extmod/modlwip: Support IPv6.

With these changes IPv6 works on the rp2 port (and possibly others that use
the lwIP socket implementation).

Things that have been tested and work:
- Neighbour solicitation for v6 link local address.
- Ping of v6 link-local address.
- Receiving a SLAAC address via router advertisement.
- Ping a v6 address allocated via SLAAC.
- Perform an outgoing connection to a routed v6-address (via default
  gateway).
- Create a listening IPv6 wildcard socked bound to ::, and trying to access
  it via link-local, SLAAC, and IPv4 (to ensure the dual-stack binding
  works).

Things that could be improved:
- socket.socket().getaddrinfo only returns the v4 address.  It could also
  return v6 addresses (getaddrinfo is actively programmed to only return a
  single address, and this is the v4-address by default, with fallback to
  the v6 address if both are enabled).

Signed-off-by: Felix Dörre <felix@dogcraft.de>

1 files changed, 5 insertions, 4 deletions

diff --git a/extmod/network_cyw43.c b/extmod/network_cyw43.c
index f8490d6b9..2f188dbad 100644
--- a/extmod/network_cyw43.c
+++ b/extmod/network_cyw43.c
@@ -78,13 +78,14 @@ STATIC void network_cyw43_print(const mp_print_t *print, mp_obj_t self_in, mp_pr
     } else {
         status_str = "fail";
     }
+    ip4_addr_t *addr = ip_2_ip4(&netif->ip_addr);
     mp_printf(print, "<CYW43 %s %s %u.%u.%u.%u>",
         self->itf == CYW43_ITF_STA ? "STA" : "AP",
         status_str,
-        netif->ip_addr.addr & 0xff,
-        netif->ip_addr.addr >> 8 & 0xff,
-        netif->ip_addr.addr >> 16 & 0xff,
-        netif->ip_addr.addr >> 24
+        addr->addr & 0xff,
+        addr->addr >> 8 & 0xff,
+        addr->addr >> 16 & 0xff,
+        addr->addr >> 24
         );
 }