summaryrefslogtreecommitdiff
path: root/fs/ncpfs/symlink.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/ncpfs/symlink.c')
-rw-r--r--fs/ncpfs/symlink.c181
1 files changed, 181 insertions, 0 deletions
diff --git a/fs/ncpfs/symlink.c b/fs/ncpfs/symlink.c
new file mode 100644
index 000000000..421b6f91e
--- /dev/null
+++ b/fs/ncpfs/symlink.c
@@ -0,0 +1,181 @@
+/*
+ * 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;
+
+ ncp_dbg(1, "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=d_inode(dentry);
+
+ 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 ----- */