unix: add GetPeerUcred and UcredGet for solaris

Change-Id: I74ba119fb729ef46899de04c686115f960975bb3
Reviewed-on: https://go-review.googlesource.com/c/sys/+/639755
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Matt Layher <mdlayher@gmail.com>

unix/syscall_solaris.go

@@ -1102,3 +1102,90 @@ func (s *Strioctl) SetInt(i int) {
 func IoctlSetStrioctlRetInt(fd int, req int, s *Strioctl) (int, error) {
 	return ioctlPtrRet(fd, req, unsafe.Pointer(s))
 }
+
+// Ucred Helpers
+// See ucred(3c) and getpeerucred(3c)
+
+//sys	getpeerucred(fd uintptr, ucred *uintptr) (err error)
+//sys	ucredFree(ucred uintptr) = ucred_free
+//sys	ucredGet(pid int) (ucred uintptr, err error) = ucred_get
+//sys	ucredGeteuid(ucred uintptr) (uid int) = ucred_geteuid
+//sys	ucredGetegid(ucred uintptr) (gid int) = ucred_getegid
+//sys	ucredGetruid(ucred uintptr) (uid int) = ucred_getruid
+//sys	ucredGetrgid(ucred uintptr) (gid int) = ucred_getrgid
+//sys	ucredGetsuid(ucred uintptr) (uid int) = ucred_getsuid
+//sys	ucredGetsgid(ucred uintptr) (gid int) = ucred_getsgid
+//sys	ucredGetpid(ucred uintptr) (pid int) = ucred_getpid
+
+// Ucred is an opaque struct that holds user credentials.
+type Ucred struct {
+	ucred uintptr
+}
+
+// We need to ensure that ucredFree is called on the underlying ucred
+// when the Ucred is garbage collected.
+func ucredFinalizer(u *Ucred) {
+	ucredFree(u.ucred)
+}
+
+func GetPeerUcred(fd uintptr) (*Ucred, error) {
+	var ucred uintptr
+	err := getpeerucred(fd, &ucred)
+	if err != nil {
+		return nil, err
+	}
+	result := &Ucred{
+		ucred: ucred,
+	}
+	// set the finalizer on the result so that the ucred will be freed
+	runtime.SetFinalizer(result, ucredFinalizer)
+	return result, nil
+}
+
+func UcredGet(pid int) (*Ucred, error) {
+	ucred, err := ucredGet(pid)
+	if err != nil {
+		return nil, err
+	}
+	result := &Ucred{
+		ucred: ucred,
+	}
+	// set the finalizer on the result so that the ucred will be freed
+	runtime.SetFinalizer(result, ucredFinalizer)
+	return result, nil
+}
+
+func (u *Ucred) Geteuid() int {
+	defer runtime.KeepAlive(u)
+	return ucredGeteuid(u.ucred)
+}
+
+func (u *Ucred) Getruid() int {
+	defer runtime.KeepAlive(u)
+	return ucredGetruid(u.ucred)
+}
+
+func (u *Ucred) Getsuid() int {
+	defer runtime.KeepAlive(u)
+	return ucredGetsuid(u.ucred)
+}
+
+func (u *Ucred) Getegid() int {
+	defer runtime.KeepAlive(u)
+	return ucredGetegid(u.ucred)
+}
+
+func (u *Ucred) Getrgid() int {
+	defer runtime.KeepAlive(u)
+	return ucredGetrgid(u.ucred)
+}
+
+func (u *Ucred) Getsgid() int {
+	defer runtime.KeepAlive(u)
+	return ucredGetsgid(u.ucred)
+}
+
+func (u *Ucred) Getpid() int {
+	defer runtime.KeepAlive(u)
+	return ucredGetpid(u.ucred)
+}

unix/syscall_solaris_test.go

@@ -8,6 +8,7 @@ package unix_test
 
 import (
 	"fmt"
+	"net"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -420,3 +421,66 @@ func TestLifreqGetMTU(t *testing.T) {
 		}
 	}
 }
+
+func TestUcredGet(t *testing.T) {
+	euid := unix.Geteuid()
+	creds, err := unix.UcredGet(unix.Getpid())
+	if err != nil {
+		t.Fatalf("unix.UcredGet failed: %v", err)
+	}
+	if euid != creds.Geteuid() {
+		t.Fatalf("mismatched euid")
+	}
+}
+
+func TestGetPeerUcred(t *testing.T) {
+	d := t.TempDir()
+	path := filepath.Join(d, "foo.sock")
+	sock, err := net.Listen("unix", path)
+	if err != nil {
+		t.Fatalf("net.Listen: %v", err)
+	}
+	defer sock.Close()
+
+	c1, err := net.Dial("unix", path)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	defer c1.Close()
+
+	c2, err := sock.Accept()
+	if err != nil {
+		t.Fatalf("Accept: %v", err)
+	}
+	defer c2.Close()
+
+	switch unixconn := c2.(type) {
+	case *net.UnixConn:
+		raw, err := unixconn.SyscallConn()
+		if err != nil {
+			t.Fatalf("SyscallConn failed: %v", err)
+		}
+
+		var creds *unix.Ucred
+		cerr := raw.Control(func(fd uintptr) {
+			creds, err = unix.GetPeerUcred(fd)
+			if err != nil {
+				err = fmt.Errorf("unix.GetPeerUcred: %w", err)
+				return
+			}
+		})
+		if cerr != nil {
+			t.Fatalf("raw.Control failed: %v", err)
+		}
+		if creds == nil {
+			t.Fatalf("Got a nil Ucred response")
+		}
+		euid := unix.Geteuid()
+		if euid != creds.Geteuid() {
+			t.Fatalf("mismatched euid")
+		}
+	default:
+		t.Fatalf("Somehow didn't get a UnixConn")
+	}
+}

unix/zsyscall_solaris_amd64.go

@@ -141,6 +141,16 @@ import (
 //go:cgo_import_dynamic libc_getpeername getpeername "libsocket.so"
 //go:cgo_import_dynamic libc_setsockopt setsockopt "libsocket.so"
 //go:cgo_import_dynamic libc_recvfrom recvfrom "libsocket.so"
+//go:cgo_import_dynamic libc_getpeerucred getpeerucred "libc.so"
+//go:cgo_import_dynamic libc_ucred_get ucred_get "libc.so"
+//go:cgo_import_dynamic libc_ucred_geteuid ucred_geteuid "libc.so"
+//go:cgo_import_dynamic libc_ucred_getegid ucred_getegid "libc.so"
+//go:cgo_import_dynamic libc_ucred_getruid ucred_getruid "libc.so"
+//go:cgo_import_dynamic libc_ucred_getrgid ucred_getrgid "libc.so"
+//go:cgo_import_dynamic libc_ucred_getsuid ucred_getsuid "libc.so"
+//go:cgo_import_dynamic libc_ucred_getsgid ucred_getsgid "libc.so"
+//go:cgo_import_dynamic libc_ucred_getpid ucred_getpid "libc.so"
+//go:cgo_import_dynamic libc_ucred_free ucred_free "libc.so"
 //go:cgo_import_dynamic libc_port_create port_create "libc.so"
 //go:cgo_import_dynamic libc_port_associate port_associate "libc.so"
 //go:cgo_import_dynamic libc_port_dissociate port_dissociate "libc.so"
@@ -280,6 +290,16 @@ import (
 //go:linkname procgetpeername libc_getpeername
 //go:linkname procsetsockopt libc_setsockopt
 //go:linkname procrecvfrom libc_recvfrom
+//go:linkname procgetpeerucred libc_getpeerucred
+//go:linkname procucred_get libc_ucred_get
+//go:linkname procucred_geteuid libc_ucred_geteuid
+//go:linkname procucred_getegid libc_ucred_getegid
+//go:linkname procucred_getruid libc_ucred_getruid
+//go:linkname procucred_getrgid libc_ucred_getrgid
+//go:linkname procucred_getsuid libc_ucred_getsuid
+//go:linkname procucred_getsgid libc_ucred_getsgid
+//go:linkname procucred_getpid libc_ucred_getpid
+//go:linkname procucred_free libc_ucred_free
 //go:linkname procport_create libc_port_create
 //go:linkname procport_associate libc_port_associate
 //go:linkname procport_dissociate libc_port_dissociate
@@ -420,6 +440,16 @@ var (
 	procgetpeername,
 	procsetsockopt,
 	procrecvfrom,
+	procgetpeerucred,
+	procucred_get,
+	procucred_geteuid,
+	procucred_getegid,
+	procucred_getruid,
+	procucred_getrgid,
+	procucred_getsuid,
+	procucred_getsgid,
+	procucred_getpid,
+	procucred_free,
 	procport_create,
 	procport_associate,
 	procport_dissociate,
@@ -2029,6 +2059,90 @@ func recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Sockl
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func getpeerucred(fd uintptr, ucred *uintptr) (err error) {
+	_, _, e1 := sysvicall6(uintptr(unsafe.Pointer(&procgetpeerucred)), 2, uintptr(fd), uintptr(unsafe.Pointer(ucred)), 0, 0, 0, 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func ucredGet(pid int) (ucred uintptr, err error) {
+	r0, _, e1 := sysvicall6(uintptr(unsafe.Pointer(&procucred_get)), 1, uintptr(pid), 0, 0, 0, 0, 0)
+	ucred = uintptr(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func ucredGeteuid(ucred uintptr) (uid int) {
+	r0, _, _ := sysvicall6(uintptr(unsafe.Pointer(&procucred_geteuid)), 1, uintptr(ucred), 0, 0, 0, 0, 0)
+	uid = int(r0)
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func ucredGetegid(ucred uintptr) (gid int) {
+	r0, _, _ := sysvicall6(uintptr(unsafe.Pointer(&procucred_getegid)), 1, uintptr(ucred), 0, 0, 0, 0, 0)
+	gid = int(r0)
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func ucredGetruid(ucred uintptr) (uid int) {
+	r0, _, _ := sysvicall6(uintptr(unsafe.Pointer(&procucred_getruid)), 1, uintptr(ucred), 0, 0, 0, 0, 0)
+	uid = int(r0)
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func ucredGetrgid(ucred uintptr) (gid int) {
+	r0, _, _ := sysvicall6(uintptr(unsafe.Pointer(&procucred_getrgid)), 1, uintptr(ucred), 0, 0, 0, 0, 0)
+	gid = int(r0)
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func ucredGetsuid(ucred uintptr) (uid int) {
+	r0, _, _ := sysvicall6(uintptr(unsafe.Pointer(&procucred_getsuid)), 1, uintptr(ucred), 0, 0, 0, 0, 0)
+	uid = int(r0)
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func ucredGetsgid(ucred uintptr) (gid int) {
+	r0, _, _ := sysvicall6(uintptr(unsafe.Pointer(&procucred_getsgid)), 1, uintptr(ucred), 0, 0, 0, 0, 0)
+	gid = int(r0)
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func ucredGetpid(ucred uintptr) (pid int) {
+	r0, _, _ := sysvicall6(uintptr(unsafe.Pointer(&procucred_getpid)), 1, uintptr(ucred), 0, 0, 0, 0, 0)
+	pid = int(r0)
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func ucredFree(ucred uintptr) {
+	sysvicall6(uintptr(unsafe.Pointer(&procucred_free)), 1, uintptr(ucred), 0, 0, 0, 0, 0)
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func port_create() (n int, err error) {
 	r0, _, e1 := sysvicall6(uintptr(unsafe.Pointer(&procport_create)), 0, 0, 0, 0, 0, 0, 0)
 	n = int(r0)