Allow listening port to accept multiple connections

Adam/Net/Tcp.HC

@@ -102,6 +102,58 @@ class CTcpPseudoHeader {
   U16 tcp_length;
 };
 
+class CTcpSocketListItem {
+  CTcpSocketListItem *prev;
+  CTcpSocketListItem *next;
+  CTcpSocket *sock;
+};
+
+static CTcpSocketListItem** tcp_socket_list;
+
+static CTcpSocket* GetTcpSocketFromList(CIPv4Packet* packet, CTcpHeader* hdr) {
+  CTcpSocketListItem* item = tcp_socket_list[ntohs(hdr->dest_port)]->next;
+  while (item) {
+    if (item->sock->remote_addr == packet->source_ip &&
+      item->sock->remote_port == ntohs(hdr->source_port)) {
+      return item->sock;
+    }
+    item = item->next;
+  }
+  return NULL;
+}
+
+U0 AddTcpSocketToList(CTcpSocket* s) {
+  CTcpSocketListItem* prev = tcp_socket_list[s->local_port];
+  CTcpSocketListItem* new = CAlloc(sizeof(CTcpSocketListItem));
+  while (prev->next) {
+    prev = prev->next;
+  }
+  new->prev = prev;
+  new->sock = s;
+  prev->next = new;
+}
+
+CTcpSocket* RemoveTcpSocketFromList(CTcpSocket* s) {
+  CTcpSocketListItem* prev = NULL;
+  CTcpSocketListItem* next = NULL;
+  CTcpSocketListItem* item = tcp_socket_list[s->local_port]->next;
+  while (item) {
+    if (item->sock==s) {
+      prev = item->prev;
+      next = item->next;
+      if (prev) {
+        prev->next = next;
+      }
+      if (next) {
+        next->prev = prev;
+      }
+      return s;
+    }
+    item = item->next;
+  }
+  return NULL;
+}
+
 // TODO: this takes up half a meg, change it to a binary tree or something
 static CTcpSocket** tcp_bound_sockets;
 
@@ -454,7 +506,8 @@ I64 TcpSocketClose(CTcpSocket* s) {
   }
 
   if (s->local_port)
-    tcp_bound_sockets[s->local_port] = NULL;
+    if (!RemoveTcpSocketFromList(s))
+      tcp_bound_sockets[s->local_port] = NULL;
 
   Free(s->recv_buf);
   Free(s);
@@ -710,8 +763,7 @@ U0 TcpSocketHandle(CTcpSocket* s, CIPv4Packet* packet, CTcpHeader* hdr, U8* data
       TcpSend2(new_socket, TCP_FLAG_SYN | TCP_FLAG_ACK);
       new_socket->state = TCP_STATE_SYN_RECEIVED;
 
-      // FIXME FIXME FIXME FIXME
-      tcp_bound_sockets[new_socket->local_port] = new_socket;
+      AddTcpSocketToList(new_socket);
 
       if (s->backlog_last)
         s->backlog_last->backlog_next = new_socket;
@@ -896,7 +948,9 @@ I64 TcpHandler(CIPv4Packet* packet) {
   U16 dest_port = ntohs(hdr->dest_port);
   //"%u => %p\n", dest_port, tcp_bound_sockets[dest_port];
 
-  CTcpSocket* s = tcp_bound_sockets[dest_port];
+  CTcpSocket* s = GetTcpSocketFromList(packet, hdr);
+  if (!s)
+    s = tcp_bound_sockets[dest_port];
 
   // FIXME: should also check that bound address is INADDR_ANY,
   //        OR packet dest IP matches bound address
@@ -911,8 +965,14 @@ I64 TcpHandler(CIPv4Packet* packet) {
 }
 
 U0 TcpInit() {
+  I64 i;
   tcp_bound_sockets = MAlloc(65536 * sizeof(CTcpSocket*));
   MemSet(tcp_bound_sockets, 0, 65536 * sizeof(CTcpSocket*));
+  tcp_socket_list = MAlloc(65536 * sizeof(CTcpSocketListItem*));
+  for (i=0; i<65536; i++)
+  {
+    tcp_socket_list[i] = CAlloc(sizeof(CTcpSocketListItem));
+  }
 }
 
 TcpInit;

Demo/Network/TcpEchoServer.HC

@@ -4,6 +4,23 @@
 
 #define PORT 8000
 
+U0 TcpEchoSession(CTcpSocket* client) {
+  U8 buffer[2048 + 1];
+  I64 count = recv(client, buffer, sizeof(buffer) - 1, 0);
+
+  if (count <= 0) {
+    "$FG,6$recv: error %d\n$FG$", count;
+  }
+  else {
+    buffer[count] = 0;
+    "$FG,8$Received %d bytes:\n$FG$%s\n", count, buffer;
+  }
+
+  send(client, buffer, count, 0);
+
+  close(client);
+}
+
 I64 TcpEchoServer() {
   SocketInit();
 
@@ -32,23 +49,14 @@ I64 TcpEchoServer() {
 
   "$FG,2$Listening on port %d\n$FG$", PORT;
 
-  I64 client = accept(sock, 0, 0);
-
-  U8 buffer[2048 + 1];
-  I64 count = recv(client, buffer, sizeof(buffer) - 1, 0);
-
-  if (count <= 0) {
-    "$FG,6$recv: error %d\n$FG$", count;
+  while (1) {
+    I64 client = accept(sock, 0, 0);
+    if (client)
+      Spawn(&TcpEchoSession, client);
+    else
+      break;
+    Yield; // loop unconditionally
   }
-  else {
-    buffer[count] = 0;
-    "$FG,8$Received %d bytes:\n$FG$%s\n", count, buffer;
-  }
-
-  send(client, buffer, count, 0);
-
-  close(client);
-
   close(sock);
   return 0;
 }