From 03b27780626d1436dddb5150543ac62d8be0312e Mon Sep 17 00:00:00 2001
From: midipix <writeonce@midipix.org>
Date: Sep 11 2022 21:05:34 +0000
Subject: ntux_cmd_chmod(): parse --strmode in a posix-compatible manner.


---

diff --git a/src/cmds/ntux_cmd_chmod.c b/src/cmds/ntux_cmd_chmod.c
index 04ebad6..7be2bc8 100644
--- a/src/cmds/ntux_cmd_chmod.c
+++ b/src/cmds/ntux_cmd_chmod.c
@@ -22,10 +22,16 @@
 #include "ntux_driver_impl.h"
 #include "ntux_nolibc_impl.h"
 #include "ntux_errinfo_impl.h"
+#include "nolibc/stdbool.h"
 
 #define __SID_SYSTEM			{1,1,{{0,0,0,0,0,5}},{18}}
 #define __SID_ADMINISTRATORS		{1,2,{{0,0,0,0,0,5}},{32,544}}
 
+#define NTUX_OPT_MODE_NEUTRAL		(0)
+#define NTUX_OPT_MODE_EQUAL		(1)
+#define NTUX_OPT_MODE_PLUS		(2)
+#define NTUX_OPT_MODE_MINUS		(3)
+
 static const nt_sid    sid_system       = __SID_SYSTEM;
 static const nt_sid_os sid_admins       = __SID_ADMINISTRATORS;
 
@@ -61,6 +67,9 @@ int ntux_cmd_chmod(const struct ntux_driver_ctx * dctx, const char * dunit)
 	int32_t			status;
 	int			fdout;
 	int			fdcwd;
+	int			optmode;
+	const char *		strmode;
+	const char *		chmode;
 	const unsigned char *	unit;
 	nt_sd *			srcsd;
 	nt_sd_common_buffer	dstsd;
@@ -77,24 +86,57 @@ int ntux_cmd_chmod(const struct ntux_driver_ctx * dctx, const char * dunit)
 	int			fd      = -1;
 	struct __ofd *		ofd     = 0;
 	void *			hasync  = 0;
-	uint32_t		buf[0x300];
-
-	/* ACE propagation: +p, -p */
-	if (!dctx->cctx->strmode)
-		ace_flags = 0;
-
-	else if (!strcmp(dctx->cctx->strmode,"+p"))
-		ace_flags = NT_ACE_CONTAINER_INHERIT | NT_ACE_OBJECT_INHERIT;
-
-	else if (!strcmp(dctx->cctx->strmode,"-p"))
-		ace_flags = 0;
-
-	else
-		return ntux_cmd_chmod_ret(
-			0,0,0,
-			NTUX_CUSTOM_ERROR(
-				dctx,
-				NTUX_ERR_FLEE_ERROR));
+	uint32_t		buf[0x300] = {0};
+
+	/* strmode */
+	strmode   = dctx->cctx->strmode ? dctx->cctx->strmode : (char *)buf;
+	optmode   = NTUX_OPT_MODE_NEUTRAL;
+	ace_flags = 0;
+
+	for (chmode=strmode; *chmode; chmode++) {
+		switch (*chmode) {
+			case '=':
+				optmode   = NTUX_OPT_MODE_EQUAL;
+				ace_flags = 0;
+				break;
+
+			case '+':
+				optmode = NTUX_OPT_MODE_PLUS;
+				break;
+
+			case '-':
+				optmode = NTUX_OPT_MODE_MINUS;
+				break;
+
+			case 'p':
+				switch (optmode) {
+					case NTUX_OPT_MODE_EQUAL:
+					case NTUX_OPT_MODE_PLUS:
+						ace_flags = NT_ACE_CONTAINER_INHERIT | NT_ACE_OBJECT_INHERIT;
+						break;
+
+					case NTUX_OPT_MODE_MINUS:
+						ace_flags = 0;
+						break;
+
+					default:
+						return ntux_cmd_chmod_ret(
+							0,0,0,
+							NTUX_CUSTOM_ERROR(
+								dctx,
+								NTUX_ERR_FLEE_ERROR));
+				}
+
+				break;
+
+			default:
+				return ntux_cmd_chmod_ret(
+					0,0,0,
+					NTUX_CUSTOM_ERROR(
+						dctx,
+						NTUX_ERR_FLEE_ERROR));
+		}
+	}
 
 	/* initial --owner and --group support: Administrators, SYSTEM */
 	owner = 0;