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 #pragma ident   "%Z%%M% %I%     %E% SMI"
  38
  39 /*
  40  * rwall_subr.c
  41  *      The server procedure for rwalld
  42  */
  43
  44 #include <stdio.h>
  45 #include <stdlib.h>
  46 #include <unistd.h>
  47 #include <rpc/rpc.h>
  48 #include <thread.h>
  49 #include <rpcsvc/rwall.h>
  50 #include <sys/types.h>
  51 #include <sys/stat.h>
  52 #include <syslog.h>
  53 #include <string.h>
  54
  55 #define WALL_PROG       "/usr/sbin/wall"
  56
  57 static mutex_t wall_mutex = DEFAULTMUTEX;
  58 static char *oldmsg;
  59
  60 /* ARGSUSED */
  61 bool_t
  62 wallproc_wall_1_svc(wrapstring *argp, void *res, struct svc_req *rqstp)
  63 {
  64         char *msg;
  65         FILE *fp;
  66         int rval;
  67         struct stat wall;
  68
  69         msg = *argp;
  70
  71         /*
  72          * Do not wall the same message twice in case of a retransmission
  73          * in the rare case that two walls arrive close enough with
  74          * a retransmission we might get a duplicate, but that is OK.
  75          */
  76         (void) mutex_lock(&wall_mutex);
  77         if ((oldmsg != 0) && (strcmp(msg, oldmsg) == 0)) {
  78                 (void) mutex_unlock(&wall_mutex);
  79                 return (TRUE);
  80         }
  81
  82         if (oldmsg)
  83                 free(oldmsg);
  84         oldmsg = strdup(msg);
  85
  86         rval = stat(WALL_PROG, &wall);
  87
  88         /*
  89          * Make sure the wall programs exists, is executeable, and runs
  90          */
  91         if (rval == -1 || (wall.st_mode & S_IXUSR) == 0 ||
  92             (fp = popen(WALL_PROG, "w")) == NULL) {
  93                 syslog(LOG_NOTICE,
  94                         "rwall message received but could not execute %s",
  95                         WALL_PROG);
  96                 syslog(LOG_NOTICE, "%s", msg);
  97 #ifdef  DEBUG
  98                 (void) fprintf(stderr,
  99                         "rwall message received but could not execute %s",
 100                         WALL_PROG);
 101                 (void) fprintf(stderr, "%s", msg);
 102 #endif
 103                 (void) mutex_unlock(&wall_mutex);
 104                 return (TRUE);
 105         }
 106
 107         (void) fprintf(fp, "%s", msg);
 108         (void) pclose(fp);
 109         (void) mutex_unlock(&wall_mutex);
 110
 111         return (TRUE);
 112 }
 113
 114 /* ARGSUSED */
 115 int
 116 wallprog_1_freeresult(SVCXPRT *transp, xdrproc_t proc, caddr_t arg)
 117 {
 118         return (TRUE);
 119 }