From patchwork Fri Aug 30 15:37:50 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Xing X-Patchwork-Id: 13785288 X-Patchwork-Delegate: kuba@kernel.org Received: from mail-pl1-f172.google.com (mail-pl1-f172.google.com [209.85.214.172]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9260C1B5307 for ; Fri, 30 Aug 2024 15:37:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725032281; cv=none; b=ivCMgq35RZVJMY4S/h/sGASfHFNaXhLeWWBVSRE5qekbQs6QZgoGVyL+D1iAvxMeh/a4uFONlYST6TII2g6KLz0JTIUlOywDxZh3rwJUwFRlMx47esnTXGo9nzXlardsp6at9eliy8v1K9TuVq0Erp4k6cRIQuwgIFx6qZCxVCs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725032281; c=relaxed/simple; bh=5ueKriG21q/E6jvCcclpCGtuZjw0L8bOYqaK3xC5BjA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=S41ulSqR2+VS8nsNx+I8pjQZHzlc+KHplARMTGFmDsvDeRfvSs74oHi0QkTcqrPvYM34OLRJRQnkzcZR75LeUV4NiCDH1ndQJCu1PrTT8RQ+Cn8mEXGi6qmS1ssO7V5sdIU7g7NWWfXyflTnldYRwp/gQPxx5wNywktrSmBfFDI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=RJeERuT9; arc=none smtp.client-ip=209.85.214.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="RJeERuT9" Received: by mail-pl1-f172.google.com with SMTP id d9443c01a7336-20203988f37so19335565ad.1 for ; Fri, 30 Aug 2024 08:37:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1725032279; x=1725637079; 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=hIRna+VK+efdPqniPGomIkjoK65+9IgoA8XYwMuK0SE=; b=RJeERuT9vyLOtw5Z4oZy8vS3TCOdp719UkDD6ytQm/PzkFbRvBDZIf858ggfpBx7Ga X5v4zXxV98EZg3fvvJ7Ry62RvSxdjz1vuhHE2OO0A8EnlMjQUjfq3vm8KQi4J9l+IUk8 gMkOfHwF134dSmbsqyonxky7SfSJth5ZTj+15ne/B84ybK7o5k68JaWbAucdbrgShOEZ hI5Dcd7h/BVjfnS6Eek3zH4ut0rdzdNCbIzcWxvvvfFEM0KBSIRubwhi9EzoqmPLoxNY 9ZMojfAJexXVL+pYQMSKum1pxDpTDFfRE6jXG8DzCRCw3PmmhSSDO+L0gtC53CSLMllL drJw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1725032279; x=1725637079; 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=hIRna+VK+efdPqniPGomIkjoK65+9IgoA8XYwMuK0SE=; b=rCgupcvYa0n/JSq7uNey/S56oFeDf4RgQ2/WvKmMENj3JJ7IZke+rnuYqpIyzvONWZ R5n1CFoqC/dwhHb1TnJWr3WcP15Rx4SDh7KujG4hLRusojiDWIGKAm0wfgJdcIXnX5xD KJqNoZOAxTFF1gHg3hdFAIOVi5YwvVS5WUExW6E2OAba5eo78ZCd5gXWaZ+Vt0M0otmG Rs6XsHgu33HVQdVhO3yYXOXLrW9u131diMS726PAy41ks+SdRQv7Iils87CIYk38scAW 8xqsG9pwCBIA9aIXPx6GYk6QD3EvVEfiIGylQuofUatyGAAR6Z2w5IrXFj0FcyiEqrVh fuog== X-Gm-Message-State: AOJu0Yzu6+mK3s8bpUM1cn6VlN82JnLAQQXq2fFUZOfPBf7LHo6B3UkS rJjlBR2xWkVE6MBBPLAprm3DKinDjDurtkvUtu94eMyjM/NBSBt+ X-Google-Smtp-Source: AGHT+IFHWS2WmPJ8gqOssjbMuFB5JS9drnODsUiZZ+PuKohopY9eJYireNrKKZy3XJSKwNVMC+15lQ== X-Received: by 2002:a17:902:e882:b0:201:fd3c:a321 with SMTP id d9443c01a7336-2050c4c367amr63207795ad.62.1725032278792; Fri, 30 Aug 2024 08:37:58 -0700 (PDT) Received: from KERNELXING-MC1.tencent.com ([114.253.36.103]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-205152cd59esm28504795ad.81.2024.08.30.08.37.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 30 Aug 2024 08:37:58 -0700 (PDT) From: Jason Xing To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, dsahern@kernel.org, willemb@google.com Cc: netdev@vger.kernel.org, Jason Xing , Willem de Bruijn Subject: [PATCH net-next v3 1/2] net-timestamp: filter out report when setting SOF_TIMESTAMPING_SOFTWARE Date: Fri, 30 Aug 2024 23:37:50 +0800 Message-Id: <20240830153751.86895-2-kerneljasonxing@gmail.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20240830153751.86895-1-kerneljasonxing@gmail.com> References: <20240830153751.86895-1-kerneljasonxing@gmail.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 From: Jason Xing introduce a new flag SOF_TIMESTAMPING_OPT_RX_SOFTWARE_FILTER in the receive path. User can set it with SOF_TIMESTAMPING_SOFTWARE to filter out rx timestamp report, especially after a process turns on netstamp_needed_key which can time stamp every incoming skb. Previously, We found out if an application starts first which turns on netstamp_needed_key, then another one only passing SOF_TIMESTAMPING_SOFTWARE could also get rx timestamp. Now we handle this case by introducing this new flag without breaking users. In this way, we have two kinds of combination: 1. setting SOF_TIMESTAMPING_SOFTWARE|SOF_TIMESTAMPING_RX_SOFTWARE, it will surely allow users to get the rx timestamp report. 2. setting SOF_TIMESTAMPING_SOFTWARE|SOF_TIMESTAMPING_OPT_RX_SOFTWARE_FILTER while the skb is timestamped, it will stop reporting the rx timestamp. Another thing about errqueue in this patch I have a few words to say: In this case, we need to handle the egress path carefully, or else reporting the tx timestamp will fail. Egress path and ingress path will finally call sock_recv_timestamp(). We have to distinguish them. Errqueue is a good indicator to reflect the flow direction. Suggested-by: Willem de Bruijn Signed-off-by: Jason Xing Reviewed-by: Willem de Bruijn --- 1. Willem suggested this alternative way to solve the issue, so I added his Suggested-by tag here. Thanks! --- Documentation/networking/timestamping.rst | 12 ++++++++++++ include/uapi/linux/net_tstamp.h | 3 ++- net/core/sock.c | 4 ++++ net/ethtool/common.c | 1 + net/ipv4/tcp.c | 7 +++++-- net/socket.c | 5 ++++- 6 files changed, 28 insertions(+), 4 deletions(-) diff --git a/Documentation/networking/timestamping.rst b/Documentation/networking/timestamping.rst index 5e93cd71f99f..ef2a334d373e 100644 --- a/Documentation/networking/timestamping.rst +++ b/Documentation/networking/timestamping.rst @@ -266,6 +266,18 @@ SOF_TIMESTAMPING_OPT_TX_SWHW: two separate messages will be looped to the socket's error queue, each containing just one timestamp. +SOF_TIMESTAMPING_OPT_RX_SOFTWARE_FILTER: + Used in the receive software timestamp. Enabling the flag along with + SOF_TIMESTAMPING_SOFTWARE will not report the rx timestamp to the + userspace so that it can filter out the case where one process starts + first which turns on netstamp_needed_key through setting generation + flags like SOF_TIMESTAMPING_RX_SOFTWARE, then another one only passing + SOF_TIMESTAMPING_SOFTWARE report flag could also get the rx timestamp. + + SOF_TIMESTAMPING_OPT_RX_SOFTWARE_FILTER prevents the application from + being influenced by others and let the application finally choose + whether to report the timestamp in the receive path or not. + New applications are encouraged to pass SOF_TIMESTAMPING_OPT_ID to disambiguate timestamps and SOF_TIMESTAMPING_OPT_TSONLY to operate regardless of the setting of sysctl net.core.tstamp_allow_data. diff --git a/include/uapi/linux/net_tstamp.h b/include/uapi/linux/net_tstamp.h index a2c66b3d7f0f..0042e91fa213 100644 --- a/include/uapi/linux/net_tstamp.h +++ b/include/uapi/linux/net_tstamp.h @@ -32,8 +32,9 @@ enum { SOF_TIMESTAMPING_OPT_TX_SWHW = (1<<14), SOF_TIMESTAMPING_BIND_PHC = (1 << 15), SOF_TIMESTAMPING_OPT_ID_TCP = (1 << 16), + SOF_TIMESTAMPING_OPT_RX_SOFTWARE_FILTER = (1 << 17), - SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_ID_TCP, + SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_RX_SOFTWARE_FILTER, SOF_TIMESTAMPING_MASK = (SOF_TIMESTAMPING_LAST - 1) | SOF_TIMESTAMPING_LAST }; diff --git a/net/core/sock.c b/net/core/sock.c index 468b1239606c..c4488f6a3ce8 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -908,6 +908,10 @@ int sock_set_timestamping(struct sock *sk, int optname, !(val & SOF_TIMESTAMPING_OPT_ID)) return -EINVAL; + if (val & SOF_TIMESTAMPING_RX_SOFTWARE && + val & SOF_TIMESTAMPING_OPT_RX_SOFTWARE_FILTER) + return -EINVAL; + if (val & SOF_TIMESTAMPING_OPT_ID && !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) { if (sk_is_tcp(sk)) { diff --git a/net/ethtool/common.c b/net/ethtool/common.c index 7257ae272296..6fde55a904b0 100644 --- a/net/ethtool/common.c +++ b/net/ethtool/common.c @@ -430,6 +430,7 @@ const char sof_timestamping_names[][ETH_GSTRING_LEN] = { [const_ilog2(SOF_TIMESTAMPING_OPT_TX_SWHW)] = "option-tx-swhw", [const_ilog2(SOF_TIMESTAMPING_BIND_PHC)] = "bind-phc", [const_ilog2(SOF_TIMESTAMPING_OPT_ID_TCP)] = "option-id-tcp", + [const_ilog2(SOF_TIMESTAMPING_OPT_RX_SOFTWARE_FILTER)] = "option-rx-software-filter", }; static_assert(ARRAY_SIZE(sof_timestamping_names) == __SOF_TIMESTAMPING_CNT); diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 8514257f4ecd..863cc6b8a208 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2235,6 +2235,7 @@ void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk, struct scm_timestamping_internal *tss) { int new_tstamp = sock_flag(sk, SOCK_TSTAMP_NEW); + u32 tsflags = READ_ONCE(sk->sk_tsflags); bool has_timestamping = false; if (tss->ts[0].tv_sec || tss->ts[0].tv_nsec) { @@ -2274,14 +2275,16 @@ void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk, } } - if (READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_SOFTWARE) + if (tsflags & SOF_TIMESTAMPING_SOFTWARE && + (tsflags & SOF_TIMESTAMPING_RX_SOFTWARE || + !(tsflags & SOF_TIMESTAMPING_OPT_RX_SOFTWARE_FILTER))) has_timestamping = true; else tss->ts[0] = (struct timespec64) {0}; } if (tss->ts[2].tv_sec || tss->ts[2].tv_nsec) { - if (READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_RAW_HARDWARE) + if (tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) has_timestamping = true; else tss->ts[2] = (struct timespec64) {0}; diff --git a/net/socket.c b/net/socket.c index fcbdd5bc47ac..5ede4146198c 100644 --- a/net/socket.c +++ b/net/socket.c @@ -946,7 +946,10 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, memset(&tss, 0, sizeof(tss)); tsflags = READ_ONCE(sk->sk_tsflags); - if ((tsflags & SOF_TIMESTAMPING_SOFTWARE) && + if ((tsflags & SOF_TIMESTAMPING_SOFTWARE && + (tsflags & SOF_TIMESTAMPING_RX_SOFTWARE || + skb_is_err_queue(skb) || + !(tsflags & SOF_TIMESTAMPING_OPT_RX_SOFTWARE_FILTER))) && ktime_to_timespec64_cond(skb->tstamp, tss.ts + 0)) empty = 0; if (shhwtstamps &&