1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2009 Ed Schouten <ed@FreeBSD.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD$");
31
32#include <sys/wait.h>
33
34#include <errno.h>
35#include <signal.h>
36#include <stdlib.h>
37#include <sysexits.h>
38#include <unistd.h>
39#include "ulog.h"
40
41#define	_PATH_ULOG_HELPER	"/usr/libexec/ulog-helper"
42
43/*
44 * Registering login sessions.
45 */
46
47static void
48ulog_exec_helper(int fd, char const * const argv[])
49{
50	sigset_t oblock, nblock;
51	pid_t pid, wpid;
52	int status;
53
54	/* Block SIGCHLD. */
55	sigemptyset(&nblock);
56	sigaddset(&nblock, SIGCHLD);
57	sigprocmask(SIG_BLOCK, &nblock, &oblock);
58
59	switch (pid = fork()) {
60	case -1:
61		break;
62	case 0:
63		/* Execute helper program. */
64		if (dup2(fd, STDIN_FILENO) == -1)
65			exit(EX_UNAVAILABLE);
66		sigprocmask(SIG_SETMASK, &oblock, NULL);
67		execv(_PATH_ULOG_HELPER, __DECONST(char * const *, argv));
68		exit(EX_UNAVAILABLE);
69	default:
70		/* Wait for helper to finish. */
71		do {
72			wpid = waitpid(pid, &status, 0);
73		} while (wpid == -1 && errno == EINTR);
74		break;
75	}
76
77	sigprocmask(SIG_SETMASK, &oblock, NULL);
78}
79
80void
81ulog_login_pseudo(int fd, const char *host)
82{
83	char const * const args[4] = { "ulog-helper", "login", host, NULL };
84
85	ulog_exec_helper(fd, args);
86}
87
88void
89ulog_logout_pseudo(int fd)
90{
91	char const * const args[3] = { "ulog-helper", "logout", NULL };
92
93	ulog_exec_helper(fd, args);
94}
95