net/tipc/node.c - LeafOS-Devices/android_kernel_realme_mt6785 - Gitiles

 /*
  * net/tipc/node.c: TIPC node management routines
  *
  * Copyright (c) 2000-2006, Ericsson AB
  * Copyright (c) 2005, 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 "cluster.h"
 #include "net.h"
 #include "addr.h"
 #include "node_subscr.h"
 #include "link.h"
 #include "port.h"
 #include "bearer.h"
 #include "name_distr.h"
 #include "net.h"

 void node_print(struct print_buf *buf, struct node *n_ptr, char *str);
 static void node_lost_contact(struct node *n_ptr);
 static void node_established_contact(struct node *n_ptr);

 struct node *nodes = NULL;	/* sorted list of nodes within cluster */

 u32 tipc_own_tag = 0;

 struct node *node_create(u32 addr)
 {
 	struct cluster *c_ptr;
 	struct node *n_ptr;
         struct node **curr_node;

 	n_ptr = kmalloc(sizeof(*n_ptr),GFP_ATOMIC);
         if (n_ptr != NULL) {
                 memset(n_ptr, 0, sizeof(*n_ptr));
                 n_ptr->addr = addr;
                 n_ptr->lock =  SPIN_LOCK_UNLOCKED;
                 INIT_LIST_HEAD(&n_ptr->nsub);

 		c_ptr = cluster_find(addr);
                 if (c_ptr == NULL)
                         c_ptr = cluster_create(addr);
                 if (c_ptr != NULL) {
                         n_ptr->owner = c_ptr;
                         cluster_attach_node(c_ptr, n_ptr);
                         n_ptr->last_router = -1;

                         /* Insert node into ordered list */
                         for (curr_node = &nodes; *curr_node;
 			     curr_node = &(*curr_node)->next) {
                                 if (addr < (*curr_node)->addr) {
                                         n_ptr->next = *curr_node;
                                         break;
                                 }
                         }
                         (*curr_node) = n_ptr;
                 } else {
                         kfree(n_ptr);
                         n_ptr = NULL;
                 }
         }
 	return n_ptr;
 }

 void node_delete(struct node *n_ptr)
 {
 	if (!n_ptr)
 		return;

 #if 0
 	/* Not needed because links are already deleted via bearer_stop() */

 	u32 l_num;

 	for (l_num = 0; l_num < MAX_BEARERS; l_num++) {
 		link_delete(n_ptr->links[l_num]);
 	}
 #endif

 	dbg("node %x deleted\n", n_ptr->addr);
 	kfree(n_ptr);
 }


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

 void node_link_up(struct node *n_ptr, struct link *l_ptr)
 {
 	struct link **active = &n_ptr->active_links[0];

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

 	if (!active[0]) {
 		dbg(" link %x into %x/%x\n", l_ptr, &active[0], &active[1]);
 		active[0] = active[1] = l_ptr;
 		node_established_contact(n_ptr);
 		return;
 	}
 	if (l_ptr->priority < active[0]->priority) {
 		info("Link is standby\n");
 		return;
 	}
 	link_send_duplicate(active[0], l_ptr);
 	if (l_ptr->priority == active[0]->priority) {
 		active[0] = l_ptr;
 		return;
 	}
 	info("Link <%s> on network plane %c becomes standby\n",
 	     active[0]->name, active[0]->b_ptr->net_plane);
 	active[0] = active[1] = l_ptr;
 }

 /**
  * node_select_active_links - select active link
  */

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

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

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

 		if (!l_ptr || !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;
 		}
 	}
 }

 /**
  * node_link_down - handle loss of link
  */

 void node_link_down(struct node *n_ptr, struct link *l_ptr)
 {
 	struct link **active;

 	if (!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 (node_is_up(n_ptr))
 		link_changeover(l_ptr);
 	else
 		node_lost_contact(n_ptr);
 }

 int node_has_active_links(struct node *n_ptr)
 {
 	return (n_ptr &&
 		((n_ptr->active_links[0]) || (n_ptr->active_links[1])));
 }

 int node_has_redundant_links(struct node *n_ptr)
 {
 	return (node_has_active_links(n_ptr) &&
 		(n_ptr->active_links[0] != n_ptr->active_links[1]));
 }

 int node_has_active_routes(struct node *n_ptr)
 {
 	return (n_ptr && (n_ptr->last_router >= 0));
 }

 int node_is_up(struct node *n_ptr)
 {
 	return (node_has_active_links(n_ptr) || node_has_active_routes(n_ptr));
 }

 struct node *node_attach_link(struct link *l_ptr)
 {
 	struct node *n_ptr = node_find(l_ptr->addr);

 	if (!n_ptr)
 		n_ptr = node_create(l_ptr->addr);
         if (n_ptr) {
 		u32 bearer_id = l_ptr->b_ptr->identity;
 		char addr_string[16];

                 assert(bearer_id < MAX_BEARERS);
                 if (n_ptr->link_cnt >= 2) {
 			char addr_string[16];

                         err("Attempt to create third link to %s\n",
 			    addr_string_fill(addr_string, n_ptr->addr));
                         return 0;
                 }

                 if (!n_ptr->links[bearer_id]) {
                         n_ptr->links[bearer_id] = l_ptr;
                         net.zones[tipc_zone(l_ptr->addr)]->links++;
                         n_ptr->link_cnt++;
                         return n_ptr;
                 }
                 err("Attempt to establish second link on <%s> to <%s> \n",
                     l_ptr->b_ptr->publ.name,
 		    addr_string_fill(addr_string, l_ptr->addr));
         }
 	return 0;
 }

 void node_detach_link(struct node *n_ptr, struct link *l_ptr)
 {
 	n_ptr->links[l_ptr->b_ptr->identity] = 0;
 	net.zones[tipc_zone(l_ptr->addr)]->links--;
 	n_ptr->link_cnt--;
 }

 /*
  * Routing table management - five cases to handle:
  *
  * 1: A link towards a zone/cluster external node comes up.
  *    => Send a multicast message updating routing tables of all
  *    system nodes within own cluster that the new destination
  *    can be reached via this node.
  *    (node.establishedContact()=>cluster.multicastNewRoute())
  *
  * 2: A link towards a slave node comes up.
  *    => Send a multicast message updating routing tables of all
  *    system nodes within own cluster that the new destination
  *    can be reached via this node.
  *    (node.establishedContact()=>cluster.multicastNewRoute())
  *    => Send a  message to the slave node about existence
  *    of all system nodes within cluster:
  *    (node.establishedContact()=>cluster.sendLocalRoutes())
  *
  * 3: A new cluster local system node becomes available.
  *    => Send message(s) to this particular node containing
  *    information about all cluster external and slave
  *     nodes which can be reached via this node.
  *    (node.establishedContact()==>network.sendExternalRoutes())
  *    (node.establishedContact()==>network.sendSlaveRoutes())
  *    => Send messages to all directly connected slave nodes
  *    containing information about the existence of the new node
  *    (node.establishedContact()=>cluster.multicastNewRoute())
  *
  * 4: The link towards a zone/cluster external node or slave
  *    node goes down.
  *    => Send a multcast message updating routing tables of all
  *    nodes within cluster that the new destination can not any
  *    longer be reached via this node.
  *    (node.lostAllLinks()=>cluster.bcastLostRoute())
  *
  * 5: A cluster local system node becomes unavailable.
  *    => Remove all references to this node from the local
  *    routing tables. Note: This is a completely node
  *    local operation.
  *    (node.lostAllLinks()=>network.removeAsRouter())
  *    => Send messages to all directly connected slave nodes
  *    containing information about loss of the node
  *    (node.establishedContact()=>cluster.multicastLostRoute())
  *
  */

 static void node_established_contact(struct node *n_ptr)
 {
 	struct cluster *c_ptr;

 	dbg("node_established_contact:-> %x\n", n_ptr->addr);
 	if (!node_has_active_routes(n_ptr)) {
 		k_signal((Handler)named_node_up, n_ptr->addr);
 	}

         /* Syncronize broadcast acks */
         n_ptr->bclink.acked = bclink_get_last_sent();

 	if (is_slave(tipc_own_addr))
 		return;
 	if (!in_own_cluster(n_ptr->addr)) {
 		/* Usage case 1 (see above) */
 		c_ptr = cluster_find(tipc_own_addr);
 		if (!c_ptr)
 			c_ptr = cluster_create(tipc_own_addr);
                 if (c_ptr)
                         cluster_bcast_new_route(c_ptr, n_ptr->addr, 1,
 						tipc_max_nodes);
 		return;
 	}

 	c_ptr = n_ptr->owner;
 	if (is_slave(n_ptr->addr)) {
 		/* Usage case 2 (see above) */
 		cluster_bcast_new_route(c_ptr, n_ptr->addr, 1, tipc_max_nodes);
 		cluster_send_local_routes(c_ptr, n_ptr->addr);
 		return;
 	}

 	if (n_ptr->bclink.supported) {
 		nmap_add(&cluster_bcast_nodes, n_ptr->addr);
 		if (n_ptr->addr < tipc_own_addr)
 			tipc_own_tag++;
 	}

 	/* Case 3 (see above) */
 	net_send_external_routes(n_ptr->addr);
 	cluster_send_slave_routes(c_ptr, n_ptr->addr);
 	cluster_bcast_new_route(c_ptr, n_ptr->addr, LOWEST_SLAVE,
 				highest_allowed_slave);
 }

 static void node_lost_contact(struct node *n_ptr)
 {
 	struct cluster *c_ptr;
 	struct node_subscr *ns, *tns;
 	char addr_string[16];
 	u32 i;

         /* Clean up broadcast reception remains */
         n_ptr->bclink.gap_after = n_ptr->bclink.gap_to = 0;
         while (n_ptr->bclink.deferred_head) {
                 struct sk_buff* buf = n_ptr->bclink.deferred_head;
                 n_ptr->bclink.deferred_head = buf->next;
                 buf_discard(buf);
         }
         if (n_ptr->bclink.defragm) {
                 buf_discard(n_ptr->bclink.defragm);
                 n_ptr->bclink.defragm = NULL;
         }
         if (in_own_cluster(n_ptr->addr) && n_ptr->bclink.supported) {
                 bclink_acknowledge(n_ptr, mod(n_ptr->bclink.acked + 10000));
         }

         /* Update routing tables */
 	if (is_slave(tipc_own_addr)) {
 		net_remove_as_router(n_ptr->addr);
 	} else {
 		if (!in_own_cluster(n_ptr->addr)) {
 			/* Case 4 (see above) */
 			c_ptr = cluster_find(tipc_own_addr);
 			cluster_bcast_lost_route(c_ptr, n_ptr->addr, 1,
 						 tipc_max_nodes);
 		} else {
 			/* Case 5 (see above) */
 			c_ptr = cluster_find(n_ptr->addr);
 			if (is_slave(n_ptr->addr)) {
 				cluster_bcast_lost_route(c_ptr, n_ptr->addr, 1,
 							 tipc_max_nodes);
 			} else {
 				if (n_ptr->bclink.supported) {
 					nmap_remove(&cluster_bcast_nodes,
 						    n_ptr->addr);
 					if (n_ptr->addr < tipc_own_addr)
 						tipc_own_tag--;
 				}
 				net_remove_as_router(n_ptr->addr);
 				cluster_bcast_lost_route(c_ptr, n_ptr->addr,
 							 LOWEST_SLAVE,
 							 highest_allowed_slave);
 			}
 		}
 	}
 	if (node_has_active_routes(n_ptr))
 		return;

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

 	/* Abort link changeover */
 	for (i = 0; i < MAX_BEARERS; i++) {
 		struct 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;
 		link_reset_fragments(l_ptr);
 	}

 	/* Notify subscribers */
 	list_for_each_entry_safe(ns, tns, &n_ptr->nsub, nodesub_list) {
                 ns->node = 0;
 		list_del_init(&ns->nodesub_list);
 		k_signal((Handler)ns->handle_node_down,
 			 (unsigned long)ns->usr_handle);
 	}
 }

 /**
  * node_select_next_hop - find the next-hop node for a message
  *
  * Called by when cluster local lookup has failed.
  */

 struct node *node_select_next_hop(u32 addr, u32 selector)
 {
 	struct node *n_ptr;
 	u32 router_addr;

         if (!addr_domain_valid(addr))
                 return 0;

 	/* Look for direct link to destination processsor */
 	n_ptr = node_find(addr);
 	if (n_ptr && node_has_active_links(n_ptr))
                 return n_ptr;

 	/* Cluster local system nodes *must* have direct links */
 	if (!is_slave(addr) && in_own_cluster(addr))
 		return 0;

 	/* Look for cluster local router with direct link to node */
 	router_addr = node_select_router(n_ptr, selector);
 	if (router_addr)
                 return node_select(router_addr, selector);

 	/* Slave nodes can only be accessed within own cluster via a
 	   known router with direct link -- if no router was found,give up */
 	if (is_slave(addr))
 		return 0;

 	/* Inter zone/cluster -- find any direct link to remote cluster */
 	addr = tipc_addr(tipc_zone(addr), tipc_cluster(addr), 0);
 	n_ptr = net_select_remote_node(addr, selector);
 	if (n_ptr && node_has_active_links(n_ptr))
                 return n_ptr;

 	/* Last resort -- look for any router to anywhere in remote zone */
 	router_addr =  net_select_router(addr, selector);
 	if (router_addr)
                 return node_select(router_addr, selector);

         return 0;
 }

 /**
  * node_select_router - select router to reach specified node
  *
  * Uses a deterministic and fair algorithm for selecting router node.
  */

 u32 node_select_router(struct node *n_ptr, u32 ref)
 {
 	u32 ulim;
 	u32 mask;
 	u32 start;
 	u32 r;

         if (!n_ptr)
                 return 0;

 	if (n_ptr->last_router < 0)
 		return 0;
 	ulim = ((n_ptr->last_router + 1) * 32) - 1;

 	/* Start entry must be random */
 	mask = tipc_max_nodes;
 	while (mask > ulim)
 		mask >>= 1;
 	start = ref & mask;
 	r = start;

 	/* Lookup upwards with wrap-around */
 	do {
 		if (((n_ptr->routers[r / 32]) >> (r % 32)) & 1)
 			break;
 	} while (++r <= ulim);
 	if (r > ulim) {
 		r = 1;
 		do {
 			if (((n_ptr->routers[r / 32]) >> (r % 32)) & 1)
 				break;
 		} while (++r < start);
 		assert(r != start);
 	}
 	assert(r && (r <= ulim));
 	return tipc_addr(own_zone(), own_cluster(), r);
 }

 void node_add_router(struct node *n_ptr, u32 router)
 {
 	u32 r_num = tipc_node(router);

 	n_ptr->routers[r_num / 32] =
 		((1 << (r_num % 32)) | n_ptr->routers[r_num / 32]);
 	n_ptr->last_router = tipc_max_nodes / 32;
 	while ((--n_ptr->last_router >= 0) &&
 	       !n_ptr->routers[n_ptr->last_router]);
 }

 void node_remove_router(struct node *n_ptr, u32 router)
 {
 	u32 r_num = tipc_node(router);

 	if (n_ptr->last_router < 0)
 		return;		/* No routes */

 	n_ptr->routers[r_num / 32] =
 		((~(1 << (r_num % 32))) & (n_ptr->routers[r_num / 32]));
 	n_ptr->last_router = tipc_max_nodes / 32;
 	while ((--n_ptr->last_router >= 0) &&
 	       !n_ptr->routers[n_ptr->last_router]);

 	if (!node_is_up(n_ptr))
 		node_lost_contact(n_ptr);
 }

 #if 0
 void node_print(struct print_buf *buf, struct node *n_ptr, char *str)
 {
 	u32 i;

 	tipc_printf(buf, "\n\n%s", str);
 	for (i = 0; i < MAX_BEARERS; i++) {
 		if (!n_ptr->links[i])
 			continue;
 		tipc_printf(buf, "Links[%u]: %x, ", i, n_ptr->links[i]);
 	}
 	tipc_printf(buf, "Active links: [%x,%x]\n",
 		    n_ptr->active_links[0], n_ptr->active_links[1]);
 }
 #endif

 u32 tipc_available_nodes(const u32 domain)
 {
 	struct node *n_ptr;
 	u32 cnt = 0;

 	for (n_ptr = nodes; n_ptr; n_ptr = n_ptr->next) {
 		if (!in_scope(domain, n_ptr->addr))
 			continue;
 		if (node_is_up(n_ptr))
 			cnt++;
 	}
 	return cnt;
 }

 struct sk_buff *node_get_nodes(const void *req_tlv_area, int req_tlv_space)
 {
 	u32 domain;
 	struct sk_buff *buf;
 	struct node *n_ptr;
         struct tipc_node_info node_info;

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

 	domain = *(u32 *)TLV_DATA(req_tlv_area);
 	domain = ntohl(domain);
 	if (!addr_domain_valid(domain))
 		return cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
 					      " (network address)");

         if (!nodes)
                 return cfg_reply_none();

 	/* For now, get space for all other nodes
 	   (will need to modify this when slave nodes are supported */

 	buf = cfg_reply_alloc(TLV_SPACE(sizeof(node_info)) *
 			    (tipc_max_nodes - 1));
 	if (!buf)
 		return NULL;

 	/* Add TLVs for all nodes in scope */

 	for (n_ptr = nodes; n_ptr; n_ptr = n_ptr->next) {
 		if (!in_scope(domain, n_ptr->addr))
 			continue;
                 node_info.addr = htonl(n_ptr->addr);
                 node_info.up = htonl(node_is_up(n_ptr));
 		cfg_append_tlv(buf, TIPC_TLV_NODE_INFO,
 			       &node_info, sizeof(node_info));
 	}

 	return buf;
 }

 struct sk_buff *node_get_links(const void *req_tlv_area, int req_tlv_space)
 {
 	u32 domain;
 	struct sk_buff *buf;
 	struct node *n_ptr;
         struct tipc_link_info link_info;

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

 	domain = *(u32 *)TLV_DATA(req_tlv_area);
 	domain = ntohl(domain);
 	if (!addr_domain_valid(domain))
 		return cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
 					      " (network address)");

         if (!nodes)
                 return cfg_reply_none();

 	/* For now, get space for 2 links to all other nodes + bcast link
 	   (will need to modify this when slave nodes are supported */

 	buf = cfg_reply_alloc(TLV_SPACE(sizeof(link_info)) *
 			    (2 * (tipc_max_nodes - 1) + 1));
 	if (!buf)
 		return NULL;

 	/* Add TLV for broadcast link */

         link_info.dest = tipc_own_addr & 0xfffff00;
 	link_info.dest = htonl(link_info.dest);
         link_info.up = htonl(1);
         sprintf(link_info.str, bc_link_name);
 	cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, &link_info, sizeof(link_info));

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

 	for (n_ptr = nodes; n_ptr; n_ptr = n_ptr->next) {
                 u32 i;

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

 	return buf;
 }
	/*
	* net/tipc/node.c: TIPC node management routines
	*
	* Copyright (c) 2000-2006, Ericsson AB
	* Copyright (c) 2005, 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 "cluster.h"
	#include "net.h"
	#include "addr.h"
	#include "node_subscr.h"
	#include "link.h"
	#include "port.h"
	#include "bearer.h"
	#include "name_distr.h"
	#include "net.h"

	void node_print(struct print_buf buf, struct node n_ptr, char *str);
	static void node_lost_contact(struct node *n_ptr);
	static void node_established_contact(struct node *n_ptr);

	struct node nodes = NULL; / sorted list of nodes within cluster */

	u32 tipc_own_tag = 0;

	struct node *node_create(u32 addr)
	{
	struct cluster *c_ptr;
	struct node *n_ptr;
	struct node **curr_node;

	n_ptr = kmalloc(sizeof(*n_ptr),GFP_ATOMIC);
	if (n_ptr != NULL) {
	memset(n_ptr, 0, sizeof(*n_ptr));
	n_ptr->addr = addr;
	n_ptr->lock = SPIN_LOCK_UNLOCKED;
	INIT_LIST_HEAD(&n_ptr->nsub);

	c_ptr = cluster_find(addr);
	if (c_ptr == NULL)
	c_ptr = cluster_create(addr);
	if (c_ptr != NULL) {
	n_ptr->owner = c_ptr;
	cluster_attach_node(c_ptr, n_ptr);
	n_ptr->last_router = -1;

	/* Insert node into ordered list */
	for (curr_node = &nodes; *curr_node;
	curr_node = &(*curr_node)->next) {
	if (addr < (*curr_node)->addr) {
	n_ptr->next = *curr_node;
	break;
	}
	}
	(*curr_node) = n_ptr;
	} else {
	kfree(n_ptr);
	n_ptr = NULL;
	}
	}
	return n_ptr;
	}

	void node_delete(struct node *n_ptr)
	{
	if (!n_ptr)
	return;

	#if 0
	/* Not needed because links are already deleted via bearer_stop() */

	u32 l_num;

	for (l_num = 0; l_num < MAX_BEARERS; l_num++) {
	link_delete(n_ptr->links[l_num]);
	}
	#endif

	dbg("node %x deleted\n", n_ptr->addr);
	kfree(n_ptr);
	}


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

	void node_link_up(struct node n_ptr, struct link l_ptr)
	{
	struct link **active = &n_ptr->active_links[0];

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

	if (!active[0]) {
	dbg(" link %x into %x/%x\n", l_ptr, &active[0], &active[1]);
	active[0] = active[1] = l_ptr;
	node_established_contact(n_ptr);
	return;
	}
	if (l_ptr->priority < active[0]->priority) {
	info("Link is standby\n");
	return;
	}
	link_send_duplicate(active[0], l_ptr);
	if (l_ptr->priority == active[0]->priority) {
	active[0] = l_ptr;
	return;
	}
	info("Link <%s> on network plane %c becomes standby\n",
	active[0]->name, active[0]->b_ptr->net_plane);
	active[0] = active[1] = l_ptr;
	}

	/**
	* node_select_active_links - select active link
	*/

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

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

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

	if (!l_ptr \|\| !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;
	}
	}
	}

	/**
	* node_link_down - handle loss of link
	*/

	void node_link_down(struct node n_ptr, struct link l_ptr)
	{
	struct link **active;

	if (!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 (node_is_up(n_ptr))
	link_changeover(l_ptr);
	else
	node_lost_contact(n_ptr);
	}

	int node_has_active_links(struct node *n_ptr)
	{
	return (n_ptr &&
	((n_ptr->active_links[0]) \|\| (n_ptr->active_links[1])));
	}

	int node_has_redundant_links(struct node *n_ptr)
	{
	return (node_has_active_links(n_ptr) &&
	(n_ptr->active_links[0] != n_ptr->active_links[1]));
	}

	int node_has_active_routes(struct node *n_ptr)
	{
	return (n_ptr && (n_ptr->last_router >= 0));
	}

	int node_is_up(struct node *n_ptr)
	{
	return (node_has_active_links(n_ptr) \|\| node_has_active_routes(n_ptr));
	}

	struct node node_attach_link(struct link l_ptr)
	{
	struct node *n_ptr = node_find(l_ptr->addr);

	if (!n_ptr)
	n_ptr = node_create(l_ptr->addr);
	if (n_ptr) {
	u32 bearer_id = l_ptr->b_ptr->identity;
	char addr_string[16];

	assert(bearer_id < MAX_BEARERS);
	if (n_ptr->link_cnt >= 2) {
	char addr_string[16];

	err("Attempt to create third link to %s\n",
	addr_string_fill(addr_string, n_ptr->addr));
	return 0;
	}

	if (!n_ptr->links[bearer_id]) {
	n_ptr->links[bearer_id] = l_ptr;
	net.zones[tipc_zone(l_ptr->addr)]->links++;
	n_ptr->link_cnt++;
	return n_ptr;
	}
	err("Attempt to establish second link on <%s> to <%s> \n",
	l_ptr->b_ptr->publ.name,
	addr_string_fill(addr_string, l_ptr->addr));
	}
	return 0;
	}

	void node_detach_link(struct node n_ptr, struct link l_ptr)
	{
	n_ptr->links[l_ptr->b_ptr->identity] = 0;
	net.zones[tipc_zone(l_ptr->addr)]->links--;
	n_ptr->link_cnt--;
	}

	/*
	* Routing table management - five cases to handle:
	*
	* 1: A link towards a zone/cluster external node comes up.
	* => Send a multicast message updating routing tables of all
	* system nodes within own cluster that the new destination
	* can be reached via this node.
	* (node.establishedContact()=>cluster.multicastNewRoute())
	*
	* 2: A link towards a slave node comes up.
	* => Send a multicast message updating routing tables of all
	* system nodes within own cluster that the new destination
	* can be reached via this node.
	* (node.establishedContact()=>cluster.multicastNewRoute())
	* => Send a message to the slave node about existence
	* of all system nodes within cluster:
	* (node.establishedContact()=>cluster.sendLocalRoutes())
	*
	* 3: A new cluster local system node becomes available.
	* => Send message(s) to this particular node containing
	* information about all cluster external and slave
	* nodes which can be reached via this node.
	* (node.establishedContact()==>network.sendExternalRoutes())
	* (node.establishedContact()==>network.sendSlaveRoutes())
	* => Send messages to all directly connected slave nodes
	* containing information about the existence of the new node
	* (node.establishedContact()=>cluster.multicastNewRoute())
	*
	* 4: The link towards a zone/cluster external node or slave
	* node goes down.
	* => Send a multcast message updating routing tables of all
	* nodes within cluster that the new destination can not any
	* longer be reached via this node.
	* (node.lostAllLinks()=>cluster.bcastLostRoute())
	*
	* 5: A cluster local system node becomes unavailable.
	* => Remove all references to this node from the local
	* routing tables. Note: This is a completely node
	* local operation.
	* (node.lostAllLinks()=>network.removeAsRouter())
	* => Send messages to all directly connected slave nodes
	* containing information about loss of the node
	* (node.establishedContact()=>cluster.multicastLostRoute())
	*
	*/

	static void node_established_contact(struct node *n_ptr)
	{
	struct cluster *c_ptr;

	dbg("node_established_contact:-> %x\n", n_ptr->addr);
	if (!node_has_active_routes(n_ptr)) {
	k_signal((Handler)named_node_up, n_ptr->addr);
	}

	/* Syncronize broadcast acks */
	n_ptr->bclink.acked = bclink_get_last_sent();

	if (is_slave(tipc_own_addr))
	return;
	if (!in_own_cluster(n_ptr->addr)) {
	/* Usage case 1 (see above) */
	c_ptr = cluster_find(tipc_own_addr);
	if (!c_ptr)
	c_ptr = cluster_create(tipc_own_addr);
	if (c_ptr)
	cluster_bcast_new_route(c_ptr, n_ptr->addr, 1,
	tipc_max_nodes);
	return;
	}

	c_ptr = n_ptr->owner;
	if (is_slave(n_ptr->addr)) {
	/* Usage case 2 (see above) */
	cluster_bcast_new_route(c_ptr, n_ptr->addr, 1, tipc_max_nodes);
	cluster_send_local_routes(c_ptr, n_ptr->addr);
	return;
	}

	if (n_ptr->bclink.supported) {
	nmap_add(&cluster_bcast_nodes, n_ptr->addr);
	if (n_ptr->addr < tipc_own_addr)
	tipc_own_tag++;
	}

	/* Case 3 (see above) */
	net_send_external_routes(n_ptr->addr);
	cluster_send_slave_routes(c_ptr, n_ptr->addr);
	cluster_bcast_new_route(c_ptr, n_ptr->addr, LOWEST_SLAVE,
	highest_allowed_slave);
	}

	static void node_lost_contact(struct node *n_ptr)
	{
	struct cluster *c_ptr;
	struct node_subscr ns, tns;
	char addr_string[16];
	u32 i;

	/* Clean up broadcast reception remains */
	n_ptr->bclink.gap_after = n_ptr->bclink.gap_to = 0;
	while (n_ptr->bclink.deferred_head) {
	struct sk_buff* buf = n_ptr->bclink.deferred_head;
	n_ptr->bclink.deferred_head = buf->next;
	buf_discard(buf);
	}
	if (n_ptr->bclink.defragm) {
	buf_discard(n_ptr->bclink.defragm);
	n_ptr->bclink.defragm = NULL;
	}
	if (in_own_cluster(n_ptr->addr) && n_ptr->bclink.supported) {
	bclink_acknowledge(n_ptr, mod(n_ptr->bclink.acked + 10000));
	}

	/* Update routing tables */
	if (is_slave(tipc_own_addr)) {
	net_remove_as_router(n_ptr->addr);
	} else {
	if (!in_own_cluster(n_ptr->addr)) {
	/* Case 4 (see above) */
	c_ptr = cluster_find(tipc_own_addr);
	cluster_bcast_lost_route(c_ptr, n_ptr->addr, 1,
	tipc_max_nodes);
	} else {
	/* Case 5 (see above) */
	c_ptr = cluster_find(n_ptr->addr);
	if (is_slave(n_ptr->addr)) {
	cluster_bcast_lost_route(c_ptr, n_ptr->addr, 1,
	tipc_max_nodes);
	} else {
	if (n_ptr->bclink.supported) {
	nmap_remove(&cluster_bcast_nodes,
	n_ptr->addr);
	if (n_ptr->addr < tipc_own_addr)
	tipc_own_tag--;
	}
	net_remove_as_router(n_ptr->addr);
	cluster_bcast_lost_route(c_ptr, n_ptr->addr,
	LOWEST_SLAVE,
	highest_allowed_slave);
	}
	}
	}
	if (node_has_active_routes(n_ptr))
	return;

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

	/* Abort link changeover */
	for (i = 0; i < MAX_BEARERS; i++) {
	struct 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;
	link_reset_fragments(l_ptr);
	}

	/* Notify subscribers */
	list_for_each_entry_safe(ns, tns, &n_ptr->nsub, nodesub_list) {
	ns->node = 0;
	list_del_init(&ns->nodesub_list);
	k_signal((Handler)ns->handle_node_down,
	(unsigned long)ns->usr_handle);
	}
	}

	/**
	* node_select_next_hop - find the next-hop node for a message
	*
	* Called by when cluster local lookup has failed.
	*/

	struct node *node_select_next_hop(u32 addr, u32 selector)
	{
	struct node *n_ptr;
	u32 router_addr;

	if (!addr_domain_valid(addr))
	return 0;

	/* Look for direct link to destination processsor */
	n_ptr = node_find(addr);
	if (n_ptr && node_has_active_links(n_ptr))
	return n_ptr;

	/* Cluster local system nodes must have direct links */
	if (!is_slave(addr) && in_own_cluster(addr))
	return 0;

	/* Look for cluster local router with direct link to node */
	router_addr = node_select_router(n_ptr, selector);
	if (router_addr)
	return node_select(router_addr, selector);

	/* Slave nodes can only be accessed within own cluster via a
	known router with direct link -- if no router was found,give up */
	if (is_slave(addr))
	return 0;

	/* Inter zone/cluster -- find any direct link to remote cluster */
	addr = tipc_addr(tipc_zone(addr), tipc_cluster(addr), 0);
	n_ptr = net_select_remote_node(addr, selector);
	if (n_ptr && node_has_active_links(n_ptr))
	return n_ptr;

	/* Last resort -- look for any router to anywhere in remote zone */
	router_addr = net_select_router(addr, selector);
	if (router_addr)
	return node_select(router_addr, selector);

	return 0;
	}

	/**
	* node_select_router - select router to reach specified node
	*
	* Uses a deterministic and fair algorithm for selecting router node.
	*/

	u32 node_select_router(struct node *n_ptr, u32 ref)
	{
	u32 ulim;
	u32 mask;
	u32 start;
	u32 r;

	if (!n_ptr)
	return 0;

	if (n_ptr->last_router < 0)
	return 0;
	ulim = ((n_ptr->last_router + 1) * 32) - 1;

	/* Start entry must be random */
	mask = tipc_max_nodes;
	while (mask > ulim)
	mask >>= 1;
	start = ref & mask;
	r = start;

	/* Lookup upwards with wrap-around */
	do {
	if (((n_ptr->routers[r / 32]) >> (r % 32)) & 1)
	break;
	} while (++r <= ulim);
	if (r > ulim) {
	r = 1;
	do {
	if (((n_ptr->routers[r / 32]) >> (r % 32)) & 1)
	break;
	} while (++r < start);
	assert(r != start);
	}
	assert(r && (r <= ulim));
	return tipc_addr(own_zone(), own_cluster(), r);
	}

	void node_add_router(struct node *n_ptr, u32 router)
	{
	u32 r_num = tipc_node(router);

	n_ptr->routers[r_num / 32] =
	((1 << (r_num % 32)) \| n_ptr->routers[r_num / 32]);
	n_ptr->last_router = tipc_max_nodes / 32;
	while ((--n_ptr->last_router >= 0) &&
	!n_ptr->routers[n_ptr->last_router]);
	}

	void node_remove_router(struct node *n_ptr, u32 router)
	{
	u32 r_num = tipc_node(router);

	if (n_ptr->last_router < 0)
	return; /* No routes */

	n_ptr->routers[r_num / 32] =
	((~(1 << (r_num % 32))) & (n_ptr->routers[r_num / 32]));
	n_ptr->last_router = tipc_max_nodes / 32;
	while ((--n_ptr->last_router >= 0) &&
	!n_ptr->routers[n_ptr->last_router]);

	if (!node_is_up(n_ptr))
	node_lost_contact(n_ptr);
	}

	#if 0
	void node_print(struct print_buf buf, struct node n_ptr, char *str)
	{
	u32 i;

	tipc_printf(buf, "\n\n%s", str);
	for (i = 0; i < MAX_BEARERS; i++) {
	if (!n_ptr->links[i])
	continue;
	tipc_printf(buf, "Links[%u]: %x, ", i, n_ptr->links[i]);
	}
	tipc_printf(buf, "Active links: [%x,%x]\n",
	n_ptr->active_links[0], n_ptr->active_links[1]);
	}
	#endif

	u32 tipc_available_nodes(const u32 domain)
	{
	struct node *n_ptr;
	u32 cnt = 0;

	for (n_ptr = nodes; n_ptr; n_ptr = n_ptr->next) {
	if (!in_scope(domain, n_ptr->addr))
	continue;
	if (node_is_up(n_ptr))
	cnt++;
	}
	return cnt;
	}

	struct sk_buff node_get_nodes(const void req_tlv_area, int req_tlv_space)
	{
	u32 domain;
	struct sk_buff *buf;
	struct node *n_ptr;
	struct tipc_node_info node_info;

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

	domain = (u32 )TLV_DATA(req_tlv_area);
	domain = ntohl(domain);
	if (!addr_domain_valid(domain))
	return cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
	" (network address)");

	if (!nodes)
	return cfg_reply_none();

	/* For now, get space for all other nodes
	(will need to modify this when slave nodes are supported */

	buf = cfg_reply_alloc(TLV_SPACE(sizeof(node_info)) *
	(tipc_max_nodes - 1));
	if (!buf)
	return NULL;

	/* Add TLVs for all nodes in scope */

	for (n_ptr = nodes; n_ptr; n_ptr = n_ptr->next) {
	if (!in_scope(domain, n_ptr->addr))
	continue;
	node_info.addr = htonl(n_ptr->addr);
	node_info.up = htonl(node_is_up(n_ptr));
	cfg_append_tlv(buf, TIPC_TLV_NODE_INFO,
	&node_info, sizeof(node_info));
	}

	return buf;
	}

	struct sk_buff node_get_links(const void req_tlv_area, int req_tlv_space)
	{
	u32 domain;
	struct sk_buff *buf;
	struct node *n_ptr;
	struct tipc_link_info link_info;

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

	domain = (u32 )TLV_DATA(req_tlv_area);
	domain = ntohl(domain);
	if (!addr_domain_valid(domain))
	return cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
	" (network address)");

	if (!nodes)
	return cfg_reply_none();

	/* For now, get space for 2 links to all other nodes + bcast link
	(will need to modify this when slave nodes are supported */

	buf = cfg_reply_alloc(TLV_SPACE(sizeof(link_info)) *
	(2 * (tipc_max_nodes - 1) + 1));
	if (!buf)
	return NULL;

	/* Add TLV for broadcast link */

	link_info.dest = tipc_own_addr & 0xfffff00;
	link_info.dest = htonl(link_info.dest);
	link_info.up = htonl(1);
	sprintf(link_info.str, bc_link_name);
	cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, &link_info, sizeof(link_info));

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

	for (n_ptr = nodes; n_ptr; n_ptr = n_ptr->next) {
	u32 i;

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

	return buf;
	}