SUNRPC: Add helpers for decoding opaque and string types

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

1 files changed, 82 insertions, 0 deletions

diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index e34f4ee7f2b6..30afbd236656 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -1519,6 +1519,88 @@ out:
 EXPORT_SYMBOL_GPL(xdr_process_buf);
 
 /**
+ * xdr_stream_decode_opaque - Decode variable length opaque
+ * @xdr: pointer to xdr_stream
+ * @ptr: location to store opaque data
+ * @size: size of storage buffer @ptr
+ *
+ * Return values:
+ *   On success, returns size of object stored in *@ptr
+ *   %-EBADMSG on XDR buffer overflow
+ *   %-EMSGSIZE on overflow of storage buffer @ptr
+ */
+ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr, size_t size)
+{
+        ssize_t ret;
+        void *p;
+
+        ret = xdr_stream_decode_opaque_inline(xdr, &p, size);
+        if (ret <= 0)
+                return ret;
+        memcpy(ptr, p, ret);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(xdr_stream_decode_opaque);
+
+/**
+ * xdr_stream_decode_opaque_dup - Decode and duplicate variable length opaque
+ * @xdr: pointer to xdr_stream
+ * @ptr: location to store pointer to opaque data
+ * @maxlen: maximum acceptable object size
+ * @gfp_flags: GFP mask to use
+ *
+ * Return values:
+ *   On success, returns size of object stored in *@ptr
+ *   %-EBADMSG on XDR buffer overflow
+ *   %-EMSGSIZE if the size of the object would exceed @maxlen
+ *   %-ENOMEM on memory allocation failure
+ */
+ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr,
+                size_t maxlen, gfp_t gfp_flags)
+{
+        ssize_t ret;
+        void *p;
+
+        ret = xdr_stream_decode_opaque_inline(xdr, &p, maxlen);
+        if (ret > 0) {
+                *ptr = kmemdup(p, ret, gfp_flags);
+                if (*ptr != NULL)
+                        return ret;
+                ret = -ENOMEM;
+        }
+        *ptr = NULL;
+        return ret;
+}
+EXPORT_SYMBOL_GPL(xdr_stream_decode_opaque_dup);
+
+/**
+ * xdr_stream_decode_string - Decode variable length string
+ * @xdr: pointer to xdr_stream
+ * @str: location to store string
+ * @size: size of storage buffer @str
+ *
+ * Return values:
+ *   On success, returns length of NUL-terminated string stored in *@str
+ *   %-EBADMSG on XDR buffer overflow
+ *   %-EMSGSIZE on overflow of storage buffer @str
+ */
+ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str, size_t size)
+{
+        ssize_t ret;
+        void *p;
+
+        ret = xdr_stream_decode_opaque_inline(xdr, &p, size);
+        if (ret > 0) {
+                memcpy(str, p, ret);
+                str[ret] = '\0';
+                return strlen(str);
+        }
+        *str = '\0';
+        return ret;
+}
+EXPORT_SYMBOL_GPL(xdr_stream_decode_string);
+
+/**
  * xdr_stream_decode_string_dup - Decode and duplicate variable length string
  * @xdr: pointer to xdr_stream
  * @str: location to store pointer to string