2861 Proxy Fixes 4bc05c62

# Proxy Tool Fix Reference

Detailed instructions for making each proxy tool coexist with Tailscale on macOS.

## Contents

- Shadowrocket (macOS ARM)
- Clash / ClashX Pro
- Surge
- NO_PROXY Environment Variable
- General Principles

## Shadowrocket (macOS ARM)

### The Problem

Shadowrocket's `tun-excluded-routes` adds a system route `100.64/10 → default gateway (en0)` for each excluded CIDR. This route has higher priority (`UGSc`) than Tailscale's route (`UCSI`), hijacking all Tailscale traffic.

### The Fix (Three Settings)

Three Shadowrocket settings work together to handle Tailscale traffic correctly:

#### 1. `[Rule]` — Add DIRECT rule (handles TUN-level routing)

```
IP-CIDR,100.64.0.0/10,DIRECT
```

This lets Tailscale traffic enter the Shadowrocket TUN interface, where the DIRECT rule passes it through without proxying. The system route table remains clean.

#### 2. `skip-proxy` — Add Tailscale CGNAT range (fixes browser 503)

In `[General]`, add `100.64.0.0/10` to `skip-proxy`:

```
skip-proxy = 192.168.0.0/16, 10.0.0.0/8, 172.16.0.0/12, 100.64.0.0/10, localhost, *.local, captive.apple.com
```

**Why this is needed**: Browsers (Chrome, Safari) use the system proxy set by the VPN profile, not `http_proxy` env vars. Without `skip-proxy`, the browser sends Tailscale requests to Shadowrocket's proxy process. The DIRECT rule tells the proxy to connect "directly" — but the proxy connects via Wi-Fi (en0), not Tailscale's utun, resulting in HTTP 503.

With `skip-proxy`, the system bypasses the proxy entirely for these IPs. The browser connects through the normal OS network stack where Tailscale's routing works correctly.

#### 3. `tun-excluded-routes` — Do NOT add `100.64.0.0/10`

**Never** add `100.64.0.0/10` to `tun-excluded-routes`. This breaks Tailscale completely:
- Shadowrocket adds `100.64/10 → en0 (UGSc)` to the system route table
- This overrides Tailscale's `100.64/10 → utun (UCSI)` route
- Result: `tailscale ping` works (Tailscale-layer), but SSH, ping, curl, browser all fail (OS-layer)
- Reverting and restarting Shadowrocket VPN restores the routes

### Config API

Shadowrocket exposes a config editor API when the **Edit Plain Text** view is open:

```bash
# Read current config
NO_PROXY="<shadowrocket-ip>" curl -s "http://<shadowrocket-ip>:8080/api/read"

# Save updated config (replaces editor buffer)
NO_PROXY="<shadowrocket-ip>" curl -s -X POST "http://<shadowrocket-ip>:8080/api/save" --data-binary @config.txt
```

**Detect Shadowrocket IP**: The device IP changes with DHCP. Do not hardcode it. Detect it before use:

```bash
# If you know the device is on the same subnet
# Check common ports or use mDNS
curl --noproxy '*' -s --connect-timeout 2 "http://192.168.31.110:8080/api/read" | head -1
```

**Critical**: Use `--data-binary`, NOT `-d`. The `-d` flag URL-encodes the content, corrupting `#`, `=`, `&` and other characters in the config. This **destroys the entire configuration** — all rules, settings, and proxy groups are lost. The user must restore from backup.

```bash
# CORRECT — preserves raw content
curl -s -X POST "http://<ip>:8080/api/save" --data-binary @config.txt

# WRONG — URL-encodes special chars, destroys config
curl -s -X POST "http://<ip>:8080/api/save" -d @config.txt
```

**Important**: The API `save` only writes to the editor buffer. The user must click **Save** in the Shadowrocket UI to persist changes. After saving, the VPN connection must be restarted for route changes to take effect.

### Example tun-excluded-routes (correct)

```
tun-excluded-routes = 10.0.0.0/8, 127.0.0.0/8, 169.254.0.0/16, 172.16.0.0/12, 192.0.0.0/24, 192.0.2.0/24, 192.88.99.0/24, 192.168.0.0/16, 198.51.100.0/24, 203.0.113.0/24, 224.0.0.0/4, 255.255.255.255/32
```

Note: `100.64.0.0/10` is intentionally absent.

## Clash / ClashX Pro

### The Fix

Add Tailscale CIDRs to the rules section before `MATCH`:

```yaml
rules:
  - IP-CIDR,100.64.0.0/10,DIRECT
  - IP-CIDR,fd7a:115c:a1e0::/48,DIRECT
  # ... other rules ...
  - MATCH,PROXY
```

For Clash with TUN mode, also add to `tun.excluded-routes` (if TUN mode doesn't create conflicting system routes on macOS):

```yaml
tun:
  enable: true
  # Only if this doesn't create conflicting system routes:
  # excluded-routes:
  #   - 100.64.0.0/10
```

Test with `route -n get 100.x.x.x` after applying to confirm no `en0` hijack.

## Surge

### The Fix

Add to the `[Rule]` section:

```
IP-CIDR,100.64.0.0/10,DIRECT
IP-CIDR,fd7a:115c:a1e0::/48,DIRECT
```

In Surge's **TUN Excluded Routes** (if available), the same caveat applies as Shadowrocket: excluding `100.64.0.0/10` may add an `en0` route. Test with `route -n get` to confirm.

Surge also supports `skip-proxy` and `always-real-ip`. Adding `skip-proxy` is **required** to fix browser 503 (same mechanism as Shadowrocket):

```
[General]
skip-proxy = 100.64.0.0/10, fd7a:115c:a1e0::/48
always-real-ip = *.ts.net
```

## NO_PROXY Environment Variable

### The Problem

Even when system routes are correct (Tailscale `utun` interface wins), HTTP clients like curl, Python requests, and Node.js fetch respect `http_proxy`/`https_proxy` env vars. If `NO_PROXY` doesn't exclude Tailscale addresses, HTTP traffic is sent to the proxy process, which may fail to reach `100.x` addresses.

This is a **different conflict layer** from route hijacking — routes are fine, but the application bypasses them by sending traffic to the local proxy port.

### The Fix

```bash
export NO_PROXY=localhost,127.0.0.1,.ts.net,100.64.0.0/10,192.168.*,10.*,172.16.*
```

### NO_PROXY Syntax Pitfalls

| Syntax | curl | Python requests | Node.js | Meaning |
|--------|------|-----------------|---------|---------|
| `.ts.net` | ✅ | ✅ | ✅ | Domain suffix match (correct) |
| `*.ts.net` | ❌ | ✅ | varies | Glob — curl does NOT support this |
| `100.64.0.0/10` | ✅ 7.86+ | ✅ 2.25+ | ❌ native | CIDR notation |
| `100.*` | ✅ | ✅ | ✅ | Too broad — covers public IPs `100.0-63.*` and `100.128-255.*` |

**Key rule**: Always use `.ts.net` (leading dot, no asterisk) for domain suffix matching. This is the most portable syntax across all HTTP clients.

### Why Not `100.*`?

`100.0.0.0/8` includes public IP space:
- `100.0.0.0 – 100.63.255.255` — **public** IPs
- `100.64.0.0 – 100.127.255.255` — CGNAT (Tailscale uses this)
- `100.128.0.0 – 100.255.255.255` — **public** IPs

Using `100.*` in `NO_PROXY` would bypass the proxy for services on public `100.x` IPs — potentially breaking access to GFW-blocked services that happen to use those addresses.

### MagicDNS Recommendation

Prefer accessing Tailscale devices by MagicDNS name (e.g., `my-server` or `my-server.tailnet.ts.net`) rather than raw IPs. This makes `.ts.net` in `NO_PROXY` the primary bypass mechanism, with `100.64.0.0/10` as a fallback for direct IP usage.

Check MagicDNS status:
```bash
tailscale dns status
```

## General Principles

### Three Conflict Layers

Proxy tools and Tailscale can conflict at three independent layers on macOS:

| Layer | Setting | What it controls | Symptom when wrong |
|-------|---------|------------------|--------------------|
| 1. Route table | `tun-excluded-routes` | OS-level IP routing | Everything broken (SSH, curl, browser). `tailscale ping` works but `ping` doesn't |
| 2. HTTP env vars | `http_proxy` / `NO_PROXY` | CLI tools (curl, wget, Python, Node.js) | `curl` times out, SSH works, browser works |
| 3. System proxy | `skip-proxy` | Browser and system HTTP clients | Browser 503, `curl` works (both with/without proxy), SSH works |

**Each layer is independent.** A fix at one layer doesn't help the others. You may need fixes at multiple layers simultaneously.

### Why tun-excluded-routes Breaks Tailscale

On macOS, when a VPN tool excludes a CIDR from its TUN interface, it typically adds a system route pointing that CIDR to the default gateway via `en0`. For `100.64.0.0/10`:

```
100.64/10  192.168.x.1  UGSc  en0       ← VPN tool adds this
100.64/10  link#N       UCSI  utun7     ← Tailscale's route
```

macOS route priority: `UGSc` > `UCSI` for same prefix length. Result: Tailscale traffic goes to the router, which has no route to 100.x addresses.

### Why skip-proxy Is Needed for Browsers

Even with correct routes and a DIRECT rule, browsers can still get 503. The flow:

1. Browser sends request to Shadowrocket's system proxy (set by VPN profile)
2. Shadowrocket matches `IP-CIDR,100.64.0.0/10,DIRECT`
3. Shadowrocket tries to connect "directly" — but from its own process context, via Wi-Fi (en0)
4. `100.x.x.x` is unreachable via en0 → 503

`curl` works because it uses the `http_proxy` env var (or no proxy with `--noproxy`), going through the OS network stack where Tailscale routing works. Browsers don't use `http_proxy` — they use the system proxy.

Adding `100.64.0.0/10` to `skip-proxy` makes the system bypass the proxy entirely for those IPs. The browser connects directly through the OS network stack → Tailscale utun handles routing → connection succeeds.

### The Correct Approach

For full Tailscale compatibility with proxy tools, apply all three:

1. **`[Rule]`**: `IP-CIDR,100.64.0.0/10,DIRECT` — handles TUN-level traffic
2. **`skip-proxy`**: Add `100.64.0.0/10` — fixes browser access
3. **`NO_PROXY` env var**: Add `100.64.0.0/10,.ts.net` — fixes CLI HTTP tools
4. **`tun-excluded-routes`**: Do NOT add `100.64.0.0/10` — this breaks everything

### Quick Verification

After any fix, always verify:

```bash
# Route should go through Tailscale utun, not en0
route -n get <tailscale-ip>

# Should show only one 100.64/10 route (Tailscale's)
netstat -rn | grep 100.64

# SSH must work
ssh -o ConnectTimeout=5 <user>@<tailscale-ip> 'echo ok'

# curl must work (with and without proxy)
curl --noproxy '*' -s -o /dev/null -w "%{http_code}" http://<tailscale-ip>:<port>/
curl -s -o /dev/null -w "%{http_code}" http://<tailscale-ip>:<port>/

# Browser must work (open in Chrome, no 503)
```

### SSH Non-Login Shell Pitfall

When SSHing to a remote macOS machine, non-login shells don't load `~/.zshrc`. Tools installed via nvm, Homebrew, or other shell-level managers won't be in `$PATH`. Proxy env vars set in `~/.zshrc` also won't be loaded.

```bash
# FAILS — non-login shell, nvm/proxy not loaded
ssh <tailscale-ip> 'node --version'
# → command not found

# WORKS — explicitly source shell config
ssh <tailscale-ip> 'source ~/.zshrc 2>/dev/null; node --version'
# → v22.18.0
```

**Note**: `bash -lc` loads `.bash_profile` but NOT `.zshrc`. On macOS (default shell is zsh), always use `source ~/.zshrc` or `zsh -ic` for interactive shell initialization.

### localhost Proxy Interception in Scripts

When `http_proxy` is set globally (common in China), any script or Makefile that curls `localhost` will fail unless it bypasses the proxy. This affects health checks, warmup scripts, and test harnesses.

**Fix**: Add `--noproxy localhost` to every localhost curl call in Makefiles and scripts:

```makefile
# Health check that works regardless of proxy settings
@curl --noproxy localhost -sf http://localhost:9000/minio/health/live && echo "OK"
```

Or set `no_proxy` in `~/.zshrc` alongside `http_proxy`:

```bash
export http_proxy=http://127.0.0.1:1082
export https_proxy=http://127.0.0.1:1082
export no_proxy=localhost,127.0.0.1   # Always add this alongside proxy vars
```

### Emergency Rollback

If a proxy config change breaks Tailscale connectivity:

```bash
# Revert the config change and restart Shadowrocket VPN
# This restores the original routes

# Or manually delete a conflicting route:
sudo route delete -net 100.64.0.0/10 <gateway-ip>
```

If `tun-excluded-routes` was modified, reverting it and restarting Shadowrocket will restore Tailscale's routing immediately.