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
56 static char *mbuf;
57
58 static char notty[] = "no tty";
59
60 static void makemsg(const char *);
61 static void usage(void) __dead2;
62
63 /* ARGSUSED */
64 int
main(int argc,char * argv[])65 main(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
106 static void
usage(void)107 usage(void)
108 {
109 fprintf(stderr, "usage: rwall host [file]\n");
110 exit(1);
111 }
112
113 static void
makemsg(const char * fname)114 makemsg(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