immortalwrt/target/linux/generic/backport-6.6/068-04-v6.7-bpf-netkit-Add-indirect-call-wrapper-for-fetching-peer-de.patch
Tianling Shen cd053d0ae7
Merge Official Source
Signed-off-by: Tianling Shen <cnsztl@immortalwrt.org>
2024-11-16 16:12:40 +08:00

109 lines
3.7 KiB
Diff

From 2c225425704078282e152ba692649237f78b3d7a Mon Sep 17 00:00:00 2001
From: Daniel Borkmann <daniel@iogearbox.net>
Date: Tue, 14 Nov 2023 01:42:18 +0100
Subject: [PATCH] bpf, netkit: Add indirect call wrapper for fetching peer dev
ndo_get_peer_dev is used in tcx BPF fast path, therefore make use of
indirect call wrapper and therefore optimize the bpf_redirect_peer()
internal handling a bit. Add a small skb_get_peer_dev() wrapper which
utilizes the INDIRECT_CALL_1() macro instead of open coding.
Future work could potentially add a peer pointer directly into struct
net_device in future and convert veth and netkit over to use it so
that eventually ndo_get_peer_dev can be removed.
Co-developed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20231114004220.6495-7-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
---
drivers/net/netkit.c | 3 ++-
include/net/netkit.h | 6 ++++++
net/core/filter.c | 18 +++++++++++++-----
3 files changed, 21 insertions(+), 6 deletions(-)
--- a/drivers/net/netkit.c
+++ b/drivers/net/netkit.c
@@ -7,6 +7,7 @@
#include <linux/filter.h>
#include <linux/netfilter_netdev.h>
#include <linux/bpf_mprog.h>
+#include <linux/indirect_call_wrapper.h>
#include <net/netkit.h>
#include <net/dst.h>
@@ -177,7 +178,7 @@ out:
rcu_read_unlock();
}
-static struct net_device *netkit_peer_dev(struct net_device *dev)
+INDIRECT_CALLABLE_SCOPE struct net_device *netkit_peer_dev(struct net_device *dev)
{
return rcu_dereference(netkit_priv(dev)->peer);
}
--- a/include/net/netkit.h
+++ b/include/net/netkit.h
@@ -10,6 +10,7 @@ int netkit_prog_attach(const union bpf_a
int netkit_link_attach(const union bpf_attr *attr, struct bpf_prog *prog);
int netkit_prog_detach(const union bpf_attr *attr, struct bpf_prog *prog);
int netkit_prog_query(const union bpf_attr *attr, union bpf_attr __user *uattr);
+INDIRECT_CALLABLE_DECLARE(struct net_device *netkit_peer_dev(struct net_device *dev));
#else
static inline int netkit_prog_attach(const union bpf_attr *attr,
struct bpf_prog *prog)
@@ -34,5 +35,10 @@ static inline int netkit_prog_query(cons
{
return -EINVAL;
}
+
+static inline struct net_device *netkit_peer_dev(struct net_device *dev)
+{
+ return NULL;
+}
#endif /* CONFIG_NETKIT */
#endif /* __NET_NETKIT_H */
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -81,6 +81,7 @@
#include <net/xdp.h>
#include <net/mptcp.h>
#include <net/netfilter/nf_conntrack_bpf.h>
+#include <net/netkit.h>
#include <linux/un.h>
#include <net/xdp_sock_drv.h>
@@ -2474,6 +2475,16 @@ static const struct bpf_func_proto bpf_c
DEFINE_PER_CPU(struct bpf_redirect_info, bpf_redirect_info);
EXPORT_PER_CPU_SYMBOL_GPL(bpf_redirect_info);
+static struct net_device *skb_get_peer_dev(struct net_device *dev)
+{
+ const struct net_device_ops *ops = dev->netdev_ops;
+
+ if (likely(ops->ndo_get_peer_dev))
+ return INDIRECT_CALL_1(ops->ndo_get_peer_dev,
+ netkit_peer_dev, dev);
+ return NULL;
+}
+
int skb_do_redirect(struct sk_buff *skb)
{
struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
@@ -2487,12 +2498,9 @@ int skb_do_redirect(struct sk_buff *skb)
if (unlikely(!dev))
goto out_drop;
if (flags & BPF_F_PEER) {
- const struct net_device_ops *ops = dev->netdev_ops;
-
- if (unlikely(!ops->ndo_get_peer_dev ||
- !skb_at_tc_ingress(skb)))
+ if (unlikely(!skb_at_tc_ingress(skb)))
goto out_drop;
- dev = ops->ndo_get_peer_dev(dev);
+ dev = skb_get_peer_dev(dev);
if (unlikely(!dev ||
!(dev->flags & IFF_UP) ||
net_eq(net, dev_net(dev))))