xref: /freebsd/lib/libprocstat/msdosfs.c (revision b740c88bfb6453416926271c089262e7164dace3)
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("$FreeBSD$");
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 
72 struct dosmount {
73 	struct dosmount *next;
74 	struct msdosfsmount *kptr;	/* Pointer in kernel space */
75 	struct msdosfsmount data;	/* User space copy of structure */
76 };
77 
78 int
79 msdosfs_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