Revert "Add path interposer"

This reverts commit a14704c12b.

Reason for revert: breaking builds

Change-Id: I920b0ff41823428a0baf59b3fd82cbcc766babca

cmd/path_interposer/main.go

@@ -1,229 +0,0 @@
-// Copyright 2018 Google Inc. All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package main
-
-import (
-	"bytes"
-	"fmt"
-	"io"
-	"io/ioutil"
-	"os"
-	"os/exec"
-	"path/filepath"
-	"strconv"
-	"syscall"
-
-	"android/soong/ui/build/paths"
-)
-
-func main() {
-	interposer, err := os.Executable()
-	if err != nil {
-		fmt.Fprintln(os.Stderr, "Unable to locate interposer executable:", err)
-		os.Exit(1)
-	}
-
-	disableError := false
-	if e, ok := os.LookupEnv("TEMPORARY_DISABLE_PATH_RESTRICTIONS"); ok {
-		disableError = e == "1" || e == "y" || e == "yes" || e == "on" || e == "true"
-	}
-
-	exitCode, err := Main(os.Stdout, os.Stderr, interposer, os.Args, mainOpts{
-		disableError: disableError,
-
-		sendLog:       paths.SendLog,
-		config:        paths.GetConfig,
-		lookupParents: lookupParents,
-	})
-	if err != nil {
-		fmt.Fprintln(os.Stderr, err.Error())
-	}
-	os.Exit(exitCode)
-}
-
-var usage = fmt.Errorf(`To use the PATH interposer:
- * Write the original PATH variable to <interposer>_origpath
- * Set up a directory of symlinks to the PATH interposer, and use that in PATH
-
-If a tool isn't in the allowed list, a log will be posted to the unix domain
-socket at <interposer>_log.`)
-
-type mainOpts struct {
-	disableError bool
-
-	sendLog       func(logSocket string, entry *paths.LogEntry, done chan interface{})
-	config        func(name string) paths.PathConfig
-	lookupParents func() []paths.LogProcess
-}
-
-func Main(stdout, stderr io.Writer, interposer string, args []string, opts mainOpts) (int, error) {
-	base := filepath.Base(args[0])
-
-	origPathFile := interposer + "_origpath"
-	if base == filepath.Base(interposer) {
-		return 1, usage
-	}
-
-	origPath, err := ioutil.ReadFile(origPathFile)
-	if err != nil {
-		if os.IsNotExist(err) {
-			return 1, usage
-		} else {
-			return 1, fmt.Errorf("Failed to read original PATH: %v", err)
-		}
-	}
-
-	cmd := &exec.Cmd{
-		Args: args,
-		Env:  os.Environ(),
-
-		Stdin:  os.Stdin,
-		Stdout: stdout,
-		Stderr: stderr,
-	}
-
-	if err := os.Setenv("PATH", string(origPath)); err != nil {
-		return 1, fmt.Errorf("Failed to set PATH env: %v", err)
-	}
-
-	if config := opts.config(base); config.Log || config.Error {
-		var procs []paths.LogProcess
-		if opts.lookupParents != nil {
-			procs = opts.lookupParents()
-		}
-
-		if opts.sendLog != nil {
-			waitForLog := make(chan interface{})
-			opts.sendLog(interposer+"_log", &paths.LogEntry{
-				Basename: base,
-				Args:     args,
-				Parents:  procs,
-			}, waitForLog)
-			defer func() { <-waitForLog }()
-		}
-		if config.Error && !opts.disableError {
-			return 1, fmt.Errorf("%q is not allowed to be used. See https://android.googlesource.com/platform/build/+/master/Changes.md#PATH_Tools for more information.", base)
-		}
-	}
-
-	cmd.Path, err = exec.LookPath(base)
-	if err != nil {
-		return 1, err
-	}
-
-	if err = cmd.Run(); err != nil {
-		if exitErr, ok := err.(*exec.ExitError); ok {
-			if status, ok := exitErr.Sys().(syscall.WaitStatus); ok {
-				if status.Exited() {
-					return status.ExitStatus(), nil
-				} else if status.Signaled() {
-					exitCode := 128 + int(status.Signal())
-					return exitCode, nil
-				} else {
-					return 1, exitErr
-				}
-			} else {
-				return 1, nil
-			}
-		}
-	}
-
-	return 0, nil
-}
-
-type procEntry struct {
-	Pid     int
-	Ppid    int
-	Command string
-}
-
-func readProcs() map[int]procEntry {
-	cmd := exec.Command("ps", "-o", "pid,ppid,command")
-	data, err := cmd.Output()
-	if err != nil {
-		return nil
-	}
-
-	return parseProcs(data)
-}
-
-func parseProcs(data []byte) map[int]procEntry {
-	lines := bytes.Split(data, []byte("\n"))
-	if len(lines) < 2 {
-		return nil
-	}
-	// Remove the header
-	lines = lines[1:]
-
-	ret := make(map[int]procEntry, len(lines))
-	for _, line := range lines {
-		fields := bytes.SplitN(line, []byte(" "), 2)
-		if len(fields) != 2 {
-			continue
-		}
-
-		pid, err := strconv.Atoi(string(fields[0]))
-		if err != nil {
-			continue
-		}
-
-		line = bytes.TrimLeft(fields[1], " ")
-
-		fields = bytes.SplitN(line, []byte(" "), 2)
-		if len(fields) != 2 {
-			continue
-		}
-
-		ppid, err := strconv.Atoi(string(fields[0]))
-		if err != nil {
-			continue
-		}
-
-		ret[pid] = procEntry{
-			Pid:     pid,
-			Ppid:    ppid,
-			Command: string(bytes.TrimLeft(fields[1], " ")),
-		}
-	}
-
-	return ret
-}
-
-func lookupParents() []paths.LogProcess {
-	procs := readProcs()
-	if procs == nil {
-		return nil
-	}
-
-	list := []paths.LogProcess{}
-	pid := os.Getpid()
-	for {
-		entry, ok := procs[pid]
-		if !ok {
-			break
-		}
-
-		list = append([]paths.LogProcess{
-			{
-				Pid:     pid,
-				Command: entry.Command,
-			},
-		}, list...)
-
-		pid = entry.Ppid
-	}
-
-	return list
-}