Add new module to handle NAT firewalls

cmd/cmd.c

@@ -41,7 +41,7 @@ static uint16_t resp_crc;
 // Start a response, returns the partial CRC
 void ICACHE_FLASH_ATTR
 cmdResponseStart(uint16_t cmd, uint32_t value, uint16_t argc) {
-  DBG("cmdResponse: cmd=%d val=%d argc=%d\n", cmd, value, argc);
+  // DBG("cmdResponse: cmd=%d val=%d argc=%d\n", cmd, value, argc);
 
   uart0_write_char(SLIP_END);
   cmdProtoWriteBuf((uint8_t*)&cmd, 2);

cmd/cmd.h

@@ -68,6 +68,10 @@ typedef enum {
   CMD_WIFI_GET_SSID,		// Query SSID currently connected to
   CMD_WIFI_START_SCAN,		// Trigger a scan (takes a long time)
 
+  CMD_UPNP_SCAN = 60,
+  CMD_UPNP_ADD_PORT,
+  CMD_UPNP_REMOVE_PORT,
+
 } CmdName;
 
 typedef void (*cmdfunc_t)(CmdPacket *cmd);

cmd/handlers.c

@@ -40,6 +40,8 @@ static void cmdWifiSignalStrength(CmdPacket *cmd);
 
 void cmdMqttGetClientId(CmdPacket *cmd);
 
+void cmdUPnPScan(CmdPacket *cmd);
+
 // keep track of last status sent to uC so we can notify it when it changes
 static uint8_t lastWifiStatus = wifiIsDisconnected;
 // keep track of whether we have registered our cb handler with the wifi subsystem
@@ -64,6 +66,8 @@ const CmdList commands[] = {
   {CMD_WIFI_GET_SSID,		"WIFI_GET_SSID",	cmdWifiQuerySSID},
   {CMD_WIFI_START_SCAN,		"WIFI_START_SCAN",	cmdWifiStartScan},
 
+  {CMD_UPNP_SCAN,		"UPNP_SCAN",		cmdUPnPScan},
+
 #ifdef MQTT
   {CMD_MQTT_SETUP,      "MQTT_SETUP",     MQTTCMD_Setup},
   {CMD_MQTT_PUBLISH,    "MQTT_PUB",       MQTTCMD_Publish},

esp-link/upnp.c

@@ -0,0 +1,124 @@
+#include "esp8266.h"
+#include "sntp.h"
+#include "cmd.h"
+#include <socket.h>
+#include <ip_addr.h>
+
+#if 1
+#define DBG_SOCK(format, ...) os_printf(format, ## __VA_ARGS__)
+#else
+#define DBG_SOCK(format, ...) do { } while(0)
+#endif
+
+#define location_size	80
+static const int counter_max = 4;
+
+enum upnp_state_t {
+	upnp_none,
+	upnp_multicasted,
+	upnp_found_igd
+};
+static enum upnp_state_t upnp_state;
+
+
+static const char *upnp_ssdp_multicast = "239.255.255.250";
+static short upnp_server_port = 1900;
+static short upnp_local_port = -1;
+static const char *ssdp_message = "M-SEARCH * HTTP/1.1\r\n"
+	"HOST: 239.255.255.250:1900\r\n"
+	"ST: urn:schemas-upnp-org:device:InternetGatewayDevice:1\r\n"
+	"MAN: \"ssdp:discover\"\r\n"
+	"MX: 2\r\n";
+static int ssdp_len;
+static char location[location_size];
+static int counter;
+
+static void ICACHE_FLASH_ATTR
+upnp_recv_cb(void *arg, char *pusrdata, unsigned short length) {
+  // struct espconn *pCon = (struct espconn *)arg;
+
+  os_printf("upnp_recv_cb : %d bytes\n", length);
+
+  switch (upnp_state) {
+  case upnp_multicasted:
+    // Find the LOCATION: field
+    for (int i=0; i<length-20; i++)
+      if (pusrdata[i] == 0x0D && pusrdata[i+1] == 0x0A
+       && os_strncmp(pusrdata+i+2, "LOCATION:", 9) == 0) {
+        // find end of LOCATION field
+        int j, k;
+        for (k=j=i+11; pusrdata[k] && pusrdata[k] != 0x0D; k++) ;
+        int len = k-j+1;
+
+        pusrdata[k] = 0; // NULL terminate
+
+	// FIXME this should be dynamically allocated
+        os_strncpy(location, pusrdata+j, len);
+        DBG_SOCK("len %d message %s\n", len, pusrdata+j);
+
+	// Trigger next query
+	break;
+      }
+    break;
+  default:
+    os_printf("UPnP FSM issue\n");
+  }
+}
+
+// Our packets are small, so this is not useful
+static void ICACHE_FLASH_ATTR
+upnp_sent_cb(void *arg) {
+  struct espconn *con = (struct espconn *)arg;
+  os_printf("upnp_sent_cb\n");
+
+  if (counter < counter_max) {
+    counter++;
+    espconn_sent(con, (uint8_t*)ssdp_message, ssdp_len);
+  }
+}
+
+void ICACHE_FLASH_ATTR
+cmdUPnPScan(CmdPacket *cmd) {
+  upnp_state = upnp_none;
+
+  os_printf("cmdUPnPScan()\n");
+  // cmdResponseStart(CMD_RESP_V, wifiState, 0);
+  // cmdResponseEnd();
+
+  struct espconn *con = (struct espconn *)os_zalloc(sizeof(struct espconn));
+  if (con == NULL) {
+    DBG_SOCK("SOCKET : Setup failed to alloc memory for client_pCon\n");
+    return;
+  }
+  counter = 0;
+
+  con->type = ESPCONN_UDP;
+  con->proto.udp = (esp_udp *)os_zalloc(sizeof(esp_udp));
+  if (con->proto.udp == NULL) {
+    DBG_SOCK("SOCKET : Setup failed to alloc memory for client->pCon->proto.udp\n");
+    return;
+  }
+
+  con->state = ESPCONN_NONE;
+
+  con->proto.udp->remote_port = upnp_server_port;
+  con->proto.udp->local_port = upnp_local_port;
+
+  espconn_regist_sentcb(con, upnp_sent_cb);
+  espconn_regist_recvcb(con, upnp_recv_cb);
+
+  DBG_SOCK("SOCKET : Create connection to ip %s:%d\n", upnp_ssdp_multicast, upnp_server_port);
+
+  if (UTILS_StrToIP((char *)upnp_ssdp_multicast, &con->proto.udp->remote_ip)) {
+    espconn_create(con);
+  } else {
+    DBG_SOCK("SOCKET : failed to copy remote_ip to &con->proto.udp->remote_ip\n");
+    return;
+  }
+
+  ssdp_len = strlen(ssdp_message);
+  espconn_sent(con, (uint8_t*)ssdp_message, ssdp_len);
+  DBG_SOCK("SOCKET : sending %d bytes\n", ssdp_len);
+  upnp_state = upnp_multicasted;
+}
+