win32: retry when command needs elevated privileges

Some installer programs have an entry in their manifest to indicate
that they need elevated privileges.  The shell in busybox-w32 was
unable to run such programs.

When a program fails to run with ERROR_ELEVATION_REQUIRED, try
again using ShellExecuteEx() with the 'runas' verb to give it
elevated privileges.

Adds 272-288 bytes.

(GitHub issue #481)

1 files changed, 6 insertions, 12 deletions

diff --git a/loginutils/suw32.c b/loginutils/suw32.c
index b3976dcfd..77c038582 100644
--- a/loginutils/suw32.c
+++ b/loginutils/suw32.c
@@ -48,8 +48,8 @@ int suw32_main(int argc UNUSED_PARAM, char **argv)
         char *opt_command = NULL;
         char *opt_shell = NULL;
         SHELLEXECUTEINFO info;
-        char *bb_path, *cwd, *realcwd, *q, *args;
-        DECLARE_PROC_ADDR(BOOL, ShellExecuteExA, SHELLEXECUTEINFOA *);
+        const char *bb_path;
+        char *cwd, *realcwd, *q, *args;
 
         opt = getopt32(argv, "^c:s:tNW" "\0" "s--N:N--s", &opt_command, &opt_shell);
         argv += optind;
@@ -70,19 +70,17 @@ int suw32_main(int argc UNUSED_PARAM, char **argv)
         }
 #endif
 
-        /* ShellExecuteEx() needs backslash as separator in UNC paths. */
         if (opt_shell) {
                 bb_path = file_is_win32_exe(opt_shell);
                 if (!bb_path)
                         bb_error_msg_and_die("%s: Not found", opt_shell);
                 args = NULL;
         } else {
-                bb_path = xstrdup(bb_busybox_exec_path);
+                bb_path = bb_busybox_exec_path;
                 args = xstrdup("--busybox ash");
                 if (!test_mode)
                         args = xappendword(args, "-t \"BusyBox ash (Admin)\"");
         }
-        slash_to_bs(bb_path);
 
         memset(&info, 0, sizeof(SHELLEXECUTEINFO));
         info.cbSize = sizeof(SHELLEXECUTEINFO);
@@ -137,12 +135,7 @@ int suw32_main(int argc UNUSED_PARAM, char **argv)
         /* info.lpDirectory = NULL; */
         info.nShow = SW_SHOWNORMAL;
 
-        if (!INIT_PROC_ADDR(shell32.dll, ShellExecuteExA)) {
-                ret = -1;
-                goto end;
-        }
-
-        if (!ShellExecuteExA(&info)) {
+        if (!mingw_shell_execute(&info)) {
                 ret = 1;
                 goto end;
         }
@@ -159,7 +152,8 @@ int suw32_main(int argc UNUSED_PARAM, char **argv)
         }
  end:
         if (ENABLE_FEATURE_CLEAN_UP) {
-                free(bb_path);
+                if (bb_path != bb_busybox_exec_path)
+                        free((void *)bb_path);
                 free(cwd);
                 free(realcwd);
                 free(args);