Move Linux client & common packages into a public repo.

portlist/portlist_darwin.go

@@ -0,0 +1,99 @@
+// Copyright (c) 2020 Tailscale Inc & 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 !linux,!windows
+
+package portlist
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"log"
+	"os"
+	"strings"
+
+	exec "tailscale.com/tempfork/osexec"
+)
+
+// We have to run netstat, which is a bit expensive, so don't do it too often.
+const POLL_SECONDS = 5
+
+func listPorts() (List, error) {
+	return listPortsNetstat("-na")
+}
+
+// In theory, lsof could replace the function of both listPorts() and
+// addProcesses(), since it provides a superset of the netstat output.
+// However, "netstat -na" runs ~100x faster than lsof on my machine, so
+// we should do it only if the list of open ports has actually changed.
+//
+// TODO(apenwarr): this fails in a macOS sandbox (ie. our usual case).
+// We might as well just delete this code if we can't find a solution.
+func addProcesses(pl []Port) ([]Port, error) {
+	exe, err := exec.LookPath("lsof")
+	if err != nil {
+		return nil, fmt.Errorf("lsof: lookup: %v", err)
+	}
+	c := exec.Cmd{
+		Path: exe,
+		Args: []string{exe, "-F", "-n", "-P", "-O", "-S2", "-T", "-i4", "-i6"},
+	}
+	output, err := c.Output()
+	if err != nil {
+		xe, ok := err.(*exec.ExitError)
+		stderr := ""
+		if ok {
+			stderr = strings.TrimSpace(string(xe.Stderr))
+		}
+		// fails when run in a macOS sandbox, so make this non-fatal.
+		log.Printf("portlist: lsof: %v (%q)\n", err, stderr)
+		return pl, nil
+	}
+
+	type ProtoPort struct {
+		proto string
+		port  uint16
+	}
+	m := map[ProtoPort]*Port{}
+	for i := range pl {
+		pp := ProtoPort{pl[i].Proto, pl[i].Port}
+		m[pp] = &pl[i]
+	}
+
+	r := bytes.NewReader(output)
+	scanner := bufio.NewScanner(r)
+
+	var cmd, proto string
+	for scanner.Scan() {
+		line := scanner.Text()
+		if line[0] == 'p' {
+			// starting a new process
+			cmd = ""
+			proto = ""
+		} else if line[0] == 'c' {
+			cmd = line[1:len(line)]
+		} else if line[0] == 'P' {
+			proto = strings.ToLower(line[1:len(line)])
+		} else if line[0] == 'n' {
+			rest := line[1:len(line)]
+			i := strings.Index(rest, "->")
+			if i < 0 {
+				// a listening port
+				port := parsePort(rest)
+				if port > 0 {
+					pp := ProtoPort{proto, uint16(port)}
+					p := m[pp]
+					if p != nil {
+						p.Process = cmd
+					} else {
+						fmt.Fprintf(os.Stderr, "weird: missing %v\n", pp)
+					}
+				}
+			}
+		}
+	}
+
+	return pl, nil
+}