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Diffstat (limited to 'net/tipc/net.c')
| -rw-r--r-- | net/tipc/net.c | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/net/tipc/net.c b/net/tipc/net.c new file mode 100644 index 00000000..68b3dd63 --- /dev/null +++ b/net/tipc/net.c @@ -0,0 +1,228 @@ +/* + * net/tipc/net.c: TIPC network routing code + * + * Copyright (c) 1995-2006, 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 "port.h" +#include "node.h" +#include "config.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 three major + * locking domains, each protected with their own disjunct set of locks. + * + * 1: The routing hierarchy. + * Comprises the structures 'zone', 'cluster', 'node', 'link' + * and 'bearer'. The whole hierarchy is protected by a big + * read/write lock, tipc_net_lock, to enssure that nothing is added + * or removed while code is accessing any of these structures. + * This layer must not be called from the two others while they + * hold any of their own locks. + * Neither must it itself do any upcalls to the other two before + * it has released tipc_net_lock and other protective locks. + * + * Within the tipc_net_lock domain there are two sub-domains;'node' and + * 'bearer', where local write operations are permitted, + * provided that those are protected by individual spin_locks + * per instance. Code holding tipc_net_lock(read) and a node spin_lock + * is permitted to poke around in both the node itself and its + * subordinate links. I.e, it can update link counters and queues, + * change link state, send protocol messages, and alter the + * "active_links" array in the node; but it can _not_ remove a link + * or a node from the overall structure. + * Correspondingly, individual bearers may change status within a + * tipc_net_lock(read), protected by an individual spin_lock ber bearer + * instance, but it needs tipc_net_lock(write) to remove/add any bearers. + * + * + * 2: 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. + * + * 3: 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. +*/ + +DEFINE_RWLOCK(tipc_net_lock); + +static void net_route_named_msg(struct sk_buff *buf) +{ + struct tipc_msg *msg = buf_msg(buf); + u32 dnode; + u32 dport; + + if (!msg_named(msg)) { + buf_discard(buf); + return; + } + + dnode = addr_domain(msg_lookup_scope(msg)); + dport = tipc_nametbl_translate(msg_nametype(msg), msg_nameinst(msg), &dnode); + if (dport) { + msg_set_destnode(msg, dnode); + msg_set_destport(msg, dport); + tipc_net_route_msg(buf); + return; + } + tipc_reject_msg(buf, TIPC_ERR_NO_NAME); +} + +void tipc_net_route_msg(struct sk_buff *buf) +{ + struct tipc_msg *msg; + u32 dnode; + + if (!buf) + return; + msg = buf_msg(buf); + + msg_incr_reroute_cnt(msg); + if (msg_reroute_cnt(msg) > 6) { + if (msg_errcode(msg)) { + buf_discard(buf); + } else { + tipc_reject_msg(buf, msg_destport(msg) ? + TIPC_ERR_NO_PORT : TIPC_ERR_NO_NAME); + } + return; + } + + /* Handle message for this node */ + dnode = msg_short(msg) ? tipc_own_addr : msg_destnode(msg); + if (tipc_in_scope(dnode, tipc_own_addr)) { + if (msg_isdata(msg)) { + if (msg_mcast(msg)) + tipc_port_recv_mcast(buf, NULL); + else if (msg_destport(msg)) + tipc_port_recv_msg(buf); + else + net_route_named_msg(buf); + return; + } + switch (msg_user(msg)) { + case NAME_DISTRIBUTOR: + tipc_named_recv(buf); + break; + case CONN_MANAGER: + tipc_port_recv_proto_msg(buf); + break; + default: + buf_discard(buf); + } + return; + } + + /* Handle message for another node */ + skb_trim(buf, msg_size(msg)); + tipc_link_send(buf, dnode, msg_link_selector(msg)); +} + +int tipc_net_start(u32 addr) +{ + char addr_string[16]; + int res; + + if (tipc_mode != TIPC_NODE_MODE) + return -ENOPROTOOPT; + + tipc_subscr_stop(); + tipc_cfg_stop(); + + tipc_own_addr = addr; + tipc_mode = TIPC_NET_MODE; + tipc_named_reinit(); + tipc_port_reinit(); + + res = tipc_bclink_init(); + if (res) + return res; + + tipc_k_signal((Handler)tipc_subscr_start, 0); + tipc_k_signal((Handler)tipc_cfg_init, 0); + + info("Started in network mode\n"); + info("Own node address %s, network identity %u\n", + tipc_addr_string_fill(addr_string, tipc_own_addr), tipc_net_id); + return 0; +} + +void tipc_net_stop(void) +{ + struct tipc_node *node, *t_node; + + if (tipc_mode != TIPC_NET_MODE) + return; + write_lock_bh(&tipc_net_lock); + tipc_bearer_stop(); + tipc_mode = TIPC_NODE_MODE; + tipc_bclink_stop(); + list_for_each_entry_safe(node, t_node, &tipc_node_list, list) + tipc_node_delete(node); + write_unlock_bh(&tipc_net_lock); + info("Left network mode\n"); +} |