xref: /linux/net/tipc/link.h (revision c0e297dc61f8d4453e07afbea1fa8d0e67cd4a34)
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  * @peer_session: link session # being used by peer end of link
111  * @peer_bearer_id: bearer id used by link's peer endpoint
112  * @bearer_id: local bearer id used by link
113  * @tolerance: minimum link continuity loss needed to reset link [in ms]
114  * @keepalive_intv: link keepalive timer interval
115  * @abort_limit: # of unacknowledged continuity probes needed to reset link
116  * @state: current state of link FSM
117  * @silent_intv_cnt: # of timer intervals without any reception from peer
118  * @proto_msg: template for control messages generated by link
119  * @pmsg: convenience pointer to "proto_msg" field
120  * @priority: current link priority
121  * @net_plane: current link network plane ('A' through 'H')
122  * @backlog_limit: backlog queue congestion thresholds (indexed by importance)
123  * @exp_msg_count: # of tunnelled messages expected during link changeover
124  * @reset_rcv_checkpt: seq # of last acknowledged message at time of link reset
125  * @mtu: current maximum packet size for this link
126  * @advertised_mtu: advertised own mtu when link is being established
127  * @transmitq: queue for sent, non-acked messages
128  * @backlogq: queue for messages waiting to be sent
129  * @snt_nxt: next sequence number to use for outbound messages
130  * @last_retransmitted: sequence number of most recently retransmitted message
131  * @stale_count: # of identical retransmit requests made by peer
132  * @rcv_nxt: next sequence number to expect for inbound messages
133  * @deferred_queue: deferred queue saved OOS b'cast message received from node
134  * @unacked_window: # of inbound messages rx'd without ack'ing back to peer
135  * @inputq: buffer queue for messages to be delivered upwards
136  * @namedq: buffer queue for name table messages to be delivered upwards
137  * @next_out: ptr to first unsent outbound message in queue
138  * @wakeupq: linked list of wakeup msgs waiting for link congestion to abate
139  * @long_msg_seq_no: next identifier to use for outbound fragmented messages
140  * @reasm_buf: head of partially reassembled inbound message fragments
141  * @stats: collects statistics regarding link activity
142  */
143 struct tipc_link {
144 	u32 addr;
145 	char name[TIPC_MAX_LINK_NAME];
146 	struct tipc_media_addr media_addr;
147 	struct timer_list timer;
148 	struct tipc_node *owner;
149 	struct kref ref;
150 
151 	/* Management and link supervision data */
152 	unsigned int flags;
153 	u32 peer_session;
154 	u32 peer_bearer_id;
155 	u32 bearer_id;
156 	u32 tolerance;
157 	unsigned long keepalive_intv;
158 	u32 abort_limit;
159 	int state;
160 	u32 silent_intv_cnt;
161 	struct {
162 		unchar hdr[INT_H_SIZE];
163 		unchar body[TIPC_MAX_IF_NAME];
164 	} proto_msg;
165 	struct tipc_msg *pmsg;
166 	u32 priority;
167 	char net_plane;
168 	u16 synch_point;
169 
170 	/* Failover */
171 	u16 failover_pkts;
172 	u16 failover_checkpt;
173 	struct sk_buff *failover_skb;
174 
175 	/* Max packet negotiation */
176 	u16 mtu;
177 	u16 advertised_mtu;
178 
179 	/* Sending */
180 	struct sk_buff_head transmq;
181 	struct sk_buff_head backlogq;
182 	struct {
183 		u16 len;
184 		u16 limit;
185 	} backlog[5];
186 	u16 snd_nxt;
187 	u16 last_retransm;
188 	u32 window;
189 	u32 stale_count;
190 
191 	/* Reception */
192 	u16 rcv_nxt;
193 	u32 rcv_unacked;
194 	struct sk_buff_head deferdq;
195 	struct sk_buff_head inputq;
196 	struct sk_buff_head namedq;
197 
198 	/* Congestion handling */
199 	struct sk_buff_head wakeupq;
200 
201 	/* Fragmentation/reassembly */
202 	struct sk_buff *reasm_buf;
203 
204 	/* Statistics */
205 	struct tipc_stats stats;
206 };
207 
208 struct tipc_port;
209 
210 struct tipc_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 tipc_link *link);
214 void tipc_link_delete_list(struct net *net, unsigned int bearer_id);
215 void tipc_link_failover_send_queue(struct tipc_link *l_ptr);
216 void tipc_link_dup_queue_xmit(struct tipc_link *l_ptr, struct tipc_link *dest);
217 void tipc_link_reset_fragments(struct tipc_link *l_ptr);
218 int tipc_link_is_up(struct tipc_link *l_ptr);
219 int tipc_link_is_active(struct tipc_link *l_ptr);
220 void tipc_link_purge_queues(struct tipc_link *l_ptr);
221 void tipc_link_purge_backlog(struct tipc_link *l);
222 void tipc_link_reset_all(struct tipc_node *node);
223 void tipc_link_reset(struct tipc_link *l_ptr);
224 int tipc_link_xmit_skb(struct net *net, struct sk_buff *skb, u32 dest,
225 		       u32 selector);
226 int tipc_link_xmit(struct net *net, struct sk_buff_head *list, u32 dest,
227 		   u32 selector);
228 int __tipc_link_xmit(struct net *net, struct tipc_link *link,
229 		     struct sk_buff_head *list);
230 void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int prob,
231 			  u32 gap, u32 tolerance, u32 priority);
232 void tipc_link_push_packets(struct tipc_link *l_ptr);
233 u32 tipc_link_defer_pkt(struct sk_buff_head *list, struct sk_buff *buf);
234 void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window);
235 void tipc_link_retransmit(struct tipc_link *l_ptr,
236 			  struct sk_buff *start, u32 retransmits);
237 struct sk_buff *tipc_skb_queue_next(const struct sk_buff_head *list,
238 				    const struct sk_buff *skb);
239 
240 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb);
241 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info);
242 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info);
243 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info);
244 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[]);
245 void link_prepare_wakeup(struct tipc_link *l);
246 
247 static inline u32 link_own_addr(struct tipc_link *l)
248 {
249 	return msg_prevnode(l->pmsg);
250 }
251 
252 /*
253  * Link status checking routines
254  */
255 static inline int link_working_working(struct tipc_link *l_ptr)
256 {
257 	return l_ptr->state == WORKING_WORKING;
258 }
259 
260 static inline int link_working_unknown(struct tipc_link *l_ptr)
261 {
262 	return l_ptr->state == WORKING_UNKNOWN;
263 }
264 
265 static inline int link_reset_unknown(struct tipc_link *l_ptr)
266 {
267 	return l_ptr->state == RESET_UNKNOWN;
268 }
269 
270 static inline int link_reset_reset(struct tipc_link *l_ptr)
271 {
272 	return l_ptr->state == RESET_RESET;
273 }
274 
275 #endif
276