vpnem: VPN infrastructure with load-balanced multi-protocol nodesHEADmain

- Multi-protocol VPS nodes (VLESS-REALITY + Hysteria2 + SOCKS5)
- Smart load balancing via recommendation API
- Windows/Linux client (Go + Wails + sing-box)
- Server API with RealIP detection and connection tracking
- Auto-deployment via vpnui control plane
- Silent Windows installer with UAC elevation
- Load-based server recommendation (no sticky sessions)
- Best Server one-click connection workflow

1 files changed, 63 insertions, 0 deletions

diff --git a/internal/engine/healthcheck.go b/internal/engine/healthcheck.go
new file mode 100644
index 0000000..a856608
--- /dev/null
+++ b/internal/engine/healthcheck.go
@@ -0,0 +1,63 @@
+package engine
+
+import (
+	"io"
+	"net/http"
+	"strings"
+	"time"
+
+	"vpnem/internal/config"
+)
+
+const DefaultBlockedSiteProbeURL = "https://rutracker.org"
+
+func ModeRequiresExitIP(mode config.Mode) bool {
+	return mode.Final == "proxy"
+}
+
+func CheckExitIP(localProxyPort int) string {
+	client, err := HTTPClientViaSOCKS5(config.LocalProxyHost, localProxyPort, 5*time.Second)
+	if err != nil {
+		return ""
+	}
+	resp, err := client.Get("http://ifconfig.me/ip")
+	if err != nil {
+		return ""
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(io.LimitReader(resp.Body, 64))
+	if err != nil {
+		return ""
+	}
+	return strings.TrimSpace(string(body))
+}
+
+func ProbeBlockedSite(localProxyPort int, rawURL string, timeout time.Duration) (int, error) {
+	client, err := HTTPClientViaSOCKS5(config.LocalProxyHost, localProxyPort, timeout)
+	if err != nil {
+		return 0, err
+	}
+
+	req, err := http.NewRequest(http.MethodGet, rawURL, nil)
+	if err != nil {
+		return 0, err
+	}
+	req.Header.Set("User-Agent", "vpnem-health/1.0")
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return 0, err
+	}
+	defer resp.Body.Close()
+
+	_, _ = io.Copy(io.Discard, io.LimitReader(resp.Body, 256))
+	return resp.StatusCode, nil
+}
+
+func DeepCheckRequiresRestart(mode config.Mode, exitIP string, probeErr error) bool {
+	if ModeRequiresExitIP(mode) {
+		return exitIP == ""
+	}
+	return probeErr != nil
+}