On 6/8/23 1:41 PM, Gilad Sever wrote:
When calling bpf_sk_lookup_tcp(), bpf_sk_lookup_udp() or
bpf_skc_lookup_tcp() from tc/xdp ingress, VRF socket bindings aren't
respoected, i.e. unbound sockets are returned, and bound sockets aren't
found.
VRF binding is determined by the sdif argument to sk_lookup(), however
when called from tc the IP SKB control block isn't initialized and thus
inet{,6}_sdif() always returns 0.
Fix by calculating sdif for the tc/xdp flows by observing the device's
l3 enslaved state.
The cg/sk_skb hooking points which are expected to support
inet{,6}_sdif() pass sdif=-1 which makes __bpf_skc_lookup() use the
existing logic.
Fixes: 6acc9b432e67 ("bpf: Add helper to retrieve socket in BPF")
Acked-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
Reviewed-by: Shmulik Ladkani <shmulik.ladkani@xxxxxxxxx>
Reviewed-by: Eyal Birger <eyal.birger@xxxxxxxxx>
Signed-off-by: Gilad Sever <gilad9366@xxxxxxxxx>
Overall this series looks good to go, just small nits which would be great
to still address.
---
v5: Use reverse xmas tree indentation
v4: Move dev_sdif() to include/linux/netdevice.h as suggested by Stanislav Fomichev
v3: Rename bpf_l2_sdif() to dev_sdif() as suggested by Stanislav Fomichev
---
include/linux/netdevice.h | 9 +++++++
net/core/filter.c | 54 ++++++++++++++++++++++++---------------
2 files changed, 42 insertions(+), 21 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index c2f0c6002a84..db1bfca6b8b4 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -5093,6 +5093,15 @@ static inline bool netif_is_l3_slave(const struct net_device *dev)
return dev->priv_flags & IFF_L3MDEV_SLAVE;
}
+static inline int dev_sdif(const struct net_device *dev)
+{
+#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
Why IS_ENABLED? config NET_L3_MASTER_DEV says bool, so #ifdef CONFIG_NET_L3_MASTER_DEV
should suffice?
+ if (netif_is_l3_slave(dev))
+ return dev->ifindex;
+#endif
+ return 0;
+}
+
static inline bool netif_is_bridge_master(const struct net_device *dev)
{
return dev->priv_flags & IFF_EBRIDGE;
[...]
static const struct bpf_func_proto bpf_tc_sk_lookup_tcp_proto = {
@@ -6778,10 +6782,11 @@ BPF_CALL_5(bpf_tc_sk_lookup_udp, struct sk_buff *, skb,
{
struct net *caller_net = dev_net(skb->dev);
int ifindex = skb->dev->ifindex;
+ int sdif = dev_sdif(skb->dev);
return (unsigned long)__bpf_sk_lookup(skb, tuple, len, caller_net,
ifindex, IPPROTO_UDP, netns_id,
- flags);
+ flags, sdif);
}
static const struct bpf_func_proto bpf_tc_sk_lookup_udp_proto = {
@@ -6814,11 +6819,13 @@ BPF_CALL_5(bpf_xdp_sk_lookup_udp, struct xdp_buff *, ctx,
struct bpf_sock_tuple *, tuple, u32, len, u32, netns_id, u64, flags)
{
struct net *caller_net = dev_net(ctx->rxq->dev);
- int ifindex = ctx->rxq->dev->ifindex;
+ struct net_device *dev = ctx->rxq->dev;
Why not doing this before the struct net *caller_net and also use it there
for the dev_net()? Same in other XDP places. It would be nice to also do the
same for the tc helpers.
+ int ifindex = dev->ifindex;
+ int sdif = dev_sdif(dev);
return (unsigned long)__bpf_sk_lookup(NULL, tuple, len, caller_net,
ifindex, IPPROTO_UDP, netns_id,
- flags);
+ flags, sdif);
}
static const struct bpf_func_proto bpf_xdp_sk_lookup_udp_proto = {
@@ -6837,11 +6844,13 @@ BPF_CALL_5(bpf_xdp_skc_lookup_tcp, struct xdp_buff *, ctx,
struct bpf_sock_tuple *, tuple, u32, len, u32, netns_id, u64, flags)
{
struct net *caller_net = dev_net(ctx->rxq->dev);
- int ifindex = ctx->rxq->dev->ifindex;
+ struct net_device *dev = ctx->rxq->dev;
+ int ifindex = dev->ifindex;
+ int sdif = dev_sdif(dev);
return (unsigned long)__bpf_skc_lookup(NULL, tuple, len, caller_net,
ifindex, IPPROTO_TCP, netns_id,
- flags);
+ flags, sdif);
}
static const struct bpf_func_proto bpf_xdp_skc_lookup_tcp_proto = {
