On 11/17/2010 07:43 PM, Chuck Lever wrote:
> We're interested in taking advantage of the safety benefits of
> xdr_streams. These data structures allow more careful checking for
> buffer overflow while encoding. More careful type checking is also
> introduced in the new functions.
>
> For efficiency, we also eventually want to be able to pass xdr_streams
> from call_encode() to all XDR encoding functions, rather than building
> an xdr_stream in every XDR encoding function in the kernel. To do
> this means all encoders must be ready to handle a passed-in
> xdr_stream.
>
> We follow the modern paradigm for encoders of BUGging on error and
> always returning a zero status code.
>
> Static helper functions are left without the "inline" directive. This
> allows the compiler to choose automatically how to optimize these for
> size or speed.
>
> Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
> Tested-by: J. Bruce Fields <bfields@xxxxxxxxxx>
> ---
>
> fs/nfs/nfs2xdr.c | 406 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 files changed, 403 insertions(+), 3 deletions(-)
>
> diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c
> index e6bf457..77a3eb9 100644
> --- a/fs/nfs/nfs2xdr.c
> +++ b/fs/nfs/nfs2xdr.c
> @@ -61,6 +61,23 @@
> #define NFS_readdirres_sz (1)
> #define NFS_statfsres_sz (1+NFS_info_sz)
>
> +
> +/*
> + * While encoding arguments, set up the reply buffer in advance to
> + * receive reply data directly into the page cache.
> + */
> +static void prepare_reply_buffer(struct rpc_rqst *req, struct page **pages,
> + unsigned int base, unsigned int len,
> + unsigned int bufsize)
> +{
> + struct rpc_auth *auth = req->rq_cred->cr_auth;
> + unsigned int replen;
> +
> + replen = RPC_REPHDRSIZE + auth->au_rslack + bufsize;
> + xdr_inline_pages(&req->rq_rcv_buf, replen << 2, pages, base, len);
> +}
> +
> +
> /*
> * Common NFS XDR functions as inlines
> */
> @@ -81,7 +98,7 @@ xdr_decode_fhandle(__be32 *p, struct nfs_fh *fhandle)
> }
>
> static inline __be32*
> -xdr_encode_time(__be32 *p, struct timespec *timep)
> +xdr_encode_time(__be32 *p, const struct timespec *timep)
> {
> *p++ = htonl(timep->tv_sec);
Please use cpu_to_beXX like below?
Boaz
> /* Convert nanoseconds into microseconds */
> @@ -90,7 +107,7 @@ xdr_encode_time(__be32 *p, struct timespec *timep)
> }
>
> static inline __be32*
> -xdr_encode_current_server_time(__be32 *p, struct timespec *timep)
> +xdr_encode_current_server_time(__be32 *p, const struct timespec *timep)
> {
> /*
> * Passing the invalid value useconds=1000000 is a
> @@ -174,6 +191,136 @@ xdr_encode_sattr(__be32 *p, struct iattr *attr)
> }
>
> /*
> + * Encode/decode NFSv2 basic data types
> + *
> + * Basic NFSv2 data types are defined in section 2.3 of RFC 1094:
> + * "NFS: Network File System Protocol Specification".
> + *
> + * Not all basic data types have their own encoding and decoding
> + * functions. For run-time efficiency, some data types are encoded
> + * or decoded inline.
> + */
> +
> +/*
> + * 2.3.3. fhandle
> + *
> + * typedef opaque fhandle[FHSIZE];
> + */
> +static void encode_fhandle(struct xdr_stream *xdr, const struct nfs_fh *fh)
> +{
> + __be32 *p;
> +
> + BUG_ON(fh->size != NFS2_FHSIZE);
> + p = xdr_reserve_space(xdr, NFS2_FHSIZE);
> + memcpy(p, fh->data, NFS2_FHSIZE);
> +}
> +
> +/*
> + * 2.3.6. sattr
> + *
> + * struct sattr {
> + * unsigned int mode;
> + * unsigned int uid;
> + * unsigned int gid;
> + * unsigned int size;
> + * timeval atime;
> + * timeval mtime;
> + * };
> + */
> +
> +#define NFS2_SATTR_NOT_SET (0xffffffff)
> +
> +static __be32 *xdr_time_not_set(__be32 *p)
> +{
> + *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
> + *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
> + return p;
> +}
> +
> +static void encode_sattr(struct xdr_stream *xdr, const struct iattr *attr)
> +{
> + __be32 *p;
> +
> + p = xdr_reserve_space(xdr, NFS_sattr_sz << 2);
> +
> + if (attr->ia_valid & ATTR_MODE)
> + *p++ = cpu_to_be32(attr->ia_mode);
> + else
> + *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
> + if (attr->ia_valid & ATTR_UID)
> + *p++ = cpu_to_be32(attr->ia_uid);
> + else
> + *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
> + if (attr->ia_valid & ATTR_GID)
> + *p++ = cpu_to_be32(attr->ia_gid);
> + else
> + *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
> + if (attr->ia_valid & ATTR_SIZE)
> + *p++ = cpu_to_be32((u32)attr->ia_size);
> + else
> + *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
> +
> + if (attr->ia_valid & ATTR_ATIME_SET)
> + p = xdr_encode_time(p, &attr->ia_atime);
> + else if (attr->ia_valid & ATTR_ATIME)
> + p = xdr_encode_current_server_time(p, &attr->ia_atime);
> + else
> + p = xdr_time_not_set(p);
> + if (attr->ia_valid & ATTR_MTIME_SET)
> + xdr_encode_time(p, &attr->ia_mtime);
> + else if (attr->ia_valid & ATTR_MTIME)
> + xdr_encode_current_server_time(p, &attr->ia_mtime);
> + else
> + xdr_time_not_set(p);
> +}
> +
> +/*
> + * 2.3.7. filename
> + *
> + * typedef string filename<MAXNAMLEN>;
> + */
> +static void encode_filename(struct xdr_stream *xdr,
> + const char *name, u32 length)
> +{
> + __be32 *p;
> +
> + BUG_ON(length > NFS2_MAXNAMLEN);
> + p = xdr_reserve_space(xdr, 4 + length);
> + xdr_encode_opaque(p, name, length);
> +}
> +
> +/*
> + * 2.3.8. path
> + *
> + * typedef string path<MAXPATHLEN>;
> + */
> +static void encode_path(struct xdr_stream *xdr, struct page **pages, u32 length)
> +{
> + __be32 *p;
> +
> + BUG_ON(length > NFS2_MAXPATHLEN);
> + p = xdr_reserve_space(xdr, 4);
> + *p = cpu_to_be32(length);
> + xdr_write_pages(xdr, pages, 0, length);
> +}
> +
> +/*
> + * 2.3.10. diropargs
> + *
> + * struct diropargs {
> + * fhandle dir;
> + * filename name;
> + * };
> + */
> +static void encode_diropargs(struct xdr_stream *xdr, const struct nfs_fh *fh,
> + const char *name, u32 length)
> +{
> + encode_fhandle(xdr, fh);
> + encode_filename(xdr, name, length);
> +}
> +
> +
> +/*
> * NFS encode functions
> */
> /*
> @@ -188,6 +335,16 @@ nfs_xdr_fhandle(struct rpc_rqst *req, __be32 *p, struct nfs_fh *fh)
> return 0;
> }
>
> +static int nfs2_xdr_enc_fhandle(struct rpc_rqst *req, __be32 *p,
> + const struct nfs_fh *fh)
> +{
> + struct xdr_stream xdr;
> +
> + xdr_init_encode(&xdr, &req->rq_snd_buf, p);
> + encode_fhandle(&xdr, fh);
> + return 0;
> +}
> +
> /*
> * Encode SETATTR arguments
> */
> @@ -201,6 +358,25 @@ nfs_xdr_sattrargs(struct rpc_rqst *req, __be32 *p, struct nfs_sattrargs *args)
> }
>
> /*
> + * 2.2.3. sattrargs
> + *
> + * struct sattrargs {
> + * fhandle file;
> + * sattr attributes;
> + * };
> + */
> +static int nfs2_xdr_enc_sattrargs(struct rpc_rqst *req, __be32 *p,
> + const struct nfs_sattrargs *args)
> +{
> + struct xdr_stream xdr;
> +
> + xdr_init_encode(&xdr, &req->rq_snd_buf, p);
> + encode_fhandle(&xdr, args->fh);
> + encode_sattr(&xdr, args->sattr);
> + return 0;
> +}
> +
> +/*
> * Encode directory ops argument
> * LOOKUP, RMDIR
> */
> @@ -213,6 +389,16 @@ nfs_xdr_diropargs(struct rpc_rqst *req, __be32 *p, struct nfs_diropargs *args)
> return 0;
> }
>
> +static int nfs2_xdr_enc_diropargs(struct rpc_rqst *req, __be32 *p,
> + const struct nfs_diropargs *args)
> +{
> + struct xdr_stream xdr;
> +
> + xdr_init_encode(&xdr, &req->rq_snd_buf, p);
> + encode_diropargs(&xdr, args->fh, args->name, args->len);
> + return 0;
> +}
> +
> /*
> * Encode REMOVE argument
> */
> @@ -225,6 +411,18 @@ nfs_xdr_removeargs(struct rpc_rqst *req, __be32 *p, const struct nfs_removeargs
> return 0;
> }
>
> +static int nfs2_xdr_enc_readlinkargs(struct rpc_rqst *req, __be32 *p,
> + const struct nfs_readlinkargs *args)
> +{
> + struct xdr_stream xdr;
> +
> + xdr_init_encode(&xdr, &req->rq_snd_buf, p);
> + encode_fhandle(&xdr, args->fh);
> + prepare_reply_buffer(req, args->pages, args->pgbase,
> + args->pglen, NFS_readlinkres_sz);
> + return 0;
> +}
> +
> /*
> * Arguments to a READ call. Since we read data directly into the page
> * cache, we also set up the reply iovec here so that iov[1] points
> @@ -253,6 +451,44 @@ nfs_xdr_readargs(struct rpc_rqst *req, __be32 *p, struct nfs_readargs *args)
> }
>
> /*
> + * 2.2.7. readargs
> + *
> + * struct readargs {
> + * fhandle file;
> + * unsigned offset;
> + * unsigned count;
> + * unsigned totalcount;
> + * };
> + */
> +static void encode_readargs(struct xdr_stream *xdr,
> + const struct nfs_readargs *args)
> +{
> + u32 offset = args->offset;
> + u32 count = args->count;
> + __be32 *p;
> +
> + encode_fhandle(xdr, args->fh);
> +
> + p = xdr_reserve_space(xdr, 4 + 4 + 4);
> + *p++ = cpu_to_be32(offset);
> + *p++ = cpu_to_be32(count);
> + *p = cpu_to_be32(count);
> +}
> +
> +static int nfs2_xdr_enc_readargs(struct rpc_rqst *req, __be32 *p,
> + const struct nfs_readargs *args)
> +{
> + struct xdr_stream xdr;
> +
> + xdr_init_encode(&xdr, &req->rq_snd_buf, p);
> + encode_readargs(&xdr, args);
> + prepare_reply_buffer(req, args->pages, args->pgbase,
> + args->count, NFS_readres_sz);
> + req->rq_rcv_buf.flags |= XDRBUF_READ;
> + return 0;
> +}
> +
> +/*
> * Decode READ reply
> */
> static int
> @@ -318,6 +554,47 @@ nfs_xdr_writeargs(struct rpc_rqst *req, __be32 *p, struct nfs_writeargs *args)
> }
>
> /*
> + * 2.2.9. writeargs
> + *
> + * struct writeargs {
> + * fhandle file;
> + * unsigned beginoffset;
> + * unsigned offset;
> + * unsigned totalcount;
> + * nfsdata data;
> + * };
> + */
> +static void encode_writeargs(struct xdr_stream *xdr,
> + const struct nfs_writeargs *args)
> +{
> + u32 offset = args->offset;
> + u32 count = args->count;
> + __be32 *p;
> +
> + encode_fhandle(xdr, args->fh);
> +
> + p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
> + *p++ = cpu_to_be32(offset);
> + *p++ = cpu_to_be32(offset);
> + *p++ = cpu_to_be32(count);
> +
> + /* nfsdata */
> + *p = cpu_to_be32(count);
> + xdr_write_pages(xdr, args->pages, args->pgbase, count);
> +}
> +
> +static int nfs2_xdr_enc_writeargs(struct rpc_rqst *req, __be32 *p,
> + const struct nfs_writeargs *args)
> +{
> + struct xdr_stream xdr;
> +
> + xdr_init_encode(&xdr, &req->rq_snd_buf, p);
> + encode_writeargs(&xdr, args);
> + xdr.buf->flags |= XDRBUF_WRITE;
> + return 0;
> +}
> +
> +/*
> * Encode create arguments
> * CREATE, MKDIR
> */
> @@ -332,6 +609,35 @@ nfs_xdr_createargs(struct rpc_rqst *req, __be32 *p, struct nfs_createargs *args)
> }
>
> /*
> + * 2.2.10. createargs
> + *
> + * struct createargs {
> + * diropargs where;
> + * sattr attributes;
> + * };
> + */
> +static int nfs2_xdr_enc_createargs(struct rpc_rqst *req, __be32 *p,
> + const struct nfs_createargs *args)
> +{
> + struct xdr_stream xdr;
> +
> + xdr_init_encode(&xdr, &req->rq_snd_buf, p);
> + encode_diropargs(&xdr, args->fh, args->name, args->len);
> + encode_sattr(&xdr, args->sattr);
> + return 0;
> +}
> +
> +static int nfs2_xdr_enc_removeargs(struct rpc_rqst *req, __be32 *p,
> + const struct nfs_removeargs *args)
> +{
> + struct xdr_stream xdr;
> +
> + xdr_init_encode(&xdr, &req->rq_snd_buf, p);
> + encode_diropargs(&xdr, args->fh, args->name.name, args->name.len);
> + return 0;
> +}
> +
> +/*
> * Encode RENAME arguments
> */
> static int
> @@ -346,6 +652,27 @@ nfs_xdr_renameargs(struct rpc_rqst *req, __be32 *p, struct nfs_renameargs *args)
> }
>
> /*
> + * 2.2.12. renameargs
> + *
> + * struct renameargs {
> + * diropargs from;
> + * diropargs to;
> + * };
> + */
> +static int nfs2_xdr_enc_renameargs(struct rpc_rqst *req, __be32 *p,
> + const struct nfs_renameargs *args)
> +{
> + const struct qstr *old = args->old_name;
> + const struct qstr *new = args->new_name;
> + struct xdr_stream xdr;
> +
> + xdr_init_encode(&xdr, &req->rq_snd_buf, p);
> + encode_diropargs(&xdr, args->old_dir, old->name, old->len);
> + encode_diropargs(&xdr, args->new_dir, new->name, new->len);
> + return 0;
> +}
> +
> +/*
> * Encode LINK arguments
> */
> static int
> @@ -359,6 +686,25 @@ nfs_xdr_linkargs(struct rpc_rqst *req, __be32 *p, struct nfs_linkargs *args)
> }
>
> /*
> + * 2.2.13. linkargs
> + *
> + * struct linkargs {
> + * fhandle from;
> + * diropargs to;
> + * };
> + */
> +static int nfs2_xdr_enc_linkargs(struct rpc_rqst *req, __be32 *p,
> + const struct nfs_linkargs *args)
> +{
> + struct xdr_stream xdr;
> +
> + xdr_init_encode(&xdr, &req->rq_snd_buf, p);
> + encode_fhandle(&xdr, args->fromfh);
> + encode_diropargs(&xdr, args->tofh, args->toname, args->tolen);
> + return 0;
> +}
> +
> +/*
> * Encode SYMLINK arguments
> */
> static int
> @@ -388,6 +734,27 @@ nfs_xdr_symlinkargs(struct rpc_rqst *req, __be32 *p, struct nfs_symlinkargs *arg
> }
>
> /*
> + * 2.2.14. symlinkargs
> + *
> + * struct symlinkargs {
> + * diropargs from;
> + * path to;
> + * sattr attributes;
> + * };
> + */
> +static int nfs2_xdr_enc_symlinkargs(struct rpc_rqst *req, __be32 *p,
> + const struct nfs_symlinkargs *args)
> +{
> + struct xdr_stream xdr;
> +
> + xdr_init_encode(&xdr, &req->rq_snd_buf, p);
> + encode_diropargs(&xdr, args->fromfh, args->fromname, args->fromlen);
> + encode_path(&xdr, args->pages, args->pathlen);
> + encode_sattr(&xdr, args->sattr);
> + return 0;
> +}
> +
> +/*
> * Encode arguments to readdir call
> */
> static int
> @@ -409,6 +776,39 @@ nfs_xdr_readdirargs(struct rpc_rqst *req, __be32 *p, struct nfs_readdirargs *arg
> }
>
> /*
> + * 2.2.17. readdirargs
> + *
> + * struct readdirargs {
> + * fhandle dir;
> + * nfscookie cookie;
> + * unsigned count;
> + * };
> + */
> +static void encode_readdirargs(struct xdr_stream *xdr,
> + const struct nfs_readdirargs *args)
> +{
> + __be32 *p;
> +
> + encode_fhandle(xdr, args->fh);
> +
> + p = xdr_reserve_space(xdr, 4 + 4);
> + *p++ = cpu_to_be32(args->cookie);
> + *p = cpu_to_be32(args->count);
> +}
> +
> +static int nfs2_xdr_enc_readdirargs(struct rpc_rqst *req, __be32 *p,
> + const struct nfs_readdirargs *args)
> +{
> + struct xdr_stream xdr;
> +
> + xdr_init_encode(&xdr, &req->rq_snd_buf, p);
> + encode_readdirargs(&xdr, args);
> + prepare_reply_buffer(req, args->pages, 0,
> + args->count, NFS_readdirres_sz);
> + return 0;
> +}
> +
> +/*
> * Decode the result of a readdir call.
> * We're not really decoding anymore, we just leave the buffer untouched
> * and only check that it is syntactically correct.
> @@ -696,7 +1096,7 @@ nfs_stat_to_errno(int stat)
> #define PROC(proc, argtype, restype, timer) \
> [NFSPROC_##proc] = { \
> .p_proc = NFSPROC_##proc, \
> - .p_encode = (kxdrproc_t) nfs_xdr_##argtype, \
> + .p_encode = (kxdrproc_t)nfs2_xdr_enc_##argtype, \
> .p_decode = (kxdrproc_t) nfs_xdr_##restype, \
> .p_arglen = NFS_##argtype##_sz, \
> .p_replen = NFS_##restype##_sz, \
>
> --
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