From a34e620f120c1436b00da9dc94c9e98a7ed7b89c Mon Sep 17 00:00:00 2001 From: Gilad Sever Date: Wed, 21 Jun 2023 13:42:10 +0300 Subject: [PATCH] UPSTREAM: bpf: Fix bpf socket lookup from tc/xdp to respect socket VRF bindings 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") Change-Id: I28fbfacf5f3666dd26552e701bd19cf5fae08b52 Signed-off-by: Gilad Sever Signed-off-by: Daniel Borkmann Reviewed-by: Shmulik Ladkani Reviewed-by: Eyal Birger Acked-by: Stanislav Fomichev Cc: David Ahern Link: https://lore.kernel.org/bpf/20230621104211.301902-4-gilad9366@gmail.com --- include/linux/netdevice.h | 9 ++++++++ net/core/filter.c | 48 ++++++++++++++++++++++----------------- 2 files changed, 36 insertions(+), 21 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 642a285f0784..773a335c2c5e 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -4782,6 +4782,15 @@ 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 6aec3c2ea2cc..477fa754dba0 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -5986,12 +5986,11 @@ 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; u8 family = AF_UNSPEC; struct net *net; - int sdif; if (len == sizeof(tuple->ipv4)) family = AF_INET; @@ -6004,10 +6003,12 @@ __bpf_skc_lookup(struct sk_buff *skb, struct bpf_sock_tuple *tuple, u32 len, !((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; @@ -6027,10 +6028,11 @@ out: 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); @@ -6070,7 +6072,7 @@ 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 * @@ -6176,12 +6178,13 @@ 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 = { @@ -6199,12 +6202,13 @@ 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 = { @@ -6222,12 +6226,13 @@ 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 = { @@ -6247,7 +6252,8 @@ 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 = { @@ -6266,7 +6272,7 @@ 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 = { @@ -6285,7 +6291,7 @@ 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 = {