Merge pull request #160 from gregcotten/abstract-unix-paths

Add support for unix "abstract namespace" addresses

Author: swhitty

FlyingSocks/Sources/Socket+Android.swift

@@ -99,6 +99,24 @@ extension Socket {
         return addr
     }
 
+    static func makeAbstractNamespaceUnix(name: String) -> Android.sockaddr_un {
+        var addr: sockaddr_un = Android.sockaddr_un()
+        addr.sun_family = sa_family_t(AF_UNIX)
+
+        _ = withUnsafeMutableBytes(of: &addr.sun_path) { raw in
+            raw.initializeMemory(as: CChar.self, repeating: 0)
+        }
+
+        let nameBytes = Array(name.utf8.prefix(107))
+        nameBytes.withUnsafeBytes { src in
+            withUnsafeMutableBytes(of: &addr.sun_path) { dst in
+                dst[1 ..< 1 + src.count].copyBytes(from: src)
+            }
+        }
+
+        return addr
+    }
+
     static func socket(_ domain: Int32, _ type: Int32, _ protocol: Int32) -> FileDescriptorType {
         Android.socket(domain, type, `protocol`)
     }

FlyingSocks/Sources/Socket+Glibc.swift

@@ -96,6 +96,24 @@ extension Socket {
         return addr
     }
 
+    static func makeAbstractNamespaceUnix(name: String) -> Glibc.sockaddr_un {
+        var addr: sockaddr_un = Glibc.sockaddr_un()
+        addr.sun_family = sa_family_t(AF_UNIX)
+
+        _ = withUnsafeMutableBytes(of: &addr.sun_path) { raw in
+            raw.initializeMemory(as: CChar.self, repeating: 0)
+        }
+
+        let nameBytes = Array(name.utf8.prefix(107))
+        nameBytes.withUnsafeBytes { src in
+            withUnsafeMutableBytes(of: &addr.sun_path) { dst in
+                dst[1 ..< 1 + src.count].copyBytes(from: src)
+            }
+        }
+
+        return addr
+    }
+
     static func socket(_ domain: Int32, _ type: Int32, _ protocol: Int32) -> FileDescriptorType {
         Glibc.socket(domain, type, `protocol`)
     }

FlyingSocks/Sources/Socket+Musl.swift

@@ -96,6 +96,24 @@ extension Socket {
         return addr
     }
 
+    static func makeAbstractNamespaceUnix(name: String) -> Musl.sockaddr_un {
+        var addr: sockaddr_un = Musl.sockaddr_un()
+        addr.sun_family = sa_family_t(AF_UNIX)
+
+        _ = withUnsafeMutableBytes(of: &addr.sun_path) { raw in
+            raw.initializeMemory(as: CChar.self, repeating: 0)
+        }
+
+        let nameBytes = Array(name.utf8.prefix(107))
+        nameBytes.withUnsafeBytes { src in
+            withUnsafeMutableBytes(of: &addr.sun_path) { dst in
+                dst[1 ..< 1 + src.count].copyBytes(from: src)
+            }
+        }
+
+        return addr
+    }
+
     static func socket(_ domain: Int32, _ type: Int32, _ protocol: Int32) -> FileDescriptorType {
         Musl.socket(domain, type, `protocol`)
     }

FlyingSocks/Sources/Socket+WinSock2.swift

@@ -107,6 +107,24 @@ extension Socket {
         return addr
     }
 
+    static func makeAbstractNamespaceUnix(name: String) -> WinSDK.sockaddr_un {
+        var addr: sockaddr_un = WinSDK.sockaddr_un()
+        addr.sun_family = ADDRESS_FAMILY(AF_UNIX)
+
+        _ = withUnsafeMutableBytes(of: &addr.sun_path) { raw in
+            raw.initializeMemory(as: CChar.self, repeating: 0)
+        }
+
+        let nameBytes = Array(name.utf8.prefix(107))
+        nameBytes.withUnsafeBytes { src in
+            withUnsafeMutableBytes(of: &addr.sun_path) { dst in
+                dst[1 ..< 1 + src.count].copyBytes(from: src)
+            }
+        }
+
+        return addr
+    }
+
     static func fcntl(_ fd: FileDescriptorType, _ cmd: Int32) -> Int32 {
         return -1
     }

FlyingSocks/Sources/SocketAddress.swift

@@ -107,10 +107,15 @@ public extension SocketAddress where Self == sockaddr_in6 {
 }
 
 public extension SocketAddress where Self == sockaddr_un {
-
     static func unix(path: String) -> Self {
         Socket.makeAddressUnix(path: path)
     }
+
+    #if canImport(Glibc) || canImport(Musl) || canImport(Android) || canImport(WinSDK)
+    static func unix(abstractNamespace: String) -> Self {
+        Socket.makeAbstractNamespaceUnix(name: abstractNamespace)
+    }
+    #endif
 }
 
 #if compiler(>=6.0)

FlyingSocks/Tests/SocketAddressTests.swift

@@ -148,6 +148,23 @@ struct SocketAddressTests {
         )
     }
 
+    #if canImport(Glibc) || canImport(Musl) || canImport(Android) || canImport(WinSDK)
+    @Test
+    func unixAbstractNamespace_IsCorrectlyDecodedFromStorage() throws {
+        let storage = sockaddr_un
+            .unix(abstractNamespace: "mygreatnamespace")
+            .makeStorage()
+
+        var unix = try sockaddr_un.make(from: storage)
+        let path = withUnsafePointer(to: &unix.sun_path.1) {
+            return String(cString: $0)
+        }
+        #expect(
+            path == "mygreatnamespace"
+        )
+    }
+    #endif
+
     @Test
     func unix_ThrowsInvalidAddress_WhenFamilyIncorrect() {
         let storage = sockaddr_in6
@@ -183,6 +200,16 @@ struct SocketAddressTests {
         )
     }
 
+    #if canImport(Glibc) || canImport(Musl) || canImport(Android) || canImport(WinSDK)
+    @Test
+    func unixAbstractNamespace_CheckSize() throws {
+        let sun = sockaddr_un.unix(abstractNamespace: "some_great_namespace")
+        #expect(
+            sun.size == socklen_t(MemoryLayout<sockaddr_un>.size)
+        )
+    }
+    #endif
+
     @Test
     func unknown_CheckSize() throws {
         var sa = sockaddr()