xref: /freebsd/usr.bin/rwall/rwall.c (revision 5b31cc94b10d4bb7109c6b27940a0fc76a44a331)
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 
44 #include <sys/cdefs.h>
45 /*
46  * This program is not related to David Wall, whose Stanford Ph.D. thesis
47  * is entitled "Mechanisms for Broadcast and Selective Broadcast".
48  */
49 
50 #include <sys/param.h>
51 #include <sys/stat.h>
52 #include <sys/uio.h>
53 #include <rpc/rpc.h>
54 #include <rpcsvc/rwall.h>
55 #include <err.h>
56 #include <paths.h>
57 #include <pwd.h>
58 #include <stdio.h>
59 #include <stdlib.h>
60 #include <string.h>
61 #include <time.h>
62 #include <unistd.h>
63 
64 static char *mbuf;
65 
66 static char notty[] = "no tty";
67 
68 static void	makemsg(const char *);
69 static void usage(void) __dead2;
70 
71 /* ARGSUSED */
72 int
73 main(int argc, char *argv[])
74 {
75 	char *wallhost, res;
76 	CLIENT *cl;
77 	struct timeval tv;
78 
79 	if ((argc < 2) || (argc > 3))
80 		usage();
81 
82 	wallhost = argv[1];
83 
84 	makemsg(argv[2]);
85 
86 	/*
87 	 * Create client "handle" used for calling MESSAGEPROG on the
88 	 * server designated on the command line. We tell the rpc package
89 	 * to use the "tcp" protocol when contacting the server.
90 	*/
91 	cl = clnt_create(wallhost, WALLPROG, WALLVERS, "udp");
92 	if (cl == NULL) {
93 		/*
94 		 * Couldn't establish connection with server.
95 		 * Print error message and die.
96 		 */
97 		errx(1, "%s", clnt_spcreateerror(wallhost));
98 	}
99 
100 	tv.tv_sec = 15;		/* XXX ?? */
101 	tv.tv_usec = 0;
102 	if (clnt_call(cl, WALLPROC_WALL, (xdrproc_t)xdr_wrapstring, &mbuf,
103 	    (xdrproc_t)xdr_void, &res, tv) != RPC_SUCCESS) {
104 		/*
105 		 * An error occurred while calling the server.
106 		 * Print error message and die.
107 		 */
108 		errx(1, "%s", clnt_sperror(cl, wallhost));
109 	}
110 
111 	return (0);
112 }
113 
114 static void
115 usage(void)
116 {
117 	fprintf(stderr, "usage: rwall host [file]\n");
118 	exit(1);
119 }
120 
121 static void
122 makemsg(const char *fname)
123 {
124 	struct tm *lt;
125 	struct passwd *pw;
126 	struct stat sbuf;
127 	time_t now;
128 	FILE *fp;
129 	int fd;
130 	size_t mbufsize;
131 	char *tty, hostname[MAXHOSTNAMELEN], lbuf[256], tmpname[64];
132 	const char *whom;
133 
134 	snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXX", _PATH_TMP);
135 	if ((fd = mkstemp(tmpname)) == -1 || (fp = fdopen(fd, "r+")) == NULL)
136 		err(1, "can't open temporary file");
137 	unlink(tmpname);
138 
139 	whom = getlogin();
140 	if (!whom) {
141 		pw = getpwuid(getuid());
142 		whom = pw ? pw->pw_name : "???";
143 	}
144 	gethostname(hostname, sizeof(hostname));
145 	time(&now);
146 	lt = localtime(&now);
147 
148 	/*
149 	 * all this stuff is to blank out a square for the message;
150 	 * we wrap message lines at column 79, not 80, because some
151 	 * terminals wrap after 79, some do not, and we can't tell.
152 	 * Which means that we may leave a non-blank character
153 	 * in column 80, but that can't be helped.
154 	 */
155 	fprintf(fp, "Remote Broadcast Message from %s@%s\n",
156 	    whom, hostname);
157 	tty = ttyname(STDERR_FILENO);
158 	if (tty == NULL)
159 		tty = notty;
160 	fprintf(fp, "        (%s) at %d:%02d ...\n", tty,
161 	    lt->tm_hour, lt->tm_min);
162 
163 	putc('\n', fp);
164 
165 	if (fname && !(freopen(fname, "r", stdin)))
166 		err(1, "can't read %s", fname);
167 	while (fgets(lbuf, sizeof(lbuf), stdin))
168 		fputs(lbuf, fp);
169 	rewind(fp);
170 
171 	if (fstat(fd, &sbuf))
172 		err(1, "can't stat temporary file");
173 	mbufsize = (size_t)sbuf.st_size;
174 	mbuf = malloc(mbufsize);
175 	if (mbuf == NULL)
176 		err(1, "out of memory");
177 	if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != (u_int)mbufsize)
178 		err(1, "can't read temporary file");
179 	close(fd);
180 }
181