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