text: /*
   * net/tipc/name_table.c: TIPC name table code
   *
   * Copyright (c) 2000-2006, Ericsson AB
   * Copyright (c) 2004-2008, Wind River Systems
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. Neither the names of the copyright holders nor the names of its
   *    contributors may be used to endorse or promote products derived from
   *    this software without specific prior written permission.
   *
   * Alternatively, this software may be distributed under the terms of the
   * GNU General Public License ("GPL") version 2 as published by the Free
   * Software Foundation.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include "core.h"
  #include "config.h"
  #include "dbg.h"
  #include "name_table.h"
  #include "name_distr.h"
  #include "addr.h"
  #include "node_subscr.h"
  #include "subscr.h"
  #include "port.h"
  #include "cluster.h"
  #include "bcast.h"
  
  static int tipc_nametbl_size = 1024;		/* must be a power of 2 */
  
  /**
   * struct sub_seq - container for all published instances of a name sequence
   * @lower: name sequence lower bound
   * @upper: name sequence upper bound
   * @node_list: circular list of publications made by own node
   * @cluster_list: circular list of publications made by own cluster
   * @zone_list: circular list of publications made by own zone
   * @node_list_size: number of entries in "node_list"
   * @cluster_list_size: number of entries in "cluster_list"
   * @zone_list_size: number of entries in "zone_list"
   *
   * Note: The zone list always contains at least one entry, since all
   *       publications of the associated name sequence belong to it.
   *       (The cluster and node lists may be empty.)
   */
  
  struct sub_seq {
  	u32 lower;
  	u32 upper;
  	struct publication *node_list;
  	struct publication *cluster_list;
  	struct publication *zone_list;
  	u32 node_list_size;
  	u32 cluster_list_size;
  	u32 zone_list_size;
  };
  
  /**
   * struct name_seq - container for all published instances of a name type
   * @type: 32 bit 'type' value for name sequence
   * @sseq: pointer to dynamically-sized array of sub-sequences of this 'type';
   *        sub-sequences are sorted in ascending order
   * @alloc: number of sub-sequences currently in array
   * @first_free: array index of first unused sub-sequence entry
   * @ns_list: links to adjacent name sequences in hash chain
   * @subscriptions: list of subscriptions for this 'type'
   * @lock: spinlock controlling access to publication lists of all sub-sequences
   */
  
  struct name_seq {
  	u32 type;
  	struct sub_seq *sseqs;
  	u32 alloc;
  	u32 first_free;
  	struct hlist_node ns_list;
  	struct list_head subscriptions;
  	spinlock_t lock;
  };
  
  /**
   * struct name_table - table containing all existing port name publications
   * @types: pointer to fixed-sized array of name sequence lists,
   *         accessed via hashing on 'type'; name sequence lists are *not* sorted
   * @local_publ_count: number of publications issued by this node
   */
  
  struct name_table {
  	struct hlist_head *types;
  	u32 local_publ_count;
  };
  
  static struct name_table table = { NULL } ;
  static atomic_t rsv_publ_ok = ATOMIC_INIT(0);
  DEFINE_RWLOCK(tipc_nametbl_lock);
  
  
  static int hash(int x)
  {
  	return(x & (tipc_nametbl_size - 1));
  }
  
  /**
   * publ_create - create a publication structure
   */
  
  static struct publication *publ_create(u32 type, u32 lower, u32 upper,
  				       u32 scope, u32 node, u32 port_ref,
  				       u32 key)
  {
  	struct publication *publ = kzalloc(sizeof(*publ), GFP_ATOMIC);
  	if (publ == NULL) {
  		warn("Publication creation failure, no memory\n");
  		return NULL;
  	}
  
  	publ->type = type;
  	publ->lower = lower;
  	publ->upper = upper;
  	publ->scope = scope;
  	publ->node = node;
  	publ->ref = port_ref;
  	publ->key = key;
  	INIT_LIST_HEAD(&publ->local_list);
  	INIT_LIST_HEAD(&publ->pport_list);
  	INIT_LIST_HEAD(&publ->subscr.nodesub_list);
  	return publ;
  }
  
  /**
   * tipc_subseq_alloc - allocate a specified number of sub-sequence structures
   */
  
  static struct sub_seq *tipc_subseq_alloc(u32 cnt)
  {
  	struct sub_seq *sseq = kcalloc(cnt, sizeof(struct sub_seq), GFP_ATOMIC);
  	return sseq;
  }
  
  /**
   * tipc_nameseq_create - create a name sequence structure for the specified 'type'
   *
   * Allocates a single sub-sequence structure and sets it to all 0's.
   */
  
  static struct name_seq *tipc_nameseq_create(u32 type, struct hlist_head *seq_head)
  {
  	struct name_seq *nseq = kzalloc(sizeof(*nseq), GFP_ATOMIC);
  	struct sub_seq *sseq = tipc_subseq_alloc(1);
  
  	if (!nseq || !sseq) {
  		warn("Name sequence creation failed, no memory\n");
  		kfree(nseq);
  		kfree(sseq);
  		return NULL;
  	}
  
  	spin_lock_init(&nseq->lock);
  	nseq->type = type;
  	nseq->sseqs = sseq;
  	dbg("tipc_nameseq_create(): nseq = %p, type %u, ssseqs %p, ff: %u\n",
  	    nseq, type, nseq->sseqs, nseq->first_free);
  	nseq->alloc = 1;
  	INIT_HLIST_NODE(&nseq->ns_list);
  	INIT_LIST_HEAD(&nseq->subscriptions);
  	hlist_add_head(&nseq->ns_list, seq_head);
  	return nseq;
  }
  
  /**
   * nameseq_find_subseq - find sub-sequence (if any) matching a name instance
   *
   * Very time-critical, so binary searches through sub-sequence array.
   */
  
  static struct sub_seq *nameseq_find_subseq(struct name_seq *nseq,
  					   u32 instance)
  {
  	struct sub_seq *sseqs = nseq->sseqs;
  	int low = 0;
  	int high = nseq->first_free - 1;
  	int mid;
  
  	while (low <= high) {
  		mid = (low + high) / 2;
  		if (instance < sseqs[mid].lower)
  			high = mid - 1;
  		else if (instance > sseqs[mid].upper)
  			low = mid + 1;
  		else
  			return &sseqs[mid];
  	}
  	return NULL;
  }
  
  /**
   * nameseq_locate_subseq - determine position of name instance in sub-sequence
   *
   * Returns index in sub-sequence array of the entry that contains the specified
   * instance value; if no entry contains that value, returns the position
   * where a new entry for it would be inserted in the array.
   *
   * Note: Similar to binary search code for locating a sub-sequence.
   */
  
  static u32 nameseq_locate_subseq(struct name_seq *nseq, u32 instance)
  {
  	struct sub_seq *sseqs = nseq->sseqs;
  	int low = 0;
  	int high = nseq->first_free - 1;
  	int mid;
  
  	while (low <= high) {
  		mid = (low + high) / 2;
  		if (instance < sseqs[mid].lower)
  			high = mid - 1;
  		else if (instance > sseqs[mid].upper)
  			low = mid + 1;
  		else
  			return mid;
  	}
  	return low;
  }
  
  /**
   * tipc_nameseq_insert_publ -
   */
  
  static struct publication *tipc_nameseq_insert_publ(struct name_seq *nseq,
  						    u32 type, u32 lower, u32 upper,
  						    u32 scope, u32 node, u32 port, u32 key)
  {
  	struct subscription *s;
  	struct subscription *st;
  	struct publication *publ;
  	struct sub_seq *sseq;
  	int created_subseq = 0;
  
  	sseq = nameseq_find_subseq(nseq, lower);
  	dbg("nameseq_ins: for seq %p, {%u,%u}, found sseq %p\n",
  	    nseq, type, lower, sseq);
  	if (sseq) {
  
  		/* Lower end overlaps existing entry => need an exact match */
  
  		if ((sseq->lower != lower) || (sseq->upper != upper)) {
  			warn("Cannot publish {%u,%u,%u}, overlap error\n",
  			     type, lower, upper);
  			return NULL;
  		}
  	} else {
  		u32 inspos;
  		struct sub_seq *freesseq;
  
  		/* Find where lower end should be inserted */
  
  		inspos = nameseq_locate_subseq(nseq, lower);
  
  		/* Fail if upper end overlaps into an existing entry */
  
  		if ((inspos < nseq->first_free) &&
  		    (upper >= nseq->sseqs[inspos].lower)) {
  			warn("Cannot publish {%u,%u,%u}, overlap error\n",
  			     type, lower, upper);
  			return NULL;
  		}
  
  		/* Ensure there is space for new sub-sequence */
  
  		if (nseq->first_free == nseq->alloc) {
  			struct sub_seq *sseqs = tipc_subseq_alloc(nseq->alloc * 2);
  
  			if (!sseqs) {
  				warn("Cannot publish {%u,%u,%u}, no memory\n",
  				     type, lower, upper);
  				return NULL;
  			}
  			dbg("Allocated %u more sseqs\n", nseq->alloc);
  			memcpy(sseqs, nseq->sseqs,
  			       nseq->alloc * sizeof(struct sub_seq));
  			kfree(nseq->sseqs);
  			nseq->sseqs = sseqs;
  			nseq->alloc *= 2;
  		}
  		dbg("Have %u sseqs for type %u\n", nseq->alloc, type);
  
  		/* Insert new sub-sequence */
  
  		dbg("ins in pos %u, ff = %u\n", inspos, nseq->first_free);
  		sseq = &nseq->sseqs[inspos];
  		freesseq = &nseq->sseqs[nseq->first_free];
  		memmove(sseq + 1, sseq, (freesseq - sseq) * sizeof (*sseq));
  		memset(sseq, 0, sizeof (*sseq));
  		nseq->first_free++;
  		sseq->lower = lower;
  		sseq->upper = upper;
  		created_subseq = 1;
  	}
  	dbg("inserting {%u,%u,%u} from <0x%x:%u> into sseq %p(%u,%u) of seq %p\n",
  	    type, lower, upper, node, port, sseq,
  	    sseq->lower, sseq->upper, nseq);
  
  	/* Insert a publication: */
  
  	publ = publ_create(type, lower, upper, scope, node, port, key);
  	if (!publ)
  		return NULL;
  	dbg("inserting publ %p, node=0x%x publ->node=0x%x, subscr->node=%p\n",
  	    publ, node, publ->node, publ->subscr.node);
  
  	sseq->zone_list_size++;
  	if (!sseq->zone_list)
  		sseq->zone_list = publ->zone_list_next = publ;
  	else {
  		publ->zone_list_next = sseq->zone_list->zone_list_next;
  		sseq->zone_list->zone_list_next = publ;
  	}
  
  	if (in_own_cluster(node)) {
  		sseq->cluster_list_size++;
  		if (!sseq->cluster_list)
  			sseq->cluster_list = publ->cluster_list_next = publ;
  		else {
  			publ->cluster_list_next =
  			sseq->cluster_list->cluster_list_next;
  			sseq->cluster_list->cluster_list_next = publ;
  		}
  	}
  
  	if (node == tipc_own_addr) {
  		sseq->node_list_size++;
  		if (!sseq->node_list)
  			sseq->node_list = publ->node_list_next = publ;
  		else {
  			publ->node_list_next = sseq->node_list->node_list_next;
  			sseq->node_list->node_list_next = publ;
  		}
  	}
  
  	/*
  	 * Any subscriptions waiting for notification?
  	 */
  	list_for_each_entry_safe(s, st, &nseq->subscriptions, nameseq_list) {
  		dbg("calling report_overlap()\n");
  		tipc_subscr_report_overlap(s,
  					   publ->lower,
  					   publ->upper,
  					   TIPC_PUBLISHED,
  					   publ->ref,
  					   publ->node,
  					   created_subseq);
  	}
  	return publ;
  }
  
  /**
   * tipc_nameseq_remove_publ -
   *
   * NOTE: There may be cases where TIPC is asked to remove a publication
   * that is not in the name table.  For example, if another node issues a
   * publication for a name sequence that overlaps an existing name sequence
   * the publication will not be recorded, which means the publication won't
   * be found when the name sequence is later withdrawn by that node.
   * A failed withdraw request simply returns a failure indication and lets the
   * caller issue any error or warning messages associated with such a problem.
   */
  
  static struct publication *tipc_nameseq_remove_publ(struct name_seq *nseq, u32 inst,
  						    u32 node, u32 ref, u32 key)
  {
  	struct publication *publ;
  	struct publication *curr;
  	struct publication *prev;
  	struct sub_seq *sseq = nameseq_find_subseq(nseq, inst);
  	struct sub_seq *free;
  	struct subscription *s, *st;
  	int removed_subseq = 0;
  
  	if (!sseq)
  		return NULL;
  
  	dbg("tipc_nameseq_remove_publ: seq: %p, sseq %p, {%u,%u}, key %u\n",
  	    nseq, sseq, nseq->type, inst, key);
  
  	/* Remove publication from zone scope list */
  
  	prev = sseq->zone_list;
  	publ = sseq->zone_list->zone_list_next;
  	while ((publ->key != key) || (publ->ref != ref) ||
  	       (publ->node && (publ->node != node))) {
  		prev = publ;
  		publ = publ->zone_list_next;
  		if (prev == sseq->zone_list) {
  
  			/* Prevent endless loop if publication not found */
  
  			return NULL;
  		}
  	}
  	if (publ != sseq->zone_list)
  		prev->zone_list_next = publ->zone_list_next;
  	else if (publ->zone_list_next != publ) {
  		prev->zone_list_next = publ->zone_list_next;
  		sseq->zone_list = publ->zone_list_next;
  	} else {
  		sseq->zone_list = NULL;
  	}
  	sseq->zone_list_size--;
  
  	/* Remove publication from cluster scope list, if present */
  
  	if (in_own_cluster(node)) {
  		prev = sseq->cluster_list;
  		curr = sseq->cluster_list->cluster_list_next;
  		while (curr != publ) {
  			prev = curr;
  			curr = curr->cluster_list_next;
  			if (prev == sseq->cluster_list) {
  
  				/* Prevent endless loop for malformed list */
  
  				err("Unable to de-list cluster publication\n"
  				    "{%u%u}, node=0x%x, ref=%u, key=%u)\n",
  				    publ->type, publ->lower, publ->node,
  				    publ->ref, publ->key);
  				goto end_cluster;
  			}
  		}
  		if (publ != sseq->cluster_list)
  			prev->cluster_list_next = publ->cluster_list_next;
  		else if (publ->cluster_list_next != publ) {
  			prev->cluster_list_next = publ->cluster_list_next;
  			sseq->cluster_list = publ->cluster_list_next;
  		} else {
  			sseq->cluster_list = NULL;
  		}
  		sseq->cluster_list_size--;
  	}
  end_cluster:
  
  	/* Remove publication from node scope list, if present */
  
  	if (node == tipc_own_addr) {
  		prev = sseq->node_list;
  		curr = sseq->node_list->node_list_next;
  		while (curr != publ) {
  			prev = curr;
  			curr = curr->node_list_next;
  			if (prev == sseq->node_list) {
  
  				/* Prevent endless loop for malformed list */
  
  				err("Unable to de-list node publication\n"
  				    "{%u%u}, node=0x%x, ref=%u, key=%u)\n",
  				    publ->type, publ->lower, publ->node,
  				    publ->ref, publ->key);
  				goto end_node;
  			}
  		}
  		if (publ != sseq->node_list)
  			prev->node_list_next = publ->node_list_next;
  		else if (publ->node_list_next != publ) {
  			prev->node_list_next = publ->node_list_next;
  			sseq->node_list = publ->node_list_next;
  		} else {
  			sseq->node_list = NULL;
  		}
  		sseq->node_list_size--;
  	}
  end_node:
  
  	/* Contract subseq list if no more publications for that subseq */
  
  	if (!sseq->zone_list) {
  		free = &nseq->sseqs[nseq->first_free--];
  		memmove(sseq, sseq + 1, (free - (sseq + 1)) * sizeof (*sseq));
  		removed_subseq = 1;
  	}
  
  	/* Notify any waiting subscriptions */
  
  	list_for_each_entry_safe(s, st, &nseq->subscriptions, nameseq_list) {
  		tipc_subscr_report_overlap(s,
  					   publ->lower,
  					   publ->upper,
  					   TIPC_WITHDRAWN,
  					   publ->ref,
  					   publ->node,
  					   removed_subseq);
  	}
  
  	return publ;
  }
  
  /**
   * tipc_nameseq_subscribe: attach a subscription, and issue
   * the prescribed number of events if there is any sub-
   * sequence overlapping with the requested sequence
   */
  
  static void tipc_nameseq_subscribe(struct name_seq *nseq, struct subscription *s)
  {
  	struct sub_seq *sseq = nseq->sseqs;
  
  	list_add(&s->nameseq_list, &nseq->subscriptions);
  
  	if (!sseq)
  		return;
  
  	while (sseq != &nseq->sseqs[nseq->first_free]) {
  		struct publication *zl = sseq->zone_list;
  		if (zl && tipc_subscr_overlap(s,sseq->lower,sseq->upper)) {
  			struct publication *crs = zl;
  			int must_report = 1;
  
  			do {
  				tipc_subscr_report_overlap(s,
  							   sseq->lower,
  							   sseq->upper,
  							   TIPC_PUBLISHED,
  							   crs->ref,
  							   crs->node,
  							   must_report);
  				must_report = 0;
  				crs = crs->zone_list_next;
  			} while (crs != zl);
  		}
  		sseq++;
  	}
  }
  
  static struct name_seq *nametbl_find_seq(u32 type)
  {
  	struct hlist_head *seq_head;
  	struct hlist_node *seq_node;
  	struct name_seq *ns;
  
  	dbg("find_seq %u,(%u,0x%x) table = %p, hash[type] = %u\n",
  	    type, htonl(type), type, table.types, hash(type));
  
  	seq_head = &table.types[hash(type)];
  	hlist_for_each_entry(ns, seq_node, seq_head, ns_list) {
  		if (ns->type == type) {
  			dbg("found %p\n", ns);
  			return ns;
  		}
  	}
  
  	return NULL;
  };
  
  struct publication *tipc_nametbl_insert_publ(u32 type, u32 lower, u32 upper,
  					     u32 scope, u32 node, u32 port, u32 key)
  {
  	struct name_seq *seq = nametbl_find_seq(type);
  
  	dbg("tipc_nametbl_insert_publ: {%u,%u,%u} found %p\n", type, lower, upper, seq);
  	if (lower > upper) {
  		warn("Failed to publish illegal {%u,%u,%u}\n",
  		     type, lower, upper);
  		return NULL;
  	}
  
  	dbg("Publishing {%u,%u,%u} from 0x%x\n", type, lower, upper, node);
  	if (!seq) {
  		seq = tipc_nameseq_create(type, &table.types[hash(type)]);
  		dbg("tipc_nametbl_insert_publ: created %p\n", seq);
  	}
  	if (!seq)
  		return NULL;
  
  	return tipc_nameseq_insert_publ(seq, type, lower, upper,
  					scope, node, port, key);
  }
  
  struct publication *tipc_nametbl_remove_publ(u32 type, u32 lower,
  					     u32 node, u32 ref, u32 key)
  {
  	struct publication *publ;
  	struct name_seq *seq = nametbl_find_seq(type);
  
  	if (!seq)
  		return NULL;
  
  	dbg("Withdrawing {%u,%u} from 0x%x\n", type, lower, node);
  	publ = tipc_nameseq_remove_publ(seq, lower, node, ref, key);
  
  	if (!seq->first_free && list_empty(&seq->subscriptions)) {
  		hlist_del_init(&seq->ns_list);
  		kfree(seq->sseqs);
  		kfree(seq);
  	}
  	return publ;
  }
  
  /*
   * tipc_nametbl_translate(): Translate tipc_name -> tipc_portid.
   *                      Very time-critical.
   *
   * Note: on entry 'destnode' is the search domain used during translation;
   *       on exit it passes back the node address of the matching port (if any)
   */
  
  u32 tipc_nametbl_translate(u32 type, u32 instance, u32 *destnode)
  {
  	struct sub_seq *sseq;
  	struct publication *publ = NULL;
  	struct name_seq *seq;
  	u32 ref;
  
  	if (!tipc_in_scope(*destnode, tipc_own_addr))
  		return 0;
  
  	read_lock_bh(&tipc_nametbl_lock);
  	seq = nametbl_find_seq(type);
  	if (unlikely(!seq))
  		goto not_found;
  	sseq = nameseq_find_subseq(seq, instance);
  	if (unlikely(!sseq))
  		goto not_found;
  	spin_lock_bh(&seq->lock);
  
  	/* Closest-First Algorithm: */
  	if (likely(!*destnode)) {
  		publ = sseq->node_list;
  		if (publ) {
  			sseq->node_list = publ->node_list_next;
  found:
  			ref = publ->ref;
  			*destnode = publ->node;
  			spin_unlock_bh(&seq->lock);
  			read_unlock_bh(&tipc_nametbl_lock);
  			return ref;
  		}
  		publ = sseq->cluster_list;
  		if (publ) {
  			sseq->cluster_list = publ->cluster_list_next;
  			goto found;
  		}
  		publ = sseq->zone_list;
  		if (publ) {
  			sseq->zone_list = publ->zone_list_next;
  			goto found;
  		}
  	}
  
  	/* Round-Robin Algorithm: */
  	else if (*destnode == tipc_own_addr) {
  		publ = sseq->node_list;
  		if (publ) {
  			sseq->node_list = publ->node_list_next;
  			goto found;
  		}
  	} else if (in_own_cluster(*destnode)) {
  		publ = sseq->cluster_list;
  		if (publ) {
  			sseq->cluster_list = publ->cluster_list_next;
  			goto found;
  		}
  	} else {
  		publ = sseq->zone_list;
  		if (publ) {
  			sseq->zone_list = publ->zone_list_next;
  			goto found;
  		}
  	}
  	spin_unlock_bh(&seq->lock);
  not_found:
  	*destnode = 0;
  	read_unlock_bh(&tipc_nametbl_lock);
  	return 0;
  }
  
  /**
   * tipc_nametbl_mc_translate - find multicast destinations
   *
   * Creates list of all local ports that overlap the given multicast address;
   * also determines if any off-node ports overlap.
   *
   * Note: Publications with a scope narrower than 'limit' are ignored.
   * (i.e. local node-scope publications mustn't receive messages arriving
   * from another node, even if the multcast link brought it here)
   *
   * Returns non-zero if any off-node ports overlap
   */
  
  int tipc_nametbl_mc_translate(u32 type, u32 lower, u32 upper, u32 limit,
  			      struct port_list *dports)
  {
  	struct name_seq *seq;
  	struct sub_seq *sseq;
  	struct sub_seq *sseq_stop;
  	int res = 0;
  
  	read_lock_bh(&tipc_nametbl_lock);
  	seq = nametbl_find_seq(type);
  	if (!seq)
  		goto exit;
  
  	spin_lock_bh(&seq->lock);
  
  	sseq = seq->sseqs + nameseq_locate_subseq(seq, lower);
  	sseq_stop = seq->sseqs + seq->first_free;
  	for (; sseq != sseq_stop; sseq++) {
  		struct publication *publ;
  
  		if (sseq->lower > upper)
  			break;
  
  		publ = sseq->node_list;
  		if (publ) {
  			do {
  				if (publ->scope <= limit)
  					tipc_port_list_add(dports, publ->ref);
  				publ = publ->node_list_next;
  			} while (publ != sseq->node_list);
  		}
  
  		if (sseq->cluster_list_size != sseq->node_list_size)
  			res = 1;
  	}
  
  	spin_unlock_bh(&seq->lock);
  exit:
  	read_unlock_bh(&tipc_nametbl_lock);
  	return res;
  }
  
  /**
   * tipc_nametbl_publish_rsv - publish port name using a reserved name type
   */
  
  int tipc_nametbl_publish_rsv(u32 ref, unsigned int scope,
  			struct tipc_name_seq const *seq)
  {
  	int res;
  
  	atomic_inc(&rsv_publ_ok);
  	res = tipc_publish(ref, scope, seq);
  	atomic_dec(&rsv_publ_ok);
  	return res;
  }
  
  /**
   * tipc_nametbl_publish - add name publication to network name tables
   */
  
  struct publication *tipc_nametbl_publish(u32 type, u32 lower, u32 upper,
  				    u32 scope, u32 port_ref, u32 key)
  {
  	struct publication *publ;
  
  	if (table.local_publ_count >= tipc_max_publications) {
  		warn("Publication failed, local publication limit reached (%u)\n",
  		     tipc_max_publications);
  		return NULL;
  	}
  	if ((type < TIPC_RESERVED_TYPES) && !atomic_read(&rsv_publ_ok)) {
  		warn("Publication failed, reserved name {%u,%u,%u}\n",
  		     type, lower, upper);
  		return NULL;
  	}
  
  	write_lock_bh(&tipc_nametbl_lock);
  	table.local_publ_count++;
  	publ = tipc_nametbl_insert_publ(type, lower, upper, scope,
  				   tipc_own_addr, port_ref, key);
  	if (publ && (scope != TIPC_NODE_SCOPE)) {
  		tipc_named_publish(publ);
  	}
  	write_unlock_bh(&tipc_nametbl_lock);
  	return publ;
  }
  
  /**
   * tipc_nametbl_withdraw - withdraw name publication from network name tables
   */
  
  int tipc_nametbl_withdraw(u32 type, u32 lower, u32 ref, u32 key)
  {
  	struct publication *publ;
  
  	dbg("tipc_nametbl_withdraw: {%u,%u}, key=%u\n", type, lower, key);
  	write_lock_bh(&tipc_nametbl_lock);
  	publ = tipc_nametbl_remove_publ(type, lower, tipc_own_addr, ref, key);
  	if (likely(publ)) {
  		table.local_publ_count--;
  		if (publ->scope != TIPC_NODE_SCOPE)
  			tipc_named_withdraw(publ);
  		write_unlock_bh(&tipc_nametbl_lock);
  		list_del_init(&publ->pport_list);
  		kfree(publ);
  		return 1;
  	}
  	write_unlock_bh(&tipc_nametbl_lock);
  	err("Unable to remove local publication\n"
  	    "(type=%u, lower=%u, ref=%u, key=%u)\n",
  	    type, lower, ref, key);
  	return 0;
  }
  
  /**
   * tipc_nametbl_subscribe - add a subscription object to the name table
   */
  
  void tipc_nametbl_subscribe(struct subscription *s)
  {
  	u32 type = s->seq.type;
  	struct name_seq *seq;
  
  	write_lock_bh(&tipc_nametbl_lock);
  	seq = nametbl_find_seq(type);
  	if (!seq) {
  		seq = tipc_nameseq_create(type, &table.types[hash(type)]);
  	}
  	if (seq){
  		spin_lock_bh(&seq->lock);
  		dbg("tipc_nametbl_subscribe:found %p for {%u,%u,%u}\n",
  		    seq, type, s->seq.lower, s->seq.upper);
  		tipc_nameseq_subscribe(seq, s);
  		spin_unlock_bh(&seq->lock);
  	} else {
  		warn("Failed to create subscription for {%u,%u,%u}\n",
  		     s->seq.type, s->seq.lower, s->seq.upper);
  	}
  	write_unlock_bh(&tipc_nametbl_lock);
  }
  
  /**
   * tipc_nametbl_unsubscribe - remove a subscription object from name table
   */
  
  void tipc_nametbl_unsubscribe(struct subscription *s)
  {
  	struct name_seq *seq;
  
  	write_lock_bh(&tipc_nametbl_lock);
  	seq = nametbl_find_seq(s->seq.type);
  	if (seq != NULL){
  		spin_lock_bh(&seq->lock);
  		list_del_init(&s->nameseq_list);
  		spin_unlock_bh(&seq->lock);
  		if ((seq->first_free == 0) && list_empty(&seq->subscriptions)) {
  			hlist_del_init(&seq->ns_list);
  			kfree(seq->sseqs);
  			kfree(seq);
  		}
  	}
  	write_unlock_bh(&tipc_nametbl_lock);
  }
  
  
  /**
   * subseq_list: print specified sub-sequence contents into the given buffer
   */
  
  static void subseq_list(struct sub_seq *sseq, struct print_buf *buf, u32 depth,
  			u32 index)
  {
  	char portIdStr[27];
  	char *scopeStr;
  	struct publication *publ = sseq->zone_list;
  
  	tipc_printf(buf, "%-10u %-10u ", sseq->lower, sseq->upper);
  
  	if (depth == 2 || !publ) {
  		tipc_printf(buf, "\n");
  		return;
  	}
  
  	do {
  		sprintf (portIdStr, "<%u.%u.%u:%u>",
  			 tipc_zone(publ->node), tipc_cluster(publ->node),
  			 tipc_node(publ->node), publ->ref);
  		tipc_printf(buf, "%-26s ", portIdStr);
  		if (depth > 3) {
  			if (publ->node != tipc_own_addr)
  				scopeStr = "";
  			else if (publ->scope == TIPC_NODE_SCOPE)
  				scopeStr = "node";
  			else if (publ->scope == TIPC_CLUSTER_SCOPE)
  				scopeStr = "cluster";
  			else
  				scopeStr = "zone";
  			tipc_printf(buf, "%-10u %s", publ->key, scopeStr);
  		}
  
  		publ = publ->zone_list_next;
  		if (publ == sseq->zone_list)
  			break;
  
  		tipc_printf(buf, "\n%33s", " ");
  	} while (1);
  
  	tipc_printf(buf, "\n");
  }
  
  /**
   * nameseq_list: print specified name sequence contents into the given buffer
   */
  
  static void nameseq_list(struct name_seq *seq, struct print_buf *buf, u32 depth,
  			 u32 type, u32 lowbound, u32 upbound, u32 index)
  {
  	struct sub_seq *sseq;
  	char typearea[11];
  
  	if (seq->first_free == 0)
  		return;
  
  	sprintf(typearea, "%-10u", seq->type);
  
  	if (depth == 1) {
  		tipc_printf(buf, "%s\n", typearea);
  		return;
  	}
  
  	for (sseq = seq->sseqs; sseq != &seq->sseqs[seq->first_free]; sseq++) {
  		if ((lowbound <= sseq->upper) && (upbound >= sseq->lower)) {
  			tipc_printf(buf, "%s ", typearea);
  			spin_lock_bh(&seq->lock);
  			subseq_list(sseq, buf, depth, index);
  			spin_unlock_bh(&seq->lock);
  			sprintf(typearea, "%10s", " ");
  		}
  	}
  }
  
  /**
   * nametbl_header - print name table header into the given buffer
   */
  
  static void nametbl_header(struct print_buf *buf, u32 depth)
  {
  	tipc_printf(buf, "Type       ");
  
  	if (depth > 1)
  		tipc_printf(buf, "Lower      Upper      ");
  	if (depth > 2)
  		tipc_printf(buf, "Port Identity              ");
  	if (depth > 3)
  		tipc_printf(buf, "Publication");
  
  	tipc_printf(buf, "\n-----------");
  
  	if (depth > 1)
  		tipc_printf(buf, "--------------------- ");
  	if (depth > 2)
  		tipc_printf(buf, "-------------------------- ");
  	if (depth > 3)
  		tipc_printf(buf, "------------------");
  
  	tipc_printf(buf, "\n");
  }
  
  /**
   * nametbl_list - print specified name table contents into the given buffer
   */
  
  static void nametbl_list(struct print_buf *buf, u32 depth_info,
  			 u32 type, u32 lowbound, u32 upbound)
  {
  	struct hlist_head *seq_head;
  	struct hlist_node *seq_node;
  	struct name_seq *seq;
  	int all_types;
  	u32 depth;
  	u32 i;
  
  	all_types = (depth_info & TIPC_NTQ_ALLTYPES);
  	depth = (depth_info & ~TIPC_NTQ_ALLTYPES);
  
  	if (depth == 0)
  		return;
  
  	if (all_types) {
  		/* display all entries in name table to specified depth */
  		nametbl_header(buf, depth);
  		lowbound = 0;
  		upbound = ~0;
  		for (i = 0; i < tipc_nametbl_size; i++) {
  			seq_head = &table.types[i];
  			hlist_for_each_entry(seq, seq_node, seq_head, ns_list) {
  				nameseq_list(seq, buf, depth, seq->type,
  					     lowbound, upbound, i);
  			}
  		}
  	} else {
  		/* display only the sequence that matches the specified type */
  		if (upbound < lowbound) {
  			tipc_printf(buf, "invalid name sequence specified\n");
  			return;
  		}
  		nametbl_header(buf, depth);
  		i = hash(type);
  		seq_head = &table.types[i];
  		hlist_for_each_entry(seq, seq_node, seq_head, ns_list) {
  			if (seq->type == type) {
  				nameseq_list(seq, buf, depth, type,
  					     lowbound, upbound, i);
  				break;
  			}
  		}
  	}
  }
  
  
  #define MAX_NAME_TBL_QUERY 32768
  
  struct sk_buff *tipc_nametbl_get(const void *req_tlv_area, int req_tlv_space)
  {
  	struct sk_buff *buf;
  	struct tipc_name_table_query *argv;
  	struct tlv_desc *rep_tlv;
  	struct print_buf b;
  	int str_len;
  
  	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NAME_TBL_QUERY))
  		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
  
  	buf = tipc_cfg_reply_alloc(TLV_SPACE(MAX_NAME_TBL_QUERY));
  	if (!buf)
  		return NULL;
  
  	rep_tlv = (struct tlv_desc *)buf->data;
  	tipc_printbuf_init(&b, TLV_DATA(rep_tlv), MAX_NAME_TBL_QUERY);
  	argv = (struct tipc_name_table_query *)TLV_DATA(req_tlv_area);
  	read_lock_bh(&tipc_nametbl_lock);
  	nametbl_list(&b, ntohl(argv->depth), ntohl(argv->type),
  		     ntohl(argv->lowbound), ntohl(argv->upbound));
  	read_unlock_bh(&tipc_nametbl_lock);
  	str_len = tipc_printbuf_validate(&b);
  
  	skb_put(buf, TLV_SPACE(str_len));
  	TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
  
  	return buf;
  }
  
  
  int tipc_nametbl_init(void)
  {
  	table.types = kcalloc(tipc_nametbl_size, sizeof(struct hlist_head),
  			      GFP_ATOMIC);
  	if (!table.types)
  		return -ENOMEM;
  
  	table.local_publ_count = 0;
  	return 0;
  }
  
  void tipc_nametbl_stop(void)
  {
  	u32 i;
  
  	if (!table.types)
  		return;
  
  	/* Verify name table is empty, then release it */
  
  	write_lock_bh(&tipc_nametbl_lock);
  	for (i = 0; i < tipc_nametbl_size; i++) {
  		if (!hlist_empty(&table.types[i]))
  			err("tipc_nametbl_stop(): hash chain %u is non-null\n", i);
  	}
  	kfree(table.types);
  	table.types = NULL;
  	write_unlock_bh(&tipc_nametbl_lock);
  }
  