add IpAddr type serailize to byte representation

Author: canoriz

src/bipaddr.rs

@@ -0,0 +1,160 @@
+//! Byte string which helps with the deserialization.
+
+use core::{
+    borrow::{Borrow, BorrowMut},
+    fmt, net,
+    ops::{Deref, DerefMut},
+};
+
+use serde::{
+    de::{self, Visitor},
+    Deserialize, Deserializer,
+};
+
+/// IpAddr serialize to and deserialize from big-endian bytes representation.
+///
+/// Bencoded "strings" are not necessarily UTF-8 encoded values so if a field is
+/// not guranteed to be a UTF-8 string, then you should use a `ByteString` or
+/// another equivalent type.
+///
+/// Due to a limitation within `serde` and Rust, a `IpAddr::V4` and `IpAddr::V6` will
+/// serialize and deserialize as a list of individual byte elements. Serializing `IpAddr`
+/// requires serialize enum which this bencode/library does not support yet.
+///
+/// # Examples
+///
+/// ```rust
+/// use bt_bencode::ByteIpAddr;
+/// use core::net;
+///
+/// let v4_bytes = [1,2,3,4];
+/// let v6_bytes = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16];
+/// let v4 = net::IpAddr::from(v4_bytes);
+/// let v6 = net::IpAddr::from(v6_bytes);
+/// let bip4 = ByteIpAddr::from(v4);
+///
+///
+/// let encoded = bt_bencode::to_vec(&bip4)?;
+/// assert_eq!(encoded, b"4:\x01\x02\x03\x04");
+///
+/// let decoded: ByteIpAddr = bt_bencode::from_slice(&encoded)?;
+/// assert_eq!(decoded, v4.into());
+/// 
+/// let bip6 = ByteIpAddr::from(v6);
+///
+/// let encoded = bt_bencode::to_vec(&bip6)?;
+/// assert_eq!(encoded, b"16:\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10");
+///
+/// let decoded: ByteIpAddr = bt_bencode::from_slice(&encoded)?;
+/// assert_eq!(decoded, v6.into());
+/// 
+/// // test invalid bytes
+/// assert!(bt_bencode::from_slice::<ByteIpAddr>(b"5:\x01\x02\x03\x04\x05").is_err());
+///
+/// # Ok::<(), bt_bencode::Error>(())
+/// ```
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct ByteIpAddr(net::IpAddr);
+
+impl AsRef<net::IpAddr> for ByteIpAddr {
+    fn as_ref(&self) -> &net::IpAddr {
+        &self.0
+    }
+}
+
+impl AsMut<net::IpAddr> for ByteIpAddr {
+    fn as_mut(&mut self) -> &mut net::IpAddr {
+        &mut self.0
+    }
+}
+
+impl Borrow<net::IpAddr> for ByteIpAddr {
+    fn borrow(&self) -> &net::IpAddr {
+        &self.0
+    }
+}
+
+impl BorrowMut<net::IpAddr> for ByteIpAddr {
+    fn borrow_mut(&mut self) -> &mut net::IpAddr {
+        &mut self.0
+    }
+}
+
+impl fmt::Debug for ByteIpAddr {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Debug::fmt(&self.0, f)
+    }
+}
+
+impl Deref for ByteIpAddr {
+    type Target = net::IpAddr;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for ByteIpAddr {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+impl<T> From<T> for ByteIpAddr
+where
+    T: Into<net::IpAddr>,
+{
+    fn from(value: T) -> Self {
+        Self(value.into())
+    }
+}
+
+impl serde::Serialize for ByteIpAddr {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        match self.0 {
+            net::IpAddr::V4(ip) => serializer.serialize_bytes(&ip.octets()),
+            net::IpAddr::V6(ip) => serializer.serialize_bytes(&ip.octets()),
+        }
+    }
+}
+
+struct IpAddrVisitor;
+
+impl<'de> Visitor<'de> for IpAddrVisitor {
+    type Value = ByteIpAddr;
+
+    fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        formatter.write_str("byte string of length 4(ipv4) or 16(ipv6)")
+    }
+
+    fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
+    where
+        E: de::Error,
+    {
+        match v.len() {
+            4 => Ok(ByteIpAddr(net::IpAddr::V4(net::Ipv4Addr::from([
+                v[0], v[1], v[2], v[3],
+            ])))),
+            16 => Ok(ByteIpAddr(net::IpAddr::V6(net::Ipv6Addr::from([
+                v[0], v[1], v[2], v[3], v[4], v[5], v[6], v[7], v[8], v[9], v[10], v[11], v[12],
+                v[13], v[14], v[15],
+            ])))),
+            other => Err(de::Error::invalid_value(
+                de::Unexpected::Str(&format!("get byte string {v:02x?} of length {other}")),
+                &self,
+            )),
+        }
+    }
+}
+
+impl<'de> Deserialize<'de> for ByteIpAddr {
+    fn deserialize<D>(deserializer: D) -> Result<ByteIpAddr, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        deserializer.deserialize_byte_buf(IpAddrVisitor)
+    }
+}

src/lib.rs

@@ -108,6 +108,7 @@ extern crate serde;
 mod bstring;
 mod de;
 mod error;
+mod bipaddr;
 
 pub mod read;
 pub mod write;
@@ -122,6 +123,8 @@ pub use de::{from_slice, Deserializer};
 #[doc(inline)]
 pub use error::{Error, ErrorKind, Result};
 #[doc(inline)]
+pub use bipaddr::ByteIpAddr;
+#[doc(inline)]
 pub use value::{from_value, to_value, Value};
 
 #[doc(inline)]