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 "link.h"
45 #include "netlink.h"
46 #include "monitor.h"
47
48 /*
49 * The TIPC locking policy is designed to ensure a very fine locking
50 * granularity, permitting complete parallel access to individual
51 * port and node/link instances. The code consists of four major
52 * locking domains, each protected with their own disjunct set of locks.
53 *
54 * 1: The bearer level.
55 * RTNL lock is used to serialize the process of configuring bearer
56 * on update side, and RCU lock is applied on read side to make
57 * bearer instance valid on both paths of message transmission and
58 * reception.
59 *
60 * 2: The node and link level.
61 * All node instances are saved into two tipc_node_list and node_htable
62 * lists. The two lists are protected by node_list_lock on write side,
63 * and they are guarded with RCU lock on read side. Especially node
64 * instance is destroyed only when TIPC module is removed, and we can
65 * confirm that there has no any user who is accessing the node at the
66 * moment. Therefore, Except for iterating the two lists within RCU
67 * protection, it's no needed to hold RCU that we access node instance
68 * in other places.
69 *
70 * In addition, all members in node structure including link instances
71 * are protected by node spin lock.
72 *
73 * 3: The transport level of the protocol.
74 * This consists of the structures port, (and its user level
75 * representations, such as user_port and tipc_sock), reference and
76 * tipc_user (port.c, reg.c, socket.c).
77 *
78 * This layer has four different locks:
79 * - The tipc_port spin_lock. This is protecting each port instance
80 * from parallel data access and removal. Since we can not place
81 * this lock in the port itself, it has been placed in the
82 * corresponding reference table entry, which has the same life
83 * cycle as the module. This entry is difficult to access from
84 * outside the TIPC core, however, so a pointer to the lock has
85 * been added in the port instance, -to be used for unlocking
86 * only.
87 * - A read/write lock to protect the reference table itself (teg.c).
88 * (Nobody is using read-only access to this, so it can just as
89 * well be changed to a spin_lock)
90 * - A spin lock to protect the registry of kernel/driver users (reg.c)
91 * - A global spin_lock (tipc_port_lock), which only task is to ensure
92 * consistency where more than one port is involved in an operation,
93 * i.e., when a port is part of a linked list of ports.
94 * There are two such lists; 'port_list', which is used for management,
95 * and 'wait_list', which is used to queue ports during congestion.
96 *
97 * 4: The name table (name_table.c, name_distr.c, subscription.c)
98 * - There is one big read/write-lock (tipc_nametbl_lock) protecting the
99 * overall name table structure. Nothing must be added/removed to
100 * this structure without holding write access to it.
101 * - There is one local spin_lock per sub_sequence, which can be seen
102 * as a sub-domain to the tipc_nametbl_lock domain. It is used only
103 * for translation operations, and is needed because a translation
104 * steps the root of the 'publication' linked list between each lookup.
105 * This is always used within the scope of a tipc_nametbl_lock(read).
106 * - A local spin_lock protecting the queue of subscriber events.
107 */
108
109 static void tipc_net_finalize(struct net *net, u32 addr);
110
111 int tipc_net_init(struct net *net, u8 *node_id, u32 addr)
112 {
113 if (tipc_own_id(net)) {
114 pr_info("Cannot configure node identity twice\n");
115 return -1;
116 }
117 pr_info("Started in network mode\n");
118
119 if (node_id)
120 tipc_set_node_id(net, node_id);
121 if (addr)
122 tipc_net_finalize(net, addr);
123 return 0;
124 }
125
126 static void tipc_net_finalize(struct net *net, u32 addr)
127 {
128 struct tipc_net *tn = tipc_net(net);
129 struct tipc_socket_addr sk = {0, addr};
130 struct tipc_uaddr ua;
131
132 tipc_uaddr(&ua, TIPC_SERVICE_RANGE, TIPC_CLUSTER_SCOPE,
133 TIPC_NODE_STATE, addr, addr);
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, &ua, &sk, addr);
142 }
143
144 void tipc_net_finalize_work(struct work_struct *work)
145 {
146 struct tipc_net *tn = container_of(work, struct tipc_net, work);
147
148 tipc_net_finalize(tipc_link_net(tn->bcl), tn->trial_addr);
149 }
150
151 void tipc_net_stop(struct net *net)
152 {
153 if (!tipc_own_id(net))
154 return;
155
156 rtnl_lock();
157 tipc_bearer_stop(net);
158 tipc_node_stop(net);
159 rtnl_unlock();
160
161 pr_info("Left network mode\n");
162 }
163
164 static int __tipc_nl_add_net(struct net *net, struct tipc_nl_msg *msg)
165 {
166 struct tipc_net *tn = net_generic(net, tipc_net_id);
167 u64 *w0 = (u64 *)&tn->node_id[0];
168 u64 *w1 = (u64 *)&tn->node_id[8];
169 struct nlattr *attrs;
170 void *hdr;
171
172 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
173 NLM_F_MULTI, TIPC_NL_NET_GET);
174 if (!hdr)
175 return -EMSGSIZE;
176
177 attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_NET);
178 if (!attrs)
179 goto msg_full;
180
181 if (nla_put_u32(msg->skb, TIPC_NLA_NET_ID, tn->net_id))
182 goto attr_msg_full;
183 if (nla_put_u64_64bit(msg->skb, TIPC_NLA_NET_NODEID, *w0, 0))
184 goto attr_msg_full;
185 if (nla_put_u64_64bit(msg->skb, TIPC_NLA_NET_NODEID_W1, *w1, 0))
186 goto attr_msg_full;
187 nla_nest_end(msg->skb, attrs);
188 genlmsg_end(msg->skb, hdr);
189
190 return 0;
191
192 attr_msg_full:
193 nla_nest_cancel(msg->skb, attrs);
194 msg_full:
195 genlmsg_cancel(msg->skb, hdr);
196
197 return -EMSGSIZE;
198 }
199
200 int tipc_nl_net_dump(struct sk_buff *skb, struct netlink_callback *cb)
201 {
202 struct net *net = sock_net(skb->sk);
203 int err;
204 int done = cb->args[0];
205 struct tipc_nl_msg msg;
206
207 if (done)
208 return 0;
209
210 msg.skb = skb;
211 msg.portid = NETLINK_CB(cb->skb).portid;
212 msg.seq = cb->nlh->nlmsg_seq;
213
214 err = __tipc_nl_add_net(net, &msg);
215 if (err)
216 goto out;
217
218 done = 1;
219 out:
220 cb->args[0] = done;
221
222 return skb->len;
223 }
224
225 int __tipc_nl_net_set(struct sk_buff *skb, struct genl_info *info)
226 {
227 struct nlattr *attrs[TIPC_NLA_NET_MAX + 1];
228 struct net *net = sock_net(skb->sk);
229 struct tipc_net *tn = tipc_net(net);
230 int err;
231
232 if (!info->attrs[TIPC_NLA_NET])
233 return -EINVAL;
234
235 err = nla_parse_nested_deprecated(attrs, TIPC_NLA_NET_MAX,
236 info->attrs[TIPC_NLA_NET],
237 tipc_nl_net_policy, info->extack);
238
239 if (err)
240 return err;
241
242 /* Can't change net id once TIPC has joined a network */
243 if (tipc_own_addr(net))
244 return -EPERM;
245
246 if (attrs[TIPC_NLA_NET_ID]) {
247 u32 val;
248
249 val = nla_get_u32(attrs[TIPC_NLA_NET_ID]);
250 if (val < 1 || val > 9999)
251 return -EINVAL;
252
253 tn->net_id = val;
254 }
255
256 if (attrs[TIPC_NLA_NET_ADDR]) {
257 u32 addr;
258
259 addr = nla_get_u32(attrs[TIPC_NLA_NET_ADDR]);
260 if (!addr)
261 return -EINVAL;
262 tn->legacy_addr_format = true;
263 tipc_net_init(net, NULL, addr);
264 }
265
266 if (attrs[TIPC_NLA_NET_NODEID]) {
267 u8 node_id[NODE_ID_LEN];
268 u64 *w0 = (u64 *)&node_id[0];
269 u64 *w1 = (u64 *)&node_id[8];
270
271 if (!attrs[TIPC_NLA_NET_NODEID_W1])
272 return -EINVAL;
273 *w0 = nla_get_u64(attrs[TIPC_NLA_NET_NODEID]);
274 *w1 = nla_get_u64(attrs[TIPC_NLA_NET_NODEID_W1]);
275 tipc_net_init(net, node_id, 0);
276 }
277 return 0;
278 }
279
280 int tipc_nl_net_set(struct sk_buff *skb, struct genl_info *info)
281 {
282 int err;
283
284 rtnl_lock();
285 err = __tipc_nl_net_set(skb, info);
286 rtnl_unlock();
287
288 return err;
289 }
290
291 static int __tipc_nl_addr_legacy_get(struct net *net, struct tipc_nl_msg *msg)
292 {
293 struct tipc_net *tn = tipc_net(net);
294 struct nlattr *attrs;
295 void *hdr;
296
297 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
298 0, TIPC_NL_ADDR_LEGACY_GET);
299 if (!hdr)
300 return -EMSGSIZE;
301
302 attrs = nla_nest_start(msg->skb, TIPC_NLA_NET);
303 if (!attrs)
304 goto msg_full;
305
306 if (tn->legacy_addr_format)
307 if (nla_put_flag(msg->skb, TIPC_NLA_NET_ADDR_LEGACY))
308 goto attr_msg_full;
309
310 nla_nest_end(msg->skb, attrs);
311 genlmsg_end(msg->skb, hdr);
312
313 return 0;
314
315 attr_msg_full:
316 nla_nest_cancel(msg->skb, attrs);
317 msg_full:
318 genlmsg_cancel(msg->skb, hdr);
319
320 return -EMSGSIZE;
321 }
322
323 int tipc_nl_net_addr_legacy_get(struct sk_buff *skb, struct genl_info *info)
324 {
325 struct net *net = sock_net(skb->sk);
326 struct tipc_nl_msg msg;
327 struct sk_buff *rep;
328 int err;
329
330 rep = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
331 if (!rep)
332 return -ENOMEM;
333
334 msg.skb = rep;
335 msg.portid = info->snd_portid;
336 msg.seq = info->snd_seq;
337
338 err = __tipc_nl_addr_legacy_get(net, &msg);
339 if (err) {
340 nlmsg_free(msg.skb);
341 return err;
342 }
343
344 return genlmsg_reply(msg.skb, info);
345 }
346
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