Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/ncpfs/symlink.c | |
3 | * | |
4 | * Code for allowing symbolic links on NCPFS (i.e. NetWare) | |
5 | * Symbolic links are not supported on native NetWare, so we use an | |
6 | * infrequently-used flag (Sh) and store a two-word magic header in | |
7 | * the file to make sure we don't accidentally use a non-link file | |
8 | * as a link. | |
9 | * | |
10 | * When using the NFS namespace, we set the mode to indicate a symlink and | |
11 | * don't bother with the magic numbers. | |
12 | * | |
13 | * from linux/fs/ext2/symlink.c | |
14 | * | |
15 | * Copyright (C) 1998-99, Frank A. Vorstenbosch | |
16 | * | |
17 | * ncpfs symlink handling code | |
18 | * NLS support (c) 1999 Petr Vandrovec | |
19 | * Modified 2000 Ben Harris, University of Cambridge for NFS NS meta-info | |
20 | * | |
21 | */ | |
22 | ||
23 | #include <linux/config.h> | |
24 | ||
25 | #include <asm/uaccess.h> | |
26 | ||
27 | #include <linux/errno.h> | |
28 | #include <linux/fs.h> | |
29 | #include <linux/ncp_fs.h> | |
30 | #include <linux/time.h> | |
31 | #include <linux/mm.h> | |
32 | #include <linux/stat.h> | |
33 | #include "ncplib_kernel.h" | |
34 | ||
35 | ||
36 | /* these magic numbers must appear in the symlink file -- this makes it a bit | |
37 | more resilient against the magic attributes being set on random files. */ | |
38 | ||
39 | #define NCP_SYMLINK_MAGIC0 cpu_to_le32(0x6c6d7973) /* "symlnk->" */ | |
40 | #define NCP_SYMLINK_MAGIC1 cpu_to_le32(0x3e2d6b6e) | |
41 | ||
42 | /* ----- read a symbolic link ------------------------------------------ */ | |
43 | ||
44 | static int ncp_symlink_readpage(struct file *file, struct page *page) | |
45 | { | |
46 | struct inode *inode = page->mapping->host; | |
47 | int error, length, len; | |
48 | char *link, *rawlink; | |
49 | char *buf = kmap(page); | |
50 | ||
51 | error = -ENOMEM; | |
52 | rawlink=(char *)kmalloc(NCP_MAX_SYMLINK_SIZE, GFP_KERNEL); | |
53 | if (!rawlink) | |
54 | goto fail; | |
55 | ||
56 | if (ncp_make_open(inode,O_RDONLY)) | |
57 | goto failEIO; | |
58 | ||
59 | error=ncp_read_kernel(NCP_SERVER(inode),NCP_FINFO(inode)->file_handle, | |
60 | 0,NCP_MAX_SYMLINK_SIZE,rawlink,&length); | |
61 | ||
62 | ncp_inode_close(inode); | |
63 | /* Close file handle if no other users... */ | |
64 | ncp_make_closed(inode); | |
65 | if (error) | |
66 | goto failEIO; | |
67 | ||
68 | if (NCP_FINFO(inode)->flags & NCPI_KLUDGE_SYMLINK) { | |
69 | if (length<NCP_MIN_SYMLINK_SIZE || | |
70 | ((__le32 *)rawlink)[0]!=NCP_SYMLINK_MAGIC0 || | |
71 | ((__le32 *)rawlink)[1]!=NCP_SYMLINK_MAGIC1) | |
72 | goto failEIO; | |
73 | link = rawlink + 8; | |
74 | length -= 8; | |
75 | } else { | |
76 | link = rawlink; | |
77 | } | |
78 | ||
79 | len = NCP_MAX_SYMLINK_SIZE; | |
80 | error = ncp_vol2io(NCP_SERVER(inode), buf, &len, link, length, 0); | |
81 | kfree(rawlink); | |
82 | if (error) | |
83 | goto fail; | |
84 | SetPageUptodate(page); | |
85 | kunmap(page); | |
86 | unlock_page(page); | |
87 | return 0; | |
88 | ||
89 | failEIO: | |
90 | error = -EIO; | |
91 | kfree(rawlink); | |
92 | fail: | |
93 | SetPageError(page); | |
94 | kunmap(page); | |
95 | unlock_page(page); | |
96 | return error; | |
97 | } | |
98 | ||
99 | /* | |
100 | * symlinks can't do much... | |
101 | */ | |
102 | struct address_space_operations ncp_symlink_aops = { | |
103 | .readpage = ncp_symlink_readpage, | |
104 | }; | |
105 | ||
106 | /* ----- create a new symbolic link -------------------------------------- */ | |
107 | ||
108 | int ncp_symlink(struct inode *dir, struct dentry *dentry, const char *symname) { | |
109 | struct inode *inode; | |
110 | char *rawlink; | |
111 | int length, err, i, outlen; | |
112 | int kludge; | |
113 | int mode; | |
114 | __le32 attr; | |
115 | unsigned int hdr; | |
116 | ||
117 | DPRINTK("ncp_symlink(dir=%p,dentry=%p,symname=%s)\n",dir,dentry,symname); | |
118 | ||
119 | if (ncp_is_nfs_extras(NCP_SERVER(dir), NCP_FINFO(dir)->volNumber)) | |
120 | kludge = 0; | |
121 | else | |
122 | #ifdef CONFIG_NCPFS_EXTRAS | |
123 | if (NCP_SERVER(dir)->m.flags & NCP_MOUNT_SYMLINKS) | |
124 | kludge = 1; | |
125 | else | |
126 | #endif | |
127 | /* EPERM is returned by VFS if symlink procedure does not exist */ | |
128 | return -EPERM; | |
129 | ||
130 | rawlink=(char *)kmalloc(NCP_MAX_SYMLINK_SIZE, GFP_KERNEL); | |
131 | if (!rawlink) | |
132 | return -ENOMEM; | |
133 | ||
134 | if (kludge) { | |
135 | mode = 0; | |
136 | attr = aSHARED | aHIDDEN; | |
137 | ((__le32 *)rawlink)[0]=NCP_SYMLINK_MAGIC0; | |
138 | ((__le32 *)rawlink)[1]=NCP_SYMLINK_MAGIC1; | |
139 | hdr = 8; | |
140 | } else { | |
141 | mode = S_IFLNK | S_IRWXUGO; | |
142 | attr = 0; | |
143 | hdr = 0; | |
144 | } | |
145 | ||
146 | length = strlen(symname); | |
147 | /* map to/from server charset, do not touch upper/lower case as | |
148 | symlink can point out of ncp filesystem */ | |
149 | outlen = NCP_MAX_SYMLINK_SIZE - hdr; | |
150 | err = ncp_io2vol(NCP_SERVER(dir), rawlink + hdr, &outlen, symname, length, 0); | |
151 | if (err) | |
152 | goto failfree; | |
153 | ||
154 | outlen += hdr; | |
155 | ||
156 | err = -EIO; | |
157 | if (ncp_create_new(dir,dentry,mode,0,attr)) { | |
158 | goto failfree; | |
159 | } | |
160 | ||
161 | inode=dentry->d_inode; | |
162 | ||
163 | if (ncp_make_open(inode, O_WRONLY)) | |
164 | goto failfree; | |
165 | ||
166 | if (ncp_write_kernel(NCP_SERVER(inode), NCP_FINFO(inode)->file_handle, | |
167 | 0, outlen, rawlink, &i) || i!=outlen) { | |
168 | goto fail; | |
169 | } | |
170 | ||
171 | ncp_inode_close(inode); | |
172 | ncp_make_closed(inode); | |
173 | kfree(rawlink); | |
174 | return 0; | |
175 | fail:; | |
176 | ncp_inode_close(inode); | |
177 | ncp_make_closed(inode); | |
178 | failfree:; | |
179 | kfree(rawlink); | |
180 | return err; | |
181 | } | |
182 | ||
183 | /* ----- EOF ----- */ |