net/tipc/name_distr.c - linux - Git at Google

 /*
  * net/tipc/name_distr.c: TIPC name distribution code
  *
  * Copyright (c) 2000-2006, Ericsson AB
  * Copyright (c) 2005, 2010-2011, 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 "link.h"
 #include "name_distr.h"

 #define ITEM_SIZE sizeof(struct distr_item)

 /**
  * struct distr_item - publication info distributed to other nodes
  * @type: name sequence type
  * @lower: name sequence lower bound
  * @upper: name sequence upper bound
  * @ref: publishing port reference
  * @key: publication key
  *
  * ===> All fields are stored in network byte order. <===
  *
  * First 3 fields identify (name or) name sequence being published.
  * Reference field uniquely identifies port that published name sequence.
  * Key field uniquely identifies publication, in the event a port has
  * multiple publications of the same name sequence.
  *
  * Note: There is no field that identifies the publishing node because it is
  * the same for all items contained within a publication message.
  */

 struct distr_item {
 	__be32 type;
 	__be32 lower;
 	__be32 upper;
 	__be32 ref;
 	__be32 key;
 };

 /**
  * List of externally visible publications by this node --
  * that is, all publications having scope > TIPC_NODE_SCOPE.
  */

 static LIST_HEAD(publ_root);
 static u32 publ_cnt;

 /**
  * publ_to_item - add publication info to a publication message
  */

 static void publ_to_item(struct distr_item *i, struct publication *p)
 {
 	i->type = htonl(p->type);
 	i->lower = htonl(p->lower);
 	i->upper = htonl(p->upper);
 	i->ref = htonl(p->ref);
 	i->key = htonl(p->key);
 }

 /**
  * named_prepare_buf - allocate & initialize a publication message
  */

 static struct sk_buff *named_prepare_buf(u32 type, u32 size, u32 dest)
 {
 	struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE + size);
 	struct tipc_msg *msg;

 	if (buf != NULL) {
 		msg = buf_msg(buf);
 		tipc_msg_init(msg, NAME_DISTRIBUTOR, type, INT_H_SIZE, dest);
 		msg_set_size(msg, INT_H_SIZE + size);
 	}
 	return buf;
 }

 static void named_cluster_distribute(struct sk_buff *buf)
 {
 	struct sk_buff *buf_copy;
 	struct tipc_node *n_ptr;

 	list_for_each_entry(n_ptr, &tipc_node_list, list) {
 		if (tipc_node_active_links(n_ptr)) {
 			buf_copy = skb_copy(buf, GFP_ATOMIC);
 			if (!buf_copy)
 				break;
 			msg_set_destnode(buf_msg(buf_copy), n_ptr->addr);
 			tipc_link_send(buf_copy, n_ptr->addr, n_ptr->addr);
 		}
 	}

 	buf_discard(buf);
 }

 /**
  * tipc_named_publish - tell other nodes about a new publication by this node
  */

 void tipc_named_publish(struct publication *publ)
 {
 	struct sk_buff *buf;
 	struct distr_item *item;

 	list_add_tail(&publ->local_list, &publ_root);
 	publ_cnt++;

 	buf = named_prepare_buf(PUBLICATION, ITEM_SIZE, 0);
 	if (!buf) {
 		warn("Publication distribution failure\n");
 		return;
 	}

 	item = (struct distr_item *)msg_data(buf_msg(buf));
 	publ_to_item(item, publ);
 	named_cluster_distribute(buf);
 }

 /**
  * tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
  */

 void tipc_named_withdraw(struct publication *publ)
 {
 	struct sk_buff *buf;
 	struct distr_item *item;

 	list_del(&publ->local_list);
 	publ_cnt--;

 	buf = named_prepare_buf(WITHDRAWAL, ITEM_SIZE, 0);
 	if (!buf) {
 		warn("Withdrawal distribution failure\n");
 		return;
 	}

 	item = (struct distr_item *)msg_data(buf_msg(buf));
 	publ_to_item(item, publ);
 	named_cluster_distribute(buf);
 }

 /**
  * tipc_named_node_up - tell specified node about all publications by this node
  */

 void tipc_named_node_up(unsigned long node)
 {
 	struct publication *publ;
 	struct distr_item *item = NULL;
 	struct sk_buff *buf = NULL;
 	u32 left = 0;
 	u32 rest;
 	u32 max_item_buf;

 	read_lock_bh(&tipc_nametbl_lock);
 	max_item_buf = TIPC_MAX_USER_MSG_SIZE / ITEM_SIZE;
 	max_item_buf *= ITEM_SIZE;
 	rest = publ_cnt * ITEM_SIZE;

 	list_for_each_entry(publ, &publ_root, local_list) {
 		if (!buf) {
 			left = (rest <= max_item_buf) ? rest : max_item_buf;
 			rest -= left;
 			buf = named_prepare_buf(PUBLICATION, left, node);
 			if (!buf) {
 				warn("Bulk publication distribution failure\n");
 				goto exit;
 			}
 			item = (struct distr_item *)msg_data(buf_msg(buf));
 		}
 		publ_to_item(item, publ);
 		item++;
 		left -= ITEM_SIZE;
 		if (!left) {
 			msg_set_link_selector(buf_msg(buf), node);
 			tipc_link_send(buf, node, node);
 			buf = NULL;
 		}
 	}
 exit:
 	read_unlock_bh(&tipc_nametbl_lock);
 }

 /**
  * named_purge_publ - remove publication associated with a failed node
  *
  * Invoked for each publication issued by a newly failed node.
  * Removes publication structure from name table & deletes it.
  * In rare cases the link may have come back up again when this
  * function is called, and we have two items representing the same
  * publication. Nudge this item's key to distinguish it from the other.
  */

 static void named_purge_publ(struct publication *publ)
 {
 	struct publication *p;

 	write_lock_bh(&tipc_nametbl_lock);
 	publ->key += 1222345;
 	p = tipc_nametbl_remove_publ(publ->type, publ->lower,
 				     publ->node, publ->ref, publ->key);
 	if (p)
 		tipc_nodesub_unsubscribe(&p->subscr);
 	write_unlock_bh(&tipc_nametbl_lock);

 	if (p != publ) {
 		err("Unable to remove publication from failed node\n"
 		    "(type=%u, lower=%u, node=0x%x, ref=%u, key=%u)\n",
 		    publ->type, publ->lower, publ->node, publ->ref, publ->key);
 	}

 	kfree(p);
 }

 /**
  * tipc_named_recv - process name table update message sent by another node
  */

 void tipc_named_recv(struct sk_buff *buf)
 {
 	struct publication *publ;
 	struct tipc_msg *msg = buf_msg(buf);
 	struct distr_item *item = (struct distr_item *)msg_data(msg);
 	u32 count = msg_data_sz(msg) / ITEM_SIZE;

 	write_lock_bh(&tipc_nametbl_lock);
 	while (count--) {
 		if (msg_type(msg) == PUBLICATION) {
 			publ = tipc_nametbl_insert_publ(ntohl(item->type),
 							ntohl(item->lower),
 							ntohl(item->upper),
 							TIPC_CLUSTER_SCOPE,
 							msg_orignode(msg),
 							ntohl(item->ref),
 							ntohl(item->key));
 			if (publ) {
 				tipc_nodesub_subscribe(&publ->subscr,
 						       msg_orignode(msg),
 						       publ,
 						       (net_ev_handler)
 						       named_purge_publ);
 			}
 		} else if (msg_type(msg) == WITHDRAWAL) {
 			publ = tipc_nametbl_remove_publ(ntohl(item->type),
 							ntohl(item->lower),
 							msg_orignode(msg),
 							ntohl(item->ref),
 							ntohl(item->key));

 			if (publ) {
 				tipc_nodesub_unsubscribe(&publ->subscr);
 				kfree(publ);
 			} else {
 				err("Unable to remove publication by node 0x%x\n"
 				    "(type=%u, lower=%u, ref=%u, key=%u)\n",
 				    msg_orignode(msg),
 				    ntohl(item->type), ntohl(item->lower),
 				    ntohl(item->ref), ntohl(item->key));
 			}
 		} else {
 			warn("Unrecognized name table message received\n");
 		}
 		item++;
 	}
 	write_unlock_bh(&tipc_nametbl_lock);
 	buf_discard(buf);
 }

 /**
  * tipc_named_reinit - re-initialize local publication list
  *
  * This routine is called whenever TIPC networking is (re)enabled.
  * All existing publications by this node that have "cluster" or "zone" scope
  * are updated to reflect the node's current network address.
  * (If the node's address is unchanged, the update loop terminates immediately.)
  */

 void tipc_named_reinit(void)
 {
 	struct publication *publ;

 	write_lock_bh(&tipc_nametbl_lock);
 	list_for_each_entry(publ, &publ_root, local_list) {
 		if (publ->node == tipc_own_addr)
 			break;
 		publ->node = tipc_own_addr;
 	}
 	write_unlock_bh(&tipc_nametbl_lock);
 }
	/*
	* net/tipc/name_distr.c: TIPC name distribution code
	*
	* Copyright (c) 2000-2006, Ericsson AB
	* Copyright (c) 2005, 2010-2011, 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 "link.h"
	#include "name_distr.h"

	#define ITEM_SIZE sizeof(struct distr_item)

	/**
	* struct distr_item - publication info distributed to other nodes
	* @type: name sequence type
	* @lower: name sequence lower bound
	* @upper: name sequence upper bound
	* @ref: publishing port reference
	* @key: publication key
	*
	* ===> All fields are stored in network byte order. <===
	*
	* First 3 fields identify (name or) name sequence being published.
	* Reference field uniquely identifies port that published name sequence.
	* Key field uniquely identifies publication, in the event a port has
	* multiple publications of the same name sequence.
	*
	* Note: There is no field that identifies the publishing node because it is
	* the same for all items contained within a publication message.
	*/

	struct distr_item {
	__be32 type;
	__be32 lower;
	__be32 upper;
	__be32 ref;
	__be32 key;
	};

	/**
	* List of externally visible publications by this node --
	* that is, all publications having scope > TIPC_NODE_SCOPE.
	*/

	static LIST_HEAD(publ_root);
	static u32 publ_cnt;

	/**
	* publ_to_item - add publication info to a publication message
	*/

	static void publ_to_item(struct distr_item i, struct publication p)
	{
	i->type = htonl(p->type);
	i->lower = htonl(p->lower);
	i->upper = htonl(p->upper);
	i->ref = htonl(p->ref);
	i->key = htonl(p->key);
	}

	/**
	* named_prepare_buf - allocate & initialize a publication message
	*/

	static struct sk_buff *named_prepare_buf(u32 type, u32 size, u32 dest)
	{
	struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE + size);
	struct tipc_msg *msg;

	if (buf != NULL) {
	msg = buf_msg(buf);
	tipc_msg_init(msg, NAME_DISTRIBUTOR, type, INT_H_SIZE, dest);
	msg_set_size(msg, INT_H_SIZE + size);
	}
	return buf;
	}

	static void named_cluster_distribute(struct sk_buff *buf)
	{
	struct sk_buff *buf_copy;
	struct tipc_node *n_ptr;

	list_for_each_entry(n_ptr, &tipc_node_list, list) {
	if (tipc_node_active_links(n_ptr)) {
	buf_copy = skb_copy(buf, GFP_ATOMIC);
	if (!buf_copy)
	break;
	msg_set_destnode(buf_msg(buf_copy), n_ptr->addr);
	tipc_link_send(buf_copy, n_ptr->addr, n_ptr->addr);
	}
	}

	buf_discard(buf);
	}

	/**
	* tipc_named_publish - tell other nodes about a new publication by this node
	*/

	void tipc_named_publish(struct publication *publ)
	{
	struct sk_buff *buf;
	struct distr_item *item;

	list_add_tail(&publ->local_list, &publ_root);
	publ_cnt++;

	buf = named_prepare_buf(PUBLICATION, ITEM_SIZE, 0);
	if (!buf) {
	warn("Publication distribution failure\n");
	return;
	}

	item = (struct distr_item *)msg_data(buf_msg(buf));
	publ_to_item(item, publ);
	named_cluster_distribute(buf);
	}

	/**
	* tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
	*/

	void tipc_named_withdraw(struct publication *publ)
	{
	struct sk_buff *buf;
	struct distr_item *item;

	list_del(&publ->local_list);
	publ_cnt--;

	buf = named_prepare_buf(WITHDRAWAL, ITEM_SIZE, 0);
	if (!buf) {
	warn("Withdrawal distribution failure\n");
	return;
	}

	item = (struct distr_item *)msg_data(buf_msg(buf));
	publ_to_item(item, publ);
	named_cluster_distribute(buf);
	}

	/**
	* tipc_named_node_up - tell specified node about all publications by this node
	*/

	void tipc_named_node_up(unsigned long node)
	{
	struct publication *publ;
	struct distr_item *item = NULL;
	struct sk_buff *buf = NULL;
	u32 left = 0;
	u32 rest;
	u32 max_item_buf;

	read_lock_bh(&tipc_nametbl_lock);
	max_item_buf = TIPC_MAX_USER_MSG_SIZE / ITEM_SIZE;
	max_item_buf *= ITEM_SIZE;
	rest = publ_cnt * ITEM_SIZE;

	list_for_each_entry(publ, &publ_root, local_list) {
	if (!buf) {
	left = (rest <= max_item_buf) ? rest : max_item_buf;
	rest -= left;
	buf = named_prepare_buf(PUBLICATION, left, node);
	if (!buf) {
	warn("Bulk publication distribution failure\n");
	goto exit;
	}
	item = (struct distr_item *)msg_data(buf_msg(buf));
	}
	publ_to_item(item, publ);
	item++;
	left -= ITEM_SIZE;
	if (!left) {
	msg_set_link_selector(buf_msg(buf), node);
	tipc_link_send(buf, node, node);
	buf = NULL;
	}
	}
	exit:
	read_unlock_bh(&tipc_nametbl_lock);
	}

	/**
	* named_purge_publ - remove publication associated with a failed node
	*
	* Invoked for each publication issued by a newly failed node.
	* Removes publication structure from name table & deletes it.
	* In rare cases the link may have come back up again when this
	* function is called, and we have two items representing the same
	* publication. Nudge this item's key to distinguish it from the other.
	*/

	static void named_purge_publ(struct publication *publ)
	{
	struct publication *p;

	write_lock_bh(&tipc_nametbl_lock);
	publ->key += 1222345;
	p = tipc_nametbl_remove_publ(publ->type, publ->lower,
	publ->node, publ->ref, publ->key);
	if (p)
	tipc_nodesub_unsubscribe(&p->subscr);
	write_unlock_bh(&tipc_nametbl_lock);

	if (p != publ) {
	err("Unable to remove publication from failed node\n"
	"(type=%u, lower=%u, node=0x%x, ref=%u, key=%u)\n",
	publ->type, publ->lower, publ->node, publ->ref, publ->key);
	}

	kfree(p);
	}

	/**
	* tipc_named_recv - process name table update message sent by another node
	*/

	void tipc_named_recv(struct sk_buff *buf)
	{
	struct publication *publ;
	struct tipc_msg *msg = buf_msg(buf);
	struct distr_item item = (struct distr_item )msg_data(msg);
	u32 count = msg_data_sz(msg) / ITEM_SIZE;

	write_lock_bh(&tipc_nametbl_lock);
	while (count--) {
	if (msg_type(msg) == PUBLICATION) {
	publ = tipc_nametbl_insert_publ(ntohl(item->type),
	ntohl(item->lower),
	ntohl(item->upper),
	TIPC_CLUSTER_SCOPE,
	msg_orignode(msg),
	ntohl(item->ref),
	ntohl(item->key));
	if (publ) {
	tipc_nodesub_subscribe(&publ->subscr,
	msg_orignode(msg),
	publ,
	(net_ev_handler)
	named_purge_publ);
	}
	} else if (msg_type(msg) == WITHDRAWAL) {
	publ = tipc_nametbl_remove_publ(ntohl(item->type),
	ntohl(item->lower),
	msg_orignode(msg),
	ntohl(item->ref),
	ntohl(item->key));

	if (publ) {
	tipc_nodesub_unsubscribe(&publ->subscr);
	kfree(publ);
	} else {
	err("Unable to remove publication by node 0x%x\n"
	"(type=%u, lower=%u, ref=%u, key=%u)\n",
	msg_orignode(msg),
	ntohl(item->type), ntohl(item->lower),
	ntohl(item->ref), ntohl(item->key));
	}
	} else {
	warn("Unrecognized name table message received\n");
	}
	item++;
	}
	write_unlock_bh(&tipc_nametbl_lock);
	buf_discard(buf);
	}

	/**
	* tipc_named_reinit - re-initialize local publication list
	*
	* This routine is called whenever TIPC networking is (re)enabled.
	* All existing publications by this node that have "cluster" or "zone" scope
	* are updated to reflect the node's current network address.
	* (If the node's address is unchanged, the update loop terminates immediately.)
	*/

	void tipc_named_reinit(void)
	{
	struct publication *publ;

	write_lock_bh(&tipc_nametbl_lock);
	list_for_each_entry(publ, &publ_root, local_list) {
	if (publ->node == tipc_own_addr)
	break;
	publ->node = tipc_own_addr;
	}
	write_unlock_bh(&tipc_nametbl_lock);
	}