Add SMB AAPL Extensions Phase 1-6 + VFS xattr support

Phase 1: AAPL Create Context negotiation
Phase 2: AFP_AfpInfo Stream structure (Finder info + creation time)
Phase 2.5: SMB Named Stream Backend (NamedStreamPath)
Phase 2.6: Backend Named Stream Support in handlers
Phase 2.7: VFS Extended Attributes (get/set/remove/list_xattr)
Phase 4: Time Machine share config (time_machine field)
Phase 5: Server/Volume Capabilities
Phase 6: macOS Unicode mapping (private range ↔ ASCII)

Tests: 174 smb-server tests pass, 52 VFS tests pass

vendor/smb-server/src/unicode_mapping.rs

@@ -0,0 +1,123 @@
+//! macOS Unicode Private Range Mapping for SMB
+//!
+//! macOS SMB client maps NTFS illegal characters to Unicode private range.
+//! Reference: Samba vfs_fruit.c encoding handling
+
+pub const FRUIT_ENC_NATIVE: bool = true;
+pub const FRUIT_ENC_PRIVATE: bool = false;
+
+const APPLE_SLASH: u16 = 0xF026;
+const APPLE_COLON: u16 = 0xF02A;
+const APPLE_ASTERISK: u16 = 0xF02A;
+const APPLE_QUESTION: u16 = 0xF03F;
+const APPLE_QUOTE: u16 = 0xF022;
+const APPLE_LESS_THAN: u16 = 0xF03C;
+const APPLE_GREATER_THAN: u16 = 0xF03E;
+const APPLE_PIPE: u16 = 0xF07C;
+
+const ASCII_SLASH: u16 = '/' as u16;
+const ASCII_COLON: u16 = ':' as u16;
+const ASCII_ASTERISK: u16 = '*' as u16;
+const ASCII_QUESTION: u16 = '?' as u16;
+const ASCII_QUOTE: u16 = '"' as u16;
+const ASCII_LESS_THAN: u16 = '<' as u16;
+const ASCII_GREATER_THAN: u16 = '>' as u16;
+const ASCII_PIPE: u16 = '|' as u16;
+
+pub fn map_private_to_ascii(units: &[u16]) -> Vec<u16> {
+    units.iter().map(|u| {
+        match *u {
+            APPLE_SLASH => ASCII_SLASH,
+            APPLE_COLON => ASCII_COLON,
+            APPLE_ASTERISK => ASCII_ASTERISK,
+            APPLE_QUESTION => ASCII_QUESTION,
+            APPLE_QUOTE => ASCII_QUOTE,
+            APPLE_LESS_THAN => ASCII_LESS_THAN,
+            APPLE_GREATER_THAN => ASCII_GREATER_THAN,
+            APPLE_PIPE => ASCII_PIPE,
+            _ => *u,
+        }
+    }).collect()
+}
+
+pub fn map_ascii_to_private(units: &[u16]) -> Vec<u16> {
+    units.iter().map(|u| {
+        match *u {
+            ASCII_SLASH => APPLE_SLASH,
+            ASCII_COLON => APPLE_COLON,
+            ASCII_ASTERISK => APPLE_ASTERISK,
+            ASCII_QUESTION => APPLE_QUESTION,
+            ASCII_QUOTE => APPLE_QUOTE,
+            ASCII_LESS_THAN => APPLE_LESS_THAN,
+            ASCII_GREATER_THAN => APPLE_GREATER_THAN,
+            ASCII_PIPE => APPLE_PIPE,
+            _ => *u,
+        }
+    }).collect()
+}
+
+pub fn has_private_range_chars(units: &[u16]) -> bool {
+    units.iter().any(|u| {
+        matches!(*u,
+            APPLE_SLASH | APPLE_COLON | APPLE_ASTERISK |
+            APPLE_QUESTION | APPLE_QUOTE | APPLE_LESS_THAN |
+            APPLE_GREATER_THAN | APPLE_PIPE
+        )
+    })
+}
+
+pub fn has_ntfs_illegal_chars(units: &[u16]) -> bool {
+    units.iter().any(|u| {
+        matches!(*u,
+            ASCII_SLASH | ASCII_COLON | ASCII_ASTERISK |
+            ASCII_QUESTION | ASCII_QUOTE | ASCII_LESS_THAN |
+            ASCII_GREATER_THAN | ASCII_PIPE
+        )
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_map_private_to_ascii() {
+        let input = [APPLE_SLASH, APPLE_COLON, APPLE_QUESTION];
+        let output = map_private_to_ascii(&input);
+        assert_eq!(output, [ASCII_SLASH, ASCII_COLON, ASCII_QUESTION]);
+    }
+
+    #[test]
+    fn test_map_ascii_to_private() {
+        let input = [ASCII_SLASH, ASCII_COLON, ASCII_ASTERISK];
+        let output = map_ascii_to_private(&input);
+        assert_eq!(output, [APPLE_SLASH, APPLE_COLON, APPLE_ASTERISK]);
+    }
+
+    #[test]
+    fn test_roundtrip() {
+        let original = [ASCII_SLASH, ASCII_COLON, 'a' as u16];
+        let to_private = map_ascii_to_private(&original);
+        let back_to_ascii = map_private_to_ascii(&to_private);
+        assert_eq!(back_to_ascii, original);
+    }
+
+    #[test]
+    fn test_has_private_range_chars() {
+        assert!(has_private_range_chars(&[APPLE_SLASH, 'a' as u16]));
+        assert!(!has_private_range_chars(&[ASCII_SLASH, 'a' as u16]));
+    }
+
+    #[test]
+    fn test_has_ntfs_illegal_chars() {
+        assert!(has_ntfs_illegal_chars(&[ASCII_SLASH, 'a' as u16]));
+        assert!(!has_ntfs_illegal_chars(&['a' as u16, 'b' as u16]));
+    }
+
+    #[test]
+    fn test_preserve_non_mapped() {
+        let input = ['a' as u16, 'b' as u16, 'c' as u16];
+        let output = map_private_to_ascii(&input);
+        assert_eq!(output, input);
+    }
+}