From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0CD8F2BE058; Tue, 26 Aug 2025 14:17:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756217824; cv=none; b=fsExGcy4IoB8p+HIVN4qJoa6EU75vk7eSIzhXqrsaHXQgj8vJP1JiqyTblrdy1I/yQDfOD1avIeTtI2HEtfXxtw1/U1WI3/iWwlatzXn/EwbxsiQmxhFRx37KfVTnckLa7dziQXG9n/ja9jdG/VgcKbHxEt/TPmqn2KI9/Ier9k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756217824; c=relaxed/simple; bh=IopkWH9+e/W55DZrRFByNeRKdYJBDk78j9z8dXLCZz8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=bZfdFpxQy6sghlJjjKr4dmU5S3S/7WQfS74SR9RaX5QqontdjLmwPCpNTEeXW+PgCHOdLZL3HdYA11zvB4M9HzS3gu1fFJmwqkBDzGByl45SYhGReZmBmJneOS0e/NfRgcWw3bx9Y8iiFG+7+GvV8m9LOUJ7/wPVx0M00uhV/iI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=z+NGAYrG; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="z+NGAYrG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 910C7C113CF; Tue, 26 Aug 2025 14:17:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1756217823; bh=IopkWH9+e/W55DZrRFByNeRKdYJBDk78j9z8dXLCZz8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=z+NGAYrGXcNaygevTsyRmMkVVAw7k/xbsvse31C4LBbJ4srUKU2qmHd16RM64qTqZ MUCuQBu0vfeyKhhDvljJlvjxt9FXP7QsBi5PDksp24/2i4r089gAZoWq2MI/3Lcdul +1LA+QlL5XxOEFHn40aZtcxUvuKBLVXSKja43VZ0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jakub Kicinski , Sasha Levin Subject: [PATCH 5.10 288/523] uapi: in6: restore visibility of most IPv6 socket options Date: Tue, 26 Aug 2025 13:08:18 +0200 Message-ID: <20250826110931.549270375@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250826110924.562212281@linuxfoundation.org> References: <20250826110924.562212281@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jakub Kicinski [ Upstream commit 31557b3487b349464daf42bc4366153743c1e727 ] A decade ago commit 6d08acd2d32e ("in6: fix conflict with glibc") hid the definitions of IPV6 options, because GCC was complaining about duplicates. The commit did not list the warnings seen, but trying to recreate them now I think they are (building iproute2): In file included from ./include/uapi/rdma/rdma_user_cm.h:39, from rdma.h:16, from res.h:9, from res-ctx.c:7: ../include/uapi/linux/in6.h:171:9: warning: ‘IPV6_ADD_MEMBERSHIP’ redefined 171 | #define IPV6_ADD_MEMBERSHIP 20 | ^~~~~~~~~~~~~~~~~~~ In file included from /usr/include/netinet/in.h:37, from rdma.h:13: /usr/include/bits/in.h:233:10: note: this is the location of the previous definition 233 | # define IPV6_ADD_MEMBERSHIP IPV6_JOIN_GROUP | ^~~~~~~~~~~~~~~~~~~ ../include/uapi/linux/in6.h:172:9: warning: ‘IPV6_DROP_MEMBERSHIP’ redefined 172 | #define IPV6_DROP_MEMBERSHIP 21 | ^~~~~~~~~~~~~~~~~~~~ /usr/include/bits/in.h:234:10: note: this is the location of the previous definition 234 | # define IPV6_DROP_MEMBERSHIP IPV6_LEAVE_GROUP | ^~~~~~~~~~~~~~~~~~~~ Compilers don't complain about redefinition if the defines are identical, but here we have the kernel using the literal value, and glibc using an indirection (defining to a name of another define, with the same numerical value). Problem is, the commit in question hid all the IPV6 socket options, and glibc has a pretty sparse list. For instance it lacks Flow Label related options. Willem called this out in commit 3fb321fde22d ("selftests/net: ipv6 flowlabel"): /* uapi/glibc weirdness may leave this undefined */ #ifndef IPV6_FLOWINFO #define IPV6_FLOWINFO 11 #endif More interestingly some applications (socat) use a #ifdef IPV6_FLOWINFO to gate compilation of thier rudimentary flow label support. (For added confusion socat misspells it as IPV4_FLOWINFO in some places.) Hide only the two defines we know glibc has a problem with. If we discover more warnings we can hide more but we should avoid covering the entire block of defines for "IPV6 socket options". Link: https://patch.msgid.link/20250609143933.1654417-1-kuba@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- include/uapi/linux/in6.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/uapi/linux/in6.h b/include/uapi/linux/in6.h index 5ad396a57eb3..327fd76c0962 100644 --- a/include/uapi/linux/in6.h +++ b/include/uapi/linux/in6.h @@ -151,7 +151,6 @@ struct in6_flowlabel_req { /* * IPV6 socket options */ -#if __UAPI_DEF_IPV6_OPTIONS #define IPV6_ADDRFORM 1 #define IPV6_2292PKTINFO 2 #define IPV6_2292HOPOPTS 3 @@ -168,8 +167,10 @@ struct in6_flowlabel_req { #define IPV6_MULTICAST_IF 17 #define IPV6_MULTICAST_HOPS 18 #define IPV6_MULTICAST_LOOP 19 +#if __UAPI_DEF_IPV6_OPTIONS #define IPV6_ADD_MEMBERSHIP 20 #define IPV6_DROP_MEMBERSHIP 21 +#endif #define IPV6_ROUTER_ALERT 22 #define IPV6_MTU_DISCOVER 23 #define IPV6_MTU 24 @@ -202,7 +203,6 @@ struct in6_flowlabel_req { #define IPV6_IPSEC_POLICY 34 #define IPV6_XFRM_POLICY 35 #define IPV6_HDRINCL 36 -#endif /* * Multicast: -- 2.39.5