2006-01-02 19:04:38 +01:00
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/*
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* net/tipc/discover.c
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2007-02-09 15:25:21 +01:00
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*
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2006-01-11 18:40:41 +01:00
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* Copyright (c) 2003-2006, Ericsson AB
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2011-01-07 19:00:11 +01:00
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* Copyright (c) 2005-2006, 2010-2011, Wind River Systems
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2006-01-02 19:04:38 +01:00
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* All rights reserved.
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*
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2006-01-11 13:30:43 +01:00
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* Redistribution and use in source and binary forms, with or without
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2006-01-02 19:04:38 +01:00
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* modification, are permitted provided that the following conditions are met:
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*
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2006-01-11 13:30:43 +01:00
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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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2006-01-02 19:04:38 +01:00
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*
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2006-01-11 13:30:43 +01:00
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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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2006-01-02 19:04:38 +01:00
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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 "discover.h"
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#define TIPC_LINK_REQ_INIT 125 /* min delay during bearer start up */
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2011-04-22 03:34:03 +02:00
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#define TIPC_LINK_REQ_FAST 1000 /* max delay if bearer has no links */
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#define TIPC_LINK_REQ_SLOW 60000 /* max delay if bearer has links */
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#define TIPC_LINK_REQ_INACTIVE 0xffffffff /* indicates no timer in use */
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2006-01-02 19:04:38 +01:00
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/**
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2011-12-30 02:58:42 +01:00
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* struct tipc_link_req - information about an ongoing link setup request
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2006-01-02 19:04:38 +01:00
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* @bearer: bearer issuing requests
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* @dest: destination address for request messages
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2011-04-20 23:24:07 +02:00
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* @domain: network domain to which links can be established
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2011-04-22 02:05:25 +02:00
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* @num_nodes: number of nodes currently discovered (i.e. with an active link)
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2014-01-07 23:02:43 +01:00
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* @lock: spinlock for controlling access to requests
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2006-01-02 19:04:38 +01:00
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* @buf: request message to be (repeatedly) sent
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* @timer: timer governing period between requests
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* @timer_intv: current interval between requests (in ms)
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*/
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2011-12-30 02:58:42 +01:00
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struct tipc_link_req {
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2011-01-07 19:00:11 +01:00
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struct tipc_bearer *bearer;
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2006-01-02 19:04:38 +01:00
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struct tipc_media_addr dest;
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2011-04-20 23:24:07 +02:00
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u32 domain;
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2011-04-22 02:05:25 +02:00
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int num_nodes;
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2014-01-07 23:02:43 +01:00
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spinlock_t lock;
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2006-01-02 19:04:38 +01:00
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struct sk_buff *buf;
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struct timer_list timer;
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unsigned int timer_intv;
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};
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2007-02-09 15:25:21 +01:00
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/**
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2006-01-18 00:38:21 +01:00
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* tipc_disc_init_msg - initialize a link setup message
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2006-01-02 19:04:38 +01:00
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* @type: message type (request or response)
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* @dest_domain: network domain of node(s) which should respond to message
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* @b_ptr: ptr to bearer issuing message
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*/
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2013-06-17 16:54:47 +02:00
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static struct sk_buff *tipc_disc_init_msg(u32 type, u32 dest_domain,
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2011-01-07 19:00:11 +01:00
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struct tipc_bearer *b_ptr)
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2006-01-02 19:04:38 +01:00
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{
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2011-02-28 22:02:30 +01:00
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struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE);
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2006-01-02 19:04:38 +01:00
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struct tipc_msg *msg;
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if (buf) {
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msg = buf_msg(buf);
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2011-02-28 22:02:30 +01:00
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tipc_msg_init(msg, LINK_CONFIG, type, INT_H_SIZE, dest_domain);
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2008-06-05 02:54:48 +02:00
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msg_set_non_seq(msg, 1);
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2011-10-28 22:26:41 +02:00
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msg_set_node_sig(msg, tipc_random);
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2006-01-02 19:04:38 +01:00
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msg_set_dest_domain(msg, dest_domain);
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msg_set_bc_netid(msg, tipc_net_id);
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2011-10-07 21:19:11 +02:00
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b_ptr->media->addr2msg(&b_ptr->addr, msg_media_addr(msg));
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2006-01-02 19:04:38 +01:00
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}
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return buf;
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}
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2006-10-17 06:44:59 +02:00
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/**
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* disc_dupl_alert - issue node address duplication alert
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* @b_ptr: pointer to bearer detecting duplication
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* @node_addr: duplicated node address
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* @media_addr: media address advertised by duplicated node
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*/
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2011-01-07 19:00:11 +01:00
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static void disc_dupl_alert(struct tipc_bearer *b_ptr, u32 node_addr,
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2006-10-17 06:44:59 +02:00
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struct tipc_media_addr *media_addr)
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{
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char node_addr_str[16];
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char media_addr_str[64];
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2010-05-11 16:30:12 +02:00
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tipc_addr_string_fill(node_addr_str, node_addr);
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2012-06-29 06:50:23 +02:00
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tipc_media_addr_printf(media_addr_str, sizeof(media_addr_str),
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media_addr);
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2012-06-29 06:16:37 +02:00
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pr_warn("Duplicate %s using %s seen on <%s>\n", node_addr_str,
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media_addr_str, b_ptr->name);
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2006-10-17 06:44:59 +02:00
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}
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2006-01-02 19:04:38 +01:00
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/**
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2006-01-18 00:38:21 +01:00
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* tipc_disc_recv_msg - handle incoming link setup message (request or response)
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2006-01-02 19:04:38 +01:00
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* @buf: buffer containing message
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2008-06-05 02:32:35 +02:00
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* @b_ptr: bearer that message arrived on
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2006-01-02 19:04:38 +01:00
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*/
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2011-01-07 19:00:11 +01:00
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void tipc_disc_recv_msg(struct sk_buff *buf, struct tipc_bearer *b_ptr)
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2006-01-02 19:04:38 +01:00
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{
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2011-02-28 16:03:05 +01:00
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struct tipc_node *n_ptr;
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2011-12-30 02:58:42 +01:00
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struct tipc_link *link;
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2011-10-28 23:30:08 +02:00
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struct tipc_media_addr media_addr;
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2011-02-28 16:03:05 +01:00
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struct sk_buff *rbuf;
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2006-01-02 19:04:38 +01:00
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struct tipc_msg *msg = buf_msg(buf);
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u32 dest = msg_dest_domain(msg);
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u32 orig = msg_prevnode(msg);
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u32 net_id = msg_bc_netid(msg);
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u32 type = msg_type(msg);
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2011-10-28 22:26:41 +02:00
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u32 signature = msg_node_sig(msg);
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2011-10-28 23:30:08 +02:00
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int addr_mismatch;
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2011-02-28 16:03:05 +01:00
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int link_fully_up;
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2006-01-02 19:04:38 +01:00
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2011-10-07 21:48:41 +02:00
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media_addr.broadcast = 1;
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2013-04-17 08:18:26 +02:00
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b_ptr->media->msg2addr(b_ptr, &media_addr, msg_media_addr(msg));
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2011-11-04 18:24:29 +01:00
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kfree_skb(buf);
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2006-01-02 19:04:38 +01:00
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2011-10-28 23:30:08 +02:00
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/* Ensure message from node is valid and communication is permitted */
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2006-01-02 19:04:38 +01:00
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if (net_id != tipc_net_id)
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return;
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2011-10-07 21:48:41 +02:00
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if (media_addr.broadcast)
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return;
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2006-01-18 00:38:21 +01:00
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if (!tipc_addr_domain_valid(dest))
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2006-01-02 19:04:38 +01:00
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return;
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2006-01-18 00:38:21 +01:00
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if (!tipc_addr_node_valid(orig))
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2006-01-02 19:04:38 +01:00
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return;
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2006-10-17 06:44:59 +02:00
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if (orig == tipc_own_addr) {
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2011-01-07 19:00:11 +01:00
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if (memcmp(&media_addr, &b_ptr->addr, sizeof(media_addr)))
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2006-10-17 06:44:59 +02:00
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disc_dupl_alert(b_ptr, tipc_own_addr, &media_addr);
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2006-01-02 19:04:38 +01:00
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return;
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2006-10-17 06:44:59 +02:00
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}
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2010-05-11 16:30:12 +02:00
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if (!tipc_in_scope(dest, tipc_own_addr))
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2006-01-02 19:04:38 +01:00
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return;
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2011-04-20 23:24:07 +02:00
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if (!tipc_in_scope(b_ptr->link_req->domain, orig))
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2011-02-28 16:03:05 +01:00
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return;
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2010-08-17 13:00:16 +02:00
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2011-02-28 16:03:05 +01:00
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/* Locate structure corresponding to requesting node */
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n_ptr = tipc_node_find(orig);
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if (!n_ptr) {
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n_ptr = tipc_node_create(orig);
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if (!n_ptr)
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2010-08-17 13:00:16 +02:00
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return;
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2011-02-28 16:03:05 +01:00
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}
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tipc_node_lock(n_ptr);
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2011-10-28 23:30:08 +02:00
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/* Prepare to validate requesting node's signature and media address */
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2011-02-28 16:03:05 +01:00
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link = n_ptr->links[b_ptr->identity];
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2011-10-28 23:30:08 +02:00
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addr_mismatch = (link != NULL) &&
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memcmp(&link->media_addr, &media_addr, sizeof(media_addr));
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2011-02-28 16:03:05 +01:00
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2011-10-28 23:30:08 +02:00
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/*
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* Ensure discovery message's signature is correct
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*
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* If signature is incorrect and there is no working link to the node,
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* accept the new signature but invalidate all existing links to the
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* node so they won't re-activate without a new discovery message.
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*
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* If signature is incorrect and the requested link to the node is
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* working, accept the new signature. (This is an instance of delayed
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* rediscovery, where a link endpoint was able to re-establish contact
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* with its peer endpoint on a node that rebooted before receiving a
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* discovery message from that node.)
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*
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* If signature is incorrect and there is a working link to the node
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* that is not the requested link, reject the request (must be from
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* a duplicate node).
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*/
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if (signature != n_ptr->signature) {
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if (n_ptr->working_links == 0) {
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struct tipc_link *curr_link;
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int i;
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for (i = 0; i < MAX_BEARERS; i++) {
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curr_link = n_ptr->links[i];
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if (curr_link) {
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memset(&curr_link->media_addr, 0,
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sizeof(media_addr));
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tipc_link_reset(curr_link);
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}
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}
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addr_mismatch = (link != NULL);
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} else if (tipc_link_is_up(link) && !addr_mismatch) {
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/* delayed rediscovery */
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} else {
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disc_dupl_alert(b_ptr, orig, &media_addr);
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2011-02-28 16:03:05 +01:00
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tipc_node_unlock(n_ptr);
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return;
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2006-01-02 19:04:38 +01:00
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}
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2011-10-28 23:30:08 +02:00
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n_ptr->signature = signature;
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2011-02-28 16:03:05 +01:00
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}
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/*
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* Ensure requesting node's media address is correct
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*
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* If media address doesn't match and the link is working, reject the
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* request (must be from a duplicate node).
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*
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* If media address doesn't match and the link is not working, accept
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* the new media address and reset the link to ensure it starts up
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* cleanly.
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*/
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2011-10-28 23:30:08 +02:00
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if (addr_mismatch) {
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if (tipc_link_is_up(link)) {
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2011-02-28 16:03:05 +01:00
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disc_dupl_alert(b_ptr, orig, &media_addr);
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tipc_node_unlock(n_ptr);
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2006-01-02 19:04:38 +01:00
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return;
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2011-10-28 23:30:08 +02:00
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} else {
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memcpy(&link->media_addr, &media_addr,
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sizeof(media_addr));
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tipc_link_reset(link);
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}
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}
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/* Create a link endpoint for this bearer, if necessary */
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if (!link) {
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link = tipc_link_create(n_ptr, b_ptr, &media_addr);
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if (!link) {
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tipc_node_unlock(n_ptr);
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return;
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2006-01-02 19:04:38 +01:00
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}
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2011-02-28 16:03:05 +01:00
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}
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/* Accept discovery message & send response, if necessary */
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link_fully_up = link_working_working(link);
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2011-02-28 16:56:23 +01:00
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tipc: remove interface state mirroring in bearer
struct 'tipc_bearer' is a generic representation of the underlying
media type, and exists in a one-to-one relationship to each interface
TIPC is using. The struct contains a 'blocked' flag that mirrors the
operational and execution state of the represented interface, and is
updated through notification calls from the latter. The users of
tipc_bearer are checking this flag before each attempt to send a
packet via the interface.
This state mirroring serves no purpose in the current code base. TIPC
links will not discover a media failure any faster through this
mechanism, and in reality the flag only adds overhead at packet
sending and reception.
Furthermore, the fact that the flag needs to be protected by a spinlock
aggregated into tipc_bearer has turned out to cause a serious and
completely unnecessary deadlock problem.
CPU0 CPU1
---- ----
Time 0: bearer_disable() link_timeout()
Time 1: spin_lock_bh(&b_ptr->lock) tipc_link_push_queue()
Time 2: tipc_link_delete() tipc_bearer_blocked(b_ptr)
Time 3: k_cancel_timer(&req->timer) spin_lock_bh(&b_ptr->lock)
Time 4: del_timer_sync(&req->timer)
I.e., del_timer_sync() on CPU0 never returns, because the timer handler
on CPU1 is waiting for the bearer lock.
We eliminate the 'blocked' flag from struct tipc_bearer, along with all
tests on this flag. This not only resolves the deadlock, but also
simplifies and speeds up the data path execution of TIPC. It also fits
well into our ongoing effort to make the locking policy simpler and
more manageable.
An effect of this change is that we can get rid of functions such as
tipc_bearer_blocked(), tipc_continue() and tipc_block_bearer().
We replace the latter with a new function, tipc_reset_bearer(), which
resets all links associated to the bearer immediately after an
interface goes down.
A user might notice one slight change in link behaviour after this
change. When an interface goes down, (e.g. through a NETDEV_DOWN
event) all attached links will be reset immediately, instead of
leaving it to each link to detect the failure through a timer-driven
mechanism. We consider this an improvement, and see no obvious risks
with the new behavior.
Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <Paul.Gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-06 16:08:00 +01:00
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|
|
if ((type == DSC_REQ_MSG) && !link_fully_up) {
|
2011-02-28 16:56:23 +01:00
|
|
|
rbuf = tipc_disc_init_msg(DSC_RESP_MSG, orig, b_ptr);
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if (rbuf) {
|
2012-11-15 04:34:45 +01:00
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|
tipc_bearer_send(b_ptr, rbuf, &media_addr);
|
2011-11-04 18:24:29 +01:00
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|
kfree_skb(rbuf);
|
2011-02-28 16:56:23 +01:00
|
|
|
}
|
2006-01-02 19:04:38 +01:00
|
|
|
}
|
2011-02-28 16:56:23 +01:00
|
|
|
|
|
|
|
tipc_node_unlock(n_ptr);
|
2006-01-02 19:04:38 +01:00
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
2011-04-22 02:05:25 +02:00
|
|
|
* disc_update - update frequency of periodic link setup requests
|
2006-01-02 19:04:38 +01:00
|
|
|
* @req: ptr to link request structure
|
2011-04-22 03:34:03 +02:00
|
|
|
*
|
|
|
|
* Reinitiates discovery process if discovery object has no associated nodes
|
|
|
|
* and is either not currently searching or is searching at a slow rate
|
2006-01-02 19:04:38 +01:00
|
|
|
*/
|
2011-12-30 02:58:42 +01:00
|
|
|
static void disc_update(struct tipc_link_req *req)
|
2006-01-02 19:04:38 +01:00
|
|
|
{
|
2011-04-22 03:34:03 +02:00
|
|
|
if (!req->num_nodes) {
|
|
|
|
if ((req->timer_intv == TIPC_LINK_REQ_INACTIVE) ||
|
|
|
|
(req->timer_intv > TIPC_LINK_REQ_FAST)) {
|
|
|
|
req->timer_intv = TIPC_LINK_REQ_INIT;
|
2006-01-02 19:04:38 +01:00
|
|
|
k_start_timer(&req->timer, req->timer_intv);
|
|
|
|
}
|
|
|
|
}
|
2007-02-09 15:25:21 +01:00
|
|
|
}
|
2006-01-02 19:04:38 +01:00
|
|
|
|
2011-04-22 02:05:25 +02:00
|
|
|
/**
|
|
|
|
* tipc_disc_add_dest - increment set of discovered nodes
|
|
|
|
* @req: ptr to link request structure
|
|
|
|
*/
|
2011-12-30 02:58:42 +01:00
|
|
|
void tipc_disc_add_dest(struct tipc_link_req *req)
|
2011-04-22 02:05:25 +02:00
|
|
|
{
|
2014-01-07 23:02:43 +01:00
|
|
|
spin_lock_bh(&req->lock);
|
2011-04-22 02:05:25 +02:00
|
|
|
req->num_nodes++;
|
2014-01-07 23:02:43 +01:00
|
|
|
spin_unlock_bh(&req->lock);
|
2011-04-22 02:05:25 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* tipc_disc_remove_dest - decrement set of discovered nodes
|
|
|
|
* @req: ptr to link request structure
|
|
|
|
*/
|
2011-12-30 02:58:42 +01:00
|
|
|
void tipc_disc_remove_dest(struct tipc_link_req *req)
|
2011-04-22 02:05:25 +02:00
|
|
|
{
|
2014-01-07 23:02:43 +01:00
|
|
|
spin_lock_bh(&req->lock);
|
2011-04-22 02:05:25 +02:00
|
|
|
req->num_nodes--;
|
|
|
|
disc_update(req);
|
2014-01-07 23:02:43 +01:00
|
|
|
spin_unlock_bh(&req->lock);
|
2011-04-22 02:05:25 +02:00
|
|
|
}
|
|
|
|
|
2006-01-02 19:04:38 +01:00
|
|
|
/**
|
|
|
|
* disc_timeout - send a periodic link setup request
|
|
|
|
* @req: ptr to link request structure
|
2007-02-09 15:25:21 +01:00
|
|
|
*
|
2006-01-02 19:04:38 +01:00
|
|
|
* Called whenever a link setup request timer associated with a bearer expires.
|
|
|
|
*/
|
2011-12-30 02:58:42 +01:00
|
|
|
static void disc_timeout(struct tipc_link_req *req)
|
2006-01-02 19:04:38 +01:00
|
|
|
{
|
2011-04-22 03:34:03 +02:00
|
|
|
int max_delay;
|
|
|
|
|
2014-01-07 23:02:43 +01:00
|
|
|
spin_lock_bh(&req->lock);
|
2006-01-02 19:04:38 +01:00
|
|
|
|
2011-04-22 03:34:03 +02:00
|
|
|
/* Stop searching if only desired node has been found */
|
|
|
|
if (tipc_node(req->domain) && req->num_nodes) {
|
|
|
|
req->timer_intv = TIPC_LINK_REQ_INACTIVE;
|
|
|
|
goto exit;
|
2006-01-02 19:04:38 +01:00
|
|
|
}
|
|
|
|
|
2011-04-22 03:34:03 +02:00
|
|
|
/*
|
|
|
|
* Send discovery message, then update discovery timer
|
|
|
|
*
|
|
|
|
* Keep doubling time between requests until limit is reached;
|
|
|
|
* hold at fast polling rate if don't have any associated nodes,
|
|
|
|
* otherwise hold at slow polling rate
|
|
|
|
*/
|
tipc: remove interface state mirroring in bearer
struct 'tipc_bearer' is a generic representation of the underlying
media type, and exists in a one-to-one relationship to each interface
TIPC is using. The struct contains a 'blocked' flag that mirrors the
operational and execution state of the represented interface, and is
updated through notification calls from the latter. The users of
tipc_bearer are checking this flag before each attempt to send a
packet via the interface.
This state mirroring serves no purpose in the current code base. TIPC
links will not discover a media failure any faster through this
mechanism, and in reality the flag only adds overhead at packet
sending and reception.
Furthermore, the fact that the flag needs to be protected by a spinlock
aggregated into tipc_bearer has turned out to cause a serious and
completely unnecessary deadlock problem.
CPU0 CPU1
---- ----
Time 0: bearer_disable() link_timeout()
Time 1: spin_lock_bh(&b_ptr->lock) tipc_link_push_queue()
Time 2: tipc_link_delete() tipc_bearer_blocked(b_ptr)
Time 3: k_cancel_timer(&req->timer) spin_lock_bh(&b_ptr->lock)
Time 4: del_timer_sync(&req->timer)
I.e., del_timer_sync() on CPU0 never returns, because the timer handler
on CPU1 is waiting for the bearer lock.
We eliminate the 'blocked' flag from struct tipc_bearer, along with all
tests on this flag. This not only resolves the deadlock, but also
simplifies and speeds up the data path execution of TIPC. It also fits
well into our ongoing effort to make the locking policy simpler and
more manageable.
An effect of this change is that we can get rid of functions such as
tipc_bearer_blocked(), tipc_continue() and tipc_block_bearer().
We replace the latter with a new function, tipc_reset_bearer(), which
resets all links associated to the bearer immediately after an
interface goes down.
A user might notice one slight change in link behaviour after this
change. When an interface goes down, (e.g. through a NETDEV_DOWN
event) all attached links will be reset immediately, instead of
leaving it to each link to detect the failure through a timer-driven
mechanism. We consider this an improvement, and see no obvious risks
with the new behavior.
Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <Paul.Gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-06 16:08:00 +01:00
|
|
|
tipc_bearer_send(req->bearer, req->buf, &req->dest);
|
|
|
|
|
2011-04-22 03:34:03 +02:00
|
|
|
|
|
|
|
req->timer_intv *= 2;
|
|
|
|
if (req->num_nodes)
|
|
|
|
max_delay = TIPC_LINK_REQ_SLOW;
|
|
|
|
else
|
|
|
|
max_delay = TIPC_LINK_REQ_FAST;
|
|
|
|
if (req->timer_intv > max_delay)
|
|
|
|
req->timer_intv = max_delay;
|
|
|
|
|
|
|
|
k_start_timer(&req->timer, req->timer_intv);
|
|
|
|
exit:
|
2014-01-07 23:02:43 +01:00
|
|
|
spin_unlock_bh(&req->lock);
|
2006-01-02 19:04:38 +01:00
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
2011-04-21 20:58:26 +02:00
|
|
|
* tipc_disc_create - create object to send periodic link setup requests
|
2006-01-02 19:04:38 +01:00
|
|
|
* @b_ptr: ptr to bearer issuing requests
|
|
|
|
* @dest: destination address for request messages
|
2011-04-20 23:24:07 +02:00
|
|
|
* @dest_domain: network domain to which links can be established
|
2007-02-09 15:25:21 +01:00
|
|
|
*
|
2011-04-21 20:58:26 +02:00
|
|
|
* Returns 0 if successful, otherwise -errno.
|
2006-01-02 19:04:38 +01:00
|
|
|
*/
|
2013-06-17 16:54:47 +02:00
|
|
|
int tipc_disc_create(struct tipc_bearer *b_ptr, struct tipc_media_addr *dest,
|
|
|
|
u32 dest_domain)
|
2006-01-02 19:04:38 +01:00
|
|
|
{
|
2011-12-30 02:58:42 +01:00
|
|
|
struct tipc_link_req *req;
|
2006-01-02 19:04:38 +01:00
|
|
|
|
2006-07-22 00:52:20 +02:00
|
|
|
req = kmalloc(sizeof(*req), GFP_ATOMIC);
|
2006-01-02 19:04:38 +01:00
|
|
|
if (!req)
|
2011-04-21 20:58:26 +02:00
|
|
|
return -ENOMEM;
|
2006-01-02 19:04:38 +01:00
|
|
|
|
2011-01-25 20:39:59 +01:00
|
|
|
req->buf = tipc_disc_init_msg(DSC_REQ_MSG, dest_domain, b_ptr);
|
2006-01-02 19:04:38 +01:00
|
|
|
if (!req->buf) {
|
|
|
|
kfree(req);
|
2011-04-21 20:58:26 +02:00
|
|
|
return -ENOMSG;
|
2006-01-02 19:04:38 +01:00
|
|
|
}
|
|
|
|
|
|
|
|
memcpy(&req->dest, dest, sizeof(*dest));
|
|
|
|
req->bearer = b_ptr;
|
2011-04-20 23:24:07 +02:00
|
|
|
req->domain = dest_domain;
|
2011-04-22 02:05:25 +02:00
|
|
|
req->num_nodes = 0;
|
2006-01-02 19:04:38 +01:00
|
|
|
req->timer_intv = TIPC_LINK_REQ_INIT;
|
2014-01-07 23:02:43 +01:00
|
|
|
spin_lock_init(&req->lock);
|
2006-01-02 19:04:38 +01:00
|
|
|
k_init_timer(&req->timer, (Handler)disc_timeout, (unsigned long)req);
|
|
|
|
k_start_timer(&req->timer, req->timer_intv);
|
2011-04-21 20:58:26 +02:00
|
|
|
b_ptr->link_req = req;
|
tipc: remove interface state mirroring in bearer
struct 'tipc_bearer' is a generic representation of the underlying
media type, and exists in a one-to-one relationship to each interface
TIPC is using. The struct contains a 'blocked' flag that mirrors the
operational and execution state of the represented interface, and is
updated through notification calls from the latter. The users of
tipc_bearer are checking this flag before each attempt to send a
packet via the interface.
This state mirroring serves no purpose in the current code base. TIPC
links will not discover a media failure any faster through this
mechanism, and in reality the flag only adds overhead at packet
sending and reception.
Furthermore, the fact that the flag needs to be protected by a spinlock
aggregated into tipc_bearer has turned out to cause a serious and
completely unnecessary deadlock problem.
CPU0 CPU1
---- ----
Time 0: bearer_disable() link_timeout()
Time 1: spin_lock_bh(&b_ptr->lock) tipc_link_push_queue()
Time 2: tipc_link_delete() tipc_bearer_blocked(b_ptr)
Time 3: k_cancel_timer(&req->timer) spin_lock_bh(&b_ptr->lock)
Time 4: del_timer_sync(&req->timer)
I.e., del_timer_sync() on CPU0 never returns, because the timer handler
on CPU1 is waiting for the bearer lock.
We eliminate the 'blocked' flag from struct tipc_bearer, along with all
tests on this flag. This not only resolves the deadlock, but also
simplifies and speeds up the data path execution of TIPC. It also fits
well into our ongoing effort to make the locking policy simpler and
more manageable.
An effect of this change is that we can get rid of functions such as
tipc_bearer_blocked(), tipc_continue() and tipc_block_bearer().
We replace the latter with a new function, tipc_reset_bearer(), which
resets all links associated to the bearer immediately after an
interface goes down.
A user might notice one slight change in link behaviour after this
change. When an interface goes down, (e.g. through a NETDEV_DOWN
event) all attached links will be reset immediately, instead of
leaving it to each link to detect the failure through a timer-driven
mechanism. We consider this an improvement, and see no obvious risks
with the new behavior.
Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <Paul.Gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-06 16:08:00 +01:00
|
|
|
tipc_bearer_send(req->bearer, req->buf, &req->dest);
|
2011-04-21 20:58:26 +02:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* tipc_disc_delete - destroy object sending periodic link setup requests
|
|
|
|
* @req: ptr to link request structure
|
|
|
|
*/
|
2011-12-30 02:58:42 +01:00
|
|
|
void tipc_disc_delete(struct tipc_link_req *req)
|
2011-04-21 20:58:26 +02:00
|
|
|
{
|
|
|
|
k_cancel_timer(&req->timer);
|
|
|
|
k_term_timer(&req->timer);
|
2011-11-04 18:24:29 +01:00
|
|
|
kfree_skb(req->buf);
|
2011-04-21 20:58:26 +02:00
|
|
|
kfree(req);
|
2007-02-09 15:25:21 +01:00
|
|
|
}
|