Compare commits

..

5 Commits

Author SHA1 Message Date
Cuong Manh Le
78ea2d6361 .github/workflows: upgrade staticcheck-action to v1.4.0
While at it, also bump go version to 1.24
2025-11-12 15:22:01 +07:00
Cuong Manh Le
df3cf7ef62 Upgrade quic-go to v0.56.0 2025-11-12 15:15:16 +07:00
Cuong Manh Le
80e652b8d9 fix: ensure log and cache flags are processed during reload
During reload operations, log and cache flags were not being processed,
which prevented runtime internal logs from working correctly. To fix this,
processLogAndCacheFlags was refactored to accept explicit viper and config
parameters instead of relying on global state, enabling it to be called
during reload with the new configuration. This ensures that log and cache
settings are properly applied when the service reloads its configuration.
2025-11-12 15:15:05 +07:00
Cuong Manh Le
091c7edb19 Fix: Filter root domain from search domains on Linux
Remove empty and root domain (".") entries from search domains list
to prevent systemd-resolved errors. This addresses the issue where
systemd doesn't allow root domain in search domains configuration.

The filtering ensures only valid search domains are passed to
systemd-resolved, preventing DNS operation failures.
2025-11-12 15:14:40 +07:00
Cuong Manh Le
6c550b1d74 Upgrade quic-go to v0.55.0
While at it, also bump required go version to 1.24
2025-11-12 15:14:26 +07:00
19 changed files with 61 additions and 2630 deletions

View File

@@ -19,8 +19,8 @@ jobs:
with:
go-version: ${{ matrix.go }}
- run: "go test -race ./..."
- uses: dominikh/staticcheck-action@v1.3.1
- uses: dominikh/staticcheck-action@v1.4.0
with:
version: "2025.1"
version: "2025.1.1"
install-go: false
cache-key: ${{ matrix.go }}

View File

@@ -100,7 +100,7 @@ docker build -t controldns/ctrld . -f docker/Dockerfile
# Usage
The cli is self documenting, so feel free to run `--help` on any sub-command to get specific usages.
The cli is self documenting, so free free to run `--help` on any sub-command to get specific usages.
## Arguments
```

View File

@@ -282,7 +282,7 @@ func run(appCallback *AppCallback, stopCh chan struct{}) {
}
p.mu.Unlock()
processLogAndCacheFlags()
processLogAndCacheFlags(v, &cfg)
// Log config do not have thing to validate, so it's safe to init log here,
// so it's able to log information in processCDFlags.
@@ -342,7 +342,7 @@ func run(appCallback *AppCallback, stopCh chan struct{}) {
updated := updateListenerConfig(&cfg, notifyExitToLogServer)
if cdUID != "" {
processLogAndCacheFlags()
processLogAndCacheFlags(v, &cfg)
}
if updated {
@@ -780,7 +780,8 @@ func processListenFlag() {
})
}
func processLogAndCacheFlags() {
// processLogAndCacheFlags processes log and cache related flags
func processLogAndCacheFlags(v *viper.Viper, cfg *ctrld.Config) {
if logPath != "" {
cfg.Service.LogPath = logPath
}

View File

@@ -72,7 +72,15 @@ func setDNS(iface *net.Interface, nameservers []string) error {
SearchDomains: []dnsname.FQDN{},
}
if sds, err := searchDomains(); err == nil {
osConfig.SearchDomains = sds
// Filter the root domain, since it's not allowed by systemd.
// See https://github.com/systemd/systemd/issues/9515
filteredSds := slices.DeleteFunc(sds, func(s dnsname.FQDN) bool {
return s == "" || s == "."
})
if len(filteredSds) != len(sds) {
mainLog.Load().Debug().Msg(`Removed root domain "." from search domains list`)
}
osConfig.SearchDomains = filteredSds
} else {
mainLog.Load().Debug().Err(err).Msg("failed to get search domains list")
}

View File

@@ -213,7 +213,8 @@ func (p *prog) runWait() {
continue
}
if cdUID != "" {
if rc, err := processCDFlags(newCfg); err != nil {
rc, err := processCDFlags(newCfg)
if err != nil {
logger.Err(err).Msg("could not fetch ControlD config")
waitOldRunDone()
continue
@@ -225,6 +226,10 @@ func (p *prog) runWait() {
}
}
// Though the log configuration could not be changed during reloading, we still need to
// process the current flags here, so runtime internal logs can be used correctly.
processLogAndCacheFlags(v, newCfg)
waitOldRunDone()
p.mu.Lock()

View File

@@ -1,585 +0,0 @@
# Netstack - Full Packet Capture for Mobile VPN
Complete TCP/UDP/DNS packet capture implementation using gVisor netstack for Android and iOS.
## Overview
Provides full packet capture for mobile VPN applications:
- **DNS filtering** through ControlD proxy
- **IP whitelisting** - only allows connections to DNS-resolved IPs
- **TCP forwarding** for all TCP traffic (with whitelist enforcement)
- **UDP forwarding** with session tracking (with whitelist enforcement)
- **QUIC blocking** for better content filtering
## Master Architecture Diagram
```
┌──────────────────────────────────────────────────────────────────────────────┐
│ MOBILE APP (Android/iOS) │
│ │
│ ┌─────────────────────────────────────────────────────────────────────┐ │
│ │ VPN Configuration │ │
│ │ │ │
│ │ Android: iOS: │ │
│ │ ┌──────────────────────┐ ┌──────────────────────┐ │ │
│ │ │ Builder() │ │ NEIPv4Settings │ │ │
│ │ │ .addAddress( │ │ addresses: [ │ │ │
│ │ │ "10.0.0.2", 24) │ │ "10.0.0.2"] │ │ │
│ │ │ .addDnsServer( │ │ │ │ │
│ │ │ "10.0.0.1") │ │ NEDNSSettings │ │ │
│ │ │ │ │ servers: [ │ │ │
│ │ │ FIREWALL MODE: │ │ "10.0.0.1"] │ │ │
│ │ │ .addRoute( │ │ │ │ │
│ │ │ "0.0.0.0", 0) │ │ FIREWALL MODE: │ │ │
│ │ │ │ │ includedRoutes: │ │ │
│ │ │ DNS-ONLY MODE: │ │ [.default()] │ │ │
│ │ │ .addRoute( │ │ │ │ │
│ │ │ "10.0.0.1", 32) │ │ DNS-ONLY MODE: │ │ │
│ │ │ │ │ includedRoutes: │ │ │
│ │ │ .addDisallowedApp( │ │ [10.0.0.1/32] │ │ │
│ │ │ "com.controld.*") │ │ │ │ │
│ │ └──────────────────────┘ └──────────────────────┘ │ │
│ │ │ │
│ │ Result: │ │
│ │ • Firewall: ALL traffic → VPN │ │
│ │ • DNS-only: ONLY DNS (port 53) → VPN │ │
│ └─────────────────────────────────────────────────────────────────────┘ │
└──────────────────────────┬───────────────────────────────────────────────────┘
│ Packets
┌──────────────────────────────────────────────────────────────────────────────┐
│ GOMOBILE LIBRARY (ctrld_library) │
│ │
│ ┌─────────────────────────────────────────────────────────────────────┐ │
│ │ PacketCaptureController.StartWithPacketCapture() │ │
│ │ │ │
│ │ Parameters: │ │
│ │ • tunAddress: "10.0.0.1" (gateway) │ │
│ │ • deviceAddress: "10.0.0.2" (device IP) │ │
│ │ • dnsProxyAddress: "127.0.0.1:5354" (Android) / ":53" (iOS) │ │
│ │ • cdUID, upstreamProto, etc. │ │
│ └──────────────────────────┬──────────────────────────────────────────┘ │
│ │ │
│ ↓ │
│ ┌──────────────────────────────────────────────────────────────────┐ │
│ │ NETSTACK CONTROLLER │ │
│ │ │ │
│ │ Components: │ │
│ │ ┌────────────────┐ ┌─────────────┐ ┌──────────────┐ │ │
│ │ │ DNS Filter │ │ IP Tracker │ │ TCP Forwarder│ │ │
│ │ │ (port 53) │ │ (5min TTL) │ │ (firewall) │ │ │
│ │ └────────────────┘ └─────────────┘ └──────────────┘ │ │
│ │ ┌────────────────┐ │ │
│ │ │ UDP Forwarder │ │ │
│ │ │ (firewall) │ │ │
│ │ └────────────────┘ │ │
│ └──────────────────────────┬───────────────────────────────────────┘ │
└─────────────────────────────┼───────────────────────────────────────────────┘
┌──────────────────────────────────────────────────────────────────────────────┐
│ PACKET FLOW DETAILS │
│ │
│ INCOMING PACKET (from TUN) │
│ │ │
│ ├──→ Is DNS? (port 53) │
│ │ ├─ YES → DNS Filter │
│ │ │ ├─→ Forward to ControlD DNS Proxy │
│ │ │ │ (127.0.0.1:5354 or 127.0.0.1:53) │
│ │ │ ├─→ Get DNS response │
│ │ │ ├─→ Extract A/AAAA records │
│ │ │ ├─→ TrackIP() for each resolved IP │
│ │ │ │ • Store: resolvedIPs["93.184.216.34"] = now+5min │
│ │ │ └─→ Return DNS response to app │
│ │ │ │
│ │ └─ NO → Is TCP/UDP? │
│ │ │ │
│ │ ├──→ TCP Packet │
│ │ │ ├─→ Extract destination IP │
│ │ │ ├─→ Check: ipTracker.IsTracked(destIP) │
│ │ │ │ ├─ NOT TRACKED → BLOCK │
│ │ │ │ │ Log: "BLOCKED hardcoded IP" │
│ │ │ │ │ Return (connection reset) │
│ │ │ │ │ │
│ │ │ │ └─ TRACKED → ALLOW │
│ │ │ │ net.Dial("tcp", destIP) │
│ │ │ │ Bidirectional copy (app ↔ internet) │
│ │ │ │ │
│ │ └──→ UDP Packet │
│ │ ├─→ Is QUIC? (port 443/80) │
│ │ │ └─ YES → BLOCK (force TCP fallback) │
│ │ │ │
│ │ ├─→ Extract destination IP │
│ │ ├─→ Check: ipTracker.IsTracked(destIP) │
│ │ │ ├─ NOT TRACKED → BLOCK │
│ │ │ │ Log: "BLOCKED hardcoded IP" │
│ │ │ │ Return (drop packet) │
│ │ │ │ │
│ │ │ └─ TRACKED → ALLOW │
│ │ │ net.Dial("udp", destIP) │
│ │ │ Forward packets (app ↔ internet) │
│ │ │ 30s timeout per session │
│ │ │
│ IP TRACKER STATE (in-memory map): │
│ ┌────────────────────────────────────────────────────────────┐ │
│ │ resolvedIPs map: │ │
│ │ │ │
│ │ "93.184.216.34" → expires: 2026-03-20 23:35:00 │ │
│ │ "2606:2800:220::1" → expires: 2026-03-20 23:36:15 │ │
│ │ "8.8.8.8" → expires: 2026-03-20 23:37:42 │ │
│ │ │ │
│ │ Cleanup: Every 30 seconds, remove expired entries │ │
│ │ TTL: 5 minutes (configurable) │ │
│ └────────────────────────────────────────────────────────────┘ │
│ │
│ EXAMPLE SCENARIO: │
│ ─────────────────────────────────────────────────────────────────────── │
│ │
│ T=0s: App tries: connect(1.2.3.4:443) │
│ → IsTracked(1.2.3.4)? NO │
│ → ❌ BLOCKED │
│ │
│ T=1s: App queries: DNS "example.com" │
│ → Response: A 93.184.216.34 │
│ → TrackIP(93.184.216.34) with TTL=5min │
│ │
│ T=2s: App tries: connect(93.184.216.34:443) │
│ → IsTracked(93.184.216.34)? YES (expires T+301s) │
│ → ✅ ALLOWED │
│ │
│ T=302s: App tries: connect(93.184.216.34:443) │
│ → IsTracked(93.184.216.34)? NO (expired) │
│ → ❌ BLOCKED (must do DNS again) │
└──────────────────────────────────────────────────────────────────────────────┘
┌──────────────────────────────────────────────────────────────────────────────┐
│ MODE COMPARISON (Firewall vs DNS-only) │
│ │
│ ┌─────────────────────────────────┬─────────────────────────────────┐ │
│ │ FIREWALL MODE │ DNS-ONLY MODE │ │
│ │ (Default Routes Configured) │ (Only DNS Route Configured) │ │
│ ├─────────────────────────────────┼─────────────────────────────────┤ │
│ │ Routes (Android): │ Routes (Android): │ │
│ │ • addRoute("0.0.0.0", 0) │ • addRoute("10.0.0.1", 32) │ │
│ │ │ │ │
│ │ Routes (iOS): │ Routes (iOS): │ │
│ │ • includedRoutes: [.default()] │ • includedRoutes: │ │
│ │ │ [10.0.0.1/32] │ │
│ ├─────────────────────────────────┼─────────────────────────────────┤ │
│ │ Traffic Sent to VPN: │ Traffic Sent to VPN: │ │
│ │ ✅ DNS (port 53) │ ✅ DNS (port 53) │ │
│ │ ✅ TCP (all ports) │ ❌ TCP (bypasses VPN) │ │
│ │ ✅ UDP (all ports) │ ❌ UDP (bypasses VPN) │ │
│ ├─────────────────────────────────┼─────────────────────────────────┤ │
│ │ IP Tracker Behavior: │ IP Tracker Behavior: │ │
│ │ • Tracks DNS-resolved IPs │ • Tracks DNS-resolved IPs │ │
│ │ • Blocks hardcoded TCP/UDP IPs │ • No TCP/UDP to block │ │
│ │ • Enforces DNS-first policy │ • N/A (no non-DNS traffic) │ │
│ ├─────────────────────────────────┼─────────────────────────────────┤ │
│ │ Use Case: │ Use Case: │ │
│ │ • Full content filtering │ • DNS filtering only │ │
│ │ • Block DNS bypass attempts │ • Minimal battery impact │ │
│ │ • Enforce ControlD policies │ • Fast web browsing │ │
│ └─────────────────────────────────┴─────────────────────────────────┘ │
│ │
│ MODE SWITCHING: │
│ • Android: VpnController.setFirewallMode(enabled) → recreates VPN │
│ • iOS: sendProviderMessage("set_firewall_mode") → updates routes │
│ • Both: No app restart needed │
└──────────────────────────────────────────────────────────────────────────────┘
┌──────────────────────────────────────────────────────────────────────────────┐
│ DETAILED PACKET FLOW (Firewall Mode) │
│ │
│ 1. APP MAKES REQUEST │
│ ─────────────────────────────────────────────────────────────────────── │
│ App: connect("example.com", 443) │
│ ↓ │
│ OS: Perform DNS lookup for "example.com" │
│ ↓ │
│ OS: Send DNS query to VPN DNS server (10.0.0.1) │
│ │
│ 2. DNS PACKET FLOW │
│ ─────────────────────────────────────────────────────────────────────── │
│ [DNS Query Packet: 10.0.0.2:12345 → 10.0.0.1:53] │
│ ↓ │
│ TUN Interface → readPacket() │
│ ↓ │
│ DNSFilter.ProcessPacket() │
│ ├─ Detect port 53 (DNS) │
│ ├─ Extract DNS payload │
│ ├─ Forward to ControlD DNS proxy (127.0.0.1:5354 or :53) │
│ │ ↓ │
│ │ ControlD DNS Proxy │
│ │ ├─ Apply filtering rules │
│ │ ├─ Query upstream DNS (DoH/DoT/DoQ) │
│ │ └─ Return response: A 93.184.216.34 │
│ │ ↓ │
│ ├─ Parse DNS response │
│ ├─ extractAndTrackIPs() │
│ │ └─ IPTracker.TrackIP(93.184.216.34) │
│ │ • Store: resolvedIPs["93.184.216.34"] = now + 5min │
│ ├─ Build DNS response packet │
│ └─ writePacket() → TUN → App │
│ │
│ OS receives DNS response → resolves "example.com" to 93.184.216.34 │
│ │
│ 3. TCP CONNECTION FLOW │
│ ─────────────────────────────────────────────────────────────────────── │
│ OS: connect(93.184.216.34:443) │
│ ↓ │
│ [TCP SYN Packet: 10.0.0.2:54321 → 93.184.216.34:443] │
│ ↓ │
│ TUN Interface → readPacket() │
│ ↓ │
│ gVisor Netstack → TCPForwarder.handleConnection() │
│ ├─ Extract destination IP: 93.184.216.34 │
│ ├─ Check internal VPN subnet (10.0.0.0/24)? │
│ │ └─ NO (skip check) │
│ ├─ ipTracker.IsTracked(93.184.216.34)? │
│ │ ├─ Check resolvedIPs map │
│ │ ├─ Found: expires at T+300s │
│ │ ├─ Not expired yet │
│ │ └─ YES ✅ │
│ ├─ ALLOWED - create upstream connection │
│ ├─ net.Dial("tcp", "93.184.216.34:443") │
│ │ ↓ │
│ │ [Real Network Connection] │
│ │ ↓ │
│ └─ Bidirectional copy (TUN ↔ Internet) │
│ │
│ 4. BLOCKED SCENARIO (Hardcoded IP) │
│ ─────────────────────────────────────────────────────────────────────── │
│ App: connect(1.2.3.4:443) // Hardcoded IP, no DNS! │
│ ↓ │
│ [TCP SYN Packet: 10.0.0.2:54322 → 1.2.3.4:443] │
│ ↓ │
│ TUN Interface → readPacket() │
│ ↓ │
│ gVisor Netstack → TCPForwarder.handleConnection() │
│ ├─ Extract destination IP: 1.2.3.4 │
│ ├─ ipTracker.IsTracked(1.2.3.4)? │
│ │ └─ Check resolvedIPs map → NOT FOUND │
│ │ └─ NO ❌ │
│ ├─ BLOCKED │
│ ├─ Log: "[TCP] BLOCKED hardcoded IP: 10.0.0.2:54322 → 1.2.3.4:443" │
│ └─ Return (send TCP RST to app) │
│ │
│ App receives connection refused/reset │
└──────────────────────────────────────────────────────────────────────────────┘
┌──────────────────────────────────────────────────────────────────────────────┐
│ PLATFORM-SPECIFIC DETAILS │
│ │
│ ANDROID │
│ ──────────────────────────────────────────────────────────────────────── │
│ • VPN Config: ControlDService.kt │
│ • Packet I/O: FileInputStream/FileOutputStream on VPN fd │
│ • DNS Proxy: Listens on 0.0.0.0:5354 (connects via 127.0.0.1:5354) │
│ • Self-Exclusion: addDisallowedApplication(packageName) │
│ • Mode Switch: Recreates VPN interface with new routes │
│ • No routing loops: App traffic bypasses VPN │
│ │
│ IOS │
│ ──────────────────────────────────────────────────────────────────────── │
│ • VPN Config: PacketTunnelProvider.swift │
│ • Packet I/O: NEPacketTunnelFlow (async → blocking via PacketQueue) │
│ • DNS Proxy: Listens on 127.0.0.1:53 │
│ • Self-Exclusion: Network Extension sockets auto-bypass │
│ • Mode Switch: setTunnelNetworkSettings() with new routes │
│ • Write Batching: 16 packets per batch, 5ms flush timer │
│ • No routing loops: Extension traffic bypasses VPN │
└──────────────────────────────────────────────────────────────────────────────┘
## Components
### DNS Filter (`dns_filter.go`)
- Detects DNS packets on port 53 (UDP/TCP)
- Forwards to ControlD DNS proxy (via DNS bridge)
- Parses DNS responses to extract A/AAAA records
- Automatically tracks resolved IPs via IP Tracker
- Builds DNS response packets and sends back to TUN
### DNS Bridge (`dns_bridge.go`)
- Bridges between netstack and ControlD DNS proxy
- Tracks DNS queries by transaction ID
- 5-second timeout per query
- Returns responses to DNS filter
### IP Tracker (`ip_tracker.go`)
- **Always enabled** - tracks all DNS-resolved IPs
- In-memory whitelist with 5-minute TTL per IP
- Background cleanup every 30 seconds (removes expired IPs)
- Thread-safe with RWMutex (optimized for read-heavy workload)
- Used by TCP/UDP forwarders to enforce DNS-first policy
### TCP Forwarder (`tcp_forwarder.go`)
- Handles TCP connections via gVisor's `tcp.NewForwarder()`
- Checks `ipTracker != nil` (always true) for firewall enforcement
- Allows internal VPN subnet (10.0.0.0/24) without checks
- Blocks connections to non-tracked IPs (logs: "BLOCKED hardcoded IP")
- Forwards allowed connections via `net.Dial("tcp")` to real network
- Bidirectional copy between TUN and internet
### UDP Forwarder (`udp_forwarder.go`)
- Handles UDP packets via gVisor's `udp.NewForwarder()`
- Session tracking with 30-second read timeout
- Checks `ipTracker != nil` (always true) for firewall enforcement
- Blocks QUIC (UDP/443, UDP/80) to force TCP fallback
- Blocks connections to non-tracked IPs (logs: "BLOCKED hardcoded IP")
- Forwards allowed packets via `net.Dial("udp")` to real network
### Packet Handler (`packet_handler.go`)
- Interface for TUN I/O operations (read, write, close)
- `MobilePacketHandler` wraps mobile platform callbacks
- Bridges gomobile interface with netstack
### Netstack Controller (`netstack.go`)
- Manages gVisor TCP/IP stack
- Coordinates DNS Filter, IP Tracker, TCP/UDP Forwarders
- Always creates IP Tracker (firewall always on)
- Reads packets from TUN → injects into netstack
- Writes packets from netstack → sends to TUN
- Filters outbound packets (source = 10.0.0.x)
- Blocks QUIC before injection into netstack
## Platform Configuration
### Android
```kotlin
// Base VPN configuration (same for both modes)
Builder()
.addAddress("10.0.0.2", 24)
.addDnsServer("10.0.0.1")
.setMtu(1500)
.setBlocking(true)
.addDisallowedApplication(packageName) // Exclude self from VPN!
// Firewall mode - route ALL traffic
if (isFirewallMode) {
vpnBuilder.addRoute("0.0.0.0", 0)
}
// DNS-only mode - route ONLY DNS server IP
else {
vpnBuilder.addRoute("10.0.0.1", 32)
}
vpnInterface = vpnBuilder.establish()
// DNS Proxy listens on: 0.0.0.0:5354
// Library connects to: 127.0.0.1:5354
```
**Important:**
- App MUST exclude itself using `addDisallowedApplication()` to prevent routing loops
- Mode switching: Call `setFirewallMode(enabled)` to recreate VPN interface with new routes
### iOS
```swift
// Base configuration (same for both modes)
let ipv4Settings = NEIPv4Settings(
addresses: ["10.0.0.2"],
subnetMasks: ["255.255.255.0"]
)
// Firewall mode - route ALL traffic
if isFirewallMode {
ipv4Settings.includedRoutes = [NEIPv4Route.default()]
}
// DNS-only mode - route ONLY DNS server IP
else {
ipv4Settings.includedRoutes = [
NEIPv4Route(destinationAddress: "10.0.0.1", subnetMask: "255.255.255.255")
]
}
let dnsSettings = NEDNSSettings(servers: ["10.0.0.1"])
dnsSettings.matchDomains = [""]
networkSettings.ipv4Settings = ipv4Settings
networkSettings.dnsSettings = dnsSettings
networkSettings.mtu = 1500
setTunnelNetworkSettings(networkSettings)
// DNS Proxy listens on: 127.0.0.1:53
// Library connects to: 127.0.0.1:53
```
**Note:**
- Network Extension sockets automatically bypass VPN - no routing loops
- Mode switching: Send message `{"action": "set_firewall_mode", "enabled": "true"}` to extension
## Protocol Support
| Protocol | Support |
|----------|---------|
| DNS (UDP/TCP port 53) | ✅ Full |
| TCP (all ports) | ✅ Full |
| UDP (except 53, 80, 443) | ✅ Full |
| QUIC (UDP/443, UDP/80) | 🚫 Blocked |
| ICMP | ⚠️ Partial |
| IPv4 | ✅ Full |
| IPv6 | ✅ Full |
## QUIC Blocking
Blocks UDP packets on ports 443 and 80 to force TCP fallback.
**Where it's blocked:**
- `netstack.go:354-369` - Blocks QUIC **before** injection into gVisor stack
- Early blocking (pre-netstack) for efficiency
- Checks destination port (UDP/443, UDP/80) in raw packet
**Why:**
- QUIC/HTTP3 can use cached IPs, bypassing DNS filtering entirely
- TCP/TLS provides visible SNI for content filtering
- Ensures consistent ControlD policy enforcement
- IP tracker alone isn't enough (apps cache QUIC IPs aggressively)
**Result:**
- Apps automatically fallback to TCP/TLS (HTTP/2, HTTP/1.1)
- No user-visible errors (fallback is seamless)
- Slightly slower initial connection, then normal performance
**Note:** IP tracker ALSO blocks hardcoded IPs, but QUIC blocking provides additional layer of protection since QUIC apps often cache IPs longer than 5 minutes.
## IP Blocking (DNS Bypass Prevention)
**Firewall is ALWAYS enabled.** The IP tracker runs in all modes and tracks all DNS-resolved IPs.
**How it works:**
1. DNS responses are parsed to extract A and AAAA records
2. Resolved IPs are tracked in memory whitelist for 5 minutes (TTL)
3. In **firewall mode**: TCP/UDP connections to **non-whitelisted** IPs are **BLOCKED**
4. In **DNS-only mode**: Only DNS traffic reaches the VPN, so IP blocking is inactive
**Mode Behavior:**
- **Firewall mode** (default routes): OS sends ALL traffic to VPN
- DNS queries → tracked IPs
- TCP/UDP connections → checked against tracker → blocked if not tracked
- **DNS-only mode** (DNS route only): OS sends ONLY DNS to VPN
- DNS queries → tracked IPs
- TCP/UDP connections → bypass VPN entirely (never reach tracker)
**Why IP tracker is always on:**
- Simplifies implementation (no enable/disable logic)
- Ready for mode switching at runtime
- In DNS-only mode, tracker tracks IPs but never blocks (no TCP/UDP traffic)
**Example (Firewall Mode):**
```
T=0s: App connects to 1.2.3.4 directly
→ ❌ BLOCKED (not in tracker)
T=1s: App queries "example.com" → DNS returns 93.184.216.34
→ Tracker stores: 93.184.216.34 (expires in 5min)
T=2s: App connects to 93.184.216.34
→ ✅ ALLOWED (found in tracker, not expired)
T=302s: App connects to 93.184.216.34
→ ❌ BLOCKED (expired, must query DNS again)
```
**Components:**
- `ip_tracker.go` - Always-on whitelist with 5min TTL, 30s cleanup
- `dns_filter.go` - Extracts A/AAAA records, tracks IPs automatically
- `tcp_forwarder.go` - Checks `ipTracker != nil` (always true)
- `udp_forwarder.go` - Checks `ipTracker != nil` (always true)
## Usage (Android)
```kotlin
// Create callback
val callback = object : PacketAppCallback {
override fun readPacket(): ByteArray { ... }
override fun writePacket(packet: ByteArray) { ... }
override fun closePacketIO() { ... }
override fun exit(s: String) { ... }
override fun hostname(): String = "android-device"
override fun lanIp(): String = "10.0.0.2"
override fun macAddress(): String = "00:00:00:00:00:00"
}
// Create controller
val controller = Ctrld_library.newPacketCaptureController(callback)
// Start with all parameters
controller.startWithPacketCapture(
callback, // PacketAppCallback
"10.0.0.1", // TUN address (gateway)
"10.0.0.2", // Device address
1500, // MTU
"127.0.0.1:5354", // DNS proxy address
"your-cd-uid", // ControlD UID
"", // Provision ID (optional)
"", // Custom hostname (optional)
filesDir.absolutePath, // Home directory
"doh", // Upstream protocol (doh/dot/doq)
2, // Log level (0-3)
"$filesDir/ctrld.log" // Log path
)
// Stop
controller.stop(false, 0)
// Runtime mode switching (no restart needed)
VpnController.instance?.setFirewallMode(context, isFirewallMode = true)
```
## Usage (iOS)
```swift
// Start LocalProxy with all parameters
let proxy = LocalProxy()
proxy.mode = .firewall // or .dnsOnly
proxy.start(
tunAddress: "10.0.0.1", // TUN address (gateway)
deviceAddress: "10.0.0.2", // Device address
mtu: 1500, // MTU
dnsProxyAddress: "127.0.0.1:53", // DNS proxy address
cUID: cdUID, // ControlD UID
provisionID: "", // Provision ID (optional)
customHostname: "", // Custom hostname (optional)
homeDir: FileManager().temporaryDirectory.path, // Home directory
upstreamProto: "doh", // Upstream protocol
logLevel: 2, // Log level (0-3)
logPath: FileManager().temporaryDirectory.appendingPathComponent("ctrld.log").path,
deviceName: UIDevice.current.name, // Device name
packetFlow: packetFlow // NEPacketTunnelFlow
)
// Stop
proxy.stop()
// Runtime mode switching (no restart needed)
// Send message from main app to extension:
let message = ["action": "set_firewall_mode", "enabled": "true"]
session.sendProviderMessage(JSONEncoder().encode(message)) { response in }
```
## Requirements
- **Android**: API 24+ (Android 7.0+)
- **iOS**: iOS 12.0+
- **Go**: 1.23+
- **gVisor**: v0.0.0-20240722211153-64c016c92987
## Files
- `packet_handler.go` - TUN I/O interface
- `netstack.go` - gVisor controller
- `dns_filter.go` - DNS packet detection and IP extraction
- `dns_bridge.go` - Transaction tracking
- `ip_tracker.go` - DNS-resolved IP whitelist with TTL
- `tcp_forwarder.go` - TCP forwarding with whitelist enforcement
- `udp_forwarder.go` - UDP forwarding with whitelist enforcement
## License
Same as parent ctrld project.

View File

@@ -1,228 +0,0 @@
package netstack
import (
"fmt"
"sync"
"time"
"github.com/miekg/dns"
)
// DNSBridge provides a bridge between the netstack DNS filter and the existing ctrld DNS proxy.
// It allows DNS queries captured from packets to be processed by the same logic as traditional DNS queries.
type DNSBridge struct {
// Channel for sending DNS queries
queryCh chan *DNSQuery
// Channel for receiving DNS responses
responseCh chan *DNSResponse
// Map to track pending queries by transaction ID
pendingQueries map[uint16]*PendingQuery
mu sync.RWMutex
// Timeout for DNS queries
queryTimeout time.Duration
// Running state
running bool
stopCh chan struct{}
wg sync.WaitGroup
}
// DNSQuery represents a DNS query to be processed
type DNSQuery struct {
ID uint16 // Transaction ID for matching response
Query []byte // Raw DNS query bytes
RespCh chan []byte // Response channel
SrcIP string // Source IP for logging
SrcPort uint16 // Source port
}
// DNSResponse represents a DNS response
type DNSResponse struct {
ID uint16
Response []byte
}
// PendingQuery tracks a query waiting for response
type PendingQuery struct {
Query *DNSQuery
Timestamp time.Time
}
// NewDNSBridge creates a new DNS bridge
func NewDNSBridge() *DNSBridge {
return &DNSBridge{
queryCh: make(chan *DNSQuery, 100),
responseCh: make(chan *DNSResponse, 100),
pendingQueries: make(map[uint16]*PendingQuery),
queryTimeout: 5 * time.Second,
stopCh: make(chan struct{}),
}
}
// Start starts the DNS bridge
func (b *DNSBridge) Start() {
b.mu.Lock()
if b.running {
b.mu.Unlock()
return
}
b.running = true
b.mu.Unlock()
// Start response handler
b.wg.Add(1)
go b.handleResponses()
// Start timeout checker
b.wg.Add(1)
go b.checkTimeouts()
}
// Stop stops the DNS bridge
func (b *DNSBridge) Stop() {
b.mu.Lock()
if !b.running {
b.mu.Unlock()
return
}
b.running = false
b.mu.Unlock()
close(b.stopCh)
b.wg.Wait()
// Clean up pending queries
b.mu.Lock()
for _, pending := range b.pendingQueries {
close(pending.Query.RespCh)
}
b.pendingQueries = make(map[uint16]*PendingQuery)
b.mu.Unlock()
}
// ProcessQuery processes a DNS query and waits for response
func (b *DNSBridge) ProcessQuery(query []byte, srcIP string, srcPort uint16) ([]byte, error) {
if len(query) < 12 {
return nil, fmt.Errorf("invalid DNS query: too short")
}
// Parse DNS message to get transaction ID
msg := new(dns.Msg)
if err := msg.Unpack(query); err != nil {
return nil, fmt.Errorf("failed to parse DNS query: %v", err)
}
// Create response channel
respCh := make(chan []byte, 1)
// Create query
dnsQuery := &DNSQuery{
ID: msg.Id,
Query: query,
RespCh: respCh,
SrcIP: srcIP,
SrcPort: srcPort,
}
// Store as pending
b.mu.Lock()
b.pendingQueries[msg.Id] = &PendingQuery{
Query: dnsQuery,
Timestamp: time.Now(),
}
b.mu.Unlock()
// Send query
select {
case b.queryCh <- dnsQuery:
case <-time.After(time.Second):
b.mu.Lock()
delete(b.pendingQueries, msg.Id)
b.mu.Unlock()
return nil, fmt.Errorf("query channel full")
}
// Wait for response with timeout
select {
case response := <-respCh:
b.mu.Lock()
delete(b.pendingQueries, msg.Id)
b.mu.Unlock()
return response, nil
case <-time.After(b.queryTimeout):
b.mu.Lock()
delete(b.pendingQueries, msg.Id)
b.mu.Unlock()
return nil, fmt.Errorf("DNS query timeout")
}
}
// GetQueryChannel returns the channel for receiving DNS queries
func (b *DNSBridge) GetQueryChannel() <-chan *DNSQuery {
return b.queryCh
}
// SendResponse sends a DNS response back to the waiting query
func (b *DNSBridge) SendResponse(id uint16, response []byte) error {
b.mu.RLock()
pending, exists := b.pendingQueries[id]
b.mu.RUnlock()
if !exists {
return fmt.Errorf("no pending query for ID %d", id)
}
select {
case pending.Query.RespCh <- response:
return nil
case <-time.After(time.Second):
return fmt.Errorf("failed to send response: channel blocked")
}
}
// handleResponses handles incoming responses
func (b *DNSBridge) handleResponses() {
defer b.wg.Done()
for {
select {
case <-b.stopCh:
return
case resp := <-b.responseCh:
if err := b.SendResponse(resp.ID, resp.Response); err != nil {
// Log error but continue
}
}
}
}
// checkTimeouts periodically checks for and removes timed out queries
func (b *DNSBridge) checkTimeouts() {
defer b.wg.Done()
ticker := time.NewTicker(time.Second)
defer ticker.Stop()
for {
select {
case <-b.stopCh:
return
case <-ticker.C:
now := time.Now()
b.mu.Lock()
for id, pending := range b.pendingQueries {
if now.Sub(pending.Timestamp) > b.queryTimeout {
close(pending.Query.RespCh)
delete(b.pendingQueries, id)
}
}
b.mu.Unlock()
}
}
}

View File

@@ -1,365 +0,0 @@
package netstack
import (
"encoding/binary"
"fmt"
"net"
"github.com/miekg/dns"
"gvisor.dev/gvisor/pkg/tcpip"
"gvisor.dev/gvisor/pkg/tcpip/header"
)
// DNSFilter intercepts and processes DNS packets.
type DNSFilter struct {
dnsHandler func([]byte) ([]byte, error)
ipTracker *IPTracker
}
// NewDNSFilter creates a new DNS filter with the given handler.
func NewDNSFilter(handler func([]byte) ([]byte, error), ipTracker *IPTracker) *DNSFilter {
return &DNSFilter{
dnsHandler: handler,
ipTracker: ipTracker,
}
}
// ProcessPacket checks if a packet is a DNS query and processes it.
// Returns:
// - isDNS: true if this is a DNS packet
// - response: DNS response packet (if handled), nil otherwise
// - error: any error that occurred
func (df *DNSFilter) ProcessPacket(packet []byte) (isDNS bool, response []byte, err error) {
if len(packet) < header.IPv4MinimumSize {
return false, nil, nil
}
// Parse IP version
ipVersion := packet[0] >> 4
switch ipVersion {
case 4:
return df.processIPv4(packet)
case 6:
return df.processIPv6(packet)
default:
return false, nil, nil
}
}
// processIPv4 processes an IPv4 packet and checks if it's DNS.
func (df *DNSFilter) processIPv4(packet []byte) (bool, []byte, error) {
if len(packet) < header.IPv4MinimumSize {
return false, nil, nil
}
// Parse IPv4 header
ipHdr := header.IPv4(packet)
if !ipHdr.IsValid(len(packet)) {
return false, nil, nil
}
// Check if it's UDP
if ipHdr.TransportProtocol() != header.UDPProtocolNumber {
return false, nil, nil
}
// Get IP header length
ihl := int(ipHdr.HeaderLength())
if len(packet) < ihl+header.UDPMinimumSize {
return false, nil, nil
}
// Parse UDP header
udpHdr := header.UDP(packet[ihl:])
srcPort := udpHdr.SourcePort()
dstPort := udpHdr.DestinationPort()
// Check if destination port is 53 (DNS)
if dstPort != 53 {
return false, nil, nil
}
srcIP := ipHdr.SourceAddress()
dstIP := ipHdr.DestinationAddress()
// Extract DNS payload
udpPayloadOffset := ihl + header.UDPMinimumSize
if len(packet) <= udpPayloadOffset {
return true, nil, fmt.Errorf("invalid UDP packet length")
}
dnsQuery := packet[udpPayloadOffset:]
if len(dnsQuery) == 0 {
return true, nil, fmt.Errorf("empty DNS query")
}
// Process DNS query
if df.dnsHandler == nil {
return true, nil, fmt.Errorf("no DNS handler configured")
}
dnsResponse, err := df.dnsHandler(dnsQuery)
if err != nil {
return true, nil, fmt.Errorf("DNS handler error: %v", err)
}
// Track IPs from DNS response
if df.ipTracker != nil {
df.extractAndTrackIPs(dnsResponse)
}
// Build response packet
responsePacket := df.buildIPv4UDPPacket(
dstIP.As4(), // Swap src/dst
srcIP.As4(),
dstPort, // Swap ports
srcPort,
dnsResponse,
)
return true, responsePacket, nil
}
// processIPv6 processes an IPv6 packet and checks if it's DNS.
func (df *DNSFilter) processIPv6(packet []byte) (bool, []byte, error) {
if len(packet) < header.IPv6MinimumSize {
return false, nil, nil
}
// Parse IPv6 header
ipHdr := header.IPv6(packet)
if !ipHdr.IsValid(len(packet)) {
return false, nil, nil
}
// Check if it's UDP
if ipHdr.TransportProtocol() != header.UDPProtocolNumber {
return false, nil, nil
}
// IPv6 header is fixed size
if len(packet) < header.IPv6MinimumSize+header.UDPMinimumSize {
return false, nil, nil
}
// Parse UDP header
udpHdr := header.UDP(packet[header.IPv6MinimumSize:])
srcPort := udpHdr.SourcePort()
dstPort := udpHdr.DestinationPort()
// Check if destination port is 53 (DNS)
if dstPort != 53 {
return false, nil, nil
}
// Extract DNS payload
udpPayloadOffset := header.IPv6MinimumSize + header.UDPMinimumSize
if len(packet) <= udpPayloadOffset {
return true, nil, fmt.Errorf("invalid UDP packet length")
}
dnsQuery := packet[udpPayloadOffset:]
if len(dnsQuery) == 0 {
return true, nil, fmt.Errorf("empty DNS query")
}
// Process DNS query
if df.dnsHandler == nil {
return true, nil, fmt.Errorf("no DNS handler configured")
}
dnsResponse, err := df.dnsHandler(dnsQuery)
if err != nil {
return true, nil, fmt.Errorf("DNS handler error: %v", err)
}
// Track IPs from DNS response
if df.ipTracker != nil {
df.extractAndTrackIPs(dnsResponse)
}
// Build response packet
srcIP := ipHdr.SourceAddress()
dstIP := ipHdr.DestinationAddress()
responsePacket := df.buildIPv6UDPPacket(
dstIP.As16(), // Swap src/dst
srcIP.As16(),
dstPort, // Swap ports
srcPort,
dnsResponse,
)
return true, responsePacket, nil
}
// buildIPv4UDPPacket builds a complete IPv4/UDP packet with the given payload.
func (df *DNSFilter) buildIPv4UDPPacket(srcIP, dstIP [4]byte, srcPort, dstPort uint16, payload []byte) []byte {
// Calculate lengths
udpLen := header.UDPMinimumSize + len(payload)
ipLen := header.IPv4MinimumSize + udpLen
packet := make([]byte, ipLen)
// Build IPv4 header
ipHdr := header.IPv4(packet)
ipHdr.Encode(&header.IPv4Fields{
TotalLength: uint16(ipLen),
TTL: 64,
Protocol: uint8(header.UDPProtocolNumber),
SrcAddr: tcpip.AddrFrom4(srcIP),
DstAddr: tcpip.AddrFrom4(dstIP),
})
ipHdr.SetChecksum(^ipHdr.CalculateChecksum())
// Build UDP header
udpHdr := header.UDP(packet[header.IPv4MinimumSize:])
udpHdr.Encode(&header.UDPFields{
SrcPort: srcPort,
DstPort: dstPort,
Length: uint16(udpLen),
})
// Copy payload
copy(packet[header.IPv4MinimumSize+header.UDPMinimumSize:], payload)
// Calculate UDP checksum
xsum := header.PseudoHeaderChecksum(
header.UDPProtocolNumber,
tcpip.AddrFrom4(srcIP),
tcpip.AddrFrom4(dstIP),
uint16(udpLen),
)
xsum = checksum(payload, xsum)
udpHdr.SetChecksum(^udpHdr.CalculateChecksum(xsum))
return packet
}
// buildIPv6UDPPacket builds a complete IPv6/UDP packet with the given payload.
func (df *DNSFilter) buildIPv6UDPPacket(srcIP, dstIP [16]byte, srcPort, dstPort uint16, payload []byte) []byte {
// Calculate lengths
udpLen := header.UDPMinimumSize + len(payload)
ipLen := header.IPv6MinimumSize + udpLen
packet := make([]byte, ipLen)
// Build IPv6 header
ipHdr := header.IPv6(packet)
ipHdr.Encode(&header.IPv6Fields{
PayloadLength: uint16(udpLen),
TransportProtocol: header.UDPProtocolNumber,
HopLimit: 64,
SrcAddr: tcpip.AddrFrom16(srcIP),
DstAddr: tcpip.AddrFrom16(dstIP),
})
// Build UDP header
udpHdr := header.UDP(packet[header.IPv6MinimumSize:])
udpHdr.Encode(&header.UDPFields{
SrcPort: srcPort,
DstPort: dstPort,
Length: uint16(udpLen),
})
// Copy payload
copy(packet[header.IPv6MinimumSize+header.UDPMinimumSize:], payload)
// Calculate UDP checksum
xsum := header.PseudoHeaderChecksum(
header.UDPProtocolNumber,
tcpip.AddrFrom16(srcIP),
tcpip.AddrFrom16(dstIP),
uint16(udpLen),
)
xsum = checksum(payload, xsum)
udpHdr.SetChecksum(^udpHdr.CalculateChecksum(xsum))
return packet
}
// checksum calculates the checksum for the given data.
func checksum(buf []byte, initial uint16) uint16 {
v := uint32(initial)
l := len(buf)
if l&1 != 0 {
l--
v += uint32(buf[l]) << 8
}
for i := 0; i < l; i += 2 {
v += (uint32(buf[i]) << 8) + uint32(buf[i+1])
}
return reduceChecksum(v)
}
// reduceChecksum reduces a 32-bit checksum to 16 bits.
func reduceChecksum(v uint32) uint16 {
v = (v >> 16) + (v & 0xffff)
v = (v >> 16) + (v & 0xffff)
return uint16(v)
}
// IPv4Address is a helper to create an IPv4 address from a byte array.
func IPv4Address(b [4]byte) net.IP {
return net.IPv4(b[0], b[1], b[2], b[3])
}
// IPv6Address is a helper to create an IPv6 address from a byte array.
func IPv6Address(b [16]byte) net.IP {
return net.IP(b[:])
}
// parseIPv4 extracts source and destination IPs from an IPv4 packet.
func parseIPv4(packet []byte) (srcIP, dstIP [4]byte, ok bool) {
if len(packet) < header.IPv4MinimumSize {
return
}
ipHdr := header.IPv4(packet)
if !ipHdr.IsValid(len(packet)) {
return
}
srcAddr := ipHdr.SourceAddress().As4()
dstAddr := ipHdr.DestinationAddress().As4()
copy(srcIP[:], srcAddr[:])
copy(dstIP[:], dstAddr[:])
ok = true
return
}
// parseUDP extracts UDP header information.
func parseUDP(udpHeader []byte) (srcPort, dstPort uint16, ok bool) {
if len(udpHeader) < header.UDPMinimumSize {
return
}
srcPort = binary.BigEndian.Uint16(udpHeader[0:2])
dstPort = binary.BigEndian.Uint16(udpHeader[2:4])
ok = true
return
}
// extractAndTrackIPs parses DNS response and tracks resolved IP addresses
func (df *DNSFilter) extractAndTrackIPs(dnsResponse []byte) {
if len(dnsResponse) < 12 {
return // Invalid DNS response
}
msg := new(dns.Msg)
if err := msg.Unpack(dnsResponse); err != nil {
return // Failed to parse DNS response
}
// Extract IPs from answer section
for _, answer := range msg.Answer {
switch rr := answer.(type) {
case *dns.A:
// IPv4 address
if rr.A != nil {
df.ipTracker.TrackIP(rr.A)
}
case *dns.AAAA:
// IPv6 address
if rr.AAAA != nil {
df.ipTracker.TrackIP(rr.AAAA)
}
}
}
}

View File

@@ -1,150 +0,0 @@
package netstack
import (
"net"
"sync"
"time"
)
// IPTracker tracks IP addresses that have been resolved through DNS.
// This allows blocking direct IP connections that bypass DNS filtering.
type IPTracker struct {
// Map of IP address string -> expiration time
resolvedIPs map[string]time.Time
mu sync.RWMutex
// TTL for tracked IPs (how long to remember them)
ttl time.Duration
// Running state
running bool
stopCh chan struct{}
wg sync.WaitGroup
}
// NewIPTracker creates a new IP tracker with the specified TTL
func NewIPTracker(ttl time.Duration) *IPTracker {
if ttl == 0 {
ttl = 5 * time.Minute // Default 5 minutes
}
return &IPTracker{
resolvedIPs: make(map[string]time.Time),
ttl: ttl,
stopCh: make(chan struct{}),
}
}
// Start starts the IP tracker cleanup routine
func (t *IPTracker) Start() {
t.mu.Lock()
if t.running {
t.mu.Unlock()
return
}
t.running = true
t.mu.Unlock()
// Start cleanup goroutine to remove expired IPs
t.wg.Add(1)
go t.cleanupExpiredIPs()
}
// Stop stops the IP tracker
func (t *IPTracker) Stop() {
if t == nil {
return
}
t.mu.Lock()
if !t.running {
t.mu.Unlock()
return
}
t.running = false
t.mu.Unlock()
// Close stop channel (protected against double close)
select {
case <-t.stopCh:
// Already closed
default:
close(t.stopCh)
}
t.wg.Wait()
// Clear all tracked IPs
t.mu.Lock()
t.resolvedIPs = make(map[string]time.Time)
t.mu.Unlock()
}
// TrackIP adds an IP address to the tracking list
func (t *IPTracker) TrackIP(ip net.IP) {
if ip == nil {
return
}
// Normalize to string format
ipStr := ip.String()
t.mu.Lock()
t.resolvedIPs[ipStr] = time.Now().Add(t.ttl)
t.mu.Unlock()
}
// IsTracked checks if an IP address is in the tracking list
// Optimized to minimize lock contention by avoiding write locks in the hot path
func (t *IPTracker) IsTracked(ip net.IP) bool {
if ip == nil {
return false
}
ipStr := ip.String()
t.mu.RLock()
expiration, exists := t.resolvedIPs[ipStr]
t.mu.RUnlock()
if !exists {
return false
}
// Check if expired - but DON'T delete here to avoid write lock
// Let the cleanup goroutine handle expired entries
// This keeps IsTracked fast with only read locks
return !time.Now().After(expiration)
}
// GetTrackedCount returns the number of currently tracked IPs
func (t *IPTracker) GetTrackedCount() int {
t.mu.RLock()
defer t.mu.RUnlock()
return len(t.resolvedIPs)
}
// cleanupExpiredIPs periodically removes expired IP entries
func (t *IPTracker) cleanupExpiredIPs() {
defer t.wg.Done()
ticker := time.NewTicker(30 * time.Second)
defer ticker.Stop()
for {
select {
case <-t.stopCh:
return
case <-ticker.C:
now := time.Now()
t.mu.Lock()
for ip, expiration := range t.resolvedIPs {
if now.After(expiration) {
delete(t.resolvedIPs, ip)
}
}
t.mu.Unlock()
}
}
}

View File

@@ -1,417 +0,0 @@
package netstack
import (
"context"
"fmt"
"net"
"net/netip"
"sync"
"time"
"github.com/Control-D-Inc/ctrld"
"gvisor.dev/gvisor/pkg/buffer"
"gvisor.dev/gvisor/pkg/tcpip"
"gvisor.dev/gvisor/pkg/tcpip/header"
"gvisor.dev/gvisor/pkg/tcpip/link/channel"
"gvisor.dev/gvisor/pkg/tcpip/network/ipv4"
"gvisor.dev/gvisor/pkg/tcpip/network/ipv6"
"gvisor.dev/gvisor/pkg/tcpip/stack"
"gvisor.dev/gvisor/pkg/tcpip/transport/tcp"
"gvisor.dev/gvisor/pkg/tcpip/transport/udp"
)
const (
// Default MTU for the TUN interface
defaultMTU = 1500
// NICID is the ID of the network interface
NICID = 1
// Channel capacity for packet buffers
channelCapacity = 512
)
// NetstackController manages the gVisor netstack integration for mobile packet capture.
type NetstackController struct {
stack *stack.Stack
linkEP *channel.Endpoint
packetHandler PacketHandler
dnsFilter *DNSFilter
ipTracker *IPTracker
tcpForwarder *TCPForwarder
udpForwarder *UDPForwarder
ctx context.Context
cancel context.CancelFunc
wg sync.WaitGroup
started bool
mu sync.Mutex
}
// Config holds configuration for NetstackController.
type Config struct {
// MTU is the maximum transmission unit
MTU uint32
// TUNIPv4 is the IPv4 address assigned to the TUN interface
TUNIPv4 netip.Addr
// TUNIPv6 is the IPv6 address assigned to the TUN interface (optional)
TUNIPv6 netip.Addr
// DNSHandler is the function to process DNS queries
DNSHandler func([]byte) ([]byte, error)
// UpstreamInterface is the real network interface for routing non-DNS traffic
UpstreamInterface *net.Interface
}
// NewNetstackController creates a new netstack controller.
func NewNetstackController(handler PacketHandler, cfg *Config) (*NetstackController, error) {
if handler == nil {
return nil, fmt.Errorf("packet handler cannot be nil")
}
if cfg == nil {
cfg = &Config{
MTU: defaultMTU,
TUNIPv4: netip.MustParseAddr("10.0.0.1"),
}
}
if cfg.MTU == 0 {
cfg.MTU = defaultMTU
}
ctx, cancel := context.WithCancel(context.Background())
// Create gVisor stack
s := stack.New(stack.Options{
NetworkProtocols: []stack.NetworkProtocolFactory{
ipv4.NewProtocol,
ipv6.NewProtocol,
},
TransportProtocols: []stack.TransportProtocolFactory{
tcp.NewProtocol,
udp.NewProtocol,
},
})
// Create link endpoint
linkEP := channel.New(channelCapacity, cfg.MTU, "")
// Always create IP tracker (5 minute TTL for tracked IPs)
// In firewall mode (default routes): blocks direct IP connections
// In DNS-only mode: no non-DNS traffic to block
ipTracker := NewIPTracker(5 * time.Minute)
// Create DNS filter with IP tracker
dnsFilter := NewDNSFilter(cfg.DNSHandler, ipTracker)
// Create TCP forwarder with IP tracker
tcpForwarder := NewTCPForwarder(s, ctx, ipTracker)
// Create UDP forwarder with IP tracker
udpForwarder := NewUDPForwarder(s, ctx, ipTracker)
// Create NIC
if err := s.CreateNIC(NICID, linkEP); err != nil {
cancel()
return nil, fmt.Errorf("failed to create NIC: %v", err)
}
// Enable spoofing to allow packets with any source IP
if err := s.SetSpoofing(NICID, true); err != nil {
cancel()
return nil, fmt.Errorf("failed to enable spoofing: %v", err)
}
// Enable promiscuous mode to accept all packets
if err := s.SetPromiscuousMode(NICID, true); err != nil {
cancel()
return nil, fmt.Errorf("failed to enable promiscuous mode: %v", err)
}
// Add IPv4 address
protocolAddr := tcpip.ProtocolAddress{
Protocol: ipv4.ProtocolNumber,
AddressWithPrefix: tcpip.AddressWithPrefix{
Address: tcpip.AddrFromSlice(cfg.TUNIPv4.AsSlice()),
PrefixLen: 24,
},
}
if err := s.AddProtocolAddress(NICID, protocolAddr, stack.AddressProperties{}); err != nil {
cancel()
return nil, fmt.Errorf("failed to add IPv4 address: %v", err)
}
// Add IPv6 address if provided
if cfg.TUNIPv6.IsValid() {
protocolAddr6 := tcpip.ProtocolAddress{
Protocol: ipv6.ProtocolNumber,
AddressWithPrefix: tcpip.AddressWithPrefix{
Address: tcpip.AddrFromSlice(cfg.TUNIPv6.AsSlice()),
PrefixLen: 64,
},
}
if err := s.AddProtocolAddress(NICID, protocolAddr6, stack.AddressProperties{}); err != nil {
cancel()
return nil, fmt.Errorf("failed to add IPv6 address: %v", err)
}
}
// Add default routes
s.SetRouteTable([]tcpip.Route{
{
Destination: header.IPv4EmptySubnet,
NIC: NICID,
},
{
Destination: header.IPv6EmptySubnet,
NIC: NICID,
},
})
// Register forwarders with the stack
s.SetTransportProtocolHandler(tcp.ProtocolNumber, tcpForwarder.forwarder.HandlePacket)
s.SetTransportProtocolHandler(udp.ProtocolNumber, udpForwarder.forwarder.HandlePacket)
nc := &NetstackController{
stack: s,
linkEP: linkEP,
packetHandler: handler,
dnsFilter: dnsFilter,
ipTracker: ipTracker,
tcpForwarder: tcpForwarder,
udpForwarder: udpForwarder,
ctx: ctx,
cancel: cancel,
started: false,
}
ctrld.ProxyLogger.Load().Info().Msg("[Netstack] Controller created with TCP/UDP forwarders")
return nc, nil
}
// Start starts the netstack controller and begins processing packets.
func (nc *NetstackController) Start() error {
nc.mu.Lock()
defer nc.mu.Unlock()
if nc.started {
return fmt.Errorf("netstack controller already started")
}
nc.started = true
// Start IP tracker
nc.ipTracker.Start()
// Start packet reader goroutine (TUN -> netstack)
nc.wg.Add(1)
go nc.readPackets()
// Start packet writer goroutine (netstack -> TUN)
nc.wg.Add(1)
go nc.writePackets()
ctrld.ProxyLogger.Load().Info().Msg("[Netstack] Packet processing started (read/write goroutines + IP tracker)")
return nil
}
// Stop stops the netstack controller and waits for all goroutines to finish.
func (nc *NetstackController) Stop() error {
ctrld.ProxyLogger.Load().Info().Msg("[Netstack] Stop() called - starting shutdown")
nc.mu.Lock()
if !nc.started {
nc.mu.Unlock()
ctrld.ProxyLogger.Load().Info().Msg("[Netstack] Stop() - already stopped, returning")
return nil
}
nc.mu.Unlock()
ctrld.ProxyLogger.Load().Info().Msg("[Netstack] Stop() - canceling context")
nc.cancel()
// Close packet handler FIRST to unblock all pending reads
ctrld.ProxyLogger.Load().Info().Msg("[Netstack] Stop() - closing packet handler to unblock goroutines")
if err := nc.packetHandler.Close(); err != nil {
ctrld.ProxyLogger.Load().Error().Msgf("[Netstack] Stop() - failed to close packet handler: %v", err)
// Continue shutdown even if close fails
}
ctrld.ProxyLogger.Load().Info().Msg("[Netstack] Stop() - packet handler closed")
ctrld.ProxyLogger.Load().Info().Msg("[Netstack] Stop() - waiting for goroutines (max 2 seconds)")
// Wait for goroutines with timeout
done := make(chan struct{})
go func() {
nc.wg.Wait()
close(done)
}()
select {
case <-done:
ctrld.ProxyLogger.Load().Info().Msg("[Netstack] Stop() - all goroutines finished")
case <-time.After(2 * time.Second):
ctrld.ProxyLogger.Load().Warn().Msg("[Netstack] Stop() - timeout waiting for goroutines, proceeding anyway")
}
// Stop IP tracker
if nc.ipTracker != nil {
ctrld.ProxyLogger.Load().Info().Msg("[Netstack] Stop() - stopping IP tracker")
nc.ipTracker.Stop()
ctrld.ProxyLogger.Load().Info().Msg("[Netstack] Stop() - IP tracker stopped")
}
// Close UDP forwarder
if nc.udpForwarder != nil {
ctrld.ProxyLogger.Load().Info().Msg("[Netstack] Stop() - closing UDP forwarder")
nc.udpForwarder.Close()
ctrld.ProxyLogger.Load().Info().Msg("[Netstack] Stop() - UDP forwarder closed")
}
nc.mu.Lock()
nc.started = false
nc.mu.Unlock()
ctrld.ProxyLogger.Load().Info().Msg("[Netstack] Stop() - shutdown complete")
return nil
}
// readPackets reads packets from the TUN interface and injects them into the netstack.
func (nc *NetstackController) readPackets() {
defer nc.wg.Done()
for {
select {
case <-nc.ctx.Done():
return
default:
}
// Read packet from TUN
packet, err := nc.packetHandler.ReadPacket()
if err != nil {
if nc.ctx.Err() != nil {
return
}
time.Sleep(10 * time.Millisecond)
continue
}
if len(packet) == 0 {
continue
}
// Check if this is a DNS packet
isDNS, response, err := nc.dnsFilter.ProcessPacket(packet)
if err != nil {
continue
}
if isDNS && response != nil {
// DNS packet was handled, send response back to TUN
nc.packetHandler.WritePacket(response)
ctrld.ProxyLogger.Load().Debug().Msgf("[Netstack] DNS response sent (%d bytes)", len(response))
continue
}
if isDNS {
continue
}
// Not a DNS packet - check if it's an OUTBOUND packet (source = 10.0.0.x)
// We should ONLY inject outbound packets, not return packets
if len(packet) >= 20 {
// Check if source is in our VPN subnet (10.0.0.x)
isOutbound := packet[12] == 10 && packet[13] == 0 && packet[14] == 0
if !isOutbound {
// This is a return packet (server -> mobile)
// Drop it - return packets come through forwarder's upstream connection
continue
}
// Block QUIC protocol (UDP on port 443)
// QUIC runs over UDP and bypasses DNS, so we block it to force HTTP/2 or HTTP/3 over TCP
protocol := packet[9]
if protocol == 17 { // UDP
// Get IP header length
ihl := int(packet[0]&0x0f) * 4
if len(packet) >= ihl+4 {
// Parse UDP destination port (bytes 2-3 of UDP header)
dstPort := uint16(packet[ihl+2])<<8 | uint16(packet[ihl+3])
if dstPort == 443 || dstPort == 80 {
// Block QUIC (UDP/443) and HTTP/3 (UDP/80)
// Apps will fallback to TCP automatically
dstIP := net.IPv4(packet[16], packet[17], packet[18], packet[19])
ctrld.ProxyLogger.Load().Debug().Msgf("[Netstack] Blocked QUIC packet to %s:%d", dstIP, dstPort)
continue
}
}
}
}
// Create packet buffer
pkt := stack.NewPacketBuffer(stack.PacketBufferOptions{
Payload: buffer.MakeWithData(packet),
})
// Determine protocol number
var proto tcpip.NetworkProtocolNumber
if len(packet) > 0 {
version := packet[0] >> 4
switch version {
case 4:
proto = header.IPv4ProtocolNumber
case 6:
proto = header.IPv6ProtocolNumber
default:
pkt.DecRef()
continue
}
} else {
pkt.DecRef()
continue
}
// Inject into netstack - TCP/UDP forwarders will handle it
nc.linkEP.InjectInbound(proto, pkt)
}
}
// writePackets reads packets from netstack and writes them to the TUN interface.
func (nc *NetstackController) writePackets() {
defer nc.wg.Done()
for {
select {
case <-nc.ctx.Done():
return
default:
}
// Read packet from netstack
pkt := nc.linkEP.ReadContext(nc.ctx)
if pkt == nil {
continue
}
// Convert packet to bytes
vv := pkt.ToView()
packet := vv.AsSlice()
// Write to TUN
if err := nc.packetHandler.WritePacket(packet); err != nil {
// Log error
continue
}
pkt.DecRef()
}
}

View File

@@ -1,97 +0,0 @@
package netstack
import (
"fmt"
"sync"
)
// PacketHandler defines the interface for reading and writing raw IP packets
// from/to the mobile TUN interface.
type PacketHandler interface {
// ReadPacket reads a raw IP packet from the TUN interface.
// This should be a blocking call.
ReadPacket() ([]byte, error)
// WritePacket writes a raw IP packet back to the TUN interface.
WritePacket(packet []byte) error
// Close closes the packet handler and releases resources.
Close() error
}
// MobilePacketHandler implements PacketHandler using callbacks from mobile platforms.
// This bridges Go Mobile interface with the netstack implementation.
type MobilePacketHandler struct {
readFunc func() ([]byte, error)
writeFunc func([]byte) error
closeFunc func() error
mu sync.Mutex
closed bool
}
// NewMobilePacketHandler creates a new packet handler with mobile callbacks.
func NewMobilePacketHandler(
readFunc func() ([]byte, error),
writeFunc func([]byte) error,
closeFunc func() error,
) *MobilePacketHandler {
return &MobilePacketHandler{
readFunc: readFunc,
writeFunc: writeFunc,
closeFunc: closeFunc,
closed: false,
}
}
// ReadPacket reads a packet from mobile TUN interface.
func (m *MobilePacketHandler) ReadPacket() ([]byte, error) {
m.mu.Lock()
closed := m.closed
m.mu.Unlock()
if closed {
return nil, fmt.Errorf("packet handler is closed")
}
if m.readFunc == nil {
return nil, fmt.Errorf("read function not set")
}
return m.readFunc()
}
// WritePacket writes a packet back to mobile TUN interface.
func (m *MobilePacketHandler) WritePacket(packet []byte) error {
m.mu.Lock()
closed := m.closed
m.mu.Unlock()
if closed {
return fmt.Errorf("packet handler is closed")
}
if m.writeFunc == nil {
return fmt.Errorf("write function not set")
}
return m.writeFunc(packet)
}
// Close closes the packet handler.
func (m *MobilePacketHandler) Close() error {
m.mu.Lock()
defer m.mu.Unlock()
if m.closed {
return nil
}
m.closed = true
if m.closeFunc != nil {
return m.closeFunc()
}
return nil
}

View File

@@ -1,130 +0,0 @@
package netstack
import (
"context"
"io"
"net"
"time"
"github.com/Control-D-Inc/ctrld"
"gvisor.dev/gvisor/pkg/tcpip/adapters/gonet"
"gvisor.dev/gvisor/pkg/tcpip/stack"
"gvisor.dev/gvisor/pkg/tcpip/transport/tcp"
"gvisor.dev/gvisor/pkg/waiter"
)
// TCPForwarder handles TCP connections from the TUN interface
type TCPForwarder struct {
ctx context.Context
forwarder *tcp.Forwarder
ipTracker *IPTracker
}
// NewTCPForwarder creates a new TCP forwarder
func NewTCPForwarder(s *stack.Stack, ctx context.Context, ipTracker *IPTracker) *TCPForwarder {
f := &TCPForwarder{
ctx: ctx,
ipTracker: ipTracker,
}
// Create gVisor TCP forwarder with handler callback
// rcvWnd=0 (use default), maxInFlight=1024
f.forwarder = tcp.NewForwarder(s, 0, 1024, f.handleRequest)
return f
}
// GetForwarder returns the underlying gVisor forwarder
func (f *TCPForwarder) GetForwarder() *tcp.Forwarder {
return f.forwarder
}
// handleRequest handles an incoming TCP connection request
func (f *TCPForwarder) handleRequest(req *tcp.ForwarderRequest) {
// Get the endpoint ID
id := req.ID()
// Create waiter queue
var wq waiter.Queue
// Create endpoint from request
ep, err := req.CreateEndpoint(&wq)
if err != nil {
req.Complete(true) // Send RST
return
}
// Accept the connection
req.Complete(false)
// Cast to TCP endpoint
tcpEP, ok := ep.(*tcp.Endpoint)
if !ok {
ep.Close()
return
}
// Handle in goroutine
go f.handleConnection(tcpEP, &wq, id)
}
func (f *TCPForwarder) handleConnection(ep *tcp.Endpoint, wq *waiter.Queue, id stack.TransportEndpointID) {
// Convert endpoint to Go net.Conn
tunConn := gonet.NewTCPConn(wq, ep)
defer tunConn.Close()
// In gVisor's TransportEndpointID for an inbound connection:
// - LocalAddress/LocalPort = the destination (where packet is going TO)
// - RemoteAddress/RemotePort = the source (where packet is coming FROM)
// We want to dial the DESTINATION (LocalAddress/LocalPort)
dstIP := net.IP(id.LocalAddress.AsSlice())
dstAddr := net.TCPAddr{
IP: dstIP,
Port: int(id.LocalPort),
}
// Check if IP blocking is enabled (firewall mode only)
// Skip blocking for internal VPN subnet (10.0.0.0/24)
if f.ipTracker != nil {
// Allow internal VPN traffic (10.0.0.0/24)
if !(dstIP[0] == 10 && dstIP[1] == 0 && dstIP[2] == 0) {
// Check if destination IP was resolved through ControlD DNS
// ONLY allow connections to IPs that went through DNS (whitelist approach)
if !f.ipTracker.IsTracked(dstIP) {
srcAddr := net.IP(id.RemoteAddress.AsSlice())
ctrld.ProxyLogger.Load().Info().Msgf("[TCP] BLOCKED hardcoded IP: %s:%d -> %s:%d (not resolved via DNS)",
srcAddr, id.RemotePort, dstIP, id.LocalPort)
return
}
}
}
// Create outbound connection
dialer := &net.Dialer{
Timeout: 30 * time.Second,
}
upstreamConn, err := dialer.DialContext(f.ctx, "tcp", dstAddr.String())
if err != nil {
return
}
defer upstreamConn.Close()
// Log successful TCP connection
srcAddr := net.IP(id.RemoteAddress.AsSlice())
ctrld.ProxyLogger.Load().Debug().Msgf("[TCP] %s:%d -> %s:%d", srcAddr, id.RemotePort, dstAddr.IP, dstAddr.Port)
// Bidirectional copy
done := make(chan struct{}, 2)
go func() {
io.Copy(upstreamConn, tunConn)
done <- struct{}{}
}()
go func() {
io.Copy(tunConn, upstreamConn)
done <- struct{}{}
}()
// Wait for one direction to finish
<-done
}

View File

@@ -1,238 +0,0 @@
package netstack
import (
"context"
"fmt"
"net"
"sync"
"time"
"github.com/Control-D-Inc/ctrld"
"gvisor.dev/gvisor/pkg/tcpip/adapters/gonet"
"gvisor.dev/gvisor/pkg/tcpip/stack"
"gvisor.dev/gvisor/pkg/tcpip/transport/udp"
"gvisor.dev/gvisor/pkg/waiter"
)
// UDPForwarder handles UDP packets from the TUN interface
type UDPForwarder struct {
ctx context.Context
forwarder *udp.Forwarder
ipTracker *IPTracker
// Track UDP "connections" (address pairs)
connections map[string]*udpConn
mu sync.Mutex
}
type udpConn struct {
tunEP *gonet.UDPConn
upstreamConn *net.UDPConn
cancel context.CancelFunc
}
// NewUDPForwarder creates a new UDP forwarder
func NewUDPForwarder(s *stack.Stack, ctx context.Context, ipTracker *IPTracker) *UDPForwarder {
f := &UDPForwarder{
ctx: ctx,
ipTracker: ipTracker,
connections: make(map[string]*udpConn),
}
// Create gVisor UDP forwarder with handler callback
f.forwarder = udp.NewForwarder(s, f.handlePacket)
return f
}
// GetForwarder returns the underlying gVisor forwarder
func (f *UDPForwarder) GetForwarder() *udp.Forwarder {
return f.forwarder
}
// handlePacket handles an incoming UDP packet
func (f *UDPForwarder) handlePacket(req *udp.ForwarderRequest) {
// Get the endpoint ID
id := req.ID()
// Create connection key (source -> destination)
connKey := fmt.Sprintf("%s:%d->%s:%d",
net.IP(id.RemoteAddress.AsSlice()),
id.RemotePort,
net.IP(id.LocalAddress.AsSlice()),
id.LocalPort,
)
f.mu.Lock()
conn, exists := f.connections[connKey]
if !exists {
// Create new connection
conn = f.createConnection(req, connKey)
if conn == nil {
f.mu.Unlock()
return
}
f.connections[connKey] = conn
// Log new UDP session
srcAddr := net.IP(id.RemoteAddress.AsSlice())
dstAddr := net.IP(id.LocalAddress.AsSlice())
ctrld.ProxyLogger.Load().Debug().Msgf("[UDP] New session: %s:%d -> %s:%d (total: %d)",
srcAddr, id.RemotePort, dstAddr, id.LocalPort, len(f.connections))
}
f.mu.Unlock()
}
func (f *UDPForwarder) createConnection(req *udp.ForwarderRequest, connKey string) *udpConn {
id := req.ID()
// Create waiter queue
var wq waiter.Queue
// Create endpoint from request
ep, err := req.CreateEndpoint(&wq)
if err != nil {
return nil
}
// Convert to Go UDP conn
tunConn := gonet.NewUDPConn(&wq, ep)
// Extract destination address
// LocalAddress/LocalPort = destination (where packet is going TO)
// RemoteAddress/RemotePort = source (where packet is coming FROM)
dstIP := net.IP(id.LocalAddress.AsSlice())
dstAddr := &net.UDPAddr{
IP: dstIP,
Port: int(id.LocalPort),
}
// Check if IP blocking is enabled (firewall mode only)
// Skip blocking for internal VPN subnet (10.0.0.0/24)
if f.ipTracker != nil {
// Allow internal VPN traffic (10.0.0.0/24)
if !(dstIP[0] == 10 && dstIP[1] == 0 && dstIP[2] == 0) {
// Check if destination IP was resolved through ControlD DNS
// ONLY allow connections to IPs that went through DNS (whitelist approach)
if !f.ipTracker.IsTracked(dstIP) {
srcAddr := net.IP(id.RemoteAddress.AsSlice())
ctrld.ProxyLogger.Load().Info().Msgf("[UDP] BLOCKED hardcoded IP: %s:%d -> %s:%d (not resolved via DNS)",
srcAddr, id.RemotePort, dstIP, id.LocalPort)
return nil
}
}
}
// Create dialer
dialer := &net.Dialer{}
// Create outbound UDP connection
dialConn, dialErr := dialer.Dial("udp", dstAddr.String())
if dialErr != nil {
tunConn.Close()
return nil
}
upstreamConn, ok := dialConn.(*net.UDPConn)
if !ok {
dialConn.Close()
tunConn.Close()
return nil
}
// Create connection context
ctx, cancel := context.WithCancel(f.ctx)
udpConnection := &udpConn{
tunEP: tunConn,
upstreamConn: upstreamConn,
cancel: cancel,
}
// Start forwarding goroutines
go f.forwardTunToUpstream(udpConnection, ctx)
go f.forwardUpstreamToTun(udpConnection, ctx, connKey)
return udpConnection
}
func (f *UDPForwarder) forwardTunToUpstream(conn *udpConn, ctx context.Context) {
buffer := make([]byte, 65535)
for {
select {
case <-ctx.Done():
return
default:
}
// Read from TUN
n, err := conn.tunEP.Read(buffer)
if err != nil {
return
}
// Write to upstream
_, err = conn.upstreamConn.Write(buffer[:n])
if err != nil {
return
}
}
}
func (f *UDPForwarder) forwardUpstreamToTun(conn *udpConn, ctx context.Context, connKey string) {
defer func() {
conn.tunEP.Close()
conn.upstreamConn.Close()
f.mu.Lock()
delete(f.connections, connKey)
f.mu.Unlock()
}()
buffer := make([]byte, 65535)
// Set read timeout
conn.upstreamConn.SetReadDeadline(time.Now().Add(30 * time.Second))
for {
select {
case <-ctx.Done():
return
default:
}
// Read from upstream
n, err := conn.upstreamConn.Read(buffer)
if err != nil {
return
}
// Reset read deadline
conn.upstreamConn.SetReadDeadline(time.Now().Add(30 * time.Second))
// Write to TUN
_, err = conn.tunEP.Write(buffer[:n])
if err != nil {
return
}
}
}
// Close closes all UDP connections
func (f *UDPForwarder) Close() {
ctrld.ProxyLogger.Load().Info().Msg("[UDP] Close() called - closing all connections")
f.mu.Lock()
defer f.mu.Unlock()
ctrld.ProxyLogger.Load().Info().Msgf("[UDP] Close() - closing %d connections", len(f.connections))
for key, conn := range f.connections {
ctrld.ProxyLogger.Load().Debug().Msgf("[UDP] Close() - closing connection: %s", key)
conn.cancel()
conn.tunEP.Close()
conn.upstreamConn.Close()
}
f.connections = make(map[string]*udpConn)
ctrld.ProxyLogger.Load().Info().Msg("[UDP] Close() - all connections closed")
}

View File

@@ -1,277 +0,0 @@
package ctrld_library
import (
"fmt"
"net/netip"
"time"
"github.com/Control-D-Inc/ctrld"
"github.com/Control-D-Inc/ctrld/cmd/cli"
"github.com/Control-D-Inc/ctrld/cmd/ctrld_library/netstack"
"github.com/miekg/dns"
)
// PacketAppCallback extends AppCallback with packet read/write capabilities.
// Mobile platforms implementing full packet capture should use this interface.
type PacketAppCallback interface {
AppCallback
// ReadPacket reads a raw IP packet from the TUN interface.
// This should be a blocking call that returns when a packet is available.
ReadPacket() ([]byte, error)
// WritePacket writes a raw IP packet back to the TUN interface.
WritePacket(packet []byte) error
// ClosePacketIO closes packet I/O resources.
ClosePacketIO() error
}
// PacketCaptureController holds state for packet capture mode
type PacketCaptureController struct {
baseController *Controller
// Packet capture mode fields
netstackCtrl *netstack.NetstackController
dnsBridge *netstack.DNSBridge
packetStopCh chan struct{}
dnsProxyAddress string
}
// NewPacketCaptureController creates a new packet capture controller
func NewPacketCaptureController(appCallback PacketAppCallback) *PacketCaptureController {
return &PacketCaptureController{
baseController: &Controller{AppCallback: appCallback},
packetStopCh: make(chan struct{}),
}
}
// StartWithPacketCapture starts ctrld in full packet capture mode for mobile.
// This method enables full IP packet processing with DNS filtering and upstream routing.
// It requires a PacketAppCallback that provides packet read/write capabilities.
func (pc *PacketCaptureController) StartWithPacketCapture(
packetCallback PacketAppCallback,
tunAddress string,
deviceAddress string,
mtu int64,
dnsProxyAddress string,
CdUID string,
ProvisionID string,
CustomHostname string,
HomeDir string,
UpstreamProto string,
logLevel int,
logPath string,
) error {
if pc.baseController.stopCh != nil {
return fmt.Errorf("controller already running")
}
// Store DNS proxy address for handleDNSQuery
pc.dnsProxyAddress = dnsProxyAddress
// Set defaults
if mtu == 0 {
mtu = 1500
}
// Set up configuration
pc.baseController.Config = cli.AppConfig{
CdUID: CdUID,
ProvisionID: ProvisionID,
CustomHostname: CustomHostname,
HomeDir: HomeDir,
UpstreamProto: UpstreamProto,
Verbose: logLevel,
LogPath: logPath,
}
pc.baseController.AppCallback = packetCallback
// Create DNS bridge for communication between netstack and DNS proxy
pc.dnsBridge = netstack.NewDNSBridge()
pc.dnsBridge.Start()
// Create packet handler that wraps the mobile callbacks
packetHandler := netstack.NewMobilePacketHandler(
packetCallback.ReadPacket,
packetCallback.WritePacket,
packetCallback.ClosePacketIO,
)
// Create DNS handler that uses the bridge
dnsHandler := func(query []byte) ([]byte, error) {
// Use device address as the source of DNS queries
return pc.dnsBridge.ProcessQuery(query, deviceAddress, 0)
}
// Parse TUN IP address
tunIPv4, err := netip.ParseAddr(tunAddress)
if err != nil {
return fmt.Errorf("failed to parse TUN IPv4 address '%s': %v", tunAddress, err)
}
netstackCfg := &netstack.Config{
MTU: uint32(mtu),
TUNIPv4: tunIPv4,
DNSHandler: dnsHandler,
UpstreamInterface: nil, // Will use default interface
}
ctrld.ProxyLogger.Load().Info().Msgf("[PacketCapture] Network config - TUN: %s, Device: %s, MTU: %d, DNS Proxy: %s",
tunAddress, deviceAddress, mtu, dnsProxyAddress)
// Create netstack controller
netstackCtrl, err := netstack.NewNetstackController(packetHandler, netstackCfg)
if err != nil {
pc.dnsBridge.Stop()
return fmt.Errorf("failed to create netstack controller: %v", err)
}
pc.netstackCtrl = netstackCtrl
// Start netstack processing
if err := pc.netstackCtrl.Start(); err != nil {
pc.dnsBridge.Stop()
return fmt.Errorf("failed to start netstack: %v", err)
}
// Start regular ctrld DNS processing in background
// This allows us to use existing DNS filtering logic
pc.baseController.stopCh = make(chan struct{})
// Start DNS query processor that receives queries from the bridge
// and sends them to the ctrld DNS proxy
go pc.processDNSQueries()
// Start the main ctrld mobile runner
go func() {
appCallback := mapCallback(pc.baseController.AppCallback)
cli.RunMobile(&pc.baseController.Config, &appCallback, pc.baseController.stopCh)
}()
// BLOCK here until stopped (critical - Swift expects this to block!)
ctrld.ProxyLogger.Load().Info().Msg("[PacketCapture] Blocking until stop signal...")
<-pc.baseController.stopCh
ctrld.ProxyLogger.Load().Info().Msg("[PacketCapture] Stop signal received, exiting")
return nil
}
// processDNSQueries processes DNS queries from the bridge using the ctrld DNS proxy
func (pc *PacketCaptureController) processDNSQueries() {
queryCh := pc.dnsBridge.GetQueryChannel()
for {
select {
case <-pc.packetStopCh:
return
case <-pc.baseController.stopCh:
return
case query := <-queryCh:
go pc.handleDNSQuery(query)
}
}
}
// handleDNSQuery handles a single DNS query
func (pc *PacketCaptureController) handleDNSQuery(query *netstack.DNSQuery) {
// Parse DNS message
msg := new(dns.Msg)
if err := msg.Unpack(query.Query); err != nil {
return
}
// Send query to actual DNS proxy using configured address
client := &dns.Client{
Net: "udp",
Timeout: 3 * time.Second,
}
response, _, err := client.Exchange(msg, pc.dnsProxyAddress)
if err != nil {
// Create SERVFAIL response
response = new(dns.Msg)
response.SetReply(msg)
response.Rcode = dns.RcodeServerFailure
}
// Pack response
responseBytes, err := response.Pack()
if err != nil {
return
}
// Send response back through bridge
pc.dnsBridge.SendResponse(query.ID, responseBytes)
}
// Stop stops the packet capture controller
func (pc *PacketCaptureController) Stop(restart bool, pin int64) int {
ctrld.ProxyLogger.Load().Info().Msg("[PacketCapture] Stop() called - starting shutdown")
var errorCode = 0
// Stop DNS bridge
if pc.dnsBridge != nil {
ctrld.ProxyLogger.Load().Info().Msg("[PacketCapture] Stop() - stopping DNS bridge")
pc.dnsBridge.Stop()
pc.dnsBridge = nil
ctrld.ProxyLogger.Load().Info().Msg("[PacketCapture] Stop() - DNS bridge stopped")
}
// Stop netstack
if pc.netstackCtrl != nil {
ctrld.ProxyLogger.Load().Info().Msg("[PacketCapture] Stop() - stopping netstack controller")
if err := pc.netstackCtrl.Stop(); err != nil {
// Log error but continue shutdown
ctrld.ProxyLogger.Load().Error().Msgf("[PacketCapture] Stop() - error stopping netstack: %v", err)
}
pc.netstackCtrl = nil
ctrld.ProxyLogger.Load().Info().Msg("[PacketCapture] Stop() - netstack controller stopped")
}
// Close packet stop channel
if pc.packetStopCh != nil {
ctrld.ProxyLogger.Load().Info().Msg("[PacketCapture] Stop() - closing packet stop channel")
select {
case <-pc.packetStopCh:
// Already closed
ctrld.ProxyLogger.Load().Info().Msg("[PacketCapture] Stop() - packet stop channel already closed")
default:
close(pc.packetStopCh)
ctrld.ProxyLogger.Load().Info().Msg("[PacketCapture] Stop() - packet stop channel closed")
}
pc.packetStopCh = make(chan struct{})
}
// Stop base controller
ctrld.ProxyLogger.Load().Info().Msgf("[PacketCapture] Stop() - stopping base controller (restart=%v, pin=%d)", restart, pin)
if !restart {
errorCode = cli.CheckDeactivationPin(pin, pc.baseController.stopCh)
ctrld.ProxyLogger.Load().Info().Msgf("[PacketCapture] Stop() - deactivation pin check returned: %d", errorCode)
}
if errorCode == 0 && pc.baseController.stopCh != nil {
ctrld.ProxyLogger.Load().Info().Msg("[PacketCapture] Stop() - closing base controller stop channel")
select {
case <-pc.baseController.stopCh:
// Already closed
ctrld.ProxyLogger.Load().Info().Msg("[PacketCapture] Stop() - base controller stop channel already closed")
default:
close(pc.baseController.stopCh)
ctrld.ProxyLogger.Load().Info().Msg("[PacketCapture] Stop() - base controller stop channel closed")
}
pc.baseController.stopCh = nil
}
ctrld.ProxyLogger.Load().Info().Msgf("[PacketCapture] Stop() - shutdown complete, errorCode=%d", errorCode)
return errorCode
}
// IsRunning returns true if the controller is running
func (pc *PacketCaptureController) IsRunning() bool {
return pc.baseController.stopCh != nil
}
// IsPacketMode returns true (always in packet mode for this controller)
func (pc *PacketCaptureController) IsPacketMode() bool {
return true
}

View File

@@ -21,7 +21,6 @@ import (
"strings"
"sync"
"sync/atomic"
"syscall"
"time"
"github.com/ameshkov/dnsstamps"
@@ -556,24 +555,7 @@ func (uc *UpstreamConfig) newDOHTransport(addrs []string) *http.Transport {
transport.DialContext = func(ctx context.Context, network, addr string) (net.Conn, error) {
_, port, _ := net.SplitHostPort(addr)
if uc.BootstrapIP != "" {
// Create custom dialer with socket protection - matches working example pattern
dialer := &net.Dialer{
Timeout: dialerTimeout,
KeepAlive: dialerTimeout,
}
// Access underlying socket fd before connecting to it
dialer.Control = func(network, address string, c syscall.RawConn) error {
return c.Control(func(fd uintptr) {
Log(ctx, ProxyLogger.Load().Debug(), "Received DoH socket fd %d for %s", fd, address)
i := int(fd)
// Protect socket from VPN routing
if err := ProtectSocket(i); err != nil {
Log(ctx, ProxyLogger.Load().Warn(), "Failed to protect DoH socket fd=%d: %v", i, err)
} else {
Log(ctx, ProxyLogger.Load().Debug(), "Protected DoH socket fd=%d", i)
}
})
}
dialer := net.Dialer{Timeout: dialerTimeout, KeepAlive: dialerTimeout}
addr := net.JoinHostPort(uc.BootstrapIP, port)
Log(ctx, ProxyLogger.Load().Debug(), "sending doh request to: %s", addr)
return dialer.DialContext(ctx, network, addr)
@@ -589,21 +571,6 @@ func (uc *UpstreamConfig) newDOHTransport(addrs []string) *http.Transport {
if err != nil {
return nil, err
}
// Protect DoH socket from VPN routing
if tcpConn, ok := conn.(*net.TCPConn); ok {
if rawConn, err := tcpConn.SyscallConn(); err == nil {
rawConn.Control(func(fd uintptr) {
i := int(fd)
if err := ProtectSocket(i); err != nil {
Log(ctx, ProxyLogger.Load().Warn(), "Failed to protect DoH socket fd=%d: %v", i, err)
} else {
Log(ctx, ProxyLogger.Load().Debug(), "Protected DoH socket fd=%d", i)
}
})
}
}
Log(ctx, ProxyLogger.Load().Debug(), "sending doh request to: %s", conn.RemoteAddr())
return conn, nil
}

29
go.mod
View File

@@ -1,11 +1,11 @@
module github.com/Control-D-Inc/ctrld
go 1.25.5
go 1.24
require (
github.com/Masterminds/semver/v3 v3.2.1
github.com/ameshkov/dnsstamps v1.0.3
github.com/coreos/go-systemd/v22 v22.6.0
github.com/coreos/go-systemd/v22 v22.5.0
github.com/cuonglm/osinfo v0.0.0-20230921071424-e0e1b1e0bbbf
github.com/docker/go-units v0.5.0
github.com/frankban/quicktest v1.14.6
@@ -27,18 +27,17 @@ require (
github.com/prometheus/client_golang v1.19.1
github.com/prometheus/client_model v0.5.0
github.com/prometheus/prom2json v1.3.3
github.com/quic-go/quic-go v0.54.0
github.com/quic-go/quic-go v0.56.0
github.com/rs/zerolog v1.28.0
github.com/spf13/cobra v1.8.1
github.com/spf13/pflag v1.0.5
github.com/spf13/viper v1.16.0
github.com/stretchr/testify v1.9.0
github.com/vishvananda/netlink v1.2.1-beta.2
golang.org/x/net v0.52.0
golang.org/x/sync v0.20.0
golang.org/x/sys v0.42.0
golang.org/x/net v0.43.0
golang.org/x/sync v0.16.0
golang.org/x/sys v0.35.0
golang.zx2c4.com/wireguard/windows v0.5.3
gvisor.dev/gvisor v0.0.0-20240722211153-64c016c92987
tailscale.com v1.74.0
)
@@ -54,8 +53,7 @@ require (
github.com/go-playground/locales v0.14.0 // indirect
github.com/go-playground/universal-translator v0.18.0 // indirect
github.com/golang/protobuf v1.5.4 // indirect
github.com/google/btree v1.1.2 // indirect
github.com/google/go-cmp v0.7.0 // indirect
github.com/google/go-cmp v0.6.0 // indirect
github.com/google/uuid v1.6.0 // indirect
github.com/hashicorp/hcl v1.0.0 // indirect
github.com/inconshreveable/mousetrap v1.1.0 // indirect
@@ -86,17 +84,14 @@ require (
github.com/subosito/gotenv v1.4.2 // indirect
github.com/u-root/uio v0.0.0-20240118234441-a3c409a6018e // indirect
github.com/vishvananda/netns v0.0.4 // indirect
go.uber.org/mock v0.5.0 // indirect
go4.org/mem v0.0.0-20220726221520-4f986261bf13 // indirect
go4.org/netipx v0.0.0-20231129151722-fdeea329fbba // indirect
golang.org/x/crypto v0.49.0 // indirect
golang.org/x/crypto v0.41.0 // indirect
golang.org/x/exp v0.0.0-20240506185415-9bf2ced13842 // indirect
golang.org/x/mobile v0.0.0-20260312152759-81488f6aeb60 // indirect
golang.org/x/mod v0.34.0 // indirect
golang.org/x/text v0.35.0 // indirect
golang.org/x/time v0.12.0 // indirect
golang.org/x/tools v0.43.0 // indirect
google.golang.org/protobuf v1.36.8 // indirect
golang.org/x/mod v0.27.0 // indirect
golang.org/x/text v0.28.0 // indirect
golang.org/x/tools v0.36.0 // indirect
google.golang.org/protobuf v1.33.0 // indirect
gopkg.in/ini.v1 v1.67.0 // indirect
gopkg.in/yaml.v3 v3.0.1 // indirect
)

53
go.sum
View File

@@ -62,9 +62,8 @@ github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDk
github.com/cncf/udpa/go v0.0.0-20191209042840-269d4d468f6f/go.mod h1:M8M6+tZqaGXZJjfX53e64911xZQV5JYwmTeXPW+k8Sc=
github.com/cncf/udpa/go v0.0.0-20200629203442-efcf912fb354/go.mod h1:WmhPx2Nbnhtbo57+VJT5O0JRkEi1Wbu0z5j0R8u5Hbk=
github.com/cncf/udpa/go v0.0.0-20201120205902-5459f2c99403/go.mod h1:WmhPx2Nbnhtbo57+VJT5O0JRkEi1Wbu0z5j0R8u5Hbk=
github.com/coreos/go-systemd/v22 v22.5.0 h1:RrqgGjYQKalulkV8NGVIfkXQf6YYmOyiJKk8iXXhfZs=
github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
github.com/coreos/go-systemd/v22 v22.6.0 h1:aGVa/v8B7hpb0TKl0MWoAavPDmHvobFe5R5zn0bCJWo=
github.com/coreos/go-systemd/v22 v22.6.0/go.mod h1:iG+pp635Fo7ZmV/j14KUcmEyWF+0X7Lua8rrTWzYgWU=
github.com/cpuguy83/go-md2man/v2 v2.0.4/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
github.com/cuonglm/osinfo v0.0.0-20230921071424-e0e1b1e0bbbf h1:40DHYsri+d1bnroFDU2FQAeq68f3kAlOzlQ93kCf26Q=
@@ -134,8 +133,6 @@ github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek
github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
github.com/google/btree v0.0.0-20180813153112-4030bb1f1f0c/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
github.com/google/btree v1.0.0/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
github.com/google/btree v1.1.2 h1:xf4v41cLI2Z6FxbKm+8Bu+m8ifhj15JuZ9sa0jZCMUU=
github.com/google/btree v1.1.2/go.mod h1:qOPhT0dTNdNzV6Z/lhRX0YXUafgPLFUh+gZMl761Gm4=
github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
@@ -146,8 +143,8 @@ github.com/google/go-cmp v0.5.1/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/
github.com/google/go-cmp v0.5.2/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
github.com/google/go-cmp v0.5.4/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
github.com/google/martian v2.1.0+incompatible/go.mod h1:9I4somxYTbIHy5NJKHRl3wXiIaQGbYVAs8BPL6v8lEs=
github.com/google/martian/v3 v3.0.0/go.mod h1:y5Zk1BBys9G+gd6Jrk0W3cC1+ELVxBWuIGO+w/tUAp0=
github.com/google/martian/v3 v3.1.0/go.mod h1:y5Zk1BBys9G+gd6Jrk0W3cC1+ELVxBWuIGO+w/tUAp0=
@@ -264,8 +261,8 @@ github.com/prometheus/prom2json v1.3.3 h1:IYfSMiZ7sSOfliBoo89PcufjWO4eAR0gznGcET
github.com/prometheus/prom2json v1.3.3/go.mod h1:Pv4yIPktEkK7btWsrUTWDDDrnpUrAELaOCj+oFwlgmc=
github.com/quic-go/qpack v0.5.1 h1:giqksBPnT/HDtZ6VhtFKgoLOWmlyo9Ei6u9PqzIMbhI=
github.com/quic-go/qpack v0.5.1/go.mod h1:+PC4XFrEskIVkcLzpEkbLqq1uCoxPhQuvK5rH1ZgaEg=
github.com/quic-go/quic-go v0.54.0 h1:6s1YB9QotYI6Ospeiguknbp2Znb/jZYjZLRXn9kMQBg=
github.com/quic-go/quic-go v0.54.0/go.mod h1:e68ZEaCdyviluZmy44P6Iey98v/Wfz6HCjQEm+l8zTY=
github.com/quic-go/quic-go v0.56.0 h1:q/TW+OLismmXAehgFLczhCDTYB3bFmua4D9lsNBWxvY=
github.com/quic-go/quic-go v0.56.0/go.mod h1:9gx5KsFQtw2oZ6GZTyh+7YEvOxWCL9WZAepnHxgAo6c=
github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
github.com/rivo/uniseg v0.4.4 h1:8TfxU8dW6PdqD27gjM8MVNuicgxIjxpm4K7x4jp8sis=
github.com/rivo/uniseg v0.4.4/go.mod h1:FN3SvrM+Zdj16jyLfmOkMNblXMcoc8DfTHruCPUcx88=
@@ -323,8 +320,8 @@ go.opencensus.io v0.22.2/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
go.opencensus.io v0.22.3/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
go.opencensus.io v0.22.4/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
go.opencensus.io v0.22.5/go.mod h1:5pWMHQbX5EPX2/62yrJeAkowc+lfs/XD7Uxpq3pI6kk=
go.uber.org/mock v0.5.0 h1:KAMbZvZPyBPWgD14IrIQ38QCyjwpvVVV6K/bHl1IwQU=
go.uber.org/mock v0.5.0/go.mod h1:ge71pBPLYDk7QIi1LupWxdAykm7KIEFchiOqd6z7qMM=
go.uber.org/mock v0.5.2 h1:LbtPTcP8A5k9WPXj54PPPbjcI4Y6lhyOZXn+VS7wNko=
go.uber.org/mock v0.5.2/go.mod h1:wLlUxC2vVTPTaE3UD51E0BGOAElKrILxhVSDYQLld5o=
go4.org/mem v0.0.0-20220726221520-4f986261bf13 h1:CbZeCBZ0aZj8EfVgnqQcYZgf0lpZ3H9rmp5nkDTAst8=
go4.org/mem v0.0.0-20220726221520-4f986261bf13/go.mod h1:reUoABIJ9ikfM5sgtSF3Wushcza7+WeD01VB9Lirh3g=
go4.org/netipx v0.0.0-20231129151722-fdeea329fbba h1:0b9z3AuHCjxk0x/opv64kcgZLBseWJUpBw5I82+2U4M=
@@ -339,8 +336,8 @@ golang.org/x/crypto v0.0.0-20210421170649-83a5a9bb288b/go.mod h1:T9bdIzuCu7OtxOm
golang.org/x/crypto v0.0.0-20211209193657-4570a0811e8b/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
golang.org/x/crypto v0.0.0-20211215153901-e495a2d5b3d3/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
golang.org/x/crypto v0.0.0-20220722155217-630584e8d5aa/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
golang.org/x/crypto v0.49.0 h1:+Ng2ULVvLHnJ/ZFEq4KdcDd/cfjrrjjNSXNzxg0Y4U4=
golang.org/x/crypto v0.49.0/go.mod h1:ErX4dUh2UM+CFYiXZRTcMpEcN8b/1gxEuv3nODoYtCA=
golang.org/x/crypto v0.41.0 h1:WKYxWedPGCTVVl5+WHSSrOBT0O8lx32+zxmHxijgXp4=
golang.org/x/crypto v0.41.0/go.mod h1:pO5AFd7FA68rFak7rOAGVuygIISepHftHnr8dr6+sUc=
golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
golang.org/x/exp v0.0.0-20190306152737-a1d7652674e8/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
golang.org/x/exp v0.0.0-20190510132918-efd6b22b2522/go.mod h1:ZjyILWgesfNpC6sMxTJOJm9Kp84zZh5NQWvqDGG3Qr8=
@@ -368,8 +365,6 @@ golang.org/x/lint v0.0.0-20200302205851-738671d3881b/go.mod h1:3xt1FjdF8hUf6vQPI
golang.org/x/lint v0.0.0-20201208152925-83fdc39ff7b5/go.mod h1:3xt1FjdF8hUf6vQPIChWIBhFzV8gjjsPE/fR3IyQdNY=
golang.org/x/mobile v0.0.0-20190312151609-d3739f865fa6/go.mod h1:z+o9i4GpDbdi3rU15maQ/Ox0txvL9dWGYEHz965HBQE=
golang.org/x/mobile v0.0.0-20190719004257-d2bd2a29d028/go.mod h1:E/iHnbuqvinMTCcRqshq8CkpyQDoeVncDDYHnLhea+o=
golang.org/x/mobile v0.0.0-20260312152759-81488f6aeb60 h1:MOzyaj0wu2xneBkzkg9LHNYjDBB4W5vP043A2SYQRPA=
golang.org/x/mobile v0.0.0-20260312152759-81488f6aeb60/go.mod h1:th6VJvzjMbrYF8SduQY5rpD0HG0GleGxjadkqSxFs3k=
golang.org/x/mod v0.0.0-20190513183733-4bf6d317e70e/go.mod h1:mXi4GBBbnImb6dmsKGUJ2LatrhH/nqhxcFungHvyanc=
golang.org/x/mod v0.1.0/go.mod h1:0QHyrYULN0/3qlju5TqG8bIK38QM8yzMo5ekMj3DlcY=
golang.org/x/mod v0.1.1-0.20191105210325-c90efee705ee/go.mod h1:QqPTAvyqsEbceGzBzNggFXnrqF1CaUcvgkdR5Ot7KZg=
@@ -378,8 +373,8 @@ golang.org/x/mod v0.2.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
golang.org/x/mod v0.4.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
golang.org/x/mod v0.4.1/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
golang.org/x/mod v0.34.0 h1:xIHgNUUnW6sYkcM5Jleh05DvLOtwc6RitGHbDk4akRI=
golang.org/x/mod v0.34.0/go.mod h1:ykgH52iCZe79kzLLMhyCUzhMci+nQj+0XkbXpNYtVjY=
golang.org/x/mod v0.27.0 h1:kb+q2PyFnEADO2IEF935ehFUXlWiNjJWtRNgBLSfbxQ=
golang.org/x/mod v0.27.0/go.mod h1:rWI627Fq0DEoudcK+MBkNkCe0EetEaDSwJJkCcjpazc=
golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
golang.org/x/net v0.0.0-20190108225652-1e06a53dbb7e/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
@@ -412,8 +407,8 @@ golang.org/x/net v0.0.0-20201209123823-ac852fbbde11/go.mod h1:m0MpNAwzfU5UDzcl9v
golang.org/x/net v0.0.0-20201224014010-6772e930b67b/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
golang.org/x/net v0.52.0 h1:He/TN1l0e4mmR3QqHMT2Xab3Aj3L9qjbhRm78/6jrW0=
golang.org/x/net v0.52.0/go.mod h1:R1MAz7uMZxVMualyPXb+VaqGSa3LIaUqk0eEt3w36Sw=
golang.org/x/net v0.43.0 h1:lat02VYK2j4aLzMzecihNvTlJNQUq316m2Mr9rnM6YE=
golang.org/x/net v0.43.0/go.mod h1:vhO1fvI4dGsIjh73sWfUVjj3N7CA9WkKJNQm2svM6Jg=
golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
golang.org/x/oauth2 v0.0.0-20190604053449-0f29369cfe45/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
@@ -433,8 +428,8 @@ golang.org/x/sync v0.0.0-20200317015054-43a5402ce75a/go.mod h1:RxMgew5VJxzue5/jJ
golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
golang.org/x/sync v0.0.0-20201207232520-09787c993a3a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
golang.org/x/sync v0.20.0 h1:e0PTpb7pjO8GAtTs2dQ6jYa5BWYlMuX047Dco/pItO4=
golang.org/x/sync v0.20.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
golang.org/x/sync v0.16.0 h1:ycBJEhp9p4vXvUZNszeOq0kGTPghopOL8q0fq3vstxw=
golang.org/x/sync v0.16.0/go.mod h1:1dzgHSNfp02xaA81J2MS99Qcpr2w7fw1gpm99rleRqA=
golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
golang.org/x/sys v0.0.0-20190312061237-fead79001313/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -483,8 +478,8 @@ golang.org/x/sys v0.1.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.4.1-0.20230131160137-e7d7f63158de/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.42.0 h1:omrd2nAlyT5ESRdCLYdm3+fMfNFE/+Rf4bDIQImRJeo=
golang.org/x/sys v0.42.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
golang.org/x/sys v0.35.0 h1:vz1N37gP5bs89s7He8XuIYXpyY0+QlsKmzipCbUtyxI=
golang.org/x/sys v0.35.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
golang.org/x/term v0.0.0-20201117132131-f5c789dd3221/go.mod h1:Nr5EML6q2oocZ2LXRh80K7BxOlk5/8JxuGnuhpl+muw=
golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
@@ -495,8 +490,8 @@ golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
golang.org/x/text v0.3.4/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
golang.org/x/text v0.35.0 h1:JOVx6vVDFokkpaq1AEptVzLTpDe9KGpj5tR4/X+ybL8=
golang.org/x/text v0.35.0/go.mod h1:khi/HExzZJ2pGnjenulevKNX1W67CUy0AsXcNubPGCA=
golang.org/x/text v0.28.0 h1:rhazDwis8INMIwQ4tpjLDzUhx6RlXqZNPEM0huQojng=
golang.org/x/text v0.28.0/go.mod h1:U8nCwOR8jO/marOQ0QbDiOngZVEBB7MAiitBuMjXiNU=
golang.org/x/time v0.0.0-20181108054448-85acf8d2951c/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
golang.org/x/time v0.0.0-20190308202827-9d24e82272b4/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
golang.org/x/time v0.0.0-20191024005414-555d28b269f0/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
@@ -549,8 +544,8 @@ golang.org/x/tools v0.0.0-20201208233053-a543418bbed2/go.mod h1:emZCQorbCU4vsT4f
golang.org/x/tools v0.0.0-20210105154028-b0ab187a4818/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
golang.org/x/tools v0.0.0-20210108195828-e2f9c7f1fc8e/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
golang.org/x/tools v0.1.0/go.mod h1:xkSsbof2nBLbhDlRMhhhyNLN/zl3eTqcnHD5viDpcZ0=
golang.org/x/tools v0.43.0 h1:12BdW9CeB3Z+J/I/wj34VMl8X+fEXBxVR90JeMX5E7s=
golang.org/x/tools v0.43.0/go.mod h1:uHkMso649BX2cZK6+RpuIPXS3ho2hZo4FVwfoy1vIk0=
golang.org/x/tools v0.36.0 h1:kWS0uv/zsvHEle1LbV5LE8QujrxB3wfQyxHfhOk0Qkg=
golang.org/x/tools v0.36.0/go.mod h1:WBDiHKJK8YgLHlcQPYQzNCkUxUypCaa5ZegCVutKm+s=
golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
@@ -645,8 +640,8 @@ google.golang.org/protobuf v1.23.0/go.mod h1:EGpADcykh3NcUnDUJcl1+ZksZNG86OlYog2
google.golang.org/protobuf v1.23.1-0.20200526195155-81db48ad09cc/go.mod h1:EGpADcykh3NcUnDUJcl1+ZksZNG86OlYog2l/sGQquU=
google.golang.org/protobuf v1.24.0/go.mod h1:r/3tXBNzIEhYS9I1OUVjXDlt8tc493IdKGjtUeSXeh4=
google.golang.org/protobuf v1.25.0/go.mod h1:9JNX74DMeImyA3h4bdi1ymwjUzf21/xIlbajtzgsN7c=
google.golang.org/protobuf v1.36.8 h1:xHScyCOEuuwZEc6UtSOvPbAT4zRh0xcNRYekJwfqyMc=
google.golang.org/protobuf v1.36.8/go.mod h1:fuxRtAxBytpl4zzqUh6/eyUujkJdNiuEkXntxiD/uRU=
google.golang.org/protobuf v1.33.0 h1:uNO2rsAINq/JlFpSdYEKIZ0uKD/R9cpdv0T+yoGwGmI=
google.golang.org/protobuf v1.33.0/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
@@ -659,8 +654,6 @@ gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C
gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
gvisor.dev/gvisor v0.0.0-20240722211153-64c016c92987 h1:TU8z2Lh3Bbq77w0t1eG8yRlLcNHzZu3x6mhoH2Mk0c8=
gvisor.dev/gvisor v0.0.0-20240722211153-64c016c92987/go.mod h1:sxc3Uvk/vHcd3tj7/DHVBoR5wvWT/MmRq2pj7HRJnwU=
honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
honnef.co/go/tools v0.0.0-20190106161140-3f1c8253044a/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
honnef.co/go/tools v0.0.0-20190418001031-e561f6794a2a/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=

View File

@@ -13,11 +13,11 @@ import (
"os"
"runtime"
"strings"
"syscall"
"time"
"github.com/Control-D-Inc/ctrld"
"github.com/Control-D-Inc/ctrld/internal/certs"
ctrldnet "github.com/Control-D-Inc/ctrld/internal/net"
"github.com/Control-D-Inc/ctrld/internal/router"
"github.com/Control-D-Inc/ctrld/internal/router/ddwrt"
)
@@ -244,38 +244,8 @@ func apiTransport(cdDev bool) *http.Transport {
}
dial := func(ctx context.Context, network string, addrs []string) (net.Conn, error) {
// Create custom dialer with socket protection - matches working example pattern
baseDialer := &net.Dialer{
Timeout: 10 * time.Second,
KeepAlive: 30 * time.Second,
}
// Access underlying socket fd before connecting to it
baseDialer.Control = func(network, address string, c syscall.RawConn) error {
return c.Control(func(fd uintptr) {
ctrld.ProxyLogger.Load().Debug().Msgf("Received API socket fd %d for %s", fd, address)
i := int(fd)
// Protect socket from VPN routing
if err := ctrld.ProtectSocket(i); err != nil {
ctrld.ProxyLogger.Load().Warn().Err(err).Msgf("Failed to protect API socket fd=%d", i)
} else {
ctrld.ProxyLogger.Load().Debug().Msgf("Protected API socket fd=%d", i)
}
})
}
// Try each address with the protected dialer
var lastErr error
for _, addr := range addrs {
ctrld.ProxyLogger.Load().Debug().Msgf("dialing to %s", addr)
conn, err := baseDialer.DialContext(ctx, network, addr)
if err == nil {
return conn, nil
}
lastErr = err
ctrld.ProxyLogger.Load().Debug().Err(err).Msgf("failed to dial %s", addr)
}
return nil, lastErr
d := &ctrldnet.ParallelDialer{}
return d.DialContext(ctx, network, addrs, ctrld.ProxyLogger.Load())
}
_, port, _ := net.SplitHostPort(addr)

View File

@@ -62,29 +62,8 @@ var (
or *osResolver
defaultLocalIPv4 atomic.Value // holds net.IP (IPv4)
defaultLocalIPv6 atomic.Value // holds net.IP (IPv6)
// socketProtector is a global function that can be set by mobile apps to protect
// sockets from being routed through the VPN. This prevents routing loops.
socketProtector atomic.Value // holds func(int) error
)
// SetSocketProtector sets the global socket protection function.
// This should be called by mobile VPN apps to prevent routing loops.
func SetSocketProtector(protectFunc func(int) error) {
socketProtector.Store(protectFunc)
}
// ProtectSocket protects a socket using the globally set protector.
// Returns nil if no protector is set.
func ProtectSocket(fd int) error {
if v := socketProtector.Load(); v != nil {
if protectFunc, ok := v.(func(int) error); ok {
return protectFunc(fd)
}
}
return nil
}
func newLocalResolver() Resolver {
var nss []string
for _, addr := range Rfc1918Addresses() {