From b1c08e4a9f68f20b8f7983543dbc249af6b689bb Mon Sep 17 00:00:00 2001
From: belliash <belliash@codingworkshop.eu.org>
Date: Tue, 25 Oct 2022 23:45:12 +0200
Subject: [PATCH] Implement RtlStringLength() and RtlStringToWideString()
 routines

---
 sdk/xtdk/rtlfuncs.h     |  11 +++++
 xtoskrnl/CMakeLists.txt |   1 +
 xtoskrnl/rtl/string.c   | 101 ++++++++++++++++++++++++++++++++++++++++
 xtoskrnl/xtoskrnl.spec  |   2 +
 4 files changed, 115 insertions(+)
 create mode 100644 xtoskrnl/rtl/string.c

diff --git a/sdk/xtdk/rtlfuncs.h b/sdk/xtdk/rtlfuncs.h
index 3da0b38..9bfe9f8 100644
--- a/sdk/xtdk/rtlfuncs.h
+++ b/sdk/xtdk/rtlfuncs.h
@@ -67,6 +67,17 @@ RtlSetMemory(OUT PVOID Destination,
              IN UCHAR Byte,
              IN SIZE_T Length);
 
+XTCDECL
+SIZE_T
+RtlStringLength(IN CONST PUCHAR String,
+                IN SIZE_T MaxLength);
+
+XTCDECL
+INT
+RtlStringToWideString(PWCHAR Destination,
+                      CONST PUCHAR *Source,
+                      SIZE_T Length);
+
 XTCDECL
 INT
 RtlWideStringCompare(IN CONST PWCHAR String1,
diff --git a/xtoskrnl/CMakeLists.txt b/xtoskrnl/CMakeLists.txt
index 2ddaf6b..11bf37c 100644
--- a/xtoskrnl/CMakeLists.txt
+++ b/xtoskrnl/CMakeLists.txt
@@ -12,6 +12,7 @@ list(APPEND XTOSKRNL_SOURCE
     ${XTOSKRNL_SOURCE_DIR}/ke/krnlinit.c
     ${XTOSKRNL_SOURCE_DIR}/rtl/memory.c
     ${XTOSKRNL_SOURCE_DIR}/rtl/plist.c
+    ${XTOSKRNL_SOURCE_DIR}/rtl/string.c
     ${XTOSKRNL_SOURCE_DIR}/rtl/widestr.c)
 
 # Set module definition SPEC file
diff --git a/xtoskrnl/rtl/string.c b/xtoskrnl/rtl/string.c
new file mode 100644
index 0000000..cc4940b
--- /dev/null
+++ b/xtoskrnl/rtl/string.c
@@ -0,0 +1,101 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            xtoskrnl/rtl/string.c
+ * DESCRIPTION:     String support
+ * DEVELOPERS:      Rafal Kupiec <belliash@codingworkshop.eu.org>
+ */
+
+#include "xtkmapi.h"
+
+
+/**
+ * Calculates the length of a given string.
+ *
+ * @param String
+ *        Pointer to the null-terminated string to be examined.
+ *
+ * @param MaxLength
+ *        Maximum number of characters to examine. If no limit set, it examines whole string.
+ *
+ * @return The length of the null-terminated string.
+ *
+ * @since: XT 1.0
+ */
+XTCDECL
+SIZE_T
+RtlStringLength(IN CONST PUCHAR String,
+                IN SIZE_T MaxLength)
+{
+    SIZE_T Length;
+
+    /* Check if NULL pointer passed */
+    if(String == NULL)
+    {
+        return 0;
+    }
+
+    /* Iterate through the wide string */
+    for(Length = 0; ; Length++)
+    {
+
+        /* Check if NULL found or max length limit reached */
+        if((Length != 0 && Length == MaxLength) || !String[Length])
+        {
+            /* Finish examination */
+            break;
+        }
+    }
+
+    /* Return wide string length */
+    return Length;
+}
+
+/**
+ * Converts a multibyte character string to its wide character representation.
+ *
+ * @param Destination
+ *        Pointer to wide character array where the wide string will be stored
+ *
+ * @param Source
+ *        Pointer to the first element of a multibyte string to convert.
+ *
+ * @param Length
+ *        Number of characters in the source string.
+ *
+ * @return Returns the number of wide characters written to the destination array on success, or -1 on error.
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+INT
+RtlStringToWideString(PWCHAR Destination,
+                      CONST PUCHAR *Source,
+                      SIZE_T Length)
+{
+    PUCHAR LocalSource = *Source;
+    SIZE_T Count = Length;
+
+    if(Destination == NULL)
+    {
+        return 0;
+    }
+
+    while(Count)
+    {
+        if((*Destination = (UCHAR)*LocalSource) == 0)
+        {
+            LocalSource = NULL;
+            break;
+        }
+        if(*Destination >= 0x80)
+        {
+            return -1;
+        }
+        LocalSource++;
+        Destination++;
+        Count--;
+    }
+
+    return Length - Count;
+}
diff --git a/xtoskrnl/xtoskrnl.spec b/xtoskrnl/xtoskrnl.spec
index 987c3dd..ff19369 100644
--- a/xtoskrnl/xtoskrnl.spec
+++ b/xtoskrnl/xtoskrnl.spec
@@ -6,6 +6,8 @@
 @ stdcall RtlMoveMemory(ptr ptr long)
 @ stdcall RtlSameMemory(ptr ptr long)
 @ stdcall RtlSetMemory(ptr long long)
+@ cdecl RtlStringLength(str long)
+@ cdecl RtlStringToWideString(wstr str long)
 @ cdecl RtlWideStringCompare(wstr wstr long)
 @ cdecl RtlWideStringConcatenate(wstr wstr long)
 @ cdecl RtlWideStringLength(wstr long)