xref: /linux/net/tipc/net.c (revision 15a1fbdcfb519c2bd291ed01c6c94e0b89537a77)
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  }
305  
306  static int __tipc_nl_addr_legacy_get(struct net *net, struct tipc_nl_msg *msg)
307  {
308  	struct tipc_net *tn = tipc_net(net);
309  	struct nlattr *attrs;
310  	void *hdr;
311  
312  	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
313  			  0, TIPC_NL_ADDR_LEGACY_GET);
314  	if (!hdr)
315  		return -EMSGSIZE;
316  
317  	attrs = nla_nest_start(msg->skb, TIPC_NLA_NET);
318  	if (!attrs)
319  		goto msg_full;
320  
321  	if (tn->legacy_addr_format)
322  		if (nla_put_flag(msg->skb, TIPC_NLA_NET_ADDR_LEGACY))
323  			goto attr_msg_full;
324  
325  	nla_nest_end(msg->skb, attrs);
326  	genlmsg_end(msg->skb, hdr);
327  
328  	return 0;
329  
330  attr_msg_full:
331  	nla_nest_cancel(msg->skb, attrs);
332  msg_full:
333  	genlmsg_cancel(msg->skb, hdr);
334  
335  	return -EMSGSIZE;
336  }
337  
338  int tipc_nl_net_addr_legacy_get(struct sk_buff *skb, struct genl_info *info)
339  {
340  	struct net *net = sock_net(skb->sk);
341  	struct tipc_nl_msg msg;
342  	struct sk_buff *rep;
343  	int err;
344  
345  	rep = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
346  	if (!rep)
347  		return -ENOMEM;
348  
349  	msg.skb = rep;
350  	msg.portid = info->snd_portid;
351  	msg.seq = info->snd_seq;
352  
353  	err = __tipc_nl_addr_legacy_get(net, &msg);
354  	if (err) {
355  		nlmsg_free(msg.skb);
356  		return err;
357  	}
358  
359  	return genlmsg_reply(msg.skb, info);
360  }
361