refactor: network - harden TCP/IP and unify HTTP clients

kernel/src/Net/Udp.cpp

@@ -11,6 +11,7 @@
 #include <Libraries/Memory.hpp>
 #include <Terminal/Terminal.hpp>
 #include <CppLib/Stream.hpp>
+#include <CppLib/Spinlock.hpp>
 
 using namespace Kt;
 
@@ -22,8 +23,9 @@ namespace Net::Udp {
         bool         Active;
     };
 
-    static constexpr uint32_t MAX_BINDINGS = 16;
+    static constexpr uint32_t MAX_BINDINGS = 64;
     static PortBinding g_bindings[MAX_BINDINGS] = {};
+    static kcp::Spinlock g_bindingsLock;
 
     void Initialize() {
         for (uint32_t i = 0; i < MAX_BINDINGS; i++) {
@@ -58,13 +60,18 @@ namespace Net::Udp {
         const uint8_t* payload = data + HEADER_SIZE;
         uint16_t payloadLen = udpLen - HEADER_SIZE;
 
-        // Dispatch to bound callback
+        // Snapshot the callback under the binding lock, then invoke it after
+        // releasing the lock so callbacks may safely bind/unbind other ports.
+        RecvCallback callback = nullptr;
+        g_bindingsLock.Acquire();
         for (uint32_t i = 0; i < MAX_BINDINGS; i++) {
             if (g_bindings[i].Active && g_bindings[i].Port == dstPort) {
-                g_bindings[i].Callback(srcIp, srcPort, dstPort, payload, payloadLen);
-                return;
+                callback = g_bindings[i].Callback;
+                break;
             }
         }
+        g_bindingsLock.Release();
+        if (callback) callback(srcIp, srcPort, dstPort, payload, payloadLen);
     }
 
     bool Send(uint32_t destIp, uint16_t srcPort, uint16_t destPort,
@@ -96,9 +103,12 @@ namespace Net::Udp {
     }
 
     bool Bind(uint16_t port, RecvCallback callback) {
+        if (port == 0 || callback == nullptr) return false;
+        g_bindingsLock.Acquire();
         // Check for duplicate
         for (uint32_t i = 0; i < MAX_BINDINGS; i++) {
             if (g_bindings[i].Active && g_bindings[i].Port == port) {
+                g_bindingsLock.Release();
                 return false;
             }
         }
@@ -109,19 +119,25 @@ namespace Net::Udp {
                 g_bindings[i].Port = port;
                 g_bindings[i].Callback = callback;
                 g_bindings[i].Active = true;
+                g_bindingsLock.Release();
                 return true;
             }
         }
+        g_bindingsLock.Release();
         return false;
     }
 
     void Unbind(uint16_t port) {
+        g_bindingsLock.Acquire();
         for (uint32_t i = 0; i < MAX_BINDINGS; i++) {
             if (g_bindings[i].Active && g_bindings[i].Port == port) {
                 g_bindings[i].Active = false;
+                g_bindings[i].Callback = nullptr;
+                g_bindingsLock.Release();
                 return;
             }
         }
+        g_bindingsLock.Release();
     }
 
 }