Simplified NBD handle comparisons

8 bytes, therefore a uing64_t to compare to, no need for memcmp()

Signed-off-by: Michel Pollet <buserror@gmail.com>

src/common/nbdtypes.c

@@ -27,7 +27,7 @@ void nbd_r2h_request( struct nbd_request_raw *from, struct nbd_request * to )
 {
 	to->magic = htobe32( from->magic );
 	to->type = htobe32( from->type );
-	memcpy( to->handle, from->handle, 8 );
+	to->handle.w = from->handle.w;
 	to->from = htobe64( from->from );
 	to->len = htobe32( from->len );
 }
@@ -36,7 +36,7 @@ void nbd_h2r_request( struct nbd_request * from, struct nbd_request_raw * to )
 {
 	to->magic = be32toh( from->magic );
 	to->type = be32toh( from->type );
-	memcpy( to->handle, from->handle, 8 );
+	to->handle.w = from->handle.w;
 	to->from = be64toh( from->from );
 	to->len = be32toh( from->len );
 }
@@ -46,13 +46,13 @@ void nbd_r2h_reply( struct nbd_reply_raw * from, struct nbd_reply * to )
 {
 	to->magic = htobe32( from->magic );
 	to->error = htobe32( from->error );
-	memcpy( to->handle, from->handle, 8 );
+	to->handle.w = from->handle.w;
 }
 
 void nbd_h2r_reply( struct nbd_reply * from, struct nbd_reply_raw * to )
 {
 	to->magic = be32toh( from->magic );
 	to->error = be32toh( from->error );
-	memcpy( to->handle, from->handle, 8 );
+	to->handle.w = from->handle.w;
 }
 

src/common/nbdtypes.h

@@ -24,6 +24,11 @@
 #include <linux/types.h>
 #include <inttypes.h>
 
+typedef union nbd_handle_t {
+	uint8_t b[8];
+	uint64_t w;
+} nbd_handle_t;
+
 /* The _raw types are the types as they appear on the wire.  Non-_raw
  * types are in host-format.
  * Conversion functions are _r2h_ for converting raw to host, and _h2r_
@@ -39,7 +44,7 @@ struct nbd_init_raw {
 struct nbd_request_raw {
 	__be32 magic;
 	__be32 type;    /* == READ || == WRITE  */
-	char handle[8];
+	nbd_handle_t handle;
 	__be64 from;
 	__be32 len;
 } __attribute__((packed));
@@ -47,7 +52,7 @@ struct nbd_request_raw {
 struct nbd_reply_raw {
 	__be32 magic;
 	__be32 error;           /* 0 = ok, else error   */
-	char handle[8];         /* handle you got from request  */
+	nbd_handle_t handle;         /* handle you got from request  */
 };
 
 
@@ -62,7 +67,7 @@ struct nbd_init {
 struct nbd_request {
 	uint32_t magic;
 	uint32_t type;    /* == READ || == WRITE || == DISCONNECT */
-	char handle[8];
+	nbd_handle_t handle;
 	uint64_t from;
 	uint32_t len;
 } __attribute__((packed));
@@ -70,7 +75,7 @@ struct nbd_request {
 struct nbd_reply {
 	uint32_t magic;
 	uint32_t error;           /* 0 = ok, else error   */
-	char handle[8];         /* handle you got from request  */
+	nbd_handle_t handle;      /* handle you got from request  */
 };
 
 void nbd_r2h_init( struct nbd_init_raw * from, struct nbd_init * to );

src/common/readwrite.c

@@ -105,9 +105,7 @@ void fill_request(struct nbd_request *request, int type, uint64_t from, uint32_t
 {
 	request->magic  = htobe32(REQUEST_MAGIC);
 	request->type   = htobe32(type);
-	uint32_t * randa = (uint32_t*)request->handle;
-	randa[0] = rand();
-	randa[1] = rand();
+	request->handle.w = (((uint64_t)rand()) << 32) | ((uint64_t)rand());
 	request->from   = htobe64(from);
 	request->len    = htobe32(len);
 }
@@ -127,7 +125,7 @@ void read_reply(int fd, struct nbd_request *request, struct nbd_reply *reply)
 	if (reply->error != 0) {
 		error("Server replied with error %d", reply->error);
 	}
-	if (strncmp(request->handle, reply->handle, 8) != 0) {
+	if (request->handle.w != reply->handle.w) {
 		error("Did not reply with correct handle");
 	}
 }