diff options
Diffstat (limited to 'src/modules/mavlink/mavlink_ftp.cpp')
-rw-r--r-- | src/modules/mavlink/mavlink_ftp.cpp | 694 |
1 files changed, 534 insertions, 160 deletions
diff --git a/src/modules/mavlink/mavlink_ftp.cpp b/src/modules/mavlink/mavlink_ftp.cpp index 00c8df18c..f17497aa8 100644 --- a/src/modules/mavlink/mavlink_ftp.cpp +++ b/src/modules/mavlink/mavlink_ftp.cpp @@ -31,38 +31,39 @@ * ****************************************************************************/ +/// @file mavlink_ftp.cpp +/// @author px4dev, Don Gagne <don@thegagnes.com> + #include <crc32.h> #include <unistd.h> #include <stdio.h> #include <fcntl.h> #include <sys/stat.h> +#include <errno.h> #include "mavlink_ftp.h" +#include "mavlink_tests/mavlink_ftp_test.h" // Uncomment the line below to get better debug output. Never commit with this left on. //#define MAVLINK_FTP_DEBUG -MavlinkFTP *MavlinkFTP::_server; - MavlinkFTP * -MavlinkFTP::getServer() +MavlinkFTP::get_server(void) { - // XXX this really cries out for some locking... - if (_server == nullptr) { - _server = new MavlinkFTP; - } - return _server; + static MavlinkFTP server; + return &server; } MavlinkFTP::MavlinkFTP() : - _session_fds{}, - _workBufs{}, - _workFree{}, - _lock{} + _request_bufs{}, + _request_queue{}, + _request_queue_sem{}, + _utRcvMsgFunc{}, + _ftp_test{} { // initialise the request freelist - dq_init(&_workFree); - sem_init(&_lock, 0, 1); + dq_init(&_request_queue); + sem_init(&_request_queue_sem, 0, 1); // initialize session list for (size_t i=0; i<kMaxSession; i++) { @@ -71,161 +72,258 @@ MavlinkFTP::MavlinkFTP() : // drop work entries onto the free list for (unsigned i = 0; i < kRequestQueueSize; i++) { - _qFree(&_workBufs[i]); + _return_request(&_request_bufs[i]); } } +#ifdef MAVLINK_FTP_UNIT_TEST +void +MavlinkFTP::set_unittest_worker(ReceiveMessageFunc_t rcvMsgFunc, MavlinkFtpTest *ftp_test) +{ + _utRcvMsgFunc = rcvMsgFunc; + _ftp_test = ftp_test; +} +#endif + void MavlinkFTP::handle_message(Mavlink* mavlink, mavlink_message_t *msg) { // get a free request - auto req = _dqFree(); + struct Request* req = _get_request(); // if we couldn't get a request slot, just drop it - if (req != nullptr) { - - // decode the request - if (req->decode(mavlink, msg)) { + if (req == nullptr) { + warnx("Dropping FTP request: queue full\n"); + return; + } - // and queue it for the worker - work_queue(LPWORK, &req->work, &MavlinkFTP::_workerTrampoline, req, 0); - } else { - _qFree(req); + if (msg->msgid == MAVLINK_MSG_ID_FILE_TRANSFER_PROTOCOL) { + mavlink_msg_file_transfer_protocol_decode(msg, &req->message); + +#ifdef MAVLINK_FTP_UNIT_TEST + if (!_utRcvMsgFunc) { + warnx("Incorrectly written unit test\n"); + return; + } + // We use fake ids when unit testing + req->serverSystemId = MavlinkFtpTest::serverSystemId; + req->serverComponentId = MavlinkFtpTest::serverComponentId; + req->serverChannel = MavlinkFtpTest::serverChannel; +#else + // Not unit testing, use the real thing + req->serverSystemId = mavlink->get_system_id(); + req->serverComponentId = mavlink->get_component_id(); + req->serverChannel = mavlink->get_channel(); +#endif + + // This is the system id we want to target when sending + req->targetSystemId = msg->sysid; + + if (req->message.target_system == req->serverSystemId) { + req->mavlink = mavlink; +#ifdef MAVLINK_FTP_UNIT_TEST + // We are running in Unit Test mode. Don't queue, just call _worket directly. + _process_request(req); +#else + // We are running in normal mode. Queue the request to the worker + work_queue(LPWORK, &req->work, &MavlinkFTP::_worker_trampoline, req, 0); +#endif + return; } } + + _return_request(req); } +/// @brief Queued static work queue routine to handle mavlink messages void -MavlinkFTP::_workerTrampoline(void *arg) +MavlinkFTP::_worker_trampoline(void *arg) { - auto req = reinterpret_cast<Request *>(arg); - auto server = MavlinkFTP::getServer(); + Request* req = reinterpret_cast<Request *>(arg); + MavlinkFTP* server = MavlinkFTP::get_server(); // call the server worker with the work item - server->_worker(req); + server->_process_request(req); } +/// @brief Processes an FTP message void -MavlinkFTP::_worker(Request *req) +MavlinkFTP::_process_request(Request *req) { - auto hdr = req->header(); + PayloadHeader *payload = reinterpret_cast<PayloadHeader *>(&req->message.payload[0]); + ErrorCode errorCode = kErrNone; - uint32_t messageCRC; // basic sanity checks; must validate length before use - if ((hdr->magic != kProtocolMagic) || (hdr->size > kMaxDataLength)) { - errorCode = kErrNoRequest; - goto out; - } - - // check request CRC to make sure this is one of ours - messageCRC = hdr->crc32; - hdr->crc32 = 0; - if (crc32(req->rawData(), req->dataSize()) != messageCRC) { - errorCode = kErrNoRequest; + if (payload->size > kMaxDataLength) { + errorCode = kErrInvalidDataSize; goto out; - warnx("ftp: bad crc"); } #ifdef MAVLINK_FTP_DEBUG - printf("ftp: channel %u opc %u size %u offset %u\n", req->channel(), hdr->opcode, hdr->size, hdr->offset); + printf("ftp: channel %u opc %u size %u offset %u\n", req->serverChannel, payload->opcode, payload->size, payload->offset); #endif - switch (hdr->opcode) { + switch (payload->opcode) { case kCmdNone: break; - case kCmdTerminate: - errorCode = _workTerminate(req); + case kCmdTerminateSession: + errorCode = _workTerminate(payload); + break; + + case kCmdResetSessions: + errorCode = _workReset(payload); + break; + + case kCmdListDirectory: + errorCode = _workList(payload); + break; + + case kCmdOpenFileRO: + errorCode = _workOpen(payload, O_RDONLY); + break; + + case kCmdCreateFile: + errorCode = _workOpen(payload, O_CREAT | O_EXCL | O_WRONLY); + break; + + case kCmdOpenFileWO: + errorCode = _workOpen(payload, O_CREAT | O_WRONLY); break; - case kCmdReset: - errorCode = _workReset(); + case kCmdReadFile: + errorCode = _workRead(payload); break; - case kCmdList: - errorCode = _workList(req); + case kCmdWriteFile: + errorCode = _workWrite(payload); break; - case kCmdOpen: - errorCode = _workOpen(req, false); + case kCmdRemoveFile: + errorCode = _workRemoveFile(payload); break; - case kCmdCreate: - errorCode = _workOpen(req, true); + case kCmdRename: + errorCode = _workRename(payload); break; - case kCmdRead: - errorCode = _workRead(req); + case kCmdTruncateFile: + errorCode = _workTruncateFile(payload); break; - case kCmdWrite: - errorCode = _workWrite(req); + case kCmdCreateDirectory: + errorCode = _workCreateDirectory(payload); break; + + case kCmdRemoveDirectory: + errorCode = _workRemoveDirectory(payload); + break; + - case kCmdRemove: - errorCode = _workRemove(req); + case kCmdCalcFileCRC32: + errorCode = _workCalcFileCRC32(payload); break; default: - errorCode = kErrNoRequest; + errorCode = kErrUnknownCommand; break; } out: // handle success vs. error if (errorCode == kErrNone) { - hdr->opcode = kRspAck; + payload->req_opcode = payload->opcode; + payload->opcode = kRspAck; #ifdef MAVLINK_FTP_DEBUG warnx("FTP: ack\n"); #endif } else { + int r_errno = errno; warnx("FTP: nak %u", errorCode); - hdr->opcode = kRspNak; - hdr->size = 1; - hdr->data[0] = errorCode; + payload->req_opcode = payload->opcode; + payload->opcode = kRspNak; + payload->size = 1; + payload->data[0] = errorCode; + if (errorCode == kErrFailErrno) { + payload->size = 2; + payload->data[1] = r_errno; + } } + // respond to the request _reply(req); - // free the request buffer back to the freelist - _qFree(req); + _return_request(req); } +/// @brief Sends the specified FTP reponse message out through mavlink void MavlinkFTP::_reply(Request *req) { - auto hdr = req->header(); + PayloadHeader *payload = reinterpret_cast<PayloadHeader *>(&req->message.payload[0]); - hdr->magic = kProtocolMagic; + payload->seqNumber = payload->seqNumber + 1; - // message is assumed to be already constructed in the request buffer, so generate the CRC - hdr->crc32 = 0; - hdr->crc32 = crc32(req->rawData(), req->dataSize()); + mavlink_message_t msg; + msg.checksum = 0; +#ifndef MAVLINK_FTP_UNIT_TEST + uint16_t len = +#endif + mavlink_msg_file_transfer_protocol_pack_chan(req->serverSystemId, // Sender system id + req->serverComponentId, // Sender component id + req->serverChannel, // Channel to send on + &msg, // Message to pack payload into + 0, // Target network + req->targetSystemId, // Target system id + 0, // Target component id + (const uint8_t*)payload); // Payload to pack into message + + bool success = true; +#ifdef MAVLINK_FTP_UNIT_TEST + // Unit test hook is set, call that instead + _utRcvMsgFunc(&msg, _ftp_test); +#else + Mavlink *mavlink = req->mavlink; + + mavlink->lockMessageBufferMutex(); + success = mavlink->message_buffer_write(&msg, len); + mavlink->unlockMessageBufferMutex(); + +#endif - // then pack and send the reply back to the request source - req->reply(); + if (!success) { + warnx("FTP TX ERR"); + } +#ifdef MAVLINK_FTP_DEBUG + else { + warnx("wrote: sys: %d, comp: %d, chan: %d, checksum: %d", + req->serverSystemId, + req->serverComponentId, + req->serverChannel, + msg.checksum); + } +#endif } +/// @brief Responds to a List command MavlinkFTP::ErrorCode -MavlinkFTP::_workList(Request *req) +MavlinkFTP::_workList(PayloadHeader* payload) { - auto hdr = req->header(); - char dirPath[kMaxDataLength]; - strncpy(dirPath, req->dataAsCString(), kMaxDataLength); + strncpy(dirPath, _data_as_cstring(payload), kMaxDataLength); DIR *dp = opendir(dirPath); if (dp == nullptr) { warnx("FTP: can't open path '%s'", dirPath); - return kErrNotDir; + return kErrFailErrno; } #ifdef MAVLINK_FTP_DEBUG - warnx("FTP: list %s offset %d", dirPath, hdr->offset); + warnx("FTP: list %s offset %d", dirPath, payload->offset); #endif ErrorCode errorCode = kErrNone; @@ -233,19 +331,19 @@ MavlinkFTP::_workList(Request *req) unsigned offset = 0; // move to the requested offset - seekdir(dp, hdr->offset); + seekdir(dp, payload->offset); for (;;) { // read the directory entry if (readdir_r(dp, &entry, &result)) { warnx("FTP: list %s readdir_r failure\n", dirPath); - errorCode = kErrIO; + errorCode = kErrFailErrno; break; } // no more entries? if (result == nullptr) { - if (hdr->offset != 0 && offset == 0) { + if (payload->offset != 0 && offset == 0) { // User is requesting subsequent dir entries but there were none. This means the user asked // to seek past EOF. errorCode = kErrEOF; @@ -270,14 +368,22 @@ MavlinkFTP::_workList(Request *req) } break; case DTYPE_DIRECTORY: - direntType = kDirentDir; + if (strcmp(entry.d_name, ".") == 0 || strcmp(entry.d_name, "..") == 0) { + // Don't bother sending these back + direntType = kDirentSkip; + } else { + direntType = kDirentDir; + } break; default: - direntType = kDirentUnknown; - break; + // We only send back file and diretory entries, skip everything else + direntType = kDirentSkip; } - if (entry.d_type == DTYPE_FILE) { + if (direntType == kDirentSkip) { + // Skip send only dirent identifier + buf[0] = '\0'; + } else if (direntType == kDirentFile) { // Files send filename and file length snprintf(buf, sizeof(buf), "%s\t%d", entry.d_name, fileSize); } else { @@ -293,145 +399,230 @@ MavlinkFTP::_workList(Request *req) } // Move the data into the buffer - hdr->data[offset++] = direntType; - strcpy((char *)&hdr->data[offset], buf); + payload->data[offset++] = direntType; + strcpy((char *)&payload->data[offset], buf); #ifdef MAVLINK_FTP_DEBUG - printf("FTP: list %s %s\n", dirPath, (char *)&hdr->data[offset-1]); + printf("FTP: list %s %s\n", dirPath, (char *)&payload->data[offset-1]); #endif offset += nameLen + 1; } closedir(dp); - hdr->size = offset; + payload->size = offset; return errorCode; } +/// @brief Responds to an Open command MavlinkFTP::ErrorCode -MavlinkFTP::_workOpen(Request *req, bool create) +MavlinkFTP::_workOpen(PayloadHeader* payload, int oflag) { - auto hdr = req->header(); - - int session_index = _findUnusedSession(); + int session_index = _find_unused_session(); if (session_index < 0) { - return kErrNoSession; + 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(req->dataAsCString(), &st) != 0) { - return kErrNotFile; - } - fileSize = st.st_size; + 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 oflag = create ? (O_CREAT | O_EXCL | O_APPEND) : O_RDONLY; - - int fd = ::open(req->dataAsCString(), oflag); + int fd = ::open(filename, oflag); if (fd < 0) { - return create ? kErrPerm : kErrNotFile; + return kErrFailErrno; } _session_fds[session_index] = fd; - hdr->session = session_index; - if (create) { - hdr->size = 0; - } else { - hdr->size = sizeof(uint32_t); - *((uint32_t*)hdr->data) = fileSize; - } + payload->session = session_index; + payload->size = sizeof(uint32_t); + *((uint32_t*)payload->data) = fileSize; return kErrNone; } +/// @brief Responds to a Read command MavlinkFTP::ErrorCode -MavlinkFTP::_workRead(Request *req) +MavlinkFTP::_workRead(PayloadHeader* payload) { - auto hdr = req->header(); - - int session_index = hdr->session; + int session_index = payload->session; - if (!_validSession(session_index)) { - return kErrNoSession; + if (!_valid_session(session_index)) { + return kErrInvalidSession; } // Seek to the specified position #ifdef MAVLINK_FTP_DEBUG - warnx("seek %d", hdr->offset); + warnx("seek %d", payload->offset); #endif - if (lseek(_session_fds[session_index], hdr->offset, SEEK_SET) < 0) { + if (lseek(_session_fds[session_index], payload->offset, SEEK_SET) < 0) { // Unable to see to the specified location warnx("seek fail"); return kErrEOF; } - int bytes_read = ::read(_session_fds[session_index], &hdr->data[0], kMaxDataLength); + int bytes_read = ::read(_session_fds[session_index], &payload->data[0], kMaxDataLength); if (bytes_read < 0) { // Negative return indicates error other than eof warnx("read fail %d", bytes_read); - return kErrIO; + return kErrFailErrno; } - hdr->size = bytes_read; + payload->size = bytes_read; return kErrNone; } +/// @brief Responds to a Write command MavlinkFTP::ErrorCode -MavlinkFTP::_workWrite(Request *req) +MavlinkFTP::_workWrite(PayloadHeader* payload) { -#if 0 - // NYI: Coming soon - auto hdr = req->header(); + int session_index = payload->session; - // look up session - auto session = getSession(hdr->session); - if (session == nullptr) { - return kErrNoSession; + if (!_valid_session(session_index)) { + return kErrInvalidSession; } - // append to file - int result = session->append(hdr->offset, &hdr->data[0], hdr->size); + // Seek to the specified position +#ifdef MAVLINK_FTP_DEBUG + warnx("seek %d", payload->offset); +#endif + if (lseek(_session_fds[session_index], payload->offset, SEEK_SET) < 0) { + // Unable to see to the specified location + warnx("seek fail"); + return kErrFailErrno; + } - if (result < 0) { - // XXX might also be no space, I/O, etc. - return kErrNotAppend; + int bytes_written = ::write(_session_fds[session_index], &payload->data[0], payload->size); + if (bytes_written < 0) { + // Negative return indicates error other than eof + warnx("write fail %d", bytes_written); + return kErrFailErrno; } - hdr->size = result; + payload->size = sizeof(uint32_t); + *((uint32_t*)payload->data) = bytes_written; + return kErrNone; -#else - return kErrPerm; -#endif } +/// @brief Responds to a RemoveFile command MavlinkFTP::ErrorCode -MavlinkFTP::_workRemove(Request *req) +MavlinkFTP::_workRemoveFile(PayloadHeader* payload) { - //auto hdr = req->header(); + char file[kMaxDataLength]; + strncpy(file, _data_as_cstring(payload), kMaxDataLength); + + if (unlink(file) == 0) { + payload->size = 0; + return kErrNone; + } else { + return kErrFailErrno; + } +} + +/// @brief Responds to a TruncateFile command +MavlinkFTP::ErrorCode +MavlinkFTP::_workTruncateFile(PayloadHeader* payload) +{ + char file[kMaxDataLength]; + const char temp_file[] = "/fs/microsd/.trunc.tmp"; + strncpy(file, _data_as_cstring(payload), kMaxDataLength); + payload->size = 0; + + // emulate truncate(file, payload->offset) by + // copying to temp and overwrite with O_TRUNC flag. + + struct stat st; + if (stat(file, &st) != 0) { + return kErrFailErrno; + } + + if (!S_ISREG(st.st_mode)) { + errno = EISDIR; + return kErrFailErrno; + } + + // check perms allow us to write (not romfs) + if (!(st.st_mode & (S_IWUSR | S_IWGRP | S_IWOTH))) { + errno = EROFS; + return kErrFailErrno; + } + + if (payload->offset == (unsigned)st.st_size) { + // nothing to do + return kErrNone; + } + else if (payload->offset == 0) { + // 1: truncate all data + int fd = ::open(file, O_TRUNC | O_WRONLY); + if (fd < 0) { + return kErrFailErrno; + } + + ::close(fd); + return kErrNone; + } + else if (payload->offset > (unsigned)st.st_size) { + // 2: extend file + int fd = ::open(file, O_WRONLY); + if (fd < 0) { + return kErrFailErrno; + } - // for now, send error reply - return kErrPerm; + if (lseek(fd, payload->offset - 1, SEEK_SET) < 0) { + ::close(fd); + return kErrFailErrno; + } + + bool ok = 1 == ::write(fd, "", 1); + ::close(fd); + + return (ok)? kErrNone : kErrFailErrno; + } + else { + // 3: truncate + if (_copy_file(file, temp_file, payload->offset) != 0) { + return kErrFailErrno; + } + if (_copy_file(temp_file, file, payload->offset) != 0) { + return kErrFailErrno; + } + if (::unlink(temp_file) != 0) { + return kErrFailErrno; + } + + return kErrNone; + } } +/// @brief Responds to a Terminate command MavlinkFTP::ErrorCode -MavlinkFTP::_workTerminate(Request *req) +MavlinkFTP::_workTerminate(PayloadHeader* payload) { - auto hdr = req->header(); - - if (!_validSession(hdr->session)) { - return kErrNoSession; + if (!_valid_session(payload->session)) { + return kErrInvalidSession; } - ::close(_session_fds[hdr->session]); + ::close(_session_fds[payload->session]); + _session_fds[payload->session] = -1; + + payload->size = 0; return kErrNone; } +/// @brief Responds to a Reset command MavlinkFTP::ErrorCode -MavlinkFTP::_workReset(void) +MavlinkFTP::_workReset(PayloadHeader* payload) { for (size_t i=0; i<kMaxSession; i++) { if (_session_fds[i] != -1) { @@ -440,11 +631,104 @@ MavlinkFTP::_workReset(void) } } + payload->size = 0; + + return kErrNone; +} + +/// @brief Responds to a Rename command +MavlinkFTP::ErrorCode +MavlinkFTP::_workRename(PayloadHeader* payload) +{ + char oldpath[kMaxDataLength]; + char newpath[kMaxDataLength]; + + char *ptr = _data_as_cstring(payload); + size_t oldpath_sz = strlen(ptr); + + if (oldpath_sz == payload->size) { + // no newpath + errno = EINVAL; + return kErrFailErrno; + } + + strncpy(oldpath, ptr, kMaxDataLength); + strncpy(newpath, ptr + oldpath_sz + 1, kMaxDataLength); + + if (rename(oldpath, newpath) == 0) { + payload->size = 0; + return kErrNone; + } else { + return kErrFailErrno; + } +} + +/// @brief Responds to a RemoveDirectory command +MavlinkFTP::ErrorCode +MavlinkFTP::_workRemoveDirectory(PayloadHeader* payload) +{ + char dir[kMaxDataLength]; + strncpy(dir, _data_as_cstring(payload), kMaxDataLength); + + if (rmdir(dir) == 0) { + payload->size = 0; + return kErrNone; + } else { + return kErrFailErrno; + } +} + +/// @brief Responds to a CreateDirectory command +MavlinkFTP::ErrorCode +MavlinkFTP::_workCreateDirectory(PayloadHeader* payload) +{ + char dir[kMaxDataLength]; + strncpy(dir, _data_as_cstring(payload), kMaxDataLength); + + if (mkdir(dir, S_IRWXU | S_IRWXG | S_IRWXO) == 0) { + payload->size = 0; + return kErrNone; + } else { + return kErrFailErrno; + } +} + +/// @brief Responds to a CalcFileCRC32 command +MavlinkFTP::ErrorCode +MavlinkFTP::_workCalcFileCRC32(PayloadHeader* payload) +{ + char file_buf[256]; + uint32_t checksum = 0; + ssize_t bytes_read; + strncpy(file_buf, _data_as_cstring(payload), kMaxDataLength); + + int fd = ::open(file_buf, O_RDONLY); + if (fd < 0) { + return kErrFailErrno; + } + + do { + bytes_read = ::read(fd, file_buf, sizeof(file_buf)); + if (bytes_read < 0) { + int r_errno = errno; + ::close(fd); + errno = r_errno; + return kErrFailErrno; + } + + checksum = crc32part((uint8_t*)file_buf, bytes_read, checksum); + } while (bytes_read == sizeof(file_buf)); + + ::close(fd); + + payload->size = sizeof(uint32_t); + *((uint32_t*)payload->data) = checksum; return kErrNone; } +/// @brief Returns true if the specified session is a valid open session bool -MavlinkFTP::_validSession(unsigned index) +MavlinkFTP::_valid_session(unsigned index) { if ((index >= kMaxSession) || (_session_fds[index] < 0)) { return false; @@ -452,8 +736,9 @@ MavlinkFTP::_validSession(unsigned index) return true; } +/// @brief Returns an unused session index int -MavlinkFTP::_findUnusedSession(void) +MavlinkFTP::_find_unused_session(void) { for (size_t i=0; i<kMaxSession; i++) { if (_session_fds[i] == -1) { @@ -464,16 +749,105 @@ MavlinkFTP::_findUnusedSession(void) return -1; } +/// @brief Guarantees that the payload data is null terminated. +/// @return Returns a pointer to the payload data as a char * char * -MavlinkFTP::Request::dataAsCString() +MavlinkFTP::_data_as_cstring(PayloadHeader* payload) { // guarantee nul termination - if (header()->size < kMaxDataLength) { - requestData()[header()->size] = '\0'; + if (payload->size < kMaxDataLength) { + payload->data[payload->size] = '\0'; } else { - requestData()[kMaxDataLength - 1] = '\0'; + payload->data[kMaxDataLength - 1] = '\0'; } // and return data - return (char *)&(header()->data[0]); + return (char *)&(payload->data[0]); +} + +/// @brief Returns a unused Request entry. NULL if none available. +MavlinkFTP::Request * +MavlinkFTP::_get_request(void) +{ + _lock_request_queue(); + Request* req = reinterpret_cast<Request *>(dq_remfirst(&_request_queue)); + _unlock_request_queue(); + return req; +} + +/// @brief Locks a semaphore to provide exclusive access to the request queue +void +MavlinkFTP::_lock_request_queue(void) +{ + do {} + while (sem_wait(&_request_queue_sem) != 0); +} + +/// @brief Unlocks the semaphore providing exclusive access to the request queue +void +MavlinkFTP::_unlock_request_queue(void) +{ + sem_post(&_request_queue_sem); +} + +/// @brief Returns a no longer needed request to the queue +void +MavlinkFTP::_return_request(Request *req) +{ + _lock_request_queue(); + dq_addlast(&req->work.dq, &_request_queue); + _unlock_request_queue(); +} + +/// @brief Copy file (with limited space) +int +MavlinkFTP::_copy_file(const char *src_path, const char *dst_path, ssize_t length) +{ + char buff[512]; + int src_fd = -1, dst_fd = -1; + int op_errno = 0; + + src_fd = ::open(src_path, O_RDONLY); + if (src_fd < 0) { + return -1; + } + + dst_fd = ::open(dst_path, O_CREAT | O_TRUNC | O_WRONLY); + if (dst_fd < 0) { + op_errno = errno; + ::close(src_fd); + errno = op_errno; + return -1; + } + + while (length > 0) { + ssize_t bytes_read, bytes_written; + size_t blen = (length > sizeof(buff))? sizeof(buff) : length; + + bytes_read = ::read(src_fd, buff, blen); + if (bytes_read == 0) { + // EOF + break; + } + else if (bytes_read < 0) { + warnx("cp: read"); + op_errno = errno; + break; + } + + bytes_written = ::write(dst_fd, buff, bytes_read); + if (bytes_written != bytes_read) { + warnx("cp: short write"); + op_errno = errno; + break; + } + + length -= bytes_written; + } + + ::close(src_fd); + ::close(dst_fd); + + errno = op_errno; + return (length > 0)? -1 : 0; } |