Add support for solaris

go.mod

@@ -2,4 +2,4 @@ module github.com/tailscale/peercred
 
 go 1.18
 
-require golang.org/x/sys v0.0.0-20210301091718-77cc2087c03b
+require golang.org/x/sys v0.29.1-0.20250107080300-1c14dcadc3ab

go.sum

@@ -1,2 +1,2 @@
-golang.org/x/sys v0.0.0-20210301091718-77cc2087c03b h1:kHlr0tATeLRMEiZJu5CknOw/E8V6h69sXXQFGoPtjcc=
+golang.org/x/sys v0.29.1-0.20250107080300-1c14dcadc3ab h1:BMkEEWYOjkvOX7+YKOGbp6jCyQ5pR2j0Ah47p1Vdsx4=
-golang.org/x/sys v0.0.0-20210301091718-77cc2087c03b/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.29.1-0.20250107080300-1c14dcadc3ab/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=

peercred_solaris.go

@@ -0,0 +1,53 @@
+// 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 = getSolaris
+}
+
+func getSolaris(c net.Conn) (*Creds, error) {
+	switch c := c.(type) {
+	case *net.UnixConn:
+		return getUnix(c)
+	case *net.TCPConn:
+		// TODO: Need ideas
+	}
+	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 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 {
+		return nil, fmt.Errorf("raw.Control: %w", cerr)
+	}
+	if err != nil {
+		return nil, err
+	}
+	return &Creds{
+		pid: creds.Getpid(),
+		uid: strconv.FormatUint(uint64(creds.Geteuid()), 10),
+	}, nil
+}

peercred_unix_test.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.15 && (linux || darwin || freebsd)
+//go:build go1.15 && (linux || darwin || freebsd || illumos || solaris)
 
 package peercred