X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning-c-bindings%2Fsrc%2Fc_types%2Fmod.rs;h=f23f002d05c7ccfe8607ffd5b30eae0c79d0017b;hb=bcf07b1fad32d14e92c9c30976aa66b72a3860b0;hp=98e964ff6efb5b7d20ec7fe419103ee25f98c6f0;hpb=ce0ec2494f33662d8cfb14efc00cb49d22190e2c;p=ldk-c-bindings diff --git a/lightning-c-bindings/src/c_types/mod.rs b/lightning-c-bindings/src/c_types/mod.rs index 98e964f..f23f002 100644 --- a/lightning-c-bindings/src/c_types/mod.rs +++ b/lightning-c-bindings/src/c_types/mod.rs @@ -4,18 +4,29 @@ pub mod derived; use bitcoin::Transaction as BitcoinTransaction; +use bitcoin::Witness as BitcoinWitness; use bitcoin::hashes::Hash; -use bitcoin::secp256k1::key::PublicKey as SecpPublicKey; -use bitcoin::secp256k1::key::SecretKey as SecpSecretKey; -use bitcoin::secp256k1::Signature as SecpSignature; +use bitcoin::secp256k1::PublicKey as SecpPublicKey; +use bitcoin::secp256k1::SecretKey as SecpSecretKey; +use bitcoin::secp256k1::ecdsa::Signature as SecpSignature; use bitcoin::secp256k1::Error as SecpError; -use bitcoin::secp256k1::recovery::RecoveryId; -use bitcoin::secp256k1::recovery::RecoverableSignature as SecpRecoverableSignature; +use bitcoin::secp256k1::ecdsa::RecoveryId; +use bitcoin::secp256k1::ecdsa::RecoverableSignature as SecpRecoverableSignature; +use bitcoin::secp256k1::Scalar as SecpScalar; use bitcoin::bech32; +use bitcoin::util::address; -use std::convert::TryInto; // Bindings need at least rustc 1.34 +use core::convert::TryInto; // Bindings need at least rustc 1.34 use core::ffi::c_void; -use std::io::{Cursor, Read}; // TODO: We should use core2 here when we support no_std + +#[cfg(feature = "std")] +pub(crate) use std::io::{self, Cursor, Read}; +#[cfg(feature = "no-std")] +pub(crate) use core2::io::{self, Cursor, Read}; +#[cfg(feature = "no-std")] +use alloc::{boxed::Box, vec::Vec, string::String}; + +use core::convert::TryFrom; #[repr(C)] /// A dummy struct of which an instance must never exist. @@ -31,15 +42,58 @@ impl From for NotConstructable { #[derive(PartialEq, Eq, Copy, Clone)] #[allow(non_camel_case_types)] #[repr(C)] -pub struct u5(u8); +pub struct U5(u8); -impl From for u5 { +impl From for U5 { fn from(o: bech32::u5) -> Self { Self(o.to_u8()) } } -impl Into for u5 { +impl Into for U5 { fn into(self) -> bech32::u5 { bech32::u5::try_from_u8(self.0).expect("u5 objects must be in the range 0..32") } } +/// Unsigned, 128-bit integer. +/// +/// Because LLVM implements an incorrect ABI for 128-bit integers, a wrapper type is defined here. +/// See https://github.com/rust-lang/rust/issues/54341 for more details. +#[derive(PartialEq, Eq, Copy, Clone)] +#[allow(non_camel_case_types)] +#[repr(C)] +pub struct U128 { + /// The 128-bit integer, as 16 little-endian bytes + pub le_bytes: [u8; 16], +} + +#[no_mangle] +/// Gets the 128-bit integer, as 16 little-endian bytes +pub extern "C" fn U128_le_bytes(val: U128) -> SixteenBytes { SixteenBytes { data: val.le_bytes } } +#[no_mangle] +/// Constructs a new U128 from 16 little-endian bytes +pub extern "C" fn U128_new(le_bytes: SixteenBytes) -> U128 { U128 { le_bytes: le_bytes.data } } + +impl From for U128 { + fn from(o: u128) -> Self { Self { le_bytes: o.to_le_bytes() } } +} +impl From<&mut u128> for U128 { + fn from(o: &mut u128) -> U128 { Self::from(*o) } +} +impl Into for U128 { + fn into(self) -> u128 { u128::from_le_bytes(self.le_bytes) } +} + +/// Integer in the range `0..=16` +#[derive(PartialEq, Eq, Copy, Clone)] +#[repr(C)] +pub struct WitnessVersion(u8); + +impl From for WitnessVersion { + fn from(o: address::WitnessVersion) -> Self { Self(o.to_num()) } +} +impl Into for WitnessVersion { + fn into(self) -> address::WitnessVersion { + address::WitnessVersion::try_from(self.0).expect("WitnessVersion objects must be in the range 0..=16") + } +} + #[derive(Clone)] #[repr(C)] /// Represents a valid secp256k1 public key serialized in "compressed form" as a 33 byte array. @@ -61,6 +115,7 @@ impl PublicKey { } #[repr(C)] +#[derive(Clone)] /// Represents a valid secp256k1 secret key serialized as a 32 byte array. pub struct SecretKey { /// The bytes of the secret key @@ -125,6 +180,28 @@ impl RecoverableSignature { } } +#[repr(C)] +#[derive(Clone)] +/// Represents a scalar value between zero and the secp256k1 curve order, in big endian. +pub struct BigEndianScalar { + /// The bytes of the scalar value. + pub big_endian_bytes: [u8; 32], +} +impl BigEndianScalar { + pub(crate) fn from_rust(scalar: &SecpScalar) -> Self { + Self { big_endian_bytes: scalar.to_be_bytes() } + } + pub(crate) fn into_rust(&self) -> SecpScalar { + SecpScalar::from_be_bytes(self.big_endian_bytes).expect("Scalar greater than the curve order") + } +} + +#[no_mangle] +/// Convenience function for constructing a new BigEndianScalar +pub extern "C" fn BigEndianScalar_new(big_endian_bytes: ThirtyTwoBytes) -> BigEndianScalar { + BigEndianScalar { big_endian_bytes: big_endian_bytes.data } +} + #[repr(C)] #[derive(Copy, Clone)] /// Represents an error returned from libsecp256k1 during validation of some secp256k1 data @@ -139,14 +216,18 @@ pub enum Secp256k1Error { InvalidSignature, /// Bad secret key InvalidSecretKey, + /// Bad shared secret. + InvalidSharedSecret, /// Bad recovery id InvalidRecoveryId, /// Invalid tweak for add_assign or mul_assign InvalidTweak, - /// tweak_add_check failed on an xonly public key - TweakCheckFailed, /// Didn't pass enough memory to context creation with preallocated memory NotEnoughMemory, + /// Bad set of public keys. + InvalidPublicKeySum, + /// The only valid parity values are 0 or 1. + InvalidParityValue, } impl Secp256k1Error { pub(crate) fn from_rust(err: SecpError) -> Self { @@ -156,12 +237,88 @@ impl Secp256k1Error { SecpError::InvalidPublicKey => Secp256k1Error::InvalidPublicKey, SecpError::InvalidSignature => Secp256k1Error::InvalidSignature, SecpError::InvalidSecretKey => Secp256k1Error::InvalidSecretKey, + SecpError::InvalidSharedSecret => Secp256k1Error::InvalidSharedSecret, SecpError::InvalidRecoveryId => Secp256k1Error::InvalidRecoveryId, SecpError::InvalidTweak => Secp256k1Error::InvalidTweak, - SecpError::TweakCheckFailed => Secp256k1Error::TweakCheckFailed, SecpError::NotEnoughMemory => Secp256k1Error::NotEnoughMemory, + SecpError::InvalidPublicKeySum => Secp256k1Error::InvalidPublicKeySum, + SecpError::InvalidParityValue(_) => Secp256k1Error::InvalidParityValue, } } + pub(crate) fn into_rust(self) -> SecpError { + let invalid_parity = secp256k1::Parity::from_i32(42).unwrap_err(); + match self { + Secp256k1Error::IncorrectSignature => SecpError::IncorrectSignature, + Secp256k1Error::InvalidMessage => SecpError::InvalidMessage, + Secp256k1Error::InvalidPublicKey => SecpError::InvalidPublicKey, + Secp256k1Error::InvalidSignature => SecpError::InvalidSignature, + Secp256k1Error::InvalidSecretKey => SecpError::InvalidSecretKey, + Secp256k1Error::InvalidSharedSecret => SecpError::InvalidSharedSecret, + Secp256k1Error::InvalidRecoveryId => SecpError::InvalidRecoveryId, + Secp256k1Error::InvalidTweak => SecpError::InvalidTweak, + Secp256k1Error::NotEnoughMemory => SecpError::NotEnoughMemory, + Secp256k1Error::InvalidPublicKeySum => SecpError::InvalidPublicKeySum, + Secp256k1Error::InvalidParityValue => SecpError::InvalidParityValue(invalid_parity), + } + } +} + +#[repr(C)] +#[derive(Copy, Clone)] +/// Represents an error returned from the bech32 library during validation of some bech32 data +pub enum Bech32Error { + /// String does not contain the separator character + MissingSeparator, + /// The checksum does not match the rest of the data + InvalidChecksum, + /// The data or human-readable part is too long or too short + InvalidLength, + /// Some part of the string contains an invalid character + InvalidChar(u32), + /// Some part of the data has an invalid value + InvalidData(u8), + /// The bit conversion failed due to a padding issue + InvalidPadding, + /// The whole string must be of one case + MixedCase, +} +impl Bech32Error { + pub(crate) fn from_rust(err: bech32::Error) -> Self { + match err { + bech32::Error::MissingSeparator => Self::MissingSeparator, + bech32::Error::InvalidChecksum => Self::InvalidChecksum, + bech32::Error::InvalidLength => Self::InvalidLength, + bech32::Error::InvalidChar(c) => Self::InvalidChar(c as u32), + bech32::Error::InvalidData(d) => Self::InvalidData(d), + bech32::Error::InvalidPadding => Self::InvalidPadding, + bech32::Error::MixedCase => Self::MixedCase, + } + } + pub(crate) fn into_rust(self) -> bech32::Error { + match self { + Self::MissingSeparator => bech32::Error::MissingSeparator, + Self::InvalidChecksum => bech32::Error::InvalidChecksum, + Self::InvalidLength => bech32::Error::InvalidLength, + Self::InvalidChar(c) => bech32::Error::InvalidChar(core::char::from_u32(c).expect("Invalid UTF-8 character in Bech32Error::InvalidChar")), + Self::InvalidData(d) => bech32::Error::InvalidData(d), + Self::InvalidPadding => bech32::Error::InvalidPadding, + Self::MixedCase => bech32::Error::MixedCase, + } + } +} +#[no_mangle] +/// Creates a new Bech32Error which has the same data as `orig` +pub extern "C" fn Bech32Error_clone(orig: &Bech32Error) -> Bech32Error { orig.clone() } +#[no_mangle] +/// Releases any memory held by the given `Bech32Error` (which is currently none) +pub extern "C" fn Bech32Error_free(o: Bech32Error) { } + +#[repr(C)] +#[derive(Clone, Copy, PartialEq)] +/// Sub-errors which don't have specific information in them use this type. +pub struct Error { + /// Zero-Sized_types aren't consistent across Rust/C/C++, so we add some size here + pub _dummy: u8, } #[repr(C)] @@ -189,50 +346,56 @@ pub enum IOError { UnexpectedEof, } impl IOError { - pub(crate) fn from_rust(err: std::io::Error) -> Self { - match err.kind() { - std::io::ErrorKind::NotFound => IOError::NotFound, - std::io::ErrorKind::PermissionDenied => IOError::PermissionDenied, - std::io::ErrorKind::ConnectionRefused => IOError::ConnectionRefused, - std::io::ErrorKind::ConnectionReset => IOError::ConnectionReset, - std::io::ErrorKind::ConnectionAborted => IOError::ConnectionAborted, - std::io::ErrorKind::NotConnected => IOError::NotConnected, - std::io::ErrorKind::AddrInUse => IOError::AddrInUse, - std::io::ErrorKind::AddrNotAvailable => IOError::AddrNotAvailable, - std::io::ErrorKind::BrokenPipe => IOError::BrokenPipe, - std::io::ErrorKind::AlreadyExists => IOError::AlreadyExists, - std::io::ErrorKind::WouldBlock => IOError::WouldBlock, - std::io::ErrorKind::InvalidInput => IOError::InvalidInput, - std::io::ErrorKind::InvalidData => IOError::InvalidData, - std::io::ErrorKind::TimedOut => IOError::TimedOut, - std::io::ErrorKind::WriteZero => IOError::WriteZero, - std::io::ErrorKind::Interrupted => IOError::Interrupted, - std::io::ErrorKind::Other => IOError::Other, - std::io::ErrorKind::UnexpectedEof => IOError::UnexpectedEof, + pub(crate) fn from_rust_kind(err: io::ErrorKind) -> Self { + match err { + io::ErrorKind::NotFound => IOError::NotFound, + io::ErrorKind::PermissionDenied => IOError::PermissionDenied, + io::ErrorKind::ConnectionRefused => IOError::ConnectionRefused, + io::ErrorKind::ConnectionReset => IOError::ConnectionReset, + io::ErrorKind::ConnectionAborted => IOError::ConnectionAborted, + io::ErrorKind::NotConnected => IOError::NotConnected, + io::ErrorKind::AddrInUse => IOError::AddrInUse, + io::ErrorKind::AddrNotAvailable => IOError::AddrNotAvailable, + io::ErrorKind::BrokenPipe => IOError::BrokenPipe, + io::ErrorKind::AlreadyExists => IOError::AlreadyExists, + io::ErrorKind::WouldBlock => IOError::WouldBlock, + io::ErrorKind::InvalidInput => IOError::InvalidInput, + io::ErrorKind::InvalidData => IOError::InvalidData, + io::ErrorKind::TimedOut => IOError::TimedOut, + io::ErrorKind::WriteZero => IOError::WriteZero, + io::ErrorKind::Interrupted => IOError::Interrupted, + io::ErrorKind::Other => IOError::Other, + io::ErrorKind::UnexpectedEof => IOError::UnexpectedEof, _ => IOError::Other, } } - pub(crate) fn to_rust(&self) -> std::io::Error { - std::io::Error::new(match self { - IOError::NotFound => std::io::ErrorKind::NotFound, - IOError::PermissionDenied => std::io::ErrorKind::PermissionDenied, - IOError::ConnectionRefused => std::io::ErrorKind::ConnectionRefused, - IOError::ConnectionReset => std::io::ErrorKind::ConnectionReset, - IOError::ConnectionAborted => std::io::ErrorKind::ConnectionAborted, - IOError::NotConnected => std::io::ErrorKind::NotConnected, - IOError::AddrInUse => std::io::ErrorKind::AddrInUse, - IOError::AddrNotAvailable => std::io::ErrorKind::AddrNotAvailable, - IOError::BrokenPipe => std::io::ErrorKind::BrokenPipe, - IOError::AlreadyExists => std::io::ErrorKind::AlreadyExists, - IOError::WouldBlock => std::io::ErrorKind::WouldBlock, - IOError::InvalidInput => std::io::ErrorKind::InvalidInput, - IOError::InvalidData => std::io::ErrorKind::InvalidData, - IOError::TimedOut => std::io::ErrorKind::TimedOut, - IOError::WriteZero => std::io::ErrorKind::WriteZero, - IOError::Interrupted => std::io::ErrorKind::Interrupted, - IOError::Other => std::io::ErrorKind::Other, - IOError::UnexpectedEof => std::io::ErrorKind::UnexpectedEof, - }, "") + pub(crate) fn from_rust(err: io::Error) -> Self { + Self::from_rust_kind(err.kind()) + } + pub(crate) fn to_rust_kind(&self) -> io::ErrorKind { + match self { + IOError::NotFound => io::ErrorKind::NotFound, + IOError::PermissionDenied => io::ErrorKind::PermissionDenied, + IOError::ConnectionRefused => io::ErrorKind::ConnectionRefused, + IOError::ConnectionReset => io::ErrorKind::ConnectionReset, + IOError::ConnectionAborted => io::ErrorKind::ConnectionAborted, + IOError::NotConnected => io::ErrorKind::NotConnected, + IOError::AddrInUse => io::ErrorKind::AddrInUse, + IOError::AddrNotAvailable => io::ErrorKind::AddrNotAvailable, + IOError::BrokenPipe => io::ErrorKind::BrokenPipe, + IOError::AlreadyExists => io::ErrorKind::AlreadyExists, + IOError::WouldBlock => io::ErrorKind::WouldBlock, + IOError::InvalidInput => io::ErrorKind::InvalidInput, + IOError::InvalidData => io::ErrorKind::InvalidData, + IOError::TimedOut => io::ErrorKind::TimedOut, + IOError::WriteZero => io::ErrorKind::WriteZero, + IOError::Interrupted => io::ErrorKind::Interrupted, + IOError::Other => io::ErrorKind::Other, + IOError::UnexpectedEof => io::ErrorKind::UnexpectedEof, + } + } + pub(crate) fn to_rust(&self) -> io::Error { + io::Error::new(self.to_rust_kind(), "") } } @@ -272,7 +435,7 @@ impl Transaction { } pub(crate) fn into_bitcoin(&self) -> BitcoinTransaction { if self.datalen == 0 { panic!("0-length buffer can never represent a valid Transaction"); } - ::bitcoin::consensus::encode::deserialize(unsafe { std::slice::from_raw_parts(self.data, self.datalen) }).unwrap() + ::bitcoin::consensus::encode::deserialize(unsafe { core::slice::from_raw_parts(self.data, self.datalen) }).unwrap() } pub(crate) fn from_bitcoin(btc: &BitcoinTransaction) -> Self { let vec = ::bitcoin::consensus::encode::serialize(btc); @@ -288,7 +451,7 @@ impl Drop for Transaction { } impl Clone for Transaction { fn clone(&self) -> Self { - let sl = unsafe { std::slice::from_raw_parts(self.data, self.datalen) }; + let sl = unsafe { core::slice::from_raw_parts(self.data, self.datalen) }; let mut v = Vec::new(); v.extend_from_slice(&sl); Self::from_vec(v) @@ -298,6 +461,57 @@ impl Clone for Transaction { /// Frees the data buffer, if data_is_owned is set and datalen > 0. pub extern "C" fn Transaction_free(_res: Transaction) { } +#[repr(C)] +/// A serialized witness. +pub struct Witness { + /// The serialized transaction data. + /// + /// This is non-const for your convenience, an object passed to Rust is never written to. + pub data: *mut u8, + /// The length of the serialized transaction + pub datalen: usize, + /// Whether the data pointed to by `data` should be freed or not. + pub data_is_owned: bool, +} +impl Witness { + fn from_vec(vec: Vec) -> Self { + let datalen = vec.len(); + let data = Box::into_raw(vec.into_boxed_slice()); + Self { + data: unsafe { (*data).as_mut_ptr() }, + datalen, + data_is_owned: true, + } + } + pub(crate) fn into_bitcoin(&self) -> BitcoinWitness { + ::bitcoin::consensus::encode::deserialize(unsafe { core::slice::from_raw_parts(self.data, self.datalen) }).unwrap() + } + pub(crate) fn from_bitcoin(btc: &BitcoinWitness) -> Self { + let vec = ::bitcoin::consensus::encode::serialize(btc); + Self::from_vec(vec) + } +} + +impl Drop for Witness { + fn drop(&mut self) { + if self.data_is_owned && self.datalen != 0 { + let _ = derived::CVec_u8Z { data: self.data as *mut u8, datalen: self.datalen }; + } + } +} +impl Clone for Witness { + fn clone(&self) -> Self { + let sl = unsafe { core::slice::from_raw_parts(self.data, self.datalen) }; + let mut v = Vec::new(); + v.extend_from_slice(&sl); + Self::from_vec(v) + } +} + +#[no_mangle] +/// Frees the data pointed to by data +pub extern "C" fn Witness_free(_res: Witness) { } + pub(crate) fn bitcoin_to_C_outpoint(outpoint: ::bitcoin::blockdata::transaction::OutPoint) -> crate::lightning::chain::transaction::OutPoint { crate::lightning::chain::transaction::OutPoint_new(ThirtyTwoBytes { data: outpoint.txid.into_inner() }, outpoint.vout.try_into().unwrap()) } @@ -365,7 +579,7 @@ impl u8slice { } pub(crate) fn to_slice(&self) -> &[u8] { if self.datalen == 0 { return &[]; } - unsafe { std::slice::from_raw_parts(self.data, self.datalen) } + unsafe { core::slice::from_raw_parts(self.data, self.datalen) } } pub(crate) fn to_reader<'a>(&'a self) -> Cursor<&'a [u8]> { let sl = self.to_slice(); @@ -404,8 +618,8 @@ pub struct ThreeBytes { /** The three bytes */ pub data: [u8; 3], } pub struct FourBytes { /** The four bytes */ pub data: [u8; 4], } #[derive(Clone)] #[repr(C)] -/// A 10-byte byte array. -pub struct TenBytes { /** The ten bytes */ pub data: [u8; 10], } +/// A 12-byte byte array. +pub struct TwelveBytes { /** The twelve bytes */ pub data: [u8; 12], } #[derive(Clone)] #[repr(C)] /// A 16-byte byte array. @@ -417,7 +631,7 @@ pub struct TwentyBytes { /** The twenty bytes */ pub data: [u8; 20], } pub(crate) struct VecWriter(pub Vec); impl lightning::util::ser::Writer for VecWriter { - fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> { + fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error> { self.0.extend_from_slice(buf); Ok(()) } @@ -463,20 +677,20 @@ impl Into for &mut &'static str { impl Str { pub(crate) fn into_str(&self) -> &'static str { if self.len == 0 { return ""; } - std::str::from_utf8(unsafe { std::slice::from_raw_parts(self.chars, self.len) }).unwrap() + core::str::from_utf8(unsafe { core::slice::from_raw_parts(self.chars, self.len) }).unwrap() } pub(crate) fn into_string(mut self) -> String { let bytes = if self.len == 0 { Vec::new() } else if self.chars_is_owned { let ret = unsafe { - Box::from_raw(std::slice::from_raw_parts_mut(unsafe { self.chars as *mut u8 }, self.len)) + Box::from_raw(core::slice::from_raw_parts_mut(unsafe { self.chars as *mut u8 }, self.len)) }.into(); self.chars_is_owned = false; ret } else { let mut ret = Vec::with_capacity(self.len); - ret.extend_from_slice(unsafe { std::slice::from_raw_parts(self.chars, self.len) }); + ret.extend_from_slice(unsafe { core::slice::from_raw_parts(self.chars, self.len) }); ret }; String::from_utf8(bytes).unwrap() @@ -490,7 +704,7 @@ impl Into for String { } impl Clone for Str { fn clone(&self) -> Self { - self.into_str().clone().into() + String::from(self.into_str()).into() } } @@ -543,10 +757,10 @@ impl Drop for CResultTempl { fn drop(&mut self) { if self.result_ok { if unsafe { !self.contents.result.is_null() } { - unsafe { Box::from_raw(self.contents.result) }; + let _ = unsafe { Box::from_raw(self.contents.result) }; } } else if unsafe { !self.contents.err.is_null() } { - unsafe { Box::from_raw(self.contents.err) }; + let _ = unsafe { Box::from_raw(self.contents.err) }; } } } @@ -558,20 +772,23 @@ pub(crate) trait TakePointer { impl TakePointer<*const T> for *const T { fn take_ptr(&mut self) -> *const T { let ret = *self; - *self = std::ptr::null(); + *self = core::ptr::null(); ret } } impl TakePointer<*mut T> for *mut T { fn take_ptr(&mut self) -> *mut T { let ret = *self; - *self = std::ptr::null_mut(); + *self = core::ptr::null_mut(); ret } } pub(crate) mod ObjOps { + #[cfg(feature = "no-std")] + use alloc::boxed::Box; + #[inline] #[must_use = "returns new dangling pointer"] pub(crate) fn heap_alloc(obj: T) -> *mut T { @@ -638,17 +855,17 @@ impl SmartPtr { Self { ptr: Box::into_raw(Box::new(o)) } } pub(crate) fn null() -> Self { - Self { ptr: std::ptr::null_mut() } + Self { ptr: core::ptr::null_mut() } } } impl Drop for SmartPtr { fn drop(&mut self) { - if self.ptr != std::ptr::null_mut() { - unsafe { Box::from_raw(self.ptr); } + if self.ptr != core::ptr::null_mut() { + let _ = unsafe { Box::from_raw(self.ptr) }; } } } -impl std::ops::Deref for SmartPtr { +impl core::ops::Deref for SmartPtr { type Target = *mut T; fn deref(&self) -> &*mut T { &self.ptr