| /* |
| * net/tipc/net.c: TIPC network routing code |
| * |
| * Copyright (c) 1995-2006, 2014, Ericsson AB |
| * Copyright (c) 2005, 2010-2011, Wind River Systems |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. Neither the names of the copyright holders nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * Alternatively, this software may be distributed under the terms of the |
| * GNU General Public License ("GPL") version 2 as published by the Free |
| * Software Foundation. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| * POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "core.h" |
| #include "net.h" |
| #include "name_distr.h" |
| #include "subscr.h" |
| #include "socket.h" |
| #include "node.h" |
| #include "bcast.h" |
| #include "netlink.h" |
| |
| /* |
| * The TIPC locking policy is designed to ensure a very fine locking |
| * granularity, permitting complete parallel access to individual |
| * port and node/link instances. The code consists of four major |
| * locking domains, each protected with their own disjunct set of locks. |
| * |
| * 1: The bearer level. |
| * RTNL lock is used to serialize the process of configuring bearer |
| * on update side, and RCU lock is applied on read side to make |
| * bearer instance valid on both paths of message transmission and |
| * reception. |
| * |
| * 2: The node and link level. |
| * All node instances are saved into two tipc_node_list and node_htable |
| * lists. The two lists are protected by node_list_lock on write side, |
| * and they are guarded with RCU lock on read side. Especially node |
| * instance is destroyed only when TIPC module is removed, and we can |
| * confirm that there has no any user who is accessing the node at the |
| * moment. Therefore, Except for iterating the two lists within RCU |
| * protection, it's no needed to hold RCU that we access node instance |
| * in other places. |
| * |
| * In addition, all members in node structure including link instances |
| * are protected by node spin lock. |
| * |
| * 3: The transport level of the protocol. |
| * This consists of the structures port, (and its user level |
| * representations, such as user_port and tipc_sock), reference and |
| * tipc_user (port.c, reg.c, socket.c). |
| * |
| * This layer has four different locks: |
| * - The tipc_port spin_lock. This is protecting each port instance |
| * from parallel data access and removal. Since we can not place |
| * this lock in the port itself, it has been placed in the |
| * corresponding reference table entry, which has the same life |
| * cycle as the module. This entry is difficult to access from |
| * outside the TIPC core, however, so a pointer to the lock has |
| * been added in the port instance, -to be used for unlocking |
| * only. |
| * - A read/write lock to protect the reference table itself (teg.c). |
| * (Nobody is using read-only access to this, so it can just as |
| * well be changed to a spin_lock) |
| * - A spin lock to protect the registry of kernel/driver users (reg.c) |
| * - A global spin_lock (tipc_port_lock), which only task is to ensure |
| * consistency where more than one port is involved in an operation, |
| * i.e., whe a port is part of a linked list of ports. |
| * There are two such lists; 'port_list', which is used for management, |
| * and 'wait_list', which is used to queue ports during congestion. |
| * |
| * 4: The name table (name_table.c, name_distr.c, subscription.c) |
| * - There is one big read/write-lock (tipc_nametbl_lock) protecting the |
| * overall name table structure. Nothing must be added/removed to |
| * this structure without holding write access to it. |
| * - There is one local spin_lock per sub_sequence, which can be seen |
| * as a sub-domain to the tipc_nametbl_lock domain. It is used only |
| * for translation operations, and is needed because a translation |
| * steps the root of the 'publication' linked list between each lookup. |
| * This is always used within the scope of a tipc_nametbl_lock(read). |
| * - A local spin_lock protecting the queue of subscriber events. |
| */ |
| |
| int tipc_net_start(struct net *net, u32 addr) |
| { |
| struct tipc_net *tn = net_generic(net, tipc_net_id); |
| char addr_string[16]; |
| |
| tn->own_addr = addr; |
| |
| /* Ensure that the new address is visible before we reinit. */ |
| smp_mb(); |
| |
| tipc_named_reinit(net); |
| tipc_sk_reinit(net); |
| |
| tipc_nametbl_publish(net, TIPC_CFG_SRV, tn->own_addr, tn->own_addr, |
| TIPC_ZONE_SCOPE, 0, tn->own_addr); |
| |
| pr_info("Started in network mode\n"); |
| pr_info("Own node address %s, network identity %u\n", |
| tipc_addr_string_fill(addr_string, tn->own_addr), |
| tn->net_id); |
| return 0; |
| } |
| |
| void tipc_net_stop(struct net *net) |
| { |
| struct tipc_net *tn = net_generic(net, tipc_net_id); |
| |
| if (!tn->own_addr) |
| return; |
| |
| tipc_nametbl_withdraw(net, TIPC_CFG_SRV, tn->own_addr, 0, |
| tn->own_addr); |
| rtnl_lock(); |
| tipc_bearer_stop(net); |
| tipc_node_stop(net); |
| rtnl_unlock(); |
| |
| pr_info("Left network mode\n"); |
| } |
| |
| static int __tipc_nl_add_net(struct net *net, struct tipc_nl_msg *msg) |
| { |
| struct tipc_net *tn = net_generic(net, tipc_net_id); |
| void *hdr; |
| struct nlattr *attrs; |
| |
| hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family, |
| NLM_F_MULTI, TIPC_NL_NET_GET); |
| if (!hdr) |
| return -EMSGSIZE; |
| |
| attrs = nla_nest_start(msg->skb, TIPC_NLA_NET); |
| if (!attrs) |
| goto msg_full; |
| |
| if (nla_put_u32(msg->skb, TIPC_NLA_NET_ID, tn->net_id)) |
| goto attr_msg_full; |
| |
| nla_nest_end(msg->skb, attrs); |
| genlmsg_end(msg->skb, hdr); |
| |
| return 0; |
| |
| attr_msg_full: |
| nla_nest_cancel(msg->skb, attrs); |
| msg_full: |
| genlmsg_cancel(msg->skb, hdr); |
| |
| return -EMSGSIZE; |
| } |
| |
| int tipc_nl_net_dump(struct sk_buff *skb, struct netlink_callback *cb) |
| { |
| struct net *net = sock_net(skb->sk); |
| int err; |
| int done = cb->args[0]; |
| struct tipc_nl_msg msg; |
| |
| if (done) |
| return 0; |
| |
| msg.skb = skb; |
| msg.portid = NETLINK_CB(cb->skb).portid; |
| msg.seq = cb->nlh->nlmsg_seq; |
| |
| err = __tipc_nl_add_net(net, &msg); |
| if (err) |
| goto out; |
| |
| done = 1; |
| out: |
| cb->args[0] = done; |
| |
| return skb->len; |
| } |
| |
| int tipc_nl_net_set(struct sk_buff *skb, struct genl_info *info) |
| { |
| struct net *net = sock_net(skb->sk); |
| struct tipc_net *tn = net_generic(net, tipc_net_id); |
| struct nlattr *attrs[TIPC_NLA_NET_MAX + 1]; |
| int err; |
| |
| if (!info->attrs[TIPC_NLA_NET]) |
| return -EINVAL; |
| |
| err = nla_parse_nested(attrs, TIPC_NLA_NET_MAX, |
| info->attrs[TIPC_NLA_NET], |
| tipc_nl_net_policy); |
| if (err) |
| return err; |
| |
| if (attrs[TIPC_NLA_NET_ID]) { |
| u32 val; |
| |
| /* Can't change net id once TIPC has joined a network */ |
| if (tn->own_addr) |
| return -EPERM; |
| |
| val = nla_get_u32(attrs[TIPC_NLA_NET_ID]); |
| if (val < 1 || val > 9999) |
| return -EINVAL; |
| |
| tn->net_id = val; |
| } |
| |
| if (attrs[TIPC_NLA_NET_ADDR]) { |
| u32 addr; |
| |
| /* Can't change net addr once TIPC has joined a network */ |
| if (tn->own_addr) |
| return -EPERM; |
| |
| addr = nla_get_u32(attrs[TIPC_NLA_NET_ADDR]); |
| if (!tipc_addr_node_valid(addr)) |
| return -EINVAL; |
| |
| rtnl_lock(); |
| tipc_net_start(net, addr); |
| rtnl_unlock(); |
| } |
| |
| return 0; |
| } |