usr.bin/rwall/rwall.c

   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  * @(#) Copyright (c) 1988 Regents of the University of California. All rights reserved.
  35  * @(#)wall.c   5.14 (Berkeley) 3/2/91
  36  * $FreeBSD: src/usr.bin/rwall/rwall.c,v 1.8.2.1 2001/02/18 02:27:54 kris Exp $
  37  * $DragonFly: src/usr.bin/rwall/rwall.c,v 1.7 2005/07/30 18:44:12 liamfoy Exp $
  38  */
  39
  40 /*
  41  * This program is not related to David Wall, whose Stanford Ph.D. thesis
  42  * is entitled "Mechanisms for Broadcast and Selective Broadcast".
  43  */
  44
  45 #include <sys/types.h>
  46 #include <sys/param.h>
  47 #include <sys/stat.h>
  48 #include <sys/time.h>
  49
  50 #include <err.h>
  51 #include <paths.h>
  52 #include <pwd.h>
  53 #include <stdio.h>
  54 #include <stdlib.h>
  55 #include <time.h>
  56 #include <unistd.h>
  57
  58 #include <rpc/rpc.h>
  59 #include <rpcsvc/rwall.h>
  60
  61 static size_t   mbufsize;
  62 static char     *mbuf;
  63
  64 static void     makemsg(const char *);
  65 static void     usage(void);
  66
  67 int
  68 main(int argc, char **argv)
  69 {
  70         const char *wallhost;
  71         char *res;
  72         CLIENT *cl;
  73         struct timeval tv;
  74         int c;
  75
  76         while ((c = getopt(argc, argv, "")) != -1) {
  77                 switch (c) {
  78                 default:
  79                         usage();
  80                 }
  81         }
  82
  83         argc -= optind;
  84         argv += optind;
  85
  86         if (argc < 1 || argc > 2)
  87                 usage();
  88
  89         wallhost = argv[0];
  90
  91         /*
  92          * Create client "handle" used for calling MESSAGEPROG on the
  93          * server designated on the command line. We tell the rpc package
  94          * to use the "tcp" protocol when contacting the server.
  95         */
  96         cl = clnt_create(wallhost, WALLPROG, WALLVERS, "udp");
  97         if (cl == NULL) {
  98                 /*
  99                  * Couldn't establish connection with server.
 100                  * Print error message and die.
 101                  */
 102                 clnt_pcreateerror(wallhost);
 103                 exit(1);
 104         }
 105
 106         makemsg(argv[1]);
 107
 108         tv.tv_sec = 15;         /* XXX ?? */
 109         tv.tv_usec = 0;
 110         if (clnt_call(cl, WALLPROC_WALL, (xdrproc_t)xdr_wrapstring, &mbuf, xdr_void,
 111                       &res, tv) != RPC_SUCCESS) {
 112                 /*
 113                  * An error occurred while calling the server.
 114                  * Print error message and die.
 115                  */
 116                 clnt_perror(cl, wallhost);
 117                 exit(1);
 118         }
 119
 120         exit(0);
 121 }
 122
 123 static void
 124 usage(void)
 125 {
 126         fprintf(stderr, "usage: rwall hostname [file]\n");
 127         exit(1);
 128 }
 129
 130 static void
 131 makemsg(const char *fname)
 132 {
 133         struct tm *lt;
 134         struct passwd *pw;
 135         struct stat sbuf;
 136         time_t now;
 137         FILE *fp;
 138         int fd;
 139         char hostname[MAXHOSTNAMELEN], lbuf[256], tmpname[MAXPATHLEN];
 140         const char *whom, *tty;
 141
 142         snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXX", _PATH_TMP);
 143         if ((fd = mkstemp(tmpname)) == -1 || (fp = fdopen(fd, "r+")) == NULL)
 144                 err(1, "can't open temporary file");
 145
 146         if (unlink(tmpname) == -1)
 147                 err(1, "unlink failed: %s", tmpname);
 148
 149         if ((whom = getlogin()) == NULL)
 150                 whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
 151         gethostname(hostname, sizeof(hostname));
 152
 153         time(&now);
 154         lt = localtime(&now);
 155
 156         /*
 157          * all this stuff is to blank out a square for the message;
 158          * we wrap message lines at column 79, not 80, because some
 159          * terminals wrap after 79, some do not, and we can't tell.
 160          * Which means that we may leave a non-blank character
 161          * in column 80, but that can't be helped.
 162          */
 163         fprintf(fp, "Remote Broadcast Message from %s@%s\n", whom, hostname);
 164         tty = ttyname(STDERR_FILENO);
 165         if (tty == NULL)
 166                 tty = "no tty";
 167         fprintf(fp, "        (%s) at %d:%02d ...\n", tty,
 168                 lt->tm_hour, lt->tm_min);
 169
 170         putc('\n', fp);
 171
 172         if (fname && !(freopen(fname, "r", stdin)))
 173                 err(1, "can't read %s", fname);
 174         while (fgets(lbuf, sizeof(lbuf), stdin))
 175                 fputs(lbuf, fp);
 176         rewind(fp);
 177
 178         if (fstat(fd, &sbuf))
 179                 err(1, "can't stat temporary file");
 180         mbufsize = (size_t)sbuf.st_size;
 181         if ((mbuf = malloc(mbufsize)) == NULL)
 182                 err(1, "malloc failed");
 183         if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize)
 184                 err(1, "can't read temporary file");
 185         if (close(fd))
 186                 warn("close failed");
 187 }