Add TCP retransmission support to the HTTP webserver in the Webserver project, so that lost segments are retransmitted as needed.

1 files changed, 39 insertions, 17 deletions

diff --git a/Projects/Webserver/Lib/HTTPServerApp.c b/Projects/Webserver/Lib/HTTPServerApp.c
index 3f8a2c338..78c1b131c 100644
--- a/Projects/Webserver/Lib/HTTPServerApp.c
+++ b/Projects/Webserver/Lib/HTTPServerApp.c
@@ -96,17 +96,16 @@ void WebserverApp_Callback(void)
 	char*                     AppData     = (char*)uip_appdata;

 	uint16_t                  AppDataSize = 0;

 

-	if (uip_aborted() || uip_timedout())

+	if (uip_aborted() || uip_timedout() || uip_closed())

 	{

-		/* Close the file before terminating, if it is open */

-		f_close(&AppState->FileToSend);

+		/* Check if the open file needs to be closed */

+		if (AppState->FileOpen)

+		{

+			f_close(&AppState->FileHandle);

+			AppState->FileOpen = false;

+		}

 

-		AppState->CurrentState = WEBSERVER_STATE_Closed;

-

-		return;

-	}

-	else if (uip_closed())

-	{

+		AppState->PrevState    = WEBSERVER_STATE_Closed;

 		AppState->CurrentState = WEBSERVER_STATE_Closed;

 

 		return;

@@ -114,14 +113,20 @@ void WebserverApp_Callback(void)
 	else if (uip_connected())

 	{

 		/* New connection - initialize connection state and data pointer to the appropriate HTTP header */

+		AppState->PrevState    = WEBSERVER_STATE_OpenRequestedFile;

 		AppState->CurrentState = WEBSERVER_STATE_OpenRequestedFile;

 	}

+	else if (uip_rexmit())

+	{

+		/* Re-try last state */

+		AppState->CurrentState = AppState->PrevState;

+	}

 	

 	switch (AppState->CurrentState)

 	{

 		case WEBSERVER_STATE_OpenRequestedFile:

 			/* Wait for the packet containing the request header */

-			if (uip_datalen())

+			if (uip_newdata())

 			{

 				/* Must be a GET request, abort otherwise */

 				if (strncmp(AppData, "GET ", (sizeof("GET ") - 1)) != 0)

@@ -150,8 +155,10 @@ void WebserverApp_Callback(void)
 				  strcpy(AppState->FileName, "index.htm");

 				

 				/* Try to open the file from the Dataflash disk */

-				AppState->FileOpen = (f_open(&AppState->FileToSend, AppState->FileName, FA_OPEN_EXISTING | FA_READ) == FR_OK);

+				AppState->FileOpen       = (f_open(&AppState->FileHandle, AppState->FileName, FA_OPEN_EXISTING | FA_READ) == FR_OK);

+				AppState->CurrentFilePos = 0;

 

+				AppState->PrevState    = WEBSERVER_STATE_OpenRequestedFile;

 				AppState->CurrentState = WEBSERVER_STATE_SendResponseHeader;

 			}

 

@@ -171,6 +178,7 @@ void WebserverApp_Callback(void)
 			

 			uip_send(AppData, AppDataSize);

 			

+			AppState->PrevState    = WEBSERVER_STATE_SendResponseHeader;

 			AppState->CurrentState = WEBSERVER_STATE_SendMIMETypeHeader;

 			break;

 		case WEBSERVER_STATE_SendMIMETypeHeader:

@@ -209,28 +217,42 @@ void WebserverApp_Callback(void)
 				uip_send(AppData, AppDataSize);

 			}

 				

+			AppState->PrevState    = WEBSERVER_STATE_SendMIMETypeHeader;

 			AppState->CurrentState = WEBSERVER_STATE_SendData;				

 			break;

 		case WEBSERVER_STATE_SendData:

 			/* If end of file/file not open, progress to the close state */

-			if (!(AppState->FileOpen))

+			if (!(AppState->FileOpen) && !(uip_rexmit()))

 			{

-				f_close(&AppState->FileToSend);

+				f_close(&AppState->FileHandle);

 				uip_close();

+

+				AppState->PrevState    = WEBSERVER_STATE_Closed;

 				AppState->CurrentState = WEBSERVER_STATE_Closed;

 				break;

 			}

 

 			uint16_t MaxSegSize = uip_mss();

 			

+			/* Return file pointer to the last ACKed position if retransmitting */

+			f_lseek(&AppState->FileHandle, AppState->CurrentFilePos);

+

 			/* Read the next chunk of data from the open file */

-			f_read(&AppState->FileToSend, AppData, MaxSegSize, &AppDataSize);

-			AppState->FileOpen = (MaxSegSize == AppDataSize);

+			f_read(&AppState->FileHandle, AppData, MaxSegSize, &AppDataSize);

+			AppState->FileOpen = (AppDataSize > 0);

 

 			/* If data was read, send it to the client */

 			if (AppDataSize)

-			  uip_send(AppData, AppDataSize);

-					

+			{

+				/* If we are not re-transmitting a lost segment, advance file position */

+				if (!(uip_rexmit()))

+				  AppState->CurrentFilePos += AppDataSize;

+

+				uip_send(AppData, AppDataSize);

+			}

+			

+			AppState->PrevState = WEBSERVER_STATE_SendData;

+

 			break;

 	}

 }