[deliverable/linux.git] / net / tipc / node.c

/*
 * net/tipc/node.c: TIPC node management routines
 *
 * Copyright (c) 2000-2006, Ericsson AB
 * Copyright (c) 2005-2006, 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 "config.h"
#include "node.h"
#include "name_distr.h"

#define NODE_HTABLE_SIZE 512

static void node_lost_contact(struct tipc_node *n_ptr);
static void node_established_contact(struct tipc_node *n_ptr);

static DEFINE_SPINLOCK(node_create_lock);

static struct hlist_head node_htable[NODE_HTABLE_SIZE];
LIST_HEAD(tipc_node_list);
static u32 tipc_num_nodes;

static atomic_t tipc_num_links = ATOMIC_INIT(0);

/*
 * A trivial power-of-two bitmask technique is used for speed, since this
 * operation is done for every incoming TIPC packet. The number of hash table
 * entries has been chosen so that no hash chain exceeds 8 nodes and will
 * usually be much smaller (typically only a single node).
 */
static inline unsigned int tipc_hashfn(u32 addr)
{
	return addr & (NODE_HTABLE_SIZE - 1);
}

/*
 * tipc_node_find - locate specified node object, if it exists
 */

struct tipc_node *tipc_node_find(u32 addr)
{
	struct tipc_node *node;
	struct hlist_node *pos;

	if (unlikely(!in_own_cluster_exact(addr)))
		return NULL;

	hlist_for_each_entry(node, pos, &node_htable[tipc_hashfn(addr)], hash) {
		if (node->addr == addr)
			return node;
	}
	return NULL;
}

/**
 * tipc_node_create - create neighboring node
 *
 * Currently, this routine is called by neighbor discovery code, which holds
 * net_lock for reading only.  We must take node_create_lock to ensure a node
 * isn't created twice if two different bearers discover the node at the same
 * time.  (It would be preferable to switch to holding net_lock in write mode,
 * but this is a non-trivial change.)
 */

struct tipc_node *tipc_node_create(u32 addr)
{
	struct tipc_node *n_ptr, *temp_node;

	spin_lock_bh(&node_create_lock);

	n_ptr = tipc_node_find(addr);
	if (n_ptr) {
		spin_unlock_bh(&node_create_lock);
		return n_ptr;
	}

	n_ptr = kzalloc(sizeof(*n_ptr), GFP_ATOMIC);
	if (!n_ptr) {
		spin_unlock_bh(&node_create_lock);
		warn("Node creation failed, no memory\n");
		return NULL;
	}

	n_ptr->addr = addr;
	spin_lock_init(&n_ptr->lock);
	INIT_HLIST_NODE(&n_ptr->hash);
	INIT_LIST_HEAD(&n_ptr->list);
	INIT_LIST_HEAD(&n_ptr->nsub);

	hlist_add_head(&n_ptr->hash, &node_htable[tipc_hashfn(addr)]);

	list_for_each_entry(temp_node, &tipc_node_list, list) {
		if (n_ptr->addr < temp_node->addr)
			break;
	}
	list_add_tail(&n_ptr->list, &temp_node->list);
	n_ptr->block_setup = WAIT_PEER_DOWN;
	n_ptr->signature = INVALID_NODE_SIG;

	tipc_num_nodes++;

	spin_unlock_bh(&node_create_lock);
	return n_ptr;
}

void tipc_node_delete(struct tipc_node *n_ptr)
{
	list_del(&n_ptr->list);
	hlist_del(&n_ptr->hash);
	kfree(n_ptr);

	tipc_num_nodes--;
}


/**
 * tipc_node_link_up - handle addition of link
 *
 * Link becomes active (alone or shared) or standby, depending on its priority.
 */

void tipc_node_link_up(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
{
	struct tipc_link **active = &n_ptr->active_links[0];

	n_ptr->working_links++;

	info("Established link <%s> on network plane %c\n",
	     l_ptr->name, l_ptr->b_ptr->net_plane);

	if (!active[0]) {
		active[0] = active[1] = l_ptr;
		node_established_contact(n_ptr);
		return;
	}
	if (l_ptr->priority < active[0]->priority) {
		info("New link <%s> becomes standby\n", l_ptr->name);
		return;
	}
	tipc_link_send_duplicate(active[0], l_ptr);
	if (l_ptr->priority == active[0]->priority) {
		active[0] = l_ptr;
		return;
	}
	info("Old link <%s> becomes standby\n", active[0]->name);
	if (active[1] != active[0])
		info("Old link <%s> becomes standby\n", active[1]->name);
	active[0] = active[1] = l_ptr;
}

/**
 * node_select_active_links - select active link
 */

static void node_select_active_links(struct tipc_node *n_ptr)
{
	struct tipc_link **active = &n_ptr->active_links[0];
	u32 i;
	u32 highest_prio = 0;

	active[0] = active[1] = NULL;

	for (i = 0; i < MAX_BEARERS; i++) {
		struct tipc_link *l_ptr = n_ptr->links[i];

		if (!l_ptr || !tipc_link_is_up(l_ptr) ||
		    (l_ptr->priority < highest_prio))
			continue;

		if (l_ptr->priority > highest_prio) {
			highest_prio = l_ptr->priority;
			active[0] = active[1] = l_ptr;
		} else {
			active[1] = l_ptr;
		}
	}
}

/**
 * tipc_node_link_down - handle loss of link
 */

void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
{
	struct tipc_link **active;

	n_ptr->working_links--;

	if (!tipc_link_is_active(l_ptr)) {
		info("Lost standby link <%s> on network plane %c\n",
		     l_ptr->name, l_ptr->b_ptr->net_plane);
		return;
	}
	info("Lost link <%s> on network plane %c\n",
		l_ptr->name, l_ptr->b_ptr->net_plane);

	active = &n_ptr->active_links[0];
	if (active[0] == l_ptr)
		active[0] = active[1];
	if (active[1] == l_ptr)
		active[1] = active[0];
	if (active[0] == l_ptr)
		node_select_active_links(n_ptr);
	if (tipc_node_is_up(n_ptr))
		tipc_link_changeover(l_ptr);
	else
		node_lost_contact(n_ptr);
}

int tipc_node_active_links(struct tipc_node *n_ptr)
{
	return n_ptr->active_links[0] != NULL;
}

int tipc_node_redundant_links(struct tipc_node *n_ptr)
{
	return n_ptr->working_links > 1;
}

int tipc_node_is_up(struct tipc_node *n_ptr)
{
	return tipc_node_active_links(n_ptr);
}

void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
{
	n_ptr->links[l_ptr->b_ptr->identity] = l_ptr;
	atomic_inc(&tipc_num_links);
	n_ptr->link_cnt++;
}

void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
{
	n_ptr->links[l_ptr->b_ptr->identity] = NULL;
	atomic_dec(&tipc_num_links);
	n_ptr->link_cnt--;
}

static void node_established_contact(struct tipc_node *n_ptr)
{
	tipc_k_signal((Handler)tipc_named_node_up, n_ptr->addr);

	if (n_ptr->bclink.supportable) {
		n_ptr->bclink.acked = tipc_bclink_get_last_sent();
		tipc_bclink_add_node(n_ptr->addr);
		n_ptr->bclink.supported = 1;
	}
}

static void node_name_purge_complete(unsigned long node_addr)
{
	struct tipc_node *n_ptr;

	read_lock_bh(&tipc_net_lock);
	n_ptr = tipc_node_find(node_addr);
	if (n_ptr) {
		tipc_node_lock(n_ptr);
		n_ptr->block_setup &= ~WAIT_NAMES_GONE;
		tipc_node_unlock(n_ptr);
	}
	read_unlock_bh(&tipc_net_lock);
}

static void node_lost_contact(struct tipc_node *n_ptr)
{
	char addr_string[16];
	u32 i;

	info("Lost contact with %s\n",
	     tipc_addr_string_fill(addr_string, n_ptr->addr));

	/* Flush broadcast link info associated with lost node */

	if (n_ptr->bclink.supported) {
		while (n_ptr->bclink.deferred_head) {
			struct sk_buff *buf = n_ptr->bclink.deferred_head;
			n_ptr->bclink.deferred_head = buf->next;
			kfree_skb(buf);
		}
		n_ptr->bclink.deferred_size = 0;

		if (n_ptr->bclink.defragm) {
			kfree_skb(n_ptr->bclink.defragm);
			n_ptr->bclink.defragm = NULL;
		}

		tipc_bclink_remove_node(n_ptr->addr);
		tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ);

		n_ptr->bclink.supported = 0;
	}

	/* Abort link changeover */
	for (i = 0; i < MAX_BEARERS; i++) {
		struct tipc_link *l_ptr = n_ptr->links[i];
		if (!l_ptr)
			continue;
		l_ptr->reset_checkpoint = l_ptr->next_in_no;
		l_ptr->exp_msg_count = 0;
		tipc_link_reset_fragments(l_ptr);
	}

	/* Notify subscribers */
	tipc_nodesub_notify(n_ptr);

	/* Prevent re-contact with node until cleanup is done */

	n_ptr->block_setup = WAIT_PEER_DOWN | WAIT_NAMES_GONE;
	tipc_k_signal((Handler)node_name_purge_complete, n_ptr->addr);
}

struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space)
{
	u32 domain;
	struct sk_buff *buf;
	struct tipc_node *n_ptr;
	struct tipc_node_info node_info;
	u32 payload_size;

	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);

	domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
	if (!tipc_addr_domain_valid(domain))
		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
						   " (network address)");

	read_lock_bh(&tipc_net_lock);
	if (!tipc_num_nodes) {
		read_unlock_bh(&tipc_net_lock);
		return tipc_cfg_reply_none();
	}

	/* For now, get space for all other nodes */

	payload_size = TLV_SPACE(sizeof(node_info)) * tipc_num_nodes;
	if (payload_size > 32768u) {
		read_unlock_bh(&tipc_net_lock);
		return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
						   " (too many nodes)");
	}
	buf = tipc_cfg_reply_alloc(payload_size);
	if (!buf) {
		read_unlock_bh(&tipc_net_lock);
		return NULL;
	}

	/* Add TLVs for all nodes in scope */

	list_for_each_entry(n_ptr, &tipc_node_list, list) {
		if (!tipc_in_scope(domain, n_ptr->addr))
			continue;
		node_info.addr = htonl(n_ptr->addr);
		node_info.up = htonl(tipc_node_is_up(n_ptr));
		tipc_cfg_append_tlv(buf, TIPC_TLV_NODE_INFO,
				    &node_info, sizeof(node_info));
	}

	read_unlock_bh(&tipc_net_lock);
	return buf;
}

struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space)
{
	u32 domain;
	struct sk_buff *buf;
	struct tipc_node *n_ptr;
	struct tipc_link_info link_info;
	u32 payload_size;

	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);

	domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
	if (!tipc_addr_domain_valid(domain))
		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
						   " (network address)");

	if (!tipc_own_addr)
		return tipc_cfg_reply_none();

	read_lock_bh(&tipc_net_lock);

	/* Get space for all unicast links + broadcast link */

	payload_size = TLV_SPACE(sizeof(link_info)) *
		(atomic_read(&tipc_num_links) + 1);
	if (payload_size > 32768u) {
		read_unlock_bh(&tipc_net_lock);
		return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
						   " (too many links)");
	}
	buf = tipc_cfg_reply_alloc(payload_size);
	if (!buf) {
		read_unlock_bh(&tipc_net_lock);
		return NULL;
	}

	/* Add TLV for broadcast link */

	link_info.dest = htonl(tipc_cluster_mask(tipc_own_addr));
	link_info.up = htonl(1);
	strlcpy(link_info.str, tipc_bclink_name, TIPC_MAX_LINK_NAME);
	tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, &link_info, sizeof(link_info));

	/* Add TLVs for any other links in scope */

	list_for_each_entry(n_ptr, &tipc_node_list, list) {
		u32 i;

		if (!tipc_in_scope(domain, n_ptr->addr))
			continue;
		tipc_node_lock(n_ptr);
		for (i = 0; i < MAX_BEARERS; i++) {
			if (!n_ptr->links[i])
				continue;
			link_info.dest = htonl(n_ptr->addr);
			link_info.up = htonl(tipc_link_is_up(n_ptr->links[i]));
			strcpy(link_info.str, n_ptr->links[i]->name);
			tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO,
					    &link_info, sizeof(link_info));
		}
		tipc_node_unlock(n_ptr);
	}

	read_unlock_bh(&tipc_net_lock);
	return buf;
}
Commit	Line	Data
b97bf3fd PL	1	/*
b97bf3fd PL	2	* net/tipc/node.c: TIPC node management routines
c4307285	3	*
593a5f22	4	* Copyright (c) 2000-2006, Ericsson AB
2d627b92	5	* Copyright (c) 2005-2006, 2010-2011, Wind River Systems
b97bf3fd PL	6	* All rights reserved.
b97bf3fd PL	7	*
9ea1fd3c	8	* Redistribution and use in source and binary forms, with or without
b97bf3fd PL	9	* modification, are permitted provided that the following conditions are met:
b97bf3fd PL	10	*
9ea1fd3c PL	11	* 1. Redistributions of source code must retain the above copyright
	12	* notice, this list of conditions and the following disclaimer.
	13	* 2. Redistributions in binary form must reproduce the above copyright
	14	* notice, this list of conditions and the following disclaimer in the
	15	* documentation and/or other materials provided with the distribution.
	16	* 3. Neither the names of the copyright holders nor the names of its
	17	* contributors may be used to endorse or promote products derived from
	18	* this software without specific prior written permission.
b97bf3fd	19	*
9ea1fd3c PL	20	* Alternatively, this software may be distributed under the terms of the
	21	* GNU General Public License ("GPL") version 2 as published by the Free
	22	* Software Foundation.
	23	*
	24	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
	25	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	26	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	27	* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
	28	* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	29	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	30	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	31	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	32	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	33	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
b97bf3fd PL	34	* POSSIBILITY OF SUCH DAMAGE.
	35	*/
	36
	37	#include "core.h"
	38	#include "config.h"
	39	#include "node.h"
b97bf3fd	40	#include "name_distr.h"
b97bf3fd	41
a635b46b AS	42	#define NODE_HTABLE_SIZE 512
a635b46b AS	43
6c00055a DM	44	static void node_lost_contact(struct tipc_node *n_ptr);
6c00055a DM	45	static void node_established_contact(struct tipc_node *n_ptr);
b97bf3fd	46
2ecb0924 AS	47	static DEFINE_SPINLOCK(node_create_lock);
2ecb0924 AS	48
672d99e1 AS	49	static struct hlist_head node_htable[NODE_HTABLE_SIZE];
	50	LIST_HEAD(tipc_node_list);
	51	static u32 tipc_num_nodes;
34e46258 AS	52
34e46258 AS	53	static atomic_t tipc_num_links = ATOMIC_INIT(0);
b97bf3fd	54
a635b46b AS	55	/*
	56	* A trivial power-of-two bitmask technique is used for speed, since this
	57	* operation is done for every incoming TIPC packet. The number of hash table
	58	* entries has been chosen so that no hash chain exceeds 8 nodes and will
	59	* usually be much smaller (typically only a single node).
	60	*/
	61	static inline unsigned int tipc_hashfn(u32 addr)
	62	{
	63	return addr & (NODE_HTABLE_SIZE - 1);
	64	}
	65
1ec2bb08	66	/*
672d99e1 AS	67	* tipc_node_find - locate specified node object, if it exists
	68	*/
	69
	70	struct tipc_node *tipc_node_find(u32 addr)
	71	{
	72	struct tipc_node *node;
	73	struct hlist_node *pos;
	74
336ebf5b	75	if (unlikely(!in_own_cluster_exact(addr)))
672d99e1 AS	76	return NULL;
	77
	78	hlist_for_each_entry(node, pos, &node_htable[tipc_hashfn(addr)], hash) {
	79	if (node->addr == addr)
	80	return node;
	81	}
	82	return NULL;
	83	}
	84
2ecb0924 AS	85	/**
	86	* tipc_node_create - create neighboring node
	87	*
	88	* Currently, this routine is called by neighbor discovery code, which holds
	89	* net_lock for reading only. We must take node_create_lock to ensure a node
	90	* isn't created twice if two different bearers discover the node at the same
	91	* time. (It would be preferable to switch to holding net_lock in write mode,
	92	* but this is a non-trivial change.)
	93	*/
	94
6c00055a	95	struct tipc_node *tipc_node_create(u32 addr)
b97bf3fd	96	{
672d99e1	97	struct tipc_node n_ptr, temp_node;
b97bf3fd	98
2ecb0924 AS	99	spin_lock_bh(&node_create_lock);
2ecb0924 AS	100
5af54792 AS	101	n_ptr = tipc_node_find(addr);
	102	if (n_ptr) {
	103	spin_unlock_bh(&node_create_lock);
	104	return n_ptr;
2ecb0924 AS	105	}
2ecb0924 AS	106
5af54792	107	n_ptr = kzalloc(sizeof(*n_ptr), GFP_ATOMIC);
a10bd924	108	if (!n_ptr) {
2ecb0924	109	spin_unlock_bh(&node_create_lock);
a10bd924 AS	110	warn("Node creation failed, no memory\n");
	111	return NULL;
	112	}
	113
a10bd924	114	n_ptr->addr = addr;
51a8e4de	115	spin_lock_init(&n_ptr->lock);
672d99e1 AS	116	INIT_HLIST_NODE(&n_ptr->hash);
672d99e1 AS	117	INIT_LIST_HEAD(&n_ptr->list);
a10bd924	118	INIT_LIST_HEAD(&n_ptr->nsub);
8f92df6a	119
672d99e1 AS	120	hlist_add_head(&n_ptr->hash, &node_htable[tipc_hashfn(addr)]);
	121
	122	list_for_each_entry(temp_node, &tipc_node_list, list) {
	123	if (n_ptr->addr < temp_node->addr)
	124	break;
	125	}
	126	list_add_tail(&n_ptr->list, &temp_node->list);
b4b56102	127	n_ptr->block_setup = WAIT_PEER_DOWN;
fc0eea69	128	n_ptr->signature = INVALID_NODE_SIG;
672d99e1 AS	129
672d99e1 AS	130	tipc_num_nodes++;
a10bd924	131
2ecb0924	132	spin_unlock_bh(&node_create_lock);
b97bf3fd PL	133	return n_ptr;
	134	}
	135
6c00055a	136	void tipc_node_delete(struct tipc_node *n_ptr)
b97bf3fd	137	{
672d99e1 AS	138	list_del(&n_ptr->list);
672d99e1 AS	139	hlist_del(&n_ptr->hash);
b97bf3fd	140	kfree(n_ptr);
8f92df6a	141
672d99e1	142	tipc_num_nodes--;
b97bf3fd PL	143	}
	144
	145
	146	/**
4323add6	147	* tipc_node_link_up - handle addition of link
c4307285	148	*
b97bf3fd PL	149	* Link becomes active (alone or shared) or standby, depending on its priority.
	150	*/
	151
a18c4bc3	152	void tipc_node_link_up(struct tipc_node n_ptr, struct tipc_link l_ptr)
b97bf3fd	153	{
a18c4bc3	154	struct tipc_link **active = &n_ptr->active_links[0];
b97bf3fd	155
5392d646 AS	156	n_ptr->working_links++;
5392d646 AS	157
b97bf3fd PL	158	info("Established link <%s> on network plane %c\n",
b97bf3fd PL	159	l_ptr->name, l_ptr->b_ptr->net_plane);
c4307285	160
b97bf3fd	161	if (!active[0]) {
b97bf3fd PL	162	active[0] = active[1] = l_ptr;
	163	node_established_contact(n_ptr);
	164	return;
	165	}
c4307285	166	if (l_ptr->priority < active[0]->priority) {
a10bd924	167	info("New link <%s> becomes standby\n", l_ptr->name);
b97bf3fd PL	168	return;
b97bf3fd PL	169	}
4323add6	170	tipc_link_send_duplicate(active[0], l_ptr);
c4307285	171	if (l_ptr->priority == active[0]->priority) {
b97bf3fd PL	172	active[0] = l_ptr;
	173	return;
	174	}
a10bd924 AS	175	info("Old link <%s> becomes standby\n", active[0]->name);
	176	if (active[1] != active[0])
	177	info("Old link <%s> becomes standby\n", active[1]->name);
b97bf3fd PL	178	active[0] = active[1] = l_ptr;
	179	}
	180
	181	/**
	182	* node_select_active_links - select active link
	183	*/
	184
6c00055a	185	static void node_select_active_links(struct tipc_node *n_ptr)
b97bf3fd	186	{
a18c4bc3	187	struct tipc_link **active = &n_ptr->active_links[0];
b97bf3fd PL	188	u32 i;
	189	u32 highest_prio = 0;
	190
c4307285	191	active[0] = active[1] = NULL;
b97bf3fd PL	192
b97bf3fd PL	193	for (i = 0; i < MAX_BEARERS; i++) {
a18c4bc3	194	struct tipc_link *l_ptr = n_ptr->links[i];
b97bf3fd	195
4323add6	196	if (!l_ptr \|\| !tipc_link_is_up(l_ptr) \|\|
b97bf3fd PL	197	(l_ptr->priority < highest_prio))
	198	continue;
	199
	200	if (l_ptr->priority > highest_prio) {
c4307285	201	highest_prio = l_ptr->priority;
b97bf3fd PL	202	active[0] = active[1] = l_ptr;
	203	} else {
	204	active[1] = l_ptr;
	205	}
	206	}
	207	}
	208
	209	/**
4323add6	210	* tipc_node_link_down - handle loss of link
b97bf3fd PL	211	*/
b97bf3fd PL	212
a18c4bc3	213	void tipc_node_link_down(struct tipc_node n_ptr, struct tipc_link l_ptr)
b97bf3fd	214	{
a18c4bc3	215	struct tipc_link **active;
b97bf3fd	216
5392d646 AS	217	n_ptr->working_links--;
5392d646 AS	218
4323add6	219	if (!tipc_link_is_active(l_ptr)) {
b97bf3fd PL	220	info("Lost standby link <%s> on network plane %c\n",
	221	l_ptr->name, l_ptr->b_ptr->net_plane);
	222	return;
	223	}
	224	info("Lost link <%s> on network plane %c\n",
	225	l_ptr->name, l_ptr->b_ptr->net_plane);
	226
	227	active = &n_ptr->active_links[0];
	228	if (active[0] == l_ptr)
	229	active[0] = active[1];
	230	if (active[1] == l_ptr)
	231	active[1] = active[0];
	232	if (active[0] == l_ptr)
	233	node_select_active_links(n_ptr);
c4307285	234	if (tipc_node_is_up(n_ptr))
4323add6	235	tipc_link_changeover(l_ptr);
c4307285	236	else
b97bf3fd PL	237	node_lost_contact(n_ptr);
	238	}
	239
8f19afb2	240	int tipc_node_active_links(struct tipc_node *n_ptr)
b97bf3fd	241	{
76ae0d71	242	return n_ptr->active_links[0] != NULL;
b97bf3fd PL	243	}
b97bf3fd PL	244
8f19afb2	245	int tipc_node_redundant_links(struct tipc_node *n_ptr)
b97bf3fd	246	{
a02cec21	247	return n_ptr->working_links > 1;
b97bf3fd PL	248	}
b97bf3fd PL	249
6c00055a	250	int tipc_node_is_up(struct tipc_node *n_ptr)
b97bf3fd	251	{
8f19afb2	252	return tipc_node_active_links(n_ptr);
b97bf3fd PL	253	}
b97bf3fd PL	254
a18c4bc3	255	void tipc_node_attach_link(struct tipc_node n_ptr, struct tipc_link l_ptr)
b97bf3fd	256	{
37b9c08a AS	257	n_ptr->links[l_ptr->b_ptr->identity] = l_ptr;
	258	atomic_inc(&tipc_num_links);
	259	n_ptr->link_cnt++;
b97bf3fd PL	260	}
b97bf3fd PL	261
a18c4bc3	262	void tipc_node_detach_link(struct tipc_node n_ptr, struct tipc_link l_ptr)
b97bf3fd	263	{
1fc54d8f	264	n_ptr->links[l_ptr->b_ptr->identity] = NULL;
d1bcb115	265	atomic_dec(&tipc_num_links);
b97bf3fd PL	266	n_ptr->link_cnt--;
	267	}
	268
6c00055a	269	static void node_established_contact(struct tipc_node *n_ptr)
b97bf3fd	270	{
51a8e4de	271	tipc_k_signal((Handler)tipc_named_node_up, n_ptr->addr);
b97bf3fd	272
93499313	273	if (n_ptr->bclink.supportable) {
75aba9af	274	n_ptr->bclink.acked = tipc_bclink_get_last_sent();
cd3decdf	275	tipc_bclink_add_node(n_ptr->addr);
93499313	276	n_ptr->bclink.supported = 1;
b97bf3fd	277	}
b97bf3fd PL	278	}
b97bf3fd PL	279
b4b56102	280	static void node_name_purge_complete(unsigned long node_addr)
5a68d5ee AS	281	{
	282	struct tipc_node *n_ptr;
	283
	284	read_lock_bh(&tipc_net_lock);
	285	n_ptr = tipc_node_find(node_addr);
	286	if (n_ptr) {
	287	tipc_node_lock(n_ptr);
b4b56102	288	n_ptr->block_setup &= ~WAIT_NAMES_GONE;
5a68d5ee AS	289	tipc_node_unlock(n_ptr);
	290	}
	291	read_unlock_bh(&tipc_net_lock);
	292	}
	293
6c00055a	294	static void node_lost_contact(struct tipc_node *n_ptr)
b97bf3fd	295	{
b97bf3fd PL	296	char addr_string[16];
	297	u32 i;
	298
c5bd4d85 AS	299	info("Lost contact with %s\n",
	300	tipc_addr_string_fill(addr_string, n_ptr->addr));
	301
	302	/* Flush broadcast link info associated with lost node */
c4307285	303
51a8e4de	304	if (n_ptr->bclink.supported) {
c5bd4d85 AS	305	while (n_ptr->bclink.deferred_head) {
	306	struct sk_buff *buf = n_ptr->bclink.deferred_head;
	307	n_ptr->bclink.deferred_head = buf->next;
5f6d9123	308	kfree_skb(buf);
c5bd4d85	309	}
7a54d4a9	310	n_ptr->bclink.deferred_size = 0;
c5bd4d85 AS	311
c5bd4d85 AS	312	if (n_ptr->bclink.defragm) {
5f6d9123	313	kfree_skb(n_ptr->bclink.defragm);
c5bd4d85 AS	314	n_ptr->bclink.defragm = NULL;
	315	}
	316
cd3decdf	317	tipc_bclink_remove_node(n_ptr->addr);
36559591	318	tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ);
b97bf3fd	319
c5bd4d85 AS	320	n_ptr->bclink.supported = 0;
c5bd4d85 AS	321	}
b97bf3fd PL	322
	323	/* Abort link changeover */
	324	for (i = 0; i < MAX_BEARERS; i++) {
a18c4bc3	325	struct tipc_link *l_ptr = n_ptr->links[i];
c4307285	326	if (!l_ptr)
b97bf3fd PL	327	continue;
	328	l_ptr->reset_checkpoint = l_ptr->next_in_no;
	329	l_ptr->exp_msg_count = 0;
4323add6	330	tipc_link_reset_fragments(l_ptr);
b97bf3fd PL	331	}
	332
	333	/* Notify subscribers */
f1379173	334	tipc_nodesub_notify(n_ptr);
5a68d5ee	335
b4b56102	336	/* Prevent re-contact with node until cleanup is done */
5a68d5ee	337
b4b56102 AS	338	n_ptr->block_setup = WAIT_PEER_DOWN \| WAIT_NAMES_GONE;
b4b56102 AS	339	tipc_k_signal((Handler)node_name_purge_complete, n_ptr->addr);
b97bf3fd PL	340	}
b97bf3fd PL	341
4323add6	342	struct sk_buff tipc_node_get_nodes(const void req_tlv_area, int req_tlv_space)
b97bf3fd PL	343	{
	344	u32 domain;
	345	struct sk_buff *buf;
6c00055a	346	struct tipc_node *n_ptr;
c4307285	347	struct tipc_node_info node_info;
ea13847b	348	u32 payload_size;
b97bf3fd PL	349
b97bf3fd PL	350	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
4323add6	351	return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
b97bf3fd	352
3e6c8cd5	353	domain = ntohl((__be32 )TLV_DATA(req_tlv_area));
4323add6 PL	354	if (!tipc_addr_domain_valid(domain))
	355	return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
	356	" (network address)");
b97bf3fd	357
1aad72d6	358	read_lock_bh(&tipc_net_lock);
672d99e1	359	if (!tipc_num_nodes) {
1aad72d6	360	read_unlock_bh(&tipc_net_lock);
c4307285	361	return tipc_cfg_reply_none();
1aad72d6	362	}
b97bf3fd	363
08c80e9a	364	/* For now, get space for all other nodes */
b97bf3fd	365
672d99e1	366	payload_size = TLV_SPACE(sizeof(node_info)) * tipc_num_nodes;
1aad72d6 AS	367	if (payload_size > 32768u) {
1aad72d6 AS	368	read_unlock_bh(&tipc_net_lock);
ea13847b AS	369	return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
ea13847b AS	370	" (too many nodes)");
1aad72d6	371	}
ea13847b	372	buf = tipc_cfg_reply_alloc(payload_size);
1aad72d6 AS	373	if (!buf) {
1aad72d6 AS	374	read_unlock_bh(&tipc_net_lock);
b97bf3fd	375	return NULL;
1aad72d6	376	}
b97bf3fd PL	377
	378	/* Add TLVs for all nodes in scope */
	379
672d99e1 AS	380	list_for_each_entry(n_ptr, &tipc_node_list, list) {
672d99e1 AS	381	if (!tipc_in_scope(domain, n_ptr->addr))
b97bf3fd	382	continue;
c4307285 YH	383	node_info.addr = htonl(n_ptr->addr);
	384	node_info.up = htonl(tipc_node_is_up(n_ptr));
	385	tipc_cfg_append_tlv(buf, TIPC_TLV_NODE_INFO,
4323add6	386	&node_info, sizeof(node_info));
b97bf3fd PL	387	}
b97bf3fd PL	388
1aad72d6	389	read_unlock_bh(&tipc_net_lock);
b97bf3fd PL	390	return buf;
	391	}
	392
4323add6	393	struct sk_buff tipc_node_get_links(const void req_tlv_area, int req_tlv_space)
b97bf3fd PL	394	{
	395	u32 domain;
	396	struct sk_buff *buf;
6c00055a	397	struct tipc_node *n_ptr;
c4307285	398	struct tipc_link_info link_info;
ea13847b	399	u32 payload_size;
b97bf3fd PL	400
b97bf3fd PL	401	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
4323add6	402	return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
b97bf3fd	403
3e6c8cd5	404	domain = ntohl((__be32 )TLV_DATA(req_tlv_area));
4323add6 PL	405	if (!tipc_addr_domain_valid(domain))
	406	return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
	407	" (network address)");
b97bf3fd	408
b58343f9	409	if (!tipc_own_addr)
c4307285 YH	410	return tipc_cfg_reply_none();
c4307285 YH	411
1aad72d6 AS	412	read_lock_bh(&tipc_net_lock);
1aad72d6 AS	413
7a54d4a9	414	/* Get space for all unicast links + broadcast link */
ea13847b	415
9df3b7eb	416	payload_size = TLV_SPACE(sizeof(link_info)) *
d1bcb115	417	(atomic_read(&tipc_num_links) + 1);
1aad72d6 AS	418	if (payload_size > 32768u) {
1aad72d6 AS	419	read_unlock_bh(&tipc_net_lock);
ea13847b AS	420	return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
ea13847b AS	421	" (too many links)");
1aad72d6	422	}
ea13847b	423	buf = tipc_cfg_reply_alloc(payload_size);
1aad72d6 AS	424	if (!buf) {
1aad72d6 AS	425	read_unlock_bh(&tipc_net_lock);
b97bf3fd	426	return NULL;
1aad72d6	427	}
b97bf3fd PL	428
	429	/* Add TLV for broadcast link */
	430
a3796f89	431	link_info.dest = htonl(tipc_cluster_mask(tipc_own_addr));
c4307285	432	link_info.up = htonl(1);
4b704d59	433	strlcpy(link_info.str, tipc_bclink_name, TIPC_MAX_LINK_NAME);
4323add6	434	tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, &link_info, sizeof(link_info));
b97bf3fd PL	435
	436	/* Add TLVs for any other links in scope */
	437
672d99e1	438	list_for_each_entry(n_ptr, &tipc_node_list, list) {
c4307285	439	u32 i;
b97bf3fd	440
672d99e1	441	if (!tipc_in_scope(domain, n_ptr->addr))
b97bf3fd	442	continue;
1aad72d6	443	tipc_node_lock(n_ptr);
c4307285 YH	444	for (i = 0; i < MAX_BEARERS; i++) {
	445	if (!n_ptr->links[i])
	446	continue;
	447	link_info.dest = htonl(n_ptr->addr);
	448	link_info.up = htonl(tipc_link_is_up(n_ptr->links[i]));
	449	strcpy(link_info.str, n_ptr->links[i]->name);
	450	tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO,
4323add6	451	&link_info, sizeof(link_info));
c4307285	452	}
1aad72d6	453	tipc_node_unlock(n_ptr);
b97bf3fd PL	454	}
b97bf3fd PL	455
1aad72d6	456	read_unlock_bh(&tipc_net_lock);
b97bf3fd PL	457	return buf;
b97bf3fd PL	458	}