bgpd: support for Ethernet Segments and Type-1/EAD routes

This is the base patch that brings in support for Type-1 routes.
It includes support for -
- Ethernet Segment (ES) management
- EAD route handling
- MAC-IP (Type-2) routes with a non-zero ESI i.e. Aliasing for
  active-active multihoming
- Initial infra for consistency checking. Consistency checking
  is a fundamental feature for active-active solutions like MLAG.
  We will try to levarage the info in the EAD-ES/EAD-EVI routes to
  detect inconsitencies in access config across VTEPs attached to
  the same Ethernet Segment.

Functionality Overview -
========================
1. Ethernet segments are created in zebra and associated with
access VLANs. zebra sends that info as ES and ES-EVI objects to BGP.
2. BGP advertises EAD-ES and EAD-EVI routes for the locally attached
ethernet segments.
3. Similarly BGP processes EAD-ES and EAD-EVI routes from peers
and translates them into ES-VTEP objects which are then sent to zebra
as remote ESs.
4. Each ES in zebra is associated with a list of active VTEPs which
is then translated into a L2-NHG (nexthop group). This is the ES
"Alias" entry
5. MAC-IP routes with a non-zero ESI use the alias entry created in
(4.) to forward traffic i.e. a MAC-ECMP is done to these remote-ES
destinations.

EAD route management (route table and key) -
============================================
1. Local EAD-ES routes
a. route-table: per-ES route-table
key: {RD=ES-RD, ESI, ET=0xffffffff, VTEP-IP)
b. route-table: per-VNI route-table
Not added
c. route-table: global route-table
key: {RD=ES-RD, ESI, ET=0xffffffff)

2. Remote EAD-ES routes
a. route-table: per-ES route-table
Not added
b. route-table: per-VNI route-table
key: {RD=ES-RD, ESI, ET=0xffffffff, VTEP-IP)
c. route-table: global route-table
key: {RD=ES-RD, ESI, ET=0xffffffff)

3. Local EAD-EVI routes
a. route-table: per-ES route-table
Not added
b. route-table: per-VNI route-table
key: {RD=0, ESI, ET=0, VTEP-IP)
c. route-table: global route-table
key: {RD=L2-VNI-RD, ESI, ET=0)

4. Remote EAD-EVI routes
a. route-table: per-ES route-table
Not added
b. route-table: per-VNI route-table
key: {RD=0, ESI, ET=0, VTEP-IP)
c. route-table: global route-table
key: {RD=L2-VNI-RD, ESI, ET=0)

Please refer to bgp_evpn_mh.h for info on how the data-structures are
organized.

Signed-off-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>

1 files changed, 84 insertions, 41 deletions

diff --git a/bgpd/bgp_evpn_private.h b/bgpd/bgp_evpn_private.h
index 839785d3a0..4ac626e4cb 100644
--- a/bgpd/bgp_evpn_private.h
+++ b/bgpd/bgp_evpn_private.h
@@ -34,6 +34,20 @@
  * in bits  */
 #define EVPN_ROUTE_PREFIXLEN (sizeof(struct evpn_addr) * 8)
 
+/* EVPN route RD buffer length */
+#define BGP_EVPN_PREFIX_RD_LEN 100
+
+/* packet sizes for EVPN routes */
+/* Type-1 route should be 25 bytes
+ *  RD (8), ESI (10), eth-tag (4), vni (3)
+ */
+#define BGP_EVPN_TYPE1_PSIZE 25
+/* Type-4 route should be either 23 or 35 bytes
+ *  RD (8), ESI (10), ip-len (1), ip (4 or 16)
+ */
+#define BGP_EVPN_TYPE4_V4_PSIZE 23
+#define BGP_EVPN_TYPE4_V6_PSIZE 34
+
 /* EVPN route types. */
 typedef enum {
 	BGP_EVPN_AD_ROUTE = 1,    /* Ethernet Auto-Discovery (A-D) route */
@@ -43,6 +57,9 @@ typedef enum {
 	BGP_EVPN_IP_PREFIX_ROUTE, /* IP Prefix route */
 } bgp_evpn_route_type;
 
+RB_HEAD(bgp_es_evi_rb_head, bgp_evpn_es_evi);
+RB_PROTOTYPE(bgp_es_evi_rb_head, bgp_evpn_es_evi, rb_node,
+		bgp_es_evi_rb_cmp);
 /*
  * Hash table of EVIs. Right now, the only type of EVI supported is with
  * VxLAN encapsulation, hence each EVI corresponds to a L2 VNI.
@@ -98,46 +115,16 @@ struct bgpevpn {
 	 * this VNI. */
 	struct bgp_table *route_table;
 
-	QOBJ_FIELDS
-};
-
-DECLARE_QOBJ_TYPE(bgpevpn)
-
-struct evpnes {
-
-	/* Ethernet Segment Identifier */
-	esi_t esi;
-
-	/* es flags */
-	uint16_t flags;
-#define EVPNES_LOCAL	0x01
-#define EVPNES_REMOTE	0x02
-
-	/*
-	 * Id for deriving the RD
-	 * automatically for this ESI
-	 */
-	uint16_t rd_id;
-
-	/* RD for this VNI. */
-	struct prefix_rd prd;
+	/* RB tree of ES-EVIs */
+	struct bgp_es_evi_rb_head es_evi_rb_tree;
 
-	/* originator ip address  */
-	struct ipaddr originator_ip;
-
-	/* list of VTEPs in the same site */
-	struct list *vtep_list;
-
-	/*
-	 * Route table for EVPN routes for
-	 * this ESI. - type4 routes
-	 */
-	struct bgp_table *route_table;
+	/* List of local ESs */
+	struct list *local_es_evi_list;
 
 	QOBJ_FIELDS
 };
 
-DECLARE_QOBJ_TYPE(evpnes)
+DECLARE_QOBJ_TYPE(bgpevpn)
 
 /* Mapping of Import RT to VNIs.
  * The Import RTs of all VNIs are maintained in a hash table with each
@@ -330,6 +317,16 @@ static inline void encode_es_rt_extcomm(struct ecommunity_val *eval,
 	memcpy(&eval->val[2], mac, ETH_ALEN);
 }
 
+static inline void encode_esi_label_extcomm(struct ecommunity_val *eval,
+					bool single_active)
+{
+	memset(eval, 0, sizeof(struct ecommunity_val));
+	eval->val[0] = ECOMMUNITY_ENCODE_EVPN;
+	eval->val[1] = ECOMMUNITY_EVPN_SUBTYPE_ESI_LABEL;
+	if (single_active)
+		eval->val[2] |= (1 << 0);
+}
+
 static inline void encode_rmac_extcomm(struct ecommunity_val *eval,
 				       struct ethaddr *rmac)
 {
@@ -487,6 +484,47 @@ static inline void build_evpn_type4_prefix(struct prefix_evpn *p,
 	memcpy(&p->prefix.es_addr.esi, esi, sizeof(esi_t));
 }
 
+static inline void build_evpn_type1_prefix(struct prefix_evpn *p,
+		uint32_t eth_tag,
+		esi_t *esi,
+		struct in_addr originator_ip)
+{
+	memset(p, 0, sizeof(struct prefix_evpn));
+	p->family = AF_EVPN;
+	p->prefixlen = EVPN_ROUTE_PREFIXLEN;
+	p->prefix.route_type = BGP_EVPN_AD_ROUTE;
+	p->prefix.ead_addr.eth_tag = eth_tag;
+	p->prefix.ead_addr.ip_prefix_length = IPV4_MAX_BITLEN;
+	p->prefix.ead_addr.ip.ipa_type = IPADDR_V4;
+	p->prefix.ead_addr.ip.ipaddr_v4 = originator_ip;
+	memcpy(&p->prefix.ead_addr.esi, esi, sizeof(esi_t));
+}
+
+static inline void evpn_type1_prefix_global_copy(struct prefix_evpn *global_p,
+		const struct prefix_evpn *vni_p)
+{
+	memcpy(global_p, vni_p, sizeof(*global_p));
+	global_p->prefix.ead_addr.ip_prefix_length = 0;
+	global_p->prefix.ead_addr.ip.ipa_type = 0;
+	global_p->prefix.ead_addr.ip.ipaddr_v4.s_addr = 0;
+}
+
+/* EAD prefix in the global table doesn't include the VTEP-IP so
+ * we need to create a different copy for the VNI
+ */
+static inline struct prefix_evpn *evpn_type1_prefix_vni_copy(
+		struct prefix_evpn *vni_p,
+		const struct prefix_evpn *global_p,
+		struct in_addr originator_ip)
+{
+	memcpy(vni_p, global_p, sizeof(*vni_p));
+	vni_p->prefix.ead_addr.ip_prefix_length = IPV4_MAX_BITLEN;
+	vni_p->prefix.ead_addr.ip.ipa_type = IPADDR_V4;
+	vni_p->prefix.ead_addr.ip.ipaddr_v4 = originator_ip;
+
+	return vni_p;
+}
+
 static inline int evpn_default_originate_set(struct bgp *bgp, afi_t afi,
 					     safi_t safi)
 {
@@ -511,11 +549,6 @@ static inline void es_get_system_mac(esi_t *esi,
 	memcpy(mac, &esi->val[1], ETH_ALEN);
 }
 
-static inline int is_es_local(struct evpnes *es)
-{
-	return CHECK_FLAG(es->flags, EVPNES_LOCAL) ? 1 : 0;
-}
-
 static inline bool bgp_evpn_is_svi_macip_enabled(struct bgpevpn *vpn)
 {
 	struct bgp *bgp_evpn = NULL;
@@ -526,6 +559,8 @@ static inline bool bgp_evpn_is_svi_macip_enabled(struct bgpevpn *vpn)
 		vpn->advertise_svi_macip);
 }
 
+extern struct zclient *zclient;
+
 extern void bgp_evpn_install_uninstall_default_route(struct bgp *bgp_vrf,
 						     afi_t afi, safi_t safi,
 						     bool add);
@@ -563,10 +598,18 @@ extern struct bgpevpn *bgp_evpn_new(struct bgp *bgp, vni_t vni,
 		vrf_id_t tenant_vrf_id,
 		struct in_addr mcast_grp);
 extern void bgp_evpn_free(struct bgp *bgp, struct bgpevpn *vpn);
-extern struct evpnes *bgp_evpn_lookup_es(struct bgp *bgp, esi_t *esi);
 extern bool bgp_evpn_lookup_l3vni_l2vni_table(vni_t vni);
 extern int update_routes_for_vni(struct bgp *bgp, struct bgpevpn *vpn);
 extern void delete_evpn_route_entry(struct bgp *bgp, afi_t afi, safi_t safi,
 				    struct bgp_dest *dest,
 				    struct bgp_path_info **pi);
+int vni_list_cmp(void *p1, void *p2);
+extern int evpn_route_select_install(struct bgp *bgp, struct bgpevpn *vpn,
+		struct bgp_node *rn);
+extern struct bgp_node *bgp_global_evpn_node_get(
+		struct bgp_table *table, afi_t afi, safi_t safi,
+		const struct prefix_evpn *evp, struct prefix_rd *prd);
+extern struct bgp_node *bgp_global_evpn_node_lookup(
+		struct bgp_table *table, afi_t afi, safi_t safi,
+		const struct prefix_evpn *evp, struct prefix_rd *prd);
 #endif /* _BGP_EVPN_PRIVATE_H */