xref: /linux/net/tipc/link.h (revision add4b1b02da7e7ec35c34dd04d351ac53f3f0dd8)
1 /*
2  * net/tipc/link.h: Include file for TIPC link code
3  *
4  * Copyright (c) 1995-2006, 2013-2014, 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 <net/genetlink.h>
41 #include "msg.h"
42 #include "node.h"
43 
44 /* Out-of-range value for link sequence numbers
45  */
46 #define INVALID_LINK_SEQ 0x10000
47 
48 /* Link working states
49  */
50 #define WORKING_WORKING 560810u
51 #define WORKING_UNKNOWN 560811u
52 #define RESET_UNKNOWN   560812u
53 #define RESET_RESET     560813u
54 
55 /* Link endpoint execution states
56  */
57 #define LINK_STARTED    0x0001
58 #define LINK_STOPPED    0x0002
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 deferred_recv;
86 	u32 duplicates;
87 	u32 max_queue_sz;	/* send queue size high water mark */
88 	u32 accu_queue_sz;	/* used for send queue size profiling */
89 	u32 queue_sz_counts;	/* used for send queue size profiling */
90 	u32 msg_length_counts;	/* used for message length profiling */
91 	u32 msg_lengths_total;	/* used for message length profiling */
92 	u32 msg_length_profile[7]; /* used for msg. length profiling */
93 };
94 
95 /**
96  * struct tipc_link - TIPC link data structure
97  * @addr: network address of link's peer node
98  * @name: link name character string
99  * @media_addr: media address to use when sending messages over link
100  * @timer: link timer
101  * @owner: pointer to peer node
102  * @flags: execution state flags for link endpoint instance
103  * @checkpoint: reference point for triggering link continuity checking
104  * @peer_session: link session # being used by peer end of link
105  * @peer_bearer_id: bearer id used by link's peer endpoint
106  * @bearer_id: local bearer id used by link
107  * @tolerance: minimum link continuity loss needed to reset link [in ms]
108  * @continuity_interval: link continuity testing interval [in ms]
109  * @abort_limit: # of unacknowledged continuity probes needed to reset link
110  * @state: current state of link FSM
111  * @fsm_msg_cnt: # of protocol messages link FSM has sent in current state
112  * @proto_msg: template for control messages generated by link
113  * @pmsg: convenience pointer to "proto_msg" field
114  * @priority: current link priority
115  * @net_plane: current link network plane ('A' through 'H')
116  * @queue_limit: outbound message queue congestion thresholds (indexed by user)
117  * @exp_msg_count: # of tunnelled messages expected during link changeover
118  * @reset_checkpoint: seq # of last acknowledged message at time of link reset
119  * @max_pkt: current maximum packet size for this link
120  * @max_pkt_target: desired maximum packet size for this link
121  * @max_pkt_probes: # of probes based on current (max_pkt, max_pkt_target)
122  * @outqueue: outbound message queue
123  * @next_out_no: next sequence number to use for outbound messages
124  * @last_retransmitted: sequence number of most recently retransmitted message
125  * @stale_count: # of identical retransmit requests made by peer
126  * @next_in_no: next sequence number to expect for inbound messages
127  * @deferred_queue: deferred queue saved OOS b'cast message received from node
128  * @unacked_window: # of inbound messages rx'd without ack'ing back to peer
129  * @next_out: ptr to first unsent outbound message in queue
130  * @waiting_sks: linked list of sockets waiting for link congestion to abate
131  * @long_msg_seq_no: next identifier to use for outbound fragmented messages
132  * @reasm_buf: head of partially reassembled inbound message fragments
133  * @stats: collects statistics regarding link activity
134  */
135 struct tipc_link {
136 	u32 addr;
137 	char name[TIPC_MAX_LINK_NAME];
138 	struct tipc_media_addr media_addr;
139 	struct timer_list timer;
140 	struct tipc_node *owner;
141 
142 	/* Management and link supervision data */
143 	unsigned int flags;
144 	u32 checkpoint;
145 	u32 peer_session;
146 	u32 peer_bearer_id;
147 	u32 bearer_id;
148 	u32 tolerance;
149 	u32 continuity_interval;
150 	u32 abort_limit;
151 	int state;
152 	u32 fsm_msg_cnt;
153 	struct {
154 		unchar hdr[INT_H_SIZE];
155 		unchar body[TIPC_MAX_IF_NAME];
156 	} proto_msg;
157 	struct tipc_msg *pmsg;
158 	u32 priority;
159 	char net_plane;
160 	u32 queue_limit[15];	/* queue_limit[0]==window limit */
161 
162 	/* Changeover */
163 	u32 exp_msg_count;
164 	u32 reset_checkpoint;
165 
166 	/* Max packet negotiation */
167 	u32 max_pkt;
168 	u32 max_pkt_target;
169 	u32 max_pkt_probes;
170 
171 	/* Sending */
172 	struct sk_buff_head outqueue;
173 	u32 next_out_no;
174 	u32 last_retransmitted;
175 	u32 stale_count;
176 
177 	/* Reception */
178 	u32 next_in_no;
179 	struct sk_buff_head deferred_queue;
180 	u32 unacked_window;
181 
182 	/* Congestion handling */
183 	struct sk_buff *next_out;
184 	struct sk_buff_head waiting_sks;
185 
186 	/* Fragmentation/reassembly */
187 	u32 long_msg_seq_no;
188 	struct sk_buff *reasm_buf;
189 
190 	/* Statistics */
191 	struct tipc_stats stats;
192 };
193 
194 struct tipc_port;
195 
196 struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
197 			      struct tipc_bearer *b_ptr,
198 			      const struct tipc_media_addr *media_addr);
199 void tipc_link_delete_list(unsigned int bearer_id, bool shutting_down);
200 void tipc_link_failover_send_queue(struct tipc_link *l_ptr);
201 void tipc_link_dup_queue_xmit(struct tipc_link *l_ptr, struct tipc_link *dest);
202 void tipc_link_reset_fragments(struct tipc_link *l_ptr);
203 int tipc_link_is_up(struct tipc_link *l_ptr);
204 int tipc_link_is_active(struct tipc_link *l_ptr);
205 void tipc_link_purge_queues(struct tipc_link *l_ptr);
206 struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area,
207 				     int req_tlv_space,
208 				     u16 cmd);
209 struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area,
210 					 int req_tlv_space);
211 struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area,
212 					  int req_tlv_space);
213 void tipc_link_reset_all(struct tipc_node *node);
214 void tipc_link_reset(struct tipc_link *l_ptr);
215 void tipc_link_reset_list(unsigned int bearer_id);
216 int tipc_link_xmit_skb(struct sk_buff *skb, u32 dest, u32 selector);
217 int tipc_link_xmit(struct sk_buff_head *list, u32 dest, u32 selector);
218 int __tipc_link_xmit(struct tipc_link *link, struct sk_buff_head *list);
219 u32 tipc_link_get_max_pkt(u32 dest, u32 selector);
220 void tipc_link_bundle_rcv(struct sk_buff *buf);
221 void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int prob,
222 			  u32 gap, u32 tolerance, u32 priority, u32 acked_mtu);
223 void tipc_link_push_packets(struct tipc_link *l_ptr);
224 u32 tipc_link_defer_pkt(struct sk_buff_head *list, struct sk_buff *buf);
225 void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window);
226 void tipc_link_retransmit(struct tipc_link *l_ptr,
227 			  struct sk_buff *start, u32 retransmits);
228 struct sk_buff *tipc_skb_queue_next(const struct sk_buff_head *list,
229 				    const struct sk_buff *skb);
230 
231 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb);
232 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info);
233 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info);
234 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info);
235 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[]);
236 
237 /*
238  * Link sequence number manipulation routines (uses modulo 2**16 arithmetic)
239  */
240 static inline u32 buf_seqno(struct sk_buff *buf)
241 {
242 	return msg_seqno(buf_msg(buf));
243 }
244 
245 static inline u32 mod(u32 x)
246 {
247 	return x & 0xffffu;
248 }
249 
250 static inline int less_eq(u32 left, u32 right)
251 {
252 	return mod(right - left) < 32768u;
253 }
254 
255 static inline int more(u32 left, u32 right)
256 {
257 	return !less_eq(left, right);
258 }
259 
260 static inline int less(u32 left, u32 right)
261 {
262 	return less_eq(left, right) && (mod(right) != mod(left));
263 }
264 
265 static inline u32 lesser(u32 left, u32 right)
266 {
267 	return less_eq(left, right) ? left : right;
268 }
269 
270 
271 /*
272  * Link status checking routines
273  */
274 static inline int link_working_working(struct tipc_link *l_ptr)
275 {
276 	return l_ptr->state == WORKING_WORKING;
277 }
278 
279 static inline int link_working_unknown(struct tipc_link *l_ptr)
280 {
281 	return l_ptr->state == WORKING_UNKNOWN;
282 }
283 
284 static inline int link_reset_unknown(struct tipc_link *l_ptr)
285 {
286 	return l_ptr->state == RESET_UNKNOWN;
287 }
288 
289 static inline int link_reset_reset(struct tipc_link *l_ptr)
290 {
291 	return l_ptr->state == RESET_RESET;
292 }
293 
294 static inline int link_congested(struct tipc_link *l_ptr)
295 {
296 	return skb_queue_len(&l_ptr->outqueue) >= l_ptr->queue_limit[0];
297 }
298 
299 #endif
300