xref: /titanic_41/usr/src/lib/libmail/common/notifyu.c (revision d24234c24aeaca4ca56ee3ac2794507968f274c4)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #include "libmail.h"
33 #include <sys/types.h>
34 #include <sys/stat.h>
35 #include <fcntl.h>
36 #include <utmpx.h>
37 #include <syslog.h>
38 #if !defined(__cplusplus) && !defined(c_plusplus)
39 typedef void (*SIG_PF) (int);
40 #endif
41 #include <unistd.h>
42 #include <signal.h>
43 
44 static SIG_PF catcher(void);
45 
46 static SIG_PF catcher(void)
47 {
48 	/* do nothing, but allow the write() to break */
49 	return (0);
50 }
51 
52 void
53 notify(char *user, char *msg, int check_mesg_y, char *etcdir)
54 {
55 	/* search the utmp file for this user */
56 	SIG_PF old;
57 	unsigned int oldalarm;
58 	struct utmpx utmpx, *putmpx = &utmpx;
59 
60 	setutxent();
61 
62 	/* grab the tty name */
63 	while ((putmpx = getutxent()) != NULL) {
64 		if (strncmp(user, utmpx.ut_name,
65 		    sizeof (utmpx.ut_name)) == 0) {
66 			char tty[sizeof (utmpx.ut_line)+1];
67 			char dev[MAXFILENAME];
68 			FILE *port;
69 			size_t i;
70 			int fd;
71 
72 			for (i = 0; i < sizeof (utmpx.ut_line); i++)
73 				tty[i] = utmpx.ut_line[i];
74 			tty[i] = '\0';
75 
76 			/* stick /dev/ in front */
77 			(void) sprintf(dev, "%s/dev/%s", etcdir, tty);
78 
79 			/* break out if write() to the tty hangs */
80 			old = (SIG_PF)signal(SIGALRM, (SIG_PF)catcher);
81 			oldalarm = alarm(300);
82 
83 			/* check if device is really a tty */
84 			if ((fd = open(dev, O_WRONLY|O_NOCTTY)) == -1) {
85 				(void) fprintf(stderr,
86 				    "Cannot open %s.\n", dev);
87 				continue;
88 			} else {
89 				if (!isatty(fd)) {
90 					(void) fprintf(stderr, "%s in utmpx is "
91 					    "not a tty\n", tty);
92 					openlog("mail", 0, LOG_AUTH);
93 					syslog(LOG_CRIT, "%s in utmp is "
94 					    "not a tty\n", tty);
95 					closelog();
96 					(void) close(fd);
97 					continue;
98 				}
99 			}
100 			(void) close(fd);
101 
102 			/* write to the tty */
103 			port = fopen(dev, "w");
104 			if (port != 0) {
105 				(void) fprintf(port, "\r\n%s\r\n", msg);
106 				(void) fclose(port);
107 			}
108 
109 			/* clean up our alarm */
110 			(void) alarm(0);
111 			(void) signal(SIGALRM, old);
112 			(void) alarm(oldalarm);
113 		}
114 	}
115 	endutxent();
116 }
117