xref: /netbsd/lib/libquota/quota_open.c (revision abf0121a)
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 *
quota_open(const char * path)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 *
quota_getmountpoint(struct quotahandle * qh)132 quota_getmountpoint(struct quotahandle *qh)
133 {
134 	return qh->qh_mountpoint;
135 }
136 
137 const char *
quota_getmountdevice(struct quotahandle * qh)138 quota_getmountdevice(struct quotahandle *qh)
139 {
140 	return qh->qh_mountdevice;
141 }
142 
143 void
quota_close(struct quotahandle * qh)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
quota_quotaon(struct quotahandle * qh,int idtype)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
quota_quotaoff(struct quotahandle * qh,int idtype)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