From 53401bef63013dfee01b65d071ffbd88e457539f Mon Sep 17 00:00:00 2001 From: Ondrej Zajicek Date: Tue, 12 Nov 2019 18:13:21 +0100 Subject: Netlink: Handle IPv4 routes with IPv6 nexthops Accept RTA_VIA attribute in all cases. The old code always used RTA_GATEWAY for IPv4 / IPv6 and RTA_VIA for MPLS. The new code uses RTA_VIA in cases where AF of network and AF of nexthop differs. --- sysdep/linux/netlink.c | 42 +++++++++++++++++++++++++----------------- 1 file changed, 25 insertions(+), 17 deletions(-) (limited to 'sysdep/linux/netlink.c') diff --git a/sysdep/linux/netlink.c b/sysdep/linux/netlink.c index 10e9a18b..4714263a 100644 --- a/sysdep/linux/netlink.c +++ b/sysdep/linux/netlink.c @@ -171,6 +171,7 @@ nl_send(struct nl_sock *nl, struct nlmsghdr *nh) sa.nl_family = AF_NETLINK; nh->nlmsg_pid = 0; nh->nlmsg_seq = ++(nl->seq); + nh->nlmsg_len = NLMSG_ALIGN(nh->nlmsg_len); if (sendto(nl->fd, nh, nh->nlmsg_len, 0, (struct sockaddr *)&sa, sizeof(sa)) < 0) die("rtnetlink sendto: %m"); nl->last_hdr = NULL; @@ -343,12 +344,14 @@ static struct nl_want_attrs ifa_attr_want6[BIRD_IFA_MAX] = { static struct nl_want_attrs nexthop_attr_want4[BIRD_RTA_MAX] = { [RTA_GATEWAY] = { 1, 1, sizeof(ip4_addr) }, + [RTA_VIA] = { 1, 0, 0 }, [RTA_ENCAP_TYPE]= { 1, 1, sizeof(u16) }, [RTA_ENCAP] = { 1, 0, 0 }, }; static struct nl_want_attrs nexthop_attr_want6[BIRD_RTA_MAX] = { [RTA_GATEWAY] = { 1, 1, sizeof(ip6_addr) }, + [RTA_VIA] = { 1, 0, 0 }, [RTA_ENCAP_TYPE]= { 1, 1, sizeof(u16) }, [RTA_ENCAP] = { 1, 0, 0 }, }; @@ -369,6 +372,7 @@ static struct nl_want_attrs rtm_attr_want4[BIRD_RTA_MAX] = { [RTA_MULTIPATH] = { 1, 0, 0 }, [RTA_FLOW] = { 1, 1, sizeof(u32) }, [RTA_TABLE] = { 1, 1, sizeof(u32) }, + [RTA_VIA] = { 1, 0, 0 }, [RTA_ENCAP_TYPE]= { 1, 1, sizeof(u16) }, [RTA_ENCAP] = { 1, 0, 0 }, }; @@ -385,6 +389,7 @@ static struct nl_want_attrs rtm_attr_want6[BIRD_RTA_MAX] = { [RTA_MULTIPATH] = { 1, 0, 0 }, [RTA_FLOW] = { 1, 1, sizeof(u32) }, [RTA_TABLE] = { 1, 1, sizeof(u32) }, + [RTA_VIA] = { 1, 0, 0 }, [RTA_ENCAP_TYPE]= { 1, 1, sizeof(u16) }, [RTA_ENCAP] = { 1, 0, 0 }, }; @@ -622,10 +627,12 @@ nl_add_nexthop(struct nlmsghdr *h, uint bufsize, struct nexthop *nh, int af UNUS nl_add_attr_mpls_encap(h, bufsize, nh->labels, nh->label); if (ipa_nonzero(nh->gw)) - if (af == AF_MPLS) - nl_add_attr_via(h, bufsize, nh->gw); - else + { + if (af == (ipa_is_ip4(nh->gw) ? AF_INET : AF_INET6)) nl_add_attr_ipa(h, bufsize, RTA_GATEWAY, nh->gw); + else + nl_add_attr_via(h, bufsize, nh->gw); + } #else if (ipa_nonzero(nh->gw)) @@ -701,9 +708,15 @@ nl_parse_multipath(struct nl_parse_state *s, struct krt_proto *p, struct rtattr } if (a[RTA_GATEWAY]) - { - rv->gw = rta_get_ipa(a[RTA_GATEWAY]); + rv->gw = rta_get_ipa(a[RTA_GATEWAY]); +#ifdef HAVE_MPLS_KERNEL + if (a[RTA_VIA]) + rv->gw = rta_get_via(a[RTA_VIA]); +#endif + + if (ipa_nonzero(rv->gw)) + { if (nh->rtnh_flags & RTNH_F_ONLINK) rv->flags |= RNF_ONLINK; @@ -713,8 +726,6 @@ nl_parse_multipath(struct nl_parse_state *s, struct krt_proto *p, struct rtattr if (!nbr || (nbr->scope == SCOPE_HOST)) return NULL; } - else - rv->gw = IPA_NONE; #ifdef HAVE_MPLS_KERNEL if (a[RTA_ENCAP] && a[RTA_ENCAP_TYPE]) @@ -1644,19 +1655,16 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h) return; } - if ((i->rtm_family != AF_MPLS) && a[RTA_GATEWAY] -#ifdef HAVE_MPLS_KERNEL - || (i->rtm_family == AF_MPLS) && a[RTA_VIA] -#endif - ) - { + if (a[RTA_GATEWAY]) + ra->nh.gw = rta_get_ipa(a[RTA_GATEWAY]); + #ifdef HAVE_MPLS_KERNEL - if (i->rtm_family == AF_MPLS) - ra->nh.gw = rta_get_via(a[RTA_VIA]); - else + if (a[RTA_VIA]) + ra->nh.gw = rta_get_via(a[RTA_VIA]); #endif - ra->nh.gw = rta_get_ipa(a[RTA_GATEWAY]); + if (ipa_nonzero(ra->nh.gw)) + { /* Silently skip strange 6to4 routes */ const net_addr_ip6 sit = NET_ADDR_IP6(IP6_NONE, 96); if ((i->rtm_family == AF_INET6) && ipa_in_netX(ra->nh.gw, (net_addr *) &sit)) -- cgit v1.2.3