From patchwork Wed Dec 8 17:38:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Lunn X-Patchwork-Id: 12664933 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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BC09AC433F5 for ; Wed, 8 Dec 2021 17:39:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232953AbhLHRmt (ORCPT ); Wed, 8 Dec 2021 12:42:49 -0500 Received: from vps0.lunn.ch ([185.16.172.187]:46014 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238580AbhLHRmU (ORCPT ); Wed, 8 Dec 2021 12:42:20 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:From:Sender:Reply-To:Subject:Date: Message-ID:To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Content-Disposition:In-Reply-To:References; bh=zZhEg393bQHegjBU9DittoyGG4fweeLFP2n4A/jAM3U=; b=VmpXPnrRGQGPg1HHzWUpRuG+LP 9c+5R1kDIzsqOKI/d3kqCY6TKnW/55M8Jp50KpI4mIpink82xwOJDkIaHysoeHxUKnHDz4AB4V+kF mAsF9pJOQ0YlWsj/cNKLsp/6mN7LZMCW59Br3LrIaHWcfAncE6FNExrbJcz4CDRAX7pg=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1mv0to-00FuGX-Ba; Wed, 08 Dec 2021 18:38:36 +0100 From: Andrew Lunn To: David Miller , Jakub Kicinski Cc: Hideaki YOSHIFUJI , David Ahern , Willem de Bruijn , James Prestwood , Justin Iurman , Praveen Chaudhary , "Jason A . Donenfeld" , Eric Dumazet , netdev , Andrew Lunn Subject: [PATCH net-next v4 1/3] seg6: export get_srh() for ICMP handling Date: Wed, 8 Dec 2021 18:38:30 +0100 Message-Id: <20211208173831.3791157-3-andrew@lunn.ch> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20211208173831.3791157-1-andrew@lunn.ch> References: <20211208173831.3791157-1-andrew@lunn.ch> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From 387a5e9d6b2749d0457ccc760a5b785c2df8f799 Mon Sep 17 00:00:00 2001 From: Andrew Lunn Date: Sat, 20 Nov 2021 12:51:07 -0600 Subject: [PATCH net-next v4 2/3] icmp: ICMPV6: Examine invoking packet for Segment Route Headers. RFC8754 says: ICMP error packets generated within the SR domain are sent to source nodes within the SR domain. The invoking packet in the ICMP error message may contain an SRH. Since the destination address of a packet with an SRH changes as each segment is processed, it may not be the destination used by the socket or application that generated the invoking packet. For the source of an invoking packet to process the ICMP error message, the ultimate destination address of the IPv6 header may be required. The following logic is used to determine the destination address for use by protocol-error handlers. * Walk all extension headers of the invoking IPv6 packet to the routing extension header preceding the upper-layer header. - If routing header is type 4 Segment Routing Header (SRH) o The SID at Segment List[0] may be used as the destination address of the invoking packet. Mangle the skb so the network header points to the invoking packet inside the ICMP packet. The seg6 helpers can then be used on the skb to find any segment routing headers. If found, mark this fact in the IPv6 control block of the skb, and store the offset into the packet of the SRH. Then restore the skb back to its old state. Signed-off-by: Andrew Lunn --- include/linux/ipv6.h | 2 ++ include/net/seg6.h | 1 + net/ipv6/icmp.c | 6 +++++- net/ipv6/seg6.c | 30 ++++++++++++++++++++++++++++++ 4 files changed, 38 insertions(+), 1 deletion(-) diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index 20c1f968da7c..a59d25f19385 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -133,6 +133,7 @@ struct inet6_skb_parm { __u16 dsthao; #endif __u16 frag_max_size; + __u16 srhoff; #define IP6SKB_XFRM_TRANSFORMED 1 #define IP6SKB_FORWARDED 2 @@ -142,6 +143,7 @@ struct inet6_skb_parm { #define IP6SKB_HOPBYHOP 32 #define IP6SKB_L3SLAVE 64 #define IP6SKB_JUMBOGRAM 128 +#define IP6SKB_SEG6 256 }; #if defined(CONFIG_NET_L3_MASTER_DEV) diff --git a/include/net/seg6.h b/include/net/seg6.h index a6f25983670a..02b0cd305787 100644 --- a/include/net/seg6.h +++ b/include/net/seg6.h @@ -59,6 +59,7 @@ extern void seg6_local_exit(void); extern bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len, bool reduced); extern struct ipv6_sr_hdr *seg6_get_srh(struct sk_buff *skb, int flags); +extern void seg6_icmp_srh(struct sk_buff *skb, struct inet6_skb_parm *opt); extern int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr *osrh, int proto); extern int seg6_do_srh_inline(struct sk_buff *skb, struct ipv6_sr_hdr *osrh); diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index a7c31ab67c5d..96c5cc0f30ce 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -57,6 +57,7 @@ #include #include #include +#include #include #include #include @@ -820,6 +821,7 @@ static void icmpv6_echo_reply(struct sk_buff *skb) void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info) { + struct inet6_skb_parm *opt = IP6CB(skb); const struct inet6_protocol *ipprot; int inner_offset; __be16 frag_off; @@ -829,6 +831,8 @@ void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info) if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) goto out; + seg6_icmp_srh(skb, opt); + nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr; if (ipv6_ext_hdr(nexthdr)) { /* now skip over extension headers */ @@ -853,7 +857,7 @@ void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info) ipprot = rcu_dereference(inet6_protos[nexthdr]); if (ipprot && ipprot->err_handler) - ipprot->err_handler(skb, NULL, type, code, inner_offset, info); + ipprot->err_handler(skb, opt, type, code, inner_offset, info); raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info); return; diff --git a/net/ipv6/seg6.c b/net/ipv6/seg6.c index 5bc9bf892199..73aaabf0e966 100644 --- a/net/ipv6/seg6.c +++ b/net/ipv6/seg6.c @@ -104,6 +104,36 @@ struct ipv6_sr_hdr *seg6_get_srh(struct sk_buff *skb, int flags) return srh; } +/* Determine if an ICMP invoking packet contains a segment routing + * header. If it does, extract the offset to the true destination + * address, which is in the first segment address. + */ +void seg6_icmp_srh(struct sk_buff *skb, struct inet6_skb_parm *opt) +{ + __u16 network_header = skb->network_header; + struct ipv6_sr_hdr *srh; + + /* Update network header to point to the invoking packet + * inside the ICMP packet, so we can use the seg6_get_srh() + * helper. + */ + skb_reset_network_header(skb); + + srh = seg6_get_srh(skb, 0); + if (!srh) + goto out; + + if (srh->type != IPV6_SRCRT_TYPE_4) + goto out; + + opt->flags |= IP6SKB_SEG6; + opt->srhoff = (unsigned char *)srh - skb->data; + +out: + /* Restore the network header back to the ICMP packet */ + skb->network_header = network_header; +} + static struct genl_family seg6_genl_family; static const struct nla_policy seg6_genl_policy[SEG6_ATTR_MAX + 1] = { From patchwork Wed Dec 8 17:38:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Lunn X-Patchwork-Id: 12664931 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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D5ECDC433EF for ; Wed, 8 Dec 2021 17:39:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238297AbhLHRms (ORCPT ); Wed, 8 Dec 2021 12:42:48 -0500 Received: from vps0.lunn.ch ([185.16.172.187]:46012 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238575AbhLHRmU (ORCPT ); Wed, 8 Dec 2021 12:42:20 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:From:Sender:Reply-To:Subject:Date: Message-ID:To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Content-Disposition:In-Reply-To:References; bh=Qy0HNmvKN1NQ9cRGMYMemHBBkRhEZCvU0Ib1HaFMnzk=; b=YlW/4mrJUTQ26g1kIgyB/AGO1+ KE72vI2jz0Wk/AfiNbzpqAXI76KLgmBoYzmHggrx4NhPsJhxOHKDRibCve5/6YFDm+2EO63NbpLjL LXWsEHJi3BNv00WxjKuMR6dgOBkirDH9gLTBXvTZElsB63P43cojJJZfIKEkBCsf9U9c=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1mv0to-00FuGa-Cu; Wed, 08 Dec 2021 18:38:36 +0100 From: Andrew Lunn To: David Miller , Jakub Kicinski Cc: Hideaki YOSHIFUJI , David Ahern , Willem de Bruijn , James Prestwood , Justin Iurman , Praveen Chaudhary , "Jason A . Donenfeld" , Eric Dumazet , netdev , Andrew Lunn Subject: [PATCH net-next v4 3/3] udp6: Use Segment Routing Header for dest address if present Date: Wed, 8 Dec 2021 18:38:31 +0100 Message-Id: <20211208173831.3791157-4-andrew@lunn.ch> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20211208173831.3791157-1-andrew@lunn.ch> References: <20211208173831.3791157-1-andrew@lunn.ch> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org When finding the socket to report an error on, if the invoking packet is using Segment Routing, the IPv6 destination address is that of an intermediate router, not the end destination. Extract the ultimate destination address from the segment address. This change allows traceroute to function in the presence of Segment Routing. Signed-off-by: Andrew Lunn --- include/net/seg6.h | 19 +++++++++++++++++++ net/ipv6/udp.c | 3 ++- 2 files changed, 21 insertions(+), 1 deletion(-) diff --git a/include/net/seg6.h b/include/net/seg6.h index 02b0cd305787..af668f17b398 100644 --- a/include/net/seg6.h +++ b/include/net/seg6.h @@ -65,4 +65,23 @@ extern int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr *osrh, extern int seg6_do_srh_inline(struct sk_buff *skb, struct ipv6_sr_hdr *osrh); extern int seg6_lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr, u32 tbl_id); + +/* If the packet which invoked an ICMP error contains an SRH return + * the true destination address from within the SRH, otherwise use the + * destination address in the IP header. + */ +static inline const struct in6_addr *seg6_get_daddr(struct sk_buff *skb, + struct inet6_skb_parm *opt) +{ + struct ipv6_sr_hdr *srh; + + if (opt->flags & IP6SKB_SEG6) { + srh = (struct ipv6_sr_hdr *)(skb->data + opt->srhoff); + return &srh->segments[0]; + } + + return NULL; +} + + #endif diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 6a0e569f0bb8..a14375e3f923 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -40,6 +40,7 @@ #include #include #include +#include #include #include #include @@ -561,7 +562,7 @@ int __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt, struct ipv6_pinfo *np; const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data; const struct in6_addr *saddr = &hdr->saddr; - const struct in6_addr *daddr = &hdr->daddr; + const struct in6_addr *daddr = seg6_get_daddr(skb, opt) ? : &hdr->daddr; struct udphdr *uh = (struct udphdr *)(skb->data+offset); bool tunnel = false; struct sock *sk;