From patchwork Fri May 10 12:25:02 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Xing X-Patchwork-Id: 13661543 X-Patchwork-Delegate: kuba@kernel.org Received: from mail-pf1-f169.google.com (mail-pf1-f169.google.com [209.85.210.169]) (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 CA4F516D4F4 for ; Fri, 10 May 2024 12:25:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.169 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715343925; cv=none; b=d87KshJVyDtBVliRfVQLqvOuiTSOLyyDjSv/CBtiy8/O5tbyYbMxmpYl+pR07a4T/FUeZa+zoZnOJASzHzfadNEXpoTgj1z7yk1/YDIP295RBS+KW/NVwgkHQfZlcOUpYZX5yJlwXT0RHK2K3D8RyDTuIH5WAaIwy+bGWr9WYL4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715343925; c=relaxed/simple; bh=dOPWA5oUMFLJMkyrjOLwiNM4jqXOocS06R2V1tpKFlo=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=UOhh8SCbxWVIWPDo8gSSamx2RK6CR4DcIvHAd4WYxk3ups5SN3bcdUmamTNIHmGVUZZ8dwOKBKyS6PbYPbhMYSWuvsRPTYLWag58capboLrx5EY2S4f+LEk94IWgTicRHzEQ2S2GHRYxjbHOz1aEJtFo2fvuC1EWBOMqUbjEAyI= 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=XTwmRuBu; arc=none smtp.client-ip=209.85.210.169 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="XTwmRuBu" Received: by mail-pf1-f169.google.com with SMTP id d2e1a72fcca58-6f449ea8e37so1671044b3a.3 for ; Fri, 10 May 2024 05:25:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1715343923; x=1715948723; 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=UlCmy+iZAQgDelBlhi5+PpnGFmqq4Df4VsGrbrOxgsM=; b=XTwmRuBuSHjYjk1Cczq03RjEyWWuRO1tCmYxaBJ7z4D2B6NMHRKLqZNVk9JV5kC+Tw tF+LWOxgqUcYoVyO0IBYty3ujpCF/D7vZvi+z+tXUlowkZnlM2/BydA/n1wReVCejHyB 0+dKkjbitAkJrPobOUSkw2JyxbKEk+tccHmT7m0/6///8tuIuqWdvLDSQ8OtfJptW8nE iR0s/K/PYQ+Hn+SIW8Q8JxTAO5/QntwP7/HNYeqJZCv7c0XoO2o3nAZGk4dlBkxL07Zx bJK/e64iYzcu3Z/rBpHbnqOYChADNU9k3Sakx97++QLBUjtRc2uRqR1tvZMyoqyf8StL SKfw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1715343923; x=1715948723; 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=UlCmy+iZAQgDelBlhi5+PpnGFmqq4Df4VsGrbrOxgsM=; b=FggrKHuZ7O70R5OGUtSA4bNtQjvxSaJdDsb4iuTfYhQC4Xny1XvnFBIPumauB2/o8L rZLxXDekm5IiMN8loDzjc6QObzh3gasRA5/JYq1BSYHKra0Nq/zR4bwEXf2Orp0VR4pq tO4blBrXRklHzkh7lTWb9I/RGJOek2bApUDQ8xQMjmznFJKJ7xM4qDPBb4o4zwpWRSQD YoEJimIzRzOQOzkHGpGZgCvJCQ0ZY5qHVaMOVjoE2tkIzCVZAB63ajNxeVLtLXMLyath MXHvyOUEkMCsEzxrtfO9YshzhSAOnru89X5As6U/CxGwJwl6a1EFLe8Fp91w1y4D8JQ6 4zZA== X-Gm-Message-State: AOJu0YzAd40DAUBIVhzAnzkmSgx+gl6GAgvYr/NcDptYf1iRmcEU6tpp UoHqXgm5sBDR8tVuhPW8gX5y5wsebkUHrcsC7KHl2qvPbCcI3rVY X-Google-Smtp-Source: AGHT+IHa1IEfofgHSTXuWQF1qnE6SdHpidxY8sgIYZD8gh/Ipx0le+uaNxiPvtGwUu3qOXD+zuaWdw== X-Received: by 2002:a05:6a00:391a:b0:6f3:876a:c029 with SMTP id d2e1a72fcca58-6f4e02ac99bmr2752898b3a.10.1715343922979; Fri, 10 May 2024 05:25:22 -0700 (PDT) Received: from KERNELXING-MB0.tencent.com ([43.132.141.25]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-6340b57f362sm2943530a12.30.2024.05.10.05.25.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 May 2024 05:25:22 -0700 (PDT) From: Jason Xing To: edumazet@google.com, dsahern@kernel.org, kuba@kernel.org, pabeni@redhat.com, davem@davemloft.net Cc: netdev@vger.kernel.org, kerneljasonxing@gmail.com, Jason Xing Subject: [PATCH net-next v2 5/5] tcp: rstreason: fully support in tcp_check_req() Date: Fri, 10 May 2024 20:25:02 +0800 Message-Id: <20240510122502.27850-6-kerneljasonxing@gmail.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20240510122502.27850-1-kerneljasonxing@gmail.com> References: <20240510122502.27850-1-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 We're going to send an RST due to invalid syn packet which is already checked whether 1) it is in sequence, 2) it is a retransmitted skb. As RFC 793 says, if the state of socket is not CLOSED/LISTEN/SYN-SENT, then we should send an RST when receiving bad syn packet: "fourth, check the SYN bit,...If the SYN is in the window it is an error, send a reset" Signed-off-by: Jason Xing --- include/net/rstreason.h | 8 ++++++++ net/ipv4/tcp_minisocks.c | 2 +- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/include/net/rstreason.h b/include/net/rstreason.h index 7ae5bb55559b..2575c85d7f7a 100644 --- a/include/net/rstreason.h +++ b/include/net/rstreason.h @@ -16,6 +16,7 @@ FN(TCP_OLD_ACK) \ FN(TCP_ABORT_ON_DATA) \ FN(TCP_TIMEWAIT_SOCKET) \ + FN(INVALID_SYN) \ FN(MPTCP_RST_EUNSPEC) \ FN(MPTCP_RST_EMPTCP) \ FN(MPTCP_RST_ERESOURCE) \ @@ -76,6 +77,13 @@ enum sk_rst_reason { /* Here start with the independent reasons */ /** @SK_RST_REASON_TCP_TIMEWAIT_SOCKET: happen on the timewait socket */ SK_RST_REASON_TCP_TIMEWAIT_SOCKET, + /** + * @SK_RST_REASON_INVALID_SYN: receive bad syn packet + * RFC 793 says if the state is not CLOSED/LISTEN/SYN-SENT then + * "fourth, check the SYN bit,...If the SYN is in the window it is + * an error, send a reset" + */ + SK_RST_REASON_INVALID_SYN, /* Copy from include/uapi/linux/mptcp.h. * These reset fields will not be changed since they adhere to diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 7d543569a180..b93619b2384b 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -879,7 +879,7 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, * avoid becoming vulnerable to outside attack aiming at * resetting legit local connections. */ - req->rsk_ops->send_reset(sk, skb, SK_RST_REASON_NOT_SPECIFIED); + req->rsk_ops->send_reset(sk, skb, SK_RST_REASON_INVALID_SYN); } else if (fastopen) { /* received a valid RST pkt */ reqsk_fastopen_remove(sk, req, true); tcp_reset(sk, skb);