From patchwork Mon May 16 03:45:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Menglong Dong X-Patchwork-Id: 12850252 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 D78CCC433EF for ; Mon, 16 May 2022 03:47:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239891AbiEPDrU (ORCPT ); Sun, 15 May 2022 23:47:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56166 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239869AbiEPDqn (ORCPT ); Sun, 15 May 2022 23:46:43 -0400 Received: from mail-pf1-x443.google.com (mail-pf1-x443.google.com [IPv6:2607:f8b0:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3134336143; Sun, 15 May 2022 20:46:10 -0700 (PDT) Received: by mail-pf1-x443.google.com with SMTP id y41so12895243pfw.12; Sun, 15 May 2022 20:46:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=4h0zgMDxpbPpu7uK7IrYU1z+wSYdiXLHkR9K2kpvGrM=; b=Pswn3QCQrz7he6ge1lmOsqYf+aYwknurixcmoPz4XUa2J0Otr8NMZrGsDrWdeHP1Vl XEf2MSsYe9/VL1Mp6LB98x0lN6qHFBPN2N1f+fULXI6clrgeNN0TLXXWmnlfPKaZ4KyC D0Ug6MNa5bk2yCkqQ4FStFiEYhumzJYyRokHUz3sqLby8YMRuPSaEvHMPr6i81hvPfzE RDwqHAM6TUko10wsIzQLJ8G/3UezLOP+Rptsme21KqZG1NMXPlrloan4dCUcRdsKnfqN g+TbZEkoTXGqYTBoVAx2CNC3nS2i5RfSFSAxVzNfvGSsu3yP4riSiZEVWt2r23xqS7Kf rXsA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=4h0zgMDxpbPpu7uK7IrYU1z+wSYdiXLHkR9K2kpvGrM=; b=zr0lweOMwM3oPjxGFsHxTZeHdWLppVyfeAD2wZF8zZIFIJpmfKu4/KvAaQ3YMUG2/r 2KxCAO1Qls1kBi0lJA3jTIucvc5YLPVUqbbzov6y8fRg+rXpzzAsvC0mahx3jO9rtoL9 d1UGpmpmCavXpD6gu6oWBtxatsikPsOPDIsnrAMEikdEbUJ0BrMmLVXdlM9d26u0Q5vK tPmmmfRYNzQ+nWKuYzbb7CeCDxGIGxljjqCGG5yAB6rK3/UwUM5977PGxXQo/35BWaek n1RCQd+Njl3wdwC9wsYGuMZNZoFo1KwMyIv7/qvhY+G0+z4GiTQumsu2PnPjKkSpgmpj eLiw== X-Gm-Message-State: AOAM5319w+lHxGPtFGb2ALJc7N3YEQ2u9zs0/rLbNpEJQJsVgA5Mjs9g HzzJcAewqoPWgWYSirD+eT8= X-Google-Smtp-Source: ABdhPJxhcWu1+NUPaGpDgeZqp9U4i53btRj2OqiRs+GdjQd2351BYlKBlhMoGqXEek5MUDc3ab+nqA== X-Received: by 2002:a63:e155:0:b0:3c6:7514:6c0d with SMTP id h21-20020a63e155000000b003c675146c0dmr13605514pgk.249.1652672770441; Sun, 15 May 2022 20:46:10 -0700 (PDT) Received: from localhost.localdomain ([203.205.141.24]) by smtp.gmail.com with ESMTPSA id x184-20020a6286c1000000b0050dc762819bsm5636854pfd.117.2022.05.15.20.46.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 15 May 2022 20:46:10 -0700 (PDT) From: menglong8.dong@gmail.com X-Google-Original-From: imagedong@tencent.com To: edumazet@google.com Cc: rostedt@goodmis.org, mingo@redhat.com, davem@davemloft.net, yoshfuji@linux-ipv6.org, dsahern@kernel.org, kuba@kernel.org, pabeni@redhat.com, imagedong@tencent.com, kafai@fb.com, talalahmad@google.com, keescook@chromium.org, dongli.zhang@oracle.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH net-next 8/9] net: tcp: add skb drop reasons to tcp tw code path Date: Mon, 16 May 2022 11:45:18 +0800 Message-Id: <20220516034519.184876-9-imagedong@tencent.com> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220516034519.184876-1-imagedong@tencent.com> References: <20220516034519.184876-1-imagedong@tencent.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Menglong Dong In order to get the reasons of skb drops, add a function argument of type 'enum skb_drop_reason *reason' to tcp_timewait_state_process(). In the origin code, all packets to time-wait socket are treated as dropping with kfree_skb(), which can make users confused. Therefore, we use consume_skb() for the skbs that are 'good'. We can check the value of 'reason' to decide use kfree_skb() or consume_skb(). The new reason 'TIMEWAIT' is added for the case that the skb is dropped as the socket in time-wait state. Signed-off-by: Menglong Dong Reported-by: kernel test robot --- include/linux/skbuff.h | 5 +++++ include/net/tcp.h | 7 ++++--- net/ipv4/tcp_ipv4.c | 11 +++++++++-- net/ipv4/tcp_minisocks.c | 24 ++++++++++++++++++++---- net/ipv6/tcp_ipv6.c | 10 ++++++++-- 5 files changed, 46 insertions(+), 11 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 4578bbab5a3e..8d18fc5a5af6 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -560,6 +560,10 @@ struct sk_buff; * SKB_DROP_REASON_TCP_REQQFULLDROP * request queue of the listen socket is full, corresponding to * LINUX_MIB_TCPREQQFULLDROP + * + * SKB_DROP_REASON_TIMEWAIT + * socket is in time-wait state and all packet that received will + * be treated as 'drop', except a good 'SYN' packet */ #define __DEFINE_SKB_DROP_REASON(FN) \ FN(NOT_SPECIFIED) \ @@ -631,6 +635,7 @@ struct sk_buff; FN(TCP_ABORTONDATA) \ FN(LISTENOVERFLOWS) \ FN(TCP_REQQFULLDROP) \ + FN(TIMEWAIT) \ FN(MAX) /* The reason of skb drop, which is used in kfree_skb_reason(). diff --git a/include/net/tcp.h b/include/net/tcp.h index 082dd0627e2e..88217b8d95ac 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -380,9 +380,10 @@ enum tcp_tw_status { }; -enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw, - struct sk_buff *skb, - const struct tcphdr *th); +enum tcp_tw_status +tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb, + const struct tcphdr *th, + enum skb_drop_reason *reason); struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, struct request_sock *req, bool fastopen, bool *lost_race); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 708f92b03f42..9174ee162633 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -2134,7 +2134,8 @@ int tcp_v4_rcv(struct sk_buff *skb) inet_twsk_put(inet_twsk(sk)); goto csum_error; } - switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) { + switch (tcp_timewait_state_process(inet_twsk(sk), skb, th, + &drop_reason)) { case TCP_TW_SYN: { struct sock *sk2 = inet_lookup_listener(dev_net(skb->dev), &tcp_hashinfo, skb, @@ -2150,12 +2151,18 @@ int tcp_v4_rcv(struct sk_buff *skb) refcounted = false; goto process; } + /* TCP_FLAGS or NO_SOCKET? */ + SKB_DR_SET(drop_reason, TCP_FLAGS); } /* to ACK */ fallthrough; case TCP_TW_ACK: tcp_v4_timewait_ack(sk, skb); - break; + refcounted = false; + if (drop_reason) + goto discard_it; + else + goto put_and_return; case TCP_TW_RST: tcp_v4_send_reset(sk, skb); inet_twsk_deschedule_put(inet_twsk(sk)); diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 1a21018f6f64..329724118b7f 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -83,13 +83,15 @@ tcp_timewait_check_oow_rate_limit(struct inet_timewait_sock *tw, */ enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb, - const struct tcphdr *th) + const struct tcphdr *th, + enum skb_drop_reason *reason) { struct tcp_options_received tmp_opt; struct tcp_timewait_sock *tcptw = tcp_twsk((struct sock *)tw); bool paws_reject = false; tmp_opt.saw_tstamp = 0; + *reason = SKB_DROP_REASON_NOT_SPECIFIED; if (th->doff > (sizeof(*th) >> 2) && tcptw->tw_ts_recent_stamp) { tcp_parse_options(twsk_net(tw), skb, &tmp_opt, 0, NULL); @@ -113,11 +115,16 @@ tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb, return tcp_timewait_check_oow_rate_limit( tw, skb, LINUX_MIB_TCPACKSKIPPEDFINWAIT2); - if (th->rst) + if (th->rst) { + SKB_DR_SET(*reason, TCP_RESET); goto kill; + } - if (th->syn && !before(TCP_SKB_CB(skb)->seq, tcptw->tw_rcv_nxt)) + if (th->syn && !before(TCP_SKB_CB(skb)->seq, + tcptw->tw_rcv_nxt)) { + SKB_DR_SET(*reason, TCP_FLAGS); return TCP_TW_RST; + } /* Dup ACK? */ if (!th->ack || @@ -143,6 +150,9 @@ tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb, } inet_twsk_reschedule(tw, TCP_TIMEWAIT_LEN); + + /* skb should be free normally on this case. */ + *reason = SKB_NOT_DROPPED_YET; return TCP_TW_ACK; } @@ -174,6 +184,7 @@ tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb, * protocol bug yet. */ if (twsk_net(tw)->ipv4.sysctl_tcp_rfc1337 == 0) { + SKB_DR_SET(*reason, TCP_RESET); kill: inet_twsk_deschedule_put(tw); return TCP_TW_SUCCESS; @@ -216,11 +227,14 @@ tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb, if (isn == 0) isn++; TCP_SKB_CB(skb)->tcp_tw_isn = isn; + *reason = SKB_NOT_DROPPED_YET; return TCP_TW_SYN; } - if (paws_reject) + if (paws_reject) { + SKB_DR_SET(*reason, TCP_RFC7323_PAWS); __NET_INC_STATS(twsk_net(tw), LINUX_MIB_PAWSESTABREJECTED); + } if (!th->rst) { /* In this case we must reset the TIMEWAIT timer. @@ -232,9 +246,11 @@ tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb, if (paws_reject || th->ack) inet_twsk_reschedule(tw, TCP_TIMEWAIT_LEN); + SKB_DR_OR(*reason, TIMEWAIT); return tcp_timewait_check_oow_rate_limit( tw, skb, LINUX_MIB_TCPACKSKIPPEDTIMEWAIT); } + SKB_DR_SET(*reason, TCP_RESET); inet_twsk_put(tw); return TCP_TW_SUCCESS; } diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 27c51991bd54..5c777006de3d 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1795,7 +1795,8 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb) goto csum_error; } - switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) { + switch (tcp_timewait_state_process(inet_twsk(sk), skb, th, + &drop_reason)) { case TCP_TW_SYN: { struct sock *sk2; @@ -1815,12 +1816,17 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb) refcounted = false; goto process; } + SKB_DR_SET(drop_reason, TCP_FLAGS); } /* to ACK */ fallthrough; case TCP_TW_ACK: tcp_v6_timewait_ack(sk, skb); - break; + refcounted = false; + if (drop_reason) + goto discard_it; + else + goto put_and_return; case TCP_TW_RST: tcp_v6_send_reset(sk, skb); inet_twsk_deschedule_put(inet_twsk(sk));