From 29a1bd6bf8c7a9ff511aaaf7e40fd6ca5198babe Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Wed, 17 Jun 2009 18:02:11 -0700 Subject: [PATCH] NFS: Use xdr_stream-based XDR encoder for MNT's dirpath argument Check the length of the supplied dirpath, and see that it fits properly in the RPC buffer. Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust --- fs/nfs/mount_clnt.c | 49 ++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 44 insertions(+), 5 deletions(-) diff --git a/fs/nfs/mount_clnt.c b/fs/nfs/mount_clnt.c index af45a374d56..93361afcd5d 100644 --- a/fs/nfs/mount_clnt.c +++ b/fs/nfs/mount_clnt.c @@ -20,6 +20,21 @@ # define NFSDBG_FACILITY NFSDBG_MOUNT #endif +/* + * Defined by RFC 1094, section A.3; and RFC 1813, section 5.1.4 + */ +#define MNTPATHLEN (1024) + +/* + * XDR data type sizes + */ +#define encode_dirpath_sz (1 + XDR_QUADLEN(MNTPATHLEN)) + +/* + * XDR argument and result sizes + */ +#define MNT_enc_dirpath_sz encode_dirpath_sz + /* * Defined by RFC 1094, section A.5 */ @@ -135,6 +150,31 @@ static int xdr_encode_dirpath(struct rpc_rqst *req, __be32 *p, return 0; } +static int encode_mntdirpath(struct xdr_stream *xdr, const char *pathname) +{ + const u32 pathname_len = strlen(pathname); + __be32 *p; + + if (unlikely(pathname_len > MNTPATHLEN)) + return -EIO; + + p = xdr_reserve_space(xdr, sizeof(u32) + pathname_len); + if (unlikely(p == NULL)) + return -EIO; + xdr_encode_opaque(p, pathname, pathname_len); + + return 0; +} + +static int mnt_enc_dirpath(struct rpc_rqst *req, __be32 *p, + const char *dirpath) +{ + struct xdr_stream xdr; + + xdr_init_encode(&xdr, &req->rq_snd_buf, p); + return encode_mntdirpath(&xdr, dirpath); +} + static int xdr_decode_fhstatus(struct rpc_rqst *req, __be32 *p, struct mnt_fhstatus *res) { @@ -164,16 +204,15 @@ static int xdr_decode_fhstatus3(struct rpc_rqst *req, __be32 *p, return 0; } -#define MNT_dirpath_sz (1 + 256) #define MNT_fhstatus_sz (1 + 8) #define MNT_fhstatus3_sz (1 + 16) static struct rpc_procinfo mnt_procedures[] = { [MOUNTPROC_MNT] = { .p_proc = MOUNTPROC_MNT, - .p_encode = (kxdrproc_t) xdr_encode_dirpath, + .p_encode = (kxdrproc_t)mnt_enc_dirpath, .p_decode = (kxdrproc_t) xdr_decode_fhstatus, - .p_arglen = MNT_dirpath_sz, + .p_arglen = MNT_enc_dirpath_sz, .p_replen = MNT_fhstatus_sz, .p_statidx = MOUNTPROC_MNT, .p_name = "MOUNT", @@ -183,9 +222,9 @@ static struct rpc_procinfo mnt_procedures[] = { static struct rpc_procinfo mnt3_procedures[] = { [MOUNTPROC3_MNT] = { .p_proc = MOUNTPROC3_MNT, - .p_encode = (kxdrproc_t) xdr_encode_dirpath, + .p_encode = (kxdrproc_t)mnt_enc_dirpath, .p_decode = (kxdrproc_t) xdr_decode_fhstatus3, - .p_arglen = MNT_dirpath_sz, + .p_arglen = MNT_enc_dirpath_sz, .p_replen = MNT_fhstatus3_sz, .p_statidx = MOUNTPROC3_MNT, .p_name = "MOUNT",