[DCCP]: Introduce DCCPv6

Still needs mucho polishing, specially in the checksum code, but works
just fine, inet_diag/iproute2 and all 8)
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/dccp/Makefile

+obj-$(CONFIG_IPV6) += dccp_ipv6.o
+
+dccp_ipv6-y := ipv6.o
+
 obj-$(CONFIG_IP_DCCP) += dccp.o
 
 dccp-y := ccid.o input.o ipv4.o minisocks.o options.o output.o proto.o \

net/dccp/ipv6.h

+#ifndef _DCCP_IPV6_H
+#define _DCCP_IPV6_H
+/*
+ *  net/dccp/ipv6.h
+ *
+ *  An implementation of the DCCP protocol
+ *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
+ *
+ *	This program is free software; you can redistribute it and/or modify it
+ *	under the terms of the GNU General Public License version 2 as
+ *	published by the Free Software Foundation.
+ */
+
+#include <linux/config.h>
+#include <linux/dccp.h>
+#include <linux/ipv6.h>
+
+struct dccp6_sock {
+	struct dccp_sock  dccp;
+	/*
+	 * ipv6_pinfo has to be the last member of dccp6_sock,
+	 * see inet6_sk_generic.
+	 */
+	struct ipv6_pinfo inet6;
+};
+
+struct dccp6_request_sock {
+	struct dccp_request_sock  dccp;
+	struct inet6_request_sock inet6;
+};
+
+struct dccp6_timewait_sock {
+	struct inet_timewait_sock   inet;
+	struct inet6_timewait_sock  tw6;
+};
+
+#endif /* _DCCP_IPV6_H */

net/dccp/minisocks.c

@@ -52,7 +52,18 @@ void dccp_time_wait(struct sock *sk, int state, int timeo)
 	if (tw != NULL) {
 		const struct inet_connection_sock *icsk = inet_csk(sk);
 		const int rto = (icsk->icsk_rto << 2) - (icsk->icsk_rto >> 1);
-
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+		if (tw->tw_family == PF_INET6) {
+			const struct ipv6_pinfo *np = inet6_sk(sk);
+			struct inet6_timewait_sock *tw6;
+
+			tw->tw_ipv6_offset = inet6_tw_offset(sk->sk_prot);
+			tw6 = inet6_twsk((struct sock *)tw);
+			ipv6_addr_copy(&tw6->tw_v6_daddr, &np->daddr);
+			ipv6_addr_copy(&tw6->tw_v6_rcv_saddr, &np->rcv_saddr);
+			tw->tw_ipv6only = np->ipv6only;
+		}
+#endif
 		/* Linkage updates. */
 		__inet_twsk_hashdance(tw, sk, &dccp_hashinfo);