msdosfs.c revision 331722 
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
37#include <sys/cdefs.h>
38__FBSDID("$FreeBSD: stable/11/lib/libprocstat/msdosfs.c 331722 2018-03-29 02:50:57Z eadler $");
39
40#include <sys/param.h>
41#include <sys/time.h>
42#include <sys/stat.h>
43#include <sys/vnode.h>
44
45#include <netinet/in.h>
46
47#define	_KERNEL
48#include <sys/mount.h>
49#include <fs/msdosfs/bpb.h>
50#include <fs/msdosfs/msdosfsmount.h>
51#undef _KERNEL
52
53#include <fs/msdosfs/denode.h>
54#include <fs/msdosfs/direntry.h>
55#include <fs/msdosfs/fat.h>
56
57#include <err.h>
58#include <kvm.h>
59#include <stdio.h>
60#include <stdlib.h>
61
62/*
63 * XXX -
64 * VTODE is defined in denode.h only if _KERNEL is defined, but that leads to
65 * header explosion
66 */
67#define VTODE(vp) ((struct denode *)getvnodedata(vp))
68
69#include "libprocstat.h"
70#include "common_kvm.h"
71
72struct dosmount {
73	struct dosmount *next;
74	struct msdosfsmount *kptr;	/* Pointer in kernel space */
75	struct msdosfsmount data;	/* User space copy of structure */
76};
77
78int
79msdosfs_filestat(kvm_t *kd, struct vnode *vp, struct vnstat *vn)
80{
81	struct denode denode;
82	static struct dosmount *mounts;
83	struct dosmount *mnt;
84	u_long dirsperblk;
85	int fileid;
86
87	if (!kvm_read_all(kd, (unsigned long)VTODE(vp), &denode,
88	    sizeof(denode))) {
89		warnx("can't read denode at %p", (void *)VTODE(vp));
90		return (1);
91	}
92
93	/*
94	 * Find msdosfsmount structure for the vnode's filesystem. Needed
95	 * for some filesystem parameters
96	 */
97	for (mnt = mounts; mnt; mnt = mnt->next)
98		if (mnt->kptr == denode.de_pmp)
99			break;
100
101	if (!mnt) {
102		if ((mnt = malloc(sizeof(struct dosmount))) == NULL) {
103			warn("malloc()");
104			return (1);
105		}
106		if (!kvm_read_all(kd, (unsigned long)denode.de_pmp,
107		    &mnt->data, sizeof(mnt->data))) {
108			free(mnt);
109			    warnx("can't read mount info at %p",
110			    (void *)denode.de_pmp);
111			return (1);
112		}
113		mnt->next = mounts;
114		mounts = mnt;
115		mnt->kptr = denode.de_pmp;
116	}
117
118	vn->vn_fsid = dev2udev(kd, mnt->data.pm_dev);
119	vn->vn_mode = 0555;
120	vn->vn_mode |= denode.de_Attributes & ATTR_READONLY ? 0 : 0222;
121	vn->vn_mode &= mnt->data.pm_mask;
122
123	/* Distinguish directories and files. No "special" files in FAT. */
124	vn->vn_mode |= denode.de_Attributes & ATTR_DIRECTORY ? S_IFDIR : S_IFREG;
125	vn->vn_size = denode.de_FileSize;
126
127	/*
128	 * XXX -
129	 * Culled from msdosfs_vnops.c. There appears to be a problem
130	 * here, in that a directory has the same inode number as the first
131	 * file in the directory. stat(2) suffers from this problem also, so
132	 * I won't try to fix it here.
133	 *
134	 * The following computation of the fileid must be the same as that
135	 * used in msdosfs_readdir() to compute d_fileno. If not, pwd
136	 * doesn't work.
137	 */
138	dirsperblk = mnt->data.pm_BytesPerSec / sizeof(struct direntry);
139	if (denode.de_Attributes & ATTR_DIRECTORY) {
140		fileid = cntobn(&mnt->data, denode.de_StartCluster)
141		    * dirsperblk;
142		if (denode.de_StartCluster == MSDOSFSROOT)
143			fileid = 1;
144	} else {
145		fileid = cntobn(&mnt->data, denode.de_dirclust) * dirsperblk;
146		if (denode.de_dirclust == MSDOSFSROOT)
147			fileid = roottobn(&mnt->data, 0) * dirsperblk;
148		fileid += denode.de_diroffset / sizeof(struct direntry);
149	}
150
151	vn->vn_fileid = fileid;
152	return (0);
153}
154