Routes can carry lightweight tunnel (LWT) encapsulation metadata; for IP encapsulation this includes a tunnel id (e.g. a VXLAN VNI). FRR uses this to attach the L3 VNI to EVPN type-5 routes.
Parse the LWT IP/IP6 encap tunnel id (LWTUNNEL_IP_ID) from RTA_ENCAP into a new 'vni' field in struct route_data, so that users of the route-table library (such as OVN) can learn it. Assisted-by: Claude Opus 4.8, Cursor Signed-off-by: Han Zhou <[email protected]> --- lib/route-table.c | 42 ++++++++++++++++++++++++++++++++++++ lib/route-table.h | 6 ++++++ tests/system-route.at | 14 ++++++++++++ tests/test-lib-route-table.c | 6 +++++- 4 files changed, 67 insertions(+), 1 deletion(-) diff --git a/lib/route-table.c b/lib/route-table.c index 2a13a5cc7d93..ecaf6fc4e42b 100644 --- a/lib/route-table.c +++ b/lib/route-table.c @@ -27,6 +27,7 @@ #include <linux/rtnetlink.h> #include <net/if.h> +#include "byte-order.h" #include "coverage.h" #include "hash.h" #include "netdev.h" @@ -48,6 +49,16 @@ #define FRA_SUPPRESS_PREFIXLEN 14 /* Linux 3.12 */ #define FRA_TABLE 15 /* Linux 2.6.19 */ #define FRA_PROTOCOL 21 /* Linux 4.17 */ +#define RTA_ENCAP_TYPE 21 /* Linux 4.3 */ +#define RTA_ENCAP 22 /* Linux 4.3 */ + +/* Lightweight tunnel encapsulation types and attributes (Linux 4.3+), + * from linux/lwtunnel.h. Defined here so we can parse EVPN type-5 routes + * that carry the L3 VNI without depending on newer build headers. */ +#define OVN_LWTUNNEL_ENCAP_IP 2 +#define OVN_LWTUNNEL_ENCAP_IP6 4 +/* LWTUNNEL_IP_ID and LWTUNNEL_IP6_ID share the same attribute number (1). */ +#define OVN_LWTUNNEL_IP_ID 1 /* Linux 4.1 added RTA_VIA. */ #ifndef HAVE_RTA_VIA @@ -468,6 +479,8 @@ route_table_parse__(struct ofpbuf *buf, size_t ofs, [RTA_PRIORITY] = { .type = NL_A_U32, .optional = true }, [RTA_VIA] = { .type = NL_A_RTA_VIA, .optional = true }, [RTA_MULTIPATH] = { .type = NL_A_NESTED, .optional = true }, + [RTA_ENCAP_TYPE] = { .type = NL_A_U16, .optional = true }, + [RTA_ENCAP] = { .type = NL_A_NESTED, .optional = true }, }; static const struct nl_policy policy6[] = { @@ -480,6 +493,8 @@ route_table_parse__(struct ofpbuf *buf, size_t ofs, [RTA_PRIORITY] = { .type = NL_A_U32, .optional = true }, [RTA_VIA] = { .type = NL_A_RTA_VIA, .optional = true }, [RTA_MULTIPATH] = { .type = NL_A_NESTED, .optional = true }, + [RTA_ENCAP_TYPE] = { .type = NL_A_U16, .optional = true }, + [RTA_ENCAP] = { .type = NL_A_NESTED, .optional = true }, }; struct nlattr *attrs[ARRAY_SIZE(policy)]; @@ -585,6 +600,27 @@ route_table_parse__(struct ofpbuf *buf, size_t ofs, if (attrs[RTA_PRIORITY]) { change->rd.rta_priority = nl_attr_get_u32(attrs[RTA_PRIORITY]); } + if (attrs[RTA_ENCAP_TYPE] && attrs[RTA_ENCAP]) { + uint16_t encap_type = nl_attr_get_u16(attrs[RTA_ENCAP_TYPE]); + + if (encap_type == OVN_LWTUNNEL_ENCAP_IP || + encap_type == OVN_LWTUNNEL_ENCAP_IP6) { + static const struct nl_policy encap_policy[] = { + [OVN_LWTUNNEL_IP_ID] = { .type = NL_A_BE64, + .optional = true }, + }; + struct nlattr *encap_attrs[ARRAY_SIZE(encap_policy)]; + + if (nl_parse_nested(attrs[RTA_ENCAP], encap_policy, + encap_attrs, ARRAY_SIZE(encap_policy)) + && encap_attrs[OVN_LWTUNNEL_IP_ID]) { + ovs_be64 id = + nl_attr_get_be64(encap_attrs[OVN_LWTUNNEL_IP_ID]); + change->rd.vni = ntohll(id); + change->rd.vni_present = true; + } + } + } if (attrs[RTA_VIA]) { const struct rtvia *rtvia = nl_attr_get(attrs[RTA_VIA]); ovs_be32 addr; @@ -668,6 +704,12 @@ route_table_parse__(struct ofpbuf *buf, size_t ofs, } ovs_list_push_back_all(&change->rd.nexthops, &mp_change.rd.nexthops); + /* Per-nexthop LWT encap may carry the VNI. Adopt the first + * one seen for the route as a whole. */ + if (mp_change.rd.vni_present && !change->rd.vni_present) { + change->rd.vni = mp_change.rd.vni; + change->rd.vni_present = true; + } } } if (route_type_needs_nexthop(rtm->rtm_type) diff --git a/lib/route-table.h b/lib/route-table.h index b49fbb14ebe0..672d4e96d1d7 100644 --- a/lib/route-table.h +++ b/lib/route-table.h @@ -141,6 +141,12 @@ struct route_data { uint32_t rta_mark; /* 0 if missing. */ uint32_t rta_table_id; /* 0 if missing. */ uint32_t rta_priority; /* 0 if missing. */ + + /* Lightweight tunnel (LWT) encapsulation, e.g. as used by EVPN type-5 + * routes to carry the L3 VNI (RTA_ENCAP_TYPE == LWTUNNEL_ENCAP_IP/IP6 + * with a nested LWTUNNEL_IP_ID/LWTUNNEL_IP6_ID tunnel id). */ + bool vni_present; /* True if 'vni' was extracted. */ + uint32_t vni; /* Valid only if 'vni_present'. */ }; struct rule_data { diff --git a/tests/system-route.at b/tests/system-route.at index a074c51f9fd0..ed70a2443e76 100644 --- a/tests/system-route.at +++ b/tests/system-route.at @@ -331,6 +331,20 @@ AT_CHECK([ovstest test-lib-route-table-dump | \ 192.168.10.12/32 rtm_protocol: RTPROT_BOOT ]) +dnl Add route with a lightweight-tunnel (LWT) IP encapsulation tunnel id, as +dnl used to carry an EVPN L3 VNI. The tunnel id must be parsed into the route's +dnl vni field. +AT_CHECK([ip route add 192.168.10.13/32 encap ip id 5000 dst 10.0.0.19 \ + dev p1-route via 10.0.0.18], [0], [stdout]) +AT_CHECK([ovstest test-lib-route-table-dump | grep '^192.168.10.13' | \ + grep -o 'vni: [[0-9]]*'], [0], [dnl +vni: 5000 +]) + +dnl A route without an encap id has no vni field. +AT_CHECK([ovstest test-lib-route-table-dump | grep '^192.168.10.12' | \ + grep 'vni:'], [1]) + AT_CLEANUP dnl Checks that OVS ignores unsupported routing rules. diff --git a/tests/test-lib-route-table.c b/tests/test-lib-route-table.c index f99f056c8ddc..3bdaf517f132 100644 --- a/tests/test-lib-route-table.c +++ b/tests/test-lib-route-table.c @@ -86,11 +86,15 @@ test_lib_route_table_handle_msg(const struct route_table_msg *change, printf("%s/%u relevant: %d nlmsg_type: %d rtm_protocol: %s (%u) " "rtn_local: %d rta_prefsrc: %s rta_mark: %"PRIu32" " - "rta_table_id: %s rta_priority: %"PRIu32"\n", + "rta_table_id: %s rta_priority: %"PRIu32, ds_cstr(&rta_dst), rd->rtm_dst_len, change->relevant, change->nlmsg_type, rt_prot_name(rd->rtm_protocol), rd->rtm_protocol, rd->rtn_local, ds_cstr(&rta_prefsrc), rd->rta_mark, rt_table_name(rd->rta_table_id), rd->rta_priority); + if (rd->vni_present) { + printf(" vni: %"PRIu32, rd->vni); + } + printf("\n"); LIST_FOR_EACH (rdnh, nexthop_node, &rd->nexthops) { ds_clear(&nexthop_addr); -- 2.38.1 _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
