From mboxrd@z Thu Jan 1 00:00:00 1970 From: Craig Gallek Subject: [PATCH net-next 5/7] soreuseport: Prep for fast reuseport TCP socket selection Date: Thu, 4 Feb 2016 10:35:16 -0500 Message-ID: <1454600118-30152-6-git-send-email-kraigatgoog@gmail.com> References: <1454600118-30152-1-git-send-email-kraigatgoog@gmail.com> To: netdev@vger.kernel.org, David Miller Return-path: Received: from mail-qg0-f51.google.com ([209.85.192.51]:35627 "EHLO mail-qg0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756701AbcBDPf2 (ORCPT ); Thu, 4 Feb 2016 10:35:28 -0500 Received: by mail-qg0-f51.google.com with SMTP id o11so44076907qge.2 for ; Thu, 04 Feb 2016 07:35:28 -0800 (PST) In-Reply-To: <1454600118-30152-1-git-send-email-kraigatgoog@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Craig Gallek Both of the lines in this patch probably should have been included in the initial implementation of this code for generic socket support, but weren't technically necessary since only UDP sockets were supported. First, the sk_reuseport_cb points to a structure which assumes each socket in the group has this pointer assigned at the same time it's added to the array in the structure. The sk_clone_lock function breaks this assumption. Since a child socket shouldn't implicitly be in a reuseport group, the simple fix is to clear the field in the clone. Second, the SO_ATTACH_REUSEPORT_xBPF socket options require that SO_REUSEPORT also be set first. For UDP sockets, this is easily enforced at bind-time since that process both puts the socket in the appropriate receive hlist and updates the reuseport structures. Since these operations can happen at two different times for TCP sockets (bind and listen) it must be explicitly checked to enforce the use of SO_REUSEPORT with SO_ATTACH_REUSEPORT_xBPF in the setsockopt call. Signed-off-by: Craig Gallek --- net/core/filter.c | 2 +- net/core/sock.c | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/net/core/filter.c b/net/core/filter.c index 94d26201080d..2a6e9562f1ab 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -1181,7 +1181,7 @@ static int __reuseport_attach_prog(struct bpf_prog *prog, struct sock *sk) if (bpf_prog_size(prog->len) > sysctl_optmem_max) return -ENOMEM; - if (sk_unhashed(sk)) { + if (sk_unhashed(sk) && sk->sk_reuseport) { err = reuseport_alloc(sk); if (err) return err; diff --git a/net/core/sock.c b/net/core/sock.c index 6c1c8bc93412..46dc8ad7d050 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1531,6 +1531,7 @@ struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority) newsk = NULL; goto out; } + RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL); newsk->sk_err = 0; newsk->sk_priority = 0; -- 2.7.0.rc3.207.g0ac5344