Allow state db to take modified entries made to the tunnel decap table

[developfast]

What I did
Allow state db to take modified entries made to the tunnel decap table

Why I did it
Prevent DB inconsistency between state, asic and appl db

How I verified it
redis-cli -n 6 HGETALL "TUNNEL_DECAP_TABLE|IPINIP_V6_TUNNEL"

1. "tunnel_type"
2. "IPINIP"
3. "dscp_mode"
4. "pipe"
5. "ecn_mode"
6. "standard"
7. "ttl_mode"
8. "pipe"

/var/log/syslog.1:2025 Nov 10 19:18:32.730385 bjw-can-2700-2 NOTICE swss#orchagent: :- doDecapTunnelTask: Fields for TUNNEL_DECAP_TABLE entry 'IPINIP_TUNNEL' have been synchronised in STATE_DB
/var/log/syslog.1:2025 Nov 10 19:18:32.740298 bjw-can-2700-2 NOTICE swss#orchagent: :- doDecapTunnelTask: Fields for TUNNEL_DECAP_TABLE entry 'IPINIP_V6_TUNNEL' have been synchronised in STATE_DB

Added comprehensive unit tests too which pass

make  check-TESTS
make[1]: Entering directory '/home/devojha/data/sonic-swss/tests/mock_tests'
make[2]: Entering directory '/home/devojha/data/sonic-swss/tests/mock_tests'
PASS: tests
PASS: tests_intfmgrd
PASS: tests_teammgrd
PASS: tests_portsyncd
PASS: tests_fpmsyncd
PASS: tests_response_publisher
============================================================================
Testsuite summary for sonic-swss 1.0
============================================================================
# TOTAL: 6
# PASS:  6
# SKIP:  0
# XFAIL: 0
# FAIL:  0
# XPASS: 0
# ERROR: 0
============================================================================
make[2]: Leaving directory '/home/devojha/data/sonic-swss/tests/mock_tests'
make[1]: Leaving directory '/home/devojha/data/sonic-swss/tests/mock_tests'

Details if related

[mssonicbld]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[mssonicbld]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[mssonicbld]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[Copilot]

Pull Request Overview

This PR enables synchronization of tunnel decap table modifications to STATE_DB, preventing database inconsistencies between STATE_DB, ASIC_DB, and APPL_DB. The implementation tracks field changes via a state_changed flag and publishes updates to STATE_DB when modifications occur to existing tunnel entries.

Key Changes

• Added state_changed flag tracking in doDecapTunnelTask() to detect when tunnel fields are modified
• Set the flag when modifiable fields (dscp_mode, ttl_mode, QoS maps) are updated on existing tunnels
• Added STATE_DB synchronization call when changes are detected

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
orchagent/tunneldecaporch.cpp	Implements state change tracking and STATE_DB synchronization for tunnel decap table modifications
tests/mock_tests/tunneldecaporch_ut.cpp	Adds comprehensive unit tests for TunnelDecapOrch functionality including creation, modification, and deletion scenarios
tests/mock_tests/Makefile.am	Registers the new tunneldecaporch_ut.cpp test file in the build system

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[mssonicbld]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[developfast]

@kperumalbfn can you pls check why the checks won't run? The agents don't seem to be grabbing the workers before the 45 min timeout

[developfast]

@prsunny @kperumalbfn can you pls review?