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 working states
  53  */
  54 #define WORKING_WORKING 560810u
  55 #define WORKING_UNKNOWN 560811u
  56 #define RESET_UNKNOWN   560812u
  57 #define RESET_RESET     560813u
  58
  59 /* Link endpoint execution states
  60  */
  61 #define LINK_STARTED    0x0001
  62 #define LINK_STOPPED    0x0002
  63
  64 /* Starting value for maximum packet size negotiation on unicast links
  65  * (unless bearer MTU is less)
  66  */
  67 #define MAX_PKT_DEFAULT 1500
  68
  69 struct tipc_stats {
  70         u32 sent_info;          /* used in counting # sent packets */
  71         u32 recv_info;          /* used in counting # recv'd packets */
  72         u32 sent_states;
  73         u32 recv_states;
  74         u32 sent_probes;
  75         u32 recv_probes;
  76         u32 sent_nacks;
  77         u32 recv_nacks;
  78         u32 sent_acks;
  79         u32 sent_bundled;
  80         u32 sent_bundles;
  81         u32 recv_bundled;
  82         u32 recv_bundles;
  83         u32 retransmitted;
  84         u32 sent_fragmented;
  85         u32 sent_fragments;
  86         u32 recv_fragmented;
  87         u32 recv_fragments;
  88         u32 link_congs;         /* # port sends blocked by congestion */
  89         u32 deferred_recv;
  90         u32 duplicates;
  91         u32 max_queue_sz;       /* send queue size high water mark */
  92         u32 accu_queue_sz;      /* used for send queue size profiling */
  93         u32 queue_sz_counts;    /* used for send queue size profiling */
  94         u32 msg_length_counts;  /* used for message length profiling */
  95         u32 msg_lengths_total;  /* used for message length profiling */
  96         u32 msg_length_profile[7]; /* used for msg. length profiling */
  97 };
  98
  99 /**
 100  * struct tipc_link - TIPC link data structure
 101  * @addr: network address of link's peer node
 102  * @name: link name character string
 103  * @media_addr: media address to use when sending messages over link
 104  * @timer: link timer
 105  * @owner: pointer to peer node
 106  * @refcnt: reference counter for permanent references (owner node & timer)
 107  * @flags: execution state flags for link endpoint instance
 108  * @checkpoint: reference point for triggering link continuity checking
 109  * @peer_session: link session # being used by peer end of link
 110  * @peer_bearer_id: bearer id used by link's peer endpoint
 111  * @bearer_id: local bearer id used by link
 112  * @tolerance: minimum link continuity loss needed to reset link [in ms]
 113  * @cont_intv: link continuity testing interval
 114  * @abort_limit: # of unacknowledged continuity probes needed to reset link
 115  * @state: current state of link FSM
 116  * @fsm_msg_cnt: # of protocol messages link FSM has sent in current state
 117  * @proto_msg: template for control messages generated by link
 118  * @pmsg: convenience pointer to "proto_msg" field
 119  * @priority: current link priority
 120  * @net_plane: current link network plane ('A' through 'H')
 121  * @queue_limit: outbound message queue congestion thresholds (indexed by user)
 122  * @exp_msg_count: # of tunnelled messages expected during link changeover
 123  * @reset_checkpoint: seq # of last acknowledged message at time of link reset
 124  * @max_pkt: current maximum packet size for this link
 125  * @max_pkt_target: desired maximum packet size for this link
 126  * @max_pkt_probes: # of probes based on current (max_pkt, max_pkt_target)
 127  * @outqueue: outbound message 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_queue: deferred queue saved OOS b'cast message received from node
 133  * @unacked_window: # of inbound messages rx'd without ack'ing back to peer
 134  * @inputq: buffer queue for messages to be delivered upwards
 135  * @namedq: buffer queue for name table messages to be delivered upwards
 136  * @next_out: ptr to first unsent outbound message in queue
 137  * @wakeupq: linked list of wakeup msgs waiting for link congestion to abate
 138  * @long_msg_seq_no: next identifier to use for outbound fragmented messages
 139  * @reasm_buf: head of partially reassembled inbound message fragments
 140  * @stats: collects statistics regarding link activity
 141  */
 142 struct tipc_link {
 143         u32 addr;
 144         char name[TIPC_MAX_LINK_NAME];
 145         struct tipc_media_addr media_addr;
 146         struct timer_list timer;
 147         struct tipc_node *owner;
 148         struct kref ref;
 149
 150         /* Management and link supervision data */
 151         unsigned int flags;
 152         u32 checkpoint;
 153         u32 peer_session;
 154         u32 peer_bearer_id;
 155         u32 bearer_id;
 156         u32 tolerance;
 157         unsigned long cont_intv;
 158         u32 abort_limit;
 159         int state;
 160         u32 fsm_msg_cnt;
 161         struct {
 162                 unchar hdr[INT_H_SIZE];
 163                 unchar body[TIPC_MAX_IF_NAME];
 164         } proto_msg;
 165         struct tipc_msg *pmsg;
 166         u32 priority;
 167         char net_plane;
 168         u32 queue_limit[15];    /* queue_limit[0]==window limit */
 169
 170         /* Changeover */
 171         u32 exp_msg_count;
 172         u32 reset_checkpoint;
 173
 174         /* Max packet negotiation */
 175         u32 max_pkt;
 176         u32 max_pkt_target;
 177         u32 max_pkt_probes;
 178
 179         /* Sending */
 180         struct sk_buff_head outqueue;
 181         u32 next_out_no;
 182         u32 last_retransmitted;
 183         u32 stale_count;
 184
 185         /* Reception */
 186         u32 next_in_no;
 187         struct sk_buff_head deferred_queue;
 188         u32 unacked_window;
 189         struct sk_buff_head inputq;
 190         struct sk_buff_head namedq;
 191
 192         /* Congestion handling */
 193         struct sk_buff *next_out;
 194         struct sk_buff_head wakeupq;
 195
 196         /* Fragmentation/reassembly */
 197         u32 long_msg_seq_no;
 198         struct sk_buff *reasm_buf;
 199
 200         /* Statistics */
 201         struct tipc_stats stats;
 202 };
 203
 204 struct tipc_port;
 205
 206 struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
 207                               struct tipc_bearer *b_ptr,
 208                               const struct tipc_media_addr *media_addr);
 209 void tipc_link_delete(struct tipc_link *link);
 210 void tipc_link_delete_list(struct net *net, unsigned int bearer_id,
 211                            bool shutting_down);
 212 void tipc_link_failover_send_queue(struct tipc_link *l_ptr);
 213 void tipc_link_dup_queue_xmit(struct tipc_link *l_ptr, struct tipc_link *dest);
 214 void tipc_link_reset_fragments(struct tipc_link *l_ptr);
 215 int tipc_link_is_up(struct tipc_link *l_ptr);
 216 int tipc_link_is_active(struct tipc_link *l_ptr);
 217 void tipc_link_purge_queues(struct tipc_link *l_ptr);
 218 void tipc_link_reset_all(struct tipc_node *node);
 219 void tipc_link_reset(struct tipc_link *l_ptr);
 220 void tipc_link_reset_list(struct net *net, unsigned int bearer_id);
 221 int tipc_link_xmit_skb(struct net *net, struct sk_buff *skb, u32 dest,
 222                        u32 selector);
 223 int tipc_link_xmit(struct net *net, struct sk_buff_head *list, u32 dest,
 224                    u32 selector);
 225 int __tipc_link_xmit(struct net *net, struct tipc_link *link,
 226                      struct sk_buff_head *list);
 227 void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int prob,
 228                           u32 gap, u32 tolerance, u32 priority, u32 acked_mtu);
 229 void tipc_link_push_packets(struct tipc_link *l_ptr);
 230 u32 tipc_link_defer_pkt(struct sk_buff_head *list, struct sk_buff *buf);
 231 void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window);
 232 void tipc_link_retransmit(struct tipc_link *l_ptr,
 233                           struct sk_buff *start, u32 retransmits);
 234 struct sk_buff *tipc_skb_queue_next(const struct sk_buff_head *list,
 235                                     const struct sk_buff *skb);
 236
 237 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb);
 238 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info);
 239 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info);
 240 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info);
 241 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[]);
 242 void link_prepare_wakeup(struct tipc_link *l);
 243
 244 /*
 245  * Link sequence number manipulation routines (uses modulo 2**16 arithmetic)
 246  */
 247 static inline u32 buf_seqno(struct sk_buff *buf)
 248 {
 249         return msg_seqno(buf_msg(buf));
 250 }
 251
 252 static inline u32 mod(u32 x)
 253 {
 254         return x & 0xffffu;
 255 }
 256
 257 static inline int less_eq(u32 left, u32 right)
 258 {
 259         return mod(right - left) < 32768u;
 260 }
 261
 262 static inline int more(u32 left, u32 right)
 263 {
 264         return !less_eq(left, right);
 265 }
 266
 267 static inline int less(u32 left, u32 right)
 268 {
 269         return less_eq(left, right) && (mod(right) != mod(left));
 270 }
 271
 272 static inline u32 lesser(u32 left, u32 right)
 273 {
 274         return less_eq(left, right) ? left : right;
 275 }
 276
 277 static inline u32 link_own_addr(struct tipc_link *l)
 278 {
 279         return msg_prevnode(l->pmsg);
 280 }
 281
 282 /*
 283  * Link status checking routines
 284  */
 285 static inline int link_working_working(struct tipc_link *l_ptr)
 286 {
 287         return l_ptr->state == WORKING_WORKING;
 288 }
 289
 290 static inline int link_working_unknown(struct tipc_link *l_ptr)
 291 {
 292         return l_ptr->state == WORKING_UNKNOWN;
 293 }
 294
 295 static inline int link_reset_unknown(struct tipc_link *l_ptr)
 296 {
 297         return l_ptr->state == RESET_UNKNOWN;
 298 }
 299
 300 static inline int link_reset_reset(struct tipc_link *l_ptr)
 301 {
 302         return l_ptr->state == RESET_RESET;
 303 }
 304
 305 static inline int link_congested(struct tipc_link *l_ptr)
 306 {
 307         return skb_queue_len(&l_ptr->outqueue) >= l_ptr->queue_limit[0];
 308 }
 309
 310 #endif