From patchwork Mon Jan 3 17:11:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Lunn X-Patchwork-Id: 12702688 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 75572C433EF for ; Mon, 3 Jan 2022 17:11:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235087AbiACRL5 (ORCPT ); Mon, 3 Jan 2022 12:11:57 -0500 Received: from vps0.lunn.ch ([185.16.172.187]:48560 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235023AbiACRL5 (ORCPT ); Mon, 3 Jan 2022 12:11:57 -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=0dnpjcmCgOgIpXfUOtknOifu7NP7md5OouKk3KXQtJI=; b=1RZnrJOe0FvlAI8iXN54jbj9d8 kD4n2NBnUbO9jrFIhecKHV6InVf9dTMWynMFskuFfJdlsmljqmx9uhOecebQHag7SOcAW8w8r12Wg /4e2WUCfuN0scynvFeg4qHk0ARfRuD+g6fqoQj2E2bA4djXGszryMc9v6Sw7PCFY9sYA=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1n4Qs0-000OKD-S4; Mon, 03 Jan 2022 18:11:40 +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 v5 net-next 1/3] seg6: export get_srh() for ICMP handling Date: Mon, 3 Jan 2022 18:11:30 +0100 Message-Id: <20220103171132.93456-2-andrew@lunn.ch> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220103171132.93456-1-andrew@lunn.ch> References: <20220103171132.93456-1-andrew@lunn.ch> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org An ICMP error message can contain in its message body part of an IPv6 packet which invoked the error. Such a packet might contain a segment router header. Export get_srh() so the ICMP code can make use of it. Since his changes the scope of the function from local to global, add the seg6_ prefix to keep the namespace clean. And move it into seg6.c so it is always available, not just when IPV6_SEG6_LWTUNNEL is enabled. Signed-off-by: Andrew Lunn Reviewed-by: David Ahern Reviewed-by: Willem de Bruijn --- include/net/seg6.h | 1 + net/ipv6/seg6.c | 29 +++++++++++++++++++++++++++++ net/ipv6/seg6_local.c | 33 ++------------------------------- 3 files changed, 32 insertions(+), 31 deletions(-) diff --git a/include/net/seg6.h b/include/net/seg6.h index 9d19c15e8545..a6f25983670a 100644 --- a/include/net/seg6.h +++ b/include/net/seg6.h @@ -58,6 +58,7 @@ extern int seg6_local_init(void); 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 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/seg6.c b/net/ipv6/seg6.c index a8b5784afb1a..5bc9bf892199 100644 --- a/net/ipv6/seg6.c +++ b/net/ipv6/seg6.c @@ -75,6 +75,35 @@ bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len, bool reduced) return true; } +struct ipv6_sr_hdr *seg6_get_srh(struct sk_buff *skb, int flags) +{ + struct ipv6_sr_hdr *srh; + int len, srhoff = 0; + + if (ipv6_find_hdr(skb, &srhoff, IPPROTO_ROUTING, NULL, &flags) < 0) + return NULL; + + if (!pskb_may_pull(skb, srhoff + sizeof(*srh))) + return NULL; + + srh = (struct ipv6_sr_hdr *)(skb->data + srhoff); + + len = (srh->hdrlen + 1) << 3; + + if (!pskb_may_pull(skb, srhoff + len)) + return NULL; + + /* note that pskb_may_pull may change pointers in header; + * for this reason it is necessary to reload them when needed. + */ + srh = (struct ipv6_sr_hdr *)(skb->data + srhoff); + + if (!seg6_validate_srh(srh, len, true)) + return NULL; + + return srh; +} + static struct genl_family seg6_genl_family; static const struct nla_policy seg6_genl_policy[SEG6_ATTR_MAX + 1] = { diff --git a/net/ipv6/seg6_local.c b/net/ipv6/seg6_local.c index a5eea182149d..9fbe243a0e81 100644 --- a/net/ipv6/seg6_local.c +++ b/net/ipv6/seg6_local.c @@ -151,40 +151,11 @@ static struct seg6_local_lwt *seg6_local_lwtunnel(struct lwtunnel_state *lwt) return (struct seg6_local_lwt *)lwt->data; } -static struct ipv6_sr_hdr *get_srh(struct sk_buff *skb, int flags) -{ - struct ipv6_sr_hdr *srh; - int len, srhoff = 0; - - if (ipv6_find_hdr(skb, &srhoff, IPPROTO_ROUTING, NULL, &flags) < 0) - return NULL; - - if (!pskb_may_pull(skb, srhoff + sizeof(*srh))) - return NULL; - - srh = (struct ipv6_sr_hdr *)(skb->data + srhoff); - - len = (srh->hdrlen + 1) << 3; - - if (!pskb_may_pull(skb, srhoff + len)) - return NULL; - - /* note that pskb_may_pull may change pointers in header; - * for this reason it is necessary to reload them when needed. - */ - srh = (struct ipv6_sr_hdr *)(skb->data + srhoff); - - if (!seg6_validate_srh(srh, len, true)) - return NULL; - - return srh; -} - static struct ipv6_sr_hdr *get_and_validate_srh(struct sk_buff *skb) { struct ipv6_sr_hdr *srh; - srh = get_srh(skb, IP6_FH_F_SKIP_RH); + srh = seg6_get_srh(skb, IP6_FH_F_SKIP_RH); if (!srh) return NULL; @@ -201,7 +172,7 @@ static bool decap_and_validate(struct sk_buff *skb, int proto) struct ipv6_sr_hdr *srh; unsigned int off = 0; - srh = get_srh(skb, 0); + srh = seg6_get_srh(skb, 0); if (srh && srh->segments_left > 0) return false; From patchwork Mon Jan 3 17:11:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Lunn X-Patchwork-Id: 12702691 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 D5927C433FE for ; Mon, 3 Jan 2022 17:11:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235109AbiACRL7 (ORCPT ); Mon, 3 Jan 2022 12:11:59 -0500 Received: from vps0.lunn.ch ([185.16.172.187]:48564 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235030AbiACRL5 (ORCPT ); Mon, 3 Jan 2022 12:11:57 -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=q71yBXkWpnHmqVYYhwWNLWcfsaAdC6LUYwApTrEBA2o=; b=QhO21K5oRM1+U6R5kkYdyqaKSL 7A5TtdpjuS2fqWsf6y8DkvaX9b/9akWQxfjKpJB4hA6K8QVE1zmLNJgkdMKYtkjnOtr/lpN3pZtJx HygCBO51fmSL1IIb1KFHgXO4dAlUe37pWheC0mTuDCGyw49rA3v2WvX6n9oHis4IxHD0=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1n4Qs0-000OKG-TY; Mon, 03 Jan 2022 18:11:40 +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 v5 net-next 2/3] icmp: ICMPV6: Examine invoking packet for Segment Route Headers. Date: Mon, 3 Jan 2022 18:11:31 +0100 Message-Id: <20220103171132.93456-3-andrew@lunn.ch> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220103171132.93456-1-andrew@lunn.ch> References: <20220103171132.93456-1-andrew@lunn.ch> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org 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 Reviewed-by: David Ahern Reviewed-by: Willem de Bruijn --- 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 Mon Jan 3 17:11:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Lunn X-Patchwork-Id: 12702689 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 D06F8C433F5 for ; Mon, 3 Jan 2022 17:11:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235089AbiACRL5 (ORCPT ); Mon, 3 Jan 2022 12:11:57 -0500 Received: from vps0.lunn.ch ([185.16.172.187]:48558 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230316AbiACRL5 (ORCPT ); Mon, 3 Jan 2022 12:11:57 -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=XIJzjC4tEAGFoIhNjwKKSvz3/L4fw2WVs8Z+uLD/AME=; b=XxJyDBf85gcZGR0WtW9mabY6rm mb2QEdD0vSPUm9ZNBjwoOHrmJtAL+qvu+ZvIKBFFlwg6kUfb8W1nlkvWkALOhzpMS5p1UMIoAi6KU zc44FdVVN9nfgkx84bN1nNbCBGA984uJ5o3DnTN6g8JfIAn/5n9EtcCL4EzM5DYqSPlU=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1n4Qs0-000OKJ-V6; Mon, 03 Jan 2022 18:11:40 +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 v5 net-next 3/3] udp6: Use Segment Routing Header for dest address if present Date: Mon, 3 Jan 2022 18:11:32 +0100 Message-Id: <20220103171132.93456-4-andrew@lunn.ch> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220103171132.93456-1-andrew@lunn.ch> References: <20220103171132.93456-1-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 Reviewed-by: David Ahern Reviewed-by: Willem de Bruijn --- 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 1accc06abc54..df216268cb02 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -41,6 +41,7 @@ #include #include #include +#include #include #include #include @@ -562,7 +563,7 @@ 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;