Commit 9ff74384 authored by David Ahern's avatar David Ahern Committed by David S. Miller

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%<vrf> fail)

3. move the setting of the flow oif to the first dst lookup and revert
   the change in icmpv6_echo_reply made in ca254490 ("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: default avatarDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ba46ee4c
......@@ -785,9 +785,63 @@ static bool ipv6_ndisc_frame(const struct sk_buff *skb)
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
......
......@@ -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);
......
......@@ -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));
......
......@@ -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 @@ static struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
}
}
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)
......
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