xref: /freebsd/usr.bin/rwall/rwall.c (revision 7f3dea244c40159a41ab22da77a434d7c5b5e85a)
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
36 static 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
43 static char sccsid[] = "from: @(#)wall.c	5.14 (Berkeley) 3/2/91";
44 #endif
45 static const char rcsid[] =
46 	"$Id: rwall.c,v 1.6 1997/08/08 12:18:16 charnier 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 
70 int mbufsize;
71 char *mbuf;
72 
73 void makemsg __P((char *));
74 static void usage __P((void));
75 
76 /* ARGSUSED */
77 int
78 main(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 
120 static void
121 usage()
122 {
123 	fprintf(stderr, "usage: rwall hostname [file]\n");
124 	exit(1);
125 }
126 
127 void
128 makemsg(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[256], tmpname[64];
138 
139 	snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXX", _PATH_TMP);
140 	if (!(fd = mkstemp(tmpname)) || !(fp = fdopen(fd, "r+")))
141 		errx(1, "can't open temporary file");
142 	(void)unlink(tmpname);
143 
144 	if (!(whom = getlogin()))
145 		whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
146 	(void)gethostname(hostname, sizeof(hostname));
147 	(void)time(&now);
148 	lt = localtime(&now);
149 
150 	/*
151 	 * all this stuff is to blank out a square for the message;
152 	 * we wrap message lines at column 79, not 80, because some
153 	 * terminals wrap after 79, some do not, and we can't tell.
154 	 * Which means that we may leave a non-blank character
155 	 * in column 80, but that can't be helped.
156 	 */
157 	(void)fprintf(fp, "Remote Broadcast Message from %s@%s\n",
158 	    whom, hostname);
159 	(void)fprintf(fp, "        (%s) at %d:%02d ...\n", ttyname(2),
160 	    lt->tm_hour, lt->tm_min);
161 
162 	putc('\n', fp);
163 
164 	if (fname && !(freopen(fname, "r", stdin)))
165 		errx(1, "can't read %s", fname);
166 	while (fgets(lbuf, sizeof(lbuf), stdin))
167 		fputs(lbuf, fp);
168 	rewind(fp);
169 
170 	if (fstat(fd, &sbuf))
171 		errx(1, "can't stat temporary file");
172 	mbufsize = sbuf.st_size;
173 	if (!(mbuf = malloc((u_int)mbufsize)))
174 		errx(1, "out of memory");
175 	if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize)
176 		errx(1, "can't read temporary file");
177 	(void)close(fd);
178 }
179