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

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