From 936a192f974018b4f6040f6f77b1cc1e75bd8666 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima <kuniyu@amazon.com> Date: Mon, 26 Dec 2022 22:27:52 +0900 Subject: tcp: Add TIME_WAIT sockets in bhash2. Jiri Slaby reported regression of bind() with a simple repro. [0] The repro creates a TIME_WAIT socket and tries to bind() a new socket with the same local address and port. Before commit 28044fc1d495 ("net: Add a bhash2 table hashed by port and address"), the bind() failed with -EADDRINUSE, but now it succeeds. The cited commit should have put TIME_WAIT sockets into bhash2; otherwise, inet_bhash2_conflict() misses TIME_WAIT sockets when validating bind() requests if the address is not a wildcard one. The straight option is to move sk_bind2_node from struct sock to struct sock_common to add twsk to bhash2 as implemented as RFC. [1] However, the binary layout change in the struct sock could affect performances moving hot fields on different cachelines. To avoid that, we add another TIME_WAIT list in inet_bind2_bucket and check it while validating bind(). [0]: https://lore.kernel.org/netdev/6b971a4e-c7d8-411e-1f92-fda29b5b2fb9@kernel.org/ [1]: https://lore.kernel.org/netdev/20221221151258.25748-2-kuniyu@amazon.com/ Fixes: 28044fc1d495 ("net: Add a bhash2 table hashed by port and address") Reported-by: Jiri Slaby <jirislaby@kernel.org> Suggested-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Joanne Koong <joannelkoong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> --- include/net/inet_hashtables.h | 4 ++++ include/net/inet_timewait_sock.h | 5 +++++ 2 files changed, 9 insertions(+) (limited to 'include') diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h index 69174093078f..99bd823e97f6 100644 --- a/include/net/inet_hashtables.h +++ b/include/net/inet_hashtables.h @@ -108,6 +108,10 @@ struct inet_bind2_bucket { struct hlist_node node; /* List of sockets hashed to this bucket */ struct hlist_head owners; + /* bhash has twsk in owners, but bhash2 has twsk in + * deathrow not to add a member in struct sock_common. + */ + struct hlist_head deathrow; }; static inline struct net *ib_net(const struct inet_bind_bucket *ib) diff --git a/include/net/inet_timewait_sock.h b/include/net/inet_timewait_sock.h index 5b47545f22d3..4a8e578405cb 100644 --- a/include/net/inet_timewait_sock.h +++ b/include/net/inet_timewait_sock.h @@ -73,9 +73,14 @@ struct inet_timewait_sock { u32 tw_priority; struct timer_list tw_timer; struct inet_bind_bucket *tw_tb; + struct inet_bind2_bucket *tw_tb2; + struct hlist_node tw_bind2_node; }; #define tw_tclass tw_tos +#define twsk_for_each_bound_bhash2(__tw, list) \ + hlist_for_each_entry(__tw, list, tw_bind2_node) + static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk) { return (struct inet_timewait_sock *)sk; -- cgit v1.2.3-70-g09d2