net/tipc/link.h

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