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, 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
 112 struct 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
 214 struct port;
 215
 216 struct link *tipc_link_create(struct bearer *b_ptr, const u32 peer,
 217                               const struct tipc_media_addr *media_addr);
 218 void tipc_link_delete(struct link *l_ptr);
 219 void tipc_link_changeover(struct link *l_ptr);
 220 void tipc_link_send_duplicate(struct link *l_ptr, struct link *dest);
 221 void tipc_link_reset_fragments(struct link *l_ptr);
 222 int tipc_link_is_up(struct link *l_ptr);
 223 int tipc_link_is_active(struct link *l_ptr);
 224 u32 tipc_link_push_packet(struct link *l_ptr);
 225 void tipc_link_stop(struct link *l_ptr);
 226 struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area, int req_tlv_space, u16 cmd);
 227 struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area, int req_tlv_space);
 228 struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area, int req_tlv_space);
 229 void tipc_link_reset(struct link *l_ptr);
 230 int tipc_link_send(struct sk_buff *buf, u32 dest, u32 selector);
 231 int tipc_link_send_buf(struct link *l_ptr, struct sk_buff *buf);
 232 u32 tipc_link_get_max_pkt(u32 dest, u32 selector);
 233 int tipc_link_send_sections_fast(struct port *sender,
 234                                  struct iovec const *msg_sect,
 235                                  const u32 num_sect,
 236                                  u32 destnode);
 237 void tipc_link_recv_bundle(struct sk_buff *buf);
 238 int  tipc_link_recv_fragment(struct sk_buff **pending,
 239                              struct sk_buff **fb,
 240                              struct tipc_msg **msg);
 241 void tipc_link_send_proto_msg(struct link *l_ptr, u32 msg_typ, int prob, u32 gap,
 242                               u32 tolerance, u32 priority, u32 acked_mtu);
 243 void tipc_link_push_queue(struct link *l_ptr);
 244 u32 tipc_link_defer_pkt(struct sk_buff **head, struct sk_buff **tail,
 245                    struct sk_buff *buf);
 246 void tipc_link_wakeup_ports(struct link *l_ptr, int all);
 247 void tipc_link_set_queue_limits(struct link *l_ptr, u32 window);
 248 void 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
 254 static inline u32 mod(u32 x)
 255 {
 256         return x & 0xffffu;
 257 }
 258
 259 static 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
 268 static inline int less_eq(u32 left, u32 right)
 269 {
 270         return mod(right - left) < 32768u;
 271 }
 272
 273 static inline int less(u32 left, u32 right)
 274 {
 275         return less_eq(left, right) && (mod(right) != mod(left));
 276 }
 277
 278 static 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
 288 static inline int link_working_working(struct link *l_ptr)
 289 {
 290         return l_ptr->state == WORKING_WORKING;
 291 }
 292
 293 static inline int link_working_unknown(struct link *l_ptr)
 294 {
 295         return l_ptr->state == WORKING_UNKNOWN;
 296 }
 297
 298 static inline int link_reset_unknown(struct link *l_ptr)
 299 {
 300         return l_ptr->state == RESET_UNKNOWN;
 301 }
 302
 303 static inline int link_reset_reset(struct link *l_ptr)
 304 {
 305         return l_ptr->state == RESET_RESET;
 306 }
 307
 308 static inline int link_blocked(struct link *l_ptr)
 309 {
 310         return l_ptr->exp_msg_count || l_ptr->blocked;
 311 }
 312
 313 static 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