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292a089d78
Due to several bugs caused by timers being re-armed after they are shutdown and just before they are freed, a new state of timers was added called "shutdown". After a timer is set to this state, then it can no longer be re-armed. The following script was run to find all the trivial locations where del_timer() or del_timer_sync() is called in the same function that the object holding the timer is freed. It also ignores any locations where the timer->function is modified between the del_timer*() and the free(), as that is not considered a "trivial" case. This was created by using a coccinelle script and the following commands: $ cat timer.cocci @@ expression ptr, slab; identifier timer, rfield; @@ ( - del_timer(&ptr->timer); + timer_shutdown(&ptr->timer); | - del_timer_sync(&ptr->timer); + timer_shutdown_sync(&ptr->timer); ) ... when strict when != ptr->timer ( kfree_rcu(ptr, rfield); | kmem_cache_free(slab, ptr); | kfree(ptr); ) $ spatch timer.cocci . > /tmp/t.patch $ patch -p1 < /tmp/t.patch Link: https://lore.kernel.org/lkml/20221123201306.823305113@linutronix.de/ Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Acked-by: Pavel Machek <pavel@ucw.cz> [ LED ] Acked-by: Kalle Valo <kvalo@kernel.org> [ wireless ] Acked-by: Paolo Abeni <pabeni@redhat.com> [ networking ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
421 lines
13 KiB
C
421 lines
13 KiB
C
/*
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* net/tipc/discover.c
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*
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* Copyright (c) 2003-2006, 2014-2018, Ericsson AB
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* Copyright (c) 2005-2006, 2010-2011, 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 "node.h"
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#include "discover.h"
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/* min delay during bearer start up */
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#define TIPC_DISC_INIT msecs_to_jiffies(125)
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/* max delay if bearer has no links */
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#define TIPC_DISC_FAST msecs_to_jiffies(1000)
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/* max delay if bearer has links */
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#define TIPC_DISC_SLOW msecs_to_jiffies(60000)
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/* indicates no timer in use */
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#define TIPC_DISC_INACTIVE 0xffffffff
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/**
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* struct tipc_discoverer - information about an ongoing link setup request
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* @bearer_id: identity of bearer issuing requests
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* @net: network namespace instance
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* @dest: destination address for request messages
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* @domain: network domain to which links can be established
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* @num_nodes: number of nodes currently discovered (i.e. with an active link)
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* @lock: spinlock for controlling access to requests
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* @skb: 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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struct tipc_discoverer {
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u32 bearer_id;
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struct tipc_media_addr dest;
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struct net *net;
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u32 domain;
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int num_nodes;
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spinlock_t lock;
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struct sk_buff *skb;
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struct timer_list timer;
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unsigned long timer_intv;
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};
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/**
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* tipc_disc_init_msg - initialize a link setup message
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* @net: the applicable net namespace
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* @skb: buffer containing message
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* @mtyp: message type (request or response)
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* @b: ptr to bearer issuing message
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*/
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static void tipc_disc_init_msg(struct net *net, struct sk_buff *skb,
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u32 mtyp, struct tipc_bearer *b)
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{
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struct tipc_net *tn = tipc_net(net);
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u32 dest_domain = b->domain;
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struct tipc_msg *hdr;
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hdr = buf_msg(skb);
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tipc_msg_init(tn->trial_addr, hdr, LINK_CONFIG, mtyp,
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MAX_H_SIZE, dest_domain);
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msg_set_size(hdr, MAX_H_SIZE + NODE_ID_LEN);
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msg_set_non_seq(hdr, 1);
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msg_set_node_sig(hdr, tn->random);
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msg_set_node_capabilities(hdr, TIPC_NODE_CAPABILITIES);
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msg_set_dest_domain(hdr, dest_domain);
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msg_set_bc_netid(hdr, tn->net_id);
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b->media->addr2msg(msg_media_addr(hdr), &b->addr);
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msg_set_peer_net_hash(hdr, tipc_net_hash_mixes(net, tn->random));
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msg_set_node_id(hdr, tipc_own_id(net));
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}
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static void tipc_disc_msg_xmit(struct net *net, u32 mtyp, u32 dst,
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u32 src, u32 sugg_addr,
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struct tipc_media_addr *maddr,
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struct tipc_bearer *b)
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{
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struct tipc_msg *hdr;
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struct sk_buff *skb;
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skb = tipc_buf_acquire(MAX_H_SIZE + NODE_ID_LEN, GFP_ATOMIC);
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if (!skb)
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return;
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hdr = buf_msg(skb);
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tipc_disc_init_msg(net, skb, mtyp, b);
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msg_set_sugg_node_addr(hdr, sugg_addr);
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msg_set_dest_domain(hdr, dst);
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tipc_bearer_xmit_skb(net, b->identity, skb, maddr);
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}
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/**
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* disc_dupl_alert - issue node address duplication alert
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* @b: 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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static void disc_dupl_alert(struct tipc_bearer *b, u32 node_addr,
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struct tipc_media_addr *media_addr)
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{
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char media_addr_str[64];
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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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pr_warn("Duplicate %x using %s seen on <%s>\n", node_addr,
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media_addr_str, b->name);
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}
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/* tipc_disc_addr_trial(): - handle an address uniqueness trial from peer
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* Returns true if message should be dropped by caller, i.e., if it is a
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* trial message or we are inside trial period. Otherwise false.
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*/
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static bool tipc_disc_addr_trial_msg(struct tipc_discoverer *d,
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struct tipc_media_addr *maddr,
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struct tipc_bearer *b,
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u32 dst, u32 src,
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u32 sugg_addr,
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u8 *peer_id,
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int mtyp)
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{
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struct net *net = d->net;
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struct tipc_net *tn = tipc_net(net);
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u32 self = tipc_own_addr(net);
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bool trial = time_before(jiffies, tn->addr_trial_end) && !self;
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if (mtyp == DSC_TRIAL_FAIL_MSG) {
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if (!trial)
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return true;
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/* Ignore if somebody else already gave new suggestion */
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if (dst != tn->trial_addr)
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return true;
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/* Otherwise update trial address and restart trial period */
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tn->trial_addr = sugg_addr;
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msg_set_prevnode(buf_msg(d->skb), sugg_addr);
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tn->addr_trial_end = jiffies + msecs_to_jiffies(1000);
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return true;
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}
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/* Apply trial address if we just left trial period */
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if (!trial && !self) {
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schedule_work(&tn->work);
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msg_set_prevnode(buf_msg(d->skb), tn->trial_addr);
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msg_set_type(buf_msg(d->skb), DSC_REQ_MSG);
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}
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/* Accept regular link requests/responses only after trial period */
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if (mtyp != DSC_TRIAL_MSG)
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return trial;
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sugg_addr = tipc_node_try_addr(net, peer_id, src);
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if (sugg_addr)
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tipc_disc_msg_xmit(net, DSC_TRIAL_FAIL_MSG, src,
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self, sugg_addr, maddr, b);
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return true;
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}
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/**
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* tipc_disc_rcv - handle incoming discovery message (request or response)
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* @net: applicable net namespace
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* @skb: buffer containing message
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* @b: bearer that message arrived on
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*/
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void tipc_disc_rcv(struct net *net, struct sk_buff *skb,
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struct tipc_bearer *b)
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{
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struct tipc_net *tn = tipc_net(net);
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struct tipc_msg *hdr = buf_msg(skb);
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u32 pnet_hash = msg_peer_net_hash(hdr);
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u16 caps = msg_node_capabilities(hdr);
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bool legacy = tn->legacy_addr_format;
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u32 sugg = msg_sugg_node_addr(hdr);
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u32 signature = msg_node_sig(hdr);
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u8 peer_id[NODE_ID_LEN] = {0,};
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u32 dst = msg_dest_domain(hdr);
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u32 net_id = msg_bc_netid(hdr);
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struct tipc_media_addr maddr;
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u32 src = msg_prevnode(hdr);
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u32 mtyp = msg_type(hdr);
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bool dupl_addr = false;
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bool respond = false;
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u32 self;
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int err;
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if (skb_linearize(skb)) {
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kfree_skb(skb);
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return;
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}
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hdr = buf_msg(skb);
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if (caps & TIPC_NODE_ID128)
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memcpy(peer_id, msg_node_id(hdr), NODE_ID_LEN);
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else
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sprintf(peer_id, "%x", src);
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err = b->media->msg2addr(b, &maddr, msg_media_addr(hdr));
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kfree_skb(skb);
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if (err || maddr.broadcast) {
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pr_warn_ratelimited("Rcv corrupt discovery message\n");
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return;
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}
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/* Ignore discovery messages from own node */
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if (!memcmp(&maddr, &b->addr, sizeof(maddr)))
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return;
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if (net_id != tn->net_id)
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return;
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if (tipc_disc_addr_trial_msg(b->disc, &maddr, b, dst,
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src, sugg, peer_id, mtyp))
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return;
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self = tipc_own_addr(net);
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/* Message from somebody using this node's address */
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if (in_own_node(net, src)) {
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disc_dupl_alert(b, self, &maddr);
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return;
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}
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if (!tipc_in_scope(legacy, dst, self))
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return;
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if (!tipc_in_scope(legacy, b->domain, src))
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return;
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tipc_node_check_dest(net, src, peer_id, b, caps, signature, pnet_hash,
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&maddr, &respond, &dupl_addr);
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if (dupl_addr)
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disc_dupl_alert(b, src, &maddr);
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if (!respond)
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return;
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if (mtyp != DSC_REQ_MSG)
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return;
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tipc_disc_msg_xmit(net, DSC_RESP_MSG, src, self, 0, &maddr, b);
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}
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/* tipc_disc_add_dest - increment set of discovered nodes
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*/
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void tipc_disc_add_dest(struct tipc_discoverer *d)
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{
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spin_lock_bh(&d->lock);
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d->num_nodes++;
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spin_unlock_bh(&d->lock);
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}
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/* tipc_disc_remove_dest - decrement set of discovered nodes
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*/
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void tipc_disc_remove_dest(struct tipc_discoverer *d)
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{
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int intv, num;
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spin_lock_bh(&d->lock);
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d->num_nodes--;
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num = d->num_nodes;
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intv = d->timer_intv;
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if (!num && (intv == TIPC_DISC_INACTIVE || intv > TIPC_DISC_FAST)) {
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d->timer_intv = TIPC_DISC_INIT;
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mod_timer(&d->timer, jiffies + d->timer_intv);
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}
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spin_unlock_bh(&d->lock);
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}
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/* tipc_disc_timeout - send a periodic link setup request
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* Called whenever a link setup request timer associated with a bearer expires.
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* - Keep doubling time between sent request until limit is reached;
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* - Hold at fast polling rate if we don't have any associated nodes
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* - Otherwise hold at slow polling rate
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*/
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static void tipc_disc_timeout(struct timer_list *t)
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{
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struct tipc_discoverer *d = from_timer(d, t, timer);
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struct tipc_net *tn = tipc_net(d->net);
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struct tipc_media_addr maddr;
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struct sk_buff *skb = NULL;
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struct net *net = d->net;
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u32 bearer_id;
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spin_lock_bh(&d->lock);
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/* Stop searching if only desired node has been found */
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if (tipc_node(d->domain) && d->num_nodes) {
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d->timer_intv = TIPC_DISC_INACTIVE;
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goto exit;
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}
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/* Did we just leave trial period ? */
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if (!time_before(jiffies, tn->addr_trial_end) && !tipc_own_addr(net)) {
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mod_timer(&d->timer, jiffies + TIPC_DISC_INIT);
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spin_unlock_bh(&d->lock);
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schedule_work(&tn->work);
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return;
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}
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/* Adjust timeout interval according to discovery phase */
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if (time_before(jiffies, tn->addr_trial_end)) {
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d->timer_intv = TIPC_DISC_INIT;
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} else {
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d->timer_intv *= 2;
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if (d->num_nodes && d->timer_intv > TIPC_DISC_SLOW)
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d->timer_intv = TIPC_DISC_SLOW;
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else if (!d->num_nodes && d->timer_intv > TIPC_DISC_FAST)
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d->timer_intv = TIPC_DISC_FAST;
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msg_set_type(buf_msg(d->skb), DSC_REQ_MSG);
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msg_set_prevnode(buf_msg(d->skb), tn->trial_addr);
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}
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mod_timer(&d->timer, jiffies + d->timer_intv);
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memcpy(&maddr, &d->dest, sizeof(maddr));
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skb = skb_clone(d->skb, GFP_ATOMIC);
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bearer_id = d->bearer_id;
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exit:
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spin_unlock_bh(&d->lock);
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if (skb)
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tipc_bearer_xmit_skb(net, bearer_id, skb, &maddr);
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}
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/**
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* tipc_disc_create - create object to send periodic link setup requests
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* @net: the applicable net namespace
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* @b: ptr to bearer issuing requests
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* @dest: destination address for request messages
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* @skb: pointer to created frame
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*
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* Return: 0 if successful, otherwise -errno.
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*/
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int tipc_disc_create(struct net *net, struct tipc_bearer *b,
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struct tipc_media_addr *dest, struct sk_buff **skb)
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{
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struct tipc_net *tn = tipc_net(net);
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struct tipc_discoverer *d;
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d = kmalloc(sizeof(*d), GFP_ATOMIC);
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if (!d)
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return -ENOMEM;
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d->skb = tipc_buf_acquire(MAX_H_SIZE + NODE_ID_LEN, GFP_ATOMIC);
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if (!d->skb) {
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kfree(d);
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return -ENOMEM;
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}
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tipc_disc_init_msg(net, d->skb, DSC_REQ_MSG, b);
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/* Do we need an address trial period first ? */
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if (!tipc_own_addr(net)) {
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tn->addr_trial_end = jiffies + msecs_to_jiffies(1000);
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msg_set_type(buf_msg(d->skb), DSC_TRIAL_MSG);
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}
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memcpy(&d->dest, dest, sizeof(*dest));
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d->net = net;
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d->bearer_id = b->identity;
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d->domain = b->domain;
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d->num_nodes = 0;
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d->timer_intv = TIPC_DISC_INIT;
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spin_lock_init(&d->lock);
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timer_setup(&d->timer, tipc_disc_timeout, 0);
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mod_timer(&d->timer, jiffies + d->timer_intv);
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b->disc = d;
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*skb = skb_clone(d->skb, GFP_ATOMIC);
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return 0;
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}
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/**
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* tipc_disc_delete - destroy object sending periodic link setup requests
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* @d: ptr to link dest structure
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*/
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void tipc_disc_delete(struct tipc_discoverer *d)
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{
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timer_shutdown_sync(&d->timer);
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kfree_skb(d->skb);
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kfree(d);
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}
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/**
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* tipc_disc_reset - reset object to send periodic link setup requests
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* @net: the applicable net namespace
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* @b: ptr to bearer issuing requests
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*/
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void tipc_disc_reset(struct net *net, struct tipc_bearer *b)
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{
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struct tipc_discoverer *d = b->disc;
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struct tipc_media_addr maddr;
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struct sk_buff *skb;
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spin_lock_bh(&d->lock);
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tipc_disc_init_msg(net, d->skb, DSC_REQ_MSG, b);
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d->net = net;
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d->bearer_id = b->identity;
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d->domain = b->domain;
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d->num_nodes = 0;
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d->timer_intv = TIPC_DISC_INIT;
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memcpy(&maddr, &d->dest, sizeof(maddr));
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mod_timer(&d->timer, jiffies + d->timer_intv);
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skb = skb_clone(d->skb, GFP_ATOMIC);
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spin_unlock_bh(&d->lock);
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if (skb)
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tipc_bearer_xmit_skb(net, b->identity, skb, &maddr);
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}
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