srv6: add srv6 module

Add Segment Routing (SR) over IPv6 (SRv6). SR over MPLS is not addressed.

Endpoints, SR policies and steering rules can be configured as static rules
through api/cli. Integration with BGP/IGP is future work.

This patch addresses part of the following RFC:

RFC8402: Segment Routing Architecture
	https://www.rfc-editor.org/rfc/rfc8402

RFC8754: IPv6 Segment Routing Header (SRH)
	https://www.rfc-editor.org/rfc/rfc8754

RFC8986: Segment Routing over IPv6 (SRv6) Network Programming
	https://www.rfc-editor.org/rfc/rfc8986

Headend node implements H.Encaps and H.Encaps.Red.
Local node implements End, End.T (with PSP, USD flavors), End.DT6,
End.DT4 and End.DT46.

Signed-off-by: Olivier Gournet <[email protected]>

Author: ogournet

docs/graph.svg

@@ -26,6 +26,8 @@ typedef enum : uint16_t {
 typedef enum : uint8_t {
 	GR_NH_IPV4 = 1,
 	GR_NH_IPV6,
+	GR_NH_SR6_IPV4,
+	GR_NH_SR6_IPV6,
 	GR_NH_TYPE_COUNT
 } gr_nh_type_t;
 
@@ -82,8 +84,10 @@ static inline const char *gr_nh_flag_name(const gr_nh_flags_t flag) {
 static inline uint8_t nh_af(const struct gr_nexthop *nh) {
 	switch (nh->type) {
 	case GR_NH_IPV4:
+	case GR_NH_SR6_IPV4:
 		return AF_INET;
 	case GR_NH_IPV6:
+	case GR_NH_SR6_IPV6:
 		return AF_INET6;
 	case GR_NH_TYPE_COUNT:
 		break;

modules/infra/api/gr_nexthop.h

@@ -48,9 +48,11 @@ nexthop_new(gr_nh_type_t type, uint16_t vrf_id, uint16_t iface_id, const void *a
 	nh->type = type;
 	switch (type) {
 	case GR_NH_IPV4:
+	case GR_NH_SR6_IPV4:
 		nh->ipv4 = *(ip4_addr_t *)addr;
 		break;
 	case GR_NH_IPV6:
+	case GR_NH_SR6_IPV6:
 		nh->ipv6 = *(struct rte_ipv6_addr *)addr;
 		break;
 	default:
@@ -101,10 +103,12 @@ static void nh_lookup_cb(struct nexthop *nh, void *priv) {
 
 	switch (filter->type) {
 	case GR_NH_IPV4:
+	case GR_NH_SR6_IPV4:
 		if (nh->ipv4 == *(ip4_addr_t *)filter->addr)
 			filter->nh = nh;
 		break;
 	case GR_NH_IPV6:
+	case GR_NH_SR6_IPV6:
 		if (rte_ipv6_addr_eq(&nh->ipv6, filter->addr)) {
 			bool is_linklocal = rte_ipv6_addr_is_linklocal(&nh->ipv6);
 			if (!is_linklocal || nh->iface_id == filter->iface_id)

modules/infra/control/nexthop.c

@@ -6,3 +6,4 @@ subdir('ip')
 subdir('ip6')
 subdir('ipip')
 subdir('l4')
+subdir('srv6')