1 /*
2  * Copyright (c) 2000-2004 Niels Provos <provos@citi.umich.edu>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. The name of the author may not be used to endorse or promote products
14  *    derived from this software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <sys/types.h>
29 #include <sys/time.h>
30 #include <sys/socket.h>
31 
32 #include <netdb.h>
33 #include <asr.h>
34 #include <event.h>
35 #include <stdlib.h>
36 
37 /*
38  * Libevent glue for ASR.
39  */
40 struct event_asr {
41 	struct event	 ev;
42 	struct asr_query *async;
43 	void		(*cb)(struct asr_result *, void *);
44 	void		*arg;
45 };
46 
47 static void
48 event_asr_dispatch(int fd __attribute__((__unused__)),
49     short ev __attribute__((__unused__)), void *arg)
50 {
51 	struct event_asr	*eva = arg;
52 	struct asr_result	 ar;
53 	struct timeval		 tv;
54 
55 	event_del(&eva->ev);
56 
57 	if (asr_run(eva->async, &ar)) {
58 		eva->cb(&ar, eva->arg);
59 		free(eva);
60 	} else {
61 		event_set(&eva->ev, ar.ar_fd,
62 		    ar.ar_cond == ASR_WANT_READ ? EV_READ : EV_WRITE,
63 		    event_asr_dispatch, eva);
64 		tv.tv_sec = ar.ar_timeout / 1000;
65 		tv.tv_usec = (ar.ar_timeout % 1000) * 1000;
66 		event_add(&eva->ev, &tv);
67 	}
68 }
69 
70 struct event_asr *
71 event_asr_run(struct asr_query *async, void (*cb)(struct asr_result *, void *),
72     void *arg)
73 {
74 	struct event_asr *eva;
75 	struct timeval tv;
76 
77 	eva = calloc(1, sizeof *eva);
78 	if (eva == NULL)
79 		return (NULL);
80 	eva->async = async;
81 	eva->cb = cb;
82 	eva->arg = arg;
83 	tv.tv_sec = 0;
84 	tv.tv_usec = 0;
85 	evtimer_set(&eva->ev, event_asr_dispatch, eva);
86 	evtimer_add(&eva->ev, &tv);
87 	return (eva);
88 }
89 
90 void
91 event_asr_abort(struct event_asr *eva)
92 {
93 	asr_abort(eva->async);
94 	event_del(&eva->ev);
95 	free(eva);
96 }