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From:   Kuniyuki Iwashima <kuniyu@amazon.com>
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Subject: Re: [PATCH bpf-next v3 2/7] net: export inet_lookup_reuseport and inet6_lookup_reuseport
Date:   Mon, 26 Jun 2023 10:32:49 -0700
Message-ID: <20230626173249.57682-1-kuniyu@amazon.com>
In-Reply-To: <20230613-so-reuseport-v3-2-907b4cbb7b99@isovalent.com>
References: <20230613-so-reuseport-v3-2-907b4cbb7b99@isovalent.com>
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From: Lorenz Bauer <lmb@isovalent.com>
Date: Mon, 26 Jun 2023 16:08:59 +0100
> Rename the existing reuseport helpers for IPv4 and IPv6 so that they
> can be invoked in the follow up commit. Export them so that DCCP which
> may be built as a module can access them.

We need not export the functions unless there is a real user.

I added a deprecation notice for DCCP recently, so I bet DCCP
will not get SO_REUSEPORT support.
https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=b144fcaf46d4


> 
> No change in functionality.
> 
> Signed-off-by: Lorenz Bauer <lmb@isovalent.com>
> ---
>  include/net/inet6_hashtables.h |  7 +++++++
>  include/net/inet_hashtables.h  |  5 +++++
>  net/ipv4/inet_hashtables.c     | 15 ++++++++-------
>  net/ipv6/inet6_hashtables.c    | 19 ++++++++++---------
>  4 files changed, 30 insertions(+), 16 deletions(-)
> 
> diff --git a/include/net/inet6_hashtables.h b/include/net/inet6_hashtables.h
> index 56f1286583d3..032ddab48f8f 100644
> --- a/include/net/inet6_hashtables.h
> +++ b/include/net/inet6_hashtables.h
> @@ -48,6 +48,13 @@ struct sock *__inet6_lookup_established(struct net *net,
>  					const u16 hnum, const int dif,
>  					const int sdif);
>  
> +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);
> +
>  struct sock *inet6_lookup_listener(struct net *net,
>  				   struct inet_hashinfo *hashinfo,
>  				   struct sk_buff *skb, int doff,
> diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h
> index 99bd823e97f6..8734f3488f5d 100644
> --- a/include/net/inet_hashtables.h
> +++ b/include/net/inet_hashtables.h
> @@ -379,6 +379,11 @@ struct sock *__inet_lookup_established(struct net *net,
>  				       const __be32 daddr, const u16 hnum,
>  				       const int dif, const int sdif);
>  
> +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);
> +
>  static inline struct sock *
>  	inet_lookup_established(struct net *net, struct inet_hashinfo *hashinfo,
>  				const __be32 saddr, const __be16 sport,
> diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
> index e7391bf310a7..920131e4a65d 100644
> --- a/net/ipv4/inet_hashtables.c
> +++ b/net/ipv4/inet_hashtables.c
> @@ -332,10 +332,10 @@ 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 *inet_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;
> @@ -346,6 +346,7 @@ static inline struct sock *lookup_reuseport(struct net *net, struct sock *sk,
>  	}
>  	return reuse_sk;
>  }
> +EXPORT_SYMBOL_GPL(inet_lookup_reuseport);
>  
>  /*
>   * Here are some nice properties to exploit here. The BSD API
> @@ -369,8 +370,8 @@ static struct sock *inet_lhash2_lookup(struct net *net,
>  	sk_nulls_for_each_rcu(sk, node, &ilb2->nulls_head) {
>  		score = compute_score(sk, net, hnum, daddr, dif, sdif);
>  		if (score > hiscore) {
> -			result = lookup_reuseport(net, sk, skb, doff,
> -						  saddr, sport, daddr, hnum);
> +			result = inet_lookup_reuseport(net, sk, skb, doff,
> +						       saddr, sport, daddr, hnum);
>  			if (result)
>  				return result;
>  
> @@ -399,7 +400,7 @@ static inline struct sock *inet_lookup_run_bpf(struct net *net,
>  	if (no_reuseport || IS_ERR_OR_NULL(sk))
>  		return sk;
>  
> -	reuse_sk = lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum);
> +	reuse_sk = inet_lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum);
>  	if (reuse_sk)
>  		sk = reuse_sk;
>  	return sk;
> diff --git a/net/ipv6/inet6_hashtables.c b/net/ipv6/inet6_hashtables.c
> index b64b49012655..b7c56867314e 100644
> --- a/net/ipv6/inet6_hashtables.c
> +++ b/net/ipv6/inet6_hashtables.c
> @@ -111,12 +111,12 @@ 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,
> -					    const struct in6_addr *saddr,
> -					    __be16 sport,
> -					    const struct in6_addr *daddr,
> -					    unsigned short hnum)
> +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)
>  {
>  	struct sock *reuse_sk = NULL;
>  	u32 phash;
> @@ -127,6 +127,7 @@ static inline struct sock *lookup_reuseport(struct net *net, struct sock *sk,
>  	}
>  	return reuse_sk;
>  }
> +EXPORT_SYMBOL_GPL(inet6_lookup_reuseport);
>  
>  /* called with rcu_read_lock() */
>  static struct sock *inet6_lhash2_lookup(struct net *net,
> @@ -143,8 +144,8 @@ static struct sock *inet6_lhash2_lookup(struct net *net,
>  	sk_nulls_for_each_rcu(sk, node, &ilb2->nulls_head) {
>  		score = compute_score(sk, net, hnum, daddr, dif, sdif);
>  		if (score > hiscore) {
> -			result = lookup_reuseport(net, sk, skb, doff,
> -						  saddr, sport, daddr, hnum);
> +			result = inet6_lookup_reuseport(net, sk, skb, doff,
> +							saddr, sport, daddr, hnum);
>  			if (result)
>  				return result;
>  
> @@ -175,7 +176,7 @@ static inline struct sock *inet6_lookup_run_bpf(struct net *net,
>  	if (no_reuseport || IS_ERR_OR_NULL(sk))
>  		return sk;
>  
> -	reuse_sk = lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum);
> +	reuse_sk = inet6_lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum);
>  	if (reuse_sk)
>  		sk = reuse_sk;
>  	return sk;
> 
> -- 
> 2.40.1