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 44A2032274C; Mon, 18 Aug 2025 13:32:14 +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=1755523935; cv=none; b=unJYAtVUvkqqCihhhect5qZzxvHS9I0WJYS7g1rAUEDpEwuKEkfJJEU1sP+SqKywTOLTo3+GUqj2L3ssXu+wAtKZlkqZIsm+hu1ZvHccfuku0eoeQu9MvKl5/XlmpAHiKNeBSo0YAil/xtDLoss/zOxqQqAT6cEQXpXyRvSurgc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755523935; c=relaxed/simple; bh=/PmaUWA8Ipn7vfgTRwiRR1X70wsQe5akPQz7gKFETjU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=a+RK3rJ4d2irk9n33PfBzfbmUhYG7onPVi2dikHVPuzqUm70uKj9+YEEVJPsbpGUFBQKWM7uvGNUfxjGNO0m7F7UXhbeUzYLIjIlPYDaHHuxJKOgPzjfp+O6FIy0fbPoHZ0wFqdKI4rGEVsugqEnggaO0mgB7QMzSfzXuLFaNAs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=OsvN/B1S; 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="OsvN/B1S" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 653A6C4CEEB; Mon, 18 Aug 2025 13:32:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1755523934; bh=/PmaUWA8Ipn7vfgTRwiRR1X70wsQe5akPQz7gKFETjU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OsvN/B1S5w5/tXHrF1X5GJA+sbqrPAFlYrfqYrngxk74isoHFQwRS9YJfdPHfcqMn X6AgOW+BgcEftKHMSlUEoEApCVM+dz4XX3x/AVGo8rqBnkK2KgvcPaC2dMaSh5JD/1 flZZgC0SiH4W0caVa/VcsyusbqkZ0cympsih7u9c= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jakub Kicinski , Sasha Levin Subject: [PATCH 6.15 317/515] uapi: in6: restore visibility of most IPv6 socket options Date: Mon, 18 Aug 2025 14:45:03 +0200 Message-ID: <20250818124510.636906816@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250818124458.334548733@linuxfoundation.org> References: <20250818124458.334548733@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 6.15-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 ff8d21f9e95b..5a47339ef7d7 100644 --- a/include/uapi/linux/in6.h +++ b/include/uapi/linux/in6.h @@ -152,7 +152,6 @@ struct in6_flowlabel_req { /* * IPV6 socket options */ -#if __UAPI_DEF_IPV6_OPTIONS #define IPV6_ADDRFORM 1 #define IPV6_2292PKTINFO 2 #define IPV6_2292HOPOPTS 3 @@ -169,8 +168,10 @@ 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 @@ -203,7 +204,6 @@ struct in6_flowlabel_req { #define IPV6_IPSEC_POLICY 34 #define IPV6_XFRM_POLICY 35 #define IPV6_HDRINCL 36 -#endif /* * Multicast: -- 2.39.5