1 files changed, 178 insertions, 0 deletions
diff --git a/src/backend/linux_raw/net/addr.rs b/src/backend/linux_raw/net/addr.rs
new file mode 100644
index 0000000..85ba875
--- /dev/null
+++ b/src/backend/linux_raw/net/addr.rs
@@ -0,0 +1,178 @@
+//! Socket address utilities.
+//!
+//! # Safety
+//!
+//! This file uses `CStr::from_bytes_with_nul_unchecked` on a string it knows
+//! to be NUL-terminated.
+#![allow(unsafe_code)]
+
+use crate::backend::c;
+use crate::ffi::CStr;
+use crate::{io, path};
+use core::cmp::Ordering;
+use core::fmt;
+use core::hash::{Hash, Hasher};
+use core::slice;
+
+/// `struct sockaddr_un`
+#[derive(Clone)]
+#[doc(alias = "sockaddr_un")]
+pub struct SocketAddrUnix {
+    pub(crate) unix: c::sockaddr_un,
+    len: c::socklen_t,
+}
+
+impl SocketAddrUnix {
+    /// Construct a new Unix-domain address from a filesystem path.
+    #[inline]
+    pub fn new<P: path::Arg>(path: P) -> io::Result<Self> {
+        path.into_with_c_str(Self::_new)
+    }
+
+    #[inline]
+    fn _new(path: &CStr) -> io::Result<Self> {
+        let mut unix = Self::init();
+        let bytes = path.to_bytes_with_nul();
+        if bytes.len() > unix.sun_path.len() {
+            return Err(io::Errno::NAMETOOLONG);
+        }
+        for (i, b) in bytes.iter().enumerate() {
+            unix.sun_path[i] = *b as _;
+        }
+        let len = offsetof_sun_path() + bytes.len();
+        let len = len.try_into().unwrap();
+        Ok(Self { unix, len })
+    }
+
+    /// Construct a new abstract Unix-domain address from a byte slice.
+    #[inline]
+    pub fn new_abstract_name(name: &[u8]) -> io::Result<Self> {
+        let mut unix = Self::init();
+        let id = &mut unix.sun_path[1..];
+
+        // SAFETY: Convert `&mut [c_char]` to `&mut [u8]`.
+        let id = unsafe { slice::from_raw_parts_mut(id.as_mut_ptr().cast::<u8>(), id.len()) };
+
+        if let Some(id) = id.get_mut(..name.len()) {
+            id.copy_from_slice(name);
+            let len = offsetof_sun_path() + 1 + name.len();
+            let len = len.try_into().unwrap();
+            Ok(Self { unix, len })
+        } else {
+            Err(io::Errno::NAMETOOLONG)
+        }
+    }
+
+    const fn init() -> c::sockaddr_un {
+        c::sockaddr_un {
+            sun_family: c::AF_UNIX as _,
+            sun_path: [0; 108],
+        }
+    }
+
+    /// For a filesystem path address, return the path.
+    #[inline]
+    pub fn path(&self) -> Option<&CStr> {
+        let len = self.len();
+        if len != 0 && self.unix.sun_path[0] as u8 != b'\0' {
+            let end = len as usize - offsetof_sun_path();
+            let bytes = &self.unix.sun_path[..end];
+
+            // SAFETY: Convert `&[c_char]` to `&[u8]`.
+            let bytes = unsafe { slice::from_raw_parts(bytes.as_ptr().cast::<u8>(), bytes.len()) };
+
+            // SAFETY: `from_bytes_with_nul_unchecked` since the string is
+            // NUL-terminated.
+            unsafe { Some(CStr::from_bytes_with_nul_unchecked(bytes)) }
+        } else {
+            None
+        }
+    }
+
+    /// For an abstract address, return the identifier.
+    #[inline]
+    pub fn abstract_name(&self) -> Option<&[u8]> {
+        let len = self.len();
+        if len != 0 && self.unix.sun_path[0] as u8 == b'\0' {
+            let end = len as usize - offsetof_sun_path();
+            let bytes = &self.unix.sun_path[1..end];
+
+            // SAFETY: Convert `&[c_char]` to `&[u8]`.
+            let bytes = unsafe { slice::from_raw_parts(bytes.as_ptr().cast::<u8>(), bytes.len()) };
+
+            Some(bytes)
+        } else {
+            None
+        }
+    }
+
+    #[inline]
+    pub(crate) fn addr_len(&self) -> c::socklen_t {
+        self.len
+    }
+
+    #[inline]
+    pub(crate) fn len(&self) -> usize {
+        self.addr_len() as usize
+    }
+}
+
+impl PartialEq for SocketAddrUnix {
+    #[inline]
+    fn eq(&self, other: &Self) -> bool {
+        let self_len = self.len() - offsetof_sun_path();
+        let other_len = other.len() - offsetof_sun_path();
+        self.unix.sun_path[..self_len].eq(&other.unix.sun_path[..other_len])
+    }
+}
+
+impl Eq for SocketAddrUnix {}
+
+impl PartialOrd for SocketAddrUnix {
+    #[inline]
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl Ord for SocketAddrUnix {
+    #[inline]
+    fn cmp(&self, other: &Self) -> Ordering {
+        let self_len = self.len() - offsetof_sun_path();
+        let other_len = other.len() - offsetof_sun_path();
+        self.unix.sun_path[..self_len].cmp(&other.unix.sun_path[..other_len])
+    }
+}
+
+impl Hash for SocketAddrUnix {
+    #[inline]
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        let self_len = self.len() - offsetof_sun_path();
+        self.unix.sun_path[..self_len].hash(state)
+    }
+}
+
+impl fmt::Debug for SocketAddrUnix {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        if let Some(path) = self.path() {
+            path.fmt(fmt)
+        } else if let Some(name) = self.abstract_name() {
+            name.fmt(fmt)
+        } else {
+            "(unnamed)".fmt(fmt)
+        }
+    }
+}
+
+/// `struct sockaddr_storage` as a raw struct.
+pub type SocketAddrStorage = c::sockaddr;
+
+/// Return the offset of the `sun_path` field of `sockaddr_un`.
+#[inline]
+pub(crate) fn offsetof_sun_path() -> usize {
+    let z = c::sockaddr_un {
+        sun_family: 0_u16,
+        sun_path: [0; 108],
+    };
+    (crate::utils::as_ptr(&z.sun_path) as usize) - (crate::utils::as_ptr(&z) as usize)
+}