diff --git a/libknet/threads_rx.c b/libknet/threads_rx.c
new file mode 100644
index 00000000..37375346
--- /dev/null
+++ b/libknet/threads_rx.c
@@ -0,0 +1,1302 @@
+/*
+ * Copyright (C) 2010-2015 Red Hat, Inc.  All rights reserved.
+ *
+ * Authors: Fabio M. Di Nitto <fabbione@kronosnet.org>
+ *          Federico Simoncelli <fsimon@kronosnet.org>
+ *
+ * This software licensed under GPL-2.0+, LGPL-2.0+
+ */
+
+#include "config.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <pthread.h>
+#include <math.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+#include <sys/uio.h>
+
+#include "crypto.h"
+#include "compat.h"
+#include "host.h"
+#include "link.h"
+#include "logging.h"
+#include "transports.h"
+#include "threads_common.h"
+#include "threads_heartbeat.h"
+#include "threads_send_recv.h"
+#include "netutils.h"
+
+/*
+ * SEND
+ */
+
+static int _dispatch_to_links(knet_handle_t knet_h, struct knet_host *dst_host, struct iovec *iov_out)
+{
+	int link_idx, msg_idx, sent_msgs, msgs_to_send, prev_sent, progress;
+	struct mmsghdr msg[PCKT_FRAG_MAX];
+	int err = 0, savederrno = 0;
+
+	memset(&msg, 0, sizeof(struct mmsghdr));
+
+	for (link_idx = 0; link_idx < dst_host->active_link_entries; link_idx++) {
+
+		msgs_to_send = knet_h->send_to_links_buf[0]->khp_data_frag_num;
+		sent_msgs = 0;
+		prev_sent = 0;
+		progress = 1;
+
+retry:
+		msg_idx = 0;
+
+		while (msg_idx < msgs_to_send) {
+			memset(&msg[msg_idx].msg_hdr, 0, sizeof(struct msghdr));
+			msg[msg_idx].msg_hdr.msg_name = &dst_host->link[dst_host->active_links[link_idx]].dst_addr;
+			msg[msg_idx].msg_hdr.msg_namelen = sizeof(struct sockaddr_storage);
+			msg[msg_idx].msg_hdr.msg_iov = &iov_out[msg_idx + prev_sent];
+			msg[msg_idx].msg_hdr.msg_iovlen = 1;
+			msg_idx++;
+		}
+
+		sent_msgs = sendmmsg(dst_host->link[dst_host->active_links[link_idx]].outsock,
+				     msg, msg_idx, MSG_DONTWAIT | MSG_NOSIGNAL);
+		savederrno = errno;
+
+		err = knet_h->transport_ops[dst_host->link[dst_host->active_links[link_idx]].transport_type]->transport_tx_sock_error(knet_h, dst_host->link[dst_host->active_links[link_idx]].outsock, sent_msgs, savederrno);
+		switch(err) {
+			case -1: /* unrecoverable error */
+				goto out_unlock;
+				break;
+			case 0: /* ignore error and continue */
+				break;
+			case 1: /* retry to send those same data */
+				goto retry;
+				break;
+		}
+
+		if ((sent_msgs >= 0) && (sent_msgs < msg_idx)) {
+			if ((sent_msgs) || (progress)) {
+				msgs_to_send = msg_idx - sent_msgs;
+				prev_sent = prev_sent + sent_msgs;
+				if (sent_msgs) {
+					progress = 1;
+				} else {
+					progress = 0;
+				}
+				log_debug(knet_h, KNET_SUB_TX, "Unable to send all (%d/%d) data packets to host %s (%u) link %s:%s (%u)",
+					  sent_msgs, msg_idx,
+					  dst_host->name, dst_host->host_id,
+					  dst_host->link[dst_host->active_links[link_idx]].status.dst_ipaddr,
+					  dst_host->link[dst_host->active_links[link_idx]].status.dst_port,
+					  dst_host->link[dst_host->active_links[link_idx]].link_id);
+				goto retry;
+			}
+			if (!progress) {
+				savederrno = EAGAIN;
+				err = -1;
+				goto out_unlock;
+			}
+		}
+
+		if ((dst_host->link_handler_policy == KNET_LINK_POLICY_RR) &&
+		    (dst_host->active_link_entries > 1)) {
+			uint8_t cur_link_id = dst_host->active_links[0];
+
+			memmove(&dst_host->active_links[0], &dst_host->active_links[1], KNET_MAX_LINK - 1);
+			dst_host->active_links[dst_host->active_link_entries - 1] = cur_link_id;
+
+			break;
+		}
+	}
+
+out_unlock:
+	errno = savederrno;
+	return err;
+}
+
+static int _parse_recv_from_sock(knet_handle_t knet_h, int buf_idx, ssize_t inlen, int8_t channel, int is_sync)
+{
+	ssize_t outlen, frag_len;
+	struct knet_host *dst_host;
+	uint16_t dst_host_ids_temp[KNET_MAX_HOST];
+	size_t dst_host_ids_entries_temp = 0;
+	uint16_t dst_host_ids[KNET_MAX_HOST];
+	size_t dst_host_ids_entries = 0;
+	int bcast = 1;
+	struct knet_hostinfo *knet_hostinfo;
+	struct iovec iov_out[PCKT_FRAG_MAX];
+	uint8_t frag_idx;
+	unsigned int temp_data_mtu;
+	int host_idx;
+	int send_mcast = 0;
+	struct knet_header *inbuf;
+	int savederrno = 0;
+	int err = 0;
+	seq_num_t tx_seq_num;
+
+	inbuf = knet_h->recv_from_sock_buf[buf_idx];
+
+	if ((knet_h->enabled != 1) &&
+	    (inbuf->kh_type != KNET_HEADER_TYPE_HOST_INFO)) { /* data forward is disabled */
+		log_debug(knet_h, KNET_SUB_TX, "Received data packet but forwarding is disabled");
+		savederrno = ECANCELED;
+		err = -1;
+		goto out_unlock;
+	}
+
+	/*
+	 * move this into a separate function to expand on
+	 * extra switching rules
+	 */
+	switch(inbuf->kh_type) {
+		case KNET_HEADER_TYPE_DATA:
+			if (knet_h->dst_host_filter_fn) {
+				bcast = knet_h->dst_host_filter_fn(
+						knet_h->dst_host_filter_fn_private_data,
+						(const unsigned char *)inbuf->khp_data_userdata,
+						inlen,
+						KNET_NOTIFY_TX,
+						knet_h->host_id,
+						knet_h->host_id,
+						&channel,
+						dst_host_ids_temp,
+						&dst_host_ids_entries_temp);
+				if (bcast < 0) {
+					log_debug(knet_h, KNET_SUB_TX, "Error from dst_host_filter_fn: %d", bcast);
+					savederrno = EFAULT;
+					err = -1;
+					goto out_unlock;
+				}
+
+				if ((!bcast) && (!dst_host_ids_entries_temp)) {
+					log_debug(knet_h, KNET_SUB_TX, "Message is unicast but no dst_host_ids_entries");
+					savederrno = EINVAL;
+					err = -1;
+					goto out_unlock;
+				}
+			}
+			break;
+		case KNET_HEADER_TYPE_HOST_INFO:
+			knet_hostinfo = (struct knet_hostinfo *)inbuf->khp_data_userdata;
+			if (knet_hostinfo->khi_bcast == KNET_HOSTINFO_UCAST) {
+				bcast = 0;
+				dst_host_ids_temp[0] = knet_hostinfo->khi_dst_node_id;
+				dst_host_ids_entries_temp = 1;
+				knet_hostinfo->khi_dst_node_id = htons(knet_hostinfo->khi_dst_node_id);
+			}
+			break;
+		default:
+			log_warn(knet_h, KNET_SUB_TX, "Receiving unknown messages from socket");
+			savederrno = ENOMSG;
+			err = -1;
+			goto out_unlock;
+			break;
+	}
+
+	if (is_sync) {
+		if ((bcast) ||
+		    ((!bcast) && (dst_host_ids_entries_temp > 1))) {
+			log_debug(knet_h, KNET_SUB_TX, "knet_send_sync is only supported with unicast packets for one destination");
+			savederrno = E2BIG;
+			err = -1;
+			goto out_unlock;
+		}
+	}
+
+	/*
+	 * check destinations hosts before spending time
+	 * in fragmenting/encrypting packets to save
+	 * time processing data for unrechable hosts.
+	 * for unicast, also remap the destination data
+	 * to skip unreachable hosts.
+	 */
+
+	if (!bcast) {
+		dst_host_ids_entries = 0;
+		for (host_idx = 0; host_idx < dst_host_ids_entries_temp; host_idx++) {
+			dst_host = knet_h->host_index[dst_host_ids_temp[host_idx]];
+			if (!dst_host) {
+				continue;
+			}
+			if (dst_host->status.reachable) {
+				dst_host_ids[dst_host_ids_entries] = dst_host_ids_temp[host_idx];
+				dst_host_ids_entries++;
+			}
+		}
+		if (!dst_host_ids_entries) {
+			savederrno = EHOSTDOWN;
+			err = -1;
+			goto out_unlock;
+		}
+	} else {
+		send_mcast = 0;
+		for (dst_host = knet_h->host_head; dst_host != NULL; dst_host = dst_host->next) {
+			if (dst_host->status.reachable) {
+				send_mcast = 1;
+				break;
+			}
+		}
+		if (!send_mcast) {
+			savederrno = EHOSTDOWN;
+			err = -1;
+			goto out_unlock;
+		}
+	}
+
+	if (!knet_h->data_mtu) {
+		/*
+		 * using MIN_MTU_V4 for data mtu is not completely accurate but safe enough
+		 */
+		log_debug(knet_h, KNET_SUB_TX,
+			  "Received data packet but data MTU is still unknown."
+			  " Packet might not be delivered."
+			  " Assuming mininum IPv4 mtu (%d)",
+			  KNET_PMTUD_MIN_MTU_V4);
+		temp_data_mtu = KNET_PMTUD_MIN_MTU_V4;
+	} else {
+		/*
+		 * take a copy of the mtu to avoid value changing under
+		 * our feet while we are sending a fragmented pckt
+		 */
+		temp_data_mtu = knet_h->data_mtu;
+	}
+
+	/*
+	 * prepare the outgoing buffers
+	 */
+
+	frag_len = inlen;
+	frag_idx = 0;
+
+	inbuf->khp_data_bcast = bcast;
+	inbuf->khp_data_frag_num = ceil((float)inlen / temp_data_mtu);
+	inbuf->khp_data_channel = channel;
+
+	if (pthread_mutex_lock(&knet_h->tx_seq_num_mutex)) {
+		log_debug(knet_h, KNET_SUB_TX, "Unable to get seq mutex lock");
+		goto out_unlock;
+	}
+	knet_h->tx_seq_num++;
+	/*
+	 * force seq_num 0 to detect a node that has crashed and rejoining
+	 * the knet instance. seq_num 0 will clear the buffers in the RX
+	 * thread
+	 */
+	if (knet_h->tx_seq_num == 0) {
+		knet_h->tx_seq_num++;
+	}
+	/*
+	 * cache the value in locked context
+	 */
+	tx_seq_num = knet_h->tx_seq_num;
+	knet_h->send_to_links_buf[0]->khp_data_seq_num = htons(knet_h->tx_seq_num);
+	pthread_mutex_unlock(&knet_h->tx_seq_num_mutex);
+
+	/*
+	 * forcefully broadcast a ping to all nodes every SEQ_MAX / 8
+	 * pckts.
+	 * this solves 2 problems:
+	 * 1) on TX socket overloads we generate extra pings to keep links alive
+	 * 2) in 3+ nodes setup, where all the traffic is flowing between node 1 and 2,
+	 *    node 3+ will be able to keep in sync on the TX seq_num even without
+	 *    receiving traffic or pings in betweens. This avoids issues with
+	 *    rollover of the circular buffer
+	 */
+
+	if (tx_seq_num % (SEQ_MAX / 8) == 0) {
+		_send_pings(knet_h, 0);
+	}
+
+	while (frag_idx < inbuf->khp_data_frag_num) {
+		/*
+		 * set the iov_base
+		 */
+		iov_out[frag_idx].iov_base = (void *)knet_h->send_to_links_buf[frag_idx];
+
+		/*
+		 * set the len
+		 */
+		if (frag_len > temp_data_mtu) {
+			iov_out[frag_idx].iov_len = temp_data_mtu + KNET_HEADER_DATA_SIZE;
+		} else {
+			iov_out[frag_idx].iov_len = frag_len + KNET_HEADER_DATA_SIZE;
+		}
+
+		/*
+		 * copy the frag info on all buffers
+		 */
+		knet_h->send_to_links_buf[frag_idx]->kh_type = inbuf->kh_type;
+
+		knet_h->send_to_links_buf[frag_idx]->khp_data_seq_num = knet_h->send_to_links_buf[0]->khp_data_seq_num;
+		knet_h->send_to_links_buf[frag_idx]->khp_data_frag_num = inbuf->khp_data_frag_num;
+		knet_h->send_to_links_buf[frag_idx]->khp_data_bcast = inbuf->khp_data_bcast;
+		knet_h->send_to_links_buf[frag_idx]->khp_data_channel = inbuf->khp_data_channel;
+
+		memmove(knet_h->send_to_links_buf[frag_idx]->khp_data_userdata,
+			inbuf->khp_data_userdata + (temp_data_mtu * frag_idx),
+			iov_out[frag_idx].iov_len - KNET_HEADER_DATA_SIZE);
+
+		frag_len = frag_len - temp_data_mtu;
+		frag_idx++;
+	}
+
+	if (knet_h->crypto_instance) {
+		frag_idx = 0;
+		while (frag_idx < knet_h->send_to_links_buf[0]->khp_data_frag_num) {
+			if (crypto_encrypt_and_sign(
+					knet_h,
+					(const unsigned char *)knet_h->send_to_links_buf[frag_idx],
+					iov_out[frag_idx].iov_len,
+					knet_h->send_to_links_buf_crypt[frag_idx],
+					&outlen) < 0) {
+				log_debug(knet_h, KNET_SUB_TX, "Unable to encrypt unicast packet");
+				savederrno = ECHILD;
+				err = -1;
+				goto out_unlock;
+			}
+			iov_out[frag_idx].iov_base = knet_h->send_to_links_buf_crypt[frag_idx];
+			iov_out[frag_idx].iov_len = outlen;
+			frag_idx++;
+		}
+	}
+
+	if (!bcast) {
+		for (host_idx = 0; host_idx < dst_host_ids_entries; host_idx++) {
+			dst_host = knet_h->host_index[dst_host_ids[host_idx]];
+
+			err = _dispatch_to_links(knet_h, dst_host, iov_out);
+			savederrno = errno;
+			if (err) {
+				goto out_unlock;
+			}
+		}
+	} else {
+		for (dst_host = knet_h->host_head; dst_host != NULL; dst_host = dst_host->next) {
+			if (dst_host->status.reachable) {
+				err = _dispatch_to_links(knet_h, dst_host, iov_out);
+				savederrno = errno;
+				if (err) {
+					goto out_unlock;
+				}
+			}
+		}
+	}
+
+out_unlock:
+	errno = savederrno;
+	return err;
+}
+
+int knet_send_sync(knet_handle_t knet_h, const char *buff, const size_t buff_len, const int8_t channel)
+{
+	int savederrno = 0, err = 0;
+
+	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_TX, "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;
+	}
+
+	savederrno = pthread_mutex_lock(&knet_h->tx_mutex);
+	if (savederrno) {
+		log_err(knet_h, KNET_SUB_TX, "Unable to get TX mutex lock: %s",
+			strerror(savederrno));
+		err = -1;
+		goto out;
+	}
+
+	knet_h->recv_from_sock_buf[0]->kh_type = KNET_HEADER_TYPE_DATA;
+	memmove(knet_h->recv_from_sock_buf[0]->khp_data_userdata, buff, buff_len);
+	err = _parse_recv_from_sock(knet_h, 0, buff_len, channel, 1);
+	savederrno = errno;
+
+	pthread_mutex_unlock(&knet_h->tx_mutex);
+
+out:
+	pthread_rwlock_unlock(&knet_h->global_rwlock);
+
+	errno = savederrno;
+	return err;
+}
+
+static void _handle_send_to_links(knet_handle_t knet_h, int sockfd, int8_t channel, struct mmsghdr *msg, int type)
+{
+	ssize_t inlen = 0;
+	struct iovec iov_in;
+	int msg_recv, i;
+	int savederrno = 0, docallback = 0;
+
+	if ((channel >= 0) &&
+	    (channel < KNET_DATAFD_MAX) &&
+	    (!knet_h->sockfd[channel].is_socket)) {
+		memset(&iov_in, 0, sizeof(iov_in));
+		iov_in.iov_base = (void *)knet_h->recv_from_sock_buf[0]->khp_data_userdata;
+		iov_in.iov_len = KNET_MAX_PACKET_SIZE;
+
+		inlen = readv(sockfd, &iov_in, 1);
+
+		if (inlen <= 0) {
+			savederrno = errno;
+			docallback = 1;
+			goto out;
+		}
+
+		msg_recv = 1;
+		knet_h->recv_from_sock_buf[0]->kh_type = type;
+		_parse_recv_from_sock(knet_h, 0, inlen, channel, 0);
+	} else {
+		msg_recv = recvmmsg(sockfd, msg, PCKT_FRAG_MAX, MSG_DONTWAIT | MSG_NOSIGNAL, NULL);
+		if (msg_recv < 0) {
+			inlen = msg_recv;
+			savederrno = errno;
+			docallback = 1;
+			goto out;
+		}
+		for (i = 0; i < msg_recv; i++) {
+			inlen = msg[i].msg_len;
+			if (inlen  == 0) {
+				savederrno = 0;
+				docallback = 1;
+				goto out;
+				break;
+			}
+			knet_h->recv_from_sock_buf[i]->kh_type = type;
+			_parse_recv_from_sock(knet_h, i, inlen, channel, 0);
+		}
+	}
+
+out:
+	if (inlen < 0) {
+		struct epoll_event ev;
+
+		memset(&ev, 0, sizeof(struct epoll_event));
+
+		if (epoll_ctl(knet_h->send_to_links_epollfd,
+			      EPOLL_CTL_DEL, knet_h->sockfd[channel].sockfd[knet_h->sockfd[channel].is_created], &ev)) {
+			log_err(knet_h, KNET_SUB_TX, "Unable to del datafd %d from linkfd epoll pool: %s",
+				knet_h->sockfd[channel].sockfd[0], strerror(savederrno));
+		} else {
+			knet_h->sockfd[channel].has_error = 1;
+		}
+
+	}
+
+	if (docallback) {
+		knet_h->sock_notify_fn(knet_h->sock_notify_fn_private_data,
+				       knet_h->sockfd[channel].sockfd[0],
+				       channel,
+				       KNET_NOTIFY_TX,
+				       inlen,
+				       savederrno);
+	}
+}
+
+void *_handle_send_to_links_thread(void *data)
+{
+	knet_handle_t knet_h = (knet_handle_t) data;
+	struct epoll_event events[KNET_EPOLL_MAX_EVENTS];
+	struct sockaddr_storage address[PCKT_FRAG_MAX];
+	struct mmsghdr msg[PCKT_FRAG_MAX];
+	struct iovec iov_in[PCKT_FRAG_MAX];
+	int i, nev, type;
+	int8_t channel;
+
+	memset(&msg, 0, sizeof(struct mmsghdr));
+
+	/* preparing data buffer */
+	for (i = 0; i < PCKT_FRAG_MAX; i++) {
+		iov_in[i].iov_base = (void *)knet_h->recv_from_sock_buf[i]->khp_data_userdata;
+		iov_in[i].iov_len = KNET_MAX_PACKET_SIZE;
+
+		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;
+
+		knet_h->recv_from_sock_buf[i]->kh_version = KNET_HEADER_VERSION;
+		knet_h->recv_from_sock_buf[i]->khp_data_frag_seq = 0;
+		knet_h->recv_from_sock_buf[i]->kh_node = htons(knet_h->host_id);
+
+		knet_h->send_to_links_buf[i]->kh_version = KNET_HEADER_VERSION;
+		knet_h->send_to_links_buf[i]->khp_data_frag_seq = i + 1;
+		knet_h->send_to_links_buf[i]->kh_node = htons(knet_h->host_id);
+	}
+
+	while (!shutdown_in_progress(knet_h)) {
+		nev = epoll_wait(knet_h->send_to_links_epollfd, events, KNET_EPOLL_MAX_EVENTS + 1, -1);
+
+		if (pthread_rwlock_rdlock(&knet_h->global_rwlock) != 0) {
+			log_debug(knet_h, KNET_SUB_TX, "Unable to get read lock");
+			continue;
+		}
+
+		for (i = 0; i < nev; i++) {
+			if (events[i].data.fd == knet_h->hostsockfd[0]) {
+				type = KNET_HEADER_TYPE_HOST_INFO;
+				channel = -1;
+			} else {
+				type = KNET_HEADER_TYPE_DATA;
+				for (channel = 0; channel < KNET_DATAFD_MAX; channel++) {
+					if ((knet_h->sockfd[channel].in_use) &&
+					    (knet_h->sockfd[channel].sockfd[knet_h->sockfd[channel].is_created] == events[i].data.fd)) {
+						break;
+					}
+				}
+			}
+			if (pthread_mutex_lock(&knet_h->tx_mutex) != 0) {
+				log_debug(knet_h, KNET_SUB_TX, "Unable to get mutex lock");
+				continue;
+			}
+			_handle_send_to_links(knet_h, events[i].data.fd, channel, msg, type);
+			pthread_mutex_unlock(&knet_h->tx_mutex);
+		}
+		pthread_rwlock_unlock(&knet_h->global_rwlock);
+	}
+
+	return NULL;
+}
+
+/*
+ * 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) {
+		if (errno == ETIME) {
+			log_debug(knet_h, KNET_SUB_RX, "Defrag buffer expired");
+		}
+		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;
+	}
+
+	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 mmsghdr *msg)
+{
+	int err = 0, savederrno = 0;
+	ssize_t outlen;
+	struct knet_host *src_host;
+	struct knet_link *src_link;
+	unsigned long long latency_last;
+	uint16_t dst_host_ids[KNET_MAX_HOST];
+	size_t dst_host_ids_entries = 0;
+	int bcast = 1;
+	struct timespec recvtime;
+	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 knet_hostinfo *knet_hostinfo;
+	struct iovec iov_out[1];
+	int8_t channel;
+	struct sockaddr_storage pckt_src;
+	seq_num_t recv_seq_num;
+	int wipe_bufs = 0;
+
+	if (knet_h->crypto_instance) {
+		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");
+			return;
+		}
+		len = outlen;
+		inbuf = (struct knet_header *)knet_h->recv_from_links_buf_decrypt;
+	}
+
+	if (len < (KNET_HEADER_SIZE + 1)) {
+		log_debug(knet_h, KNET_SUB_RX, "Packet is too short: %ld", 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;
+	}
+
+	src_link = NULL;
+
+	if ((inbuf->kh_type & KNET_HEADER_TYPE_PMSK) != 0) {
+		src_link = src_host->link +
+				(inbuf->khp_ping_link % KNET_MAX_LINK);
+		if (src_link->dynamic == KNET_LINK_DYNIP) {
+			/*
+			 * cpyaddrport will only copy address and port of the incoming
+			 * packet and strip extra bits such as flow and scopeid
+			 */
+			cpyaddrport(&pckt_src, msg->msg_hdr.msg_name);
+
+			if (cmpaddr(&src_link->dst_addr, sockaddr_len(&src_link->dst_addr),
+				    &pckt_src, sockaddr_len(&pckt_src)) != 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, &pckt_src, sizeof(struct sockaddr_storage));
+				if (knet_addrtostr(&src_link->dst_addr, sockaddr_len(msg->msg_hdr.msg_name),
+						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
+			 */
+			knet_h->transport_ops[src_link->transport_type]->transport_link_dyn_connect(knet_h, sockfd, src_link);
+		}
+	}
+
+	switch (inbuf->kh_type) {
+	case KNET_HEADER_TYPE_HOST_INFO:
+	case KNET_HEADER_TYPE_DATA:
+		/*
+		 * TODO: should we accept data even if we can't reply to the other node?
+		 *       how would that work with SCTP and guaranteed delivery?
+		 */
+
+		if (!src_host->status.reachable) {
+			log_debug(knet_h, KNET_SUB_RX, "Source host %u not reachable yet", 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)) {
+			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)) {
+				return;
+			}
+			len = len + KNET_HEADER_DATA_SIZE;
+		}
+
+		if (inbuf->kh_type == KNET_HEADER_TYPE_DATA) {
+			if (knet_h->enabled != 1) /* data forward is disabled */
+				break;
+
+			if (knet_h->dst_host_filter_fn) {
+				int 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) {
+					log_debug(knet_h, KNET_SUB_RX, "Error from dst_host_filter_fn: %d", bcast);
+					return;
+				}
+
+				if ((!bcast) && (!dst_host_ids_entries)) {
+					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) {
+					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) {
+						log_debug(knet_h, KNET_SUB_RX, "Packet is not for us");
+						return;
+					}
+				}
+			}
+		}
+
+		if (inbuf->kh_type == KNET_HEADER_TYPE_DATA) {
+			if (!knet_h->sockfd[channel].in_use) {
+				log_debug(knet_h, KNET_SUB_RX,
+					  "received packet for channel %d but there is no local sock connected",
+					  channel);
+				return;
+			}
+
+			memset(iov_out, 0, sizeof(iov_out));
+			iov_out[0].iov_base = (void *) inbuf->khp_data_userdata;
+			iov_out[0].iov_len = len - KNET_HEADER_DATA_SIZE;
+
+			outlen = writev(knet_h->sockfd[channel].sockfd[knet_h->sockfd[channel].is_created], iov_out, 1);
+			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);
+				return;
+			}
+			if (outlen == iov_out[0].iov_len) {
+				_seq_num_set(src_host, inbuf->khp_data_seq_num, 0);
+			}
+		} else { /* HOSTINFO */
+			knet_hostinfo = (struct knet_hostinfo *)inbuf->khp_data_userdata;
+			if (knet_hostinfo->khi_bcast == KNET_HOSTINFO_UCAST) {
+				bcast = 0;
+				knet_hostinfo->khi_dst_node_id = ntohs(knet_hostinfo->khi_dst_node_id);
+			}
+			if (!_seq_num_lookup(src_host, inbuf->khp_data_seq_num, 0, 0)) {
+				return;
+			}
+			_seq_num_set(src_host, inbuf->khp_data_seq_num, 0);
+			switch(knet_hostinfo->khi_type) {
+				case KNET_HOSTINFO_TYPE_LINK_UP_DOWN:
+					break;
+				case KNET_HOSTINFO_TYPE_LINK_TABLE:
+					break;
+				default:
+					log_warn(knet_h, KNET_SUB_RX, "Receiving unknown host info message from host %u", src_host->host_id);
+					break;
+			}
+		}
+		break;
+	case KNET_HEADER_TYPE_PING:
+		outlen = KNET_HEADER_PING_SIZE;
+		inbuf->kh_type = KNET_HEADER_TYPE_PONG;
+		inbuf->kh_node = htons(knet_h->host_id);
+		recv_seq_num = ntohs(inbuf->khp_ping_seq_num);
+
+		wipe_bufs = 0;
+
+		if (!inbuf->khp_ping_timed) {
+			/*
+			 * we might be receiving this message from all links, but we want
+			 * to process it only the first time
+			 */
+			if (recv_seq_num != src_host->untimed_rx_seq_num) {
+				/*
+				 * cache the untimed seq num
+				 */
+				src_host->untimed_rx_seq_num = recv_seq_num;
+				/*
+				 * if the host has received data in between
+				 * untimed ping, then we don't need to wipe the bufs
+				 */
+				if (src_host->got_data) {
+					src_host->got_data = 0;
+					wipe_bufs = 0;
+				} else {
+					wipe_bufs = 1;
+				}
+			}
+			_seq_num_lookup(src_host, recv_seq_num, 0, wipe_bufs);
+		} else {
+			/*
+			 * pings always arrives in bursts over all the link
+			 * catch the first of them to cache the seq num and
+			 * avoid duplicate processing
+			 */
+			if (recv_seq_num != src_host->timed_rx_seq_num) {
+				src_host->timed_rx_seq_num = recv_seq_num;
+
+				if (recv_seq_num == 0) {
+					_seq_num_lookup(src_host, recv_seq_num, 0, 1);
+				}
+			}
+		}
+
+		if (knet_h->crypto_instance) {
+			if (crypto_encrypt_and_sign(knet_h,
+						    (const unsigned char *)inbuf,
+						    len,
+						    knet_h->recv_from_links_buf_crypt,
+						    &outlen) < 0) {
+				log_debug(knet_h, KNET_SUB_RX, "Unable to encrypt pong packet");
+				break;
+			}
+			outbuf = knet_h->recv_from_links_buf_crypt;
+		}
+
+retry_pong:
+		len = sendto(src_link->outsock, outbuf, outlen, MSG_DONTWAIT | MSG_NOSIGNAL,
+				(struct sockaddr *) &src_link->dst_addr,
+				sizeof(struct sockaddr_storage));
+		savederrno = errno;
+		if (len != outlen) {
+			err = knet_h->transport_ops[src_link->transport_type]->transport_tx_sock_error(knet_h, src_link->outsock, len, savederrno);
+			switch(err) {
+				case -1: /* unrecoverable error */
+					log_debug(knet_h, KNET_SUB_RX,
+						  "Unable to send pong 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);
+					break;
+				case 0: /* ignore error and continue */
+					break;
+				case 1: /* retry to send those same data */
+					goto retry_pong;
+					break;
+			}
+		}
+		break;
+	case KNET_HEADER_TYPE_PONG:
+		clock_gettime(CLOCK_MONOTONIC, &src_link->status.pong_last);
+
+		memmove(&recvtime, &inbuf->khp_ping_time[0], sizeof(struct timespec));
+		timespec_diff(recvtime,
+				src_link->status.pong_last, &latency_last);
+
+		src_link->status.latency =
+			((src_link->status.latency * src_link->latency_exp) +
+			((latency_last / 1000llu) *
+				(src_link->latency_fix - src_link->latency_exp))) /
+					src_link->latency_fix;
+
+		if (src_link->status.latency < src_link->pong_timeout) {
+			if (!src_link->status.connected) {
+				if (src_link->received_pong >= src_link->pong_count) {
+					log_info(knet_h, KNET_SUB_RX, "host: %u link: %u is up",
+						 src_host->host_id, src_link->link_id);
+					_link_updown(knet_h, src_host->host_id, src_link->link_id, src_link->status.enabled, 1);
+				} else {
+					src_link->received_pong++;
+					log_debug(knet_h, KNET_SUB_RX, "host: %u link: %u received pong: %u",
+						  src_host->host_id, src_link->link_id, src_link->received_pong);
+				}
+			}
+		}
+
+		break;
+	case KNET_HEADER_TYPE_PMTUD:
+		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_instance) {
+			if (crypto_encrypt_and_sign(knet_h,
+						    (const unsigned char *)inbuf,
+						    len,
+						    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;
+		}
+
+retry_pmtud:
+		len = sendto(src_link->outsock, outbuf, outlen, MSG_DONTWAIT | MSG_NOSIGNAL,
+				(struct sockaddr *) &src_link->dst_addr,
+				sizeof(struct sockaddr_storage));
+		if (len != outlen) {
+			err = knet_h->transport_ops[src_link->transport_type]->transport_tx_sock_error(knet_h, src_link->outsock, len, savederrno);
+			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);
+					break;
+				case 0: /* ignore error and continue */
+					break;
+				case 1: /* retry to send those same data */
+					goto retry_pmtud;
+					break;
+			}
+		}
+
+		break;
+	case KNET_HEADER_TYPE_PMTUD_REPLY:
+		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);
+		break;
+	default:
+		return;
+	}
+}
+
+static void _handle_recv_from_links(knet_handle_t knet_h, int sockfd, struct 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_FRAG_MAX; i++) {
+		msg[i].msg_hdr.msg_namelen = sizeof(struct sockaddr_storage);
+	}
+
+	msg_recv = recvmmsg(sockfd, msg, PCKT_FRAG_MAX, MSG_DONTWAIT | MSG_NOSIGNAL, NULL);
+	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) {
+		knet_h->transport_ops[transport]->transport_rx_sock_error(knet_h, sockfd, msg_recv, savederrno);
+		goto exit_unlock;
+	}
+
+	for (i = 0; i < msg_recv; i++) {
+		err = knet_h->transport_ops[transport]->transport_rx_is_data(knet_h, sockfd, &msg[i]);
+
+		/*
+		 * TODO: make this section silent once we are confident
+		 *       all protocols packet handlers are good
+		 */
+
+		switch(err) {
+			case -1: /* on error */
+				log_debug(knet_h, KNET_SUB_RX, "Transport reported error parsing packet");
+				goto exit_unlock;
+				break;
+			case 0: /* 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 1: /* 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 2: /* packet is data and should be parsed as such */
+				_parse_recv_from_links(knet_h, sockfd, &msg[i]);
+				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_FRAG_MAX];
+	struct mmsghdr msg[PCKT_FRAG_MAX];
+	struct iovec iov_in[PCKT_FRAG_MAX];
+
+	memset(&msg, 0, sizeof(msg));
+
+	for (i = 0; i < PCKT_FRAG_MAX; 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, -1);
+
+		for (i = 0; i < nev; i++) {
+			_handle_recv_from_links(knet_h, events[i].data.fd, msg);
+		}
+	}
+
+	return NULL;
+}
diff --git a/libknet/threads_rx.h b/libknet/threads_rx.h
new file mode 100644
index 00000000..fec6e5f1
--- /dev/null
+++ b/libknet/threads_rx.h
@@ -0,0 +1,16 @@
+/*
+ * Copyright (C) 2010-2015 Red Hat, Inc.  All rights reserved.
+ *
+ * Authors: Fabio M. Di Nitto <fabbione@kronosnet.org>
+ *          Federico Simoncelli <fsimon@kronosnet.org>
+ *
+ * This software licensed under GPL-2.0+, LGPL-2.0+
+ */
+
+#ifndef __THREADS_SEND_RECV_H__
+#define __THREADS_SEND_RECV_H__
+
+void *_handle_send_to_links_thread(void *data);
+void *_handle_recv_from_links_thread(void *data);
+
+#endif
diff --git a/libknet/threads_tx.c b/libknet/threads_tx.c
new file mode 100644
index 00000000..37375346
--- /dev/null
+++ b/libknet/threads_tx.c
@@ -0,0 +1,1302 @@
+/*
+ * Copyright (C) 2010-2015 Red Hat, Inc.  All rights reserved.
+ *
+ * Authors: Fabio M. Di Nitto <fabbione@kronosnet.org>
+ *          Federico Simoncelli <fsimon@kronosnet.org>
+ *
+ * This software licensed under GPL-2.0+, LGPL-2.0+
+ */
+
+#include "config.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <pthread.h>
+#include <math.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+#include <sys/uio.h>
+
+#include "crypto.h"
+#include "compat.h"
+#include "host.h"
+#include "link.h"
+#include "logging.h"
+#include "transports.h"
+#include "threads_common.h"
+#include "threads_heartbeat.h"
+#include "threads_send_recv.h"
+#include "netutils.h"
+
+/*
+ * SEND
+ */
+
+static int _dispatch_to_links(knet_handle_t knet_h, struct knet_host *dst_host, struct iovec *iov_out)
+{
+	int link_idx, msg_idx, sent_msgs, msgs_to_send, prev_sent, progress;
+	struct mmsghdr msg[PCKT_FRAG_MAX];
+	int err = 0, savederrno = 0;
+
+	memset(&msg, 0, sizeof(struct mmsghdr));
+
+	for (link_idx = 0; link_idx < dst_host->active_link_entries; link_idx++) {
+
+		msgs_to_send = knet_h->send_to_links_buf[0]->khp_data_frag_num;
+		sent_msgs = 0;
+		prev_sent = 0;
+		progress = 1;
+
+retry:
+		msg_idx = 0;
+
+		while (msg_idx < msgs_to_send) {
+			memset(&msg[msg_idx].msg_hdr, 0, sizeof(struct msghdr));
+			msg[msg_idx].msg_hdr.msg_name = &dst_host->link[dst_host->active_links[link_idx]].dst_addr;
+			msg[msg_idx].msg_hdr.msg_namelen = sizeof(struct sockaddr_storage);
+			msg[msg_idx].msg_hdr.msg_iov = &iov_out[msg_idx + prev_sent];
+			msg[msg_idx].msg_hdr.msg_iovlen = 1;
+			msg_idx++;
+		}
+
+		sent_msgs = sendmmsg(dst_host->link[dst_host->active_links[link_idx]].outsock,
+				     msg, msg_idx, MSG_DONTWAIT | MSG_NOSIGNAL);
+		savederrno = errno;
+
+		err = knet_h->transport_ops[dst_host->link[dst_host->active_links[link_idx]].transport_type]->transport_tx_sock_error(knet_h, dst_host->link[dst_host->active_links[link_idx]].outsock, sent_msgs, savederrno);
+		switch(err) {
+			case -1: /* unrecoverable error */
+				goto out_unlock;
+				break;
+			case 0: /* ignore error and continue */
+				break;
+			case 1: /* retry to send those same data */
+				goto retry;
+				break;
+		}
+
+		if ((sent_msgs >= 0) && (sent_msgs < msg_idx)) {
+			if ((sent_msgs) || (progress)) {
+				msgs_to_send = msg_idx - sent_msgs;
+				prev_sent = prev_sent + sent_msgs;
+				if (sent_msgs) {
+					progress = 1;
+				} else {
+					progress = 0;
+				}
+				log_debug(knet_h, KNET_SUB_TX, "Unable to send all (%d/%d) data packets to host %s (%u) link %s:%s (%u)",
+					  sent_msgs, msg_idx,
+					  dst_host->name, dst_host->host_id,
+					  dst_host->link[dst_host->active_links[link_idx]].status.dst_ipaddr,
+					  dst_host->link[dst_host->active_links[link_idx]].status.dst_port,
+					  dst_host->link[dst_host->active_links[link_idx]].link_id);
+				goto retry;
+			}
+			if (!progress) {
+				savederrno = EAGAIN;
+				err = -1;
+				goto out_unlock;
+			}
+		}
+
+		if ((dst_host->link_handler_policy == KNET_LINK_POLICY_RR) &&
+		    (dst_host->active_link_entries > 1)) {
+			uint8_t cur_link_id = dst_host->active_links[0];
+
+			memmove(&dst_host->active_links[0], &dst_host->active_links[1], KNET_MAX_LINK - 1);
+			dst_host->active_links[dst_host->active_link_entries - 1] = cur_link_id;
+
+			break;
+		}
+	}
+
+out_unlock:
+	errno = savederrno;
+	return err;
+}
+
+static int _parse_recv_from_sock(knet_handle_t knet_h, int buf_idx, ssize_t inlen, int8_t channel, int is_sync)
+{
+	ssize_t outlen, frag_len;
+	struct knet_host *dst_host;
+	uint16_t dst_host_ids_temp[KNET_MAX_HOST];
+	size_t dst_host_ids_entries_temp = 0;
+	uint16_t dst_host_ids[KNET_MAX_HOST];
+	size_t dst_host_ids_entries = 0;
+	int bcast = 1;
+	struct knet_hostinfo *knet_hostinfo;
+	struct iovec iov_out[PCKT_FRAG_MAX];
+	uint8_t frag_idx;
+	unsigned int temp_data_mtu;
+	int host_idx;
+	int send_mcast = 0;
+	struct knet_header *inbuf;
+	int savederrno = 0;
+	int err = 0;
+	seq_num_t tx_seq_num;
+
+	inbuf = knet_h->recv_from_sock_buf[buf_idx];
+
+	if ((knet_h->enabled != 1) &&
+	    (inbuf->kh_type != KNET_HEADER_TYPE_HOST_INFO)) { /* data forward is disabled */
+		log_debug(knet_h, KNET_SUB_TX, "Received data packet but forwarding is disabled");
+		savederrno = ECANCELED;
+		err = -1;
+		goto out_unlock;
+	}
+
+	/*
+	 * move this into a separate function to expand on
+	 * extra switching rules
+	 */
+	switch(inbuf->kh_type) {
+		case KNET_HEADER_TYPE_DATA:
+			if (knet_h->dst_host_filter_fn) {
+				bcast = knet_h->dst_host_filter_fn(
+						knet_h->dst_host_filter_fn_private_data,
+						(const unsigned char *)inbuf->khp_data_userdata,
+						inlen,
+						KNET_NOTIFY_TX,
+						knet_h->host_id,
+						knet_h->host_id,
+						&channel,
+						dst_host_ids_temp,
+						&dst_host_ids_entries_temp);
+				if (bcast < 0) {
+					log_debug(knet_h, KNET_SUB_TX, "Error from dst_host_filter_fn: %d", bcast);
+					savederrno = EFAULT;
+					err = -1;
+					goto out_unlock;
+				}
+
+				if ((!bcast) && (!dst_host_ids_entries_temp)) {
+					log_debug(knet_h, KNET_SUB_TX, "Message is unicast but no dst_host_ids_entries");
+					savederrno = EINVAL;
+					err = -1;
+					goto out_unlock;
+				}
+			}
+			break;
+		case KNET_HEADER_TYPE_HOST_INFO:
+			knet_hostinfo = (struct knet_hostinfo *)inbuf->khp_data_userdata;
+			if (knet_hostinfo->khi_bcast == KNET_HOSTINFO_UCAST) {
+				bcast = 0;
+				dst_host_ids_temp[0] = knet_hostinfo->khi_dst_node_id;
+				dst_host_ids_entries_temp = 1;
+				knet_hostinfo->khi_dst_node_id = htons(knet_hostinfo->khi_dst_node_id);
+			}
+			break;
+		default:
+			log_warn(knet_h, KNET_SUB_TX, "Receiving unknown messages from socket");
+			savederrno = ENOMSG;
+			err = -1;
+			goto out_unlock;
+			break;
+	}
+
+	if (is_sync) {
+		if ((bcast) ||
+		    ((!bcast) && (dst_host_ids_entries_temp > 1))) {
+			log_debug(knet_h, KNET_SUB_TX, "knet_send_sync is only supported with unicast packets for one destination");
+			savederrno = E2BIG;
+			err = -1;
+			goto out_unlock;
+		}
+	}
+
+	/*
+	 * check destinations hosts before spending time
+	 * in fragmenting/encrypting packets to save
+	 * time processing data for unrechable hosts.
+	 * for unicast, also remap the destination data
+	 * to skip unreachable hosts.
+	 */
+
+	if (!bcast) {
+		dst_host_ids_entries = 0;
+		for (host_idx = 0; host_idx < dst_host_ids_entries_temp; host_idx++) {
+			dst_host = knet_h->host_index[dst_host_ids_temp[host_idx]];
+			if (!dst_host) {
+				continue;
+			}
+			if (dst_host->status.reachable) {
+				dst_host_ids[dst_host_ids_entries] = dst_host_ids_temp[host_idx];
+				dst_host_ids_entries++;
+			}
+		}
+		if (!dst_host_ids_entries) {
+			savederrno = EHOSTDOWN;
+			err = -1;
+			goto out_unlock;
+		}
+	} else {
+		send_mcast = 0;
+		for (dst_host = knet_h->host_head; dst_host != NULL; dst_host = dst_host->next) {
+			if (dst_host->status.reachable) {
+				send_mcast = 1;
+				break;
+			}
+		}
+		if (!send_mcast) {
+			savederrno = EHOSTDOWN;
+			err = -1;
+			goto out_unlock;
+		}
+	}
+
+	if (!knet_h->data_mtu) {
+		/*
+		 * using MIN_MTU_V4 for data mtu is not completely accurate but safe enough
+		 */
+		log_debug(knet_h, KNET_SUB_TX,
+			  "Received data packet but data MTU is still unknown."
+			  " Packet might not be delivered."
+			  " Assuming mininum IPv4 mtu (%d)",
+			  KNET_PMTUD_MIN_MTU_V4);
+		temp_data_mtu = KNET_PMTUD_MIN_MTU_V4;
+	} else {
+		/*
+		 * take a copy of the mtu to avoid value changing under
+		 * our feet while we are sending a fragmented pckt
+		 */
+		temp_data_mtu = knet_h->data_mtu;
+	}
+
+	/*
+	 * prepare the outgoing buffers
+	 */
+
+	frag_len = inlen;
+	frag_idx = 0;
+
+	inbuf->khp_data_bcast = bcast;
+	inbuf->khp_data_frag_num = ceil((float)inlen / temp_data_mtu);
+	inbuf->khp_data_channel = channel;
+
+	if (pthread_mutex_lock(&knet_h->tx_seq_num_mutex)) {
+		log_debug(knet_h, KNET_SUB_TX, "Unable to get seq mutex lock");
+		goto out_unlock;
+	}
+	knet_h->tx_seq_num++;
+	/*
+	 * force seq_num 0 to detect a node that has crashed and rejoining
+	 * the knet instance. seq_num 0 will clear the buffers in the RX
+	 * thread
+	 */
+	if (knet_h->tx_seq_num == 0) {
+		knet_h->tx_seq_num++;
+	}
+	/*
+	 * cache the value in locked context
+	 */
+	tx_seq_num = knet_h->tx_seq_num;
+	knet_h->send_to_links_buf[0]->khp_data_seq_num = htons(knet_h->tx_seq_num);
+	pthread_mutex_unlock(&knet_h->tx_seq_num_mutex);
+
+	/*
+	 * forcefully broadcast a ping to all nodes every SEQ_MAX / 8
+	 * pckts.
+	 * this solves 2 problems:
+	 * 1) on TX socket overloads we generate extra pings to keep links alive
+	 * 2) in 3+ nodes setup, where all the traffic is flowing between node 1 and 2,
+	 *    node 3+ will be able to keep in sync on the TX seq_num even without
+	 *    receiving traffic or pings in betweens. This avoids issues with
+	 *    rollover of the circular buffer
+	 */
+
+	if (tx_seq_num % (SEQ_MAX / 8) == 0) {
+		_send_pings(knet_h, 0);
+	}
+
+	while (frag_idx < inbuf->khp_data_frag_num) {
+		/*
+		 * set the iov_base
+		 */
+		iov_out[frag_idx].iov_base = (void *)knet_h->send_to_links_buf[frag_idx];
+
+		/*
+		 * set the len
+		 */
+		if (frag_len > temp_data_mtu) {
+			iov_out[frag_idx].iov_len = temp_data_mtu + KNET_HEADER_DATA_SIZE;
+		} else {
+			iov_out[frag_idx].iov_len = frag_len + KNET_HEADER_DATA_SIZE;
+		}
+
+		/*
+		 * copy the frag info on all buffers
+		 */
+		knet_h->send_to_links_buf[frag_idx]->kh_type = inbuf->kh_type;
+
+		knet_h->send_to_links_buf[frag_idx]->khp_data_seq_num = knet_h->send_to_links_buf[0]->khp_data_seq_num;
+		knet_h->send_to_links_buf[frag_idx]->khp_data_frag_num = inbuf->khp_data_frag_num;
+		knet_h->send_to_links_buf[frag_idx]->khp_data_bcast = inbuf->khp_data_bcast;
+		knet_h->send_to_links_buf[frag_idx]->khp_data_channel = inbuf->khp_data_channel;
+
+		memmove(knet_h->send_to_links_buf[frag_idx]->khp_data_userdata,
+			inbuf->khp_data_userdata + (temp_data_mtu * frag_idx),
+			iov_out[frag_idx].iov_len - KNET_HEADER_DATA_SIZE);
+
+		frag_len = frag_len - temp_data_mtu;
+		frag_idx++;
+	}
+
+	if (knet_h->crypto_instance) {
+		frag_idx = 0;
+		while (frag_idx < knet_h->send_to_links_buf[0]->khp_data_frag_num) {
+			if (crypto_encrypt_and_sign(
+					knet_h,
+					(const unsigned char *)knet_h->send_to_links_buf[frag_idx],
+					iov_out[frag_idx].iov_len,
+					knet_h->send_to_links_buf_crypt[frag_idx],
+					&outlen) < 0) {
+				log_debug(knet_h, KNET_SUB_TX, "Unable to encrypt unicast packet");
+				savederrno = ECHILD;
+				err = -1;
+				goto out_unlock;
+			}
+			iov_out[frag_idx].iov_base = knet_h->send_to_links_buf_crypt[frag_idx];
+			iov_out[frag_idx].iov_len = outlen;
+			frag_idx++;
+		}
+	}
+
+	if (!bcast) {
+		for (host_idx = 0; host_idx < dst_host_ids_entries; host_idx++) {
+			dst_host = knet_h->host_index[dst_host_ids[host_idx]];
+
+			err = _dispatch_to_links(knet_h, dst_host, iov_out);
+			savederrno = errno;
+			if (err) {
+				goto out_unlock;
+			}
+		}
+	} else {
+		for (dst_host = knet_h->host_head; dst_host != NULL; dst_host = dst_host->next) {
+			if (dst_host->status.reachable) {
+				err = _dispatch_to_links(knet_h, dst_host, iov_out);
+				savederrno = errno;
+				if (err) {
+					goto out_unlock;
+				}
+			}
+		}
+	}
+
+out_unlock:
+	errno = savederrno;
+	return err;
+}
+
+int knet_send_sync(knet_handle_t knet_h, const char *buff, const size_t buff_len, const int8_t channel)
+{
+	int savederrno = 0, err = 0;
+
+	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_TX, "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;
+	}
+
+	savederrno = pthread_mutex_lock(&knet_h->tx_mutex);
+	if (savederrno) {
+		log_err(knet_h, KNET_SUB_TX, "Unable to get TX mutex lock: %s",
+			strerror(savederrno));
+		err = -1;
+		goto out;
+	}
+
+	knet_h->recv_from_sock_buf[0]->kh_type = KNET_HEADER_TYPE_DATA;
+	memmove(knet_h->recv_from_sock_buf[0]->khp_data_userdata, buff, buff_len);
+	err = _parse_recv_from_sock(knet_h, 0, buff_len, channel, 1);
+	savederrno = errno;
+
+	pthread_mutex_unlock(&knet_h->tx_mutex);
+
+out:
+	pthread_rwlock_unlock(&knet_h->global_rwlock);
+
+	errno = savederrno;
+	return err;
+}
+
+static void _handle_send_to_links(knet_handle_t knet_h, int sockfd, int8_t channel, struct mmsghdr *msg, int type)
+{
+	ssize_t inlen = 0;
+	struct iovec iov_in;
+	int msg_recv, i;
+	int savederrno = 0, docallback = 0;
+
+	if ((channel >= 0) &&
+	    (channel < KNET_DATAFD_MAX) &&
+	    (!knet_h->sockfd[channel].is_socket)) {
+		memset(&iov_in, 0, sizeof(iov_in));
+		iov_in.iov_base = (void *)knet_h->recv_from_sock_buf[0]->khp_data_userdata;
+		iov_in.iov_len = KNET_MAX_PACKET_SIZE;
+
+		inlen = readv(sockfd, &iov_in, 1);
+
+		if (inlen <= 0) {
+			savederrno = errno;
+			docallback = 1;
+			goto out;
+		}
+
+		msg_recv = 1;
+		knet_h->recv_from_sock_buf[0]->kh_type = type;
+		_parse_recv_from_sock(knet_h, 0, inlen, channel, 0);
+	} else {
+		msg_recv = recvmmsg(sockfd, msg, PCKT_FRAG_MAX, MSG_DONTWAIT | MSG_NOSIGNAL, NULL);
+		if (msg_recv < 0) {
+			inlen = msg_recv;
+			savederrno = errno;
+			docallback = 1;
+			goto out;
+		}
+		for (i = 0; i < msg_recv; i++) {
+			inlen = msg[i].msg_len;
+			if (inlen  == 0) {
+				savederrno = 0;
+				docallback = 1;
+				goto out;
+				break;
+			}
+			knet_h->recv_from_sock_buf[i]->kh_type = type;
+			_parse_recv_from_sock(knet_h, i, inlen, channel, 0);
+		}
+	}
+
+out:
+	if (inlen < 0) {
+		struct epoll_event ev;
+
+		memset(&ev, 0, sizeof(struct epoll_event));
+
+		if (epoll_ctl(knet_h->send_to_links_epollfd,
+			      EPOLL_CTL_DEL, knet_h->sockfd[channel].sockfd[knet_h->sockfd[channel].is_created], &ev)) {
+			log_err(knet_h, KNET_SUB_TX, "Unable to del datafd %d from linkfd epoll pool: %s",
+				knet_h->sockfd[channel].sockfd[0], strerror(savederrno));
+		} else {
+			knet_h->sockfd[channel].has_error = 1;
+		}
+
+	}
+
+	if (docallback) {
+		knet_h->sock_notify_fn(knet_h->sock_notify_fn_private_data,
+				       knet_h->sockfd[channel].sockfd[0],
+				       channel,
+				       KNET_NOTIFY_TX,
+				       inlen,
+				       savederrno);
+	}
+}
+
+void *_handle_send_to_links_thread(void *data)
+{
+	knet_handle_t knet_h = (knet_handle_t) data;
+	struct epoll_event events[KNET_EPOLL_MAX_EVENTS];
+	struct sockaddr_storage address[PCKT_FRAG_MAX];
+	struct mmsghdr msg[PCKT_FRAG_MAX];
+	struct iovec iov_in[PCKT_FRAG_MAX];
+	int i, nev, type;
+	int8_t channel;
+
+	memset(&msg, 0, sizeof(struct mmsghdr));
+
+	/* preparing data buffer */
+	for (i = 0; i < PCKT_FRAG_MAX; i++) {
+		iov_in[i].iov_base = (void *)knet_h->recv_from_sock_buf[i]->khp_data_userdata;
+		iov_in[i].iov_len = KNET_MAX_PACKET_SIZE;
+
+		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;
+
+		knet_h->recv_from_sock_buf[i]->kh_version = KNET_HEADER_VERSION;
+		knet_h->recv_from_sock_buf[i]->khp_data_frag_seq = 0;
+		knet_h->recv_from_sock_buf[i]->kh_node = htons(knet_h->host_id);
+
+		knet_h->send_to_links_buf[i]->kh_version = KNET_HEADER_VERSION;
+		knet_h->send_to_links_buf[i]->khp_data_frag_seq = i + 1;
+		knet_h->send_to_links_buf[i]->kh_node = htons(knet_h->host_id);
+	}
+
+	while (!shutdown_in_progress(knet_h)) {
+		nev = epoll_wait(knet_h->send_to_links_epollfd, events, KNET_EPOLL_MAX_EVENTS + 1, -1);
+
+		if (pthread_rwlock_rdlock(&knet_h->global_rwlock) != 0) {
+			log_debug(knet_h, KNET_SUB_TX, "Unable to get read lock");
+			continue;
+		}
+
+		for (i = 0; i < nev; i++) {
+			if (events[i].data.fd == knet_h->hostsockfd[0]) {
+				type = KNET_HEADER_TYPE_HOST_INFO;
+				channel = -1;
+			} else {
+				type = KNET_HEADER_TYPE_DATA;
+				for (channel = 0; channel < KNET_DATAFD_MAX; channel++) {
+					if ((knet_h->sockfd[channel].in_use) &&
+					    (knet_h->sockfd[channel].sockfd[knet_h->sockfd[channel].is_created] == events[i].data.fd)) {
+						break;
+					}
+				}
+			}
+			if (pthread_mutex_lock(&knet_h->tx_mutex) != 0) {
+				log_debug(knet_h, KNET_SUB_TX, "Unable to get mutex lock");
+				continue;
+			}
+			_handle_send_to_links(knet_h, events[i].data.fd, channel, msg, type);
+			pthread_mutex_unlock(&knet_h->tx_mutex);
+		}
+		pthread_rwlock_unlock(&knet_h->global_rwlock);
+	}
+
+	return NULL;
+}
+
+/*
+ * 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) {
+		if (errno == ETIME) {
+			log_debug(knet_h, KNET_SUB_RX, "Defrag buffer expired");
+		}
+		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;
+	}
+
+	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 mmsghdr *msg)
+{
+	int err = 0, savederrno = 0;
+	ssize_t outlen;
+	struct knet_host *src_host;
+	struct knet_link *src_link;
+	unsigned long long latency_last;
+	uint16_t dst_host_ids[KNET_MAX_HOST];
+	size_t dst_host_ids_entries = 0;
+	int bcast = 1;
+	struct timespec recvtime;
+	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 knet_hostinfo *knet_hostinfo;
+	struct iovec iov_out[1];
+	int8_t channel;
+	struct sockaddr_storage pckt_src;
+	seq_num_t recv_seq_num;
+	int wipe_bufs = 0;
+
+	if (knet_h->crypto_instance) {
+		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");
+			return;
+		}
+		len = outlen;
+		inbuf = (struct knet_header *)knet_h->recv_from_links_buf_decrypt;
+	}
+
+	if (len < (KNET_HEADER_SIZE + 1)) {
+		log_debug(knet_h, KNET_SUB_RX, "Packet is too short: %ld", 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;
+	}
+
+	src_link = NULL;
+
+	if ((inbuf->kh_type & KNET_HEADER_TYPE_PMSK) != 0) {
+		src_link = src_host->link +
+				(inbuf->khp_ping_link % KNET_MAX_LINK);
+		if (src_link->dynamic == KNET_LINK_DYNIP) {
+			/*
+			 * cpyaddrport will only copy address and port of the incoming
+			 * packet and strip extra bits such as flow and scopeid
+			 */
+			cpyaddrport(&pckt_src, msg->msg_hdr.msg_name);
+
+			if (cmpaddr(&src_link->dst_addr, sockaddr_len(&src_link->dst_addr),
+				    &pckt_src, sockaddr_len(&pckt_src)) != 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, &pckt_src, sizeof(struct sockaddr_storage));
+				if (knet_addrtostr(&src_link->dst_addr, sockaddr_len(msg->msg_hdr.msg_name),
+						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
+			 */
+			knet_h->transport_ops[src_link->transport_type]->transport_link_dyn_connect(knet_h, sockfd, src_link);
+		}
+	}
+
+	switch (inbuf->kh_type) {
+	case KNET_HEADER_TYPE_HOST_INFO:
+	case KNET_HEADER_TYPE_DATA:
+		/*
+		 * TODO: should we accept data even if we can't reply to the other node?
+		 *       how would that work with SCTP and guaranteed delivery?
+		 */
+
+		if (!src_host->status.reachable) {
+			log_debug(knet_h, KNET_SUB_RX, "Source host %u not reachable yet", 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)) {
+			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)) {
+				return;
+			}
+			len = len + KNET_HEADER_DATA_SIZE;
+		}
+
+		if (inbuf->kh_type == KNET_HEADER_TYPE_DATA) {
+			if (knet_h->enabled != 1) /* data forward is disabled */
+				break;
+
+			if (knet_h->dst_host_filter_fn) {
+				int 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) {
+					log_debug(knet_h, KNET_SUB_RX, "Error from dst_host_filter_fn: %d", bcast);
+					return;
+				}
+
+				if ((!bcast) && (!dst_host_ids_entries)) {
+					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) {
+					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) {
+						log_debug(knet_h, KNET_SUB_RX, "Packet is not for us");
+						return;
+					}
+				}
+			}
+		}
+
+		if (inbuf->kh_type == KNET_HEADER_TYPE_DATA) {
+			if (!knet_h->sockfd[channel].in_use) {
+				log_debug(knet_h, KNET_SUB_RX,
+					  "received packet for channel %d but there is no local sock connected",
+					  channel);
+				return;
+			}
+
+			memset(iov_out, 0, sizeof(iov_out));
+			iov_out[0].iov_base = (void *) inbuf->khp_data_userdata;
+			iov_out[0].iov_len = len - KNET_HEADER_DATA_SIZE;
+
+			outlen = writev(knet_h->sockfd[channel].sockfd[knet_h->sockfd[channel].is_created], iov_out, 1);
+			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);
+				return;
+			}
+			if (outlen == iov_out[0].iov_len) {
+				_seq_num_set(src_host, inbuf->khp_data_seq_num, 0);
+			}
+		} else { /* HOSTINFO */
+			knet_hostinfo = (struct knet_hostinfo *)inbuf->khp_data_userdata;
+			if (knet_hostinfo->khi_bcast == KNET_HOSTINFO_UCAST) {
+				bcast = 0;
+				knet_hostinfo->khi_dst_node_id = ntohs(knet_hostinfo->khi_dst_node_id);
+			}
+			if (!_seq_num_lookup(src_host, inbuf->khp_data_seq_num, 0, 0)) {
+				return;
+			}
+			_seq_num_set(src_host, inbuf->khp_data_seq_num, 0);
+			switch(knet_hostinfo->khi_type) {
+				case KNET_HOSTINFO_TYPE_LINK_UP_DOWN:
+					break;
+				case KNET_HOSTINFO_TYPE_LINK_TABLE:
+					break;
+				default:
+					log_warn(knet_h, KNET_SUB_RX, "Receiving unknown host info message from host %u", src_host->host_id);
+					break;
+			}
+		}
+		break;
+	case KNET_HEADER_TYPE_PING:
+		outlen = KNET_HEADER_PING_SIZE;
+		inbuf->kh_type = KNET_HEADER_TYPE_PONG;
+		inbuf->kh_node = htons(knet_h->host_id);
+		recv_seq_num = ntohs(inbuf->khp_ping_seq_num);
+
+		wipe_bufs = 0;
+
+		if (!inbuf->khp_ping_timed) {
+			/*
+			 * we might be receiving this message from all links, but we want
+			 * to process it only the first time
+			 */
+			if (recv_seq_num != src_host->untimed_rx_seq_num) {
+				/*
+				 * cache the untimed seq num
+				 */
+				src_host->untimed_rx_seq_num = recv_seq_num;
+				/*
+				 * if the host has received data in between
+				 * untimed ping, then we don't need to wipe the bufs
+				 */
+				if (src_host->got_data) {
+					src_host->got_data = 0;
+					wipe_bufs = 0;
+				} else {
+					wipe_bufs = 1;
+				}
+			}
+			_seq_num_lookup(src_host, recv_seq_num, 0, wipe_bufs);
+		} else {
+			/*
+			 * pings always arrives in bursts over all the link
+			 * catch the first of them to cache the seq num and
+			 * avoid duplicate processing
+			 */
+			if (recv_seq_num != src_host->timed_rx_seq_num) {
+				src_host->timed_rx_seq_num = recv_seq_num;
+
+				if (recv_seq_num == 0) {
+					_seq_num_lookup(src_host, recv_seq_num, 0, 1);
+				}
+			}
+		}
+
+		if (knet_h->crypto_instance) {
+			if (crypto_encrypt_and_sign(knet_h,
+						    (const unsigned char *)inbuf,
+						    len,
+						    knet_h->recv_from_links_buf_crypt,
+						    &outlen) < 0) {
+				log_debug(knet_h, KNET_SUB_RX, "Unable to encrypt pong packet");
+				break;
+			}
+			outbuf = knet_h->recv_from_links_buf_crypt;
+		}
+
+retry_pong:
+		len = sendto(src_link->outsock, outbuf, outlen, MSG_DONTWAIT | MSG_NOSIGNAL,
+				(struct sockaddr *) &src_link->dst_addr,
+				sizeof(struct sockaddr_storage));
+		savederrno = errno;
+		if (len != outlen) {
+			err = knet_h->transport_ops[src_link->transport_type]->transport_tx_sock_error(knet_h, src_link->outsock, len, savederrno);
+			switch(err) {
+				case -1: /* unrecoverable error */
+					log_debug(knet_h, KNET_SUB_RX,
+						  "Unable to send pong 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);
+					break;
+				case 0: /* ignore error and continue */
+					break;
+				case 1: /* retry to send those same data */
+					goto retry_pong;
+					break;
+			}
+		}
+		break;
+	case KNET_HEADER_TYPE_PONG:
+		clock_gettime(CLOCK_MONOTONIC, &src_link->status.pong_last);
+
+		memmove(&recvtime, &inbuf->khp_ping_time[0], sizeof(struct timespec));
+		timespec_diff(recvtime,
+				src_link->status.pong_last, &latency_last);
+
+		src_link->status.latency =
+			((src_link->status.latency * src_link->latency_exp) +
+			((latency_last / 1000llu) *
+				(src_link->latency_fix - src_link->latency_exp))) /
+					src_link->latency_fix;
+
+		if (src_link->status.latency < src_link->pong_timeout) {
+			if (!src_link->status.connected) {
+				if (src_link->received_pong >= src_link->pong_count) {
+					log_info(knet_h, KNET_SUB_RX, "host: %u link: %u is up",
+						 src_host->host_id, src_link->link_id);
+					_link_updown(knet_h, src_host->host_id, src_link->link_id, src_link->status.enabled, 1);
+				} else {
+					src_link->received_pong++;
+					log_debug(knet_h, KNET_SUB_RX, "host: %u link: %u received pong: %u",
+						  src_host->host_id, src_link->link_id, src_link->received_pong);
+				}
+			}
+		}
+
+		break;
+	case KNET_HEADER_TYPE_PMTUD:
+		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_instance) {
+			if (crypto_encrypt_and_sign(knet_h,
+						    (const unsigned char *)inbuf,
+						    len,
+						    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;
+		}
+
+retry_pmtud:
+		len = sendto(src_link->outsock, outbuf, outlen, MSG_DONTWAIT | MSG_NOSIGNAL,
+				(struct sockaddr *) &src_link->dst_addr,
+				sizeof(struct sockaddr_storage));
+		if (len != outlen) {
+			err = knet_h->transport_ops[src_link->transport_type]->transport_tx_sock_error(knet_h, src_link->outsock, len, savederrno);
+			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);
+					break;
+				case 0: /* ignore error and continue */
+					break;
+				case 1: /* retry to send those same data */
+					goto retry_pmtud;
+					break;
+			}
+		}
+
+		break;
+	case KNET_HEADER_TYPE_PMTUD_REPLY:
+		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);
+		break;
+	default:
+		return;
+	}
+}
+
+static void _handle_recv_from_links(knet_handle_t knet_h, int sockfd, struct 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_FRAG_MAX; i++) {
+		msg[i].msg_hdr.msg_namelen = sizeof(struct sockaddr_storage);
+	}
+
+	msg_recv = recvmmsg(sockfd, msg, PCKT_FRAG_MAX, MSG_DONTWAIT | MSG_NOSIGNAL, NULL);
+	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) {
+		knet_h->transport_ops[transport]->transport_rx_sock_error(knet_h, sockfd, msg_recv, savederrno);
+		goto exit_unlock;
+	}
+
+	for (i = 0; i < msg_recv; i++) {
+		err = knet_h->transport_ops[transport]->transport_rx_is_data(knet_h, sockfd, &msg[i]);
+
+		/*
+		 * TODO: make this section silent once we are confident
+		 *       all protocols packet handlers are good
+		 */
+
+		switch(err) {
+			case -1: /* on error */
+				log_debug(knet_h, KNET_SUB_RX, "Transport reported error parsing packet");
+				goto exit_unlock;
+				break;
+			case 0: /* 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 1: /* 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 2: /* packet is data and should be parsed as such */
+				_parse_recv_from_links(knet_h, sockfd, &msg[i]);
+				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_FRAG_MAX];
+	struct mmsghdr msg[PCKT_FRAG_MAX];
+	struct iovec iov_in[PCKT_FRAG_MAX];
+
+	memset(&msg, 0, sizeof(msg));
+
+	for (i = 0; i < PCKT_FRAG_MAX; 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, -1);
+
+		for (i = 0; i < nev; i++) {
+			_handle_recv_from_links(knet_h, events[i].data.fd, msg);
+		}
+	}
+
+	return NULL;
+}
diff --git a/libknet/threads_tx.h b/libknet/threads_tx.h
new file mode 100644
index 00000000..fec6e5f1
--- /dev/null
+++ b/libknet/threads_tx.h
@@ -0,0 +1,16 @@
+/*
+ * Copyright (C) 2010-2015 Red Hat, Inc.  All rights reserved.
+ *
+ * Authors: Fabio M. Di Nitto <fabbione@kronosnet.org>
+ *          Federico Simoncelli <fsimon@kronosnet.org>
+ *
+ * This software licensed under GPL-2.0+, LGPL-2.0+
+ */
+
+#ifndef __THREADS_SEND_RECV_H__
+#define __THREADS_SEND_RECV_H__
+
+void *_handle_send_to_links_thread(void *data);
+void *_handle_recv_from_links_thread(void *data);
+
+#endif