SRv6 End.DT46 Behavior is defined in the IETF RFC 8986 [1] along with SRv6
End.DT4 and End.DT6 Behaviors.
The proposed End.DT46 implementation is meant to support the decapsulation
of both IPv4 and IPv6 traffic coming from a *single* SRv6 tunnel.
The SRv6 End.DT46 Behavior greatly simplifies the setup and operations of
SRv6 VPNs in the Linux kernel.
- patch 1/2 is the core patch that adds support for the SRv6 End.DT46
Behavior;
- patch 2/2 adds the selftest for SRv6 End.DT46 Behavior.
The patch introducing the new SRv6 End.DT46 Behavior in iproute2 will
follow shortly.
Comments, suggestions and improvements are very welcome as always!
Thanks,
Andrea
[1] https://www.rfc-editor.org/rfc/rfc8986.html#name-enddt46-decapsulation-and-s
Andrea Mayer (2):
seg6: add support for SRv6 End.DT46 Behavior
selftests: seg6: add selftest for SRv6 End.DT46 Behavior
include/uapi/linux/seg6_local.h | 2 +
net/ipv6/seg6_local.c | 94 ++-
.../selftests/net/srv6_end_dt46_l3vpn_test.sh | 573 ++++++++++++++++++
3 files changed, 647 insertions(+), 22 deletions(-)
create mode 100755 tools/testing/selftests/net/srv6_end_dt46_l3vpn_test.sh
--
2.20.1
IETF RFC 8986 [1] includes the definition of SRv6 End.DT4, End.DT6, and
End.DT46 Behaviors.
The current SRv6 code in the Linux kernel only implements End.DT4 and
End.DT6 which can be used respectively to support IPv4-in-IPv6 and
IPv6-in-IPv6 VPNs. With End.DT4 and End.DT6 it is not possible to create a
single SRv6 VPN tunnel to carry both IPv4 and IPv6 traffic.
The proposed End.DT46 implementation is meant to support the decapsulation
of IPv4 and IPv6 traffic coming from a single SRv6 tunnel.
The implementation of the SRv6 End.DT46 Behavior in the Linux kernel
greatly simplifies the setup and operations of SRv6 VPNs.
The SRv6 End.DT46 Behavior leverages the infrastructure of SRv6 End.DT{4,6}
Behaviors implemented so far, because it makes use of a VRF device in
order to force the routing lookup into the associated routing table.
To make the End.DT46 work properly, it must be guaranteed that the routing
table used for routing lookup operations is bound to one and only one VRF
during the tunnel creation. Such constraint has to be enforced by enabling
the VRF strict_mode sysctl parameter, i.e.:
$ sysctl -wq net.vrf.strict_mode=1
Note that the same approach is used for the SRv6 End.DT4 Behavior and for
the End.DT6 Behavior in VRF mode.
The command used to instantiate an SRv6 End.DT46 Behavior is
straightforward, i.e.:
$ ip -6 route add 2001:db8::1 encap seg6local action End.DT46 vrftable 100 dev vrf100.
[1] https://www.rfc-editor.org/rfc/rfc8986.html#name-enddt46-decapsulation-and-s
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Performance and impact of SRv6 End.DT46 Behavior on the SRv6 Networking
=======================================================================
This patch aims to add the SRv6 End.DT46 Behavior with minimal impact on
the performance of SRv6 End.DT4 and End.DT6 Behaviors.
In order to verify this, we tested the performance of the newly introduced
SRv6 End.DT46 Behavior and compared it with the performance of SRv6
End.DT{4,6} Behaviors, considering both the patched kernel and the kernel
before applying the End.DT46 patch (referred to as vanilla kernel).
In details, the following decapsulation scenarios were considered:
1.a) IPv6 traffic in SRv6 End.DT46 Behavior on patched kernel;
1.b) IPv4 traffic in SRv6 End.DT46 Behavior on patched kernel;
2.a) SRv6 End.DT6 Behavior (VRF mode) on patched kernel;
2.b) SRv6 End.DT4 Behavior on patched kernel;
3.a) SRv6 End.DT6 Behavior (VRF mode) on vanilla kernel (without the
End.DT46 patch);
3.b) SRv6 End.DT4 Behavior on vanilla kernel (without the End.DT46 patch).
All tests were performed on a testbed deployed on the CloudLab [2]
facilities. We considered IPv{4,6} traffic handled by a single core (at 2.4
GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.13-rc1 using packets of size
~ 100 bytes.
Scenario (1.a): average 684.70 kpps; std. dev. 0.7 kpps;
Scenario (1.b): average 711.69 kpps; std. dev. 1.2 kpps;
Scenario (2.a): average 690.70 kpps; std. dev. 1.2 kpps;
Scenario (2.b): average 722.22 kpps; std. dev. 1.7 kpps;
Scenario (3.a): average 690.02 kpps; std. dev. 2.6 kpps;
Scenario (3.b): average 721.91 kpps; std. dev. 1.2 kpps;
Considering the results for the patched kernel (1.a, 1.b, 2.a, 2.b) we
observe that the performance degradation incurred in using End.DT46 rather
than End.DT6 and End.DT4 respectively for IPv6 and IPv4 traffic is minimal,
around 0.9% and 1.5%. Such very minimal performance degradation is the
price to be paid if one prefers to use a single tunnel capable of handling
both types of traffic (IPv4 and IPv6).
Comparing the results for End.DT4 and End.DT6 under the patched and the
vanilla kernel (2.a, 2.b, 3.a, 3.b) we observe that the introduction of the
End.DT46 patch has no impact on the performance of End.DT4 and End.DT6.
[2] https://www.cloudlab.us
Signed-off-by: Andrea Mayer <[email protected]>
---
include/uapi/linux/seg6_local.h | 2 +
net/ipv6/seg6_local.c | 94 +++++++++++++++++++++++++--------
2 files changed, 74 insertions(+), 22 deletions(-)
diff --git a/include/uapi/linux/seg6_local.h b/include/uapi/linux/seg6_local.h
index 5ae3ace84de0..332b18f318f8 100644
--- a/include/uapi/linux/seg6_local.h
+++ b/include/uapi/linux/seg6_local.h
@@ -64,6 +64,8 @@ enum {
SEG6_LOCAL_ACTION_END_AM = 14,
/* custom BPF action */
SEG6_LOCAL_ACTION_END_BPF = 15,
+ /* decap and lookup of DA in v4 or v6 table */
+ SEG6_LOCAL_ACTION_END_DT46 = 16,
__SEG6_LOCAL_ACTION_MAX,
};
diff --git a/net/ipv6/seg6_local.c b/net/ipv6/seg6_local.c
index 4ff38cb08f4b..60bf3b877957 100644
--- a/net/ipv6/seg6_local.c
+++ b/net/ipv6/seg6_local.c
@@ -87,10 +87,10 @@ struct seg6_end_dt_info {
int vrf_ifindex;
int vrf_table;
- /* tunneled packet proto and family (IPv4 or IPv6) */
- __be16 proto;
+ /* tunneled packet family (IPv4 or IPv6).
+ * Protocol and header length are inferred from family.
+ */
u16 family;
- int hdrlen;
};
struct pcpu_seg6_local_counters {
@@ -521,19 +521,6 @@ static int __seg6_end_dt_vrf_build(struct seg6_local_lwt *slwt, const void *cfg,
info->net = net;
info->vrf_ifindex = vrf_ifindex;
- switch (family) {
- case AF_INET:
- info->proto = htons(ETH_P_IP);
- info->hdrlen = sizeof(struct iphdr);
- break;
- case AF_INET6:
- info->proto = htons(ETH_P_IPV6);
- info->hdrlen = sizeof(struct ipv6hdr);
- break;
- default:
- return -EINVAL;
- }
-
info->family = family;
info->mode = DT_VRF_MODE;
@@ -622,22 +609,44 @@ static struct net_device *end_dt_get_vrf_rcu(struct sk_buff *skb,
}
static struct sk_buff *end_dt_vrf_core(struct sk_buff *skb,
- struct seg6_local_lwt *slwt)
+ struct seg6_local_lwt *slwt, u16 family)
{
struct seg6_end_dt_info *info = &slwt->dt_info;
struct net_device *vrf;
+ __be16 protocol;
+ int hdrlen;
vrf = end_dt_get_vrf_rcu(skb, info);
if (unlikely(!vrf))
goto drop;
- skb->protocol = info->proto;
+ switch (family) {
+ case AF_INET:
+ protocol = htons(ETH_P_IP);
+ hdrlen = sizeof(struct iphdr);
+ break;
+ case AF_INET6:
+ protocol = htons(ETH_P_IPV6);
+ hdrlen = sizeof(struct ipv6hdr);
+ break;
+ case AF_UNSPEC:
+ fallthrough;
+ default:
+ goto drop;
+ }
+
+ if (unlikely(info->family != AF_UNSPEC && info->family != family)) {
+ pr_warn_once("seg6local: SRv6 End.DT* family mismatch");
+ goto drop;
+ }
+
+ skb->protocol = protocol;
skb_dst_drop(skb);
- skb_set_transport_header(skb, info->hdrlen);
+ skb_set_transport_header(skb, hdrlen);
- return end_dt_vrf_rcv(skb, info->family, vrf);
+ return end_dt_vrf_rcv(skb, family, vrf);
drop:
kfree_skb(skb);
@@ -656,7 +665,7 @@ static int input_action_end_dt4(struct sk_buff *skb,
if (!pskb_may_pull(skb, sizeof(struct iphdr)))
goto drop;
- skb = end_dt_vrf_core(skb, slwt);
+ skb = end_dt_vrf_core(skb, slwt, AF_INET);
if (!skb)
/* packet has been processed and consumed by the VRF */
return 0;
@@ -739,7 +748,7 @@ static int input_action_end_dt6(struct sk_buff *skb,
goto legacy_mode;
/* DT6_VRF_MODE */
- skb = end_dt_vrf_core(skb, slwt);
+ skb = end_dt_vrf_core(skb, slwt, AF_INET6);
if (!skb)
/* packet has been processed and consumed by the VRF */
return 0;
@@ -767,6 +776,36 @@ static int input_action_end_dt6(struct sk_buff *skb,
return -EINVAL;
}
+#ifdef CONFIG_NET_L3_MASTER_DEV
+static int seg6_end_dt46_build(struct seg6_local_lwt *slwt, const void *cfg,
+ struct netlink_ext_ack *extack)
+{
+ return __seg6_end_dt_vrf_build(slwt, cfg, AF_UNSPEC, extack);
+}
+
+static int input_action_end_dt46(struct sk_buff *skb,
+ struct seg6_local_lwt *slwt)
+{
+ unsigned int off = 0;
+ int nexthdr;
+
+ nexthdr = ipv6_find_hdr(skb, &off, -1, NULL, NULL);
+ if (unlikely(nexthdr < 0))
+ goto drop;
+
+ switch (nexthdr) {
+ case IPPROTO_IPIP:
+ return input_action_end_dt4(skb, slwt);
+ case IPPROTO_IPV6:
+ return input_action_end_dt6(skb, slwt);
+ }
+
+drop:
+ kfree_skb(skb);
+ return -EINVAL;
+}
+#endif
+
/* push an SRH on top of the current one */
static int input_action_end_b6(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
@@ -968,6 +1007,17 @@ static struct seg6_action_desc seg6_action_table[] = {
#endif
.input = input_action_end_dt6,
},
+ {
+ .action = SEG6_LOCAL_ACTION_END_DT46,
+ .attrs = SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE),
+ .optattrs = SEG6_F_LOCAL_COUNTERS,
+#ifdef CONFIG_NET_L3_MASTER_DEV
+ .input = input_action_end_dt46,
+ .slwt_ops = {
+ .build_state = seg6_end_dt46_build,
+ },
+#endif
+ },
{
.action = SEG6_LOCAL_ACTION_END_B6,
.attrs = SEG6_F_ATTR(SEG6_LOCAL_SRH),
--
2.20.1
this selftest is designed for evaluating the new SRv6 End.DT46 Behavior
used, in this example, for implementing IPv4/IPv6 L3 VPN use cases.
Signed-off-by: Andrea Mayer <[email protected]>
Signed-off-by: Paolo Lungaroni <[email protected]>
---
.../selftests/net/srv6_end_dt46_l3vpn_test.sh | 573 ++++++++++++++++++
1 file changed, 573 insertions(+)
create mode 100755 tools/testing/selftests/net/srv6_end_dt46_l3vpn_test.sh
diff --git a/tools/testing/selftests/net/srv6_end_dt46_l3vpn_test.sh b/tools/testing/selftests/net/srv6_end_dt46_l3vpn_test.sh
new file mode 100755
index 000000000000..d1e156433b98
--- /dev/null
+++ b/tools/testing/selftests/net/srv6_end_dt46_l3vpn_test.sh
@@ -0,0 +1,573 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# author: Andrea Mayer <[email protected]>
+# author: Paolo Lungaroni <[email protected]>
+
+# This test is designed for evaluating the new SRv6 End.DT46 Behavior used for
+# implementing IPv4/IPv6 L3 VPN use cases.
+#
+# The current SRv6 code in the Linux kernel only implements SRv6 End.DT4 and
+# End.DT6 Behaviors which can be used respectively to support IPv4-in-IPv6 and
+# IPv6-in-IPv6 VPNs. With End.DT4 and End.DT6 it is not possible to create a
+# single SRv6 VPN tunnel to carry both IPv4 and IPv6 traffic.
+# The SRv6 End.DT46 Behavior implementation is meant to support the
+# decapsulation of IPv4 and IPv6 traffic coming from a single SRv6 tunnel.
+# Therefore, the SRv6 End.DT46 Behavior in the Linux kernel greatly simplifies
+# the setup and operations of SRv6 VPNs.
+#
+# Hereafter a network diagram is shown, where two different tenants (named 100
+# and 200) offer IPv4/IPv6 L3 VPN services allowing hosts to communicate with
+# each other across an IPv6 network.
+#
+# Only hosts belonging to the same tenant (and to the same VPN) can communicate
+# with each other. Instead, the communication among hosts of different tenants
+# is forbidden.
+# In other words, hosts hs-t100-1 and hs-t100-2 are connected through the
+# IPv4/IPv6 L3 VPN of tenant 100 while hs-t200-3 and hs-t200-4 are connected
+# using the IPv4/IPv6 L3 VPN of tenant 200. Cross connection between tenant 100
+# and tenant 200 is forbidden and thus, for example, hs-t100-1 cannot reach
+# hs-t200-3 and vice versa.
+#
+# Routers rt-1 and rt-2 implement IPv4/IPv6 L3 VPN services leveraging the SRv6
+# architecture. The key components for such VPNs are: a) SRv6 Encap behavior,
+# b) SRv6 End.DT46 Behavior and c) VRF.
+#
+# To explain how an IPv4/IPv6 L3 VPN based on SRv6 works, let us briefly
+# consider an example where, within the same domain of tenant 100, the host
+# hs-t100-1 pings the host hs-t100-2.
+#
+# First of all, L2 reachability of the host hs-t100-2 is taken into account by
+# the router rt-1 which acts as a arp/ndp proxy.
+#
+# When the host hs-t100-1 sends an IPv6 or IPv4 packet destined to hs-t100-2,
+# the router rt-1 receives the packet on the internal veth-t100 interface. Such
+# interface is enslaved to the VRF vrf-100 whose associated table contains the
+# SRv6 Encap route for encapsulating any IPv6 or IPv4 packet in a IPv6 plus the
+# Segment Routing Header (SRH) packet. This packet is sent through the (IPv6)
+# core network up to the router rt-2 that receives it on veth0 interface.
+#
+# The rt-2 router uses the 'localsid' routing table to process incoming
+# IPv6+SRH packets which belong to the VPN of the tenant 100. For each of these
+# packets, the SRv6 End.DT46 Behavior removes the outer IPv6+SRH headers and
+# performs the lookup on the vrf-100 table using the destination address of
+# the decapsulated IPv6 or IPv4 packet. Afterwards, the packet is sent to the
+# host hs-t100-2 through the veth-t100 interface.
+#
+# The ping response follows the same processing but this time the role of rt-1
+# and rt-2 are swapped.
+#
+# Of course, the IPv4/IPv6 L3 VPN for tenant 200 works exactly as the IPv4/IPv6
+# L3 VPN for tenant 100. In this case, only hosts hs-t200-3 and hs-t200-4 are
+# able to connect with each other.
+#
+#
+# +-------------------+ +-------------------+
+# | | | |
+# | hs-t100-1 netns | | hs-t100-2 netns |
+# | | | |
+# | +-------------+ | | +-------------+ |
+# | | veth0 | | | | veth0 | |
+# | | cafe::1/64 | | | | cafe::2/64 | |
+# | | 10.0.0.1/24 | | | | 10.0.0.2/24 | |
+# | +-------------+ | | +-------------+ |
+# | . | | . |
+# +-------------------+ +-------------------+
+# . .
+# . .
+# . .
+# +-----------------------------------+ +-----------------------------------+
+# | . | | . |
+# | +---------------+ | | +---------------- |
+# | | veth-t100 | | | | veth-t100 | |
+# | | cafe::254/64 | | | | cafe::254/64 | |
+# | | 10.0.0.254/24 | +----------+ | | +----------+ | 10.0.0.254/24 | |
+# | +-------+-------+ | localsid | | | | localsid | +-------+-------- |
+# | | | table | | | | table | | |
+# | +----+----+ +----------+ | | +----------+ +----+----+ |
+# | | vrf-100 | | | | vrf-100 | |
+# | +---------+ +------------+ | | +------------+ +---------+ |
+# | | veth0 | | | | veth0 | |
+# | | fd00::1/64 |.|...|.| fd00::2/64 | |
+# | +---------+ +------------+ | | +------------+ +---------+ |
+# | | vrf-200 | | | | vrf-200 | |
+# | +----+----+ | | +----+----+ |
+# | | | | | |
+# | +-------+-------+ | | +-------+-------- |
+# | | veth-t200 | | | | veth-t200 | |
+# | | cafe::254/64 | | | | cafe::254/64 | |
+# | | 10.0.0.254/24 | | | | 10.0.0.254/24 | |
+# | +---------------+ rt-1 netns | | rt-2 netns +---------------- |
+# | . | | . |
+# +-----------------------------------+ +-----------------------------------+
+# . .
+# . .
+# . .
+# . .
+# +-------------------+ +-------------------+
+# | . | | . |
+# | +-------------+ | | +-------------+ |
+# | | veth0 | | | | veth0 | |
+# | | cafe::3/64 | | | | cafe::4/64 | |
+# | | 10.0.0.3/24 | | | | 10.0.0.4/24 | |
+# | +-------------+ | | +-------------+ |
+# | | | |
+# | hs-t200-3 netns | | hs-t200-4 netns |
+# | | | |
+# +-------------------+ +-------------------+
+#
+#
+# ~~~~~~~~~~~~~~~~~~~~~~~~~
+# | Network configuration |
+# ~~~~~~~~~~~~~~~~~~~~~~~~~
+#
+# rt-1: localsid table (table 90)
+# +--------------------------------------------------+
+# |SID |Action |
+# +--------------------------------------------------+
+# |fc00:21:100::6046|apply SRv6 End.DT46 vrftable 100|
+# +--------------------------------------------------+
+# |fc00:21:200::6046|apply SRv6 End.DT46 vrftable 200|
+# +--------------------------------------------------+
+#
+# rt-1: VRF tenant 100 (table 100)
+# +---------------------------------------------------+
+# |host |Action |
+# +---------------------------------------------------+
+# |cafe::2 |apply seg6 encap segs fc00:12:100::6046|
+# +---------------------------------------------------+
+# |cafe::/64 |forward to dev veth-t100 |
+# +---------------------------------------------------+
+# |10.0.0.2 |apply seg6 encap segs fc00:12:100::6046|
+# +---------------------------------------------------+
+# |10.0.0.0/24|forward to dev veth-t100 |
+# +---------------------------------------------------+
+#
+# rt-1: VRF tenant 200 (table 200)
+# +---------------------------------------------------+
+# |host |Action |
+# +---------------------------------------------------+
+# |cafe::4 |apply seg6 encap segs fc00:12:200::6046|
+# +---------------------------------------------------+
+# |cafe::/64 |forward to dev veth-t200 |
+# +---------------------------------------------------+
+# |10.0.0.4 |apply seg6 encap segs fc00:12:200::6046|
+# +---------------------------------------------------+
+# |10.0.0.0/24|forward to dev veth-t200 |
+# +---------------------------------------------------+
+#
+#
+# rt-2: localsid table (table 90)
+# +--------------------------------------------------+
+# |SID |Action |
+# +--------------------------------------------------+
+# |fc00:12:100::6046|apply SRv6 End.DT46 vrftable 100|
+# +--------------------------------------------------+
+# |fc00:12:200::6046|apply SRv6 End.DT46 vrftable 200|
+# +--------------------------------------------------+
+#
+# rt-2: VRF tenant 100 (table 100)
+# +---------------------------------------------------+
+# |host |Action |
+# +---------------------------------------------------+
+# |cafe::1 |apply seg6 encap segs fc00:21:100::6046|
+# +---------------------------------------------------+
+# |cafe::/64 |forward to dev veth-t100 |
+# +---------------------------------------------------+
+# |10.0.0.1 |apply seg6 encap segs fc00:21:100::6046|
+# +---------------------------------------------------+
+# |10.0.0.0/24|forward to dev veth-t100 |
+# +---------------------------------------------------+
+#
+# rt-2: VRF tenant 200 (table 200)
+# +---------------------------------------------------+
+# |host |Action |
+# +---------------------------------------------------+
+# |cafe::3 |apply seg6 encap segs fc00:21:200::6046|
+# +---------------------------------------------------+
+# |cafe::/64 |forward to dev veth-t200 |
+# +---------------------------------------------------+
+# |10.0.0.3 |apply seg6 encap segs fc00:21:200::6046|
+# +---------------------------------------------------+
+# |10.0.0.0/24|forward to dev veth-t200 |
+# +---------------------------------------------------+
+#
+
+readonly LOCALSID_TABLE_ID=90
+readonly IPv6_RT_NETWORK=fd00
+readonly IPv6_HS_NETWORK=cafe
+readonly IPv4_HS_NETWORK=10.0.0
+readonly VPN_LOCATOR_SERVICE=fc00
+PING_TIMEOUT_SEC=4
+
+ret=0
+
+PAUSE_ON_FAIL=${PAUSE_ON_FAIL:=no}
+
+log_test()
+{
+ local rc=$1
+ local expected=$2
+ local msg="$3"
+
+ if [ ${rc} -eq ${expected} ]; then
+ nsuccess=$((nsuccess+1))
+ printf "\n TEST: %-60s [ OK ]\n" "${msg}"
+ else
+ ret=1
+ nfail=$((nfail+1))
+ printf "\n TEST: %-60s [FAIL]\n" "${msg}"
+ if [ "${PAUSE_ON_FAIL}" = "yes" ]; then
+ echo
+ echo "hit enter to continue, 'q' to quit"
+ read a
+ [ "$a" = "q" ] && exit 1
+ fi
+ fi
+}
+
+print_log_test_results()
+{
+ if [ "$TESTS" != "none" ]; then
+ printf "\nTests passed: %3d\n" ${nsuccess}
+ printf "Tests failed: %3d\n" ${nfail}
+ fi
+}
+
+log_section()
+{
+ echo
+ echo "################################################################################"
+ echo "TEST SECTION: $*"
+ echo "################################################################################"
+}
+
+cleanup()
+{
+ ip link del veth-rt-1 2>/dev/null || true
+ ip link del veth-rt-2 2>/dev/null || true
+
+ # destroy routers rt-* and hosts hs-*
+ for ns in $(ip netns show | grep -E 'rt-*|hs-*'); do
+ ip netns del ${ns} || true
+ done
+}
+
+# Setup the basic networking for the routers
+setup_rt_networking()
+{
+ local rt=$1
+ local nsname=rt-${rt}
+
+ ip netns add ${nsname}
+ ip link set veth-rt-${rt} netns ${nsname}
+ ip -netns ${nsname} link set veth-rt-${rt} name veth0
+
+ ip netns exec ${nsname} sysctl -wq net.ipv6.conf.all.accept_dad=0
+ ip netns exec ${nsname} sysctl -wq net.ipv6.conf.default.accept_dad=0
+
+ ip -netns ${nsname} addr add ${IPv6_RT_NETWORK}::${rt}/64 dev veth0 nodad
+ ip -netns ${nsname} link set veth0 up
+ ip -netns ${nsname} link set lo up
+
+ ip netns exec ${nsname} sysctl -wq net.ipv4.ip_forward=1
+ ip netns exec ${nsname} sysctl -wq net.ipv6.conf.all.forwarding=1
+}
+
+setup_hs()
+{
+ local hs=$1
+ local rt=$2
+ local tid=$3
+ local hsname=hs-t${tid}-${hs}
+ local rtname=rt-${rt}
+ local rtveth=veth-t${tid}
+
+ # set the networking for the host
+ ip netns add ${hsname}
+
+ ip netns exec ${hsname} sysctl -wq net.ipv6.conf.all.accept_dad=0
+ ip netns exec ${hsname} sysctl -wq net.ipv6.conf.default.accept_dad=0
+
+ ip -netns ${hsname} link add veth0 type veth peer name ${rtveth}
+ ip -netns ${hsname} link set ${rtveth} netns ${rtname}
+ ip -netns ${hsname} addr add ${IPv6_HS_NETWORK}::${hs}/64 dev veth0 nodad
+ ip -netns ${hsname} addr add ${IPv4_HS_NETWORK}.${hs}/24 dev veth0
+ ip -netns ${hsname} link set veth0 up
+ ip -netns ${hsname} link set lo up
+
+ # configure the VRF for the tenant X on the router which is directly
+ # connected to the source host.
+ ip -netns ${rtname} link add vrf-${tid} type vrf table ${tid}
+ ip -netns ${rtname} link set vrf-${tid} up
+
+ ip netns exec ${rtname} sysctl -wq net.ipv6.conf.all.accept_dad=0
+ ip netns exec ${rtname} sysctl -wq net.ipv6.conf.default.accept_dad=0
+
+ # enslave the veth-tX interface to the vrf-X in the access router
+ ip -netns ${rtname} link set ${rtveth} master vrf-${tid}
+ ip -netns ${rtname} addr add ${IPv6_HS_NETWORK}::254/64 dev ${rtveth} nodad
+ ip -netns ${rtname} addr add ${IPv4_HS_NETWORK}.254/24 dev ${rtveth}
+ ip -netns ${rtname} link set ${rtveth} up
+
+ ip netns exec ${rtname} sysctl -wq net.ipv6.conf.${rtveth}.proxy_ndp=1
+ ip netns exec ${rtname} sysctl -wq net.ipv4.conf.${rtveth}.proxy_arp=1
+
+ # disable the rp_filter otherwise the kernel gets confused about how
+ # to route decap ipv4 packets.
+ ip netns exec ${rtname} sysctl -wq net.ipv4.conf.all.rp_filter=0
+ ip netns exec ${rtname} sysctl -wq net.ipv4.conf.${rtveth}.rp_filter=0
+
+ ip netns exec ${rtname} sh -c "echo 1 > /proc/sys/net/vrf/strict_mode"
+}
+
+setup_vpn_config()
+{
+ local hssrc=$1
+ local rtsrc=$2
+ local hsdst=$3
+ local rtdst=$4
+ local tid=$5
+
+ local hssrc_name=hs-t${tid}-${hssrc}
+ local hsdst_name=hs-t${tid}-${hsdst}
+ local rtsrc_name=rt-${rtsrc}
+ local rtdst_name=rt-${rtdst}
+ local rtveth=veth-t${tid}
+ local vpn_sid=${VPN_LOCATOR_SERVICE}:${hssrc}${hsdst}:${tid}::6046
+
+ ip -netns ${rtsrc_name} -6 neigh add proxy ${IPv6_HS_NETWORK}::${hsdst} dev ${rtveth}
+
+ # set the encap route for encapsulating packets which arrive from the
+ # host hssrc and destined to the access router rtsrc.
+ ip -netns ${rtsrc_name} -6 route add ${IPv6_HS_NETWORK}::${hsdst}/128 vrf vrf-${tid} \
+ encap seg6 mode encap segs ${vpn_sid} dev veth0
+ ip -netns ${rtsrc_name} -4 route add ${IPv4_HS_NETWORK}.${hsdst}/32 vrf vrf-${tid} \
+ encap seg6 mode encap segs ${vpn_sid} dev veth0
+ ip -netns ${rtsrc_name} -6 route add ${vpn_sid}/128 vrf vrf-${tid} \
+ via fd00::${rtdst} dev veth0
+
+ # set the decap route for decapsulating packets which arrive from
+ # the rtdst router and destined to the hsdst host.
+ ip -netns ${rtdst_name} -6 route add ${vpn_sid}/128 table ${LOCALSID_TABLE_ID} \
+ encap seg6local action End.DT46 vrftable ${tid} dev vrf-${tid}
+
+ # all sids for VPNs start with a common locator which is fc00::/16.
+ # Routes for handling the SRv6 End.DT46 behavior instances are grouped
+ # together in the 'localsid' table.
+ #
+ # NOTE: added only once
+ if [ -z "$(ip -netns ${rtdst_name} -6 rule show | \
+ grep "to ${VPN_LOCATOR_SERVICE}::/16 lookup ${LOCALSID_TABLE_ID}")" ]; then
+ ip -netns ${rtdst_name} -6 rule add \
+ to ${VPN_LOCATOR_SERVICE}::/16 \
+ lookup ${LOCALSID_TABLE_ID} prio 999
+ fi
+
+ # set default routes to unreachable for both ipv4 and ipv6
+ ip -netns ${rtsrc_name} -6 route add unreachable default metric 4278198272 \
+ vrf vrf-${tid}
+
+ ip -netns ${rtsrc_name} -4 route add unreachable default metric 4278198272 \
+ vrf vrf-${tid}
+}
+
+setup()
+{
+ ip link add veth-rt-1 type veth peer name veth-rt-2
+ # setup the networking for router rt-1 and router rt-2
+ setup_rt_networking 1
+ setup_rt_networking 2
+
+ # setup two hosts for the tenant 100.
+ # - host hs-1 is directly connected to the router rt-1;
+ # - host hs-2 is directly connected to the router rt-2.
+ setup_hs 1 1 100 #args: host router tenant
+ setup_hs 2 2 100
+
+ # setup two hosts for the tenant 200
+ # - host hs-3 is directly connected to the router rt-1;
+ # - host hs-4 is directly connected to the router rt-2.
+ setup_hs 3 1 200
+ setup_hs 4 2 200
+
+ # setup the IPv4/IPv6 L3 VPN which connects the host hs-t100-1 and host
+ # hs-t100-2 within the same tenant 100.
+ setup_vpn_config 1 1 2 2 100 #args: src_host src_router dst_host dst_router tenant
+ setup_vpn_config 2 2 1 1 100
+
+ # setup the IPv4/IPv6 L3 VPN which connects the host hs-t200-3 and host
+ # hs-t200-4 within the same tenant 200.
+ setup_vpn_config 3 1 4 2 200
+ setup_vpn_config 4 2 3 1 200
+}
+
+check_rt_connectivity()
+{
+ local rtsrc=$1
+ local rtdst=$2
+
+ ip netns exec rt-${rtsrc} ping -c 1 -W 1 ${IPv6_RT_NETWORK}::${rtdst} \
+ >/dev/null 2>&1
+}
+
+check_and_log_rt_connectivity()
+{
+ local rtsrc=$1
+ local rtdst=$2
+
+ check_rt_connectivity ${rtsrc} ${rtdst}
+ log_test $? 0 "Routers connectivity: rt-${rtsrc} -> rt-${rtdst}"
+}
+
+check_hs_ipv6_connectivity()
+{
+ local hssrc=$1
+ local hsdst=$2
+ local tid=$3
+
+ ip netns exec hs-t${tid}-${hssrc} ping -c 1 -W ${PING_TIMEOUT_SEC} \
+ ${IPv6_HS_NETWORK}::${hsdst} >/dev/null 2>&1
+}
+
+check_hs_ipv4_connectivity()
+{
+ local hssrc=$1
+ local hsdst=$2
+ local tid=$3
+
+ ip netns exec hs-t${tid}-${hssrc} ping -c 1 -W ${PING_TIMEOUT_SEC} \
+ ${IPv4_HS_NETWORK}.${hsdst} >/dev/null 2>&1
+}
+
+check_and_log_hs_connectivity()
+{
+ local hssrc=$1
+ local hsdst=$2
+ local tid=$3
+
+ check_hs_ipv6_connectivity ${hssrc} ${hsdst} ${tid}
+ log_test $? 0 "IPv6 Hosts connectivity: hs-t${tid}-${hssrc} -> hs-t${tid}-${hsdst} (tenant ${tid})"
+
+ check_hs_ipv4_connectivity ${hssrc} ${hsdst} ${tid}
+ log_test $? 0 "IPv4 Hosts connectivity: hs-t${tid}-${hssrc} -> hs-t${tid}-${hsdst} (tenant ${tid})"
+
+}
+
+check_and_log_hs_isolation()
+{
+ local hssrc=$1
+ local tidsrc=$2
+ local hsdst=$3
+ local tiddst=$4
+
+ check_hs_ipv6_connectivity ${hssrc} ${hsdst} ${tidsrc}
+ # NOTE: ping should fail
+ log_test $? 1 "IPv6 Hosts isolation: hs-t${tidsrc}-${hssrc} -X-> hs-t${tiddst}-${hsdst}"
+
+ check_hs_ipv4_connectivity ${hssrc} ${hsdst} ${tidsrc}
+ # NOTE: ping should fail
+ log_test $? 1 "IPv4 Hosts isolation: hs-t${tidsrc}-${hssrc} -X-> hs-t${tiddst}-${hsdst}"
+
+}
+
+
+check_and_log_hs2gw_connectivity()
+{
+ local hssrc=$1
+ local tid=$2
+
+ check_hs_ipv6_connectivity ${hssrc} 254 ${tid}
+ log_test $? 0 "IPv6 Hosts connectivity: hs-t${tid}-${hssrc} -> gw (tenant ${tid})"
+
+ check_hs_ipv4_connectivity ${hssrc} 254 ${tid}
+ log_test $? 0 "IPv4 Hosts connectivity: hs-t${tid}-${hssrc} -> gw (tenant ${tid})"
+
+}
+
+router_tests()
+{
+ log_section "IPv6 routers connectivity test"
+
+ check_and_log_rt_connectivity 1 2
+ check_and_log_rt_connectivity 2 1
+}
+
+host2gateway_tests()
+{
+ log_section "IPv4/IPv6 connectivity test among hosts and gateway"
+
+ check_and_log_hs2gw_connectivity 1 100
+ check_and_log_hs2gw_connectivity 2 100
+
+ check_and_log_hs2gw_connectivity 3 200
+ check_and_log_hs2gw_connectivity 4 200
+}
+
+host_vpn_tests()
+{
+ log_section "SRv6 VPN connectivity test among hosts in the same tenant"
+
+ check_and_log_hs_connectivity 1 2 100
+ check_and_log_hs_connectivity 2 1 100
+
+ check_and_log_hs_connectivity 3 4 200
+ check_and_log_hs_connectivity 4 3 200
+}
+
+host_vpn_isolation_tests()
+{
+ local i
+ local j
+ local k
+ local tmp
+ local l1="1 2"
+ local l2="3 4"
+ local t1=100
+ local t2=200
+
+ log_section "SRv6 VPN isolation test among hosts in different tentants"
+
+ for k in 0 1; do
+ for i in ${l1}; do
+ for j in ${l2}; do
+ check_and_log_hs_isolation ${i} ${t1} ${j} ${t2}
+ done
+ done
+
+ # let us test the reverse path
+ tmp="${l1}"; l1="${l2}"; l2="${tmp}"
+ tmp=${t1}; t1=${t2}; t2=${tmp}
+ done
+}
+
+if [ "$(id -u)" -ne 0 ];then
+ echo "SKIP: Need root privileges"
+ exit 0
+fi
+
+if [ ! -x "$(command -v ip)" ]; then
+ echo "SKIP: Could not run test without ip tool"
+ exit 0
+fi
+
+modprobe vrf &>/dev/null
+if [ ! -e /proc/sys/net/vrf/strict_mode ]; then
+ echo "SKIP: vrf sysctl does not exist"
+ exit 0
+fi
+
+cleanup &>/dev/null
+
+setup
+
+router_tests
+host2gateway_tests
+host_vpn_tests
+host_vpn_isolation_tests
+
+print_log_test_results
+
+cleanup &>/dev/null
+
+exit ${ret}
--
2.20.1
On 6/8/21 4:40 AM, Andrea Mayer wrote:
> this selftest is designed for evaluating the new SRv6 End.DT46 Behavior
> used, in this example, for implementing IPv4/IPv6 L3 VPN use cases.
>
> Signed-off-by: Andrea Mayer <[email protected]>
> Signed-off-by: Paolo Lungaroni <[email protected]>
> ---
> .../selftests/net/srv6_end_dt46_l3vpn_test.sh | 573 ++++++++++++++++++
> 1 file changed, 573 insertions(+)
> create mode 100755 tools/testing/selftests/net/srv6_end_dt46_l3vpn_test.sh
>
> diff --git a/tools/testing/selftests/net/srv6_end_dt46_l3vpn_test.sh b/tools/testing/selftests/net/srv6_end_dt46_l3vpn_test.sh
> new file mode 100755
> index 000000000000..d1e156433b98
> --- /dev/null
> +++ b/tools/testing/selftests/net/srv6_end_dt46_l3vpn_test.sh
> @@ -0,0 +1,573 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +#
> +# author: Andrea Mayer <[email protected]>
> +# author: Paolo Lungaroni <[email protected]>
> +
> +# This test is designed for evaluating the new SRv6 End.DT46 Behavior used for
> +# implementing IPv4/IPv6 L3 VPN use cases.
> +#
> +# The current SRv6 code in the Linux kernel only implements SRv6 End.DT4 and
> +# End.DT6 Behaviors which can be used respectively to support IPv4-in-IPv6 and
> +# IPv6-in-IPv6 VPNs. With End.DT4 and End.DT6 it is not possible to create a
> +# single SRv6 VPN tunnel to carry both IPv4 and IPv6 traffic.
> +# The SRv6 End.DT46 Behavior implementation is meant to support the
> +# decapsulation of IPv4 and IPv6 traffic coming from a single SRv6 tunnel.
> +# Therefore, the SRv6 End.DT46 Behavior in the Linux kernel greatly simplifies
> +# the setup and operations of SRv6 VPNs.
> +#
> +# Hereafter a network diagram is shown, where two different tenants (named 100
> +# and 200) offer IPv4/IPv6 L3 VPN services allowing hosts to communicate with
> +# each other across an IPv6 network.
> +#
> +# Only hosts belonging to the same tenant (and to the same VPN) can communicate
> +# with each other. Instead, the communication among hosts of different tenants
> +# is forbidden.
> +# In other words, hosts hs-t100-1 and hs-t100-2 are connected through the
> +# IPv4/IPv6 L3 VPN of tenant 100 while hs-t200-3 and hs-t200-4 are connected
> +# using the IPv4/IPv6 L3 VPN of tenant 200. Cross connection between tenant 100
> +# and tenant 200 is forbidden and thus, for example, hs-t100-1 cannot reach
> +# hs-t200-3 and vice versa.
> +#
> +# Routers rt-1 and rt-2 implement IPv4/IPv6 L3 VPN services leveraging the SRv6
> +# architecture. The key components for such VPNs are: a) SRv6 Encap behavior,
> +# b) SRv6 End.DT46 Behavior and c) VRF.
> +#
> +# To explain how an IPv4/IPv6 L3 VPN based on SRv6 works, let us briefly
> +# consider an example where, within the same domain of tenant 100, the host
> +# hs-t100-1 pings the host hs-t100-2.
> +#
> +# First of all, L2 reachability of the host hs-t100-2 is taken into account by
> +# the router rt-1 which acts as a arp/ndp proxy.
> +#
> +# When the host hs-t100-1 sends an IPv6 or IPv4 packet destined to hs-t100-2,
> +# the router rt-1 receives the packet on the internal veth-t100 interface. Such
> +# interface is enslaved to the VRF vrf-100 whose associated table contains the
> +# SRv6 Encap route for encapsulating any IPv6 or IPv4 packet in a IPv6 plus the
> +# Segment Routing Header (SRH) packet. This packet is sent through the (IPv6)
> +# core network up to the router rt-2 that receives it on veth0 interface.
> +#
> +# The rt-2 router uses the 'localsid' routing table to process incoming
> +# IPv6+SRH packets which belong to the VPN of the tenant 100. For each of these
> +# packets, the SRv6 End.DT46 Behavior removes the outer IPv6+SRH headers and
> +# performs the lookup on the vrf-100 table using the destination address of
> +# the decapsulated IPv6 or IPv4 packet. Afterwards, the packet is sent to the
> +# host hs-t100-2 through the veth-t100 interface.
> +#
> +# The ping response follows the same processing but this time the role of rt-1
> +# and rt-2 are swapped.
> +#
> +# Of course, the IPv4/IPv6 L3 VPN for tenant 200 works exactly as the IPv4/IPv6
> +# L3 VPN for tenant 100. In this case, only hosts hs-t200-3 and hs-t200-4 are
> +# able to connect with each other.
> +#
> +#
> +# +-------------------+ +-------------------+
> +# | | | |
> +# | hs-t100-1 netns | | hs-t100-2 netns |
> +# | | | |
> +# | +-------------+ | | +-------------+ |
> +# | | veth0 | | | | veth0 | |
> +# | | cafe::1/64 | | | | cafe::2/64 | |
> +# | | 10.0.0.1/24 | | | | 10.0.0.2/24 | |
> +# | +-------------+ | | +-------------+ |
> +# | . | | . |
> +# +-------------------+ +-------------------+
> +# . .
> +# . .
> +# . .
> +# +-----------------------------------+ +-----------------------------------+
> +# | . | | . |
> +# | +---------------+ | | +---------------- |
> +# | | veth-t100 | | | | veth-t100 | |
> +# | | cafe::254/64 | | | | cafe::254/64 | |
> +# | | 10.0.0.254/24 | +----------+ | | +----------+ | 10.0.0.254/24 | |
> +# | +-------+-------+ | localsid | | | | localsid | +-------+-------- |
> +# | | | table | | | | table | | |
> +# | +----+----+ +----------+ | | +----------+ +----+----+ |
> +# | | vrf-100 | | | | vrf-100 | |
> +# | +---------+ +------------+ | | +------------+ +---------+ |
> +# | | veth0 | | | | veth0 | |
> +# | | fd00::1/64 |.|...|.| fd00::2/64 | |
> +# | +---------+ +------------+ | | +------------+ +---------+ |
> +# | | vrf-200 | | | | vrf-200 | |
> +# | +----+----+ | | +----+----+ |
> +# | | | | | |
> +# | +-------+-------+ | | +-------+-------- |
> +# | | veth-t200 | | | | veth-t200 | |
> +# | | cafe::254/64 | | | | cafe::254/64 | |
> +# | | 10.0.0.254/24 | | | | 10.0.0.254/24 | |
> +# | +---------------+ rt-1 netns | | rt-2 netns +---------------- |
> +# | . | | . |
> +# +-----------------------------------+ +-----------------------------------+
> +# . .
> +# . .
> +# . .
> +# . .
> +# +-------------------+ +-------------------+
> +# | . | | . |
> +# | +-------------+ | | +-------------+ |
> +# | | veth0 | | | | veth0 | |
> +# | | cafe::3/64 | | | | cafe::4/64 | |
> +# | | 10.0.0.3/24 | | | | 10.0.0.4/24 | |
> +# | +-------------+ | | +-------------+ |
> +# | | | |
> +# | hs-t200-3 netns | | hs-t200-4 netns |
> +# | | | |
> +# +-------------------+ +-------------------+
> +#
> +#
> +# ~~~~~~~~~~~~~~~~~~~~~~~~~
> +# | Network configuration |
> +# ~~~~~~~~~~~~~~~~~~~~~~~~~
> +#
> +# rt-1: localsid table (table 90)
> +# +--------------------------------------------------+
> +# |SID |Action |
> +# +--------------------------------------------------+
> +# |fc00:21:100::6046|apply SRv6 End.DT46 vrftable 100|
> +# +--------------------------------------------------+
> +# |fc00:21:200::6046|apply SRv6 End.DT46 vrftable 200|
> +# +--------------------------------------------------+
> +#
> +# rt-1: VRF tenant 100 (table 100)
> +# +---------------------------------------------------+
> +# |host |Action |
> +# +---------------------------------------------------+
> +# |cafe::2 |apply seg6 encap segs fc00:12:100::6046|
> +# +---------------------------------------------------+
> +# |cafe::/64 |forward to dev veth-t100 |
> +# +---------------------------------------------------+
> +# |10.0.0.2 |apply seg6 encap segs fc00:12:100::6046|
> +# +---------------------------------------------------+
> +# |10.0.0.0/24|forward to dev veth-t100 |
> +# +---------------------------------------------------+
> +#
> +# rt-1: VRF tenant 200 (table 200)
> +# +---------------------------------------------------+
> +# |host |Action |
> +# +---------------------------------------------------+
> +# |cafe::4 |apply seg6 encap segs fc00:12:200::6046|
> +# +---------------------------------------------------+
> +# |cafe::/64 |forward to dev veth-t200 |
> +# +---------------------------------------------------+
> +# |10.0.0.4 |apply seg6 encap segs fc00:12:200::6046|
> +# +---------------------------------------------------+
> +# |10.0.0.0/24|forward to dev veth-t200 |
> +# +---------------------------------------------------+
> +#
> +#
> +# rt-2: localsid table (table 90)
> +# +--------------------------------------------------+
> +# |SID |Action |
> +# +--------------------------------------------------+
> +# |fc00:12:100::6046|apply SRv6 End.DT46 vrftable 100|
> +# +--------------------------------------------------+
> +# |fc00:12:200::6046|apply SRv6 End.DT46 vrftable 200|
> +# +--------------------------------------------------+
> +#
> +# rt-2: VRF tenant 100 (table 100)
> +# +---------------------------------------------------+
> +# |host |Action |
> +# +---------------------------------------------------+
> +# |cafe::1 |apply seg6 encap segs fc00:21:100::6046|
> +# +---------------------------------------------------+
> +# |cafe::/64 |forward to dev veth-t100 |
> +# +---------------------------------------------------+
> +# |10.0.0.1 |apply seg6 encap segs fc00:21:100::6046|
> +# +---------------------------------------------------+
> +# |10.0.0.0/24|forward to dev veth-t100 |
> +# +---------------------------------------------------+
> +#
> +# rt-2: VRF tenant 200 (table 200)
> +# +---------------------------------------------------+
> +# |host |Action |
> +# +---------------------------------------------------+
> +# |cafe::3 |apply seg6 encap segs fc00:21:200::6046|
> +# +---------------------------------------------------+
> +# |cafe::/64 |forward to dev veth-t200 |
> +# +---------------------------------------------------+
> +# |10.0.0.3 |apply seg6 encap segs fc00:21:200::6046|
> +# +---------------------------------------------------+
> +# |10.0.0.0/24|forward to dev veth-t200 |
> +# +---------------------------------------------------+
> +#
> +
Great description of the test; thanks for adding that documentation.
Acked-by: David Ahern <[email protected]>
On 6/8/21 4:40 AM, Andrea Mayer wrote:
> IETF RFC 8986 [1] includes the definition of SRv6 End.DT4, End.DT6, and
> End.DT46 Behaviors.
>
> The current SRv6 code in the Linux kernel only implements End.DT4 and
> End.DT6 which can be used respectively to support IPv4-in-IPv6 and
> IPv6-in-IPv6 VPNs. With End.DT4 and End.DT6 it is not possible to create a
> single SRv6 VPN tunnel to carry both IPv4 and IPv6 traffic.
>
> The proposed End.DT46 implementation is meant to support the decapsulation
> of IPv4 and IPv6 traffic coming from a single SRv6 tunnel.
> The implementation of the SRv6 End.DT46 Behavior in the Linux kernel
> greatly simplifies the setup and operations of SRv6 VPNs.
>
> The SRv6 End.DT46 Behavior leverages the infrastructure of SRv6 End.DT{4,6}
> Behaviors implemented so far, because it makes use of a VRF device in
> order to force the routing lookup into the associated routing table.
>
> To make the End.DT46 work properly, it must be guaranteed that the routing
> table used for routing lookup operations is bound to one and only one VRF
> during the tunnel creation. Such constraint has to be enforced by enabling
> the VRF strict_mode sysctl parameter, i.e.:
>
> $ sysctl -wq net.vrf.strict_mode=1
>
> Note that the same approach is used for the SRv6 End.DT4 Behavior and for
> the End.DT6 Behavior in VRF mode.
>
> The command used to instantiate an SRv6 End.DT46 Behavior is
> straightforward, i.e.:
>
> $ ip -6 route add 2001:db8::1 encap seg6local action End.DT46 vrftable 100 dev vrf100.
>
> [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-enddt46-decapsulation-and-s
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Performance and impact of SRv6 End.DT46 Behavior on the SRv6 Networking
> =======================================================================
>
> This patch aims to add the SRv6 End.DT46 Behavior with minimal impact on
> the performance of SRv6 End.DT4 and End.DT6 Behaviors.
> In order to verify this, we tested the performance of the newly introduced
> SRv6 End.DT46 Behavior and compared it with the performance of SRv6
> End.DT{4,6} Behaviors, considering both the patched kernel and the kernel
> before applying the End.DT46 patch (referred to as vanilla kernel).
>
> In details, the following decapsulation scenarios were considered:
>
> 1.a) IPv6 traffic in SRv6 End.DT46 Behavior on patched kernel;
> 1.b) IPv4 traffic in SRv6 End.DT46 Behavior on patched kernel;
> 2.a) SRv6 End.DT6 Behavior (VRF mode) on patched kernel;
> 2.b) SRv6 End.DT4 Behavior on patched kernel;
> 3.a) SRv6 End.DT6 Behavior (VRF mode) on vanilla kernel (without the
> End.DT46 patch);
> 3.b) SRv6 End.DT4 Behavior on vanilla kernel (without the End.DT46 patch).
>
> All tests were performed on a testbed deployed on the CloudLab [2]
> facilities. We considered IPv{4,6} traffic handled by a single core (at 2.4
> GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.13-rc1 using packets of size
> ~ 100 bytes.
>
> Scenario (1.a): average 684.70 kpps; std. dev. 0.7 kpps;
> Scenario (1.b): average 711.69 kpps; std. dev. 1.2 kpps;
> Scenario (2.a): average 690.70 kpps; std. dev. 1.2 kpps;
> Scenario (2.b): average 722.22 kpps; std. dev. 1.7 kpps;
> Scenario (3.a): average 690.02 kpps; std. dev. 2.6 kpps;
> Scenario (3.b): average 721.91 kpps; std. dev. 1.2 kpps;
>
> Considering the results for the patched kernel (1.a, 1.b, 2.a, 2.b) we
> observe that the performance degradation incurred in using End.DT46 rather
> than End.DT6 and End.DT4 respectively for IPv6 and IPv4 traffic is minimal,
> around 0.9% and 1.5%. Such very minimal performance degradation is the
> price to be paid if one prefers to use a single tunnel capable of handling
> both types of traffic (IPv4 and IPv6).
>
> Comparing the results for End.DT4 and End.DT6 under the patched and the
> vanilla kernel (2.a, 2.b, 3.a, 3.b) we observe that the introduction of the
> End.DT46 patch has no impact on the performance of End.DT4 and End.DT6.
>
> [2] https://www.cloudlab.us
>
> Signed-off-by: Andrea Mayer <[email protected]>
> ---
> include/uapi/linux/seg6_local.h | 2 +
> net/ipv6/seg6_local.c | 94 +++++++++++++++++++++++++--------
> 2 files changed, 74 insertions(+), 22 deletions(-)
>
Reviewed-by: David Ahern <[email protected]>