2 * net/tipc/net.c: TIPC network routing code
4 * Copyright (c) 1995-2006, Ericsson AB
5 * Copyright (c) 2005, Wind River Systems
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40 #include "name_table.h"
41 #include "name_distr.h"
48 * The TIPC locking policy is designed to ensure a very fine locking
49 * granularity, permitting complete parallel access to individual
50 * port and node/link instances. The code consists of three major
51 * locking domains, each protected with their own disjunct set of locks.
53 * 1: The routing hierarchy.
54 * Comprises the structures 'zone', 'cluster', 'node', 'link'
55 * and 'bearer'. The whole hierarchy is protected by a big
56 * read/write lock, tipc_net_lock, to enssure that nothing is added
57 * or removed while code is accessing any of these structures.
58 * This layer must not be called from the two others while they
59 * hold any of their own locks.
60 * Neither must it itself do any upcalls to the other two before
61 * it has released tipc_net_lock and other protective locks.
63 * Within the tipc_net_lock domain there are two sub-domains;'node' and
64 * 'bearer', where local write operations are permitted,
65 * provided that those are protected by individual spin_locks
66 * per instance. Code holding tipc_net_lock(read) and a node spin_lock
67 * is permitted to poke around in both the node itself and its
68 * subordinate links. I.e, it can update link counters and queues,
69 * change link state, send protocol messages, and alter the
70 * "active_links" array in the node; but it can _not_ remove a link
71 * or a node from the overall structure.
72 * Correspondingly, individual bearers may change status within a
73 * tipc_net_lock(read), protected by an individual spin_lock ber bearer
74 * instance, but it needs tipc_net_lock(write) to remove/add any bearers.
77 * 2: The transport level of the protocol.
78 * This consists of the structures port, (and its user level
79 * representations, such as user_port and tipc_sock), reference and
80 * tipc_user (port.c, reg.c, socket.c).
82 * This layer has four different locks:
83 * - The tipc_port spin_lock. This is protecting each port instance
84 * from parallel data access and removal. Since we can not place
85 * this lock in the port itself, it has been placed in the
86 * corresponding reference table entry, which has the same life
87 * cycle as the module. This entry is difficult to access from
88 * outside the TIPC core, however, so a pointer to the lock has
89 * been added in the port instance, -to be used for unlocking
91 * - A read/write lock to protect the reference table itself (teg.c).
92 * (Nobody is using read-only access to this, so it can just as
93 * well be changed to a spin_lock)
94 * - A spin lock to protect the registry of kernel/driver users (reg.c)
95 * - A global spin_lock (tipc_port_lock), which only task is to ensure
96 * consistency where more than one port is involved in an operation,
97 * i.e., whe a port is part of a linked list of ports.
98 * There are two such lists; 'port_list', which is used for management,
99 * and 'wait_list', which is used to queue ports during congestion.
101 * 3: The name table (name_table.c, name_distr.c, subscription.c)
102 * - There is one big read/write-lock (tipc_nametbl_lock) protecting the
103 * overall name table structure. Nothing must be added/removed to
104 * this structure without holding write access to it.
105 * - There is one local spin_lock per sub_sequence, which can be seen
106 * as a sub-domain to the tipc_nametbl_lock domain. It is used only
107 * for translation operations, and is needed because a translation
108 * steps the root of the 'publication' linked list between each lookup.
109 * This is always used within the scope of a tipc_nametbl_lock(read).
110 * - A local spin_lock protecting the queue of subscriber events.
113 DEFINE_RWLOCK(tipc_net_lock);
114 static struct _zone *tipc_zones[256] = { NULL, };
115 struct network tipc_net = { tipc_zones };
117 struct tipc_node *tipc_net_select_remote_node(u32 addr, u32 ref)
119 return tipc_zone_select_remote_node(tipc_net.zones[tipc_zone(addr)], addr, ref);
122 u32 tipc_net_select_router(u32 addr, u32 ref)
124 return tipc_zone_select_router(tipc_net.zones[tipc_zone(addr)], addr, ref);
127 void tipc_net_remove_as_router(u32 router)
131 for (z_num = 1; z_num <= tipc_max_zones; z_num++) {
132 if (!tipc_net.zones[z_num])
134 tipc_zone_remove_as_router(tipc_net.zones[z_num], router);
138 void tipc_net_send_external_routes(u32 dest)
142 for (z_num = 1; z_num <= tipc_max_zones; z_num++) {
143 if (tipc_net.zones[z_num])
144 tipc_zone_send_external_routes(tipc_net.zones[z_num], dest);
148 static void net_stop(void)
152 for (z_num = 1; z_num <= tipc_max_zones; z_num++)
153 tipc_zone_delete(tipc_net.zones[z_num]);
156 static void net_route_named_msg(struct sk_buff *buf)
158 struct tipc_msg *msg = buf_msg(buf);
162 if (!msg_named(msg)) {
163 msg_dbg(msg, "tipc_net->drop_nam:");
168 dnode = addr_domain(msg_lookup_scope(msg));
169 dport = tipc_nametbl_translate(msg_nametype(msg), msg_nameinst(msg), &dnode);
170 dbg("tipc_net->lookup<%u,%u>-><%u,%x>\n",
171 msg_nametype(msg), msg_nameinst(msg), dport, dnode);
173 msg_set_destnode(msg, dnode);
174 msg_set_destport(msg, dport);
175 tipc_net_route_msg(buf);
178 msg_dbg(msg, "tipc_net->rej:NO NAME: ");
179 tipc_reject_msg(buf, TIPC_ERR_NO_NAME);
182 void tipc_net_route_msg(struct sk_buff *buf)
184 struct tipc_msg *msg;
191 msg_incr_reroute_cnt(msg);
192 if (msg_reroute_cnt(msg) > 6) {
193 if (msg_errcode(msg)) {
194 msg_dbg(msg, "NET>DISC>:");
197 msg_dbg(msg, "NET>REJ>:");
198 tipc_reject_msg(buf, msg_destport(msg) ?
199 TIPC_ERR_NO_PORT : TIPC_ERR_NO_NAME);
204 msg_dbg(msg, "tipc_net->rout: ");
206 /* Handle message for this node */
207 dnode = msg_short(msg) ? tipc_own_addr : msg_destnode(msg);
208 if (tipc_in_scope(dnode, tipc_own_addr)) {
209 if (msg_isdata(msg)) {
211 tipc_port_recv_mcast(buf, NULL);
212 else if (msg_destport(msg))
213 tipc_port_recv_msg(buf);
215 net_route_named_msg(buf);
218 switch (msg_user(msg)) {
219 case ROUTE_DISTRIBUTOR:
220 tipc_cltr_recv_routing_table(buf);
222 case NAME_DISTRIBUTOR:
223 tipc_named_recv(buf);
226 tipc_port_recv_proto_msg(buf);
229 msg_dbg(msg,"DROP/NET/<REC<");
235 /* Handle message for another node */
236 msg_dbg(msg, "NET>SEND>: ");
237 skb_trim(buf, msg_size(msg));
238 tipc_link_send(buf, dnode, msg_link_selector(msg));
241 int tipc_net_start(u32 addr)
243 char addr_string[16];
246 if (tipc_mode != TIPC_NODE_MODE)
252 tipc_own_addr = addr;
253 tipc_mode = TIPC_NET_MODE;
257 if ((res = tipc_cltr_init()) ||
258 (res = tipc_bclink_init())) {
262 tipc_k_signal((Handler)tipc_subscr_start, 0);
263 tipc_k_signal((Handler)tipc_cfg_init, 0);
265 info("Started in network mode\n");
266 info("Own node address %s, network identity %u\n",
267 tipc_addr_string_fill(addr_string, tipc_own_addr), tipc_net_id);
271 void tipc_net_stop(void)
273 if (tipc_mode != TIPC_NET_MODE)
275 write_lock_bh(&tipc_net_lock);
277 tipc_mode = TIPC_NODE_MODE;
280 write_unlock_bh(&tipc_net_lock);
281 info("Left network mode\n");