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/****************************************************************************
*
* Copyright (c) 2014 PX4 Development Team. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name PX4 nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
#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_message_t *msg,
mavlink_channel_t channel);
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
};
class Session
{
public:
Session() : _fd(-1) {}
static int allocate();
static Session *get(unsigned index);
static bool terminate(unsigned index);
static void reset();
void terminate();
bool open(const char *path, bool create);
int read(off_t offset, uint8_t *buf, uint8_t count);
int append(off_t offset, uint8_t *buf, uint8_t count);
private:
static const unsigned kMaxSession = 2;
static Session _sessions[kMaxSession];
int _fd;
};
class Request
{
public:
union {
dq_entry_t entry;
work_s work;
};
mavlink_channel_t channel;
void decode(mavlink_channel_t fromChannel, mavlink_message_t *fromMessage) {
switch (fromMessage->msgid) {
case MAVLINK_MSG_ID_ENCAPSULATED_DATA:
channel = fromChannel;
mavlink_msg_encapsulated_data_decode(fromMessage, &_message);
warnx("got enc data");
break;
default:
warnx("unknown msg");
}
}
RequestHeader *header() { return reinterpret_cast<RequestHeader *>(&_message.data[0]); }
uint8_t *data() { return &_message.data[0]; }
unsigned dataSize() { return header()->size + sizeof(RequestHeader); }
uint16_t sequence() const { return _message.seqnr; }
char *dataAsCString();
private:
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);
// 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;
}
};
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