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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
118struct 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
214struct tipc_port;
215
216struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
217 struct tipc_bearer *b_ptr,
218 const struct tipc_media_addr *media_addr);
219void tipc_link_delete(struct tipc_link *l_ptr);
220void tipc_link_changeover(struct tipc_link *l_ptr);
221void tipc_link_send_duplicate(struct tipc_link *l_ptr, struct tipc_link *dest);
222void tipc_link_reset_fragments(struct tipc_link *l_ptr);
223int tipc_link_is_up(struct tipc_link *l_ptr);
224int tipc_link_is_active(struct tipc_link *l_ptr);
225u32 tipc_link_push_packet(struct tipc_link *l_ptr);
226void tipc_link_stop(struct tipc_link *l_ptr);
227struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area, int req_tlv_space, u16 cmd);
228struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area, int req_tlv_space);
229struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area, int req_tlv_space);
230void tipc_link_reset(struct tipc_link *l_ptr);
231int tipc_link_send(struct sk_buff *buf, u32 dest, u32 selector);
232void tipc_link_send_names(struct list_head *message_list, u32 dest);
233int tipc_link_send_buf(struct tipc_link *l_ptr, struct sk_buff *buf);
234u32 tipc_link_get_max_pkt(u32 dest, u32 selector);
235int 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);
240void tipc_link_recv_bundle(struct sk_buff *buf);
241int tipc_link_recv_fragment(struct sk_buff **pending,
242 struct sk_buff **fb,
243 struct tipc_msg **msg);
244void 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);
247void tipc_link_push_queue(struct tipc_link *l_ptr);
248u32 tipc_link_defer_pkt(struct sk_buff **head, struct sk_buff **tail,
249 struct sk_buff *buf);
250void tipc_link_wakeup_ports(struct tipc_link *l_ptr, int all);
251void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window);
252void 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
259static inline u32 buf_seqno(struct sk_buff *buf)
260{
261 return msg_seqno(buf_msg(buf));
262}
263
264static inline u32 mod(u32 x)
265{
266 return x & 0xffffu;
267}
268
269static 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
278static inline int less_eq(u32 left, u32 right)
279{
280 return mod(right - left) < 32768u;
281}
282
283static inline int less(u32 left, u32 right)
284{
285 return less_eq(left, right) && (mod(right) != mod(left));
286}
287
288static 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
298static inline int link_working_working(struct tipc_link *l_ptr)
299{
300 return l_ptr->state == WORKING_WORKING;
301}
302
303static inline int link_working_unknown(struct tipc_link *l_ptr)
304{
305 return l_ptr->state == WORKING_UNKNOWN;
306}
307
308static inline int link_reset_unknown(struct tipc_link *l_ptr)
309{
310 return l_ptr->state == RESET_UNKNOWN;
311}
312
313static inline int link_reset_reset(struct tipc_link *l_ptr)
314{
315 return l_ptr->state == RESET_RESET;
316}
317
318static inline int link_blocked(struct tipc_link *l_ptr)
319{
320 return l_ptr->exp_msg_count || l_ptr->blocked;
321}
322
323static 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