msg: Fix Windows IPv6 support

The Windows AF_INET6 definition doesn't match the Linux one, thus
sockaddr structures must be converted when being sent over the wire.
Otherwise, Linux hosts will not be able to recognize the address
family and reject Windows client connections:

  handle_client_ident peer is trying to reach
  v2:(unrecognized address family 23)/0 which is not us

Note that this isn't the case with AF_INET, which has the same
definition on both platforms.

Signed-off-by: Lucian Petrut <[email protected]>

src/msg/msg_types.h

@@ -26,6 +26,11 @@
 
 #define MAX_PORT_NUMBER 65535
 
+#ifdef _WIN32
+// ceph_sockaddr_storage matches the Linux format.
+#define AF_INET6_LINUX 10
+#endif
+
 namespace ceph {
   class Formatter;
 }
@@ -161,6 +166,14 @@ static inline void encode(const sockaddr_storage& a, ceph::buffer::list& bl) {
 				  (unsigned char*)(&ss + 1) - dst);
   ::memcpy(dst, src, copy_size);
   encode(ss, bl);
+#elif defined(_WIN32)
+  ceph_sockaddr_storage ss{};
+  ::memcpy(&ss, &a, std::min(sizeof(ss), sizeof(a)));
+  // The Windows AF_INET6 definition doesn't match the Linux one.
+  if (a.ss_family == AF_INET6) {
+    ss.ss_family = AF_INET6_LINUX;
+  }
+  encode(ss, bl);
 #else
   ceph_sockaddr_storage ss;
   ::memset(&ss, '\0', sizeof(ss));
@@ -186,6 +199,13 @@ static inline void decode(sockaddr_storage& a,
   auto const copy_size = std::min((unsigned char*)(&ss + 1) - src,
 				  (unsigned char*)(&a + 1) - dst);
   ::memcpy(dst, src, copy_size);
+#elif defined(_WIN32)
+  ceph_sockaddr_storage ss{};
+  decode(ss, bl);
+  ::memcpy(&a, &ss, std::min(sizeof(ss), sizeof(a)));
+  if (a.ss_family == AF_INET6_LINUX) {
+    a.ss_family = AF_INET6;
+  }
 #else
   ceph_sockaddr_storage ss{};
   decode(ss, bl);
@@ -463,7 +483,11 @@ struct entity_addr_t {
     encode(elen, bl);
     if (elen) {
       uint16_t ss_family = u.sa.sa_family;
-
+#if defined(_WIN32)
+      if (ss_family == AF_INET6) {
+        ss_family = AF_INET6_LINUX;
+      }
+#endif
       encode(ss_family, bl);
       elen -= sizeof(u.sa.sa_family);
       bl.append(u.sa.sa_data, elen);
@@ -494,6 +518,11 @@ struct entity_addr_t {
 	throw ceph::buffer::malformed_input("elen smaller than family len");
       }
       decode(ss_family, bl);
+#if defined(_WIN32)
+      if (ss_family == AF_INET6_LINUX) {
+        ss_family = AF_INET6;
+      }
+#endif
       u.sa.sa_family = ss_family;
       elen -= sizeof(ss_family);
       if (elen > get_sockaddr_len() - sizeof(u.sa.sa_family)) {