From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dl1-f48.google.com (mail-dl1-f48.google.com [74.125.82.48]) (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 A86BB2D592C for ; Sat, 14 Mar 2026 17:44:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.48 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773510261; cv=none; b=koWSKTqAK0PP+GDRhWCSM7Rk2TUvJXSrUkjdDE1ZwwRxDazvVnorfF8HdMAZV4zVkqBY21p2HxedKEXU5uFL3Sko9NoAZEFNsrrzVbUYjC/tjWyzkwc8tqznm0pw1jRuGgPGGF3QrXr+3198iD8r12MfHzAveG+QFci592snSpA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773510261; c=relaxed/simple; bh=uItdHPzM8/YhmEnZVDdGZfkeDxlbuzv/yCC5R1HveNc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KfAwpIWA+G0X7088+d/W/LnLxQsEgjzwUlI4gHawvYRaIJO0KpjP1hRuSMUzSieq3/fxURVbpXpEuUp/4UAccXJ4SJ5BTcbGc4iDg1TILSpJ0ETXBdcdZEYDoAm4/L0VqMMAGgLw5bztKuYZwAmF3qMGhh0Wl9NeW1+7zxcQ5sY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=herbertland.com; spf=pass smtp.mailfrom=herbertland.com; dkim=pass (2048-bit key) header.d=herbertland.com header.i=@herbertland.com header.b=AO3hffKX; arc=none smtp.client-ip=74.125.82.48 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=herbertland.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=herbertland.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=herbertland.com header.i=@herbertland.com header.b="AO3hffKX" Received: by mail-dl1-f48.google.com with SMTP id a92af1059eb24-12732e6a123so1777966c88.1 for ; Sat, 14 Mar 2026 10:44:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=herbertland.com; s=google; t=1773510260; x=1774115060; 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=A6arbcjbT27jtKab9iAQCIQYW6MTuFeHR9L7LFxRYIY=; b=AO3hffKXEkJ6dpjALZtyWh7QzLIkqrzlNb33VWVmi1Nqg/Ym2jHvoy1FlDQj2luzqY 1/g9/TsbJK2E5/Lma+ei7lIETXEZCVFHmVsmtRC5UVh1tn46RifkPytAQ9LYZnwomlpf M3u5QF2eRN9I1RckzYMW2iVXAx1aIA09S+fT4qmV4sncKpEs0qiJd5RqH5OQv8Ov44uW TiT2jfGSjppbIJUg+4YLfAQaY7vKnIvmouMCNrWSKK2anS0Eq6XkJW7xz+dZBheulO/v ZKTMHIXgop2LDqMSo4m+c6hu7yzSRxdyntbyhFWVBc/8fer7XGrna1XSsKhWRSwh3kMR 2G4w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1773510260; x=1774115060; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=A6arbcjbT27jtKab9iAQCIQYW6MTuFeHR9L7LFxRYIY=; b=Lmk1dVdT6BfRzLl2YIEbTU9wAmYnpb0WcrAUJfQNLeGqhOLGWX/ISlxsNlav9oGe8S JbqGKON6Lr4u4KQGC/9Zki34yRhXFDphO7c5oAuxHaO++OV6Y0Oj7OYXaiBWkk0SvqhW UnqJQq/js/BWb3auHWP7BBAMz7F9BOlFLXabIIH2OfYMotNByisYZRQZvChxXZvW1QhV tNCY4fM9ziDhjdAXOLPdXREnIVZd2mFdaxPWnuK8AOSRC+I5eY7f+iQT76TqN2jCdjpR Ws1fpDdNVWxGIlU/mTWi/HUtunlokafPM+qjYRVAnZ+fftBEFEZctxhkVMBZiNHCCdg0 uu8A== X-Forwarded-Encrypted: i=1; AJvYcCVNkobsmxw9OgDPQc2opwQ2D1CsGTxeUeri6bNJbgLKwgULiwbumCyJNXZ2ge3nZaB7SKXimHM=@vger.kernel.org X-Gm-Message-State: AOJu0YxANRNnYFBOGa9p2YpkWY3q4iOzt3hDYvh4bk7N3yBZ+c0iQHV0 rBqRYexxxVsly/VOuDhu1ivA5Y0pICjdzFNPVdAbgBW/6tf5f1eQFjkgypUb5y+xPw== X-Gm-Gg: ATEYQzyPxnvZnxgOQT6XaM9XvpN4zgpH3jZ1cQI4LAQ7BwsuJvkYF08TZWa03Ny4kNR Vb97Rii0GiFeNebK7w9svkKLWSnSoZdyMtlY6PjCzpvwU0na5d9EupmxBwoSapFZddSzycpdhb6 iIhdr4TGpU2nUkCm4FKB+Kna9yHN7SyNtVijXi+NLd3RMYyJx3Wpvwygfo4HnDamjL8Ym/zUvE+ 76u7yq8oHzuBdvtE3W/oj+BPj088qp9IDiBVM9z5y3IQ3shWVNMKZj0lsSzaIKUdDjhf8jA9u/w lVtiYxcaB9b8b47gzfEl54JDjdpCknNhz6nQycfQz5gHrm7jofPcdshmRy1efsr1KsV/2vDxDY3 a1f1NSk+aNORPowXRvnSUzB6W0/sDXYU+s+SSLucIkIV9Wqit/VQJ3fPublHAf4ONoLKKGpMHlf 9Tg777GcBcTukFTf/wAojHLhPq360Et1bOXmkRsE1T5PsKZmwjEqF8a506EDoET6NTLjCIwQ== X-Received: by 2002:a05:7022:4186:b0:11b:88a7:e1b0 with SMTP id a92af1059eb24-128f3dc48a8mr3629234c88.26.1773510259679; Sat, 14 Mar 2026 10:44:19 -0700 (PDT) Received: from pong.herbertland.com ([2601:646:8980:b330:eb38:94c4:209f:a764]) by smtp.gmail.com with ESMTPSA id a92af1059eb24-128f62837ccsm8326734c88.3.2026.03.14.10.44.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 14 Mar 2026 10:44:19 -0700 (PDT) From: Tom Herbert To: davem@davemloft.net, kuba@kernel.org, netdev@vger.kernel.org, justin.iurman@uliege.be, willemdebruijn.kernel@gmail.com, pabeni@redhat.com Cc: Tom Herbert , Justin Iurman Subject: [net-next v8 05/10] ipv6: Document defaults for max_{dst|hbh}_opts_number sysctls Date: Sat, 14 Mar 2026 10:43:28 -0700 Message-ID: <20260314174333.46406-6-tom@herbertland.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260314174333.46406-1-tom@herbertland.com> References: <20260314174333.46406-1-tom@herbertland.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit In the descriptions of max_dst_opts_number and max_hbh_opts_number sysctls add text about how a zero setting means that a packet with any Destination or Hop-by-Hop options is dropped. Report the defaults for max_dst_opts_number and max_hbh_opts_number are 2 which means up to two options may be accepted. Signed-off-by: Tom Herbert Reviewed-by: Justin Iurman --- Documentation/networking/ip-sysctl.rst | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst index 2e3a746fcc6d..453643c70c8d 100644 --- a/Documentation/networking/ip-sysctl.rst +++ b/Documentation/networking/ip-sysctl.rst @@ -2511,19 +2511,25 @@ mld_qrv - INTEGER max_dst_opts_number - INTEGER Maximum number of non-padding TLVs allowed in a Destination - options extension header. If this value is less than zero - then unknown options are disallowed and the number of known - TLVs allowed is the absolute value of this number. + options extension header. If this value is zero then receive + Destination Options processing is disabled in which case packets + with the Destination Options extension header are dropped. If + this value is less than zero then unknown options are disallowed + and the number of known TLVs allowed is the absolute value of + this number. - Default: 8 + Default: 2 max_hbh_opts_number - INTEGER Maximum number of non-padding TLVs allowed in a Hop-by-Hop - options extension header. If this value is less than zero - then unknown options are disallowed and the number of known - TLVs allowed is the absolute value of this number. + options extension header. If this value is zero then receive + Hop-by-Hop Options processing is disabled in which case packets + with the Hop-by-Hop Options extension header are dropped. + If this value is less than zero then unknown options are disallowed + and the number of known TLVs allowed is the absolute value of this + number. - Default: 8 + Default: 2 max_dst_opts_length - INTEGER Maximum length allowed for a Destination options extension -- 2.43.0