![Jon Paul Maloy](/assets/img/avatar_default.png)
When a link is being established, the two endpoints advertise their respective interface MTU in the transmitted RESET and ACTIVATE messages. If there is any difference, the lower of the two MTUs will be selected for use by both endpoints. However, as a remnant of earlier attempts to introduce TIPC level routing. there also exists an MTU discovery mechanism. If an intermediate node has a lower MTU than the two endpoints, they will discover this through a bisectional approach, and finally adopt this MTU for common use. Since there is no TIPC level routing, and probably never will be, this mechanism doesn't make any sense, and only serves to make the link level protocol unecessarily complex. In this commit, we eliminate the MTU discovery algorithm,and fall back to the simple MTU advertising approach. This change is fully backwards compatible. Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
622 lines
16 KiB
C
622 lines
16 KiB
C
/*
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* net/tipc/node.c: TIPC node management routines
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*
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* Copyright (c) 2000-2006, 2012-2014, Ericsson AB
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* Copyright (c) 2005-2006, 2010-2014, Wind River Systems
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the names of the copyright holders nor the names of its
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* contributors may be used to endorse or promote products derived from
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* this software without specific prior written permission.
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*
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* Alternatively, this software may be distributed under the terms of the
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* GNU General Public License ("GPL") version 2 as published by the Free
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* Software Foundation.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "core.h"
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#include "link.h"
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#include "node.h"
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#include "name_distr.h"
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#include "socket.h"
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static void node_lost_contact(struct tipc_node *n_ptr);
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static void node_established_contact(struct tipc_node *n_ptr);
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static void tipc_node_delete(struct tipc_node *node);
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struct tipc_sock_conn {
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u32 port;
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u32 peer_port;
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u32 peer_node;
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struct list_head list;
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};
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static const struct nla_policy tipc_nl_node_policy[TIPC_NLA_NODE_MAX + 1] = {
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[TIPC_NLA_NODE_UNSPEC] = { .type = NLA_UNSPEC },
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[TIPC_NLA_NODE_ADDR] = { .type = NLA_U32 },
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[TIPC_NLA_NODE_UP] = { .type = NLA_FLAG }
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};
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/*
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* A trivial power-of-two bitmask technique is used for speed, since this
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* operation is done for every incoming TIPC packet. The number of hash table
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* entries has been chosen so that no hash chain exceeds 8 nodes and will
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* usually be much smaller (typically only a single node).
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*/
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static unsigned int tipc_hashfn(u32 addr)
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{
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return addr & (NODE_HTABLE_SIZE - 1);
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}
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static void tipc_node_kref_release(struct kref *kref)
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{
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struct tipc_node *node = container_of(kref, struct tipc_node, kref);
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tipc_node_delete(node);
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}
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void tipc_node_put(struct tipc_node *node)
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{
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kref_put(&node->kref, tipc_node_kref_release);
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}
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static void tipc_node_get(struct tipc_node *node)
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{
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kref_get(&node->kref);
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}
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/*
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* tipc_node_find - locate specified node object, if it exists
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*/
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struct tipc_node *tipc_node_find(struct net *net, u32 addr)
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{
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struct tipc_net *tn = net_generic(net, tipc_net_id);
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struct tipc_node *node;
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if (unlikely(!in_own_cluster_exact(net, addr)))
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return NULL;
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rcu_read_lock();
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hlist_for_each_entry_rcu(node, &tn->node_htable[tipc_hashfn(addr)],
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hash) {
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if (node->addr == addr) {
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tipc_node_get(node);
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rcu_read_unlock();
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return node;
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}
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}
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rcu_read_unlock();
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return NULL;
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}
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struct tipc_node *tipc_node_create(struct net *net, u32 addr)
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{
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struct tipc_net *tn = net_generic(net, tipc_net_id);
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struct tipc_node *n_ptr, *temp_node;
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spin_lock_bh(&tn->node_list_lock);
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n_ptr = tipc_node_find(net, addr);
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if (n_ptr)
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goto exit;
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n_ptr = kzalloc(sizeof(*n_ptr), GFP_ATOMIC);
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if (!n_ptr) {
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pr_warn("Node creation failed, no memory\n");
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goto exit;
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}
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n_ptr->addr = addr;
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n_ptr->net = net;
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kref_init(&n_ptr->kref);
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spin_lock_init(&n_ptr->lock);
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INIT_HLIST_NODE(&n_ptr->hash);
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INIT_LIST_HEAD(&n_ptr->list);
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INIT_LIST_HEAD(&n_ptr->publ_list);
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INIT_LIST_HEAD(&n_ptr->conn_sks);
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__skb_queue_head_init(&n_ptr->bclink.deferdq);
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hlist_add_head_rcu(&n_ptr->hash, &tn->node_htable[tipc_hashfn(addr)]);
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list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
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if (n_ptr->addr < temp_node->addr)
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break;
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}
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list_add_tail_rcu(&n_ptr->list, &temp_node->list);
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n_ptr->action_flags = TIPC_WAIT_PEER_LINKS_DOWN;
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n_ptr->signature = INVALID_NODE_SIG;
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tipc_node_get(n_ptr);
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exit:
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spin_unlock_bh(&tn->node_list_lock);
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return n_ptr;
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}
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static void tipc_node_delete(struct tipc_node *node)
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{
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list_del_rcu(&node->list);
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hlist_del_rcu(&node->hash);
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kfree_rcu(node, rcu);
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}
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void tipc_node_stop(struct net *net)
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{
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struct tipc_net *tn = net_generic(net, tipc_net_id);
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struct tipc_node *node, *t_node;
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spin_lock_bh(&tn->node_list_lock);
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list_for_each_entry_safe(node, t_node, &tn->node_list, list)
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tipc_node_put(node);
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spin_unlock_bh(&tn->node_list_lock);
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}
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int tipc_node_add_conn(struct net *net, u32 dnode, u32 port, u32 peer_port)
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{
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struct tipc_node *node;
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struct tipc_sock_conn *conn;
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int err = 0;
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if (in_own_node(net, dnode))
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return 0;
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node = tipc_node_find(net, dnode);
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if (!node) {
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pr_warn("Connecting sock to node 0x%x failed\n", dnode);
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return -EHOSTUNREACH;
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}
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conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
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if (!conn) {
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err = -EHOSTUNREACH;
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goto exit;
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}
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conn->peer_node = dnode;
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conn->port = port;
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conn->peer_port = peer_port;
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tipc_node_lock(node);
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list_add_tail(&conn->list, &node->conn_sks);
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tipc_node_unlock(node);
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exit:
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tipc_node_put(node);
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return err;
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}
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void tipc_node_remove_conn(struct net *net, u32 dnode, u32 port)
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{
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struct tipc_node *node;
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struct tipc_sock_conn *conn, *safe;
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if (in_own_node(net, dnode))
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return;
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node = tipc_node_find(net, dnode);
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if (!node)
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return;
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tipc_node_lock(node);
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list_for_each_entry_safe(conn, safe, &node->conn_sks, list) {
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if (port != conn->port)
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continue;
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list_del(&conn->list);
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kfree(conn);
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}
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tipc_node_unlock(node);
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tipc_node_put(node);
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}
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/**
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* tipc_node_link_up - handle addition of link
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*
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* Link becomes active (alone or shared) or standby, depending on its priority.
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*/
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void tipc_node_link_up(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
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{
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struct tipc_link **active = &n_ptr->active_links[0];
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n_ptr->working_links++;
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n_ptr->action_flags |= TIPC_NOTIFY_LINK_UP;
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n_ptr->link_id = l_ptr->peer_bearer_id << 16 | l_ptr->bearer_id;
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pr_debug("Established link <%s> on network plane %c\n",
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l_ptr->name, l_ptr->net_plane);
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if (!active[0]) {
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active[0] = active[1] = l_ptr;
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node_established_contact(n_ptr);
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goto exit;
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}
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if (l_ptr->priority < active[0]->priority) {
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pr_debug("New link <%s> becomes standby\n", l_ptr->name);
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goto exit;
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}
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tipc_link_dup_queue_xmit(active[0], l_ptr);
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if (l_ptr->priority == active[0]->priority) {
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active[0] = l_ptr;
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goto exit;
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}
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pr_debug("Old link <%s> becomes standby\n", active[0]->name);
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if (active[1] != active[0])
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pr_debug("Old link <%s> becomes standby\n", active[1]->name);
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active[0] = active[1] = l_ptr;
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exit:
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/* Leave room for changeover header when returning 'mtu' to users: */
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n_ptr->act_mtus[0] = active[0]->mtu - INT_H_SIZE;
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n_ptr->act_mtus[1] = active[1]->mtu - INT_H_SIZE;
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}
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/**
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* node_select_active_links - select active link
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*/
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static void node_select_active_links(struct tipc_node *n_ptr)
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{
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struct tipc_link **active = &n_ptr->active_links[0];
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u32 i;
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u32 highest_prio = 0;
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active[0] = active[1] = NULL;
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for (i = 0; i < MAX_BEARERS; i++) {
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struct tipc_link *l_ptr = n_ptr->links[i];
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if (!l_ptr || !tipc_link_is_up(l_ptr) ||
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(l_ptr->priority < highest_prio))
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continue;
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if (l_ptr->priority > highest_prio) {
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highest_prio = l_ptr->priority;
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active[0] = active[1] = l_ptr;
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} else {
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active[1] = l_ptr;
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}
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}
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}
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/**
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* tipc_node_link_down - handle loss of link
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*/
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void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
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{
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struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id);
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struct tipc_link **active;
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n_ptr->working_links--;
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n_ptr->action_flags |= TIPC_NOTIFY_LINK_DOWN;
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n_ptr->link_id = l_ptr->peer_bearer_id << 16 | l_ptr->bearer_id;
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if (!tipc_link_is_active(l_ptr)) {
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pr_debug("Lost standby link <%s> on network plane %c\n",
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l_ptr->name, l_ptr->net_plane);
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return;
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}
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pr_debug("Lost link <%s> on network plane %c\n",
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l_ptr->name, l_ptr->net_plane);
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active = &n_ptr->active_links[0];
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if (active[0] == l_ptr)
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active[0] = active[1];
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if (active[1] == l_ptr)
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active[1] = active[0];
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if (active[0] == l_ptr)
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node_select_active_links(n_ptr);
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if (tipc_node_is_up(n_ptr))
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tipc_link_failover_send_queue(l_ptr);
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else
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node_lost_contact(n_ptr);
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/* Leave room for changeover header when returning 'mtu' to users: */
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if (active[0]) {
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n_ptr->act_mtus[0] = active[0]->mtu - INT_H_SIZE;
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n_ptr->act_mtus[1] = active[1]->mtu - INT_H_SIZE;
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return;
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}
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/* Loopback link went down? No fragmentation needed from now on. */
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if (n_ptr->addr == tn->own_addr) {
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n_ptr->act_mtus[0] = MAX_MSG_SIZE;
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n_ptr->act_mtus[1] = MAX_MSG_SIZE;
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}
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}
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int tipc_node_active_links(struct tipc_node *n_ptr)
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{
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return n_ptr->active_links[0] != NULL;
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}
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int tipc_node_is_up(struct tipc_node *n_ptr)
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{
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return tipc_node_active_links(n_ptr);
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}
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void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
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{
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n_ptr->links[l_ptr->bearer_id] = l_ptr;
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n_ptr->link_cnt++;
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}
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void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
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{
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int i;
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for (i = 0; i < MAX_BEARERS; i++) {
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if (l_ptr != n_ptr->links[i])
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continue;
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n_ptr->links[i] = NULL;
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n_ptr->link_cnt--;
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}
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}
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static void node_established_contact(struct tipc_node *n_ptr)
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{
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n_ptr->action_flags |= TIPC_NOTIFY_NODE_UP;
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n_ptr->bclink.oos_state = 0;
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n_ptr->bclink.acked = tipc_bclink_get_last_sent(n_ptr->net);
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tipc_bclink_add_node(n_ptr->net, n_ptr->addr);
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}
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static void node_lost_contact(struct tipc_node *n_ptr)
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{
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char addr_string[16];
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struct tipc_sock_conn *conn, *safe;
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struct list_head *conns = &n_ptr->conn_sks;
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struct sk_buff *skb;
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struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id);
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uint i;
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pr_debug("Lost contact with %s\n",
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tipc_addr_string_fill(addr_string, n_ptr->addr));
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/* Flush broadcast link info associated with lost node */
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if (n_ptr->bclink.recv_permitted) {
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__skb_queue_purge(&n_ptr->bclink.deferdq);
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if (n_ptr->bclink.reasm_buf) {
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kfree_skb(n_ptr->bclink.reasm_buf);
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n_ptr->bclink.reasm_buf = NULL;
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}
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tipc_bclink_remove_node(n_ptr->net, n_ptr->addr);
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tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ);
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n_ptr->bclink.recv_permitted = false;
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}
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/* Abort any ongoing link failover */
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for (i = 0; i < MAX_BEARERS; i++) {
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struct tipc_link *l_ptr = n_ptr->links[i];
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if (!l_ptr)
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continue;
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l_ptr->flags &= ~LINK_FAILINGOVER;
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l_ptr->failover_checkpt = 0;
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l_ptr->failover_pkts = 0;
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kfree_skb(l_ptr->failover_skb);
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l_ptr->failover_skb = NULL;
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tipc_link_reset_fragments(l_ptr);
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}
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n_ptr->action_flags &= ~TIPC_WAIT_OWN_LINKS_DOWN;
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/* Prevent re-contact with node until cleanup is done */
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n_ptr->action_flags |= TIPC_WAIT_PEER_LINKS_DOWN;
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/* Notify publications from this node */
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n_ptr->action_flags |= TIPC_NOTIFY_NODE_DOWN;
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/* Notify sockets connected to node */
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list_for_each_entry_safe(conn, safe, conns, list) {
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skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,
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SHORT_H_SIZE, 0, tn->own_addr,
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conn->peer_node, conn->port,
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conn->peer_port, TIPC_ERR_NO_NODE);
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if (likely(skb)) {
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skb_queue_tail(n_ptr->inputq, skb);
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n_ptr->action_flags |= TIPC_MSG_EVT;
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}
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list_del(&conn->list);
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kfree(conn);
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}
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}
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/**
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* tipc_node_get_linkname - get the name of a link
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*
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* @bearer_id: id of the bearer
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* @node: peer node address
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* @linkname: link name output buffer
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*
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* Returns 0 on success
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*/
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int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 addr,
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char *linkname, size_t len)
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{
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struct tipc_link *link;
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int err = -EINVAL;
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struct tipc_node *node = tipc_node_find(net, addr);
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if (!node)
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return err;
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if (bearer_id >= MAX_BEARERS)
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goto exit;
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tipc_node_lock(node);
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link = node->links[bearer_id];
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if (link) {
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strncpy(linkname, link->name, len);
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err = 0;
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}
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exit:
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tipc_node_unlock(node);
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tipc_node_put(node);
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return err;
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}
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void tipc_node_unlock(struct tipc_node *node)
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{
|
|
struct net *net = node->net;
|
|
u32 addr = 0;
|
|
u32 flags = node->action_flags;
|
|
u32 link_id = 0;
|
|
struct list_head *publ_list;
|
|
struct sk_buff_head *inputq = node->inputq;
|
|
struct sk_buff_head *namedq;
|
|
|
|
if (likely(!flags || (flags == TIPC_MSG_EVT))) {
|
|
node->action_flags = 0;
|
|
spin_unlock_bh(&node->lock);
|
|
if (flags == TIPC_MSG_EVT)
|
|
tipc_sk_rcv(net, inputq);
|
|
return;
|
|
}
|
|
|
|
addr = node->addr;
|
|
link_id = node->link_id;
|
|
namedq = node->namedq;
|
|
publ_list = &node->publ_list;
|
|
|
|
node->action_flags &= ~(TIPC_MSG_EVT |
|
|
TIPC_NOTIFY_NODE_DOWN | TIPC_NOTIFY_NODE_UP |
|
|
TIPC_NOTIFY_LINK_DOWN | TIPC_NOTIFY_LINK_UP |
|
|
TIPC_WAKEUP_BCAST_USERS | TIPC_BCAST_MSG_EVT |
|
|
TIPC_NAMED_MSG_EVT | TIPC_BCAST_RESET);
|
|
|
|
spin_unlock_bh(&node->lock);
|
|
|
|
if (flags & TIPC_NOTIFY_NODE_DOWN)
|
|
tipc_publ_notify(net, publ_list, addr);
|
|
|
|
if (flags & TIPC_WAKEUP_BCAST_USERS)
|
|
tipc_bclink_wakeup_users(net);
|
|
|
|
if (flags & TIPC_NOTIFY_NODE_UP)
|
|
tipc_named_node_up(net, addr);
|
|
|
|
if (flags & TIPC_NOTIFY_LINK_UP)
|
|
tipc_nametbl_publish(net, TIPC_LINK_STATE, addr, addr,
|
|
TIPC_NODE_SCOPE, link_id, addr);
|
|
|
|
if (flags & TIPC_NOTIFY_LINK_DOWN)
|
|
tipc_nametbl_withdraw(net, TIPC_LINK_STATE, addr,
|
|
link_id, addr);
|
|
|
|
if (flags & TIPC_MSG_EVT)
|
|
tipc_sk_rcv(net, inputq);
|
|
|
|
if (flags & TIPC_NAMED_MSG_EVT)
|
|
tipc_named_rcv(net, namedq);
|
|
|
|
if (flags & TIPC_BCAST_MSG_EVT)
|
|
tipc_bclink_input(net);
|
|
|
|
if (flags & TIPC_BCAST_RESET)
|
|
tipc_link_reset_all(node);
|
|
}
|
|
|
|
/* Caller should hold node lock for the passed node */
|
|
static int __tipc_nl_add_node(struct tipc_nl_msg *msg, struct tipc_node *node)
|
|
{
|
|
void *hdr;
|
|
struct nlattr *attrs;
|
|
|
|
hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
|
|
NLM_F_MULTI, TIPC_NL_NODE_GET);
|
|
if (!hdr)
|
|
return -EMSGSIZE;
|
|
|
|
attrs = nla_nest_start(msg->skb, TIPC_NLA_NODE);
|
|
if (!attrs)
|
|
goto msg_full;
|
|
|
|
if (nla_put_u32(msg->skb, TIPC_NLA_NODE_ADDR, node->addr))
|
|
goto attr_msg_full;
|
|
if (tipc_node_is_up(node))
|
|
if (nla_put_flag(msg->skb, TIPC_NLA_NODE_UP))
|
|
goto attr_msg_full;
|
|
|
|
nla_nest_end(msg->skb, attrs);
|
|
genlmsg_end(msg->skb, hdr);
|
|
|
|
return 0;
|
|
|
|
attr_msg_full:
|
|
nla_nest_cancel(msg->skb, attrs);
|
|
msg_full:
|
|
genlmsg_cancel(msg->skb, hdr);
|
|
|
|
return -EMSGSIZE;
|
|
}
|
|
|
|
int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb)
|
|
{
|
|
int err;
|
|
struct net *net = sock_net(skb->sk);
|
|
struct tipc_net *tn = net_generic(net, tipc_net_id);
|
|
int done = cb->args[0];
|
|
int last_addr = cb->args[1];
|
|
struct tipc_node *node;
|
|
struct tipc_nl_msg msg;
|
|
|
|
if (done)
|
|
return 0;
|
|
|
|
msg.skb = skb;
|
|
msg.portid = NETLINK_CB(cb->skb).portid;
|
|
msg.seq = cb->nlh->nlmsg_seq;
|
|
|
|
rcu_read_lock();
|
|
if (last_addr) {
|
|
node = tipc_node_find(net, last_addr);
|
|
if (!node) {
|
|
rcu_read_unlock();
|
|
/* We never set seq or call nl_dump_check_consistent()
|
|
* this means that setting prev_seq here will cause the
|
|
* consistence check to fail in the netlink callback
|
|
* handler. Resulting in the NLMSG_DONE message having
|
|
* the NLM_F_DUMP_INTR flag set if the node state
|
|
* changed while we released the lock.
|
|
*/
|
|
cb->prev_seq = 1;
|
|
return -EPIPE;
|
|
}
|
|
tipc_node_put(node);
|
|
}
|
|
|
|
list_for_each_entry_rcu(node, &tn->node_list, list) {
|
|
if (last_addr) {
|
|
if (node->addr == last_addr)
|
|
last_addr = 0;
|
|
else
|
|
continue;
|
|
}
|
|
|
|
tipc_node_lock(node);
|
|
err = __tipc_nl_add_node(&msg, node);
|
|
if (err) {
|
|
last_addr = node->addr;
|
|
tipc_node_unlock(node);
|
|
goto out;
|
|
}
|
|
|
|
tipc_node_unlock(node);
|
|
}
|
|
done = 1;
|
|
out:
|
|
cb->args[0] = done;
|
|
cb->args[1] = last_addr;
|
|
rcu_read_unlock();
|
|
|
|
return skb->len;
|
|
}
|