Commit 24b711ed authored by David Ahern's avatar David Ahern Committed by David S. Miller
Browse files

net/ipv6: Fix linklocal to global address with VRF 



Example setup:
    host: ip -6 addr add dev eth1 2001:db8:104::4
           where eth1 is enslaved to a VRF

    switch: ip -6 ro add 2001:db8:104::4/128 dev br1
            where br1 only has an LLA

           ping6 2001:db8:104::4
           ssh   2001:db8:104::4

(NOTE: UDP works fine if the PKTINFO has the address set to the global
address and ifindex is set to the index of eth1 with a destination an
LLA).

For ICMP, icmp6_iif needs to be updated to check if skb->dev is an
L3 master. If it is then return the ifindex from rt6i_idev similar
to what is done for loopback.

For TCP, restore the original tcp_v6_iif definition which is needed in
most places and add a new tcp_v6_iif_l3_slave that considers the
l3_slave variability. This latter check is only needed for socket
lookups.

Fixes: 9ff74384 ("net: vrf: Handle ipv6 multicast and link-local addresses")
Signed-off-by: default avatarDavid Ahern <dsahern@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f95de8aa

include/net/tcp.h

+5 −0
Original line number Diff line number Diff line
@@ -840,6 +840,11 @@ static inline void bpf_compute_data_end_sk_skb(struct sk_buff *skb) 
 * as TCP moves IP6CB into a different location in skb->cb[]

 */

static inline int tcp_v6_iif(const struct sk_buff *skb)

{

	return TCP_SKB_CB(skb)->header.h6.iif;

}



static inline int tcp_v6_iif_l3_slave(const struct sk_buff *skb)

{

	bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags);

net/ipv6/icmp.c

+3 −2
Original line number Diff line number Diff line
@@ -402,9 +402,10 @@ static int icmp6_iif(const struct sk_buff *skb) 


	/* for local traffic to local address, skb dev is the loopback

	 * device. Check if there is a dst attached to the skb and if so

	 * get the real device index.

	 * get the real device index. Same is needed for replies to a link

	 * local address on a device enslaved to an L3 master device

	 */

	if (unlikely(iif == LOOPBACK_IFINDEX)) {

	if (unlikely(iif == LOOPBACK_IFINDEX || netif_is_l3_master(skb->dev))) {

		const struct rt6_info *rt6 = skb_rt6_info(skb);



		if (rt6)

net/ipv6/tcp_ipv6.c

+4 −2
Original line number Diff line number Diff line
@@ -938,7 +938,8 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) 
					   &tcp_hashinfo, NULL, 0,

					   &ipv6h->saddr,

					   th->source, &ipv6h->daddr,

					   ntohs(th->source), tcp_v6_iif(skb),

					   ntohs(th->source),

					   tcp_v6_iif_l3_slave(skb),

					   tcp_v6_sdif(skb));

		if (!sk1)

			goto out;
@@ -1609,7 +1610,8 @@ do_time_wait: 
					    skb, __tcp_hdrlen(th),

					    &ipv6_hdr(skb)->saddr, th->source,

					    &ipv6_hdr(skb)->daddr,

					    ntohs(th->dest), tcp_v6_iif(skb),

					    ntohs(th->dest),

					    tcp_v6_iif_l3_slave(skb),

					    sdif);

		if (sk2) {

			struct inet_timewait_sock *tw = inet_twsk(sk);

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