xref: /dragonfly/usr.bin/fstat/msdosfs.c (revision 984263bc)
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  */
38 
39 #include <sys/param.h>
40 #include <sys/time.h>
41 #include <sys/stat.h>
42 #include <sys/vnode.h>
43 
44 #define	_KERNEL
45 #include <sys/mount.h>
46 #include <msdosfs/bpb.h>
47 #include <msdosfs/msdosfsmount.h>
48 #undef _KERNEL
49 
50 #include <msdosfs/denode.h>
51 #include <msdosfs/direntry.h>
52 #include <msdosfs/fat.h>
53 
54 #include <err.h>
55 #include <kvm.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 
59 /*
60  * XXX -
61  * VTODE is defined in denode.h only if _KERNEL is defined, but that leads to
62  * header explosion
63  */
64 #define VTODE(vp) ((struct denode *)(vp)->v_data)
65 
66 #include "fstat.h"
67 
68 struct dosmount {
69 	struct dosmount *next;
70 	struct msdosfsmount *kptr;	/* Pointer in kernel space */
71 	struct msdosfsmount data;	/* User space copy of structure */
72 };
73 
74 int
75 msdosfs_filestat(vp, fsp)
76 	struct vnode *vp;
77 	struct filestat *fsp;
78 {
79 	struct denode denode;
80 	static struct dosmount *mounts;
81 	struct dosmount *mnt;
82 	u_long dirsperblk;
83 	int fileid;
84 
85 	if (!KVM_READ(VTODE(vp), &denode, sizeof (denode))) {
86 		dprintf(stderr, "can't read denode at %p for pid %d\n",
87 		    (void *)VTODE(vp), Pid);
88 		return 0;
89 	}
90 
91 	/*
92 	 * Find msdosfsmount structure for the vnode's filesystem. Needed
93 	 * for some filesystem parameters
94 	 */
95 	for (mnt = mounts; mnt; mnt = mnt->next)
96 		if (mnt->kptr == denode.de_pmp)
97 			break;
98 
99 	if (!mnt) {
100 		if ((mnt = malloc(sizeof(struct dosmount))) == NULL)
101 			err(1, NULL);
102 		mnt->next = mounts;
103 		mounts = mnt;
104 		mnt->kptr = denode.de_pmp;
105 		if (!KVM_READ(denode.de_pmp, &mnt->data, sizeof mnt->data)) {
106 			dprintf(stderr,
107 			    "can't read mount info at %p for pid %d\n",
108 			    (void *)denode.de_pmp, Pid);
109 			return 0;
110 		}
111 	}
112 
113 	fsp->fsid = dev2udev(denode.de_dev);
114 	fsp->mode = 0555;
115 	fsp->mode |= denode.de_Attributes & ATTR_READONLY ? 0 : 0222;
116 	fsp->mode &= mnt->data.pm_mask;
117 
118 	/* Distinguish directories and files. No "special" files in FAT. */
119 	fsp->mode |= denode.de_Attributes & ATTR_DIRECTORY ? S_IFDIR : S_IFREG;
120 
121 	fsp->size = denode.de_FileSize;
122 	fsp->rdev = denode.de_dev;
123 
124 	/*
125 	 * XXX -
126 	 * Culled from msdosfs_vnops.c. There appears to be a problem
127 	 * here, in that a directory has the same inode number as the first
128 	 * file in the directory. stat(2) suffers from this problem also, so
129 	 * I won't try to fix it here.
130 	 *
131 	 * The following computation of the fileid must be the same as that
132 	 * used in msdosfs_readdir() to compute d_fileno. If not, pwd
133 	 * doesn't work.
134 	 */
135 	dirsperblk = mnt->data.pm_BytesPerSec / sizeof(struct direntry);
136 	if (denode.de_Attributes & ATTR_DIRECTORY) {
137 		fileid = cntobn(&mnt->data, denode.de_StartCluster)
138 		    * dirsperblk;
139 		if (denode.de_StartCluster == MSDOSFSROOT)
140 			fileid = 1;
141 	} else {
142 		fileid = cntobn(&mnt->data, denode.de_dirclust) * dirsperblk;
143 		if (denode.de_dirclust == MSDOSFSROOT)
144 			fileid = roottobn(&mnt->data, 0) * dirsperblk;
145 		fileid += denode.de_diroffset / sizeof(struct direntry);
146 	}
147 
148 	fsp->fileid = fileid;
149 	return 1;
150 }
151