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 #include "monitor.h"
46
47 /*
48 * The TIPC locking policy is designed to ensure a very fine locking
49 * granularity, permitting complete parallel access to individual
50 * port and node/link instances. The code consists of four major
51 * locking domains, each protected with their own disjunct set of locks.
52 *
53 * 1: The bearer level.
54 * RTNL lock is used to serialize the process of configuring bearer
55 * on update side, and RCU lock is applied on read side to make
56 * bearer instance valid on both paths of message transmission and
57 * reception.
58 *
59 * 2: The node and link level.
60 * All node instances are saved into two tipc_node_list and node_htable
61 * lists. The two lists are protected by node_list_lock on write side,
62 * and they are guarded with RCU lock on read side. Especially node
63 * instance is destroyed only when TIPC module is removed, and we can
64 * confirm that there has no any user who is accessing the node at the
65 * moment. Therefore, Except for iterating the two lists within RCU
66 * protection, it's no needed to hold RCU that we access node instance
67 * in other places.
68 *
69 * In addition, all members in node structure including link instances
70 * are protected by node spin lock.
71 *
72 * 3: The transport level of the protocol.
73 * This consists of the structures port, (and its user level
74 * representations, such as user_port and tipc_sock), reference and
75 * tipc_user (port.c, reg.c, socket.c).
76 *
77 * This layer has four different locks:
78 * - The tipc_port spin_lock. This is protecting each port instance
79 * from parallel data access and removal. Since we can not place
80 * this lock in the port itself, it has been placed in the
81 * corresponding reference table entry, which has the same life
82 * cycle as the module. This entry is difficult to access from
83 * outside the TIPC core, however, so a pointer to the lock has
84 * been added in the port instance, -to be used for unlocking
85 * only.
86 * - A read/write lock to protect the reference table itself (teg.c).
87 * (Nobody is using read-only access to this, so it can just as
88 * well be changed to a spin_lock)
89 * - A spin lock to protect the registry of kernel/driver users (reg.c)
90 * - A global spin_lock (tipc_port_lock), which only task is to ensure
91 * consistency where more than one port is involved in an operation,
92 * i.e., whe a port is part of a linked list of ports.
93 * There are two such lists; 'port_list', which is used for management,
94 * and 'wait_list', which is used to queue ports during congestion.
95 *
96 * 4: The name table (name_table.c, name_distr.c, subscription.c)
97 * - There is one big read/write-lock (tipc_nametbl_lock) protecting the
98 * overall name table structure. Nothing must be added/removed to
99 * this structure without holding write access to it.
100 * - There is one local spin_lock per sub_sequence, which can be seen
101 * as a sub-domain to the tipc_nametbl_lock domain. It is used only
102 * for translation operations, and is needed because a translation
103 * steps the root of the 'publication' linked list between each lookup.
104 * This is always used within the scope of a tipc_nametbl_lock(read).
105 * - A local spin_lock protecting the queue of subscriber events.
106 */
107
108 struct tipc_net_work {
109 struct work_struct work;
110 struct net *net;
111 u32 addr;
112 };
113
114 static void tipc_net_finalize(struct net *net, u32 addr);
115
116 int tipc_net_init(struct net *net, u8 *node_id, u32 addr)
117 {
118 if (tipc_own_id(net)) {
119 pr_info("Cannot configure node identity twice\n");
120 return -1;
121 }
122 pr_info("Started in network mode\n");
123
124 if (node_id)
125 tipc_set_node_id(net, node_id);
126 if (addr)
127 tipc_net_finalize(net, addr);
128 return 0;
129 }
130
131 static void tipc_net_finalize(struct net *net, u32 addr)
132 {
133 struct tipc_net *tn = tipc_net(net);
134
135 if (cmpxchg(&tn->node_addr, 0, addr))
136 return;
137 tipc_set_node_addr(net, addr);
138 tipc_named_reinit(net);
139 tipc_sk_reinit(net);
140 tipc_mon_reinit_self(net);
141 tipc_nametbl_publish(net, TIPC_CFG_SRV, addr, addr,
142 TIPC_CLUSTER_SCOPE, 0, addr);
143 }
144
145 static void tipc_net_finalize_work(struct work_struct *work)
146 {
147 struct tipc_net_work *fwork;
148
149 fwork = container_of(work, struct tipc_net_work, work);
150 tipc_net_finalize(fwork->net, fwork->addr);
151 kfree(fwork);
152 }
153
154 void tipc_sched_net_finalize(struct net *net, u32 addr)
155 {
156 struct tipc_net_work *fwork = kzalloc(sizeof(*fwork), GFP_ATOMIC);
157
158 if (!fwork)
159 return;
160 INIT_WORK(&fwork->work, tipc_net_finalize_work);
161 fwork->net = net;
162 fwork->addr = addr;
163 schedule_work(&fwork->work);
164 }
165
166 void tipc_net_stop(struct net *net)
167 {
168 if (!tipc_own_id(net))
169 return;
170
171 rtnl_lock();
172 tipc_bearer_stop(net);
173 tipc_node_stop(net);
174 rtnl_unlock();
175
176 pr_info("Left network mode\n");
177 }
178
179 static int __tipc_nl_add_net(struct net *net, struct tipc_nl_msg *msg)
180 {
181 struct tipc_net *tn = net_generic(net, tipc_net_id);
182 u64 *w0 = (u64 *)&tn->node_id[0];
183 u64 *w1 = (u64 *)&tn->node_id[8];
184 struct nlattr *attrs;
185 void *hdr;
186
187 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
188 NLM_F_MULTI, TIPC_NL_NET_GET);
189 if (!hdr)
190 return -EMSGSIZE;
191
192 attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_NET);
193 if (!attrs)
194 goto msg_full;
195
196 if (nla_put_u32(msg->skb, TIPC_NLA_NET_ID, tn->net_id))
197 goto attr_msg_full;
198 if (nla_put_u64_64bit(msg->skb, TIPC_NLA_NET_NODEID, *w0, 0))
199 goto attr_msg_full;
200 if (nla_put_u64_64bit(msg->skb, TIPC_NLA_NET_NODEID_W1, *w1, 0))
201 goto attr_msg_full;
202 nla_nest_end(msg->skb, attrs);
203 genlmsg_end(msg->skb, hdr);
204
205 return 0;
206
207 attr_msg_full:
208 nla_nest_cancel(msg->skb, attrs);
209 msg_full:
210 genlmsg_cancel(msg->skb, hdr);
211
212 return -EMSGSIZE;
213 }
214
215 int tipc_nl_net_dump(struct sk_buff *skb, struct netlink_callback *cb)
216 {
217 struct net *net = sock_net(skb->sk);
218 int err;
219 int done = cb->args[0];
220 struct tipc_nl_msg msg;
221
222 if (done)
223 return 0;
224
225 msg.skb = skb;
226 msg.portid = NETLINK_CB(cb->skb).portid;
227 msg.seq = cb->nlh->nlmsg_seq;
228
229 err = __tipc_nl_add_net(net, &msg);
230 if (err)
231 goto out;
232
233 done = 1;
234 out:
235 cb->args[0] = done;
236
237 return skb->len;
238 }
239
240 int __tipc_nl_net_set(struct sk_buff *skb, struct genl_info *info)
241 {
242 struct nlattr *attrs[TIPC_NLA_NET_MAX + 1];
243 struct net *net = sock_net(skb->sk);
244 struct tipc_net *tn = tipc_net(net);
245 int err;
246
247 if (!info->attrs[TIPC_NLA_NET])
248 return -EINVAL;
249
250 err = nla_parse_nested_deprecated(attrs, TIPC_NLA_NET_MAX,
251 info->attrs[TIPC_NLA_NET],
252 tipc_nl_net_policy, info->extack);
253
254 if (err)
255 return err;
256
257 /* Can't change net id once TIPC has joined a network */
258 if (tipc_own_addr(net))
259 return -EPERM;
260
261 if (attrs[TIPC_NLA_NET_ID]) {
262 u32 val;
263
264 val = nla_get_u32(attrs[TIPC_NLA_NET_ID]);
265 if (val < 1 || val > 9999)
266 return -EINVAL;
267
268 tn->net_id = val;
269 }
270
271 if (attrs[TIPC_NLA_NET_ADDR]) {
272 u32 addr;
273
274 addr = nla_get_u32(attrs[TIPC_NLA_NET_ADDR]);
275 if (!addr)
276 return -EINVAL;
277 tn->legacy_addr_format = true;
278 tipc_net_init(net, NULL, addr);
279 }
280
281 if (attrs[TIPC_NLA_NET_NODEID]) {
282 u8 node_id[NODE_ID_LEN];
283 u64 *w0 = (u64 *)&node_id[0];
284 u64 *w1 = (u64 *)&node_id[8];
285
286 if (!attrs[TIPC_NLA_NET_NODEID_W1])
287 return -EINVAL;
288 *w0 = nla_get_u64(attrs[TIPC_NLA_NET_NODEID]);
289 *w1 = nla_get_u64(attrs[TIPC_NLA_NET_NODEID_W1]);
290 tipc_net_init(net, node_id, 0);
291 }
292 return 0;
293 }
294
295 int tipc_nl_net_set(struct sk_buff *skb, struct genl_info *info)
296 {
297 int err;
298
299 rtnl_lock();
300 err = __tipc_nl_net_set(skb, info);
301 rtnl_unlock();
302
303 return err;
304 }