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/net/tipc/net.c

http://github.com/mirrors/linux
C | 360 lines | 208 code | 56 blank | 96 comment | 29 complexity | 169d7c7cf6de85e47f7253d6a8415930 MD5 | raw file
  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
108struct tipc_net_work {
109	struct work_struct work;
110	struct net *net;
111	u32 addr;
112};
113
114static void tipc_net_finalize(struct net *net, u32 addr);
115
116int 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
131static 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
145static 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
154void 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
166void 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
179static 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
207attr_msg_full:
208	nla_nest_cancel(msg->skb, attrs);
209msg_full:
210	genlmsg_cancel(msg->skb, hdr);
211
212	return -EMSGSIZE;
213}
214
215int 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;
234out:
235	cb->args[0] = done;
236
237	return skb->len;
238}
239
240int __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
295int 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
306static 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
330attr_msg_full:
331	nla_nest_cancel(msg->skb, attrs);
332msg_full:
333	genlmsg_cancel(msg->skb, hdr);
334
335	return -EMSGSIZE;
336}
337
338int 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}