From: David Lebrun Date: Sat, 5 Aug 2017 10:38:24 +0000 (+0200) Subject: ipv6: sr: allow SRH insertion with arbitrary segments_left value X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=925615ceda94532ba612e641549c7b1e41ebff10;p=openwrt%2Fstaging%2Fblogic.git ipv6: sr: allow SRH insertion with arbitrary segments_left value The seg6_validate_srh() function only allows SRHs whose active segment is the first segment of the path. However, an application may insert an SRH whose active segment is not the first one. Such an application might be for example an SR-aware Virtual Network Function. This patch enables to insert SRHs with an arbitrary active segment. Signed-off-by: David Lebrun Signed-off-by: David S. Miller --- diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c index 3cec529c6113..95516138e861 100644 --- a/net/ipv6/exthdrs.c +++ b/net/ipv6/exthdrs.c @@ -882,7 +882,7 @@ static void ipv6_push_rthdr4(struct sk_buff *skb, u8 *proto, (hops - 1) * sizeof(struct in6_addr)); sr_phdr->segments[0] = **addr_p; - *addr_p = &sr_ihdr->segments[hops - 1]; + *addr_p = &sr_ihdr->segments[sr_ihdr->segments_left]; #ifdef CONFIG_IPV6_SEG6_HMAC if (sr_has_hmac(sr_phdr)) { @@ -1174,7 +1174,7 @@ struct in6_addr *fl6_update_dst(struct flowi6 *fl6, { struct ipv6_sr_hdr *srh = (struct ipv6_sr_hdr *)opt->srcrt; - fl6->daddr = srh->segments[srh->first_segment]; + fl6->daddr = srh->segments[srh->segments_left]; break; } default: diff --git a/net/ipv6/seg6.c b/net/ipv6/seg6.c index 15fba55e3da8..81c2339b3285 100644 --- a/net/ipv6/seg6.c +++ b/net/ipv6/seg6.c @@ -40,7 +40,7 @@ bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len) if (((srh->hdrlen + 1) << 3) != len) return false; - if (srh->segments_left != srh->first_segment) + if (srh->segments_left > srh->first_segment) return false; tlv_offset = sizeof(*srh) + ((srh->first_segment + 1) << 4);