SUNRPC: Use unsigned string lengths in xdr_decode_string_inplace

XDR strings, opaques, and net objects should all use unsigned lengths.
To wit, RFC 4506 says:

4.2.  Unsigned Integer

   An XDR unsigned integer is a 32-bit datum that encodes a non-negative
   integer in the range [0,4294967295].

 ...

4.11.  String

   The standard defines a string of n (numbered 0 through n-1) ASCII
   bytes to be the number n encoded as an unsigned integer (as described
   above), and followed by the n bytes of the string.

After this patch, xdr_decode_string_inplace now matches the other XDR
string and array helpers that take a string length argument.  See:

xdr_encode_opaque_fixed, xdr_encode_opaque, xdr_encode_array

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-By: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h
index 0751c94..e4057d7 100644 (file)
--- a/include/linux/sunrpc/xdr.h
+++ b/include/linux/sunrpc/xdr.h
@@ -112,7 +112,8 @@ struct xdr_buf {
 __be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len);
 __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len);
 __be32 *xdr_encode_string(__be32 *p, const char *s);
-__be32 *xdr_decode_string_inplace(__be32 *p, char **sp, int *lenp, int maxlen);
+__be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp,
+                       unsigned int maxlen);
 __be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *);
 __be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *);
 

diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index 5426406..995c3fd 100644 (file)
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -96,11 +96,13 @@ xdr_encode_string(__be32 *p, const char *string)
 EXPORT_SYMBOL(xdr_encode_string);
 
 __be32 *
-xdr_decode_string_inplace(__be32 *p, char **sp, int *lenp, int maxlen)
+xdr_decode_string_inplace(__be32 *p, char **sp,
+                         unsigned int *lenp, unsigned int maxlen)
 {
-       unsigned int    len;
+       u32 len;
 
-       if ((len = ntohl(*p++)) > maxlen)
+       len = ntohl(*p++);
+       if (len > maxlen)
                return NULL;
        *lenp = len;
        *sp = (char *) p;