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Commit 1d6e55f1 authored by Thomas Goff's avatar Thomas Goff Committed by David S. Miller
Browse files

IPv6: Fix multicast routing bugs. 



This patch addresses the IPv6 multicast routing issues described
below.  It was tested with XORP 1.4/1.5 as the IPv6 PIM-SM routing
daemon against FreeBSD peers.

net/ipv6/ip6_input.c:

  - Don't try to forward link-local multicast packets.

  - Don't reset skb2->dev before calling ip6_mr_input() so packets can
    be identified as coming from the PIM register vif properly.

net/ipv6/ip6mr.c:

  - Fix incoming PIM register messages processing:

    * The IPv6 pseudo-header should be included when checksumming PIM
      messages (RFC 4601 section 4.9; RFC 3973 section 4.7.1).

    * Packets decapsulated from PIM register messages should have
      skb->protocol ETH_P_IPV6.

  - Enable/disable IPv6 multicast forwarding on the corresponding
    interface when a routing daemon adds/removes a multicast virtual
    interface.

  - Remove incorrect skb_pull() to fix userspace signaling.

  - Enable/disable global IPv6 multicast forwarding when an IPv6
    multicast routing socket is opened/closed.

net/ipv6/route.c:

  - Don't use strict routing logic for packets decapsulated from PIM
    register messages (similar to disabling rp_filter for the IPv4
    case).

Signed-off-by: default avatarThomas Goff <thomas.goff@boeing.com>
Reviewed-by: default avatarFred Templin <fred.l.templin@boeing.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6c06a478

net/ipv6/ip6_input.c

+1 −1
Original line number Diff line number Diff line
@@ -255,6 +255,7 @@ int ip6_mc_input(struct sk_buff *skb) 
	 *      IPv6 multicast router mode is now supported ;)

	 */

	if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding &&

	    !(ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) &&

	    likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) {

		/*

		 * Okay, we try to forward - split and duplicate
@@ -316,7 +317,6 @@ int ip6_mc_input(struct sk_buff *skb) 
		}



		if (skb2) {

			skb2->dev = skb2->dst->dev;

			ip6_mr_input(skb2);

		}

	}

net/ipv6/ip6mr.c

+18 −5
Original line number Diff line number Diff line
@@ -365,7 +365,9 @@ static int pim6_rcv(struct sk_buff *skb) 
	pim = (struct pimreghdr *)skb_transport_header(skb);

	if (pim->type != ((PIM_VERSION << 4) | PIM_REGISTER) ||

	    (pim->flags & PIM_NULL_REGISTER) ||

	    (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&

	    (csum_ipv6_magic(&ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,

			     sizeof(*pim), IPPROTO_PIM,

			     csum_partial((void *)pim, sizeof(*pim), 0)) &&

	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))

		goto drop;
@@ -392,7 +394,7 @@ static int pim6_rcv(struct sk_buff *skb) 
	skb_pull(skb, (u8 *)encap - skb->data);

	skb_reset_network_header(skb);

	skb->dev = reg_dev;

	skb->protocol = htons(ETH_P_IP);

	skb->protocol = htons(ETH_P_IPV6);

	skb->ip_summed = 0;

	skb->pkt_type = PACKET_HOST;

	dst_release(skb->dst);
@@ -481,6 +483,7 @@ static int mif6_delete(struct net *net, int vifi) 
{

	struct mif_device *v;

	struct net_device *dev;

	struct inet6_dev *in6_dev;

	if (vifi < 0 || vifi >= net->ipv6.maxvif)

		return -EADDRNOTAVAIL;
@@ -513,6 +516,10 @@ static int mif6_delete(struct net *net, int vifi) 


	dev_set_allmulti(dev, -1);



	in6_dev = __in6_dev_get(dev);

	if (in6_dev)

		in6_dev->cnf.mc_forwarding--;



	if (v->flags & MIFF_REGISTER)

		unregister_netdevice(dev);
@@ -622,6 +629,7 @@ static int mif6_add(struct net *net, struct mif6ctl *vifc, int mrtsock) 
	int vifi = vifc->mif6c_mifi;

	struct mif_device *v = &net->ipv6.vif6_table[vifi];

	struct net_device *dev;

	struct inet6_dev *in6_dev;

	int err;



	/* Is vif busy ? */
@@ -662,6 +670,10 @@ static int mif6_add(struct net *net, struct mif6ctl *vifc, int mrtsock) 
		return -EINVAL;

	}



	in6_dev = __in6_dev_get(dev);

	if (in6_dev)

		in6_dev->cnf.mc_forwarding++;



	/*

	 *	Fill in the VIF structures

	 */
@@ -838,8 +850,6 @@ static int ip6mr_cache_report(struct net *net, struct sk_buff *pkt, mifi_t mifi, 


	skb->dst = dst_clone(pkt->dst);

	skb->ip_summed = CHECKSUM_UNNECESSARY;



	skb_pull(skb, sizeof(struct ipv6hdr));

	}



	if (net->ipv6.mroute6_sk == NULL) {
@@ -1222,8 +1232,10 @@ static int ip6mr_sk_init(struct sock *sk) 


	rtnl_lock();

	write_lock_bh(&mrt_lock);

	if (likely(net->ipv6.mroute6_sk == NULL))

	if (likely(net->ipv6.mroute6_sk == NULL)) {

		net->ipv6.mroute6_sk = sk;

		net->ipv6.devconf_all->mc_forwarding++;

	}

	else

		err = -EADDRINUSE;

	write_unlock_bh(&mrt_lock);
@@ -1242,6 +1254,7 @@ int ip6mr_sk_done(struct sock *sk) 
	if (sk == net->ipv6.mroute6_sk) {

		write_lock_bh(&mrt_lock);

		net->ipv6.mroute6_sk = NULL;

		net->ipv6.devconf_all->mc_forwarding--;

		write_unlock_bh(&mrt_lock);



		mroute_clean_tables(net);

net/ipv6/route.c

+1 −1
Original line number Diff line number Diff line
@@ -794,7 +794,7 @@ void ip6_route_input(struct sk_buff *skb) 
		.proto = iph->nexthdr,

	};



	if (rt6_need_strict(&iph->daddr))

	if (rt6_need_strict(&iph->daddr) && skb->dev->type != ARPHRD_PIMREG)

		flags |= RT6_LOOKUP_F_IFACE;



	skb->dst = fib6_rule_lookup(net, &fl, flags, ip6_pol_route_input);