usr/src/cmd/rpcsvc/rwall_subr.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  *
  22  * Copyright 2002 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
  26 /* All Rights Reserved */
  27 /*
  28  * University Copyright- Copyright (c) 1982, 1986, 1988
  29  * The Regents of the University of California
  30  * All Rights Reserved
  31  *
  32  * University Acknowledgment- Portions of this document are derived from
  33  * software developed by the University of California, Berkeley, and its
  34  * contributors.
  35  */
  36
  37 /*
  38  * rwall_subr.c
  39  *      The server procedure for rwalld
  40  */
  41
  42 #include <stdio.h>
  43 #include <stdlib.h>
  44 #include <unistd.h>
  45 #include <rpc/rpc.h>
  46 #include <thread.h>
  47 #include <rpcsvc/rwall.h>
  48 #include <sys/types.h>
  49 #include <sys/stat.h>
  50 #include <syslog.h>
  51 #include <string.h>
  52
  53 #define WALL_PROG       "/usr/sbin/wall"
  54
  55 static mutex_t wall_mutex = DEFAULTMUTEX;
  56 static char *oldmsg;
  57
  58 /* ARGSUSED */
  59 bool_t
  60 wallproc_wall_1_svc(wrapstring *argp, void *res, struct svc_req *rqstp)
  61 {
  62         char *msg;
  63         FILE *fp;
  64         int rval;
  65         struct stat wall;
  66
  67         msg = *argp;
  68
  69         /*
  70          * Do not wall the same message twice in case of a retransmission
  71          * in the rare case that two walls arrive close enough with
  72          * a retransmission we might get a duplicate, but that is OK.
  73          */
  74         (void) mutex_lock(&wall_mutex);
  75         if ((oldmsg != 0) && (strcmp(msg, oldmsg) == 0)) {
  76                 (void) mutex_unlock(&wall_mutex);
  77                 return (TRUE);
  78         }
  79
  80         free(oldmsg);
  81         oldmsg = strdup(msg);
  82
  83         rval = stat(WALL_PROG, &wall);
  84
  85         /*
  86          * Make sure the wall programs exists, is executeable, and runs
  87          */
  88         if (rval == -1 || (wall.st_mode & S_IXUSR) == 0 ||
  89             (fp = popen(WALL_PROG, "w")) == NULL) {
  90                 syslog(LOG_NOTICE,
  91                         "rwall message received but could not execute %s",
  92                         WALL_PROG);
  93                 syslog(LOG_NOTICE, "%s", msg);
  94 #ifdef  DEBUG
  95                 (void) fprintf(stderr,
  96                         "rwall message received but could not execute %s",
  97                         WALL_PROG);
  98                 (void) fprintf(stderr, "%s", msg);
  99 #endif
 100                 (void) mutex_unlock(&wall_mutex);
 101                 return (TRUE);
 102         }
 103
 104         (void) fprintf(fp, "%s", msg);
 105         (void) pclose(fp);
 106         (void) mutex_unlock(&wall_mutex);
 107
 108         return (TRUE);
 109 }
 110
 111 /* ARGSUSED */
 112 int
 113 wallprog_1_freeresult(SVCXPRT *transp, xdrproc_t proc, caddr_t arg)
 114 {
 115         return (TRUE);
 116 }