summaryrefslogtreecommitdiff
path: root/fs/ncpfs/symlink.c
blob: 52439ddc8de051bc5693f14220e25ce2d7fcfe39 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
/*
 *  linux/fs/ncpfs/symlink.c
 *
 *  Code for allowing symbolic links on NCPFS (i.e. NetWare)
 *  Symbolic links are not supported on native NetWare, so we use an
 *  infrequently-used flag (Sh) and store a two-word magic header in
 *  the file to make sure we don't accidentally use a non-link file
 *  as a link.
 *
 *  When using the NFS namespace, we set the mode to indicate a symlink and
 *  don't bother with the magic numbers.
 *
 *  from linux/fs/ext2/symlink.c
 *
 *  Copyright (C) 1998-99, Frank A. Vorstenbosch
 *
 *  ncpfs symlink handling code
 *  NLS support (c) 1999 Petr Vandrovec
 *  Modified 2000 Ben Harris, University of Cambridge for NFS NS meta-info
 *
 */


#include <asm/uaccess.h>

#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/time.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/stat.h>
#include "ncp_fs.h"

/* these magic numbers must appear in the symlink file -- this makes it a bit
   more resilient against the magic attributes being set on random files. */

#define NCP_SYMLINK_MAGIC0	cpu_to_le32(0x6c6d7973)     /* "symlnk->" */
#define NCP_SYMLINK_MAGIC1	cpu_to_le32(0x3e2d6b6e)

/* ----- read a symbolic link ------------------------------------------ */

static int ncp_symlink_readpage(struct file *file, struct page *page)
{
	struct inode *inode = page->mapping->host;
	int error, length, len;
	char *link, *rawlink;
	char *buf = kmap(page);

	error = -ENOMEM;
	rawlink = kmalloc(NCP_MAX_SYMLINK_SIZE, GFP_KERNEL);
	if (!rawlink)
		goto fail;

	if (ncp_make_open(inode,O_RDONLY))
		goto failEIO;

	error=ncp_read_kernel(NCP_SERVER(inode),NCP_FINFO(inode)->file_handle,
                         0,NCP_MAX_SYMLINK_SIZE,rawlink,&length);

	ncp_inode_close(inode);
	/* Close file handle if no other users... */
	ncp_make_closed(inode);
	if (error)
		goto failEIO;

	if (NCP_FINFO(inode)->flags & NCPI_KLUDGE_SYMLINK) {
		if (length<NCP_MIN_SYMLINK_SIZE || 
		    ((__le32 *)rawlink)[0]!=NCP_SYMLINK_MAGIC0 ||
		    ((__le32 *)rawlink)[1]!=NCP_SYMLINK_MAGIC1)
		    	goto failEIO;
		link = rawlink + 8;
		length -= 8;
	} else {
		link = rawlink;
	}

	len = NCP_MAX_SYMLINK_SIZE;
	error = ncp_vol2io(NCP_SERVER(inode), buf, &len, link, length, 0);
	kfree(rawlink);
	if (error)
		goto fail;
	SetPageUptodate(page);
	kunmap(page);
	unlock_page(page);
	return 0;

failEIO:
	error = -EIO;
	kfree(rawlink);
fail:
	SetPageError(page);
	kunmap(page);
	unlock_page(page);
	return error;
}

/*
 * symlinks can't do much...
 */
const struct address_space_operations ncp_symlink_aops = {
	.readpage	= ncp_symlink_readpage,
};
	
/* ----- create a new symbolic link -------------------------------------- */
 
int ncp_symlink(struct inode *dir, struct dentry *dentry, const char *symname) {
	struct inode *inode;
	char *rawlink;
	int length, err, i, outlen;
	int kludge;
	umode_t mode;
	__le32 attr;
	unsigned int hdr;

	DPRINTK("ncp_symlink(dir=%p,dentry=%p,symname=%s)\n",dir,dentry,symname);

	if (ncp_is_nfs_extras(NCP_SERVER(dir), NCP_FINFO(dir)->volNumber))
		kludge = 0;
	else
#ifdef CONFIG_NCPFS_EXTRAS
	if (NCP_SERVER(dir)->m.flags & NCP_MOUNT_SYMLINKS)
		kludge = 1;
	else
#endif
	/* EPERM is returned by VFS if symlink procedure does not exist */
		return -EPERM;
  
	rawlink = kmalloc(NCP_MAX_SYMLINK_SIZE, GFP_KERNEL);
	if (!rawlink)
		return -ENOMEM;

	if (kludge) {
		mode = 0;
		attr = aSHARED | aHIDDEN;
		((__le32 *)rawlink)[0]=NCP_SYMLINK_MAGIC0;
		((__le32 *)rawlink)[1]=NCP_SYMLINK_MAGIC1;
		hdr = 8;
	} else {
		mode = S_IFLNK | S_IRWXUGO;
		attr = 0;
		hdr = 0;
	}			

	length = strlen(symname);
	/* map to/from server charset, do not touch upper/lower case as
	   symlink can point out of ncp filesystem */
	outlen = NCP_MAX_SYMLINK_SIZE - hdr;
	err = ncp_io2vol(NCP_SERVER(dir), rawlink + hdr, &outlen, symname, length, 0);
	if (err)
		goto failfree;

	outlen += hdr;

	err = -EIO;
	if (ncp_create_new(dir,dentry,mode,0,attr)) {
		goto failfree;
	}

	inode=dentry->d_inode;

	if (ncp_make_open(inode, O_WRONLY))
		goto failfree;

	if (ncp_write_kernel(NCP_SERVER(inode), NCP_FINFO(inode)->file_handle, 
			     0, outlen, rawlink, &i) || i!=outlen) {
		goto fail;
	}

	ncp_inode_close(inode);
	ncp_make_closed(inode);
	kfree(rawlink);
	return 0;
fail:;
	ncp_inode_close(inode);
	ncp_make_closed(inode);
failfree:;
	kfree(rawlink);
	return err;
}

/* ----- EOF ----- */