From 60c63f48729f028ec9f5b6de93da91873d152bfd Mon Sep 17 00:00:00 2001
From: Vladimir Ermakov <vooon341@gmail.com>
Date: Wed, 17 Sep 2014 10:07:29 +0400
Subject: [PATCH] FTP: Add new open command for write.

All open commands now return file size.
---
 src/modules/mavlink/mavlink_ftp.cpp | 46 ++++++++++++++---------------
 src/modules/mavlink/mavlink_ftp.h   |  7 +++--
 2 files changed, 27 insertions(+), 26 deletions(-)

diff --git a/src/modules/mavlink/mavlink_ftp.cpp b/src/modules/mavlink/mavlink_ftp.cpp
index 2a85c3702a..b17036c8ee 100644
--- a/src/modules/mavlink/mavlink_ftp.cpp
+++ b/src/modules/mavlink/mavlink_ftp.cpp
@@ -180,12 +180,16 @@ MavlinkFTP::_process_request(Request *req)
 		errorCode = _workList(payload);
 		break;
 
-	case kCmdOpenFile:
-		errorCode = _workOpen(payload, false);
+	case kCmdOpenFileRO:
+		errorCode = _workOpen(payload, O_RDONLY);
 		break;
 
 	case kCmdCreateFile:
-		errorCode = _workOpen(payload, true);
+		errorCode = _workOpen(payload, O_CREAT | O_EXCL | O_WRONLY);
+		break;
+
+	case kCmdOpenFileWO:
+		errorCode = _workOpen(payload, O_CREAT | O_WRONLY);
 		break;
 
 	case kCmdReadFile:
@@ -396,27 +400,27 @@ MavlinkFTP::_workList(PayloadHeader* payload)
 
 /// @brief Responds to an Open command
 MavlinkFTP::ErrorCode
-MavlinkFTP::_workOpen(PayloadHeader* payload, bool create)
+MavlinkFTP::_workOpen(PayloadHeader* payload, int oflag)
 {
 	int session_index = _find_unused_session();
 	if (session_index < 0) {
 		warnx("FTP: Open failed - out of sessions\n");
 		return kErrNoSessionsAvailable;
 	}
-	
-	char *filename = _data_as_cstring(payload);
-	
-	uint32_t fileSize = 0;
-	if (!create) {
-		struct stat st;
-		if (stat(filename, &st) != 0) {
-			return kErrFailErrno;
-		}
-		fileSize = st.st_size;
-	}
 
-	int oflag = create ? (O_CREAT | O_EXCL | O_APPEND) : O_RDONLY;
-    
+	char *filename = _data_as_cstring(payload);
+
+	uint32_t fileSize = 0;
+	struct stat st;
+	if (stat(filename, &st) != 0) {
+		// fail only if requested open for read
+		if (oflag & O_RDONLY)
+			return kErrFailErrno;
+		else
+			st.st_size = 0;
+	}
+	fileSize = st.st_size;
+
 	int fd = ::open(filename, oflag);
 	if (fd < 0) {
 		return kErrFailErrno;
@@ -424,12 +428,8 @@ MavlinkFTP::_workOpen(PayloadHeader* payload, bool create)
 	_session_fds[session_index] = fd;
 
 	payload->session = session_index;
-	if (create) {
-		payload->size = 0;
-	} else {
-		payload->size = sizeof(uint32_t);
-		*((uint32_t*)payload->data) = fileSize;
-	}
+	payload->size = sizeof(uint32_t);
+	*((uint32_t*)payload->data) = fileSize;
 
 	return kErrNone;
 }
diff --git a/src/modules/mavlink/mavlink_ftp.h b/src/modules/mavlink/mavlink_ftp.h
index 657e2f855b..1c873fe9f0 100644
--- a/src/modules/mavlink/mavlink_ftp.h
+++ b/src/modules/mavlink/mavlink_ftp.h
@@ -89,13 +89,14 @@ public:
 		kCmdTerminateSession,	///< Terminates open Read session
 		kCmdResetSessions,	///< Terminates all open Read sessions
 		kCmdListDirectory,	///< List files in <path> from <offset>
-		kCmdOpenFile,		///< Opens file at <path> for reading, returns <session>
+		kCmdOpenFileRO,		///< Opens file at <path> for reading, returns <session>
 		kCmdReadFile,		///< Reads <size> bytes from <offset> in <session>
 		kCmdCreateFile,		///< Creates file at <path> for writing, returns <session>
-		kCmdWriteFile,		///< Appends <size> bytes to file in <session>
+		kCmdWriteFile,		///< Writes <size> bytes to <offset> in <session>
 		kCmdRemoveFile,		///< Remove file at <path>
 		kCmdCreateDirectory,	///< Creates directory at <path>
 		kCmdRemoveDirectory,	///< Removes Directory at <path>, must be empty
+		kCmdOpenFileWO,		///< Opens file at <path> for writing, returns <session>
 		
 		kRspAck = 128,		///< Ack response
 		kRspNak			///< Nak response
@@ -140,7 +141,7 @@ private:
 	void		_reply(Request *req);
 
 	ErrorCode	_workList(PayloadHeader *payload);
-	ErrorCode	_workOpen(PayloadHeader *payload, bool create);
+	ErrorCode	_workOpen(PayloadHeader *payload, int oflag);
 	ErrorCode	_workRead(PayloadHeader *payload);
 	ErrorCode	_workWrite(PayloadHeader *payload);
 	ErrorCode	_workTerminate(PayloadHeader *payload);