Merge branch 'main' of github.com:fosrl/gerbil

Bump golang.org/x/crypto from 0.42.0 to 0.43.0 in the prod-minor-updates group

.dockerignore

@@ -6,4 +6,5 @@ README.md
 Makefile
 public/
 LICENSE
-CONTRIBUTING.md
+CONTRIBUTING.md
+.git

.github/DISCUSSION_TEMPLATE/feature-requests.yml

@@ -0,0 +1,47 @@
+body:
+    - type: textarea
+      attributes:
+          label: Summary
+          description: A clear and concise summary of the requested feature.
+      validations:
+          required: true
+
+    - type: textarea
+      attributes:
+          label: Motivation
+          description: |
+              Why is this feature important?
+              Explain the problem this feature would solve or what use case it would enable.
+      validations:
+          required: true
+
+    - type: textarea
+      attributes:
+          label: Proposed Solution
+          description: |
+              How would you like to see this feature implemented?
+              Provide as much detail as possible about the desired behavior, configuration, or changes.
+      validations:
+          required: true
+
+    - type: textarea
+      attributes:
+          label: Alternatives Considered
+          description: Describe any alternative solutions or workarounds you've thought about.
+      validations:
+          required: false
+
+    - type: textarea
+      attributes:
+          label: Additional Context
+          description: Add any other context, mockups, or screenshots about the feature request here.
+      validations:
+          required: false
+
+    - type: markdown
+      attributes:
+          value: |
+              Before submitting, please:
+              - Check if there is an existing issue for this feature.
+              - Clearly explain the benefit and use case.
+              - Be as specific as possible to help contributors evaluate and implement.

.github/ISSUE_TEMPLATE/1.bug_report.yml

@@ -0,0 +1,51 @@
+name: Bug Report
+description: Create a bug report
+labels: []
+body:
+    - type: textarea
+      attributes:
+          label: Describe the Bug
+          description: A clear and concise description of what the bug is.
+      validations:
+          required: true
+
+    - type: textarea
+      attributes:
+          label: Environment
+          description: Please fill out the relevant details below for your environment.
+          value: |
+              - OS Type & Version: (e.g., Ubuntu 22.04)
+              - Pangolin Version:
+              - Gerbil Version:
+              - Traefik Version:
+              - Newt Version:
+              - Olm Version: (if applicable)
+      validations:
+          required: true
+
+    - type: textarea
+      attributes:
+          label: To Reproduce
+          description: |
+              Steps to reproduce the behavior, please provide a clear description of how to reproduce the issue, based on the linked minimal reproduction. Screenshots can be provided in the issue body below.
+
+              If using code blocks, make sure syntax highlighting is correct and double-check that the rendered preview is not broken.
+      validations:
+          required: true
+
+    - type: textarea
+      attributes:
+          label: Expected Behavior
+          description: A clear and concise description of what you expected to happen.
+      validations:
+          required: true
+
+    - type: markdown
+      attributes:
+          value: |
+              Before posting the issue go through the steps you've written down to make sure the steps provided are detailed and clear.
+
+    - type: markdown
+      attributes:
+          value: |
+              Contributors should be able to follow the steps provided in order to reproduce the bug.

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,8 @@
+blank_issues_enabled: false
+contact_links:
+    - name: Need help or have questions?
+      url: https://github.com/orgs/fosrl/discussions
+      about: Ask questions, get help, and discuss with other community members
+    - name: Request a Feature
+      url: https://github.com/orgs/fosrl/discussions/new?category=feature-requests
+      about: Feature requests should be opened as discussions so others can upvote and comment

.github/dependabot.yml

@@ -0,0 +1,40 @@
+version: 2
+updates:
+  - package-ecosystem: "gomod"
+    directory: "/"
+    schedule:
+      interval: "daily"
+    groups:
+      dev-patch-updates:
+        dependency-type: "development"
+        update-types:
+          - "patch"
+      dev-minor-updates:
+        dependency-type: "development"
+        update-types:
+          - "minor"
+      prod-patch-updates:
+        dependency-type: "production"
+        update-types:
+          - "patch"
+      prod-minor-updates:
+        dependency-type: "production"
+        update-types:
+          - "minor"
+
+  - package-ecosystem: "docker"
+    directory: "/"
+    schedule:
+      interval: "daily"
+    groups:
+      patch-updates:
+        update-types:
+          - "patch"
+      minor-updates:
+        update-types:
+          - "minor"
+
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"

.github/workflows/cicd.yml

@@ -0,0 +1,52 @@
+name: CI/CD Pipeline
+
+on:
+    push:
+        tags:
+            - "*"
+
+jobs:
+    release:
+        name: Build and Release
+        runs-on: ubuntu-latest
+
+        steps:
+            - name: Checkout code
+              uses: actions/checkout@v5
+
+            - name: Set up QEMU
+              uses: docker/setup-qemu-action@v3
+
+            - name: Set up Docker Buildx
+              uses: docker/setup-buildx-action@v3
+
+            - name: Log in to Docker Hub
+              uses: docker/login-action@v3
+              with:
+                  username: ${{ secrets.DOCKER_HUB_USERNAME }}
+                  password: ${{ secrets.DOCKER_HUB_ACCESS_TOKEN }}
+
+            - name: Extract tag name
+              id: get-tag
+              run: echo "TAG=${GITHUB_REF#refs/tags/}" >> $GITHUB_ENV
+
+            - name: Install Go
+              uses: actions/setup-go@v6
+              with:
+                  go-version: 1.25
+
+            - name: Build and push Docker images
+              run: |
+                  TAG=${{ env.TAG }}
+                  make docker-build-release tag=$TAG
+
+            - name: Build binaries
+              run: |
+                  make go-build-release
+
+            - name: Upload artifacts from /bin
+              uses: actions/upload-artifact@v4
+              with:
+                  name: binaries
+                  path: bin/
+

.github/workflows/test.yml

@@ -0,0 +1,28 @@
+name: Run Tests
+
+on:
+  pull_request:
+    branches:
+      - main
+      - dev
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v5
+
+      - name: Set up Go
+        uses: actions/setup-go@v6
+        with:
+          go-version: '1.25'
+
+      - name: Build go
+        run: go build
+
+      - name: Build Docker image
+        run: make build
+
+      - name: Build binaries
+        run: make go-build-release

.go-version

@@ -0,0 +1 @@
+1.25

Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.23.1-alpine AS builder
+FROM golang:1.25-alpine AS builder
 
 # Set the working directory inside the container
 WORKDIR /app
@@ -16,18 +16,13 @@ COPY . .
 RUN CGO_ENABLED=0 GOOS=linux go build -o /gerbil
 
 # Start a new stage from scratch
-FROM ubuntu:22.04 AS runner
+FROM alpine:3.22 AS runner
 
-RUN apt-get update && apt-get install -y iptables iproute2 && rm -rf /var/lib/apt/lists/*
+RUN apk add --no-cache iptables iproute2
 
-# Copy the pre-built binary file from the previous stage and the entrypoint script
 COPY --from=builder /gerbil /usr/local/bin/
 COPY entrypoint.sh /
 
 RUN chmod +x /entrypoint.sh
-
-# Copy the entrypoint script
 ENTRYPOINT ["/entrypoint.sh"]
-
-# Command to run the executable
 CMD ["gerbil"]

Makefile

@@ -1,6 +1,14 @@
 
 all: build push
 
+docker-build-release:
+	@if [ -z "$(tag)" ]; then \
+		echo "Error: tag is required. Usage: make docker-build-release tag=<tag>"; \
+		exit 1; \
+	fi
+	docker buildx build --platform linux/arm64,linux/amd64 -t fosrl/gerbil:latest -f Dockerfile --push .
+	docker buildx build --platform linux/arm64,linux/amd64 -t fosrl/gerbil:$(tag) -f Dockerfile --push .
+
 build:
 	docker build -t fosrl/gerbil:latest .
 
@@ -13,9 +21,9 @@ test:
 local: 
 	 CGO_ENABLED=0 GOOS=linux go build -o gerbil
 
-release:
+go-build-release:
 	CGO_ENABLED=0 GOOS=linux GOARCH=arm64 go build -o bin/gerbil_linux_arm64
 	CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -o bin/gerbil_linux_amd64
 
 clean:
-	rm gerbil
+	rm gerbil

README.md

@@ -4,17 +4,10 @@ Gerbil is a simple [WireGuard](https://www.wireguard.com/) interface management
 
 ### Installation and Documentation
 
-Gerbil can be used standalone with your own API, a static JSON file, or with Pangolin and Newt as part of the larger system. See documentation below:
+Gerbil works with Pangolin, Newt, and Olm as part of the larger system. See documentation below:
 
--   [Installation Instructions](https://docs.fossorial.io)
 -   [Full Documentation](https://docs.fossorial.io)
 
-## Preview
-
-<img src="public/screenshots/preview.png" alt="Preview"/>
-
-_Sample output of a Gerbil container connected to Pangolin and terminating various peers._
-
 ## Key Functions
 
 ### Setup WireGuard
@@ -27,7 +20,25 @@ Gerbil will create the peers defined in the config on the WireGuard interface. T
 
 ### Report Bandwidth
 
-Bytes transmitted in and out of each peer are collected every 10 seconds, and incremental usage is reported via the "reportBandwidthTo" endpoint. This can be used to track data usage of each peer on the remote server.
+Bytes transmitted in and out of each peer are collected every 10 seconds, and incremental usage is reported via the api endpoint. This can be used to track data usage of each peer on the remote server.
+
+### Handle client relaying
+
+Gerbil listens on port 21820 for incoming UDP hole punch packets to orchestrate NAT hole punching between olm and newt clients. Additionally, it handles relaying data through the gerbil server down to the newt. This is accomplished by scanning each packet for headers and handling them appropriately.
+
+### SNI Proxy
+
+Gerbil includes an SNI (Server Name Indication) proxy that enables intelligent routing of HTTPS traffic between Pangolin nodes. When a TLS connection comes in, the proxy extracts the hostname from the SNI extension and queries Pangolin to determine the correct routing destination. This allows seamless routing of web traffic through the WireGuard mesh network:
+
+- If the hostname is configured for local handling (via local overrides or local SNIs), traffic is routed to the local proxy
+- Otherwise, the proxy queries Pangolin's routing API to determine which node should handle the traffic
+- Supports caching of routing decisions to improve performance
+- Handles connection pooling and graceful shutdown
+- Optional PROXY protocol v1 support to preserve original client IP addresses when forwarding to downstream proxies (HAProxy, Nginx, etc.)
+
+The PROXY protocol allows downstream proxies to know the real client IP address instead of seeing the SNI proxy's IP. When enabled with `--proxy-protocol`, the SNI proxy will prepend a PROXY protocol header to each connection containing the original client's IP and port information.
+
+In single node (self hosted) Pangolin deployments this can be bypassed by using port 443:443 to route to Traefik instead of the SNI proxy at 8443.
 
 ## CLI Args
 
@@ -38,19 +49,44 @@ Bytes transmitted in and out of each peer are collected every 10 seconds, and in
 
 Note: You must use either `config` or `remoteConfig` to configure WireGuard.
 
-- `reportBandwidthTo` (optional): Remote HTTP endpoint to send peer bandwidth data
+- `reportBandwidthTo` (optional): **DEPRECATED** - Use `remoteConfig` instead. Remote HTTP endpoint to send peer bandwidth data
 - `interface` (optional): Name of the WireGuard interface created by Gerbil. Default: `wg0`
-- `listen` (optional): Port to listen on for HTTP server. Default: `3003`
-- `log-level` (optional): The log level to use. Default: INFO
+- `listen` (optional): Port to listen on for HTTP server. Default: `:3004`
+- `log-level` (optional): The log level to use (DEBUG, INFO, WARN, ERROR, FATAL). Default: `INFO`
+- `mtu` (optional): MTU of the WireGuard interface. Default: `1280`
+- `notify` (optional): URL to notify on peer changes
+- `sni-port` (optional): Port for the SNI proxy to listen on. Default: `8443`
+- `local-proxy` (optional): Address for local proxy when routing local traffic. Default: `localhost`
+- `local-proxy-port` (optional): Port for local proxy when routing local traffic. Default: `443`
+- `local-overrides` (optional): Comma-separated list of domain names that should always be routed to the local proxy
+- `proxy-protocol` (optional): Enable PROXY protocol v1 for preserving client IP addresses when forwarding to downstream proxies. Default: `false`
+
+## Environment Variables
+
+All CLI arguments can also be provided via environment variables:
+
+- `INTERFACE`: Name of the WireGuard interface
+- `CONFIG`: Path to local configuration file
+- `REMOTE_CONFIG`: URL of the remote config server
+- `LISTEN`: Address to listen on for HTTP server
+- `GENERATE_AND_SAVE_KEY_TO`: Path to save generated private key
+- `REACHABLE_AT`: Endpoint of the HTTP server to tell remote config about
+- `LOG_LEVEL`: Log level (DEBUG, INFO, WARN, ERROR, FATAL)
+- `MTU`: MTU of the WireGuard interface
+- `NOTIFY_URL`: URL to notify on peer changes
+- `SNI_PORT`: Port for the SNI proxy to listen on
+- `LOCAL_PROXY`: Address for local proxy when routing local traffic
+- `LOCAL_PROXY_PORT`: Port for local proxy when routing local traffic
+- `LOCAL_OVERRIDES`: Comma-separated list of domain names that should always be routed to the local proxy
+- `PROXY_PROTOCOL`: Enable PROXY protocol v1 for preserving client IP addresses (true/false)
 
 Example:
 
 ```bash
 ./gerbil \
---reachableAt=http://gerbil:3003 \
+--reachableAt=http://gerbil:3004 \
 --generateAndSaveKeyTo=/var/config/key \
---remoteConfig=http://pangolin:3001/api/v1/gerbil/get-config \
---reportBandwidthTo=http://pangolin:3001/api/v1/gerbil/receive-bandwidth
+--remoteConfig=http://pangolin:3001/api/v1/
 ```
 
 ```yaml
@@ -62,8 +98,7 @@ services:
     command:
       - --reachableAt=http://gerbil:3003
       - --generateAndSaveKeyTo=/var/config/key
-      - --remoteConfig=http://pangolin:3001/api/v1/gerbil/get-config
-      - --reportBandwidthTo=http://pangolin:3001/api/v1/gerbil/receive-bandwidth
+      - --remoteConfig=http://pangolin:3001/api/v1/
     volumes:
       - ./config/:/var/config
     cap_add:
@@ -71,6 +106,8 @@ services:
       - SYS_MODULE
     ports:
       - 51820:51820/udp
+      - 21820:21820/udp
+      - 443:8443/tcp  # SNI proxy port
 ```
 
 ## Build

go.mod

@@ -1,10 +1,11 @@
 module github.com/fosrl/gerbil
 
-go 1.23.1
+go 1.25
 
-toolchain go1.23.2
 require (
-	github.com/vishvananda/netlink v1.3.0
+	github.com/patrickmn/go-cache v2.1.0+incompatible
+	github.com/vishvananda/netlink v1.3.1
+	golang.org/x/crypto v0.43.0
 	golang.zx2c4.com/wireguard/wgctrl v0.0.0-20230429144221-925a1e7659e6
 )
 
@@ -14,10 +15,9 @@ require (
 	github.com/mdlayher/genetlink v1.3.2 // indirect
 	github.com/mdlayher/netlink v1.7.2 // indirect
 	github.com/mdlayher/socket v0.4.1 // indirect
-	github.com/vishvananda/netns v0.0.4 // indirect
-	golang.org/x/crypto v0.8.0 // indirect
-	golang.org/x/net v0.9.0 // indirect
+	github.com/vishvananda/netns v0.0.5 // indirect
+	golang.org/x/net v0.45.0 // indirect
 	golang.org/x/sync v0.1.0 // indirect
-	golang.org/x/sys v0.10.0 // indirect
+	golang.org/x/sys v0.37.0 // indirect
 	golang.zx2c4.com/wireguard v0.0.0-20230325221338-052af4a8072b // indirect
 )

go.sum

@@ -8,21 +8,24 @@ github.com/mdlayher/netlink v1.7.2 h1:/UtM3ofJap7Vl4QWCPDGXY8d3GIY2UGSDbK+QWmY8/
 github.com/mdlayher/netlink v1.7.2/go.mod h1:xraEF7uJbxLhc5fpHL4cPe221LI2bdttWlU+ZGLfQSw=
 github.com/mdlayher/socket v0.4.1 h1:eM9y2/jlbs1M615oshPQOHZzj6R6wMT7bX5NPiQvn2U=
 github.com/mdlayher/socket v0.4.1/go.mod h1:cAqeGjoufqdxWkD7DkpyS+wcefOtmu5OQ8KuoJGIReA=
-github.com/vishvananda/netlink v1.3.0 h1:X7l42GfcV4S6E4vHTsw48qbrV+9PVojNfIhZcwQdrZk=
-github.com/vishvananda/netlink v1.3.0/go.mod h1:i6NetklAujEcC6fK0JPjT8qSwWyO0HLn4UKG+hGqeJs=
-github.com/vishvananda/netns v0.0.4 h1:Oeaw1EM2JMxD51g9uhtC0D7erkIjgmj8+JZc26m1YX8=
-github.com/vishvananda/netns v0.0.4/go.mod h1:SpkAiCQRtJ6TvvxPnOSyH3BMl6unz3xZlaprSwhNNJM=
-golang.org/x/crypto v0.8.0 h1:pd9TJtTueMTVQXzk8E2XESSMQDj/U7OUu0PqJqPXQjQ=
-golang.org/x/crypto v0.8.0/go.mod h1:mRqEX+O9/h5TFCrQhkgjo2yKi0yYA+9ecGkdQoHrywE=
-golang.org/x/net v0.9.0 h1:aWJ/m6xSmxWBx+V0XRHTlrYrPG56jKsLdTFmsSsCzOM=
-golang.org/x/net v0.9.0/go.mod h1:d48xBJpPfHeWQsugry2m+kC02ZBRGRgulfHnEXEuWns=
+github.com/mikioh/ipaddr v0.0.0-20190404000644-d465c8ab6721 h1:RlZweED6sbSArvlE924+mUcZuXKLBHA35U7LN621Bws=
+github.com/mikioh/ipaddr v0.0.0-20190404000644-d465c8ab6721/go.mod h1:Ickgr2WtCLZ2MDGd4Gr0geeCH5HybhRJbonOgQpvSxc=
+github.com/patrickmn/go-cache v2.1.0+incompatible h1:HRMgzkcYKYpi3C8ajMPV8OFXaaRUnok+kx1WdO15EQc=
+github.com/patrickmn/go-cache v2.1.0+incompatible/go.mod h1:3Qf8kWWT7OJRJbdiICTKqZju1ZixQ/KpMGzzAfe6+WQ=
+github.com/vishvananda/netlink v1.3.1 h1:3AEMt62VKqz90r0tmNhog0r/PpWKmrEShJU0wJW6bV0=
+github.com/vishvananda/netlink v1.3.1/go.mod h1:ARtKouGSTGchR8aMwmkzC0qiNPrrWO5JS/XMVl45+b4=
+github.com/vishvananda/netns v0.0.5 h1:DfiHV+j8bA32MFM7bfEunvT8IAqQ/NzSJHtcmW5zdEY=
+github.com/vishvananda/netns v0.0.5/go.mod h1:SpkAiCQRtJ6TvvxPnOSyH3BMl6unz3xZlaprSwhNNJM=
+golang.org/x/crypto v0.43.0 h1:dduJYIi3A3KOfdGOHX8AVZ/jGiyPa3IbBozJ5kNuE04=
+golang.org/x/crypto v0.43.0/go.mod h1:BFbav4mRNlXJL4wNeejLpWxB7wMbc79PdRGhWKncxR0=
+golang.org/x/net v0.45.0 h1:RLBg5JKixCy82FtLJpeNlVM0nrSqpCRYzVU1n8kj0tM=
+golang.org/x/net v0.45.0/go.mod h1:ECOoLqd5U3Lhyeyo/QDCEVQ4sNgYsqvCZ722XogGieY=
 golang.org/x/sync v0.1.0 h1:wsuoTGHzEhffawBOhz5CYhcrV4IdKZbEyZjBMuTp12o=
 golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.2.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.7.0 h1:3jlCCIQZPdOYu1h8BkNvLz8Kgwtae2cagcG/VamtZRU=
-golang.org/x/sys v0.7.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.10.0 h1:SqMFp9UcQJZa+pmYuAKjd9xq1f0j5rLcDIk0mj4qAsA=
 golang.org/x/sys v0.10.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.37.0 h1:fdNQudmxPjkdUTPnLn5mdQv7Zwvbvpaxqs831goi9kQ=
+golang.org/x/sys v0.37.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
 golang.zx2c4.com/wireguard v0.0.0-20230325221338-052af4a8072b h1:J1CaxgLerRR5lgx3wnr6L04cJFbWoceSK9JWBdglINo=
 golang.zx2c4.com/wireguard v0.0.0-20230325221338-052af4a8072b/go.mod h1:tqur9LnfstdR9ep2LaJT4lFUl0EjlHtge+gAjmsHUG4=
 golang.zx2c4.com/wireguard/wgctrl v0.0.0-20230429144221-925a1e7659e6 h1:CawjfCvYQH2OU3/TnxLx97WDSUDRABfT18pCOYwc2GE=

main.go

@@ -10,12 +10,16 @@ import (
 	"net/http"
 	"os"
 	"os/exec"
+	"os/signal"
 	"strconv"
 	"strings"
 	"sync"
+	"syscall"
 	"time"
 
 	"github.com/fosrl/gerbil/logger"
+	"github.com/fosrl/gerbil/proxy"
+	"github.com/fosrl/gerbil/relay"
 	"github.com/vishvananda/netlink"
 	"golang.zx2c4.com/wireguard/wgctrl"
 	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
@@ -27,6 +31,10 @@ var (
 	mtuInt        int
 	lastReadings  = make(map[string]PeerReading)
 	mu            sync.Mutex
+	wgMu          sync.Mutex // Protects WireGuard operations
+	notifyURL     string
+	proxyRelay    *relay.UDPProxyServer
+	proxySNI      *proxy.SNIProxy
 )
 
 type WgConfig struct {
@@ -57,6 +65,31 @@ var (
 	wgClient *wgctrl.Client
 )
 
+// Add this new type at the top with other type definitions
+type ClientEndpoint struct {
+	OlmID     string `json:"olmId"`
+	NewtID    string `json:"newtId"`
+	IP        string `json:"ip"`
+	Port      int    `json:"port"`
+	Timestamp int64  `json:"timestamp"`
+}
+
+type HolePunchMessage struct {
+	OlmID  string `json:"olmId"`
+	NewtID string `json:"newtId"`
+}
+
+type ProxyMappingUpdate struct {
+	OldDestination relay.PeerDestination `json:"oldDestination"`
+	NewDestination relay.PeerDestination `json:"newDestination"`
+}
+
+type UpdateDestinationsRequest struct {
+	SourceIP     string                  `json:"sourceIp"`
+	SourcePort   int                     `json:"sourcePort"`
+	Destinations []relay.PeerDestination `json:"destinations"`
+}
+
 func parseLogLevel(level string) logger.LogLevel {
 	switch strings.ToUpper(level) {
 	case "DEBUG":
@@ -80,22 +113,34 @@ func main() {
 		wgconfig             WgConfig
 		configFile           string
 		remoteConfigURL      string
-		reportBandwidthTo    string
 		generateAndSaveKeyTo string
 		reachableAt          string
 		logLevel             string
 		mtu                  string
+		sniProxyPort         int
+		localProxyAddr       string
+		localProxyPort       int
+		localOverridesStr    string
+		trustedUpstreamsStr  string
+		proxyProtocol        bool
 	)
 
 	interfaceName = os.Getenv("INTERFACE")
 	configFile = os.Getenv("CONFIG")
 	remoteConfigURL = os.Getenv("REMOTE_CONFIG")
 	listenAddr = os.Getenv("LISTEN")
-	reportBandwidthTo = os.Getenv("REPORT_BANDWIDTH_TO")
 	generateAndSaveKeyTo = os.Getenv("GENERATE_AND_SAVE_KEY_TO")
 	reachableAt = os.Getenv("REACHABLE_AT")
 	logLevel = os.Getenv("LOG_LEVEL")
 	mtu = os.Getenv("MTU")
+	notifyURL = os.Getenv("NOTIFY_URL")
+
+	sniProxyPortStr := os.Getenv("SNI_PORT")
+	localProxyAddr = os.Getenv("LOCAL_PROXY")
+	localProxyPortStr := os.Getenv("LOCAL_PROXY_PORT")
+	localOverridesStr = os.Getenv("LOCAL_OVERRIDES")
+	trustedUpstreamsStr = os.Getenv("TRUSTED_UPSTREAMS")
+	proxyProtocolStr := os.Getenv("PROXY_PROTOCOL")
 
 	if interfaceName == "" {
 		flag.StringVar(&interfaceName, "interface", "wg0", "Name of the WireGuard interface")
@@ -104,31 +149,90 @@ func main() {
 		flag.StringVar(&configFile, "config", "", "Path to local configuration file")
 	}
 	if remoteConfigURL == "" {
-		flag.StringVar(&remoteConfigURL, "remoteConfig", "", "URL to fetch remote configuration")
+		flag.StringVar(&remoteConfigURL, "remoteConfig", "", "URL of the Pangolin server")
 	}
 	if listenAddr == "" {
-		flag.StringVar(&listenAddr, "listen", ":3003", "Address to listen on")
-	}
-	if reportBandwidthTo == "" {
-		flag.StringVar(&reportBandwidthTo, "reportBandwidthTo", "", "Address to listen on")
+		flag.StringVar(&listenAddr, "listen", "", "DEPRECATED (overridden by reachableAt): Address to listen on")
 	}
+	// DEPRECATED AND UNSED: reportBandwidthTo
+	// allow reportBandwidthTo to be passed but dont do anything with it just thow it away
+	reportBandwidthTo := ""
+	flag.StringVar(&reportBandwidthTo, "reportBandwidthTo", "", "DEPRECATED: Use remoteConfig instead")
+
 	if generateAndSaveKeyTo == "" {
 		flag.StringVar(&generateAndSaveKeyTo, "generateAndSaveKeyTo", "", "Path to save generated private key")
 	}
+
 	if reachableAt == "" {
 		flag.StringVar(&reachableAt, "reachableAt", "", "Endpoint of the http server to tell remote config about")
 	}
+
 	if logLevel == "" {
 		flag.StringVar(&logLevel, "log-level", "INFO", "Log level (DEBUG, INFO, WARN, ERROR, FATAL)")
 	}
 	if mtu == "" {
 		flag.StringVar(&mtu, "mtu", "1280", "MTU of the WireGuard interface")
 	}
+	if notifyURL == "" {
+		flag.StringVar(&notifyURL, "notify", "", "URL to notify on peer changes")
+	}
+
+	if sniProxyPortStr != "" {
+		if port, err := strconv.Atoi(sniProxyPortStr); err == nil {
+			sniProxyPort = port
+		}
+	}
+	if sniProxyPortStr == "" {
+		flag.IntVar(&sniProxyPort, "sni-port", 8443, "Port to listen on")
+	}
+
+	if localProxyAddr == "" {
+		flag.StringVar(&localProxyAddr, "local-proxy", "localhost", "Local proxy address")
+	}
+
+	if localProxyPortStr != "" {
+		if port, err := strconv.Atoi(localProxyPortStr); err == nil {
+			localProxyPort = port
+		}
+	}
+	if localProxyPortStr == "" {
+		flag.IntVar(&localProxyPort, "local-proxy-port", 443, "Local proxy port")
+	}
+	if localOverridesStr != "" {
+		flag.StringVar(&localOverridesStr, "local-overrides", "", "Comma-separated list of local overrides for SNI proxy")
+	}
+	if trustedUpstreamsStr == "" {
+		flag.StringVar(&trustedUpstreamsStr, "trusted-upstreams", "", "Comma-separated list of trusted upstream proxy domain names/IPs that can send PROXY protocol")
+	}
+
+	if proxyProtocolStr != "" {
+		proxyProtocol = strings.ToLower(proxyProtocolStr) == "true"
+	}
+	if proxyProtocolStr == "" {
+		flag.BoolVar(&proxyProtocol, "proxy-protocol", true, "Enable PROXY protocol v1 for preserving client IP")
+	}
+
 	flag.Parse()
 
 	logger.Init()
 	logger.GetLogger().SetLevel(parseLogLevel(logLevel))
 
+	// try to parse as http://host:port and set the listenAddr to the :port from this reachableAt.
+	if reachableAt != "" && listenAddr == "" {
+		if strings.HasPrefix(reachableAt, "http://") || strings.HasPrefix(reachableAt, "https://") {
+			parts := strings.Split(reachableAt, ":")
+			if len(parts) == 3 {
+				port := parts[2]
+				if strings.Contains(port, "/") {
+					port = strings.Split(port, "/")[0]
+				}
+				listenAddr = ":" + port
+			}
+		}
+	} else if listenAddr == "" {
+		listenAddr = ":3003"
+	}
+
 	mtuInt, err = strconv.Atoi(mtu)
 	if err != nil {
 		logger.Fatal("Failed to parse MTU: %v", err)
@@ -144,6 +248,10 @@ func main() {
 		logger.Fatal("You must provide either a config file or a remote config URL, not both")
 	}
 
+	// clean up the reomte config URL for backwards compatibility
+	remoteConfigURL = strings.TrimSuffix(remoteConfigURL, "/gerbil/get-config")
+	remoteConfigURL = strings.TrimSuffix(remoteConfigURL, "/")
+
 	var key wgtypes.Key
 	// if generateAndSaveKeyTo is provided, generate a private key and save it to the file. if the file already exists, load the key from the file
 	if generateAndSaveKeyTo != "" {
@@ -191,8 +299,8 @@ func main() {
 	} else {
 		// loop until we get the config
 		for wgconfig.PrivateKey == "" {
-			logger.Info("Fetching remote config from %s", remoteConfigURL)
-			wgconfig, err = loadRemoteConfig(remoteConfigURL, key, reachableAt)
+			logger.Info("Fetching remote config from %s", remoteConfigURL+"/gerbil/get-config")
+			wgconfig, err = loadRemoteConfig(remoteConfigURL+"/gerbil/get-config", key, reachableAt)
 			if err != nil {
 				logger.Error("Failed to load configuration: %v", err)
 				time.Sleep(5 * time.Second)
@@ -216,13 +324,65 @@ func main() {
 	// Ensure the WireGuard peers exist
 	ensureWireguardPeers(wgconfig.Peers)
 
-	if reportBandwidthTo != "" {
-		go periodicBandwidthCheck(reportBandwidthTo)
+	go periodicBandwidthCheck(remoteConfigURL + "/gerbil/receive-bandwidth")
+
+	// Start the UDP proxy server
+	proxyRelay = relay.NewUDPProxyServer(":21820", remoteConfigURL, key, reachableAt)
+	err = proxyRelay.Start()
+	if err != nil {
+		logger.Fatal("Failed to start UDP proxy server: %v", err)
+	}
+	defer proxyRelay.Stop()
+
+	// TODO: WE SHOULD PULL THIS OUT OF THE CONFIG OR SOMETHING
+	// 		 SO YOU DON'T NEED TO SET THIS SEPARATELY
+	// Parse local overrides
+	var localOverrides []string
+	if localOverridesStr != "" {
+		localOverrides = strings.Split(localOverridesStr, ",")
+		for i, domain := range localOverrides {
+			localOverrides[i] = strings.TrimSpace(domain)
+		}
+		logger.Info("Local overrides configured: %v", localOverrides)
 	}
 
+	var trustedUpstreams []string
+	if trustedUpstreamsStr != "" {
+		trustedUpstreams = strings.Split(trustedUpstreamsStr, ",")
+		for i, upstream := range trustedUpstreams {
+			trustedUpstreams[i] = strings.TrimSpace(upstream)
+		}
+		logger.Info("Trusted upstreams configured: %v", trustedUpstreams)
+	}
+
+	proxySNI, err = proxy.NewSNIProxy(sniProxyPort, remoteConfigURL, key.PublicKey().String(), localProxyAddr, localProxyPort, localOverrides, proxyProtocol, trustedUpstreams)
+	if err != nil {
+		logger.Fatal("Failed to create proxy: %v", err)
+	}
+
+	if err := proxySNI.Start(); err != nil {
+		logger.Fatal("Failed to start proxy: %v", err)
+	}
+
+	// Set up HTTP server
 	http.HandleFunc("/peer", handlePeer)
-	logger.Info("Starting server on %s", listenAddr)
-	logger.Fatal("Failed to start server: %v", http.ListenAndServe(listenAddr, nil))
+	http.HandleFunc("/update-proxy-mapping", handleUpdateProxyMapping)
+	http.HandleFunc("/update-destinations", handleUpdateDestinations)
+	http.HandleFunc("/update-local-snis", handleUpdateLocalSNIs)
+	logger.Info("Starting HTTP server on %s", listenAddr)
+
+	// Run HTTP server in a goroutine
+	go func() {
+		if err := http.ListenAndServe(listenAddr, nil); err != nil {
+			logger.Error("HTTP server failed: %v", err)
+		}
+	}()
+
+	// Keep the main goroutine running
+	sigCh := make(chan os.Signal, 1)
+	signal.Notify(sigCh, syscall.SIGINT, syscall.SIGTERM)
+	<-sigCh
+	logger.Info("Shutting down servers...")
 }
 
 func loadRemoteConfig(url string, key wgtypes.Key, reachableAt string) (WgConfig, error) {
@@ -377,6 +537,9 @@ func assignIPAddress(ipAddress string) error {
 }
 
 func ensureWireguardPeers(peers []Peer) error {
+	wgMu.Lock()
+	defer wgMu.Unlock()
+
 	// get the current peers
 	device, err := wgClient.Device(interfaceName)
 	if err != nil {
@@ -399,8 +562,8 @@ func ensureWireguardPeers(peers []Peer) error {
 			}
 		}
 		if !found {
-			err := removePeer(peer)
-			if err != nil {
+			// Note: We need to call the internal removal logic without re-acquiring the lock
+			if err := removePeerInternal(peer); err != nil {
 				return fmt.Errorf("failed to remove peer: %v", err)
 			}
 		}
@@ -416,8 +579,8 @@ func ensureWireguardPeers(peers []Peer) error {
 			}
 		}
 		if !found {
-			err := addPeer(configPeer)
-			if err != nil {
+			// Note: We need to call the internal addition logic without re-acquiring the lock
+			if err := addPeerInternal(configPeer); err != nil {
 				return fmt.Errorf("failed to add peer: %v", err)
 			}
 		}
@@ -477,7 +640,7 @@ func ensureMSSClamping() error {
 			errMsg := fmt.Sprintf("Failed to add MSS clamping rule for chain %s: %v (output: %s)",
 				chain, err, string(out))
 			logger.Error(errMsg)
-			errors = append(errors, fmt.Errorf(errMsg))
+			errors = append(errors, fmt.Errorf("%s", errMsg))
 			continue
 		}
 
@@ -494,7 +657,7 @@ func ensureMSSClamping() error {
 			errMsg := fmt.Sprintf("Rule verification failed for chain %s: %v (output: %s)",
 				chain, err, string(out))
 			logger.Error(errMsg)
-			errors = append(errors, fmt.Errorf(errMsg))
+			errors = append(errors, fmt.Errorf("%s", errMsg))
 			continue
 		}
 
@@ -538,11 +701,20 @@ func handleAddPeer(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	// Notify if notifyURL is set
+	go notifyPeerChange("add", peer.PublicKey)
+
 	w.WriteHeader(http.StatusCreated)
 	json.NewEncoder(w).Encode(map[string]string{"status": "Peer added successfully"})
 }
 
 func addPeer(peer Peer) error {
+	wgMu.Lock()
+	defer wgMu.Unlock()
+	return addPeerInternal(peer)
+}
+
+func addPeerInternal(peer Peer) error {
 	pubKey, err := wgtypes.ParseKey(peer.PublicKey)
 	if err != nil {
 		return fmt.Errorf("failed to parse public key: %v", err)
@@ -550,12 +722,15 @@ func addPeer(peer Peer) error {
 
 	// parse allowed IPs into array of net.IPNet
 	var allowedIPs []net.IPNet
+	var wgIPs []string
 	for _, ipStr := range peer.AllowedIPs {
 		_, ipNet, err := net.ParseCIDR(ipStr)
 		if err != nil {
 			return fmt.Errorf("failed to parse allowed IP: %v", err)
 		}
 		allowedIPs = append(allowedIPs, *ipNet)
+		// Extract the IP address from the CIDR for relay cleanup
+		wgIPs = append(wgIPs, ipNet.IP.String())
 	}
 
 	peerConfig := wgtypes.PeerConfig{
@@ -571,6 +746,13 @@ func addPeer(peer Peer) error {
 		return fmt.Errorf("failed to add peer: %v", err)
 	}
 
+	// Clear relay connections for the peer's WireGuard IPs
+	if proxyRelay != nil {
+		for _, wgIP := range wgIPs {
+			proxyRelay.OnPeerAdded(wgIP)
+		}
+	}
+
 	logger.Info("Peer %s added successfully", peer.PublicKey)
 
 	return nil
@@ -589,16 +771,42 @@ func handleRemovePeer(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	// Notify if notifyURL is set
+	go notifyPeerChange("remove", publicKey)
+
 	w.WriteHeader(http.StatusOK)
 	json.NewEncoder(w).Encode(map[string]string{"status": "Peer removed successfully"})
 }
 
 func removePeer(publicKey string) error {
+	wgMu.Lock()
+	defer wgMu.Unlock()
+	return removePeerInternal(publicKey)
+}
+
+func removePeerInternal(publicKey string) error {
 	pubKey, err := wgtypes.ParseKey(publicKey)
 	if err != nil {
 		return fmt.Errorf("failed to parse public key: %v", err)
 	}
 
+	// Get current peer info before removing to clear relay connections
+	var wgIPs []string
+	if proxyRelay != nil {
+		device, err := wgClient.Device(interfaceName)
+		if err == nil {
+			for _, peer := range device.Peers {
+				if peer.PublicKey.String() == publicKey {
+					// Extract WireGuard IPs from this peer's allowed IPs
+					for _, allowedIP := range peer.AllowedIPs {
+						wgIPs = append(wgIPs, allowedIP.IP.String())
+					}
+					break
+				}
+			}
+		}
+	}
+
 	peerConfig := wgtypes.PeerConfig{
 		PublicKey: pubKey,
 		Remove:    true,
@@ -612,11 +820,163 @@ func removePeer(publicKey string) error {
 		return fmt.Errorf("failed to remove peer: %v", err)
 	}
 
+	// Clear relay connections for the peer's WireGuard IPs
+	if proxyRelay != nil {
+		for _, wgIP := range wgIPs {
+			proxyRelay.OnPeerRemoved(wgIP)
+		}
+	}
+
 	logger.Info("Peer %s removed successfully", publicKey)
 
 	return nil
 }
 
+func handleUpdateProxyMapping(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		logger.Error("Invalid method: %s", r.Method)
+		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	var update ProxyMappingUpdate
+	if err := json.NewDecoder(r.Body).Decode(&update); err != nil {
+		logger.Error("Failed to decode request body: %v", err)
+		http.Error(w, fmt.Sprintf("Failed to decode request body: %v", err), http.StatusBadRequest)
+		return
+	}
+
+	// Validate the update request
+	if update.OldDestination.DestinationIP == "" || update.NewDestination.DestinationIP == "" {
+		logger.Error("Both old and new destination IP addresses are required")
+		http.Error(w, "Both old and new destination IP addresses are required", http.StatusBadRequest)
+		return
+	}
+
+	if update.OldDestination.DestinationPort <= 0 || update.NewDestination.DestinationPort <= 0 {
+		logger.Error("Both old and new destination ports must be positive integers")
+		http.Error(w, "Both old and new destination ports must be positive integers", http.StatusBadRequest)
+		return
+	}
+
+	// Update the proxy mappings in the relay server
+	if proxyRelay == nil {
+		logger.Error("Proxy server is not available")
+		http.Error(w, "Proxy server is not available", http.StatusInternalServerError)
+		return
+	}
+
+	updatedCount := proxyRelay.UpdateDestinationInMappings(update.OldDestination, update.NewDestination)
+
+	logger.Info("Updated %d proxy mappings: %s:%d -> %s:%d",
+		updatedCount,
+		update.OldDestination.DestinationIP, update.OldDestination.DestinationPort,
+		update.NewDestination.DestinationIP, update.NewDestination.DestinationPort)
+
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(map[string]interface{}{
+		"status":         "Proxy mappings updated successfully",
+		"updatedCount":   updatedCount,
+		"oldDestination": update.OldDestination,
+		"newDestination": update.NewDestination,
+	})
+}
+
+func handleUpdateDestinations(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		logger.Error("Invalid method: %s", r.Method)
+		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	var request UpdateDestinationsRequest
+	if err := json.NewDecoder(r.Body).Decode(&request); err != nil {
+		logger.Error("Failed to decode request body: %v", err)
+		http.Error(w, fmt.Sprintf("Failed to decode request body: %v", err), http.StatusBadRequest)
+		return
+	}
+
+	// Validate the request
+	if request.SourceIP == "" {
+		logger.Error("Source IP address is required")
+		http.Error(w, "Source IP address is required", http.StatusBadRequest)
+		return
+	}
+
+	if request.SourcePort <= 0 {
+		logger.Error("Source port must be a positive integer")
+		http.Error(w, "Source port must be a positive integer", http.StatusBadRequest)
+		return
+	}
+
+	if len(request.Destinations) == 0 {
+		logger.Error("At least one destination is required")
+		http.Error(w, "At least one destination is required", http.StatusBadRequest)
+		return
+	}
+
+	// Validate each destination
+	for i, dest := range request.Destinations {
+		if dest.DestinationIP == "" {
+			logger.Error("Destination IP is required for destination %d", i)
+			http.Error(w, fmt.Sprintf("Destination IP is required for destination %d", i), http.StatusBadRequest)
+			return
+		}
+		if dest.DestinationPort <= 0 {
+			logger.Error("Destination port must be a positive integer for destination %d", i)
+			http.Error(w, fmt.Sprintf("Destination port must be a positive integer for destination %d", i), http.StatusBadRequest)
+			return
+		}
+	}
+
+	// Update the proxy mappings in the relay server
+	if proxyRelay == nil {
+		logger.Error("Proxy server is not available")
+		http.Error(w, "Proxy server is not available", http.StatusInternalServerError)
+		return
+	}
+
+	proxyRelay.UpdateProxyMapping(request.SourceIP, request.SourcePort, request.Destinations)
+
+	logger.Info("Updated proxy mapping for %s:%d with %d destinations",
+		request.SourceIP, request.SourcePort, len(request.Destinations))
+
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(map[string]interface{}{
+		"status":           "Destinations updated successfully",
+		"sourceIP":         request.SourceIP,
+		"sourcePort":       request.SourcePort,
+		"destinationCount": len(request.Destinations),
+		"destinations":     request.Destinations,
+	})
+}
+
+// UpdateLocalSNIsRequest represents the JSON payload for updating local SNIs
+type UpdateLocalSNIsRequest struct {
+	FullDomains []string `json:"fullDomains"`
+}
+
+func handleUpdateLocalSNIs(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		logger.Error("Invalid method: %s", r.Method)
+		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	var req UpdateLocalSNIsRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		http.Error(w, "Invalid JSON payload", http.StatusBadRequest)
+		return
+	}
+
+	proxySNI.UpdateLocalSNIs(req.FullDomains)
+
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(map[string]interface{}{
+		"status": "Local SNIs updated successfully",
+	})
+}
+
 func periodicBandwidthCheck(endpoint string) {
 	ticker := time.NewTicker(10 * time.Second)
 	defer ticker.Stop()
@@ -629,7 +989,10 @@ func periodicBandwidthCheck(endpoint string) {
 }
 
 func calculatePeerBandwidth() ([]PeerBandwidth, error) {
+	wgMu.Lock()
 	device, err := wgClient.Device(interfaceName)
+	wgMu.Unlock()
+
 	if err != nil {
 		return nil, fmt.Errorf("failed to get device: %v", err)
 	}
@@ -736,3 +1099,28 @@ func reportPeerBandwidth(apiURL string) error {
 
 	return nil
 }
+
+// notifyPeerChange sends a POST request to notifyURL with the action and public key.
+func notifyPeerChange(action, publicKey string) {
+	if notifyURL == "" {
+		return
+	}
+	payload := map[string]string{
+		"action":    action,
+		"publicKey": publicKey,
+	}
+	data, err := json.Marshal(payload)
+	if err != nil {
+		logger.Warn("Failed to marshal notify payload: %v", err)
+		return
+	}
+	resp, err := http.Post(notifyURL, "application/json", bytes.NewBuffer(data))
+	if err != nil {
+		logger.Warn("Failed to notify peer change: %v", err)
+		return
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		logger.Warn("Notify server returned non-OK: %s", resp.Status)
+	}
+}

proxy/proxy.go

@@ -0,0 +1,845 @@
+package proxy
+
+import (
+	"bytes"
+	"context"
+	"crypto/tls"
+	"encoding/json"
+	"fmt"
+	"hash/fnv"
+	"io"
+	"log"
+	"net"
+	"net/http"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/fosrl/gerbil/logger"
+	"github.com/patrickmn/go-cache"
+)
+
+// RouteRecord represents a routing configuration
+type RouteRecord struct {
+	Hostname   string
+	TargetHost string
+	TargetPort int
+}
+
+// RouteAPIResponse represents the response from the route API
+type RouteAPIResponse struct {
+	Endpoints []string `json:"endpoints"`
+}
+
+// ProxyProtocolInfo holds information parsed from incoming PROXY protocol header
+type ProxyProtocolInfo struct {
+	Protocol     string // TCP4 or TCP6
+	SrcIP        string
+	DestIP       string
+	SrcPort      int
+	DestPort     int
+	OriginalConn net.Conn // The original connection after PROXY protocol parsing
+}
+
+// SNIProxy represents the main proxy server
+type SNIProxy struct {
+	port            int
+	cache           *cache.Cache
+	listener        net.Listener
+	ctx             context.Context
+	cancel          context.CancelFunc
+	wg              sync.WaitGroup
+	localProxyAddr  string
+	localProxyPort  int
+	remoteConfigURL string
+	publicKey       string
+	proxyProtocol   bool // Enable PROXY protocol v1
+
+	// New fields for fast local SNI lookup
+	localSNIs     map[string]struct{}
+	localSNIsLock sync.RWMutex
+
+	// Local overrides for domains that should always use local proxy
+	localOverrides map[string]struct{}
+
+	// Track active tunnels by SNI
+	activeTunnels     map[string]*activeTunnel
+	activeTunnelsLock sync.Mutex
+
+	// Trusted upstream proxies that can send PROXY protocol
+	trustedUpstreams map[string]struct{}
+}
+
+type activeTunnel struct {
+	conns []net.Conn
+}
+
+// readOnlyConn is a wrapper for io.Reader that implements net.Conn
+type readOnlyConn struct {
+	reader io.Reader
+}
+
+func (conn readOnlyConn) Read(p []byte) (int, error)         { return conn.reader.Read(p) }
+func (conn readOnlyConn) Write(p []byte) (int, error)        { return 0, io.ErrClosedPipe }
+func (conn readOnlyConn) Close() error                       { return nil }
+func (conn readOnlyConn) LocalAddr() net.Addr                { return nil }
+func (conn readOnlyConn) RemoteAddr() net.Addr               { return nil }
+func (conn readOnlyConn) SetDeadline(t time.Time) error      { return nil }
+func (conn readOnlyConn) SetReadDeadline(t time.Time) error  { return nil }
+func (conn readOnlyConn) SetWriteDeadline(t time.Time) error { return nil }
+
+// parseProxyProtocolHeader parses a PROXY protocol v1 header from the connection
+func (p *SNIProxy) parseProxyProtocolHeader(conn net.Conn) (*ProxyProtocolInfo, net.Conn, error) {
+	// Check if the connection comes from a trusted upstream
+	remoteHost, _, err := net.SplitHostPort(conn.RemoteAddr().String())
+	if err != nil {
+		return nil, conn, fmt.Errorf("failed to parse remote address: %w", err)
+	}
+
+	// Resolve the remote IP to hostname to check if it's trusted
+	// For simplicity, we'll check the IP directly in trusted upstreams
+	// In production, you might want to do reverse DNS lookup
+	if _, isTrusted := p.trustedUpstreams[remoteHost]; !isTrusted {
+		// Not from trusted upstream, return original connection
+		return nil, conn, nil
+	}
+
+	// Set read timeout for PROXY protocol parsing
+	if err := conn.SetReadDeadline(time.Now().Add(5 * time.Second)); err != nil {
+		return nil, conn, fmt.Errorf("failed to set read deadline: %w", err)
+	}
+
+	// Read the first line (PROXY protocol header)
+	buffer := make([]byte, 512) // PROXY protocol header should be much smaller
+	n, err := conn.Read(buffer)
+	if err != nil {
+		// If we can't read from trusted upstream, treat as regular connection
+		logger.Debug("Could not read from trusted upstream %s, treating as regular connection: %v", remoteHost, err)
+		// Clear read timeout before returning
+		if clearErr := conn.SetReadDeadline(time.Time{}); clearErr != nil {
+			logger.Debug("Failed to clear read deadline: %v", clearErr)
+		}
+		return nil, conn, nil
+	}
+
+	// Find the end of the first line (CRLF)
+	headerEnd := bytes.Index(buffer[:n], []byte("\r\n"))
+	if headerEnd == -1 {
+		// No PROXY protocol header found, treat as regular TLS connection
+		// Return the connection with the buffered data prepended
+		logger.Debug("No PROXY protocol header from trusted upstream %s, treating as regular TLS connection", remoteHost)
+
+		// Clear read timeout
+		if err := conn.SetReadDeadline(time.Time{}); err != nil {
+			logger.Debug("Failed to clear read deadline: %v", err)
+		}
+
+		// Create a reader that includes the buffered data + original connection
+		newReader := io.MultiReader(bytes.NewReader(buffer[:n]), conn)
+		wrappedConn := &proxyProtocolConn{
+			Conn:   conn,
+			reader: newReader,
+		}
+		return nil, wrappedConn, nil
+	}
+
+	headerLine := string(buffer[:headerEnd])
+	remainingData := buffer[headerEnd+2 : n]
+
+	// Parse PROXY protocol line: "PROXY TCP4/TCP6 srcIP destIP srcPort destPort"
+	parts := strings.Fields(headerLine)
+	if len(parts) != 6 || parts[0] != "PROXY" {
+		// Check for PROXY UNKNOWN
+		if len(parts) == 2 && parts[0] == "PROXY" && parts[1] == "UNKNOWN" {
+			// PROXY UNKNOWN - use original connection info
+			return nil, conn, nil
+		}
+		// Invalid PROXY protocol, but might be regular TLS - treat as such
+		logger.Debug("Invalid PROXY protocol from trusted upstream %s, treating as regular TLS connection: %s", remoteHost, headerLine)
+
+		// Clear read timeout
+		if err := conn.SetReadDeadline(time.Time{}); err != nil {
+			logger.Debug("Failed to clear read deadline: %v", err)
+		}
+
+		// Return the connection with all buffered data prepended
+		newReader := io.MultiReader(bytes.NewReader(buffer[:n]), conn)
+		wrappedConn := &proxyProtocolConn{
+			Conn:   conn,
+			reader: newReader,
+		}
+		return nil, wrappedConn, nil
+	}
+
+	protocol := parts[1]
+	srcIP := parts[2]
+	destIP := parts[3]
+	srcPort, err := strconv.Atoi(parts[4])
+	if err != nil {
+		return nil, conn, fmt.Errorf("invalid source port in PROXY header: %s", parts[4])
+	}
+	destPort, err := strconv.Atoi(parts[5])
+	if err != nil {
+		return nil, conn, fmt.Errorf("invalid destination port in PROXY header: %s", parts[5])
+	}
+
+	// Create a new reader that includes remaining data + original connection
+	var newReader io.Reader
+	if len(remainingData) > 0 {
+		newReader = io.MultiReader(bytes.NewReader(remainingData), conn)
+	} else {
+		newReader = conn
+	}
+
+	// Create a wrapper connection that reads from the combined reader
+	wrappedConn := &proxyProtocolConn{
+		Conn:   conn,
+		reader: newReader,
+	}
+
+	proxyInfo := &ProxyProtocolInfo{
+		Protocol:     protocol,
+		SrcIP:        srcIP,
+		DestIP:       destIP,
+		SrcPort:      srcPort,
+		DestPort:     destPort,
+		OriginalConn: wrappedConn,
+	}
+
+	// Clear read timeout
+	if err := conn.SetReadDeadline(time.Time{}); err != nil {
+		return nil, conn, fmt.Errorf("failed to clear read deadline: %w", err)
+	}
+
+	return proxyInfo, wrappedConn, nil
+}
+
+// proxyProtocolConn wraps a connection to read from a custom reader
+type proxyProtocolConn struct {
+	net.Conn
+	reader io.Reader
+}
+
+func (c *proxyProtocolConn) Read(b []byte) (int, error) {
+	return c.reader.Read(b)
+}
+
+// buildProxyProtocolHeaderFromInfo creates a PROXY protocol v1 header using ProxyProtocolInfo
+func (p *SNIProxy) buildProxyProtocolHeaderFromInfo(proxyInfo *ProxyProtocolInfo, targetAddr net.Addr) string {
+	targetTCP, ok := targetAddr.(*net.TCPAddr)
+	if !ok {
+		// Fallback for unknown address types
+		return "PROXY UNKNOWN\r\n"
+	}
+
+	// Use the original client information from the PROXY protocol
+	var targetIP string
+	var protocol string
+
+	// Parse source IP to determine protocol family
+	srcIP := net.ParseIP(proxyInfo.SrcIP)
+	if srcIP == nil {
+		return "PROXY UNKNOWN\r\n"
+	}
+
+	if srcIP.To4() != nil {
+		// Source is IPv4, use TCP4 protocol
+		protocol = "TCP4"
+		if targetTCP.IP.To4() != nil {
+			// Target is also IPv4, use as-is
+			targetIP = targetTCP.IP.String()
+		} else {
+			// Target is IPv6, but we need IPv4 for consistent protocol family
+			if targetTCP.IP.IsLoopback() {
+				targetIP = "127.0.0.1"
+			} else {
+				targetIP = "127.0.0.1" // Safe fallback
+			}
+		}
+	} else {
+		// Source is IPv6, use TCP6 protocol
+		protocol = "TCP6"
+		if targetTCP.IP.To4() != nil {
+			// Target is IPv4, convert to IPv6 representation
+			targetIP = "::ffff:" + targetTCP.IP.String()
+		} else {
+			// Target is also IPv6, use as-is
+			targetIP = targetTCP.IP.String()
+		}
+	}
+
+	return fmt.Sprintf("PROXY %s %s %s %d %d\r\n",
+		protocol,
+		proxyInfo.SrcIP,
+		targetIP,
+		proxyInfo.SrcPort,
+		targetTCP.Port)
+}
+
+// buildProxyProtocolHeader creates a PROXY protocol v1 header
+func buildProxyProtocolHeader(clientAddr, targetAddr net.Addr) string {
+	clientTCP, ok := clientAddr.(*net.TCPAddr)
+	if !ok {
+		// Fallback for unknown address types
+		return "PROXY UNKNOWN\r\n"
+	}
+
+	targetTCP, ok := targetAddr.(*net.TCPAddr)
+	if !ok {
+		// Fallback for unknown address types
+		return "PROXY UNKNOWN\r\n"
+	}
+
+	// Determine protocol family based on client IP and normalize target IP accordingly
+	var protocol string
+	var targetIP string
+
+	if clientTCP.IP.To4() != nil {
+		// Client is IPv4, use TCP4 protocol
+		protocol = "TCP4"
+		if targetTCP.IP.To4() != nil {
+			// Target is also IPv4, use as-is
+			targetIP = targetTCP.IP.String()
+		} else {
+			// Target is IPv6, but we need IPv4 for consistent protocol family
+			// Use the IPv4 loopback if target is IPv6 loopback, otherwise use 127.0.0.1
+			if targetTCP.IP.IsLoopback() {
+				targetIP = "127.0.0.1"
+			} else {
+				// For non-loopback IPv6 targets, we could try to extract embedded IPv4
+				// or fall back to a sensible IPv4 address based on the target
+				targetIP = "127.0.0.1" // Safe fallback
+			}
+		}
+	} else {
+		// Client is IPv6, use TCP6 protocol
+		protocol = "TCP6"
+		if targetTCP.IP.To4() != nil {
+			// Target is IPv4, convert to IPv6 representation
+			targetIP = "::ffff:" + targetTCP.IP.String()
+		} else {
+			// Target is also IPv6, use as-is
+			targetIP = targetTCP.IP.String()
+		}
+	}
+
+	return fmt.Sprintf("PROXY %s %s %s %d %d\r\n",
+		protocol,
+		clientTCP.IP.String(),
+		targetIP,
+		clientTCP.Port,
+		targetTCP.Port)
+}
+
+// NewSNIProxy creates a new SNI proxy instance
+func NewSNIProxy(port int, remoteConfigURL, publicKey, localProxyAddr string, localProxyPort int, localOverrides []string, proxyProtocol bool, trustedUpstreams []string) (*SNIProxy, error) {
+	ctx, cancel := context.WithCancel(context.Background())
+
+	// Create local overrides map
+	overridesMap := make(map[string]struct{})
+	for _, domain := range localOverrides {
+		if domain != "" {
+			overridesMap[domain] = struct{}{}
+		}
+	}
+
+	// Create trusted upstreams map
+	trustedMap := make(map[string]struct{})
+	for _, upstream := range trustedUpstreams {
+		if upstream != "" {
+			// Add both the domain and potentially resolved IPs
+			trustedMap[upstream] = struct{}{}
+
+			// Try to resolve the domain to IPs and add them too
+			if ips, err := net.LookupIP(upstream); err == nil {
+				for _, ip := range ips {
+					trustedMap[ip.String()] = struct{}{}
+				}
+			}
+		}
+	}
+
+	proxy := &SNIProxy{
+		port:             port,
+		cache:            cache.New(3*time.Second, 10*time.Minute),
+		ctx:              ctx,
+		cancel:           cancel,
+		localProxyAddr:   localProxyAddr,
+		localProxyPort:   localProxyPort,
+		remoteConfigURL:  remoteConfigURL,
+		publicKey:        publicKey,
+		proxyProtocol:    proxyProtocol,
+		localSNIs:        make(map[string]struct{}),
+		localOverrides:   overridesMap,
+		activeTunnels:    make(map[string]*activeTunnel),
+		trustedUpstreams: trustedMap,
+	}
+
+	return proxy, nil
+}
+
+// Start begins listening for connections
+func (p *SNIProxy) Start() error {
+	listener, err := net.Listen("tcp", fmt.Sprintf(":%d", p.port))
+	if err != nil {
+		return fmt.Errorf("failed to listen on port %d: %w", p.port, err)
+	}
+
+	p.listener = listener
+	logger.Debug("SNI Proxy listening on port %d", p.port)
+
+	// Accept connections in a goroutine
+	go p.acceptConnections()
+
+	return nil
+}
+
+// Stop gracefully shuts down the proxy
+func (p *SNIProxy) Stop() error {
+	log.Println("Stopping SNI Proxy...")
+
+	p.cancel()
+
+	if p.listener != nil {
+		p.listener.Close()
+	}
+
+	// Wait for all goroutines to finish with timeout
+	done := make(chan struct{})
+	go func() {
+		p.wg.Wait()
+		close(done)
+	}()
+
+	select {
+	case <-done:
+		log.Println("All connections closed gracefully")
+	case <-time.After(30 * time.Second):
+		log.Println("Timeout waiting for connections to close")
+	}
+
+	log.Println("SNI Proxy stopped")
+	return nil
+}
+
+// acceptConnections handles incoming connections
+func (p *SNIProxy) acceptConnections() {
+	for {
+		conn, err := p.listener.Accept()
+		if err != nil {
+			select {
+			case <-p.ctx.Done():
+				return
+			default:
+				logger.Debug("Accept error: %v", err)
+				continue
+			}
+		}
+
+		p.wg.Add(1)
+		go p.handleConnection(conn)
+	}
+}
+
+// readClientHello reads and parses the TLS ClientHello message
+func (p *SNIProxy) readClientHello(reader io.Reader) (*tls.ClientHelloInfo, error) {
+	var hello *tls.ClientHelloInfo
+	err := tls.Server(readOnlyConn{reader: reader}, &tls.Config{
+		GetConfigForClient: func(argHello *tls.ClientHelloInfo) (*tls.Config, error) {
+			hello = new(tls.ClientHelloInfo)
+			*hello = *argHello
+			return nil, nil
+		},
+	}).Handshake()
+	if hello == nil {
+		return nil, err
+	}
+	return hello, nil
+}
+
+// peekClientHello reads the ClientHello while preserving the data for forwarding
+func (p *SNIProxy) peekClientHello(reader io.Reader) (*tls.ClientHelloInfo, io.Reader, error) {
+	peekedBytes := new(bytes.Buffer)
+	hello, err := p.readClientHello(io.TeeReader(reader, peekedBytes))
+	if err != nil {
+		return nil, nil, err
+	}
+	return hello, io.MultiReader(peekedBytes, reader), nil
+}
+
+// extractSNI extracts the SNI hostname from the TLS ClientHello
+func (p *SNIProxy) extractSNI(conn net.Conn) (string, io.Reader, error) {
+	clientHello, clientReader, err := p.peekClientHello(conn)
+	if err != nil {
+		return "", nil, fmt.Errorf("failed to peek ClientHello: %w", err)
+	}
+
+	if clientHello.ServerName == "" {
+		return "", clientReader, fmt.Errorf("no SNI hostname found in ClientHello")
+	}
+
+	return clientHello.ServerName, clientReader, nil
+}
+
+// handleConnection processes a single client connection
+func (p *SNIProxy) handleConnection(clientConn net.Conn) {
+	defer p.wg.Done()
+	defer clientConn.Close()
+
+	logger.Debug("Accepted connection from %s", clientConn.RemoteAddr())
+
+	// Check for PROXY protocol from trusted upstream
+	var proxyInfo *ProxyProtocolInfo
+	var actualClientConn net.Conn = clientConn
+
+	if len(p.trustedUpstreams) > 0 {
+		var err error
+		proxyInfo, actualClientConn, err = p.parseProxyProtocolHeader(clientConn)
+		if err != nil {
+			logger.Debug("Failed to parse PROXY protocol: %v", err)
+			return
+		}
+		if proxyInfo != nil {
+			logger.Debug("Received PROXY protocol from trusted upstream: %s:%d -> %s:%d",
+				proxyInfo.SrcIP, proxyInfo.SrcPort, proxyInfo.DestIP, proxyInfo.DestPort)
+		} else {
+			// No PROXY protocol detected, but connection is from trusted upstream
+			// This is fine - treat as regular connection
+			logger.Debug("No PROXY protocol detected from trusted upstream, treating as regular connection")
+		}
+	}
+
+	// Set read timeout for SNI extraction
+	if err := actualClientConn.SetReadDeadline(time.Now().Add(5 * time.Second)); err != nil {
+		logger.Debug("Failed to set read deadline: %v", err)
+		return
+	}
+
+	// Extract SNI hostname
+	hostname, clientReader, err := p.extractSNI(actualClientConn)
+	if err != nil {
+		logger.Debug("SNI extraction failed: %v", err)
+		return
+	}
+
+	if hostname == "" {
+		log.Println("No SNI hostname found")
+		return
+	}
+
+	logger.Debug("SNI hostname detected: %s", hostname)
+
+	// Remove read timeout for normal operation
+	if err := actualClientConn.SetReadDeadline(time.Time{}); err != nil {
+		logger.Debug("Failed to clear read deadline: %v", err)
+		return
+	}
+
+	// Get routing information - use original client address if available from PROXY protocol
+	var clientAddrStr string
+	if proxyInfo != nil {
+		clientAddrStr = fmt.Sprintf("%s:%d", proxyInfo.SrcIP, proxyInfo.SrcPort)
+	} else {
+		clientAddrStr = clientConn.RemoteAddr().String()
+	}
+
+	route, err := p.getRoute(hostname, clientAddrStr)
+	if err != nil {
+		logger.Debug("Failed to get route for %s: %v", hostname, err)
+		return
+	}
+
+	if route == nil {
+		logger.Debug("No route found for hostname: %s", hostname)
+		return
+	}
+
+	logger.Debug("Routing %s to %s:%d", hostname, route.TargetHost, route.TargetPort)
+
+	// Connect to target server
+	targetConn, err := net.DialTimeout("tcp",
+		fmt.Sprintf("%s:%d", route.TargetHost, route.TargetPort),
+		10*time.Second)
+	if err != nil {
+		logger.Debug("Failed to connect to target %s:%d: %v",
+			route.TargetHost, route.TargetPort, err)
+		return
+	}
+	defer targetConn.Close()
+
+	logger.Debug("Connected to target: %s:%d", route.TargetHost, route.TargetPort)
+
+	// Send PROXY protocol header if enabled
+	if p.proxyProtocol {
+		var proxyHeader string
+		if proxyInfo != nil {
+			// Use original client info from PROXY protocol
+			proxyHeader = p.buildProxyProtocolHeaderFromInfo(proxyInfo, targetConn.LocalAddr())
+		} else {
+			// Use direct client connection info
+			proxyHeader = buildProxyProtocolHeader(clientConn.RemoteAddr(), targetConn.LocalAddr())
+		}
+		logger.Debug("Sending PROXY protocol header: %s", strings.TrimSpace(proxyHeader))
+
+		if _, err := targetConn.Write([]byte(proxyHeader)); err != nil {
+			logger.Debug("Failed to send PROXY protocol header: %v", err)
+			return
+		}
+	}
+
+	// Track this tunnel by SNI
+	p.activeTunnelsLock.Lock()
+	tunnel, ok := p.activeTunnels[hostname]
+	if !ok {
+		tunnel = &activeTunnel{}
+		p.activeTunnels[hostname] = tunnel
+	}
+	tunnel.conns = append(tunnel.conns, actualClientConn)
+	p.activeTunnelsLock.Unlock()
+
+	defer func() {
+		// Remove this conn from active tunnels
+		p.activeTunnelsLock.Lock()
+		if tunnel, ok := p.activeTunnels[hostname]; ok {
+			newConns := make([]net.Conn, 0, len(tunnel.conns))
+			for _, c := range tunnel.conns {
+				if c != actualClientConn {
+					newConns = append(newConns, c)
+				}
+			}
+			if len(newConns) == 0 {
+				delete(p.activeTunnels, hostname)
+			} else {
+				tunnel.conns = newConns
+			}
+		}
+		p.activeTunnelsLock.Unlock()
+	}()
+
+	// Start bidirectional data transfer
+	p.pipe(actualClientConn, targetConn, clientReader)
+}
+
+// getRoute retrieves routing information for a hostname
+func (p *SNIProxy) getRoute(hostname, clientAddr string) (*RouteRecord, error) {
+	// Check local overrides first
+	if _, isOverride := p.localOverrides[hostname]; isOverride {
+		logger.Debug("Local override matched for hostname: %s", hostname)
+		return &RouteRecord{
+			Hostname:   hostname,
+			TargetHost: p.localProxyAddr,
+			TargetPort: p.localProxyPort,
+		}, nil
+	}
+
+	// Fast path: check if hostname is in localSNIs
+	p.localSNIsLock.RLock()
+	_, isLocal := p.localSNIs[hostname]
+	p.localSNIsLock.RUnlock()
+	if isLocal {
+		return &RouteRecord{
+			Hostname:   hostname,
+			TargetHost: p.localProxyAddr,
+			TargetPort: p.localProxyPort,
+		}, nil
+	}
+
+	// Check cache first
+	if cached, found := p.cache.Get(hostname); found {
+		if cached == nil {
+			return nil, nil // Cached negative result
+		}
+		logger.Debug("Cache hit for hostname: %s", hostname)
+		return cached.(*RouteRecord), nil
+	}
+
+	logger.Debug("Cache miss for hostname: %s, querying API", hostname)
+
+	// Query API with timeout
+	ctx, cancel := context.WithTimeout(p.ctx, 5*time.Second)
+	defer cancel()
+
+	// Construct API URL (without hostname in path)
+	apiURL := fmt.Sprintf("%s/gerbil/get-resolved-hostname", p.remoteConfigURL)
+
+	// Create request body with hostname and public key
+	requestBody := map[string]string{
+		"hostname":  hostname,
+		"publicKey": p.publicKey,
+	}
+
+	jsonBody, err := json.Marshal(requestBody)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal request body: %w", err)
+	}
+
+	// Create HTTP request
+	req, err := http.NewRequestWithContext(ctx, "POST", apiURL, bytes.NewBuffer(jsonBody))
+	if err != nil {
+		return nil, fmt.Errorf("failed to create request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+
+	// Make HTTP request
+	client := &http.Client{Timeout: 5 * time.Second}
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("API request failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode == http.StatusNotFound {
+		// Cache negative result for shorter time (1 minute)
+		p.cache.Set(hostname, nil, 1*time.Minute)
+		return nil, nil
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("API returned status %d", resp.StatusCode)
+	}
+
+	// Parse response
+	var apiResponse RouteAPIResponse
+	if err := json.NewDecoder(resp.Body).Decode(&apiResponse); err != nil {
+		return nil, fmt.Errorf("failed to decode API response: %w", err)
+	}
+
+	endpoints := apiResponse.Endpoints
+
+	// Default target configuration
+	targetHost := p.localProxyAddr
+	targetPort := p.localProxyPort
+
+	// If no endpoints returned, use local node
+	if len(endpoints) == 0 {
+		logger.Debug("No endpoints returned for hostname: %s, using local node", hostname)
+	} else {
+		// Select endpoint using consistent hashing for stickiness
+		selectedEndpoint := p.selectStickyEndpoint(clientAddr, endpoints)
+		targetHost = selectedEndpoint
+		targetPort = 443 // Default HTTPS port
+		logger.Debug("Selected endpoint %s for hostname %s from client %s", selectedEndpoint, hostname, clientAddr)
+	}
+
+	route := &RouteRecord{
+		Hostname:   hostname,
+		TargetHost: targetHost,
+		TargetPort: targetPort,
+	}
+
+	// Cache the result
+	p.cache.Set(hostname, route, cache.DefaultExpiration)
+	logger.Debug("Cached route for hostname: %s", hostname)
+
+	return route, nil
+}
+
+// selectStickyEndpoint selects an endpoint using consistent hashing to ensure
+// the same client always routes to the same endpoint for load balancing
+func (p *SNIProxy) selectStickyEndpoint(clientAddr string, endpoints []string) string {
+	if len(endpoints) == 0 {
+		return p.localProxyAddr
+	}
+	if len(endpoints) == 1 {
+		return endpoints[0]
+	}
+
+	// Use FNV hash for consistent selection based on client address
+	hash := fnv.New32a()
+	hash.Write([]byte(clientAddr))
+	index := hash.Sum32() % uint32(len(endpoints))
+
+	return endpoints[index]
+}
+
+// pipe handles bidirectional data transfer between connections
+func (p *SNIProxy) pipe(clientConn, targetConn net.Conn, clientReader io.Reader) {
+	var wg sync.WaitGroup
+	wg.Add(2)
+
+	// Copy data from client to target (using the buffered reader)
+	go func() {
+		defer wg.Done()
+		defer func() {
+			if tcpConn, ok := targetConn.(*net.TCPConn); ok {
+				tcpConn.CloseWrite()
+			}
+		}()
+
+		// Use a large buffer for better performance
+		buf := make([]byte, 32*1024)
+		_, err := io.CopyBuffer(targetConn, clientReader, buf)
+		if err != nil && err != io.EOF {
+			logger.Debug("Copy client->target error: %v", err)
+		}
+	}()
+
+	// Copy data from target to client
+	go func() {
+		defer wg.Done()
+		defer func() {
+			if tcpConn, ok := clientConn.(*net.TCPConn); ok {
+				tcpConn.CloseWrite()
+			}
+		}()
+
+		// Use a large buffer for better performance
+		buf := make([]byte, 32*1024)
+		_, err := io.CopyBuffer(clientConn, targetConn, buf)
+		if err != nil && err != io.EOF {
+			logger.Debug("Copy target->client error: %v", err)
+		}
+	}()
+
+	wg.Wait()
+}
+
+// GetCacheStats returns cache statistics
+func (p *SNIProxy) GetCacheStats() (int, int) {
+	return p.cache.ItemCount(), len(p.cache.Items())
+}
+
+// ClearCache clears all cached entries
+func (p *SNIProxy) ClearCache() {
+	p.cache.Flush()
+	log.Println("Cache cleared")
+}
+
+// UpdateLocalSNIs updates the local SNIs and invalidates cache for changed domains
+func (p *SNIProxy) UpdateLocalSNIs(fullDomains []string) {
+	newSNIs := make(map[string]struct{})
+	for _, domain := range fullDomains {
+		newSNIs[domain] = struct{}{}
+		// Invalidate any cached route for this domain
+		p.cache.Delete(domain)
+	}
+
+	// Update localSNIs
+	p.localSNIsLock.Lock()
+	removed := make([]string, 0)
+	for sni := range p.localSNIs {
+		if _, stillLocal := newSNIs[sni]; !stillLocal {
+			removed = append(removed, sni)
+		}
+	}
+	p.localSNIs = newSNIs
+	p.localSNIsLock.Unlock()
+
+	logger.Debug("Updated local SNIs, added %d, removed %d", len(newSNIs), len(removed))
+
+	// Terminate tunnels for removed SNIs
+	if len(removed) > 0 {
+		p.activeTunnelsLock.Lock()
+		for _, sni := range removed {
+			if tunnels, ok := p.activeTunnels[sni]; ok {
+				for _, conn := range tunnels.conns {
+					conn.Close()
+				}
+				delete(p.activeTunnels, sni)
+				logger.Debug("Closed tunnels for SNI target change: %s", sni)
+			}
+		}
+		p.activeTunnelsLock.Unlock()
+	}
+}

proxy/proxy_test.go

@@ -0,0 +1,119 @@
+package proxy
+
+import (
+	"net"
+	"testing"
+)
+
+func TestBuildProxyProtocolHeader(t *testing.T) {
+	tests := []struct {
+		name       string
+		clientAddr string
+		targetAddr string
+		expected   string
+	}{
+		{
+			name:       "IPv4 client and target",
+			clientAddr: "192.168.1.100:12345",
+			targetAddr: "10.0.0.1:443",
+			expected:   "PROXY TCP4 192.168.1.100 10.0.0.1 12345 443\r\n",
+		},
+		{
+			name:       "IPv6 client and target",
+			clientAddr: "[2001:db8::1]:12345",
+			targetAddr: "[2001:db8::2]:443",
+			expected:   "PROXY TCP6 2001:db8::1 2001:db8::2 12345 443\r\n",
+		},
+		{
+			name:       "IPv4 client with IPv6 loopback target",
+			clientAddr: "192.168.1.100:12345",
+			targetAddr: "[::1]:443",
+			expected:   "PROXY TCP4 192.168.1.100 127.0.0.1 12345 443\r\n",
+		},
+		{
+			name:       "IPv4 client with IPv6 target",
+			clientAddr: "192.168.1.100:12345",
+			targetAddr: "[2001:db8::2]:443",
+			expected:   "PROXY TCP4 192.168.1.100 127.0.0.1 12345 443\r\n",
+		},
+		{
+			name:       "IPv6 client with IPv4 target",
+			clientAddr: "[2001:db8::1]:12345",
+			targetAddr: "10.0.0.1:443",
+			expected:   "PROXY TCP6 2001:db8::1 ::ffff:10.0.0.1 12345 443\r\n",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			clientTCP, err := net.ResolveTCPAddr("tcp", tt.clientAddr)
+			if err != nil {
+				t.Fatalf("Failed to resolve client address: %v", err)
+			}
+
+			targetTCP, err := net.ResolveTCPAddr("tcp", tt.targetAddr)
+			if err != nil {
+				t.Fatalf("Failed to resolve target address: %v", err)
+			}
+
+			result := buildProxyProtocolHeader(clientTCP, targetTCP)
+			if result != tt.expected {
+				t.Errorf("Expected %q, got %q", tt.expected, result)
+			}
+		})
+	}
+}
+
+func TestBuildProxyProtocolHeaderUnknownType(t *testing.T) {
+	// Test with non-TCP address type
+	clientAddr := &net.UDPAddr{IP: net.ParseIP("192.168.1.100"), Port: 12345}
+	targetAddr := &net.UDPAddr{IP: net.ParseIP("10.0.0.1"), Port: 443}
+
+	result := buildProxyProtocolHeader(clientAddr, targetAddr)
+	expected := "PROXY UNKNOWN\r\n"
+
+	if result != expected {
+		t.Errorf("Expected %q, got %q", expected, result)
+	}
+}
+
+func TestBuildProxyProtocolHeaderFromInfo(t *testing.T) {
+	proxy, err := NewSNIProxy(8443, "", "", "127.0.0.1", 443, nil, true, nil)
+	if err != nil {
+		t.Fatalf("Failed to create SNI proxy: %v", err)
+	}
+
+	// Test IPv4 case
+	proxyInfo := &ProxyProtocolInfo{
+		Protocol: "TCP4",
+		SrcIP:    "10.0.0.1",
+		DestIP:   "192.168.1.100",
+		SrcPort:  12345,
+		DestPort: 443,
+	}
+
+	targetAddr, _ := net.ResolveTCPAddr("tcp", "127.0.0.1:8080")
+	header := proxy.buildProxyProtocolHeaderFromInfo(proxyInfo, targetAddr)
+
+	expected := "PROXY TCP4 10.0.0.1 127.0.0.1 12345 8080\r\n"
+	if header != expected {
+		t.Errorf("Expected header '%s', got '%s'", expected, header)
+	}
+
+	// Test IPv6 case
+	proxyInfo = &ProxyProtocolInfo{
+		Protocol: "TCP6",
+		SrcIP:    "2001:db8::1",
+		DestIP:   "2001:db8::2",
+		SrcPort:  12345,
+		DestPort: 443,
+	}
+
+	targetAddr, _ = net.ResolveTCPAddr("tcp6", "[::1]:8080")
+	header = proxy.buildProxyProtocolHeaderFromInfo(proxyInfo, targetAddr)
+
+	expected = "PROXY TCP6 2001:db8::1 ::1 12345 8080\r\n"
+	if header != expected {
+		t.Errorf("Expected header '%s', got '%s'", expected, header)
+	}
+}

relay/relay.go

@@ -0,0 +1,965 @@
+package relay
+
+import (
+	"bytes"
+	"encoding/binary"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"sync"
+	"time"
+
+	"github.com/fosrl/gerbil/logger"
+	"golang.org/x/crypto/chacha20poly1305"
+	"golang.org/x/crypto/curve25519"
+	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
+)
+
+type EncryptedHolePunchMessage struct {
+	EphemeralPublicKey string `json:"ephemeralPublicKey"`
+	Nonce              []byte `json:"nonce"`
+	Ciphertext         []byte `json:"ciphertext"`
+}
+
+type HolePunchMessage struct {
+	OlmID  string `json:"olmId"`
+	NewtID string `json:"newtId"`
+	Token  string `json:"token"`
+}
+
+type ClientEndpoint struct {
+	OlmID       string `json:"olmId"`
+	NewtID      string `json:"newtId"`
+	Token       string `json:"token"`
+	IP          string `json:"ip"`
+	Port        int    `json:"port"`
+	Timestamp   int64  `json:"timestamp"`
+	ReachableAt string `json:"reachableAt"`
+	PublicKey   string `json:"publicKey"`
+}
+
+// Updated to support multiple destination peers
+type ProxyMapping struct {
+	Destinations []PeerDestination `json:"destinations"`
+	LastUsed     time.Time         `json:"-"` // Not serialized, used for cleanup
+}
+
+type PeerDestination struct {
+	DestinationIP   string `json:"destinationIP"`
+	DestinationPort int    `json:"destinationPort"`
+}
+
+type DestinationConn struct {
+	conn     *net.UDPConn
+	lastUsed time.Time
+}
+
+// Type for storing WireGuard handshake information
+type WireGuardSession struct {
+	ReceiverIndex uint32
+	SenderIndex   uint32
+	DestAddr      *net.UDPAddr
+	LastSeen      time.Time
+}
+
+// Type for tracking bidirectional communication patterns to rebuild sessions
+type CommunicationPattern struct {
+	FromClient     *net.UDPAddr // The client address
+	ToDestination  *net.UDPAddr // The destination address
+	ClientIndex    uint32       // The receiver index seen from client
+	DestIndex      uint32       // The receiver index seen from destination
+	LastFromClient time.Time    // Last packet from client to destination
+	LastFromDest   time.Time    // Last packet from destination to client
+	PacketCount    int          // Number of packets observed
+}
+
+type InitialMappings struct {
+	Mappings map[string]ProxyMapping `json:"mappings"` // key is "ip:port"
+}
+
+// Packet is a simple struct to hold the packet data and sender info.
+type Packet struct {
+	data       []byte
+	remoteAddr *net.UDPAddr
+	n          int
+}
+
+// WireGuard message types
+const (
+	WireGuardMessageTypeHandshakeInitiation = 1
+	WireGuardMessageTypeHandshakeResponse   = 2
+	WireGuardMessageTypeCookieReply         = 3
+	WireGuardMessageTypeTransportData       = 4
+)
+
+// --- End Types ---
+
+// bufferPool allows reusing buffers to reduce allocations.
+var bufferPool = sync.Pool{
+	New: func() interface{} {
+		return make([]byte, 1500)
+	},
+}
+
+// UDPProxyServer has a channel for incoming packets.
+type UDPProxyServer struct {
+	addr          string
+	serverURL     string
+	conn          *net.UDPConn
+	proxyMappings sync.Map // map[string]ProxyMapping where key is "ip:port"
+	connections   sync.Map // map[string]*DestinationConn where key is destination "ip:port"
+	privateKey    wgtypes.Key
+	packetChan    chan Packet
+
+	// Session tracking for WireGuard peers
+	// Key format: "senderIndex:receiverIndex"
+	wgSessions sync.Map
+	// Communication pattern tracking for rebuilding sessions
+	// Key format: "clientIP:clientPort-destIP:destPort"
+	commPatterns sync.Map
+	// ReachableAt is the URL where this server can be reached
+	ReachableAt string
+}
+
+// NewUDPProxyServer initializes the server with a buffered packet channel.
+func NewUDPProxyServer(addr, serverURL string, privateKey wgtypes.Key, reachableAt string) *UDPProxyServer {
+	return &UDPProxyServer{
+		addr:        addr,
+		serverURL:   serverURL,
+		privateKey:  privateKey,
+		packetChan:  make(chan Packet, 1000),
+		ReachableAt: reachableAt,
+	}
+}
+
+// Start sets up the UDP listener, worker pool, and begins reading packets.
+func (s *UDPProxyServer) Start() error {
+	// Fetch initial mappings.
+	if err := s.fetchInitialMappings(); err != nil {
+		return fmt.Errorf("failed to fetch initial mappings: %v", err)
+	}
+
+	udpAddr, err := net.ResolveUDPAddr("udp", s.addr)
+	if err != nil {
+		return err
+	}
+	conn, err := net.ListenUDP("udp", udpAddr)
+	if err != nil {
+		return err
+	}
+	s.conn = conn
+	logger.Info("UDP server listening on %s", s.addr)
+
+	// Start a fixed number of worker goroutines.
+	workerCount := 10 // TODO: Make this configurable or pick it better!
+	for i := 0; i < workerCount; i++ {
+		go s.packetWorker()
+	}
+
+	// Start the goroutine that reads packets from the UDP socket.
+	go s.readPackets()
+
+	// Start the idle connection cleanup routine.
+	go s.cleanupIdleConnections()
+
+	// Start the session cleanup routine
+	go s.cleanupIdleSessions()
+
+	// Start the proxy mapping cleanup routine
+	go s.cleanupIdleProxyMappings()
+
+	// Start the communication pattern cleanup routine
+	go s.cleanupIdleCommunicationPatterns()
+
+	return nil
+}
+
+func (s *UDPProxyServer) Stop() {
+	s.conn.Close()
+}
+
+// readPackets continuously reads from the UDP socket and pushes packets into the channel.
+func (s *UDPProxyServer) readPackets() {
+	for {
+		buf := bufferPool.Get().([]byte)
+		n, remoteAddr, err := s.conn.ReadFromUDP(buf)
+		if err != nil {
+			logger.Error("Error reading UDP packet: %v", err)
+			continue
+		}
+		s.packetChan <- Packet{data: buf[:n], remoteAddr: remoteAddr, n: n}
+	}
+}
+
+// packetWorker processes incoming packets from the channel.
+func (s *UDPProxyServer) packetWorker() {
+	for packet := range s.packetChan {
+		// Determine packet type by inspecting the first byte.
+		if packet.n > 0 && packet.data[0] >= 1 && packet.data[0] <= 4 {
+			// Process as a WireGuard packet.
+			s.handleWireGuardPacket(packet.data, packet.remoteAddr)
+		} else {
+			// Process as an encrypted hole punch message
+			var encMsg EncryptedHolePunchMessage
+			if err := json.Unmarshal(packet.data, &encMsg); err != nil {
+				logger.Error("Error unmarshaling encrypted message: %v", err)
+				// Return the buffer to the pool for reuse and continue with next packet
+				bufferPool.Put(packet.data[:1500])
+				continue
+			}
+
+			if encMsg.EphemeralPublicKey == "" {
+				logger.Error("Received malformed message without ephemeral key")
+				// Return the buffer to the pool for reuse and continue with next packet
+				bufferPool.Put(packet.data[:1500])
+				continue
+			}
+
+			// This appears to be an encrypted message
+			decryptedData, err := s.decryptMessage(encMsg)
+			if err != nil {
+				logger.Error("Failed to decrypt message: %v", err)
+				// Return the buffer to the pool for reuse and continue with next packet
+				bufferPool.Put(packet.data[:1500])
+				continue
+			}
+
+			// Process the decrypted hole punch message
+			var msg HolePunchMessage
+			if err := json.Unmarshal(decryptedData, &msg); err != nil {
+				logger.Error("Error unmarshaling decrypted message: %v", err)
+				// Return the buffer to the pool for reuse and continue with next packet
+				bufferPool.Put(packet.data[:1500])
+				continue
+			}
+
+			endpoint := ClientEndpoint{
+				NewtID:      msg.NewtID,
+				OlmID:       msg.OlmID,
+				Token:       msg.Token,
+				IP:          packet.remoteAddr.IP.String(),
+				Port:        packet.remoteAddr.Port,
+				Timestamp:   time.Now().Unix(),
+				ReachableAt: s.ReachableAt,
+				PublicKey:   s.privateKey.PublicKey().String(),
+			}
+			logger.Debug("Created endpoint from packet remoteAddr %s: IP=%s, Port=%d", packet.remoteAddr.String(), endpoint.IP, endpoint.Port)
+			s.notifyServer(endpoint)
+			s.clearSessionsForIP(endpoint.IP) // Clear sessions for this IP to allow re-establishment
+		}
+		// Return the buffer to the pool for reuse.
+		bufferPool.Put(packet.data[:1500])
+	}
+}
+
+// decryptMessage decrypts the message using the server's private key
+func (s *UDPProxyServer) decryptMessage(encMsg EncryptedHolePunchMessage) ([]byte, error) {
+	// Parse the ephemeral public key
+	ephPubKey, err := wgtypes.ParseKey(encMsg.EphemeralPublicKey)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse ephemeral public key: %v", err)
+	}
+
+	// Use X25519 for key exchange instead of ScalarMult
+	sharedSecret, err := curve25519.X25519(s.privateKey[:], ephPubKey[:])
+	if err != nil {
+		return nil, fmt.Errorf("failed to perform X25519 key exchange: %v", err)
+	}
+
+	// Create the AEAD cipher using the shared secret
+	aead, err := chacha20poly1305.New(sharedSecret)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create AEAD cipher: %v", err)
+	}
+
+	// Verify nonce size
+	if len(encMsg.Nonce) != aead.NonceSize() {
+		return nil, fmt.Errorf("invalid nonce size")
+	}
+
+	// Decrypt the ciphertext
+	plaintext, err := aead.Open(nil, encMsg.Nonce, encMsg.Ciphertext, nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to decrypt message: %v", err)
+	}
+
+	return plaintext, nil
+}
+
+func (s *UDPProxyServer) fetchInitialMappings() error {
+	body := bytes.NewBuffer([]byte(fmt.Sprintf(`{"publicKey": "%s"}`, s.privateKey.PublicKey().String())))
+	resp, err := http.Post(s.serverURL+"/gerbil/get-all-relays", "application/json", body)
+	if err != nil {
+		return fmt.Errorf("failed to fetch mappings: %v", err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(resp.Body)
+		return fmt.Errorf("server returned non-OK status: %d, body: %s",
+			resp.StatusCode, string(body))
+	}
+	data, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return fmt.Errorf("failed to read response body: %v", err)
+	}
+	logger.Info("Received initial mappings: %s", string(data))
+	var initialMappings InitialMappings
+	if err := json.Unmarshal(data, &initialMappings); err != nil {
+		return fmt.Errorf("failed to unmarshal initial mappings: %v", err)
+	}
+	// Store mappings in our sync.Map.
+	for key, mapping := range initialMappings.Mappings {
+		// Initialize LastUsed timestamp for initial mappings
+		mapping.LastUsed = time.Now()
+		s.proxyMappings.Store(key, mapping)
+	}
+	logger.Info("Loaded %d initial proxy mappings", len(initialMappings.Mappings))
+	return nil
+}
+
+// Extract WireGuard message indices
+func extractWireGuardIndices(packet []byte) (uint32, uint32, bool) {
+	if len(packet) < 12 {
+		return 0, 0, false
+	}
+
+	messageType := packet[0]
+	if messageType == WireGuardMessageTypeHandshakeInitiation {
+		// Handshake initiation: extract sender index at offset 4
+		senderIndex := binary.LittleEndian.Uint32(packet[4:8])
+		return 0, senderIndex, true
+	} else if messageType == WireGuardMessageTypeHandshakeResponse {
+		// Handshake response: extract sender index at offset 4 and receiver index at offset 8
+		senderIndex := binary.LittleEndian.Uint32(packet[4:8])
+		receiverIndex := binary.LittleEndian.Uint32(packet[8:12])
+		return receiverIndex, senderIndex, true
+	} else if messageType == WireGuardMessageTypeTransportData {
+		// Transport data: extract receiver index at offset 4
+		receiverIndex := binary.LittleEndian.Uint32(packet[4:8])
+		return receiverIndex, 0, true
+	}
+
+	return 0, 0, false
+}
+
+// Updated to handle multi-peer WireGuard communication
+func (s *UDPProxyServer) handleWireGuardPacket(packet []byte, remoteAddr *net.UDPAddr) {
+	if len(packet) == 0 {
+		logger.Error("Received empty packet")
+		return
+	}
+
+	messageType := packet[0]
+	receiverIndex, senderIndex, ok := extractWireGuardIndices(packet)
+
+	if !ok {
+		logger.Error("Failed to extract WireGuard indices")
+		return
+	}
+
+	key := remoteAddr.String()
+	mappingObj, ok := s.proxyMappings.Load(key)
+	if !ok {
+		logger.Error("No proxy mapping found for %s", key)
+		return
+	}
+
+	proxyMapping := mappingObj.(ProxyMapping)
+	// Update the last used timestamp and store it back
+	proxyMapping.LastUsed = time.Now()
+	s.proxyMappings.Store(key, proxyMapping)
+
+	// Handle different WireGuard message types
+	switch messageType {
+	case WireGuardMessageTypeHandshakeInitiation:
+		// Initial handshake: forward to all peers
+		logger.Debug("Forwarding handshake initiation from %s (sender index: %d) to peers %v", remoteAddr, senderIndex, proxyMapping.Destinations)
+
+		for _, dest := range proxyMapping.Destinations {
+			destAddr, err := net.ResolveUDPAddr("udp", fmt.Sprintf("%s:%d", dest.DestinationIP, dest.DestinationPort))
+			if err != nil {
+				logger.Error("Failed to resolve destination address: %v", err)
+				continue
+			}
+
+			conn, err := s.getOrCreateConnection(destAddr, remoteAddr)
+			if err != nil {
+				logger.Error("Failed to get/create connection: %v", err)
+				continue
+			}
+
+			_, err = conn.Write(packet)
+			if err != nil {
+				logger.Error("Failed to forward handshake initiation: %v", err)
+			}
+		}
+
+	case WireGuardMessageTypeHandshakeResponse:
+		// Received handshake response: establish session mapping
+		logger.Debug("Received handshake response with receiver index %d and sender index %d from %s",
+			receiverIndex, senderIndex, remoteAddr)
+
+		// Create a session key for the peer that sent the initial handshake
+		sessionKey := fmt.Sprintf("%d:%d", receiverIndex, senderIndex)
+
+		// Store the session information
+		s.wgSessions.Store(sessionKey, &WireGuardSession{
+			ReceiverIndex: receiverIndex,
+			SenderIndex:   senderIndex,
+			DestAddr:      remoteAddr,
+			LastSeen:      time.Now(),
+		})
+
+		// Forward the response to the original sender
+		for _, dest := range proxyMapping.Destinations {
+			destAddr, err := net.ResolveUDPAddr("udp", fmt.Sprintf("%s:%d", dest.DestinationIP, dest.DestinationPort))
+			if err != nil {
+				logger.Error("Failed to resolve destination address: %v", err)
+				continue
+			}
+
+			conn, err := s.getOrCreateConnection(destAddr, remoteAddr)
+			if err != nil {
+				logger.Error("Failed to get/create connection: %v", err)
+				continue
+			}
+
+			_, err = conn.Write(packet)
+			if err != nil {
+				logger.Error("Failed to forward handshake response: %v", err)
+			}
+		}
+
+	case WireGuardMessageTypeTransportData:
+		// Data packet: forward only to the established session peer
+		// logger.Debug("Received transport data with receiver index %d from %s", receiverIndex, remoteAddr)
+
+		// Look up the session based on the receiver index
+		var destAddr *net.UDPAddr
+
+		// First check for existing sessions to see if we know where to send this packet
+		s.wgSessions.Range(func(k, v interface{}) bool {
+			session := v.(*WireGuardSession)
+			if session.SenderIndex == receiverIndex {
+				// Found matching session
+				destAddr = session.DestAddr
+
+				// Update last seen time
+				session.LastSeen = time.Now()
+				s.wgSessions.Store(k, session)
+				return false // stop iteration
+			}
+			return true // continue iteration
+		})
+
+		if destAddr != nil {
+			// We found a specific peer to forward to
+			conn, err := s.getOrCreateConnection(destAddr, remoteAddr)
+			if err != nil {
+				logger.Error("Failed to get/create connection: %v", err)
+				return
+			}
+
+			// Track communication pattern for session rebuilding
+			s.trackCommunicationPattern(remoteAddr, destAddr, receiverIndex, true)
+
+			_, err = conn.Write(packet)
+			if err != nil {
+				logger.Debug("Failed to forward transport data: %v", err)
+			}
+		} else {
+			// No known session, fall back to forwarding to all peers
+			logger.Debug("No session found for receiver index %d, forwarding to all destinations", receiverIndex)
+			for _, dest := range proxyMapping.Destinations {
+				destAddr, err := net.ResolveUDPAddr("udp", fmt.Sprintf("%s:%d", dest.DestinationIP, dest.DestinationPort))
+				if err != nil {
+					logger.Error("Failed to resolve destination address: %v", err)
+					continue
+				}
+
+				conn, err := s.getOrCreateConnection(destAddr, remoteAddr)
+				if err != nil {
+					logger.Error("Failed to get/create connection: %v", err)
+					continue
+				}
+
+				// Track communication pattern for session rebuilding
+				s.trackCommunicationPattern(remoteAddr, destAddr, receiverIndex, true)
+
+				_, err = conn.Write(packet)
+				if err != nil {
+					logger.Debug("Failed to forward transport data: %v", err)
+				}
+			}
+		}
+
+	default:
+		// Other packet types (like cookie reply)
+		logger.Debug("Forwarding WireGuard packet type %d from %s", messageType, remoteAddr)
+
+		// Forward to all peers
+		for _, dest := range proxyMapping.Destinations {
+			destAddr, err := net.ResolveUDPAddr("udp", fmt.Sprintf("%s:%d", dest.DestinationIP, dest.DestinationPort))
+			if err != nil {
+				logger.Error("Failed to resolve destination address: %v", err)
+				continue
+			}
+
+			conn, err := s.getOrCreateConnection(destAddr, remoteAddr)
+			if err != nil {
+				logger.Error("Failed to get/create connection: %v", err)
+				continue
+			}
+
+			_, err = conn.Write(packet)
+			if err != nil {
+				logger.Error("Failed to forward WireGuard packet: %v", err)
+			}
+		}
+	}
+}
+
+func (s *UDPProxyServer) getOrCreateConnection(destAddr *net.UDPAddr, remoteAddr *net.UDPAddr) (*net.UDPConn, error) {
+	key := destAddr.String() + "-" + remoteAddr.String()
+
+	// Check if we have an existing connection
+	if conn, ok := s.connections.Load(key); ok {
+		destConn := conn.(*DestinationConn)
+		destConn.lastUsed = time.Now()
+		return destConn.conn, nil
+	}
+
+	// Create new connection
+	newConn, err := net.DialUDP("udp", nil, destAddr)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create UDP connection: %v", err)
+	}
+
+	// Store the new connection
+	s.connections.Store(key, &DestinationConn{
+		conn:     newConn,
+		lastUsed: time.Now(),
+	})
+
+	// Start a goroutine to handle responses
+	go s.handleResponses(newConn, destAddr, remoteAddr)
+
+	return newConn, nil
+}
+
+func (s *UDPProxyServer) handleResponses(conn *net.UDPConn, destAddr *net.UDPAddr, remoteAddr *net.UDPAddr) {
+	buffer := make([]byte, 1500)
+	for {
+		n, err := conn.Read(buffer)
+		if err != nil {
+			logger.Debug("Error reading response from %s: %v", destAddr.String(), err)
+			return
+		}
+
+		// Process the response to track sessions if it's a WireGuard packet
+		if n > 0 && buffer[0] >= 1 && buffer[0] <= 4 {
+			receiverIndex, senderIndex, ok := extractWireGuardIndices(buffer[:n])
+			if ok && buffer[0] == WireGuardMessageTypeHandshakeResponse {
+				// Store the session mapping for the handshake response
+				sessionKey := fmt.Sprintf("%d:%d", senderIndex, receiverIndex)
+				s.wgSessions.Store(sessionKey, &WireGuardSession{
+					ReceiverIndex: receiverIndex,
+					SenderIndex:   senderIndex,
+					DestAddr:      destAddr,
+					LastSeen:      time.Now(),
+				})
+				logger.Debug("Stored session mapping: %s -> %s", sessionKey, destAddr.String())
+			} else if ok && buffer[0] == WireGuardMessageTypeTransportData {
+				// Track communication pattern for session rebuilding (reverse direction)
+				s.trackCommunicationPattern(destAddr, remoteAddr, receiverIndex, false)
+			}
+		}
+
+		// Forward the response back through the main listener
+		_, err = s.conn.WriteToUDP(buffer[:n], remoteAddr)
+		if err != nil {
+			logger.Error("Failed to forward response: %v", err)
+		}
+	}
+}
+
+// Add a cleanup method to periodically remove idle connections
+func (s *UDPProxyServer) cleanupIdleConnections() {
+	ticker := time.NewTicker(5 * time.Minute)
+	for range ticker.C {
+		now := time.Now()
+		s.connections.Range(func(key, value interface{}) bool {
+			destConn := value.(*DestinationConn)
+			if now.Sub(destConn.lastUsed) > 10*time.Minute {
+				destConn.conn.Close()
+				s.connections.Delete(key)
+			}
+			return true
+		})
+	}
+}
+
+// New method to periodically remove idle sessions
+func (s *UDPProxyServer) cleanupIdleSessions() {
+	ticker := time.NewTicker(5 * time.Minute)
+	for range ticker.C {
+		now := time.Now()
+		s.wgSessions.Range(func(key, value interface{}) bool {
+			session := value.(*WireGuardSession)
+			if now.Sub(session.LastSeen) > 15*time.Minute {
+				s.wgSessions.Delete(key)
+				logger.Debug("Removed idle session: %s", key)
+			}
+			return true
+		})
+	}
+}
+
+// New method to periodically remove idle proxy mappings
+func (s *UDPProxyServer) cleanupIdleProxyMappings() {
+	ticker := time.NewTicker(10 * time.Minute)
+	for range ticker.C {
+		now := time.Now()
+		s.proxyMappings.Range(func(key, value interface{}) bool {
+			mapping := value.(ProxyMapping)
+			// Remove mappings that haven't been used in 30 minutes
+			if now.Sub(mapping.LastUsed) > 30*time.Minute {
+				s.proxyMappings.Delete(key)
+				logger.Debug("Removed idle proxy mapping: %s", key)
+			}
+			return true
+		})
+	}
+}
+
+func (s *UDPProxyServer) notifyServer(endpoint ClientEndpoint) {
+	logger.Debug("notifyServer called with endpoint: IP=%s, Port=%d", endpoint.IP, endpoint.Port)
+
+	jsonData, err := json.Marshal(endpoint)
+	if err != nil {
+		logger.Error("Failed to marshal endpoint data: %v", err)
+		return
+	}
+
+	resp, err := http.Post(s.serverURL+"/gerbil/update-hole-punch", "application/json", bytes.NewBuffer(jsonData))
+	if err != nil {
+		logger.Error("Failed to notify server: %v", err)
+		return
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(resp.Body)
+		logger.Error("Server returned non-OK status: %d, body: %s",
+			resp.StatusCode, string(body))
+		return
+	}
+
+	// Parse the proxy mapping response
+	var mapping ProxyMapping
+	if err := json.NewDecoder(resp.Body).Decode(&mapping); err != nil {
+		logger.Error("Failed to decode proxy mapping: %v", err)
+		return
+	}
+
+	logger.Debug("Received proxy mapping from server: %v", mapping)
+
+	// Store the mapping with current timestamp
+	key := fmt.Sprintf("%s:%d", endpoint.IP, endpoint.Port)
+	logger.Debug("About to store proxy mapping with key: %s (from endpoint IP=%s, Port=%d)", key, endpoint.IP, endpoint.Port)
+	mapping.LastUsed = time.Now()
+	s.proxyMappings.Store(key, mapping)
+
+	logger.Debug("Stored proxy mapping for %s with %d destinations (timestamp: %v)", key, len(mapping.Destinations), mapping.LastUsed)
+}
+
+// Updated to support multiple destinations
+func (s *UDPProxyServer) UpdateProxyMapping(sourceIP string, sourcePort int, destinations []PeerDestination) {
+	key := fmt.Sprintf("%s:%d", sourceIP, sourcePort)
+	mapping := ProxyMapping{
+		Destinations: destinations,
+		LastUsed:     time.Now(),
+	}
+	s.proxyMappings.Store(key, mapping)
+}
+
+// OnPeerAdded clears connections and sessions for a specific WireGuard IP to allow re-establishment
+func (s *UDPProxyServer) OnPeerAdded(wgIP string) {
+	logger.Info("Clearing connections for added peer with WG IP: %s", wgIP)
+	s.clearConnectionsForWGIP(wgIP)
+	// s.clearSessionsForWGIP(wgIP) THE DEST ADDR IS NOT THE WG IP, SO THIS IS NOT NEEDED
+	// s.clearProxyMappingsForWGIP(wgIP)
+}
+
+// OnPeerRemoved clears connections and sessions for a specific WireGuard IP
+func (s *UDPProxyServer) OnPeerRemoved(wgIP string) {
+	logger.Info("Clearing connections for removed peer with WG IP: %s", wgIP)
+	s.clearConnectionsForWGIP(wgIP)
+	// s.clearSessionsForWGIP(wgIP) THE DEST ADDR IS NOT THE WG IP, SO THIS IS NOT NEEDED
+	// s.clearProxyMappingsForWGIP(wgIP)
+}
+
+// clearConnectionsForWGIP removes all connections associated with a specific WireGuard IP
+func (s *UDPProxyServer) clearConnectionsForWGIP(wgIP string) {
+	var keysToDelete []string
+
+	s.connections.Range(func(key, value interface{}) bool {
+		keyStr := key.(string)
+		destConn := value.(*DestinationConn)
+
+		// Connection keys are in format "destAddr-remoteAddr"
+		// Check if either destination or remote address contains the WG IP
+		if containsIP(keyStr, wgIP) {
+			keysToDelete = append(keysToDelete, keyStr)
+			destConn.conn.Close()
+			logger.Debug("Closing connection for WG IP %s: %s", wgIP, keyStr)
+		}
+		return true
+	})
+
+	// Delete the connections
+	for _, key := range keysToDelete {
+		s.connections.Delete(key)
+	}
+
+	logger.Info("Cleared %d connections for WG IP: %s", len(keysToDelete), wgIP)
+}
+
+// clearSessionsForWGIP removes all WireGuard sessions associated with a specific WireGuard IP
+func (s *UDPProxyServer) clearSessionsForIP(ip string) {
+	var keysToDelete []string
+
+	s.wgSessions.Range(func(key, value interface{}) bool {
+		keyStr := key.(string)
+		session := value.(*WireGuardSession)
+
+		// Check if the session's destination address contains the WG IP
+		if session.DestAddr != nil && session.DestAddr.IP.String() == ip {
+			keysToDelete = append(keysToDelete, keyStr)
+			logger.Debug("Marking session for deletion for WG IP %s: %s", ip, keyStr)
+		}
+		return true
+	})
+
+	// Delete the sessions
+	for _, key := range keysToDelete {
+		s.wgSessions.Delete(key)
+	}
+
+	logger.Info("Cleared %d sessions for WG IP: %s", len(keysToDelete), ip)
+}
+
+// // clearProxyMappingsForWGIP removes all proxy mappings that have destinations pointing to a specific WireGuard IP
+// func (s *UDPProxyServer) clearProxyMappingsForWGIP(wgIP string) {
+// 	var keysToDelete []string
+
+// 	s.proxyMappings.Range(func(key, value interface{}) bool {
+// 		keyStr := key.(string)
+// 		mapping := value.(ProxyMapping)
+
+// 		// Check if any destination in the mapping contains the WG IP
+// 		for _, dest := range mapping.Destinations {
+// 			if dest.DestinationIP == wgIP {
+// 				keysToDelete = append(keysToDelete, keyStr)
+// 				logger.Debug("Marking proxy mapping for deletion for WG IP %s: %s -> %s:%d", wgIP, keyStr, dest.DestinationIP, dest.DestinationPort)
+// 				break // Found one destination, no need to check others in this mapping
+// 			}
+// 		}
+// 		return true
+// 	})
+
+// 	// Delete the proxy mappings
+// 	for _, key := range keysToDelete {
+// 		s.proxyMappings.Delete(key)
+// 		logger.Debug("Deleted proxy mapping: %s", key)
+// 	}
+
+// 	logger.Info("Cleared %d proxy mappings for WG IP: %s", len(keysToDelete), wgIP)
+// }
+
+// containsIP checks if a connection key string contains the specified IP address
+func containsIP(connectionKey, ip string) bool {
+	// Connection keys are in format "destIP:destPort-remoteIP:remotePort"
+	// Check if the IP appears at the beginning (destination) or after the dash (remote)
+	ipWithColon := ip + ":"
+
+	// Check if connection key starts with the IP (destination address)
+	if len(connectionKey) >= len(ipWithColon) && connectionKey[:len(ipWithColon)] == ipWithColon {
+		return true
+	}
+
+	// Check if connection key contains the IP after a dash (remote address)
+	dashIndex := -1
+	for i := 0; i < len(connectionKey); i++ {
+		if connectionKey[i] == '-' {
+			dashIndex = i
+			break
+		}
+	}
+
+	if dashIndex != -1 && dashIndex+1 < len(connectionKey) {
+		remainingPart := connectionKey[dashIndex+1:]
+		if len(remainingPart) >= len(ip)+1 && remainingPart[:len(ip)+1] == ipWithColon {
+			return true
+		}
+	}
+
+	return false
+}
+
+// UpdateDestinationInMappings updates all proxy mappings that contain the old destination with the new destination
+// Returns the number of mappings that were updated
+func (s *UDPProxyServer) UpdateDestinationInMappings(oldDest, newDest PeerDestination) int {
+	updatedCount := 0
+
+	s.proxyMappings.Range(func(key, value interface{}) bool {
+		keyStr := key.(string)
+		mapping := value.(ProxyMapping)
+		updated := false
+
+		// Check each destination in the mapping
+		for i, dest := range mapping.Destinations {
+			if dest.DestinationIP == oldDest.DestinationIP && dest.DestinationPort == oldDest.DestinationPort {
+				// Update this destination
+				mapping.Destinations[i] = newDest
+				updated = true
+				logger.Debug("Updated destination in mapping %s: %s:%d -> %s:%d",
+					keyStr, oldDest.DestinationIP, oldDest.DestinationPort,
+					newDest.DestinationIP, newDest.DestinationPort)
+			}
+		}
+
+		// If we updated any destinations, store the updated mapping back
+		if updated {
+			mapping.LastUsed = time.Now()
+			s.proxyMappings.Store(keyStr, mapping)
+			updatedCount++
+		}
+
+		return true // continue iteration
+	})
+
+	if updatedCount > 0 {
+		logger.Info("Updated %d proxy mappings from %s:%d to %s:%d",
+			updatedCount, oldDest.DestinationIP, oldDest.DestinationPort,
+			newDest.DestinationIP, newDest.DestinationPort)
+	}
+
+	return updatedCount
+}
+
+// trackCommunicationPattern tracks bidirectional communication patterns to rebuild sessions
+func (s *UDPProxyServer) trackCommunicationPattern(fromAddr, toAddr *net.UDPAddr, receiverIndex uint32, fromClient bool) {
+	var clientAddr, destAddr *net.UDPAddr
+	var clientIndex, destIndex uint32
+
+	if fromClient {
+		clientAddr = fromAddr
+		destAddr = toAddr
+		clientIndex = receiverIndex
+		destIndex = 0 // We don't know the destination index yet
+	} else {
+		clientAddr = toAddr
+		destAddr = fromAddr
+		clientIndex = 0 // We don't know the client index yet
+		destIndex = receiverIndex
+	}
+
+	patternKey := fmt.Sprintf("%s-%s", clientAddr.String(), destAddr.String())
+	now := time.Now()
+
+	if existingPattern, ok := s.commPatterns.Load(patternKey); ok {
+		pattern := existingPattern.(*CommunicationPattern)
+
+		// Update the pattern
+		if fromClient {
+			pattern.LastFromClient = now
+			if pattern.ClientIndex == 0 {
+				pattern.ClientIndex = clientIndex
+			}
+		} else {
+			pattern.LastFromDest = now
+			if pattern.DestIndex == 0 {
+				pattern.DestIndex = destIndex
+			}
+		}
+
+		pattern.PacketCount++
+		s.commPatterns.Store(patternKey, pattern)
+
+		// Check if we have bidirectional communication and can rebuild a session
+		s.tryRebuildSession(pattern)
+	} else {
+		// Create new pattern
+		pattern := &CommunicationPattern{
+			FromClient:    clientAddr,
+			ToDestination: destAddr,
+			ClientIndex:   clientIndex,
+			DestIndex:     destIndex,
+			PacketCount:   1,
+		}
+
+		if fromClient {
+			pattern.LastFromClient = now
+		} else {
+			pattern.LastFromDest = now
+		}
+
+		s.commPatterns.Store(patternKey, pattern)
+	}
+}
+
+// tryRebuildSession attempts to rebuild a WireGuard session from communication patterns
+func (s *UDPProxyServer) tryRebuildSession(pattern *CommunicationPattern) {
+	// Check if we have bidirectional communication within a reasonable time window
+	timeDiff := pattern.LastFromClient.Sub(pattern.LastFromDest)
+	if timeDiff < 0 {
+		timeDiff = -timeDiff
+	}
+
+	// Only rebuild if we have recent bidirectional communication and both indices
+	if timeDiff < 30*time.Second && pattern.ClientIndex != 0 && pattern.DestIndex != 0 && pattern.PacketCount >= 4 {
+		// Create session mapping: client's index maps to destination
+		sessionKey := fmt.Sprintf("%d:%d", pattern.DestIndex, pattern.ClientIndex)
+
+		// Check if we already have this session
+		if _, exists := s.wgSessions.Load(sessionKey); !exists {
+			session := &WireGuardSession{
+				ReceiverIndex: pattern.DestIndex,
+				SenderIndex:   pattern.ClientIndex,
+				DestAddr:      pattern.ToDestination,
+				LastSeen:      time.Now(),
+			}
+
+			s.wgSessions.Store(sessionKey, session)
+			logger.Info("Rebuilt WireGuard session from communication pattern: %s -> %s (packets: %d)",
+				sessionKey, pattern.ToDestination.String(), pattern.PacketCount)
+		}
+	}
+}
+
+// cleanupIdleCommunicationPatterns periodically removes idle communication patterns
+func (s *UDPProxyServer) cleanupIdleCommunicationPatterns() {
+	ticker := time.NewTicker(10 * time.Minute)
+	for range ticker.C {
+		now := time.Now()
+		s.commPatterns.Range(func(key, value interface{}) bool {
+			pattern := value.(*CommunicationPattern)
+
+			// Get the most recent activity
+			lastActivity := pattern.LastFromClient
+			if pattern.LastFromDest.After(lastActivity) {
+				lastActivity = pattern.LastFromDest
+			}
+
+			// Remove patterns that haven't had activity in 20 minutes
+			if now.Sub(lastActivity) > 20*time.Minute {
+				s.commPatterns.Delete(key)
+				logger.Debug("Removed idle communication pattern: %s", key)
+			}
+			return true
+		})
+	}
+}