xref: /openbmc/linux/net/tipc/link.h (revision 827634ad)
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 /* TIPC-specific error codes
45 */
46 #define ELINKCONG EAGAIN	/* link congestion <=> resource unavailable */
47 
48 /* Out-of-range value for link sequence numbers
49  */
50 #define INVALID_LINK_SEQ 0x10000
51 
52 /* Link working states
53  */
54 #define WORKING_WORKING 560810u
55 #define WORKING_UNKNOWN 560811u
56 #define RESET_UNKNOWN   560812u
57 #define RESET_RESET     560813u
58 
59 /* Link endpoint execution states
60  */
61 #define LINK_STARTED     0x0001
62 #define LINK_STOPPED     0x0002
63 #define LINK_SYNCHING    0x0004
64 #define LINK_FAILINGOVER 0x0008
65 
66 /* Starting value for maximum packet size negotiation on unicast links
67  * (unless bearer MTU is less)
68  */
69 #define MAX_PKT_DEFAULT 1500
70 
71 struct tipc_stats {
72 	u32 sent_info;		/* used in counting # sent packets */
73 	u32 recv_info;		/* used in counting # recv'd packets */
74 	u32 sent_states;
75 	u32 recv_states;
76 	u32 sent_probes;
77 	u32 recv_probes;
78 	u32 sent_nacks;
79 	u32 recv_nacks;
80 	u32 sent_acks;
81 	u32 sent_bundled;
82 	u32 sent_bundles;
83 	u32 recv_bundled;
84 	u32 recv_bundles;
85 	u32 retransmitted;
86 	u32 sent_fragmented;
87 	u32 sent_fragments;
88 	u32 recv_fragmented;
89 	u32 recv_fragments;
90 	u32 link_congs;		/* # port sends blocked by congestion */
91 	u32 deferred_recv;
92 	u32 duplicates;
93 	u32 max_queue_sz;	/* send queue size high water mark */
94 	u32 accu_queue_sz;	/* used for send queue size profiling */
95 	u32 queue_sz_counts;	/* used for send queue size profiling */
96 	u32 msg_length_counts;	/* used for message length profiling */
97 	u32 msg_lengths_total;	/* used for message length profiling */
98 	u32 msg_length_profile[7]; /* used for msg. length profiling */
99 };
100 
101 /**
102  * struct tipc_link - TIPC link data structure
103  * @addr: network address of link's peer node
104  * @name: link name character string
105  * @media_addr: media address to use when sending messages over link
106  * @timer: link timer
107  * @owner: pointer to peer node
108  * @refcnt: reference counter for permanent references (owner node & timer)
109  * @flags: execution state flags for link endpoint instance
110  * @checkpoint: reference point for triggering link continuity checking
111  * @peer_session: link session # being used by peer end of link
112  * @peer_bearer_id: bearer id used by link's peer endpoint
113  * @bearer_id: local bearer id used by link
114  * @tolerance: minimum link continuity loss needed to reset link [in ms]
115  * @cont_intv: link continuity testing interval
116  * @abort_limit: # of unacknowledged continuity probes needed to reset link
117  * @state: current state of link FSM
118  * @fsm_msg_cnt: # of protocol messages link FSM has sent in current state
119  * @proto_msg: template for control messages generated by link
120  * @pmsg: convenience pointer to "proto_msg" field
121  * @priority: current link priority
122  * @net_plane: current link network plane ('A' through 'H')
123  * @backlog_limit: backlog queue congestion thresholds (indexed by importance)
124  * @exp_msg_count: # of tunnelled messages expected during link changeover
125  * @reset_checkpoint: seq # of last acknowledged message at time of link reset
126  * @mtu: current maximum packet size for this link
127  * @advertised_mtu: advertised own mtu when link is being established
128  * @transmitq: queue for sent, non-acked messages
129  * @backlogq: queue for messages waiting to be sent
130  * @next_out_no: next sequence number to use for outbound messages
131  * @last_retransmitted: sequence number of most recently retransmitted message
132  * @stale_count: # of identical retransmit requests made by peer
133  * @next_in_no: next sequence number to expect for inbound messages
134  * @deferred_queue: deferred queue saved OOS b'cast message received from node
135  * @unacked_window: # of inbound messages rx'd without ack'ing back to peer
136  * @inputq: buffer queue for messages to be delivered upwards
137  * @namedq: buffer queue for name table messages to be delivered upwards
138  * @next_out: ptr to first unsent outbound message in queue
139  * @wakeupq: linked list of wakeup msgs waiting for link congestion to abate
140  * @long_msg_seq_no: next identifier to use for outbound fragmented messages
141  * @reasm_buf: head 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 kref ref;
151 
152 	/* Management and link supervision data */
153 	unsigned int flags;
154 	u32 checkpoint;
155 	u32 peer_session;
156 	u32 peer_bearer_id;
157 	u32 bearer_id;
158 	u32 tolerance;
159 	unsigned long cont_intv;
160 	u32 abort_limit;
161 	int state;
162 	u32 fsm_msg_cnt;
163 	struct {
164 		unchar hdr[INT_H_SIZE];
165 		unchar body[TIPC_MAX_IF_NAME];
166 	} proto_msg;
167 	struct tipc_msg *pmsg;
168 	u32 priority;
169 	char net_plane;
170 	u16 synch_point;
171 
172 	/* Failover */
173 	u16 failover_pkts;
174 	u16 failover_checkpt;
175 	struct sk_buff *failover_skb;
176 
177 	/* Max packet negotiation */
178 	u16 mtu;
179 	u16 advertised_mtu;
180 
181 	/* Sending */
182 	struct sk_buff_head transmq;
183 	struct sk_buff_head backlogq;
184 	struct {
185 		u16 len;
186 		u16 limit;
187 	} backlog[5];
188 	u32 next_out_no;
189 	u32 window;
190 	u32 last_retransmitted;
191 	u32 stale_count;
192 
193 	/* Reception */
194 	u32 next_in_no;
195 	u32 rcv_unacked;
196 	struct sk_buff_head deferdq;
197 	struct sk_buff_head inputq;
198 	struct sk_buff_head namedq;
199 
200 	/* Congestion handling */
201 	struct sk_buff_head wakeupq;
202 
203 	/* Fragmentation/reassembly */
204 	struct sk_buff *reasm_buf;
205 
206 	/* Statistics */
207 	struct tipc_stats stats;
208 };
209 
210 struct tipc_port;
211 
212 struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
213 			      struct tipc_bearer *b_ptr,
214 			      const struct tipc_media_addr *media_addr);
215 void tipc_link_delete(struct tipc_link *link);
216 void tipc_link_delete_list(struct net *net, unsigned int bearer_id,
217 			   bool shutting_down);
218 void tipc_link_failover_send_queue(struct tipc_link *l_ptr);
219 void tipc_link_dup_queue_xmit(struct tipc_link *l_ptr, struct tipc_link *dest);
220 void tipc_link_reset_fragments(struct tipc_link *l_ptr);
221 int tipc_link_is_up(struct tipc_link *l_ptr);
222 int tipc_link_is_active(struct tipc_link *l_ptr);
223 void tipc_link_purge_queues(struct tipc_link *l_ptr);
224 void tipc_link_reset_all(struct tipc_node *node);
225 void tipc_link_reset(struct tipc_link *l_ptr);
226 void tipc_link_reset_list(struct net *net, unsigned int bearer_id);
227 int tipc_link_xmit_skb(struct net *net, struct sk_buff *skb, u32 dest,
228 		       u32 selector);
229 int tipc_link_xmit(struct net *net, struct sk_buff_head *list, u32 dest,
230 		   u32 selector);
231 int __tipc_link_xmit(struct net *net, struct tipc_link *link,
232 		     struct sk_buff_head *list);
233 void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int prob,
234 			  u32 gap, u32 tolerance, u32 priority);
235 void tipc_link_push_packets(struct tipc_link *l_ptr);
236 u32 tipc_link_defer_pkt(struct sk_buff_head *list, struct sk_buff *buf);
237 void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window);
238 void tipc_link_retransmit(struct tipc_link *l_ptr,
239 			  struct sk_buff *start, u32 retransmits);
240 struct sk_buff *tipc_skb_queue_next(const struct sk_buff_head *list,
241 				    const struct sk_buff *skb);
242 
243 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb);
244 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info);
245 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info);
246 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info);
247 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[]);
248 void link_prepare_wakeup(struct tipc_link *l);
249 
250 /*
251  * Link sequence number manipulation routines (uses modulo 2**16 arithmetic)
252  */
253 static inline u32 buf_seqno(struct sk_buff *buf)
254 {
255 	return msg_seqno(buf_msg(buf));
256 }
257 
258 static inline u32 mod(u32 x)
259 {
260 	return x & 0xffffu;
261 }
262 
263 static inline int less_eq(u32 left, u32 right)
264 {
265 	return mod(right - left) < 32768u;
266 }
267 
268 static inline int more(u32 left, u32 right)
269 {
270 	return !less_eq(left, right);
271 }
272 
273 static inline int less(u32 left, u32 right)
274 {
275 	return less_eq(left, right) && (mod(right) != mod(left));
276 }
277 
278 static inline u32 lesser(u32 left, u32 right)
279 {
280 	return less_eq(left, right) ? left : right;
281 }
282 
283 static inline u32 link_own_addr(struct tipc_link *l)
284 {
285 	return msg_prevnode(l->pmsg);
286 }
287 
288 /*
289  * Link status checking routines
290  */
291 static inline int link_working_working(struct tipc_link *l_ptr)
292 {
293 	return l_ptr->state == WORKING_WORKING;
294 }
295 
296 static inline int link_working_unknown(struct tipc_link *l_ptr)
297 {
298 	return l_ptr->state == WORKING_UNKNOWN;
299 }
300 
301 static inline int link_reset_unknown(struct tipc_link *l_ptr)
302 {
303 	return l_ptr->state == RESET_UNKNOWN;
304 }
305 
306 static inline int link_reset_reset(struct tipc_link *l_ptr)
307 {
308 	return l_ptr->state == RESET_RESET;
309 }
310 
311 #endif
312