Files
ARTEX-chixuweihu/intercept/python_modules.go
T

308 lines
9.2 KiB
Go

package intercept
import (
"fmt"
"io"
"os"
"os/exec"
"path/filepath"
"regexp"
"strings"
"mvdan.cc/sh/v3/syntax"
)
var pythonVersionName = regexp.MustCompile(`^python([0-9]+\.[0-9]+)(?:[a-z]*)$`)
var pythonModuleName = regexp.MustCompile(`^[A-Za-z_][A-Za-z_0-9]*(?:\.[A-Za-z_][A-Za-z_0-9]*)*$`)
// Find module entry sources from the interpreter's filesystem layout. Never
// execute Python, import the requested module, or run site/startup hooks.
func pythonModuleReferences(name, module, dir string, args, wrapperArgs []*syntax.Word, call *syntax.CallExpr, generated map[string]scriptReference, constants map[string]shellConstant) []scriptReference {
problem := func(message string) []scriptReference { return []scriptReference{{problem: message}} }
if !pythonModuleName.MatchString(module) {
return problem("Python 模块名称无法静态解析")
}
env := map[string]string{}
for _, key := range []string{"PATH", "PYTHONPATH", "PYTHONHOME", "PYTHONUSERBASE", "HOME", "PYTHONSAFEPATH"} {
env[key] = os.Getenv(key)
}
valueOf := func(word *syntax.Word) (string, bool) {
if value, known := staticWord(word); known {
return value, true
}
fields, known := constantWordFields(word, constants)
if known && len(fields) == 1 {
return fields[0], true
}
return "", false
}
for _, assign := range call.Assigns {
if assign.Name == nil {
continue
}
if _, relevant := env[assign.Name.Value]; !relevant {
continue
}
value, known := valueOf(assign.Value)
if assign.Value == nil {
value, known = "", true
}
if !known {
return problem("Python 模块搜索路径包含未知环境展开")
}
env[assign.Name.Value] = value
}
for _, word := range wrapperArgs {
value, known := valueOf(word)
if !known {
continue
}
// These wrappers can change PATH/HOME or discard/unset inherited
// Python search settings. Do not resolve against the parent process
// environment when the child's environment is not modeled.
switch value {
case "sudo", "-i", "--ignore-environment", "-u", "--unset", "-c", "-p":
return problem("包装命令改变 Python 模块运行环境,无法确认源码入口")
}
if strings.HasPrefix(value, "--unset=") || filepath.Base(value) == "sudo" {
return problem("包装命令改变 Python 模块运行环境,无法确认源码入口")
}
key, value, assignment := strings.Cut(value, "=")
if assignment {
if _, relevant := env[key]; relevant {
env[key] = value
}
}
}
isolated, ignoreEnv, safePath, noSite, noUser := false, false, false, false, false
for i := 1; i < len(args); i++ {
value, known := staticWord(args[i])
if !known || value == "-m" {
break
}
if !strings.HasPrefix(value, "-") || strings.HasPrefix(value, "--") {
continue
}
flags := strings.TrimPrefix(value, "-")
flagsLoop:
for j := 0; j < len(flags); j++ {
switch flags[j] {
case 'I':
isolated = true
case 'E':
ignoreEnv = true
case 'P':
safePath = true
case 'S':
noSite = true
case 's':
noUser = true
case 'W', 'X':
if j == len(flags)-1 {
i++
}
break flagsLoop
}
}
}
ignoreEnv = ignoreEnv || isolated
safePath = safePath || isolated || (!ignoreEnv && env["PYTHONSAFEPATH"] != "")
if !safePath && dir == "" {
return problem("执行目录不确定,无法确认实际 Python 模块")
}
executable := name
if !strings.Contains(name, "/") {
if env["PATH"] == os.Getenv("PATH") {
var err error
executable, err = exec.LookPath(name)
if err != nil {
return problem("无法定位 Python 解释器及模块源码")
}
} else {
executable = ""
for _, entry := range filepath.SplitList(env["PATH"]) {
if !filepath.IsAbs(entry) {
if dir == "" {
return problem("Python 解释器搜索路径依赖未知目录")
}
entry = filepath.Join(dir, entry)
}
candidate := filepath.Join(entry, name)
if info, err := os.Stat(candidate); err == nil && info.Mode().IsRegular() && info.Mode()&0111 != 0 {
executable = candidate
break
}
}
if executable == "" {
return problem("无法定位 Python 解释器及模块源码")
}
}
} else if !filepath.IsAbs(executable) {
if dir == "" {
return problem("Python 解释器路径依赖未知目录")
}
executable = filepath.Join(dir, executable)
}
resolved, err := filepath.EvalSymlinks(executable)
if err != nil {
return problem("无法读取 Python 解释器路径")
}
if !nativeInterpreterFile(resolved) {
return problem("Python 入口不是可确定的本机解释器,无法静态定位模块")
}
version := pythonVersionName.FindStringSubmatch(filepath.Base(resolved))
if len(version) != 2 {
version = pythonVersionName.FindStringSubmatch(filepath.Base(executable))
}
if len(version) != 2 {
return problem("无法静态确定 Python 版本和模块目录")
}
prefix := filepath.Dir(filepath.Dir(executable))
base := filepath.Dir(filepath.Dir(resolved))
library := filepath.Join(base, "lib", "python"+version[1])
if !ignoreEnv && (env["PYTHONHOME"] != "" || env["PYTHONUSERBASE"] != "") {
return problem("Python 自定义库目录未提供可确定的模块来源")
}
roots := []string{}
seen := map[string]bool{}
addRoot := func(root string) {
root = filepath.Clean(root)
if !seen[root] {
roots = append(roots, root)
seen[root] = true
}
}
if !safePath {
addRoot(dir)
}
if !ignoreEnv {
for _, root := range filepath.SplitList(env["PYTHONPATH"]) {
if root == "" {
continue
}
if !filepath.IsAbs(root) {
if dir == "" {
return problem("Python 模块搜索路径依赖未知目录")
}
root = filepath.Join(dir, root)
}
addRoot(root)
}
}
addRoot(library)
venv := false
includeSystem := true
if config, err := readScript(filepath.Join(prefix, "pyvenv.cfg")); err == nil {
venv = true
includeSystem = false
for _, line := range strings.Split(string(config), "\n") {
key, value, ok := strings.Cut(line, "=")
if ok && strings.TrimSpace(key) == "include-system-site-packages" {
includeSystem = strings.TrimSpace(value) == "true"
}
}
}
if !noSite {
if !isolated && !noUser && (!venv || includeSystem) && env["HOME"] != "" {
addRoot(filepath.Join(env["HOME"], ".local", "lib", "python"+version[1], "site-packages"))
}
if venv {
addRoot(filepath.Join(prefix, "lib", "python"+version[1], "site-packages"))
}
if !venv || includeSystem {
addRoot(filepath.Join(library, "site-packages"))
// Debian's system interpreter adds dist-packages; a /usr/local Python
// does not inherit those paths merely because they exist.
if site, err := readScript(filepath.Join(library, "site.py")); err == nil && strings.Contains(string(site), "dist-packages") {
addRoot(filepath.Join("/usr/local/lib", "python"+version[1], "dist-packages"))
addRoot(filepath.Join(base, "lib", "python3", "dist-packages"))
addRoot(filepath.Join(library, "dist-packages"))
}
}
}
refs, err := moduleEntryReferences(module, roots, generated)
if err != nil {
return problem(err.Error())
}
return refs
}
func moduleEntryReferences(module string, roots []string, generated map[string]scriptReference) ([]scriptReference, error) {
exists := func(path string) bool {
if _, ok := generated[path]; ok {
return true
}
info, err := os.Stat(path)
return err == nil && info.Mode().IsRegular()
}
reference := func(path string) scriptReference {
if ref, ok := generated[path]; ok {
return ref
}
return scriptReference{path: path}
}
parts := strings.Split(module, ".")
for _, root := range roots {
var refs []scriptReference
dir := root
matched := true
for i, part := range parts {
packageDir := filepath.Join(dir, part)
init := filepath.Join(packageDir, "__init__.py")
if exists(init) {
refs = append(refs, reference(init))
dir = packageDir
if i == len(parts)-1 {
main := filepath.Join(dir, "__main__.py")
if !exists(main) {
return nil, fmt.Errorf("Python 模块 %s 缺少可读取的 __main__.py", module)
}
refs = append(refs, reference(main))
return refs, nil
}
continue
}
source := filepath.Join(dir, part+".py")
if exists(source) {
if i != len(parts)-1 {
return nil, fmt.Errorf("Python 模块 %s 的父模块不是可读取的包", module)
}
refs = append(refs, reference(source))
return refs, nil
}
// A regular parent package shadows later search roots even when the
// requested child is absent; do not substitute an unrelated module.
if len(refs) > 0 {
return nil, fmt.Errorf("无法定位 Python 模块 %s 的源码", module)
}
matched = false
break
}
if matched {
return refs, nil
}
}
return nil, fmt.Errorf("无法定位 Python 模块 %s 的源码", module)
}
func nativeInterpreterFile(path string) bool {
info, err := os.Stat(path)
if err != nil || !info.Mode().IsRegular() {
return false
}
file, err := os.Open(path)
if err != nil {
return false
}
defer file.Close()
header := make([]byte, 4)
if _, err := io.ReadFull(file, header); err != nil {
return false
}
switch string(header) {
case "\x7fELF", "\xfe\xed\xfa\xce", "\xfe\xed\xfa\xcf", "\xce\xfa\xed\xfe", "\xcf\xfa\xed\xfe", "\xca\xfe\xba\xbe", "\xbe\xba\xfe\xca":
return true
}
return header[0] == 'M' && header[1] == 'Z'
}