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Message-Id: <1465850659-27830-4-git-send-email-dsa@cumulusnetworks.com>
Date: Mon, 13 Jun 2016 13:44:19 -0700
From: David Ahern <dsa@...ulusnetworks.com>
To: netdev@...r.kernel.org
Cc: David Ahern <dsa@...ulusnetworks.com>
Subject: [PATCH net-next 3/3] 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 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@...0::18f8:83ff:fe4b:7a2e%eth1
Signed-off-by: David Ahern <dsa@...ulusnetworks.com>
---
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 @@ 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
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 @@ 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)
--
2.1.4
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