bgpd,lib,sharpd,zebra: srv6 introduce multiple segs/SIDs in nexthop

Append zebra and lib to use muliple SRv6 segs SIDs, and keep one
seg SID for bgpd and sharpd.

Note: bgpd and sharpd compilation relies on the lib and zebra files,
i.e if we separate this: lib or zebra or bgpd or sharpd in different
commits - this will not compile.

Signed-off-by: Dmytro Shytyi <dmytro.shytyi@6wind.com>

12 files changed, 194 insertions, 88 deletions

diff --git a/bgpd/bgp_zebra.c b/bgpd/bgp_zebra.c
index 3d993e12c..9e02f1b55 100644
--- a/bgpd/bgp_zebra.c
+++ b/bgpd/bgp_zebra.c
@@ -1557,17 +1557,17 @@ void bgp_zebra_announce(struct bgp_dest *dest, const struct prefix *p,
 		api_nh->weight = nh_weight;
 
 		if (((mpinfo->attr->srv6_l3vpn &&
-		      !sid_zero(&mpinfo->attr->srv6_l3vpn->sid)) ||
+		      !sid_zero_ipv6(&mpinfo->attr->srv6_l3vpn->sid)) ||
 		     (mpinfo->attr->srv6_vpn &&
-		      !sid_zero(&mpinfo->attr->srv6_vpn->sid))) &&
+		      !sid_zero_ipv6(&mpinfo->attr->srv6_vpn->sid))) &&
 		    !is_evpn && bgp_is_valid_label(&labels[0])) {
 			struct in6_addr *sid_tmp =
 				mpinfo->attr->srv6_l3vpn
 					? (&mpinfo->attr->srv6_l3vpn->sid)
 					: (&mpinfo->attr->srv6_vpn->sid);
 
-			memcpy(&api_nh->seg6_segs, sid_tmp,
-			       sizeof(api_nh->seg6_segs));
+			memcpy(&api_nh->seg6_segs[0], sid_tmp,
+			       sizeof(api_nh->seg6_segs[0]));
 
 			if (mpinfo->attr->srv6_l3vpn &&
 			    mpinfo->attr->srv6_l3vpn->transposition_len != 0) {
@@ -1581,13 +1581,14 @@ void bgp_zebra_announce(struct bgp_dest *dest, const struct prefix *p,
 					continue;
 				}
 
-				transpose_sid(&api_nh->seg6_segs, nh_label,
+				transpose_sid(&api_nh->seg6_segs[0], nh_label,
 					      mpinfo->attr->srv6_l3vpn
 						      ->transposition_offset,
 					      mpinfo->attr->srv6_l3vpn
 						      ->transposition_len);
 			}
 
+			api_nh->seg_num = 1;
 			SET_FLAG(api_nh->flags, ZAPI_NEXTHOP_FLAG_SEG6);
 		}
 
@@ -1704,7 +1705,7 @@ void bgp_zebra_announce(struct bgp_dest *dest, const struct prefix *p,
 			if (CHECK_FLAG(api_nh->flags, ZAPI_NEXTHOP_FLAG_SEG6) &&
 			    !CHECK_FLAG(api_nh->flags,
 					ZAPI_NEXTHOP_FLAG_EVPN)) {
-				inet_ntop(AF_INET6, &api_nh->seg6_segs,
+				inet_ntop(AF_INET6, &api_nh->seg6_segs[0],
 					  sid_buf, sizeof(sid_buf));
 				snprintf(segs_buf, sizeof(segs_buf), "segs %s",
 					 sid_buf);
diff --git a/include/linux/seg6.h b/include/linux/seg6.h
index 329163e4a..5b572ba3d 100644
--- a/include/linux/seg6.h
+++ b/include/linux/seg6.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+// SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note
 /*
  *  SR-IPv6 implementation
  *
@@ -30,7 +30,7 @@ struct ipv6_sr_hdr {
 	__u8	flags;
 	__u16	tag;
 
-	struct in6_addr segments[0];
+	struct in6_addr segments[];
 };
 
 #define SR6_FLAG1_PROTECTED	(1 << 6)
diff --git a/lib/nexthop.c b/lib/nexthop.c
index 4f92ef9c8..92fbed5ea 100644
--- a/lib/nexthop.c
+++ b/lib/nexthop.c
@@ -570,13 +570,15 @@ void nexthop_del_srv6_seg6local(struct nexthop *nexthop)
 
 	nexthop->nh_srv6->seg6local_action = ZEBRA_SEG6_LOCAL_ACTION_UNSPEC;
 
-	if (sid_zero(&nexthop->nh_srv6->seg6_segs))
+	if (nexthop->nh_srv6->seg6_segs == NULL)
 		XFREE(MTYPE_NH_SRV6, nexthop->nh_srv6);
 }
 
-void nexthop_add_srv6_seg6(struct nexthop *nexthop,
-			   const struct in6_addr *segs)
+void nexthop_add_srv6_seg6(struct nexthop *nexthop, const struct in6_addr *segs,
+			   int num_segs)
 {
+	int i;
+
 	if (!segs)
 		return;
 
@@ -584,7 +586,22 @@ void nexthop_add_srv6_seg6(struct nexthop *nexthop,
 		nexthop->nh_srv6 = XCALLOC(MTYPE_NH_SRV6,
 					   sizeof(struct nexthop_srv6));
 
-	nexthop->nh_srv6->seg6_segs = *segs;
+	/* Enforce limit on srv6 seg stack size */
+	if (num_segs > SRV6_MAX_SIDS)
+		num_segs = SRV6_MAX_SIDS;
+
+	if (!nexthop->nh_srv6->seg6_segs) {
+		nexthop->nh_srv6->seg6_segs =
+			XCALLOC(MTYPE_NH_SRV6,
+				sizeof(struct seg6_seg_stack) +
+					num_segs * sizeof(struct in6_addr));
+	}
+
+	nexthop->nh_srv6->seg6_segs->num_segs = num_segs;
+
+	for (i = 0; i < num_segs; i++)
+		memcpy(&nexthop->nh_srv6->seg6_segs->seg[i], &segs[i],
+		       sizeof(struct in6_addr));
 }
 
 void nexthop_del_srv6_seg6(struct nexthop *nexthop)
@@ -810,9 +827,13 @@ void nexthop_copy_no_recurse(struct nexthop *copy,
 			nexthop_add_srv6_seg6local(copy,
 				nexthop->nh_srv6->seg6local_action,
 				&nexthop->nh_srv6->seg6local_ctx);
-		if (!sid_zero(&nexthop->nh_srv6->seg6_segs))
+		if (nexthop->nh_srv6->seg6_segs &&
+		    nexthop->nh_srv6->seg6_segs->num_segs &&
+		    !sid_zero(nexthop->nh_srv6->seg6_segs))
 			nexthop_add_srv6_seg6(copy,
-				&nexthop->nh_srv6->seg6_segs);
+					      &nexthop->nh_srv6->seg6_segs->seg[0],
+					      nexthop->nh_srv6->seg6_segs
+						      ->num_segs);
 	}
 }
 
diff --git a/lib/nexthop.h b/lib/nexthop.h
index 2be89f824..bed6447d4 100644
--- a/lib/nexthop.h
+++ b/lib/nexthop.h
@@ -157,8 +157,8 @@ void nexthop_del_labels(struct nexthop *);
 void nexthop_add_srv6_seg6local(struct nexthop *nexthop, uint32_t action,
 				const struct seg6local_context *ctx);
 void nexthop_del_srv6_seg6local(struct nexthop *nexthop);
-void nexthop_add_srv6_seg6(struct nexthop *nexthop,
-			   const struct in6_addr *segs);
+void nexthop_add_srv6_seg6(struct nexthop *nexthop, const struct in6_addr *seg,
+			   int num_segs);
 void nexthop_del_srv6_seg6(struct nexthop *nexthop);
 
 /*
diff --git a/lib/srv6.h b/lib/srv6.h
index 7c8c6b4a6..fb34f861c 100644
--- a/lib/srv6.h
+++ b/lib/srv6.h
@@ -14,8 +14,11 @@
 #include <arpa/inet.h>
 #include <netinet/in.h>
 
-#define SRV6_MAX_SIDS 16
+#define SRV6_MAX_SIDS	  16
+#define SRV6_MAX_SEGS	  8
 #define SRV6_LOCNAME_SIZE 256
+#define SRH_BASE_HEADER_LENGTH 8
+#define SRH_SEGMENT_LENGTH     16
 
 #ifdef __cplusplus
 extern "C" {
@@ -74,6 +77,8 @@ enum seg6local_flavor_op {
 	ZEBRA_SEG6_LOCAL_FLV_OP_NEXT_CSID    = 4,
 };
 
+#define SRV6_SEG_STRLEN 1024
+
 struct seg6_segs {
 	size_t num_segs;
 	struct in6_addr segs[256];
@@ -89,6 +94,11 @@ struct seg6local_flavors_info {
 	uint8_t lcnode_func_len;
 };
 
+struct seg6_seg_stack {
+	uint8_t num_segs;
+	struct in6_addr seg[0]; /* 1 or more segs */
+};
+
 struct seg6local_context {
 	struct in_addr nh4;
 	struct in6_addr nh6;
@@ -170,7 +180,7 @@ struct nexthop_srv6 {
 	struct seg6local_context seg6local_ctx;
 
 	/* SRv6 Headend-behaviour */
-	struct in6_addr seg6_segs;
+	struct seg6_seg_stack *seg6_segs;
 };
 
 static inline const char *seg6_mode2str(enum seg6_mode_t mode)
@@ -206,12 +216,21 @@ static inline bool sid_diff(
 	return !sid_same(a, b);
 }
 
-static inline bool sid_zero(
-		const struct in6_addr *a)
+
+static inline bool sid_zero(const struct seg6_seg_stack *a)
+{
+	struct in6_addr zero = {};
+
+	assert(a);
+
+	return sid_same(&a->seg[0], &zero);
+}
+
+static inline bool sid_zero_ipv6(const struct in6_addr *a)
 {
 	struct in6_addr zero = {};
 
-	return sid_same(a, &zero);
+	return sid_same(&a[0], &zero);
 }
 
 static inline void *sid_copy(struct in6_addr *dst,
diff --git a/lib/zclient.c b/lib/zclient.c
index 68a342982..f8f9cf7ab 100644
--- a/lib/zclient.c
+++ b/lib/zclient.c
@@ -1061,10 +1061,11 @@ int zapi_nexthop_encode(struct stream *s, const struct zapi_nexthop *api_nh,
 			     sizeof(struct seg6local_context));
 	}
 
-	if (CHECK_FLAG(nh_flags, ZAPI_NEXTHOP_FLAG_SEG6))
-		stream_write(s, &api_nh->seg6_segs,
-			     sizeof(struct in6_addr));
-
+	if (CHECK_FLAG(nh_flags, ZAPI_NEXTHOP_FLAG_SEG6)) {
+		stream_putc(s, api_nh->seg_num);
+		stream_put(s, &api_nh->seg6_segs[0],
+			   api_nh->seg_num * sizeof(struct in6_addr));
+	}
 done:
 	return ret;
 }
@@ -1430,9 +1431,18 @@ int zapi_nexthop_decode(struct stream *s, struct zapi_nexthop *api_nh,
 			   sizeof(struct seg6local_context));
 	}
 
-	if (CHECK_FLAG(api_nh->flags, ZAPI_NEXTHOP_FLAG_SEG6))
-		STREAM_GET(&api_nh->seg6_segs, s,
-			   sizeof(struct in6_addr));
+	if (CHECK_FLAG(api_nh->flags, ZAPI_NEXTHOP_FLAG_SEG6)) {
+		STREAM_GETC(s, api_nh->seg_num);
+		if (api_nh->seg_num > SRV6_MAX_SIDS) {
+			flog_err(EC_LIB_ZAPI_ENCODE,
+				 "%s: invalid number of SRv6 Segs (%u)",
+				 __func__, api_nh->seg_num);
+			return -1;
+		}
+
+		STREAM_GET(&api_nh->seg6_segs[0], s,
+			   api_nh->seg_num * sizeof(struct in6_addr));
+	}
 
 	/* Success */
 	ret = 0;
@@ -2132,8 +2142,8 @@ struct nexthop *nexthop_from_zapi_nexthop(const struct zapi_nexthop *znh)
 		nexthop_add_srv6_seg6local(n, znh->seg6local_action,
 					   &znh->seg6local_ctx);
 
-	if (!sid_zero(&znh->seg6_segs))
-		nexthop_add_srv6_seg6(n, &znh->seg6_segs);
+	if (znh->seg_num && !sid_zero_ipv6(znh->seg6_segs))
+		nexthop_add_srv6_seg6(n, &znh->seg6_segs[0], znh->seg_num);
 
 	return n;
 }
@@ -2193,10 +2203,14 @@ int zapi_nexthop_from_nexthop(struct zapi_nexthop *znh,
 			       sizeof(struct seg6local_context));
 		}
 
-		if (!sid_zero(&nh->nh_srv6->seg6_segs)) {
+		if (nh->nh_srv6->seg6_segs && nh->nh_srv6->seg6_segs->num_segs &&
+		    !sid_zero(nh->nh_srv6->seg6_segs)) {
 			SET_FLAG(znh->flags, ZAPI_NEXTHOP_FLAG_SEG6);
-			memcpy(&znh->seg6_segs, &nh->nh_srv6->seg6_segs,
-			       sizeof(struct in6_addr));
+			znh->seg_num = nh->nh_srv6->seg6_segs->num_segs;
+			for (i = 0; i < nh->nh_srv6->seg6_segs->num_segs; i++)
+				memcpy(&znh->seg6_segs[i],
+				       &nh->nh_srv6->seg6_segs->seg[i],
+				       sizeof(struct in6_addr));
 		}
 	}
 
diff --git a/lib/zclient.h b/lib/zclient.h
index 42c5a5fda..2a3ce4e48 100644
--- a/lib/zclient.h
+++ b/lib/zclient.h
@@ -438,7 +438,8 @@ struct zapi_nexthop {
 	struct seg6local_context seg6local_ctx;
 
 	/* SRv6 Headend-behaviour */
-	struct in6_addr seg6_segs;
+	int seg_num;
+	struct in6_addr seg6_segs[SRV6_MAX_SEGS];
 };
 
 /*
diff --git a/sharpd/sharp_vty.c b/sharpd/sharp_vty.c
index f0a75a5fc..e891c1b6b 100644
--- a/sharpd/sharp_vty.c
+++ b/sharpd/sharp_vty.c
@@ -402,7 +402,7 @@ DEFPY (install_seg6_routes,
 	sg.r.nhop.gate.ipv6 = seg6_nh6;
 	sg.r.nhop.vrf_id = vrf->vrf_id;
 	sg.r.nhop_group.nexthop = &sg.r.nhop;
-	nexthop_add_srv6_seg6(&sg.r.nhop, &seg6_seg);
+	nexthop_add_srv6_seg6(&sg.r.nhop, &seg6_seg, 1);
 
 	sg.r.vrf_id = vrf->vrf_id;
 	sharp_install_routes_helper(&prefix, sg.r.vrf_id, sg.r.inst, 0,
diff --git a/zebra/rt_netlink.c b/zebra/rt_netlink.c
index 9d8ef00b5..bfe1910a5 100644
--- a/zebra/rt_netlink.c
+++ b/zebra/rt_netlink.c
@@ -66,6 +66,7 @@
 #include "zebra/zebra_evpn_mh.h"
 #include "zebra/zebra_trace.h"
 #include "zebra/zebra_neigh.h"
+#include "lib/srv6.h"
 
 #ifndef AF_MPLS
 #define AF_MPLS 28
@@ -77,6 +78,8 @@
 #define BR_SPH_LIST_SIZE 10
 #endif
 
+DEFINE_MTYPE_STATIC(LIB, NH_SRV6, "Nexthop srv6");
+
 static vlanid_t filter_vlan = 0;
 
 /* We capture whether the current kernel supports nexthop ids; by
@@ -476,19 +479,19 @@ static int parse_encap_seg6(struct rtattr *tb, struct in6_addr *segs)
 {
 	struct rtattr *tb_encap[SEG6_IPTUNNEL_MAX + 1] = {};
 	struct seg6_iptunnel_encap *ipt = NULL;
-	struct in6_addr *segments = NULL;
+	int i;
 
 	netlink_parse_rtattr_nested(tb_encap, SEG6_IPTUNNEL_MAX, tb);
 
-	/*
-	 * TODO: It's not support multiple SID list.
-	 */
 	if (tb_encap[SEG6_IPTUNNEL_SRH]) {
 		ipt = (struct seg6_iptunnel_encap *)
 			RTA_DATA(tb_encap[SEG6_IPTUNNEL_SRH]);
-		segments = ipt->srh[0].segments;
-		*segs = segments[0];
-		return 1;
+
+		for (i = ipt->srh[0].first_segment; i >= 0; i--)
+			memcpy(&segs[i], &ipt->srh[0].segments[i],
+			       sizeof(struct in6_addr));
+
+		return ipt->srh[0].first_segment + 1;
 	}
 
 	return 0;
@@ -506,7 +509,7 @@ parse_nexthop_unicast(ns_id_t ns_id, struct rtmsg *rtm, struct rtattr **tb,
 	int num_labels = 0;
 	enum seg6local_action_t seg6l_act = ZEBRA_SEG6_LOCAL_ACTION_UNSPEC;
 	struct seg6local_context seg6l_ctx = {};
-	struct in6_addr seg6_segs = {};
+	struct in6_addr segs[SRV6_MAX_SIDS] = {};
 	int num_segs = 0;
 
 	vrf_id_t nh_vrf_id = vrf_id;
@@ -555,7 +558,7 @@ parse_nexthop_unicast(ns_id_t ns_id, struct rtmsg *rtm, struct rtattr **tb,
 	if (tb[RTA_ENCAP] && tb[RTA_ENCAP_TYPE]
 	    && *(uint16_t *)RTA_DATA(tb[RTA_ENCAP_TYPE])
 		       == LWTUNNEL_ENCAP_SEG6) {
-		num_segs = parse_encap_seg6(tb[RTA_ENCAP], &seg6_segs);
+		num_segs = parse_encap_seg6(tb[RTA_ENCAP], segs);
 	}
 
 	if (rtm->rtm_flags & RTNH_F_ONLINK)
@@ -581,7 +584,7 @@ parse_nexthop_unicast(ns_id_t ns_id, struct rtmsg *rtm, struct rtattr **tb,
 		nexthop_add_srv6_seg6local(&nh, seg6l_act, &seg6l_ctx);
 
 	if (num_segs)
-		nexthop_add_srv6_seg6(&nh, &seg6_segs);
+		nexthop_add_srv6_seg6(&nh, segs, num_segs);
 
 	return nh;
 }
@@ -601,7 +604,7 @@ static uint8_t parse_multipath_nexthops_unicast(ns_id_t ns_id,
 	int num_labels = 0;
 	enum seg6local_action_t seg6l_act = ZEBRA_SEG6_LOCAL_ACTION_UNSPEC;
 	struct seg6local_context seg6l_ctx = {};
-	struct in6_addr seg6_segs = {};
+	struct in6_addr segs[SRV6_MAX_SIDS] = {};
 	int num_segs = 0;
 	struct rtattr *rtnh_tb[RTA_MAX + 1] = {};
 
@@ -657,7 +660,7 @@ static uint8_t parse_multipath_nexthops_unicast(ns_id_t ns_id,
 			    && *(uint16_t *)RTA_DATA(rtnh_tb[RTA_ENCAP_TYPE])
 				       == LWTUNNEL_ENCAP_SEG6) {
 				num_segs = parse_encap_seg6(rtnh_tb[RTA_ENCAP],
-							   &seg6_segs);
+							    segs);
 			}
 		}
 
@@ -700,7 +703,7 @@ static uint8_t parse_multipath_nexthops_unicast(ns_id_t ns_id,
 							   &seg6l_ctx);
 
 			if (num_segs)
-				nexthop_add_srv6_seg6(nh, &seg6_segs);
+				nexthop_add_srv6_seg6(nh, segs, num_segs);
 
 			if (rtnh->rtnh_flags & RTNH_F_ONLINK)
 				SET_FLAG(nh->flags, NEXTHOP_FLAG_ONLINK);
@@ -1514,37 +1517,40 @@ static bool _netlink_route_encode_nexthop_src(const struct nexthop *nexthop,
 }
 
 static ssize_t fill_seg6ipt_encap(char *buffer, size_t buflen,
-				  const struct in6_addr *seg)
+				  struct seg6_seg_stack *segs)
 {
 	struct seg6_iptunnel_encap *ipt;
 	struct ipv6_sr_hdr *srh;
-	const size_t srhlen = 24;
+	size_t srhlen;
+	int i;
 
-	/*
-	 * Caution: Support only SINGLE-SID, not MULTI-SID
-	 * This function only supports the case where segs represents
-	 * a single SID. If you want to extend the SRv6 functionality,
-	 * you should improve the Boundary Check.
-	 * Ex. In case of set a SID-List include multiple-SIDs as an
-	 * argument of the Transit Behavior, we must support variable
-	 * boundary check for buflen.
-	 */
-	if (buflen < (sizeof(struct seg6_iptunnel_encap) +
-		      sizeof(struct ipv6_sr_hdr) + 16))
+	if (segs->num_segs > SRV6_MAX_SEGS) {
+		/* Exceeding maximum supported SIDs */
+		return -1;
+	}
+
+	srhlen = SRH_BASE_HEADER_LENGTH + SRH_SEGMENT_LENGTH * segs->num_segs;
+
+	if (buflen < (sizeof(struct seg6_iptunnel_encap) + srhlen))
 		return -1;
 
 	memset(buffer, 0, buflen);
 
 	ipt = (struct seg6_iptunnel_encap *)buffer;
 	ipt->mode = SEG6_IPTUN_MODE_ENCAP;
-	srh = ipt->srh;
+
+	srh = (struct ipv6_sr_hdr *)&ipt->srh;
 	srh->hdrlen = (srhlen >> 3) - 1;
 	srh->type = 4;
-	srh->segments_left = 0;
-	srh->first_segment = 0;
-	memcpy(&srh->segments[0], seg, sizeof(struct in6_addr));
+	srh->segments_left = segs->num_segs - 1;
+	srh->first_segment = segs->num_segs - 1;
+
+	for (i = 0; i < segs->num_segs; i++) {
+		memcpy(&srh->segments[i], &segs->seg[i],
+		       sizeof(struct in6_addr));
+	}
 
-	return srhlen + 4;
+	return sizeof(struct seg6_iptunnel_encap) + srhlen;
 }
 
 static bool
@@ -1726,7 +1732,9 @@ static bool _netlink_route_build_singlepath(const struct prefix *p,
 			nl_attr_nest_end(nlmsg, nest);
 		}
 
-		if (!sid_zero(&nexthop->nh_srv6->seg6_segs)) {
+		if (nexthop->nh_srv6->seg6_segs &&
+		    nexthop->nh_srv6->seg6_segs->num_segs &&
+		    !sid_zero(nexthop->nh_srv6->seg6_segs)) {
 			char tun_buf[4096];
 			ssize_t tun_len;
 			struct rtattr *nest;
@@ -1737,8 +1745,9 @@ static bool _netlink_route_build_singlepath(const struct prefix *p,
 			nest = nl_attr_nest(nlmsg, req_size, RTA_ENCAP);
 			if (!nest)
 				return false;
-			tun_len = fill_seg6ipt_encap(tun_buf, sizeof(tun_buf),
-					&nexthop->nh_srv6->seg6_segs);
+			tun_len =
+				fill_seg6ipt_encap(tun_buf, sizeof(tun_buf),
+						   nexthop->nh_srv6->seg6_segs);
 			if (tun_len < 0)
 				return false;
 			if (!nl_attr_put(nlmsg, req_size, SEG6_IPTUNNEL_SRH,
@@ -2971,7 +2980,9 @@ ssize_t netlink_nexthop_msg_encode(uint16_t cmd,
 					nl_attr_nest_end(&req->n, nest);
 				}
 
-				if (!sid_zero(&nh->nh_srv6->seg6_segs)) {
+				if (nh->nh_srv6->seg6_segs &&
+				    nh->nh_srv6->seg6_segs->num_segs &&
+				    !sid_zero(nh->nh_srv6->seg6_segs)) {
 					char tun_buf[4096];
 					ssize_t tun_len;
 					struct rtattr *nest;
@@ -2984,9 +2995,9 @@ ssize_t netlink_nexthop_msg_encode(uint16_t cmd,
 					    NHA_ENCAP | NLA_F_NESTED);
 					if (!nest)
 						return 0;
-					tun_len = fill_seg6ipt_encap(tun_buf,
-					    sizeof(tun_buf),
-					    &nh->nh_srv6->seg6_segs);
+					tun_len = fill_seg6ipt_encap(
+						tun_buf, sizeof(tun_buf),
+						nh->nh_srv6->seg6_segs);
 					if (tun_len < 0)
 						return 0;
 					if (!nl_attr_put(&req->n, buflen,
diff --git a/zebra/zapi_msg.c b/zebra/zapi_msg.c
index 6bed6d872..8a480cfa1 100644
--- a/zebra/zapi_msg.c
+++ b/zebra/zapi_msg.c
@@ -1794,7 +1794,8 @@ static bool zapi_read_nexthops(struct zserv *client, struct prefix *p,
 			if (IS_ZEBRA_DEBUG_RECV)
 				zlog_debug("%s: adding seg6", __func__);
 
-			nexthop_add_srv6_seg6(nexthop, &api_nh->seg6_segs);
+			nexthop_add_srv6_seg6(nexthop, &api_nh->seg6_segs[0],
+					      api_nh->seg_num);
 		}
 
 		if (IS_ZEBRA_DEBUG_RECV) {
diff --git a/zebra/zebra_nhg.c b/zebra/zebra_nhg.c
index 3a56bf2a5..9588f65fc 100644
--- a/zebra/zebra_nhg.c
+++ b/zebra/zebra_nhg.c
@@ -1868,11 +1868,18 @@ static struct nexthop *nexthop_set_resolved(afi_t afi,
 				   labels);
 
 	if (nexthop->nh_srv6) {
-		nexthop_add_srv6_seg6local(resolved_hop,
-					   nexthop->nh_srv6->seg6local_action,
-					   &nexthop->nh_srv6->seg6local_ctx);
-		nexthop_add_srv6_seg6(resolved_hop,
-				      &nexthop->nh_srv6->seg6_segs);
+		if (nexthop->nh_srv6->seg6local_action !=
+		    ZEBRA_SEG6_LOCAL_ACTION_UNSPEC)
+			nexthop_add_srv6_seg6local(resolved_hop,
+						   nexthop->nh_srv6
+							   ->seg6local_action,
+						   &nexthop->nh_srv6
+							    ->seg6local_ctx);
+		if (nexthop->nh_srv6->seg6_segs)
+			nexthop_add_srv6_seg6(resolved_hop,
+					      &nexthop->nh_srv6->seg6_segs->seg[0],
+					      nexthop->nh_srv6->seg6_segs
+						      ->num_segs);
 	}
 
 	resolved_hop->rparent = nexthop;
diff --git a/zebra/zebra_rnh.c b/zebra/zebra_rnh.c
index 28b83ce8b..30d92c30f 100644
--- a/zebra/zebra_rnh.c
+++ b/zebra/zebra_rnh.c
@@ -1268,6 +1268,7 @@ void show_nexthop_json_helper(json_object *json_nexthop,
 	json_object *json_backups = NULL;
 	json_object *json_seg6local = NULL;
 	json_object *json_seg6 = NULL;
+	json_object *json_segs = NULL;
 	int i;
 
 	json_object_int_add(json_nexthop, "flags", nexthop->flags);
@@ -1425,11 +1426,31 @@ void show_nexthop_json_helper(json_object *json_nexthop,
 				nexthop->nh_srv6->seg6local_action));
 		json_object_object_add(json_nexthop, "seg6local",
 				       json_seg6local);
-
-		json_seg6 = json_object_new_object();
-		json_object_string_addf(json_seg6, "segs", "%pI6",
-					&nexthop->nh_srv6->seg6_segs);
-		json_object_object_add(json_nexthop, "seg6", json_seg6);
+		if (nexthop->nh_srv6->seg6_segs &&
+		    nexthop->nh_srv6->seg6_segs->num_segs == 1) {
+			json_seg6 = json_object_new_object();
+			json_object_string_addf(json_seg6, "segs", "%pI6",
+						&nexthop->nh_srv6->seg6_segs
+							 ->seg[0]);
+			json_object_object_add(json_nexthop, "seg6", json_seg6);
+		} else {
+			json_segs = json_object_new_array();
+			if (nexthop->nh_srv6->seg6_segs) {
+				for (int seg_idx = 0;
+				     seg_idx <
+				     nexthop->nh_srv6->seg6_segs->num_segs;
+				     seg_idx++)
+					json_object_array_add(
+						json_segs,
+						json_object_new_stringf(
+							"%pI6",
+							&nexthop->nh_srv6
+								 ->seg6_segs
+								 ->seg[seg_idx]));
+				json_object_object_add(json_nexthop, "seg6",
+						       json_segs);
+			}
+		}
 	}
 }
 
@@ -1440,7 +1461,9 @@ void show_route_nexthop_helper(struct vty *vty, const struct route_entry *re,
 			       const struct nexthop *nexthop)
 {
 	char buf[MPLS_LABEL_STRLEN];
-	int i;
+	char seg_buf[SRV6_SEG_STRLEN];
+	struct seg6_segs segs;
+	uint8_t i;
 
 	switch (nexthop->type) {
 	case NEXTHOP_TYPE_IPV4:
@@ -1538,9 +1561,17 @@ void show_route_nexthop_helper(struct vty *vty, const struct route_entry *re,
 				seg6local_action2str(
 					nexthop->nh_srv6->seg6local_action),
 				buf);
-		if (IPV6_ADDR_CMP(&nexthop->nh_srv6->seg6_segs, &in6addr_any))
-			vty_out(vty, ", seg6 %pI6",
-				&nexthop->nh_srv6->seg6_segs);
+		if (nexthop->nh_srv6->seg6_segs &&
+		    IPV6_ADDR_CMP(&nexthop->nh_srv6->seg6_segs->seg[0],
+				  &in6addr_any)) {
+			segs.num_segs = nexthop->nh_srv6->seg6_segs->num_segs;
+			for (i = 0; i < segs.num_segs; i++)
+				memcpy(&segs.segs[i],
+				       &nexthop->nh_srv6->seg6_segs->seg[i],
+				       sizeof(struct in6_addr));
+			snprintf_seg6_segs(seg_buf, SRV6_SEG_STRLEN, &segs);
+			vty_out(vty, ", seg6 %s", seg_buf);
+		}
 	}
 
 	if (nexthop->weight)