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/*
38 * This program is not related to David Wall, whose Stanford Ph.D. thesis
39 * is entitled "Mechanisms for Broadcast and Selective Broadcast".
40 */
41
42#include <sys/param.h>
43#include <sys/stat.h>
44#include <sys/uio.h>
45#include <rpc/rpc.h>
46#include <rpcsvc/rwall.h>
47#include <err.h>
48#include <paths.h>
49#include <pwd.h>
50#include <stdio.h>
51#include <stdlib.h>
52#include <string.h>
53#include <time.h>
54#include <unistd.h>
55
56static char *mbuf;
57
58static char notty[] = "no tty";
59
60static void	makemsg(const char *);
61static void usage(void) __dead2;
62
63/* ARGSUSED */
64int
65main(int argc, char *argv[])
66{
67	char *wallhost, res;
68	CLIENT *cl;
69	struct timeval tv;
70
71	if ((argc < 2) || (argc > 3))
72		usage();
73
74	wallhost = argv[1];
75
76	makemsg(argv[2]);
77
78	/*
79	 * Create client "handle" used for calling MESSAGEPROG on the
80	 * server designated on the command line. We tell the rpc package
81	 * to use the "tcp" protocol when contacting the server.
82	*/
83	cl = clnt_create(wallhost, WALLPROG, WALLVERS, "udp");
84	if (cl == NULL) {
85		/*
86		 * Couldn't establish connection with server.
87		 * Print error message and die.
88		 */
89		errx(1, "%s", clnt_spcreateerror(wallhost));
90	}
91
92	tv.tv_sec = 15;		/* XXX ?? */
93	tv.tv_usec = 0;
94	if (clnt_call(cl, WALLPROC_WALL, (xdrproc_t)xdr_wrapstring, &mbuf,
95	    (xdrproc_t)xdr_void, &res, tv) != RPC_SUCCESS) {
96		/*
97		 * An error occurred while calling the server.
98		 * Print error message and die.
99		 */
100		errx(1, "%s", clnt_sperror(cl, wallhost));
101	}
102
103	return (0);
104}
105
106static void
107usage(void)
108{
109	fprintf(stderr, "usage: rwall host [file]\n");
110	exit(1);
111}
112
113static void
114makemsg(const char *fname)
115{
116	struct tm *lt;
117	struct passwd *pw;
118	struct stat sbuf;
119	time_t now;
120	FILE *fp;
121	int fd;
122	size_t mbufsize;
123	char *tty, hostname[MAXHOSTNAMELEN], lbuf[256], tmpname[64];
124	const char *whom;
125
126	snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXX", _PATH_TMP);
127	if ((fd = mkstemp(tmpname)) == -1 || (fp = fdopen(fd, "r+")) == NULL)
128		err(1, "can't open temporary file");
129	unlink(tmpname);
130
131	whom = getlogin();
132	if (!whom) {
133		pw = getpwuid(getuid());
134		whom = pw ? pw->pw_name : "???";
135	}
136	gethostname(hostname, sizeof(hostname));
137	time(&now);
138	lt = localtime(&now);
139
140	/*
141	 * all this stuff is to blank out a square for the message;
142	 * we wrap message lines at column 79, not 80, because some
143	 * terminals wrap after 79, some do not, and we can't tell.
144	 * Which means that we may leave a non-blank character
145	 * in column 80, but that can't be helped.
146	 */
147	fprintf(fp, "Remote Broadcast Message from %s@%s\n",
148	    whom, hostname);
149	tty = ttyname(STDERR_FILENO);
150	if (tty == NULL)
151		tty = notty;
152	fprintf(fp, "        (%s) at %d:%02d ...\n", tty,
153	    lt->tm_hour, lt->tm_min);
154
155	putc('\n', fp);
156
157	if (fname && !(freopen(fname, "r", stdin)))
158		err(1, "can't read %s", fname);
159	while (fgets(lbuf, sizeof(lbuf), stdin))
160		fputs(lbuf, fp);
161	rewind(fp);
162
163	if (fstat(fd, &sbuf))
164		err(1, "can't stat temporary file");
165	mbufsize = (size_t)sbuf.st_size;
166	mbuf = malloc(mbufsize);
167	if (mbuf == NULL)
168		err(1, "out of memory");
169	if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != (u_int)mbufsize)
170		err(1, "can't read temporary file");
171	close(fd);
172}
173