From ae42c70a60fe330d9c2af7c4b92ce78484308e37 Mon Sep 17 00:00:00 2001 From: Bryan Schumaker Date: Thu, 21 Oct 2010 16:33:17 -0400 Subject: [PATCH] NFS: introduce generic decode_getattr function Getattr should be able to decode errors and the readdir file handle. decode_getfattr_attrs does the actual attribute decoding, while decode_getfattr_generic will check the opcode before decoding. This will let other functions call decode_getfattr_attrs to decode their attributes. Signed-off-by: Bryan Schumaker Signed-off-by: Trond Myklebust --- fs/nfs/nfs4xdr.c | 117 ++++++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 98 insertions(+), 19 deletions(-) diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c index 8346e97..b7eff20 100644 --- a/fs/nfs/nfs4xdr.c +++ b/fs/nfs/nfs4xdr.c @@ -2848,6 +2848,58 @@ out_overflow: return -EIO; } +static int decode_attr_error(struct xdr_stream *xdr, uint32_t *bitmap) +{ + __be32 *p; + + if (unlikely(bitmap[0] & (FATTR4_WORD0_RDATTR_ERROR - 1U))) + return -EIO; + if (likely(bitmap[0] & FATTR4_WORD0_RDATTR_ERROR)) { + p = xdr_inline_decode(xdr, 4); + if (unlikely(!p)) + goto out_overflow; + bitmap[0] &= ~FATTR4_WORD0_RDATTR_ERROR; + } + return 0; +out_overflow: + print_overflow_msg(__func__, xdr); + return -EIO; +} + +static int decode_attr_filehandle(struct xdr_stream *xdr, uint32_t *bitmap, struct nfs_fh *fh) +{ + __be32 *p; + int len; + + if (fh == NULL) { + bitmap[0] &= ~FATTR4_WORD0_FILEHANDLE; + return 0; + } + + memset(fh, 0, sizeof(*fh)); + + if (unlikely(bitmap[0] & (FATTR4_WORD0_FILEHANDLE - 1U))) + return -EIO; + if (likely(bitmap[0] & FATTR4_WORD0_FILEHANDLE)) { + p = xdr_inline_decode(xdr, 4); + if (unlikely(!p)) + goto out_overflow; + len = be32_to_cpup(p); + if (len > NFS4_FHSIZE) + return -EIO; + fh->size = len; + p = xdr_inline_decode(xdr, len); + if (unlikely(!p)) + goto out_overflow; + memcpy(fh->data, p, len); + bitmap[0] &= ~FATTR4_WORD0_FILEHANDLE; + } + return 0; +out_overflow: + print_overflow_msg(__func__, xdr); + return -EIO; +} + static int decode_attr_aclsupport(struct xdr_stream *xdr, uint32_t *bitmap, uint32_t *res) { __be32 *p; @@ -3744,29 +3796,14 @@ xdr_error: return status; } -static int decode_getfattr(struct xdr_stream *xdr, struct nfs_fattr *fattr, +static int decode_getfattr_attrs(struct xdr_stream *xdr, uint32_t *bitmap, + struct nfs_fattr *fattr, struct nfs_fh *fh, const struct nfs_server *server, int may_sleep) { - __be32 *savep; - uint32_t attrlen, - bitmap[2] = {0}, - type; int status; umode_t fmode = 0; uint64_t fileid; - - status = decode_op_hdr(xdr, OP_GETATTR); - if (status < 0) - goto xdr_error; - - status = decode_attr_bitmap(xdr, bitmap); - if (status < 0) - goto xdr_error; - - status = decode_attr_length(xdr, &attrlen, &savep); - if (status < 0) - goto xdr_error; - + uint32_t type; status = decode_attr_type(xdr, bitmap, &type); if (status < 0) @@ -3792,6 +3829,14 @@ static int decode_getfattr(struct xdr_stream *xdr, struct nfs_fattr *fattr, goto xdr_error; fattr->valid |= status; + status = decode_attr_error(xdr, bitmap); + if (status < 0) + goto xdr_error; + + status = decode_attr_filehandle(xdr, bitmap, fh); + if (status < 0) + goto xdr_error; + status = decode_attr_fileid(xdr, bitmap, &fattr->fileid); if (status < 0) goto xdr_error; @@ -3857,17 +3902,51 @@ static int decode_getfattr(struct xdr_stream *xdr, struct nfs_fattr *fattr, status = decode_attr_mounted_on_fileid(xdr, bitmap, &fileid); if (status < 0) goto xdr_error; - if (status != 0 && !(fattr->valid & status)) { + if (status != 0) { fattr->fileid = fileid; fattr->valid |= status; } +xdr_error: + dprintk("%s: xdr returned %d\n", __func__, -status); + return status; +} + +static int decode_getfattr_generic(struct xdr_stream *xdr, struct nfs_fattr *fattr, + struct nfs_fh *fh, const struct nfs_server *server, int may_sleep) +{ + __be32 *savep; + uint32_t attrlen, + bitmap[2] = {0}; + int status; + + status = decode_op_hdr(xdr, OP_GETATTR); + if (status < 0) + goto xdr_error; + + status = decode_attr_bitmap(xdr, bitmap); + if (status < 0) + goto xdr_error; + + status = decode_attr_length(xdr, &attrlen, &savep); + if (status < 0) + goto xdr_error; + + status = decode_getfattr_attrs(xdr, bitmap, fattr, fh, server, may_sleep); + if (status < 0) + goto xdr_error; + status = verify_attr_len(xdr, savep, attrlen); xdr_error: dprintk("%s: xdr returned %d\n", __func__, -status); return status; } +static int decode_getfattr(struct xdr_stream *xdr, struct nfs_fattr *fattr, + const struct nfs_server *server, int may_sleep) +{ + return decode_getfattr_generic(xdr, fattr, NULL, server, may_sleep); +} static int decode_fsinfo(struct xdr_stream *xdr, struct nfs_fsinfo *fsinfo) { -- 2.7.4