diff options
Diffstat (limited to 'fs/ncpfs/symlink.c')
| -rw-r--r-- | fs/ncpfs/symlink.c | 181 |
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 ----- */ |