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*
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#pragma once
/**
* @file mavlink_ftp.h
*
* MAVLink remote file server.
*
* Messages are wrapped in ENCAPSULATED_DATA messages. Every message includes
* a session ID and sequence number.
*
* A limited number of requests (currently 2) may be outstanding at a time.
* Additional messages will be discarded.
*
* Messages consist of a fixed header, followed by a data area.
*
*/
#include <dirent.h>
#include <queue.h>
#include <nuttx/wqueue.h>
#include <systemlib/err.h>
#include "mavlink_messages.h"
class MavlinkFTP
{
public:
MavlinkFTP();
static MavlinkFTP *getServer();
// static interface
void handle_message(Mavlink* mavlink,
mavlink_message_t *msg);
private:
static const unsigned kRequestQueueSize = 2;
static MavlinkFTP *_server;
struct RequestHeader
{
uint8_t magic;
uint8_t session;
uint8_t opcode;
uint8_t size;
uint32_t crc32;
uint32_t offset;
uint8_t data[];
};
enum Opcode : uint8_t
{
kCmdNone, // ignored, always acked
kCmdTerminate, // releases sessionID, closes file
kCmdReset, // terminates all sessions
kCmdList, // list files in <path> from <offset>
kCmdOpen, // opens <path> for reading, returns <session>
kCmdRead, // reads <size> bytes from <offset> in <session>
kCmdCreate, // creates <path> for writing, returns <session>
kCmdWrite, // appends <size> bytes at <offset> in <session>
kCmdRemove, // remove file (only if created by server?)
kRspAck,
kRspNak
};
enum ErrorCode : uint8_t
{
kErrNone,
kErrNoRequest,
kErrNoSession,
kErrSequence,
kErrNotDir,
kErrNotFile,
kErrEOF,
kErrNotAppend,
kErrTooBig,
kErrIO,
kErrPerm
};
int _findUnusedSession(void);
bool _validSession(unsigned index);
static const unsigned kMaxSession = 2;
int _session_fds[kMaxSession];
class Request
{
public:
union {
dq_entry_t entry;
work_s work;
};
bool decode(Mavlink *mavlink, mavlink_message_t *fromMessage) {
if (fromMessage->msgid == MAVLINK_MSG_ID_ENCAPSULATED_DATA) {
_mavlink = mavlink;
mavlink_msg_encapsulated_data_decode(fromMessage, &_message);
return true;
}
return false;
}
void reply() {
// XXX the proper way would be an IOCTL / uORB call, rather than exploiting the
// flat memory architecture, as we're operating between threads here.
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->lockMessageBufferMutex();
bool success = _mavlink->message_buffer_write(&msg, len);
_mavlink->unlockMessageBufferMutex();
if (!success) {
warnx("FTP TX ERR");
}
// else {
// warnx("wrote: sys: %d, comp: %d, chan: %d, len: %d, checksum: %d",
// _mavlink->get_system_id(),
// _mavlink->get_component_id(),
// _mavlink->get_channel(),
// len,
// msg.checksum);
// }
}
uint8_t *rawData() { return &_message.data[0]; }
RequestHeader *header() { return reinterpret_cast<RequestHeader *>(&_message.data[0]); }
uint8_t *requestData() { return &(header()->data[0]); }
unsigned dataSize() { return header()->size + sizeof(RequestHeader); }
uint16_t sequence() const { return _message.seqnr; }
mavlink_channel_t channel() { return _mavlink->get_channel(); }
char *dataAsCString();
private:
Mavlink *_mavlink;
mavlink_encapsulated_data_t _message;
};
static const uint8_t kProtocolMagic = 'f';
static const char kDirentFile = 'F';
static const char kDirentDir = 'D';
static const char kDirentUnknown = 'U';
static const uint8_t kMaxDataLength = MAVLINK_MSG_ENCAPSULATED_DATA_FIELD_DATA_LEN - sizeof(RequestHeader);
/// Request worker; runs on the low-priority work queue to service
/// remote requests.
///
static void _workerTrampoline(void *arg);
void _worker(Request *req);
/// Reply to a request (XXX should be a Request method)
///
void _reply(Request *req);
ErrorCode _workList(Request *req);
ErrorCode _workOpen(Request *req, bool create);
ErrorCode _workRead(Request *req);
ErrorCode _workWrite(Request *req);
ErrorCode _workRemove(Request *req);
ErrorCode _workTerminate(Request *req);
ErrorCode _workReset();
// work freelist
Request _workBufs[kRequestQueueSize];
dq_queue_t _workFree;
sem_t _lock;
void _qLock() { do {} while (sem_wait(&_lock) != 0); }
void _qUnlock() { sem_post(&_lock); }
void _qFree(Request *req) {
_qLock();
dq_addlast(&req->entry, &_workFree);
_qUnlock();
}
Request *_dqFree() {
_qLock();
auto req = reinterpret_cast<Request *>(dq_remfirst(&_workFree));
_qUnlock();
return req;
}
};
