net/tipc/bearer.c - kernel/msm-4.9 - Gitiles

 /*
  * net/tipc/bearer.c: TIPC bearer code
  *
  * Copyright (c) 1996-2006, Ericsson AB
  * Copyright (c) 2004-2006, 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 "bearer.h"
 #include "discover.h"

 #define MAX_ADDR_STR 60

 static struct tipc_media *media_list[MAX_MEDIA];
 static u32 media_count;

 struct tipc_bearer tipc_bearers[MAX_BEARERS];

 static void bearer_disable(struct tipc_bearer *b_ptr);

 /**
  * tipc_media_find - locates specified media object by name
  */
 struct tipc_media *tipc_media_find(const char *name)
 {
 	u32 i;

 	for (i = 0; i < media_count; i++) {
 		if (!strcmp(media_list[i]->name, name))
 			return media_list[i];
 	}
 	return NULL;
 }

 /**
  * media_find_id - locates specified media object by type identifier
  */
 static struct tipc_media *media_find_id(u8 type)
 {
 	u32 i;

 	for (i = 0; i < media_count; i++) {
 		if (media_list[i]->type_id == type)
 			return media_list[i];
 	}
 	return NULL;
 }

 /**
  * tipc_register_media - register a media type
  *
  * Bearers for this media type must be activated separately at a later stage.
  */
 int tipc_register_media(struct tipc_media *m_ptr)
 {
 	int res = -EINVAL;

 	write_lock_bh(&tipc_net_lock);

 	if ((strlen(m_ptr->name) + 1) > TIPC_MAX_MEDIA_NAME)
 		goto exit;
 	if (m_ptr->priority > TIPC_MAX_LINK_PRI)
 		goto exit;
 	if ((m_ptr->tolerance < TIPC_MIN_LINK_TOL) ||
 	    (m_ptr->tolerance > TIPC_MAX_LINK_TOL))
 		goto exit;
 	if (media_count >= MAX_MEDIA)
 		goto exit;
 	if (tipc_media_find(m_ptr->name) || media_find_id(m_ptr->type_id))
 		goto exit;

 	media_list[media_count] = m_ptr;
 	media_count++;
 	res = 0;
 exit:
 	write_unlock_bh(&tipc_net_lock);
 	if (res)
 		pr_warn("Media <%s> registration error\n", m_ptr->name);
 	return res;
 }

 /**
  * tipc_media_addr_printf - record media address in print buffer
  */
 void tipc_media_addr_printf(char *buf, int len, struct tipc_media_addr *a)
 {
 	char addr_str[MAX_ADDR_STR];
 	struct tipc_media *m_ptr;
 	int ret;

 	m_ptr = media_find_id(a->media_id);

 	if (m_ptr && !m_ptr->addr2str(a, addr_str, sizeof(addr_str)))
 		ret = tipc_snprintf(buf, len, "%s(%s)", m_ptr->name, addr_str);
 	else {
 		u32 i;

 		ret = tipc_snprintf(buf, len, "UNKNOWN(%u)", a->media_id);
 		for (i = 0; i < sizeof(a->value); i++)
 			ret += tipc_snprintf(buf - ret, len + ret,
 					    "-%02x", a->value[i]);
 	}
 }

 /**
  * tipc_media_get_names - record names of registered media in buffer
  */
 struct sk_buff *tipc_media_get_names(void)
 {
 	struct sk_buff *buf;
 	int i;

 	buf = tipc_cfg_reply_alloc(MAX_MEDIA * TLV_SPACE(TIPC_MAX_MEDIA_NAME));
 	if (!buf)
 		return NULL;

 	read_lock_bh(&tipc_net_lock);
 	for (i = 0; i < media_count; i++) {
 		tipc_cfg_append_tlv(buf, TIPC_TLV_MEDIA_NAME,
 				    media_list[i]->name,
 				    strlen(media_list[i]->name) + 1);
 	}
 	read_unlock_bh(&tipc_net_lock);
 	return buf;
 }

 /**
  * bearer_name_validate - validate & (optionally) deconstruct bearer name
  * @name: ptr to bearer name string
  * @name_parts: ptr to area for bearer name components (or NULL if not needed)
  *
  * Returns 1 if bearer name is valid, otherwise 0.
  */
 static int bearer_name_validate(const char *name,
 				struct tipc_bearer_names *name_parts)
 {
 	char name_copy[TIPC_MAX_BEARER_NAME];
 	char *media_name;
 	char *if_name;
 	u32 media_len;
 	u32 if_len;

 	/* copy bearer name & ensure length is OK */
 	name_copy[TIPC_MAX_BEARER_NAME - 1] = 0;
 	/* need above in case non-Posix strncpy() doesn't pad with nulls */
 	strncpy(name_copy, name, TIPC_MAX_BEARER_NAME);
 	if (name_copy[TIPC_MAX_BEARER_NAME - 1] != 0)
 		return 0;

 	/* ensure all component parts of bearer name are present */
 	media_name = name_copy;
 	if_name = strchr(media_name, ':');
 	if (if_name == NULL)
 		return 0;
 	*(if_name++) = 0;
 	media_len = if_name - media_name;
 	if_len = strlen(if_name) + 1;

 	/* validate component parts of bearer name */
 	if ((media_len <= 1) || (media_len > TIPC_MAX_MEDIA_NAME) ||
 	    (if_len <= 1) || (if_len > TIPC_MAX_IF_NAME))
 		return 0;

 	/* return bearer name components, if necessary */
 	if (name_parts) {
 		strcpy(name_parts->media_name, media_name);
 		strcpy(name_parts->if_name, if_name);
 	}
 	return 1;
 }

 /**
  * tipc_bearer_find - locates bearer object with matching bearer name
  */
 struct tipc_bearer *tipc_bearer_find(const char *name)
 {
 	struct tipc_bearer *b_ptr;
 	u32 i;

 	for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) {
 		if (b_ptr->active && (!strcmp(b_ptr->name, name)))
 			return b_ptr;
 	}
 	return NULL;
 }

 /**
  * tipc_bearer_find_interface - locates bearer object with matching interface name
  */
 struct tipc_bearer *tipc_bearer_find_interface(const char *if_name)
 {
 	struct tipc_bearer *b_ptr;
 	char *b_if_name;
 	u32 i;

 	for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) {
 		if (!b_ptr->active)
 			continue;
 		b_if_name = strchr(b_ptr->name, ':') + 1;
 		if (!strcmp(b_if_name, if_name))
 			return b_ptr;
 	}
 	return NULL;
 }

 /**
  * tipc_bearer_get_names - record names of bearers in buffer
  */
 struct sk_buff *tipc_bearer_get_names(void)
 {
 	struct sk_buff *buf;
 	struct tipc_bearer *b_ptr;
 	int i, j;

 	buf = tipc_cfg_reply_alloc(MAX_BEARERS * TLV_SPACE(TIPC_MAX_BEARER_NAME));
 	if (!buf)
 		return NULL;

 	read_lock_bh(&tipc_net_lock);
 	for (i = 0; i < media_count; i++) {
 		for (j = 0; j < MAX_BEARERS; j++) {
 			b_ptr = &tipc_bearers[j];
 			if (b_ptr->active && (b_ptr->media == media_list[i])) {
 				tipc_cfg_append_tlv(buf, TIPC_TLV_BEARER_NAME,
 						    b_ptr->name,
 						    strlen(b_ptr->name) + 1);
 			}
 		}
 	}
 	read_unlock_bh(&tipc_net_lock);
 	return buf;
 }

 void tipc_bearer_add_dest(struct tipc_bearer *b_ptr, u32 dest)
 {
 	tipc_nmap_add(&b_ptr->nodes, dest);
 	tipc_bcbearer_sort();
 	tipc_disc_add_dest(b_ptr->link_req);
 }

 void tipc_bearer_remove_dest(struct tipc_bearer *b_ptr, u32 dest)
 {
 	tipc_nmap_remove(&b_ptr->nodes, dest);
 	tipc_bcbearer_sort();
 	tipc_disc_remove_dest(b_ptr->link_req);
 }

 /*
  * Interrupt enabling new requests after bearer blocking:
  * See bearer_send().
  */
 void tipc_continue(struct tipc_bearer *b)
 {
 	spin_lock_bh(&b->lock);
 	b->blocked = 0;
 	spin_unlock_bh(&b->lock);
 }

 /*
  * tipc_bearer_blocked - determines if bearer is currently blocked
  */
 int tipc_bearer_blocked(struct tipc_bearer *b)
 {
 	int res;

 	spin_lock_bh(&b->lock);
 	res = b->blocked;
 	spin_unlock_bh(&b->lock);

 	return res;
 }

 /**
  * tipc_enable_bearer - enable bearer with the given name
  */
 int tipc_enable_bearer(const char *name, u32 disc_domain, u32 priority)
 {
 	struct tipc_bearer *b_ptr;
 	struct tipc_media *m_ptr;
 	struct tipc_bearer_names b_names;
 	char addr_string[16];
 	u32 bearer_id;
 	u32 with_this_prio;
 	u32 i;
 	int res = -EINVAL;

 	if (!tipc_own_addr) {
 		pr_warn("Bearer <%s> rejected, not supported in standalone mode\n",
 			name);
 		return -ENOPROTOOPT;
 	}
 	if (!bearer_name_validate(name, &b_names)) {
 		pr_warn("Bearer <%s> rejected, illegal name\n", name);
 		return -EINVAL;
 	}
 	if (tipc_addr_domain_valid(disc_domain) &&
 	    (disc_domain != tipc_own_addr)) {
 		if (tipc_in_scope(disc_domain, tipc_own_addr)) {
 			disc_domain = tipc_own_addr & TIPC_CLUSTER_MASK;
 			res = 0;   /* accept any node in own cluster */
 		} else if (in_own_cluster_exact(disc_domain))
 			res = 0;   /* accept specified node in own cluster */
 	}
 	if (res) {
 		pr_warn("Bearer <%s> rejected, illegal discovery domain\n",
 			name);
 		return -EINVAL;
 	}
 	if ((priority > TIPC_MAX_LINK_PRI) &&
 	    (priority != TIPC_MEDIA_LINK_PRI)) {
 		pr_warn("Bearer <%s> rejected, illegal priority\n", name);
 		return -EINVAL;
 	}

 	write_lock_bh(&tipc_net_lock);

 	m_ptr = tipc_media_find(b_names.media_name);
 	if (!m_ptr) {
 		pr_warn("Bearer <%s> rejected, media <%s> not registered\n",
 			name, b_names.media_name);
 		goto exit;
 	}

 	if (priority == TIPC_MEDIA_LINK_PRI)
 		priority = m_ptr->priority;

 restart:
 	bearer_id = MAX_BEARERS;
 	with_this_prio = 1;
 	for (i = MAX_BEARERS; i-- != 0; ) {
 		if (!tipc_bearers[i].active) {
 			bearer_id = i;
 			continue;
 		}
 		if (!strcmp(name, tipc_bearers[i].name)) {
 			pr_warn("Bearer <%s> rejected, already enabled\n",
 				name);
 			goto exit;
 		}
 		if ((tipc_bearers[i].priority == priority) &&
 		    (++with_this_prio > 2)) {
 			if (priority-- == 0) {
 				pr_warn("Bearer <%s> rejected, duplicate priority\n",
 					name);
 				goto exit;
 			}
 			pr_warn("Bearer <%s> priority adjustment required %u->%u\n",
 				name, priority + 1, priority);
 			goto restart;
 		}
 	}
 	if (bearer_id >= MAX_BEARERS) {
 		pr_warn("Bearer <%s> rejected, bearer limit reached (%u)\n",
 			name, MAX_BEARERS);
 		goto exit;
 	}

 	b_ptr = &tipc_bearers[bearer_id];
 	strcpy(b_ptr->name, name);
 	res = m_ptr->enable_bearer(b_ptr);
 	if (res) {
 		pr_warn("Bearer <%s> rejected, enable failure (%d)\n",
 			name, -res);
 		goto exit;
 	}

 	b_ptr->identity = bearer_id;
 	b_ptr->media = m_ptr;
 	b_ptr->tolerance = m_ptr->tolerance;
 	b_ptr->window = m_ptr->window;
 	b_ptr->net_plane = bearer_id + 'A';
 	b_ptr->active = 1;
 	b_ptr->priority = priority;
 	INIT_LIST_HEAD(&b_ptr->links);
 	spin_lock_init(&b_ptr->lock);

 	res = tipc_disc_create(b_ptr, &b_ptr->bcast_addr, disc_domain);
 	if (res) {
 		bearer_disable(b_ptr);
 		pr_warn("Bearer <%s> rejected, discovery object creation failed\n",
 			name);
 		goto exit;
 	}
 	pr_info("Enabled bearer <%s>, discovery domain %s, priority %u\n",
 		name,
 		tipc_addr_string_fill(addr_string, disc_domain), priority);
 exit:
 	write_unlock_bh(&tipc_net_lock);
 	return res;
 }

 /**
  * tipc_block_bearer - Block the bearer with the given name, and reset all its links
  */
 int tipc_block_bearer(const char *name)
 {
 	struct tipc_bearer *b_ptr = NULL;
 	struct tipc_link *l_ptr;
 	struct tipc_link *temp_l_ptr;

 	read_lock_bh(&tipc_net_lock);
 	b_ptr = tipc_bearer_find(name);
 	if (!b_ptr) {
 		pr_warn("Attempt to block unknown bearer <%s>\n", name);
 		read_unlock_bh(&tipc_net_lock);
 		return -EINVAL;
 	}

 	pr_info("Blocking bearer <%s>\n", name);
 	spin_lock_bh(&b_ptr->lock);
 	b_ptr->blocked = 1;
 	list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) {
 		struct tipc_node *n_ptr = l_ptr->owner;

 		spin_lock_bh(&n_ptr->lock);
 		tipc_link_reset(l_ptr);
 		spin_unlock_bh(&n_ptr->lock);
 	}
 	spin_unlock_bh(&b_ptr->lock);
 	read_unlock_bh(&tipc_net_lock);
 	return 0;
 }

 /**
  * bearer_disable
  *
  * Note: This routine assumes caller holds tipc_net_lock.
  */
 static void bearer_disable(struct tipc_bearer *b_ptr)
 {
 	struct tipc_link *l_ptr;
 	struct tipc_link *temp_l_ptr;

 	pr_info("Disabling bearer <%s>\n", b_ptr->name);
 	spin_lock_bh(&b_ptr->lock);
 	b_ptr->blocked = 1;
 	b_ptr->media->disable_bearer(b_ptr);
 	list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) {
 		tipc_link_delete(l_ptr);
 	}
 	if (b_ptr->link_req)
 		tipc_disc_delete(b_ptr->link_req);
 	spin_unlock_bh(&b_ptr->lock);
 	memset(b_ptr, 0, sizeof(struct tipc_bearer));
 }

 int tipc_disable_bearer(const char *name)
 {
 	struct tipc_bearer *b_ptr;
 	int res;

 	write_lock_bh(&tipc_net_lock);
 	b_ptr = tipc_bearer_find(name);
 	if (b_ptr == NULL) {
 		pr_warn("Attempt to disable unknown bearer <%s>\n", name);
 		res = -EINVAL;
 	} else {
 		bearer_disable(b_ptr);
 		res = 0;
 	}
 	write_unlock_bh(&tipc_net_lock);
 	return res;
 }


 void tipc_bearer_stop(void)
 {
 	u32 i;

 	for (i = 0; i < MAX_BEARERS; i++) {
 		if (tipc_bearers[i].active)
 			bearer_disable(&tipc_bearers[i]);
 	}
 	media_count = 0;
 }
	/*
	* net/tipc/bearer.c: TIPC bearer code
	*
	* Copyright (c) 1996-2006, Ericsson AB
	* Copyright (c) 2004-2006, 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 "bearer.h"
	#include "discover.h"

	#define MAX_ADDR_STR 60

	static struct tipc_media *media_list[MAX_MEDIA];
	static u32 media_count;

	struct tipc_bearer tipc_bearers[MAX_BEARERS];

	static void bearer_disable(struct tipc_bearer *b_ptr);

	/**
	* tipc_media_find - locates specified media object by name
	*/
	struct tipc_media tipc_media_find(const char name)
	{
	u32 i;

	for (i = 0; i < media_count; i++) {
	if (!strcmp(media_list[i]->name, name))
	return media_list[i];
	}
	return NULL;
	}

	/**
	* media_find_id - locates specified media object by type identifier
	*/
	static struct tipc_media *media_find_id(u8 type)
	{
	u32 i;

	for (i = 0; i < media_count; i++) {
	if (media_list[i]->type_id == type)
	return media_list[i];
	}
	return NULL;
	}

	/**
	* tipc_register_media - register a media type
	*
	* Bearers for this media type must be activated separately at a later stage.
	*/
	int tipc_register_media(struct tipc_media *m_ptr)
	{
	int res = -EINVAL;

	write_lock_bh(&tipc_net_lock);

	if ((strlen(m_ptr->name) + 1) > TIPC_MAX_MEDIA_NAME)
	goto exit;
	if (m_ptr->priority > TIPC_MAX_LINK_PRI)
	goto exit;
	if ((m_ptr->tolerance < TIPC_MIN_LINK_TOL) \|\|
	(m_ptr->tolerance > TIPC_MAX_LINK_TOL))
	goto exit;
	if (media_count >= MAX_MEDIA)
	goto exit;
	if (tipc_media_find(m_ptr->name) \|\| media_find_id(m_ptr->type_id))
	goto exit;

	media_list[media_count] = m_ptr;
	media_count++;
	res = 0;
	exit:
	write_unlock_bh(&tipc_net_lock);
	if (res)
	pr_warn("Media <%s> registration error\n", m_ptr->name);
	return res;
	}

	/**
	* tipc_media_addr_printf - record media address in print buffer
	*/
	void tipc_media_addr_printf(char buf, int len, struct tipc_media_addr a)
	{
	char addr_str[MAX_ADDR_STR];
	struct tipc_media *m_ptr;
	int ret;

	m_ptr = media_find_id(a->media_id);

	if (m_ptr && !m_ptr->addr2str(a, addr_str, sizeof(addr_str)))
	ret = tipc_snprintf(buf, len, "%s(%s)", m_ptr->name, addr_str);
	else {
	u32 i;

	ret = tipc_snprintf(buf, len, "UNKNOWN(%u)", a->media_id);
	for (i = 0; i < sizeof(a->value); i++)
	ret += tipc_snprintf(buf - ret, len + ret,
	"-%02x", a->value[i]);
	}
	}

	/**
	* tipc_media_get_names - record names of registered media in buffer
	*/
	struct sk_buff *tipc_media_get_names(void)
	{
	struct sk_buff *buf;
	int i;

	buf = tipc_cfg_reply_alloc(MAX_MEDIA * TLV_SPACE(TIPC_MAX_MEDIA_NAME));
	if (!buf)
	return NULL;

	read_lock_bh(&tipc_net_lock);
	for (i = 0; i < media_count; i++) {
	tipc_cfg_append_tlv(buf, TIPC_TLV_MEDIA_NAME,
	media_list[i]->name,
	strlen(media_list[i]->name) + 1);
	}
	read_unlock_bh(&tipc_net_lock);
	return buf;
	}

	/**
	* bearer_name_validate - validate & (optionally) deconstruct bearer name
	* @name: ptr to bearer name string
	* @name_parts: ptr to area for bearer name components (or NULL if not needed)
	*
	* Returns 1 if bearer name is valid, otherwise 0.
	*/
	static int bearer_name_validate(const char *name,
	struct tipc_bearer_names *name_parts)
	{
	char name_copy[TIPC_MAX_BEARER_NAME];
	char *media_name;
	char *if_name;
	u32 media_len;
	u32 if_len;

	/* copy bearer name & ensure length is OK */
	name_copy[TIPC_MAX_BEARER_NAME - 1] = 0;
	/* need above in case non-Posix strncpy() doesn't pad with nulls */
	strncpy(name_copy, name, TIPC_MAX_BEARER_NAME);
	if (name_copy[TIPC_MAX_BEARER_NAME - 1] != 0)
	return 0;

	/* ensure all component parts of bearer name are present */
	media_name = name_copy;
	if_name = strchr(media_name, ':');
	if (if_name == NULL)
	return 0;
	*(if_name++) = 0;
	media_len = if_name - media_name;
	if_len = strlen(if_name) + 1;

	/* validate component parts of bearer name */
	if ((media_len <= 1) \|\| (media_len > TIPC_MAX_MEDIA_NAME) \|\|
	(if_len <= 1) \|\| (if_len > TIPC_MAX_IF_NAME))
	return 0;

	/* return bearer name components, if necessary */
	if (name_parts) {
	strcpy(name_parts->media_name, media_name);
	strcpy(name_parts->if_name, if_name);
	}
	return 1;
	}

	/**
	* tipc_bearer_find - locates bearer object with matching bearer name
	*/
	struct tipc_bearer tipc_bearer_find(const char name)
	{
	struct tipc_bearer *b_ptr;
	u32 i;

	for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) {
	if (b_ptr->active && (!strcmp(b_ptr->name, name)))
	return b_ptr;
	}
	return NULL;
	}

	/**
	* tipc_bearer_find_interface - locates bearer object with matching interface name
	*/
	struct tipc_bearer tipc_bearer_find_interface(const char if_name)
	{
	struct tipc_bearer *b_ptr;
	char *b_if_name;
	u32 i;

	for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) {
	if (!b_ptr->active)
	continue;
	b_if_name = strchr(b_ptr->name, ':') + 1;
	if (!strcmp(b_if_name, if_name))
	return b_ptr;
	}
	return NULL;
	}

	/**
	* tipc_bearer_get_names - record names of bearers in buffer
	*/
	struct sk_buff *tipc_bearer_get_names(void)
	{
	struct sk_buff *buf;
	struct tipc_bearer *b_ptr;
	int i, j;

	buf = tipc_cfg_reply_alloc(MAX_BEARERS * TLV_SPACE(TIPC_MAX_BEARER_NAME));
	if (!buf)
	return NULL;

	read_lock_bh(&tipc_net_lock);
	for (i = 0; i < media_count; i++) {
	for (j = 0; j < MAX_BEARERS; j++) {
	b_ptr = &tipc_bearers[j];
	if (b_ptr->active && (b_ptr->media == media_list[i])) {
	tipc_cfg_append_tlv(buf, TIPC_TLV_BEARER_NAME,
	b_ptr->name,
	strlen(b_ptr->name) + 1);
	}
	}
	}
	read_unlock_bh(&tipc_net_lock);
	return buf;
	}

	void tipc_bearer_add_dest(struct tipc_bearer *b_ptr, u32 dest)
	{
	tipc_nmap_add(&b_ptr->nodes, dest);
	tipc_bcbearer_sort();
	tipc_disc_add_dest(b_ptr->link_req);
	}

	void tipc_bearer_remove_dest(struct tipc_bearer *b_ptr, u32 dest)
	{
	tipc_nmap_remove(&b_ptr->nodes, dest);
	tipc_bcbearer_sort();
	tipc_disc_remove_dest(b_ptr->link_req);
	}

	/*
	* Interrupt enabling new requests after bearer blocking:
	* See bearer_send().
	*/
	void tipc_continue(struct tipc_bearer *b)
	{
	spin_lock_bh(&b->lock);
	b->blocked = 0;
	spin_unlock_bh(&b->lock);
	}

	/*
	* tipc_bearer_blocked - determines if bearer is currently blocked
	*/
	int tipc_bearer_blocked(struct tipc_bearer *b)
	{
	int res;

	spin_lock_bh(&b->lock);
	res = b->blocked;
	spin_unlock_bh(&b->lock);

	return res;
	}

	/**
	* tipc_enable_bearer - enable bearer with the given name
	*/
	int tipc_enable_bearer(const char *name, u32 disc_domain, u32 priority)
	{
	struct tipc_bearer *b_ptr;
	struct tipc_media *m_ptr;
	struct tipc_bearer_names b_names;
	char addr_string[16];
	u32 bearer_id;
	u32 with_this_prio;
	u32 i;
	int res = -EINVAL;

	if (!tipc_own_addr) {
	pr_warn("Bearer <%s> rejected, not supported in standalone mode\n",
	name);
	return -ENOPROTOOPT;
	}
	if (!bearer_name_validate(name, &b_names)) {
	pr_warn("Bearer <%s> rejected, illegal name\n", name);
	return -EINVAL;
	}
	if (tipc_addr_domain_valid(disc_domain) &&
	(disc_domain != tipc_own_addr)) {
	if (tipc_in_scope(disc_domain, tipc_own_addr)) {
	disc_domain = tipc_own_addr & TIPC_CLUSTER_MASK;
	res = 0; /* accept any node in own cluster */
	} else if (in_own_cluster_exact(disc_domain))
	res = 0; /* accept specified node in own cluster */
	}
	if (res) {
	pr_warn("Bearer <%s> rejected, illegal discovery domain\n",
	name);
	return -EINVAL;
	}
	if ((priority > TIPC_MAX_LINK_PRI) &&
	(priority != TIPC_MEDIA_LINK_PRI)) {
	pr_warn("Bearer <%s> rejected, illegal priority\n", name);
	return -EINVAL;
	}

	write_lock_bh(&tipc_net_lock);

	m_ptr = tipc_media_find(b_names.media_name);
	if (!m_ptr) {
	pr_warn("Bearer <%s> rejected, media <%s> not registered\n",
	name, b_names.media_name);
	goto exit;
	}

	if (priority == TIPC_MEDIA_LINK_PRI)
	priority = m_ptr->priority;

	restart:
	bearer_id = MAX_BEARERS;
	with_this_prio = 1;
	for (i = MAX_BEARERS; i-- != 0; ) {
	if (!tipc_bearers[i].active) {
	bearer_id = i;
	continue;
	}
	if (!strcmp(name, tipc_bearers[i].name)) {
	pr_warn("Bearer <%s> rejected, already enabled\n",
	name);
	goto exit;
	}
	if ((tipc_bearers[i].priority == priority) &&
	(++with_this_prio > 2)) {
	if (priority-- == 0) {
	pr_warn("Bearer <%s> rejected, duplicate priority\n",
	name);
	goto exit;
	}
	pr_warn("Bearer <%s> priority adjustment required %u->%u\n",
	name, priority + 1, priority);
	goto restart;
	}
	}
	if (bearer_id >= MAX_BEARERS) {
	pr_warn("Bearer <%s> rejected, bearer limit reached (%u)\n",
	name, MAX_BEARERS);
	goto exit;
	}

	b_ptr = &tipc_bearers[bearer_id];
	strcpy(b_ptr->name, name);
	res = m_ptr->enable_bearer(b_ptr);
	if (res) {
	pr_warn("Bearer <%s> rejected, enable failure (%d)\n",
	name, -res);
	goto exit;
	}

	b_ptr->identity = bearer_id;
	b_ptr->media = m_ptr;
	b_ptr->tolerance = m_ptr->tolerance;
	b_ptr->window = m_ptr->window;
	b_ptr->net_plane = bearer_id + 'A';
	b_ptr->active = 1;
	b_ptr->priority = priority;
	INIT_LIST_HEAD(&b_ptr->links);
	spin_lock_init(&b_ptr->lock);

	res = tipc_disc_create(b_ptr, &b_ptr->bcast_addr, disc_domain);
	if (res) {
	bearer_disable(b_ptr);
	pr_warn("Bearer <%s> rejected, discovery object creation failed\n",
	name);
	goto exit;
	}
	pr_info("Enabled bearer <%s>, discovery domain %s, priority %u\n",
	name,
	tipc_addr_string_fill(addr_string, disc_domain), priority);
	exit:
	write_unlock_bh(&tipc_net_lock);
	return res;
	}

	/**
	* tipc_block_bearer - Block the bearer with the given name, and reset all its links
	*/
	int tipc_block_bearer(const char *name)
	{
	struct tipc_bearer *b_ptr = NULL;
	struct tipc_link *l_ptr;
	struct tipc_link *temp_l_ptr;

	read_lock_bh(&tipc_net_lock);
	b_ptr = tipc_bearer_find(name);
	if (!b_ptr) {
	pr_warn("Attempt to block unknown bearer <%s>\n", name);
	read_unlock_bh(&tipc_net_lock);
	return -EINVAL;
	}

	pr_info("Blocking bearer <%s>\n", name);
	spin_lock_bh(&b_ptr->lock);
	b_ptr->blocked = 1;
	list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) {
	struct tipc_node *n_ptr = l_ptr->owner;

	spin_lock_bh(&n_ptr->lock);
	tipc_link_reset(l_ptr);
	spin_unlock_bh(&n_ptr->lock);
	}
	spin_unlock_bh(&b_ptr->lock);
	read_unlock_bh(&tipc_net_lock);
	return 0;
	}

	/**
	* bearer_disable
	*
	* Note: This routine assumes caller holds tipc_net_lock.
	*/
	static void bearer_disable(struct tipc_bearer *b_ptr)
	{
	struct tipc_link *l_ptr;
	struct tipc_link *temp_l_ptr;

	pr_info("Disabling bearer <%s>\n", b_ptr->name);
	spin_lock_bh(&b_ptr->lock);
	b_ptr->blocked = 1;
	b_ptr->media->disable_bearer(b_ptr);
	list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) {
	tipc_link_delete(l_ptr);
	}
	if (b_ptr->link_req)
	tipc_disc_delete(b_ptr->link_req);
	spin_unlock_bh(&b_ptr->lock);
	memset(b_ptr, 0, sizeof(struct tipc_bearer));
	}

	int tipc_disable_bearer(const char *name)
	{
	struct tipc_bearer *b_ptr;
	int res;

	write_lock_bh(&tipc_net_lock);
	b_ptr = tipc_bearer_find(name);
	if (b_ptr == NULL) {
	pr_warn("Attempt to disable unknown bearer <%s>\n", name);
	res = -EINVAL;
	} else {
	bearer_disable(b_ptr);
	res = 0;
	}
	write_unlock_bh(&tipc_net_lock);
	return res;
	}



	void tipc_bearer_stop(void)
	{
	u32 i;

	for (i = 0; i < MAX_BEARERS; i++) {
	if (tipc_bearers[i].active)
	bearer_disable(&tipc_bearers[i]);
	}
	media_count = 0;
	}