xref: /dragonfly/usr.bin/fstat/msdosfs.c (revision 1d1731fa)
1 /*
2  * Copyright (c) 2000 Peter Edwards
3  * Copyright (c) 1988, 1993
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * This code is derived from software contributed to Berkeley by Peter Edwards
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  * $FreeBSD: src/usr.bin/fstat/msdosfs.c,v 1.1.2.2 2001/11/21 10:49:37 dwmalone Exp $
37  * $DragonFly: src/usr.bin/fstat/msdosfs.c,v 1.5 2003/10/04 20:36:44 hmp Exp $
38  */
39 
40 #define	_KERNEL_STRUCTURES
41 
42 #include <sys/param.h>
43 #include <sys/time.h>
44 #include <sys/stat.h>
45 #include <sys/vnode.h>
46 
47 #include <sys/mount.h>
48 #include <vfs/msdosfs/bpb.h>
49 #include <vfs/msdosfs/msdosfsmount.h>
50 
51 #include <vfs/msdosfs/denode.h>
52 #include <vfs/msdosfs/direntry.h>
53 #include <vfs/msdosfs/fat.h>
54 
55 #include <err.h>
56 #include <kvm.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 
60 /*
61  * XXX -
62  * VTODE is defined in denode.h only if _KERNEL is defined, but that leads to
63  * header explosion
64  */
65 #define VTODE(vp) ((struct denode *)(vp)->v_data)
66 
67 #include "fstat.h"
68 
69 struct dosmount {
70 	struct dosmount *next;
71 	struct msdosfsmount *kptr;	/* Pointer in kernel space */
72 	struct msdosfsmount data;	/* User space copy of structure */
73 };
74 
75 int
76 msdosfs_filestat(struct vnode *vp, struct filestat *fsp)
77 {
78 	struct denode denode;
79 	static struct dosmount *mounts;
80 	struct dosmount *mnt;
81 	u_long dirsperblk;
82 	int fileid;
83 
84 	if (!KVM_READ(VTODE(vp), &denode, sizeof (denode))) {
85 		dprintf(stderr, "can't read denode at %p for pid %d\n",
86 		    (void *)VTODE(vp), Pid);
87 		return 0;
88 	}
89 
90 	/*
91 	 * Find msdosfsmount structure for the vnode's filesystem. Needed
92 	 * for some filesystem parameters
93 	 */
94 	for (mnt = mounts; mnt; mnt = mnt->next)
95 		if (mnt->kptr == denode.de_pmp)
96 			break;
97 
98 	if (!mnt) {
99 		if ((mnt = malloc(sizeof(struct dosmount))) == NULL)
100 			err(1, NULL);
101 		mnt->next = mounts;
102 		mounts = mnt;
103 		mnt->kptr = denode.de_pmp;
104 		if (!KVM_READ(denode.de_pmp, &mnt->data, sizeof mnt->data)) {
105 			dprintf(stderr,
106 			    "can't read mount info at %p for pid %d\n",
107 			    (void *)denode.de_pmp, Pid);
108 			return 0;
109 		}
110 	}
111 
112 	fsp->fsid = dev2udev(denode.de_dev);
113 	fsp->mode = 0555;
114 	fsp->mode |= denode.de_Attributes & ATTR_READONLY ? 0 : 0222;
115 	fsp->mode &= mnt->data.pm_mask;
116 
117 	/* Distinguish directories and files. No "special" files in FAT. */
118 	fsp->mode |= denode.de_Attributes & ATTR_DIRECTORY ? S_IFDIR : S_IFREG;
119 
120 	fsp->size = denode.de_FileSize;
121 	fsp->rdev = denode.de_dev;
122 
123 	/*
124 	 * XXX -
125 	 * Culled from msdosfs_vnops.c. There appears to be a problem
126 	 * here, in that a directory has the same inode number as the first
127 	 * file in the directory. stat(2) suffers from this problem also, so
128 	 * I won't try to fix it here.
129 	 *
130 	 * The following computation of the fileid must be the same as that
131 	 * used in msdosfs_readdir() to compute d_fileno. If not, pwd
132 	 * doesn't work.
133 	 */
134 	dirsperblk = mnt->data.pm_BytesPerSec / sizeof(struct direntry);
135 	if (denode.de_Attributes & ATTR_DIRECTORY) {
136 		fileid = cntobn(&mnt->data, denode.de_StartCluster)
137 		    * dirsperblk;
138 		if (denode.de_StartCluster == MSDOSFSROOT)
139 			fileid = 1;
140 	} else {
141 		fileid = cntobn(&mnt->data, denode.de_dirclust) * dirsperblk;
142 		if (denode.de_dirclust == MSDOSFSROOT)
143 			fileid = roottobn(&mnt->data, 0) * dirsperblk;
144 		fileid += denode.de_diroffset / sizeof(struct direntry);
145 	}
146 
147 	fsp->fileid = fileid;
148 	return 1;
149 }
150