net: unify SocketAddrUnix value extraction

bytecodealliance · Dec 19, 2024 · 6c5cbcd · 6c5cbcd
1 parent 4c5dc02
commit 6c5cbcd
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Showing 2 changed files with 38 additions and 36 deletions.
diff --git a/src/backend/libc/net/addr.rs b/src/backend/libc/net/addr.rs
@@ -121,19 +121,10 @@ impl SocketAddrUnix {
     /// 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] != 0 {
-            let end = len as usize - offsetof_sun_path();
-            let bytes = &self.unix.sun_path[..end];
-            // SAFETY: `from_raw_parts` to convert from `&[c_char]` to `&[u8]`.
-            // And `from_bytes_with_nul_unchecked` since the string is
-            // NUL-terminated.
-            unsafe {
-                Some(CStr::from_bytes_with_nul_unchecked(slice::from_raw_parts(
-                    bytes.as_ptr().cast(),
-                    bytes.len(),
-                )))
-            }
+        let bytes = self.bytes()?;
+        if !bytes.is_empty() && bytes[0] != 0 {
+            // SAFETY: `from_bytes_with_nul_unchecked` since the string is NUL-terminated.
+            Some(unsafe { CStr::from_bytes_with_nul_unchecked(bytes) })
         } else {
             None
         }
@@ -143,11 +134,8 @@ impl SocketAddrUnix {
     #[cfg(linux_kernel)]
     #[inline]
     pub fn abstract_name(&self) -> Option<&[u8]> {
-        let end = self.len().saturating_sub(offsetof_sun_path());
-        if end > 0 && self.unix.sun_path[0] as u8 == b'\0' {
-            let bytes = &self.unix.sun_path[1..end];
-            // SAFETY: Convert `&[c_char]` to `&[u8]`.
-            Some(unsafe { slice::from_raw_parts(bytes.as_ptr().cast::<u8>(), bytes.len()) })
+        if let [0, ref bytes @ ..] = self.bytes()? {
+            Some(bytes)
         } else {
             None
         }
@@ -157,7 +145,7 @@ impl SocketAddrUnix {
     #[cfg(linux_kernel)]
     #[inline]
     pub fn is_unnamed(&self) -> bool {
-        self.len() == offsetof_sun_path()
+        self.bytes() == Some(&[])
     }
 
     #[inline]
@@ -176,6 +164,18 @@ impl SocketAddrUnix {
     pub(crate) fn len(&self) -> usize {
         self.addr_len() as usize
     }
+
+    #[inline]
+    fn bytes(&self) -> Option<&[u8]> {
+        let len = self.len() as usize;
+        if len != 0 {
+            let bytes = &self.unix.sun_path[..len - offsetof_sun_path()];
+            // SAFETY: `from_raw_parts` to convert from `&[c_char]` to `&[u8]`.
+            Some(unsafe { slice::from_raw_parts(bytes.as_ptr().cast(), bytes.len()) })
+        } else {
+            None
+        }
+    }
 }
 
 #[cfg(unix)]

diff --git a/src/backend/linux_raw/net/addr.rs b/src/backend/linux_raw/net/addr.rs
@@ -92,17 +92,10 @@ impl SocketAddrUnix {
     /// 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)) }
+        let bytes = self.bytes()?;
+        if !bytes.is_empty() && bytes[0] != 0 {
+            // SAFETY: `from_bytes_with_nul_unchecked` since the string is NUL-terminated.
+            Some(unsafe { CStr::from_bytes_with_nul_unchecked(bytes) })
         } else {
             None
         }
@@ -111,11 +104,8 @@ impl SocketAddrUnix {
     /// For an abstract address, return the identifier.
     #[inline]
     pub fn abstract_name(&self) -> Option<&[u8]> {
-        let end = self.len().saturating_sub(offsetof_sun_path());
-        if end > 0 && self.unix.sun_path[0] as u8 == b'\0' {
-            let bytes = &self.unix.sun_path[1..end];
-            // SAFETY: Convert `&[c_char]` to `&[u8]`.
-            Some(unsafe { slice::from_raw_parts(bytes.as_ptr().cast::<u8>(), bytes.len()) })
+        if let [0, ref bytes @ ..] = self.bytes()? {
+            Some(bytes)
         } else {
             None
         }
@@ -125,7 +115,7 @@ impl SocketAddrUnix {
     #[cfg(linux_kernel)]
     #[inline]
     pub fn is_unnamed(&self) -> bool {
-        self.len() == offsetof_sun_path()
+        self.bytes() == Some(&[])
     }
 
     #[inline]
@@ -137,6 +127,18 @@ impl SocketAddrUnix {
     pub(crate) fn len(&self) -> usize {
         self.addr_len() as usize
     }
+
+    #[inline]
+    fn bytes(&self) -> Option<&[u8]> {
+        let len = self.len() as usize;
+        if len != 0 {
+            let bytes = &self.unix.sun_path[..len - offsetof_sun_path()];
+            // SAFETY: `from_raw_parts` to convert from `&[c_char]` to `&[u8]`.
+            Some(unsafe { slice::from_raw_parts(bytes.as_ptr().cast(), bytes.len()) })
+        } else {
+            None
+        }
+    }
 }
 
 impl PartialEq for SocketAddrUnix {