RDKBNETWOR-84: DSLite feature integration with WanManager (Wg network11 development) #176

devinmungan · 2025-12-11T10:58:37Z

Implement stateful DS-Lite V2 in Wan Manager

Summary
This PR integrates the new generation of DS-Lite into wan-manager and
dhcp-manager. Unlike the previous stateless implementation, this version
is stateful and fully integrated into the Wan Manager state machine.

This implementation moves significant logic (including service_dslite.c
and data model handling) out of Utopia and ccsp-p-and-m into
wan-manager, while maintaining backward compatibility for non-volatile
storage keys.

Technical Implementation

Architecture Migration:
- Migrated Device.DSLite TR-181 data model handling from
  ccsp-p-and-m to wan-manager.
- Moved service_dslite.c logic and non-volatile configuration
  storage from Utopia to wan-manager.
- Backward Compatibility: Retained existing syscfg keys for
  non-volatile storage to ensure seamless upgrades.
Data Model & Mapping:
- InterfaceSetting entries are now maintained in a separate linked
  list.
- Introduced #define PSM_WANMANAGER_IF_VIRIF_DSLITE_PATH to map
  InterfaceSetting entries to their corresponding Virtual Interfaces
  using the Alias field.
DHCP Integration:
- DHCPv6 Option 64 is now received by dhcp-manager and propagated to
  wan-manager, where it is stored in the mapped DSLite entry.
State Machine:
- Extended the Virtual Interface state machine to explicitly support
  DS-Lite transition states.

New Features

DNS TTL Tracking & Reliability
Added logic to handle endpoint changes and failures gracefully:

TTL Tracking: Tracks DNS TTL and resolution timestamps for endpoint
FQDNs.
Smart Re-resolution: Periodically checks TTL in the DSLITE_ACTIVE
state. Re-resolves endpoint when TTL expires, but only restarts the
tunnel if the resolved address has changed.
Failure Handling: Tears down the tunnel if DNS re-resolution fails to
prevent stale endpoint usage.
Retry Logic: Implemented automatic retry every 5 seconds after tunnel
setup failures (Note: Future improvement planned to make this
configurable via DM parameter).
Optimization: Added address caching to avoid redundant DNS queries.

Dual Stack Provisioning Support
Introduced specific support for dual-stack provisioning scenarios where
standard IPv6-only DS-Lite is not sufficient.

Flag: FEATURE_DSLITE_V2_DUALSTACK_SUPPORT (Distro feature:
dslite_v2_dualstack_support).
Behavior: If the DS-Lite tunnel fails (e.g., FQDN resolution
failure), the device will gracefully fallback to the IPv4 address on
the WAN interface.

Build Configuration
This feature is gated by the following preprocessor macros:

FEATURE_DSLITE_V2 (Distro feature: dslite_v2)
FEATURE_DSLITE_V2_DUALSTACK_SUPPORT (Distro feature:
dslite_v2_dualstack_support)

…11 development) * RDKBNETWOR-86 : Move Device.DSLite. datamodel implementation to WAN Manager * DSLite Data Model Migration to WAN Manager Signed-off-by: Devin Mungan <devin.mungan@infosys.com>

…11 development) * RDKBNETWOR-85 : DHCP Manager changes for option 64 * parse and import endpoint name data coming from dhcp-manager Signed-off-by: Devin Mungan <devin.mungan@infosys.com>

…11 development) * RDKBNETWOR-88 : WAN Manager state machine for DSLite * Interface state machine is extended to cover DS-Lite mode as well Signed-off-by: Devin Mungan <devin.mungan@infosys.com>

…11 development) * RDKBNETWOR-87: DSLite tunnel interface management * Moved service_dslite from Utopia to WanManager. Signed-off-by: Govindaraja N B <gnb.ext@libertyglobal.com>

…11 development) * RDKBNETWOR-89 : WAN Manager DSLite failure/failover handling Summary Added DNS TTL tracking with periodic re-resolution and retry logic to handle endpoint changes and failures gracefully. Key Changes - Track DNS TTL and resolution timestamp for endpoint FQDNs - Periodically check TTL expiration in DSLITE_ACTIVE state - Re-resolve endpoint when TTL expires; only restart tunnel if address changed - Tear down tunnel if DNS re-resolution fails (prevents stale endpoint usage) - Automatic retry every 5 seconds after tunnel setup failures (TODO is adding a DM parameter for it) - Optimize DNS queries with address caching to avoid redundant resolutions Signed-off-by: Devin Mungan <devin.mungan@infosys.com>

…11 development) * RDKBNETWOR-89 : WAN Manager DSLite failure/failover handling Add Dual-Stack device-mode awareness to the DS-Lite feature. By design, DS-Lite is enabled only when the CPE operates in IPv6-only mode. For platforms that intentionally want DS-Lite in Dual-Stack mode, enable the distro feature: dslite_v2_dualstack_support Signed-off-by: Devin Mungan <devin.mungan@infosys.com>

…11 development) * Enhance error handling and update the state-machine flow to align with the latest design agreed with the Tiger Team.

github-actions · 2025-12-11T10:58:48Z

All contributors have signed the CLA ✍️ ✅
_{Posted by the CLA Assistant Lite bot.}

Copilot

Pull request overview

This PR integrates stateful DS-Lite V2 into WAN Manager, moving significant logic from Utopia and ccsp-p-and-m while maintaining backward compatibility. The implementation includes DNS TTL tracking with smart re-resolution, failure handling with automatic retry logic, and optional dual-stack provisioning support.

Key Changes:

Migrated Device.DSLite TR-181 data model handling and service_dslite.c logic to WAN Manager
Added DS-Lite states to WAN interface state machine with DNS TTL-based endpoint management
Integrated DHCPv6 Option 64 handling for dynamic endpoint provisioning

Reviewed changes

Copilot reviewed 25 out of 25 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
wanmgr_interface_sm.c	Extended state machine with DS-Lite states, setup/teardown logic, and retry mechanism
wanmgr_dslite.c	Core DS-Lite implementation including DNS resolution with TTL tracking and tunnel management
wanmgr_dslite.h	DS-Lite public API definitions for tunnel and configuration management
wanmgr_data.c	DS-Lite data structures and access functions for configuration management
wanmgr_dml_dslite_apis.c	TR-181 data model implementation for Device.DSLite object
wanmgr_dhcp_event_handler.c	DHCPv6 Option 64 endpoint name integration
wanmgr_telemetry.h/.c	DS-Lite telemetry event definitions and handlers
configure.ac	Build configuration for DS-Lite V2 feature flag

Comments suppressed due to low confidence (1)

source/WanManager/wanmgr_dslite.c:1

The function WanMgr_SysCfgSetStr should validate that the value parameter is not NULL before calling strlen() or other string operations on it. Without this check, there's potential for undefined behavior if value is NULL.

/*

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govindaraja-nb · 2025-12-11T11:10:07Z

I have read the CLA Document and I hereby sign the CLA

sichevoi

I'll continue later this week.

config/RdkWanManager_v2.xml

source/TR-181/include/wanmgr_dml.h

source/TR-181/middle_layer_src/wanmgr_dml_dslite_apis.h

source/TR-181/middle_layer_src/wanmgr_dml_iface_v2_apis.c

source/TR-181/middle_layer_src/wanmgr_rdkbus_apis.c

source/WanManager/Makefile.am

sichevoi

I've finished this part.

config/RdkWanManager_v2.xml

source/TR-181/include/wanmgr_dml.h

source/TR-181/middle_layer_src/wanmgr_dml_dslite_apis.h

source/WanManager/wanmgr_data.c

sichevoi · 2026-01-05T12:32:12Z

source/WanManager/wanmgr_sysevents.c

+
+    if (pid > 0)
+    {
+        sprintf(cmdline_buf, "/proc/%d/cmdline", pid);


Could you please comment why is this needed? I have trouble understanding the logic.

probably copied from utopia. @govindaraja-nb need your input pls

Yes, this logic was copied from Utopia (service_dslite).
So instead of keeping this logic, I updated it to simply restart Zebra. Also moved all service restarts into helper WanMgr_Dslite_RestartServices().

source/WanManager/wanmgr_t2_telemetry.c

- change dhcpv6 & dml related AFTR FQDN naming to aftr instead of endpointName keep internal naming as "endpointName" since internals also will have endpointAddr and these parameters are already under DSLite context therefore both function and struct namings suggest endPointName is a DSLite related field. - change TunnelV4Addr to X_RDKCENTRAL-COM_TunnelV4Addr as it's not a standard TR-181 DM - convert ANSC to generic - link libevent to wanmgr only if DSLITE_SUPPORT flag exists - add telemetry event for the case WAN_ERROR_DSLITE_STATUS_FAILED

- add helper to restart required services during DSLite up/down - remove wanmgr_restart_zebra() and move zebra restart into the helper function. Signed-off-by: Govindaraja N B <gnb.ext@libertyglobal.com>

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devinmungan and others added 7 commits December 10, 2025 01:10

RDKBNETWOR-84: DSLite feature integration with WanManager (Wg network…

3de10af

…11 development) * RDKBNETWOR-86 : Move Device.DSLite. datamodel implementation to WAN Manager * DSLite Data Model Migration to WAN Manager Signed-off-by: Devin Mungan <devin.mungan@infosys.com>

RDKBNETWOR-84: DSLite feature integration with WanManager (Wg network…

61b6673

…11 development) * RDKBNETWOR-85 : DHCP Manager changes for option 64 * parse and import endpoint name data coming from dhcp-manager Signed-off-by: Devin Mungan <devin.mungan@infosys.com>

RDKBNETWOR-84: DSLite feature integration with WanManager (Wg network…

f6f89a6

…11 development) * RDKBNETWOR-88 : WAN Manager state machine for DSLite * Interface state machine is extended to cover DS-Lite mode as well Signed-off-by: Devin Mungan <devin.mungan@infosys.com>

RDKBNETWOR-84: DSLite feature integration with WanManager (Wg network…

83e4736

…11 development) * RDKBNETWOR-87: DSLite tunnel interface management * Moved service_dslite from Utopia to WanManager. Signed-off-by: Govindaraja N B <gnb.ext@libertyglobal.com>

RDKBNETWOR-84: DSLite feature integration with WanManager (Wg network…

5985514

…11 development) * Enhance error handling and update the state-machine flow to align with the latest design agreed with the Tiger Team.

Copilot AI review requested due to automatic review settings December 11, 2025 10:58

devinmungan requested a review from a team as a code owner December 11, 2025 10:58

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sichevoi reviewed Dec 15, 2025

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sichevoi reviewed Jan 5, 2026

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devinmungan and others added 2 commits January 12, 2026 14:37

Improve DSLite service restart handling

20700b1

- add helper to restart required services during DSLite up/down - remove wanmgr_restart_zebra() and move zebra restart into the helper function. Signed-off-by: Govindaraja N B <gnb.ext@libertyglobal.com>

Copilot AI review requested due to automatic review settings January 12, 2026 15:07

Copilot AI reviewed Jan 12, 2026

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RDKBNETWOR-84: DSLite feature integration with WanManager (Wg network11 development) #176

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github-actions bot commented Dec 11, 2025 •

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