xref: /freebsd/sys/rpc/replay.h (revision e796cc77c586c2955b2f3940dbf4991b31e8d289)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2008 Isilon Inc http://www.isilon.com/
5  * Authors: Doug Rabson <dfr@rabson.org>
6  * Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org>
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
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  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 
32 #ifndef _RPC_REPLAY_H
33 #define _RPC_REPLAY_H
34 
35 enum replay_state {
36 	RS_NEW,			/* new request - caller should execute */
37 	RS_DONE,		/* request was executed and reply sent */
38 	RS_INPROGRESS,		/* request is being executed now */
39 	RS_ERROR		/* allocation or other failure */
40 };
41 
42 struct replay_cache;
43 
44 /*
45  * Create a new replay cache.
46  */
47 struct replay_cache	*replay_newcache(size_t);
48 
49 /*
50  * Set the replay cache size.
51  */
52 void			replay_setsize(struct replay_cache *, size_t);
53 
54 /*
55  * Free a replay cache. Caller must ensure that no cache entries are
56  * in-progress.
57  */
58 void			replay_freecache(struct replay_cache *rc);
59 
60 /*
61  * Check a replay cache for a message from a given address.
62  *
63  * If this is a new request, RS_NEW is returned. Caller should call
64  * replay_setreply with the results of the request.
65  *
66  * If this is a request which is currently executing
67  * (i.e. replay_setreply hasn't been called for it yet), RS_INPROGRESS
68  * is returned. The caller should silently drop the request.
69  *
70  * If a reply to this message already exists, *repmsg and *mp are set
71  * to point at the reply and, RS_DONE is returned. The caller should
72  * re-send this reply.
73  *
74  * If the attempt to update the replay cache or copy a replay failed
75  * for some reason (typically memory shortage), RS_ERROR is returned.
76  */
77 enum replay_state	replay_find(struct replay_cache *rc,
78     struct rpc_msg *msg, struct sockaddr *addr,
79     struct rpc_msg *repmsg, struct mbuf **mp);
80 
81 /*
82  * Call this after executing a request to record the reply.
83  */
84 void			replay_setreply(struct replay_cache *rc,
85     struct rpc_msg *repmsg,  struct sockaddr *addr, struct mbuf *m);
86 
87 #endif /* !_RPC_REPLAY_H */
88