xref: /linux/net/tipc/link.h (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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 FSM events:
53  */
54 enum {
55 	LINK_ESTABLISH_EVT       = 0xec1ab1e,
56 	LINK_PEER_RESET_EVT      = 0x9eed0e,
57 	LINK_FAILURE_EVT         = 0xfa110e,
58 	LINK_RESET_EVT           = 0x10ca1d0e,
59 	LINK_FAILOVER_BEGIN_EVT  = 0xfa110bee,
60 	LINK_FAILOVER_END_EVT    = 0xfa110ede,
61 	LINK_SYNCH_BEGIN_EVT     = 0xc1ccbee,
62 	LINK_SYNCH_END_EVT       = 0xc1ccede
63 };
64 
65 /* Events returned from link at packet reception or at timeout
66  */
67 enum {
68 	TIPC_LINK_UP_EVT       = 1,
69 	TIPC_LINK_DOWN_EVT     = (1 << 1)
70 };
71 
72 /* Starting value for maximum packet size negotiation on unicast links
73  * (unless bearer MTU is less)
74  */
75 #define MAX_PKT_DEFAULT 1500
76 
77 struct tipc_stats {
78 	u32 sent_info;		/* used in counting # sent packets */
79 	u32 recv_info;		/* used in counting # recv'd packets */
80 	u32 sent_states;
81 	u32 recv_states;
82 	u32 sent_probes;
83 	u32 recv_probes;
84 	u32 sent_nacks;
85 	u32 recv_nacks;
86 	u32 sent_acks;
87 	u32 sent_bundled;
88 	u32 sent_bundles;
89 	u32 recv_bundled;
90 	u32 recv_bundles;
91 	u32 retransmitted;
92 	u32 sent_fragmented;
93 	u32 sent_fragments;
94 	u32 recv_fragmented;
95 	u32 recv_fragments;
96 	u32 link_congs;		/* # port sends blocked by congestion */
97 	u32 deferred_recv;
98 	u32 duplicates;
99 	u32 max_queue_sz;	/* send queue size high water mark */
100 	u32 accu_queue_sz;	/* used for send queue size profiling */
101 	u32 queue_sz_counts;	/* used for send queue size profiling */
102 	u32 msg_length_counts;	/* used for message length profiling */
103 	u32 msg_lengths_total;	/* used for message length profiling */
104 	u32 msg_length_profile[7]; /* used for msg. length profiling */
105 };
106 
107 /**
108  * struct tipc_link - TIPC link data structure
109  * @addr: network address of link's peer node
110  * @name: link name character string
111  * @media_addr: media address to use when sending messages over link
112  * @timer: link timer
113  * @owner: pointer to peer node
114  * @refcnt: reference counter for permanent references (owner node & timer)
115  * @peer_session: link session # being used by peer end of link
116  * @peer_bearer_id: bearer id used by link's peer endpoint
117  * @bearer_id: local bearer id used by link
118  * @tolerance: minimum link continuity loss needed to reset link [in ms]
119  * @keepalive_intv: link keepalive timer interval
120  * @abort_limit: # of unacknowledged continuity probes needed to reset link
121  * @state: current state of link FSM
122  * @silent_intv_cnt: # of timer intervals without any reception from peer
123  * @proto_msg: template for control messages generated by link
124  * @pmsg: convenience pointer to "proto_msg" field
125  * @priority: current link priority
126  * @net_plane: current link network plane ('A' through 'H')
127  * @backlog_limit: backlog queue congestion thresholds (indexed by importance)
128  * @exp_msg_count: # of tunnelled messages expected during link changeover
129  * @reset_rcv_checkpt: seq # of last acknowledged message at time of link reset
130  * @mtu: current maximum packet size for this link
131  * @advertised_mtu: advertised own mtu when link is being established
132  * @transmitq: queue for sent, non-acked messages
133  * @backlogq: queue for messages waiting to be sent
134  * @snt_nxt: next sequence number to use for outbound messages
135  * @last_retransmitted: sequence number of most recently retransmitted message
136  * @stale_count: # of identical retransmit requests made by peer
137  * @rcv_nxt: next sequence number to expect for inbound messages
138  * @deferred_queue: deferred queue saved OOS b'cast message received from node
139  * @unacked_window: # of inbound messages rx'd without ack'ing back to peer
140  * @inputq: buffer queue for messages to be delivered upwards
141  * @namedq: buffer queue for name table messages to be delivered upwards
142  * @next_out: ptr to first unsent outbound message in queue
143  * @wakeupq: linked list of wakeup msgs waiting for link congestion to abate
144  * @long_msg_seq_no: next identifier to use for outbound fragmented messages
145  * @reasm_buf: head of partially reassembled inbound message fragments
146  * @stats: collects statistics regarding link activity
147  */
148 struct tipc_link {
149 	u32 addr;
150 	char name[TIPC_MAX_LINK_NAME];
151 	struct tipc_media_addr *media_addr;
152 	struct tipc_node *owner;
153 
154 	/* Management and link supervision data */
155 	u32 peer_session;
156 	u32 peer_bearer_id;
157 	u32 bearer_id;
158 	u32 tolerance;
159 	unsigned long keepalive_intv;
160 	u32 abort_limit;
161 	u32 state;
162 	u32 silent_intv_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 
171 	/* Failover/synch */
172 	u16 drop_point;
173 	struct sk_buff *failover_reasm_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 bool tipc_link_create(struct tipc_node *n, struct tipc_bearer *b, u32 session,
209 		      u32 ownnode, u32 peer, struct tipc_media_addr *maddr,
210 		      struct sk_buff_head *inputq, struct sk_buff_head *namedq,
211 		      struct tipc_link **link);
212 void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
213 			   int mtyp, struct sk_buff_head *xmitq);
214 void tipc_link_build_bcast_sync_msg(struct tipc_link *l,
215 				    struct sk_buff_head *xmitq);
216 int tipc_link_fsm_evt(struct tipc_link *l, int evt);
217 void tipc_link_reset_fragments(struct tipc_link *l_ptr);
218 bool tipc_link_is_up(struct tipc_link *l);
219 bool tipc_link_is_reset(struct tipc_link *l);
220 bool tipc_link_is_synching(struct tipc_link *l);
221 bool tipc_link_is_failingover(struct tipc_link *l);
222 bool tipc_link_is_blocked(struct tipc_link *l);
223 int tipc_link_is_active(struct tipc_link *l_ptr);
224 void tipc_link_purge_queues(struct tipc_link *l_ptr);
225 void tipc_link_purge_backlog(struct tipc_link *l);
226 void tipc_link_reset(struct tipc_link *l_ptr);
227 int __tipc_link_xmit(struct net *net, struct tipc_link *link,
228 		     struct sk_buff_head *list);
229 int tipc_link_xmit(struct tipc_link *link,	struct sk_buff_head *list,
230 		   struct sk_buff_head *xmitq);
231 void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int prob,
232 			  u32 gap, u32 tolerance, u32 priority);
233 void tipc_link_push_packets(struct tipc_link *l_ptr);
234 u32 tipc_link_defer_pkt(struct sk_buff_head *list, struct sk_buff *buf);
235 void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window);
236 void tipc_link_retransmit(struct tipc_link *l_ptr,
237 			  struct sk_buff *start, u32 retransmits);
238 struct sk_buff *tipc_skb_queue_next(const struct sk_buff_head *list,
239 				    const struct sk_buff *skb);
240 
241 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb);
242 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info);
243 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info);
244 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info);
245 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[]);
246 int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq);
247 int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
248 		  struct sk_buff_head *xmitq);
249 
250 #endif
251