From patchwork Mon Oct 23 19:22:11 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Safonov X-Patchwork-Id: 13433455 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 96637224D7 for ; Mon, 23 Oct 2023 19:23:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=arista.com header.i=@arista.com header.b="UbS5Tx/F" Received: from mail-wm1-x32a.google.com (mail-wm1-x32a.google.com [IPv6:2a00:1450:4864:20::32a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BB37B19B2 for ; Mon, 23 Oct 2023 12:23:07 -0700 (PDT) Received: by mail-wm1-x32a.google.com with SMTP id 5b1f17b1804b1-4083f613272so31358205e9.1 for ; Mon, 23 Oct 2023 12:23:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=google; t=1698088983; x=1698693783; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=yFuTyTJaPxOlc+JRRqn8TS1+jZrCOoj8k+Va4Di7hSE=; b=UbS5Tx/FTwa44h+qaKvnKCeSPT2M013EBqImC5t66Y52QoAXzy2r19gCcxpMfu5QLz J8guOTXOagpwEsNAForVAYKrU4bG6xJTbBc++vay8XjTJgCSUf4m1EgmTfII9RRX8UWx oW8QL0+7Wexy5Z8jj9NIAFu+8+VUjKaCQoGox4IhW24OdoqK9EwjMyAYtoqOE5a8NmbO lEzNDPZ7ry9F26KPKR4bAS3WqFkMF7fyG9UwNlsiGrQXpPtPxurHjd+WxLDGWRi2amBo YrTE1bqyz3KKUpjzg/FElTpKvMjpWFYopaYQFf4YMT0ekqAsKBGdeySVS8U7dfnW9k9P kdcA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698088983; x=1698693783; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=yFuTyTJaPxOlc+JRRqn8TS1+jZrCOoj8k+Va4Di7hSE=; b=Uh1SeCUQXonUIR6dEfDKWeitrkcifBPpdJgSVQuxzv4rMogHZhLqprk4c3b3Hn41UW DFxs3QDAaR29JrfN/Y9yg4E8QlK3YRkBaOxYsjjDP1uRwrI+JJFnX54rL3uIXTgP7Tb8 U7AQaLZUZv/wIIKyWjMAKuY5IycDkRzowGeZ3nVHBwxdDjq/KbRpEIYVSFtcBfGAWgff /tO5a8m84whlMf/vPc8Khc1a9PSWCV7cQ+pWm0hQlG5ZPNwUA9lORoXaHC80rsqCjErw bNak4+AwFNxGjHmeyN4NjpFRpbSdRJwk4jRcMBSS+pl8n9wEVhEJFuefMCBS+T/wKvuo /A0A== X-Gm-Message-State: AOJu0Ywm/m1JKZAYNgJ27tNNqS/Ht+/WpYRGM+dL+hAshm7ixKH8hkqi JUex0gQYkODZH15ZAhTYaeOnEw== X-Google-Smtp-Source: AGHT+IEkU0UE2UV/2QCpyBRM6SL5/HKL1bS4Te14BiGK1Bmcb3ihENmREHJjFOK7cgl57ufzdVdTcA== X-Received: by 2002:a05:600c:4748:b0:409:325:e499 with SMTP id w8-20020a05600c474800b004090325e499mr2352197wmo.32.1698088982727; Mon, 23 Oct 2023 12:23:02 -0700 (PDT) Received: from Mindolluin.ire.aristanetworks.com ([217.173.96.166]) by smtp.gmail.com with ESMTPSA id ay20-20020a05600c1e1400b00407460234f9sm10142088wmb.21.2023.10.23.12.23.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 23 Oct 2023 12:23:02 -0700 (PDT) From: Dmitry Safonov To: David Ahern , Eric Dumazet , Paolo Abeni , Jakub Kicinski , "David S. Miller" Cc: linux-kernel@vger.kernel.org, Dmitry Safonov , Andy Lutomirski , Ard Biesheuvel , Bob Gilligan , Dan Carpenter , David Laight , Dmitry Safonov <0x7f454c46@gmail.com>, Donald Cassidy , Eric Biggers , "Eric W. Biederman" , Francesco Ruggeri , "Gaillardetz, Dominik" , Herbert Xu , Hideaki YOSHIFUJI , Ivan Delalande , Leonard Crestez , "Nassiri, Mohammad" , Salam Noureddine , Simon Horman , "Tetreault, Francois" , netdev@vger.kernel.org Subject: [PATCH v16 net-next 19/23] net/tcp: Allow asynchronous delete for TCP-AO keys (MKTs) Date: Mon, 23 Oct 2023 20:22:11 +0100 Message-ID: <20231023192217.426455-20-dima@arista.com> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231023192217.426455-1-dima@arista.com> References: <20231023192217.426455-1-dima@arista.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org Delete becomes very, very fast - almost free, but after setsockopt() syscall returns, the key is still alive until next RCU grace period. Which is fine for listen sockets as userspace needs to be aware of setsockopt(TCP_AO) and accept() race and resolve it with verification by getsockopt() after TCP connection was accepted. The benchmark results (on non-loaded box, worse with more RCU work pending): > ok 33 Worst case delete 16384 keys: min=5ms max=10ms mean=6.93904ms stddev=0.263421 > ok 34 Add a new key 16384 keys: min=1ms max=4ms mean=2.17751ms stddev=0.147564 > ok 35 Remove random-search 16384 keys: min=5ms max=10ms mean=6.50243ms stddev=0.254999 > ok 36 Remove async 16384 keys: min=0ms max=0ms mean=0.0296107ms stddev=0.0172078 Co-developed-by: Francesco Ruggeri Signed-off-by: Francesco Ruggeri Co-developed-by: Salam Noureddine Signed-off-by: Salam Noureddine Signed-off-by: Dmitry Safonov Acked-by: David Ahern --- include/uapi/linux/tcp.h | 3 ++- net/ipv4/tcp_ao.c | 21 ++++++++++++++++++--- 2 files changed, 20 insertions(+), 4 deletions(-) diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h index 201b3cbd6020..be34d7c5c531 100644 --- a/include/uapi/linux/tcp.h +++ b/include/uapi/linux/tcp.h @@ -396,7 +396,8 @@ struct tcp_ao_del { /* setsockopt(TCP_AO_DEL_KEY) */ __s32 ifindex; /* L3 dev index for VRF */ __u32 set_current :1, /* corresponding ::current_key */ set_rnext :1, /* corresponding ::rnext */ - reserved :30; /* must be 0 */ + del_async :1, /* only valid for listen sockets */ + reserved :29; /* must be 0 */ __u16 reserved2; /* padding, must be 0 */ __u8 prefix; /* peer's address prefix */ __u8 sndid; /* SendID for outgoing segments */ diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c index cbc1ee0f5b9a..acbeb635fe29 100644 --- a/net/ipv4/tcp_ao.c +++ b/net/ipv4/tcp_ao.c @@ -1628,7 +1628,7 @@ static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family, } static int tcp_ao_delete_key(struct sock *sk, struct tcp_ao_info *ao_info, - struct tcp_ao_key *key, + bool del_async, struct tcp_ao_key *key, struct tcp_ao_key *new_current, struct tcp_ao_key *new_rnext) { @@ -1636,11 +1636,24 @@ static int tcp_ao_delete_key(struct sock *sk, struct tcp_ao_info *ao_info, hlist_del_rcu(&key->node); + /* Support for async delete on listening sockets: as they don't + * need current_key/rnext_key maintaining, we don't need to check + * them and we can just free all resources in RCU fashion. + */ + if (del_async) { + atomic_sub(tcp_ao_sizeof_key(key), &sk->sk_omem_alloc); + call_rcu(&key->rcu, tcp_ao_key_free_rcu); + return 0; + } + /* At this moment another CPU could have looked this key up * while it was unlinked from the list. Wait for RCU grace period, * after which the key is off-list and can't be looked up again; * the rx path [just before RCU came] might have used it and set it * as current_key (very unlikely). + * Free the key with next RCU grace period (in case it was + * current_key before tcp_ao_current_rnext() might have + * changed it in forced-delete). */ synchronize_rcu(); if (new_current) @@ -1711,6 +1724,8 @@ static int tcp_ao_del_cmd(struct sock *sk, unsigned short int family, if (!new_rnext) return -ENOENT; } + if (cmd.del_async && sk->sk_state != TCP_LISTEN) + return -EINVAL; if (family == AF_INET) { struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.addr; @@ -1758,8 +1773,8 @@ static int tcp_ao_del_cmd(struct sock *sk, unsigned short int family, if (key == new_current || key == new_rnext) continue; - return tcp_ao_delete_key(sk, ao_info, key, - new_current, new_rnext); + return tcp_ao_delete_key(sk, ao_info, cmd.del_async, key, + new_current, new_rnext); } return -ENOENT; }