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. Neither the name of the University nor the names of its contributors
  15  *    may be used to endorse or promote products derived from this software
  16  *    without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  *
  30  * @(#) Copyright (c) 1988 Regents of the University of California. All rights reserved.
  31  * @(#)wall.c   5.14 (Berkeley) 3/2/91
  32  * $FreeBSD: src/usr.bin/rwall/rwall.c,v 1.14 2005/05/21 09:55:08 ru Exp $
  33  * $DragonFly: src/usr.bin/rwall/rwall.c,v 1.7 2005/07/30 16:44:12 liamfoy Exp $
  34  */
  35
  36 /*
  37  * This program is not related to David Wall, whose Stanford Ph.D. thesis
  38  * is entitled "Mechanisms for Broadcast and Selective Broadcast".
  39  */
  40
  41 #include <sys/types.h>
  42 #include <sys/param.h>
  43 #include <sys/stat.h>
  44
  45 #include <err.h>
  46 #include <paths.h>
  47 #include <pwd.h>
  48 #include <stdio.h>
  49 #include <stdlib.h>
  50 #include <time.h>
  51 #include <unistd.h>
  52
  53 #include <rpc/rpc.h>
  54 #include <rpcsvc/rwall.h>
  55
  56 static char     *mbuf;
  57
  58 static void     makemsg(const char *);
  59 static void     usage(void);
  60
  61 int
  62 main(int argc, char **argv)
  63 {
  64         const char *wallhost;
  65         char *res;
  66         CLIENT *cl;
  67         struct timeval tv;
  68         int c;
  69
  70         while ((c = getopt(argc, argv, "")) != -1) {
  71                 switch (c) {
  72                 default:
  73                         usage();
  74                 }
  75         }
  76
  77         argc -= optind;
  78         argv += optind;
  79
  80         if (argc < 1 || argc > 2)
  81                 usage();
  82
  83         wallhost = argv[0];
  84
  85         /*
  86          * Create client "handle" used for calling MESSAGEPROG on the
  87          * server designated on the command line. We tell the rpc package
  88          * to use the "tcp" protocol when contacting the server.
  89         */
  90         cl = clnt_create(wallhost, WALLPROG, WALLVERS, "udp");
  91         if (cl == NULL) {
  92                 /*
  93                  * Couldn't establish connection with server.
  94                  * Print error message and die.
  95                  */
  96                 clnt_pcreateerror(wallhost);
  97                 exit(1);
  98         }
  99
 100         makemsg(argv[1]);
 101
 102         tv.tv_sec = 15;         /* XXX ?? */
 103         tv.tv_usec = 0;
 104         if (clnt_call(cl, WALLPROC_WALL, (xdrproc_t)xdr_wrapstring, &mbuf,
 105             (xdrproc_t)xdr_void, &res, tv) != RPC_SUCCESS) {
 106                 /*
 107                  * An error occurred while calling the server.
 108                  * Print error message and die.
 109                  */
 110                 clnt_perror(cl, wallhost);
 111                 exit(1);
 112         }
 113
 114         return(0);
 115 }
 116
 117 static void
 118 usage(void)
 119 {
 120         fprintf(stderr, "usage: rwall host [file]\n");
 121         exit(1);
 122 }
 123
 124 static void
 125 makemsg(const char *fname)
 126 {
 127         struct tm *lt;
 128         struct passwd *pw;
 129         struct stat sbuf;
 130         time_t now;
 131         FILE *fp;
 132         int fd;
 133         size_t mbufsize;
 134         char hostname[MAXHOSTNAMELEN], lbuf[256], tmpname[MAXPATHLEN];
 135         const char *whom, *tty;
 136
 137         snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXX", _PATH_TMP);
 138         if ((fd = mkstemp(tmpname)) == -1 || (fp = fdopen(fd, "r+")) == NULL)
 139                 err(1, "can't open temporary file");
 140
 141         if (unlink(tmpname) == -1)
 142                 err(1, "unlink failed: %s", tmpname);
 143
 144         if ((whom = getlogin()) == NULL)
 145                 whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
 146         gethostname(hostname, sizeof(hostname));
 147
 148         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         fprintf(fp, "Remote Broadcast Message from %s@%s\n", whom, hostname);
 159         tty = ttyname(STDERR_FILENO);
 160         if (tty == NULL)
 161                 tty = "notty";
 162         fprintf(fp, "        (%s) at %d:%02d ...\n", tty,
 163                 lt->tm_hour, lt->tm_min);
 164
 165         putc('\n', fp);
 166
 167         if (fname && !(freopen(fname, "r", stdin)))
 168                 err(1, "can't read %s", fname);
 169         while (fgets(lbuf, sizeof(lbuf), stdin))
 170                 fputs(lbuf, fp);
 171         rewind(fp);
 172
 173         if (fstat(fd, &sbuf))
 174                 err(1, "can't stat temporary file");
 175         mbufsize = (size_t)sbuf.st_size;
 176         if ((mbuf = malloc(mbufsize)) == NULL)
 177                 err(1, "malloc failed");
 178         if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != (u_int)mbufsize)
 179                 err(1, "can't read temporary file");
 180         if (close(fd))
 181                 warn("close failed");
 182 }