[PATCH V3 2/2] SUNRPC: Rename xdr_buf_read_netobj to xdr_buf_read_mic

[Benjamin Coddington <bcodding@redhat.com>]

Let the name reflect the single use.  The function now assumes the GSS MIC
is the last object in the buffer.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
---
 include/linux/sunrpc/xdr.h     |  2 +-
 net/sunrpc/auth_gss/auth_gss.c |  2 +-
 net/sunrpc/xdr.c               | 52 ++++++++++++++++++++--------------
 3 files changed, 32 insertions(+), 24 deletions(-)

diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h
index 8a87d8bcb197..f33e5013bdfb 100644
--- a/include/linux/sunrpc/xdr.h
+++ b/include/linux/sunrpc/xdr.h
@@ -186,7 +186,7 @@ xdr_adjust_iovec(struct kvec *iov, __be32 *p)
 extern void xdr_shift_buf(struct xdr_buf *, size_t);
 extern void xdr_buf_from_iov(struct kvec *, struct xdr_buf *);
 extern int xdr_buf_subsegment(struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
-extern int xdr_buf_read_netobj(struct xdr_buf *, struct xdr_netobj *, unsigned int);
+extern int xdr_buf_read_mic(struct xdr_buf *, struct xdr_netobj *, unsigned int);
 extern int read_bytes_from_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
 extern int write_bytes_to_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
 
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 4ce42c62458e..d75fddca44c9 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1960,7 +1960,7 @@ gss_unwrap_resp_integ(struct rpc_task *task, struct rpc_cred *cred,
 
 	if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset, integ_len))
 		goto unwrap_failed;
-	if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
+	if (xdr_buf_read_mic(rcv_buf, &mic, mic_offset))
 		goto unwrap_failed;
 	maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
 	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index b256806d69cd..74ae4c54b51a 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -1236,52 +1236,60 @@ xdr_encode_word(struct xdr_buf *buf, unsigned int base, u32 obj)
 }
 EXPORT_SYMBOL_GPL(xdr_encode_word);
 
-/* If the netobj starting offset bytes from the start of xdr_buf is contained
- * entirely in the head, pages, or tail, set object to point to it; otherwise
- * shift the buffer until it is contained entirely within the pages or tail.
+/**
+ * xdr_buf_read_mic() - obtain the address of the GSS mic from xdr buf
+ * @buf: pointer to buffer containing a mic
+ * @mic: on success, returns the address of the mic
+ * @offset: the offset in buf where mic may be found
+ *
+ * This function may modify the xdr buf if the mic is found to be straddling
+ * a boundary between head, pages, and tail.  On success the mic can be read
+ * from the address returned.  There is no need to free the mic.
+ *
+ * Return: Success returns 0, otherwise an integer error.
  */
-int xdr_buf_read_netobj(struct xdr_buf *buf, struct xdr_netobj *obj, unsigned int offset)
+int xdr_buf_read_mic(struct xdr_buf *buf, struct xdr_netobj *mic, unsigned int offset)
 {
 	struct xdr_buf subbuf;
 	unsigned int boundary;
 
-	if (xdr_decode_word(buf, offset, &obj->len))
+	if (xdr_decode_word(buf, offset, &mic->len))
 		return -EFAULT;
 	offset += 4;
 
-	/* Is the obj partially in the head? */
+	/* Is the mic partially in the head? */
 	boundary = buf->head[0].iov_len;
-	if (offset < boundary && (offset + obj->len) > boundary)
+	if (offset < boundary && (offset + mic->len) > boundary)
 		xdr_shift_buf(buf, boundary - offset);
 
-	/* Is the obj partially in the pages? */
+	/* Is the mic partially in the pages? */
 	boundary += buf->page_len;
-	if (offset < boundary && (offset + obj->len) > boundary)
+	if (offset < boundary && (offset + mic->len) > boundary)
 		xdr_shrink_pagelen(buf, boundary - offset);
 
-	if (xdr_buf_subsegment(buf, &subbuf, offset, obj->len))
+	if (xdr_buf_subsegment(buf, &subbuf, offset, mic->len))
 		return -EFAULT;
 
-	/* Is the obj contained entirely in the head? */
-	obj->data = subbuf.head[0].iov_base;
-	if (subbuf.head[0].iov_len == obj->len)
+	/* Is the mic contained entirely in the head? */
+	mic->data = subbuf.head[0].iov_base;
+	if (subbuf.head[0].iov_len == mic->len)
 		return 0;
-	/* ..or is the obj contained entirely in the tail? */
-	obj->data = subbuf.tail[0].iov_base;
-	if (subbuf.tail[0].iov_len == obj->len)
+	/* ..or is the mic contained entirely in the tail? */
+	mic->data = subbuf.tail[0].iov_base;
+	if (subbuf.tail[0].iov_len == mic->len)
 		return 0;
 
-	/* Find a contiguous area in @buf to hold all of @obj */
-	if (obj->len > buf->buflen - buf->len)
+	/* Find a contiguous area in @buf to hold all of @mic */
+	if (mic->len > buf->buflen - buf->len)
 		return -ENOMEM;
 	if (buf->tail[0].iov_len != 0)
-		obj->data = buf->tail[0].iov_base + buf->tail[0].iov_len;
+		mic->data = buf->tail[0].iov_base + buf->tail[0].iov_len;
 	else
-		obj->data = buf->head[0].iov_base + buf->head[0].iov_len;
-	__read_bytes_from_xdr_buf(&subbuf, obj->data, obj->len);
+		mic->data = buf->head[0].iov_base + buf->head[0].iov_len;
+	__read_bytes_from_xdr_buf(&subbuf, mic->data, mic->len);
 	return 0;
 }
-EXPORT_SYMBOL_GPL(xdr_buf_read_netobj);
+EXPORT_SYMBOL_GPL(xdr_buf_read_mic);
 
 /* Returns 0 on success, or else a negative error code. */
 static int
-- 
2.20.1