usr/src/cmd/fs.d/autofs/autod_lookup.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 (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  *      autod_lookup.c
  23  *
  24  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
  25  * Use is subject to license terms.
  26  */
  27
  28 #pragma ident   "%Z%%M% %I%     %E% SMI"
  29
  30 #include <stdio.h>
  31 #include <ctype.h>
  32 #include <string.h>
  33 #include <syslog.h>
  34 #include <errno.h>
  35 #include <locale.h>
  36 #include <stdlib.h>
  37 #include <unistd.h>
  38 #include <assert.h>
  39 #include "automount.h"
  40
  41 int
  42 do_lookup1(
  43         char *mapname,
  44         char *key,
  45         char *subdir,
  46         char *mapopts,
  47         char *path,
  48         uint_t isdirect,
  49         uid_t uid,
  50         autofs_action_t *action,
  51         struct linka *linkp)
  52 {
  53         struct mapline ml;
  54         struct mapent *mapents = NULL;
  55         int err;
  56         struct autofs_rddir_cache *rdcp;
  57         int found = 0;
  58         bool_t iswildcard = FALSE;
  59         bool_t isrestricted = hasrestrictopt(mapopts);
  60         char *stack[STACKSIZ];
  61         char **stkptr = stack;
  62
  63         /*
  64          * Default action is for no work to be done by kernel AUTOFS.
  65          */
  66         *action = AUTOFS_NONE;
  67
  68         /*
  69          * Is there a cache for this map?
  70          */
  71         rw_rdlock(&autofs_rddir_cache_lock);
  72         err = autofs_rddir_cache_lookup(mapname, &rdcp);
  73         if (!err && rdcp->full) {
  74                 rw_unlock(&autofs_rddir_cache_lock);
  75                 /*
  76                  * Try to lock readdir cache entry for reading, if
  77                  * the entry can not be locked, then avoid blocking
  78                  * and go to the name service. I'm assuming it is
  79                  * faster to go to the name service than to wait for
  80                  * the cache to be populated.
  81                  */
  82                 if (rw_tryrdlock(&rdcp->rwlock) == 0) {
  83                         found = (rddir_entry_lookup(key, rdcp->entp) != NULL);
  84                         rw_unlock(&rdcp->rwlock);
  85                 }
  86         } else
  87                 rw_unlock(&autofs_rddir_cache_lock);
  88
  89         if (!err) {
  90                 /*
  91                  * release reference on cache entry
  92                  */
  93                 mutex_lock(&rdcp->lock);
  94                 rdcp->in_use--;
  95                 assert(rdcp->in_use >= 0);
  96                 mutex_unlock(&rdcp->lock);
  97         }
  98
  99         if (found)
 100                 return (0);
 101
 102         /*
 103          * entry not found in cache, try the name service now
 104          */
 105         err = 0;
 106
 107         /* initialize the stack of open files for this thread */
 108         stack_op(INIT, NULL, stack, &stkptr);
 109
 110         err = getmapent(key, mapname, &ml, stack, &stkptr, &iswildcard,
 111                 isrestricted);
 112         if (err == 0) /* call parser w default mount_access = TRUE */
 113                 mapents = parse_entry(key, mapname, mapopts, &ml,
 114                                     subdir, isdirect, TRUE);
 115
 116         /*
 117          * Now we indulge in a bit of hanky-panky.
 118          * If the entry isn't found in the map and the
 119          * name begins with an "=" then we assume that
 120          * the name is an undocumented control message
 121          * for the daemon.  This is accessible only
 122          * to superusers.
 123          */
 124         if (mapents == NULL && *action == AUTOFS_NONE) {
 125                 if (*key == '=' && uid == 0) {
 126                         if (isdigit(*(key+1))) {
 127                                 /*
 128                                  * If next character is a digit
 129                                  * then set the trace level.
 130                                  */
 131                                 trace = atoi(key+1);
 132                                 trace_prt(1, "Automountd: trace level = %d\n",
 133                                         trace);
 134                         } else if (*(key+1) == 'v') {
 135                                 /*
 136                                  * If it's a "v" then
 137                                  * toggle verbose mode.
 138                                  */
 139                                 verbose = !verbose;
 140                                 trace_prt(1, "Automountd: verbose %s\n",
 141                                                 verbose ? "on" : "off");
 142                         }
 143                 }
 144
 145                 err = ENOENT;
 146                 goto done;
 147         }
 148
 149         /*
 150          * Each mapent in the list describes a mount to be done.
 151          * Since I'm only doing a lookup, I only care whether a mapentry
 152          * was found or not. The mount will be done on a later RPC to
 153          * do_mount1.
 154          */
 155         if (mapents == NULL && *action == AUTOFS_NONE)
 156                 err = ENOENT;
 157
 158 done:   if (mapents)
 159                 free_mapent(mapents);
 160
 161         if (*action == AUTOFS_NONE && (iswildcard == TRUE)) {
 162                 *action = AUTOFS_MOUNT_RQ;
 163         }
 164         if (trace > 1) {
 165                 trace_prt(1, "  do_lookup1: action=%d wildcard=%s error=%d\n",
 166                         *action, iswildcard ? "TRUE" : "FALSE", err);
 167         }
 168         return (err);
 169 }