1/*	$NetBSD: stream_trigger.c,v 1.2 2017/02/14 01:16:49 christos Exp $	*/
2
3/*++
4/* NAME
5/*	stream_trigger 3
6/* SUMMARY
7/*	wakeup stream server
8/* SYNOPSIS
9/*	#include <trigger.h>
10/*
11/*	int	stream_trigger(service, buf, len, timeout)
12/*	const char *service;
13/*	const char *buf;
14/*	ssize_t	len;
15/*	int	timeout;
16/* DESCRIPTION
17/*	stream_trigger() wakes up the named stream server by making
18/*	a brief connection to it and writing the named buffer.
19/*
20/*	The connection is closed by a background thread. Some kernels
21/*	cannot handle client-side disconnect before the server has
22/*	received the message.
23/*
24/*	Arguments:
25/* .IP service
26/*	Name of the communication endpoint.
27/* .IP buf
28/*	Address of data to be written.
29/* .IP len
30/*	Amount of data to be written.
31/* .IP timeout
32/*	Deadline in seconds. Specify a value <= 0 to disable
33/*	the time limit.
34/* DIAGNOSTICS
35/*	The result is zero in case of success, -1 in case of problems.
36/* SEE ALSO
37/*	stream_connect(3), stream client
38/* LICENSE
39/* .ad
40/* .fi
41/*	The Secure Mailer license must be distributed with this software.
42/* AUTHOR(S)
43/*	Wietse Venema
44/*	IBM T.J. Watson Research
45/*	P.O. Box 704
46/*	Yorktown Heights, NY 10598, USA
47/*--*/
48
49/* System library. */
50
51#include <sys_defs.h>
52#include <unistd.h>
53#include <string.h>
54
55/* Utility library. */
56
57#include <msg.h>
58#include <connect.h>
59#include <iostuff.h>
60#include <mymalloc.h>
61#include <events.h>
62#include <trigger.h>
63
64struct stream_trigger {
65    int     fd;
66    char   *service;
67};
68
69/* stream_trigger_event - disconnect from peer */
70
71static void stream_trigger_event(int event, void *context)
72{
73    struct stream_trigger *sp = (struct stream_trigger *) context;
74    static const char *myname = "stream_trigger_event";
75
76    /*
77     * Disconnect.
78     */
79    if (event == EVENT_TIME)
80	msg_warn("%s: read timeout for service %s", myname, sp->service);
81    event_disable_readwrite(sp->fd);
82    event_cancel_timer(stream_trigger_event, context);
83    if (close(sp->fd) < 0)
84	msg_warn("%s: close %s: %m", myname, sp->service);
85    myfree(sp->service);
86    myfree((void *) sp);
87}
88
89/* stream_trigger - wakeup stream server */
90
91int     stream_trigger(const char *service, const char *buf, ssize_t len, int timeout)
92{
93    const char *myname = "stream_trigger";
94    struct stream_trigger *sp;
95    int     fd;
96
97    if (msg_verbose > 1)
98	msg_info("%s: service %s", myname, service);
99
100    /*
101     * Connect...
102     */
103    if ((fd = stream_connect(service, BLOCKING, timeout)) < 0) {
104	if (msg_verbose)
105	    msg_warn("%s: connect to %s: %m", myname, service);
106	return (-1);
107    }
108    close_on_exec(fd, CLOSE_ON_EXEC);
109
110    /*
111     * Stash away context.
112     */
113    sp = (struct stream_trigger *) mymalloc(sizeof(*sp));
114    sp->fd = fd;
115    sp->service = mystrdup(service);
116
117    /*
118     * Write the request...
119     */
120    if (write_buf(fd, buf, len, timeout) < 0
121	|| write_buf(fd, "", 1, timeout) < 0)
122	if (msg_verbose)
123	    msg_warn("%s: write to %s: %m", myname, service);
124
125    /*
126     * Wakeup when the peer disconnects, or when we lose patience.
127     */
128    if (timeout > 0)
129	event_request_timer(stream_trigger_event, (void *) sp, timeout + 100);
130    event_enable_read(fd, stream_trigger_event, (void *) sp);
131    return (0);
132}
133