[PATCH net-next v2 1/4] net: use indirect call helpers for dst_input

From: Brian Vazquez
Date: Fri Dec 11 2020 - 18:35:36 EST


From: brianvv <brianvv@xxxxxxxxxx>

This patch avoids the indirect call for the common case:
ip_local_deliver and ip6_input

Signed-off-by: brianvv <brianvv@xxxxxxxxxx>
---
include/net/dst.h | 6 +++++-
net/ipv4/ip_input.c | 1 +
2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/include/net/dst.h b/include/net/dst.h
index 10f0a8399867..98cf6e8c06c4 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -18,6 +18,7 @@
#include <linux/refcount.h>
#include <net/neighbour.h>
#include <asm/processor.h>
+#include <linux/indirect_call_wrapper.h>

struct sk_buff;

@@ -441,10 +442,13 @@ static inline int dst_output(struct net *net, struct sock *sk, struct sk_buff *s
return skb_dst(skb)->output(net, sk, skb);
}

+INDIRECT_CALLABLE_DECLARE(int ip6_input(struct sk_buff *));
+INDIRECT_CALLABLE_DECLARE(int ip_local_deliver(struct sk_buff *));
/* Input packet from network to transport. */
static inline int dst_input(struct sk_buff *skb)
{
- return skb_dst(skb)->input(skb);
+ return INDIRECT_CALL_INET(skb_dst(skb)->input,
+ ip6_input, ip_local_deliver, skb);
}

static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index b0c244af1e4d..3a025c011971 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -253,6 +253,7 @@ int ip_local_deliver(struct sk_buff *skb)
net, NULL, skb, skb->dev, NULL,
ip_local_deliver_finish);
}
+EXPORT_SYMBOL(ip_local_deliver);

static inline bool ip_rcv_options(struct sk_buff *skb, struct net_device *dev)
{
--
2.29.2.576.ga3fc446d84-goog