drop: changes to ctrl-c handling

Use the new kill_child_ctrl_handler() function:

- Ctrl-C can be used to terminate non-console applications.

- Ctrl-C in an interactive cmd.exe or PowerShell session won't
  cause drop to terminate.

Also:

- Use getopt32() to process options.

- Update usage messages.

Adds 96-160 bytes.

1 files changed, 25 insertions, 12 deletions

diff --git a/miscutils/drop.c b/miscutils/drop.c
index 342de41d6..6b8e0f183 100644
--- a/miscutils/drop.c
+++ b/miscutils/drop.c
@@ -36,21 +36,21 @@
 //kbuild:lib-$(CONFIG_PDROP) += drop.o
 
 //usage:#define drop_trivial_usage
-//usage:        "[COMMAND | -c [ARG...]]"
+//usage:        "[COMMAND [ARG...] | -c CMD_STRING [ARG...]]"
 //usage:#define drop_full_usage "\n\n"
-//usage:        "Drop elevated privileges and run a command. If no COMMAND\n"
+//usage:        "Drop elevated privileges and run a command. If no command\n"
 //usage:        "is provided run the BusyBox shell.\n"
 
 //usage:#define cdrop_trivial_usage
-//usage:        "[COMMAND | /c [ARG...]]"
+//usage:        "[COMMAND [ARG...] | -c CMD_STRING [ARG...]]"
 //usage:#define cdrop_full_usage "\n\n"
-//usage:        "Drop elevated privileges and run a command. If no COMMAND\n"
+//usage:        "Drop elevated privileges and run a command. If no command\n"
 //usage:        "is provided run cmd.exe.\n"
 
 //usage:#define pdrop_trivial_usage
-//usage:        "[COMMAND | -c [ARG...]]"
+//usage:        "[COMMAND [ARG...] | -c CMD_STRING [ARG...]]"
 //usage:#define pdrop_full_usage "\n\n"
-//usage:        "Drop elevated privileges and run a command. If no COMMAND\n"
+//usage:        "Drop elevated privileges and run a command. If no command\n"
 //usage:        "is provided run PowerShell.\n"
 
 #include "libbb.h"
@@ -108,12 +108,16 @@ int drop_main(int argc, char **argv)
                 TIL.Label.Attributes = SE_GROUP_INTEGRITY;
                 if (SetTokenInformation(token, TokenIntegrityLevel, &TIL,
                                                 sizeof(TOKEN_MANDATORY_LABEL))) {
-                        char **a = argv + 1;
-                        const char *arg;
-                        char *exe, *cmd;
+                        char *opt_command = NULL;
+                        char **a;
+                        const char *opt, *arg;
+                        char *exe, *cmd, *q;
 
-                        if (argc == 1 || strcmp(argv[1], "-c") == 0
-                                                IF_CDROP(|| strcmp(argv[1], "/c") == 0)) {
+                        getopt32(argv, "c:", &opt_command);
+                        a = argv + optind;
+                        opt = "-c";
+
+                        if (argc == 1 || opt_command) {
                                 switch (*applet_name) {
 #if ENABLE_PDROP
                                 case 'p':
@@ -123,6 +127,7 @@ int drop_main(int argc, char **argv)
 #endif
 #if ENABLE_CDROP
                                 case 'c':
+                                        opt = "/c";
                                         arg = "cmd.exe";
                                         exe = find_first_executable(arg);
                                         break;
@@ -161,10 +166,16 @@ int drop_main(int argc, char **argv)
 
                         slash_to_bs(exe);
                         cmd = quote_arg(arg);
+                        if (opt_command) {
+                                cmd = xappendword(cmd, opt);
+                                q = quote_arg(opt_command);
+                                cmd = xappendword(cmd, q);
+                                free(q);
+                        }
 
                         // Build the command line
                         while (*a) {
-                                char *q = quote_arg(*a++);
+                                q = quote_arg(*a++);
                                 cmd = xappendword(cmd, q);
                                 free(q);
                         }
@@ -186,6 +197,8 @@ int drop_main(int argc, char **argv)
                                 bb_error_msg_and_die("can't execute '%s'", exe);
                         }
 
+                        kill_child_ctrl_handler(pi.dwProcessId);
+                        SetConsoleCtrlHandler(kill_child_ctrl_handler, TRUE);
                         WaitForSingleObject(pi.hProcess, INFINITE);
                         if (GetExitCodeProcess(pi.hProcess, &code)) {
                                 return (int)code;