From patchwork Wed Mar 2 19:55:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin KaFai Lau X-Patchwork-Id: 12766653 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 15EDDC433EF for ; Wed, 2 Mar 2022 19:55:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242470AbiCBT4h (ORCPT ); Wed, 2 Mar 2022 14:56:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242488AbiCBT4d (ORCPT ); Wed, 2 Mar 2022 14:56:33 -0500 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 91ABAD95ED for ; Wed, 2 Mar 2022 11:55:49 -0800 (PST) Received: from pps.filterd (m0148461.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.1.2/8.16.1.2) with ESMTP id 222JMhA0012035 for ; Wed, 2 Mar 2022 11:55:49 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=WRkKvD9Ln1BF31cy79ItEby3Tja1SmNRAJaXQh89H7E=; b=juK52Pb/G4C8+8pUTVsaGSjz9BdnTQZOfKJjCBHheBDho5ZO6aC4OFXxv+1Xrc8DzP0v feFc4/YcgwUx9W7Uruf3nJG95Dh6NkKmoPAyz5SatOt5UAXuTugV6hHWqSfceFoSnp0S XRHjLujcXb8ems5WRGKfUJibcAwHgzOXc2U= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3ehyr6r9g4-3 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 02 Mar 2022 11:55:49 -0800 Received: from twshared7500.02.ash7.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::f) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Wed, 2 Mar 2022 11:55:46 -0800 Received: by devbig005.ftw2.facebook.com (Postfix, from userid 6611) id 204E67BD3595; Wed, 2 Mar 2022 11:55:38 -0800 (PST) From: Martin KaFai Lau To: , CC: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , David Miller , Eric Dumazet , Jakub Kicinski , , Willem de Bruijn Subject: [PATCH v6 net-next 03/13] net: Handle delivery_time in skb->tstamp during network tapping with af_packet Date: Wed, 2 Mar 2022 11:55:38 -0800 Message-ID: <20220302195538.3480753-1-kafai@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220302195519.3479274-1-kafai@fb.com> References: <20220302195519.3479274-1-kafai@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-GUID: yMSgFZF7lrJX2LpyGaIzm5UfdeOYrR4v X-Proofpoint-ORIG-GUID: yMSgFZF7lrJX2LpyGaIzm5UfdeOYrR4v X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.816,Hydra:6.0.425,FMLib:17.11.64.514 definitions=2022-03-02_12,2022-02-26_01,2022-02-23_01 X-Proofpoint-Spam-Details: rule=fb_outbound_notspam policy=fb_outbound score=0 spamscore=0 clxscore=1015 priorityscore=1501 mlxscore=0 phishscore=0 adultscore=0 impostorscore=0 malwarescore=0 suspectscore=0 mlxlogscore=968 bulkscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2201110000 definitions=main-2203020084 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org A latter patch will set the skb->mono_delivery_time to flag the skb->tstamp is used as the mono delivery_time (EDT) instead of the (rcv) timestamp. skb_clear_tstamp() will then keep this delivery_time during forwarding. This patch is to make the network tapping (with af_packet) to handle the delivery_time stored in skb->tstamp. Regardless of tapping at the ingress or egress, the tapped skb is received by the af_packet socket, so it is ingress to the af_packet socket and it expects the (rcv) timestamp. When tapping at egress, dev_queue_xmit_nit() is used. It has already expected skb->tstamp may have delivery_time, so it does skb_clone()+net_timestamp_set() to ensure the cloned skb has the (rcv) timestamp before passing to the af_packet sk. This patch only adds to clear the skb->mono_delivery_time bit in net_timestamp_set(). When tapping at ingress, it currently expects the skb->tstamp is either 0 or the (rcv) timestamp. Meaning, the tapping at ingress path has already expected the skb->tstamp could be 0 and it will get the (rcv) timestamp by ktime_get_real() when needed. There are two cases for tapping at ingress: One case is af_packet queues the skb to its sk_receive_queue. The skb is either not shared or new clone created. The newly added skb_clear_delivery_time() is called to clear the delivery_time (if any) and set the (rcv) timestamp if needed before the skb is queued to the sk_receive_queue. Another case, the ingress skb is directly copied to the rx_ring and tpacket_get_timestamp() is used to get the (rcv) timestamp. The newly added skb_tstamp() is used in tpacket_get_timestamp() to check the skb->mono_delivery_time bit before returning skb->tstamp. As mentioned earlier, the tapping@ingress has already expected the skb may not have the (rcv) timestamp (because no sk has asked for it) and has handled this case by directly calling ktime_get_real(). Signed-off-by: Martin KaFai Lau --- include/linux/skbuff.h | 24 ++++++++++++++++++++++++ net/core/dev.c | 4 +++- net/packet/af_packet.c | 4 +++- 3 files changed, 30 insertions(+), 2 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 27a28920e7b3..7e2d796ece80 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -3996,6 +3996,22 @@ static inline void skb_set_delivery_time(struct sk_buff *skb, ktime_t kt, skb->mono_delivery_time = 0; } +DECLARE_STATIC_KEY_FALSE(netstamp_needed_key); + +/* It is used in the ingress path to clear the delivery_time. + * If needed, set the skb->tstamp to the (rcv) timestamp. + */ +static inline void skb_clear_delivery_time(struct sk_buff *skb) +{ + if (skb->mono_delivery_time) { + skb->mono_delivery_time = 0; + if (static_branch_unlikely(&netstamp_needed_key)) + skb->tstamp = ktime_get_real(); + else + skb->tstamp = 0; + } +} + static inline void skb_clear_tstamp(struct sk_buff *skb) { if (skb->mono_delivery_time) @@ -4004,6 +4020,14 @@ static inline void skb_clear_tstamp(struct sk_buff *skb) skb->tstamp = 0; } +static inline ktime_t skb_tstamp(const struct sk_buff *skb) +{ + if (skb->mono_delivery_time) + return 0; + + return skb->tstamp; +} + static inline u8 skb_metadata_len(const struct sk_buff *skb) { return skb_shinfo(skb)->meta_len; diff --git a/net/core/dev.c b/net/core/dev.c index 2d6771075720..6d81b5a7ef3f 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2020,7 +2020,8 @@ void net_dec_egress_queue(void) EXPORT_SYMBOL_GPL(net_dec_egress_queue); #endif -static DEFINE_STATIC_KEY_FALSE(netstamp_needed_key); +DEFINE_STATIC_KEY_FALSE(netstamp_needed_key); +EXPORT_SYMBOL(netstamp_needed_key); #ifdef CONFIG_JUMP_LABEL static atomic_t netstamp_needed_deferred; static atomic_t netstamp_wanted; @@ -2081,6 +2082,7 @@ EXPORT_SYMBOL(net_disable_timestamp); static inline void net_timestamp_set(struct sk_buff *skb) { skb->tstamp = 0; + skb->mono_delivery_time = 0; if (static_branch_unlikely(&netstamp_needed_key)) __net_timestamp(skb); } diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index ab87f22cc7ec..1b93ce1a5600 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -460,7 +460,7 @@ static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec64 *ts, return TP_STATUS_TS_RAW_HARDWARE; if ((flags & SOF_TIMESTAMPING_SOFTWARE) && - ktime_to_timespec64_cond(skb->tstamp, ts)) + ktime_to_timespec64_cond(skb_tstamp(skb), ts)) return TP_STATUS_TS_SOFTWARE; return 0; @@ -2199,6 +2199,7 @@ static int packet_rcv(struct sk_buff *skb, struct net_device *dev, spin_lock(&sk->sk_receive_queue.lock); po->stats.stats1.tp_packets++; sock_skb_set_dropcount(sk, skb); + skb_clear_delivery_time(skb); __skb_queue_tail(&sk->sk_receive_queue, skb); spin_unlock(&sk->sk_receive_queue.lock); sk->sk_data_ready(sk); @@ -2377,6 +2378,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, po->stats.stats1.tp_packets++; if (copy_skb) { status |= TP_STATUS_COPY; + skb_clear_delivery_time(copy_skb); __skb_queue_tail(&sk->sk_receive_queue, copy_skb); } spin_unlock(&sk->sk_receive_queue.lock);