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1/*
2 * net/tipc/net.c: TIPC network routing code
3 *
4 * Copyright (c) 1995-2006, Ericsson AB
5 * Copyright (c) 2005, 2010-2011, Wind River Systems
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the names of the copyright holders nor the names of its
17 * contributors may be used to endorse or promote products derived from
18 * this software without specific prior written permission.
19 *
20 * Alternatively, this software may be distributed under the terms of the
21 * GNU General Public License ("GPL") version 2 as published by the Free
22 * Software Foundation.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34 * POSSIBILITY OF SUCH DAMAGE.
35 */
36
37#include "core.h"
38#include "net.h"
39#include "name_distr.h"
40#include "subscr.h"
41#include "port.h"
42#include "node.h"
43#include "config.h"
44
45/*
46 * The TIPC locking policy is designed to ensure a very fine locking
47 * granularity, permitting complete parallel access to individual
48 * port and node/link instances. The code consists of three major
49 * locking domains, each protected with their own disjunct set of locks.
50 *
51 * 1: The routing hierarchy.
52 * Comprises the structures 'zone', 'cluster', 'node', 'link'
53 * and 'bearer'. The whole hierarchy is protected by a big
54 * read/write lock, tipc_net_lock, to enssure that nothing is added
55 * or removed while code is accessing any of these structures.
56 * This layer must not be called from the two others while they
57 * hold any of their own locks.
58 * Neither must it itself do any upcalls to the other two before
59 * it has released tipc_net_lock and other protective locks.
60 *
61 * Within the tipc_net_lock domain there are two sub-domains;'node' and
62 * 'bearer', where local write operations are permitted,
63 * provided that those are protected by individual spin_locks
64 * per instance. Code holding tipc_net_lock(read) and a node spin_lock
65 * is permitted to poke around in both the node itself and its
66 * subordinate links. I.e, it can update link counters and queues,
67 * change link state, send protocol messages, and alter the
68 * "active_links" array in the node; but it can _not_ remove a link
69 * or a node from the overall structure.
70 * Correspondingly, individual bearers may change status within a
71 * tipc_net_lock(read), protected by an individual spin_lock ber bearer
72 * instance, but it needs tipc_net_lock(write) to remove/add any bearers.
73 *
74 *
75 * 2: The transport level of the protocol.
76 * This consists of the structures port, (and its user level
77 * representations, such as user_port and tipc_sock), reference and
78 * tipc_user (port.c, reg.c, socket.c).
79 *
80 * This layer has four different locks:
81 * - The tipc_port spin_lock. This is protecting each port instance
82 * from parallel data access and removal. Since we can not place
83 * this lock in the port itself, it has been placed in the
84 * corresponding reference table entry, which has the same life
85 * cycle as the module. This entry is difficult to access from
86 * outside the TIPC core, however, so a pointer to the lock has
87 * been added in the port instance, -to be used for unlocking
88 * only.
89 * - A read/write lock to protect the reference table itself (teg.c).
90 * (Nobody is using read-only access to this, so it can just as
91 * well be changed to a spin_lock)
92 * - A spin lock to protect the registry of kernel/driver users (reg.c)
93 * - A global spin_lock (tipc_port_lock), which only task is to ensure
94 * consistency where more than one port is involved in an operation,
95 * i.e., whe a port is part of a linked list of ports.
96 * There are two such lists; 'port_list', which is used for management,
97 * and 'wait_list', which is used to queue ports during congestion.
98 *
99 * 3: The name table (name_table.c, name_distr.c, subscription.c)
100 * - There is one big read/write-lock (tipc_nametbl_lock) protecting the
101 * overall name table structure. Nothing must be added/removed to
102 * this structure without holding write access to it.
103 * - There is one local spin_lock per sub_sequence, which can be seen
104 * as a sub-domain to the tipc_nametbl_lock domain. It is used only
105 * for translation operations, and is needed because a translation
106 * steps the root of the 'publication' linked list between each lookup.
107 * This is always used within the scope of a tipc_nametbl_lock(read).
108 * - A local spin_lock protecting the queue of subscriber events.
109*/
110
111DEFINE_RWLOCK(tipc_net_lock);
112
113static void net_route_named_msg(struct sk_buff *buf)
114{
115 struct tipc_msg *msg = buf_msg(buf);
116 u32 dnode;
117 u32 dport;
118
119 if (!msg_named(msg)) {
120 kfree_skb(buf);
121 return;
122 }
123
124 dnode = addr_domain(msg_lookup_scope(msg));
125 dport = tipc_nametbl_translate(msg_nametype(msg), msg_nameinst(msg), &dnode);
126 if (dport) {
127 msg_set_destnode(msg, dnode);
128 msg_set_destport(msg, dport);
129 tipc_net_route_msg(buf);
130 return;
131 }
132 tipc_reject_msg(buf, TIPC_ERR_NO_NAME);
133}
134
135void tipc_net_route_msg(struct sk_buff *buf)
136{
137 struct tipc_msg *msg;
138 u32 dnode;
139
140 if (!buf)
141 return;
142 msg = buf_msg(buf);
143
144 /* Handle message for this node */
145 dnode = msg_short(msg) ? tipc_own_addr : msg_destnode(msg);
146 if (tipc_in_scope(dnode, tipc_own_addr)) {
147 if (msg_isdata(msg)) {
148 if (msg_mcast(msg))
149 tipc_port_mcast_rcv(buf, NULL);
150 else if (msg_destport(msg))
151 tipc_port_rcv(buf);
152 else
153 net_route_named_msg(buf);
154 return;
155 }
156 switch (msg_user(msg)) {
157 case NAME_DISTRIBUTOR:
158 tipc_named_rcv(buf);
159 break;
160 case CONN_MANAGER:
161 tipc_port_proto_rcv(buf);
162 break;
163 default:
164 kfree_skb(buf);
165 }
166 return;
167 }
168
169 /* Handle message for another node */
170 skb_trim(buf, msg_size(msg));
171 tipc_link_xmit(buf, dnode, msg_link_selector(msg));
172}
173
174void tipc_net_start(u32 addr)
175{
176 char addr_string[16];
177
178 write_lock_bh(&tipc_net_lock);
179 tipc_own_addr = addr;
180 tipc_named_reinit();
181 tipc_port_reinit();
182 tipc_bclink_init();
183 write_unlock_bh(&tipc_net_lock);
184
185 tipc_nametbl_publish(TIPC_CFG_SRV, tipc_own_addr, tipc_own_addr,
186 TIPC_ZONE_SCOPE, 0, tipc_own_addr);
187 pr_info("Started in network mode\n");
188 pr_info("Own node address %s, network identity %u\n",
189 tipc_addr_string_fill(addr_string, tipc_own_addr), tipc_net_id);
190}
191
192void tipc_net_stop(void)
193{
194 if (!tipc_own_addr)
195 return;
196
197 tipc_nametbl_withdraw(TIPC_CFG_SRV, tipc_own_addr, 0, tipc_own_addr);
198 write_lock_bh(&tipc_net_lock);
199 tipc_bearer_stop();
200 tipc_bclink_stop();
201 tipc_node_stop();
202 write_unlock_bh(&tipc_net_lock);
203
204 pr_info("Left network mode\n");
205}
1/*
2 * net/tipc/net.c: TIPC network routing code
3 *
4 * Copyright (c) 1995-2006, 2014, Ericsson AB
5 * Copyright (c) 2005, 2010-2011, Wind River Systems
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the names of the copyright holders nor the names of its
17 * contributors may be used to endorse or promote products derived from
18 * this software without specific prior written permission.
19 *
20 * Alternatively, this software may be distributed under the terms of the
21 * GNU General Public License ("GPL") version 2 as published by the Free
22 * Software Foundation.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34 * POSSIBILITY OF SUCH DAMAGE.
35 */
36
37#include "core.h"
38#include "net.h"
39#include "name_distr.h"
40#include "subscr.h"
41#include "socket.h"
42#include "node.h"
43#include "bcast.h"
44#include "netlink.h"
45
46/*
47 * The TIPC locking policy is designed to ensure a very fine locking
48 * granularity, permitting complete parallel access to individual
49 * port and node/link instances. The code consists of four major
50 * locking domains, each protected with their own disjunct set of locks.
51 *
52 * 1: The bearer level.
53 * RTNL lock is used to serialize the process of configuring bearer
54 * on update side, and RCU lock is applied on read side to make
55 * bearer instance valid on both paths of message transmission and
56 * reception.
57 *
58 * 2: The node and link level.
59 * All node instances are saved into two tipc_node_list and node_htable
60 * lists. The two lists are protected by node_list_lock on write side,
61 * and they are guarded with RCU lock on read side. Especially node
62 * instance is destroyed only when TIPC module is removed, and we can
63 * confirm that there has no any user who is accessing the node at the
64 * moment. Therefore, Except for iterating the two lists within RCU
65 * protection, it's no needed to hold RCU that we access node instance
66 * in other places.
67 *
68 * In addition, all members in node structure including link instances
69 * are protected by node spin lock.
70 *
71 * 3: The transport level of the protocol.
72 * This consists of the structures port, (and its user level
73 * representations, such as user_port and tipc_sock), reference and
74 * tipc_user (port.c, reg.c, socket.c).
75 *
76 * This layer has four different locks:
77 * - The tipc_port spin_lock. This is protecting each port instance
78 * from parallel data access and removal. Since we can not place
79 * this lock in the port itself, it has been placed in the
80 * corresponding reference table entry, which has the same life
81 * cycle as the module. This entry is difficult to access from
82 * outside the TIPC core, however, so a pointer to the lock has
83 * been added in the port instance, -to be used for unlocking
84 * only.
85 * - A read/write lock to protect the reference table itself (teg.c).
86 * (Nobody is using read-only access to this, so it can just as
87 * well be changed to a spin_lock)
88 * - A spin lock to protect the registry of kernel/driver users (reg.c)
89 * - A global spin_lock (tipc_port_lock), which only task is to ensure
90 * consistency where more than one port is involved in an operation,
91 * i.e., whe a port is part of a linked list of ports.
92 * There are two such lists; 'port_list', which is used for management,
93 * and 'wait_list', which is used to queue ports during congestion.
94 *
95 * 4: The name table (name_table.c, name_distr.c, subscription.c)
96 * - There is one big read/write-lock (tipc_nametbl_lock) protecting the
97 * overall name table structure. Nothing must be added/removed to
98 * this structure without holding write access to it.
99 * - There is one local spin_lock per sub_sequence, which can be seen
100 * as a sub-domain to the tipc_nametbl_lock domain. It is used only
101 * for translation operations, and is needed because a translation
102 * steps the root of the 'publication' linked list between each lookup.
103 * This is always used within the scope of a tipc_nametbl_lock(read).
104 * - A local spin_lock protecting the queue of subscriber events.
105*/
106
107int tipc_net_start(struct net *net, u32 addr)
108{
109 struct tipc_net *tn = net_generic(net, tipc_net_id);
110 char addr_string[16];
111
112 tn->own_addr = addr;
113 tipc_named_reinit(net);
114 tipc_sk_reinit(net);
115
116 tipc_nametbl_publish(net, TIPC_CFG_SRV, tn->own_addr, tn->own_addr,
117 TIPC_ZONE_SCOPE, 0, tn->own_addr);
118
119 pr_info("Started in network mode\n");
120 pr_info("Own node address %s, network identity %u\n",
121 tipc_addr_string_fill(addr_string, tn->own_addr),
122 tn->net_id);
123 return 0;
124}
125
126void tipc_net_stop(struct net *net)
127{
128 struct tipc_net *tn = net_generic(net, tipc_net_id);
129
130 if (!tn->own_addr)
131 return;
132
133 tipc_nametbl_withdraw(net, TIPC_CFG_SRV, tn->own_addr, 0,
134 tn->own_addr);
135 rtnl_lock();
136 tipc_bearer_stop(net);
137 tipc_node_stop(net);
138 rtnl_unlock();
139
140 pr_info("Left network mode\n");
141}
142
143static int __tipc_nl_add_net(struct net *net, struct tipc_nl_msg *msg)
144{
145 struct tipc_net *tn = net_generic(net, tipc_net_id);
146 void *hdr;
147 struct nlattr *attrs;
148
149 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
150 NLM_F_MULTI, TIPC_NL_NET_GET);
151 if (!hdr)
152 return -EMSGSIZE;
153
154 attrs = nla_nest_start(msg->skb, TIPC_NLA_NET);
155 if (!attrs)
156 goto msg_full;
157
158 if (nla_put_u32(msg->skb, TIPC_NLA_NET_ID, tn->net_id))
159 goto attr_msg_full;
160
161 nla_nest_end(msg->skb, attrs);
162 genlmsg_end(msg->skb, hdr);
163
164 return 0;
165
166attr_msg_full:
167 nla_nest_cancel(msg->skb, attrs);
168msg_full:
169 genlmsg_cancel(msg->skb, hdr);
170
171 return -EMSGSIZE;
172}
173
174int tipc_nl_net_dump(struct sk_buff *skb, struct netlink_callback *cb)
175{
176 struct net *net = sock_net(skb->sk);
177 int err;
178 int done = cb->args[0];
179 struct tipc_nl_msg msg;
180
181 if (done)
182 return 0;
183
184 msg.skb = skb;
185 msg.portid = NETLINK_CB(cb->skb).portid;
186 msg.seq = cb->nlh->nlmsg_seq;
187
188 err = __tipc_nl_add_net(net, &msg);
189 if (err)
190 goto out;
191
192 done = 1;
193out:
194 cb->args[0] = done;
195
196 return skb->len;
197}
198
199int tipc_nl_net_set(struct sk_buff *skb, struct genl_info *info)
200{
201 struct net *net = sock_net(skb->sk);
202 struct tipc_net *tn = net_generic(net, tipc_net_id);
203 struct nlattr *attrs[TIPC_NLA_NET_MAX + 1];
204 int err;
205
206 if (!info->attrs[TIPC_NLA_NET])
207 return -EINVAL;
208
209 err = nla_parse_nested(attrs, TIPC_NLA_NET_MAX,
210 info->attrs[TIPC_NLA_NET],
211 tipc_nl_net_policy);
212 if (err)
213 return err;
214
215 if (attrs[TIPC_NLA_NET_ID]) {
216 u32 val;
217
218 /* Can't change net id once TIPC has joined a network */
219 if (tn->own_addr)
220 return -EPERM;
221
222 val = nla_get_u32(attrs[TIPC_NLA_NET_ID]);
223 if (val < 1 || val > 9999)
224 return -EINVAL;
225
226 tn->net_id = val;
227 }
228
229 if (attrs[TIPC_NLA_NET_ADDR]) {
230 u32 addr;
231
232 /* Can't change net addr once TIPC has joined a network */
233 if (tn->own_addr)
234 return -EPERM;
235
236 addr = nla_get_u32(attrs[TIPC_NLA_NET_ADDR]);
237 if (!tipc_addr_node_valid(addr))
238 return -EINVAL;
239
240 rtnl_lock();
241 tipc_net_start(net, addr);
242 rtnl_unlock();
243 }
244
245 return 0;
246}