/*      $OpenBSD: rwall.c,v 1.13 2015/01/16 06:40:11 deraadt Exp $      */

/*
 * Copyright (c) 1993 Christopher G. Demetriou
 * Copyright (c) 1988, 1990 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * This program is not related to David Wall, whose Stanford Ph.D. thesis
 * is entitled "Mechanisms for Broadcast and Selective Broadcast".
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <pwd.h>
#include <unistd.h>
#include <limits.h>
#include <paths.h>
#include <err.h>

#include <rpc/rpc.h>
#include <rpcsvc/rwall.h>

struct timeval timeout = { 25, 0 };
int mbufsize;
char *mbuf;

void makemsg(char *);

int
main(int argc, char *argv[])
{
        extern char *__progname;
        char *wallhost, res;
        CLIENT *cl;

        if ((argc < 2) || (argc > 3)) {
                fprintf(stderr, "usage: %s host [file]\n", __progname);
                exit(1);
        }

        wallhost = argv[1];

        makemsg(argv[2]);

        /*
         * Create client "handle" used for calling MESSAGEPROG on the
         * server designated on the command line. We tell the rpc package
         * to use the "tcp" protocol when contacting the server.
        */
        cl = clnt_create(wallhost, WALLPROG, WALLVERS, "udp");
        if (cl == NULL) {
                /*
                 * Couldn't establish connection with server.
                 * Print error message and die.
                 */
                clnt_pcreateerror(wallhost);
                exit(1);
        }

        if (clnt_call(cl, WALLPROC_WALL, xdr_wrapstring, &mbuf, xdr_void,
            &res, timeout) != RPC_SUCCESS) {
                /*
                 * An error occurred while calling the server.
                 * Print error message and die.
                 */
                clnt_perror(cl, wallhost);
                exit(1);
        }

        exit(0);
}

void
makemsg(char *fname)
{
        struct tm *lt;
        struct passwd *pw;
        struct stat sbuf;
        time_t now;
        FILE *fp;
        int fd;
        char *whom, hostname[HOST_NAME_MAX+1], lbuf[100], tmpname[PATH_MAX];

        snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXXXXXX", _PATH_TMP);
        if ((fd = mkstemp(tmpname)) == -1 || !(fp = fdopen(fd, "r+")))
                err(1, "can't open temporary file");
        (void)unlink(tmpname);

        if (!(whom = getlogin()))
                whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
        (void)gethostname(hostname, sizeof(hostname));
        (void)time(&now);
        lt = localtime(&now);

        /*
         * all this stuff is to blank out a square for the message;
         * we wrap message lines at column 79, not 80, because some
         * terminals wrap after 79, some do not, and we can't tell.
         * Which means that we may leave a non-blank character
         * in column 80, but that can't be helped.
         */
        (void)fprintf(fp, "Remote Broadcast Message from %s@%s\n",
            whom, hostname);
        (void)fprintf(fp, "        (%s) at %d:%02d ...\n", ttyname(2),
            lt->tm_hour, lt->tm_min);

        putc('\n', fp);

        if (fname && !(freopen(fname, "r", stdin)))
                err(1, "%s", fname);
        while (fgets(lbuf, sizeof(lbuf), stdin))
                fputs(lbuf, fp);
        rewind(fp);

        if (fstat(fd, &sbuf))
                err(1, "can't stat temporary file");
        mbufsize = sbuf.st_size;
        if (!(mbuf = malloc((u_int)mbufsize)))
                err(1, "malloc");
        if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize)
                err(1, "can't read temporary file");
        (void)close(fd);
}