From: Linus Lüssing <linus.luessing@xxxxxxxxx> So far Multicast Router Advertisements and Multicast Router Solicitations from the Multicast Router Discovery protocol (RFC4286) would be marked as INVALID for IPv6, even if they are in fact intact and adhering to RFC4286. This broke MRA reception and by that multicast reception on IPv6 multicast routers in a Proxmox managed setup, where Proxmox would install a rule like "-m conntrack --ctstate INVALID -j DROP" at the top of the FORWARD chain with br-nf-call-ip6tables enabled by default. Similar to as it's done for MLDv1, MLDv2 and IPv6 Neighbor Discovery already, fix this issue by excluding MRD from connection tracking handling as MRD always uses predefined multicast destinations for its messages, too. This changes the ct-state for ICMPv6 MRD messages from INVALID to UNTRACKED. This issue was found and fixed with the help of the mrdisc tool (https://github.com/troglobit/mrdisc). Signed-off-by: Linus Lüssing <linus.luessing@xxxxxxxxx> Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> --- include/uapi/linux/icmpv6.h | 1 + net/netfilter/nf_conntrack_proto_icmpv6.c | 4 +++- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/icmpv6.h b/include/uapi/linux/icmpv6.h index ecaece3af38d..4eaab89e2856 100644 --- a/include/uapi/linux/icmpv6.h +++ b/include/uapi/linux/icmpv6.h @@ -112,6 +112,7 @@ struct icmp6hdr { #define ICMPV6_MOBILE_PREFIX_ADV 147 #define ICMPV6_MRDISC_ADV 151 +#define ICMPV6_MRDISC_SOL 152 #define ICMPV6_MSG_MAX 255 diff --git a/net/netfilter/nf_conntrack_proto_icmpv6.c b/net/netfilter/nf_conntrack_proto_icmpv6.c index 1020d67600a9..327b8059025d 100644 --- a/net/netfilter/nf_conntrack_proto_icmpv6.c +++ b/net/netfilter/nf_conntrack_proto_icmpv6.c @@ -62,7 +62,9 @@ static const u_int8_t noct_valid_new[] = { [NDISC_ROUTER_ADVERTISEMENT - 130] = 1, [NDISC_NEIGHBOUR_SOLICITATION - 130] = 1, [NDISC_NEIGHBOUR_ADVERTISEMENT - 130] = 1, - [ICMPV6_MLD2_REPORT - 130] = 1 + [ICMPV6_MLD2_REPORT - 130] = 1, + [ICMPV6_MRDISC_ADV - 130] = 1, + [ICMPV6_MRDISC_SOL - 130] = 1 }; bool nf_conntrack_invert_icmpv6_tuple(struct nf_conntrack_tuple *tuple, -- 2.30.2
