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 "bcast.h"
  41
  42 #define MAX_BEARERS 8
  43 #define MAX_MEDIA 4
  44
  45 /*
  46  * Identifiers of supported TIPC media types
  47  */
  48 #define TIPC_MEDIA_TYPE_ETH     1
  49
  50 /*
  51  * Destination address structure used by TIPC bearers when sending messages
  52  *
  53  * IMPORTANT: The fields of this structure MUST be stored using the specified
  54  * byte order indicated below, as the structure is exchanged between nodes
  55  * as part of a link setup process.
  56  */
  57 struct tipc_media_addr {
  58         __be32  type;                   /* bearer type (network byte order) */
  59         union {
  60                 __u8   eth_addr[6];     /* 48 bit Ethernet addr (byte array) */
  61         } dev_addr;
  62 };
  63
  64 /**
  65  * struct tipc_bearer - TIPC bearer info available to media code
  66  * @usr_handle: pointer to additional media-specific information about bearer
  67  * @mtu: max packet size bearer can support
  68  * @blocked: non-zero if bearer is blocked
  69  * @lock: spinlock for controlling access to bearer
  70  * @addr: media-specific address associated with bearer
  71  * @name: bearer name (format = media:interface)
  72  *
  73  * Note: TIPC initializes "name" and "lock" fields; media code is responsible
  74  * for initialization all other fields when a bearer is enabled.
  75  */
  76 struct tipc_bearer {
  77         void *usr_handle;
  78         u32 mtu;
  79         int blocked;
  80         spinlock_t lock;
  81         struct tipc_media_addr addr;
  82         char name[TIPC_MAX_BEARER_NAME];
  83 };
  84
  85 /**
  86  * struct media - TIPC media information available to internal users
  87  * @send_msg: routine which handles buffer transmission
  88  * @enable_bearer: routine which enables a bearer
  89  * @disable_bearer: routine which disables a bearer
  90  * @addr2str: routine which converts bearer's address to string form
  91  * @bcast_addr: media address used in broadcasting
  92  * @bcast: non-zero if media supports broadcasting [currently mandatory]
  93  * @priority: default link (and bearer) priority
  94  * @tolerance: default time (in ms) before declaring link failure
  95  * @window: default window (in packets) before declaring link congestion
  96  * @type_id: TIPC media identifier
  97  * @name: media name
  98  */
  99
 100 struct media {
 101         int (*send_msg)(struct sk_buff *buf,
 102                         struct tipc_bearer *b_ptr,
 103                         struct tipc_media_addr *dest);
 104         int (*enable_bearer)(struct tipc_bearer *b_ptr);
 105         void (*disable_bearer)(struct tipc_bearer *b_ptr);
 106         char *(*addr2str)(struct tipc_media_addr *a,
 107                           char *str_buf, int str_size);
 108         struct tipc_media_addr bcast_addr;
 109         int bcast;
 110         u32 priority;
 111         u32 tolerance;
 112         u32 window;
 113         u32 type_id;
 114         char name[TIPC_MAX_MEDIA_NAME];
 115 };
 116
 117 /**
 118  * struct bearer - TIPC bearer information available to internal users
 119  * @publ: bearer information available to privileged users
 120  * @media: ptr to media structure associated with bearer
 121  * @priority: default link priority for bearer
 122  * @detect_scope: network address mask used during automatic link creation
 123  * @identity: array index of this bearer within TIPC bearer array
 124  * @link_req: ptr to (optional) structure making periodic link setup requests
 125  * @links: list of non-congested links associated with bearer
 126  * @cong_links: list of congested links associated with bearer
 127  * @continue_count: # of times bearer has resumed after congestion or blocking
 128  * @active: non-zero if bearer structure is represents a bearer
 129  * @net_plane: network plane ('A' through 'H') currently associated with bearer
 130  * @nodes: indicates which nodes in cluster can be reached through bearer
 131  */
 132
 133 struct bearer {
 134         struct tipc_bearer publ;
 135         struct media *media;
 136         u32 priority;
 137         u32 detect_scope;
 138         u32 identity;
 139         struct link_req *link_req;
 140         struct list_head links;
 141         struct list_head cong_links;
 142         u32 continue_count;
 143         int active;
 144         char net_plane;
 145         struct tipc_node_map nodes;
 146 };
 147
 148 struct bearer_name {
 149         char media_name[TIPC_MAX_MEDIA_NAME];
 150         char if_name[TIPC_MAX_IF_NAME];
 151 };
 152
 153 struct link;
 154
 155 extern struct bearer tipc_bearers[];
 156
 157 /*
 158  * TIPC routines available to supported media types
 159  */
 160 int tipc_register_media(u32 media_type,
 161                  char *media_name, int (*enable)(struct tipc_bearer *),
 162                  void (*disable)(struct tipc_bearer *),
 163                  int (*send_msg)(struct sk_buff *,
 164                         struct tipc_bearer *, struct tipc_media_addr *),
 165                  char *(*addr2str)(struct tipc_media_addr *a,
 166                         char *str_buf, int str_size),
 167                  struct tipc_media_addr *bcast_addr, const u32 bearer_priority,
 168                  const u32 link_tolerance,  /* [ms] */
 169                  const u32 send_window_limit);
 170
 171 void tipc_recv_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr);
 172
 173 int  tipc_block_bearer(const char *name);
 174 void tipc_continue(struct tipc_bearer *tb_ptr);
 175
 176 int tipc_enable_bearer(const char *bearer_name, u32 bcast_scope, u32 priority);
 177 int tipc_disable_bearer(const char *name);
 178
 179 /*
 180  * Routines made available to TIPC by supported media types
 181  */
 182 int  tipc_eth_media_start(void);
 183 void tipc_eth_media_stop(void);
 184
 185 void tipc_media_addr_printf(struct print_buf *pb, struct tipc_media_addr *a);
 186 struct sk_buff *tipc_media_get_names(void);
 187
 188 struct sk_buff *tipc_bearer_get_names(void);
 189 void tipc_bearer_add_dest(struct bearer *b_ptr, u32 dest);
 190 void tipc_bearer_remove_dest(struct bearer *b_ptr, u32 dest);
 191 void tipc_bearer_schedule(struct bearer *b_ptr, struct link *l_ptr);
 192 struct bearer *tipc_bearer_find_interface(const char *if_name);
 193 int tipc_bearer_resolve_congestion(struct bearer *b_ptr, struct link *l_ptr);
 194 int tipc_bearer_congested(struct bearer *b_ptr, struct link *l_ptr);
 195 void tipc_bearer_stop(void);
 196 void tipc_bearer_lock_push(struct bearer *b_ptr);
 197
 198
 199 /**
 200  * tipc_bearer_send- sends buffer to destination over bearer
 201  *
 202  * Returns true (1) if successful, or false (0) if unable to send
 203  *
 204  * IMPORTANT:
 205  * The media send routine must not alter the buffer being passed in
 206  * as it may be needed for later retransmission!
 207  *
 208  * If the media send routine returns a non-zero value (indicating that
 209  * it was unable to send the buffer), it must:
 210  *   1) mark the bearer as blocked,
 211  *   2) call tipc_continue() once the bearer is able to send again.
 212  * Media types that are unable to meet these two critera must ensure their
 213  * send routine always returns success -- even if the buffer was not sent --
 214  * and let TIPC's link code deal with the undelivered message.
 215  */
 216
 217 static inline int tipc_bearer_send(struct bearer *b_ptr, struct sk_buff *buf,
 218                                    struct tipc_media_addr *dest)
 219 {
 220         return !b_ptr->media->send_msg(buf, &b_ptr->publ, dest);
 221 }
 222
 223 #endif  /* _TIPC_BEARER_H */