xref: /openbmc/linux/net/tipc/link.h (revision 367b8112)
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 
114 struct 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 
222 struct port;
223 
224 struct link *tipc_link_create(struct bearer *b_ptr, const u32 peer,
225 			      const struct tipc_media_addr *media_addr);
226 void tipc_link_delete(struct link *l_ptr);
227 void tipc_link_changeover(struct link *l_ptr);
228 void tipc_link_send_duplicate(struct link *l_ptr, struct link *dest);
229 void tipc_link_reset_fragments(struct link *l_ptr);
230 int tipc_link_is_up(struct link *l_ptr);
231 int tipc_link_is_active(struct link *l_ptr);
232 void tipc_link_start(struct link *l_ptr);
233 u32 tipc_link_push_packet(struct link *l_ptr);
234 void tipc_link_stop(struct link *l_ptr);
235 struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area, int req_tlv_space, u16 cmd);
236 struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area, int req_tlv_space);
237 struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area, int req_tlv_space);
238 void tipc_link_reset(struct link *l_ptr);
239 int tipc_link_send(struct sk_buff *buf, u32 dest, u32 selector);
240 int tipc_link_send_buf(struct link *l_ptr, struct sk_buff *buf);
241 u32 tipc_link_get_max_pkt(u32 dest,u32 selector);
242 int tipc_link_send_sections_fast(struct port* sender,
243 				 struct iovec const *msg_sect,
244 				 const u32 num_sect,
245 				 u32 destnode);
246 int tipc_link_send_long_buf(struct link *l_ptr, struct sk_buff *buf);
247 void tipc_link_tunnel(struct link *l_ptr, struct tipc_msg *tnl_hdr,
248 		      struct tipc_msg *msg, u32 selector);
249 void tipc_link_recv_bundle(struct sk_buff *buf);
250 int  tipc_link_recv_fragment(struct sk_buff **pending,
251 			     struct sk_buff **fb,
252 			     struct tipc_msg **msg);
253 void tipc_link_send_proto_msg(struct link *l_ptr, u32 msg_typ, int prob, u32 gap,
254 			      u32 tolerance, u32 priority, u32 acked_mtu);
255 void tipc_link_push_queue(struct link *l_ptr);
256 u32 tipc_link_defer_pkt(struct sk_buff **head, struct sk_buff **tail,
257 		   struct sk_buff *buf);
258 void tipc_link_wakeup_ports(struct link *l_ptr, int all);
259 void tipc_link_set_queue_limits(struct link *l_ptr, u32 window);
260 void 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 
266 static inline u32 mod(u32 x)
267 {
268 	return x & 0xffffu;
269 }
270 
271 static 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 
280 static inline int less_eq(u32 left, u32 right)
281 {
282 	return (mod(right - left) < 32768u);
283 }
284 
285 static inline int less(u32 left, u32 right)
286 {
287 	return (less_eq(left, right) && (mod(right) != mod(left)));
288 }
289 
290 static inline u32 lesser(u32 left, u32 right)
291 {
292 	return less_eq(left, right) ? left : right;
293 }
294 
295 #endif
296