xref: /netbsd-src/lib/libutil/ttyaction.c (revision 4472dbe5e3bd91ef2540bada7a7ca7384627ff9b)
1 /*	$NetBSD: ttyaction.c,v 1.13 1999/09/20 04:48:10 lukem Exp $	*/
2 
3 /*-
4  * Copyright (c) 1996 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Gordon W. Ross.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * For each matching "tty" and "action" run the "command."
41  * See fnmatch() for matching the tty name.
42  */
43 
44 #include <sys/types.h>
45 #include <sys/wait.h>
46 
47 #include <assert.h>
48 #include <err.h>
49 #include <errno.h>
50 #include <fcntl.h>
51 #include <fnmatch.h>
52 #include <paths.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <string.h>
56 #include <unistd.h>
57 
58 #include "util.h"
59 
60 #ifndef _PATH_TTYACTION
61 #define _PATH_TTYACTION "/etc/ttyaction"
62 #endif
63 
64 static char *actfile = _PATH_TTYACTION;
65 static char *pathenv = __CONCAT("PATH=",_PATH_STDPATH);
66 
67 int
68 ttyaction(tty, act, user)
69 	const char *tty;
70 	const char *act;
71 	const char *user;
72 {
73 	FILE *fp;
74 	char *p1, *p2;
75 	char *argv[4];
76 	char *envp[8];
77 	char *lastp;
78 	char line[1024];
79 	char env_tty[64];
80 	char env_act[64];
81 	char env_user[256];
82 	int error, linenum, pid, status;
83 
84 	_DIAGASSERT(tty != NULL);
85 	_DIAGASSERT(act != NULL);
86 	_DIAGASSERT(user != NULL);
87 
88 	fp = fopen(actfile, "r");
89 	if (fp == NULL)
90 		return 0;
91 
92 	/* Skip the "/dev/" part of the first arg. */
93 	if (!strncmp(tty, "/dev/", 5))
94 		tty += 5;
95 
96 	/* Args will be: "sh -c ..." */
97 	argv[0] = _PATH_BSHELL;
98 	argv[1] = "-c";
99 	argv[2] = NULL;	/* see below */
100 	argv[3] = NULL;
101 
102 	/*
103 	 * Environment needs: TTY, ACT, USER
104 	 */
105 	snprintf(env_tty, sizeof(env_tty), "TTY=%s", tty);
106 	snprintf(env_act, sizeof(env_act), "ACT=%s", act);
107 	snprintf(env_user, sizeof(env_user), "USER=%s", user);
108 	envp[0] = pathenv;
109 	envp[1] = env_tty;
110 	envp[2] = env_act;
111 	envp[3] = env_user;
112 	envp[4] = NULL;
113 
114 	linenum = 0;
115 	status = 0;
116 	while (fgets(line, sizeof(line), fp)) {
117 		linenum++;
118 
119 		/* Allow comment lines. */
120 		if (line[0] == '#')
121 			continue;
122 
123 		p1 = strtok_r(line, " \t", &lastp);
124 		p2 = strtok_r(NULL, " \t", &lastp);
125 		/* This arg goes to end of line. */
126 		argv[2] = strtok_r(NULL, "\n", &lastp);
127 		if (!p1 || !p2 || !argv[2]) {
128 			warnx("%s: line %d format error", actfile, linenum);
129 			continue;
130 		}
131 		if (fnmatch(p1, tty, 0) || fnmatch(p2, act, 0))
132 			continue;
133 		/* OK, this is a match.  Run the command. */
134 		pid = fork();
135 		if (pid == -1) {
136 			warnx("fork failed: %s", strerror(errno));
137 			continue;
138 		}
139 		if (pid == 0) {
140 			/* This is the child. */
141 			error = execve(argv[0], argv, envp);
142 			/* If we get here, it is an error. */
143 			warnx("%s: line %d: exec failed: %s",
144 				  actfile, linenum, strerror(errno));
145 			_exit(1);
146 		}
147 		/* This is the parent. */
148 		error = waitpid(pid, &status, 0);
149 		if (error == -1) {
150 			warnx("%s: line %d: wait failed: %s",
151 				  actfile, linenum, strerror(errno));
152 			continue;
153 		}
154 		if (WTERMSIG(status)) {
155 			warnx("%s: line %d: child died with signal %d",
156 				  actfile, linenum, WTERMSIG(status));
157 			continue;
158 		}
159 	}
160 	fclose(fp);
161 	return status;
162 }
163