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      1 /*	$NetBSD: quota_open.c,v 1.7 2012/02/01 05:34:40 dholland Exp $	*/
      2 /*-
      3  * Copyright (c) 2011 The NetBSD Foundation, Inc.
      4  * All rights reserved.
      5  *
      6  * This code is derived from software contributed to The NetBSD Foundation
      7  * by David A. Holland.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     19  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     20  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     21  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     22  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     28  * POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #include <sys/cdefs.h>
     32 __RCSID("$NetBSD: quota_open.c,v 1.7 2012/02/01 05:34:40 dholland Exp $");
     33 
     34 #include <sys/types.h>
     35 #include <sys/statvfs.h>
     36 #include <stdlib.h>
     37 #include <string.h>
     38 #include <unistd.h>
     39 #include <errno.h>
     40 
     41 #include <quota.h>
     42 #include "quotapvt.h"
     43 
     44 struct quotahandle *
     45 quota_open(const char *path)
     46 {
     47 
     48 	struct statvfs stv;
     49 	struct quotahandle *qh;
     50 	int mode;
     51 	int serrno;
     52 
     53 	/*
     54 	 * Probe order:
     55 	 *
     56 	 *    1. Check for NFS. NFS quota ops don't go to the kernel
     57 	 *    at all but instead do RPCs to the NFS server's
     58 	 *    rpc.rquotad, so it doesn't matter what the kernel
     59 	 *    thinks.
     60 	 *
     61 	 *    2. Check if quotas are enabled in the mount flags. If
     62 	 *    so, we can do quotactl calls.
     63 	 *
     64 	 *    3. Check if the volume is listed in fstab as one of
     65 	 *    the filesystem types supported by quota_oldfiles.c,
     66 	 *    and with the proper mount options to enable quotas.
     67 	 *
     68 	 * Note that (as of this writing) the mount options for
     69 	 * enabling quotas are accepted by mount for *all* filesystem
     70 	 * types and then ignored -- the kernel mount flag (ST_QUOTA /
     71 	 * MNT_QUOTA) gets set either by the filesystem based on its
     72 	 * own criteria, or for old-style quotas, during quotaon. The
     73 	 * quota filenames specified in fstab are not passed to or
     74 	 * known by the kernel except via quota_oldfiles.c! This is
     75 	 * generally gross but not easily fixed.
     76 	 */
     77 
     78 	if (statvfs(path, &stv) < 0) {
     79 		return NULL;
     80 	}
     81 
     82 	__quota_oldfiles_load_fstab();
     83 
     84 	if (!strcmp(stv.f_fstypename, "nfs")) {
     85 		mode = QUOTA_MODE_NFS;
     86 	} else if ((stv.f_flag & ST_QUOTA) != 0) {
     87 		mode = QUOTA_MODE_KERNEL;
     88 	} else if (__quota_oldfiles_infstab(stv.f_mntonname)) {
     89 		mode = QUOTA_MODE_OLDFILES;
     90 	} else {
     91 		errno = EOPNOTSUPP;
     92 		return NULL;
     93 	}
     94 
     95 	qh = malloc(sizeof(*qh));
     96 	if (qh == NULL) {
     97 		return NULL;
     98 	}
     99 
    100 	/*
    101 	 * Get the mount point from statvfs; this way the passed-in
    102 	 * path can be any path on the volume.
    103 	 */
    104 
    105 	qh->qh_mountpoint = strdup(stv.f_mntonname);
    106 	if (qh->qh_mountpoint == NULL) {
    107 		serrno = errno;
    108 		free(qh);
    109 		errno = serrno;
    110 		return NULL;
    111 	}
    112 
    113 	qh->qh_mountdevice = strdup(stv.f_mntfromname);
    114 	if (qh->qh_mountdevice == NULL) {
    115 		serrno = errno;
    116 		free(qh->qh_mountpoint);
    117 		free(qh);
    118 		errno = serrno;
    119 		return NULL;
    120 	}
    121 
    122 	qh->qh_mode = mode;
    123 
    124 	qh->qh_oldfilesopen = 0;
    125 	qh->qh_userfile = -1;
    126 	qh->qh_groupfile = -1;
    127 
    128 	return qh;
    129 }
    130 
    131 const char *
    132 quota_getmountpoint(struct quotahandle *qh)
    133 {
    134 	return qh->qh_mountpoint;
    135 }
    136 
    137 const char *
    138 quota_getmountdevice(struct quotahandle *qh)
    139 {
    140 	return qh->qh_mountdevice;
    141 }
    142 
    143 void
    144 quota_close(struct quotahandle *qh)
    145 {
    146 	if (qh->qh_userfile >= 0) {
    147 		close(qh->qh_userfile);
    148 	}
    149 	if (qh->qh_groupfile >= 0) {
    150 		close(qh->qh_groupfile);
    151 	}
    152 	free(qh->qh_mountdevice);
    153 	free(qh->qh_mountpoint);
    154 	free(qh);
    155 }
    156 
    157 int
    158 quota_quotaon(struct quotahandle *qh, int idtype)
    159 {
    160 	switch (qh->qh_mode) {
    161 	    case QUOTA_MODE_NFS:
    162 		errno = EOPNOTSUPP;
    163 		break;
    164 	    case QUOTA_MODE_OLDFILES:
    165 		return __quota_oldfiles_quotaon(qh, idtype);
    166 	    case QUOTA_MODE_KERNEL:
    167 		return __quota_kernel_quotaon(qh, idtype);
    168 	    default:
    169 		errno = EINVAL;
    170 		break;
    171 	}
    172 	return -1;
    173 }
    174 
    175 int
    176 quota_quotaoff(struct quotahandle *qh, int idtype)
    177 {
    178 	switch (qh->qh_mode) {
    179 	    case QUOTA_MODE_NFS:
    180 		errno = EOPNOTSUPP;
    181 		break;
    182 	    case QUOTA_MODE_OLDFILES:
    183 		/* can't quotaoff if we haven't quotaon'd */
    184 		errno = ENOTCONN;
    185 		break;
    186 	    case QUOTA_MODE_KERNEL:
    187 		return __quota_kernel_quotaoff(qh, idtype);
    188 	    default:
    189 		errno = EINVAL;
    190 		break;
    191 	}
    192 	return -1;
    193 }
    194