unix: add SockaddrUnix tests on darwin and *bsd

Change-Id: I65b4c1073208079ea5ac28d21c829ecf28e28d84
Reviewed-on: https://go-review.googlesource.com/c/sys/+/229878
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matt Layher <mdlayher@gmail.com>

unix/syscall_internal_bsd_test.go

@@ -0,0 +1,175 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build darwin dragonfly freebsd netbsd openbsd
+
+package unix
+
+import (
+	"reflect"
+	"strings"
+	"testing"
+	"unsafe"
+)
+
+// as per socket(2)
+type SocketSpec struct {
+	domain   int
+	typ      int
+	protocol int
+}
+
+func Test_anyToSockaddr(t *testing.T) {
+	tests := []struct {
+		name string
+		rsa  *RawSockaddrAny
+		sa   Sockaddr
+		err  error
+		skt  SocketSpec
+	}{
+		{
+			name: "AF_UNIX zero length",
+			rsa: sockaddrUnixToAny(RawSockaddrUnix{
+				Family: AF_UNIX,
+			}),
+			err: EINVAL,
+		},
+		{
+			name: "AF_UNIX unnamed",
+			rsa: sockaddrUnixToAny(RawSockaddrUnix{
+				Len:    2, // family (uint16)
+				Family: AF_UNIX,
+			}),
+			sa: &SockaddrUnix{},
+		},
+		{
+			name: "AF_UNIX named",
+			rsa: sockaddrUnixToAny(RawSockaddrUnix{
+				Len:    uint8(2 + len("gopher")), // family (uint16) + len(gopher)
+				Family: AF_UNIX,
+				Path:   [104]int8{'g', 'o', 'p', 'h', 'e', 'r'},
+			}),
+			sa: &SockaddrUnix{
+				Name: "gopher",
+			},
+		},
+		{
+			name: "AF_UNIX named",
+			rsa: sockaddrUnixToAny(RawSockaddrUnix{
+				Len:    uint8(2 + len("go")),
+				Family: AF_UNIX,
+				Path:   [104]int8{'g', 'o', 'p', 'h', 'e', 'r'},
+			}),
+			sa: &SockaddrUnix{
+				Name: "go",
+			},
+		},
+		{
+			name: "AF_MAX EAFNOSUPPORT",
+			rsa: &RawSockaddrAny{
+				Addr: RawSockaddr{
+					Family: AF_MAX,
+				},
+			},
+			err: EAFNOSUPPORT,
+		},
+		// TODO: expand to support other families.
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			fd := int(0)
+			var err error
+			if tt.skt.domain != 0 {
+				fd, err = Socket(tt.skt.domain, tt.skt.typ, tt.skt.protocol)
+				// Some sockaddr types need specific kernel modules running: if these
+				// are not present we'll get EPROTONOSUPPORT back when trying to create
+				// the socket.  Skip the test in this situation.
+				if err == EPROTONOSUPPORT {
+					t.Skip("socket family/protocol not supported by kernel")
+				} else if err != nil {
+					t.Fatalf("socket(%v): %v", tt.skt, err)
+				}
+				defer Close(fd)
+			}
+			sa, err := anyToSockaddr(fd, tt.rsa)
+			if err != tt.err {
+				t.Fatalf("unexpected error: %v, want: %v", err, tt.err)
+			}
+
+			if !reflect.DeepEqual(sa, tt.sa) {
+				t.Fatalf("unexpected Sockaddr:\n got: %#v\nwant: %#v", sa, tt.sa)
+			}
+		})
+	}
+}
+
+func TestSockaddrUnix_sockaddr(t *testing.T) {
+	tests := []struct {
+		name string
+		sa   *SockaddrUnix
+		raw  *RawSockaddrUnix
+		err  error
+	}{
+		{
+			name: "unnamed",
+			sa:   &SockaddrUnix{},
+			raw: &RawSockaddrUnix{
+				Family: AF_UNIX,
+			},
+			err: EINVAL,
+		},
+		{
+			name: "named",
+			sa: &SockaddrUnix{
+				Name: "gopher",
+			},
+			raw: &RawSockaddrUnix{
+				Len:    uint8(2 + len("gopher") + 1), // family (uint16) + len(gopher) + '\0'
+				Family: AF_UNIX,
+				Path:   [104]int8{'g', 'o', 'p', 'h', 'e', 'r'},
+			},
+		},
+		{
+			name: "named too long",
+			sa: &SockaddrUnix{
+				Name: strings.Repeat("A", 104),
+			},
+			err: EINVAL,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			out, _, err := tt.sa.sockaddr()
+			if err != tt.err {
+				t.Fatalf("unexpected error: %v, want: %v", err, tt.err)
+			}
+
+			if out == nil {
+				// No pointer to cast, return early.
+				return
+			}
+
+			raw := (*RawSockaddrUnix)(out)
+			if !reflect.DeepEqual(raw, tt.raw) {
+				t.Fatalf("unexpected RawSockaddrUnix:\n got: %#v\nwant: %#v", raw, tt.raw)
+			}
+		})
+	}
+}
+
+func sockaddrUnixToAny(in RawSockaddrUnix) *RawSockaddrAny {
+	var out RawSockaddrAny
+
+	// Explicitly copy the contents of in into out to produce the correct
+	// sockaddr structure, without relying on unsafe casting to a type of a
+	// larger size.
+	copy(
+		(*(*[SizeofSockaddrAny]byte)(unsafe.Pointer(&out)))[:],
+		(*(*[SizeofSockaddrUnix]byte)(unsafe.Pointer(&in)))[:],
+	)
+
+	return &out
+}

unix/syscall_internal_linux_test.go

@@ -460,7 +460,6 @@ func TestSockaddrUnix_sockaddr(t *testing.T) {
 			}
 		})
 	}
-
 }
 
 // These helpers explicitly copy the contents of in into out to produce