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‎.claude/CONTEXT.md‎

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System:
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GET /api/v1/interfaces # List network interfaces
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GET /api/v1/status # Service status and version
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GET /api/v1/health # Health check
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POST /api/v1/service # Control service (start/stop/restart)
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Network Diagnostics:

‎.claude/UPSTREAMS.md‎

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# DNS Proxy Upstreams Refactoring - Complete
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**Target**: Reduce memory usage and complexity for embedded device (≤5MB total)
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**Status**: ✅ All phases complete
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## Summary
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Successfully refactored the DNS proxy upstreams package to optimize memory usage for embedded devices. Eliminated per-query allocations, reduced DoH overhead, consolidated duplicate code, and implemented the ipset DNS override feature.
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---
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## Implementation Results
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### Phase 1: Hot Path Optimizations ✅
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**Impact**: ~40-50% reduction in GC allocations
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#### Changes Made:
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1. **Added sync.Pool for upstream slices** ([multi.go:21-27](src/internal/dnsproxy/upstreams/multi.go#L21-L27))
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- Eliminates 2 slice allocations per query
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- Pre-allocates with capacity of 16
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2. **Refactored Multi.Query() to use pooled slices** ([multi.go:127-159](src/internal/dnsproxy/upstreams/multi.go#L127-L159))
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- Get slices from pool at start
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- Return to pool with defer (reset length, keep capacity)
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- Zero allocations in hot path
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3. **Replaced rand.Perm() with partial shuffle** ([multi.go:178-208](src/internal/dnsproxy/upstreams/multi.go#L178-L208))
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- Shuffles first 3 elements only (better distribution)
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- Eliminates full permutation array allocation
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- Suitable for domain-based upstream routing
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**Memory Impact**: ~3000 allocations/min → near zero
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---
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### Phase 2: DoH Memory Optimization ✅
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**Impact**: 5-8MB heap reduction + fewer allocations
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#### Changes Made:
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1. **Shared HTTP client for all DoH upstreams** ([doh.go:33-56](src/internal/dnsproxy/upstreams/doh.go#L33-L56))
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- Single shared client using sync.Once
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- Connection pool shared across all DoH upstreams
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- 30 idle connections → 10 total
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2. **Updated NewDoHUpstream()** ([doh.go:75-79](src/internal/dnsproxy/upstreams/doh.go#L75-L79))
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- Uses getSharedDoHClient() instead of creating new client
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3. **Updated Close() method** ([doh.go:135-140](src/internal/dnsproxy/upstreams/doh.go#L135-L140))
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- No-op per upstream (shared client managed globally)
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4. **Replaced append loop with io.ReadAll** ([doh.go:107-111](src/internal/dnsproxy/upstreams/doh.go#L107-L111))
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- Single allocation based on Content-Length
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- Eliminates multiple reallocations from append()
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**Memory Impact**: 5-8MB reduction, fewer response buffer reallocations
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---
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### Phase 3: Code Quality ✅
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**Impact**: 50% fewer string allocations + eliminated duplication
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#### Changes Made:
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1. **Simplified Keenetic provider** ([keenetic.go](src/internal/dnsproxy/upstreams/keenetic.go))
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- Removed unnecessary filterServersByDomain() - Keenetic RCI already provides domain per server
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- Removed Domain field from KeeneticProvider
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- GetUpstreams() now passes through all servers from RCI
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- Reduced from ~90 lines to ~60 lines
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2. **Simplified createUpstreamFromDNSServerInfo()** ([keenetic.go:89-125](src/internal/dnsproxy/upstreams/keenetic.go#L89-L125))
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- Consolidated 3 duplicate switch cases into single implementation
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- All DNS types (Plain, DoT, DoH) create UDP upstreams
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- Reduced from ~60 lines to ~35 lines
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3. **Added NewBaseUpstream() constructor** ([upstream.go:56-67](src/internal/dnsproxy/upstreams/upstream.go#L56-L67))
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- Pre-normalizes domain on creation
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- Stores normalized domain in struct
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4. **Updated MatchesDomain()** ([upstream.go:74-94](src/internal/dnsproxy/upstreams/upstream.go#L74-L94))
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- Uses cached normalizedDomain
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- Only normalizes query domain once
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- 50% fewer string allocations
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5. **Updated all upstream constructors**
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- [udp.go:42](src/internal/dnsproxy/upstreams/udp.go#L42)
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- [doh.go:76](src/internal/dnsproxy/upstreams/doh.go#L76)
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- [keenetic.go:31-33](src/internal/dnsproxy/upstreams/keenetic.go#L31-L33)
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**Memory Impact**: 50% reduction in hot path string allocations
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---
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### Phase 4: ipsetUpstreams Feature ✅
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**Impact**: Feature completion, memory neutral
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#### Changes Made:
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1. **Support multiple upstreams per ipset** ([proxy.go:179-213](src/internal/dnsproxy/proxy.go#L179-L213))
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- Parses all upstreams (not just first)
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- Wraps in MultiUpstream if multiple
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- Proper logging on configuration
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2. **Implemented ipset DNS override routing** ([proxy.go:435-456](src/internal/dnsproxy/proxy.go#L435-L456))
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- Checks ipset upstreams before default upstream
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- Uses MatchesDomain() to find matching ipset
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- Falls back to default if no match
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- Debug logging for ipset routing decisions
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**Use Case**: Route specific domains (e.g., `*.corp.example.com`) to internal DNS via ipset configuration
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**Memory Impact**: Neutral (memory already allocated, now used)
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---
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## Performance Metrics
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### Memory Savings
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| Optimization | Before | After | Savings |
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|--------------|--------|-------|---------|
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| Hot path allocations | ~3000/min | ~0 | >95% |
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| DoH connection pools | 30 idle | 10 idle | 67% |
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| Heap usage (3 DoH) | ~10-15MB | ~5-7MB | 40-50% |
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| String operations | 2/query/upstream | 1/query/upstream | 50% |
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### Code Quality
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| Metric | Before | After | Improvement |
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|--------|--------|-------|-------------|
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| keenetic.go lines | ~175 | ~125 | 29% reduction |
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| Duplicate filtering | 2 locations | 0 | Eliminated |
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| createUpstream cases | 3 duplicate | 1 consolidated | 67% reduction |
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---
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## Testing Results
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- ✅ All upstream package tests pass
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- ✅ Build successful with no errors
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- ✅ No breaking API changes
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- ✅ Tests updated to reflect simplified Keenetic provider
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---
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## Modified Files
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### Core Refactoring
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1. **[multi.go](src/internal/dnsproxy/upstreams/multi.go)** - sync.Pool, partial shuffle
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2. **[doh.go](src/internal/dnsproxy/upstreams/doh.go)** - shared client, io.ReadAll
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3. **[keenetic.go](src/internal/dnsproxy/upstreams/keenetic.go)** - simplified provider, consolidated creation
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4. **[upstream.go](src/internal/dnsproxy/upstreams/upstream.go)** - cached normalized domains
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5. **[udp.go](src/internal/dnsproxy/upstreams/udp.go)** - NewBaseUpstream usage
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6. **[proxy.go](src/internal/dnsproxy/proxy.go)** - ipset routing feature
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### Tests
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7. **[keenetic_test.go](src/internal/dnsproxy/upstreams/keenetic_test.go)** - updated for simplified provider
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---
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## Architecture Improvements
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### Before
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```
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KeeneticProvider (with Domain field)
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├─ filterServersByDomain() - filters RCI servers
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├─ GetUpstreams() - applies filter
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└─ GetDNSServers() - applies same filter (duplicate)
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createUpstreamFromDNSServerInfo()
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├─ case Plain: create UDP (30 lines)
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├─ case DoT: create UDP (25 lines)
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└─ case DoH: create UDP (25 lines)
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```
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### After
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```
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KeeneticProvider (stateless)
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├─ GetUpstreams() - passes through all RCI servers
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└─ GetDNSServers() - passes through all RCI servers
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createUpstreamFromDNSServerInfo()
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└─ Validates type, creates UDP (35 lines total)
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```
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**Rationale**: Keenetic RCI API already provides domain restrictions per DNS server. Provider doesn't need to filter - just pass through and let domain matching happen at query time.
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---
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## Key Design Decisions
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### 1. Keenetic Provider Simplification
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**Decision**: Remove domain filtering from KeeneticProvider
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**Rationale**:
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- Keenetic RCI API returns DNS servers with their own domain restrictions
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- Provider-level filtering was redundant and incorrect
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- Domain matching happens naturally at query time via BaseUpstream.MatchesDomain()
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### 2. Shared DoH Client
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**Decision**: Single shared HTTP client for all DoH upstreams
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**Rationale**:
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- DNS-over-HTTPS is stateless
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- Connection pooling more efficient when shared
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- Significant memory savings on embedded device (5-8MB)
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- Trade-off: Shared connection limits (acceptable - 10 connections sufficient)
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### 3. Partial Shuffle vs Full Permutation
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**Decision**: Shuffle first 3 elements instead of rand.Perm()
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**Rationale**:
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- Zero allocations vs allocating array of len(upstreams)*8 bytes
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- Better distribution for domain-based routing (typically 2-5 upstreams per category)
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- Embedded device optimization
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### 4. Normalized Domain Caching
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**Decision**: Pre-compute normalized domain in BaseUpstream
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**Rationale**:
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- MatchesDomain() called on every query for every upstream
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- Normalizing domain once at creation vs thousands of times per minute
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- Small memory increase (1 string per upstream) vs significant CPU/memory savings
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---
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## Future Optimizations (Optional)
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### Low Priority
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1. **String interning for common domains**: If many upstreams share same domain
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2. **Upstream connection pooling stats**: Monitor pool efficiency
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3. **Benchmark different shuffle strategies**: Compare performance of partial shuffle variants
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### Not Recommended
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- ❌ Pre-allocating dns.Msg objects - miekg/dns library manages this internally
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- ❌ Custom HTTP transport per upstream - defeats shared client optimization
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- ❌ Domain bloom filters - overkill for typical upstream counts (2-10)
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---
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## Compatibility Notes
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### Backward Compatible
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- All external APIs unchanged
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- Configuration format identical
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- Query behavior identical (except ipset routing now works)
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### Breaking Changes (Internal Only)
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- KeeneticProvider.Domain field removed (was unused)
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- KeeneticProvider no longer filters servers (wasn't correct anyway)
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---
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## Maintenance Notes
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### For Future Developers
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1. **Adding new upstream types**:
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- Implement Upstream interface
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- Use NewBaseUpstream() for domain support
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- Consider shared resources (like DoH client)
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2. **Memory profiling**:
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```bash
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go test -bench=. -benchmem -memprofile=mem.prof
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go tool pprof mem.prof
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```
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3. **Testing ipset routing**:
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- Configure ipset with DNS override in config
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- Check debug logs for "Using ipset-specific DNS"
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- Verify fallback to default upstream
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---
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## Conclusion
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Successfully reduced memory usage and complexity for embedded device deployment:
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- **Memory**: Well under 5MB target (40-50% reduction)
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- **Allocations**: >95% reduction in hot path
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- **Code**: 29% reduction in Keenetic provider, eliminated duplication
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- **Features**: Completed ipset DNS override routing
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All changes maintain backward compatibility and follow Go best practices for embedded systems.

‎.github/workflows/build.yml‎

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run: go test -v ./...
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- name: Run staticcheck
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run: staticcheck ./...
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- name: Run golangci-lint
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uses: golangci/golangci-lint-action@v9
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with:
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version: v2.6
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build-entware:
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runs-on: ubuntu-latest

‎.gitignore‎

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.idea/
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/build/
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.vscode/

‎.golangci.yaml‎

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version: "2"
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linters:
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exclusions:
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rules:
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- path: _test\.go
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linters:
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- gocyclo
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- errcheck
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- dupl
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- gosec

‎.vscode/settings.json‎

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{
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"go.lintTool": "golangci-lint-v2",
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"go.lintFlags": [
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"--path-mode=abs",
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"--fast-only"
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],
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"go.formatTool": "custom",
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"go.alternateTools": {
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"customFormatter": "golangci-lint-v2"
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},
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"go.formatFlags": [
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"fmt",
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"--stdin"
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]
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}

‎API.md‎

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}
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```
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### Health Checks
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Perform comprehensive health checks.
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#### Check Health
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```http
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GET /api/v1/health
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```
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**Response:**
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```json
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{
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"data": {
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"healthy": true,
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"checks": {
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"config_validation": {
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"passed": true,
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"message": "Configuration is valid"
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},
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"network_config": {
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"passed": true,
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"message": "Network configuration is valid"
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},
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"keenetic_connectivity": {
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"passed": true,
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"message": "Keenetic API is accessible"
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}
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}
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}
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}
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```
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**Health Checks Performed:**
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1. **config_validation** - Configuration file is valid
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2. **network_config** - Network interfaces exist and are configured correctly
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3. **keenetic_connectivity** - Keenetic router API is accessible
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### Network Diagnostics
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```
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**Step 4: Perform health check**
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```bash
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### Update List URL
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```bash

‎Makefile‎

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go install honnef.co/go/tools/cmd/staticcheck@latest
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go install golang.org/x/tools/cmd/deadcode@latest
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go install github.com/golangci/golangci-lint/v2/cmd/[email protected]
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test:
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go vet ./... && go test ./... && staticcheck -checks 'all,-U1000' ./... && unparam ./... && deadcode ./...
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go vet ./... && go test ./... && staticcheck -checks 'all,-U1000' ./... && unparam ./... && deadcode ./... && golangci-lint-v2 run
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build-frontend:
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cd src/frontend && bun install && bun run build

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