first commit

server.go

@@ -0,0 +1,138 @@
+package main
+
+import (
+	"fmt"
+	"net"
+	"net/http"
+	"strings"
+)
+
+type Service struct {
+	Name        string
+	Subdomains  map[string]bool
+	Directories map[string]bool
+	FilterV4    bool
+	FilterV6    bool
+}
+
+func BuildServices(cfg *Config) map[string]*Service {
+	services := make(map[string]*Service)
+
+	for name, sc := range cfg.Services {
+		if !sc.Enabled {
+			continue
+		}
+		svc := &Service{
+			Name:        name,
+			Subdomains:  make(map[string]bool),
+			Directories: make(map[string]bool),
+		}
+		for _, s := range sc.Subdomains {
+			svc.Subdomains[strings.ToLower(s)] = true
+		}
+		for _, d := range sc.Directories {
+			svc.Directories[d] = true
+		}
+		switch name {
+		case "ip4":
+			svc.FilterV4 = true
+		case "ip6":
+			svc.FilterV6 = true
+		}
+		services[name] = svc
+	}
+	return services
+}
+
+func extractIP(r *http.Request) net.IP {
+	if xff := r.Header.Get("X-Forwarded-For"); xff != "" {
+		parts := strings.Split(xff, ",")
+		if ip := net.ParseIP(strings.TrimSpace(parts[0])); ip != nil {
+			return ip
+		}
+	}
+	if xri := r.Header.Get("X-Real-IP"); xri != "" {
+		if ip := net.ParseIP(strings.TrimSpace(xri)); ip != nil {
+			return ip
+		}
+	}
+	host, _, err := net.SplitHostPort(r.RemoteAddr)
+	if err != nil {
+		return net.ParseIP(r.RemoteAddr)
+	}
+	return net.ParseIP(host)
+}
+
+func matchService(host, path string, services map[string]*Service) *Service {
+	hostname := host
+	if i := strings.IndexByte(host, ':'); i != -1 {
+		hostname = host[:i]
+	}
+
+	for _, svc := range services {
+		if svc.Subdomains[hostname] {
+			return svc
+		}
+	}
+
+	parts := strings.Split(hostname, ".")
+	if len(parts) >= 2 {
+		label := parts[len(parts)-2]
+		for _, svc := range services {
+			if svc.Subdomains[label] {
+				return svc
+			}
+		}
+	}
+
+	for _, svc := range services {
+		if svc.Directories[path] {
+			return svc
+		}
+	}
+	return nil
+}
+
+func Handle(services map[string]*Service, geo *Geo) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		svc := matchService(r.Host, r.URL.Path, services)
+		if svc == nil {
+			http.NotFound(w, r)
+			return
+		}
+
+		ip := extractIP(r)
+		if ip == nil {
+			http.Error(w, "cannot determine client IP", 500)
+			return
+		}
+
+		isV4 := ip.To4() != nil
+		if (svc.FilterV4 && !isV4) || (svc.FilterV6 && isV4) {
+			http.Error(w, fmt.Sprintf("this endpoint requires %s", map[bool]string{true: "IPv6", false: "IPv4"}[svc.FilterV6]), 400)
+			return
+		}
+
+		info := geo.Lookup(ip)
+
+		fmt.Fprintf(w, "%s\n", ip)
+		fmt.Fprintf(w, "%s\n", info.ReverseDNS)
+		fmt.Fprintf(w, "proxy=NO, type=UNKNOWN, tor=NO\n")
+		continent, country, city := info.Continent, info.Country, info.City
+		if continent == "" {
+			continent = "Unknown"
+		}
+		if country == "" {
+			country = "Unknown"
+		}
+		if city == "" {
+			city = "Unknown"
+		}
+		fmt.Fprintf(w, "%s, %s, %s\n", continent, country, city)
+		if info.Org != "" {
+			fmt.Fprintf(w, "%s / %s\n", info.Org, info.ASN)
+		} else {
+			fmt.Fprintf(w, "Unknown\n")
+		}
+	}
+}