xref: /openbsd/usr.bin/rwall/rwall.c (revision 264ca280)
1 /*	$OpenBSD: rwall.c,v 1.13 2015/01/16 06:40:11 deraadt Exp $	*/
2 
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. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*
34  * This program is not related to David Wall, whose Stanford Ph.D. thesis
35  * is entitled "Mechanisms for Broadcast and Selective Broadcast".
36  */
37 
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <time.h>
42 #include <sys/types.h>
43 #include <sys/stat.h>
44 #include <pwd.h>
45 #include <unistd.h>
46 #include <limits.h>
47 #include <paths.h>
48 #include <err.h>
49 
50 #include <rpc/rpc.h>
51 #include <rpcsvc/rwall.h>
52 
53 struct timeval timeout = { 25, 0 };
54 int mbufsize;
55 char *mbuf;
56 
57 void makemsg(char *);
58 
59 int
60 main(int argc, char *argv[])
61 {
62 	extern char *__progname;
63 	char *wallhost, res;
64 	CLIENT *cl;
65 
66 	if ((argc < 2) || (argc > 3)) {
67 		fprintf(stderr, "usage: %s host [file]\n", __progname);
68 		exit(1);
69 	}
70 
71 	wallhost = argv[1];
72 
73 	makemsg(argv[2]);
74 
75 	/*
76 	 * Create client "handle" used for calling MESSAGEPROG on the
77 	 * server designated on the command line. We tell the rpc package
78 	 * to use the "tcp" protocol when contacting the server.
79 	*/
80 	cl = clnt_create(wallhost, WALLPROG, WALLVERS, "udp");
81 	if (cl == NULL) {
82 		/*
83 		 * Couldn't establish connection with server.
84 		 * Print error message and die.
85 		 */
86 		clnt_pcreateerror(wallhost);
87 		exit(1);
88 	}
89 
90 	if (clnt_call(cl, WALLPROC_WALL, xdr_wrapstring, &mbuf, xdr_void,
91 	    &res, timeout) != RPC_SUCCESS) {
92 		/*
93 		 * An error occurred while calling the server.
94 		 * Print error message and die.
95 		 */
96 		clnt_perror(cl, wallhost);
97 		exit(1);
98 	}
99 
100 	exit(0);
101 }
102 
103 void
104 makemsg(char *fname)
105 {
106 	struct tm *lt;
107 	struct passwd *pw;
108 	struct stat sbuf;
109 	time_t now;
110 	FILE *fp;
111 	int fd;
112 	char *whom, hostname[HOST_NAME_MAX+1], lbuf[100], tmpname[PATH_MAX];
113 
114 	snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXXXXXX", _PATH_TMP);
115 	if ((fd = mkstemp(tmpname)) == -1 || !(fp = fdopen(fd, "r+")))
116 		err(1, "can't open temporary file");
117 	(void)unlink(tmpname);
118 
119 	if (!(whom = getlogin()))
120 		whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
121 	(void)gethostname(hostname, sizeof(hostname));
122 	(void)time(&now);
123 	lt = localtime(&now);
124 
125 	/*
126 	 * all this stuff is to blank out a square for the message;
127 	 * we wrap message lines at column 79, not 80, because some
128 	 * terminals wrap after 79, some do not, and we can't tell.
129 	 * Which means that we may leave a non-blank character
130 	 * in column 80, but that can't be helped.
131 	 */
132 	(void)fprintf(fp, "Remote Broadcast Message from %s@%s\n",
133 	    whom, hostname);
134 	(void)fprintf(fp, "        (%s) at %d:%02d ...\n", ttyname(2),
135 	    lt->tm_hour, lt->tm_min);
136 
137 	putc('\n', fp);
138 
139 	if (fname && !(freopen(fname, "r", stdin)))
140 		err(1, "%s", fname);
141 	while (fgets(lbuf, sizeof(lbuf), stdin))
142 		fputs(lbuf, fp);
143 	rewind(fp);
144 
145 	if (fstat(fd, &sbuf))
146 		err(1, "can't stat temporary file");
147 	mbufsize = sbuf.st_size;
148 	if (!(mbuf = malloc((u_int)mbufsize)))
149 		err(1, "malloc");
150 	if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize)
151 		err(1, "can't read temporary file");
152 	(void)close(fd);
153 }
154