Final?

wsvpn.c

@@ -10,6 +10,52 @@
 #define MAX_OPEN_CHANNELS 128
 #define MAX_PACKET_SIZE 32767
 
+/*
+```c
+// ALL integers are network-endian
+
+struct msg_info { // side: both. safe to ignore
+    uint8_t code; // 0x49, 'I'
+    uint16_t len;
+    char msg[1024]; // $.len bytes sent
+};
+
+struct msg_res_error {
+    uint8_t code; // 0x45, 'E'
+    uint16_t req_id; // request ID that caused that error
+    uint16_t len;
+    char msg[1024]; // $.len bytes sent
+};
+
+struct msg_address { // side: server
+    uint8_t code; // 0x41, 'A'
+    uint8_t size;
+    char name[256]; // $.size long
+};
+
+struct msg_res_success { // side: server
+    uint8_t code; // 0x52, 'R'
+    uint16_t req_id; // request ID we're replying to
+    void *data; // packet-specific
+};
+
+struct msg_transmission { // side: server
+    uint8_t code; // 0x54, 'T'
+    uint16_t channel;
+    uint16_t replyChannel;
+    uint16_t size;
+    void *data;
+};
+
+struct msg_req_open { // side: client
+    uint8_t code; // 0x4f, 'O'
+    uint16_t req_id; // incremental request ID
+    uint16_t channel; // channel to be open
+};
+
+```
+*/
+
 struct client {
   struct mg_connection *connection;
   uint16_t open_channels[MAX_OPEN_CHANNELS];
@@ -24,6 +70,7 @@ static void on_ws_connect(struct mg_connection *connection, struct mg_http_messa
 static void on_ws_message(struct mg_connection *connection, struct mg_ws_message *message, void *data);
 static void on_ws_disconnect(struct mg_connection *connection, void *data);
 
+bool client_is_open(struct client *client, uint16_t channel);
 static void modem_open(struct client *client, uint16_t request_id, uint16_t channel);
 static void modem_isOpen(struct client *client, uint16_t request_id, uint16_t channel);
 static void modem_close(struct client *client, uint16_t request_id, uint16_t channel);
@@ -146,12 +193,14 @@ void ws_respond(struct mg_connection *connection, uint16_t request_id, void *dat
 }
 
 static void on_ws_connect(struct mg_connection *connection, struct mg_http_message *message, void *data) {
-  static char addr_str[256];
-  mg_snprintf(addr_str, 256, "%M", mg_print_ip_port, &connection->rem);
-  ws_send_info(connection, "Hello, %s", addr_str);
   struct client *client = malloc(sizeof(struct client));
   memcpy(&connection->data[0], &client, sizeof(struct client *));
   client->connection = connection;
+
+  static char buffer[256];
+  buffer[0] = 'A';
+  buffer[1] = snprintf(&buffer[2], 250, "wsvpn_%ld", connection->id);
+  mg_ws_send(connection, buffer, 2 + buffer[1], WEBSOCKET_OP_BINARY);
 }
 
 static void on_ws_message(struct mg_connection *connection, struct mg_ws_message *message, void *data) {
@@ -171,7 +220,7 @@ static void on_ws_message(struct mg_connection *connection, struct mg_ws_message
   uint16_t request_id = ntohs(*(uint16_t*)&message->data.ptr[1]);
 
   switch (message->data.ptr[0]) {
-    case 'I': // info. We can safely ignore that channel
+    case 'I': // info. We can safely ignore that message
       break;
     case 'O': // open
       {
@@ -205,7 +254,7 @@ static void on_ws_message(struct mg_connection *connection, struct mg_ws_message
         uint16_t channel = ntohs(*(uint16_t*)&message->data.ptr[3]);
         uint16_t reply_channel = ntohs(*(uint16_t*)&message->data.ptr[5]);
         uint16_t data_length = ntohs(*(uint16_t*)&message->data.ptr[7]);
-        modem_transmit(client, request_id, channel, reply_channel, data, data_length);
+        modem_transmit(client, request_id, channel, reply_channel, (void*)&message->data.ptr[9], data_length);
       }
       return;
     default:
@@ -240,13 +289,7 @@ static void modem_open(struct client *client, uint16_t request_id, uint16_t chan
 }
 
 static void modem_isOpen(struct client *client, uint16_t request_id, uint16_t channel) {
-  unsigned char is_open = 0;
+  unsigned char is_open = client_is_open(client, channel) ? 42 : 0;
-  for (int i = 0; i < client->next_open_channel_index; i++) {
-    if (client->open_channels[i] == channel) {
-      is_open = 42;
-      break;
-    }
-  }
   ws_respond(client->connection, request_id, &is_open, 1);
 }
 
@@ -275,7 +318,7 @@ static void modem_transmit(struct client *client, uint16_t request_id, uint16_t
     return;
   }
 
-  buffer[0] = 'M';
+  buffer[0] = 'T';
   buffer[1] = (channel >> 8) & 0xFF;
   buffer[2] = channel & 0xFF;
   buffer[3] = (reply_channel >> 8) & 0xFF;
@@ -283,4 +326,25 @@ static void modem_transmit(struct client *client, uint16_t request_id, uint16_t
   buffer[5] = (size >> 8) & 0xFF;
   buffer[6] = size & 0xFF;
   memcpy(&buffer[7], data, size);
+
+  for (struct mg_connection *conn = client->connection->mgr->conns; conn != NULL; conn = conn->next) {
+    if (conn->is_websocket) {
+      struct client *other_client = *(struct client **)&conn->data[0];
+      if (other_client->connection == conn && other_client->connection != client->connection) {
+        if (client_is_open(other_client, channel)) {
+          mg_ws_send(other_client->connection, buffer, size + 7, WEBSOCKET_OP_BINARY);
+        }
+      }
+    }
+  }
+  ws_respond(client->connection, request_id, NULL, 0);
+}
+
+bool client_is_open(struct client *client, uint16_t channel) {
+  for (int i = 0; i < client->next_open_channel_index; i++) {
+    if (client->open_channels[i] == channel) {
+      return true;
+    }
+  }
+  return false;
 }

wsvpn.lua

@@ -38,11 +38,13 @@ local WSModem = {
     local serialized = textutils.serializeJSON(data)
     expect.range(#serialized, 0, 65535)
     serialized = { serialized:byte(1, 65536) }
-    return self._request(0x54, {
+    self._request(0x54, {
         bit.band(0xFF, bit.brshift(channel, 8)),
         bit.band(0xFF, channel),
         bit.band(0xFF, bit.brshift(replyChannel, 8)),
         bit.band(0xFF, replyChannel),
+        bit.band(0xFF, bit.brshift(#serialized, 8)),
+        bit.band(0xFF, #serialized),
         table.unpack(serialized, 1, #serialized)
       })
   end,
@@ -58,6 +60,9 @@ local WSModem = {
         local len, msg = self._read_u16ne(data)
         msg = string.char(table.unpack(msg))
         os.queueEvent("wsvpn:info", msg)
+      elseif opcode == 0x41 then -- Set address/side
+        local len = table.remove(data, 1)
+        self.side = string.char(table.unpack(data, 1, len))
       elseif opcode == 0x45 then -- Error
         local request_id, error_length
         request_id, data = self._read_u16ne(data)
@@ -67,6 +72,12 @@ local WSModem = {
       elseif opcode == 0x52 then -- Response
         local request_id, response = self._read_u16ne(data)
         os.queueEvent("wsvpn:response", true, request_id, response)
+      elseif opcode == 0x54 then -- Transmission
+        local channel, replyChannel, dataSize, packet
+        channel, data = self._read_u16ne(data)
+        replyChannel, data = self._read_u16ne(data)
+        dataSize, packet = self._read_u16ne(data)
+        os.queueEvent("modem_message", self.side or "wsmodem_0", channel, replyChannel, textutils.unserializeJSON(string.char(table.unpack(data, 1, dataSize))), nil)
       else
         return false, string.format("Invalid opcode 0x%02x", opcode)
       end
@@ -134,7 +145,7 @@ local WSModem = {
 
 return function(addr)
   local ws = assert(http.websocket(addr))
-  local sock = setmetatable({ _socket = ws, _req_id = 0 }, { __index = WSModem })
+  local sock = setmetatable({ _socket = ws, _req_id = 0, side = "wsmodem_unknown" }, { __index = WSModem })
   for name, method in pairs(WSModem) do
     sock[name] = function(...) return method(sock, ...) end
   end