xref: /openbsd-src/usr.bin/rwall/rwall.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*	$OpenBSD: rwall.c,v 1.5 1999/05/30 08:21:15 deraadt Exp $	*/
2 
3 /*
4  * Copyright (c) 1993 Christopher G. Demetriou
5  * Copyright (c) 1988, 1990 Regents of the University of California.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #ifndef lint
38 char copyright[] =
39 "@(#) Copyright (c) 1988 Regents of the University of California.\n\
40  All rights reserved.\n";
41 #endif /* not lint */
42 
43 #ifndef lint
44 /*static char sccsid[] = "from: @(#)wall.c	5.14 (Berkeley) 3/2/91";*/
45 static char rcsid[] = "$OpenBSD: rwall.c,v 1.5 1999/05/30 08:21:15 deraadt Exp $";
46 #endif /* not lint */
47 
48 /*
49  * This program is not related to David Wall, whose Stanford Ph.D. thesis
50  * is entitled "Mechanisms for Broadcast and Selective Broadcast".
51  */
52 
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <string.h>
56 #include <time.h>
57 #include <sys/param.h>
58 #include <sys/types.h>
59 #include <sys/stat.h>
60 #include <pwd.h>
61 #include <unistd.h>
62 #include <paths.h>
63 
64 #include <rpc/rpc.h>
65 #include <rpcsvc/rwall.h>
66 
67 struct timeval timeout = { 25, 0 };
68 int mbufsize;
69 char *mbuf;
70 
71 void makemsg ();
72 
73 int
74 main(argc, argv)
75 	int argc;
76 	char **argv;
77 {
78 	char *wallhost, res;
79 	CLIENT *cl;
80 
81 	if ((argc < 2) || (argc > 3)) {
82 		fprintf(stderr, "usage: %s hostname [file]\n", argv[0]);
83 		exit(1);
84 	}
85 
86 	wallhost = argv[1];
87 
88 	makemsg(argv[2]);
89 
90 	/*
91 	 * Create client "handle" used for calling MESSAGEPROG on the
92 	 * server designated on the command line. We tell the rpc package
93 	 * to use the "tcp" protocol when contacting the server.
94 	*/
95 	cl = clnt_create(wallhost, WALLPROG, WALLVERS, "udp");
96 	if (cl == NULL) {
97 		/*
98 		 * Couldn't establish connection with server.
99 		 * Print error message and die.
100 		 */
101 		clnt_pcreateerror(wallhost);
102 		exit(1);
103 	}
104 
105 	if (clnt_call(cl, WALLPROC_WALL, xdr_wrapstring, &mbuf, xdr_void, &res, timeout) != RPC_SUCCESS) {
106 		/*
107 		 * An error occurred while calling the server.
108 		 * Print error message and die.
109 		 */
110 		clnt_perror(cl, wallhost);
111 		exit(1);
112 	}
113 
114 	exit(0);
115 }
116 
117 void
118 makemsg(fname)
119 	char *fname;
120 {
121 	struct tm *lt;
122 	struct passwd *pw;
123 	struct stat sbuf;
124 	time_t now;
125 	FILE *fp;
126 	int fd;
127 	char *whom, hostname[MAXHOSTNAMELEN], lbuf[100], tmpname[64];
128 
129 	snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXX", _PATH_TMP);
130 	if ((fd = mkstemp(tmpname)) == -1 || !(fp = fdopen(fd, "r+"))) {
131 		(void)fprintf(stderr, "wall: can't open temporary file.\n");
132 		exit(1);
133 	}
134 	(void)unlink(tmpname);
135 
136 	if (!(whom = getlogin()))
137 		whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
138 	(void)gethostname(hostname, sizeof(hostname));
139 	(void)time(&now);
140 	lt = localtime(&now);
141 
142 	/*
143 	 * all this stuff is to blank out a square for the message;
144 	 * we wrap message lines at column 79, not 80, because some
145 	 * terminals wrap after 79, some do not, and we can't tell.
146 	 * Which means that we may leave a non-blank character
147 	 * in column 80, but that can't be helped.
148 	 */
149 	(void)fprintf(fp, "Remote Broadcast Message from %s@%s\n",
150 	    whom, hostname);
151 	(void)fprintf(fp, "        (%s) at %d:%02d ...\n", ttyname(2),
152 	    lt->tm_hour, lt->tm_min);
153 
154 	putc('\n', fp);
155 
156 	if (fname && !(freopen(fname, "r", stdin))) {
157 		(void)fprintf(stderr, "wall: can't read %s.\n", fname);
158 		exit(1);
159 	}
160 	while (fgets(lbuf, sizeof(lbuf), stdin))
161 		fputs(lbuf, fp);
162 	rewind(fp);
163 
164 	if (fstat(fd, &sbuf)) {
165 		(void)fprintf(stderr, "wall: can't stat temporary file.\n");
166 		exit(1);
167 	}
168 	mbufsize = sbuf.st_size;
169 	if (!(mbuf = malloc((u_int)mbufsize))) {
170 		(void)fprintf(stderr, "wall: out of memory.\n");
171 		exit(1);
172 	}
173 	if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize) {
174 		(void)fprintf(stderr, "wall: can't read temporary file.\n");
175 		exit(1);
176 	}
177 	(void)close(fd);
178 }
179