On 2/15/23 6:46 AM, Andrea Mayer wrote:
This selftest is designed for testing the PSP flavor in SRv6 End behavior. It instantiates a virtual network composed of several nodes: hosts and SRv6 routers. Each node is realized using a network namespace that is properly interconnected to others through veth pairs. The test makes use of the SRv6 End behavior and of the PSP flavor needed for removing the SRH from the IPv6 header at the penultimate node.
The correct execution of the behavior is verified through reachability tests carried out between hosts.
Signed-off-by: Andrea Mayer andrea.mayer@uniroma2.it Signed-off-by: Paolo Lungaroni paolo.lungaroni@uniroma2.it
tools/testing/selftests/net/Makefile | 1 + .../selftests/net/srv6_end_flavors_test.sh | 869 ++++++++++++++++++ 2 files changed, 870 insertions(+) create mode 100755 tools/testing/selftests/net/srv6_end_flavors_test.sh
diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile index 3364c548a23b..6cd8993454d7 100644 --- a/tools/testing/selftests/net/Makefile +++ b/tools/testing/selftests/net/Makefile @@ -38,6 +38,7 @@ TEST_PROGS += srv6_end_dt6_l3vpn_test.sh TEST_PROGS += srv6_hencap_red_l3vpn_test.sh TEST_PROGS += srv6_hl2encap_red_l2vpn_test.sh TEST_PROGS += srv6_end_next_csid_l3vpn_test.sh +TEST_PROGS += srv6_end_flavors_test.sh TEST_PROGS += vrf_strict_mode_test.sh TEST_PROGS += arp_ndisc_evict_nocarrier.sh TEST_PROGS += ndisc_unsolicited_na_test.sh diff --git a/tools/testing/selftests/net/srv6_end_flavors_test.sh b/tools/testing/selftests/net/srv6_end_flavors_test.sh new file mode 100755 index 000000000000..50563443a4ad --- /dev/null +++ b/tools/testing/selftests/net/srv6_end_flavors_test.sh @@ -0,0 +1,869 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# author: Andrea Mayer andrea.mayer@uniroma2.it +# author: Paolo Lungaroni paolo.lungaroni@uniroma2.it +# +# This script is designed to test the support for "flavors" in the SRv6 End +# behavior. +# +# Flavors defined in RFC8986 [1] represent additional operations that can modify +# or extend the existing SRv6 End, End.X and End.T behaviors. For the sake of +# convenience, we report the list of flavors described in [1] hereafter: +# - Penultimate Segment Pop (PSP); +# - Ultimate Segment Pop (USP); +# - Ultimate Segment Decapsulation (USD). +# +# The End, End.X, and End.T behaviors can support these flavors either +# individually or in combinations. +# Currently in this selftest we consider only the PSP flavor for the SRv6 End +# behavior. However, it is possible to extend the script as soon as other +# flavors will be supported in the kernel. +# +# The purpose of the PSP flavor consists in instructing the penultimate node +# listed in the SRv6 policy to remove (i.e. pop) the outermost SRH from the IPv6 +# header. +# A PSP enabled SRv6 End behavior instance processes the SRH by: +# - decrementing the Segment Left (SL) value from 1 to 0; +# - copying the last SID from the SID List into the IPv6 Destination Address +# (DA); +# - removing the SRH from the extension headers following the IPv6 header. +# +# Once the SRH is removed, the IPv6 packet is forwarded to the destination using +# the IPv6 DA updated during the PSP operation (i.e. the IPv6 DA corresponding +# to the last SID carried by the removed SRH). +# +# Although the PSP flavor can be set for any SRv6 End behavior instance on any +# SR node, it will be active only on such behaviors bound to a penultimate SID +# for a given SRv6 policy. +# SL=2 SL=1 SL=0 +# | | | +# For example, given the SRv6 policy (SID List := <X, Y, Z>): +# - a PSP enabled SRv6 End behavior bound to SID Y will apply the PSP operation +# as Segment Left (SL) is 1, corresponding to the Penultimate Segment of the +# SID List; +# - a PSP enabled SRv6 End behavior bound to SID X will *NOT* apply the PSP +# operation as the Segment Left is 2. This behavior instance will apply the +# "standard" End packet processing, ignoring the configured PSP flavor at +# all. +# +# [1] RFC8986: https://datatracker.ietf.org/doc/html/rfc8986 +# +# Network topology +# ================ +# +# The network topology used in this selftest is depicted hereafter, composed by +# two hosts (hs-1, hs-2) and four routers (rt-1, rt-2, rt-3, rt-4). +# Hosts hs-1 and hs-2 are connected to routers rt-1 and rt-2, respectively, +# allowing them to communicate with each other. +# Traffic exchanged between hs-1 and hs-2 can follow different network paths. +# The network operator, through specific SRv6 Policies can steer traffic to one +# path rather than another. In this selftest this is implemented as follows: +# +# i) The SRv6 H.Insert behavior applies SRv6 Policies on traffic received by +# connected hosts. It pushes the Segment Routing Header (SRH) after the +# IPv6 header. The SRH contains the SID List (i.e. SRv6 Policy) needed for +# steering traffic across the segments/waypoints specified in that list; +# +# ii) The SRv6 End behavior advances the active SID in the SID List carried by +# the SRH; +# +# iii) The PSP enabled SRv6 End behavior is used to remove the SRH when such +# behavior is configured on a node bound to the Penultimate Segment carried +# by the SID List. +# +# cafe::1 cafe::2 +# +--------+ +--------+ +# | | | | +# | hs-1 | | hs-2 | +# | | | | +# +---+----+ +--- +---+ +# cafe::/64 | | cafe::/64 +# | | +# +---+----+ +----+---+ +# | | fcf0:0:1:2::/64 | | +# | rt-1 +-------------------+ rt-2 | +# | | | | +# +---+----+ +----+---+ +# | . . | +# | fcf0:0:1:3::/64 . | +# | . . | +# | . . | +# fcf0:0:1:4::/64 | . | fcf0:0:2:3::/64 +# | . . | +# | . . | +# | fcf0:0:2:4::/64 . | +# | . . | +# +---+----+ +----+---+ +# | | | | +# | rt-4 +-------------------+ rt-3 | +# | | fcf0:0:3:4::/64 | | +# +---+----+ +----+---+ +# +# Every fcf0:0:x:y::/64 network interconnects the SRv6 routers rt-x with rt-y in +# the IPv6 operator network. +# +# +# Local SID table +# =============== +# +# Each SRv6 router is configured with a Local SID table in which SIDs are +# stored. Considering the given SRv6 router rt-x, at least two SIDs are +# configured in the Local SID table: +# +# Local SID table for SRv6 router rt-x +# +---------------------------------------------------------------------+ +# |fcff:x::e is associated with the SRv6 End behavior | +# |fcff:x::ef1 is associated with the SRv6 End behavior with PSP flavor | +# +---------------------------------------------------------------------+ +# +# The fcff::/16 prefix is reserved by the operator for the SIDs. Reachability of +# SIDs is ensured by proper configuration of the IPv6 operator's network and +# SRv6 routers. +# +# +# SRv6 Policies +# ============= +# +# An SRv6 ingress router applies different SRv6 Policies to the traffic received +# from connected hosts on the basis of the destination addresses. +# In case of SRv6 H.Insert behavior, the SRv6 Policy enforcement consists of +# pushing the SRH (carrying a given SID List) after the existing IPv6 header. +# Note that in the inserting mode, there is no encapsulation at all. +# +# Before applying an SRv6 Policy using the SRv6 H.Insert behavior +# +------+---------+ +# | IPv6 | Payload | +# +------+---------+ +# +# After applying an SRv6 Policy using the SRv6 H.Insert behavior +# +------+-----+---------+ +# | IPv6 | SRH | Payload | +# +------+-----+---------+ +# +# Traffic from hs-1 to hs-2 +# ------------------------- +# +# Packets generated from hs-1 and directed towards hs-2 are +# handled by rt-1 which applies the following SRv6 Policy: +# +# i.a) IPv6 traffic, SID List=fcff:3::e,fcff:4::ef1,fcff:2::ef1,cafe::2 +# +# Router rt-1 is configured to enforce the Policy (i.a) through the SRv6 +# H.Insert behavior which pushes the SRH after the existing IPv6 header. This +# Policy steers the traffic from hs-1 across rt-3, rt-4, rt-2 and finally to the +# destination hs-2. +# +# As the packet reaches the router rt-3, the SRv6 End behavior bound to SID +# fcff:3::e is triggered. The behavior updates the Segment Left (from SL=3 to +# SL=2) in the SRH, the IPv6 DA with fcff:4::ef1 and forwards the packet to the +# next router on the path, i.e. rt-4. +# +# When router rt-4 receives the packet, the PSP enabled SRv6 End behavior bound +# to SID fcff:4::ef1 is executed. Since the SL=2, the PSP operation is *NOT* +# kicked in and the behavior applies the default End processing: the Segment +# Left is decreased (from SL=2 to SL=1), the IPv6 DA is updated with the SID +# fcff:2::ef1 and the packet is forwarded to router rt-2. +# +# The PSP enabled SRv6 End behavior on rt-2 is associated with SID fcff:2::ef1 +# and is executed as the packet is received. Because SL=1, the behavior applies +# the PSP processing on the packet as follows: i) SL is decreased, i.e. from +# SL=1 to SL=0; ii) last SID (cafe::2) is copied into the IPv6 DA; iii) the +# outermost SRH is removed from the extension headers following the IPv6 header. +# Once the PSP processing is completed, the packet is forwarded to the host hs-2 +# (destination). +# +# Traffic from hs-2 to hs-1 +# ------------------------- +# +# Packets generated from hs-2 and directed to hs-1 are handled by rt-2 which +# applies the following SRv6 Policy: +# +# i.b) IPv6 traffic, SID List=fcff:1::ef1,cafe::1 +# +# Router rt-2 is configured to enforce the Policy (i.b) through the SRv6 +# H.Insert behavior which pushes the SRH after the existing IPv6 header. This +# Policy steers the traffic from hs-2 across rt-1 and finally to the +# destination hs-1 +# +# +# When the router rt-1 receives the packet, the PSP enabled SRv6 End behavior +# associated with the SID fcff:1::ef1 is triggered. Since the SL=1, +# the PSP operation takes place: i) the SL is decremented; ii) the IPv6 DA is +# set with the last SID; iii) the SRH is removed from the extension headers +# after the IPv6 header. At this point, the packet with IPv6 DA=cafe::1 is sent +# to the destination, i.e. hs-1.
Once again, thank you for taking the time to write a detailed description of the test and its setup. Documenting intent is such an important part of the tests.
Reviewed-by: David Ahern dsahern@kernel.org