xref: /netbsd-src/lib/libutil/ttyaction.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: ttyaction.c,v 1.8 1997/07/31 00:02:52 jtc 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 <err.h>
48 #include <errno.h>
49 #include <fcntl.h>
50 #include <fnmatch.h>
51 #include <unistd.h>
52 #include <stdlib.h>
53 #include <stdio.h>
54 #include <string.h>
55 #include <paths.h>
56 
57 #include "util.h"
58 
59 #ifndef _PATH_TTYACTION
60 #define _PATH_TTYACTION "/etc/ttyaction"
61 #endif
62 
63 static char *actfile = _PATH_TTYACTION;
64 static char *pathenv = __CONCAT("PATH=",_PATH_STDPATH);
65 
66 int
67 ttyaction(tty, act, user)
68 	char *tty;
69 	char *act;
70 	char *user;
71 {
72 	FILE *fp;
73 	char *p1, *p2;
74 	char *argv[4];
75 	char *envp[8];
76 	char line[1024];
77 	char env_tty[64];
78 	char env_act[64];
79 	char env_user[256];
80 	int err, linenum, pid, status;
81 
82 	fp = fopen(actfile, "r");
83 	if (fp == NULL)
84 		return 0;
85 
86 	/* Skip the "/dev/" part of the first arg. */
87 	if (!strncmp(tty, "/dev/", 5))
88 		tty += 5;
89 
90 	/* Args will be: "sh -c ..." */
91 	argv[0] = _PATH_BSHELL;
92 	argv[1] = "-c";
93 	argv[2] = NULL;	/* see below */
94 	argv[3] = NULL;
95 
96 	/*
97 	 * Environment needs: TTY, ACT, USER
98 	 */
99 	snprintf(env_tty, sizeof(env_tty), "TTY=%s", tty);
100 	snprintf(env_act, sizeof(env_act), "ACT=%s", act);
101 	snprintf(env_user, sizeof(env_user), "USER=%s", user);
102 	envp[0] = pathenv;
103 	envp[1] = env_tty;
104 	envp[2] = env_act;
105 	envp[3] = env_user;
106 	envp[4] = NULL;
107 
108 	linenum = 0;
109 	status = 0;
110 	while (fgets(line, sizeof(line), fp)) {
111 		linenum++;
112 
113 		/* Allow comment lines. */
114 		if (line[0] == '#')
115 			continue;
116 
117 		p1 = strtok(line, " \t");
118 		p2 = strtok(NULL, " \t");
119 		/* This arg goes to end of line. */
120 		argv[2] = strtok(NULL, "\n");
121 		if (!p1 || !p2 || !argv[2]) {
122 			warnx("%s: line %d format error", actfile, linenum);
123 			continue;
124 		}
125 		if (fnmatch(p1, tty, 0) || fnmatch(p2, act, 0))
126 			continue;
127 		/* OK, this is a match.  Run the command. */
128 		pid = fork();
129 		if (pid == -1) {
130 			warnx("fork failed: %s", strerror(errno));
131 			continue;
132 		}
133 		if (pid == 0) {
134 			/* This is the child. */
135 			err = execve(argv[0], argv, envp);
136 			/* If we get here, it is an error. */
137 			warnx("%s: line %d: exec failed: %s",
138 				  actfile, linenum, strerror(errno));
139 			_exit(1);
140 		}
141 		/* This is the parent. */
142 		err = waitpid(pid, &status, 0);
143 		if (err == -1) {
144 			warnx("%s: line %d: wait failed: %s",
145 				  actfile, linenum, strerror(errno));
146 			continue;
147 		}
148 		if (WTERMSIG(status)) {
149 			warnx("%s: line %d: child died with signal %d",
150 				  actfile, linenum, WTERMSIG(status));
151 			continue;
152 		}
153 	}
154 	fclose(fp);
155 	return status;
156 }
157 
158