From patchwork Fri Nov 20 09:26:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmytro Shytyi X-Patchwork-Id: 11919775 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AF7A7C5519F for ; Fri, 20 Nov 2020 09:27:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4778222264 for ; Fri, 20 Nov 2020 09:27:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=shytyi.net header.i=dmytro@shytyi.net header.b="TnOkOS3V" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727241AbgKTJ0v (ORCPT ); Fri, 20 Nov 2020 04:26:51 -0500 Received: from sender11-of-o52.zoho.eu ([31.186.226.238]:21381 "EHLO sender11-of-o52.zoho.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725942AbgKTJ0t (ORCPT ); Fri, 20 Nov 2020 04:26:49 -0500 ARC-Seal: i=1; a=rsa-sha256; t=1605864367; cv=none; d=zohomail.eu; s=zohoarc; b=DfwoevSeLwJHUFoHlc2BIDBj1x0PTsfCvenuoueT2wGSRXGI8s7YPmdmhjIX9DhL66RVhQ9gIu1JjtAkc4AK2j8A37t6+RpGChpH/+31ipIXivv7fVRLlo+RCJrOB6vf+PVQwRs3+7pTpij8BYSvGfxE+enFAUuS+FLZ7qUuDMc= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.eu; s=zohoarc; t=1605864367; h=Content-Type:Content-Transfer-Encoding:Date:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:To; bh=Q1Z7u3/19piKh5TPP33XogbleV1eFFi1/M1BOUwPw0M=; b=Gd3oqU3Qa6ysNlnDdFd2DdvEpYa+LAVQiDtZEmQdPLgRKw4+l96hxS8vWYJKm6punKGGShjm5HfxBYLSWdxiSzzxRn6TlshjwJMXKbzXhHcVJ3VWbJtuDZ7EgGfAAoYr9zgixpsd5Jw11qEzR3Eo99s5IgtKUSwNfG8KrKTtp5s= ARC-Authentication-Results: i=1; mx.zohomail.eu; dkim=pass header.i=shytyi.net; spf=pass smtp.mailfrom=dmytro@shytyi.net; dmarc=pass header.from= header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1605864367; s=hs; d=shytyi.net; i=dmytro@shytyi.net; h=Date:From:To:Message-ID:In-Reply-To:References:Subject:MIME-Version:Content-Type:Content-Transfer-Encoding; bh=Q1Z7u3/19piKh5TPP33XogbleV1eFFi1/M1BOUwPw0M=; b=TnOkOS3VB2Tr+kyM1vZSOinWvy6eKVQoZ4w+U91UW/5Mc+BZxq66kzNsAMWvEqS8 kQj2/+kY+tJEu5YHSPf8xhTNv1bMZfmLvjpJkjoiLgwzgmeZaoHptZmNjSwlLfsevUr O7TxKzWcT7OtM3DtdsoLK1EA6/FmR8p76EXRYnjg= Received: from mail.zoho.eu by mx.zoho.eu with SMTP id 1605864361499137.62084601263723; Fri, 20 Nov 2020 10:26:01 +0100 (CET) Date: Fri, 20 Nov 2020 10:26:01 +0100 From: Dmytro Shytyi To: "Jakub Kicinski" , "yoshfuji" , "kuznet" , "liuhangbin" , "davem" , "netdev" , "linux-kernel" Message-ID: <175e4f98e19.bcccf9b7450965.5991300381666674110@shytyi.net> In-Reply-To: <175e1fdb250.1207dca53446410.2492811916841931466@shytyi.net> References: <175b3433a4c.aea7c06513321.4158329434310691736@shytyi.net> <202011110944.7zNVZmvB-lkp@intel.com> <175bd218cf4.103c639bc117278.4209371191555514829@shytyi.net> <175bf515624.c67e02e8130655.7824060160954233592@shytyi.net> <175c31c6260.10eef97f6180313.755036504412557273@shytyi.net> <20201117124348.132862b1@kicinski-fedora-PC1C0HJN.hsd1.ca.comcast.net> <175e0b9826b.c3bb0aae425910.5834444036489233360@shytyi.net> <20201119104413.75ca9888@kicinski-fedora-PC1C0HJN.hsd1.ca.comcast.net> <175e1fdb250.1207dca53446410.2492811916841931466@shytyi.net> Subject: [PATCH net-next V7] net: Variable SLAAC: SLAAC with prefixes of arbitrary length in PIO MIME-Version: 1.0 Importance: Medium User-Agent: Zoho Mail X-Mailer: Zoho Mail Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org Variable SLAAC: SLAAC with prefixes of arbitrary length in PIO (randomly generated hostID or stable privacy + privacy extensions). The main problem is that SLAAC RA or PD allocates a /64 by the Wireless carrier 4G, 5G to a mobile hotspot, however segmentation of the /64 via SLAAC is required so that downstream interfaces can be further subnetted. Example: uCPE device (4G + WI-FI enabled) receives /64 via Wireless, and assigns /72 to VNF-Firewall, /72 to WIFI, /72 to VNF-Router, /72 to Load-Balancer and /72 to wired connected devices. IETF document that defines problem statement: draft-mishra-v6ops-variable-slaac-problem-stmt IETF document that specifies variable slaac: draft-mishra-6man-variable-slaac Signed-off-by: Dmytro Shytyi diff -rupN net-next-5.10.0-rc2/net/ipv6/addrconf.c net-next-patch-5.10.0-rc2/net/ipv6/addrconf.c --- net-next-5.10.0-rc2/net/ipv6/addrconf.c 2020-11-10 08:46:01.075193379 +0100 +++ net-next-patch-5.10.0-rc2/net/ipv6/addrconf.c 2020-11-19 21:26:39.770872898 +0100 @@ -142,7 +142,6 @@ static int ipv6_count_addresses(const st static int ipv6_generate_stable_address(struct in6_addr *addr, u8 dad_count, const struct inet6_dev *idev); - #define IN6_ADDR_HSIZE_SHIFT 8 #define IN6_ADDR_HSIZE (1 << IN6_ADDR_HSIZE_SHIFT) /* @@ -1315,6 +1314,7 @@ static int ipv6_create_tempaddr(struct i struct ifa6_config cfg; long max_desync_factor; struct in6_addr addr; + struct in6_addr temp; int ret = 0; write_lock_bh(&idev->lock); @@ -1340,9 +1340,16 @@ retry: goto out; } in6_ifa_hold(ifp); - memcpy(addr.s6_addr, ifp->addr.s6_addr, 8); - ipv6_gen_rnd_iid(&addr); + if (ifp->prefix_len == 64) { + memcpy(addr.s6_addr, ifp->addr.s6_addr, 8); + ipv6_gen_rnd_iid(&addr); + } else if (ifp->prefix_len > 0 && ifp->prefix_len <= 128) { + memcpy(addr.s6_addr32, ifp->addr.s6_addr, 16); + get_random_bytes(temp.s6_addr32, 16); + ipv6_addr_prefix_copy(&temp, &addr, ifp->prefix_len); + memcpy(addr.s6_addr, temp.s6_addr, 16); + } age = (now - ifp->tstamp) / HZ; regen_advance = idev->cnf.regen_max_retry * @@ -2569,6 +2576,41 @@ static bool is_addr_mode_generate_stable idev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_RANDOM; } +static struct inet6_ifaddr *ipv6_cmp_rcvd_prsnt_prfxs(struct inet6_ifaddr *ifp, + struct inet6_dev *in6_dev, + struct net *net, + const struct prefix_info *pinfo) +{ + struct inet6_ifaddr *result_base = NULL; + struct inet6_ifaddr *result = NULL; + struct in6_addr curr_net_prfx; + struct in6_addr net_prfx; + bool prfxs_equal; + + result_base = result; + rcu_read_lock(); + list_for_each_entry_rcu(ifp, &in6_dev->addr_list, if_list) { + if (!net_eq(dev_net(ifp->idev->dev), net)) + continue; + ipv6_addr_prefix_copy(&net_prfx, &pinfo->prefix, pinfo->prefix_len); + ipv6_addr_prefix_copy(&curr_net_prfx, &ifp->addr, pinfo->prefix_len); + prfxs_equal = + ipv6_prefix_equal(&net_prfx, &curr_net_prfx, pinfo->prefix_len); + if (prfxs_equal && pinfo->prefix_len == ifp->prefix_len) { + result = ifp; + in6_ifa_hold(ifp); + break; + } + } + rcu_read_unlock(); + if (result_base != result) + ifp = result; + else + ifp = NULL; + + return ifp; +} + int addrconf_prefix_rcv_add_addr(struct net *net, struct net_device *dev, const struct prefix_info *pinfo, struct inet6_dev *in6_dev, @@ -2576,9 +2618,16 @@ int addrconf_prefix_rcv_add_addr(struct u32 addr_flags, bool sllao, bool tokenized, __u32 valid_lft, u32 prefered_lft) { - struct inet6_ifaddr *ifp = ipv6_get_ifaddr(net, addr, dev, 1); + struct inet6_ifaddr *ifp = NULL; + int plen = pinfo->prefix_len; int create = 0; + if (plen > 0 && plen <= 128 && plen != 64 && + in6_dev->cnf.addr_gen_mode != IN6_ADDR_GEN_MODE_STABLE_PRIVACY) + ifp = ipv6_cmp_rcvd_prsnt_prfxs(ifp, in6_dev, net, pinfo); + else + ifp = ipv6_get_ifaddr(net, addr, dev, 1); + if (!ifp && valid_lft) { int max_addresses = in6_dev->cnf.max_addresses; struct ifa6_config cfg = { @@ -2657,6 +2706,91 @@ int addrconf_prefix_rcv_add_addr(struct } EXPORT_SYMBOL_GPL(addrconf_prefix_rcv_add_addr); +static bool ipv6_reserved_interfaceid(struct in6_addr address) +{ + if ((address.s6_addr32[2] | address.s6_addr32[3]) == 0) + return true; + + if (address.s6_addr32[2] == htonl(0x02005eff) && + ((address.s6_addr32[3] & htonl(0xfe000000)) == htonl(0xfe000000))) + return true; + + if (address.s6_addr32[2] == htonl(0xfdffffff) && + ((address.s6_addr32[3] & htonl(0xffffff80)) == htonl(0xffffff80))) + return true; + + return false; +} + +static int ipv6_gen_addr_var_plen(struct in6_addr *address, + u8 dad_count, + const struct inet6_dev *idev, + unsigned int rcvd_prfx_len, + bool stable_privacy_mode) +{ + static union { + char __data[SHA1_BLOCK_SIZE]; + struct { + struct in6_addr secret; + __be32 prefix[2]; + unsigned char hwaddr[MAX_ADDR_LEN]; + u8 dad_count; + } __packed; + } data; + static __u32 workspace[SHA1_WORKSPACE_WORDS]; + static __u32 digest[SHA1_DIGEST_WORDS]; + struct net *net = dev_net(idev->dev); + static DEFINE_SPINLOCK(lock); + struct in6_addr secret; + struct in6_addr temp; + + BUILD_BUG_ON(sizeof(data.__data) != sizeof(data)); + + if (stable_privacy_mode) { + if (idev->cnf.stable_secret.initialized) + secret = idev->cnf.stable_secret.secret; + else if (net->ipv6.devconf_dflt->stable_secret.initialized) + secret = net->ipv6.devconf_dflt->stable_secret.secret; + else + return -1; + } + +retry: + spin_lock_bh(&lock); + if (stable_privacy_mode) { + sha1_init(digest); + memset(&data, 0, sizeof(data)); + memset(workspace, 0, sizeof(workspace)); + memcpy(data.hwaddr, idev->dev->perm_addr, idev->dev->addr_len); + data.prefix[0] = address->s6_addr32[0]; + data.prefix[1] = address->s6_addr32[1]; + data.secret = secret; + data.dad_count = dad_count; + + sha1_transform(digest, data.__data, workspace); + + temp = *address; + temp.s6_addr32[0] = (__force __be32)digest[0]; + temp.s6_addr32[1] = (__force __be32)digest[1]; + temp.s6_addr32[2] = (__force __be32)digest[2]; + temp.s6_addr32[3] = (__force __be32)digest[3]; + } else { + temp = *address; + get_random_bytes(temp.s6_addr32, 16); + } + spin_unlock_bh(&lock); + + if (ipv6_reserved_interfaceid(temp)) { + dad_count++; + if (dad_count > dev_net(idev->dev)->ipv6.sysctl.idgen_retries) + return -1; + goto retry; + } + ipv6_addr_prefix_copy(&temp, address, rcvd_prfx_len); + *address = temp; + return 0; +} + void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len, bool sllao) { struct prefix_info *pinfo; @@ -2781,9 +2915,33 @@ void addrconf_prefix_rcv(struct net_devi dev_addr_generated = true; } goto ok; + } else if (pinfo->prefix_len != 64 && + pinfo->prefix_len > 0 && pinfo->prefix_len <= 128) { + /* SLAAC with prefixes of arbitrary length (Variable SLAAC). + * draft-mishra-6man-variable-slaac + * draft-mishra-v6ops-variable-slaac-problem-stmt + */ + memcpy(&addr, &pinfo->prefix, 16); + if (in6_dev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_STABLE_PRIVACY) { + if (!ipv6_gen_addr_var_plen(&addr, + 0, + in6_dev, + pinfo->prefix_len, + true)) { + addr_flags |= IFA_F_STABLE_PRIVACY; + goto ok; + } + } else if (!ipv6_gen_addr_var_plen(&addr, + 0, + in6_dev, + pinfo->prefix_len, + false)) { + goto ok; + } + } else { + net_dbg_ratelimited("IPv6: Prefix with unexpected length %d\n", + pinfo->prefix_len); } - net_dbg_ratelimited("IPv6 addrconf: prefix with wrong length %d\n", - pinfo->prefix_len); goto put; ok: @@ -3186,22 +3344,6 @@ void addrconf_add_linklocal(struct inet6 } EXPORT_SYMBOL_GPL(addrconf_add_linklocal); -static bool ipv6_reserved_interfaceid(struct in6_addr address) -{ - if ((address.s6_addr32[2] | address.s6_addr32[3]) == 0) - return true; - - if (address.s6_addr32[2] == htonl(0x02005eff) && - ((address.s6_addr32[3] & htonl(0xfe000000)) == htonl(0xfe000000))) - return true; - - if (address.s6_addr32[2] == htonl(0xfdffffff) && - ((address.s6_addr32[3] & htonl(0xffffff80)) == htonl(0xffffff80))) - return true; - - return false; -} - static int ipv6_generate_stable_address(struct in6_addr *address, u8 dad_count, const struct inet6_dev *idev)