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/*
* 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.
*
* from linux/fs/ext2/symlink.c
*
* Copyright (C) 1998-99, Frank A. Vorstenbosch
*
* ncpfs symlink handling code
* NLS support (c) 1999 Petr Vandrovec
*
*/
#include <linux/config.h>
#ifdef CONFIG_NCPFS_EXTRAS
#include <asm/uaccess.h>
#include <asm/segment.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/ncp_fs.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/stat.h>
#include "ncplib_kernel.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 le32_to_cpu(0x6c6d7973) /* "symlnk->" */
#define NCP_SYMLINK_MAGIC1 le32_to_cpu(0x3e2d6b6e)
int ncp_create_new(struct inode *dir, struct dentry *dentry,
int mode,int attributes);
/* ----- 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, cnt;
char *link;
char *buf = kmap(page);
error = -ENOMEM;
for (cnt = 0; (link=(char *)kmalloc(NCP_MAX_SYMLINK_SIZE, GFP_NFS))==NULL; cnt++) {
if (cnt > 10)
goto fail;
schedule();
}
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,link,&length);
ncp_inode_close(inode);
/* Close file handle if no other users... */
ncp_make_closed(inode);
if (error)
goto failEIO;
if (length<NCP_MIN_SYMLINK_SIZE ||
((__u32 *)link)[0]!=NCP_SYMLINK_MAGIC0 ||
((__u32 *)link)[1]!=NCP_SYMLINK_MAGIC1)
goto failEIO;
len = NCP_MAX_SYMLINK_SIZE;
error = ncp_vol2io(NCP_SERVER(inode), buf, &len, link+8, length-8, 0);
kfree(link);
if (error)
goto fail;
SetPageUptodate(page);
kunmap(page);
UnlockPage(page);
return 0;
failEIO:
error = -EIO;
kfree(link);
fail:
SetPageError(page);
kunmap(page);
UnlockPage(page);
return error;
}
/*
* symlinks can't do much...
*/
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 *link;
int length, err, i;
#ifdef DEBUG
PRINTK("ncp_symlink(dir=%p,dentry=%p,symname=%s)\n",dir,dentry,symname);
#endif
if (!(NCP_SERVER(dir)->m.flags & NCP_MOUNT_SYMLINKS))
return -EPERM; /* EPERM is returned by VFS if symlink procedure does not exist */
if ((length=strlen(symname))>NCP_MAX_SYMLINK_SIZE-8)
return -EINVAL;
if ((link=(char *)kmalloc(length+9,GFP_NFS))==NULL)
return -ENOMEM;
err = -EIO;
if (ncp_create_new(dir,dentry,0,aSHARED|aHIDDEN))
goto failfree;
inode=dentry->d_inode;
if (ncp_make_open(inode, O_WRONLY))
goto failfree;
((__u32 *)link)[0]=NCP_SYMLINK_MAGIC0;
((__u32 *)link)[1]=NCP_SYMLINK_MAGIC1;
/* map to/from server charset, do not touch upper/lower case as
symlink can point out of ncp filesystem */
length += 1;
err = ncp_io2vol(NCP_SERVER(inode),link+8,&length,symname,length-1,0);
if (err)
goto fail;
if(ncp_write_kernel(NCP_SERVER(inode), NCP_FINFO(inode)->file_handle,
0, length+8, link, &i) || i!=length+8) {
err = -EIO;
goto fail;
}
ncp_inode_close(inode);
ncp_make_closed(inode);
kfree(link);
return 0;
fail:
ncp_inode_close(inode);
ncp_make_closed(inode);
failfree:
kfree(link);
return err;
}
#endif
/* ----- EOF ----- */
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