xref: /freebsd/usr.bin/rwall/rwall.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*-
2  * SPDX-License-Identifier: BSD-4-Clause
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 static const 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 const char sccsid[] = "from: @(#)wall.c	5.14 (Berkeley) 3/2/91";
45 #endif
46 
47 #include <sys/cdefs.h>
48 __FBSDID("$FreeBSD$");
49 
50 /*
51  * This program is not related to David Wall, whose Stanford Ph.D. thesis
52  * is entitled "Mechanisms for Broadcast and Selective Broadcast".
53  */
54 
55 #include <sys/param.h>
56 #include <sys/stat.h>
57 #include <sys/uio.h>
58 #include <rpc/rpc.h>
59 #include <rpcsvc/rwall.h>
60 #include <err.h>
61 #include <paths.h>
62 #include <pwd.h>
63 #include <stdio.h>
64 #include <stdlib.h>
65 #include <string.h>
66 #include <time.h>
67 #include <unistd.h>
68 
69 static char *mbuf;
70 
71 static char notty[] = "no tty";
72 
73 static void	makemsg(const char *);
74 static void usage(void);
75 
76 /* ARGSUSED */
77 int
78 main(int argc, char *argv[])
79 {
80 	char *wallhost, res;
81 	CLIENT *cl;
82 	struct timeval tv;
83 
84 	if ((argc < 2) || (argc > 3))
85 		usage();
86 
87 	wallhost = argv[1];
88 
89 	makemsg(argv[2]);
90 
91 	/*
92 	 * Create client "handle" used for calling MESSAGEPROG on the
93 	 * server designated on the command line. We tell the rpc package
94 	 * to use the "tcp" protocol when contacting the server.
95 	*/
96 	cl = clnt_create(wallhost, WALLPROG, WALLVERS, "udp");
97 	if (cl == NULL) {
98 		/*
99 		 * Couldn't establish connection with server.
100 		 * Print error message and die.
101 		 */
102 		errx(1, "%s", clnt_spcreateerror(wallhost));
103 	}
104 
105 	tv.tv_sec = 15;		/* XXX ?? */
106 	tv.tv_usec = 0;
107 	if (clnt_call(cl, WALLPROC_WALL, (xdrproc_t)xdr_wrapstring, &mbuf,
108 	    (xdrproc_t)xdr_void, &res, tv) != RPC_SUCCESS) {
109 		/*
110 		 * An error occurred while calling the server.
111 		 * Print error message and die.
112 		 */
113 		errx(1, "%s", clnt_sperror(cl, wallhost));
114 	}
115 
116 	return (0);
117 }
118 
119 static void
120 usage(void)
121 {
122 	fprintf(stderr, "usage: rwall host [file]\n");
123 	exit(1);
124 }
125 
126 static void
127 makemsg(const char *fname)
128 {
129 	struct tm *lt;
130 	struct passwd *pw;
131 	struct stat sbuf;
132 	time_t now;
133 	FILE *fp;
134 	int fd;
135 	size_t mbufsize;
136 	char *tty, hostname[MAXHOSTNAMELEN], lbuf[256], tmpname[64];
137 	const char *whom;
138 
139 	snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXX", _PATH_TMP);
140 	if ((fd = mkstemp(tmpname)) == -1 || (fp = fdopen(fd, "r+")) == NULL)
141 		err(1, "can't open temporary file");
142 	unlink(tmpname);
143 
144 	whom = getlogin();
145 	if (!whom) {
146 		pw = getpwuid(getuid());
147 		whom = pw ? pw->pw_name : "???";
148 	}
149 	gethostname(hostname, sizeof(hostname));
150 	time(&now);
151 	lt = localtime(&now);
152 
153 	/*
154 	 * all this stuff is to blank out a square for the message;
155 	 * we wrap message lines at column 79, not 80, because some
156 	 * terminals wrap after 79, some do not, and we can't tell.
157 	 * Which means that we may leave a non-blank character
158 	 * in column 80, but that can't be helped.
159 	 */
160 	fprintf(fp, "Remote Broadcast Message from %s@%s\n",
161 	    whom, hostname);
162 	tty = ttyname(STDERR_FILENO);
163 	if (tty == NULL)
164 		tty = notty;
165 	fprintf(fp, "        (%s) at %d:%02d ...\n", tty,
166 	    lt->tm_hour, lt->tm_min);
167 
168 	putc('\n', fp);
169 
170 	if (fname && !(freopen(fname, "r", stdin)))
171 		err(1, "can't read %s", fname);
172 	while (fgets(lbuf, sizeof(lbuf), stdin))
173 		fputs(lbuf, fp);
174 	rewind(fp);
175 
176 	if (fstat(fd, &sbuf))
177 		err(1, "can't stat temporary file");
178 	mbufsize = (size_t)sbuf.st_size;
179 	mbuf = malloc(mbufsize);
180 	if (mbuf == NULL)
181 		err(1, "out of memory");
182 	if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != (u_int)mbufsize)
183 		err(1, "can't read temporary file");
184 	close(fd);
185 }
186