From 9ff74384600aeecba34ebdacbbde0627489ff601 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Mon, 13 Jun 2016 13:44:19 -0700 Subject: [PATCH] net: vrf: Handle ipv6 multicast and link-local addresses IPv6 multicast and link-local addresses require special handling by the VRF driver: 1. Rather than using the VRF device index and full FIB lookups, packets to/from these addresses should use direct FIB lookups based on the VRF device table. 2. fail sends/receives on a VRF device to/from a multicast address (e.g, make ping6 ff02::1% fail) 3. move the setting of the flow oif to the first dst lookup and revert the change in icmpv6_echo_reply made in ca254490c8dfd ("net: Add VRF support to IPv6 stack"). Linklocal/mcast addresses require use of the skb->dev. With this change connections into and out of a VRF enslaved device work for multicast and link-local addresses work (icmp, tcp, and udp) e.g., 1. packets into VM with VRF config: ping6 -c3 fe80::e0:f9ff:fe1c:b974%br1 ping6 -c3 ff02::1%br1 ssh -6 fe80::e0:f9ff:fe1c:b974%br1 2. packets going out a VRF enslaved device: ping6 -c3 fe80::18f8:83ff:fe4b:7a2e%eth1 ping6 -c3 ff02::1%eth1 ssh -6 root@fe80::18f8:83ff:fe4b:7a2e%eth1 Signed-off-by: David Ahern Signed-off-by: David S. Miller --- drivers/net/vrf.c | 98 ++++++++++++++++++++++++++++++++++++++--- include/net/ip6_route.h | 2 + net/ipv6/icmp.c | 2 +- net/ipv6/route.c | 5 ++- 4 files changed, 99 insertions(+), 8 deletions(-) diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c index d2ce76c9dc64..0b5b3c258c2b 100644 --- a/drivers/net/vrf.c +++ b/drivers/net/vrf.c @@ -785,9 +785,63 @@ out: return rc; } +static struct rt6_info *vrf_ip6_route_lookup(struct net *net, + const struct net_device *dev, + struct flowi6 *fl6, + int ifindex, + int flags) +{ + struct net_vrf *vrf = netdev_priv(dev); + struct fib6_table *table = NULL; + struct rt6_info *rt6; + + rcu_read_lock(); + + /* fib6_table does not have a refcnt and can not be freed */ + rt6 = rcu_dereference(vrf->rt6); + if (likely(rt6)) + table = rt6->rt6i_table; + + rcu_read_unlock(); + + if (!table) + return NULL; + + return ip6_pol_route(net, table, ifindex, fl6, flags); +} + +static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev, + int ifindex) +{ + const struct ipv6hdr *iph = ipv6_hdr(skb); + struct flowi6 fl6 = { + .daddr = iph->daddr, + .saddr = iph->saddr, + .flowlabel = ip6_flowinfo(iph), + .flowi6_mark = skb->mark, + .flowi6_proto = iph->nexthdr, + .flowi6_iif = ifindex, + }; + struct net *net = dev_net(vrf_dev); + struct rt6_info *rt6; + + rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex, + RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE); + if (unlikely(!rt6)) + return; + + if (unlikely(&rt6->dst == &net->ipv6.ip6_null_entry->dst)) + return; + + skb_dst_set(skb, &rt6->dst); +} + static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev, struct sk_buff *skb) { + int orig_iif = skb->skb_iif; + bool need_strict; + /* loopback traffic; do not push through packet taps again. * Reset pkt_type for upper layers to process skb */ @@ -798,8 +852,11 @@ static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev, goto out; } - /* if packet is NDISC keep the ingress interface */ - if (!ipv6_ndisc_frame(skb)) { + /* if packet is NDISC or addressed to multicast or link-local + * then keep the ingress interface + */ + need_strict = rt6_need_strict(&ipv6_hdr(skb)->daddr); + if (!ipv6_ndisc_frame(skb) && !need_strict) { skb->dev = vrf_dev; skb->skb_iif = vrf_dev->ifindex; @@ -810,6 +867,9 @@ static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev, IP6CB(skb)->flags |= IP6SKB_L3SLAVE; } + if (need_strict) + vrf_ip6_input_dst(skb, vrf_dev, orig_iif); + out: return skb; } @@ -863,11 +923,35 @@ static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev, static struct dst_entry *vrf_get_rt6_dst(const struct net_device *dev, struct flowi6 *fl6) { + bool need_strict = rt6_need_strict(&fl6->daddr); + struct net_vrf *vrf = netdev_priv(dev); + struct net *net = dev_net(dev); struct dst_entry *dst = NULL; + struct rt6_info *rt; - if (!(fl6->flowi6_flags & FLOWI_FLAG_L3MDEV_SRC)) { - struct net_vrf *vrf = netdev_priv(dev); - struct rt6_info *rt; + /* send to link-local or multicast address */ + if (need_strict) { + int flags = RT6_LOOKUP_F_IFACE; + + /* VRF device does not have a link-local address and + * sending packets to link-local or mcast addresses over + * a VRF device does not make sense + */ + if (fl6->flowi6_oif == dev->ifindex) { + struct dst_entry *dst = &net->ipv6.ip6_null_entry->dst; + + dst_hold(dst); + return dst; + } + + if (!ipv6_addr_any(&fl6->saddr)) + flags |= RT6_LOOKUP_F_HAS_SADDR; + + rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, flags); + if (rt) + dst = &rt->dst; + + } else if (!(fl6->flowi6_flags & FLOWI_FLAG_L3MDEV_SRC)) { rcu_read_lock(); @@ -880,6 +964,10 @@ static struct dst_entry *vrf_get_rt6_dst(const struct net_device *dev, rcu_read_unlock(); } + /* make sure oif is set to VRF device for lookup */ + if (!need_strict) + fl6->flowi6_oif = dev->ifindex; + return dst; } #endif diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h index 54c779416eec..f55bf3d294aa 100644 --- a/include/net/ip6_route.h +++ b/include/net/ip6_route.h @@ -76,6 +76,8 @@ static inline struct dst_entry *ip6_route_output(struct net *net, struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6, int flags); +struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, + int ifindex, struct flowi6 *fl6, int flags); int ip6_route_init(void); void ip6_route_cleanup(void); diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index 40454bfb534e..e32a72fb9982 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -587,7 +587,7 @@ static void icmpv6_echo_reply(struct sk_buff *skb) fl6.daddr = ipv6_hdr(skb)->saddr; if (saddr) fl6.saddr = *saddr; - fl6.flowi6_oif = l3mdev_fib_oif(skb->dev); + fl6.flowi6_oif = skb->dev->ifindex; fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY; fl6.flowi6_mark = mark; security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); diff --git a/net/ipv6/route.c b/net/ipv6/route.c index c6ae6f9b5fe3..d51a1a48b839 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1042,8 +1042,8 @@ static struct rt6_info *rt6_make_pcpu_route(struct rt6_info *rt) return pcpu_rt; } -static struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, int oif, - struct flowi6 *fl6, int flags) +struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, + int oif, struct flowi6 *fl6, int flags) { struct fib6_node *fn, *saved_fn; struct rt6_info *rt; @@ -1139,6 +1139,7 @@ redo_rt6_select: } } +EXPORT_SYMBOL_GPL(ip6_pol_route); static struct rt6_info *ip6_pol_route_input(struct net *net, struct fib6_table *table, struct flowi6 *fl6, int flags) -- 2.20.1