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 44 static const struct nla_policy tipc_nl_net_policy[TIPC_NLA_NET_MAX + 1] = { 45 [TIPC_NLA_NET_UNSPEC] = { .type = NLA_UNSPEC }, 46 [TIPC_NLA_NET_ID] = { .type = NLA_U32 } 47 }; 48 49 /* 50 * The TIPC locking policy is designed to ensure a very fine locking 51 * granularity, permitting complete parallel access to individual 52 * port and node/link instances. The code consists of four major 53 * locking domains, each protected with their own disjunct set of locks. 54 * 55 * 1: The bearer level. 56 * RTNL lock is used to serialize the process of configuring bearer 57 * on update side, and RCU lock is applied on read side to make 58 * bearer instance valid on both paths of message transmission and 59 * reception. 60 * 61 * 2: The node and link level. 62 * All node instances are saved into two tipc_node_list and node_htable 63 * lists. The two lists are protected by node_list_lock on write side, 64 * and they are guarded with RCU lock on read side. Especially node 65 * instance is destroyed only when TIPC module is removed, and we can 66 * confirm that there has no any user who is accessing the node at the 67 * moment. Therefore, Except for iterating the two lists within RCU 68 * protection, it's no needed to hold RCU that we access node instance 69 * in other places. 70 * 71 * In addition, all members in node structure including link instances 72 * are protected by node spin lock. 73 * 74 * 3: The transport level of the protocol. 75 * This consists of the structures port, (and its user level 76 * representations, such as user_port and tipc_sock), reference and 77 * tipc_user (port.c, reg.c, socket.c). 78 * 79 * This layer has four different locks: 80 * - The tipc_port spin_lock. This is protecting each port instance 81 * from parallel data access and removal. Since we can not place 82 * this lock in the port itself, it has been placed in the 83 * corresponding reference table entry, which has the same life 84 * cycle as the module. This entry is difficult to access from 85 * outside the TIPC core, however, so a pointer to the lock has 86 * been added in the port instance, -to be used for unlocking 87 * only. 88 * - A read/write lock to protect the reference table itself (teg.c). 89 * (Nobody is using read-only access to this, so it can just as 90 * well be changed to a spin_lock) 91 * - A spin lock to protect the registry of kernel/driver users (reg.c) 92 * - A global spin_lock (tipc_port_lock), which only task is to ensure 93 * consistency where more than one port is involved in an operation, 94 * i.e., whe a port is part of a linked list of ports. 95 * There are two such lists; 'port_list', which is used for management, 96 * and 'wait_list', which is used to queue ports during congestion. 97 * 98 * 4: The name table (name_table.c, name_distr.c, subscription.c) 99 * - There is one big read/write-lock (tipc_nametbl_lock) protecting the 100 * overall name table structure. Nothing must be added/removed to 101 * this structure without holding write access to it. 102 * - There is one local spin_lock per sub_sequence, which can be seen 103 * as a sub-domain to the tipc_nametbl_lock domain. It is used only 104 * for translation operations, and is needed because a translation 105 * steps the root of the 'publication' linked list between each lookup. 106 * This is always used within the scope of a tipc_nametbl_lock(read). 107 * - A local spin_lock protecting the queue of subscriber events. 108 */ 109 110 int tipc_net_start(struct net *net, u32 addr) 111 { 112 struct tipc_net *tn = net_generic(net, tipc_net_id); 113 char addr_string[16]; 114 int res; 115 116 tn->own_addr = addr; 117 tipc_named_reinit(net); 118 tipc_sk_reinit(net); 119 res = tipc_bclink_init(net); 120 if (res) 121 return res; 122 123 tipc_nametbl_publish(net, TIPC_CFG_SRV, tn->own_addr, tn->own_addr, 124 TIPC_ZONE_SCOPE, 0, tn->own_addr); 125 126 pr_info("Started in network mode\n"); 127 pr_info("Own node address %s, network identity %u\n", 128 tipc_addr_string_fill(addr_string, tn->own_addr), 129 tn->net_id); 130 return 0; 131 } 132 133 void tipc_net_stop(struct net *net) 134 { 135 struct tipc_net *tn = net_generic(net, tipc_net_id); 136 137 if (!tn->own_addr) 138 return; 139 140 tipc_nametbl_withdraw(net, TIPC_CFG_SRV, tn->own_addr, 0, 141 tn->own_addr); 142 rtnl_lock(); 143 tipc_bearer_stop(net); 144 tipc_bclink_stop(net); 145 tipc_node_stop(net); 146 rtnl_unlock(); 147 148 pr_info("Left network mode\n"); 149 } 150 151 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 void *hdr; 155 struct nlattr *attrs; 156 157 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family, 158 NLM_F_MULTI, TIPC_NL_NET_GET); 159 if (!hdr) 160 return -EMSGSIZE; 161 162 attrs = nla_nest_start(msg->skb, TIPC_NLA_NET); 163 if (!attrs) 164 goto msg_full; 165 166 if (nla_put_u32(msg->skb, TIPC_NLA_NET_ID, tn->net_id)) 167 goto attr_msg_full; 168 169 nla_nest_end(msg->skb, attrs); 170 genlmsg_end(msg->skb, hdr); 171 172 return 0; 173 174 attr_msg_full: 175 nla_nest_cancel(msg->skb, attrs); 176 msg_full: 177 genlmsg_cancel(msg->skb, hdr); 178 179 return -EMSGSIZE; 180 } 181 182 int tipc_nl_net_dump(struct sk_buff *skb, struct netlink_callback *cb) 183 { 184 struct net *net = sock_net(skb->sk); 185 int err; 186 int done = cb->args[0]; 187 struct tipc_nl_msg msg; 188 189 if (done) 190 return 0; 191 192 msg.skb = skb; 193 msg.portid = NETLINK_CB(cb->skb).portid; 194 msg.seq = cb->nlh->nlmsg_seq; 195 196 err = __tipc_nl_add_net(net, &msg); 197 if (err) 198 goto out; 199 200 done = 1; 201 out: 202 cb->args[0] = done; 203 204 return skb->len; 205 } 206 207 int tipc_nl_net_set(struct sk_buff *skb, struct genl_info *info) 208 { 209 struct net *net = sock_net(skb->sk); 210 struct tipc_net *tn = net_generic(net, tipc_net_id); 211 struct nlattr *attrs[TIPC_NLA_NET_MAX + 1]; 212 int err; 213 214 if (!info->attrs[TIPC_NLA_NET]) 215 return -EINVAL; 216 217 err = nla_parse_nested(attrs, TIPC_NLA_NET_MAX, 218 info->attrs[TIPC_NLA_NET], 219 tipc_nl_net_policy); 220 if (err) 221 return err; 222 223 if (attrs[TIPC_NLA_NET_ID]) { 224 u32 val; 225 226 /* Can't change net id once TIPC has joined a network */ 227 if (tn->own_addr) 228 return -EPERM; 229 230 val = nla_get_u32(attrs[TIPC_NLA_NET_ID]); 231 if (val < 1 || val > 9999) 232 return -EINVAL; 233 234 tn->net_id = val; 235 } 236 237 if (attrs[TIPC_NLA_NET_ADDR]) { 238 u32 addr; 239 240 /* Can't change net addr once TIPC has joined a network */ 241 if (tn->own_addr) 242 return -EPERM; 243 244 addr = nla_get_u32(attrs[TIPC_NLA_NET_ADDR]); 245 if (!tipc_addr_node_valid(addr)) 246 return -EINVAL; 247 248 rtnl_lock(); 249 tipc_net_start(net, addr); 250 rtnl_unlock(); 251 } 252 253 return 0; 254 } 255