xref: /openbmc/linux/net/tipc/link.h (revision 2223cbec)
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 "msg.h"
41 #include "node.h"
42 
43 #define PUSH_FAILED   1
44 #define PUSH_FINISHED 2
45 
46 /*
47  * Out-of-range value for link sequence numbers
48  */
49 #define INVALID_LINK_SEQ 0x10000
50 
51 /*
52  * Link states
53  */
54 #define WORKING_WORKING 560810u
55 #define WORKING_UNKNOWN 560811u
56 #define RESET_UNKNOWN   560812u
57 #define RESET_RESET     560813u
58 
59 /*
60  * Starting value for maximum packet size negotiation on unicast links
61  * (unless bearer MTU is less)
62  */
63 #define MAX_PKT_DEFAULT 1500
64 
65 struct tipc_stats {
66 	u32 sent_info;		/* used in counting # sent packets */
67 	u32 recv_info;		/* used in counting # recv'd packets */
68 	u32 sent_states;
69 	u32 recv_states;
70 	u32 sent_probes;
71 	u32 recv_probes;
72 	u32 sent_nacks;
73 	u32 recv_nacks;
74 	u32 sent_acks;
75 	u32 sent_bundled;
76 	u32 sent_bundles;
77 	u32 recv_bundled;
78 	u32 recv_bundles;
79 	u32 retransmitted;
80 	u32 sent_fragmented;
81 	u32 sent_fragments;
82 	u32 recv_fragmented;
83 	u32 recv_fragments;
84 	u32 link_congs;		/* # port sends blocked by congestion */
85 	u32 bearer_congs;
86 	u32 deferred_recv;
87 	u32 duplicates;
88 	u32 max_queue_sz;	/* send queue size high water mark */
89 	u32 accu_queue_sz;	/* used for send queue size profiling */
90 	u32 queue_sz_counts;	/* used for send queue size profiling */
91 	u32 msg_length_counts;	/* used for message length profiling */
92 	u32 msg_lengths_total;	/* used for message length profiling */
93 	u32 msg_length_profile[7]; /* used for msg. length profiling */
94 };
95 
96 /**
97  * struct tipc_link - TIPC link data structure
98  * @addr: network address of link's peer node
99  * @name: link name character string
100  * @media_addr: media address to use when sending messages over link
101  * @timer: link timer
102  * @owner: pointer to peer node
103  * @link_list: adjacent links in bearer's list of links
104  * @started: indicates if link has been started
105  * @checkpoint: reference point for triggering link continuity checking
106  * @peer_session: link session # being used by peer end of link
107  * @peer_bearer_id: bearer id used by link's peer endpoint
108  * @b_ptr: pointer to bearer used by link
109  * @tolerance: minimum link continuity loss needed to reset link [in ms]
110  * @continuity_interval: link continuity testing interval [in ms]
111  * @abort_limit: # of unacknowledged continuity probes needed to reset link
112  * @state: current state of link FSM
113  * @blocked: indicates if link has been administratively blocked
114  * @fsm_msg_cnt: # of protocol messages link FSM has sent in current state
115  * @proto_msg: template for control messages generated by link
116  * @pmsg: convenience pointer to "proto_msg" field
117  * @priority: current link priority
118  * @queue_limit: outbound message queue congestion thresholds (indexed by user)
119  * @exp_msg_count: # of tunnelled messages expected during link changeover
120  * @reset_checkpoint: seq # of last acknowledged message at time of link reset
121  * @max_pkt: current maximum packet size for this link
122  * @max_pkt_target: desired maximum packet size for this link
123  * @max_pkt_probes: # of probes based on current (max_pkt, max_pkt_target)
124  * @out_queue_size: # of messages in outbound message queue
125  * @first_out: ptr to first outbound message in queue
126  * @last_out: ptr to last outbound message in queue
127  * @next_out_no: next sequence number to use for outbound messages
128  * @last_retransmitted: sequence number of most recently retransmitted message
129  * @stale_count: # of identical retransmit requests made by peer
130  * @next_in_no: next sequence number to expect for inbound messages
131  * @deferred_inqueue_sz: # of messages in inbound message queue
132  * @oldest_deferred_in: ptr to first inbound message in queue
133  * @newest_deferred_in: ptr to last inbound message in queue
134  * @unacked_window: # of inbound messages rx'd without ack'ing back to peer
135  * @proto_msg_queue: ptr to (single) outbound control message
136  * @retransm_queue_size: number of messages to retransmit
137  * @retransm_queue_head: sequence number of first message to retransmit
138  * @next_out: ptr to first unsent outbound message in queue
139  * @waiting_ports: linked list of ports waiting for link congestion to abate
140  * @long_msg_seq_no: next identifier to use for outbound fragmented messages
141  * @defragm_buf: list of partially reassembled inbound message fragments
142  * @stats: collects statistics regarding link activity
143  */
144 struct tipc_link {
145 	u32 addr;
146 	char name[TIPC_MAX_LINK_NAME];
147 	struct tipc_media_addr media_addr;
148 	struct timer_list timer;
149 	struct tipc_node *owner;
150 	struct list_head link_list;
151 
152 	/* Management and link supervision data */
153 	int started;
154 	u32 checkpoint;
155 	u32 peer_session;
156 	u32 peer_bearer_id;
157 	struct tipc_bearer *b_ptr;
158 	u32 tolerance;
159 	u32 continuity_interval;
160 	u32 abort_limit;
161 	int state;
162 	int blocked;
163 	u32 fsm_msg_cnt;
164 	struct {
165 		unchar hdr[INT_H_SIZE];
166 		unchar body[TIPC_MAX_IF_NAME];
167 	} proto_msg;
168 	struct tipc_msg *pmsg;
169 	u32 priority;
170 	u32 queue_limit[15];	/* queue_limit[0]==window limit */
171 
172 	/* Changeover */
173 	u32 exp_msg_count;
174 	u32 reset_checkpoint;
175 
176 	/* Max packet negotiation */
177 	u32 max_pkt;
178 	u32 max_pkt_target;
179 	u32 max_pkt_probes;
180 
181 	/* Sending */
182 	u32 out_queue_size;
183 	struct sk_buff *first_out;
184 	struct sk_buff *last_out;
185 	u32 next_out_no;
186 	u32 last_retransmitted;
187 	u32 stale_count;
188 
189 	/* Reception */
190 	u32 next_in_no;
191 	u32 deferred_inqueue_sz;
192 	struct sk_buff *oldest_deferred_in;
193 	struct sk_buff *newest_deferred_in;
194 	u32 unacked_window;
195 
196 	/* Congestion handling */
197 	struct sk_buff *proto_msg_queue;
198 	u32 retransm_queue_size;
199 	u32 retransm_queue_head;
200 	struct sk_buff *next_out;
201 	struct list_head waiting_ports;
202 
203 	/* Fragmentation/defragmentation */
204 	u32 long_msg_seq_no;
205 	struct sk_buff *defragm_buf;
206 
207 	/* Statistics */
208 	struct tipc_stats stats;
209 };
210 
211 struct tipc_port;
212 
213 struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
214 			      struct tipc_bearer *b_ptr,
215 			      const struct tipc_media_addr *media_addr);
216 void tipc_link_delete(struct tipc_link *l_ptr);
217 void tipc_link_changeover(struct tipc_link *l_ptr);
218 void tipc_link_send_duplicate(struct tipc_link *l_ptr, struct tipc_link *dest);
219 void tipc_link_reset_fragments(struct tipc_link *l_ptr);
220 int tipc_link_is_up(struct tipc_link *l_ptr);
221 int tipc_link_is_active(struct tipc_link *l_ptr);
222 u32 tipc_link_push_packet(struct tipc_link *l_ptr);
223 void tipc_link_stop(struct tipc_link *l_ptr);
224 struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area, int req_tlv_space, u16 cmd);
225 struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area, int req_tlv_space);
226 struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area, int req_tlv_space);
227 void tipc_link_reset(struct tipc_link *l_ptr);
228 int tipc_link_send(struct sk_buff *buf, u32 dest, u32 selector);
229 void tipc_link_send_names(struct list_head *message_list, u32 dest);
230 int tipc_link_send_buf(struct tipc_link *l_ptr, struct sk_buff *buf);
231 u32 tipc_link_get_max_pkt(u32 dest, u32 selector);
232 int tipc_link_send_sections_fast(struct tipc_port *sender,
233 				 struct iovec const *msg_sect,
234 				 const u32 num_sect,
235 				 unsigned int total_len,
236 				 u32 destnode);
237 void tipc_link_recv_bundle(struct sk_buff *buf);
238 int  tipc_link_recv_fragment(struct sk_buff **pending,
239 			     struct sk_buff **fb,
240 			     struct tipc_msg **msg);
241 void tipc_link_send_proto_msg(struct tipc_link *l_ptr, u32 msg_typ, int prob,
242 			      u32 gap, u32 tolerance, u32 priority,
243 			      u32 acked_mtu);
244 void tipc_link_push_queue(struct tipc_link *l_ptr);
245 u32 tipc_link_defer_pkt(struct sk_buff **head, struct sk_buff **tail,
246 		   struct sk_buff *buf);
247 void tipc_link_wakeup_ports(struct tipc_link *l_ptr, int all);
248 void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window);
249 void tipc_link_retransmit(struct tipc_link *l_ptr,
250 			  struct sk_buff *start, u32 retransmits);
251 
252 /*
253  * Link sequence number manipulation routines (uses modulo 2**16 arithmetic)
254  */
255 static inline u32 buf_seqno(struct sk_buff *buf)
256 {
257 	return msg_seqno(buf_msg(buf));
258 }
259 
260 static inline u32 mod(u32 x)
261 {
262 	return x & 0xffffu;
263 }
264 
265 static inline int between(u32 lower, u32 upper, u32 n)
266 {
267 	if ((lower < n) && (n < upper))
268 		return 1;
269 	if ((upper < lower) && ((n > lower) || (n < upper)))
270 		return 1;
271 	return 0;
272 }
273 
274 static inline int less_eq(u32 left, u32 right)
275 {
276 	return mod(right - left) < 32768u;
277 }
278 
279 static inline int less(u32 left, u32 right)
280 {
281 	return less_eq(left, right) && (mod(right) != mod(left));
282 }
283 
284 static inline u32 lesser(u32 left, u32 right)
285 {
286 	return less_eq(left, right) ? left : right;
287 }
288 
289 
290 /*
291  * Link status checking routines
292  */
293 static inline int link_working_working(struct tipc_link *l_ptr)
294 {
295 	return l_ptr->state == WORKING_WORKING;
296 }
297 
298 static inline int link_working_unknown(struct tipc_link *l_ptr)
299 {
300 	return l_ptr->state == WORKING_UNKNOWN;
301 }
302 
303 static inline int link_reset_unknown(struct tipc_link *l_ptr)
304 {
305 	return l_ptr->state == RESET_UNKNOWN;
306 }
307 
308 static inline int link_reset_reset(struct tipc_link *l_ptr)
309 {
310 	return l_ptr->state == RESET_RESET;
311 }
312 
313 static inline int link_blocked(struct tipc_link *l_ptr)
314 {
315 	return l_ptr->exp_msg_count || l_ptr->blocked;
316 }
317 
318 static inline int link_congested(struct tipc_link *l_ptr)
319 {
320 	return l_ptr->out_queue_size >= l_ptr->queue_limit[0];
321 }
322 
323 #endif
324