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