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

 /*
  * net/tipc/bearer.c: TIPC bearer code
  *
  * Copyright (c) 1996-2006, 2013, Ericsson AB
  * Copyright (c) 2004-2006, 2010-2013, 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 * const media_info_array[] = {
 	&eth_media_info,
 #ifdef CONFIG_TIPC_MEDIA_IB
 	&ib_media_info,
 #endif
 	NULL
 };

 struct tipc_bearer *bearer_list[MAX_BEARERS + 1];

 static void bearer_disable(struct tipc_bearer *b_ptr, bool shutting_down);

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

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

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

 	for (i = 0; media_info_array[i] != NULL; i++) {
 		if (media_info_array[i]->type_id == type)
 			break;
 	}
 	return media_info_array[i];
 }

 /**
  * 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;

 	for (i = 0; media_info_array[i] != NULL; i++) {
 		tipc_cfg_append_tlv(buf, TIPC_TLV_MEDIA_NAME,
 				    media_info_array[i]->name,
 				    strlen(media_info_array[i]->name) + 1);
 	}
 	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; i < MAX_BEARERS; i++) {
 		b_ptr = bearer_list[i];
 		if (b_ptr && (!strcmp(b_ptr->name, 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;
 	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; media_info_array[i] != NULL; i++) {
 		for (j = 0; j < MAX_BEARERS; j++) {
 			b = bearer_list[j];
 			if (!b)
 				continue;
 			if (b->media == media_info_array[i]) {
 				tipc_cfg_append_tlv(buf, TIPC_TLV_BEARER_NAME,
 						    b->name,
 						    strlen(b->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);
 }

 /**
  * 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; ) {
 		b_ptr = bearer_list[i];
 		if (!b_ptr) {
 			bearer_id = i;
 			continue;
 		}
 		if (!strcmp(name, b_ptr->name)) {
 			pr_warn("Bearer <%s> rejected, already enabled\n",
 				name);
 			goto exit;
 		}
 		if ((b_ptr->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 = kzalloc(sizeof(*b_ptr), GFP_ATOMIC);
 	if (!b_ptr) {
 		res = -ENOMEM;
 		goto exit;
 	}
 	strcpy(b_ptr->name, name);
 	b_ptr->media = m_ptr;
 	res = m_ptr->enable_media(b_ptr);
 	if (res) {
 		pr_warn("Bearer <%s> rejected, enable failure (%d)\n",
 			name, -res);
 		goto exit;
 	}

 	b_ptr->identity = bearer_id;
 	b_ptr->tolerance = m_ptr->tolerance;
 	b_ptr->window = m_ptr->window;
 	b_ptr->domain = disc_domain;
 	b_ptr->net_plane = bearer_id + 'A';
 	b_ptr->priority = priority;

 	res = tipc_disc_create(b_ptr, &b_ptr->bcast_addr);
 	if (res) {
 		bearer_disable(b_ptr, false);
 		pr_warn("Bearer <%s> rejected, discovery object creation failed\n",
 			name);
 		goto exit;
 	}

 	bearer_list[bearer_id] = b_ptr;

 	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_reset_bearer - Reset all links established over this bearer
  */
 static int tipc_reset_bearer(struct tipc_bearer *b_ptr)
 {
 	read_lock_bh(&tipc_net_lock);
 	pr_info("Resetting bearer <%s>\n", b_ptr->name);
 	tipc_disc_delete(b_ptr->link_req);
 	tipc_link_reset_list(b_ptr->identity);
 	tipc_disc_create(b_ptr, &b_ptr->bcast_addr);
 	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, bool shutting_down)
 {
 	u32 i;

 	pr_info("Disabling bearer <%s>\n", b_ptr->name);
 	b_ptr->media->disable_media(b_ptr);

 	tipc_link_delete_list(b_ptr->identity, shutting_down);
 	if (b_ptr->link_req)
 		tipc_disc_delete(b_ptr->link_req);

 	for (i = 0; i < MAX_BEARERS; i++) {
 		if (b_ptr == bearer_list[i]) {
 			bearer_list[i] = NULL;
 			break;
 		}
 	}
 	kfree(b_ptr);
 }

 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, false);
 		res = 0;
 	}
 	write_unlock_bh(&tipc_net_lock);
 	return res;
 }


 /* tipc_l2_media_addr_set - initialize Ethernet media address structure
  *
  * Media-dependent "value" field stores MAC address in first 6 bytes
  * and zeroes out the remaining bytes.
  */
 void tipc_l2_media_addr_set(const struct tipc_bearer *b,
 			    struct tipc_media_addr *a, char *mac)
 {
 	int len = b->media->hwaddr_len;

 	if (unlikely(sizeof(a->value) < len)) {
 		WARN_ONCE(1, "Media length invalid\n");
 		return;
 	}

 	memcpy(a->value, mac, len);
 	memset(a->value + len, 0, sizeof(a->value) - len);
 	a->media_id = b->media->type_id;
 	a->broadcast = !memcmp(mac, b->bcast_addr.value, len);
 }

 int tipc_enable_l2_media(struct tipc_bearer *b)
 {
 	struct net_device *dev;
 	char *driver_name = strchr((const char *)b->name, ':') + 1;

 	/* Find device with specified name */
 	dev = dev_get_by_name(&init_net, driver_name);
 	if (!dev)
 		return -ENODEV;

 	/* Associate TIPC bearer with Ethernet bearer */
 	b->media_ptr = dev;
 	memset(b->bcast_addr.value, 0, sizeof(b->bcast_addr.value));
 	memcpy(b->bcast_addr.value, dev->broadcast, b->media->hwaddr_len);
 	b->bcast_addr.media_id = b->media->type_id;
 	b->bcast_addr.broadcast = 1;
 	b->mtu = dev->mtu;
 	tipc_l2_media_addr_set(b, &b->addr, (char *)dev->dev_addr);
 	rcu_assign_pointer(dev->tipc_ptr, b);
 	return 0;
 }

 /* tipc_disable_l2_media - detach TIPC bearer from an Ethernet interface
  *
  * Mark Ethernet bearer as inactive so that incoming buffers are thrown away,
  * then get worker thread to complete bearer cleanup.  (Can't do cleanup
  * here because cleanup code needs to sleep and caller holds spinlocks.)
  */
 void tipc_disable_l2_media(struct tipc_bearer *b)
 {
 	struct net_device *dev = (struct net_device *)b->media_ptr;
 	RCU_INIT_POINTER(dev->tipc_ptr, NULL);
 	dev_put(dev);
 }

 /**
  * tipc_l2_send_msg - send a TIPC packet out over an Ethernet interface
  * @buf: the packet to be sent
  * @b_ptr: the bearer through which the packet is to be sent
  * @dest: peer destination address
  */
 int tipc_l2_send_msg(struct sk_buff *buf, struct tipc_bearer *b,
 		     struct tipc_media_addr *dest)
 {
 	struct sk_buff *clone;
 	int delta;
 	struct net_device *dev = (struct net_device *)b->media_ptr;

 	clone = skb_clone(buf, GFP_ATOMIC);
 	if (!clone)
 		return 0;

 	delta = dev->hard_header_len - skb_headroom(buf);
 	if ((delta > 0) &&
 	    pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
 		kfree_skb(clone);
 		return 0;
 	}

 	skb_reset_network_header(clone);
 	clone->dev = dev;
 	clone->protocol = htons(ETH_P_TIPC);
 	dev_hard_header(clone, dev, ETH_P_TIPC, dest->value,
 			dev->dev_addr, clone->len);
 	dev_queue_xmit(clone);
 	return 0;
 }

 /* tipc_bearer_send- sends buffer to destination over bearer
  *
  * IMPORTANT:
  * The media send routine must not alter the buffer being passed in
  * as it may be needed for later retransmission!
  */
 void tipc_bearer_send(struct tipc_bearer *b, struct sk_buff *buf,
 		      struct tipc_media_addr *dest)
 {
 	b->media->send_msg(buf, b, dest);
 }

 /**
  * tipc_l2_rcv_msg - handle incoming TIPC message from an interface
  * @buf: the received packet
  * @dev: the net device that the packet was received on
  * @pt: the packet_type structure which was used to register this handler
  * @orig_dev: the original receive net device in case the device is a bond
  *
  * Accept only packets explicitly sent to this node, or broadcast packets;
  * ignores packets sent using interface multicast, and traffic sent to other
  * nodes (which can happen if interface is running in promiscuous mode).
  */
 static int tipc_l2_rcv_msg(struct sk_buff *buf, struct net_device *dev,
 			   struct packet_type *pt, struct net_device *orig_dev)
 {
 	struct tipc_bearer *b_ptr;

 	if (!net_eq(dev_net(dev), &init_net)) {
 		kfree_skb(buf);
 		return NET_RX_DROP;
 	}

 	rcu_read_lock();
 	b_ptr = rcu_dereference(dev->tipc_ptr);
 	if (likely(b_ptr)) {
 		if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
 			buf->next = NULL;
 			tipc_rcv(buf, b_ptr);
 			rcu_read_unlock();
 			return NET_RX_SUCCESS;
 		}
 	}
 	rcu_read_unlock();

 	kfree_skb(buf);
 	return NET_RX_DROP;
 }

 /**
  * tipc_l2_device_event - handle device events from network device
  * @nb: the context of the notification
  * @evt: the type of event
  * @ptr: the net device that the event was on
  *
  * This function is called by the Ethernet driver in case of link
  * change event.
  */
 static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
 				void *ptr)
 {
 	struct tipc_bearer *b_ptr;
 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);

 	if (!net_eq(dev_net(dev), &init_net))
 		return NOTIFY_DONE;

 	rcu_read_lock();
 	b_ptr = rcu_dereference(dev->tipc_ptr);
 	if (!b_ptr) {
 		rcu_read_unlock();
 		return NOTIFY_DONE;
 	}

 	b_ptr->mtu = dev->mtu;

 	switch (evt) {
 	case NETDEV_CHANGE:
 		if (netif_carrier_ok(dev))
 			break;
 	case NETDEV_DOWN:
 	case NETDEV_CHANGEMTU:
 		tipc_reset_bearer(b_ptr);
 		break;
 	case NETDEV_CHANGEADDR:
 		tipc_l2_media_addr_set(b_ptr, &b_ptr->addr,
 				       (char *)dev->dev_addr);
 		tipc_reset_bearer(b_ptr);
 		break;
 	case NETDEV_UNREGISTER:
 	case NETDEV_CHANGENAME:
 		tipc_disable_bearer(b_ptr->name);
 		break;
 	}
 	rcu_read_unlock();

 	return NOTIFY_OK;
 }

 static struct packet_type tipc_packet_type __read_mostly = {
 	.type = htons(ETH_P_TIPC),
 	.func = tipc_l2_rcv_msg,
 };

 static struct notifier_block notifier = {
 	.notifier_call  = tipc_l2_device_event,
 	.priority	= 0,
 };

 int tipc_bearer_setup(void)
 {
 	int err;

 	err = register_netdevice_notifier(&notifier);
 	if (err)
 		return err;
 	dev_add_pack(&tipc_packet_type);
 	return 0;
 }

 void tipc_bearer_cleanup(void)
 {
 	unregister_netdevice_notifier(&notifier);
 	dev_remove_pack(&tipc_packet_type);
 }

 void tipc_bearer_stop(void)
 {
 	struct tipc_bearer *b_ptr;
 	u32 i;

 	for (i = 0; i < MAX_BEARERS; i++) {
 		b_ptr = bearer_list[i];
 		if (b_ptr) {
 			bearer_disable(b_ptr, true);
 			bearer_list[i] = NULL;
 		}
 	}
 }
	/*
	* net/tipc/bearer.c: TIPC bearer code
	*
	* Copyright (c) 1996-2006, 2013, Ericsson AB
	* Copyright (c) 2004-2006, 2010-2013, 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 * const media_info_array[] = {
	&eth_media_info,
	#ifdef CONFIG_TIPC_MEDIA_IB
	&ib_media_info,
	#endif
	NULL
	};

	struct tipc_bearer *bearer_list[MAX_BEARERS + 1];

	static void bearer_disable(struct tipc_bearer *b_ptr, bool shutting_down);

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

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

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

	for (i = 0; media_info_array[i] != NULL; i++) {
	if (media_info_array[i]->type_id == type)
	break;
	}
	return media_info_array[i];
	}

	/**
	* 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;

	for (i = 0; media_info_array[i] != NULL; i++) {
	tipc_cfg_append_tlv(buf, TIPC_TLV_MEDIA_NAME,
	media_info_array[i]->name,
	strlen(media_info_array[i]->name) + 1);
	}
	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; i < MAX_BEARERS; i++) {
	b_ptr = bearer_list[i];
	if (b_ptr && (!strcmp(b_ptr->name, 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;
	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; media_info_array[i] != NULL; i++) {
	for (j = 0; j < MAX_BEARERS; j++) {
	b = bearer_list[j];
	if (!b)
	continue;
	if (b->media == media_info_array[i]) {
	tipc_cfg_append_tlv(buf, TIPC_TLV_BEARER_NAME,
	b->name,
	strlen(b->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);
	}

	/**
	* 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; ) {
	b_ptr = bearer_list[i];
	if (!b_ptr) {
	bearer_id = i;
	continue;
	}
	if (!strcmp(name, b_ptr->name)) {
	pr_warn("Bearer <%s> rejected, already enabled\n",
	name);
	goto exit;
	}
	if ((b_ptr->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 = kzalloc(sizeof(*b_ptr), GFP_ATOMIC);
	if (!b_ptr) {
	res = -ENOMEM;
	goto exit;
	}
	strcpy(b_ptr->name, name);
	b_ptr->media = m_ptr;
	res = m_ptr->enable_media(b_ptr);
	if (res) {
	pr_warn("Bearer <%s> rejected, enable failure (%d)\n",
	name, -res);
	goto exit;
	}

	b_ptr->identity = bearer_id;
	b_ptr->tolerance = m_ptr->tolerance;
	b_ptr->window = m_ptr->window;
	b_ptr->domain = disc_domain;
	b_ptr->net_plane = bearer_id + 'A';
	b_ptr->priority = priority;

	res = tipc_disc_create(b_ptr, &b_ptr->bcast_addr);
	if (res) {
	bearer_disable(b_ptr, false);
	pr_warn("Bearer <%s> rejected, discovery object creation failed\n",
	name);
	goto exit;
	}

	bearer_list[bearer_id] = b_ptr;

	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_reset_bearer - Reset all links established over this bearer
	*/
	static int tipc_reset_bearer(struct tipc_bearer *b_ptr)
	{
	read_lock_bh(&tipc_net_lock);
	pr_info("Resetting bearer <%s>\n", b_ptr->name);
	tipc_disc_delete(b_ptr->link_req);
	tipc_link_reset_list(b_ptr->identity);
	tipc_disc_create(b_ptr, &b_ptr->bcast_addr);
	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, bool shutting_down)
	{
	u32 i;

	pr_info("Disabling bearer <%s>\n", b_ptr->name);
	b_ptr->media->disable_media(b_ptr);

	tipc_link_delete_list(b_ptr->identity, shutting_down);
	if (b_ptr->link_req)
	tipc_disc_delete(b_ptr->link_req);

	for (i = 0; i < MAX_BEARERS; i++) {
	if (b_ptr == bearer_list[i]) {
	bearer_list[i] = NULL;
	break;
	}
	}
	kfree(b_ptr);
	}

	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, false);
	res = 0;
	}
	write_unlock_bh(&tipc_net_lock);
	return res;
	}


	/* tipc_l2_media_addr_set - initialize Ethernet media address structure
	*
	* Media-dependent "value" field stores MAC address in first 6 bytes
	* and zeroes out the remaining bytes.
	*/
	void tipc_l2_media_addr_set(const struct tipc_bearer *b,
	struct tipc_media_addr a, char mac)
	{
	int len = b->media->hwaddr_len;

	if (unlikely(sizeof(a->value) < len)) {
	WARN_ONCE(1, "Media length invalid\n");
	return;
	}

	memcpy(a->value, mac, len);
	memset(a->value + len, 0, sizeof(a->value) - len);
	a->media_id = b->media->type_id;
	a->broadcast = !memcmp(mac, b->bcast_addr.value, len);
	}

	int tipc_enable_l2_media(struct tipc_bearer *b)
	{
	struct net_device *dev;
	char driver_name = strchr((const char )b->name, ':') + 1;

	/* Find device with specified name */
	dev = dev_get_by_name(&init_net, driver_name);
	if (!dev)
	return -ENODEV;

	/* Associate TIPC bearer with Ethernet bearer */
	b->media_ptr = dev;
	memset(b->bcast_addr.value, 0, sizeof(b->bcast_addr.value));
	memcpy(b->bcast_addr.value, dev->broadcast, b->media->hwaddr_len);
	b->bcast_addr.media_id = b->media->type_id;
	b->bcast_addr.broadcast = 1;
	b->mtu = dev->mtu;
	tipc_l2_media_addr_set(b, &b->addr, (char *)dev->dev_addr);
	rcu_assign_pointer(dev->tipc_ptr, b);
	return 0;
	}

	/* tipc_disable_l2_media - detach TIPC bearer from an Ethernet interface
	*
	* Mark Ethernet bearer as inactive so that incoming buffers are thrown away,
	* then get worker thread to complete bearer cleanup. (Can't do cleanup
	* here because cleanup code needs to sleep and caller holds spinlocks.)
	*/
	void tipc_disable_l2_media(struct tipc_bearer *b)
	{
	struct net_device dev = (struct net_device )b->media_ptr;
	RCU_INIT_POINTER(dev->tipc_ptr, NULL);
	dev_put(dev);
	}

	/**
	* tipc_l2_send_msg - send a TIPC packet out over an Ethernet interface
	* @buf: the packet to be sent
	* @b_ptr: the bearer through which the packet is to be sent
	* @dest: peer destination address
	*/
	int tipc_l2_send_msg(struct sk_buff buf, struct tipc_bearer b,
	struct tipc_media_addr *dest)
	{
	struct sk_buff *clone;
	int delta;
	struct net_device dev = (struct net_device )b->media_ptr;

	clone = skb_clone(buf, GFP_ATOMIC);
	if (!clone)
	return 0;

	delta = dev->hard_header_len - skb_headroom(buf);
	if ((delta > 0) &&
	pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
	kfree_skb(clone);
	return 0;
	}

	skb_reset_network_header(clone);
	clone->dev = dev;
	clone->protocol = htons(ETH_P_TIPC);
	dev_hard_header(clone, dev, ETH_P_TIPC, dest->value,
	dev->dev_addr, clone->len);
	dev_queue_xmit(clone);
	return 0;
	}

	/* tipc_bearer_send- sends buffer to destination over bearer
	*
	* IMPORTANT:
	* The media send routine must not alter the buffer being passed in
	* as it may be needed for later retransmission!
	*/
	void tipc_bearer_send(struct tipc_bearer b, struct sk_buff buf,
	struct tipc_media_addr *dest)
	{
	b->media->send_msg(buf, b, dest);
	}

	/**
	* tipc_l2_rcv_msg - handle incoming TIPC message from an interface
	* @buf: the received packet
	* @dev: the net device that the packet was received on
	* @pt: the packet_type structure which was used to register this handler
	* @orig_dev: the original receive net device in case the device is a bond
	*
	* Accept only packets explicitly sent to this node, or broadcast packets;
	* ignores packets sent using interface multicast, and traffic sent to other
	* nodes (which can happen if interface is running in promiscuous mode).
	*/
	static int tipc_l2_rcv_msg(struct sk_buff buf, struct net_device dev,
	struct packet_type pt, struct net_device orig_dev)
	{
	struct tipc_bearer *b_ptr;

	if (!net_eq(dev_net(dev), &init_net)) {
	kfree_skb(buf);
	return NET_RX_DROP;
	}

	rcu_read_lock();
	b_ptr = rcu_dereference(dev->tipc_ptr);
	if (likely(b_ptr)) {
	if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
	buf->next = NULL;
	tipc_rcv(buf, b_ptr);
	rcu_read_unlock();
	return NET_RX_SUCCESS;
	}
	}
	rcu_read_unlock();

	kfree_skb(buf);
	return NET_RX_DROP;
	}

	/**
	* tipc_l2_device_event - handle device events from network device
	* @nb: the context of the notification
	* @evt: the type of event
	* @ptr: the net device that the event was on
	*
	* This function is called by the Ethernet driver in case of link
	* change event.
	*/
	static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
	void *ptr)
	{
	struct tipc_bearer *b_ptr;
	struct net_device *dev = netdev_notifier_info_to_dev(ptr);

	if (!net_eq(dev_net(dev), &init_net))
	return NOTIFY_DONE;

	rcu_read_lock();
	b_ptr = rcu_dereference(dev->tipc_ptr);
	if (!b_ptr) {
	rcu_read_unlock();
	return NOTIFY_DONE;
	}

	b_ptr->mtu = dev->mtu;

	switch (evt) {
	case NETDEV_CHANGE:
	if (netif_carrier_ok(dev))
	break;
	case NETDEV_DOWN:
	case NETDEV_CHANGEMTU:
	tipc_reset_bearer(b_ptr);
	break;
	case NETDEV_CHANGEADDR:
	tipc_l2_media_addr_set(b_ptr, &b_ptr->addr,
	(char *)dev->dev_addr);
	tipc_reset_bearer(b_ptr);
	break;
	case NETDEV_UNREGISTER:
	case NETDEV_CHANGENAME:
	tipc_disable_bearer(b_ptr->name);
	break;
	}
	rcu_read_unlock();

	return NOTIFY_OK;
	}

	static struct packet_type tipc_packet_type __read_mostly = {
	.type = htons(ETH_P_TIPC),
	.func = tipc_l2_rcv_msg,
	};

	static struct notifier_block notifier = {
	.notifier_call = tipc_l2_device_event,
	.priority = 0,
	};

	int tipc_bearer_setup(void)
	{
	int err;

	err = register_netdevice_notifier(&notifier);
	if (err)
	return err;
	dev_add_pack(&tipc_packet_type);
	return 0;
	}

	void tipc_bearer_cleanup(void)
	{
	unregister_netdevice_notifier(&notifier);
	dev_remove_pack(&tipc_packet_type);
	}

	void tipc_bearer_stop(void)
	{
	struct tipc_bearer *b_ptr;
	u32 i;

	for (i = 0; i < MAX_BEARERS; i++) {
	b_ptr = bearer_list[i];
	if (b_ptr) {
	bearer_disable(b_ptr, true);
	bearer_list[i] = NULL;
	}
	}
	}