1 /*
2  * net/tipc/node.h: Include file for TIPC node management routines
3  *
4  * Copyright (c) 2000-2006, Ericsson AB
5  * Copyright (c) 2005, 2010-2011, Wind River Systems
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the names of the copyright holders nor the names of its
17  *    contributors may be used to endorse or promote products derived from
18  *    this software without specific prior written permission.
19  *
20  * Alternatively, this software may be distributed under the terms of the
21  * GNU General Public License ("GPL") version 2 as published by the Free
22  * Software Foundation.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
25  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
28  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34  * POSSIBILITY OF SUCH DAMAGE.
35  */
36 
37 #ifndef _TIPC_NODE_H
38 #define _TIPC_NODE_H
39 
40 #include "node_subscr.h"
41 #include "addr.h"
42 #include "net.h"
43 #include "bearer.h"
44 
45 /**
46  * struct tipc_node - TIPC node structure
47  * @addr: network address of node
48  * @lock: spinlock governing access to structure
49  * @hash: links to adjacent nodes in unsorted hash chain
50  * @list: links to adjacent nodes in sorted list of cluster's nodes
51  * @nsub: list of "node down" subscriptions monitoring node
52  * @active_links: pointers to active links to node
53  * @links: pointers to all links to node
54  * @working_links: number of working links to node (both active and standby)
55  * @cleanup_required: non-zero if cleaning up after a prior loss of contact
56  * @link_cnt: number of links to node
57  * @permit_changeover: non-zero if node has redundant links to this system
58  * @bclink: broadcast-related info
59  *    @supported: non-zero if node supports TIPC b'cast capability
60  *    @acked: sequence # of last outbound b'cast message acknowledged by node
61  *    @last_in: sequence # of last in-sequence b'cast message received from node
62  *    @gap_after: sequence # of last message not requiring a NAK request
63  *    @gap_to: sequence # of last message requiring a NAK request
64  *    @nack_sync: counter that determines when NAK requests should be sent
65  *    @deferred_head: oldest OOS b'cast message received from node
66  *    @deferred_tail: newest OOS b'cast message received from node
67  *    @defragm: list of partially reassembled b'cast message fragments from node
68  */
69 
70 struct tipc_node {
71 	u32 addr;
72 	spinlock_t lock;
73 	struct hlist_node hash;
74 	struct list_head list;
75 	struct list_head nsub;
76 	struct link *active_links[2];
77 	struct link *links[MAX_BEARERS];
78 	int link_cnt;
79 	int working_links;
80 	int cleanup_required;
81 	int permit_changeover;
82 	struct {
83 		int supported;
84 		u32 acked;
85 		u32 last_in;
86 		u32 gap_after;
87 		u32 gap_to;
88 		u32 nack_sync;
89 		struct sk_buff *deferred_head;
90 		struct sk_buff *deferred_tail;
91 		struct sk_buff *defragm;
92 	} bclink;
93 };
94 
95 #define NODE_HTABLE_SIZE 512
96 extern struct list_head tipc_node_list;
97 
98 /*
99  * A trivial power-of-two bitmask technique is used for speed, since this
100  * operation is done for every incoming TIPC packet. The number of hash table
101  * entries has been chosen so that no hash chain exceeds 8 nodes and will
102  * usually be much smaller (typically only a single node).
103  */
tipc_hashfn(u32 addr)104 static inline unsigned int tipc_hashfn(u32 addr)
105 {
106 	return addr & (NODE_HTABLE_SIZE - 1);
107 }
108 
109 extern u32 tipc_own_tag;
110 
111 struct tipc_node *tipc_node_find(u32 addr);
112 struct tipc_node *tipc_node_create(u32 addr);
113 void tipc_node_delete(struct tipc_node *n_ptr);
114 void tipc_node_attach_link(struct tipc_node *n_ptr, struct link *l_ptr);
115 void tipc_node_detach_link(struct tipc_node *n_ptr, struct link *l_ptr);
116 void tipc_node_link_down(struct tipc_node *n_ptr, struct link *l_ptr);
117 void tipc_node_link_up(struct tipc_node *n_ptr, struct link *l_ptr);
118 int tipc_node_active_links(struct tipc_node *n_ptr);
119 int tipc_node_redundant_links(struct tipc_node *n_ptr);
120 int tipc_node_is_up(struct tipc_node *n_ptr);
121 struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space);
122 struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space);
123 
tipc_node_lock(struct tipc_node * n_ptr)124 static inline void tipc_node_lock(struct tipc_node *n_ptr)
125 {
126 	spin_lock_bh(&n_ptr->lock);
127 }
128 
tipc_node_unlock(struct tipc_node * n_ptr)129 static inline void tipc_node_unlock(struct tipc_node *n_ptr)
130 {
131 	spin_unlock_bh(&n_ptr->lock);
132 }
133 
134 #endif
135