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diff --git a/net/tipc/net.c b/net/tipc/net.c
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+/*
+ * net/tipc/net.c: TIPC network routing code
+ *
+ * Copyright (c) 1995-2006, 2014, Ericsson AB
+ * Copyright (c) 2005, 2010-2011, Wind River Systems
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "core.h"
+#include "net.h"
+#include "name_distr.h"
+#include "subscr.h"
+#include "socket.h"
+#include "node.h"
+
+static const struct nla_policy tipc_nl_net_policy[TIPC_NLA_NET_MAX + 1] = {
+ [TIPC_NLA_NET_UNSPEC] = { .type = NLA_UNSPEC },
+ [TIPC_NLA_NET_ID] = { .type = NLA_U32 }
+};
+
+/*
+ * The TIPC locking policy is designed to ensure a very fine locking
+ * granularity, permitting complete parallel access to individual
+ * port and node/link instances. The code consists of four major
+ * locking domains, each protected with their own disjunct set of locks.
+ *
+ * 1: The bearer level.
+ * RTNL lock is used to serialize the process of configuring bearer
+ * on update side, and RCU lock is applied on read side to make
+ * bearer instance valid on both paths of message transmission and
+ * reception.
+ *
+ * 2: The node and link level.
+ * All node instances are saved into two tipc_node_list and node_htable
+ * lists. The two lists are protected by node_list_lock on write side,
+ * and they are guarded with RCU lock on read side. Especially node
+ * instance is destroyed only when TIPC module is removed, and we can
+ * confirm that there has no any user who is accessing the node at the
+ * moment. Therefore, Except for iterating the two lists within RCU
+ * protection, it's no needed to hold RCU that we access node instance
+ * in other places.
+ *
+ * In addition, all members in node structure including link instances
+ * are protected by node spin lock.
+ *
+ * 3: The transport level of the protocol.
+ * This consists of the structures port, (and its user level
+ * representations, such as user_port and tipc_sock), reference and
+ * tipc_user (port.c, reg.c, socket.c).
+ *
+ * This layer has four different locks:
+ * - The tipc_port spin_lock. This is protecting each port instance
+ * from parallel data access and removal. Since we can not place
+ * this lock in the port itself, it has been placed in the
+ * corresponding reference table entry, which has the same life
+ * cycle as the module. This entry is difficult to access from
+ * outside the TIPC core, however, so a pointer to the lock has
+ * been added in the port instance, -to be used for unlocking
+ * only.
+ * - A read/write lock to protect the reference table itself (teg.c).
+ * (Nobody is using read-only access to this, so it can just as
+ * well be changed to a spin_lock)
+ * - A spin lock to protect the registry of kernel/driver users (reg.c)
+ * - A global spin_lock (tipc_port_lock), which only task is to ensure
+ * consistency where more than one port is involved in an operation,
+ * i.e., whe a port is part of a linked list of ports.
+ * There are two such lists; 'port_list', which is used for management,
+ * and 'wait_list', which is used to queue ports during congestion.
+ *
+ * 4: The name table (name_table.c, name_distr.c, subscription.c)
+ * - There is one big read/write-lock (tipc_nametbl_lock) protecting the
+ * overall name table structure. Nothing must be added/removed to
+ * this structure without holding write access to it.
+ * - There is one local spin_lock per sub_sequence, which can be seen
+ * as a sub-domain to the tipc_nametbl_lock domain. It is used only
+ * for translation operations, and is needed because a translation
+ * steps the root of the 'publication' linked list between each lookup.
+ * This is always used within the scope of a tipc_nametbl_lock(read).
+ * - A local spin_lock protecting the queue of subscriber events.
+*/
+
+int tipc_net_start(struct net *net, u32 addr)
+{
+ struct tipc_net *tn = net_generic(net, tipc_net_id);
+ char addr_string[16];
+ int res;
+
+ tn->own_addr = addr;
+ tipc_named_reinit(net);
+ tipc_sk_reinit(net);
+ res = tipc_bclink_init(net);
+ if (res)
+ return res;
+
+ tipc_nametbl_publish(net, TIPC_CFG_SRV, tn->own_addr, tn->own_addr,
+ TIPC_ZONE_SCOPE, 0, tn->own_addr);
+
+ pr_info("Started in network mode\n");
+ pr_info("Own node address %s, network identity %u\n",
+ tipc_addr_string_fill(addr_string, tn->own_addr),
+ tn->net_id);
+ return 0;
+}
+
+void tipc_net_stop(struct net *net)
+{
+ struct tipc_net *tn = net_generic(net, tipc_net_id);
+
+ if (!tn->own_addr)
+ return;
+
+ tipc_nametbl_withdraw(net, TIPC_CFG_SRV, tn->own_addr, 0,
+ tn->own_addr);
+ rtnl_lock();
+ tipc_bearer_stop(net);
+ tipc_bclink_stop(net);
+ tipc_node_stop(net);
+ rtnl_unlock();
+
+ pr_info("Left network mode\n");
+}
+
+static int __tipc_nl_add_net(struct net *net, struct tipc_nl_msg *msg)
+{
+ struct tipc_net *tn = net_generic(net, tipc_net_id);
+ void *hdr;
+ struct nlattr *attrs;
+
+ hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
+ NLM_F_MULTI, TIPC_NL_NET_GET);
+ if (!hdr)
+ return -EMSGSIZE;
+
+ attrs = nla_nest_start(msg->skb, TIPC_NLA_NET);
+ if (!attrs)
+ goto msg_full;
+
+ if (nla_put_u32(msg->skb, TIPC_NLA_NET_ID, tn->net_id))
+ 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_net_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ struct net *net = sock_net(skb->sk);
+ int err;
+ int done = cb->args[0];
+ 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;
+
+ err = __tipc_nl_add_net(net, &msg);
+ if (err)
+ goto out;
+
+ done = 1;
+out:
+ cb->args[0] = done;
+
+ return skb->len;
+}
+
+int tipc_nl_net_set(struct sk_buff *skb, struct genl_info *info)
+{
+ struct net *net = sock_net(skb->sk);
+ struct tipc_net *tn = net_generic(net, tipc_net_id);
+ struct nlattr *attrs[TIPC_NLA_NET_MAX + 1];
+ int err;
+
+ if (!info->attrs[TIPC_NLA_NET])
+ return -EINVAL;
+
+ err = nla_parse_nested(attrs, TIPC_NLA_NET_MAX,
+ info->attrs[TIPC_NLA_NET],
+ tipc_nl_net_policy);
+ if (err)
+ return err;
+
+ if (attrs[TIPC_NLA_NET_ID]) {
+ u32 val;
+
+ /* Can't change net id once TIPC has joined a network */
+ if (tn->own_addr)
+ return -EPERM;
+
+ val = nla_get_u32(attrs[TIPC_NLA_NET_ID]);
+ if (val < 1 || val > 9999)
+ return -EINVAL;
+
+ tn->net_id = val;
+ }
+
+ if (attrs[TIPC_NLA_NET_ADDR]) {
+ u32 addr;
+
+ /* Can't change net addr once TIPC has joined a network */
+ if (tn->own_addr)
+ return -EPERM;
+
+ addr = nla_get_u32(attrs[TIPC_NLA_NET_ADDR]);
+ if (!tipc_addr_node_valid(addr))
+ return -EINVAL;
+
+ rtnl_lock();
+ tipc_net_start(net, addr);
+ rtnl_unlock();
+ }
+
+ return 0;
+}