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
  62 struct 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
  95 struct 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 node_map nodes;
 108 };
 109
 110 struct bearer_name {
 111         char media_name[TIPC_MAX_MEDIA_NAME];
 112         char if_name[TIPC_MAX_IF_NAME];
 113 };
 114
 115 struct link;
 116
 117 extern struct bearer *tipc_bearers;
 118
 119 void tipc_media_addr_printf(struct print_buf *pb, struct tipc_media_addr *a);
 120 struct sk_buff *tipc_media_get_names(void);
 121
 122 struct sk_buff *tipc_bearer_get_names(void);
 123 void tipc_bearer_add_dest(struct bearer *b_ptr, u32 dest);
 124 void tipc_bearer_remove_dest(struct bearer *b_ptr, u32 dest);
 125 void tipc_bearer_schedule(struct bearer *b_ptr, struct link *l_ptr);
 126 struct bearer *tipc_bearer_find_interface(const char *if_name);
 127 int tipc_bearer_resolve_congestion(struct bearer *b_ptr, struct link *l_ptr);
 128 int tipc_bearer_init(void);
 129 void tipc_bearer_stop(void);
 130 void 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
 151 static 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
 161 static 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