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 45 static const struct nla_policy tipc_nl_net_policy[TIPC_NLA_NET_MAX + 1] = { 46 [TIPC_NLA_NET_UNSPEC] = { .type = NLA_UNSPEC }, 47 [TIPC_NLA_NET_ID] = { .type = NLA_U32 } 48 }; 49 50 /* 51 * The TIPC locking policy is designed to ensure a very fine locking 52 * granularity, permitting complete parallel access to individual 53 * port and node/link instances. The code consists of four major 54 * locking domains, each protected with their own disjunct set of locks. 55 * 56 * 1: The bearer level. 57 * RTNL lock is used to serialize the process of configuring bearer 58 * on update side, and RCU lock is applied on read side to make 59 * bearer instance valid on both paths of message transmission and 60 * reception. 61 * 62 * 2: The node and link level. 63 * All node instances are saved into two tipc_node_list and node_htable 64 * lists. The two lists are protected by node_list_lock on write side, 65 * and they are guarded with RCU lock on read side. Especially node 66 * instance is destroyed only when TIPC module is removed, and we can 67 * confirm that there has no any user who is accessing the node at the 68 * moment. Therefore, Except for iterating the two lists within RCU 69 * protection, it's no needed to hold RCU that we access node instance 70 * in other places. 71 * 72 * In addition, all members in node structure including link instances 73 * are protected by node spin lock. 74 * 75 * 3: The transport level of the protocol. 76 * This consists of the structures port, (and its user level 77 * representations, such as user_port and tipc_sock), reference and 78 * tipc_user (port.c, reg.c, socket.c). 79 * 80 * This layer has four different locks: 81 * - The tipc_port spin_lock. This is protecting each port instance 82 * from parallel data access and removal. Since we can not place 83 * this lock in the port itself, it has been placed in the 84 * corresponding reference table entry, which has the same life 85 * cycle as the module. This entry is difficult to access from 86 * outside the TIPC core, however, so a pointer to the lock has 87 * been added in the port instance, -to be used for unlocking 88 * only. 89 * - A read/write lock to protect the reference table itself (teg.c). 90 * (Nobody is using read-only access to this, so it can just as 91 * well be changed to a spin_lock) 92 * - A spin lock to protect the registry of kernel/driver users (reg.c) 93 * - A global spin_lock (tipc_port_lock), which only task is to ensure 94 * consistency where more than one port is involved in an operation, 95 * i.e., whe a port is part of a linked list of ports. 96 * There are two such lists; 'port_list', which is used for management, 97 * and 'wait_list', which is used to queue ports during congestion. 98 * 99 * 4: The name table (name_table.c, name_distr.c, subscription.c) 100 * - There is one big read/write-lock (tipc_nametbl_lock) protecting the 101 * overall name table structure. Nothing must be added/removed to 102 * this structure without holding write access to it. 103 * - There is one local spin_lock per sub_sequence, which can be seen 104 * as a sub-domain to the tipc_nametbl_lock domain. It is used only 105 * for translation operations, and is needed because a translation 106 * steps the root of the 'publication' linked list between each lookup. 107 * This is always used within the scope of a tipc_nametbl_lock(read). 108 * - A local spin_lock protecting the queue of subscriber events. 109 */ 110 111 int tipc_net_start(struct net *net, u32 addr) 112 { 113 struct tipc_net *tn = net_generic(net, tipc_net_id); 114 char addr_string[16]; 115 int res; 116 117 tn->own_addr = addr; 118 tipc_named_reinit(net); 119 tipc_sk_reinit(net); 120 res = tipc_bclink_init(net); 121 if (res) 122 return res; 123 124 tipc_nametbl_publish(net, TIPC_CFG_SRV, tn->own_addr, tn->own_addr, 125 TIPC_ZONE_SCOPE, 0, tn->own_addr); 126 127 pr_info("Started in network mode\n"); 128 pr_info("Own node address %s, network identity %u\n", 129 tipc_addr_string_fill(addr_string, tn->own_addr), 130 tn->net_id); 131 return 0; 132 } 133 134 void tipc_net_stop(struct net *net) 135 { 136 struct tipc_net *tn = net_generic(net, tipc_net_id); 137 138 if (!tn->own_addr) 139 return; 140 141 tipc_nametbl_withdraw(net, TIPC_CFG_SRV, tn->own_addr, 0, 142 tn->own_addr); 143 rtnl_lock(); 144 tipc_bearer_stop(net); 145 tipc_bclink_stop(net); 146 tipc_node_stop(net); 147 rtnl_unlock(); 148 149 pr_info("Left network mode\n"); 150 } 151 152 static int __tipc_nl_add_net(struct net *net, struct tipc_nl_msg *msg) 153 { 154 struct tipc_net *tn = net_generic(net, tipc_net_id); 155 void *hdr; 156 struct nlattr *attrs; 157 158 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family, 159 NLM_F_MULTI, TIPC_NL_NET_GET); 160 if (!hdr) 161 return -EMSGSIZE; 162 163 attrs = nla_nest_start(msg->skb, TIPC_NLA_NET); 164 if (!attrs) 165 goto msg_full; 166 167 if (nla_put_u32(msg->skb, TIPC_NLA_NET_ID, tn->net_id)) 168 goto attr_msg_full; 169 170 nla_nest_end(msg->skb, attrs); 171 genlmsg_end(msg->skb, hdr); 172 173 return 0; 174 175 attr_msg_full: 176 nla_nest_cancel(msg->skb, attrs); 177 msg_full: 178 genlmsg_cancel(msg->skb, hdr); 179 180 return -EMSGSIZE; 181 } 182 183 int tipc_nl_net_dump(struct sk_buff *skb, struct netlink_callback *cb) 184 { 185 struct net *net = sock_net(skb->sk); 186 int err; 187 int done = cb->args[0]; 188 struct tipc_nl_msg msg; 189 190 if (done) 191 return 0; 192 193 msg.skb = skb; 194 msg.portid = NETLINK_CB(cb->skb).portid; 195 msg.seq = cb->nlh->nlmsg_seq; 196 197 err = __tipc_nl_add_net(net, &msg); 198 if (err) 199 goto out; 200 201 done = 1; 202 out: 203 cb->args[0] = done; 204 205 return skb->len; 206 } 207 208 int tipc_nl_net_set(struct sk_buff *skb, struct genl_info *info) 209 { 210 struct net *net = sock_net(skb->sk); 211 struct tipc_net *tn = net_generic(net, tipc_net_id); 212 struct nlattr *attrs[TIPC_NLA_NET_MAX + 1]; 213 int err; 214 215 if (!info->attrs[TIPC_NLA_NET]) 216 return -EINVAL; 217 218 err = nla_parse_nested(attrs, TIPC_NLA_NET_MAX, 219 info->attrs[TIPC_NLA_NET], 220 tipc_nl_net_policy); 221 if (err) 222 return err; 223 224 if (attrs[TIPC_NLA_NET_ID]) { 225 u32 val; 226 227 /* Can't change net id once TIPC has joined a network */ 228 if (tn->own_addr) 229 return -EPERM; 230 231 val = nla_get_u32(attrs[TIPC_NLA_NET_ID]); 232 if (val < 1 || val > 9999) 233 return -EINVAL; 234 235 tn->net_id = val; 236 } 237 238 if (attrs[TIPC_NLA_NET_ADDR]) { 239 u32 addr; 240 241 /* Can't change net addr once TIPC has joined a network */ 242 if (tn->own_addr) 243 return -EPERM; 244 245 addr = nla_get_u32(attrs[TIPC_NLA_NET_ADDR]); 246 if (!tipc_addr_node_valid(addr)) 247 return -EINVAL; 248 249 rtnl_lock(); 250 tipc_net_start(net, addr); 251 rtnl_unlock(); 252 } 253 254 return 0; 255 } 256