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, id: 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: &ua, TIPC_SERVICE_RANGE, scope: TIPC_CLUSTER_SCOPE, |
133 | TIPC_NODE_STATE, lower: addr, upper: 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: &ua, sk: &sk, key: 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(net: tipc_link_net(l: tn->bcl), addr: 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, id: 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(skb: msg->skb, portid: msg->portid, seq: msg->seq, family: &tipc_genl_family, |
173 | NLM_F_MULTI, cmd: TIPC_NL_NET_GET); |
174 | if (!hdr) |
175 | return -EMSGSIZE; |
176 | |
177 | attrs = nla_nest_start_noflag(skb: msg->skb, attrtype: TIPC_NLA_NET); |
178 | if (!attrs) |
179 | goto msg_full; |
180 | |
181 | if (nla_put_u32(skb: msg->skb, attrtype: TIPC_NLA_NET_ID, value: tn->net_id)) |
182 | goto attr_msg_full; |
183 | if (nla_put_u64_64bit(skb: msg->skb, attrtype: TIPC_NLA_NET_NODEID, value: *w0, padattr: 0)) |
184 | goto attr_msg_full; |
185 | if (nla_put_u64_64bit(skb: msg->skb, attrtype: TIPC_NLA_NET_NODEID_W1, value: *w1, padattr: 0)) |
186 | goto attr_msg_full; |
187 | nla_nest_end(skb: msg->skb, start: attrs); |
188 | genlmsg_end(skb: msg->skb, hdr); |
189 | |
190 | return 0; |
191 | |
192 | attr_msg_full: |
193 | nla_nest_cancel(skb: msg->skb, start: attrs); |
194 | msg_full: |
195 | genlmsg_cancel(skb: 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(sk: 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: &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(sk: 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(tb: attrs, maxtype: TIPC_NLA_NET_MAX, |
236 | nla: info->attrs[TIPC_NLA_NET], |
237 | policy: tipc_nl_net_policy, extack: 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(nla: 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(nla: 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(nla: attrs[TIPC_NLA_NET_NODEID]); |
274 | *w1 = nla_get_u64(nla: attrs[TIPC_NLA_NET_NODEID_W1]); |
275 | tipc_net_init(net, node_id, addr: 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(skb: msg->skb, portid: msg->portid, seq: msg->seq, family: &tipc_genl_family, |
298 | flags: 0, cmd: TIPC_NL_ADDR_LEGACY_GET); |
299 | if (!hdr) |
300 | return -EMSGSIZE; |
301 | |
302 | attrs = nla_nest_start(skb: msg->skb, attrtype: TIPC_NLA_NET); |
303 | if (!attrs) |
304 | goto msg_full; |
305 | |
306 | if (tn->legacy_addr_format) |
307 | if (nla_put_flag(skb: msg->skb, attrtype: TIPC_NLA_NET_ADDR_LEGACY)) |
308 | goto attr_msg_full; |
309 | |
310 | nla_nest_end(skb: msg->skb, start: attrs); |
311 | genlmsg_end(skb: msg->skb, hdr); |
312 | |
313 | return 0; |
314 | |
315 | attr_msg_full: |
316 | nla_nest_cancel(skb: msg->skb, start: attrs); |
317 | msg_full: |
318 | genlmsg_cancel(skb: 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(sk: 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: &msg); |
339 | if (err) { |
340 | nlmsg_free(skb: msg.skb); |
341 | return err; |
342 | } |
343 | |
344 | return genlmsg_reply(skb: msg.skb, info); |
345 | } |
346 | |