[PATCH 2/3] lwip: clean up IPv6 address handling in init_ifs and inquire_device

[Joan Lledó]

From: Joan Lledó <jlle...@member.fsf.org>

    - init_ifs: drop redundant manual tentative-state setup; let
      netif_add_ip6_address() handle DAD state internally.
    - update_if: skip multicast addresses, remove unused prefix_len
      hardcoding and trailing dead code.
    - inquire_device: memset the addr6 output buffer, only copy addresses
      whose state is valid, and set prefix_len based on whether the
      address is static (64) or autoconf (128) instead of always 64.
---
 lwip/lwip-util.c | 40 +++++++++++++++++-----------------------
 1 file changed, 17 insertions(+), 23 deletions(-)

diff --git a/lwip/lwip-util.c b/lwip/lwip-util.c
index 35f38694..d6c3f41e 100644
--- a/lwip/lwip-util.c
+++ b/lwip/lwip-util.c
@@ -218,11 +218,7 @@ init_ifs (void *arg)
            {
              netif_add_ip6_address (netif, address6, &ipv6_addr_idx);
 
-             if (ipv6_addr_idx >= 0)
-               /* First use DAD to make sure nobody else has it */
-               netif_ip6_addr_set_state (netif, ipv6_addr_idx,
-                                         IP6_ADDR_TENTATIVE);
-             else
+             if (ipv6_addr_idx < 0)
                error (0, 0, "No free slot for IPv6 address: %s\n",
                       ip6addr_ntoa (address6));
            }
@@ -271,8 +267,8 @@ update_if (void *arg)
   if (args->addr6)
     for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++)
       {
-       ip6_addr_t *laddr6 = ((ip6_addr_t *) args->addr6 + i);
-       if (!ip6_addr_isany (laddr6))
+       ip6_addr_t *laddr6 = args->addr6 + i;
+       if (!ip6_addr_isany (laddr6) && !ip6_addr_ismulticast (laddr6))
          {
            netif_ip6_addr_set (args->netif, i, laddr6);
 
@@ -281,13 +277,7 @@ update_if (void *arg)
          }
       }
 
-  if (args->addr6_prefix_len)
-    for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++)
-      *(args->addr6_prefix_len + i) = 64;
-
   free (args);
-
-  return;
 }
 
 /* Get the IP configuration of an interface */
@@ -317,17 +307,21 @@ inquire_device (struct netif *netif, ip4_addr_t * addr, 
ip4_addr_t * netmask,
        gateway->addr = netif_ip4_gw (netif)->addr;
 
       if (addr6)
-       for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++)
-         {
-           *(addr6 + i * 4 + 0) = netif_ip6_addr (netif, i)->addr[0];
-           *(addr6 + i * 4 + 1) = netif_ip6_addr (netif, i)->addr[1];
-           *(addr6 + i * 4 + 2) = netif_ip6_addr (netif, i)->addr[2];
-           *(addr6 + i * 4 + 3) = netif_ip6_addr (netif, i)->addr[3];
-         }
+       {
+         for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++)
+           {
+             if (!ip6_addr_isvalid (netif_ip6_addr_state (netif, i)))
+               {
+                 memset (&addr6[i], 0, sizeof (ip6_addr_t));
+                 continue;
+               }
+
+             addr6[i] = *netif_ip6_addr (netif, i);
 
-      if (addr6_prefix_len)
-       for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++)
-         *(addr6_prefix_len + i) = 64;
+             if (addr6_prefix_len)
+               *(addr6_prefix_len + i) = 64;
+           }
+       }
     }
 }
 
-- 
2.50.1