.h"
	#include "transports.h"
	#include "transport_common.h"
	#include "threads_common.h"
	#include "threads_heartbeat.h"
	+#include "threads_pmtud.h"
	#include "threads_rx.h"
	#include "netutils.h"

	/*
	* RECV
	*/

	/*
	* return 1 if a > b
	* return -1 if b > a
	* return 0 if they are equal
	*/
	static inline int timecmp(struct timespec a, struct timespec b)
	{
	if (a.tv_sec != b.tv_sec) {
	if (a.tv_sec > b.tv_sec) {
	return 1;
	} else {
	return -1;
	}
	} else {
	if (a.tv_nsec > b.tv_nsec) {
	return 1;
	} else if (a.tv_nsec < b.tv_nsec) {
	return -1;
	} else {
	return 0;
	}
	}
	}

	/*
	* this functions needs to return an index (0 to 7)
	* to a knet_host_defrag_buf. (-1 on errors)
	*/

	static int find_pckt_defrag_buf(knet_handle_t knet_h, struct knet_header *inbuf)
	{
	struct knet_host *src_host = knet_h->host_index[inbuf->kh_node];
	int i, oldest;

	/*
	* check if there is a buffer already in use handling the same seq_num
	*/
	for (i = 0; i < KNET_MAX_LINK; i++) {
	if (src_host->defrag_buf[i].in_use) {
	if (src_host->defrag_buf[i].pckt_seq == inbuf->khp_data_seq_num) {
	return i;
	}
	}
	}

	/*
	* If there is no buffer that's handling the current seq_num
	* either it's new or it's been reclaimed already.
	* check if it's been reclaimed/seen before using the defrag circular
	* buffer. If the pckt has been seen before, the buffer expired (ETIME)
	* and there is no point to try to defrag it again.
	*/
	if (!_seq_num_lookup(src_host, inbuf->khp_data_seq_num, 1, 0)) {
	errno = ETIME;
	return -1;
	}

	/*
	* register the pckt as seen
	*/
	_seq_num_set(src_host, inbuf->khp_data_seq_num, 1);

	/*
	* see if there is a free buffer
	*/
	for (i = 0; i < KNET_MAX_LINK; i++) {
	if (!src_host->defrag_buf[i].in_use) {
	return i;
	}
	}

	/*
	* at this point, there are no free buffers, the pckt is new
	* and we need to reclaim a buffer, and we will take the one
	* with the oldest timestamp. It's as good as any.
	*/

	oldest = 0;

	for (i = 0; i < KNET_MAX_LINK; i++) {
	if (timecmp(src_host->defrag_buf[i].last_update, src_host->defrag_buf[oldest].last_update) < 0) {
	oldest = i;
	}
	}
	src_host->defrag_buf[oldest].in_use = 0;
	return oldest;
	}

	static int pckt_defrag(knet_handle_t knet_h, struct knet_header inbuf, ssize_t len)
	{
	struct knet_host_defrag_buf *defrag_buf;
	int defrag_buf_idx;

	defrag_buf_idx = find_pckt_defrag_buf(knet_h, inbuf);
	if (defrag_buf_idx < 0) {
	return 1;
	}

	defrag_buf = &knet_h->host_index[inbuf->kh_node]->defrag_buf[defrag_buf_idx];

	/*
	* if the buf is not is use, then make sure it's clean
	*/
	if (!defrag_buf->in_use) {
	memset(defrag_buf, 0, sizeof(struct knet_host_defrag_buf));
	defrag_buf->in_use = 1;
	defrag_buf->pckt_seq = inbuf->khp_data_seq_num;
	}

	/*
	* update timestamp on the buffer
	*/
	clock_gettime(CLOCK_MONOTONIC, &defrag_buf->last_update);

	/*
	* check if we already received this fragment
	*/
	if (defrag_buf->frag_map[inbuf->khp_data_frag_seq]) {
	/*
	* if we have received this fragment and we didn't clear the buffer
	* it means that we don't have all fragments yet
	*/
	return 1;
	}

	/*
	* we need to handle the last packet with gloves due to its different size
	*/

	if (inbuf->khp_data_frag_seq == inbuf->khp_data_frag_num) {
	defrag_buf->last_frag_size = *len;

	/*
	* in the event when the last packet arrives first,
	* we still don't know the offset vs the other fragments (based on MTU),
	* so we store the fragment at the end of the buffer where it's safe
	* and take a copy of the len so that we can restore its offset later.
	* remember we can't use the local MTU for this calculation because pMTU
	* can be asymettric between the same hosts.
	*/
	if (!defrag_buf->frag_size) {
	defrag_buf->last_first = 1;
	memmove(defrag_buf->buf + (KNET_MAX_PACKET_SIZE - *len),
	inbuf->khp_data_userdata,
	*len);
	}
	} else {
	defrag_buf->frag_size = *len;
	}

	if (defrag_buf->frag_size) {
	memmove(defrag_buf->buf + ((inbuf->khp_data_frag_seq - 1) * defrag_buf->frag_size),
	inbuf->khp_data_userdata, *len);
	}

	defrag_buf->frag_recv++;
	defrag_buf->frag_map[inbuf->khp_data_frag_seq] = 1;

	/*
	* check if we received all the fragments
	*/
	if (defrag_buf->frag_recv == inbuf->khp_data_frag_num) {
	/*
	* special case the last pckt
	*/

	if (defrag_buf->last_first) {
	memmove(defrag_buf->buf + ((inbuf->khp_data_frag_num - 1) * defrag_buf->frag_size),
	defrag_buf->buf + (KNET_MAX_PACKET_SIZE - defrag_buf->last_frag_size),
	defrag_buf->last_frag_size);
	}

	/*
	* recalculate packet lenght
	*/

	len = ((inbuf->khp_data_frag_num - 1) defrag_buf->frag_size) + defrag_buf->last_frag_size;

	/*
	* copy the pckt back in the user data
	*/
	memmove(inbuf->khp_data_userdata, defrag_buf->buf, *len);

	/*
	* free this buffer
	*/
	defrag_buf->in_use = 0;
	return 0;
	}

	return 1;
	}

	static void _parse_recv_from_links(knet_handle_t knet_h, int sockfd, const struct knet_mmsghdr *msg)
	{
	int err = 0, savederrno = 0, stats_err = 0;
	ssize_t outlen;
	struct knet_host *src_host;
	struct knet_link *src_link;
	knet_node_id_t dst_host_ids[KNET_MAX_HOST];
	size_t dst_host_ids_entries = 0;
	int bcast = 1;
	uint64_t decrypt_time = 0;
	struct knet_header *inbuf = msg->msg_hdr.msg_iov->iov_base;
	- unsigned char outbuf = (unsigned char )msg->msg_hdr.msg_iov->iov_base;
	ssize_t len = msg->msg_len;
	struct iovec iov_out[1];
	int8_t channel;
	int try_decrypt = 0, decrypted = 0, i, found_link = 0;

	for (i = 1; i <= KNET_MAX_CRYPTO_INSTANCES; i++) {
	if (knet_h->crypto_instance[i]) {
	try_decrypt = 1;
	break;
	}
	}

	if ((!try_decrypt) && (knet_h->crypto_only == KNET_CRYPTO_RX_DISALLOW_CLEAR_TRAFFIC)) {
	log_debug(knet_h, KNET_SUB_RX, "RX thread configured to accept only crypto packets, but no crypto configs are configured!");
	return;
	}

	if (try_decrypt) {
	struct timespec start_time;
	struct timespec end_time;

	clock_gettime(CLOCK_MONOTONIC, &start_time);
	if (crypto_authenticate_and_decrypt(knet_h,
	(unsigned char *)inbuf,
	len,
	knet_h->recv_from_links_buf_decrypt,
	&outlen) < 0) {
	log_debug(knet_h, KNET_SUB_RX, "Unable to decrypt/auth packet");
	if (knet_h->crypto_only == KNET_CRYPTO_RX_DISALLOW_CLEAR_TRAFFIC) {
	return;
	}
	log_debug(knet_h, KNET_SUB_RX, "Attempting to process packet as clear data");
	} else {
	clock_gettime(CLOCK_MONOTONIC, &end_time);
	timespec_diff(start_time, end_time, &decrypt_time);

	len = outlen;
	inbuf = (struct knet_header *)knet_h->recv_from_links_buf_decrypt;
	decrypted = 1;
	}
	}

	if (len < (ssize_t)(KNET_HEADER_SIZE + 1)) {
	log_debug(knet_h, KNET_SUB_RX, "Packet is too short: %ld", (long)len);
	return;
	}

	if (inbuf->kh_version != KNET_HEADER_VERSION) {
	log_debug(knet_h, KNET_SUB_RX, "Packet version does not match");
	return;
	}

	inbuf->kh_node = ntohs(inbuf->kh_node);
	src_host = knet_h->host_index[inbuf->kh_node];
	if (src_host == NULL) { /* host not found */
	log_debug(knet_h, KNET_SUB_RX, "Unable to find source host for this packet");
	return;
	}

	if ((inbuf->kh_type & KNET_HEADER_TYPE_PMSK) != 0) {
	/* be aware this works only for PING / PONG and PMTUd packets! */
	src_link = src_host->link +
	(inbuf->khp_ping_link % KNET_MAX_LINK);
	if (src_link->dynamic == KNET_LINK_DYNIP) {
	if (cmpaddr(&src_link->dst_addr, msg->msg_hdr.msg_name) != 0) {
	log_debug(knet_h, KNET_SUB_RX, "host: %u link: %u appears to have changed ip address",
	src_host->host_id, src_link->link_id);
	memmove(&src_link->dst_addr, msg->msg_hdr.msg_name, sizeof(struct sockaddr_storage));
	if (knet_addrtostr(&src_link->dst_addr, sockaddr_len(&src_link->dst_addr),
	src_link->status.dst_ipaddr, KNET_MAX_HOST_LEN,
	src_link->status.dst_port, KNET_MAX_PORT_LEN) != 0) {
	log_debug(knet_h, KNET_SUB_RX, "Unable to resolve ???");
	snprintf(src_link->status.dst_ipaddr, KNET_MAX_HOST_LEN - 1, "Unknown!!!");
	snprintf(src_link->status.dst_port, KNET_MAX_PORT_LEN - 1, "??");
	} else {
	log_info(knet_h, KNET_SUB_RX,
	"host: %u link: %u new connection established from: %s %s",
	src_host->host_id, src_link->link_id,
	src_link->status.dst_ipaddr, src_link->status.dst_port);
	}
	}
	/*
	* transport has already accepted the connection here
	* otherwise we would not be receiving packets
	*/
	transport_link_dyn_connect(knet_h, sockfd, src_link);
	}
	} else { /* data packet */
	for (i = 0; i < KNET_MAX_LINK; i++) {
	src_link = &src_host->link[i];
	if (cmpaddr(&src_link->dst_addr, msg->msg_hdr.msg_name) == 0) {
	found_link = 1;
	break;
	}
	}
	if (!found_link) {
	log_debug(knet_h, KNET_SUB_RX, "Unable to determine source link for data packet. Discarding packet.");
	return;
	}
	}

	stats_err = pthread_mutex_lock(&src_link->link_stats_mutex);
	if (stats_err) {
	log_err(knet_h, KNET_SUB_RX, "Unable to get stats mutex lock for host %u link %u: %s",
	src_host->host_id, src_link->link_id, strerror(savederrno));
	return;
	}

	switch (inbuf->kh_type) {
	case KNET_HEADER_TYPE_DATA:

	/* data stats at the top for consistency with TX */
	src_link->status.stats.rx_data_packets++;
	src_link->status.stats.rx_data_bytes += len;

	if (decrypted) {
	stats_err = pthread_mutex_lock(&knet_h->handle_stats_mutex);
	if (stats_err < 0) {
	pthread_mutex_unlock(&src_link->link_stats_mutex);
	log_err(knet_h, KNET_SUB_RX, "Unable to get mutex lock: %s", strerror(stats_err));
	return;
	}
	/* Only update the crypto overhead for data packets. Mainly to be
	consistent with TX */
	if (decrypt_time < knet_h->stats.rx_crypt_time_min) {
	knet_h->stats.rx_crypt_time_min = decrypt_time;
	}
	if (decrypt_time > knet_h->stats.rx_crypt_time_max) {
	knet_h->stats.rx_crypt_time_max = decrypt_time;
	}
	knet_h->stats.rx_crypt_time_ave =
	(knet_h->stats.rx_crypt_time_ave * knet_h->stats.rx_crypt_packets +
	decrypt_time) / (knet_h->stats.rx_crypt_packets+1);
	knet_h->stats.rx_crypt_packets++;
	pthread_mutex_unlock(&knet_h->handle_stats_mutex);
	}

	if (!src_host->status.reachable) {
	pthread_mutex_unlock(&src_link->link_stats_mutex);
	log_debug(knet_h, KNET_SUB_RX, "Source host %u not reachable yet. Discarding packet.", src_host->host_id);
	return;
	}

	inbuf->khp_data_seq_num = ntohs(inbuf->khp_data_seq_num);
	channel = inbuf->khp_data_channel;
	src_host->got_data = 1;

	if (!_seq_num_lookup(src_host, inbuf->khp_data_seq_num, 0, 0)) {
	pthread_mutex_unlock(&src_link->link_stats_mutex);
	if (src_host->link_handler_policy != KNET_LINK_POLICY_ACTIVE) {
	log_debug(knet_h, KNET_SUB_RX, "Packet has already been delivered");
	}
	return;
	}

	if (inbuf->khp_data_frag_num > 1) {
	/*
	* len as received from the socket also includes extra stuff
	* that the defrag code doesn't care about. So strip it
	* here and readd only for repadding once we are done
	* defragging
	*/
	len = len - KNET_HEADER_DATA_SIZE;
	if (pckt_defrag(knet_h, inbuf, &len)) {
	pthread_mutex_unlock(&src_link->link_stats_mutex);
	return;
	}
	len = len + KNET_HEADER_DATA_SIZE;
	}

	if (inbuf->khp_data_compress) {
	ssize_t decmp_outlen = KNET_DATABUFSIZE_COMPRESS;
	struct timespec start_time;
	struct timespec end_time;
	uint64_t compress_time;

	clock_gettime(CLOCK_MONOTONIC, &start_time);
	err = decompress(knet_h, inbuf->khp_data_compress,
	(const unsigned char *)inbuf->khp_data_userdata,
	len - KNET_HEADER_DATA_SIZE,
	knet_h->recv_from_links_buf_decompress,
	&decmp_outlen);

	stats_err = pthread_mutex_lock(&knet_h->handle_stats_mutex);
	if (stats_err < 0) {
	pthread_mutex_unlock(&src_link->link_stats_mutex);
	log_err(knet_h, KNET_SUB_RX, "Unable to get mutex lock: %s", strerror(stats_err));
	return;
	}

	clock_gettime(CLOCK_MONOTONIC, &end_time);
	timespec_diff(start_time, end_time, &compress_time);

	if (!err) {
	/* Collect stats */
	if (compress_time < knet_h->stats.rx_compress_time_min) {
	knet_h->stats.rx_compress_time_min = compress_time;
	}
	if (compress_time > knet_h->stats.rx_compress_time_max) {
	knet_h->stats.rx_compress_time_max = compress_time;
	}
	knet_h->stats.rx_compress_time_ave =
	(knet_h->stats.rx_compress_time_ave * knet_h->stats.rx_compressed_packets +
	compress_time) / (knet_h->stats.rx_compressed_packets+1);

	knet_h->stats.rx_compressed_packets++;
	knet_h->stats.rx_compressed_original_bytes += decmp_outlen;
	knet_h->stats.rx_compressed_size_bytes += len - KNET_HEADER_SIZE;

	memmove(inbuf->khp_data_userdata, knet_h->recv_from_links_buf_decompress, decmp_outlen);
	len = decmp_outlen + KNET_HEADER_DATA_SIZE;
	} else {
	knet_h->stats.rx_failed_to_decompress++;
	pthread_mutex_unlock(&knet_h->handle_stats_mutex);
	pthread_mutex_unlock(&src_link->link_stats_mutex);
	log_warn(knet_h, KNET_SUB_COMPRESS, "Unable to decompress packet (%d): %s",
	err, strerror(errno));
	return;
	}
	pthread_mutex_unlock(&knet_h->handle_stats_mutex);
	}

	if (knet_h->enabled != 1) /* data forward is disabled */
	break;

	if (knet_h->dst_host_filter_fn) {
	size_t host_idx;
	int found = 0;

	bcast = knet_h->dst_host_filter_fn(
	knet_h->dst_host_filter_fn_private_data,
	(const unsigned char *)inbuf->khp_data_userdata,
	len - KNET_HEADER_DATA_SIZE,
	KNET_NOTIFY_RX,
	knet_h->host_id,
	inbuf->kh_node,
	&channel,
	dst_host_ids,
	&dst_host_ids_entries);
	if (bcast < 0) {
	pthread_mutex_unlock(&src_link->link_stats_mutex);
	log_debug(knet_h, KNET_SUB_RX, "Error from dst_host_filter_fn: %d", bcast);
	return;
	}

	if ((!bcast) && (!dst_host_ids_entries)) {
	pthread_mutex_unlock(&src_link->link_stats_mutex);
	log_debug(knet_h, KNET_SUB_RX, "Message is unicast but no dst_host_ids_entries");
	return;
	}

	/* check if we are dst for this packet */
	if (!bcast) {
	if (dst_host_ids_entries > KNET_MAX_HOST) {
	pthread_mutex_unlock(&src_link->link_stats_mutex);
	log_debug(knet_h, KNET_SUB_RX, "dst_host_filter_fn returned too many destinations");
	return;
	}
	for (host_idx = 0; host_idx < dst_host_ids_entries; host_idx++) {
	if (dst_host_ids[host_idx] == knet_h->host_id) {
	found = 1;
	break;
	}
	}
	if (!found) {
	pthread_mutex_unlock(&src_link->link_stats_mutex);
	log_debug(knet_h, KNET_SUB_RX, "Packet is not for us");
	return;
	}
	}
	}

	if (!knet_h->sockfd[channel].in_use) {
	pthread_mutex_unlock(&src_link->link_stats_mutex);
	log_debug(knet_h, KNET_SUB_RX,
	"received packet for channel %d but there is no local sock connected",
	channel);
	return;
	}

	outlen = 0;
	memset(iov_out, 0, sizeof(iov_out));

	retry:
	iov_out[0].iov_base = (void *) inbuf->khp_data_userdata + outlen;
	iov_out[0].iov_len = len - (outlen + KNET_HEADER_DATA_SIZE);

	outlen = writev(knet_h->sockfd[channel].sockfd[knet_h->sockfd[channel].is_created], iov_out, 1);
	if ((outlen > 0) && (outlen < (ssize_t)iov_out[0].iov_len)) {
	log_debug(knet_h, KNET_SUB_RX,
	"Unable to send all data to the application in one go. Expected: %zu Sent: %zd\n",
	iov_out[0].iov_len, outlen);
	goto retry;
	}

	if (outlen <= 0) {
	knet_h->sock_notify_fn(knet_h->sock_notify_fn_private_data,
	knet_h->sockfd[channel].sockfd[0],
	channel,
	KNET_NOTIFY_RX,
	outlen,
	errno);
	pthread_mutex_unlock(&src_link->link_stats_mutex);
	return;
	}
	if ((size_t)outlen == iov_out[0].iov_len) {
	_seq_num_set(src_host, inbuf->khp_data_seq_num, 0);
	}
	break;
	case KNET_HEADER_TYPE_PING:
	process_ping(knet_h, src_host, src_link, inbuf, len);
	break;
	case KNET_HEADER_TYPE_PONG:
	process_pong(knet_h, src_host, src_link, inbuf, len);
	break;
	case KNET_HEADER_TYPE_PMTUD:
	src_link->status.stats.rx_pmtu_packets++;
	src_link->status.stats.rx_pmtu_bytes += len;
	- outlen = KNET_HEADER_PMTUD_SIZE;
	- inbuf->kh_type = KNET_HEADER_TYPE_PMTUD_REPLY;
	- inbuf->kh_node = htons(knet_h->host_id);
	-
	- if (knet_h->crypto_in_use_config) {
	- if (crypto_encrypt_and_sign(knet_h,
	- (const unsigned char *)inbuf,
	- outlen,
	- knet_h->recv_from_links_buf_crypt,
	- &outlen) < 0) {
	- log_debug(knet_h, KNET_SUB_RX, "Unable to encrypt PMTUd reply packet");
	- break;
	- }
	- outbuf = knet_h->recv_from_links_buf_crypt;
	- stats_err = pthread_mutex_lock(&knet_h->handle_stats_mutex);
	- if (stats_err < 0) {
	- log_err(knet_h, KNET_SUB_RX, "Unable to get mutex lock: %s", strerror(stats_err));
	- break;
	- }
	- knet_h->stats_extra.tx_crypt_pmtu_reply_packets++;
	- pthread_mutex_unlock(&knet_h->handle_stats_mutex);
	- }
	-
	/* Unlock so we don't deadlock with tx_mutex */
	pthread_mutex_unlock(&src_link->link_stats_mutex);
	-
	- savederrno = pthread_mutex_lock(&knet_h->tx_mutex);
	- if (savederrno) {
	- log_err(knet_h, KNET_SUB_RX, "Unable to get TX mutex lock: %s", strerror(savederrno));
	- goto out_pmtud;
	- }
	-retry_pmtud:
	- if (src_link->transport_connected) {
	- if (transport_get_connection_oriented(knet_h, src_link->transport) == TRANSPORT_PROTO_NOT_CONNECTION_ORIENTED) {
	- len = sendto(src_link->outsock, outbuf, outlen, MSG_DONTWAIT \| MSG_NOSIGNAL,
	- (struct sockaddr *) &src_link->dst_addr, sizeof(struct sockaddr_storage));
	- } else {
	- len = sendto(src_link->outsock, outbuf, outlen, MSG_DONTWAIT \| MSG_NOSIGNAL, NULL, 0);
	- }
	- savederrno = errno;
	- if (len != outlen) {
	- err = transport_tx_sock_error(knet_h, src_link->transport, src_link->outsock, len, savederrno);
	- stats_err = pthread_mutex_lock(&src_link->link_stats_mutex);
	- if (stats_err < 0) {
	- log_err(knet_h, KNET_SUB_RX, "Unable to get mutex lock: %s", strerror(stats_err));
	- break;
	- }
	- switch(err) {
	- case -1: /* unrecoverable error */
	- log_debug(knet_h, KNET_SUB_RX,
	- "Unable to send PMTUd reply (sock: %d) packet (sendto): %d %s. recorded src ip: %s src port: %s dst ip: %s dst port: %s",
	- src_link->outsock, errno, strerror(errno),
	- src_link->status.src_ipaddr, src_link->status.src_port,
	- src_link->status.dst_ipaddr, src_link->status.dst_port);
	-
	- src_link->status.stats.tx_pmtu_errors++;
	- break;
	- case 0: /* ignore error and continue */
	- src_link->status.stats.tx_pmtu_errors++;
	- break;
	- case 1: /* retry to send those same data */
	- src_link->status.stats.tx_pmtu_retries++;
	- pthread_mutex_unlock(&src_link->link_stats_mutex);
	- goto retry_pmtud;
	- break;
	- }
	- pthread_mutex_unlock(&src_link->link_stats_mutex);
	- }
	- }
	- pthread_mutex_unlock(&knet_h->tx_mutex);
	-out_pmtud:
	+ process_pmtud(knet_h, src_link, inbuf);
	return; /* Don't need to unlock link_stats_mutex */
	case KNET_HEADER_TYPE_PMTUD_REPLY:
	src_link->status.stats.rx_pmtu_packets++;
	src_link->status.stats.rx_pmtu_bytes += len;
	-
	/* pmtud_mutex can't be acquired while we hold a link_stats_mutex (ordering) */
	pthread_mutex_unlock(&src_link->link_stats_mutex);
	-
	- if (pthread_mutex_lock(&knet_h->pmtud_mutex) != 0) {
	- log_debug(knet_h, KNET_SUB_RX, "Unable to get mutex lock");
	- break;
	- }
	- src_link->last_recv_mtu = inbuf->khp_pmtud_size;
	- pthread_cond_signal(&knet_h->pmtud_cond);
	- pthread_mutex_unlock(&knet_h->pmtud_mutex);
	+ process_pmtud_reply(knet_h, src_link, inbuf);
	return;
	default:
	pthread_mutex_unlock(&src_link->link_stats_mutex);
	return;
	}
	pthread_mutex_unlock(&src_link->link_stats_mutex);
	}

	static void _handle_recv_from_links(knet_handle_t knet_h, int sockfd, struct knet_mmsghdr *msg)
	{
	int err, savederrno;
	int i, msg_recv, transport;

	if (pthread_rwlock_rdlock(&knet_h->global_rwlock) != 0) {
	log_debug(knet_h, KNET_SUB_RX, "Unable to get global read lock");
	return;
	}

	if (_is_valid_fd(knet_h, sockfd) < 1) {
	/*
	* this is normal if a fd got an event and before we grab the read lock
	* and the link is removed by another thread
	*/
	goto exit_unlock;
	}

	transport = knet_h->knet_transport_fd_tracker[sockfd].transport;

	/*
	* reset msg_namelen to buffer size because after recvmmsg
	* each msg_namelen will contain sizeof sockaddr_in or sockaddr_in6
	*/

	for (i = 0; i < PCKT_RX_BUFS; i++) {
	msg[i].msg_hdr.msg_namelen = sizeof(struct sockaddr_storage);
	}

	msg_recv = _recvmmsg(sockfd, &msg[0], PCKT_RX_BUFS, MSG_DONTWAIT \| MSG_NOSIGNAL);
	savederrno = errno;

	/*
	* WARNING: man page for recvmmsg is wrong. Kernel implementation here:
	* recvmmsg can return:
	* -1 on error
	* 0 if the previous run of recvmmsg recorded an error on the socket
	* N number of messages (see exception below).
	*
	* If there is an error from recvmsg after receiving a frame or more, the recvmmsg
	* loop is interrupted, error recorded in the socket (getsockopt(SO_ERROR) and
	* it will be visibile in the next run.
	*
	* Need to be careful how we handle errors at this stage.
	*
	* error messages need to be handled on a per transport/protocol base
	* at this point we have different layers of error handling
	* - msg_recv < 0 -> error from this run
	* msg_recv = 0 -> error from previous run and error on socket needs to be cleared
	* - per-transport message data
	* example: msg[i].msg_hdr.msg_flags & MSG_NOTIFICATION or msg_len for SCTP == EOF,
	* but for UDP it is perfectly legal to receive a 0 bytes message.. go figure
	* - NOTE: on SCTP MSG_NOTIFICATION we get msg_recv == PCKT_FRAG_MAX messages and no
	* errno set. That means the error api needs to be able to abort the loop below.
	*/

	if (msg_recv <= 0) {
	transport_rx_sock_error(knet_h, transport, sockfd, msg_recv, savederrno);
	goto exit_unlock;
	}

	for (i = 0; i < msg_recv; i++) {
	err = transport_rx_is_data(knet_h, transport, sockfd, &msg[i]);

	/*
	* TODO: make this section silent once we are confident
	* all protocols packet handlers are good
	*/

	switch(err) {
	case KNET_TRANSPORT_RX_ERROR: /* on error */
	log_debug(knet_h, KNET_SUB_RX, "Transport reported error parsing packet");
	goto exit_unlock;
	break;
	case KNET_TRANSPORT_RX_NOT_DATA_CONTINUE: /* packet is not data and we should continue the packet process loop */
	log_debug(knet_h, KNET_SUB_RX, "Transport reported no data, continue");
	break;
	case KNET_TRANSPORT_RX_NOT_DATA_STOP: /* packet is not data and we should STOP the packet process loop */
	log_debug(knet_h, KNET_SUB_RX, "Transport reported no data, stop");
	goto exit_unlock;
	break;
	case KNET_TRANSPORT_RX_IS_DATA: /* packet is data and should be parsed as such */
	/*
	* processing incoming packets vs access lists
	*/
	if ((knet_h->use_access_lists) &&
	(transport_get_acl_type(knet_h, transport) == USE_GENERIC_ACL)) {
	if (!check_validate(knet_h, sockfd, transport, msg[i].msg_hdr.msg_name)) {
	char src_ipaddr[KNET_MAX_HOST_LEN];
	char src_port[KNET_MAX_PORT_LEN];

	memset(src_ipaddr, 0, KNET_MAX_HOST_LEN);
	memset(src_port, 0, KNET_MAX_PORT_LEN);
	if (knet_addrtostr(msg[i].msg_hdr.msg_name, sockaddr_len(msg[i].msg_hdr.msg_name),
	src_ipaddr, KNET_MAX_HOST_LEN,
	src_port, KNET_MAX_PORT_LEN) < 0) {

	log_debug(knet_h, KNET_SUB_RX, "Packet rejected: unable to resolve host/port");
	} else {
	log_debug(knet_h, KNET_SUB_RX, "Packet rejected from %s/%s", src_ipaddr, src_port);
	}
	/*
	* continue processing the other packets
	*/
	continue;
	}
	}
	_parse_recv_from_links(knet_h, sockfd, &msg[i]);
	break;
	case KNET_TRANSPORT_RX_OOB_DATA_CONTINUE:
	log_debug(knet_h, KNET_SUB_RX, "Transport is processing sock OOB data, continue");
	break;
	case KNET_TRANSPORT_RX_OOB_DATA_STOP:
	log_debug(knet_h, KNET_SUB_RX, "Transport has completed processing sock OOB data, stop");
	goto exit_unlock;
	break;
	}
	}

	exit_unlock:
	pthread_rwlock_unlock(&knet_h->global_rwlock);
	}

	void _handle_recv_from_links_thread(void data)
	{
	int i, nev;
	knet_handle_t knet_h = (knet_handle_t) data;
	struct epoll_event events[KNET_EPOLL_MAX_EVENTS];
	struct sockaddr_storage address[PCKT_RX_BUFS];
	struct knet_mmsghdr msg[PCKT_RX_BUFS];
	struct iovec iov_in[PCKT_RX_BUFS];

	set_thread_status(knet_h, KNET_THREAD_RX, KNET_THREAD_STARTED);

	memset(&msg, 0, sizeof(msg));
	memset(&events, 0, sizeof(events));

	for (i = 0; i < PCKT_RX_BUFS; i++) {
	iov_in[i].iov_base = (void *)knet_h->recv_from_links_buf[i];
	iov_in[i].iov_len = KNET_DATABUFSIZE;

	memset(&msg[i].msg_hdr, 0, sizeof(struct msghdr));

	msg[i].msg_hdr.msg_name = &address[i];
	msg[i].msg_hdr.msg_namelen = sizeof(struct sockaddr_storage);
	msg[i].msg_hdr.msg_iov = &iov_in[i];
	msg[i].msg_hdr.msg_iovlen = 1;
	}

	while (!shutdown_in_progress(knet_h)) {
	nev = epoll_wait(knet_h->recv_from_links_epollfd, events, KNET_EPOLL_MAX_EVENTS, knet_h->threads_timer_res / 1000);

	/*
	* the RX threads only need to notify that there has been at least
	* one successful run after queue flush has been requested.
	* See setfwd in handle.c
	*/
	if (get_thread_flush_queue(knet_h, KNET_THREAD_RX) == KNET_THREAD_QUEUE_FLUSH) {
	set_thread_flush_queue(knet_h, KNET_THREAD_RX, KNET_THREAD_QUEUE_FLUSHED);
	}

	/*
	* we use timeout to detect if thread is shutting down
	*/
	if (nev == 0) {
	continue;
	}

	for (i = 0; i < nev; i++) {
	_handle_recv_from_links(knet_h, events[i].data.fd, msg);
	}
	}

	set_thread_status(knet_h, KNET_THREAD_RX, KNET_THREAD_STOPPED);

	return NULL;
	}

	ssize_t knet_recv(knet_handle_t knet_h, char *buff, const size_t buff_len, const int8_t channel)
	{
	int savederrno = 0;
	ssize_t err = 0;
	struct iovec iov_in;

	if (!knet_h) {
	errno = EINVAL;
	return -1;
	}

	if (buff == NULL) {
	errno = EINVAL;
	return -1;
	}

	if (buff_len <= 0) {
	errno = EINVAL;
	return -1;
	}

	if (buff_len > KNET_MAX_PACKET_SIZE) {
	errno = EINVAL;
	return -1;
	}

	if (channel < 0) {
	errno = EINVAL;
	return -1;
	}

	if (channel >= KNET_DATAFD_MAX) {
	errno = EINVAL;
	return -1;
	}

	savederrno = pthread_rwlock_rdlock(&knet_h->global_rwlock);
	if (savederrno) {
	log_err(knet_h, KNET_SUB_HANDLE, "Unable to get read lock: %s",
	strerror(savederrno));
	errno = savederrno;
	return -1;
	}

	if (!knet_h->sockfd[channel].in_use) {
	savederrno = EINVAL;
	err = -1;
	goto out_unlock;
	}

	memset(&iov_in, 0, sizeof(iov_in));
	iov_in.iov_base = (void *)buff;
	iov_in.iov_len = buff_len;

	err = readv(knet_h->sockfd[channel].sockfd[0], &iov_in, 1);
	savederrno = errno;

	out_unlock:
	pthread_rwlock_unlock(&knet_h->global_rwlock);
	errno = err ? savederrno : 0;
	return err;
	}

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