Commit 0f495f76 authored by Lorenz Bauer's avatar Lorenz Bauer Committed by Martin KaFai Lau
Browse files

net: remove duplicate reuseport_lookup functions 



There are currently four copies of reuseport_lookup: one each for
(TCP, UDP)x(IPv4, IPv6). This forces us to duplicate all callers of
those functions as well. This is already the case for sk_lookup
helpers (inet,inet6,udp4,udp6)_lookup_run_bpf.

There are two differences between the reuseport_lookup helpers:

1. They call different hash functions depending on protocol
2. UDP reuseport_lookup checks that sk_state != TCP_ESTABLISHED

Move the check for sk_state into the caller and use the INDIRECT_CALL
infrastructure to cut down the helpers to one per IP version.

Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: default avatarLorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/r/20230720-so-reuseport-v6-4-7021b683cdae@isovalent.com


Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
parent ce796e60

include/net/inet6_hashtables.h

+10 −1
Original line number Diff line number Diff line
@@ -48,12 +48,21 @@ struct sock *__inet6_lookup_established(struct net *net, 
					const u16 hnum, const int dif,

					const int sdif);



typedef u32 (inet6_ehashfn_t)(const struct net *net,

			       const struct in6_addr *laddr, const u16 lport,

			       const struct in6_addr *faddr, const __be16 fport);



inet6_ehashfn_t inet6_ehashfn;



INDIRECT_CALLABLE_DECLARE(inet6_ehashfn_t udp6_ehashfn);



struct sock *inet6_lookup_reuseport(struct net *net, struct sock *sk,

				    struct sk_buff *skb, int doff,

				    const struct in6_addr *saddr,

				    __be16 sport,

				    const struct in6_addr *daddr,

				    unsigned short hnum);

				    unsigned short hnum,

				    inet6_ehashfn_t *ehashfn);



struct sock *inet6_lookup_listener(struct net *net,

				   struct inet_hashinfo *hashinfo,

include/net/inet_hashtables.h

+10 −5
Original line number Diff line number Diff line
@@ -379,10 +379,19 @@ struct sock *__inet_lookup_established(struct net *net, 
				       const __be32 daddr, const u16 hnum,

				       const int dif, const int sdif);



typedef u32 (inet_ehashfn_t)(const struct net *net,

			      const __be32 laddr, const __u16 lport,

			      const __be32 faddr, const __be16 fport);



inet_ehashfn_t inet_ehashfn;



INDIRECT_CALLABLE_DECLARE(inet_ehashfn_t udp_ehashfn);



struct sock *inet_lookup_reuseport(struct net *net, struct sock *sk,

				   struct sk_buff *skb, int doff,

				   __be32 saddr, __be16 sport,

				   __be32 daddr, unsigned short hnum);

				   __be32 daddr, unsigned short hnum,

				   inet_ehashfn_t *ehashfn);



static inline struct sock *

	inet_lookup_established(struct net *net, struct inet_hashinfo *hashinfo,
@@ -453,10 +462,6 @@ static inline struct sock *__inet_lookup_skb(struct inet_hashinfo *hashinfo, 
			     refcounted);

}



u32 inet6_ehashfn(const struct net *net,

		  const struct in6_addr *laddr, const u16 lport,

		  const struct in6_addr *faddr, const __be16 fport);



static inline void sk_daddr_set(struct sock *sk, __be32 addr)

{

	sk->sk_daddr = addr; /* alias of inet_daddr */

net/ipv4/inet_hashtables.c

+13 −7
Original line number Diff line number Diff line
@@ -28,7 +28,7 @@ 
#include <net/tcp.h>

#include <net/sock_reuseport.h>



static u32 inet_ehashfn(const struct net *net, const __be32 laddr,

u32 inet_ehashfn(const struct net *net, const __be32 laddr,

		 const __u16 lport, const __be32 faddr,

		 const __be16 fport)

{
@@ -39,6 +39,7 @@ static u32 inet_ehashfn(const struct net *net, const __be32 laddr, 
	return __inet_ehashfn(laddr, lport, faddr, fport,

			      inet_ehash_secret + net_hash_mix(net));

}

EXPORT_SYMBOL_GPL(inet_ehashfn);



/* This function handles inet_sock, but also timewait and request sockets

 * for IPv4/IPv6.
@@ -332,16 +333,20 @@ static inline int compute_score(struct sock *sk, struct net *net, 
	return score;

}



INDIRECT_CALLABLE_DECLARE(inet_ehashfn_t udp_ehashfn);



struct sock *inet_lookup_reuseport(struct net *net, struct sock *sk,

				   struct sk_buff *skb, int doff,

				   __be32 saddr, __be16 sport,

				   __be32 daddr, unsigned short hnum)

				   __be32 daddr, unsigned short hnum,

				   inet_ehashfn_t *ehashfn)

{

	struct sock *reuse_sk = NULL;

	u32 phash;



	if (sk->sk_reuseport) {

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

		phash = INDIRECT_CALL_2(ehashfn, udp_ehashfn, inet_ehashfn,

					net, daddr, hnum, saddr, sport);

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

	}

	return reuse_sk;
@@ -371,7 +376,7 @@ static struct sock *inet_lhash2_lookup(struct net *net, 
		score = compute_score(sk, net, hnum, daddr, dif, sdif);

		if (score > hiscore) {

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

						       saddr, sport, daddr, hnum);

						       saddr, sport, daddr, hnum, inet_ehashfn);

			if (result)

				return result;
@@ -400,7 +405,8 @@ static inline struct sock *inet_lookup_run_bpf(struct net *net, 
	if (no_reuseport || IS_ERR_OR_NULL(sk))

		return sk;



	reuse_sk = inet_lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum);

	reuse_sk = inet_lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum,

					 inet_ehashfn);

	if (reuse_sk)

		sk = reuse_sk;

	return sk;

net/ipv4/udp.c

+13 −21
Original line number Diff line number Diff line
@@ -406,9 +406,9 @@ static int compute_score(struct sock *sk, struct net *net, 
	return score;

}



static u32 udp_ehashfn(const struct net *net, const __be32 laddr,

		       const __u16 lport, const __be32 faddr,

		       const __be16 fport)

INDIRECT_CALLABLE_SCOPE

u32 udp_ehashfn(const struct net *net, const __be32 laddr, const __u16 lport,

		const __be32 faddr, const __be16 fport)

{

	static u32 udp_ehash_secret __read_mostly;
@@ -418,22 +418,6 @@ static u32 udp_ehashfn(const struct net *net, const __be32 laddr, 
			      udp_ehash_secret + net_hash_mix(net));

}



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

				     struct sk_buff *skb,

				     __be32 saddr, __be16 sport,

				     __be32 daddr, unsigned short hnum)

{

	struct sock *reuse_sk = NULL;

	u32 hash;



	if (sk->sk_reuseport && sk->sk_state != TCP_ESTABLISHED) {

		hash = udp_ehashfn(net, daddr, hnum, saddr, sport);

		reuse_sk = reuseport_select_sock(sk, hash, skb,

						 sizeof(struct udphdr));

	}

	return reuse_sk;

}



/* called with rcu_read_lock() */

static struct sock *udp4_lib_lookup2(struct net *net,

				     __be32 saddr, __be16 sport,
@@ -452,7 +436,14 @@ static struct sock *udp4_lib_lookup2(struct net *net, 
				      daddr, hnum, dif, sdif);

		if (score > badness) {

			badness = score;

			result = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum);



			if (sk->sk_state == TCP_ESTABLISHED) {

				result = sk;

				continue;

			}



			result = inet_lookup_reuseport(net, sk, skb, sizeof(struct udphdr),

						       saddr, sport, daddr, hnum, udp_ehashfn);

			if (!result) {

				result = sk;

				continue;
@@ -491,7 +482,8 @@ static struct sock *udp4_lookup_run_bpf(struct net *net, 
	if (no_reuseport || IS_ERR_OR_NULL(sk))

		return sk;



	reuse_sk = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum);

	reuse_sk = inet_lookup_reuseport(net, sk, skb, sizeof(struct udphdr),

					 saddr, sport, daddr, hnum, udp_ehashfn);

	if (reuse_sk)

		sk = reuse_sk;

	return sk;

net/ipv6/inet6_hashtables.c

+10 −4
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ u32 inet6_ehashfn(const struct net *net, 
	return __inet6_ehashfn(lhash, lport, fhash, fport,

			       inet6_ehash_secret + net_hash_mix(net));

}

EXPORT_SYMBOL_GPL(inet6_ehashfn);



/*

 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
@@ -111,18 +112,22 @@ static inline int compute_score(struct sock *sk, struct net *net, 
	return score;

}



INDIRECT_CALLABLE_DECLARE(inet6_ehashfn_t udp6_ehashfn);



struct sock *inet6_lookup_reuseport(struct net *net, struct sock *sk,

				    struct sk_buff *skb, int doff,

				    const struct in6_addr *saddr,

				    __be16 sport,

				    const struct in6_addr *daddr,

				    unsigned short hnum)

				    unsigned short hnum,

				    inet6_ehashfn_t *ehashfn)

{

	struct sock *reuse_sk = NULL;

	u32 phash;



	if (sk->sk_reuseport) {

		phash = inet6_ehashfn(net, daddr, hnum, saddr, sport);

		phash = INDIRECT_CALL_INET(ehashfn, udp6_ehashfn, inet6_ehashfn,

					   net, daddr, hnum, saddr, sport);

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

	}

	return reuse_sk;
@@ -145,7 +150,7 @@ static struct sock *inet6_lhash2_lookup(struct net *net, 
		score = compute_score(sk, net, hnum, daddr, dif, sdif);

		if (score > hiscore) {

			result = inet6_lookup_reuseport(net, sk, skb, doff,

							saddr, sport, daddr, hnum);

							saddr, sport, daddr, hnum, inet6_ehashfn);

			if (result)

				return result;
@@ -176,7 +181,8 @@ static inline struct sock *inet6_lookup_run_bpf(struct net *net, 
	if (no_reuseport || IS_ERR_OR_NULL(sk))

		return sk;



	reuse_sk = inet6_lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum);

	reuse_sk = inet6_lookup_reuseport(net, sk, skb, doff,

					  saddr, sport, daddr, hnum, inet6_ehashfn);

	if (reuse_sk)

		sk = reuse_sk;

	return sk;