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")
Reviewed-by: Shmulik Ladkani <shmulik.ladkani@xxxxxxxxx>
Reviewed-by: Eyal Birger <eyal.birger@xxxxxxxxx>
Signed-off-by: Gilad Sever <gilad9366@xxxxxxxxx>
---
v3: Rename bpf_l2_sdif() to dev_sdif() as suggested by Stanislav Fomichev
---
net/core/filter.c | 63 +++++++++++++++++++++++++++++++----------------
1 file changed, 42 insertions(+), 21 deletions(-)
diff --git a/net/core/filter.c b/net/core/filter.c
index f43f86fc1235..894913aaa29f 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -6529,12 +6529,11 @@ 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;
@@ -6546,10 +6545,12 @@ __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;
@@ -6569,10 +6570,11 @@ __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);
@@ -6612,7 +6614,7 @@ 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 *
@@ -6701,15 +6703,25 @@ static const struct bpf_func_proto bpf_sk_lookup_udp_proto = {
.arg5_type = ARG_ANYTHING,
};
+static int dev_sdif(const struct net_device *dev)
+{
+#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
+ if (netif_is_l3_slave(dev))
+ return dev->ifindex;
+#endif
+ return 0;
+}
+
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 sdif = dev_sdif(skb->dev);
int ifindex = skb->dev->ifindex;
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 = {
@@ -6728,11 +6740,12 @@ 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 sdif = dev_sdif(skb->dev);
int ifindex = skb->dev->ifindex;
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 = {
@@ -6751,11 +6764,12 @@ 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 sdif = dev_sdif(skb->dev);
int ifindex = skb->dev->ifindex;
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 = {
@@ -6788,11 +6802,13 @@ 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;
+ int sdif = dev_sdif(dev);
+ int ifindex = dev->ifindex;
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 = {
@@ -6811,11 +6827,13 @@ 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 sdif = dev_sdif(dev);
+ int ifindex = dev->ifindex;
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 = {
@@ -6834,11 +6852,13 @@ 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 sdif = dev_sdif(dev);
+ int ifindex = dev->ifindex;
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 = {
@@ -6858,7 +6878,8 @@ 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 = {
@@ -6877,7 +6898,7 @@ 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 = {
@@ -6896,7 +6917,7 @@ 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 = {
--
2.34.1
