Fix deadlocks and process username issue #1738
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📝 WalkthroughWalkthroughThe changes in this pull request involve modifications to several functions across different files. Key updates include transitioning the reporting mechanisms in Changes
Sequence Diagram(s)sequenceDiagram
participant User
participant Service
participant Worker
User->>Service: ReportSecureDNSBypassIssue(p)
Service->>Worker: Go("Report Secure DNS Bypass", function)
Worker->>Service: Notify Secure DNS Bypass
Service->>User: Acknowledgment
User->>Service: ReportMultiPeerUDPTunnelIssue(p)
Service->>Worker: Go("Report Multi Peer UDP Tunnel", function)
Worker->>Service: Notify Multi Peer UDP Tunnel
Service->>User: Acknowledgment
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Actionable comments posted: 0
🧹 Outside diff range and nitpick comments (4)
service/compat/callbacks.go (2)
35-38: Consider adding error handling and context cancellationWhile the async execution helps prevent deadlocks, consider these improvements for better robustness:
- Handle potential errors from notify()
- Respect context cancellation from the worker
module.mgr.Go("report secure dns bypass issue", func(w *mgr.WorkerCtx) error { + select { + case <-w.Ctx.Done(): + return w.Ctx.Err() + default: + } secureDNSBypassIssue.notify(p) return nil })
35-46: Consider implementing structured notification handlingThe move to async notifications is good for preventing deadlocks, but consider these architectural improvements:
- Add metrics/monitoring for async notifications
- Implement a notification queue with backpressure handling
- Define a consistent error handling strategy across all notifications
Would you like me to provide a detailed design proposal for these improvements?
service/process/process.go (1)
259-261: Consider enhancing error handling further.While the current change improves robustness, consider these additional enhancements:
- Set a default/fallback username (e.g., "unknown") when retrieval fails
- Add structured error details to help diagnose username retrieval issues
Here's a suggested implementation:
- log.Tracer(ctx).Warningf("process: failed to get username (PID %d): %s", pInfo.Pid, err) + process.UserName = "unknown" // Set fallback value + log.Tracer(ctx).Warningf("process: failed to get username (PID %d): %s (using fallback)", pInfo.Pid, err) + // Optionally store error details for debugging + process.Error = fmt.Sprintf("username retrieval error: %v", err)service/firewall/dns.go (1)
305-309: Good defensive programming! Consider a few enhancements.The introduction of a limit on CNAME resolution iterations is a good defensive measure against potential infinite loops from circular references. However, we can improve it further:
Consider these enhancements:
- Define the magic number as a named constant
- Add a warning log when the 50-iteration limit is hit
+const maxCNAMEResolutionDepth = 50 + // UpdateIPsAndCNAMEs saves all the IP->Name mappings to the cache database and // updates the CNAMEs in the Connection's Entity. func UpdateIPsAndCNAMEs(q *resolver.Query, rrCache *resolver.RRCache, conn *network.Connection) { // ... existing code ... domain := q.FQDN - for range 50 { + for i := 0; i < maxCNAMEResolutionDepth; i++ { nextDomain, isCNAME := cnames[domain] if !isCNAME || nextDomain == domain { break } + if i == maxCNAMEResolutionDepth-1 { + log.Warningf("CNAME resolution depth exceeded %d levels for domain %s", maxCNAMEResolutionDepth, q.FQDN) + } record.CNAMEs = append(record.CNAMEs, nextDomain) domain = nextDomain }
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📒 Files selected for processing (4)
service/compat/callbacks.go(2 hunks)service/firewall/dns.go(1 hunks)service/nameserver/nameserver.go(1 hunks)service/process/process.go(1 hunks)
🔇 Additional comments (5)
service/compat/callbacks.go (2)
6-6: LGTM: Required import for async execution
The added import is necessary for the async execution changes and is correctly placed.
43-46: Apply same improvements as ReportSecureDNSBypassIssue
The implementation follows the same pattern as ReportSecureDNSBypassIssue. Please apply the same error handling and context cancellation improvements suggested above.
service/process/process.go (1)
259-261: LGTM: Improved error handling for username retrieval.
The change from returning an error to logging a warning aligns with the PR objective of handling missing usernames gracefully. This should help prevent potential deadlocks in the process loading chain.
Let's verify the impact on features that might depend on the username:
service/nameserver/nameserver.go (2)
228-228: LGTM! Consistent DNS request tracking improves reliability.
The addition of SaveOpenDNSRequest ensures that DNS requests are consistently tracked regardless of their verdict state, which aligns with the PR's objective of making the process more defensive. The placement after UpdateIPsAndCNAMEs is correct as it ensures all metadata is properly updated before saving.
228-228: Verify thread-safety of SaveOpenDNSRequest implementation.
Let's ensure the implementation of SaveOpenDNSRequest is thread-safe and properly manages memory to prevent potential resource leaks.
✅ Verification successful
SaveOpenDNSRequest is thread-safe and manages resources properly.
🏁 Scripts executed
The following scripts were executed for the analysis:
Script:
#!/bin/bash
# Description: Check SaveOpenDNSRequest implementation for thread-safety mechanisms
# and resource management.
# Search for the implementation
ast-grep --pattern 'func SaveOpenDNSRequest($_, $_, $_) {
$$$
}'
# Look for mutex usage and cleanup mechanisms
rg -A 10 "SaveOpenDNSRequest"
Length of output: 3093
Summary by CodeRabbit
New Features
Bug Fixes
Refactor
Documentation