From nobody Wed Feb 19 13:37:09 2025 X-Original-To: freebsd-java@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4Yycrq3BtJz5pNZp for ; Wed, 19 Feb 2025 13:37:31 +0000 (UTC) (envelope-from rb@gid.co.uk) Received: from gid2.gid.co.uk (ns0.gid.co.uk [IPv6:2001:470:94de::240]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "gid2.gid.co.uk", Issuer "gid2.gid.co.uk" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4Yycrp48lpz3SNR for ; Wed, 19 Feb 2025 13:37:30 +0000 (UTC) (envelope-from rb@gid.co.uk) Authentication-Results: mx1.freebsd.org; none Received: from mx0.gid.co.uk (mx0.gid.co.uk [194.32.164.250]) by gid2.gid.co.uk (8.15.2/8.15.2) with ESMTP id 51JDbQWu040549; Wed, 19 Feb 2025 13:37:26 GMT (envelope-from rb@gid.co.uk) Received: from smtpclient.apple (moriarty.gid.co.uk [194.32.164.17]) by mx0.gid.co.uk (8.14.2/8.14.2) with ESMTP id 51JDbKDr083600; Wed, 19 Feb 2025 13:37:21 GMT (envelope-from rb@gid.co.uk) Content-Type: multipart/signed; boundary="Apple-Mail=_B55B3E1C-A945-43D6-B4B8-1411B84C801E"; protocol="application/pgp-signature"; micalg=pgp-sha1 List-Id: Porting Java to FreeBSD List-Archive: https://lists.freebsd.org/archives/freebsd-java List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-java@FreeBSD.org Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3776.700.51.11.1\)) Subject: Re: IPv6 in Java on FreeBSD From: rb@gid.co.uk In-Reply-To: Date: Wed, 19 Feb 2025 13:37:09 +0000 Cc: FreeBSD Java mailing list Message-Id: <79B052D3-8A9F-4658-AD33-EDD26BBB1A34@gid.co.uk> References: To: Harald Eilertsen X-Mailer: Apple Mail (2.3776.700.51.11.1) X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:6939, ipnet:2001:470::/32, country:US] X-Rspamd-Queue-Id: 4Yycrp48lpz3SNR X-Spamd-Bar: ---- --Apple-Mail=_B55B3E1C-A945-43D6-B4B8-1411B84C801E Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 Hi, There are also security implications to this, see inet6(4). > On 19 Feb 2025, at 13:25, Harald Eilertsen = wrote: >=20 > Hi Bob, >=20 > On Wed, Feb 19, 2025 at 12:26:17PM +0000, Bob Bishop wrote: >> I would just point out that back in history Java used to want mapped >> IPv4 (net.inet6.ip6.v6only=3D0) if IPv6 was enabled; most people = don=E2=80=99t >> want that which may be why IPv6 support hasn=E2=80=99t been enabled. >=20 > That's really useful feedback! And the observation is still correct. > Java will by default clear the IPV6_V6ONLY flag on sockets when IPv6 = is > available and requested (the default.) >=20 > I've made a quick test, where I patch Java to leave the setting alone, > but otherwise leave IPv6 enabled. That will allow the sysctl setting = to > decide whether to use dual-socket or only accept IPv6 connections on = the > socket. >=20 > Personally I think that makes sense. I'll update the PR's accordingly. >=20 > Take care! > Harald >=20 -- Bob Bishop rb@gid.co.uk --Apple-Mail=_B55B3E1C-A945-43D6-B4B8-1411B84C801E Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=signature.asc Content-Type: application/pgp-signature; name=signature.asc Content-Description: Message signed with OpenPGP -----BEGIN PGP SIGNATURE----- iF0EARECAB0WIQR+a6Wh87I/iYwcbE+8xpPppLfFvwUCZ7XehgAKCRC8xpPppLfF v09CAJ4p0Xu4UOsoxM9rj1tbNVKjaUrfQwCePG2OMlPYcYuHVGlE/NzsD2QxOu8= =5fw9 -----END PGP SIGNATURE----- --Apple-Mail=_B55B3E1C-A945-43D6-B4B8-1411B84C801E--