feat Main HTTP Server; IP,URL Allowlist and Blocklist

internal/server/server.go

@@ -0,0 +1,112 @@
+// internal/server/server.go
+package server
+
+import (
+	"log"
+	"net"
+	"net/http"
+	"server_torii/internal/action"
+	"server_torii/internal/config"
+	"server_torii/internal/dataType"
+	"strings"
+)
+
+// StartServer starts the HTTP server
+func StartServer(port string, ruleSet *config.RuleSet, ipHeaders []string) error {
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		var clientIP string
+		for _, headerName := range ipHeaders {
+			if ipVal := r.Header.Get(headerName); ipVal != "" {
+				if strings.Contains(clientIP, ",") {
+					parts := strings.Split(ipVal, ",")
+					clientIP = strings.TrimSpace(parts[0])
+				}
+				clientIP = ipVal
+				break
+			}
+		}
+
+		if clientIP == "" {
+			remoteAddr := r.RemoteAddr
+			ipStr, _, err := net.SplitHostPort(remoteAddr)
+			if err != nil {
+				//TODO: log error
+				clientIP = remoteAddr
+			} else {
+				clientIP = ipStr
+			}
+		}
+
+		decision := action.NewDecision()
+
+		// run main check logic
+		checkIPAllow(clientIP, ruleSet.IPAllowTrie, decision)
+		checkIPBlock(clientIP, ruleSet.IPBlockTrie, decision)
+		checkURLAllow(r.RequestURI, ruleSet.URLAllowList, decision)
+		checkURLBlock(r.RequestURI, ruleSet.URLBlockList, decision)
+
+		// if still undecided, allow
+		if decision.Get() == action.Undecided {
+			decision.Set(action.Allow)
+		}
+
+		// return response
+		if decision.Get() == action.Allow {
+			w.WriteHeader(http.StatusOK)
+			w.Write([]byte("Allowed"))
+		} else if decision.Get() == action.Block {
+			w.WriteHeader(http.StatusForbidden)
+			w.Write([]byte("Blocked"))
+		} else {
+			// should not reach here
+			w.WriteHeader(http.StatusInternalServerError)
+		}
+	})
+
+	log.Printf("HTTP Server listening on :%s ...", port)
+	return http.ListenAndServe(":"+port, nil)
+}
+
+func checkIPAllow(remoteIP string, trie *dataType.TrieNode, decision *action.Decision) {
+	if decision.Get() != action.Undecided {
+		return
+	}
+	ip := net.ParseIP(remoteIP)
+	if ip == nil {
+		return
+	}
+	if trie.Search(ip) {
+		decision.Set(action.Allow)
+	}
+}
+
+func checkIPBlock(remoteIP string, trie *dataType.TrieNode, decision *action.Decision) {
+	if decision.Get() != action.Undecided {
+		return
+	}
+	ip := net.ParseIP(remoteIP)
+	if ip == nil {
+		return
+	}
+	if trie.Search(ip) {
+		decision.Set(action.Block)
+	}
+}
+
+func checkURLAllow(url string, list *dataType.URLRuleList, decision *action.Decision) {
+	if decision.Get() != action.Undecided {
+		return
+	}
+	if list.Match(url) {
+		decision.Set(action.Allow)
+	}
+}
+
+func checkURLBlock(url string, list *dataType.URLRuleList, decision *action.Decision) {
+	if decision.Get() != action.Undecided {
+		return
+	}
+	if list.Match(url) {
+		decision.Set(action.Block)
+	}
+}