NBD: Use qemu_socket functions to open TCP and UNIX sockets

This commit has the side-effect of making the qemu-nbd binary
capable of binding to IPv6 addresses. ("-b ::1", for instance).
block/nbd.c fails to parse IPv6 IP addresses correctly at this
point, but will work over IPv6 when given a hostname. It still
works over IPv4 as before.

We move the qemu-sockets object from the 'common' to the 'block'
list in the Makefile. The common list includes the block list,
so this is effectively a no-op for the rest of the code.

We also add 32-bit 'magic' attributes to nbd_(request|reply) to
facilitate calculating maximum request/response sizes later.

Signed-off-by: Nick Thomas <nick@bytemark.co.uk>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/nbd.h b/nbd.h
index fc3a5944f4..b38d0d08de 100644
--- a/nbd.h
+++ b/nbd.h
@@ -22,19 +22,22 @@
 #include <sys/types.h>
 
 #include <qemu-common.h>
+
 #include "block_int.h"
 
 struct nbd_request {
+    uint32_t magic;
     uint32_t type;
     uint64_t handle;
     uint64_t from;
     uint32_t len;
-};
+} __attribute__ ((__packed__));
 
 struct nbd_reply {
+    uint32_t magic;
     uint32_t error;
     uint64_t handle;
-};
+} __attribute__ ((__packed__));
 
 enum {
     NBD_CMD_READ = 0,
@@ -47,6 +50,8 @@ enum {
 size_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read);
 int tcp_socket_outgoing(const char *address, uint16_t port);
 int tcp_socket_incoming(const char *address, uint16_t port);
+int tcp_socket_outgoing_spec(const char *address_and_port);
+int tcp_socket_incoming_spec(const char *address_and_port);
 int unix_socket_outgoing(const char *path);
 int unix_socket_incoming(const char *path);