Root/net/tipc/bearer.h

1/*
2 * net/tipc/bearer.h: Include file for TIPC bearer code
3 *
4 * Copyright (c) 1996-2006, Ericsson AB
5 * Copyright (c) 2005, 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_BEARER_H
38#define _TIPC_BEARER_H
39
40#include "core.h"
41#include "bcast.h"
42
43#define MAX_BEARERS 8
44#define MAX_MEDIA 4
45
46
47/**
48 * struct media - TIPC media information available to internal users
49 * @send_msg: routine which handles buffer transmission
50 * @enable_bearer: routine which enables a bearer
51 * @disable_bearer: routine which disables a bearer
52 * @addr2str: routine which converts bearer's address to string form
53 * @bcast_addr: media address used in broadcasting
54 * @bcast: non-zero if media supports broadcasting [currently mandatory]
55 * @priority: default link (and bearer) priority
56 * @tolerance: default time (in ms) before declaring link failure
57 * @window: default window (in packets) before declaring link congestion
58 * @type_id: TIPC media identifier [defined in tipc_bearer.h]
59 * @name: media name
60 */
61
62struct media {
63    int (*send_msg)(struct sk_buff *buf,
64            struct tipc_bearer *b_ptr,
65            struct tipc_media_addr *dest);
66    int (*enable_bearer)(struct tipc_bearer *b_ptr);
67    void (*disable_bearer)(struct tipc_bearer *b_ptr);
68    char *(*addr2str)(struct tipc_media_addr *a,
69              char *str_buf, int str_size);
70    struct tipc_media_addr bcast_addr;
71    int bcast;
72    u32 priority;
73    u32 tolerance;
74    u32 window;
75    u32 type_id;
76    char name[TIPC_MAX_MEDIA_NAME];
77};
78
79/**
80 * struct bearer - TIPC bearer information available to internal users
81 * @publ: bearer information available to privileged users
82 * @media: ptr to media structure associated with bearer
83 * @priority: default link priority for bearer
84 * @detect_scope: network address mask used during automatic link creation
85 * @identity: array index of this bearer within TIPC bearer array
86 * @link_req: ptr to (optional) structure making periodic link setup requests
87 * @links: list of non-congested links associated with bearer
88 * @cong_links: list of congested links associated with bearer
89 * @continue_count: # of times bearer has resumed after congestion or blocking
90 * @active: non-zero if bearer structure is represents a bearer
91 * @net_plane: network plane ('A' through 'H') currently associated with bearer
92 * @nodes: indicates which nodes in cluster can be reached through bearer
93 */
94
95struct bearer {
96    struct tipc_bearer publ;
97    struct media *media;
98    u32 priority;
99    u32 detect_scope;
100    u32 identity;
101    struct link_req *link_req;
102    struct list_head links;
103    struct list_head cong_links;
104    u32 continue_count;
105    int active;
106    char net_plane;
107    struct tipc_node_map nodes;
108};
109
110struct bearer_name {
111    char media_name[TIPC_MAX_MEDIA_NAME];
112    char if_name[TIPC_MAX_IF_NAME];
113};
114
115struct link;
116
117extern struct bearer *tipc_bearers;
118
119void tipc_media_addr_printf(struct print_buf *pb, struct tipc_media_addr *a);
120struct sk_buff *tipc_media_get_names(void);
121
122struct sk_buff *tipc_bearer_get_names(void);
123void tipc_bearer_add_dest(struct bearer *b_ptr, u32 dest);
124void tipc_bearer_remove_dest(struct bearer *b_ptr, u32 dest);
125void tipc_bearer_schedule(struct bearer *b_ptr, struct link *l_ptr);
126struct bearer *tipc_bearer_find_interface(const char *if_name);
127int tipc_bearer_resolve_congestion(struct bearer *b_ptr, struct link *l_ptr);
128int tipc_bearer_init(void);
129void tipc_bearer_stop(void);
130void tipc_bearer_lock_push(struct bearer *b_ptr);
131
132
133/**
134 * tipc_bearer_send- sends buffer to destination over bearer
135 *
136 * Returns true (1) if successful, or false (0) if unable to send
137 *
138 * IMPORTANT:
139 * The media send routine must not alter the buffer being passed in
140 * as it may be needed for later retransmission!
141 *
142 * If the media send routine returns a non-zero value (indicating that
143 * it was unable to send the buffer), it must:
144 * 1) mark the bearer as blocked,
145 * 2) call tipc_continue() once the bearer is able to send again.
146 * Media types that are unable to meet these two critera must ensure their
147 * send routine always returns success -- even if the buffer was not sent --
148 * and let TIPC's link code deal with the undelivered message.
149 */
150
151static inline int tipc_bearer_send(struct bearer *b_ptr, struct sk_buff *buf,
152                   struct tipc_media_addr *dest)
153{
154    return !b_ptr->media->send_msg(buf, &b_ptr->publ, dest);
155}
156
157/**
158 * tipc_bearer_congested - determines if bearer is currently congested
159 */
160
161static inline int tipc_bearer_congested(struct bearer *b_ptr, struct link *l_ptr)
162{
163    if (unlikely(b_ptr->publ.blocked))
164        return 1;
165    if (likely(list_empty(&b_ptr->cong_links)))
166        return 0;
167    return !tipc_bearer_resolve_congestion(b_ptr, l_ptr);
168}
169
170#endif
171

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