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 "log.h"
  41 #include "msg.h"
  42 #include "node.h"
  43
  44 #define PUSH_FAILED   1
  45 #define PUSH_FINISHED 2
  46
  47 /*
  48  * Out-of-range value for link sequence numbers
  49  */
  50
  51 #define INVALID_LINK_SEQ 0x10000
  52
  53 /*
  54  * Link states
  55  */
  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
  67 #define MAX_PKT_DEFAULT 1500
  68
  69 /**
  70  * struct tipc_link - TIPC link data structure
  71  * @addr: network address of link's peer node
  72  * @name: link name character string
  73  * @media_addr: media address to use when sending messages over link
  74  * @timer: link timer
  75  * @owner: pointer to peer node
  76  * @link_list: adjacent links in bearer's list of links
  77  * @started: indicates if link has been started
  78  * @checkpoint: reference point for triggering link continuity checking
  79  * @peer_session: link session # being used by peer end of link
  80  * @peer_bearer_id: bearer id used by link's peer endpoint
  81  * @b_ptr: pointer to bearer used by link
  82  * @tolerance: minimum link continuity loss needed to reset link [in ms]
  83  * @continuity_interval: link continuity testing interval [in ms]
  84  * @abort_limit: # of unacknowledged continuity probes needed to reset link
  85  * @state: current state of link FSM
  86  * @blocked: indicates if link has been administratively blocked
  87  * @fsm_msg_cnt: # of protocol messages link FSM has sent in current state
  88  * @proto_msg: template for control messages generated by link
  89  * @pmsg: convenience pointer to "proto_msg" field
  90  * @priority: current link priority
  91  * @queue_limit: outbound message queue congestion thresholds (indexed by user)
  92  * @exp_msg_count: # of tunnelled messages expected during link changeover
  93  * @reset_checkpoint: seq # of last acknowledged message at time of link reset
  94  * @max_pkt: current maximum packet size for this link
  95  * @max_pkt_target: desired maximum packet size for this link
  96  * @max_pkt_probes: # of probes based on current (max_pkt, max_pkt_target)
  97  * @out_queue_size: # of messages in outbound message queue
  98  * @first_out: ptr to first outbound message in queue
  99  * @last_out: ptr to last outbound message in queue
 100  * @next_out_no: next sequence number to use for outbound messages
 101  * @last_retransmitted: sequence number of most recently retransmitted message
 102  * @stale_count: # of identical retransmit requests made by peer
 103  * @next_in_no: next sequence number to expect for inbound messages
 104  * @deferred_inqueue_sz: # of messages in inbound message queue
 105  * @oldest_deferred_in: ptr to first inbound message in queue
 106  * @newest_deferred_in: ptr to last inbound message in queue
 107  * @unacked_window: # of inbound messages rx'd without ack'ing back to peer
 108  * @proto_msg_queue: ptr to (single) outbound control message
 109  * @retransm_queue_size: number of messages to retransmit
 110  * @retransm_queue_head: sequence number of first message to retransmit
 111  * @next_out: ptr to first unsent outbound message in queue
 112  * @waiting_ports: linked list of ports waiting for link congestion to abate
 113  * @long_msg_seq_no: next identifier to use for outbound fragmented messages
 114  * @defragm_buf: list of partially reassembled inbound message fragments
 115  * @stats: collects statistics regarding link activity
 116  */
 117
 118 struct tipc_link {
 119         u32 addr;
 120         char name[TIPC_MAX_LINK_NAME];
 121         struct tipc_media_addr media_addr;
 122         struct timer_list timer;
 123         struct tipc_node *owner;
 124         struct list_head link_list;
 125
 126         /* Management and link supervision data */
 127         int started;
 128         u32 checkpoint;
 129         u32 peer_session;
 130         u32 peer_bearer_id;
 131         struct tipc_bearer *b_ptr;
 132         u32 tolerance;
 133         u32 continuity_interval;
 134         u32 abort_limit;
 135         int state;
 136         int blocked;
 137         u32 fsm_msg_cnt;
 138         struct {
 139                 unchar hdr[INT_H_SIZE];
 140                 unchar body[TIPC_MAX_IF_NAME];
 141         } proto_msg;
 142         struct tipc_msg *pmsg;
 143         u32 priority;
 144         u32 queue_limit[15];    /* queue_limit[0]==window limit */
 145
 146         /* Changeover */
 147         u32 exp_msg_count;
 148         u32 reset_checkpoint;
 149
 150         /* Max packet negotiation */
 151         u32 max_pkt;
 152         u32 max_pkt_target;
 153         u32 max_pkt_probes;
 154
 155         /* Sending */
 156         u32 out_queue_size;
 157         struct sk_buff *first_out;
 158         struct sk_buff *last_out;
 159         u32 next_out_no;
 160         u32 last_retransmitted;
 161         u32 stale_count;
 162
 163         /* Reception */
 164         u32 next_in_no;
 165         u32 deferred_inqueue_sz;
 166         struct sk_buff *oldest_deferred_in;
 167         struct sk_buff *newest_deferred_in;
 168         u32 unacked_window;
 169
 170         /* Congestion handling */
 171         struct sk_buff *proto_msg_queue;
 172         u32 retransm_queue_size;
 173         u32 retransm_queue_head;
 174         struct sk_buff *next_out;
 175         struct list_head waiting_ports;
 176
 177         /* Fragmentation/defragmentation */
 178         u32 long_msg_seq_no;
 179         struct sk_buff *defragm_buf;
 180
 181         /* Statistics */
 182         struct {
 183                 u32 sent_info;          /* used in counting # sent packets */
 184                 u32 recv_info;          /* used in counting # recv'd packets */
 185                 u32 sent_states;
 186                 u32 recv_states;
 187                 u32 sent_probes;
 188                 u32 recv_probes;
 189                 u32 sent_nacks;
 190                 u32 recv_nacks;
 191                 u32 sent_acks;
 192                 u32 sent_bundled;
 193                 u32 sent_bundles;
 194                 u32 recv_bundled;
 195                 u32 recv_bundles;
 196                 u32 retransmitted;
 197                 u32 sent_fragmented;
 198                 u32 sent_fragments;
 199                 u32 recv_fragmented;
 200                 u32 recv_fragments;
 201                 u32 link_congs;         /* # port sends blocked by congestion */
 202                 u32 bearer_congs;
 203                 u32 deferred_recv;
 204                 u32 duplicates;
 205                 u32 max_queue_sz;       /* send queue size high water mark */
 206                 u32 accu_queue_sz;      /* used for send queue size profiling */
 207                 u32 queue_sz_counts;    /* used for send queue size profiling */
 208                 u32 msg_length_counts;  /* used for message length profiling */
 209                 u32 msg_lengths_total;  /* used for message length profiling */
 210                 u32 msg_length_profile[7]; /* used for msg. length profiling */
 211         } stats;
 212 };
 213
 214 struct tipc_port;
 215
 216 struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
 217                               struct tipc_bearer *b_ptr,
 218                               const struct tipc_media_addr *media_addr);
 219 void tipc_link_delete(struct tipc_link *l_ptr);
 220 void tipc_link_changeover(struct tipc_link *l_ptr);
 221 void tipc_link_send_duplicate(struct tipc_link *l_ptr, 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 u32 tipc_link_push_packet(struct tipc_link *l_ptr);
 226 void tipc_link_stop(struct tipc_link *l_ptr);
 227 struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area, int req_tlv_space, u16 cmd);
 228 struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area, int req_tlv_space);
 229 struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area, int req_tlv_space);
 230 void tipc_link_reset(struct tipc_link *l_ptr);
 231 int tipc_link_send(struct sk_buff *buf, u32 dest, u32 selector);
 232 void tipc_link_send_names(struct list_head *message_list, u32 dest);
 233 int tipc_link_send_buf(struct tipc_link *l_ptr, struct sk_buff *buf);
 234 u32 tipc_link_get_max_pkt(u32 dest, u32 selector);
 235 int tipc_link_send_sections_fast(struct tipc_port *sender,
 236                                  struct iovec const *msg_sect,
 237                                  const u32 num_sect,
 238                                  unsigned int total_len,
 239                                  u32 destnode);
 240 void tipc_link_recv_bundle(struct sk_buff *buf);
 241 int  tipc_link_recv_fragment(struct sk_buff **pending,
 242                              struct sk_buff **fb,
 243                              struct tipc_msg **msg);
 244 void tipc_link_send_proto_msg(struct tipc_link *l_ptr, u32 msg_typ, int prob,
 245                               u32 gap, u32 tolerance, u32 priority,
 246                               u32 acked_mtu);
 247 void tipc_link_push_queue(struct tipc_link *l_ptr);
 248 u32 tipc_link_defer_pkt(struct sk_buff **head, struct sk_buff **tail,
 249                    struct sk_buff *buf);
 250 void tipc_link_wakeup_ports(struct tipc_link *l_ptr, int all);
 251 void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window);
 252 void tipc_link_retransmit(struct tipc_link *l_ptr,
 253                           struct sk_buff *start, u32 retransmits);
 254
 255 /*
 256  * Link sequence number manipulation routines (uses modulo 2**16 arithmetic)
 257  */
 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
 298 static inline int link_working_working(struct tipc_link *l_ptr)
 299 {
 300         return l_ptr->state == WORKING_WORKING;
 301 }
 302
 303 static inline int link_working_unknown(struct tipc_link *l_ptr)
 304 {
 305         return l_ptr->state == WORKING_UNKNOWN;
 306 }
 307
 308 static inline int link_reset_unknown(struct tipc_link *l_ptr)
 309 {
 310         return l_ptr->state == RESET_UNKNOWN;
 311 }
 312
 313 static inline int link_reset_reset(struct tipc_link *l_ptr)
 314 {
 315         return l_ptr->state == RESET_RESET;
 316 }
 317
 318 static inline int link_blocked(struct tipc_link *l_ptr)
 319 {
 320         return l_ptr->exp_msg_count || l_ptr->blocked;
 321 }
 322
 323 static inline int link_congested(struct tipc_link *l_ptr)
 324 {
 325         return l_ptr->out_queue_size >= l_ptr->queue_limit[0];
 326 }
 327
 328 #endif