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