2 * net/tipc/net.c: TIPC network routing code
4 * Copyright (c) 1995-2006, 2014, Ericsson AB
5 * Copyright (c) 2005, 2010-2011, Wind River Systems
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39 #include "name_distr.h"
46 static const struct nla_policy tipc_nl_net_policy[TIPC_NLA_NET_MAX + 1] = {
47 [TIPC_NLA_NET_UNSPEC] = { .type = NLA_UNSPEC },
48 [TIPC_NLA_NET_ID] = { .type = NLA_U32 }
52 * The TIPC locking policy is designed to ensure a very fine locking
53 * granularity, permitting complete parallel access to individual
54 * port and node/link instances. The code consists of four major
55 * locking domains, each protected with their own disjunct set of locks.
57 * 1: The bearer level.
58 * RTNL lock is used to serialize the process of configuring bearer
59 * on update side, and RCU lock is applied on read side to make
60 * bearer instance valid on both paths of message transmission and
63 * 2: The node and link level.
64 * All node instances are saved into two tipc_node_list and node_htable
65 * lists. The two lists are protected by node_list_lock on write side,
66 * and they are guarded with RCU lock on read side. Especially node
67 * instance is destroyed only when TIPC module is removed, and we can
68 * confirm that there has no any user who is accessing the node at the
69 * moment. Therefore, Except for iterating the two lists within RCU
70 * protection, it's no needed to hold RCU that we access node instance
73 * In addition, all members in node structure including link instances
74 * are protected by node spin lock.
76 * 3: The transport level of the protocol.
77 * This consists of the structures port, (and its user level
78 * representations, such as user_port and tipc_sock), reference and
79 * tipc_user (port.c, reg.c, socket.c).
81 * This layer has four different locks:
82 * - The tipc_port spin_lock. This is protecting each port instance
83 * from parallel data access and removal. Since we can not place
84 * this lock in the port itself, it has been placed in the
85 * corresponding reference table entry, which has the same life
86 * cycle as the module. This entry is difficult to access from
87 * outside the TIPC core, however, so a pointer to the lock has
88 * been added in the port instance, -to be used for unlocking
90 * - A read/write lock to protect the reference table itself (teg.c).
91 * (Nobody is using read-only access to this, so it can just as
92 * well be changed to a spin_lock)
93 * - A spin lock to protect the registry of kernel/driver users (reg.c)
94 * - A global spin_lock (tipc_port_lock), which only task is to ensure
95 * consistency where more than one port is involved in an operation,
96 * i.e., whe a port is part of a linked list of ports.
97 * There are two such lists; 'port_list', which is used for management,
98 * and 'wait_list', which is used to queue ports during congestion.
100 * 4: The name table (name_table.c, name_distr.c, subscription.c)
101 * - There is one big read/write-lock (tipc_nametbl_lock) protecting the
102 * overall name table structure. Nothing must be added/removed to
103 * this structure without holding write access to it.
104 * - There is one local spin_lock per sub_sequence, which can be seen
105 * as a sub-domain to the tipc_nametbl_lock domain. It is used only
106 * for translation operations, and is needed because a translation
107 * steps the root of the 'publication' linked list between each lookup.
108 * This is always used within the scope of a tipc_nametbl_lock(read).
109 * - A local spin_lock protecting the queue of subscriber events.
112 int tipc_net_start(struct net *net, u32 addr)
114 struct tipc_net *tn = net_generic(net, tipc_net_id);
115 char addr_string[16];
119 tipc_named_reinit(net);
121 res = tipc_bclink_init(net);
125 tipc_nametbl_publish(net, TIPC_CFG_SRV, tn->own_addr, tn->own_addr,
126 TIPC_ZONE_SCOPE, 0, tn->own_addr);
128 pr_info("Started in network mode\n");
129 pr_info("Own node address %s, network identity %u\n",
130 tipc_addr_string_fill(addr_string, tn->own_addr),
135 void tipc_net_stop(struct net *net)
137 struct tipc_net *tn = net_generic(net, tipc_net_id);
142 tipc_nametbl_withdraw(net, TIPC_CFG_SRV, tn->own_addr, 0,
145 tipc_bearer_stop(net);
146 tipc_bclink_stop(net);
150 pr_info("Left network mode\n");
153 static int __tipc_nl_add_net(struct net *net, struct tipc_nl_msg *msg)
155 struct tipc_net *tn = net_generic(net, tipc_net_id);
157 struct nlattr *attrs;
159 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
160 NLM_F_MULTI, TIPC_NL_NET_GET);
164 attrs = nla_nest_start(msg->skb, TIPC_NLA_NET);
168 if (nla_put_u32(msg->skb, TIPC_NLA_NET_ID, tn->net_id))
171 nla_nest_end(msg->skb, attrs);
172 genlmsg_end(msg->skb, hdr);
177 nla_nest_cancel(msg->skb, attrs);
179 genlmsg_cancel(msg->skb, hdr);
184 int tipc_nl_net_dump(struct sk_buff *skb, struct netlink_callback *cb)
186 struct net *net = sock_net(skb->sk);
188 int done = cb->args[0];
189 struct tipc_nl_msg msg;
195 msg.portid = NETLINK_CB(cb->skb).portid;
196 msg.seq = cb->nlh->nlmsg_seq;
198 err = __tipc_nl_add_net(net, &msg);
209 int tipc_nl_net_set(struct sk_buff *skb, struct genl_info *info)
211 struct net *net = genl_info_net(info);
212 struct tipc_net *tn = net_generic(net, tipc_net_id);
213 struct nlattr *attrs[TIPC_NLA_NET_MAX + 1];
216 if (!info->attrs[TIPC_NLA_NET])
219 err = nla_parse_nested(attrs, TIPC_NLA_NET_MAX,
220 info->attrs[TIPC_NLA_NET],
225 if (attrs[TIPC_NLA_NET_ID]) {
228 /* Can't change net id once TIPC has joined a network */
232 val = nla_get_u32(attrs[TIPC_NLA_NET_ID]);
233 if (val < 1 || val > 9999)
239 if (attrs[TIPC_NLA_NET_ADDR]) {
242 /* Can't change net addr once TIPC has joined a network */
246 addr = nla_get_u32(attrs[TIPC_NLA_NET_ADDR]);
247 if (!tipc_addr_node_valid(addr))
251 tipc_net_start(net, addr);