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