Commit 80b373f7 authored by Jakub Sitnicki's avatar Jakub Sitnicki Committed by Alexei Starovoitov
Browse files

inet: Extract helper for selecting socket from reuseport group 



Prepare for calling into reuseport from __inet_lookup_listener as well.

Signed-off-by: default avatarJakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarAndrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200717103536.397595-4-jakub@cloudflare.com
parent e9ddbb77

net/ipv4/inet_hashtables.c

+20 −9
Original line number Diff line number Diff line
@@ -246,6 +246,21 @@ static inline int compute_score(struct sock *sk, struct net *net, 
	return score;

}



static inline struct sock *lookup_reuseport(struct net *net, struct sock *sk,

					    struct sk_buff *skb, int doff,

					    __be32 saddr, __be16 sport,

					    __be32 daddr, unsigned short hnum)

{

	struct sock *reuse_sk = NULL;

	u32 phash;



	if (sk->sk_reuseport) {

		phash = inet_ehashfn(net, daddr, hnum, saddr, sport);

		reuse_sk = reuseport_select_sock(sk, phash, skb, doff);

	}

	return reuse_sk;

}



/*

 * Here are some nice properties to exploit here. The BSD API

 * does not allow a listening sock to specify the remote port nor the
@@ -265,21 +280,17 @@ static struct sock *inet_lhash2_lookup(struct net *net, 
	struct inet_connection_sock *icsk;

	struct sock *sk, *result = NULL;

	int score, hiscore = 0;

	u32 phash = 0;



	inet_lhash2_for_each_icsk_rcu(icsk, &ilb2->head) {

		sk = (struct sock *)icsk;

		score = compute_score(sk, net, hnum, daddr,

				      dif, sdif, exact_dif);

		if (score > hiscore) {

			if (sk->sk_reuseport) {

				phash = inet_ehashfn(net, daddr, hnum,

						     saddr, sport);

				result = reuseport_select_sock(sk, phash,

							       skb, doff);

			result = lookup_reuseport(net, sk, skb, doff,

						  saddr, sport, daddr, hnum);

			if (result)

				return result;

			}



			result = sk;

			hiscore = score;

		}