From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout-b-210.mailbox.org (mout-b-210.mailbox.org [195.10.208.40]) (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 B2F413D3481; Thu, 19 Mar 2026 15:22:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.10.208.40 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773933750; cv=none; b=BXLSkawsdvPHXOQrzo5qe+FzwNLi/7081ptoWxe4+k5JerefiURxa5xIy8w1hUuiNhAIrAD0OCrIEFDw//eZLZ90rgkBRmZutcNeOniTgbLYh33gxO9xpJJdE9w+/xjGZrNgB7c2RplBOiHwQVoJ5FkExuKV7viUL+IakV2Ujcs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773933750; c=relaxed/simple; bh=iTO4e6EY6LzuRBmdnlWNtywEwzjsLcLwOY1vsh6w6X8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ndRFJARN/7DgjyNpCFvW5ou4Pcy1vcpYxBmX/5BH04qtgTx3KUrkh+vLUXjJwfAgLZds7dtoo6RB6CS7Y8h+SnRVsOgFGMK80rkUnpDeMYDH3I08IIJE++wiH6kE2jp6/LIe5KAyVWbv/tdeANQditzuUUonfnEt+iDeNrsa5lA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=mandelbit.com; spf=pass smtp.mailfrom=mandelbit.com; dkim=pass (2048-bit key) header.d=mandelbit.com header.i=@mandelbit.com header.b=Afz5ifqR; arc=none smtp.client-ip=195.10.208.40 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=mandelbit.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mandelbit.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mandelbit.com header.i=@mandelbit.com header.b="Afz5ifqR" Received: from smtp102.mailbox.org (smtp102.mailbox.org [10.196.197.102]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-b-210.mailbox.org (Postfix) with ESMTPS id 4fc8MY5hxkzDqrQ; Thu, 19 Mar 2026 16:12:57 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mandelbit.com; s=MBO0001; t=1773933177; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0icos2ZBtUrsLwF58QCrTkTKUVqnIISU3RcxMFUjpAk=; b=Afz5ifqR/m3cvYhcAV+HV4VQFRBdnEgoxSlYhlEr/XS8DszzK3uqn6OeG3FT1rsJgWFDvJ PvlHyxjyrZmf5kate0iMR0mTVI8cZOZSFjY1K3+y7pOWW+bOEBSlJ/SeJfV2f/RNNvlpGj fHelUymu7cCSQ41qd2KR37p8hKj5BwTGkDRzLllSXuSTjaOcYVYPl+sQohM2dQWuROrK0f HpIUAAJ+MiXtii4JI9rH08xHqbKHgDwjLeP74tnP5COxxZj8gpMMG6fP1OpmQGuIwCXZ6M hh5uTD85JKWDOKOpZhgcDNA4niIreOLkdfnhH9U7YPD3i9fzTk3K978ucpxCrQ== From: Ralf Lici To: netdev@vger.kernel.org Cc: =?UTF-8?q?Daniel=20Gr=C3=B6ber?= , Ralf Lici , Antonio Quartulli , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , linux-kernel@vger.kernel.org Subject: [RFC net-next 02/15] ipxlat: add RFC 6052 address conversion helpers Date: Thu, 19 Mar 2026 16:12:11 +0100 Message-ID: <20260319151230.655687-3-ralf@mandelbit.com> In-Reply-To: <20260319151230.655687-1-ralf@mandelbit.com> References: <20260319151230.655687-1-ralf@mandelbit.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Introduce IPv4/IPv6 stateless address mapping helpers used by the translation pipeline. Add the core 4<->6 conversion routines, including RFC 6052 prefix embedding/extraction and the RFC 6791 fallback source selection logic used by ICMP translation paths. Signed-off-by: Ralf Lici --- drivers/net/ipxlat/Makefile | 1 + drivers/net/ipxlat/address.c | 132 +++++++++++++++++++++++++++++++++++ drivers/net/ipxlat/address.h | 59 ++++++++++++++++ 3 files changed, 192 insertions(+) create mode 100644 drivers/net/ipxlat/address.c create mode 100644 drivers/net/ipxlat/address.h diff --git a/drivers/net/ipxlat/Makefile b/drivers/net/ipxlat/Makefile index bd48c2700bf5..b6367dedd78e 100644 --- a/drivers/net/ipxlat/Makefile +++ b/drivers/net/ipxlat/Makefile @@ -5,3 +5,4 @@ obj-$(CONFIG_IPXLAT) := ipxlat.o ipxlat-objs += main.o +ipxlat-objs += address.o diff --git a/drivers/net/ipxlat/address.c b/drivers/net/ipxlat/address.c new file mode 100644 index 000000000000..d1a2b7d1768f --- /dev/null +++ b/drivers/net/ipxlat/address.c @@ -0,0 +1,132 @@ +// SPDX-License-Identifier: GPL-2.0 +/* IPXLAT - Stateless IP/ICMP Translation (SIIT) virtual device driver + * + * Copyright (C) 2024- Alberto Leiva Popper + * Copyright (C) 2026- Mandelbit SRL + * Copyright (C) 2026- Daniel Gröber + * + * Author: Alberto Leiva Popper + * Antonio Quartulli + * Daniel Gröber + * Ralf Lici + */ + +#include "address.h" + +static bool ipxlat_prefix6_contains(const struct ipv6_prefix *prefix, + const struct in6_addr *addr) +{ + return ipv6_prefix_equal(&prefix->addr, addr, prefix->len); +} + +static __be32 ipxlat_64_extract_addr(const struct in6_addr *src, + unsigned int q1, unsigned int q2, + unsigned int q3, unsigned int q4) +{ + q1 = src->s6_addr[q1]; + q2 = src->s6_addr[q2]; + q3 = src->s6_addr[q3]; + q4 = src->s6_addr[q4]; + return htonl((q1 << 24) | (q2 << 16) | (q3 << 8) | q4); +} + +static void ipxlat_46_embed_addr(__be32 __src, struct in6_addr *dst, + unsigned int q1, unsigned int q2, + unsigned int q3, unsigned int q4) +{ + u32 src = ntohl(__src); + + dst->s6_addr[q1] = ((src >> 24) & 0xFF); + dst->s6_addr[q2] = ((src >> 16) & 0xFF); + dst->s6_addr[q3] = ((src >> 8) & 0xFF); + dst->s6_addr[q4] = ((src) & 0xFF); +} + +void ipxlat_46_convert_addr(const struct ipv6_prefix *xlat_prefix6, + __be32 addr4, struct in6_addr *addr6) +{ + *addr6 = xlat_prefix6->addr; + + switch (xlat_prefix6->len) { + case 96: + addr6->s6_addr32[3] = addr4; + return; + case 64: + ipxlat_46_embed_addr(addr4, addr6, 9, 10, 11, 12); + return; + case 56: + ipxlat_46_embed_addr(addr4, addr6, 7, 9, 10, 11); + return; + case 48: + ipxlat_46_embed_addr(addr4, addr6, 6, 7, 9, 10); + return; + case 40: + ipxlat_46_embed_addr(addr4, addr6, 5, 6, 7, 9); + return; + case 32: + addr6->s6_addr32[1] = addr4; + return; + } + + DEBUG_NET_WARN_ON_ONCE(1); +} + +int ipxlat_64_convert_addrs(const struct ipv6_prefix *xlat_prefix6, + const struct ipv6hdr *hdr6, bool icmp_err, + __be32 *src, __be32 *dst) +{ + bool src_ok; + + src_ok = ipxlat_prefix6_contains(xlat_prefix6, &hdr6->saddr); + if (unlikely(!src_ok && !icmp_err)) + return -EINVAL; + if (unlikely(!ipxlat_prefix6_contains(xlat_prefix6, &hdr6->daddr))) + return -EINVAL; + + switch (xlat_prefix6->len) { + case 96: + if (likely(src_ok)) + *src = hdr6->saddr.s6_addr32[3]; + *dst = hdr6->daddr.s6_addr32[3]; + break; + case 64: + if (likely(src_ok)) + *src = ipxlat_64_extract_addr(&hdr6->saddr, 9, 10, 11, + 12); + *dst = ipxlat_64_extract_addr(&hdr6->daddr, 9, 10, 11, 12); + break; + case 56: + if (likely(src_ok)) + *src = ipxlat_64_extract_addr(&hdr6->saddr, 7, + 9, 10, 11); + *dst = ipxlat_64_extract_addr(&hdr6->daddr, 7, 9, 10, 11); + break; + case 48: + if (likely(src_ok)) + *src = ipxlat_64_extract_addr(&hdr6->saddr, 6, + 7, 9, 10); + *dst = ipxlat_64_extract_addr(&hdr6->daddr, 6, 7, 9, 10); + break; + case 40: + if (likely(src_ok)) + *src = ipxlat_64_extract_addr(&hdr6->saddr, 5, 6, 7, 9); + *dst = ipxlat_64_extract_addr(&hdr6->daddr, 5, 6, 7, 9); + break; + case 32: + if (likely(src_ok)) + *src = hdr6->saddr.s6_addr32[1]; + *dst = hdr6->daddr.s6_addr32[1]; + break; + default: + DEBUG_NET_WARN_ON_ONCE(1); + return -EINVAL; + } + + /* keep 6->4 ICMP error translation functional even when the ICMPv6 + * source is not xlat_prefix6-mapped (for example, stack-generated PTB) + */ + if (unlikely(!src_ok)) + *src = htonl(INADDR_DUMMY); + + return 0; +} diff --git a/drivers/net/ipxlat/address.h b/drivers/net/ipxlat/address.h new file mode 100644 index 000000000000..4283fdddac56 --- /dev/null +++ b/drivers/net/ipxlat/address.h @@ -0,0 +1,59 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* IPXLAT - Stateless IP/ICMP Translation (SIIT) virtual device driver + * + * Copyright (C) 2024- Alberto Leiva Popper + * Copyright (C) 2026- Mandelbit SRL + * Copyright (C) 2026- Daniel Gröber + * + * Author: Alberto Leiva Popper + * Antonio Quartulli + * Daniel Gröber + * Ralf Lici + */ + +#ifndef _NET_IPXLAT_ADDRESS_H_ +#define _NET_IPXLAT_ADDRESS_H_ + +#include +#include + +#include "ipxlpriv.h" + +/** + * ipxlat_46_convert_addr - translate one IPv4 address into RFC 6052 IPv6 form + * @xlat_prefix6: configured RFC 6052 prefix + * @addr4: IPv4 address to convert + * @addr6: output IPv6 address + */ +void ipxlat_46_convert_addr(const struct ipv6_prefix *xlat_prefix6, + __be32 addr4, struct in6_addr *addr6); + +/** + * ipxlat_64_convert_addrs - translate outer IPv6 endpoints into IPv4 pair + * @xlat_prefix6: configured RFC 6052 prefix + * @hdr6: source IPv6 header + * @icmp_err: source packet is ICMPv6 error + * @src: output IPv4 source address + * @dst: output IPv4 destination address + * + * Return: 0 on success, negative errno on non-translatable addresses. + */ +int ipxlat_64_convert_addrs(const struct ipv6_prefix *xlat_prefix6, + const struct ipv6hdr *hdr6, bool icmp_err, + __be32 *src, __be32 *dst); + +/** + * ipxlat_46_convert_addrs - translate outer IPv4 endpoints into IPv6 pair + * @xlat_prefix6: configured RFC 6052 prefix + * @iph4: source IPv4 header + * @iph6: output IPv6 header (only saddr/daddr are updated) + */ +static inline void +ipxlat_46_convert_addrs(const struct ipv6_prefix *xlat_prefix6, + const struct iphdr *iph4, struct ipv6hdr *iph6) +{ + ipxlat_46_convert_addr(xlat_prefix6, iph4->saddr, &iph6->saddr); + ipxlat_46_convert_addr(xlat_prefix6, iph4->daddr, &iph6->daddr); +} + +#endif /* _NET_IPXLAT_ADDRESS_H_ */ -- 2.53.0