From 4ac7c8341c660db654821ed2dc0273645dc19645 Mon Sep 17 00:00:00 2001
From: Ondrej Zajicek <santiago@crfreenet.org>
Date: Mon, 9 Nov 2009 23:22:53 +0100
Subject: [PATCH] Use IPv6 checksums in OSPFv3.

---
 lib/socket.h        |  4 ++++
 proto/ospf/iface.c  |  6 ++++++
 proto/ospf/packet.c |  1 -
 sysdep/unix/io.c    | 19 ++++++++++++++++++-
 4 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/lib/socket.h b/lib/socket.h
index f44e8e88..c642bdf9 100644
--- a/lib/socket.h
+++ b/lib/socket.h
@@ -60,6 +60,10 @@ int sk_setup_multicast(sock *s);
 int sk_join_group(sock *s, ip_addr maddr);
 int sk_leave_group(sock *s, ip_addr maddr);
 
+#ifdef IPV6
+int sk_set_ipv6_checksum(sock *s, int offset);
+#endif
+
 static inline int
 sk_send_buffer_empty(sock *sk)
 {
diff --git a/proto/ospf/iface.c b/proto/ospf/iface.c
index 9b65961d..e98414f2 100644
--- a/proto/ospf/iface.c
+++ b/proto/ospf/iface.c
@@ -89,6 +89,12 @@ ospf_open_socket(struct ospf_iface *ifa, int mc)
   if (sk_open(ipsk) != 0)
     goto err;
 
+#ifdef OSPFv3
+  /* 12 is an offset of the checksum in an OSPF packet */
+  if (sk_set_ipv6_checksum(ipsk, 12) < 0)
+    goto err;
+#endif
+
   if (mc)
   {
     if (sk_setup_multicast(ipsk) < 0)
diff --git a/proto/ospf/packet.c b/proto/ospf/packet.c
index 9422a9f3..94ec0109 100644
--- a/proto/ospf/packet.c
+++ b/proto/ospf/packet.c
@@ -320,7 +320,6 @@ ospf_rx_hook(sock * sk, int size)
     return 1;
   }
 
-  /* FIXME - handle checksums in OSPFv3  */ 
 #ifdef OSPFv2
   if ((ps->autype != htons(OSPF_AUTH_CRYPT)) &&
       (!ipsum_verify(ps, 16, (void *) ps + sizeof(struct ospf_packet),
diff --git a/sysdep/unix/io.c b/sysdep/unix/io.c
index 3eb2e03c..cd5c5db7 100644
--- a/sysdep/unix/io.c
+++ b/sysdep/unix/io.c
@@ -782,12 +782,29 @@ int
 sk_set_broadcast(sock *s, int enable)
 {
   if (setsockopt(s->fd, SOL_SOCKET, SO_BROADCAST, &enable, sizeof(enable)) < 0)
-    log(L_ERR "sk_set_broadcast: SO_BROADCAST: %m");
+    {
+      log(L_ERR "sk_set_broadcast: SO_BROADCAST: %m");
+      return -1;
+    }
+
+  return 0;
 }
 
 
 #ifdef IPV6
 
+int
+sk_set_ipv6_checksum(sock *s, int offset)
+{
+  if (setsockopt(s->fd, IPPROTO_IPV6, IPV6_CHECKSUM, &offset, sizeof(offset)) < 0)
+    {
+      log(L_ERR "sk_set_ipv6_checksum: IPV6_CHECKSUM: %m");
+      return -1;
+    }
+
+  return 0;
+}
+
 int
 sk_setup_multicast(sock *s)
 {