rwall.c revision 27977 
1/*
2 * Copyright (c) 1993 Christopher G. Demetriou
3 * Copyright (c) 1988, 1990 Regents of the University of California.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 *    must display the following acknowledgement:
16 *	This product includes software developed by the University of
17 *	California, Berkeley and its contributors.
18 * 4. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#ifndef lint
36static const char copyright[] =
37"@(#) Copyright (c) 1988 Regents of the University of California.\n\
38 All rights reserved.\n";
39#endif /* not lint */
40
41#ifndef lint
42#if 0
43static char sccsid[] = "from: @(#)wall.c	5.14 (Berkeley) 3/2/91";
44#endif
45static const char rcsid[] =
46	"$Id: rwall.c,v 1.5 1997/02/22 19:56:55 peter Exp $";
47#endif /* not lint */
48
49/*
50 * This program is not related to David Wall, whose Stanford Ph.D. thesis
51 * is entitled "Mechanisms for Broadcast and Selective Broadcast".
52 */
53
54#include <sys/param.h>
55#include <sys/stat.h>
56#include <sys/time.h>
57#include <sys/uio.h>
58#include <err.h>
59#include <paths.h>
60#include <pwd.h>
61#include <stdio.h>
62#include <stdlib.h>
63#include <string.h>
64#include <unistd.h>
65#include <utmp.h>
66
67#include <rpc/rpc.h>
68#include <rpcsvc/rwall.h>
69
70int mbufsize;
71char *mbuf;
72
73void makemsg __P((char *));
74static void usage __P((void));
75
76/* ARGSUSED */
77int
78main(argc, argv)
79	int argc;
80	char **argv;
81{
82	char *wallhost, res;
83	CLIENT *cl;
84	struct timeval tv;
85
86	if ((argc < 2) || (argc > 3))
87		usage();
88
89	wallhost = argv[1];
90
91	makemsg(argv[2]);
92
93	/*
94	 * Create client "handle" used for calling MESSAGEPROG on the
95	 * server designated on the command line. We tell the rpc package
96	 * to use the "tcp" protocol when contacting the server.
97	*/
98	cl = clnt_create(wallhost, WALLPROG, WALLVERS, "udp");
99	if (cl == NULL) {
100		/*
101		 * Couldn't establish connection with server.
102		 * Print error message and die.
103		 */
104		errx(1, "%s", clnt_spcreateerror(wallhost));
105	}
106
107	tv.tv_sec = 15;		/* XXX ?? */
108	tv.tv_usec = 0;
109	if (clnt_call(cl, WALLPROC_WALL, xdr_wrapstring, &mbuf, xdr_void, &res, tv) != RPC_SUCCESS) {
110		/*
111		 * An error occurred while calling the server.
112		 * Print error message and die.
113		 */
114		errx(1, "%s", clnt_sperror(cl, wallhost));
115	}
116
117	exit(0);
118}
119
120static void
121usage()
122{
123	fprintf(stderr, "usage: rwall hostname [file]\n");
124	exit(1);
125}
126
127void
128makemsg(fname)
129	char *fname;
130{
131	struct tm *lt;
132	struct passwd *pw;
133	struct stat sbuf;
134	time_t now, time();
135	FILE *fp;
136	int fd;
137	char *whom, hostname[MAXHOSTNAMELEN], lbuf[100], tmpname[15];
138
139	(void)strcpy(tmpname, _PATH_TMP);
140	(void)strcat(tmpname, "wall.XXXXXX");
141	if (!(fd = mkstemp(tmpname)) || !(fp = fdopen(fd, "r+")))
142		errx(1, "can't open temporary file");
143	(void)unlink(tmpname);
144
145	if (!(whom = getlogin()))
146		whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
147	(void)gethostname(hostname, sizeof(hostname));
148	(void)time(&now);
149	lt = localtime(&now);
150
151	/*
152	 * all this stuff is to blank out a square for the message;
153	 * we wrap message lines at column 79, not 80, because some
154	 * terminals wrap after 79, some do not, and we can't tell.
155	 * Which means that we may leave a non-blank character
156	 * in column 80, but that can't be helped.
157	 */
158	(void)fprintf(fp, "Remote Broadcast Message from %s@%s\n",
159	    whom, hostname);
160	(void)fprintf(fp, "        (%s) at %d:%02d ...\n", ttyname(2),
161	    lt->tm_hour, lt->tm_min);
162
163	putc('\n', fp);
164
165	if (fname && !(freopen(fname, "r", stdin)))
166		errx(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		errx(1, "can't stat temporary file");
173	mbufsize = sbuf.st_size;
174	if (!(mbuf = malloc((u_int)mbufsize)))
175		errx(1, "out of memory");
176	if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize)
177		errx(1, "can't read temporary file");
178	(void)close(fd);
179}
180