Merge pull request #3 from DentonGentry/main

Add FreeBSD support

go.mod

@@ -2,4 +2,4 @@ module inet.af/peercred
 
 go 1.14
 
-require golang.org/x/sys v0.0.0-20210216224549-f992740a1bac
+require golang.org/x/sys v0.0.0-20210301091718-77cc2087c03b

go.sum

@@ -2,3 +2,5 @@ golang.org/x/sys v0.0.0-20210216163648-f7da38b97c65 h1:pTMjDVnP5eVRRlWO76rEWJ8Jo
 golang.org/x/sys v0.0.0-20210216163648-f7da38b97c65/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210216224549-f992740a1bac h1:9glrpwtNjBYgRpb67AZJKHfzj1stG/8BL5H7In2oTC4=
 golang.org/x/sys v0.0.0-20210216224549-f992740a1bac/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210301091718-77cc2087c03b h1:kHlr0tATeLRMEiZJu5CknOw/E8V6h69sXXQFGoPtjcc=
+golang.org/x/sys v0.0.0-20210301091718-77cc2087c03b/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=

peercred_darwin.go

@@ -13,10 +13,10 @@ import (
 )
 
 func init() {
-	osGet = getLinux
+	osGet = getDarwin
 }
 
-func getLinux(c net.Conn) (*Creds, error) {
+func getDarwin(c net.Conn) (*Creds, error) {
 	switch c := c.(type) {
 	case *net.UnixConn:
 		return getUnix(c)

peercred_freebsd.go

@@ -0,0 +1,55 @@
+// Copyright (c) 2021 AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package peercred
+
+import (
+	"fmt"
+	"net"
+	"strconv"
+
+	"golang.org/x/sys/unix"
+)
+
+func init() {
+	osGet = getFreeBSD
+}
+
+func getFreeBSD(c net.Conn) (*Creds, error) {
+	switch c := c.(type) {
+	case *net.UnixConn:
+		return getUnix(c)
+	case *net.TCPConn:
+		// TODO: use sysctl net.inet.tcp.pcblist for localhost connections like Windows?
+	}
+	return nil, ErrUnsupportedConnType
+}
+
+func getUnix(c *net.UnixConn) (*Creds, error) {
+	raw, err := c.SyscallConn()
+	if err != nil {
+		return nil, fmt.Errorf("SyscallConn: %w", err)
+	}
+
+	var cred *unix.Xucred
+	cerr := raw.Control(func(fd uintptr) {
+		cred, err = unix.GetsockoptXucred(int(fd),
+			unix.SOL_LOCAL,
+			unix.LOCAL_PEERCRED)
+		if err != nil {
+			err = fmt.Errorf("unix.GetsockoptXucred: %w", err)
+			return
+		}
+	})
+	if cerr != nil {
+		return nil, fmt.Errorf("raw.Control: %w", err)
+	}
+	if err != nil {
+		return nil, err
+	}
+	return &Creds{
+		pid: 0, // FreeBSD 13 adds a cr_pid field, can be used here.
+		uid: strconv.FormatUint(uint64(cred.Uid), 10),
+	}, nil
+}

peercred_unix_test.go

@@ -3,7 +3,7 @@
 // license that can be found in the LICENSE file.
 
 // +build go1.15
-// +build linux darwin
+// +build linux darwin freebsd
 
 package peercred // import "inet.af/peercred"
 
@@ -12,6 +12,7 @@ import (
 	"net"
 	"os"
 	"path/filepath"
+	"runtime"
 	"testing"
 )
 
@@ -59,11 +60,16 @@ func TestUnixSock(t *testing.T) {
 		t.Errorf("UID = %q; want %q", got, want)
 	}
 	pid, ok := creds.PID()
-	if !ok {
-		t.Errorf("no PID")
+	if runtime.GOOS == "freebsd" {
+		if ok {
+			t.Error("PID ok; want !ok. Thank you for fixing FreeBSD, please update the test.")
+		}
+	} else {
+		if !ok {
+			t.Errorf("no PID")
+		}
+		if got, want := pid, os.Getpid(); got != want {
+			t.Errorf("PID = %v; want %v", got, want)
+		}
 	}
-	if got, want := pid, os.Getpid(); got != want {
-		t.Errorf("PID = %v; want %v", got, want)
-	}
-
 }