net/tipc/link.h

   1 /*
   2  * net/tipc/link.h: Include file for TIPC link code
   3  *
   4  * Copyright (c) 1995-2006, 2013-2014, 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 <net/genetlink.h>
  41 #include "msg.h"
  42 #include "node.h"
  43
  44 /* TIPC-specific error codes
  45 */
  46 #define ELINKCONG EAGAIN        /* link congestion <=> resource unavailable */
  47
  48 /* Out-of-range value for link sequence numbers
  49  */
  50 #define INVALID_LINK_SEQ 0x10000
  51
  52 /* Link FSM events:
  53  */
  54 enum {
  55         LINK_ESTABLISH_EVT       = 0xec1ab1e,
  56         LINK_PEER_RESET_EVT      = 0x9eed0e,
  57         LINK_FAILURE_EVT         = 0xfa110e,
  58         LINK_RESET_EVT           = 0x10ca1d0e,
  59         LINK_FAILOVER_BEGIN_EVT  = 0xfa110bee,
  60         LINK_FAILOVER_END_EVT    = 0xfa110ede,
  61         LINK_SYNCH_BEGIN_EVT     = 0xc1ccbee,
  62         LINK_SYNCH_END_EVT       = 0xc1ccede
  63 };
  64
  65 /* Events returned from link at packet reception or at timeout
  66  */
  67 enum {
  68         TIPC_LINK_UP_EVT       = 1,
  69         TIPC_LINK_DOWN_EVT     = (1 << 1)
  70 };
  71
  72 /* Starting value for maximum packet size negotiation on unicast links
  73  * (unless bearer MTU is less)
  74  */
  75 #define MAX_PKT_DEFAULT 1500
  76
  77 struct tipc_stats {
  78         u32 sent_info;          /* used in counting # sent packets */
  79         u32 recv_info;          /* used in counting # recv'd packets */
  80         u32 sent_states;
  81         u32 recv_states;
  82         u32 sent_probes;
  83         u32 recv_probes;
  84         u32 sent_nacks;
  85         u32 recv_nacks;
  86         u32 sent_acks;
  87         u32 sent_bundled;
  88         u32 sent_bundles;
  89         u32 recv_bundled;
  90         u32 recv_bundles;
  91         u32 retransmitted;
  92         u32 sent_fragmented;
  93         u32 sent_fragments;
  94         u32 recv_fragmented;
  95         u32 recv_fragments;
  96         u32 link_congs;         /* # port sends blocked by congestion */
  97         u32 deferred_recv;
  98         u32 duplicates;
  99         u32 max_queue_sz;       /* send queue size high water mark */
 100         u32 accu_queue_sz;      /* used for send queue size profiling */
 101         u32 queue_sz_counts;    /* used for send queue size profiling */
 102         u32 msg_length_counts;  /* used for message length profiling */
 103         u32 msg_lengths_total;  /* used for message length profiling */
 104         u32 msg_length_profile[7]; /* used for msg. length profiling */
 105 };
 106
 107 /**
 108  * struct tipc_link - TIPC link data structure
 109  * @addr: network address of link's peer node
 110  * @name: link name character string
 111  * @media_addr: media address to use when sending messages over link
 112  * @timer: link timer
 113  * @owner: pointer to peer node
 114  * @refcnt: reference counter for permanent references (owner node & timer)
 115  * @peer_session: link session # being used by peer end of link
 116  * @peer_bearer_id: bearer id used by link's peer endpoint
 117  * @bearer_id: local bearer id used by link
 118  * @tolerance: minimum link continuity loss needed to reset link [in ms]
 119  * @keepalive_intv: link keepalive timer interval
 120  * @abort_limit: # of unacknowledged continuity probes needed to reset link
 121  * @state: current state of link FSM
 122  * @silent_intv_cnt: # of timer intervals without any reception from peer
 123  * @proto_msg: template for control messages generated by link
 124  * @pmsg: convenience pointer to "proto_msg" field
 125  * @priority: current link priority
 126  * @net_plane: current link network plane ('A' through 'H')
 127  * @backlog_limit: backlog queue congestion thresholds (indexed by importance)
 128  * @exp_msg_count: # of tunnelled messages expected during link changeover
 129  * @reset_rcv_checkpt: seq # of last acknowledged message at time of link reset
 130  * @mtu: current maximum packet size for this link
 131  * @advertised_mtu: advertised own mtu when link is being established
 132  * @transmitq: queue for sent, non-acked messages
 133  * @backlogq: queue for messages waiting to be sent
 134  * @snt_nxt: next sequence number to use for outbound messages
 135  * @last_retransmitted: sequence number of most recently retransmitted message
 136  * @stale_count: # of identical retransmit requests made by peer
 137  * @ackers: # of peers that needs to ack each packet before it can be released
 138  * @acked: # last packet acked by a certain peer. Used for broadcast.
 139  * @rcv_nxt: next sequence number to expect for inbound messages
 140  * @deferred_queue: deferred queue saved OOS b'cast message received from node
 141  * @unacked_window: # of inbound messages rx'd without ack'ing back to peer
 142  * @inputq: buffer queue for messages to be delivered upwards
 143  * @namedq: buffer queue for name table messages to be delivered upwards
 144  * @next_out: ptr to first unsent outbound message in queue
 145  * @wakeupq: linked list of wakeup msgs waiting for link congestion to abate
 146  * @long_msg_seq_no: next identifier to use for outbound fragmented messages
 147  * @reasm_buf: head of partially reassembled inbound message fragments
 148  * @bc_rcvr: marks that this is a broadcast receiver link
 149  * @stats: collects statistics regarding link activity
 150  */
 151 struct tipc_link {
 152         u32 addr;
 153         char name[TIPC_MAX_LINK_NAME];
 154         struct tipc_media_addr *media_addr;
 155         struct tipc_node *owner;
 156
 157         /* Management and link supervision data */
 158         u32 peer_session;
 159         u32 peer_bearer_id;
 160         u32 bearer_id;
 161         u32 tolerance;
 162         unsigned long keepalive_intv;
 163         u32 abort_limit;
 164         u32 state;
 165         u32 silent_intv_cnt;
 166         struct {
 167                 unchar hdr[INT_H_SIZE];
 168                 unchar body[TIPC_MAX_IF_NAME];
 169         } proto_msg;
 170         struct tipc_msg *pmsg;
 171         u32 priority;
 172         char net_plane;
 173
 174         /* Failover/synch */
 175         u16 drop_point;
 176         struct sk_buff *failover_reasm_skb;
 177
 178         /* Max packet negotiation */
 179         u16 mtu;
 180         u16 advertised_mtu;
 181
 182         /* Sending */
 183         struct sk_buff_head transmq;
 184         struct sk_buff_head backlogq;
 185         struct {
 186                 u16 len;
 187                 u16 limit;
 188         } backlog[5];
 189         u16 snd_nxt;
 190         u16 last_retransm;
 191         u16 window;
 192         u32 stale_count;
 193
 194         /* Reception */
 195         u16 rcv_nxt;
 196         u32 rcv_unacked;
 197         struct sk_buff_head deferdq;
 198         struct sk_buff_head *inputq;
 199         struct sk_buff_head *namedq;
 200
 201         /* Congestion handling */
 202         struct sk_buff_head wakeupq;
 203
 204         /* Fragmentation/reassembly */
 205         struct sk_buff *reasm_buf;
 206
 207         /* Broadcast */
 208         u16 ackers;
 209         u16 acked;
 210
 211         /* Statistics */
 212         struct tipc_stats stats;
 213 };
 214
 215 bool tipc_link_create(struct tipc_node *n, char *if_name, int bearer_id,
 216                       int tolerance, char net_plane, u32 mtu, int priority,
 217                       int window, u32 session, u32 ownnode, u32 peer,
 218                       struct tipc_media_addr *maddr,
 219                       struct sk_buff_head *inputq, struct sk_buff_head *namedq,
 220                       struct tipc_link **link);
 221 bool tipc_link_bc_create(struct tipc_node *n, int mtu, int window,
 222                          struct sk_buff_head *inputq,
 223                          struct sk_buff_head *namedq,
 224                          struct tipc_link **link);
 225 void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
 226                            int mtyp, struct sk_buff_head *xmitq);
 227 void tipc_link_build_bcast_sync_msg(struct tipc_link *l,
 228                                     struct sk_buff_head *xmitq);
 229 void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq);
 230 int tipc_link_fsm_evt(struct tipc_link *l, int evt);
 231 void tipc_link_reset_fragments(struct tipc_link *l_ptr);
 232 bool tipc_link_is_up(struct tipc_link *l);
 233 bool tipc_link_peer_is_down(struct tipc_link *l);
 234 bool tipc_link_is_reset(struct tipc_link *l);
 235 bool tipc_link_is_establishing(struct tipc_link *l);
 236 bool tipc_link_is_synching(struct tipc_link *l);
 237 bool tipc_link_is_failingover(struct tipc_link *l);
 238 bool tipc_link_is_blocked(struct tipc_link *l);
 239 int tipc_link_is_active(struct tipc_link *l_ptr);
 240 void tipc_link_purge_queues(struct tipc_link *l_ptr);
 241 void tipc_link_purge_backlog(struct tipc_link *l);
 242 void tipc_link_reset(struct tipc_link *l_ptr);
 243 int __tipc_link_xmit(struct net *net, struct tipc_link *link,
 244                      struct sk_buff_head *list);
 245 int tipc_link_xmit(struct tipc_link *link,      struct sk_buff_head *list,
 246                    struct sk_buff_head *xmitq);
 247 void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int prob,
 248                           u32 gap, u32 tolerance, u32 priority);
 249 void tipc_link_push_packets(struct tipc_link *l_ptr);
 250 u32 tipc_link_defer_pkt(struct sk_buff_head *list, struct sk_buff *buf);
 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 struct sk_buff *tipc_skb_queue_next(const struct sk_buff_head *list,
 255                                     const struct sk_buff *skb);
 256
 257 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb);
 258 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info);
 259 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info);
 260 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info);
 261 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[]);
 262 int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq);
 263 int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
 264                   struct sk_buff_head *xmitq);
 265 void tipc_link_build_ack_msg(struct tipc_link *l, struct sk_buff_head *xmitq);
 266 void tipc_link_add_bc_peer(struct tipc_link *l);
 267 void tipc_link_remove_bc_peer(struct tipc_link *l);
 268 int tipc_link_bc_peers(struct tipc_link *l);
 269
 270 #endif