1 files changed, 183 insertions, 0 deletions

diff --git a/fs/ncpfs/symlink.c b/fs/ncpfs/symlink.c
new file mode 100644
index 000000000000..e935f1b34bc2
--- /dev/null
+++ b/fs/ncpfs/symlink.c
@@ -0,0 +1,183 @@
+/*
+ *  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 <linux/config.h>
+
+#include <asm/uaccess.h>
+
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/ncp_fs.h>
+#include <linux/time.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      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=(char *)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...
+ */
+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;
+        int 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=(char *)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 ----- */