From: Gilad Sever gilad9366@gmail.com
[ Upstream commit 9a5cb79762e0eda17ca15c2a6eaca4622383c21c ]
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") Signed-off-by: Gilad Sever gilad9366@gmail.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Reviewed-by: Shmulik Ladkani shmulik.ladkani@gmail.com Reviewed-by: Eyal Birger eyal.birger@gmail.com Acked-by: Stanislav Fomichev sdf@google.com Cc: David Ahern dsahern@kernel.org Link: https://lore.kernel.org/bpf/20230621104211.301902-4-gilad9366@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/netdevice.h | 9 +++++ net/core/filter.c | 69 ++++++++++++++++++++++----------------- 2 files changed, 48 insertions(+), 30 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index c2f0c6002a84b..68adc8af29efb 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) +{ +#ifdef CONFIG_NET_L3_MASTER_DEV + 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; diff --git a/net/core/filter.c b/net/core/filter.c index e06547922edcf..1c959794a8862 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -6555,12 +6555,11 @@ static struct sock *sk_lookup(struct net *net, struct bpf_sock_tuple *tuple, static struct sock * __bpf_skc_lookup(struct sk_buff *skb, struct bpf_sock_tuple *tuple, u32 len, struct net *caller_net, u32 ifindex, u8 proto, u64 netns_id, - u64 flags) + u64 flags, int sdif) { struct sock *sk = NULL; struct net *net; u8 family; - int sdif;
if (len == sizeof(tuple->ipv4)) family = AF_INET; @@ -6572,10 +6571,12 @@ __bpf_skc_lookup(struct sk_buff *skb, struct bpf_sock_tuple *tuple, u32 len, if (unlikely(flags || !((s32)netns_id < 0 || netns_id <= S32_MAX))) goto out;
- if (family == AF_INET) - sdif = inet_sdif(skb); - else - sdif = inet6_sdif(skb); + if (sdif < 0) { + if (family == AF_INET) + sdif = inet_sdif(skb); + else + sdif = inet6_sdif(skb); + }
if ((s32)netns_id < 0) { net = caller_net; @@ -6595,10 +6596,11 @@ __bpf_skc_lookup(struct sk_buff *skb, struct bpf_sock_tuple *tuple, u32 len, static struct sock * __bpf_sk_lookup(struct sk_buff *skb, struct bpf_sock_tuple *tuple, u32 len, struct net *caller_net, u32 ifindex, u8 proto, u64 netns_id, - u64 flags) + u64 flags, int sdif) { struct sock *sk = __bpf_skc_lookup(skb, tuple, len, caller_net, - ifindex, proto, netns_id, flags); + ifindex, proto, netns_id, flags, + sdif);
if (sk) { struct sock *sk2 = sk_to_full_sk(sk); @@ -6638,7 +6640,7 @@ bpf_skc_lookup(struct sk_buff *skb, struct bpf_sock_tuple *tuple, u32 len, }
return __bpf_skc_lookup(skb, tuple, len, caller_net, ifindex, proto, - netns_id, flags); + netns_id, flags, -1); }
static struct sock * @@ -6730,12 +6732,13 @@ static const struct bpf_func_proto bpf_sk_lookup_udp_proto = { BPF_CALL_5(bpf_tc_skc_lookup_tcp, struct sk_buff *, skb, struct bpf_sock_tuple *, tuple, u32, len, u64, netns_id, u64, flags) { - struct net *caller_net = dev_net(skb->dev); - int ifindex = skb->dev->ifindex; + struct net_device *dev = skb->dev; + int ifindex = dev->ifindex, sdif = dev_sdif(dev); + struct net *caller_net = dev_net(dev);
return (unsigned long)__bpf_skc_lookup(skb, tuple, len, caller_net, ifindex, IPPROTO_TCP, netns_id, - flags); + flags, sdif); }
static const struct bpf_func_proto bpf_tc_skc_lookup_tcp_proto = { @@ -6753,12 +6756,13 @@ static const struct bpf_func_proto bpf_tc_skc_lookup_tcp_proto = { BPF_CALL_5(bpf_tc_sk_lookup_tcp, struct sk_buff *, skb, struct bpf_sock_tuple *, tuple, u32, len, u64, netns_id, u64, flags) { - struct net *caller_net = dev_net(skb->dev); - int ifindex = skb->dev->ifindex; + struct net_device *dev = skb->dev; + int ifindex = dev->ifindex, sdif = dev_sdif(dev); + struct net *caller_net = dev_net(dev);
return (unsigned long)__bpf_sk_lookup(skb, tuple, len, caller_net, ifindex, IPPROTO_TCP, netns_id, - flags); + flags, sdif); }
static const struct bpf_func_proto bpf_tc_sk_lookup_tcp_proto = { @@ -6776,12 +6780,13 @@ static const struct bpf_func_proto bpf_tc_sk_lookup_tcp_proto = { BPF_CALL_5(bpf_tc_sk_lookup_udp, struct sk_buff *, skb, struct bpf_sock_tuple *, tuple, u32, len, u64, netns_id, u64, flags) { - struct net *caller_net = dev_net(skb->dev); - int ifindex = skb->dev->ifindex; + struct net_device *dev = skb->dev; + int ifindex = dev->ifindex, sdif = dev_sdif(dev); + struct net *caller_net = dev_net(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 = { @@ -6813,12 +6818,13 @@ static const struct bpf_func_proto bpf_sk_release_proto = { 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; + int ifindex = dev->ifindex, sdif = dev_sdif(dev); + struct net *caller_net = dev_net(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 = { @@ -6836,12 +6842,13 @@ static const struct bpf_func_proto bpf_xdp_sk_lookup_udp_proto = { 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, sdif = dev_sdif(dev); + struct net *caller_net = dev_net(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 = { @@ -6859,12 +6866,13 @@ static const struct bpf_func_proto bpf_xdp_skc_lookup_tcp_proto = { BPF_CALL_5(bpf_xdp_sk_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, sdif = dev_sdif(dev); + struct net *caller_net = dev_net(dev);
return (unsigned long)__bpf_sk_lookup(NULL, tuple, len, caller_net, ifindex, IPPROTO_TCP, netns_id, - flags); + flags, sdif); }
static const struct bpf_func_proto bpf_xdp_sk_lookup_tcp_proto = { @@ -6884,7 +6892,8 @@ BPF_CALL_5(bpf_sock_addr_skc_lookup_tcp, struct bpf_sock_addr_kern *, ctx, { return (unsigned long)__bpf_skc_lookup(NULL, tuple, len, sock_net(ctx->sk), 0, - IPPROTO_TCP, netns_id, flags); + IPPROTO_TCP, netns_id, flags, + -1); }
static const struct bpf_func_proto bpf_sock_addr_skc_lookup_tcp_proto = { @@ -6903,7 +6912,7 @@ BPF_CALL_5(bpf_sock_addr_sk_lookup_tcp, struct bpf_sock_addr_kern *, ctx, { return (unsigned long)__bpf_sk_lookup(NULL, tuple, len, sock_net(ctx->sk), 0, IPPROTO_TCP, - netns_id, flags); + netns_id, flags, -1); }
static const struct bpf_func_proto bpf_sock_addr_sk_lookup_tcp_proto = { @@ -6922,7 +6931,7 @@ BPF_CALL_5(bpf_sock_addr_sk_lookup_udp, struct bpf_sock_addr_kern *, ctx, { return (unsigned long)__bpf_sk_lookup(NULL, tuple, len, sock_net(ctx->sk), 0, IPPROTO_UDP, - netns_id, flags); + netns_id, flags, -1); }
static const struct bpf_func_proto bpf_sock_addr_sk_lookup_udp_proto = {