ctrld opened the WFP engine with a plain FWPM_SESSION0, so every filter and
sublayer it installed was persistent for the engine's boot lifetime: the kernel
kept enforcing them after the installing process was gone. Any exit that did
not run the shutdown path - kill, crash, or a service stop during upgrade -
left them behind.
In hard intercept mode that orphaned the DNS block filters. With Firewall Mode
enabled it orphaned machine-wide block-all filters that carry no process or SID
condition, so the entire host lost outbound traffic: browsers, other users, and
a replacement ctrld's own API bootstrap alike, with no way back short of a
reboot.
Set FWPM_SESSION_FLAG_DYNAMIC on both engine sessions (hard intercept and
loopback protect). Windows then deletes everything the session owns when the
handle closes, including on abnormal termination, so ctrld's enforcement can no
longer outlive the process that installed it.
This removes the cause. The next commit adds startup self-heal for hosts
already carrying orphaned filters from a build that predates this change.
This commit extends the documentation effort by adding detailed explanatory
comments to key CLI components and core functionality throughout the cmd/
directory. The changes focus on explaining WHY certain logic is needed,
not just WHAT the code does, improving code maintainability and helping
developers understand complex business decisions.
Key improvements:
- Main entry points: Document CLI initialization, logging setup, and cache
configuration with reasoning for design decisions
- DNS proxy core: Explain DNS proxy constants, data structures, and core
processing pipeline for handling DNS queries
- Service management: Document service command structure, configuration
patterns, and platform-specific service handling
- Logging infrastructure: Explain log buffer management, level encoders,
and log formatting decisions for different use cases
- Metrics and monitoring: Document Prometheus metrics structure, HTTP
endpoints, and conditional metric collection for performance
- Network handling: Explain Linux-specific network interface filtering,
virtual interface detection, and DNS configuration management
- Hostname validation: Document RFC1123 compliance and DNS naming
standards for system compatibility
- Mobile integration: Explain HTTP retry logic, fallback mechanisms, and
mobile platform integration patterns
- Connection management: Document connection wrapper design to prevent
log pollution during process lifecycle
Technical details:
- Added explanatory comments to 11 additional files in cmd/cli/
- Maintained consistent documentation style and format
- Preserved all existing functionality while improving code clarity
- Enhanced understanding of complex business logic and platform-specific
behavior
These comments help future developers understand the reasoning behind
complex decisions, making the codebase more maintainable and reducing
the risk of incorrect modifications during maintenance.
set service on new run, fix duplicate args
set service on new run, fix duplicate args
revert startCmd in upgrade flow due to pin compat issues
make restart reset DNS like upgrade, add debugging to uninstall method
debugging
debugging
debugging
debugging
debugging WMI
remove stackexchange lib, use ms wmi pkg
debugging
debugging
set correct class
fix os reolver init issues
fix netadapter class
use os resolver instead of fetching default nameservers while already running
remove debug lines
fix lookup IP
fix lookup IP
fix lookup IP
fix lookup IP
fix dns namserver retries when not needed
debugging
skip type 24 in nameserver detection
skip type 24 in nameserver detection
remove interface type check from valid interfaces for now
skip non hardware interfaces in DNS nameserver lookup
ignore win api log output
set retries to 5 and 1s backoff
reset DNS when upgrading to make sure we get the proper OS nameservers on start
init running iface for upgrade
update windows service options for auto restarts on failure
make upgrade use the actual stop and start commands
fix the windows service retry logic
fix the windows service retry logic
task debugging
more task debugging
windows service name fix
windows service name fix
fix start command args
fix restart delay
dont recover from non crash failures
fix upgrade flow
Cuong Manh Le