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authorDaniel Borkmann <daniel@iogearbox.net>2024-05-24 18:36:17 +0200
committerAlexei Starovoitov <ast@kernel.org>2024-05-25 19:48:57 +0200
commit3998d184267dfcff858aaa84d3de17429253629d (patch)
tree9862377f9644922177186ccfce9296e527fd3e03 /drivers/net/netkit.c
parentnetkit: Fix setting mac address in l2 mode (diff)
downloadlinux-3998d184267dfcff858aaa84d3de17429253629d.tar.xz
linux-3998d184267dfcff858aaa84d3de17429253629d.zip
netkit: Fix pkt_type override upon netkit pass verdict
When running Cilium connectivity test suite with netkit in L2 mode, we found that compared to tcx a few tests were failing which pushed traffic into an L7 proxy sitting in host namespace. The problem in particular is around the invocation of eth_type_trans() in netkit. In case of tcx, this is run before the tcx ingress is triggered inside host namespace and thus if the BPF program uses the bpf_skb_change_type() helper the newly set type is retained. However, in case of netkit, the late eth_type_trans() invocation overrides the earlier decision from the BPF program which eventually leads to the test failure. Instead of eth_type_trans(), split out the relevant parts, meaning, reset of mac header and call to eth_skb_pkt_type() before the BPF program is run in order to have the same behavior as with tcx, and refactor a small helper called eth_skb_pull_mac() which is run in case it's passed up the stack where the mac header must be pulled. With this all connectivity tests pass. Fixes: 35dfaad7188c ("netkit, bpf: Add bpf programmable net device") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://lore.kernel.org/r/20240524163619.26001-2-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'drivers/net/netkit.c')
-rw-r--r--drivers/net/netkit.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/net/netkit.c b/drivers/net/netkit.c
index 272894053e2c..16789cd446e9 100644
--- a/drivers/net/netkit.c
+++ b/drivers/net/netkit.c
@@ -55,6 +55,7 @@ static void netkit_prep_forward(struct sk_buff *skb, bool xnet)
skb_scrub_packet(skb, xnet);
skb->priority = 0;
nf_skip_egress(skb, true);
+ skb_reset_mac_header(skb);
}
static struct netkit *netkit_priv(const struct net_device *dev)
@@ -78,6 +79,7 @@ static netdev_tx_t netkit_xmit(struct sk_buff *skb, struct net_device *dev)
skb_orphan_frags(skb, GFP_ATOMIC)))
goto drop;
netkit_prep_forward(skb, !net_eq(dev_net(dev), dev_net(peer)));
+ eth_skb_pkt_type(skb, peer);
skb->dev = peer;
entry = rcu_dereference(nk->active);
if (entry)
@@ -85,7 +87,7 @@ static netdev_tx_t netkit_xmit(struct sk_buff *skb, struct net_device *dev)
switch (ret) {
case NETKIT_NEXT:
case NETKIT_PASS:
- skb->protocol = eth_type_trans(skb, skb->dev);
+ eth_skb_pull_mac(skb);
skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
if (likely(__netif_rx(skb) == NET_RX_SUCCESS)) {
dev_sw_netstats_tx_add(dev, 1, len);