src/cfdp/lv.rs

@@ -6,7 +6,7 @@ use serde::{Deserialize, Serialize};
 #[cfg(feature = "std")]
 use std::string::String;
 
-use super::TlvLvDataTooLarge;
+use super::TlvLvDataTooLargeError;
 
 pub const MIN_LV_LEN: usize = 1;
 
@@ -64,9 +64,9 @@ pub(crate) fn generic_len_check_deserialization(
 
 impl<'data> Lv<'data> {
     #[inline]
-    pub fn new(data: &[u8]) -> Result<Lv, TlvLvDataTooLarge> {
+    pub fn new(data: &[u8]) -> Result<Lv, TlvLvDataTooLargeError> {
         if data.len() > u8::MAX as usize {
-            return Err(TlvLvDataTooLarge(data.len()));
+            return Err(TlvLvDataTooLargeError(data.len()));
         }
         Ok(Lv {
             data,
@@ -86,7 +86,7 @@ impl<'data> Lv<'data> {
     /// Helper function to build a string LV. This is especially useful for the file or directory
     /// path LVs
     #[inline]
-    pub fn new_from_str(str_slice: &str) -> Result<Lv, TlvLvDataTooLarge> {
+    pub fn new_from_str(str_slice: &str) -> Result<Lv, TlvLvDataTooLargeError> {
         Self::new(str_slice.as_bytes())
     }
 
@@ -94,7 +94,7 @@ impl<'data> Lv<'data> {
     /// path LVs
     #[cfg(feature = "std")]
     #[inline]
-    pub fn new_from_string(string: &'data String) -> Result<Lv<'data>, TlvLvDataTooLarge> {
+    pub fn new_from_string(string: &'data String) -> Result<Lv<'data>, TlvLvDataTooLargeError> {
         Self::new(string.as_bytes())
     }
 

src/cfdp/mod.rs

@@ -1,11 +1,8 @@
 //! Low-level CCSDS File Delivery Protocol (CFDP) support according to [CCSDS 727.0-B-5](https://public.ccsds.org/Pubs/727x0b5.pdf).
 use crate::ByteConversionError;
-use core::fmt::{Display, Formatter};
 use num_enum::{IntoPrimitive, TryFromPrimitive};
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
-#[cfg(feature = "std")]
-use std::error::Error;
 
 pub mod lv;
 pub mod pdu;
@@ -176,97 +173,43 @@ impl Default for ChecksumType {
 
 pub const NULL_CHECKSUM_U32: [u8; 4] = [0; 4];
 
-#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, thiserror::Error)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
-pub struct TlvLvDataTooLarge(pub usize);
+#[error("data with size {0} larger than allowed {max} bytes", max = u8::MAX)]
+pub struct TlvLvDataTooLargeError(pub usize);
 
-impl Display for TlvLvDataTooLarge {
-    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
-        write!(
-            f,
-            "data with size {} larger than allowed {} bytes",
-            self.0,
-            u8::MAX
-        )
-    }
+/// First value: Found value. Second value: Expected value if there is one.
+#[derive(Debug, Copy, Clone, PartialEq, Eq, thiserror::Error)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+#[error("invalid TLV type field, found {found}, expected {expected:?}")]
+pub struct InvalidTlvTypeFieldError {
+    found: u8,
+    expected: Option<u8>,
 }
 
-#[cfg(feature = "std")]
-impl Error for TlvLvDataTooLarge {}
-
-#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, thiserror::Error)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum TlvLvError {
-    DataTooLarge(TlvLvDataTooLarge),
-    ByteConversion(ByteConversionError),
-    /// First value: Found value. Second value: Expected value if there is one.
-    InvalidTlvTypeField {
-        found: u8,
-        expected: Option<u8>,
-    },
-    /// Logically invalid value length detected. The value length may not exceed 255 bytes.
-    /// Depending on the concrete TLV type, the value length may also be logically invalid.
+    #[error("{0}")]
+    DataTooLarge(#[from] TlvLvDataTooLargeError),
+    #[error("byte conversion error: {0}")]
+    ByteConversion(#[from] ByteConversionError),
+    #[error("{0}")]
+    InvalidTlvTypeField(#[from] InvalidTlvTypeFieldError),
+    #[error("invalid value length {0}")]
     InvalidValueLength(usize),
     /// Only applies to filestore requests and responses. Second name was missing where one is
     /// expected.
+    #[error("second name missing for filestore request or response")]
     SecondNameMissing,
     /// Invalid action code for filestore requests or responses.
+    #[error("invalid action code {0}")]
     InvalidFilestoreActionCode(u8),
 }
 
-impl From<TlvLvDataTooLarge> for TlvLvError {
-    fn from(value: TlvLvDataTooLarge) -> Self {
-        Self::DataTooLarge(value)
-    }
-}
-
-impl From<ByteConversionError> for TlvLvError {
-    fn from(value: ByteConversionError) -> Self {
-        Self::ByteConversion(value)
-    }
-}
-
-impl Display for TlvLvError {
-    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
-        match self {
-            TlvLvError::DataTooLarge(e) => {
-                write!(f, "{}", e)
-            }
-            TlvLvError::ByteConversion(e) => {
-                write!(f, "tlv or lv byte conversion: {}", e)
-            }
-            TlvLvError::InvalidTlvTypeField { found, expected } => {
-                write!(
-                    f,
-                    "invalid TLV type field, found {found}, expected {expected:?}"
-                )
-            }
-            TlvLvError::InvalidValueLength(len) => {
-                write!(f, "invalid value length {len}")
-            }
-            TlvLvError::SecondNameMissing => {
-                write!(f, "second name missing for filestore request or response")
-            }
-            TlvLvError::InvalidFilestoreActionCode(raw) => {
-                write!(f, "invalid filestore action code with raw value {raw}")
-            }
-        }
-    }
-}
-
-#[cfg(feature = "std")]
-impl Error for TlvLvError {
-    fn source(&self) -> Option<&(dyn Error + 'static)> {
-        match self {
-            TlvLvError::DataTooLarge(e) => Some(e),
-            TlvLvError::ByteConversion(e) => Some(e),
-            _ => None,
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

src/cfdp/pdu/eof.rs

@@ -297,7 +297,7 @@ mod tests {
         buf[written - 1] -= 1;
         let crc: u16 = ((buf[written - 2] as u16) << 8) as u16 | buf[written - 1] as u16;
         let error = EofPdu::from_bytes(&buf).unwrap_err();
-        if let PduError::ChecksumError(e) = error {
+        if let PduError::Checksum(e) = error {
             assert_eq!(e, crc);
         } else {
             panic!("expected crc error");

src/cfdp/pdu/file_data.rs

@@ -544,7 +544,7 @@ mod tests {
         buf[written - 1] -= 1;
         let crc: u16 = ((buf[written - 2] as u16) << 8) | buf[written - 1] as u16;
         let error = FileDataPdu::from_bytes(&buf).unwrap_err();
-        if let PduError::ChecksumError(e) = error {
+        if let PduError::Checksum(e) = error {
             assert_eq!(e, crc);
         } else {
             panic!("expected crc error");
@@ -753,7 +753,7 @@ mod tests {
         assert!(pdu_reader_error.is_err());
         let error = pdu_reader_error.unwrap_err();
         match error {
-            PduError::ChecksumError(_) => (),
+            PduError::Checksum(_) => (),
             _ => {
                 panic!("unexpected PDU error {}", error)
             }

src/cfdp/pdu/finished.rs

@@ -4,14 +4,14 @@ use crate::cfdp::pdu::{
 use crate::cfdp::tlv::{
     EntityIdTlv, FilestoreResponseTlv, GenericTlv, Tlv, TlvType, TlvTypeField, WritableTlv,
 };
-use crate::cfdp::{ConditionCode, CrcFlag, Direction, PduType, TlvLvError};
+use crate::cfdp::{ConditionCode, CrcFlag, Direction, PduType};
 use crate::ByteConversionError;
 use num_enum::{IntoPrimitive, TryFromPrimitive};
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
 use super::tlv::ReadableTlv;
-use super::{CfdpPdu, WritablePduPacket};
+use super::{CfdpPdu, InvalidTlvTypeFieldError, WritablePduPacket};
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq, TryFromPrimitive, IntoPrimitive)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
@@ -332,22 +332,26 @@ impl<'buf> FinishedPduReader<'buf> {
                         // last TLV, everything else would break the whole handling of the packet
                         // TLVs.
                         if current_idx != full_len_without_crc {
-                            return Err(PduError::FormatError);
+                            return Err(PduError::Format);
                         }
                     } else {
-                        return Err(TlvLvError::InvalidTlvTypeField {
+                        return Err(PduError::TlvLv(
+                            InvalidTlvTypeFieldError {
                                 found: tlv_type.into(),
                                 expected: Some(TlvType::FilestoreResponse.into()),
                             }
-                        .into());
+                            .into(),
+                        ));
                     }
                 }
                 TlvTypeField::Custom(raw) => {
-                    return Err(TlvLvError::InvalidTlvTypeField {
+                    return Err(PduError::TlvLv(
+                        InvalidTlvTypeFieldError {
                             found: raw,
                             expected: None,
                         }
-                    .into());
+                        .into(),
+                    ));
                 }
             }
         }
@@ -564,7 +568,7 @@ mod tests {
         buf[written - 1] -= 1;
         let crc: u16 = ((buf[written - 2] as u16) << 8) as u16 | buf[written - 1] as u16;
         let error = FinishedPduReader::new(&buf).unwrap_err();
-        if let PduError::ChecksumError(e) = error {
+        if let PduError::Checksum(e) = error {
             assert_eq!(e, crc);
         } else {
             panic!("expected crc error");

src/cfdp/pdu/metadata.rs

@@ -720,7 +720,7 @@ pub mod tests {
     fn test_with_owned_opts() {
         let tlv1 = TlvOwned::new_empty(TlvType::FlowLabel);
         let msg_to_user: [u8; 4] = [1, 2, 3, 4];
-        let tlv2 = TlvOwned::new(TlvType::MsgToUser, &msg_to_user).unwrap();
+        let tlv2 = TlvOwned::new(TlvType::MsgToUser, &msg_to_user);
         let mut all_tlvs = tlv1.to_vec();
         all_tlvs.extend(tlv2.to_vec());
         let (src_filename, dest_filename, metadata_pdu) = generic_metadata_pdu(
@@ -780,7 +780,7 @@ pub mod tests {
             assert_eq!(expected, Some(FileDirectiveType::MetadataPdu));
             assert_eq!(
                 error.to_string(),
-                "invalid directive type value 255, expected Some(MetadataPdu)"
+                "invalid directive type, found 255, expected Some(MetadataPdu)"
             );
         } else {
             panic!("Expected InvalidDirectiveType error, got {:?}", error);
@@ -806,7 +806,7 @@ pub mod tests {
             assert_eq!(expected, FileDirectiveType::MetadataPdu);
             assert_eq!(
                 error.to_string(),
-                "found directive type EofPdu, expected MetadataPdu"
+                "wrong directive type, found EofPdu, expected MetadataPdu"
             );
         } else {
             panic!("Expected InvalidDirectiveType error, got {:?}", error);

src/cfdp/pdu/mod.rs

@@ -5,9 +5,6 @@ use crate::ByteConversionError;
 use crate::CRC_CCITT_FALSE;
 #[cfg(feature = "alloc")]
 use alloc::vec::Vec;
-use core::fmt::{Display, Formatter};
-#[cfg(feature = "std")]
-use std::error::Error;
 
 pub mod ack;
 pub mod eof;
@@ -30,137 +27,60 @@ pub enum FileDirectiveType {
     KeepAlivePdu = 0x0c,
 }
 
-#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, thiserror::Error)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum PduError {
-    ByteConversion(ByteConversionError),
-    /// Found version ID invalid, not equal to [CFDP_VERSION_2].
+    #[error("byte conversion error: {0}")]
+    ByteConversion(#[from] ByteConversionError),
+    /// Found version ID invalid, not equal to [super::CFDP_VERSION_2].
+    #[error("CFDP version missmatch, found {0}, expected {ver}", ver = super::CFDP_VERSION_2)]
     CfdpVersionMissmatch(u8),
     /// Invalid length for the entity ID detected. Only the values 1, 2, 4 and 8 are supported.
+    #[error("invalid PDU entity ID length {0}, only [1, 2, 4, 8] are allowed")]
     InvalidEntityLen(u8),
     /// Invalid length for the entity ID detected. Only the values 1, 2, 4 and 8 are supported.
+    #[error("invalid transaction ID length {0}")]
     InvalidTransactionSeqNumLen(u8),
+    #[error("missmatch of PDU source ID length {src_id_len} and destination ID length {dest_id_len}")]
     SourceDestIdLenMissmatch {
         src_id_len: usize,
         dest_id_len: usize,
     },
     /// Wrong directive type, for example when parsing the directive field for a file directive
     /// PDU.
+    #[error("wrong directive type, found {found:?}, expected {expected:?}")]
     WrongDirectiveType {
         found: FileDirectiveType,
         expected: FileDirectiveType,
     },
     /// The directive type field contained a value not in the range of permitted values. This can
     /// also happen if an invalid value is passed to the ACK PDU constructor.
+    #[error("invalid directive type, found {found:?}, expected {expected:?}")]
     InvalidDirectiveType {
         found: u8,
         expected: Option<FileDirectiveType>,
     },
+    #[error("invalid start or end of scope value for NAK PDU")]
     InvalidStartOrEndOfScopeValue,
     /// Invalid condition code. Contains the raw detected value.
+    #[error("invalid condition code {0}")]
     InvalidConditionCode(u8),
     /// Invalid checksum type which is not part of the checksums listed in the
     /// [SANA Checksum Types registry](https://sanaregistry.org/r/checksum_identifiers/).
+    #[error("invalid checksum type {0}")]
     InvalidChecksumType(u8),
+    #[error("file size {0} too large")]
     FileSizeTooLarge(u64),
     /// If the CRC flag for a PDU is enabled and the checksum check fails. Contains raw 16-bit CRC.
-    ChecksumError(u16),
+    #[error("checksum error for checksum {0}")]
+    Checksum(u16),
     /// Generic error for invalid PDU formats.
-    FormatError,
+    #[error("generic PDU format error")]
+    Format,
     /// Error handling a TLV field.
-    TlvLvError(TlvLvError),
-}
-
-impl Display for PduError {
-    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
-        match self {
-            PduError::InvalidEntityLen(raw_id) => {
-                write!(
-                    f,
-                    "invalid PDU entity ID length {raw_id}, only [1, 2, 4, 8] are allowed"
-                )
-            }
-            PduError::InvalidStartOrEndOfScopeValue => {
-                write!(f, "invalid start or end of scope for NAK PDU")
-            }
-            PduError::InvalidTransactionSeqNumLen(raw_id) => {
-                write!(
-                    f,
-                    "invalid PDUtransaction seq num length {raw_id}, only [1, 2, 4, 8] are allowed"
-                )
-            }
-            PduError::CfdpVersionMissmatch(raw) => {
-                write!(
-                    f,
-                    "cfdp version missmatch, found {raw}, expected {CFDP_VERSION_2}"
-                )
-            }
-            PduError::SourceDestIdLenMissmatch {
-                src_id_len,
-                dest_id_len,
-            } => {
-                write!(
-                    f,
-                    "missmatch of PDU source length {src_id_len} and destination length {dest_id_len}"
-                )
-            }
-            PduError::ByteConversion(e) => {
-                write!(f, "{}", e)
-            }
-            PduError::FileSizeTooLarge(value) => {
-                write!(f, "file size value {value} exceeds allowed 32 bit width")
-            }
-            PduError::WrongDirectiveType { found, expected } => {
-                write!(f, "found directive type {found:?}, expected {expected:?}")
-            }
-            PduError::InvalidConditionCode(raw_code) => {
-                write!(f, "found invalid condition code with raw value {raw_code}")
-            }
-            PduError::InvalidDirectiveType { found, expected } => {
-                write!(
-                    f,
-                    "invalid directive type value {found}, expected {expected:?}"
-                )
-            }
-            PduError::InvalidChecksumType(checksum_type) => {
-                write!(f, "invalid checksum type {checksum_type}")
-            }
-            PduError::ChecksumError(checksum) => {
-                write!(f, "checksum error for CRC {checksum:#04x}")
-            }
-            PduError::TlvLvError(error) => {
-                write!(f, "pdu tlv error: {error}")
-            }
-            PduError::FormatError => {
-                write!(f, "generic PDU format error")
-            }
-        }
-    }
-}
-
-#[cfg(feature = "std")]
-impl Error for PduError {
-    fn source(&self) -> Option<&(dyn Error + 'static)> {
-        match self {
-            PduError::ByteConversion(e) => Some(e),
-            PduError::TlvLvError(e) => Some(e),
-            _ => None,
-        }
-    }
-}
-
-impl From<ByteConversionError> for PduError {
-    #[inline]
-    fn from(value: ByteConversionError) -> Self {
-        Self::ByteConversion(value)
-    }
-}
-
-impl From<TlvLvError> for PduError {
-    #[inline]
-    fn from(e: TlvLvError) -> Self {
-        Self::TlvLvError(e)
-    }
+    #[error("PDU error: {0}")]
+    TlvLv(#[from] TlvLvError),
 }
 
 pub trait WritablePduPacket {
@@ -532,7 +452,7 @@ impl PduHeader {
             let mut digest = CRC_CCITT_FALSE.digest();
             digest.update(&buf[..self.pdu_len()]);
             if digest.finalize() != 0 {
-                return Err(PduError::ChecksumError(u16::from_be_bytes(
+                return Err(PduError::Checksum(u16::from_be_bytes(
                     buf[self.pdu_len() - 2..self.pdu_len()].try_into().unwrap(),
                 )));
             }
@@ -981,7 +901,7 @@ mod tests {
             assert_eq!(raw_version, CFDP_VERSION_2 + 1);
             assert_eq!(
                 error.to_string(),
-                "cfdp version missmatch, found 2, expected 1"
+                "CFDP version missmatch, found 2, expected 1"
             );
         } else {
             panic!("invalid exception: {}", error);
@@ -1029,7 +949,7 @@ mod tests {
             assert_eq!(expected, 7);
             assert_eq!(
                 error.to_string(),
-                "source slice with size 6 too small, expected at least 7 bytes"
+                "byte conversion error: source slice with size 6 too small, expected at least 7 bytes"
             );
         }
     }
@@ -1084,7 +1004,7 @@ mod tests {
             assert_eq!(dest_id_len, 2);
             assert_eq!(
                 error.to_string(),
-                "missmatch of PDU source length 1 and destination length 2"
+                "missmatch of PDU source ID length 1 and destination ID length 2"
             );
         }
     }

src/cfdp/pdu/nak.rs

@@ -751,7 +751,7 @@ mod tests {
         if let PduError::InvalidStartOrEndOfScopeValue = error {
             assert_eq!(
                 error.to_string(),
-                "invalid start or end of scope for NAK PDU"
+                "invalid start or end of scope value for NAK PDU"
             );
         } else {
             panic!("unexpected error {error}");
@@ -796,7 +796,7 @@ mod tests {
         nak_vec[nak_pdu.len_written() - 1] -= 1;
         let nak_pdu_deser = NakPduReader::new(&nak_vec);
         assert!(nak_pdu_deser.is_err());
-        if let Err(PduError::ChecksumError(raw)) = nak_pdu_deser {
+        if let Err(PduError::Checksum(raw)) = nak_pdu_deser {
             assert_eq!(
                 raw,
                 u16::from_be_bytes(nak_vec[nak_pdu.len_written() - 2..].try_into().unwrap())

src/cfdp/tlv/mod.rs

@@ -15,7 +15,7 @@ use num_enum::{IntoPrimitive, TryFromPrimitive};
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
-use super::TlvLvDataTooLarge;
+use super::{InvalidTlvTypeFieldError, TlvLvDataTooLargeError};
 
 pub mod msg_to_user;
 
@@ -153,14 +153,14 @@ pub struct Tlv<'data> {
 }
 
 impl<'data> Tlv<'data> {
-    pub fn new(tlv_type: TlvType, data: &[u8]) -> Result<Tlv, TlvLvDataTooLarge> {
+    pub fn new(tlv_type: TlvType, data: &[u8]) -> Result<Tlv, TlvLvDataTooLargeError> {
         Ok(Tlv {
             tlv_type_field: TlvTypeField::Standard(tlv_type),
             lv: Lv::new(data)?,
         })
     }
 
-    pub fn new_with_custom_type(tlv_type: u8, data: &[u8]) -> Result<Tlv, TlvLvDataTooLarge> {
+    pub fn new_with_custom_type(tlv_type: u8, data: &[u8]) -> Result<Tlv, TlvLvDataTooLargeError> {
         Ok(Tlv {
             tlv_type_field: TlvTypeField::Custom(tlv_type),
             lv: Lv::new(data)?,
@@ -179,7 +179,7 @@ impl<'data> Tlv<'data> {
     /// bytestream with the exact size of the expected TLV. This function will take care
     /// of parsing the length byte, and the length of the parsed TLV can be retrieved using
     /// [Self::len_full].
-    pub fn from_bytes(buf: &'data [u8]) -> Result<Tlv<'data>, TlvLvError> {
+    pub fn from_bytes(buf: &'data [u8]) -> Result<Tlv<'data>, ByteConversionError> {
         generic_len_check_deserialization(buf, MIN_TLV_LEN)?;
         let mut tlv = Self {
             tlv_type_field: TlvTypeField::from(buf[0]),
@@ -239,8 +239,6 @@ impl GenericTlv for Tlv<'_> {
 
 #[cfg(feature = "alloc")]
 pub mod alloc_mod {
-    use crate::cfdp::TlvLvDataTooLarge;
-
     use super::*;
 
     /// Owned variant of [Tlv] which is consequently [Clone]able and does not have a lifetime
@@ -254,24 +252,18 @@ pub mod alloc_mod {
     }
 
     impl TlvOwned {
-        pub fn new(tlv_type: TlvType, data: &[u8]) -> Result<Self, TlvLvDataTooLarge> {
-            if data.len() > u8::MAX as usize {
-                return Err(TlvLvDataTooLarge(data.len()));
-            }
-            Ok(Self {
+        pub fn new(tlv_type: TlvType, data: &[u8]) -> Self {
+            Self {
                 tlv_type_field: TlvTypeField::Standard(tlv_type),
                 data: data.to_vec(),
-            })
+            }
         }
 
-        pub fn new_with_custom_type(tlv_type: u8, data: &[u8]) -> Result<Self, TlvLvDataTooLarge> {
-            if data.len() > u8::MAX as usize {
-                return Err(TlvLvDataTooLarge(data.len()));
-            }
-            Ok(Self {
+        pub fn new_with_custom_type(tlv_type: u8, data: &[u8]) -> Self {
+            Self {
                 tlv_type_field: TlvTypeField::Custom(tlv_type),
                 data: data.to_vec(),
-            })
+            }
         }
 
         /// Creates a TLV with an empty value field.
@@ -281,15 +273,6 @@ pub mod alloc_mod {
                 data: Vec::new(),
             }
         }
-
-        pub fn as_tlv(&self) -> Tlv<'_> {
-            Tlv {
-                tlv_type_field: self.tlv_type_field,
-                // The API should ensure that the data length is never to large, so the unwrap for the
-                // LV creation should never be an issue.
-                lv: Lv::new(&self.data).expect("lv creation failed unexpectedly"),
-            }
-        }
     }
 
     impl ReadableTlv for TlvOwned {
@@ -343,7 +326,7 @@ impl EntityIdTlv {
         Self { entity_id }
     }
 
-    fn check_min_len(buf: &[u8]) -> Result<(), ByteConversionError> {
+    fn len_check(buf: &[u8]) -> Result<(), ByteConversionError> {
         if buf.len() < 2 {
             return Err(ByteConversionError::ToSliceTooSmall {
                 found: buf.len(),
@@ -366,7 +349,7 @@ impl EntityIdTlv {
     }
 
     pub fn from_bytes(buf: &[u8]) -> Result<Self, TlvLvError> {
-        Self::check_min_len(buf)?;
+        Self::len_check(buf)?;
         verify_tlv_type(buf[0], TlvType::EntityId)?;
         let len = buf[1];
         if len != 1 && len != 2 && len != 4 && len != 8 {
@@ -377,31 +360,19 @@ impl EntityIdTlv {
         Ok(Self { entity_id })
     }
 
-    /// Convert to a generic [Tlv], which also erases the type information.
+    /// Convert to a generic [Tlv], which also erases the programmatic type information.
     pub fn to_tlv(self, buf: &mut [u8]) -> Result<Tlv, ByteConversionError> {
-        Self::check_min_len(buf)?;
+        Self::len_check(buf)?;
         self.entity_id
             .write_to_be_bytes(&mut buf[2..2 + self.entity_id.size()])?;
-        if buf.len() < self.len_value() {
-            return Err(ByteConversionError::ToSliceTooSmall {
-                found: buf.len(),
-                expected: self.len_value(),
-            });
-        }
-        // We performed all checks necessary to ensure this call never panics.
+        // Can't fail.
         Ok(Tlv::new(TlvType::EntityId, &buf[2..2 + self.entity_id.size()]).unwrap())
     }
-
-    #[cfg(feature = "alloc")]
-    pub fn to_owned(&self) -> TlvOwned {
-        // Unwrap is okay here, entity ID should never be larger than maximum allowed size.
-        TlvOwned::new(TlvType::EntityId, &self.entity_id.to_vec()).unwrap()
-    }
 }
 
 impl WritableTlv for EntityIdTlv {
     fn write_to_bytes(&self, buf: &mut [u8]) -> Result<usize, ByteConversionError> {
-        Self::check_min_len(buf)?;
+        Self::len_check(buf)?;
         buf[0] = TlvType::EntityId as u8;
         buf[1] = self.entity_id.size() as u8;
         Ok(2 + self.entity_id.write_to_be_bytes(&mut buf[2..])?)
@@ -421,21 +392,23 @@ impl GenericTlv for EntityIdTlv {
 impl<'data> TryFrom<Tlv<'data>> for EntityIdTlv {
     type Error = TlvLvError;
 
-    fn try_from(value: Tlv) -> Result<Self, Self::Error> {
+    fn try_from(value: Tlv) -> Result<Self, TlvLvError> {
         match value.tlv_type_field {
             TlvTypeField::Standard(tlv_type) => {
                 if tlv_type != TlvType::EntityId {
-                    return Err(TlvLvError::InvalidTlvTypeField {
+                    return Err(InvalidTlvTypeFieldError {
                         found: tlv_type as u8,
                         expected: Some(TlvType::EntityId as u8),
-                    });
+                    }
+                    .into());
                 }
             }
             TlvTypeField::Custom(val) => {
-                return Err(TlvLvError::InvalidTlvTypeField {
+                return Err(InvalidTlvTypeFieldError {
                     found: val,
                     expected: Some(TlvType::EntityId as u8),
-                });
+                }
+                .into());
             }
         }
         let len_value = value.value().len();
@@ -640,12 +613,6 @@ impl<'first_name, 'second_name> FilestoreRequestTlv<'first_name, 'second_name> {
             },
         })
     }
-
-    #[cfg(feature = "alloc")]
-    pub fn to_owned(&self) -> TlvOwned {
-        // The API should ensure the data field is never too large, so unwrapping here is okay.
-        TlvOwned::new(TlvType::FilestoreRequest, &self.to_vec()[2..]).unwrap()
-    }
 }
 
 impl WritableTlv for FilestoreRequestTlv<'_, '_> {
@@ -831,12 +798,6 @@ impl<'first_name, 'second_name, 'fs_msg> FilestoreResponseTlv<'first_name, 'seco
             filestore_message,
         })
     }
-
-    #[cfg(feature = "alloc")]
-    pub fn to_owned(&self) -> TlvOwned {
-        // The API should ensure the data field is never too large, so unwrap is okay here.
-        TlvOwned::new(TlvType::FilestoreResponse, &self.to_vec()[2..]).unwrap()
-    }
 }
 
 impl WritableTlv for FilestoreResponseTlv<'_, '_, '_> {
@@ -878,13 +839,16 @@ impl GenericTlv for FilestoreResponseTlv<'_, '_, '_> {
     }
 }
 
-pub(crate) fn verify_tlv_type(raw_type: u8, expected_tlv_type: TlvType) -> Result<(), TlvLvError> {
-    let tlv_type = TlvType::try_from(raw_type).map_err(|_| TlvLvError::InvalidTlvTypeField {
+pub(crate) fn verify_tlv_type(
+    raw_type: u8,
+    expected_tlv_type: TlvType,
+) -> Result<(), InvalidTlvTypeFieldError> {
+    let tlv_type = TlvType::try_from(raw_type).map_err(|_| InvalidTlvTypeFieldError {
         found: raw_type,
         expected: Some(expected_tlv_type.into()),
     })?;
     if tlv_type != expected_tlv_type {
-        return Err(TlvLvError::InvalidTlvTypeField {
+        return Err(InvalidTlvTypeFieldError {
             found: tlv_type as u8,
             expected: Some(expected_tlv_type as u8),
         });
@@ -1079,12 +1043,16 @@ mod tests {
         let tlv_res = Tlv::new(TlvType::MsgToUser, &buf_too_large);
         assert!(tlv_res.is_err());
         let error = tlv_res.unwrap_err();
-        assert_eq!(error.0, u8::MAX as usize + 1);
+        match error {
+            TlvLvDataTooLargeError(size) => {
+                assert_eq!(size, u8::MAX as usize + 1);
                 assert_eq!(
                     error.to_string(),
                     "data with size 256 larger than allowed 255 bytes"
                 );
             }
+        }
+    }
 
     #[test]
     fn test_deserialization_custom_tlv_type() {
@@ -1392,7 +1360,8 @@ mod tests {
         let error = EntityIdTlv::try_from(msg_to_user_tlv);
         assert!(error.is_err());
         let error = error.unwrap_err();
-        if let TlvLvError::InvalidTlvTypeField { found, expected } = error {
+        if let TlvLvError::InvalidTlvTypeField(InvalidTlvTypeFieldError { found, expected }) = error
+        {
             assert_eq!(found, TlvType::MsgToUser as u8);
             assert_eq!(expected, Some(TlvType::EntityId as u8));
             assert_eq!(
@@ -1457,7 +1426,7 @@ mod tests {
         let entity_id = UbfU8::new(5);
         let mut buf: [u8; 4] = [0; 4];
         assert!(entity_id.write_to_be_bytes(&mut buf).is_ok());
-        let tlv_res = TlvOwned::new(TlvType::EntityId, &buf[0..1]).expect("creating TLV failed");
+        let tlv_res = TlvOwned::new(TlvType::EntityId, &buf[0..1]);
         assert_eq!(
             tlv_res.tlv_type_field(),
             TlvTypeField::Standard(TlvType::EntityId)
@@ -1484,7 +1453,7 @@ mod tests {
 
     #[test]
     fn test_owned_tlv_custom_type() {
-        let tlv_res = TlvOwned::new_with_custom_type(32, &[]).unwrap();
+        let tlv_res = TlvOwned::new_with_custom_type(32, &[]);
         assert_eq!(tlv_res.tlv_type_field(), TlvTypeField::Custom(32));
         assert_eq!(tlv_res.len_full(), 2);
         assert_eq!(tlv_res.value().len(), 0);

src/cfdp/tlv/msg_to_user.rs

@@ -2,7 +2,7 @@
 #[cfg(feature = "alloc")]
 use super::TlvOwned;
 use super::{GenericTlv, ReadableTlv, Tlv, TlvLvError, TlvType, TlvTypeField, WritableTlv};
-use crate::{cfdp::TlvLvDataTooLarge, ByteConversionError};
+use crate::{cfdp::{InvalidTlvTypeFieldError, TlvLvDataTooLargeError}, ByteConversionError};
 use delegate::delegate;
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
@@ -12,7 +12,7 @@ pub struct MsgToUserTlv<'data> {
 
 impl<'data> MsgToUserTlv<'data> {
     /// Create a new message to user TLV where the type field is set correctly.
-    pub fn new(value: &'data [u8]) -> Result<MsgToUserTlv<'data>, TlvLvDataTooLarge> {
+    pub fn new(value: &'data [u8]) -> Result<MsgToUserTlv<'data>, TlvLvDataTooLargeError> {
         Ok(Self {
             tlv: Tlv::new(TlvType::MsgToUser, value)?,
         })
@@ -62,17 +62,17 @@ impl<'data> MsgToUserTlv<'data> {
         match msg_to_user.tlv.tlv_type_field() {
             TlvTypeField::Standard(tlv_type) => {
                 if tlv_type != TlvType::MsgToUser {
-                    return Err(TlvLvError::InvalidTlvTypeField {
+                    return Err(InvalidTlvTypeFieldError {
                         found: tlv_type as u8,
                         expected: Some(TlvType::MsgToUser as u8),
-                    });
+                    }.into());
                 }
             }
             TlvTypeField::Custom(raw) => {
-                return Err(TlvLvError::InvalidTlvTypeField {
+                return Err(InvalidTlvTypeFieldError {
                     found: raw,
                     expected: Some(TlvType::MsgToUser as u8),
-                });
+                }.into());
             }
         }
         Ok(msg_to_user)
@@ -205,9 +205,9 @@ mod tests {
     fn test_reserved_msg_deserialization_invalid_type() {
         let trash: [u8; 5] = [TlvType::FlowLabel as u8, 3, 1, 2, 3];
         let error = MsgToUserTlv::from_bytes(&trash).unwrap_err();
-        if let TlvLvError::InvalidTlvTypeField { found, expected } = error {
-            assert_eq!(found, TlvType::FlowLabel as u8);
-            assert_eq!(expected, Some(TlvType::MsgToUser as u8));
+        if let TlvLvError::InvalidTlvTypeField(inner) = error {
+            assert_eq!(inner.found, TlvType::FlowLabel as u8);
+            assert_eq!(inner.expected, Some(TlvType::MsgToUser as u8));
         } else {
             panic!("Wrong error type returned: {:?}", error);
         }

src/ecss/mod.rs

@@ -6,13 +6,11 @@
 use crate::{ByteConversionError, CcsdsPacket, CRC_CCITT_FALSE};
 #[cfg(feature = "alloc")]
 use alloc::vec::Vec;
-use core::fmt::{Debug, Display, Formatter};
+use core::fmt::Debug;
 use core::mem::size_of;
 use num_enum::{IntoPrimitive, TryFromPrimitive};
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
-#[cfg(feature = "std")]
-use std::error::Error;
 
 pub mod event;
 pub mod hk;
@@ -148,50 +146,19 @@ pub enum PfcReal {
     DoubleMilStd = 4,
 }
 
-#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, thiserror::Error)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum PusError {
+    #[error("PUS version {0:?} not supported")]
     VersionNotSupported(PusVersion),
+    #[error("checksum verification for crc16 {0:#06x} failed")]
     ChecksumFailure(u16),
     /// CRC16 needs to be calculated first
-    CrcCalculationMissing,
-    ByteConversion(ByteConversionError),
-}
-
-impl Display for PusError {
-    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
-        match self {
-            PusError::VersionNotSupported(v) => {
-                write!(f, "PUS version {v:?} not supported")
-            }
-            PusError::ChecksumFailure(crc) => {
-                write!(f, "checksum verification for crc16 {crc:#06x} failed")
-            }
-            PusError::CrcCalculationMissing => {
-                write!(f, "crc16 was not calculated")
-            }
-            PusError::ByteConversion(e) => {
-                write!(f, "pus error: {e}")
-            }
-        }
-    }
-}
-
-#[cfg(feature = "std")]
-impl Error for PusError {
-    fn source(&self) -> Option<&(dyn Error + 'static)> {
-        if let PusError::ByteConversion(e) = self {
-            return Some(e);
-        }
-        None
-    }
-}
-
-impl From<ByteConversionError> for PusError {
-    fn from(e: ByteConversionError) -> Self {
-        PusError::ByteConversion(e)
-    }
+    //#[error("crc16 was not calculated")]
+    //CrcCalculationMissing,
+    #[error("pus error: {0}")]
+    ByteConversion(#[from] ByteConversionError),
 }
 
 /// Generic trait to describe common attributes for both PUS Telecommands (TC) and PUS Telemetry

src/lib.rs

@@ -61,17 +61,11 @@ extern crate alloc;
 #[cfg(any(feature = "std", test))]
 extern crate std;
 
-use core::{
-    fmt::{Debug, Display, Formatter},
-    hash::Hash,
-};
+use core::{fmt::Debug, hash::Hash};
 use crc::{Crc, CRC_16_IBM_3740};
 use delegate::delegate;
 use zerocopy::{FromBytes, IntoBytes};
 
-#[cfg(feature = "std")]
-use std::error::Error;
-
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
@@ -94,55 +88,24 @@ pub const MAX_APID: u16 = 2u16.pow(11) - 1;
 pub const MAX_SEQ_COUNT: u16 = 2u16.pow(14) - 1;
 
 /// Generic error type when converting to and from raw byte slices.
-#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, thiserror::Error)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum ByteConversionError {
     /// The passed slice is too small. Returns the passed slice length and expected minimum size
-    ToSliceTooSmall {
-        found: usize,
-        expected: usize,
-    },
+    #[error("target slice with size {found} is too small, expected size of at least {expected}")]
+    ToSliceTooSmall { found: usize, expected: usize },
     /// The provider buffer is too small. Returns the passed slice length and expected minimum size
-    FromSliceTooSmall {
-        found: usize,
-        expected: usize,
-    },
+    #[error("source slice with size {found} too small, expected at least {expected} bytes")]
+    FromSliceTooSmall { found: usize, expected: usize },
     /// The [zerocopy] library failed to write to bytes
+    #[error("zerocopy serialization error")]
     ZeroCopyToError,
+    /// The [zerocopy] library failed to read from bytes
+    #[error("zerocopy deserialization error")]
     ZeroCopyFromError,
 }
 
-impl Display for ByteConversionError {
-    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
-        match self {
-            ByteConversionError::ToSliceTooSmall { found, expected } => {
-                write!(
-                    f,
-                    "target slice with size {} is too small, expected size of at least {}",
-                    found, expected
-                )
-            }
-            ByteConversionError::FromSliceTooSmall { found, expected } => {
-                write!(
-                    f,
-                    "source slice with size {} too small, expected at least {} bytes",
-                    found, expected
-                )
-            }
-            ByteConversionError::ZeroCopyToError => {
-                write!(f, "zerocopy serialization error")
-            }
-            ByteConversionError::ZeroCopyFromError => {
-                write!(f, "zerocopy deserialization error")
-            }
-        }
-    }
-}
-
-#[cfg(feature = "std")]
-impl Error for ByteConversionError {}
-
 /// CCSDS packet type enumeration.
 #[derive(Debug, PartialEq, Eq, Copy, Clone)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]

src/time/cds.rs

@@ -7,15 +7,13 @@
 use crate::private::Sealed;
 use crate::ByteConversionError;
 use core::cmp::Ordering;
-use core::fmt::{Debug, Display, Formatter};
+use core::fmt::Debug;
 use core::ops::{Add, AddAssign};
 use core::time::Duration;
 
 #[cfg(feature = "std")]
 use super::StdTimestampError;
 #[cfg(feature = "std")]
-use std::error::Error;
-#[cfg(feature = "std")]
 use std::time::{SystemTime, SystemTimeError};
 
 #[cfg(feature = "chrono")]
@@ -91,49 +89,19 @@ pub enum SubmillisPrecision {
     Reserved = 0b11,
 }
 
-#[derive(Debug, PartialEq, Eq, Copy, Clone)]
+#[derive(Debug, PartialEq, Eq, Copy, Clone, thiserror::Error)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum CdsError {
     /// CCSDS days value exceeds maximum allowed size or is negative
+    #[error("invalid ccsds days {0}")]
     InvalidCcsdsDays(i64),
     /// There are distinct constructors depending on the days field width detected in the preamble
     /// field. This error will be returned if there is a missmatch.
+    #[error("wrong constructor for length of day {0:?} detected in preamble")]
     InvalidCtorForDaysOfLenInPreamble(LengthOfDaySegment),
-    DateBeforeCcsdsEpoch(DateBeforeCcsdsEpochError),
-}
-
-impl Display for CdsError {
-    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
-        match self {
-            CdsError::InvalidCcsdsDays(days) => {
-                write!(f, "invalid ccsds days {days}")
-            }
-            CdsError::InvalidCtorForDaysOfLenInPreamble(length_of_day) => {
-                write!(
-                    f,
-                    "wrong constructor for length of day {length_of_day:?} detected in preamble",
-                )
-            }
-            CdsError::DateBeforeCcsdsEpoch(e) => write!(f, "date before CCSDS epoch: {e}"),
-        }
-    }
-}
-
-#[cfg(feature = "std")]
-impl Error for CdsError {
-    fn source(&self) -> Option<&(dyn Error + 'static)> {
-        match self {
-            CdsError::DateBeforeCcsdsEpoch(e) => Some(e),
-            _ => None,
-        }
-    }
-}
-
-impl From<DateBeforeCcsdsEpochError> for CdsError {
-    fn from(value: DateBeforeCcsdsEpochError) -> Self {
-        Self::DateBeforeCcsdsEpoch(value)
-    }
+    #[error("date before CCSDS epoch: {0}")]
+    DateBeforeCcsdsEpoch(#[from] DateBeforeCcsdsEpochError),
 }
 
 pub fn length_of_day_segment_from_pfield(pfield: u8) -> LengthOfDaySegment {

src/time/mod.rs

@@ -63,20 +63,12 @@ pub fn ccsds_time_code_from_p_field(pfield: u8) -> Result<CcsdsTimeCode, u8> {
     CcsdsTimeCode::try_from(raw_bits).map_err(|_| raw_bits)
 }
 
-#[derive(Debug, PartialEq, Eq, Copy, Clone)]
+#[derive(Debug, PartialEq, Eq, Copy, Clone, thiserror::Error)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
+#[error("date before ccsds epoch: {0:?}")]
 pub struct DateBeforeCcsdsEpochError(UnixTime);
 
-impl Display for DateBeforeCcsdsEpochError {
-    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
-        write!(f, "date before ccsds epoch: {:?}", self.0)
-    }
-}
-
-#[cfg(feature = "std")]
-impl Error for DateBeforeCcsdsEpochError {}
-
 #[derive(Debug, PartialEq, Eq, Copy, Clone)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]