Re: [PATCH bpf-next v3 2/7] net: export inet_lookup_reuseport and inet6_lookup_reuseport

From: Kuniyuki Iwashima
Date: Mon Jun 26 2023 - 13:33:26 EST


From: Lorenz Bauer <lmb@xxxxxxxxxxxxx>
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@xxxxxxxxxxxxx>
> ---
> 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