linux/net/tipc/link.h
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   1/*
   2 * net/tipc/link.h: Include file for TIPC link code
   3 *
   4 * Copyright (c) 1995-2006, Ericsson AB
   5 * Copyright (c) 2004-2005, 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_LINK_H
  38#define _TIPC_LINK_H
  39
  40#include "msg.h"
  41#include "node.h"
  42
  43#define PUSH_FAILED   1
  44#define PUSH_FINISHED 2
  45
  46/*
  47 * Out-of-range value for link sequence numbers
  48 */
  49#define INVALID_LINK_SEQ 0x10000
  50
  51/*
  52 * Link states
  53 */
  54#define WORKING_WORKING 560810u
  55#define WORKING_UNKNOWN 560811u
  56#define RESET_UNKNOWN   560812u
  57#define RESET_RESET     560813u
  58
  59/*
  60 * Starting value for maximum packet size negotiation on unicast links
  61 * (unless bearer MTU is less)
  62 */
  63#define MAX_PKT_DEFAULT 1500
  64
  65struct tipc_stats {
  66        u32 sent_info;          /* used in counting # sent packets */
  67        u32 recv_info;          /* used in counting # recv'd packets */
  68        u32 sent_states;
  69        u32 recv_states;
  70        u32 sent_probes;
  71        u32 recv_probes;
  72        u32 sent_nacks;
  73        u32 recv_nacks;
  74        u32 sent_acks;
  75        u32 sent_bundled;
  76        u32 sent_bundles;
  77        u32 recv_bundled;
  78        u32 recv_bundles;
  79        u32 retransmitted;
  80        u32 sent_fragmented;
  81        u32 sent_fragments;
  82        u32 recv_fragmented;
  83        u32 recv_fragments;
  84        u32 link_congs;         /* # port sends blocked by congestion */
  85        u32 bearer_congs;
  86        u32 deferred_recv;
  87        u32 duplicates;
  88        u32 max_queue_sz;       /* send queue size high water mark */
  89        u32 accu_queue_sz;      /* used for send queue size profiling */
  90        u32 queue_sz_counts;    /* used for send queue size profiling */
  91        u32 msg_length_counts;  /* used for message length profiling */
  92        u32 msg_lengths_total;  /* used for message length profiling */
  93        u32 msg_length_profile[7]; /* used for msg. length profiling */
  94};
  95
  96/**
  97 * struct tipc_link - TIPC link data structure
  98 * @addr: network address of link's peer node
  99 * @name: link name character string
 100 * @media_addr: media address to use when sending messages over link
 101 * @timer: link timer
 102 * @owner: pointer to peer node
 103 * @link_list: adjacent links in bearer's list of links
 104 * @started: indicates if link has been started
 105 * @checkpoint: reference point for triggering link continuity checking
 106 * @peer_session: link session # being used by peer end of link
 107 * @peer_bearer_id: bearer id used by link's peer endpoint
 108 * @b_ptr: pointer to bearer used by link
 109 * @tolerance: minimum link continuity loss needed to reset link [in ms]
 110 * @continuity_interval: link continuity testing interval [in ms]
 111 * @abort_limit: # of unacknowledged continuity probes needed to reset link
 112 * @state: current state of link FSM
 113 * @blocked: indicates if link has been administratively blocked
 114 * @fsm_msg_cnt: # of protocol messages link FSM has sent in current state
 115 * @proto_msg: template for control messages generated by link
 116 * @pmsg: convenience pointer to "proto_msg" field
 117 * @priority: current link priority
 118 * @queue_limit: outbound message queue congestion thresholds (indexed by user)
 119 * @exp_msg_count: # of tunnelled messages expected during link changeover
 120 * @reset_checkpoint: seq # of last acknowledged message at time of link reset
 121 * @max_pkt: current maximum packet size for this link
 122 * @max_pkt_target: desired maximum packet size for this link
 123 * @max_pkt_probes: # of probes based on current (max_pkt, max_pkt_target)
 124 * @out_queue_size: # of messages in outbound message queue
 125 * @first_out: ptr to first outbound message in queue
 126 * @last_out: ptr to last outbound message in queue
 127 * @next_out_no: next sequence number to use for outbound messages
 128 * @last_retransmitted: sequence number of most recently retransmitted message
 129 * @stale_count: # of identical retransmit requests made by peer
 130 * @next_in_no: next sequence number to expect for inbound messages
 131 * @deferred_inqueue_sz: # of messages in inbound message queue
 132 * @oldest_deferred_in: ptr to first inbound message in queue
 133 * @newest_deferred_in: ptr to last inbound message in queue
 134 * @unacked_window: # of inbound messages rx'd without ack'ing back to peer
 135 * @proto_msg_queue: ptr to (single) outbound control message
 136 * @retransm_queue_size: number of messages to retransmit
 137 * @retransm_queue_head: sequence number of first message to retransmit
 138 * @next_out: ptr to first unsent outbound message in queue
 139 * @waiting_ports: linked list of ports waiting for link congestion to abate
 140 * @long_msg_seq_no: next identifier to use for outbound fragmented messages
 141 * @defragm_buf: list of partially reassembled inbound message fragments
 142 * @stats: collects statistics regarding link activity
 143 */
 144struct tipc_link {
 145        u32 addr;
 146        char name[TIPC_MAX_LINK_NAME];
 147        struct tipc_media_addr media_addr;
 148        struct timer_list timer;
 149        struct tipc_node *owner;
 150        struct list_head link_list;
 151
 152        /* Management and link supervision data */
 153        int started;
 154        u32 checkpoint;
 155        u32 peer_session;
 156        u32 peer_bearer_id;
 157        struct tipc_bearer *b_ptr;
 158        u32 tolerance;
 159        u32 continuity_interval;
 160        u32 abort_limit;
 161        int state;
 162        int blocked;
 163        u32 fsm_msg_cnt;
 164        struct {
 165                unchar hdr[INT_H_SIZE];
 166                unchar body[TIPC_MAX_IF_NAME];
 167        } proto_msg;
 168        struct tipc_msg *pmsg;
 169        u32 priority;
 170        u32 queue_limit[15];    /* queue_limit[0]==window limit */
 171
 172        /* Changeover */
 173        u32 exp_msg_count;
 174        u32 reset_checkpoint;
 175
 176        /* Max packet negotiation */
 177        u32 max_pkt;
 178        u32 max_pkt_target;
 179        u32 max_pkt_probes;
 180
 181        /* Sending */
 182        u32 out_queue_size;
 183        struct sk_buff *first_out;
 184        struct sk_buff *last_out;
 185        u32 next_out_no;
 186        u32 last_retransmitted;
 187        u32 stale_count;
 188
 189        /* Reception */
 190        u32 next_in_no;
 191        u32 deferred_inqueue_sz;
 192        struct sk_buff *oldest_deferred_in;
 193        struct sk_buff *newest_deferred_in;
 194        u32 unacked_window;
 195
 196        /* Congestion handling */
 197        struct sk_buff *proto_msg_queue;
 198        u32 retransm_queue_size;
 199        u32 retransm_queue_head;
 200        struct sk_buff *next_out;
 201        struct list_head waiting_ports;
 202
 203        /* Fragmentation/defragmentation */
 204        u32 long_msg_seq_no;
 205        struct sk_buff *defragm_buf;
 206
 207        /* Statistics */
 208        struct tipc_stats stats;
 209};
 210
 211struct tipc_port;
 212
 213struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
 214                              struct tipc_bearer *b_ptr,
 215                              const struct tipc_media_addr *media_addr);
 216void tipc_link_delete(struct tipc_link *l_ptr);
 217void tipc_link_changeover(struct tipc_link *l_ptr);
 218void tipc_link_send_duplicate(struct tipc_link *l_ptr, struct tipc_link *dest);
 219void tipc_link_reset_fragments(struct tipc_link *l_ptr);
 220int tipc_link_is_up(struct tipc_link *l_ptr);
 221int tipc_link_is_active(struct tipc_link *l_ptr);
 222u32 tipc_link_push_packet(struct tipc_link *l_ptr);
 223void tipc_link_stop(struct tipc_link *l_ptr);
 224struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area, int req_tlv_space, u16 cmd);
 225struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area, int req_tlv_space);
 226struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area, int req_tlv_space);
 227void tipc_link_reset(struct tipc_link *l_ptr);
 228int tipc_link_send(struct sk_buff *buf, u32 dest, u32 selector);
 229void tipc_link_send_names(struct list_head *message_list, u32 dest);
 230int tipc_link_send_buf(struct tipc_link *l_ptr, struct sk_buff *buf);
 231u32 tipc_link_get_max_pkt(u32 dest, u32 selector);
 232int tipc_link_send_sections_fast(struct tipc_port *sender,
 233                                 struct iovec const *msg_sect,
 234                                 const u32 num_sect,
 235                                 unsigned int total_len,
 236                                 u32 destnode);
 237void tipc_link_recv_bundle(struct sk_buff *buf);
 238int  tipc_link_recv_fragment(struct sk_buff **pending,
 239                             struct sk_buff **fb,
 240                             struct tipc_msg **msg);
 241void tipc_link_send_proto_msg(struct tipc_link *l_ptr, u32 msg_typ, int prob,
 242                              u32 gap, u32 tolerance, u32 priority,
 243                              u32 acked_mtu);
 244void tipc_link_push_queue(struct tipc_link *l_ptr);
 245u32 tipc_link_defer_pkt(struct sk_buff **head, struct sk_buff **tail,
 246                   struct sk_buff *buf);
 247void tipc_link_wakeup_ports(struct tipc_link *l_ptr, int all);
 248void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window);
 249void tipc_link_retransmit(struct tipc_link *l_ptr,
 250                          struct sk_buff *start, u32 retransmits);
 251
 252/*
 253 * Link sequence number manipulation routines (uses modulo 2**16 arithmetic)
 254 */
 255static inline u32 buf_seqno(struct sk_buff *buf)
 256{
 257        return msg_seqno(buf_msg(buf));
 258}
 259
 260static inline u32 mod(u32 x)
 261{
 262        return x & 0xffffu;
 263}
 264
 265static inline int between(u32 lower, u32 upper, u32 n)
 266{
 267        if ((lower < n) && (n < upper))
 268                return 1;
 269        if ((upper < lower) && ((n > lower) || (n < upper)))
 270                return 1;
 271        return 0;
 272}
 273
 274static inline int less_eq(u32 left, u32 right)
 275{
 276        return mod(right - left) < 32768u;
 277}
 278
 279static inline int less(u32 left, u32 right)
 280{
 281        return less_eq(left, right) && (mod(right) != mod(left));
 282}
 283
 284static inline u32 lesser(u32 left, u32 right)
 285{
 286        return less_eq(left, right) ? left : right;
 287}
 288
 289
 290/*
 291 * Link status checking routines
 292 */
 293static inline int link_working_working(struct tipc_link *l_ptr)
 294{
 295        return l_ptr->state == WORKING_WORKING;
 296}
 297
 298static inline int link_working_unknown(struct tipc_link *l_ptr)
 299{
 300        return l_ptr->state == WORKING_UNKNOWN;
 301}
 302
 303static inline int link_reset_unknown(struct tipc_link *l_ptr)
 304{
 305        return l_ptr->state == RESET_UNKNOWN;
 306}
 307
 308static inline int link_reset_reset(struct tipc_link *l_ptr)
 309{
 310        return l_ptr->state == RESET_RESET;
 311}
 312
 313static inline int link_blocked(struct tipc_link *l_ptr)
 314{
 315        return l_ptr->exp_msg_count || l_ptr->blocked;
 316}
 317
 318static inline int link_congested(struct tipc_link *l_ptr)
 319{
 320        return l_ptr->out_queue_size >= l_ptr->queue_limit[0];
 321}
 322
 323#endif
 324