diff mbox series

[ovs-dev,v11,4/5] userspace: Add SRv6 tunnel support.

Message ID 20230328064223.51144-5-nmiki@yahoo-corp.jp
State Changes Requested
Headers show
Series userspace: Add SRv6 tunnel support. | expand

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Commit Message

Nobuhiro MIKI March 28, 2023, 6:42 a.m. UTC
SRv6 (Segment Routing IPv6) tunnel vport is responsible
for encapsulation and decapsulation the inner packets with
IPv6 header and an extended header called SRH
(Segment Routing Header). See spec in:

https://datatracker.ietf.org/doc/html/rfc8754

This patch implements SRv6 tunneling in userspace datapath.
It uses `remote_ip` and `local_ip` options as with existing
tunnel protocols. It also adds a dedicated `srv6_segs` option
to define a sequence of routers called segment list.

Signed-off-by: Nobuhiro MIKI <nmiki@yahoo-corp.jp>
---
 Documentation/faq/configuration.rst |  21 +++++
 Documentation/faq/releases.rst      |   1 +
 NEWS                                |   2 +
 include/linux/openvswitch.h         |   1 +
 include/sparse/netinet/in.h         |   1 +
 lib/dpif-netlink-rtnl.c             |   5 ++
 lib/dpif-netlink.c                  |   5 ++
 lib/netdev-native-tnl.c             | 127 ++++++++++++++++++++++++++++
 lib/netdev-native-tnl.h             |  10 +++
 lib/netdev-vport.c                  |  53 ++++++++++++
 lib/netdev.h                        |   4 +
 lib/packets.h                       |  11 +++
 lib/tnl-ports.c                     |   5 +-
 ofproto/ofproto-dpif-xlate.c        |   3 +
 tests/system-kmod-macros.at         |   8 ++
 tests/system-traffic.at             | 119 ++++++++++++++++++++++++++
 tests/system-userspace-macros.at    |   6 ++
 tests/tunnel.at                     |  56 ++++++++++++
 18 files changed, 437 insertions(+), 1 deletion(-)

Comments

Ilya Maximets March 28, 2023, 12:31 p.m. UTC | #1
On 3/28/23 08:42, Nobuhiro MIKI wrote:
> SRv6 (Segment Routing IPv6) tunnel vport is responsible
> for encapsulation and decapsulation the inner packets with
> IPv6 header and an extended header called SRH
> (Segment Routing Header). See spec in:
> 
> https://datatracker.ietf.org/doc/html/rfc8754
> 
> This patch implements SRv6 tunneling in userspace datapath.
> It uses `remote_ip` and `local_ip` options as with existing
> tunnel protocols. It also adds a dedicated `srv6_segs` option
> to define a sequence of routers called segment list.
> 
> Signed-off-by: Nobuhiro MIKI <nmiki@yahoo-corp.jp>
> ---
>  Documentation/faq/configuration.rst |  21 +++++
>  Documentation/faq/releases.rst      |   1 +
>  NEWS                                |   2 +
>  include/linux/openvswitch.h         |   1 +
>  include/sparse/netinet/in.h         |   1 +
>  lib/dpif-netlink-rtnl.c             |   5 ++
>  lib/dpif-netlink.c                  |   5 ++
>  lib/netdev-native-tnl.c             | 127 ++++++++++++++++++++++++++++
>  lib/netdev-native-tnl.h             |  10 +++
>  lib/netdev-vport.c                  |  53 ++++++++++++
>  lib/netdev.h                        |   4 +
>  lib/packets.h                       |  11 +++
>  lib/tnl-ports.c                     |   5 +-
>  ofproto/ofproto-dpif-xlate.c        |   3 +
>  tests/system-kmod-macros.at         |   8 ++
>  tests/system-traffic.at             | 119 ++++++++++++++++++++++++++
>  tests/system-userspace-macros.at    |   6 ++
>  tests/tunnel.at                     |  56 ++++++++++++
>  18 files changed, 437 insertions(+), 1 deletion(-)
> 

<snip>

> +int
> +netdev_srv6_build_header(const struct netdev *netdev,
> +                         struct ovs_action_push_tnl *data,
> +                         const struct netdev_tnl_build_header_params *params)
> +{
> +    struct netdev_vport *dev = netdev_vport_cast(netdev);
> +    struct netdev_tunnel_config *tnl_cfg;
> +    const struct in6_addr *segs;
> +    struct srv6_base_hdr *srh;
> +    struct in6_addr *s;
> +    ovs_be16 dl_type;
> +    int err = 0;
> +    int nr_segs;
> +    int i;
> +
> +    ovs_mutex_lock(&dev->mutex);
> +    tnl_cfg = &dev->tnl_cfg;
> +
> +    if (tnl_cfg->srv6_num_segs) {
> +        nr_segs = tnl_cfg->srv6_num_segs;
> +        segs = tnl_cfg->srv6_segs;
> +    } else {
> +        /*
> +         * If explicit segment list setting is omitted, tunnel destination
> +         * is considered to be the first segment list.
> +         */
> +        nr_segs = 1;
> +        segs = &params->flow->tunnel.ipv6_dst;
> +    }
> +
> +    if (!ipv6_addr_equals(&segs[0], &params->flow->tunnel.ipv6_dst)) {
> +        err = EINVAL;
> +        goto out;
> +    }
> +
> +    srh = netdev_tnl_ip_build_header(data, params, IPPROTO_ROUTING);
> +    srh->rt_hdr.segments_left = nr_segs - 1;
> +    srh->rt_hdr.type = IPV6_SRCRT_TYPE_4;
> +    srh->rt_hdr.hdrlen = 2 * nr_segs;
> +    srh->last_entry = nr_segs - 1;
> +    srh->flags = 0;
> +    srh->tag = 0;
> +
> +    dl_type = params->flow->dl_type;
> +    if (dl_type == htons(ETH_TYPE_IP)) {
> +        srh->rt_hdr.nexthdr = IPPROTO_IPIP;
> +    } else if (dl_type == htons(ETH_TYPE_IPV6)) {
> +        srh->rt_hdr.nexthdr = IPPROTO_IPV6;
> +    }

We should probably error out here if for some reason it's not an IP or IPv6.

> +
> +    s = ALIGNED_CAST(struct in6_addr *,
> +                     (char *) srh + sizeof *srh);
> +    for (i = 0; i < nr_segs; i++) {
> +        /* Segment list is written to the header in reverse order. */
> +        memcpy(s, &segs[nr_segs - i - 1], sizeof *s);
> +        s++;
> +    }
> +
> +    data->header_len += sizeof *srh + 8 * srh->rt_hdr.hdrlen;
> +    data->tnl_type = OVS_VPORT_TYPE_SRV6;
> +out:
> +    ovs_mutex_unlock(&dev->mutex);
> +
> +    return err;
> +}
> +
> +void
> +netdev_srv6_push_header(const struct netdev *netdev OVS_UNUSED,
> +                        struct dp_packet *packet OVS_UNUSED,
> +                        const struct ovs_action_push_tnl *data OVS_UNUSED)

'packet' and 'data' are actually used by the function.

> +{
> +    int ip_tot_size;
> +
> +    netdev_tnl_push_ip_header(packet, data->header,
> +                              data->header_len, &ip_tot_size);
> +}
> +

<snip>

> diff --git a/ofproto/ofproto-dpif-xlate.c b/ofproto/ofproto-dpif-xlate.c
> index a9cf3cbee0be..15c814d6285b 100644
> --- a/ofproto/ofproto-dpif-xlate.c
> +++ b/ofproto/ofproto-dpif-xlate.c
> @@ -3632,6 +3632,9 @@ propagate_tunnel_data_to_flow(struct xlate_ctx *ctx, struct eth_addr dmac,
>      case OVS_VPORT_TYPE_BAREUDP:
>          nw_proto = IPPROTO_UDP;
>          break;
> +    case OVS_VPORT_TYPE_SRV6:
> +        nw_proto = IPPROTO_IPIP;

Sorry, just noticed that we're setting nw_proto to IPIP
always after encapsulation, even if the packet was IPv6.
We should check the dl_type of the original flow and set
the nw_proto appropriately.

You can check that the ping6 test fails if we request to
drop encapsulated IPv4 packets like this:

diff --git a/tests/system-traffic.at b/tests/system-traffic.at
index 65bae736f..33d60244e 100644
--- a/tests/system-traffic.at
+++ b/tests/system-traffic.at
@@ -1241,7 +1241,8 @@ dnl using veth pair. Kernel side tunnel endpoint (SID) is
 dnl 'fc00:a::1/128', so add it to the route.
 ADD_BR([br-underlay])
 ADD_VETH(p0, at_ns0, br-underlay, "fc00::1/64", [], [], "nodad")
-AT_CHECK([ovs-ofctl add-flow br-underlay "actions=normal"])
+AT_CHECK([ovs-ofctl add-flow br-underlay "priority=1,actions=normal"])
+AT_CHECK([ovs-ofctl add-flow br-underlay "priority=100,ipv6,nw_proto=4,actions=drop"])
 AT_CHECK([ip addr add dev br-underlay "fc00::100/64" nodad])
 AT_CHECK([ip link set dev br-underlay up])
 AT_CHECK([ip -6 route add fc00:a::1/128 dev br-underlay via fc00::1])
---

Even though the packet itself has nw_proto=41, the flow structure
that tracks it has nw_proto=4, and it is used for flow matching
after encapsulation.

A simple ternary operator solves the issue for me:

     case OVS_VPORT_TYPE_SRV6:
-        nw_proto = IPPROTO_IPIP;
+        nw_proto = (flow->dl_type == htons(ETH_TYPE_IP))
+                   ? IPPROTO_IPIP : IPPROTO_IPV6;
         break;

Might be good to have this case covered in tests as well.
Either by something similar to what I did above, or by a
separate test.

What do you think?

<snip>

> +dnl Set up tunnel endpoints on OVS outside the namespace.
> +ADD_OVS_TUNNEL6([srv6], [br0], [at_srv6], [fc00:a::1], [fc00:100::100/64])
> +AT_CHECK([ovs-vsctl set bridge br0 other_config:hwaddr=aa:55:aa:55:00:00])
> +dnl [sleep infinity]

This line returned. :)

The rest of the set looks fine to me.  Thanks!

Best regards, Ilya Maximets.
Nobuhiro MIKI March 29, 2023, 5:27 a.m. UTC | #2
On 2023/03/28 21:31, Ilya Maximets wrote:
> On 3/28/23 08:42, Nobuhiro MIKI wrote:
>> SRv6 (Segment Routing IPv6) tunnel vport is responsible
>> for encapsulation and decapsulation the inner packets with
>> IPv6 header and an extended header called SRH
>> (Segment Routing Header). See spec in:
>>
>> https://datatracker.ietf.org/doc/html/rfc8754
>>
>> This patch implements SRv6 tunneling in userspace datapath.
>> It uses `remote_ip` and `local_ip` options as with existing
>> tunnel protocols. It also adds a dedicated `srv6_segs` option
>> to define a sequence of routers called segment list.
>>
>> Signed-off-by: Nobuhiro MIKI <nmiki@yahoo-corp.jp>
>> ---
>>  Documentation/faq/configuration.rst |  21 +++++
>>  Documentation/faq/releases.rst      |   1 +
>>  NEWS                                |   2 +
>>  include/linux/openvswitch.h         |   1 +
>>  include/sparse/netinet/in.h         |   1 +
>>  lib/dpif-netlink-rtnl.c             |   5 ++
>>  lib/dpif-netlink.c                  |   5 ++
>>  lib/netdev-native-tnl.c             | 127 ++++++++++++++++++++++++++++
>>  lib/netdev-native-tnl.h             |  10 +++
>>  lib/netdev-vport.c                  |  53 ++++++++++++
>>  lib/netdev.h                        |   4 +
>>  lib/packets.h                       |  11 +++
>>  lib/tnl-ports.c                     |   5 +-
>>  ofproto/ofproto-dpif-xlate.c        |   3 +
>>  tests/system-kmod-macros.at         |   8 ++
>>  tests/system-traffic.at             | 119 ++++++++++++++++++++++++++
>>  tests/system-userspace-macros.at    |   6 ++
>>  tests/tunnel.at                     |  56 ++++++++++++
>>  18 files changed, 437 insertions(+), 1 deletion(-)
>>
> 
> <snip>
> 
>> +int
>> +netdev_srv6_build_header(const struct netdev *netdev,
>> +                         struct ovs_action_push_tnl *data,
>> +                         const struct netdev_tnl_build_header_params *params)
>> +{
>> +    struct netdev_vport *dev = netdev_vport_cast(netdev);
>> +    struct netdev_tunnel_config *tnl_cfg;
>> +    const struct in6_addr *segs;
>> +    struct srv6_base_hdr *srh;
>> +    struct in6_addr *s;
>> +    ovs_be16 dl_type;
>> +    int err = 0;
>> +    int nr_segs;
>> +    int i;
>> +
>> +    ovs_mutex_lock(&dev->mutex);
>> +    tnl_cfg = &dev->tnl_cfg;
>> +
>> +    if (tnl_cfg->srv6_num_segs) {
>> +        nr_segs = tnl_cfg->srv6_num_segs;
>> +        segs = tnl_cfg->srv6_segs;
>> +    } else {
>> +        /*
>> +         * If explicit segment list setting is omitted, tunnel destination
>> +         * is considered to be the first segment list.
>> +         */
>> +        nr_segs = 1;
>> +        segs = &params->flow->tunnel.ipv6_dst;
>> +    }
>> +
>> +    if (!ipv6_addr_equals(&segs[0], &params->flow->tunnel.ipv6_dst)) {
>> +        err = EINVAL;
>> +        goto out;
>> +    }
>> +
>> +    srh = netdev_tnl_ip_build_header(data, params, IPPROTO_ROUTING);
>> +    srh->rt_hdr.segments_left = nr_segs - 1;
>> +    srh->rt_hdr.type = IPV6_SRCRT_TYPE_4;
>> +    srh->rt_hdr.hdrlen = 2 * nr_segs;
>> +    srh->last_entry = nr_segs - 1;
>> +    srh->flags = 0;
>> +    srh->tag = 0;
>> +
>> +    dl_type = params->flow->dl_type;
>> +    if (dl_type == htons(ETH_TYPE_IP)) {
>> +        srh->rt_hdr.nexthdr = IPPROTO_IPIP;
>> +    } else if (dl_type == htons(ETH_TYPE_IPV6)) {
>> +        srh->rt_hdr.nexthdr = IPPROTO_IPV6;
>> +    }
> 
> We should probably error out here if for some reason it's not an IP or IPv6.
> 

For cases other than IP or IPv6, fix to return EOPNOTSUPP, which means unsupported.

>> +
>> +    s = ALIGNED_CAST(struct in6_addr *,
>> +                     (char *) srh + sizeof *srh);
>> +    for (i = 0; i < nr_segs; i++) {
>> +        /* Segment list is written to the header in reverse order. */
>> +        memcpy(s, &segs[nr_segs - i - 1], sizeof *s);
>> +        s++;
>> +    }
>> +
>> +    data->header_len += sizeof *srh + 8 * srh->rt_hdr.hdrlen;
>> +    data->tnl_type = OVS_VPORT_TYPE_SRV6;
>> +out:
>> +    ovs_mutex_unlock(&dev->mutex);
>> +
>> +    return err;
>> +}
>> +
>> +void
>> +netdev_srv6_push_header(const struct netdev *netdev OVS_UNUSED,
>> +                        struct dp_packet *packet OVS_UNUSED,
>> +                        const struct ovs_action_push_tnl *data OVS_UNUSED)
> 
> 'packet' and 'data' are actually used by the function.
> 

Thanks.
I'll remove the annotation OVS_UNUSED from 'packet' and 'data'.

>> +{
>> +    int ip_tot_size;
>> +
>> +    netdev_tnl_push_ip_header(packet, data->header,
>> +                              data->header_len, &ip_tot_size);
>> +}
>> +
> 
> <snip>
> 
>> diff --git a/ofproto/ofproto-dpif-xlate.c b/ofproto/ofproto-dpif-xlate.c
>> index a9cf3cbee0be..15c814d6285b 100644
>> --- a/ofproto/ofproto-dpif-xlate.c
>> +++ b/ofproto/ofproto-dpif-xlate.c
>> @@ -3632,6 +3632,9 @@ propagate_tunnel_data_to_flow(struct xlate_ctx *ctx, struct eth_addr dmac,
>>      case OVS_VPORT_TYPE_BAREUDP:
>>          nw_proto = IPPROTO_UDP;
>>          break;
>> +    case OVS_VPORT_TYPE_SRV6:
>> +        nw_proto = IPPROTO_IPIP;
> 
> Sorry, just noticed that we're setting nw_proto to IPIP
> always after encapsulation, even if the packet was IPv6.
> We should check the dl_type of the original flow and set
> the nw_proto appropriately.
> 
> You can check that the ping6 test fails if we request to
> drop encapsulated IPv4 packets like this:
> 
> diff --git a/tests/system-traffic.at b/tests/system-traffic.at
> index 65bae736f..33d60244e 100644
> --- a/tests/system-traffic.at
> +++ b/tests/system-traffic.at
> @@ -1241,7 +1241,8 @@ dnl using veth pair. Kernel side tunnel endpoint (SID) is
>  dnl 'fc00:a::1/128', so add it to the route.
>  ADD_BR([br-underlay])
>  ADD_VETH(p0, at_ns0, br-underlay, "fc00::1/64", [], [], "nodad")
> -AT_CHECK([ovs-ofctl add-flow br-underlay "actions=normal"])
> +AT_CHECK([ovs-ofctl add-flow br-underlay "priority=1,actions=normal"])
> +AT_CHECK([ovs-ofctl add-flow br-underlay "priority=100,ipv6,nw_proto=4,actions=drop"])
>  AT_CHECK([ip addr add dev br-underlay "fc00::100/64" nodad])
>  AT_CHECK([ip link set dev br-underlay up])
>  AT_CHECK([ip -6 route add fc00:a::1/128 dev br-underlay via fc00::1])
> ---
> 
> Even though the packet itself has nw_proto=41, the flow structure
> that tracks it has nw_proto=4, and it is used for flow matching
> after encapsulation.
> 
> A simple ternary operator solves the issue for me:
> 
>      case OVS_VPORT_TYPE_SRV6:
> -        nw_proto = IPPROTO_IPIP;
> +        nw_proto = (flow->dl_type == htons(ETH_TYPE_IP))
> +                   ? IPPROTO_IPIP : IPPROTO_IPV6;
>          break;
> 
> Might be good to have this case covered in tests as well.
> Either by something similar to what I did above, or by a
> separate test.
> 
> What do you think?
> 

I was able to reproduce this problem in my environment.
And I think your solution with ternary operator is great, so I will adopt it.

As for testing, I think it would be more robust if we implement a whitelist
to allow only IPPROTO_IPV6(41) and IPPROTO_ICMPV6(58) as shown below:

diff --git a/tests/system-traffic.at b/tests/system-traffic.at
index 165be2db5c3b..63753adbccce 100644
--- a/tests/system-traffic.at
+++ b/tests/system-traffic.at
@@ -1239,9 +1242,12 @@ NS_EXEC([at_ns0], [sysctl -w net.ipv6.conf.all.forwarding=1])
 dnl Set up underlay link from host into the namespace 'at_ns0'
 dnl using veth pair. Kernel side tunnel endpoint (SID) is
 dnl 'fc00:a::1/128', so add it to the route.
+dnl Only IPPROTO_IPV6(41) and IPPROTO_ICMPV6(58) are needed in underlay link.
 ADD_BR([br-underlay])
 ADD_VETH(p0, at_ns0, br-underlay, "fc00::1/64", [], [], "nodad")
-AT_CHECK([ovs-ofctl add-flow br-underlay "actions=normal"])
+AT_CHECK([ovs-ofctl add-flow br-underlay "priority=1,actions=drop"])
+AT_CHECK([ovs-ofctl add-flow br-underlay "priority=100,ipv6,nw_proto=41,actions=normal"])
+AT_CHECK([ovs-ofctl add-flow br-underlay "priority=100,ipv6,nw_proto=58,actions=normal"])


> <snip>
> 
>> +dnl Set up tunnel endpoints on OVS outside the namespace.
>> +ADD_OVS_TUNNEL6([srv6], [br0], [at_srv6], [fc00:a::1], [fc00:100::100/64])
>> +AT_CHECK([ovs-vsctl set bridge br0 other_config:hwaddr=aa:55:aa:55:00:00])
>> +dnl [sleep infinity]
> 
> This line returned. :)

Oops, this line will simply be deleted.

> 
> The rest of the set looks fine to me.  Thanks!
> 
> Best regards, Ilya Maximets.

Again, thanks for your review!

Best Regards,
Nobuhiro MIKI
diff mbox series

Patch

diff --git a/Documentation/faq/configuration.rst b/Documentation/faq/configuration.rst
index dc6c92446f98..4df390dc2d9d 100644
--- a/Documentation/faq/configuration.rst
+++ b/Documentation/faq/configuration.rst
@@ -238,6 +238,27 @@  Q: Does Open vSwitch support GTP-U?
                 set int gtpu0 type=gtpu options:key=<teid> \
                 options:remote_ip=172.31.1.1
 
+Q: Does Open vSwitch support SRv6?
+
+    A: Yes. Starting with version 3.2, the Open vSwitch userspace
+    datapath supports SRv6 (Segment Routing over IPv6). The following
+    example shows tunneling to fc00:300::1 via fc00:100::1 and fc00:200::1.
+    In the current implementation, if "IPv6 in IPv6" or "IPv4 in IPv6" packets
+    are routed to this interface, and these packets are not SRv6 packets, they
+    may be dropped, so be careful in workloads with a mix of these tunnels.
+    Also note the following restrictions:
+
+    * Segment list length is limited to 6.
+    * SRv6 packets with other than segments_left = 0 are simply dropped.
+
+    ::
+
+        $ ovs-vsctl add-br br0
+        $ ovs-vsctl add-port br0 srv6_0 -- \
+                set int srv6_0 type=srv6  \
+                options:remote_ip=fc00:100::1 \
+                options:srv6_segs="fc00:100::1,fc00:200::1,fc00:300::1"
+
 Q: How do I connect two bridges?
 
     A: First, why do you want to do this?  Two connected bridges are not much
diff --git a/Documentation/faq/releases.rst b/Documentation/faq/releases.rst
index 9e1b42262000..9fb679e307d9 100644
--- a/Documentation/faq/releases.rst
+++ b/Documentation/faq/releases.rst
@@ -151,6 +151,7 @@  Q: Are all features available with all datapaths?
     Tunnel - ERSPAN                 4.18           2.10         2.10     NO
     Tunnel - ERSPAN-IPv6            4.18           2.10         2.10     NO
     Tunnel - GTP-U                  NO             NO           2.14     NO
+    Tunnel - SRv6                   NO             NO           3.2      NO
     Tunnel - Bareudp                5.7            NO           NO       NO
     QoS - Policing                  YES            1.1          2.6      NO
     QoS - Shaping                   YES            1.1          NO       NO
diff --git a/NEWS b/NEWS
index 8771ee618aed..a8d77a75a248 100644
--- a/NEWS
+++ b/NEWS
@@ -21,6 +21,8 @@  Post-v3.1.0
      * ovs-vswitchd will keep the CAP_SYS_RAWIO capability when started
        with the --hw-rawio-access command line option.  This allows the
        process extra privileges when mapping physical interconnect memory.
+   - SRv6 Tunnel Protocol
+     * Only support for userspace datapath.
 
 
 v3.1.0 - 16 Feb 2023
diff --git a/include/linux/openvswitch.h b/include/linux/openvswitch.h
index bc8f74991849..e305c331516b 100644
--- a/include/linux/openvswitch.h
+++ b/include/linux/openvswitch.h
@@ -254,6 +254,7 @@  enum ovs_vport_type {
 	OVS_VPORT_TYPE_IP6GRE = 109,
 	OVS_VPORT_TYPE_GTPU = 110,
 	OVS_VPORT_TYPE_BAREUDP = 111,  /* Bareudp tunnel. */
+	OVS_VPORT_TYPE_SRV6 = 112,  /* SRv6 tunnel. */
 	__OVS_VPORT_TYPE_MAX
 };
 
diff --git a/include/sparse/netinet/in.h b/include/sparse/netinet/in.h
index 21deceb28d41..00927281643a 100644
--- a/include/sparse/netinet/in.h
+++ b/include/sparse/netinet/in.h
@@ -68,6 +68,7 @@  struct sockaddr_in6 {
 #define IPPROTO_HOPOPTS 0
 #define IPPROTO_ICMP 1
 #define IPPROTO_IGMP 2
+#define IPPROTO_IPIP 4
 #define IPPROTO_TCP 6
 #define IPPROTO_UDP 17
 #define IPPROTO_ROUTING 43
diff --git a/lib/dpif-netlink-rtnl.c b/lib/dpif-netlink-rtnl.c
index 4fc42daed2d9..5788294ae0d7 100644
--- a/lib/dpif-netlink-rtnl.c
+++ b/lib/dpif-netlink-rtnl.c
@@ -129,6 +129,8 @@  vport_type_to_kind(enum ovs_vport_type type,
         }
     case OVS_VPORT_TYPE_GTPU:
         return NULL;
+    case OVS_VPORT_TYPE_SRV6:
+        return "srv6";
     case OVS_VPORT_TYPE_BAREUDP:
         return "bareudp";
     case OVS_VPORT_TYPE_NETDEV:
@@ -319,6 +321,7 @@  dpif_netlink_rtnl_verify(const struct netdev_tunnel_config *tnl_cfg,
     case OVS_VPORT_TYPE_LISP:
     case OVS_VPORT_TYPE_STT:
     case OVS_VPORT_TYPE_GTPU:
+    case OVS_VPORT_TYPE_SRV6:
     case OVS_VPORT_TYPE_UNSPEC:
     case __OVS_VPORT_TYPE_MAX:
     default:
@@ -411,6 +414,7 @@  dpif_netlink_rtnl_create(const struct netdev_tunnel_config *tnl_cfg,
     case OVS_VPORT_TYPE_LISP:
     case OVS_VPORT_TYPE_STT:
     case OVS_VPORT_TYPE_GTPU:
+    case OVS_VPORT_TYPE_SRV6:
     case OVS_VPORT_TYPE_UNSPEC:
     case __OVS_VPORT_TYPE_MAX:
     default:
@@ -519,6 +523,7 @@  dpif_netlink_rtnl_port_destroy(const char *name, const char *type)
     case OVS_VPORT_TYPE_ERSPAN:
     case OVS_VPORT_TYPE_IP6ERSPAN:
     case OVS_VPORT_TYPE_IP6GRE:
+    case OVS_VPORT_TYPE_SRV6:
     case OVS_VPORT_TYPE_BAREUDP:
         return dpif_netlink_rtnl_destroy(name);
     case OVS_VPORT_TYPE_NETDEV:
diff --git a/lib/dpif-netlink.c b/lib/dpif-netlink.c
index ebe7b5cb1452..55b5b0a8549a 100644
--- a/lib/dpif-netlink.c
+++ b/lib/dpif-netlink.c
@@ -919,6 +919,9 @@  get_vport_type(const struct dpif_netlink_vport *vport)
     case OVS_VPORT_TYPE_GTPU:
         return "gtpu";
 
+    case OVS_VPORT_TYPE_SRV6:
+        return "srv6";
+
     case OVS_VPORT_TYPE_BAREUDP:
         return "bareudp";
 
@@ -957,6 +960,8 @@  netdev_to_ovs_vport_type(const char *type)
         return OVS_VPORT_TYPE_GRE;
     } else if (!strcmp(type, "gtpu")) {
         return OVS_VPORT_TYPE_GTPU;
+    } else if (!strcmp(type, "srv6")) {
+        return OVS_VPORT_TYPE_SRV6;
     } else if (!strcmp(type, "bareudp")) {
         return OVS_VPORT_TYPE_BAREUDP;
     } else {
diff --git a/lib/netdev-native-tnl.c b/lib/netdev-native-tnl.c
index b89dfdd52a86..7d40c40738de 100644
--- a/lib/netdev-native-tnl.c
+++ b/lib/netdev-native-tnl.c
@@ -845,6 +845,133 @@  netdev_gtpu_build_header(const struct netdev *netdev,
     return 0;
 }
 
+int
+netdev_srv6_build_header(const struct netdev *netdev,
+                         struct ovs_action_push_tnl *data,
+                         const struct netdev_tnl_build_header_params *params)
+{
+    struct netdev_vport *dev = netdev_vport_cast(netdev);
+    struct netdev_tunnel_config *tnl_cfg;
+    const struct in6_addr *segs;
+    struct srv6_base_hdr *srh;
+    struct in6_addr *s;
+    ovs_be16 dl_type;
+    int err = 0;
+    int nr_segs;
+    int i;
+
+    ovs_mutex_lock(&dev->mutex);
+    tnl_cfg = &dev->tnl_cfg;
+
+    if (tnl_cfg->srv6_num_segs) {
+        nr_segs = tnl_cfg->srv6_num_segs;
+        segs = tnl_cfg->srv6_segs;
+    } else {
+        /*
+         * If explicit segment list setting is omitted, tunnel destination
+         * is considered to be the first segment list.
+         */
+        nr_segs = 1;
+        segs = &params->flow->tunnel.ipv6_dst;
+    }
+
+    if (!ipv6_addr_equals(&segs[0], &params->flow->tunnel.ipv6_dst)) {
+        err = EINVAL;
+        goto out;
+    }
+
+    srh = netdev_tnl_ip_build_header(data, params, IPPROTO_ROUTING);
+    srh->rt_hdr.segments_left = nr_segs - 1;
+    srh->rt_hdr.type = IPV6_SRCRT_TYPE_4;
+    srh->rt_hdr.hdrlen = 2 * nr_segs;
+    srh->last_entry = nr_segs - 1;
+    srh->flags = 0;
+    srh->tag = 0;
+
+    dl_type = params->flow->dl_type;
+    if (dl_type == htons(ETH_TYPE_IP)) {
+        srh->rt_hdr.nexthdr = IPPROTO_IPIP;
+    } else if (dl_type == htons(ETH_TYPE_IPV6)) {
+        srh->rt_hdr.nexthdr = IPPROTO_IPV6;
+    }
+
+    s = ALIGNED_CAST(struct in6_addr *,
+                     (char *) srh + sizeof *srh);
+    for (i = 0; i < nr_segs; i++) {
+        /* Segment list is written to the header in reverse order. */
+        memcpy(s, &segs[nr_segs - i - 1], sizeof *s);
+        s++;
+    }
+
+    data->header_len += sizeof *srh + 8 * srh->rt_hdr.hdrlen;
+    data->tnl_type = OVS_VPORT_TYPE_SRV6;
+out:
+    ovs_mutex_unlock(&dev->mutex);
+
+    return err;
+}
+
+void
+netdev_srv6_push_header(const struct netdev *netdev OVS_UNUSED,
+                        struct dp_packet *packet OVS_UNUSED,
+                        const struct ovs_action_push_tnl *data OVS_UNUSED)
+{
+    int ip_tot_size;
+
+    netdev_tnl_push_ip_header(packet, data->header,
+                              data->header_len, &ip_tot_size);
+}
+
+struct dp_packet *
+netdev_srv6_pop_header(struct dp_packet *packet)
+{
+    const struct ovs_16aligned_ip6_hdr *nh = dp_packet_l3(packet);
+    size_t size = dp_packet_l3_size(packet) - IPV6_HEADER_LEN;
+    struct pkt_metadata *md = &packet->md;
+    struct flow_tnl *tnl = &md->tunnel;
+    const struct ip6_rt_hdr *rt_hdr;
+    uint8_t nw_proto = nh->ip6_nxt;
+    const void *data = nh + 1;
+    uint8_t nw_frag = 0;
+    unsigned int hlen;
+
+    /*
+     * Verifies that the routing header is present in the IPv6
+     * extension headers and that its type is SRv6.
+     */
+    if (!parse_ipv6_ext_hdrs(&data, &size, &nw_proto, &nw_frag,
+                             NULL, &rt_hdr)) {
+        goto err;
+    }
+
+    if (!rt_hdr || rt_hdr->type != IPV6_SRCRT_TYPE_4) {
+        goto err;
+    }
+
+    if (rt_hdr->segments_left > 0) {
+        VLOG_WARN_RL(&err_rl, "invalid srv6 segments_left=%d\n",
+                     rt_hdr->segments_left);
+        goto err;
+    }
+
+    if (rt_hdr->nexthdr == IPPROTO_IPIP) {
+        packet->packet_type = htonl(PT_IPV4);
+    } else if (rt_hdr->nexthdr == IPPROTO_IPV6) {
+        packet->packet_type = htonl(PT_IPV6);
+    } else {
+        goto err;
+    }
+
+    pkt_metadata_init_tnl(md);
+    netdev_tnl_ip_extract_tnl_md(packet, tnl, &hlen);
+    dp_packet_reset_packet(packet, hlen);
+
+    return packet;
+err:
+    dp_packet_delete(packet);
+    return NULL;
+}
+
 struct dp_packet *
 netdev_vxlan_pop_header(struct dp_packet *packet)
 {
diff --git a/lib/netdev-native-tnl.h b/lib/netdev-native-tnl.h
index 22ae2ce5369b..4dad8f978cc6 100644
--- a/lib/netdev-native-tnl.h
+++ b/lib/netdev-native-tnl.h
@@ -65,6 +65,16 @@  netdev_gtpu_build_header(const struct netdev *netdev,
                          struct ovs_action_push_tnl *data,
                          const struct netdev_tnl_build_header_params *p);
 
+struct dp_packet *netdev_srv6_pop_header(struct dp_packet *);
+
+void netdev_srv6_push_header(const struct netdev *,
+                             struct dp_packet *,
+                             const struct ovs_action_push_tnl *);
+
+int netdev_srv6_build_header(const struct netdev *,
+                             struct ovs_action_push_tnl *,
+                             const struct netdev_tnl_build_header_params *);
+
 void
 netdev_tnl_push_udp_header(const struct netdev *netdev,
                            struct dp_packet *packet,
diff --git a/lib/netdev-vport.c b/lib/netdev-vport.c
index 3b39278650d3..663ee8606c3b 100644
--- a/lib/netdev-vport.c
+++ b/lib/netdev-vport.c
@@ -424,6 +424,35 @@  parse_tunnel_ip(const char *value, bool accept_mcast, bool *flow,
     return 0;
 }
 
+static int
+parse_srv6_segs(char *s, struct in6_addr *segs, uint8_t *num_segs)
+{
+    char *save_ptr = NULL;
+    char *token;
+
+    if (!s) {
+        return EINVAL;
+    }
+
+    *num_segs = 0;
+
+    while ((token = strtok_r(s, ",", &save_ptr)) != NULL) {
+        if (*num_segs == SRV6_MAX_SEGS) {
+            return EINVAL;
+        }
+
+        if (inet_pton(AF_INET6, token, segs) != 1) {
+            return EINVAL;
+        }
+
+        segs++;
+        (*num_segs)++;
+        s = NULL;
+    }
+
+    return 0;
+}
+
 enum tunnel_layers {
     TNL_L2 = 1 << 0,       /* 1 if a tunnel type can carry Ethernet traffic. */
     TNL_L3 = 1 << 1        /* 1 if a tunnel type can carry L3 traffic. */
@@ -443,6 +472,8 @@  tunnel_supported_layers(const char *type,
         return TNL_L3;
     } else if (!strcmp(type, "bareudp")) {
         return TNL_L3;
+    } else if (!strcmp(type, "srv6")) {
+        return TNL_L3;
     } else {
         return TNL_L2;
     }
@@ -750,6 +781,17 @@  set_tunnel_config(struct netdev *dev_, const struct smap *args, char **errp)
                     goto out;
                 }
             }
+        } else if (!strcmp(node->key, "srv6_segs")) {
+            err = parse_srv6_segs(node->value,
+                                  tnl_cfg.srv6_segs,
+                                  &tnl_cfg.srv6_num_segs);
+
+            switch (err) {
+            case EINVAL:
+                ds_put_format(&errors, "%s: bad %s 'srv6_segs'\n",
+                              name, node->value);
+                break;
+            }
         } else if (!strcmp(node->key, "payload_type")) {
             if (!strcmp(node->value, "mpls")) {
                  tnl_cfg.payload_ethertype = htons(ETH_TYPE_MPLS);
@@ -1290,6 +1332,17 @@  netdev_vport_tunnel_register(void)
           },
           {{NULL, NULL, 0, 0}}
         },
+        { "srv6_sys",
+          {
+              TUNNEL_FUNCTIONS_COMMON,
+              .type = "srv6",
+              .build_header = netdev_srv6_build_header,
+              .push_header = netdev_srv6_push_header,
+              .pop_header = netdev_srv6_pop_header,
+              .get_ifindex = NETDEV_VPORT_GET_IFINDEX,
+          },
+          {{NULL, NULL, 0, 0}}
+        },
 
     };
     static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER;
diff --git a/lib/netdev.h b/lib/netdev.h
index acf174927d24..ff207f56c28c 100644
--- a/lib/netdev.h
+++ b/lib/netdev.h
@@ -140,6 +140,10 @@  struct netdev_tunnel_config {
     bool erspan_idx_flow;
     bool erspan_dir_flow;
     bool erspan_hwid_flow;
+
+    uint8_t srv6_num_segs;
+    #define SRV6_MAX_SEGS 6
+    struct in6_addr srv6_segs[SRV6_MAX_SEGS];
 };
 
 void netdev_run(void);
diff --git a/lib/packets.h b/lib/packets.h
index 70cd072228ae..83e0f6d95f36 100644
--- a/lib/packets.h
+++ b/lib/packets.h
@@ -1523,6 +1523,17 @@  BUILD_ASSERT_DECL(sizeof(struct vxlanhdr) == 8);
 #define VXLAN_F_GPE  0x4000
 #define VXLAN_HF_GPE 0x04000000
 
+/* SRv6 protocol header. */
+#define IPV6_SRCRT_TYPE_4 4
+#define SRV6_BASE_HDR_LEN 8
+struct srv6_base_hdr {
+    struct ip6_rt_hdr rt_hdr;
+    uint8_t last_entry;
+    uint8_t flags;
+    ovs_be16 tag;
+};
+BUILD_ASSERT_DECL(sizeof(struct srv6_base_hdr) == SRV6_BASE_HDR_LEN);
+
 /* Input values for PACKET_TYPE macros have to be in host byte order.
  * The _BE postfix indicates result is in network byte order. Otherwise result
  * is in host byte order. */
diff --git a/lib/tnl-ports.c b/lib/tnl-ports.c
index 829457ee50f0..f16409a0bf08 100644
--- a/lib/tnl-ports.c
+++ b/lib/tnl-ports.c
@@ -126,7 +126,7 @@  map_insert(odp_port_t port, struct eth_addr mac, struct in6_addr *addr,
          /* XXX: No fragments support. */
         match.wc.masks.nw_frag = FLOW_NW_FRAG_MASK;
 
-        /* 'tp_port' is zero for GRE tunnels. In this case it
+        /* 'tp_port' is zero for GRE and SRv6 tunnels. In this case it
          * doesn't make sense to match on UDP port numbers. */
         if (tp_port) {
             match.wc.masks.tp_dst = OVS_BE16_MAX;
@@ -174,6 +174,9 @@  tnl_type_to_nw_proto(const char type[], uint8_t nw_protos[2])
     } else if (!strcmp(type, "gre") || !strcmp(type, "erspan") ||
                !strcmp(type, "ip6erspan") || !strcmp(type, "ip6gre")) {
         nw_protos[0] = IPPROTO_GRE;
+    } else if (!strcmp(type, "srv6")) {
+        nw_protos[0] = IPPROTO_IPIP;
+        nw_protos[1] = IPPROTO_IPV6;
     }
 }
 
diff --git a/ofproto/ofproto-dpif-xlate.c b/ofproto/ofproto-dpif-xlate.c
index a9cf3cbee0be..15c814d6285b 100644
--- a/ofproto/ofproto-dpif-xlate.c
+++ b/ofproto/ofproto-dpif-xlate.c
@@ -3632,6 +3632,9 @@  propagate_tunnel_data_to_flow(struct xlate_ctx *ctx, struct eth_addr dmac,
     case OVS_VPORT_TYPE_BAREUDP:
         nw_proto = IPPROTO_UDP;
         break;
+    case OVS_VPORT_TYPE_SRV6:
+        nw_proto = IPPROTO_IPIP;
+        break;
     case OVS_VPORT_TYPE_LISP:
     case OVS_VPORT_TYPE_STT:
     case OVS_VPORT_TYPE_UNSPEC:
diff --git a/tests/system-kmod-macros.at b/tests/system-kmod-macros.at
index 822a80618d6f..fb15a5a7ce03 100644
--- a/tests/system-kmod-macros.at
+++ b/tests/system-kmod-macros.at
@@ -202,6 +202,14 @@  m4_define([OVS_CHECK_KERNEL_EXCL],
     AT_SKIP_IF([ ! ( test $version -lt $1 || ( test $version -eq $1 && test $sublevel -lt $2 ) || test $version -gt $3 || ( test $version -eq $3 && test $sublevel -gt $4 ) ) ])
 ])
 
+# OVS_CHECK_SRV6()
+#
+# The kernel datapath does not support this feature.
+m4_define([OVS_CHECK_SRV6],
+[
+    AT_SKIP_IF([:])
+])
+
 # CHECK_LATER_IPV6_FRAGMENTS()
 #
 # Upstream kernels beetween 4.20 and 5.19 are not parsing IPv6 fragments
diff --git a/tests/system-traffic.at b/tests/system-traffic.at
index 39a48175271e..65bae736f00e 100644
--- a/tests/system-traffic.at
+++ b/tests/system-traffic.at
@@ -1164,6 +1164,125 @@  OVS_WAIT_UNTIL([cat p0.pcap | grep -E "IP6 fc00:100::100 > fc00:100::1: GREv0, .
 OVS_TRAFFIC_VSWITCHD_STOP
 AT_CLEANUP
 
+AT_SETUP([datapath - ping over srv6 tunnel])
+OVS_CHECK_TUNNEL_TSO()
+OVS_CHECK_SRV6()
+
+OVS_TRAFFIC_VSWITCHD_START()
+
+ADD_NAMESPACES(at_ns0)
+ADD_NAMESPACES(at_ns1)
+NS_EXEC([at_ns0], [sysctl -w net.ipv6.conf.default.seg6_enabled=1])
+NS_EXEC([at_ns0], [sysctl -w net.ipv4.conf.default.forwarding=1])
+NS_EXEC([at_ns0], [sysctl -w net.ipv6.conf.default.forwarding=1])
+NS_EXEC([at_ns0], [sysctl -w net.ipv6.conf.all.seg6_enabled=1])
+NS_EXEC([at_ns0], [sysctl -w net.ipv4.conf.all.forwarding=1])
+NS_EXEC([at_ns0], [sysctl -w net.ipv6.conf.all.forwarding=1])
+
+dnl Set up underlay link from host into the namespace 'at_ns0'
+dnl using veth pair. Kernel side tunnel endpoint (SID) is
+dnl 'fc00:a::1/128', so add it to the route.
+ADD_BR([br-underlay])
+ADD_VETH(p0, at_ns0, br-underlay, "fc00::1/64", [], [], "nodad")
+AT_CHECK([ovs-ofctl add-flow br-underlay "actions=normal"])
+AT_CHECK([ip addr add dev br-underlay "fc00::100/64" nodad])
+AT_CHECK([ip link set dev br-underlay up])
+AT_CHECK([ip route add fc00:a::1/128 dev br-underlay via fc00::1])
+
+dnl Set up tunnel endpoints on OVS outside the namespace.
+ADD_OVS_TUNNEL6([srv6], [br0], [at_srv6], [fc00:a::1], [10.100.100.100/24])
+AT_CHECK([ovs-vsctl set bridge br0 other_config:hwaddr=aa:55:aa:55:00:00])
+AT_CHECK([ip route add 10.1.1.0/24 dev br0 via 10.100.100.1])
+AT_CHECK([arp -s 10.100.100.1 aa:55:aa:55:00:01])
+AT_CHECK([ovs-ofctl add-flow br0 in_port=LOCAL,actions=output:at_srv6])
+AT_CHECK([ovs-ofctl add-flow br0 in_port=at_srv6,actions=mod_dl_dst:aa:55:aa:55:00:00,output:LOCAL])
+
+dnl Set up tunnel endpoints on the namespace 'at_ns0',
+dnl and overlay port on the namespace 'at_ns1'
+ADD_VETH_NS([at_ns0], [veth0], [10.1.1.2/24], [at_ns1], [veth1], [10.1.1.1/24])
+NS_CHECK_EXEC([at_ns0], [ip sr tunsrc set fc00:a::1])
+NS_CHECK_EXEC([at_ns0], [ip route add 10.100.100.0/24 encap seg6 mode encap segs fc00::100 dev p0])
+NS_CHECK_EXEC([at_ns0], [ip -6 route add fc00:a::1 encap seg6local action End.DX4 nh4 0.0.0.0 dev veth0])
+NS_CHECK_EXEC([at_ns1], [ip route add 10.100.100.0/24 via 10.1.1.2 dev veth1])
+
+dnl Linux seems to take a little time to get its IPv6 stack in order. Without
+dnl waiting, we get occasional failures due to the following error:
+dnl "connect: Cannot assign requested address"
+OVS_WAIT_UNTIL([ip netns exec at_ns0 ping6 -c 1 fc00::100])
+
+dnl First, check the underlay.
+NS_CHECK_EXEC([at_ns0], [ping6 -q -c 3 -i 0.3 -w 2 fc00::100 | FORMAT_PING], [0], [dnl
+3 packets transmitted, 3 received, 0% packet loss, time 0ms
+])
+
+dnl Okay, now check the overlay.
+NS_CHECK_EXEC([at_ns1], [ping -q -c 3 -i 0.3 -w 2 10.100.100.100 | FORMAT_PING], [0], [dnl
+3 packets transmitted, 3 received, 0% packet loss, time 0ms
+])
+
+OVS_TRAFFIC_VSWITCHD_STOP
+AT_CLEANUP
+
+AT_SETUP([datapath - ping6 over srv6 tunnel])
+OVS_CHECK_TUNNEL_TSO()
+OVS_CHECK_SRV6()
+
+OVS_TRAFFIC_VSWITCHD_START()
+
+ADD_NAMESPACES(at_ns0)
+ADD_NAMESPACES(at_ns1)
+NS_EXEC([at_ns0], [sysctl -w net.ipv6.conf.default.seg6_enabled=1])
+NS_EXEC([at_ns0], [sysctl -w net.ipv6.conf.default.forwarding=1])
+NS_EXEC([at_ns0], [sysctl -w net.ipv6.conf.all.seg6_enabled=1])
+NS_EXEC([at_ns0], [sysctl -w net.ipv6.conf.all.forwarding=1])
+
+dnl Set up underlay link from host into the namespace 'at_ns0'
+dnl using veth pair. Kernel side tunnel endpoint (SID) is
+dnl 'fc00:a::1/128', so add it to the route.
+ADD_BR([br-underlay])
+ADD_VETH(p0, at_ns0, br-underlay, "fc00::1/64", [], [], "nodad")
+AT_CHECK([ovs-ofctl add-flow br-underlay "actions=normal"])
+AT_CHECK([ip addr add dev br-underlay "fc00::100/64" nodad])
+AT_CHECK([ip link set dev br-underlay up])
+AT_CHECK([ip -6 route add fc00:a::1/128 dev br-underlay via fc00::1])
+
+dnl Set up tunnel endpoints on OVS outside the namespace.
+ADD_OVS_TUNNEL6([srv6], [br0], [at_srv6], [fc00:a::1], [fc00:100::100/64])
+AT_CHECK([ovs-vsctl set bridge br0 other_config:hwaddr=aa:55:aa:55:00:00])
+dnl [sleep infinity]
+AT_CHECK([ip addr add dev br0 fc00:100::100/64])
+AT_CHECK([ip -6 route add fc00:1::1/128 dev br0 via fc00:100::1])
+AT_CHECK([ip -6 neigh add fc00:100::1 lladdr aa:55:aa:55:00:01 dev br0])
+AT_CHECK([ovs-ofctl add-flow br0 in_port=LOCAL,actions=output:at_srv6])
+AT_CHECK([ovs-ofctl add-flow br0 in_port=at_srv6,actions=mod_dl_dst:aa:55:aa:55:00:00,output:LOCAL])
+
+dnl Set up tunnel endpoints on the namespace 'at_ns0',
+dnl and overlay port on the namespace 'at_ns1'
+ADD_VETH_NS([at_ns0], [veth0], [fc00:1::2/64], [at_ns1], [veth1], [fc00:1::1/64])
+NS_CHECK_EXEC([at_ns0], [ip sr tunsrc set fc00:a::1])
+NS_CHECK_EXEC([at_ns0], [ip -6 route add fc00:100::0/64 encap seg6 mode encap segs fc00::100 dev p0])
+NS_CHECK_EXEC([at_ns0], [ip -6 route add fc00:a::1 encap seg6local action End.DX6 nh6 :: dev veth0])
+NS_CHECK_EXEC([at_ns1], [ip -6 route add fc00:100::/64 via fc00:1::2 dev veth1])
+
+dnl Linux seems to take a little time to get its IPv6 stack in order. Without
+dnl waiting, we get occasional failures due to the following error:
+dnl "connect: Cannot assign requested address"
+OVS_WAIT_UNTIL([ip netns exec at_ns0 ping6 -c 1 fc00::100])
+OVS_WAIT_UNTIL([ip netns exec at_ns1 ping6 -c 1 fc00:100::100])
+
+dnl First, check the underlay.
+NS_CHECK_EXEC([at_ns0], [ping6 -q -c 3 -i 0.3 -w 2 fc00::100 | FORMAT_PING], [0], [dnl
+3 packets transmitted, 3 received, 0% packet loss, time 0ms
+])
+
+dnl Okay, now check the overlay.
+NS_CHECK_EXEC([at_ns1], [ping6 -q -c 3 -i 0.3 -w 2 fc00:100::100 | FORMAT_PING], [0], [dnl
+3 packets transmitted, 3 received, 0% packet loss, time 0ms
+])
+
+OVS_TRAFFIC_VSWITCHD_STOP
+AT_CLEANUP
+
 AT_SETUP([datapath - clone action])
 OVS_TRAFFIC_VSWITCHD_START()
 
diff --git a/tests/system-userspace-macros.at b/tests/system-userspace-macros.at
index 610fa2e94ae8..482079386a43 100644
--- a/tests/system-userspace-macros.at
+++ b/tests/system-userspace-macros.at
@@ -301,6 +301,12 @@  m4_define([OVS_CHECK_KERNEL_EXCL],
     AT_SKIP_IF([:])
 ])
 
+# OVS_CHECK_SRV6()
+m4_define([OVS_CHECK_SRV6],
+    [AT_SKIP_IF([! ip -6 route add fc00::1/96 encap seg6 mode encap dev lo 2>&1 >/dev/null])
+     AT_CHECK([ip -6 route del fc00::1/96 2>&1 >/dev/null])
+     OVS_CHECK_FIREWALL()])
+
 # CHECK_LATER_IPV6_FRAGMENTS()
 #
 # Userspace is parsing later IPv6 fragments correctly.
diff --git a/tests/tunnel.at b/tests/tunnel.at
index 78cc3f3e99a6..ddeb66bc9fb7 100644
--- a/tests/tunnel.at
+++ b/tests/tunnel.at
@@ -1223,3 +1223,59 @@  AT_CHECK([ovs-vsctl add-port br0 p1 -- set int p1 type=dummy])
 OVS_APP_EXIT_AND_WAIT([ovs-vswitchd])
 OVS_APP_EXIT_AND_WAIT([ovsdb-server])]
 AT_CLEANUP
+
+AT_SETUP([tunnel - SRV6 basic])
+OVS_VSWITCHD_START([add-port br0 p1 -- set Interface p1 type=dummy \
+                    ofport_request=1 \
+                    -- add-port br0 p2 -- set Interface p2 type=srv6 \
+                    options:remote_ip=flow \
+                    ofport_request=2])
+OVS_VSWITCHD_DISABLE_TUNNEL_PUSH_POP
+
+dnl First setup dummy interface IP address, then add the route
+dnl so that tnl-port table can get valid IP address for the device.
+AT_CHECK([ovs-appctl netdev-dummy/ip6addr br0 fc00::1/64], [0], [OK
+])
+AT_CHECK([ovs-appctl ovs/route/add fc00::0/64 br0], [0], [OK
+])
+AT_CHECK([ovs-appctl ovs/route/show], [0], [dnl
+Route Table:
+User: fc00::/64 dev br0 SRC fc00::1
+])
+
+AT_DATA([flows.txt], [dnl
+in_port=1,actions=set_field:fc00::2->tun_ipv6_dst,output:2
+in_port=2,actions=1
+])
+AT_CHECK([ovs-ofctl add-flows br0 flows.txt])
+
+AT_CHECK([ovs-appctl dpif/show | tail -n +3], [0], [dnl
+    br0 65534/100: (dummy-internal)
+    p1 1/1: (dummy)
+    p2 2/6: (srv6: remote_ip=flow)
+])
+
+AT_CHECK([ovs-appctl tnl/ports/show |sort], [0], [dnl
+Listening ports:
+srv6_sys (6) ref_cnt=1
+srv6_sys (6) ref_cnt=1
+])
+
+AT_CHECK([ovs-appctl ofproto/list-tunnels], [0], [dnl
+port 6: p2 (srv6: ::->flow, key=0, legacy_l3, dp port=6, ttl=64)
+])
+
+dnl Encap: ipv4 inner packet
+AT_CHECK([ovs-appctl ofproto/trace ovs-dummy 'in_port(1),eth(src=50:54:00:00:00:05,dst=50:54:00:00:00:07),eth_type(0x0800),ipv4(src=192.168.0.1,dst=192.168.0.2,proto=6,tos=4,ttl=128,frag=no),tcp(src=8,dst=9)'], [0], [stdout])
+AT_CHECK([tail -1 stdout], [0],
+  [Datapath actions: set(tunnel(ipv6_dst=fc00::2,ttl=64,flags(df))),pop_eth,6
+])
+
+dnl Encap: ipv6 inner packet
+AT_CHECK([ovs-appctl ofproto/trace ovs-dummy 'in_port(1),eth(src=50:54:00:00:00:05,dst=50:54:00:00:00:07),eth_type(0x86dd),ipv6(src=2001:cafe::92,dst=2001:cafe::88,label=0,proto=47,tclass=0x0,hlimit=64)'], [0], [stdout])
+AT_CHECK([tail -1 stdout], [0],
+  [Datapath actions: set(tunnel(ipv6_dst=fc00::2,ttl=64,flags(df))),pop_eth,6
+])
+
+OVS_VSWITCHD_STOP
+AT_CLEANUP