net/tipc/port.c

/*
 * net/tipc/port.c: TIPC port code
 *
 * Copyright (c) 1992-2007, Ericsson AB
 * Copyright (c) 2004-2008, Wind River Systems
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the names of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "core.h"
#include "config.h"
#include "port.h"
#include "name_table.h"
#include "user_reg.h"

/* Connection management: */
#define PROBING_INTERVAL 3600000	/* [ms] => 1 h */
#define CONFIRMED 0
#define PROBING 1

#define MAX_REJECT_SIZE 1024

static struct sk_buff *msg_queue_head = NULL;
static struct sk_buff *msg_queue_tail = NULL;

DEFINE_SPINLOCK(tipc_port_list_lock);
static DEFINE_SPINLOCK(queue_lock);

static LIST_HEAD(ports);
static void port_handle_node_down(unsigned long ref);
static struct sk_buff* port_build_self_abort_msg(struct port *,u32 err);
static struct sk_buff* port_build_peer_abort_msg(struct port *,u32 err);
static void port_timeout(unsigned long ref);


static u32 port_peernode(struct port *p_ptr)
{
	return msg_destnode(&p_ptr->publ.phdr);
}

static u32 port_peerport(struct port *p_ptr)
{
	return msg_destport(&p_ptr->publ.phdr);
}

static u32 port_out_seqno(struct port *p_ptr)
{
	return msg_transp_seqno(&p_ptr->publ.phdr);
}

static void port_incr_out_seqno(struct port *p_ptr)
{
	struct tipc_msg *m = &p_ptr->publ.phdr;

	if (likely(!msg_routed(m)))
		return;
	msg_set_transp_seqno(m, (msg_transp_seqno(m) + 1));
}

/**
 * tipc_multicast - send a multicast message to local and remote destinations
 */

int tipc_multicast(u32 ref, struct tipc_name_seq const *seq,
		   u32 num_sect, struct iovec const *msg_sect)
{
	struct tipc_msg *hdr;
	struct sk_buff *buf;
	struct sk_buff *ibuf = NULL;
	struct port_list dports = {0, NULL, };
	struct port *oport = tipc_port_deref(ref);
	int ext_targets;
	int res;

	if (unlikely(!oport))
		return -EINVAL;

	/* Create multicast message */

	hdr = &oport->publ.phdr;
	msg_set_type(hdr, TIPC_MCAST_MSG);
	msg_set_nametype(hdr, seq->type);
	msg_set_namelower(hdr, seq->lower);
	msg_set_nameupper(hdr, seq->upper);
	msg_set_hdr_sz(hdr, MCAST_H_SIZE);
	res = tipc_msg_build(hdr, msg_sect, num_sect, MAX_MSG_SIZE,
			!oport->user_port, &buf);
	if (unlikely(!buf))
		return res;

	/* Figure out where to send multicast message */

	ext_targets = tipc_nametbl_mc_translate(seq->type, seq->lower, seq->upper,
						TIPC_NODE_SCOPE, &dports);

	/* Send message to destinations (duplicate it only if necessary) */

	if (ext_targets) {
		if (dports.count != 0) {
			ibuf = skb_copy(buf, GFP_ATOMIC);
			if (ibuf == NULL) {
				tipc_port_list_free(&dports);
				buf_discard(buf);
				return -ENOMEM;
			}
		}
		res = tipc_bclink_send_msg(buf);
		if ((res < 0) && (dports.count != 0)) {
			buf_discard(ibuf);
		}
	} else {
		ibuf = buf;
	}

	if (res >= 0) {
		if (ibuf)
			tipc_port_recv_mcast(ibuf, &dports);
	} else {
		tipc_port_list_free(&dports);
	}
	return res;
}

/**
 * tipc_port_recv_mcast - deliver multicast message to all destination ports
 *
 * If there is no port list, perform a lookup to create one
 */

void tipc_port_recv_mcast(struct sk_buff *buf, struct port_list *dp)
{
	struct tipc_msg* msg;
	struct port_list dports = {0, NULL, };
	struct port_list *item = dp;
	int cnt = 0;

	msg = buf_msg(buf);

	/* Create destination port list, if one wasn't supplied */

	if (dp == NULL) {
		tipc_nametbl_mc_translate(msg_nametype(msg),
				     msg_namelower(msg),
				     msg_nameupper(msg),
				     TIPC_CLUSTER_SCOPE,
				     &dports);
		item = dp = &dports;
	}

	/* Deliver a copy of message to each destination port */

	if (dp->count != 0) {
		if (dp->count == 1) {
			msg_set_destport(msg, dp->ports[0]);
			tipc_port_recv_msg(buf);
			tipc_port_list_free(dp);
			return;
		}
		for (; cnt < dp->count; cnt++) {
			int index = cnt % PLSIZE;
			struct sk_buff *b = skb_clone(buf, GFP_ATOMIC);

			if (b == NULL) {
				warn("Unable to deliver multicast message(s)\n");
				msg_dbg(msg, "LOST:");
				goto exit;
			}
			if ((index == 0) && (cnt != 0)) {
				item = item->next;
			}
			msg_set_destport(buf_msg(b),item->ports[index]);
			tipc_port_recv_msg(b);
		}
	}
exit:
	buf_discard(buf);
	tipc_port_list_free(dp);
}

/**
 * tipc_createport_raw - create a generic TIPC port
 *
 * Returns pointer to (locked) TIPC port, or NULL if unable to create it
 */

struct tipc_port *tipc_createport_raw(void *usr_handle,
			u32 (*dispatcher)(struct tipc_port *, struct sk_buff *),
			void (*wakeup)(struct tipc_port *),
			const u32 importance)
{
	struct port *p_ptr;
	struct tipc_msg *msg;
	u32 ref;

	p_ptr = kzalloc(sizeof(*p_ptr), GFP_ATOMIC);
	if (!p_ptr) {
		warn("Port creation failed, no memory\n");
		return NULL;
	}
	ref = tipc_ref_acquire(p_ptr, &p_ptr->publ.lock);
	if (!ref) {
		warn("Port creation failed, reference table exhausted\n");
		kfree(p_ptr);
		return NULL;
	}

	p_ptr->publ.usr_handle = usr_handle;
	p_ptr->publ.max_pkt = MAX_PKT_DEFAULT;
	p_ptr->publ.ref = ref;
	msg = &p_ptr->publ.phdr;
	tipc_msg_init(msg, importance, TIPC_NAMED_MSG, LONG_H_SIZE, 0);
	msg_set_origport(msg, ref);
	p_ptr->last_in_seqno = 41;
	p_ptr->sent = 1;
	INIT_LIST_HEAD(&p_ptr->wait_list);
	INIT_LIST_HEAD(&p_ptr->subscription.nodesub_list);
	p_ptr->dispatcher = dispatcher;
	p_ptr->wakeup = wakeup;
	p_ptr->user_port = NULL;
	k_init_timer(&p_ptr->timer, (Handler)port_timeout, ref);
	spin_lock_bh(&tipc_port_list_lock);
	INIT_LIST_HEAD(&p_ptr->publications);
	INIT_LIST_HEAD(&p_ptr->port_list);
	list_add_tail(&p_ptr->port_list, &ports);
	spin_unlock_bh(&tipc_port_list_lock);
	return &(p_ptr->publ);
}

int tipc_deleteport(u32 ref)
{
	struct port *p_ptr;
	struct sk_buff *buf = NULL;

	tipc_withdraw(ref, 0, NULL);
	p_ptr = tipc_port_lock(ref);
	if (!p_ptr)
		return -EINVAL;

	tipc_ref_discard(ref);
	tipc_port_unlock(p_ptr);

	k_cancel_timer(&p_ptr->timer);
	if (p_ptr->publ.connected) {
		buf = port_build_peer_abort_msg(p_ptr, TIPC_ERR_NO_PORT);
		tipc_nodesub_unsubscribe(&p_ptr->subscription);
	}
	if (p_ptr->user_port) {
		tipc_reg_remove_port(p_ptr->user_port);
		kfree(p_ptr->user_port);
	}

	spin_lock_bh(&tipc_port_list_lock);
	list_del(&p_ptr->port_list);
	list_del(&p_ptr->wait_list);
	spin_unlock_bh(&tipc_port_list_lock);
	k_term_timer(&p_ptr->timer);
	kfree(p_ptr);
	dbg("Deleted port %u\n", ref);
	tipc_net_route_msg(buf);
	return 0;
}

static int port_unreliable(struct port *p_ptr)
{
	return msg_src_droppable(&p_ptr->publ.phdr);
}

int tipc_portunreliable(u32 ref, unsigned int *isunreliable)
{
	struct port *p_ptr;

	p_ptr = tipc_port_lock(ref);
	if (!p_ptr)
		return -EINVAL;
	*isunreliable = port_unreliable(p_ptr);
	tipc_port_unlock(p_ptr);
	return 0;
}

int tipc_set_portunreliable(u32 ref, unsigned int isunreliable)
{
	struct port *p_ptr;

	p_ptr = tipc_port_lock(ref);
	if (!p_ptr)
		return -EINVAL;
	msg_set_src_droppable(&p_ptr->publ.phdr, (isunreliable != 0));
	tipc_port_unlock(p_ptr);
	return 0;
}

static int port_unreturnable(struct port *p_ptr)
{
	return msg_dest_droppable(&p_ptr->publ.phdr);
}

int tipc_portunreturnable(u32 ref, unsigned int *isunrejectable)
{
	struct port *p_ptr;

	p_ptr = tipc_port_lock(ref);
	if (!p_ptr)
		return -EINVAL;
	*isunrejectable = port_unreturnable(p_ptr);
	tipc_port_unlock(p_ptr);
	return 0;
}

int tipc_set_portunreturnable(u32 ref, unsigned int isunrejectable)
{
	struct port *p_ptr;

	p_ptr = tipc_port_lock(ref);
	if (!p_ptr)
		return -EINVAL;
	msg_set_dest_droppable(&p_ptr->publ.phdr, (isunrejectable != 0));
	tipc_port_unlock(p_ptr);
	return 0;
}

/*
 * port_build_proto_msg(): build a port level protocol
 * or a connection abortion message. Called with
 * tipc_port lock on.
 */
static struct sk_buff *port_build_proto_msg(u32 destport, u32 destnode,
					    u32 origport, u32 orignode,
					    u32 usr, u32 type, u32 err,
					    u32 seqno, u32 ack)
{
	struct sk_buff *buf;
	struct tipc_msg *msg;

	buf = tipc_buf_acquire(LONG_H_SIZE);
	if (buf) {
		msg = buf_msg(buf);
		tipc_msg_init(msg, usr, type, LONG_H_SIZE, destnode);
		msg_set_errcode(msg, err);
		msg_set_destport(msg, destport);
		msg_set_origport(msg, origport);
		msg_set_orignode(msg, orignode);
		msg_set_transp_seqno(msg, seqno);
		msg_set_msgcnt(msg, ack);
		msg_dbg(msg, "PORT>SEND>:");
	}
	return buf;
}

int tipc_reject_msg(struct sk_buff *buf, u32 err)
{
	struct tipc_msg *msg = buf_msg(buf);
	struct sk_buff *rbuf;
	struct tipc_msg *rmsg;
	int hdr_sz;
	u32 imp = msg_importance(msg);
	u32 data_sz = msg_data_sz(msg);

	if (data_sz > MAX_REJECT_SIZE)
		data_sz = MAX_REJECT_SIZE;
	if (msg_connected(msg) && (imp < TIPC_CRITICAL_IMPORTANCE))
		imp++;
	msg_dbg(msg, "port->rej: ");

	/* discard rejected message if it shouldn't be returned to sender */
	if (msg_errcode(msg) || msg_dest_droppable(msg)) {
		buf_discard(buf);
		return data_sz;
	}

	/* construct rejected message */
	if (msg_mcast(msg))
		hdr_sz = MCAST_H_SIZE;
	else
		hdr_sz = LONG_H_SIZE;
	rbuf = tipc_buf_acquire(data_sz + hdr_sz);
	if (rbuf == NULL) {
		buf_discard(buf);
		return data_sz;
	}
	rmsg = buf_msg(rbuf);
	tipc_msg_init(rmsg, imp, msg_type(msg), hdr_sz, msg_orignode(msg));
	msg_set_errcode(rmsg, err);
	msg_set_destport(rmsg, msg_origport(msg));
	msg_set_origport(rmsg, msg_destport(msg));
	if (msg_short(msg)) {
		msg_set_orignode(rmsg, tipc_own_addr);
		/* leave name type & instance as zeroes */
	} else {
		msg_set_orignode(rmsg, msg_destnode(msg));
		msg_set_nametype(rmsg, msg_nametype(msg));
		msg_set_nameinst(rmsg, msg_nameinst(msg));
	}
	msg_set_size(rmsg, data_sz + hdr_sz);
	skb_copy_to_linear_data_offset(rbuf, hdr_sz, msg_data(msg), data_sz);

	/* send self-abort message when rejecting on a connected port */
	if (msg_connected(msg)) {
		struct sk_buff *abuf = NULL;
		struct port *p_ptr = tipc_port_lock(msg_destport(msg));

		if (p_ptr) {
			if (p_ptr->publ.connected)
				abuf = port_build_self_abort_msg(p_ptr, err);
			tipc_port_unlock(p_ptr);
		}
		tipc_net_route_msg(abuf);
	}

	/* send rejected message */
	buf_discard(buf);
	tipc_net_route_msg(rbuf);
	return data_sz;
}

int tipc_port_reject_sections(struct port *p_ptr, struct tipc_msg *hdr,
			      struct iovec const *msg_sect, u32 num_sect,
			      int err)
{
	struct sk_buff *buf;
	int res;

	res = tipc_msg_build(hdr, msg_sect, num_sect, MAX_MSG_SIZE,
			!p_ptr->user_port, &buf);
	if (!buf)
		return res;

	return tipc_reject_msg(buf, err);
}

static void port_timeout(unsigned long ref)
{
	struct port *p_ptr = tipc_port_lock(ref);
	struct sk_buff *buf = NULL;

	if (!p_ptr)
		return;

	if (!p_ptr->publ.connected) {
		tipc_port_unlock(p_ptr);
		return;
	}

	/* Last probe answered ? */
	if (p_ptr->probing_state == PROBING) {
		buf = port_build_self_abort_msg(p_ptr, TIPC_ERR_NO_PORT);
	} else {
		buf = port_build_proto_msg(port_peerport(p_ptr),
					   port_peernode(p_ptr),
					   p_ptr->publ.ref,
					   tipc_own_addr,
					   CONN_MANAGER,
					   CONN_PROBE,
					   TIPC_OK,
					   port_out_seqno(p_ptr),
					   0);
		port_incr_out_seqno(p_ptr);
		p_ptr->probing_state = PROBING;
		k_start_timer(&p_ptr->timer, p_ptr->probing_interval);
	}
	tipc_port_unlock(p_ptr);
	tipc_net_route_msg(buf);
}


static void port_handle_node_down(unsigned long ref)
{
	struct port *p_ptr = tipc_port_lock(ref);
	struct sk_buff* buf = NULL;

	if (!p_ptr)
		return;
	buf = port_build_self_abort_msg(p_ptr, TIPC_ERR_NO_NODE);
	tipc_port_unlock(p_ptr);
	tipc_net_route_msg(buf);
}


static struct sk_buff *port_build_self_abort_msg(struct port *p_ptr, u32 err)
{
	u32 imp = msg_importance(&p_ptr->publ.phdr);

	if (!p_ptr->publ.connected)
		return NULL;
	if (imp < TIPC_CRITICAL_IMPORTANCE)
		imp++;
	return port_build_proto_msg(p_ptr->publ.ref,
				    tipc_own_addr,
				    port_peerport(p_ptr),
				    port_peernode(p_ptr),
				    imp,
				    TIPC_CONN_MSG,
				    err,
				    p_ptr->last_in_seqno + 1,
				    0);
}


static struct sk_buff *port_build_peer_abort_msg(struct port *p_ptr, u32 err)
{
	u32 imp = msg_importance(&p_ptr->publ.phdr);

	if (!p_ptr->publ.connected)
		return NULL;
	if (imp < TIPC_CRITICAL_IMPORTANCE)
		imp++;
	return port_build_proto_msg(port_peerport(p_ptr),
				    port_peernode(p_ptr),
				    p_ptr->publ.ref,
				    tipc_own_addr,
				    imp,
				    TIPC_CONN_MSG,
				    err,
				    port_out_seqno(p_ptr),
				    0);
}

void tipc_port_recv_proto_msg(struct sk_buff *buf)
{
	struct tipc_msg *msg = buf_msg(buf);
	struct port *p_ptr = tipc_port_lock(msg_destport(msg));
	u32 err = TIPC_OK;
	struct sk_buff *r_buf = NULL;
	struct sk_buff *abort_buf = NULL;

	msg_dbg(msg, "PORT<RECV<:");

	if (!p_ptr) {
		err = TIPC_ERR_NO_PORT;
	} else if (p_ptr->publ.connected) {
		if ((port_peernode(p_ptr) != msg_orignode(msg)) ||
		    (port_peerport(p_ptr) != msg_origport(msg))) {
			err = TIPC_ERR_NO_PORT;
		} else if (msg_type(msg) == CONN_ACK) {
			int wakeup = tipc_port_congested(p_ptr) &&
				     p_ptr->publ.congested &&
				     p_ptr->wakeup;
			p_ptr->acked += msg_msgcnt(msg);
			if (tipc_port_congested(p_ptr))
				goto exit;
			p_ptr->publ.congested = 0;
			if (!wakeup)
				goto exit;
			p_ptr->wakeup(&p_ptr->publ);
			goto exit;
		}
	} else if (p_ptr->publ.published) {
		err = TIPC_ERR_NO_PORT;
	}
	if (err) {
		r_buf = port_build_proto_msg(msg_origport(msg),
					     msg_orignode(msg),
					     msg_destport(msg),
					     tipc_own_addr,
					     TIPC_HIGH_IMPORTANCE,
					     TIPC_CONN_MSG,
					     err,
					     0,
					     0);
		goto exit;
	}

	/* All is fine */
	if (msg_type(msg) == CONN_PROBE) {
		r_buf = port_build_proto_msg(msg_origport(msg),
					     msg_orignode(msg),
					     msg_destport(msg),
					     tipc_own_addr,
					     CONN_MANAGER,
					     CONN_PROBE_REPLY,
					     TIPC_OK,
					     port_out_seqno(p_ptr),
					     0);
	}
	p_ptr->probing_state = CONFIRMED;
	port_incr_out_seqno(p_ptr);
exit:
	if (p_ptr)
		tipc_port_unlock(p_ptr);
	tipc_net_route_msg(r_buf);
	tipc_net_route_msg(abort_buf);
	buf_discard(buf);
}

static void port_print(struct port *p_ptr, struct print_buf *buf, int full_id)
{
	struct publication *publ;

	if (full_id)
		tipc_printf(buf, "<%u.%u.%u:%u>:",
			    tipc_zone(tipc_own_addr), tipc_cluster(tipc_own_addr),
			    tipc_node(tipc_own_addr), p_ptr->publ.ref);
	else
		tipc_printf(buf, "%-10u:", p_ptr->publ.ref);

	if (p_ptr->publ.connected) {
		u32 dport = port_peerport(p_ptr);
		u32 destnode = port_peernode(p_ptr);

		tipc_printf(buf, " connected to <%u.%u.%u:%u>",
			    tipc_zone(destnode), tipc_cluster(destnode),
			    tipc_node(destnode), dport);
		if (p_ptr->publ.conn_type != 0)
			tipc_printf(buf, " via {%u,%u}",
				    p_ptr->publ.conn_type,
				    p_ptr->publ.conn_instance);
	}
	else if (p_ptr->publ.published) {
		tipc_printf(buf, " bound to");
		list_for_each_entry(publ, &p_ptr->publications, pport_list) {
			if (publ->lower == publ->upper)
				tipc_printf(buf, " {%u,%u}", publ->type,
					    publ->lower);
			else
				tipc_printf(buf, " {%u,%u,%u}", publ->type,
					    publ->lower, publ->upper);
		}
	}
	tipc_printf(buf, "\n");
}

#define MAX_PORT_QUERY 32768

struct sk_buff *tipc_port_get_ports(void)
{
	struct sk_buff *buf;
	struct tlv_desc *rep_tlv;
	struct print_buf pb;
	struct port *p_ptr;
	int str_len;

	buf = tipc_cfg_reply_alloc(TLV_SPACE(MAX_PORT_QUERY));
	if (!buf)
		return NULL;
	rep_tlv = (struct tlv_desc *)buf->data;

	tipc_printbuf_init(&pb, TLV_DATA(rep_tlv), MAX_PORT_QUERY);
	spin_lock_bh(&tipc_port_list_lock);
	list_for_each_entry(p_ptr, &ports, port_list) {
		spin_lock_bh(p_ptr->publ.lock);
		port_print(p_ptr, &pb, 0);
		spin_unlock_bh(p_ptr->publ.lock);
	}
	spin_unlock_bh(&tipc_port_list_lock);
	str_len = tipc_printbuf_validate(&pb);

	skb_put(buf, TLV_SPACE(str_len));
	TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);

	return buf;
}

void tipc_port_reinit(void)
{
	struct port *p_ptr;
	struct tipc_msg *msg;

	spin_lock_bh(&tipc_port_list_lock);
	list_for_each_entry(p_ptr, &ports, port_list) {
		msg = &p_ptr->publ.phdr;
		if (msg_orignode(msg) == tipc_own_addr)
			break;
		msg_set_prevnode(msg, tipc_own_addr);
		msg_set_orignode(msg, tipc_own_addr);
	}
	spin_unlock_bh(&tipc_port_list_lock);
}


/*
 *  port_dispatcher_sigh(): Signal handler for messages destinated
 *                          to the tipc_port interface.
 */

static void port_dispatcher_sigh(void *dummy)
{
	struct sk_buff *buf;

	spin_lock_bh(&queue_lock);
	buf = msg_queue_head;
	msg_queue_head = NULL;
	spin_unlock_bh(&queue_lock);

	while (buf) {
		struct port *p_ptr;
		struct user_port *up_ptr;
		struct tipc_portid orig;
		struct tipc_name_seq dseq;
		void *usr_handle;
		int connected;
		int published;
		u32 message_type;

		struct sk_buff *next = buf->next;
		struct tipc_msg *msg = buf_msg(buf);
		u32 dref = msg_destport(msg);

		message_type = msg_type(msg);
		if (message_type > TIPC_DIRECT_MSG)
			goto reject;	/* Unsupported message type */

		p_ptr = tipc_port_lock(dref);
		if (!p_ptr)
			goto reject;	/* Port deleted while msg in queue */

		orig.ref = msg_origport(msg);
		orig.node = msg_orignode(msg);
		up_ptr = p_ptr->user_port;
		usr_handle = up_ptr->usr_handle;
		connected = p_ptr->publ.connected;
		published = p_ptr->publ.published;

		if (unlikely(msg_errcode(msg)))
			goto err;

		switch (message_type) {

		case TIPC_CONN_MSG:{
				tipc_conn_msg_event cb = up_ptr->conn_msg_cb;
				u32 peer_port = port_peerport(p_ptr);
				u32 peer_node = port_peernode(p_ptr);

				tipc_port_unlock(p_ptr);
				if (unlikely(!cb))
					goto reject;
				if (unlikely(!connected)) {
					if (tipc_connect2port(dref, &orig))
						goto reject;
				} else if ((msg_origport(msg) != peer_port) ||
					   (msg_orignode(msg) != peer_node))
					goto reject;
				if (unlikely(++p_ptr->publ.conn_unacked >=
					     TIPC_FLOW_CONTROL_WIN))
					tipc_acknowledge(dref,
							 p_ptr->publ.conn_unacked);
				skb_pull(buf, msg_hdr_sz(msg));
				cb(usr_handle, dref, &buf, msg_data(msg),
				   msg_data_sz(msg));
				break;
			}
		case TIPC_DIRECT_MSG:{
				tipc_msg_event cb = up_ptr->msg_cb;

				tipc_port_unlock(p_ptr);
				if (unlikely(!cb || connected))
					goto reject;
				skb_pull(buf, msg_hdr_sz(msg));
				cb(usr_handle, dref, &buf, msg_data(msg),
				   msg_data_sz(msg), msg_importance(msg),
				   &orig);
				break;
			}
		case TIPC_MCAST_MSG:
		case TIPC_NAMED_MSG:{
				tipc_named_msg_event cb = up_ptr->named_msg_cb;

				tipc_port_unlock(p_ptr);
				if (unlikely(!cb || connected || !published))
					goto reject;
				dseq.type =  msg_nametype(msg);
				dseq.lower = msg_nameinst(msg);
				dseq.upper = (message_type == TIPC_NAMED_MSG)
					? dseq.lower : msg_nameupper(msg);
				skb_pull(buf, msg_hdr_sz(msg));
				cb(usr_handle, dref, &buf, msg_data(msg),
				   msg_data_sz(msg), msg_importance(msg),
				   &orig, &dseq);
				break;
			}
		}
		if (buf)
			buf_discard(buf);
		buf = next;
		continue;
err:
		switch (message_type) {

		case TIPC_CONN_MSG:{
				tipc_conn_shutdown_event cb =
					up_ptr->conn_err_cb;
				u32 peer_port = port_peerport(p_ptr);
				u32 peer_node = port_peernode(p_ptr);

				tipc_port_unlock(p_ptr);
				if (!cb || !connected)
					break;
				if ((msg_origport(msg) != peer_port) ||
				    (msg_orignode(msg) != peer_node))
					break;
				tipc_disconnect(dref);
				skb_pull(buf, msg_hdr_sz(msg));
				cb(usr_handle, dref, &buf, msg_data(msg),
				   msg_data_sz(msg), msg_errcode(msg));
				break;
			}
		case TIPC_DIRECT_MSG:{
				tipc_msg_err_event cb = up_ptr->err_cb;

				tipc_port_unlock(p_ptr);
				if (!cb || connected)
					break;
				skb_pull(buf, msg_hdr_sz(msg));
				cb(usr_handle, dref, &buf, msg_data(msg),
				   msg_data_sz(msg), msg_errcode(msg), &orig);
				break;
			}
		case TIPC_MCAST_MSG:
		case TIPC_NAMED_MSG:{
				tipc_named_msg_err_event cb =
					up_ptr->named_err_cb;

				tipc_port_unlock(p_ptr);
				if (!cb || connected)
					break;
				dseq.type =  msg_nametype(msg);
				dseq.lower = msg_nameinst(msg);
				dseq.upper = (message_type == TIPC_NAMED_MSG)
					? dseq.lower : msg_nameupper(msg);
				skb_pull(buf, msg_hdr_sz(msg));
				cb(usr_handle, dref, &buf, msg_data(msg),
				   msg_data_sz(msg), msg_errcode(msg), &dseq);
				break;
			}
		}
		if (buf)
			buf_discard(buf);
		buf = next;
		continue;
reject:
		tipc_reject_msg(buf, TIPC_ERR_NO_PORT);
		buf = next;
	}
}

/*
 *  port_dispatcher(): Dispatcher for messages destinated
 *  to the tipc_port interface. Called with port locked.
 */

static u32 port_dispatcher(struct tipc_port *dummy, struct sk_buff *buf)
{
	buf->next = NULL;
	spin_lock_bh(&queue_lock);
	if (msg_queue_head) {
		msg_queue_tail->next = buf;
		msg_queue_tail = buf;
	} else {
		msg_queue_tail = msg_queue_head = buf;
		tipc_k_signal((Handler)port_dispatcher_sigh, 0);
	}
	spin_unlock_bh(&queue_lock);
	return 0;
}

/*
 * Wake up port after congestion: Called with port locked,
 *
 */

static void port_wakeup_sh(unsigned long ref)
{
	struct port *p_ptr;
	struct user_port *up_ptr;
	tipc_continue_event cb = NULL;
	void *uh = NULL;

	p_ptr = tipc_port_lock(ref);
	if (p_ptr) {
		up_ptr = p_ptr->user_port;
		if (up_ptr) {
			cb = up_ptr->continue_event_cb;
			uh = up_ptr->usr_handle;
		}
		tipc_port_unlock(p_ptr);
	}
	if (cb)
		cb(uh, ref);
}


static void port_wakeup(struct tipc_port *p_ptr)
{
	tipc_k_signal((Handler)port_wakeup_sh, p_ptr->ref);
}

void tipc_acknowledge(u32 ref, u32 ack)
{
	struct port *p_ptr;
	struct sk_buff *buf = NULL;

	p_ptr = tipc_port_lock(ref);
	if (!p_ptr)
		return;
	if (p_ptr->publ.connected) {
		p_ptr->publ.conn_unacked -= ack;
		buf = port_build_proto_msg(port_peerport(p_ptr),
					   port_peernode(p_ptr),
					   ref,
					   tipc_own_addr,
					   CONN_MANAGER,
					   CONN_ACK,
					   TIPC_OK,
					   port_out_seqno(p_ptr),
					   ack);
	}
	tipc_port_unlock(p_ptr);
	tipc_net_route_msg(buf);
}

/*
 * tipc_createport(): user level call. Will add port to
 *                    registry if non-zero user_ref.
 */

int tipc_createport(u32 user_ref,
		    void *usr_handle,
		    unsigned int importance,
		    tipc_msg_err_event error_cb,
		    tipc_named_msg_err_event named_error_cb,
		    tipc_conn_shutdown_event conn_error_cb,
		    tipc_msg_event msg_cb,
		    tipc_named_msg_event named_msg_cb,
		    tipc_conn_msg_event conn_msg_cb,
		    tipc_continue_event continue_event_cb,/* May be zero */
		    u32 *portref)
{
	struct user_port *up_ptr;
	struct port *p_ptr;

	up_ptr = kmalloc(sizeof(*up_ptr), GFP_ATOMIC);
	if (!up_ptr) {
		warn("Port creation failed, no memory\n");
		return -ENOMEM;
	}
	p_ptr = (struct port *)tipc_createport_raw(NULL, port_dispatcher,
						   port_wakeup, importance);
	if (!p_ptr) {
		kfree(up_ptr);
		return -ENOMEM;
	}

	p_ptr->user_port = up_ptr;
	up_ptr->user_ref = user_ref;
	up_ptr->usr_handle = usr_handle;
	up_ptr->ref = p_ptr->publ.ref;
	up_ptr->err_cb = error_cb;
	up_ptr->named_err_cb = named_error_cb;
	up_ptr->conn_err_cb = conn_error_cb;
	up_ptr->msg_cb = msg_cb;
	up_ptr->named_msg_cb = named_msg_cb;
	up_ptr->conn_msg_cb = conn_msg_cb;
	up_ptr->continue_event_cb = continue_event_cb;
	INIT_LIST_HEAD(&up_ptr->uport_list);
	tipc_reg_add_port(up_ptr);
	*portref = p_ptr->publ.ref;
	tipc_port_unlock(p_ptr);
	return 0;
}

int tipc_portimportance(u32 ref, unsigned int *importance)
{
	struct port *p_ptr;

	p_ptr = tipc_port_lock(ref);
	if (!p_ptr)
		return -EINVAL;
	*importance = (unsigned int)msg_importance(&p_ptr->publ.phdr);
	tipc_port_unlock(p_ptr);
	return 0;
}

int tipc_set_portimportance(u32 ref, unsigned int imp)
{
	struct port *p_ptr;

	if (imp > TIPC_CRITICAL_IMPORTANCE)
		return -EINVAL;

	p_ptr = tipc_port_lock(ref);
	if (!p_ptr)
		return -EINVAL;
	msg_set_importance(&p_ptr->publ.phdr, (u32)imp);
	tipc_port_unlock(p_ptr);
	return 0;
}


int tipc_publish(u32 ref, unsigned int scope, struct tipc_name_seq const *seq)
{
	struct port *p_ptr;
	struct publication *publ;
	u32 key;
	int res = -EINVAL;

	p_ptr = tipc_port_lock(ref);
	if (!p_ptr)
		return -EINVAL;

	dbg("tipc_publ %u, p_ptr = %x, conn = %x, scope = %x, "
	    "lower = %u, upper = %u\n",
	    ref, p_ptr, p_ptr->publ.connected, scope, seq->lower, seq->upper);
	if (p_ptr->publ.connected)
		goto exit;
	if (seq->lower > seq->upper)
		goto exit;
	if ((scope < TIPC_ZONE_SCOPE) || (scope > TIPC_NODE_SCOPE))
		goto exit;
	key = ref + p_ptr->pub_count + 1;
	if (key == ref) {
		res = -EADDRINUSE;
		goto exit;
	}
	publ = tipc_nametbl_publish(seq->type, seq->lower, seq->upper,
				    scope, p_ptr->publ.ref, key);
	if (publ) {
		list_add(&publ->pport_list, &p_ptr->publications);
		p_ptr->pub_count++;
		p_ptr->publ.published = 1;
		res = 0;
	}
exit:
	tipc_port_unlock(p_ptr);
	return res;
}

int tipc_withdraw(u32 ref, unsigned int scope, struct tipc_name_seq const *seq)
{
	struct port *p_ptr;
	struct publication *publ;
	struct publication *tpubl;
	int res = -EINVAL;

	p_ptr = tipc_port_lock(ref);
	if (!p_ptr)
		return -EINVAL;
	if (!seq) {
		list_for_each_entry_safe(publ, tpubl,
					 &p_ptr->publications, pport_list) {
			tipc_nametbl_withdraw(publ->type, publ->lower,
					      publ->ref, publ->key);
		}
		res = 0;
	} else {
		list_for_each_entry_safe(publ, tpubl,
					 &p_ptr->publications, pport_list) {
			if (publ->scope != scope)
				continue;
			if (publ->type != seq->type)
				continue;
			if (publ->lower != seq->lower)
				continue;
			if (publ->upper != seq->upper)
				break;
			tipc_nametbl_withdraw(publ->type, publ->lower,
					      publ->ref, publ->key);
			res = 0;
			break;
		}
	}
	if (list_empty(&p_ptr->publications))
		p_ptr->publ.published = 0;
	tipc_port_unlock(p_ptr);
	return res;
}

int tipc_connect2port(u32 ref, struct tipc_portid const *peer)
{
	struct port *p_ptr;
	struct tipc_msg *msg;
	int res = -EINVAL;

	p_ptr = tipc_port_lock(ref);
	if (!p_ptr)
		return -EINVAL;
	if (p_ptr->publ.published || p_ptr->publ.connected)
		goto exit;
	if (!peer->ref)
		goto exit;

	msg = &p_ptr->publ.phdr;
	msg_set_destnode(msg, peer->node);
	msg_set_destport(msg, peer->ref);
	msg_set_orignode(msg, tipc_own_addr);
	msg_set_origport(msg, p_ptr->publ.ref);
	msg_set_transp_seqno(msg, 42);
	msg_set_type(msg, TIPC_CONN_MSG);
	msg_set_hdr_sz(msg, SHORT_H_SIZE);

	p_ptr->probing_interval = PROBING_INTERVAL;
	p_ptr->probing_state = CONFIRMED;
	p_ptr->publ.connected = 1;
	k_start_timer(&p_ptr->timer, p_ptr->probing_interval);

	tipc_nodesub_subscribe(&p_ptr->subscription,peer->node,
			  (void *)(unsigned long)ref,
			  (net_ev_handler)port_handle_node_down);
	res = 0;
exit:
	tipc_port_unlock(p_ptr);
	p_ptr->publ.max_pkt = tipc_link_get_max_pkt(peer->node, ref);
	return res;
}

/**
 * tipc_disconnect_port - disconnect port from peer
 *
 * Port must be locked.
 */

int tipc_disconnect_port(struct tipc_port *tp_ptr)
{
	int res;

	if (tp_ptr->connected) {
		tp_ptr->connected = 0;
		/* let timer expire on it's own to avoid deadlock! */
		tipc_nodesub_unsubscribe(
			&((struct port *)tp_ptr)->subscription);
		res = 0;
	} else {
		res = -ENOTCONN;
	}
	return res;
}

/*
 * tipc_disconnect(): Disconnect port form peer.
 *                    This is a node local operation.
 */

int tipc_disconnect(u32 ref)
{
	struct port *p_ptr;
	int res;

	p_ptr = tipc_port_lock(ref);
	if (!p_ptr)
		return -EINVAL;
	res = tipc_disconnect_port((struct tipc_port *)p_ptr);
	tipc_port_unlock(p_ptr);
	return res;
}

/*
 * tipc_shutdown(): Send a SHUTDOWN msg to peer and disconnect
 */
int tipc_shutdown(u32 ref)
{
	struct port *p_ptr;
	struct sk_buff *buf = NULL;

	p_ptr = tipc_port_lock(ref);
	if (!p_ptr)
		return -EINVAL;

	if (p_ptr->publ.connected) {
		u32 imp = msg_importance(&p_ptr->publ.phdr);
		if (imp < TIPC_CRITICAL_IMPORTANCE)
			imp++;
		buf = port_build_proto_msg(port_peerport(p_ptr),
					   port_peernode(p_ptr),
					   ref,
					   tipc_own_addr,
					   imp,
					   TIPC_CONN_MSG,
					   TIPC_CONN_SHUTDOWN,
					   port_out_seqno(p_ptr),
					   0);
	}
	tipc_port_unlock(p_ptr);
	tipc_net_route_msg(buf);
	return tipc_disconnect(ref);
}

/*
 *  tipc_port_recv_sections(): Concatenate and deliver sectioned
 *                        message for this node.
 */

static int tipc_port_recv_sections(struct port *sender, unsigned int num_sect,
				   struct iovec const *msg_sect)
{
	struct sk_buff *buf;
	int res;

	res = tipc_msg_build(&sender->publ.phdr, msg_sect, num_sect,
			MAX_MSG_SIZE, !sender->user_port, &buf);
	if (likely(buf))
		tipc_port_recv_msg(buf);
	return res;
}

/**
 * tipc_send - send message sections on connection
 */

int tipc_send(u32 ref, unsigned int num_sect, struct iovec const *msg_sect)
{
	struct port *p_ptr;
	u32 destnode;
	int res;

	p_ptr = tipc_port_deref(ref);
	if (!p_ptr || !p_ptr->publ.connected)
		return -EINVAL;

	p_ptr->publ.congested = 1;
	if (!tipc_port_congested(p_ptr)) {
		destnode = port_peernode(p_ptr);
		if (likely(destnode != tipc_own_addr))
			res = tipc_link_send_sections_fast(p_ptr, msg_sect, num_sect,
							   destnode);
		else
			res = tipc_port_recv_sections(p_ptr, num_sect, msg_sect);

		if (likely(res != -ELINKCONG)) {
			port_incr_out_seqno(p_ptr);
			p_ptr->publ.congested = 0;
			p_ptr->sent++;
			return res;
		}
	}
	if (port_unreliable(p_ptr)) {
		p_ptr->publ.congested = 0;
		/* Just calculate msg length and return */
		return tipc_msg_calc_data_size(msg_sect, num_sect);
	}
	return -ELINKCONG;
}

/**
 * tipc_send2name - send message sections to port name
 */

int tipc_send2name(u32 ref, struct tipc_name const *name, unsigned int domain,
	   unsigned int num_sect, struct iovec const *msg_sect)
{
	struct port *p_ptr;
	struct tipc_msg *msg;
	u32 destnode = domain;
	u32 destport;
	int res;

	p_ptr = tipc_port_deref(ref);
	if (!p_ptr || p_ptr->publ.connected)
		return -EINVAL;

	msg = &p_ptr->publ.phdr;
	msg_set_type(msg, TIPC_NAMED_MSG);
	msg_set_orignode(msg, tipc_own_addr);
	msg_set_origport(msg, ref);
	msg_set_hdr_sz(msg, LONG_H_SIZE);
	msg_set_nametype(msg, name->type);
	msg_set_nameinst(msg, name->instance);
	msg_set_lookup_scope(msg, tipc_addr_scope(domain));
	destport = tipc_nametbl_translate(name->type, name->instance, &destnode);
	msg_set_destnode(msg, destnode);
	msg_set_destport(msg, destport);

	if (likely(destport)) {
		p_ptr->sent++;
		if (likely(destnode == tipc_own_addr))
			return tipc_port_recv_sections(p_ptr, num_sect, msg_sect);
		res = tipc_link_send_sections_fast(p_ptr, msg_sect, num_sect,
						   destnode);
		if (likely(res != -ELINKCONG))
			return res;
		if (port_unreliable(p_ptr)) {
			/* Just calculate msg length and return */
			return tipc_msg_calc_data_size(msg_sect, num_sect);
		}
		return -ELINKCONG;
	}
	return tipc_port_reject_sections(p_ptr, msg, msg_sect, num_sect,
					 TIPC_ERR_NO_NAME);
}

/**
 * tipc_send2port - send message sections to port identity
 */

int tipc_send2port(u32 ref, struct tipc_portid const *dest,
	   unsigned int num_sect, struct iovec const *msg_sect)
{
	struct port *p_ptr;
	struct tipc_msg *msg;
	int res;

	p_ptr = tipc_port_deref(ref);
	if (!p_ptr || p_ptr->publ.connected)
		return -EINVAL;

	msg = &p_ptr->publ.phdr;
	msg_set_type(msg, TIPC_DIRECT_MSG);
	msg_set_orignode(msg, tipc_own_addr);
	msg_set_origport(msg, ref);
	msg_set_destnode(msg, dest->node);
	msg_set_destport(msg, dest->ref);
	msg_set_hdr_sz(msg, DIR_MSG_H_SIZE);
	p_ptr->sent++;
	if (dest->node == tipc_own_addr)
		return tipc_port_recv_sections(p_ptr, num_sect, msg_sect);
	res = tipc_link_send_sections_fast(p_ptr, msg_sect, num_sect, dest->node);
	if (likely(res != -ELINKCONG))
		return res;
	if (port_unreliable(p_ptr)) {
		/* Just calculate msg length and return */
		return tipc_msg_calc_data_size(msg_sect, num_sect);
	}
	return -ELINKCONG;
}

/**
 * tipc_send_buf2port - send message buffer to port identity
 */

int tipc_send_buf2port(u32 ref, struct tipc_portid const *dest,
	       struct sk_buff *buf, unsigned int dsz)
{
	struct port *p_ptr;
	struct tipc_msg *msg;
	int res;

	p_ptr = (struct port *)tipc_ref_deref(ref);
	if (!p_ptr || p_ptr->publ.connected)
		return -EINVAL;

	msg = &p_ptr->publ.phdr;
	msg_set_type(msg, TIPC_DIRECT_MSG);
	msg_set_orignode(msg, tipc_own_addr);
	msg_set_origport(msg, ref);
	msg_set_destnode(msg, dest->node);
	msg_set_destport(msg, dest->ref);
	msg_set_hdr_sz(msg, DIR_MSG_H_SIZE);
	msg_set_size(msg, DIR_MSG_H_SIZE + dsz);
	if (skb_cow(buf, DIR_MSG_H_SIZE))
		return -ENOMEM;

	skb_push(buf, DIR_MSG_H_SIZE);
	skb_copy_to_linear_data(buf, msg, DIR_MSG_H_SIZE);
	msg_dbg(msg, "buf2port: ");
	p_ptr->sent++;
	if (dest->node == tipc_own_addr)
		return tipc_port_recv_msg(buf);
	res = tipc_send_buf_fast(buf, dest->node);
	if (likely(res != -ELINKCONG))
		return res;
	if (port_unreliable(p_ptr))
		return dsz;
	return -ELINKCONG;
}