Commit 0795e004 authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

xfs: create structure verifier function for short form symlinks 



Create a function to check the structure of short form symlink targets.

Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
parent 1e1bbd8e

fs/xfs/libxfs/xfs_shared.h

+1 −0
Original line number Diff line number Diff line
@@ -143,5 +143,6 @@ bool xfs_symlink_hdr_ok(xfs_ino_t ino, uint32_t offset, 
			uint32_t size, struct xfs_buf *bp);

void xfs_symlink_local_to_remote(struct xfs_trans *tp, struct xfs_buf *bp,

				 struct xfs_inode *ip, struct xfs_ifork *ifp);

xfs_failaddr_t xfs_symlink_shortform_verify(struct xfs_inode *ip);



#endif /* __XFS_SHARED_H__ */

fs/xfs/libxfs/xfs_symlink_remote.c

+34 −0
Original line number Diff line number Diff line
@@ -209,3 +209,37 @@ xfs_symlink_local_to_remote( 
	xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsymlink_hdr) +

					ifp->if_bytes - 1);

}



/* Verify the consistency of an inline symlink. */

xfs_failaddr_t

xfs_symlink_shortform_verify(

	struct xfs_inode	*ip)

{

	char			*sfp;

	char			*endp;

	struct xfs_ifork	*ifp;

	int			size;



	ASSERT(ip->i_d.di_format == XFS_DINODE_FMT_LOCAL);

	ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);

	sfp = (char *)ifp->if_u1.if_data;

	size = ifp->if_bytes;

	endp = sfp + size;



	/* Zero length symlinks can exist while we're deleting a remote one. */

	if (size == 0)

		return NULL;



	/* No negative sizes or overly long symlink targets. */

	if (size < 0 || size > XFS_SYMLINK_MAXLEN)

		return __this_address;



	/* No NULLs in the target either. */

	if (memchr(sfp, 0, size - 1))

		return __this_address;



	/* We /did/ null-terminate the buffer, right? */

	if (*endp != 0)

		return __this_address;

	return NULL;

}