Skip to content
Snippets Groups Projects
Select Git revision
  • 0266725ad4ee0f8fcf2ee73be8e68c4adbf2ac79
  • vme-testing default
  • ci-test
  • master
  • remoteproc
  • am625-sk-ov5640
  • pcal6534-upstreaming
  • lps22df-upstreaming
  • msc-upstreaming
  • imx8mp
  • iio/noa1305
  • vme-next
  • vme-next-4.14-rc4
  • v4.14-rc4
  • v4.14-rc3
  • v4.14-rc2
  • v4.14-rc1
  • v4.13
  • vme-next-4.13-rc7
  • v4.13-rc7
  • v4.13-rc6
  • v4.13-rc5
  • v4.13-rc4
  • v4.13-rc3
  • v4.13-rc2
  • v4.13-rc1
  • v4.12
  • v4.12-rc7
  • v4.12-rc6
  • v4.12-rc5
  • v4.12-rc4
  • v4.12-rc3
32 results

root.c

Blame
  • port.c 17.33 KiB
    /*
     * net/tipc/port.c: TIPC port code
     *
     * Copyright (c) 1992-2007, 2014, Ericsson AB
     * Copyright (c) 2004-2008, 2010-2013, 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 "socket.h"
    
    /* Connection management: */
    #define PROBING_INTERVAL 3600000	/* [ms] => 1 h */
    #define CONFIRMED 0
    #define PROBING 1
    
    #define MAX_REJECT_SIZE 1024
    
    DEFINE_SPINLOCK(tipc_port_list_lock);
    
    static LIST_HEAD(ports);
    static void port_handle_node_down(unsigned long ref);
    static struct sk_buff *port_build_self_abort_msg(struct tipc_port *, u32 err);
    static struct sk_buff *port_build_peer_abort_msg(struct tipc_port *, u32 err);
    static void port_timeout(unsigned long ref);
    
    /**
     * tipc_port_peer_msg - verify message was sent by connected port's peer
     *
     * Handles cases where the node's network address has changed from
     * the default of <0.0.0> to its configured setting.
     */
    int tipc_port_peer_msg(struct tipc_port *p_ptr, struct tipc_msg *msg)
    {
    	u32 peernode;
    	u32 orignode;
    
    	if (msg_origport(msg) != tipc_port_peerport(p_ptr))
    		return 0;
    
    	orignode = msg_orignode(msg);
    	peernode = tipc_port_peernode(p_ptr);
    	return (orignode == peernode) ||
    		(!orignode && (peernode == tipc_own_addr)) ||
    		(!peernode && (orignode == tipc_own_addr));
    }
    
    /**
     * tipc_port_mcast_xmit - send a multicast message to local and remote
     * destinations
     */
    int tipc_port_mcast_xmit(struct tipc_port *oport,
    			 struct tipc_name_seq const *seq,
    			 struct iovec const *msg_sect,
    			 unsigned int len)
    {
    	struct tipc_msg *hdr;
    	struct sk_buff *buf;
    	struct sk_buff *ibuf = NULL;
    	struct tipc_port_list dports = {0, NULL, };
    	int ext_targets;
    	int res;
    
    	/* Create multicast message */
    	hdr = &oport->phdr;
    	msg_set_type(hdr, TIPC_MCAST_MSG);
    	msg_set_lookup_scope(hdr, TIPC_CLUSTER_SCOPE);
    	msg_set_destport(hdr, 0);
    	msg_set_destnode(hdr, 0);
    	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, len, MAX_MSG_SIZE, &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);
    				kfree_skb(buf);
    				return -ENOMEM;
    			}
    		}
    		res = tipc_bclink_xmit(buf);
    		if ((res < 0) && (dports.count != 0))
    			kfree_skb(ibuf);
    	} else {
    		ibuf = buf;
    	}
    
    	if (res >= 0) {
    		if (ibuf)
    			tipc_port_mcast_rcv(ibuf, &dports);
    	} else {
    		tipc_port_list_free(&dports);
    	}
    	return res;
    }
    
    /**
     * tipc_port_mcast_rcv - deliver multicast message to all destination ports
     *
     * If there is no port list, perform a lookup to create one
     */
    void tipc_port_mcast_rcv(struct sk_buff *buf, struct tipc_port_list *dp)
    {
    	struct tipc_msg *msg;
    	struct tipc_port_list dports = {0, NULL, };
    	struct tipc_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) {
    		msg_set_destnode(msg, tipc_own_addr);
    		if (dp->count == 1) {
    			msg_set_destport(msg, dp->ports[0]);
    			tipc_sk_rcv(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) {
    				pr_warn("Unable to deliver multicast message(s)\n");
    				goto exit;
    			}
    			if ((index == 0) && (cnt != 0))
    				item = item->next;
    			msg_set_destport(buf_msg(b), item->ports[index]);
    			tipc_sk_rcv(b);
    		}
    	}
    exit:
    	kfree_skb(buf);
    	tipc_port_list_free(dp);
    }
    
    
    void tipc_port_wakeup(struct tipc_port *port)
    {
    	tipc_sock_wakeup(tipc_port_to_sock(port));
    }
    
    /* tipc_port_init - intiate TIPC port and lock it
     *
     * Returns obtained reference if initialization is successful, zero otherwise
     */
    u32 tipc_port_init(struct tipc_port *p_ptr,
    		   const unsigned int importance)
    {
    	struct tipc_msg *msg;
    	u32 ref;
    
    	ref = tipc_ref_acquire(p_ptr, &p_ptr->lock);
    	if (!ref) {
    		pr_warn("Port registration failed, ref. table exhausted\n");
    		return 0;
    	}
    
    	p_ptr->max_pkt = MAX_PKT_DEFAULT;
    	p_ptr->sent = 1;
    	p_ptr->ref = ref;
    	INIT_LIST_HEAD(&p_ptr->wait_list);
    	INIT_LIST_HEAD(&p_ptr->subscription.nodesub_list);
    	k_init_timer(&p_ptr->timer, (Handler)port_timeout, ref);
    	INIT_LIST_HEAD(&p_ptr->publications);
    	INIT_LIST_HEAD(&p_ptr->port_list);
    
    	/*
    	 * Must hold port list lock while initializing message header template
    	 * to ensure a change to node's own network address doesn't result
    	 * in template containing out-dated network address information
    	 */
    	spin_lock_bh(&tipc_port_list_lock);
    	msg = &p_ptr->phdr;
    	tipc_msg_init(msg, importance, TIPC_NAMED_MSG, NAMED_H_SIZE, 0);
    	msg_set_origport(msg, ref);
    	list_add_tail(&p_ptr->port_list, &ports);
    	spin_unlock_bh(&tipc_port_list_lock);
    	return ref;
    }
    
    void tipc_port_destroy(struct tipc_port *p_ptr)
    {
    	struct sk_buff *buf = NULL;
    	struct tipc_msg *msg = NULL;
    	u32 peer;
    
    	tipc_withdraw(p_ptr, 0, NULL);
    
    	spin_lock_bh(p_ptr->lock);
    	tipc_ref_discard(p_ptr->ref);
    	spin_unlock_bh(p_ptr->lock);
    
    	k_cancel_timer(&p_ptr->timer);
    	if (p_ptr->connected) {
    		buf = port_build_peer_abort_msg(p_ptr, TIPC_ERR_NO_PORT);
    		tipc_nodesub_unsubscribe(&p_ptr->subscription);
    		msg = buf_msg(buf);
    		peer = msg_destnode(msg);
    		tipc_link_xmit2(buf, peer, msg_link_selector(msg));
    	}
    	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);
    }
    
    /*
     * port_build_proto_msg(): create connection protocol message for port
     *
     * On entry the port must be locked and connected.
     */
    static struct sk_buff *port_build_proto_msg(struct tipc_port *p_ptr,
    					    u32 type, u32 ack)
    {
    	struct sk_buff *buf;
    	struct tipc_msg *msg;
    
    	buf = tipc_buf_acquire(INT_H_SIZE);
    	if (buf) {
    		msg = buf_msg(buf);
    		tipc_msg_init(msg, CONN_MANAGER, type, INT_H_SIZE,
    			      tipc_port_peernode(p_ptr));
    		msg_set_destport(msg, tipc_port_peerport(p_ptr));
    		msg_set_origport(msg, p_ptr->ref);
    		msg_set_msgcnt(msg, ack);
    		buf->next = NULL;
    	}
    	return buf;
    }
    
    static void port_timeout(unsigned long ref)
    {
    	struct tipc_port *p_ptr = tipc_port_lock(ref);
    	struct sk_buff *buf = NULL;
    	struct tipc_msg *msg = NULL;
    
    	if (!p_ptr)
    		return;
    
    	if (!p_ptr->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(p_ptr, CONN_PROBE, 0);
    		p_ptr->probing_state = PROBING;
    		k_start_timer(&p_ptr->timer, p_ptr->probing_interval);
    	}
    	tipc_port_unlock(p_ptr);
    	msg = buf_msg(buf);
    	tipc_link_xmit2(buf, msg_destnode(msg),	msg_link_selector(msg));
    }
    
    
    static void port_handle_node_down(unsigned long ref)
    {
    	struct tipc_port *p_ptr = tipc_port_lock(ref);
    	struct sk_buff *buf = NULL;
    	struct tipc_msg *msg = NULL;
    
    	if (!p_ptr)
    		return;
    	buf = port_build_self_abort_msg(p_ptr, TIPC_ERR_NO_NODE);
    	tipc_port_unlock(p_ptr);
    	msg = buf_msg(buf);
    	tipc_link_xmit2(buf, msg_destnode(msg),	msg_link_selector(msg));
    }
    
    
    static struct sk_buff *port_build_self_abort_msg(struct tipc_port *p_ptr, u32 err)
    {
    	struct sk_buff *buf = port_build_peer_abort_msg(p_ptr, err);
    
    	if (buf) {
    		struct tipc_msg *msg = buf_msg(buf);
    		msg_swap_words(msg, 4, 5);
    		msg_swap_words(msg, 6, 7);
    		buf->next = NULL;
    	}
    	return buf;
    }
    
    
    static struct sk_buff *port_build_peer_abort_msg(struct tipc_port *p_ptr, u32 err)
    {
    	struct sk_buff *buf;
    	struct tipc_msg *msg;
    	u32 imp;
    
    	if (!p_ptr->connected)
    		return NULL;
    
    	buf = tipc_buf_acquire(BASIC_H_SIZE);
    	if (buf) {
    		msg = buf_msg(buf);
    		memcpy(msg, &p_ptr->phdr, BASIC_H_SIZE);
    		msg_set_hdr_sz(msg, BASIC_H_SIZE);
    		msg_set_size(msg, BASIC_H_SIZE);
    		imp = msg_importance(msg);
    		if (imp < TIPC_CRITICAL_IMPORTANCE)
    			msg_set_importance(msg, ++imp);
    		msg_set_errcode(msg, err);
    		buf->next = NULL;
    	}
    	return buf;
    }
    
    void tipc_port_proto_rcv(struct tipc_port *p_ptr, struct sk_buff *buf)
    {
    	struct tipc_msg *msg = buf_msg(buf);
    	struct sk_buff *r_buf = NULL;
    	u32 destport = msg_destport(msg);
    	int wakeable;
    
    	/* Validate connection */
    	if (!p_ptr || !p_ptr->connected || !tipc_port_peer_msg(p_ptr, msg)) {
    		r_buf = tipc_buf_acquire(BASIC_H_SIZE);
    		if (r_buf) {
    			msg = buf_msg(r_buf);
    			tipc_msg_init(msg, TIPC_HIGH_IMPORTANCE, TIPC_CONN_MSG,
    				      BASIC_H_SIZE, msg_orignode(msg));
    			msg_set_errcode(msg, TIPC_ERR_NO_PORT);
    			msg_set_origport(msg, destport);
    			msg_set_destport(msg, msg_origport(msg));
    		}
    		goto exit;
    	}
    
    	/* Process protocol message sent by peer */
    	switch (msg_type(msg)) {
    	case CONN_ACK:
    		wakeable = tipc_port_congested(p_ptr) && p_ptr->congested;
    		p_ptr->acked += msg_msgcnt(msg);
    		if (!tipc_port_congested(p_ptr)) {
    			p_ptr->congested = 0;
    			if (wakeable)
    				tipc_port_wakeup(p_ptr);
    		}
    		break;
    	case CONN_PROBE:
    		r_buf = port_build_proto_msg(p_ptr, CONN_PROBE_REPLY, 0);
    		break;
    	default:
    		/* CONN_PROBE_REPLY or unrecognized - no action required */
    		break;
    	}
    	p_ptr->probing_state = CONFIRMED;
    exit:
    	tipc_link_xmit2(r_buf, msg_destnode(msg), msg_link_selector(msg));
    	kfree_skb(buf);
    }
    
    static int port_print(struct tipc_port *p_ptr, char *buf, int len, int full_id)
    {
    	struct publication *publ;
    	int ret;
    
    	if (full_id)
    		ret = tipc_snprintf(buf, len, "<%u.%u.%u:%u>:",
    				    tipc_zone(tipc_own_addr),
    				    tipc_cluster(tipc_own_addr),
    				    tipc_node(tipc_own_addr), p_ptr->ref);
    	else
    		ret = tipc_snprintf(buf, len, "%-10u:", p_ptr->ref);
    
    	if (p_ptr->connected) {
    		u32 dport = tipc_port_peerport(p_ptr);
    		u32 destnode = tipc_port_peernode(p_ptr);
    
    		ret += tipc_snprintf(buf + ret, len - ret,
    				     " connected to <%u.%u.%u:%u>",
    				     tipc_zone(destnode),
    				     tipc_cluster(destnode),
    				     tipc_node(destnode), dport);
    		if (p_ptr->conn_type != 0)
    			ret += tipc_snprintf(buf + ret, len - ret,
    					     " via {%u,%u}", p_ptr->conn_type,
    					     p_ptr->conn_instance);
    	} else if (p_ptr->published) {
    		ret += tipc_snprintf(buf + ret, len - ret, " bound to");
    		list_for_each_entry(publ, &p_ptr->publications, pport_list) {
    			if (publ->lower == publ->upper)
    				ret += tipc_snprintf(buf + ret, len - ret,
    						     " {%u,%u}", publ->type,
    						     publ->lower);
    			else
    				ret += tipc_snprintf(buf + ret, len - ret,
    						     " {%u,%u,%u}", publ->type,
    						     publ->lower, publ->upper);
    		}
    	}
    	ret += tipc_snprintf(buf + ret, len - ret, "\n");
    	return ret;
    }
    
    struct sk_buff *tipc_port_get_ports(void)
    {
    	struct sk_buff *buf;
    	struct tlv_desc *rep_tlv;
    	char *pb;
    	int pb_len;
    	struct tipc_port *p_ptr;
    	int str_len = 0;
    
    	buf = tipc_cfg_reply_alloc(TLV_SPACE(ULTRA_STRING_MAX_LEN));
    	if (!buf)
    		return NULL;
    	rep_tlv = (struct tlv_desc *)buf->data;
    	pb = TLV_DATA(rep_tlv);
    	pb_len = ULTRA_STRING_MAX_LEN;
    
    	spin_lock_bh(&tipc_port_list_lock);
    	list_for_each_entry(p_ptr, &ports, port_list) {
    		spin_lock_bh(p_ptr->lock);
    		str_len += port_print(p_ptr, pb, pb_len, 0);
    		spin_unlock_bh(p_ptr->lock);
    	}
    	spin_unlock_bh(&tipc_port_list_lock);
    	str_len += 1;	/* for "\0" */
    	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 tipc_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->phdr;
    		msg_set_prevnode(msg, tipc_own_addr);
    		msg_set_orignode(msg, tipc_own_addr);
    	}
    	spin_unlock_bh(&tipc_port_list_lock);
    }
    
    void tipc_acknowledge(u32 ref, u32 ack)
    {
    	struct tipc_port *p_ptr;
    	struct sk_buff *buf = NULL;
    	struct tipc_msg *msg;
    
    	p_ptr = tipc_port_lock(ref);
    	if (!p_ptr)
    		return;
    	if (p_ptr->connected) {
    		p_ptr->conn_unacked -= ack;
    		buf = port_build_proto_msg(p_ptr, CONN_ACK, ack);
    	}
    	tipc_port_unlock(p_ptr);
    	if (!buf)
    		return;
    	msg = buf_msg(buf);
    	tipc_link_xmit2(buf, msg_destnode(msg),	msg_link_selector(msg));
    }
    
    int tipc_publish(struct tipc_port *p_ptr, unsigned int scope,
    		 struct tipc_name_seq const *seq)
    {
    	struct publication *publ;
    	u32 key;
    
    	if (p_ptr->connected)
    		return -EINVAL;
    	key = p_ptr->ref + p_ptr->pub_count + 1;
    	if (key == p_ptr->ref)
    		return -EADDRINUSE;
    
    	publ = tipc_nametbl_publish(seq->type, seq->lower, seq->upper,
    				    scope, p_ptr->ref, key);
    	if (publ) {
    		list_add(&publ->pport_list, &p_ptr->publications);
    		p_ptr->pub_count++;
    		p_ptr->published = 1;
    		return 0;
    	}
    	return -EINVAL;
    }
    
    int tipc_withdraw(struct tipc_port *p_ptr, unsigned int scope,
    		  struct tipc_name_seq const *seq)
    {
    	struct publication *publ;
    	struct publication *tpubl;
    	int res = -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->published = 0;
    	return res;
    }
    
    int tipc_port_connect(u32 ref, struct tipc_portid const *peer)
    {
    	struct tipc_port *p_ptr;
    	int res;
    
    	p_ptr = tipc_port_lock(ref);
    	if (!p_ptr)
    		return -EINVAL;
    	res = __tipc_port_connect(ref, p_ptr, peer);
    	tipc_port_unlock(p_ptr);
    	return res;
    }
    
    /*
     * __tipc_port_connect - connect to a remote peer
     *
     * Port must be locked.
     */
    int __tipc_port_connect(u32 ref, struct tipc_port *p_ptr,
    			struct tipc_portid const *peer)
    {
    	struct tipc_msg *msg;
    	int res = -EINVAL;
    
    	if (p_ptr->published || p_ptr->connected)
    		goto exit;
    	if (!peer->ref)
    		goto exit;
    
    	msg = &p_ptr->phdr;
    	msg_set_destnode(msg, peer->node);
    	msg_set_destport(msg, peer->ref);
    	msg_set_type(msg, TIPC_CONN_MSG);
    	msg_set_lookup_scope(msg, 0);
    	msg_set_hdr_sz(msg, SHORT_H_SIZE);
    
    	p_ptr->probing_interval = PROBING_INTERVAL;
    	p_ptr->probing_state = CONFIRMED;
    	p_ptr->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:
    	p_ptr->max_pkt = tipc_node_get_mtu(peer->node, ref);
    	return res;
    }
    
    /*
     * __tipc_disconnect - disconnect port from peer
     *
     * Port must be locked.
     */
    int __tipc_port_disconnect(struct tipc_port *tp_ptr)
    {
    	if (tp_ptr->connected) {
    		tp_ptr->connected = 0;
    		/* let timer expire on it's own to avoid deadlock! */
    		tipc_nodesub_unsubscribe(&tp_ptr->subscription);
    		return 0;
    	}
    
    	return -ENOTCONN;
    }
    
    /*
     * tipc_port_disconnect(): Disconnect port form peer.
     *                    This is a node local operation.
     */
    int tipc_port_disconnect(u32 ref)
    {
    	struct tipc_port *p_ptr;
    	int res;
    
    	p_ptr = tipc_port_lock(ref);
    	if (!p_ptr)
    		return -EINVAL;
    	res = __tipc_port_disconnect(p_ptr);
    	tipc_port_unlock(p_ptr);
    	return res;
    }
    
    /*
     * tipc_port_shutdown(): Send a SHUTDOWN msg to peer and disconnect
     */
    int tipc_port_shutdown(u32 ref)
    {
    	struct tipc_msg *msg;
    	struct tipc_port *p_ptr;
    	struct sk_buff *buf = NULL;
    
    	p_ptr = tipc_port_lock(ref);
    	if (!p_ptr)
    		return -EINVAL;
    
    	buf = port_build_peer_abort_msg(p_ptr, TIPC_CONN_SHUTDOWN);
    	tipc_port_unlock(p_ptr);
    	msg = buf_msg(buf);
    	tipc_link_xmit2(buf, msg_destnode(msg),	msg_link_selector(msg));
    	return tipc_port_disconnect(ref);
    }