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 * Link states
49 */
50
51 #define WORKING_WORKING 560810u
52 #define WORKING_UNKNOWN 560811u
53 #define RESET_UNKNOWN 560812u
54 #define RESET_RESET 560813u
55
56 /*
57 * Starting value for maximum packet size negotiation on unicast links
58 * (unless bearer MTU is less)
59 */
60
61 #define MAX_PKT_DEFAULT 1500
62
63 /**
64 * struct link - TIPC link data structure
65 * @addr: network address of link's peer node
66 * @name: link name character string
67 * @media_addr: media address to use when sending messages over link
68 * @timer: link timer
69 * @owner: pointer to peer node
70 * @link_list: adjacent links in bearer's list of links
71 * @started: indicates if link has been started
72 * @checkpoint: reference point for triggering link continuity checking
73 * @peer_session: link session # being used by peer end of link
74 * @peer_bearer_id: bearer id used by link's peer endpoint
75 * @b_ptr: pointer to bearer used by link
76 * @tolerance: minimum link continuity loss needed to reset link [in ms]
77 * @continuity_interval: link continuity testing interval [in ms]
78 * @abort_limit: # of unacknowledged continuity probes needed to reset link
79 * @state: current state of link FSM
80 * @blocked: indicates if link has been administratively blocked
81 * @fsm_msg_cnt: # of protocol messages link FSM has sent in current state
82 * @proto_msg: template for control messages generated by link
83 * @pmsg: convenience pointer to "proto_msg" field
84 * @priority: current link priority
85 * @queue_limit: outbound message queue congestion thresholds (indexed by user)
86 * @exp_msg_count: # of tunnelled messages expected during link changeover
87 * @reset_checkpoint: seq # of last acknowledged message at time of link reset
88 * @max_pkt: current maximum packet size for this link
89 * @max_pkt_target: desired maximum packet size for this link
90 * @max_pkt_probes: # of probes based on current (max_pkt, max_pkt_target)
91 * @out_queue_size: # of messages in outbound message queue
92 * @first_out: ptr to first outbound message in queue
93 * @last_out: ptr to last outbound message in queue
94 * @next_out_no: next sequence number to use for outbound messages
95 * @last_retransmitted: sequence number of most recently retransmitted message
96 * @stale_count: # of identical retransmit requests made by peer
97 * @next_in_no: next sequence number to expect for inbound messages
98 * @deferred_inqueue_sz: # of messages in inbound message queue
99 * @oldest_deferred_in: ptr to first inbound message in queue
100 * @newest_deferred_in: ptr to last inbound message in queue
101 * @unacked_window: # of inbound messages rx'd without ack'ing back to peer
102 * @proto_msg_queue: ptr to (single) outbound control message
103 * @retransm_queue_size: number of messages to retransmit
104 * @retransm_queue_head: sequence number of first message to retransmit
105 * @next_out: ptr to first unsent outbound message in queue
106 * @waiting_ports: linked list of ports waiting for link congestion to abate
107 * @long_msg_seq_no: next identifier to use for outbound fragmented messages
108 * @defragm_buf: list of partially reassembled inbound message fragments
109 * @stats: collects statistics regarding link activity
110 */
111
112 struct link {
113 u32 addr;
114 char name[TIPC_MAX_LINK_NAME];
115 struct tipc_media_addr media_addr;
116 struct timer_list timer;
117 struct tipc_node *owner;
118 struct list_head link_list;
119
120 /* Management and link supervision data */
121 int started;
122 u32 checkpoint;
123 u32 peer_session;
124 u32 peer_bearer_id;
125 struct tipc_bearer *b_ptr;
126 u32 tolerance;
127 u32 continuity_interval;
128 u32 abort_limit;
129 int state;
130 int blocked;
131 u32 fsm_msg_cnt;
132 struct {
133 unchar hdr[INT_H_SIZE];
134 unchar body[TIPC_MAX_IF_NAME];
135 } proto_msg;
136 struct tipc_msg *pmsg;
137 u32 priority;
138 u32 queue_limit[15]; /* queue_limit[0]==window limit */
139
140 /* Changeover */
141 u32 exp_msg_count;
142 u32 reset_checkpoint;
143
144 /* Max packet negotiation */
145 u32 max_pkt;
146 u32 max_pkt_target;
147 u32 max_pkt_probes;
148
149 /* Sending */
150 u32 out_queue_size;
151 struct sk_buff *first_out;
152 struct sk_buff *last_out;
153 u32 next_out_no;
154 u32 last_retransmitted;
155 u32 stale_count;
156
157 /* Reception */
158 u32 next_in_no;
159 u32 deferred_inqueue_sz;
160 struct sk_buff *oldest_deferred_in;
161 struct sk_buff *newest_deferred_in;
162 u32 unacked_window;
163
164 /* Congestion handling */
165 struct sk_buff *proto_msg_queue;
166 u32 retransm_queue_size;
167 u32 retransm_queue_head;
168 struct sk_buff *next_out;
169 struct list_head waiting_ports;
170
171 /* Fragmentation/defragmentation */
172 u32 long_msg_seq_no;
173 struct sk_buff *defragm_buf;
174
175 /* Statistics */
176 struct {
177 u32 sent_info; /* used in counting # sent packets */
178 u32 recv_info; /* used in counting # recv'd packets */
179 u32 sent_states;
180 u32 recv_states;
181 u32 sent_probes;
182 u32 recv_probes;
183 u32 sent_nacks;
184 u32 recv_nacks;
185 u32 sent_acks;
186 u32 sent_bundled;
187 u32 sent_bundles;
188 u32 recv_bundled;
189 u32 recv_bundles;
190 u32 retransmitted;
191 u32 sent_fragmented;
192 u32 sent_fragments;
193 u32 recv_fragmented;
194 u32 recv_fragments;
195 u32 link_congs; /* # port sends blocked by congestion */
196 u32 bearer_congs;
197 u32 deferred_recv;
198 u32 duplicates;
199 u32 max_queue_sz; /* send queue size high water mark */
200 u32 accu_queue_sz; /* used for send queue size profiling */
201 u32 queue_sz_counts; /* used for send queue size profiling */
202 u32 msg_length_counts; /* used for message length profiling */
203 u32 msg_lengths_total; /* used for message length profiling */
204 u32 msg_length_profile[7]; /* used for msg. length profiling */
205 } stats;
206 };
207
208 struct tipc_port;
209
210 struct link *tipc_link_create(struct tipc_node *n_ptr,
211 struct tipc_bearer *b_ptr,
212 const struct tipc_media_addr *media_addr);
213 void tipc_link_delete(struct link *l_ptr);
214 void tipc_link_changeover(struct link *l_ptr);
215 void tipc_link_send_duplicate(struct link *l_ptr, struct link *dest);
216 void tipc_link_reset_fragments(struct link *l_ptr);
217 int tipc_link_is_up(struct link *l_ptr);
218 int tipc_link_is_active(struct link *l_ptr);
219 u32 tipc_link_push_packet(struct link *l_ptr);
220 void tipc_link_stop(struct link *l_ptr);
221 struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area, int req_tlv_space, u16 cmd);
222 struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area, int req_tlv_space);
223 struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area, int req_tlv_space);
224 void tipc_link_reset(struct link *l_ptr);
225 int tipc_link_send(struct sk_buff *buf, u32 dest, u32 selector);
226 int tipc_link_send_buf(struct link *l_ptr, struct sk_buff *buf);
227 u32 tipc_link_get_max_pkt(u32 dest, u32 selector);
228 int tipc_link_send_sections_fast(struct tipc_port *sender,
229 struct iovec const *msg_sect,
230 const u32 num_sect,
231 u32 destnode);
232 void tipc_link_recv_bundle(struct sk_buff *buf);
233 int tipc_link_recv_fragment(struct sk_buff **pending,
234 struct sk_buff **fb,
235 struct tipc_msg **msg);
236 void tipc_link_send_proto_msg(struct link *l_ptr, u32 msg_typ, int prob, u32 gap,
237 u32 tolerance, u32 priority, u32 acked_mtu);
238 void tipc_link_push_queue(struct link *l_ptr);
239 u32 tipc_link_defer_pkt(struct sk_buff **head, struct sk_buff **tail,
240 struct sk_buff *buf);
241 void tipc_link_wakeup_ports(struct link *l_ptr, int all);
242 void tipc_link_set_queue_limits(struct link *l_ptr, u32 window);
243 void tipc_link_retransmit(struct link *l_ptr, struct sk_buff *start, u32 retransmits);
244
245 /*
246 * Link sequence number manipulation routines (uses modulo 2**16 arithmetic)
247 */
248
mod(u32 x)249 static inline u32 mod(u32 x)
250 {
251 return x & 0xffffu;
252 }
253
between(u32 lower,u32 upper,u32 n)254 static inline int between(u32 lower, u32 upper, u32 n)
255 {
256 if ((lower < n) && (n < upper))
257 return 1;
258 if ((upper < lower) && ((n > lower) || (n < upper)))
259 return 1;
260 return 0;
261 }
262
less_eq(u32 left,u32 right)263 static inline int less_eq(u32 left, u32 right)
264 {
265 return mod(right - left) < 32768u;
266 }
267
less(u32 left,u32 right)268 static inline int less(u32 left, u32 right)
269 {
270 return less_eq(left, right) && (mod(right) != mod(left));
271 }
272
lesser(u32 left,u32 right)273 static inline u32 lesser(u32 left, u32 right)
274 {
275 return less_eq(left, right) ? left : right;
276 }
277
278
279 /*
280 * Link status checking routines
281 */
282
link_working_working(struct link * l_ptr)283 static inline int link_working_working(struct link *l_ptr)
284 {
285 return l_ptr->state == WORKING_WORKING;
286 }
287
link_working_unknown(struct link * l_ptr)288 static inline int link_working_unknown(struct link *l_ptr)
289 {
290 return l_ptr->state == WORKING_UNKNOWN;
291 }
292
link_reset_unknown(struct link * l_ptr)293 static inline int link_reset_unknown(struct link *l_ptr)
294 {
295 return l_ptr->state == RESET_UNKNOWN;
296 }
297
link_reset_reset(struct link * l_ptr)298 static inline int link_reset_reset(struct link *l_ptr)
299 {
300 return l_ptr->state == RESET_RESET;
301 }
302
link_blocked(struct link * l_ptr)303 static inline int link_blocked(struct link *l_ptr)
304 {
305 return l_ptr->exp_msg_count || l_ptr->blocked;
306 }
307
link_congested(struct link * l_ptr)308 static inline int link_congested(struct link *l_ptr)
309 {
310 return l_ptr->out_queue_size >= l_ptr->queue_limit[0];
311 }
312
313 #endif
314