package main
import (
"io"
"log"
"net/http"
"net/url"
"sync/atomic"
"time"
)
var breaker = newCircuitBreaker()
var (
requestsTotal uint64
requestsAllowed uint64
requestsBlocked uint64
requestsBypassed uint64
)
func metricsSnapshot() map[string]interface{} {
return map[string]interface{}{
"total": atomic.LoadUint64(&requestsTotal),
"allowed": atomic.LoadUint64(&requestsAllowed),
"blocked": atomic.LoadUint64(&requestsBlocked),
"bypassed": atomic.LoadUint64(&requestsBypassed),
"circuit": circuitStateStr(breaker.State()),
"enabled": getConfig().Enabled,
}
}
func circuitStateStr(s CircuitState) string {
switch s {
case StateClosed: return "closed"
case StateOpen: return "open"
case StateHalfOpen: return "half-open"
}
return "unknown"
}
func handleInspect(w http.ResponseWriter, r *http.Request) {
atomic.AddUint64(&requestsTotal, 1)
cfg := getConfig()
if !cfg.Enabled {
atomic.AddUint64(&requestsBypassed, 1)
proxyToBackend(w, r)
return
}
if breaker.State() == StateOpen {
atomic.AddUint64(&requestsBypassed, 1)
log.Printf("Firewall: breaker OPEN — fail-open, passing %s %s", r.Method, r.URL.Path)
proxyToBackend(w, r)
return
}
// Inspect via WAF.
status, err := inspect(r)
if err != nil {
atomic.AddUint64(&requestsBypassed, 1)
log.Printf("Firewall: inspection error — fail-open: %v", err)
breaker.RecordFailure()
proxyToBackend(w, r)
return
}
breaker.RecordSuccess()
if status == 403 {
atomic.AddUint64(&requestsBlocked, 1)
log.Printf("Firewall: BLOCKED %s %s", r.Method, r.URL.Path)
w.Header().Set("Content-Type", "text/html")
w.WriteHeader(403)
w.Write([]byte("403 Forbidden
Blocked by Firewall
"))
return
}
// WAF allows — proxy to backend.
atomic.AddUint64(&requestsAllowed, 1)
proxyToBackend(w, r)
}
// proxyToBackend forwards the request to Zoraxy's original upstream.
// The original target is passed by Zoraxy via the X-Zoraxy-Uri header.
func proxyToBackend(w http.ResponseWriter, r *http.Request) {
cfg := getConfig()
target, err := url.Parse(cfg.BackendURL)
if err != nil {
http.Error(w, "invalid backend URL", http.StatusInternalServerError)
return
}
proxyReq, err := http.NewRequestWithContext(r.Context(), r.Method, target.String()+r.URL.Path, r.Body)
if err != nil {
http.Error(w, "proxy error", http.StatusInternalServerError)
return
}
for key, vals := range r.Header {
for _, v := range vals {
proxyReq.Header.Add(key, v)
}
}
proxyReq.Header.Set("X-Forwarded-For", r.RemoteAddr)
client := &http.Client{Timeout: time.Duration(cfg.TimeoutMs) * time.Millisecond}
resp, err := client.Do(proxyReq)
if err != nil {
http.Error(w, "backend unreachable", http.StatusBadGateway)
return
}
defer resp.Body.Close()
for key, vals := range resp.Header {
for _, v := range vals {
w.Header().Add(key, v)
}
}
w.WriteHeader(resp.StatusCode)
io.Copy(w, resp.Body)
}