From 013e8167899d389075160412a8c0c5e0581e1f13 Mon Sep 17 00:00:00 2001 From: David Lebrun Date: Thu, 2 Feb 2017 11:29:38 +0100 Subject: ipv6: sr: remove cleanup flag and fix HMAC computation In the latest version of the IPv6 Segment Routing IETF draft [1] the cleanup flag is removed and the flags field length is shrunk from 16 bits to 8 bits. As a consequence, the input of the HMAC computation is modified in a non-backward compatible way by covering the whole octet of flags instead of only the cleanup bit. As such, if an implementation compatible with the latest draft computes the HMAC of an SRH who has other flags set to 1, then the HMAC result would differ from the current implementation. This patch carries those modifications to prevent conflict with other implementations of IPv6 SR. [1] https://tools.ietf.org/html/draft-ietf-6man-segment-routing-header-05 Signed-off-by: David Lebrun Signed-off-by: David S. Miller --- net/ipv6/exthdrs.c | 31 +++---------------------------- 1 file changed, 3 insertions(+), 28 deletions(-) (limited to 'net/ipv6/exthdrs.c') diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c index e4198502fd98..275cac628a95 100644 --- a/net/ipv6/exthdrs.c +++ b/net/ipv6/exthdrs.c @@ -327,7 +327,6 @@ static int ipv6_srh_rcv(struct sk_buff *skb) struct ipv6_sr_hdr *hdr; struct inet6_dev *idev; struct in6_addr *addr; - bool cleanup = false; int accept_seg6; hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); @@ -351,11 +350,7 @@ static int ipv6_srh_rcv(struct sk_buff *skb) #endif looped_back: - if (hdr->segments_left > 0) { - if (hdr->nexthdr != NEXTHDR_IPV6 && hdr->segments_left == 1 && - sr_has_cleanup(hdr)) - cleanup = true; - } else { + if (hdr->segments_left == 0) { if (hdr->nexthdr == NEXTHDR_IPV6) { int offset = (hdr->hdrlen + 1) << 3; @@ -418,21 +413,6 @@ looped_back: ipv6_hdr(skb)->daddr = *addr; - if (cleanup) { - int srhlen = (hdr->hdrlen + 1) << 3; - int nh = hdr->nexthdr; - - skb_pull_rcsum(skb, sizeof(struct ipv6hdr) + srhlen); - memmove(skb_network_header(skb) + srhlen, - skb_network_header(skb), - (unsigned char *)hdr - skb_network_header(skb)); - skb->network_header += srhlen; - ipv6_hdr(skb)->nexthdr = nh; - ipv6_hdr(skb)->payload_len = htons(skb->len - - sizeof(struct ipv6hdr)); - skb_push_rcsum(skb, sizeof(struct ipv6hdr)); - } - skb_dst_drop(skb); ip6_route_input(skb); @@ -453,13 +433,8 @@ looped_back: } ipv6_hdr(skb)->hop_limit--; - /* be sure that srh is still present before reinjecting */ - if (!cleanup) { - skb_pull(skb, sizeof(struct ipv6hdr)); - goto looped_back; - } - skb_set_transport_header(skb, sizeof(struct ipv6hdr)); - IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr); + skb_pull(skb, sizeof(struct ipv6hdr)); + goto looped_back; } dst_input(skb); -- cgit