Merge branch 'ipv6-ioam-encap'

Justin Iurman says:

====================
Support for the ip6ip6 encapsulation of IOAM

v2:
 - add prerequisite patches
 - keep uapi backwards compatible by adding two new attributes
 - add more comments to document the ioam6_iptunnel uapi

In the current implementation, IOAM can only be inserted directly (i.e., only
inside packets generated locally) by default, to be compliant with RFC8200.

This patch adds support for in-transit packets and provides the ip6ip6
encapsulation of IOAM (RFC8200 compliant). Therefore, three ioam6 encap modes
are defined:

 - inline: directly inserts IOAM inside packets (by default).

 - encap:  ip6ip6 encapsulation of IOAM inside packets.

 - auto:   either inline mode for packets generated locally or encap mode for
           in-transit packets.

With current iproute2 implementation, it is configured this way:

$ ip -6 r [...] encap ioam6 trace prealloc [...]

The old syntax does not change (for backwards compatibility) and implicitly uses
the inline mode. With the new syntax, an encap mode can be specified:

(inline mode)
$ ip -6 r [...] encap ioam6 mode inline trace prealloc [...]

(encap mode)
$ ip -6 r [...] encap ioam6 mode encap tundst fc00::2 trace prealloc [...]

(auto mode)
$ ip -6 r [...] encap ioam6 mode auto tundst fc00::2 trace prealloc [...]

A tunnel destination address must be configured when using the encap mode or the
auto mode.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ioam6.h

@@ -56,7 +56,8 @@ static inline struct ioam6_pernet_data *ioam6_pernet(struct net *net)
 struct ioam6_namespace *ioam6_namespace(struct net *net, __be16 id);
 void ioam6_fill_trace_data(struct sk_buff *skb,
 			   struct ioam6_namespace *ns,
-			   struct ioam6_trace_hdr *trace);
+			   struct ioam6_trace_hdr *trace,
+			   bool is_input);
 
 int ioam6_init(void);
 void ioam6_exit(void);

include/uapi/linux/ioam6_iptunnel.h

@@ -9,9 +9,38 @@
 #ifndef _UAPI_LINUX_IOAM6_IPTUNNEL_H
 #define _UAPI_LINUX_IOAM6_IPTUNNEL_H
 
+/* Encap modes:
+ *  - inline: direct insertion
+ *  - encap: ip6ip6 encapsulation
+ *  - auto: inline for local packets, encap for in-transit packets
+ */
+enum {
+	__IOAM6_IPTUNNEL_MODE_MIN,
+
+	IOAM6_IPTUNNEL_MODE_INLINE,
+	IOAM6_IPTUNNEL_MODE_ENCAP,
+	IOAM6_IPTUNNEL_MODE_AUTO,
+
+	__IOAM6_IPTUNNEL_MODE_MAX,
+};
+
+#define IOAM6_IPTUNNEL_MODE_MIN (__IOAM6_IPTUNNEL_MODE_MIN + 1)
+#define IOAM6_IPTUNNEL_MODE_MAX (__IOAM6_IPTUNNEL_MODE_MAX - 1)
+
 enum {
 	IOAM6_IPTUNNEL_UNSPEC,
+
+	/* Encap mode */
+	IOAM6_IPTUNNEL_MODE,		/* u8 */
+
+	/* Tunnel dst address.
+	 * For encap,auto modes.
+	 */
+	IOAM6_IPTUNNEL_DST,		/* struct in6_addr */
+
+	/* IOAM Trace Header */
 	IOAM6_IPTUNNEL_TRACE,		/* struct ioam6_trace_hdr */
+
 	__IOAM6_IPTUNNEL_MAX,
 };
 

net/ipv6/Kconfig

@@ -332,10 +332,10 @@ config IPV6_IOAM6_LWTUNNEL
 	bool "IPv6: IOAM Pre-allocated Trace insertion support"
 	depends on IPV6
 	select LWTUNNEL
+	select DST_CACHE
 	help
-	  Support for the inline insertion of IOAM Pre-allocated
-	  Trace Header (only on locally generated packets), using
-	  the lightweight tunnels mechanism.
+	  Support for the insertion of IOAM Pre-allocated Trace
+	  Header using the lightweight tunnels mechanism.
 
 	  If unsure, say N.
 

net/ipv6/exthdrs.c

@@ -979,7 +979,7 @@ static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff)
 		if (!skb_valid_dst(skb))
 			ip6_route_input(skb);
 
-		ioam6_fill_trace_data(skb, ns, trace);
+		ioam6_fill_trace_data(skb, ns, trace, true);
 		break;
 	default:
 		break;

net/ipv6/ioam6.c

@@ -631,7 +631,7 @@ static void __ioam6_fill_trace_data(struct sk_buff *skb,
 				    struct ioam6_namespace *ns,
 				    struct ioam6_trace_hdr *trace,
 				    struct ioam6_schema *sc,
-				    u8 sclen)
+				    u8 sclen, bool is_input)
 {
 	struct __kernel_sock_timeval ts;
 	u64 raw64;
@@ -645,7 +645,7 @@ static void __ioam6_fill_trace_data(struct sk_buff *skb,
 	/* hop_lim and node_id */
 	if (trace->type.bit0) {
 		byte = ipv6_hdr(skb)->hop_limit;
-		if (skb->dev)
+		if (is_input)
 			byte--;
 
 		raw32 = dev_net(skb_dst(skb)->dev)->ipv6.sysctl.ioam6_id;
@@ -730,7 +730,7 @@ static void __ioam6_fill_trace_data(struct sk_buff *skb,
 	/* hop_lim and node_id (wide) */
 	if (trace->type.bit8) {
 		byte = ipv6_hdr(skb)->hop_limit;
-		if (skb->dev)
+		if (is_input)
 			byte--;
 
 		raw64 = dev_net(skb_dst(skb)->dev)->ipv6.sysctl.ioam6_id_wide;
@@ -786,7 +786,8 @@ static void __ioam6_fill_trace_data(struct sk_buff *skb,
 /* called with rcu_read_lock() */
 void ioam6_fill_trace_data(struct sk_buff *skb,
 			   struct ioam6_namespace *ns,
-			   struct ioam6_trace_hdr *trace)
+			   struct ioam6_trace_hdr *trace,
+			   bool is_input)
 {
 	struct ioam6_schema *sc;
 	u8 sclen = 0;
@@ -822,7 +823,7 @@ void ioam6_fill_trace_data(struct sk_buff *skb,
 		return;
 	}
 
-	__ioam6_fill_trace_data(skb, ns, trace, sc, sclen);
+	__ioam6_fill_trace_data(skb, ns, trace, sc, sclen, is_input);
 	trace->remlen -= trace->nodelen + sclen;
 }
 

net/ipv6/ioam6_iptunnel.c

@@ -9,7 +9,6 @@
 #include <linux/kernel.h>
 #include <linux/skbuff.h>
 #include <linux/net.h>
-#include <linux/netlink.h>
 #include <linux/in6.h>
 #include <linux/ioam6.h>
 #include <linux/ioam6_iptunnel.h>
@@ -17,18 +16,26 @@
 #include <net/sock.h>
 #include <net/lwtunnel.h>
 #include <net/ioam6.h>
+#include <net/netlink.h>
+#include <net/ipv6.h>
+#include <net/dst_cache.h>
+#include <net/ip6_route.h>
+#include <net/addrconf.h>
 
 #define IOAM6_MASK_SHORT_FIELDS 0xff100000
 #define IOAM6_MASK_WIDE_FIELDS 0xe00000
 
 struct ioam6_lwt_encap {
-	struct ipv6_hopopt_hdr	eh;
-	u8			pad[2];	/* 2-octet padding for 4n-alignment */
-	struct ioam6_hdr	ioamh;
-	struct ioam6_trace_hdr	traceh;
+	struct ipv6_hopopt_hdr eh;
+	u8 pad[2];			/* 2-octet padding for 4n-alignment */
+	struct ioam6_hdr ioamh;
+	struct ioam6_trace_hdr traceh;
 } __packed;
 
 struct ioam6_lwt {
+	struct dst_cache cache;
+	u8 mode;
+	struct in6_addr tundst;
 	struct ioam6_lwt_encap	tuninfo;
 };
 
@@ -42,34 +49,19 @@ static struct ioam6_lwt_encap *ioam6_lwt_info(struct lwtunnel_state *lwt)
 	return &ioam6_lwt_state(lwt)->tuninfo;
 }
 
-static struct ioam6_trace_hdr *ioam6_trace(struct lwtunnel_state *lwt)
+static struct ioam6_trace_hdr *ioam6_lwt_trace(struct lwtunnel_state *lwt)
 {
 	return &(ioam6_lwt_state(lwt)->tuninfo.traceh);
 }
 
 static const struct nla_policy ioam6_iptunnel_policy[IOAM6_IPTUNNEL_MAX + 1] = {
+	[IOAM6_IPTUNNEL_MODE]	= NLA_POLICY_RANGE(NLA_U8,
+						   IOAM6_IPTUNNEL_MODE_MIN,
+						   IOAM6_IPTUNNEL_MODE_MAX),
+	[IOAM6_IPTUNNEL_DST]	= NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
 	[IOAM6_IPTUNNEL_TRACE]	= NLA_POLICY_EXACT_LEN(sizeof(struct ioam6_trace_hdr)),
 };
 
-static int nla_put_ioam6_trace(struct sk_buff *skb, int attrtype,
-			       struct ioam6_trace_hdr *trace)
-{
-	struct ioam6_trace_hdr *data;
-	struct nlattr *nla;
-	int len;
-
-	len = sizeof(*trace);
-
-	nla = nla_reserve(skb, attrtype, len);
-	if (!nla)
-		return -EMSGSIZE;
-
-	data = nla_data(nla);
-	memcpy(data, trace, len);
-
-	return 0;
-}
-
 static bool ioam6_validate_trace_hdr(struct ioam6_trace_hdr *trace)
 {
 	u32 fields;
@@ -97,9 +89,10 @@ static int ioam6_build_state(struct net *net, struct nlattr *nla,
 	struct nlattr *tb[IOAM6_IPTUNNEL_MAX + 1];
 	struct ioam6_lwt_encap *tuninfo;
 	struct ioam6_trace_hdr *trace;
-	struct lwtunnel_state *s;
-	int len_aligned;
-	int len, err;
+	struct lwtunnel_state *lwt;
+	struct ioam6_lwt *ilwt;
+	int len_aligned, err;
+	u8 mode;
 
 	if (family != AF_INET6)
 		return -EINVAL;
@@ -109,6 +102,16 @@ static int ioam6_build_state(struct net *net, struct nlattr *nla,
 	if (err < 0)
 		return err;
 
+	if (!tb[IOAM6_IPTUNNEL_MODE])
+		mode = IOAM6_IPTUNNEL_MODE_INLINE;
+	else
+		mode = nla_get_u8(tb[IOAM6_IPTUNNEL_MODE]);
+
+	if (!tb[IOAM6_IPTUNNEL_DST] && mode != IOAM6_IPTUNNEL_MODE_INLINE) {
+		NL_SET_ERR_MSG(extack, "this mode needs a tunnel destination");
+		return -EINVAL;
+	}
+
 	if (!tb[IOAM6_IPTUNNEL_TRACE]) {
 		NL_SET_ERR_MSG(extack, "missing trace");
 		return -EINVAL;
@@ -121,15 +124,24 @@ static int ioam6_build_state(struct net *net, struct nlattr *nla,
 		return -EINVAL;
 	}
 
-	len = sizeof(*tuninfo) + trace->remlen * 4;
-	len_aligned = ALIGN(len, 8);
-
-	s = lwtunnel_state_alloc(len_aligned);
-	if (!s)
+	len_aligned = ALIGN(trace->remlen * 4, 8);
+	lwt = lwtunnel_state_alloc(sizeof(*ilwt) + len_aligned);
+	if (!lwt)
 		return -ENOMEM;
 
-	tuninfo = ioam6_lwt_info(s);
-	tuninfo->eh.hdrlen = (len_aligned >> 3) - 1;
+	ilwt = ioam6_lwt_state(lwt);
+	err = dst_cache_init(&ilwt->cache, GFP_ATOMIC);
+	if (err) {
+		kfree(lwt);
+		return err;
+	}
+
+	ilwt->mode = mode;
+	if (tb[IOAM6_IPTUNNEL_DST])
+		ilwt->tundst = nla_get_in6_addr(tb[IOAM6_IPTUNNEL_DST]);
+
+	tuninfo = ioam6_lwt_info(lwt);
+	tuninfo->eh.hdrlen = ((sizeof(*tuninfo) + len_aligned) >> 3) - 1;
 	tuninfo->pad[0] = IPV6_TLV_PADN;
 	tuninfo->ioamh.type = IOAM6_TYPE_PREALLOC;
 	tuninfo->ioamh.opt_type = IPV6_TLV_IOAM;
@@ -138,27 +150,39 @@ static int ioam6_build_state(struct net *net, struct nlattr *nla,
 
 	memcpy(&tuninfo->traceh, trace, sizeof(*trace));
 
-	len = len_aligned - len;
-	if (len == 1) {
-		tuninfo->traceh.data[trace->remlen * 4] = IPV6_TLV_PAD1;
-	} else if (len > 0) {
+	if (len_aligned - trace->remlen * 4) {
 		tuninfo->traceh.data[trace->remlen * 4] = IPV6_TLV_PADN;
-		tuninfo->traceh.data[trace->remlen * 4 + 1] = len - 2;
+		tuninfo->traceh.data[trace->remlen * 4 + 1] = 2;
 	}
 
-	s->type = LWTUNNEL_ENCAP_IOAM6;
-	s->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT;
+	lwt->type = LWTUNNEL_ENCAP_IOAM6;
+	lwt->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT;
 
-	*ts = s;
+	*ts = lwt;
 
 	return 0;
 }
 
-static int ioam6_do_inline(struct sk_buff *skb, struct ioam6_lwt_encap *tuninfo)
+static int ioam6_do_fill(struct net *net, struct sk_buff *skb)
 {
 	struct ioam6_trace_hdr *trace;
-	struct ipv6hdr *oldhdr, *hdr;
 	struct ioam6_namespace *ns;
+
+	trace = (struct ioam6_trace_hdr *)(skb_transport_header(skb)
+					   + sizeof(struct ipv6_hopopt_hdr) + 2
+					   + sizeof(struct ioam6_hdr));
+
+	ns = ioam6_namespace(net, trace->namespace_id);
+	if (ns)
+		ioam6_fill_trace_data(skb, ns, trace, false);
+
+	return 0;
+}
+
+static int ioam6_do_inline(struct net *net, struct sk_buff *skb,
+			   struct ioam6_lwt_encap *tuninfo)
+{
+	struct ipv6hdr *oldhdr, *hdr;
 	int hdrlen, err;
 
 	hdrlen = (tuninfo->eh.hdrlen + 1) << 3;
@@ -187,80 +211,200 @@ static int ioam6_do_inline(struct sk_buff *skb, struct ioam6_lwt_encap *tuninfo)
 	hdr->nexthdr = NEXTHDR_HOP;
 	hdr->payload_len = cpu_to_be16(skb->len - sizeof(*hdr));
 
-	trace = (struct ioam6_trace_hdr *)(skb_transport_header(skb)
-					   + sizeof(struct ipv6_hopopt_hdr) + 2
-					   + sizeof(struct ioam6_hdr));
+	return ioam6_do_fill(net, skb);
+}
 
-	ns = ioam6_namespace(dev_net(skb_dst(skb)->dev), trace->namespace_id);
-	if (ns)
-		ioam6_fill_trace_data(skb, ns, trace);
+static int ioam6_do_encap(struct net *net, struct sk_buff *skb,
+			  struct ioam6_lwt_encap *tuninfo,
+			  struct in6_addr *tundst)
+{
+	struct dst_entry *dst = skb_dst(skb);
+	struct ipv6hdr *hdr, *inner_hdr;
+	int hdrlen, len, err;
 
-	return 0;
+	hdrlen = (tuninfo->eh.hdrlen + 1) << 3;
+	len = sizeof(*hdr) + hdrlen;
+
+	err = skb_cow_head(skb, len + skb->mac_len);
+	if (unlikely(err))
+		return err;
+
+	inner_hdr = ipv6_hdr(skb);
+
+	skb_push(skb, len);
+	skb_reset_network_header(skb);
+	skb_mac_header_rebuild(skb);
+	skb_set_transport_header(skb, sizeof(*hdr));
+
+	tuninfo->eh.nexthdr = NEXTHDR_IPV6;
+	memcpy(skb_transport_header(skb), (u8 *)tuninfo, hdrlen);
+
+	hdr = ipv6_hdr(skb);
+	memcpy(hdr, inner_hdr, sizeof(*hdr));
+
+	hdr->nexthdr = NEXTHDR_HOP;
+	hdr->payload_len = cpu_to_be16(skb->len - sizeof(*hdr));
+	hdr->daddr = *tundst;
+	ipv6_dev_get_saddr(net, dst->dev, &hdr->daddr,
+			   IPV6_PREFER_SRC_PUBLIC, &hdr->saddr);
+
+	skb_postpush_rcsum(skb, hdr, len);
+
+	return ioam6_do_fill(net, skb);
 }
 
 static int ioam6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
-	struct lwtunnel_state *lwt = skb_dst(skb)->lwtstate;
+	struct dst_entry *dst = skb_dst(skb);
+	struct in6_addr orig_daddr;
+	struct ioam6_lwt *ilwt;
 	int err = -EINVAL;
 
 	if (skb->protocol != htons(ETH_P_IPV6))
 		goto drop;
 
-	/* Only for packets we send and
-	 * that do not contain a Hop-by-Hop yet
-	 */
-	if (skb->dev || ipv6_hdr(skb)->nexthdr == NEXTHDR_HOP)
-		goto out;
-
-	err = ioam6_do_inline(skb, ioam6_lwt_info(lwt));
-	if (unlikely(err))
+	ilwt = ioam6_lwt_state(dst->lwtstate);
+	orig_daddr = ipv6_hdr(skb)->daddr;
+
+	switch (ilwt->mode) {
+	case IOAM6_IPTUNNEL_MODE_INLINE:
+do_inline:
+		/* Direct insertion - if there is no Hop-by-Hop yet */
+		if (ipv6_hdr(skb)->nexthdr == NEXTHDR_HOP)
+			goto out;
+
+		err = ioam6_do_inline(net, skb, &ilwt->tuninfo);
+		if (unlikely(err))
+			goto drop;
+
+		break;
+	case IOAM6_IPTUNNEL_MODE_ENCAP:
+do_encap:
+		/* Encapsulation (ip6ip6) */
+		err = ioam6_do_encap(net, skb, &ilwt->tuninfo, &ilwt->tundst);
+		if (unlikely(err))
+			goto drop;
+
+		break;
+	case IOAM6_IPTUNNEL_MODE_AUTO:
+		/* Automatic (RFC8200 compliant):
+		 *  - local packets -> INLINE mode
+		 *  - in-transit packets -> ENCAP mode
+		 */
+		if (!skb->dev)
+			goto do_inline;
+
+		goto do_encap;
+	default:
 		goto drop;
+	}
 
-	err = skb_cow_head(skb, LL_RESERVED_SPACE(skb_dst(skb)->dev));
+	err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev));
 	if (unlikely(err))
 		goto drop;
 
+	if (!ipv6_addr_equal(&orig_daddr, &ipv6_hdr(skb)->daddr)) {
+		preempt_disable();
+		dst = dst_cache_get(&ilwt->cache);
+		preempt_enable();
+
+		if (unlikely(!dst)) {
+			struct ipv6hdr *hdr = ipv6_hdr(skb);
+			struct flowi6 fl6;
+
+			memset(&fl6, 0, sizeof(fl6));
+			fl6.daddr = hdr->daddr;
+			fl6.saddr = hdr->saddr;
+			fl6.flowlabel = ip6_flowinfo(hdr);
+			fl6.flowi6_mark = skb->mark;
+			fl6.flowi6_proto = hdr->nexthdr;
+
+			dst = ip6_route_output(net, NULL, &fl6);
+			if (dst->error) {
+				err = dst->error;
+				dst_release(dst);
+				goto drop;
+			}
+
+			preempt_disable();
+			dst_cache_set_ip6(&ilwt->cache, dst, &fl6.saddr);
+			preempt_enable();
+		}
+
+		skb_dst_drop(skb);
+		skb_dst_set(skb, dst);
+
+		return dst_output(net, sk, skb);
+	}
 out:
-	return lwt->orig_output(net, sk, skb);
-
+	return dst->lwtstate->orig_output(net, sk, skb);
 drop:
 	kfree_skb(skb);
 	return err;
 }
 
+static void ioam6_destroy_state(struct lwtunnel_state *lwt)
+{
+	dst_cache_destroy(&ioam6_lwt_state(lwt)->cache);
+}
+
 static int ioam6_fill_encap_info(struct sk_buff *skb,
 				 struct lwtunnel_state *lwtstate)
 {
-	struct ioam6_trace_hdr *trace = ioam6_trace(lwtstate);
+	struct ioam6_lwt *ilwt = ioam6_lwt_state(lwtstate);
+	int err;
 
-	if (nla_put_ioam6_trace(skb, IOAM6_IPTUNNEL_TRACE, trace))
-		return -EMSGSIZE;
+	err = nla_put_u8(skb, IOAM6_IPTUNNEL_MODE, ilwt->mode);
+	if (err)
+		goto ret;
 
-	return 0;
+	if (ilwt->mode != IOAM6_IPTUNNEL_MODE_INLINE) {
+		err = nla_put_in6_addr(skb, IOAM6_IPTUNNEL_DST, &ilwt->tundst);
+		if (err)
+			goto ret;
+	}
+
+	err = nla_put(skb, IOAM6_IPTUNNEL_TRACE, sizeof(ilwt->tuninfo.traceh),
+		      &ilwt->tuninfo.traceh);
+ret:
+	return err;
 }
 
 static int ioam6_encap_nlsize(struct lwtunnel_state *lwtstate)
 {
-	struct ioam6_trace_hdr *trace = ioam6_trace(lwtstate);
+	struct ioam6_lwt *ilwt = ioam6_lwt_state(lwtstate);
+	int nlsize;
+
+	nlsize = nla_total_size(sizeof(ilwt->mode)) +
+		  nla_total_size(sizeof(ilwt->tuninfo.traceh));
 
-	return nla_total_size(sizeof(*trace));
+	if (ilwt->mode != IOAM6_IPTUNNEL_MODE_INLINE)
+		nlsize += nla_total_size(sizeof(ilwt->tundst));
+
+	return nlsize;
 }
 
 static int ioam6_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b)
 {
-	struct ioam6_trace_hdr *a_hdr = ioam6_trace(a);
-	struct ioam6_trace_hdr *b_hdr = ioam6_trace(b);
-
-	return (a_hdr->namespace_id != b_hdr->namespace_id);
+	struct ioam6_trace_hdr *trace_a = ioam6_lwt_trace(a);
+	struct ioam6_trace_hdr *trace_b = ioam6_lwt_trace(b);
+	struct ioam6_lwt *ilwt_a = ioam6_lwt_state(a);
+	struct ioam6_lwt *ilwt_b = ioam6_lwt_state(b);
+
+	return (ilwt_a->mode != ilwt_b->mode ||
+		(ilwt_a->mode != IOAM6_IPTUNNEL_MODE_INLINE &&
+		 !ipv6_addr_equal(&ilwt_a->tundst, &ilwt_b->tundst)) ||
+		trace_a->namespace_id != trace_b->namespace_id);
 }
 
 static const struct lwtunnel_encap_ops ioam6_iptun_ops = {
-	.build_state	= ioam6_build_state,
+	.build_state		= ioam6_build_state,
+	.destroy_state		= ioam6_destroy_state,
 	.output		= ioam6_output,
-	.fill_encap	= ioam6_fill_encap_info,
+	.fill_encap		= ioam6_fill_encap_info,
 	.get_encap_size	= ioam6_encap_nlsize,
-	.cmp_encap	= ioam6_encap_cmp,
-	.owner		= THIS_MODULE,
+	.cmp_encap		= ioam6_encap_cmp,
+	.owner			= THIS_MODULE,
 };
 
 int __init ioam6_iptunnel_init(void)

tools/testing/selftests/net/ioam6.sh

@@ -6,7 +6,7 @@
 # This script evaluates the IOAM insertion for IPv6 by checking the IOAM data
 # consistency directly inside packets on the receiver side. Tests are divided
 # into three categories: OUTPUT (evaluates the IOAM processing by the sender),
-# INPUT (evaluates the IOAM processing by the receiver) and GLOBAL (evaluates
+# INPUT (evaluates the IOAM processing by a receiver) and GLOBAL (evaluates
 # wider use cases that do not fall into the other two categories). Both OUTPUT
 # and INPUT tests only use a two-node topology (alpha and beta), while GLOBAL
 # tests use the entire three-node topology (alpha, beta, gamma). Each test is
@@ -200,7 +200,7 @@ check_kernel_compatibility()
   ip -netns ioam-tmp-node link set veth0 up
   ip -netns ioam-tmp-node link set veth1 up
 
-  ip -netns ioam-tmp-node ioam namespace add 0 &>/dev/null
+  ip -netns ioam-tmp-node ioam namespace add 0
   ns_ad=$?
 
   ip -netns ioam-tmp-node ioam namespace show | grep -q "namespace 0"
@@ -214,11 +214,11 @@ check_kernel_compatibility()
     exit 1
   fi
 
-  ip -netns ioam-tmp-node route add db02::/64 encap ioam6 trace prealloc \
-         type 0x800000 ns 0 size 4 dev veth0 &>/dev/null
+  ip -netns ioam-tmp-node route add db02::/64 encap ioam6 mode inline \
+         trace prealloc type 0x800000 ns 0 size 4 dev veth0
   tr_ad=$?
 
-  ip -netns ioam-tmp-node -6 route | grep -q "encap ioam6 trace"
+  ip -netns ioam-tmp-node -6 route | grep -q "encap ioam6"
   tr_sh=$?
 
   if [[ $tr_ad != 0 || $tr_sh != 0 ]]
@@ -232,6 +232,30 @@ check_kernel_compatibility()
 
   ip link del veth0 2>/dev/null || true
   ip netns del ioam-tmp-node || true
+
+  lsmod | grep -q "ip6_tunnel"
+  ip6tnl_loaded=$?
+
+  if [ $ip6tnl_loaded = 0 ]
+  then
+    encap_tests=0
+  else
+    modprobe ip6_tunnel &>/dev/null
+    lsmod | grep -q "ip6_tunnel"
+    encap_tests=$?
+
+    if [ $encap_tests != 0 ]
+    then
+      ip a | grep -q "ip6tnl0"
+      encap_tests=$?
+
+      if [ $encap_tests != 0 ]
+      then
+        echo "Note: ip6_tunnel not found neither as a module nor inside the" \
+             "kernel, tests that require it (encap mode) will be omitted"
+      fi
+    fi
+  fi
 }
 
 cleanup()
@@ -242,6 +266,11 @@ cleanup()
   ip netns del ioam-node-alpha || true
   ip netns del ioam-node-beta || true
   ip netns del ioam-node-gamma || true
+
+  if [ $ip6tnl_loaded != 0 ]
+  then
+    modprobe -r ip6_tunnel 2>/dev/null || true
+  fi
 }
 
 setup()
@@ -329,6 +358,12 @@ log_test_failed()
   printf "TEST: %-60s  [FAIL]\n" "${desc}"
 }
 
+log_results()
+{
+  echo "- Tests passed: ${npassed}"
+  echo "- Tests failed: ${nfailed}"
+}
+
 run_test()
 {
   local name=$1
@@ -349,16 +384,26 @@ run_test()
   ip netns exec $node_src ping6 -t 64 -c 1 -W 1 $ip6_dst &>/dev/null
   if [ $? != 0 ]
   then
+    nfailed=$((nfailed+1))
     log_test_failed "${desc}"
     kill -2 $spid &>/dev/null
   else
     wait $spid
-    [ $? = 0 ] && log_test_passed "${desc}" || log_test_failed "${desc}"
+    if [ $? = 0 ]
+    then
+      npassed=$((npassed+1))
+      log_test_passed "${desc}"
+    else
+      nfailed=$((nfailed+1))
+      log_test_failed "${desc}"
+    fi
   fi
 }
 
 run()
 {
+  echo
+  printf "%0.s-" {1..74}
   echo
   echo "OUTPUT tests"
   printf "%0.s-" {1..74}
@@ -369,7 +414,8 @@ run()
 
   for t in $TESTS_OUTPUT
   do
-    $t
+    $t "inline"
+    [ $encap_tests = 0 ] && $t "encap"
   done
 
   # clean OUTPUT settings
@@ -377,6 +423,8 @@ run()
   ip -netns ioam-node-alpha route change db01::/64 dev veth0
 
 
+  echo
+  printf "%0.s-" {1..74}
   echo
   echo "INPUT tests"
   printf "%0.s-" {1..74}
@@ -387,7 +435,8 @@ run()
 
   for t in $TESTS_INPUT
   do
-    $t
+    $t "inline"
+    [ $encap_tests = 0 ] && $t "encap"
   done
 
   # clean INPUT settings
@@ -396,7 +445,8 @@ run()
   ip -netns ioam-node-alpha ioam namespace set 123 schema ${ALPHA[8]}
   ip -netns ioam-node-alpha route change db01::/64 dev veth0
 
-
+  echo
+  printf "%0.s-" {1..74}
   echo
   echo "GLOBAL tests"
   printf "%0.s-" {1..74}
@@ -404,8 +454,12 @@ run()
 
   for t in $TESTS_GLOBAL
   do
-    $t
+    $t "inline"
+    [ $encap_tests = 0 ] && $t "encap"
   done
+
+  echo
+  log_results
 }
 
 bit2type=(
@@ -431,11 +485,16 @@ out_undef_ns()
   ##############################################################################
   local desc="Unknown IOAM namespace"
 
-  ip -netns ioam-node-alpha route change db01::/64 encap ioam6 trace prealloc \
-         type 0x800000 ns 0 size 4 dev veth0
+  [ "$1" = "encap" ] && mode="$1 tundst db01::1" || mode="$1"
+  [ "$1" = "encap" ] && ip -netns ioam-node-beta link set ip6tnl0 up
+
+  ip -netns ioam-node-alpha route change db01::/64 encap ioam6 mode $mode \
+         trace prealloc type 0x800000 ns 0 size 4 dev veth0
 
-  run_test ${FUNCNAME[0]} "${desc}" ioam-node-alpha ioam-node-beta db01::2 \
-         db01::1 veth0 0x800000 0
+  run_test ${FUNCNAME[0]} "${desc} ($1 mode)" ioam-node-alpha ioam-node-beta \
+         db01::2 db01::1 veth0 0x800000 0
+
+  [ "$1" = "encap" ] && ip -netns ioam-node-beta link set ip6tnl0 down
 }
 
 out_no_room()
@@ -446,11 +505,16 @@ out_no_room()
   ##############################################################################
   local desc="Missing trace room"
 
-  ip -netns ioam-node-alpha route change db01::/64 encap ioam6 trace prealloc \
-         type 0xc00000 ns 123 size 4 dev veth0
+  [ "$1" = "encap" ] && mode="$1 tundst db01::1" || mode="$1"
+  [ "$1" = "encap" ] && ip -netns ioam-node-beta link set ip6tnl0 up
+
+  ip -netns ioam-node-alpha route change db01::/64 encap ioam6 mode $mode \
+         trace prealloc type 0xc00000 ns 123 size 4 dev veth0
+
+  run_test ${FUNCNAME[0]} "${desc} ($1 mode)" ioam-node-alpha ioam-node-beta \
+         db01::2 db01::1 veth0 0xc00000 123
 
-  run_test ${FUNCNAME[0]} "${desc}" ioam-node-alpha ioam-node-beta db01::2 \
-         db01::1 veth0 0xc00000 123
+  [ "$1" = "encap" ] && ip -netns ioam-node-beta link set ip6tnl0 down
 }
 
 out_bits()
@@ -465,15 +529,21 @@ out_bits()
   local tmp=${bit2size[22]}
   bit2size[22]=$(( $tmp + ${#ALPHA[9]} + ((4 - (${#ALPHA[9]} % 4)) % 4) ))
 
+  [ "$1" = "encap" ] && mode="$1 tundst db01::1" || mode="$1"
+  [ "$1" = "encap" ] && ip -netns ioam-node-beta link set ip6tnl0 up
+
   for i in {0..22}
   do
-    ip -netns ioam-node-alpha route change db01::/64 encap ioam6 trace \
-           prealloc type ${bit2type[$i]} ns 123 size ${bit2size[$i]} dev veth0
+    ip -netns ioam-node-alpha route change db01::/64 encap ioam6 mode $mode \
+           trace prealloc type ${bit2type[$i]} ns 123 size ${bit2size[$i]} \
+           dev veth0
 
-    run_test "out_bit$i" "${desc/<n>/$i}" ioam-node-alpha ioam-node-beta \
-           db01::2 db01::1 veth0 ${bit2type[$i]} 123
+    run_test "out_bit$i" "${desc/<n>/$i} ($1 mode)" ioam-node-alpha \
+           ioam-node-beta db01::2 db01::1 veth0 ${bit2type[$i]} 123
   done
 
+  [ "$1" = "encap" ] && ip -netns ioam-node-beta link set ip6tnl0 down
+
   bit2size[22]=$tmp
 }
 
@@ -485,11 +555,16 @@ out_full_supp_trace()
   ##############################################################################
   local desc="Full supported trace"
 
-  ip -netns ioam-node-alpha route change db01::/64 encap ioam6 trace prealloc \
-         type 0xfff002 ns 123 size 100 dev veth0
+  [ "$1" = "encap" ] && mode="$1 tundst db01::1" || mode="$1"
+  [ "$1" = "encap" ] && ip -netns ioam-node-beta link set ip6tnl0 up
 
-  run_test ${FUNCNAME[0]} "${desc}" ioam-node-alpha ioam-node-beta db01::2 \
-         db01::1 veth0 0xfff002 123
+  ip -netns ioam-node-alpha route change db01::/64 encap ioam6 mode $mode \
+         trace prealloc type 0xfff002 ns 123 size 100 dev veth0
+
+  run_test ${FUNCNAME[0]} "${desc} ($1 mode)" ioam-node-alpha ioam-node-beta \
+         db01::2 db01::1 veth0 0xfff002 123
+
+  [ "$1" = "encap" ] && ip -netns ioam-node-beta link set ip6tnl0 down
 }
 
 
@@ -510,11 +585,16 @@ in_undef_ns()
   ##############################################################################
   local desc="Unknown IOAM namespace"
 
-  ip -netns ioam-node-alpha route change db01::/64 encap ioam6 trace prealloc \
-         type 0x800000 ns 0 size 4 dev veth0
+  [ "$1" = "encap" ] && mode="$1 tundst db01::1" || mode="$1"
+  [ "$1" = "encap" ] && ip -netns ioam-node-beta link set ip6tnl0 up
+
+  ip -netns ioam-node-alpha route change db01::/64 encap ioam6 mode $mode \
+         trace prealloc type 0x800000 ns 0 size 4 dev veth0
 
-  run_test ${FUNCNAME[0]} "${desc}" ioam-node-alpha ioam-node-beta db01::2 \
-         db01::1 veth0 0x800000 0
+  run_test ${FUNCNAME[0]} "${desc} ($1 mode)" ioam-node-alpha ioam-node-beta \
+         db01::2 db01::1 veth0 0x800000 0
+
+  [ "$1" = "encap" ] && ip -netns ioam-node-beta link set ip6tnl0 down
 }
 
 in_no_room()
@@ -525,11 +605,16 @@ in_no_room()
   ##############################################################################
   local desc="Missing trace room"
 
-  ip -netns ioam-node-alpha route change db01::/64 encap ioam6 trace prealloc \
-         type 0xc00000 ns 123 size 4 dev veth0
+  [ "$1" = "encap" ] && mode="$1 tundst db01::1" || mode="$1"
+  [ "$1" = "encap" ] && ip -netns ioam-node-beta link set ip6tnl0 up
+
+  ip -netns ioam-node-alpha route change db01::/64 encap ioam6 mode $mode \
+         trace prealloc type 0xc00000 ns 123 size 4 dev veth0
 
-  run_test ${FUNCNAME[0]} "${desc}" ioam-node-alpha ioam-node-beta db01::2 \
-         db01::1 veth0 0xc00000 123
+  run_test ${FUNCNAME[0]} "${desc} ($1 mode)" ioam-node-alpha ioam-node-beta \
+         db01::2 db01::1 veth0 0xc00000 123
+
+  [ "$1" = "encap" ] && ip -netns ioam-node-beta link set ip6tnl0 down
 }
 
 in_bits()
@@ -544,15 +629,21 @@ in_bits()
   local tmp=${bit2size[22]}
   bit2size[22]=$(( $tmp + ${#BETA[9]} + ((4 - (${#BETA[9]} % 4)) % 4) ))
 
+  [ "$1" = "encap" ] && mode="$1 tundst db01::1" || mode="$1"
+  [ "$1" = "encap" ] && ip -netns ioam-node-beta link set ip6tnl0 up
+
   for i in {0..22}
   do
-    ip -netns ioam-node-alpha route change db01::/64 encap ioam6 trace \
-           prealloc type ${bit2type[$i]} ns 123 size ${bit2size[$i]} dev veth0
+    ip -netns ioam-node-alpha route change db01::/64 encap ioam6 mode $mode \
+           trace prealloc type ${bit2type[$i]} ns 123 size ${bit2size[$i]} \
+           dev veth0
 
-    run_test "in_bit$i" "${desc/<n>/$i}" ioam-node-alpha ioam-node-beta \
-           db01::2 db01::1 veth0 ${bit2type[$i]} 123
+    run_test "in_bit$i" "${desc/<n>/$i} ($1 mode)" ioam-node-alpha \
+           ioam-node-beta db01::2 db01::1 veth0 ${bit2type[$i]} 123
   done
 
+  [ "$1" = "encap" ] && ip -netns ioam-node-beta link set ip6tnl0 down
+
   bit2size[22]=$tmp
 }
 
@@ -569,11 +660,16 @@ in_oflag()
   #   back the IOAM namespace that was previously configured on the sender.
   ip -netns ioam-node-alpha ioam namespace add 123
 
-  ip -netns ioam-node-alpha route change db01::/64 encap ioam6 trace prealloc \
-         type 0xc00000 ns 123 size 4 dev veth0
+  [ "$1" = "encap" ] && mode="$1 tundst db01::1" || mode="$1"
+  [ "$1" = "encap" ] && ip -netns ioam-node-beta link set ip6tnl0 up
+
+  ip -netns ioam-node-alpha route change db01::/64 encap ioam6 mode $mode \
+         trace prealloc type 0xc00000 ns 123 size 4 dev veth0
+
+  run_test ${FUNCNAME[0]} "${desc} ($1 mode)" ioam-node-alpha ioam-node-beta \
+         db01::2 db01::1 veth0 0xc00000 123
 
-  run_test ${FUNCNAME[0]} "${desc}" ioam-node-alpha ioam-node-beta db01::2 \
-         db01::1 veth0 0xc00000 123
+  [ "$1" = "encap" ] && ip -netns ioam-node-beta link set ip6tnl0 down
 
   # And we clean the exception for this test to get things back to normal for
   # other INPUT tests
@@ -588,11 +684,16 @@ in_full_supp_trace()
   ##############################################################################
   local desc="Full supported trace"
 
-  ip -netns ioam-node-alpha route change db01::/64 encap ioam6 trace prealloc \
-         type 0xfff002 ns 123 size 80 dev veth0
+  [ "$1" = "encap" ] && mode="$1 tundst db01::1" || mode="$1"
+  [ "$1" = "encap" ] && ip -netns ioam-node-beta link set ip6tnl0 up
 
-  run_test ${FUNCNAME[0]} "${desc}" ioam-node-alpha ioam-node-beta db01::2 \
-         db01::1 veth0 0xfff002 123
+  ip -netns ioam-node-alpha route change db01::/64 encap ioam6 mode $mode \
+         trace prealloc type 0xfff002 ns 123 size 80 dev veth0
+
+  run_test ${FUNCNAME[0]} "${desc} ($1 mode)" ioam-node-alpha ioam-node-beta \
+         db01::2 db01::1 veth0 0xfff002 123
+
+  [ "$1" = "encap" ] && ip -netns ioam-node-beta link set ip6tnl0 down
 }
 
 
@@ -611,11 +712,16 @@ fwd_full_supp_trace()
   ##############################################################################
   local desc="Forward - Full supported trace"
 
-  ip -netns ioam-node-alpha route change db02::/64 encap ioam6 trace prealloc \
-         type 0xfff002 ns 123 size 244 via db01::1 dev veth0
+  [ "$1" = "encap" ] && mode="$1 tundst db02::2" || mode="$1"
+  [ "$1" = "encap" ] && ip -netns ioam-node-gamma link set ip6tnl0 up
+
+  ip -netns ioam-node-alpha route change db02::/64 encap ioam6 mode $mode \
+         trace prealloc type 0xfff002 ns 123 size 244 via db01::1 dev veth0
 
-  run_test ${FUNCNAME[0]} "${desc}" ioam-node-alpha ioam-node-gamma db01::2 \
-         db02::2 veth0 0xfff002 123
+  run_test ${FUNCNAME[0]} "${desc} ($1 mode)" ioam-node-alpha ioam-node-gamma \
+         db01::2 db02::2 veth0 0xfff002 123
+
+  [ "$1" = "encap" ] && ip -netns ioam-node-gamma link set ip6tnl0 down
 }
 
 
@@ -625,6 +731,9 @@ fwd_full_supp_trace()
 #                                                                              #
 ################################################################################
 
+npassed=0
+nfailed=0
+
 if [ "$(id -u)" -ne 0 ]
 then
   echo "SKIP: Need root privileges"