[PATCH 6.4 194/800] bpf: Call __bpf_sk_lookup()/__bpf_skc_lookup() directly via TC hookpoint

Greg Kroah-Hartman
2023-07-16T20:01:54Z

From: Gilad Sever <gilad9366@gmail.com>

[ Upstream commit 97fbfeb86917bdbe9c41d5143e335a929147f405 ]

skb->dev always exists in the tc flow. There is no need to use
bpf_skc_lookup(), bpf_sk_lookup() from this code path.

This change facilitates fixing the tc flow to be VRF aware.

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>
Link: https://lore.kernel.org/bpf/20230621104211.301902-3-gilad9366@gmail.com
Stable-dep-of: 9a5cb79762e0 ("bpf: Fix bpf socket lookup from tc/xdp to respect socket VRF bindings")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/core/filter.c | 24 ++++++++++++++++++------
1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/net/core/filter.c b/net/core/filter.c
index 57d853460e126..e06547922edcf 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -6730,8 +6730,12 @@ 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)
{
- return (unsigned long)bpf_skc_lookup(skb, tuple, len, IPPROTO_TCP,
- netns_id, flags);
+ struct net *caller_net = dev_net(skb->dev);
+ int ifindex = skb->dev->ifindex;
+
+ return (unsigned long)__bpf_skc_lookup(skb, tuple, len, caller_net,
+ ifindex, IPPROTO_TCP, netns_id,
+ flags);
}

static const struct bpf_func_proto bpf_tc_skc_lookup_tcp_proto = {
@@ -6749,8 +6753,12 @@ 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)
{
- return (unsigned long)bpf_sk_lookup(skb, tuple, len, IPPROTO_TCP,
- netns_id, flags);
+ struct net *caller_net = dev_net(skb->dev);
+ int ifindex = skb->dev->ifindex;
+
+ return (unsigned long)__bpf_sk_lookup(skb, tuple, len, caller_net,
+ ifindex, IPPROTO_TCP, netns_id,
+ flags);
}

static const struct bpf_func_proto bpf_tc_sk_lookup_tcp_proto = {
@@ -6768,8 +6776,12 @@ 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)
{
- return (unsigned long)bpf_sk_lookup(skb, tuple, len, IPPROTO_UDP,
- netns_id, flags);
+ struct net *caller_net = dev_net(skb->dev);
+ int ifindex = skb->dev->ifindex;
+
+ return (unsigned long)__bpf_sk_lookup(skb, tuple, len, caller_net,
+ ifindex, IPPROTO_UDP, netns_id,
+ flags);
}

static const struct bpf_func_proto bpf_tc_sk_lookup_udp_proto = {
--
2.39.2