windows: add command line escaping wrappers around EscapeArg and CommandLineToArgv
DecomposeCommandLine makes CommandLineToArgv usable in an ordinary way.
There's actually a pure-Go version of this available as the private
os.commandLineToArgv function, which we could copy, but given this is
x/sys/windows, it seems best to stick to the actual Windows primitives
which will always remain current. Then, ComposeCommandLine is just a
simple wrapper around EscapeArg (which has no native win32 substitute).
Change-Id: Ia2c7ca2ded9e5713b281dade34639dfeacf1171c
Reviewed-on: https://go-review.googlesource.com/c/sys/+/319229
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Trust: Alex Brainman <alex.brainman@gmail.com>
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
diff --git a/windows/exec_windows.go b/windows/exec_windows.go
index 9eb1fb6..a020cae 100644
--- a/windows/exec_windows.go
+++ b/windows/exec_windows.go
@@ -78,6 +78,40 @@
return string(qs[:j])
}
+// ComposeCommandLine escapes and joins the given arguments suitable for use as a Windows command line,
+// in CreateProcess's CommandLine argument, CreateService/ChangeServiceConfig's BinaryPathName argument,
+// or any program that uses CommandLineToArgv.
+func ComposeCommandLine(args []string) string {
+ var commandLine string
+ for i := range args {
+ if i > 0 {
+ commandLine += " "
+ }
+ commandLine += EscapeArg(args[i])
+ }
+ return commandLine
+}
+
+// DecomposeCommandLine breaks apart its argument command line into unescaped parts using CommandLineToArgv,
+// as gathered from GetCommandLine, QUERY_SERVICE_CONFIG's BinaryPathName argument, or elsewhere that
+// command lines are passed around.
+func DecomposeCommandLine(commandLine string) ([]string, error) {
+ if len(commandLine) == 0 {
+ return []string{}, nil
+ }
+ var argc int32
+ argv, err := CommandLineToArgv(StringToUTF16Ptr(commandLine), &argc)
+ if err != nil {
+ return nil, err
+ }
+ defer LocalFree(Handle(unsafe.Pointer(argv)))
+ var args []string
+ for _, v := range (*argv)[:argc] {
+ args = append(args, UTF16ToString((*v)[:]))
+ }
+ return args, nil
+}
+
func CloseOnExec(fd Handle) {
SetHandleInformation(Handle(fd), HANDLE_FLAG_INHERIT, 0)
}
diff --git a/windows/syscall_windows_test.go b/windows/syscall_windows_test.go
index 0f17fb1..d6571b7 100644
--- a/windows/syscall_windows_test.go
+++ b/windows/syscall_windows_test.go
@@ -10,6 +10,7 @@
"errors"
"fmt"
"io/ioutil"
+ "math/rand"
"os"
"path/filepath"
"runtime"
@@ -599,3 +600,61 @@
t.Errorf("did not find </assembly> in manifest")
}
}
+
+func TestCommandLineRecomposition(t *testing.T) {
+ const (
+ maxCharsPerArg = 35
+ maxArgsPerTrial = 80
+ doubleQuoteProb = 4
+ singleQuoteProb = 1
+ backSlashProb = 3
+ spaceProb = 1
+ trials = 1000
+ )
+ randString := func(l int) []rune {
+ s := make([]rune, l)
+ for i := range s {
+ s[i] = rand.Int31()
+ }
+ return s
+ }
+ mungeString := func(s []rune, char rune, timesInTen int) {
+ if timesInTen < rand.Intn(10)+1 || len(s) == 0 {
+ return
+ }
+ s[rand.Intn(len(s))] = char
+ }
+ argStorage := make([]string, maxArgsPerTrial+1)
+ for i := 0; i < trials; i++ {
+ args := argStorage[:rand.Intn(maxArgsPerTrial)+2]
+ args[0] = "valid-filename-for-arg0"
+ for j := 1; j < len(args); j++ {
+ arg := randString(rand.Intn(maxCharsPerArg + 1))
+ mungeString(arg, '"', doubleQuoteProb)
+ mungeString(arg, '\'', singleQuoteProb)
+ mungeString(arg, '\\', backSlashProb)
+ mungeString(arg, ' ', spaceProb)
+ args[j] = string(arg)
+ }
+ commandLine := windows.ComposeCommandLine(args)
+ decomposedArgs, err := windows.DecomposeCommandLine(commandLine)
+ if err != nil {
+ t.Errorf("Unable to decompose %#q made from %v: %v", commandLine, args, err)
+ continue
+ }
+ if len(decomposedArgs) != len(args) {
+ t.Errorf("Incorrect decomposition length from %v to %#q to %v", args, commandLine, decomposedArgs)
+ continue
+ }
+ badMatches := make([]int, 0, len(args))
+ for i := range args {
+ if args[i] != decomposedArgs[i] {
+ badMatches = append(badMatches, i)
+ }
+ }
+ if len(badMatches) != 0 {
+ t.Errorf("Incorrect decomposition at indices %v from %v to %#q to %v", badMatches, args, commandLine, decomposedArgs)
+ continue
+ }
+ }
+}
