diff options
Diffstat (limited to 'net/tipc/net.c')
| -rw-r--r-- | net/tipc/net.c | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/net/tipc/net.c b/net/tipc/net.c new file mode 100644 index 000000000..a54f3cbe2 --- /dev/null +++ b/net/tipc/net.c @@ -0,0 +1,254 @@ +/* + * 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" + +static const struct nla_policy tipc_nl_net_policy[TIPC_NLA_NET_MAX + 1] = { + [TIPC_NLA_NET_UNSPEC] = { .type = NLA_UNSPEC }, + [TIPC_NLA_NET_ID] = { .type = NLA_U32 } +}; + +/* + * 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]; + int res; + + tn->own_addr = addr; + tipc_named_reinit(net); + tipc_sk_reinit(net); + res = tipc_bclink_init(net); + if (res) + return res; + + 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_bclink_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; +} |