1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994
//! # MAVLink frame
use crc_any::CRCu16;
#[cfg(feature = "async")]
use tokio::io::{AsyncRead, AsyncReadExt, AsyncWrite, AsyncWriteExt};
use crate::consts::{CHECKSUM_SIZE, SIGNATURE_LENGTH};
use crate::error::{ChecksumError, SignatureError, VersionError};
use crate::io::{Read, Write};
use crate::protocol::header::Header;
use crate::protocol::marker::{
HasCompId, HasMsgId, HasPayload, HasPayloadLen, HasSysId, Sequenced, Unset,
};
use crate::protocol::signature::{Sign, Signature, Signer, SigningConf};
use crate::protocol::{
Checksum, CompatFlags, ComponentId, CrcExtra, FrameBuilder, IncompatFlags, MavLinkVersion,
MavTimestamp, MessageId, Payload, PayloadLength, SecretKey, Sequence, SignatureBytes,
SignedLinkId, SystemId,
};
use crate::prelude::*;
/// MAVLink frame.
///
/// Represents [`MAVLink1`](https://mavlink.io/en/guide/serialization.html#v1_packet_format) or
/// [`MAVLink2`](https://mavlink.io/en/guide/serialization.html#mavlink2_packet_format) packet.
///
/// # Protocol Version
///
/// All MAVLink frames are always belong to a specific MAVLink protocol version. However, for the
/// sake of generality, this library provides a way to deal with MAVLink protocol version both
/// explicitly by operating on [`Frame<V1>`] / [`Frame<V2>`] and implicitly through
/// [`Frame<Versionless>`]. The latter can be obtained by [`Frame::into_versionless`]
/// and converted into protocol-specific form through [`Frame::try_into_versioned`]. Both versionless and
/// versioned forms of a frame could be correctly decoded into the corresponding MAVLink message.
///
/// # Encoding / Decoding
///
/// Frames can be decoded into the corresponding MAVLink message by [`Frame::decode`] method. This
/// requires appropriate MAVLink dialect to be generated by [`mavspec`]. All autogenerated dialects
/// can be found in the [`mavio::dialects`](crate::dialects) module.
///
/// To encode MAVLink message into a frame, you should use [`FrameBuilder::message`] as described in
/// [construction](#construction) section.
///
/// # Construction
///
/// Since MAVLink frames has a complex internal structure that depends on [`MavLinkVersion`],
/// encoded [`Message`] and presence of [`Signature`], there are is direct no constructor for this
/// struct. [`Frame`] can be either received as they were sent by remote or built from [`FrameBuilder`].
///
/// Use [`Frame::builder`] to create new frames via builder and [`Frame::add_signature`] (for
/// [`Frame<V2>`] only) to sign frames.
#[derive(Clone, Debug)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct Frame<V: MaybeVersioned> {
pub(super) header: Header<V>,
pub(super) payload: Payload,
pub(super) checksum: Checksum,
pub(super) signature: Option<Signature>,
}
impl Frame<Versionless> {
/// Instantiates an empty builder for [`Frame`].
pub fn builder(
) -> FrameBuilder<Versionless, Unset, Unset, Unset, Unset, Unset, Unset, Unset, Unset> {
FrameBuilder::new()
}
}
///////////////////////////////////////////////////////////////////////////////
// ALL //
///////////////////////////////////////////////////////////////////////////////
impl<V: MaybeVersioned> Frame<V> {
/// Frame [`Header`].
#[inline]
pub fn header(&self) -> &Header<V> {
&self.header
}
/// MAVLink protocol version defined by [`Header`].
///
/// # Links
///
/// * [`MavLinkVersion`]
/// * [`Header::version`]
/// * [`MavFrame::version`]
#[inline]
pub fn version(&self) -> MavLinkVersion {
self.header.version()
}
/// Payload length.
///
/// Indicates length of the following `payload` section. This may be affected by payload truncation.
///
/// # Links
///
/// * [`Header::payload_length`].
/// * [`MavFrame::payload_length`].
#[inline]
pub fn payload_length(&self) -> PayloadLength {
self.header.payload_length()
}
/// Packet sequence number.
///
/// Used to detect packet loss. Components increment value for each message sent.
///
/// # Links
///
/// * [`Header::sequence`].
/// * [`MavFrame::sequence`]
#[inline]
pub fn sequence(&self) -> Sequence {
self.header.sequence()
}
/// System `ID`.
///
/// `ID` of system (vehicle) sending the message. Used to differentiate systems on network.
///
/// > Note that the broadcast address 0 may not be used in this field as it is an invalid source
/// > address.
///
/// # Links
///
/// * [`Header::system_id`].
/// * [`MavFrame::system_id`].
#[inline]
pub fn system_id(&self) -> SystemId {
self.header.system_id()
}
/// Component `ID`.
///
/// `ID` of component sending the message. Used to differentiate components in a system (e.g.
/// autopilot and a camera). Use appropriate values in
/// [MAV_COMPONENT](https://mavlink.io/en/messages/common.html#MAV_COMPONENT).
///
/// > Note that the broadcast address `MAV_COMP_ID_ALL` may not be used in this field as it is
/// > an invalid source address.
///
/// # Links
///
/// * [`Header::component_id`].
/// * [`MavFrame::component_id`].
#[inline]
pub fn component_id(&self) -> ComponentId {
self.header.component_id()
}
/// Message `ID`.
///
/// `ID` of MAVLink message. Defines how payload will be encoded and decoded.
///
/// # Links
///
/// * [`Header::message_id`].
/// * [`MavFrame::message_id`].
#[inline]
pub fn message_id(&self) -> MessageId {
self.header.message_id()
}
/// Payload data.
///
/// Message data. Content depends on message type (i.e. `message_id`).
///
/// Returns an instance of [`Payload`]. If you are interested in payload bytes, use
/// [`Payload::bytes`].
///
/// # Links
///
/// * [`MavFrame::payload`].
#[inline]
pub fn payload(&self) -> &Payload {
&self.payload
}
/// MAVLink packet checksum.
///
/// `CRC-16/MCRF4XX` [checksum](https://mavlink.io/en/guide/serialization.html#checksum) for
/// message (excluding magic byte).
///
/// Includes [CRC_EXTRA](https://mavlink.io/en/guide/serialization.html#crc_extra) byte.
///
/// Checksum is encoded with little endian (low byte, high byte).
///
/// # Links
///
/// * [`Frame::calculate_crc`] for implementation.
/// * [MAVLink checksum definition](https://mavlink.io/en/guide/serialization.html#checksum).
/// * [CRC-16/MCRF4XX](https://ww1.microchip.com/downloads/en/AppNotes/00752a.pdf) (PDF).
/// * [`MavFrame::checksum`]
#[inline]
pub fn checksum(&self) -> Checksum {
self.checksum
}
/// Returns `true` if frame is signed.
///
/// Returns `true` if [`Frame`] contains [`Signature`]. Correctness of signature is not validated.
///
/// For `MAVLink 1` frames always returns `false`.
///
/// # Links
///
/// * [`MavFrame::is_signed`]
#[inline]
pub fn is_signed(&self) -> bool {
self.signature.is_some()
}
/// `MAVLink 2` signature.
///
/// Returns signature that ensures the link is tamper-proof.
///
/// Available only for signed `MAVLink 2` frames. For `MAVLink 1` always return `None`.
///
/// # Links
///
/// * [`Frame::is_signed`] checks that frame is signed.
/// * [`Frame::link_id`] and [`Frame::timestamp`] provide direct access to signature fields
/// ([`Frame<V2>`] only).
/// # [`MavFrame::signature`].
/// * [MAVLink 2 message signing](https://mavlink.io/en/guide/message_signing.html).
#[inline]
pub fn signature(&self) -> Option<&Signature> {
if self.matches_version(V2) {
self.signature.as_ref()
} else {
None
}
}
/// Removes `MAVLink 2` signature from frame.
///
/// Applicable only for `MAVLink 2` frames. `MAVLink 1` frames will be kept untouched.
///
/// # Links
///
/// [`MavFrame::remove_signature`]
pub fn remove_signature(&mut self) {
self.signature = None;
self.header.set_is_signed(false)
}
/// Body length.
///
/// Returns the length of the entire [`Frame`] body. The frame body consist of [`Payload::bytes`], [`Checksum`], and
/// optional [`Signature`] (for `MAVLink 2` protocol).
///
/// # Links
///
/// * [`Header::body_length`].
/// * [`MavFrame::body_length`].
#[inline]
pub fn body_length(&self) -> usize {
self.header().body_length()
}
/// Calculates CRC for frame within `crc_extra`.
///
/// Provided `crc_extra` depends on a dialect and contains a digest of message XML definition.
///
/// # Links
///
/// * [`Frame::checksum`].
/// * [`MavFrame::calculate_crc`].
/// * [MAVLink checksum definition](https://mavlink.io/en/guide/serialization.html#checksum).
/// * [CRC-16/MCRF4XX](https://ww1.microchip.com/downloads/en/AppNotes/00752a.pdf) (PDF).
pub fn calculate_crc(&self, crc_extra: CrcExtra) -> Checksum {
let mut crc_calculator = CRCu16::crc16mcrf4cc();
crc_calculator.digest(self.header.decode().crc_data());
crc_calculator.digest(self.payload.bytes());
crc_calculator.digest(&[crc_extra]);
crc_calculator.get_crc()
}
/// Validates frame in the context of specific dialect.
///
/// Receives dialect specification in `dialect_spec`, ensures that message with such ID
/// exists in this dialect, and compares checksums using `EXTRA_CRC`.
///
/// # Errors
///
/// * Returns [`Error::Spec`] if message discovery failed.
/// * Returns [`FrameError::Checksum`] (wrapped by [`Error`]) if checksum
/// validation failed.
///
/// # Links
///
/// * [`Dialect`] for dialect specification.
/// * [`Frame::calculate_crc`] for CRC implementation details.
/// * [`MavFrame::validate_checksum`].
pub fn validate_checksum<D: Dialect>(&self) -> Result<()> {
let message_info = D::message_info(self.header().message_id())?;
self.validate_checksum_with_crc_extra(message_info.crc_extra())?;
Ok(())
}
/// Validates frame's checksum using provided `crc_extra`.
///
/// # Errors
///
/// Returns [`ChecksumError`] if checksum validation failed.
///
/// # Links
///
/// * [`Frame::calculate_crc`] for CRC implementation details.
/// * [`MavFrame::validate_checksum_with_crc_extra`].
pub fn validate_checksum_with_crc_extra(
&self,
crc_extra: CrcExtra,
) -> core::result::Result<(), ChecksumError> {
if self.calculate_crc(crc_extra) != self.checksum {
return Err(ChecksumError);
}
Ok(())
}
/// Checks that frame has MAVLink version equal to the provided one.
///
/// # Links
///
/// # [`MavFrame::matches_version`]
pub fn matches_version<Version: Versioned>(
&self,
#[allow(unused_variables)] version: Version,
) -> bool {
Version::matches(self.version())
}
/// Attempts to transform frame into its versioned form.
///
/// This method never changes the internal MAVLink protocol version. It will return an error,
/// if conversion is not possible.
pub fn try_into_versioned<Version: MaybeVersioned>(
self,
) -> core::result::Result<Frame<Version>, VersionError> {
Version::expect(self.version())?;
Ok(Frame {
header: self.header.try_into_versioned::<Version>()?,
payload: self.payload,
checksum: self.checksum,
signature: self.signature,
})
}
/// Attempts to create frame of specified version from the existing one.
///
/// This method never changes the internal MAVLink protocol version. It will return an error,
/// if conversion is not possible.
pub fn try_to_versioned<Version: MaybeVersioned>(
&self,
) -> core::result::Result<Frame<Version>, VersionError> {
self.clone().try_into_versioned()
}
/// Forget about frame's version transforming it into a [`Versionless`] variant.
pub fn into_versionless(self) -> Frame<Versionless> {
Frame {
header: self.header.into_versionless(),
payload: self.payload,
checksum: self.checksum,
signature: self.signature,
}
}
/// Forget about frame's version transforming it into a [`Versionless`] variant.
pub fn to_versionless(&self) -> Frame<Versionless> {
self.clone().into_versionless()
}
/// Converts this frame into a dynamic [`MavFrame`].
pub fn into_mav_frame(self) -> MavFrame {
MavFrame::new(self)
}
/// Decodes frame into a message of particular MAVLink dialect.
///
/// Performs [`Frame::checksum`] validation before returning decoded message.
///
/// # Usage
///
/// ```rust,no_run
/// # #[cfg(feature = "minimal")] {
/// # use minimal::messages::Heartbeat;
/// # use mavio::protocol::{V2};
/// use mavio::dialects::minimal;
/// use mavio::dialects::minimal::Minimal;
/// use mavio::Frame;
///
/// let frame = // ... obtain a frame
/// # Frame::builder()
/// # .sequence(0)
/// # .system_id(1)
/// # .component_id(1)
/// # .version(V2)
/// # .message(&Heartbeat::default()).unwrap()
/// # .build();
///
/// // Decode the frame within `minimal` dialect and match result over available dialect messages
/// match frame.decode().unwrap() {
/// Minimal::ProtocolVersion(_) => {}
/// Minimal::Heartbeat(_) => {}
/// }
/// # }
/// ```
///
/// # Errors
///
/// * Returns [`FrameError::Checksum`] if checksum validation failed.
/// * Returns [`Error::Spec`] if frame can't be correctly decoded to the provided
/// [`Dialect`] (generic type argument).
///
/// # Links
///
/// * [`Frame::validate_checksum_with_crc_extra`] performs checksum validation.
/// * [`SpecError`] contains errors related to MAVLink dialect specification and message
/// encoding/decoding.
/// * [`Frame::decode`]
#[inline]
pub fn decode<D: Dialect>(&self) -> Result<D> {
let message = D::decode(self.payload()).map_err(Error::from)?;
self.validate_checksum_with_crc_extra(message.crc_extra())?;
Ok(message)
}
/// Upgrades a frame in-place to `MAVLink 2` protocol version using provided `CRC_EXTRA`.
///
/// The opposite is not possible since we need to know exact payload length.
pub fn upgrade_with_crc_extra(&mut self, crc_extra: CrcExtra) {
self.payload.upgrade();
self.header.payload_length = self.payload.length();
self.checksum = self.calculate_crc(crc_extra);
}
pub(crate) fn recv<R: Read>(reader: &mut R) -> Result<Frame<V>> {
let header = Header::<V>::recv(reader)?;
let body_length = header.body_length();
#[cfg(feature = "std")]
let mut body_buf = vec![0u8; body_length];
#[cfg(not(feature = "std"))]
let mut body_buf = [0u8; crate::consts::PAYLOAD_MAX_SIZE + SIGNATURE_LENGTH];
let body_bytes = &mut body_buf[0..body_length];
reader.read_exact(body_bytes)?;
let frame = Self::try_from_raw_body(header, body_bytes)?;
Ok(frame)
}
#[cfg(feature = "async")]
pub(crate) async fn recv_async<R: AsyncRead + Unpin>(reader: &mut R) -> Result<Frame<V>> {
let header = Header::<V>::recv_async(reader).await?;
let body_length = header.body_length();
#[cfg(feature = "std")]
let mut body_buf = vec![0u8; body_length];
#[cfg(not(feature = "std"))]
let mut body_buf = [0u8; crate::consts::PAYLOAD_MAX_SIZE + SIGNATURE_LENGTH];
let body_bytes = &mut body_buf[0..body_length];
reader.read_exact(body_bytes).await?;
let frame = Self::try_from_raw_body(header, body_bytes)?;
Ok(frame)
}
pub(crate) fn send<W: Write>(&self, writer: &mut W) -> Result<usize> {
let header_bytes_sent = self.header.send(writer)?;
#[cfg(not(feature = "alloc"))]
let mut buf = [0u8; crate::consts::PAYLOAD_MAX_SIZE + SIGNATURE_LENGTH];
#[cfg(feature = "alloc")]
let mut buf = alloc::vec![0u8; self.body_length()];
self.fill_body_buffer(&mut buf);
writer.write_all(buf.as_slice())?;
Ok(header_bytes_sent + self.body_length())
}
#[cfg(feature = "async")]
pub(crate) async fn send_async<W: AsyncWrite + Unpin>(&self, writer: &mut W) -> Result<usize> {
let header_bytes_sent = self.header.send_async(writer).await?;
#[cfg(not(feature = "alloc"))]
let mut buf = [0u8; crate::consts::PAYLOAD_MAX_SIZE + SIGNATURE_LENGTH];
#[cfg(feature = "alloc")]
let mut buf = vec![0u8; self.body_length()];
self.fill_body_buffer(&mut buf);
writer.write_all(buf.as_slice()).await?;
Ok(header_bytes_sent + self.body_length())
}
fn fill_body_buffer(&self, buf: &mut [u8]) {
let payload_length = self.payload_length() as usize;
buf[0..payload_length].copy_from_slice(self.payload.bytes());
let checksum_bytes: [u8; 2] = self.checksum.to_le_bytes();
buf[payload_length..payload_length + 2].copy_from_slice(&checksum_bytes);
if let Some(signature) = self.signature {
let signature_bytes: SignatureBytes = signature.to_byte_array();
let sig_start_idx = payload_length + 2;
buf[sig_start_idx..self.body_length()].copy_from_slice(&signature_bytes);
}
}
#[inline]
fn try_from_raw_body(header: Header<V>, body_bytes: &[u8]) -> Result<Frame<V>> {
let payload_bytes = &body_bytes[0..header.payload_length() as usize];
let payload = Payload::new(header.message_id(), payload_bytes, header.version());
let checksum_start = header.payload_length() as usize;
let checksum_bytes = [body_bytes[checksum_start], body_bytes[checksum_start + 1]];
let checksum: Checksum = Checksum::from_le_bytes(checksum_bytes);
let signature: Option<Signature> = if header.is_signed() {
let signature_start = checksum_start + CHECKSUM_SIZE;
let signature_bytes = &body_bytes[signature_start..signature_start + SIGNATURE_LENGTH];
Some(Signature::from_slice(signature_bytes))
} else {
None
};
Ok(Frame {
header,
payload,
checksum,
signature,
})
}
}
///////////////////////////////////////////////////////////////////////////////
// V1/V2 //
///////////////////////////////////////////////////////////////////////////////
impl<V: Versioned> Frame<V> {
/// Create [`FrameBuilder`] populated with current frame data.
///
/// It is not possible to simply change a particular frame field since MAVLink frame data is
/// tightly packed together, covered by CRC, and, in the case of `MAVLink 2` protocol, is
/// potentially signed. Moreover, to alter a frame correctly we need a [`CrcExtra`] byte which
/// is a part of a dialect, not the frame itself.
///
/// This method provides a limited capability to alter frame data by creating a [`FrameBuilder`]
/// populated with data of the current frame. For `MAVLink 2` frames this will drop frame's
/// [`signature`](Frame::signature) and [`IncompatFlags::MAVLINK_IFLAG_SIGNED`] in
/// [`incompat_flags`](Frame::incompat_flags) rendering frame unsigned. This process also
/// requires from caller to provide a [`CrcExtra`] value to encoded message since
/// [`checksum`](Frame::checksum) will be dropped as well and the information required to its
/// this recalculation is not stored within MAVLink frame itself.
///
/// It is not possible to rebuild [`Versionless`] frames since `MAVLink 2` [`Payload`] may
/// contain extension fields and its trailing zero bytes are truncated which means it is not
/// possible to reconstruct `MAVLink 1` [`payload_length`](Frame::payload_length) when
/// downgrading frame protocol version.
pub fn to_builder(
&self,
) -> FrameBuilder<
V,
HasPayloadLen,
Sequenced,
HasSysId,
HasCompId,
HasMsgId,
HasPayload,
Unset,
Unset,
> {
FrameBuilder {
header_builder: self.header.to_builder(),
payload: HasPayload(self.payload.clone()),
crc_extra: Unset,
signature: Unset,
}
}
}
///////////////////////////////////////////////////////////////////////////////
// V2 //
///////////////////////////////////////////////////////////////////////////////
impl Frame<V2> {
/// Incompatibility flags for `MAVLink 2` header.
///
/// Flags that must be understood for MAVLink compatibility (implementation discards packet if
/// it does not understand flag).
///
/// See: [MAVLink 2 incompatibility flags](https://mavlink.io/en/guide/serialization.html#incompat_flags).
#[inline]
pub fn incompat_flags(&self) -> IncompatFlags {
self.header.incompat_flags()
}
/// Compatibility flags for `MAVLink 2` header.
///
/// Flags that can be ignored if not understood (implementation can still handle packet even if
/// it does not understand flag).
///
/// See: [MAVLink 2 compatibility flags](https://mavlink.io/en/guide/serialization.html#compat_flags).
#[inline]
pub fn compat_flags(&self) -> CompatFlags {
self.header.compat_flags()
}
/// `MAVLink 2` signature `link_id`, an 8-bit identifier of a MAVLink channel.
///
/// Peers may have different semantics or rules for different links. For example, some links may have higher
/// priority over another during routing. Or even different secret keys for authorization.
///
/// Available only for signed `MAVLink 2` frame. For `MAVLink 1` always return `None`.
///
/// # Links
///
/// * [`Self::signature`] from which [`Signature`] can be obtained. The former contains all signature-related fields
/// (if applicable).
/// * [MAVLink 2 message signing](https://mavlink.io/en/guide/message_signing.html).
pub fn link_id(&self) -> Option<SignedLinkId> {
self.signature.map(|sig| sig.link_id)
}
/// `MAVLink 2` signature [`MavTimestamp`], a 48-bit value that specifies the moment when message was sent.
///
/// The unit of measurement is the number of millisecond * 10 since MAVLink epoch (1st January 2015 GMT).
///
/// According to MAVLink protocol, the sender must guarantee that the next timestamp is greater than the previous
/// one.
///
/// Available only for signed `MAVLink 2` frame. For `MAVLink 1` always return `None`.
///
/// # Links
///
/// * [`Self::signature`] from which [`Signature`] can be obtained. The former contains all signature-related fields
/// (if applicable).
/// * [`MavTimestamp`] type which has utility function for converting from and into Unix timestamp.
/// * [Timestamp handling](https://mavlink.io/en/guide/message_signing.html#timestamp) in MAVLink documentation.
pub fn timestamp(&self) -> Option<MavTimestamp> {
self.signature.map(|sig| sig.timestamp)
}
/// Adds signature to `MAVLink 2` frame.
///
/// Signs `MAVLink 2` frame with provided instance of `signer` that implements [`Sign`] trait and signature
/// configuration specified as [`SigningConf`].
///
/// # Links
///
/// * [`Sign`] trait.
/// * [`Signature`] struct which contains frame signature.
/// * [MAVLink 2 message signing](https://mavlink.io/en/guide/message_signing.html).
pub fn add_signature(&mut self, signer: &mut dyn Sign, conf: &SigningConf) -> &mut Self {
conf.apply(self, signer);
self
}
/// Validates frame signature using a `signer` and a secret `key`.
///
/// Returns [`SignatureError`] if frame missing a signature or have an incorrect one.
pub fn validate_signature(
&self,
signer: &mut dyn Sign,
key: &SecretKey,
) -> core::result::Result<(), SignatureError> {
let signature = if let Some(signature) = self.signature {
signature
} else {
return Err(SignatureError);
};
let mut signer = Signer::new(signer);
if !signer.validate(&self, &signature, key) {
return Err(SignatureError);
}
Ok(())
}
}
#[cfg(feature = "unsafe")]
impl<V: MaybeVersioned> TryUpdateFrom<&dyn Message> for Frame<V> {
type Error = SpecError;
/// <sup>`⚠`</sup>
/// Updates a frame with the data from the provided message.
///
/// Replaces the following fields, that are guaranteed to be correct:
///
/// * [`Frame::message_id`]
/// * [`Frame::payload_length`]
/// * [`Frame::payload`]
/// * [`Frame::checksum`]
///
/// **⚠** This method will strip [`Frame::signature`]. Make sure, that you know, how to sign
/// the updated frame afterward.
fn try_update_from(&mut self, value: &dyn Message) -> std::result::Result<(), Self::Error> {
self.check_try_update_from(&value)?;
unsafe { self.update_from_unchecked(value) }
Ok(())
}
fn check_try_update_from(&self, value: &&dyn Message) -> std::result::Result<(), Self::Error> {
value.encode(self.version())?;
Ok(())
}
unsafe fn update_from_unchecked(&mut self, value: &dyn Message) {
let payload = value.encode(self.version()).unwrap();
let crc_extra = value.crc_extra();
self.header.message_id = payload.id();
self.header.payload_length = payload.length();
self.payload = payload;
self.checksum = self.calculate_crc(crc_extra);
self.remove_signature();
}
}
///////////////////////////////////////////////////////////////////////////////
// TESTS //
///////////////////////////////////////////////////////////////////////////////
#[cfg(test)]
mod tests {
#[cfg(feature = "std")]
use std::io::Cursor;
use crc_any::CRCu16;
#[allow(unused_imports)]
use crate::protocol::{V1, V2};
#[test]
fn crc_calculation_algorithm_accepts_sequential_digests() {
// We just want to test that CRC algorithm is invariant in respect to the way we feed it
// data.
let data = [124, 12, 22, 34, 2, 148, 82, 201, 72, 0, 18, 215, 37, 63u8];
let split_at: usize = data.len() / 2;
// Get all data as one slice
let mut crc_calculator_bulk = CRCu16::crc16mcrf4cc();
crc_calculator_bulk.digest(&data);
// Get data as two chunks sequentially
let mut crc_calculator_seq = CRCu16::crc16mcrf4cc();
crc_calculator_seq.digest(&data[0..split_at]);
crc_calculator_seq.digest(&data[split_at..data.len()]);
assert_eq!(crc_calculator_bulk.get_crc(), crc_calculator_seq.get_crc());
}
#[test]
#[cfg(feature = "std")]
fn multiple_magic_bytes_in_stream_v1() {
use crate::consts::STX_V1;
let seq = STX_V1;
let reader = Cursor::new(vec![
STX_V1, // magic byte
8, // payload_length
seq, // sequence
10, // system ID
255, // component ID
0, // message ID
// -------------------------------
1, 1, 1, 1, 1, 1, 1, 1, // Payload
// -------------------------------
0, 0, // Checksum (fake)
]);
let mut receiver = crate::Receiver::new::<V1>(reader);
let frame = receiver.recv().unwrap();
assert_eq!(frame.payload_length(), 8);
assert_eq!(frame.sequence(), seq);
assert_eq!(frame.system_id(), 10);
assert_eq!(frame.component_id(), 255);
}
#[test]
#[cfg(feature = "std")]
fn multiple_magic_bytes_in_stream_v2() {
use crate::consts::STX_V2;
let seq = STX_V2;
let reader = Cursor::new(vec![
STX_V2, // magic byte
8, // payload_length
0, // incompatibility flags
0, // compatibility flags
seq, // sequence
10, // system ID
255, // component ID
0, // \
0, // | message ID
0, // /
// -------------------------------
1, 1, 1, 1, 1, 1, 1, 1, // Payload
// -------------------------------
0, 0, // Checksum (fake)
]);
let mut receiver = crate::Receiver::new::<V2>(reader);
let frame = receiver.recv().unwrap();
assert_eq!(frame.payload_length(), 8);
assert_eq!(frame.sequence(), seq);
assert_eq!(frame.system_id(), 10);
assert_eq!(frame.component_id(), 255);
}
#[cfg(feature = "minimal")]
mod dialect_utils {
pub(super) use crate::dialects::minimal as dialect;
pub(super) use crate::dialects::minimal::enums::{
MavAutopilot, MavModeFlag, MavState, MavType,
};
pub(super) use crate::protocol::V1;
pub(super) use dialect::messages::Heartbeat;
pub(super) use super::super::*;
pub(super) fn default_incompat_flags() -> IncompatFlags {
IncompatFlags::BIT_3 | IncompatFlags::BIT_4
}
pub(super) fn default_compat_flags() -> CompatFlags {
CompatFlags::BIT_5 | CompatFlags::BIT_6
}
pub(super) fn default_heartbeat_message() -> Heartbeat {
Heartbeat {
type_: MavType::FixedWing,
autopilot: MavAutopilot::Generic,
base_mode: MavModeFlag::TEST_ENABLED & MavModeFlag::CUSTOM_MODE_ENABLED,
custom_mode: 0,
system_status: MavState::Active,
mavlink_version: dialect::Minimal::version().unwrap_or(0),
}
}
pub(super) fn default_v1_heartbeat_frame() -> Frame<V1> {
let message = default_heartbeat_message();
Frame::builder()
.sequence(7)
.system_id(22)
.component_id(17)
.version(V1)
.message(&message)
.unwrap()
.build()
}
pub(super) fn default_v2_heartbeat_frame() -> Frame<V2> {
let message = default_heartbeat_message();
Frame::builder()
.sequence(7)
.system_id(22)
.component_id(17)
.version(V2)
.incompat_flags(default_incompat_flags())
.compat_flags(default_compat_flags())
.message(&message)
.unwrap()
.build()
}
}
#[cfg(feature = "minimal")]
use dialect_utils::*;
#[test]
#[cfg(feature = "minimal")]
#[cfg(feature = "std")]
fn test_signing() {
use crate::consts::SIGNATURE_SECRET_KEY_LENGTH;
use crate::utils::MavSha256;
let mut frame = default_v2_heartbeat_frame();
let frame = frame.add_signature(
&mut MavSha256::default(),
&SigningConf {
link_id: 0,
timestamp: Default::default(),
secret: [0u8; SIGNATURE_SECRET_KEY_LENGTH].into(),
},
);
assert!(frame.is_signed());
}
#[test]
#[cfg(feature = "minimal")]
fn test_decoding_to_message() {
let _: dialect::Minimal = default_v2_heartbeat_frame().decode().unwrap();
}
#[test]
#[cfg(feature = "minimal")]
#[cfg(feature = "std")]
fn test_rebuild_frame() {
use crate::consts::SIGNATURE_SECRET_KEY_LENGTH;
use crate::utils::MavSha256;
let mut frame = default_v2_heartbeat_frame();
frame.add_signature(
&mut MavSha256::default(),
&SigningConf {
link_id: 0,
timestamp: Default::default(),
secret: [0u8; SIGNATURE_SECRET_KEY_LENGTH].into(),
},
);
let updated = frame
.to_builder()
.crc_extra(dialect::messages::heartbeat::spec().crc_extra())
.build();
assert_eq!(updated.sequence(), frame.sequence());
assert_eq!(updated.system_id(), frame.system_id());
assert_eq!(updated.component_id(), frame.component_id());
assert_eq!(updated.payload_length(), frame.payload_length());
assert_eq!(updated.payload().bytes(), frame.payload().bytes());
assert_eq!(updated.checksum(), frame.checksum());
assert_eq!(
updated.incompat_flags().bits(),
default_incompat_flags().bits()
);
assert_eq!(updated.compat_flags().bits(), default_compat_flags().bits());
assert!(!updated.is_signed());
}
#[test]
#[cfg(feature = "minimal")]
fn test_upgrade_frame() {
let expected = default_v2_heartbeat_frame();
let upgraded = default_v1_heartbeat_frame()
.to_builder()
.crc_extra(dialect::messages::heartbeat::spec().crc_extra())
.upgrade()
.incompat_flags(default_incompat_flags())
.compat_flags(default_compat_flags())
.build();
assert_eq!(upgraded.payload_length(), expected.payload_length());
assert_eq!(upgraded.payload().bytes(), expected.payload().bytes());
assert_eq!(upgraded.checksum(), expected.checksum());
}
#[test]
#[cfg(feature = "minimal")]
fn test_try_versioned() {
let v1 = default_v1_heartbeat_frame();
assert!(v1.clone().try_into_versioned::<V1>().is_ok());
assert!(v1.clone().try_into_versioned::<V2>().is_err());
assert!(v1.clone().try_into_versioned::<Versionless>().is_ok());
let versionless_v1 = v1.into_versionless();
assert!(versionless_v1.clone().try_into_versioned::<V1>().is_ok());
assert!(versionless_v1.clone().try_into_versioned::<V2>().is_err());
assert!(versionless_v1
.clone()
.try_into_versioned::<Versionless>()
.is_ok());
let v2 = default_v2_heartbeat_frame();
assert!(v2.clone().try_into_versioned::<V1>().is_err());
assert!(v2.clone().try_into_versioned::<V2>().is_ok());
assert!(v2.clone().try_into_versioned::<Versionless>().is_ok());
let versionless_v2 = v2.into_versionless();
assert!(versionless_v2.clone().try_into_versioned::<V1>().is_err());
assert!(versionless_v2.clone().try_into_versioned::<V2>().is_ok());
assert!(versionless_v2
.clone()
.try_into_versioned::<Versionless>()
.is_ok());
}
}