More FTP support

Added:
- sequence numbers
- directory list returns file sizes
- open command returns file size in data

src/modules/mavlink/mavlink_ftp.cpp

@@ -35,6 +35,7 @@
 #include <unistd.h>
 #include <stdio.h>
 #include <fcntl.h>
+#include <sys/stat.h>
 
 #include "mavlink_ftp.h"
 
@@ -190,6 +191,8 @@ void
 MavlinkFTP::_reply(Request *req)
 {
 	auto hdr = req->header();
+	
+	hdr->magic = kProtocolMagic;
 
 	// message is assumed to be already constructed in the request buffer, so generate the CRC
 	hdr->crc32 = 0;
@@ -242,15 +245,18 @@ MavlinkFTP::_workList(Request *req)
 			break;
 		}
 
-		// name too big to fit?
-		if ((strlen(entry.d_name) + offset + 2) > kMaxDataLength) {
-			break;
-		}
+		uint32_t fileSize = 0;
+		char buf[256];
 
 		// store the type marker
 		switch (entry.d_type) {
 		case DTYPE_FILE:
 			hdr->data[offset++] = kDirentFile;
+			snprintf(buf, sizeof(buf), "%s/%s", dirPath, entry.d_name);
+			struct stat st;
+			if (stat(buf, &st) == 0) {
+				fileSize = st.st_size;
+			}
 			break;
 		case DTYPE_DIRECTORY:
 			hdr->data[offset++] = kDirentDir;
@@ -259,11 +265,24 @@ MavlinkFTP::_workList(Request *req)
 			hdr->data[offset++] = kDirentUnknown;
 			break;
 		}
+		
+		if (entry.d_type == DTYPE_FILE) {
+			snprintf(buf, sizeof(buf), "%s\t%d", entry.d_name, fileSize);
+		} else {
+			strncpy(buf, entry.d_name, sizeof(buf));
+			buf[sizeof(buf)-1] = 0;
+		}
+		size_t nameLen = strlen(buf);
 
+		// name too big to fit?
+		if ((nameLen + offset + 2) > kMaxDataLength) {
+			break;
+		}
+		
 		// copy the name, which we know will fit
-		strcpy((char *)&hdr->data[offset], entry.d_name);
+		strcpy((char *)&hdr->data[offset], buf);
 		//printf("FTP: list %s %s\n", dirPath, (char *)&hdr->data[offset-1]);
-		offset += strlen(entry.d_name) + 1;
+		offset += nameLen + 1;
 	}
 
 	closedir(dp);
@@ -282,6 +301,16 @@ MavlinkFTP::_workOpen(Request *req, bool create)
 		return kErrNoSession;
 	}
 
+	
+	uint32_t fileSize = 0;
+	if (!create) {
+		struct stat st;
+		if (stat(req->dataAsCString(), &st) != 0) {
+			return kErrNotFile;
+		}
+		fileSize = st.st_size;
+	}
+
 	int oflag = create ? (O_CREAT | O_EXCL | O_APPEND) : O_RDONLY;
     
 	int fd = ::open(req->dataAsCString(), oflag);
@@ -291,7 +320,12 @@ MavlinkFTP::_workOpen(Request *req, bool create)
 	_session_fds[session_index] = fd;
 
 	hdr->session = session_index;
-	hdr->size = 0;
+	if (create) {
+		hdr->size = 0;
+	} else {
+		hdr->size = sizeof(uint32_t);
+		*((uint32_t*)hdr->data) = fileSize;
+	}
 
 	return kErrNone;
 }

src/modules/mavlink/mavlink_ftp.h

@@ -146,7 +146,7 @@ private:
 			mavlink_message_t msg;
 			msg.checksum = 0;
 			unsigned len = mavlink_msg_encapsulated_data_pack_chan(_mavlink->get_system_id(), _mavlink->get_component_id(),
-				_mavlink->get_channel(), &msg, sequence(), rawData());
+				_mavlink->get_channel(), &msg, sequence()+1, rawData());
 
 			_mavlink->lockMessageBufferMutex();
 			bool success = _mavlink->message_buffer_write(&msg, len);