ardupilot/libraries/AP_HAL_Linux/CAN.cpp

617 lines
17 KiB
C++

/*
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
* Many thanks to members of the UAVCAN project:
* Pavel Kirienko <pavel.kirienko@gmail.com>
* Ilia Sheremet <illia.sheremet@gmail.com>
*
* license info can be found in the uavcan submodule located:
* modules/uavcan/libuavcan_drivers/linux/include/uavcan_linux/socketcan.hpp
*/
#include <AP_HAL/AP_HAL.h>
#include <AP_HAL/system.h>
#include <AP_BoardConfig/AP_BoardConfig.h>
#if HAL_WITH_UAVCAN
#include "CAN.h"
#include <AP_UAVCAN/AP_UAVCAN.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <linux/can/raw.h>
extern const AP_HAL::HAL& hal;
using namespace Linux;
uavcan::MonotonicTime getMonotonic()
{
return uavcan::MonotonicTime::fromUSec(AP_HAL::micros64());
}
static can_frame makeSocketCanFrame(const uavcan::CanFrame& uavcan_frame)
{
can_frame sockcan_frame { uavcan_frame.id& uavcan::CanFrame::MaskExtID, uavcan_frame.dlc, { } };
std::copy(uavcan_frame.data, uavcan_frame.data + uavcan_frame.dlc, sockcan_frame.data);
if (uavcan_frame.isExtended()) {
sockcan_frame.can_id |= CAN_EFF_FLAG;
}
if (uavcan_frame.isErrorFrame()) {
sockcan_frame.can_id |= CAN_ERR_FLAG;
}
if (uavcan_frame.isRemoteTransmissionRequest()) {
sockcan_frame.can_id |= CAN_RTR_FLAG;
}
return sockcan_frame;
}
static uavcan::CanFrame makeUavcanFrame(const can_frame& sockcan_frame)
{
uavcan::CanFrame uavcan_frame(sockcan_frame.can_id & CAN_EFF_MASK, sockcan_frame.data, sockcan_frame.can_dlc);
if (sockcan_frame.can_id & CAN_EFF_FLAG) {
uavcan_frame.id |= uavcan::CanFrame::FlagEFF;
}
if (sockcan_frame.can_id & CAN_ERR_FLAG) {
uavcan_frame.id |= uavcan::CanFrame::FlagERR;
}
if (sockcan_frame.can_id & CAN_RTR_FLAG) {
uavcan_frame.id |= uavcan::CanFrame::FlagRTR;
}
return uavcan_frame;
}
bool CAN::begin(uint32_t bitrate)
{
if (_initialized) return _initialized;
// TODO: Add possibility change bitrate
_fd = openSocket(HAL_BOARD_CAN_IFACE_NAME);
if (_fd > 0) {
_bitrate = bitrate;
_initialized = true;
} else {
_initialized = false;
}
return _initialized;
}
void CAN::reset()
{
if (_initialized && _bitrate != 0) {
close(_fd);
begin(_bitrate);
}
}
void CAN::end()
{
_initialized = false;
close(_fd);
}
bool CAN::is_initialized()
{
return _initialized;
}
int32_t CAN::tx_pending()
{
if (_initialized) {
return _tx_queue.size();
} else {
return -1;
}
}
int32_t CAN::available()
{
if (_initialized) {
return _rx_queue.size();
} else {
return -1;
}
}
int CAN::openSocket(const std::string& iface_name)
{
errno = 0;
int s = socket(PF_CAN, SOCK_RAW, CAN_RAW);
if (s < 0) {
return s;
}
std::shared_ptr<void> defer(&s, [](int* fd) { if (*fd >= 0) close(*fd); });
const int ret = s;
// Detect the iface index
auto ifr = ifreq();
if (iface_name.length() >= IFNAMSIZ) {
errno = ENAMETOOLONG;
return -1;
}
std::strncpy(ifr.ifr_name, iface_name.c_str(), iface_name.length());
if (ioctl(s, SIOCGIFINDEX, &ifr) < 0 || ifr.ifr_ifindex < 0) {
return -1;
}
// Bind to the specified CAN iface
{
auto addr = sockaddr_can();
addr.can_family = AF_CAN;
addr.can_ifindex = ifr.ifr_ifindex;
if (bind(s, reinterpret_cast<sockaddr*>(&addr), sizeof(addr)) < 0) {
return -1;
}
}
// Configure
{
const int on = 1;
// Timestamping
if (setsockopt(s, SOL_SOCKET, SO_TIMESTAMP, &on, sizeof(on)) < 0) {
return -1;
}
// Socket loopback
if (setsockopt(s, SOL_CAN_RAW, CAN_RAW_RECV_OWN_MSGS, &on, sizeof(on)) < 0) {
return -1;
}
// Non-blocking
if (fcntl(s, F_SETFL, O_NONBLOCK) < 0) {
return -1;
}
}
// Validate the resulting socket
{
int socket_error = 0;
socklen_t errlen = sizeof(socket_error);
getsockopt(s, SOL_SOCKET, SO_ERROR, reinterpret_cast<void*>(&socket_error), &errlen);
if (socket_error != 0) {
errno = socket_error;
return -1;
}
}
s = -1;
return ret;
}
int16_t CAN::send(const uavcan::CanFrame& frame, const uavcan::MonotonicTime tx_deadline,
const uavcan::CanIOFlags flags)
{
_tx_queue.emplace(frame, tx_deadline, flags, _tx_frame_counter);
_tx_frame_counter++;
_pollRead(); // Read poll is necessary because it can release the pending TX flag
_pollWrite();
return 1;
}
int16_t CAN::receive(uavcan::CanFrame& out_frame, uavcan::MonotonicTime& out_ts_monotonic,
uavcan::UtcTime& out_ts_utc, uavcan::CanIOFlags& out_flags)
{
if (_rx_queue.empty()) {
_pollRead(); // This allows to use the socket not calling poll() explicitly.
if (_rx_queue.empty()) {
return 0;
}
}
{
const RxItem& rx = _rx_queue.front();
out_frame = rx.frame;
out_ts_monotonic = rx.ts_mono;
out_ts_utc = rx.ts_utc;
out_flags = rx.flags;
}
_rx_queue.pop();
return 1;
}
bool CAN::hasReadyTx() const
{
return !_tx_queue.empty() && (_frames_in_socket_tx_queue < _max_frames_in_socket_tx_queue);
}
bool CAN::hasReadyRx() const
{
return !_rx_queue.empty();
}
void CAN::poll(bool read, bool write)
{
if (read) {
_pollRead(); // Read poll must be executed first because it may decrement _frames_in_socket_tx_queue
}
if (write) {
_pollWrite();
}
}
int16_t CAN::configureFilters(const uavcan::CanFilterConfig* const filter_configs,
const std::uint16_t num_configs)
{
if (filter_configs == nullptr) {
return -1;
}
_hw_filters_container.clear();
_hw_filters_container.resize(num_configs);
for (unsigned i = 0; i < num_configs; i++) {
const uavcan::CanFilterConfig& fc = filter_configs[i];
_hw_filters_container[i].can_id = fc.id & uavcan::CanFrame::MaskExtID;
_hw_filters_container[i].can_mask = fc.mask & uavcan::CanFrame::MaskExtID;
if (fc.id & uavcan::CanFrame::FlagEFF) {
_hw_filters_container[i].can_id |= CAN_EFF_FLAG;
}
if (fc.id & uavcan::CanFrame::FlagRTR) {
_hw_filters_container[i].can_id |= CAN_RTR_FLAG;
}
if (fc.mask & uavcan::CanFrame::FlagEFF) {
_hw_filters_container[i].can_mask |= CAN_EFF_FLAG;
}
if (fc.mask & uavcan::CanFrame::FlagRTR) {
_hw_filters_container[i].can_mask |= CAN_RTR_FLAG;
}
}
return 0;
}
/**
* SocketCAN emulates the CAN filters in software, so the number of filters is virtually unlimited.
* This method returns a constant value.
*/
static constexpr unsigned NumFilters = CAN_FILTER_NUMBER;
uint16_t CAN::getNumFilters() const { return NumFilters; }
uint64_t CAN::getErrorCount() const
{
uint64_t ec = 0;
for (auto& kv : _errors) { ec += kv.second; }
return ec;
}
void CAN::_pollWrite()
{
while (hasReadyTx()) {
const TxItem tx = _tx_queue.top();
if (tx.deadline >= getMonotonic()) {
const int res = _write(tx.frame);
if (res == 1) { // Transmitted successfully
_incrementNumFramesInSocketTxQueue();
if (tx.flags & uavcan::CanIOFlagLoopback) {
_pending_loopback_ids.insert(tx.frame.id);
}
} else if (res == 0) { // Not transmitted, nor is it an error
break; // Leaving the loop, the frame remains enqueued for the next retry
} else { // Transmission error
_registerError(SocketCanError::SocketWriteFailure);
}
} else {
_registerError(SocketCanError::TxTimeout);
}
// Removing the frame from the queue even if transmission failed
_tx_queue.pop();
}
}
void CAN::_pollRead()
{
uint8_t iterations_count = 0;
while (iterations_count < CAN_MAX_POLL_ITERATIONS_COUNT)
{
iterations_count++;
RxItem rx;
rx.ts_mono = getMonotonic(); // Monotonic timestamp is not required to be precise (unlike UTC)
bool loopback = false;
const int res = _read(rx.frame, rx.ts_utc, loopback);
if (res == 1) {
bool accept = true;
if (loopback) { // We receive loopback for all CAN frames
_confirmSentFrame();
rx.flags |= uavcan::CanIOFlagLoopback;
accept = _wasInPendingLoopbackSet(rx.frame);
}
if (accept) {
_rx_queue.push(rx);
}
} else if (res == 0) {
break;
} else {
_registerError(SocketCanError::SocketReadFailure);
break;
}
}
}
int CAN::_write(const uavcan::CanFrame& frame) const
{
errno = 0;
const can_frame sockcan_frame = makeSocketCanFrame(frame);
const int res = write(_fd, &sockcan_frame, sizeof(sockcan_frame));
if (res <= 0) {
if (errno == ENOBUFS || errno == EAGAIN) { // Writing is not possible atm, not an error
return 0;
}
return res;
}
if (res != sizeof(sockcan_frame)) {
return -1;
}
return 1;
}
int CAN::_read(uavcan::CanFrame& frame, uavcan::UtcTime& ts_utc, bool& loopback) const
{
auto iov = iovec();
auto sockcan_frame = can_frame();
iov.iov_base = &sockcan_frame;
iov.iov_len = sizeof(sockcan_frame);
struct Control
{
cmsghdr cm;
std::uint8_t data[sizeof(::timeval)];
} control;
auto msg = msghdr();
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = &control;
msg.msg_controllen = sizeof(control);
const int res = recvmsg(_fd, &msg, MSG_DONTWAIT);
if (res <= 0) {
return (res < 0 && errno == EWOULDBLOCK) ? 0 : res;
}
/*
* Flags
*/
loopback = (msg.msg_flags & static_cast<int>(MSG_CONFIRM)) != 0;
if (!loopback && !_checkHWFilters(sockcan_frame)) {
return 0;
}
frame = makeUavcanFrame(sockcan_frame);
/*
* Timestamp
*/
const cmsghdr* const cmsg = CMSG_FIRSTHDR(&msg);
if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SO_TIMESTAMP) {
auto tv = timeval();
std::memcpy(&tv, CMSG_DATA(cmsg), sizeof(tv)); // Copy to avoid alignment problems
ts_utc = uavcan::UtcTime::fromUSec(std::uint64_t(tv.tv_sec) * 1000000ULL + tv.tv_usec);
} else {
return -1;
}
return 1;
}
void CAN::_incrementNumFramesInSocketTxQueue()
{
_frames_in_socket_tx_queue++;
}
void CAN::_confirmSentFrame()
{
if (_frames_in_socket_tx_queue > 0) {
_frames_in_socket_tx_queue--;
}
}
bool CAN::_wasInPendingLoopbackSet(const uavcan::CanFrame& frame)
{
if (_pending_loopback_ids.count(frame.id) > 0) {
_pending_loopback_ids.erase(frame.id);
return true;
}
return false;
}
bool CAN::_checkHWFilters(const can_frame& frame) const
{
if (!_hw_filters_container.empty()) {
for (auto& f : _hw_filters_container) {
if (((frame.can_id & f.can_mask) ^ f.can_id) == 0) {
return true;
}
}
return false;
} else {
return true;
}
}
void CANManager::IfaceWrapper::updateDownStatusFromPollResult(const pollfd& pfd)
{
if (!_down&& (pfd.revents & POLLERR)) {
int error = 0;
socklen_t errlen = sizeof(error);
getsockopt(pfd.fd, SOL_SOCKET, SO_ERROR, reinterpret_cast<void*>(&error), &errlen);
_down= error == ENETDOWN || error == ENODEV;
hal.console->printf("Iface %d is dead; error %d", this->getFileDescriptor(), error);
}
}
void CANManager::_timer_tick()
{
if (!_initialized) return;
if (p_uavcan != nullptr) {
p_uavcan->do_cyclic();
} else {
hal.console->printf("p_uavcan is nullptr");
}
}
bool CANManager::begin(uint32_t bitrate, uint8_t can_number)
{
if (init(can_number) >= 0) {
_initialized = true;
}
return _initialized;
}
bool CANManager::is_initialized()
{
return _initialized;
}
void CANManager::initialized(bool val)
{
_initialized = val;
}
AP_UAVCAN *CANManager::get_UAVCAN(void)
{
return p_uavcan;
}
void CANManager::set_UAVCAN(AP_UAVCAN *uavcan)
{
p_uavcan = uavcan;
}
CAN* CANManager::getIface(uint8_t iface_index)
{
return (iface_index >= _ifaces.size()) ? nullptr : _ifaces[iface_index].get();
}
int CANManager::init(uint8_t can_number)
{
int res = -1;
char iface_name[16];
sprintf(iface_name, "can%u", can_number);
res = addIface(iface_name);
if (res < 0) {
hal.console->printf("CANManager: init %s failed\n", iface_name);
}
return res;
}
int16_t CANManager::select(uavcan::CanSelectMasks& inout_masks,
const uavcan::CanFrame* (&)[uavcan::MaxCanIfaces],
uavcan::MonotonicTime blocking_deadline)
{
// Detecting whether we need to block at all
bool need_block = (inout_masks.write == 0); // Write queue is infinite
for (unsigned i = 0; need_block && (i < _ifaces.size()); i++) {
const bool need_read = inout_masks.read & (1 << i);
if (need_read && _ifaces[i]->hasReadyRx()) {
need_block = false;
}
}
if (need_block) {
// Poll FD set setup
pollfd pollfds[uavcan::MaxCanIfaces] = {};
unsigned num_pollfds = 0;
IfaceWrapper* pollfd_index_to_iface[uavcan::MaxCanIfaces] = {};
for (unsigned i = 0; i < _ifaces.size(); i++) {
if (!_ifaces[i]->isDown()) {
pollfds[num_pollfds].fd = _ifaces[i]->getFileDescriptor();
pollfds[num_pollfds].events = POLLIN;
if (_ifaces[i]->hasReadyTx() || (inout_masks.write & (1U << i))) {
pollfds[num_pollfds].events |= POLLOUT;
}
pollfd_index_to_iface[num_pollfds] = _ifaces[i].get();
num_pollfds++;
}
}
if (num_pollfds == 0) {
return 0;
}
// Timeout conversion
const std::int64_t timeout_usec = (blocking_deadline - getMonotonic()).toUSec();
auto ts = timespec();
if (timeout_usec > 0) {
ts.tv_sec = timeout_usec / 1000000LL;
ts.tv_nsec = (timeout_usec % 1000000LL) * 1000;
}
// Blocking here
const int res = ppoll(pollfds, num_pollfds, &ts, nullptr);
if (res < 0) {
return res;
}
// Handling poll output
for (unsigned i = 0; i < num_pollfds; i++) {
pollfd_index_to_iface[i]->updateDownStatusFromPollResult(pollfds[i]);
const bool poll_read = pollfds[i].revents & POLLIN;
const bool poll_write = pollfds[i].revents & POLLOUT;
pollfd_index_to_iface[i]->poll(poll_read, poll_write);
}
}
// Writing the output masks
inout_masks = uavcan::CanSelectMasks();
for (unsigned i = 0; i < _ifaces.size(); i++) {
if (!_ifaces[i]->isDown()) {
inout_masks.write |= std::uint8_t(1U << i); // Always ready to write if not down
}
if (_ifaces[i]->hasReadyRx()) {
inout_masks.read |= std::uint8_t(1U << i); // Readability depends only on RX buf, even if down
}
}
// Return value is irrelevant as long as it's non-negative
return _ifaces.size();
}
int CANManager::addIface(const std::string& iface_name)
{
if (_ifaces.size() >= uavcan::MaxCanIfaces) {
return -1;
}
// Open the socket
const int fd = CAN::openSocket(iface_name);
if (fd < 0) {
return fd;
}
// Construct the iface - upon successful construction the iface will take ownership of the fd.
_ifaces.emplace_back(new IfaceWrapper(fd));
hal.console->printf("New iface '%s' fd %d\n", iface_name.c_str(), fd);
return _ifaces.size() - 1;
}
#endif