From 9bf96d63c4815fd6f4480102be400517e9c8d387 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michael=20M=C3=BCller?= <michael@fds-team.de>
Date: Mon, 3 Apr 2017 05:30:27 +0200
Subject: [PATCH] ntdll: Implement HashLinks field in LDR module data.

---
 dlls/kernel32/tests/loader.c | 75 ++++++++++++++++++++++++++++++++++++
 dlls/ntdll/loader.c          | 64 ++++++++++++++++++++++++++++++
 include/winternl.h           |  2 +-
 3 files changed, 140 insertions(+), 1 deletion(-)

diff --git a/dlls/kernel32/tests/loader.c b/dlls/kernel32/tests/loader.c
index 757a230ae15..466e5a444f4 100644
--- a/dlls/kernel32/tests/loader.c
+++ b/dlls/kernel32/tests/loader.c
@@ -30,6 +30,7 @@
 #include "winbase.h"
 #include "winternl.h"
 #include "winnls.h"
+#include "winuser.h"
 #include "wine/test.h"
 #include "delayloadhandler.h"
 
@@ -3970,6 +3971,79 @@ static void test_LoadPackagedLibrary(void)
             h, GetLastError());
 }
 
+static inline WCHAR toupperW(WCHAR c)
+{
+    WCHAR tmp = c;
+    CharUpperBuffW(&tmp, 1);
+    return tmp;
+}
+
+static ULONG hash_basename(const WCHAR *basename)
+{
+    WORD version = MAKEWORD(NtCurrentTeb()->Peb->OSMinorVersion,
+                            NtCurrentTeb()->Peb->OSMajorVersion);
+    ULONG hash = 0;
+
+    if (version >= 0x0602)
+    {
+        for (; *basename; basename++)
+            hash = hash * 65599 + toupperW(*basename);
+    }
+    else if (version == 0x0601)
+    {
+        for (; *basename; basename++)
+            hash = hash + 65599 * toupperW(*basename);
+    }
+    else
+        hash = toupperW(basename[0]) - 'A';
+
+    return hash & 31;
+}
+
+static void test_HashLinks(void)
+{
+    static WCHAR ntdllW[] = {'n','t','d','l','l','.','d','l','l',0};
+    static WCHAR kernel32W[] = {'k','e','r','n','e','l','3','2','.','d','l','l',0};
+
+    LIST_ENTRY *hash_map, *entry, *mark;
+    LDR_DATA_TABLE_ENTRY *module;
+    BOOL found;
+
+    entry = &NtCurrentTeb()->Peb->LdrData->InLoadOrderModuleList;
+    entry = entry->Flink;
+
+    module = CONTAINING_RECORD(entry, LDR_DATA_TABLE_ENTRY, InLoadOrderLinks);
+    entry = module->HashLinks.Blink;
+
+    hash_map = entry - hash_basename(module->BaseDllName.Buffer);
+
+    mark = &hash_map[hash_basename(ntdllW)];
+    found = FALSE;
+    for (entry = mark->Flink; entry != mark; entry = entry->Flink)
+    {
+        module = CONTAINING_RECORD(entry, LDR_DATA_TABLE_ENTRY, HashLinks);
+        if (!lstrcmpiW(module->BaseDllName.Buffer, ntdllW))
+        {
+            found = TRUE;
+            break;
+        }
+    }
+    ok(found, "Could not find ntdll\n");
+
+    mark = &hash_map[hash_basename(kernel32W)];
+    found = FALSE;
+    for (entry = mark->Flink; entry != mark; entry = entry->Flink)
+    {
+        module = CONTAINING_RECORD(entry, LDR_DATA_TABLE_ENTRY, HashLinks);
+        if (!lstrcmpiW(module->BaseDllName.Buffer, kernel32W))
+        {
+            found = TRUE;
+            break;
+        }
+    }
+    ok(found, "Could not find kernel32\n");
+}
+
 START_TEST(loader)
 {
     int argc;
@@ -4042,6 +4116,7 @@ START_TEST(loader)
     test_InMemoryOrderModuleList();
     test_LoadPackagedLibrary();
     test_wow64_redirection();
+    test_HashLinks();
     test_dll_file( "ntdll.dll", FALSE );
     test_dll_file( "kernel32.dll", TRUE );
     test_dll_file( "advapi32.dll", TRUE );
diff --git a/dlls/ntdll/loader.c b/dlls/ntdll/loader.c
index 6290cbcb4e6..9953746bdaa 100644
--- a/dlls/ntdll/loader.c
+++ b/dlls/ntdll/loader.c
@@ -118,6 +118,9 @@ struct file_id
     BYTE ObjectId[16];
 };
 
+#define HASH_MAP_SIZE 32
+static LIST_ENTRY hash_table[HASH_MAP_SIZE];
+
 /* internal representation of loaded modules */
 typedef struct _wine_modref
 {
@@ -457,6 +460,52 @@ static void call_ldr_notifications( ULONG reason, LDR_DATA_TABLE_ENTRY *module )
     }
 }
 
+/*************************************************************************
+ *      hash_basename
+ *
+ * Calculates the bucket index of a dll using the basename.
+ */
+static ULONG hash_basename(const WCHAR *basename)
+{
+    WORD version = MAKEWORD(NtCurrentTeb()->Peb->OSMinorVersion,
+                            NtCurrentTeb()->Peb->OSMajorVersion);
+    ULONG hash = 0;
+
+    if (version >= 0x0602)
+    {
+        for (; *basename; basename++)
+            hash = hash * 65599 + towupper(*basename);
+    }
+    else if (version == 0x0601)
+    {
+        for (; *basename; basename++)
+            hash = hash + 65599 * towupper(*basename);
+    }
+    else
+        hash = towupper(basename[0]) - 'A';
+
+    return hash & (HASH_MAP_SIZE-1);
+}
+
+/*************************************************************************
+ *      recompute_hash_maps
+ *
+ * Recomputes the LDR hash map (necessary when windows version changes).
+ */
+static void recompute_hash_map(void)
+{
+    LIST_ENTRY *mark, *entry;
+    LDR_DATA_TABLE_ENTRY *mod;
+
+    mark = &NtCurrentTeb()->Peb->LdrData->InLoadOrderModuleList;
+    for (entry = mark->Flink; entry != mark; entry = entry->Flink)
+    {
+        mod = CONTAINING_RECORD(entry, LDR_DATA_TABLE_ENTRY, InLoadOrderLinks);
+        RemoveEntryList( &mod->HashLinks );
+        InsertTailList( &hash_table[hash_basename(mod->BaseDllName.Buffer)], &mod->HashLinks );
+    }
+}
+
 /*************************************************************************
  *		get_modref
  *
@@ -1198,7 +1247,12 @@ static WINE_MODREF *alloc_module( HMODULE hModule, const UNICODE_STRING *nt_name
                    &wm->ldr.InLoadOrderLinks);
     InsertTailList(&NtCurrentTeb()->Peb->LdrData->InMemoryOrderModuleList,
                    &wm->ldr.InMemoryOrderLinks);
+    InsertTailList(&hash_table[hash_basename(wm->ldr.BaseDllName.Buffer)],
+                   &wm->ldr.HashLinks);
+
     /* wait until init is called for inserting into InInitializationOrderModuleList */
+    wm->ldr.InInitializationOrderLinks.Flink = NULL;
+    wm->ldr.InInitializationOrderLinks.Blink = NULL;
 
     if (!(nt->OptionalHeader.DllCharacteristics & IMAGE_DLLCHARACTERISTICS_NX_COMPAT))
     {
@@ -1903,6 +1957,7 @@ static NTSTATUS build_module( LPCWSTR load_path, const UNICODE_STRING *nt_name,
             /* the module has only be inserted in the load & memory order lists */
             RemoveEntryList(&wm->ldr.InLoadOrderLinks);
             RemoveEntryList(&wm->ldr.InMemoryOrderLinks);
+            RemoveEntryList(&wm->ldr.HashLinks);
 
             /* FIXME: there are several more dangling references
              * left. Including dlls loaded by this dll before the
@@ -3239,6 +3294,7 @@ static void free_modref( WINE_MODREF *wm )
 {
     RemoveEntryList(&wm->ldr.InLoadOrderLinks);
     RemoveEntryList(&wm->ldr.InMemoryOrderLinks);
+    RemoveEntryList(&wm->ldr.HashLinks);
     if (wm->ldr.InInitializationOrderLinks.Flink)
         RemoveEntryList(&wm->ldr.InInitializationOrderLinks);
 
@@ -3908,6 +3964,7 @@ void __wine_process_init(void)
     INITIAL_TEB stack;
     TEB *teb = NtCurrentTeb();
     PEB *peb = teb->Peb;
+    DWORD i;
 
     peb->LdrData            = &ldr;
     peb->FastPebLock        = &peb_lock;
@@ -3946,6 +4003,10 @@ void __wine_process_init(void)
     load_global_options();
     version_init();
 
+    /* initialize hash table */
+    for (i = 0; i < HASH_MAP_SIZE; i++)
+        InitializeListHead(&hash_table[i]);
+
     /* setup the load callback and create ntdll modref */
     RtlInitUnicodeString( &nt_name, ntdllW );
     NtQueryVirtualMemory( GetCurrentProcess(), __wine_process_init, MemoryBasicInformation,
@@ -4032,6 +4093,9 @@ void __wine_process_init(void)
     teb->Tib.StackLimit = stack.StackLimit;
     teb->DeallocationStack = stack.DeallocationStack;
 
+    /* the windows version was not set yet when ntdll and kernel32 were loaded */
+    recompute_hash_map();
+
     unix_funcs->server_init_process_done( kernel32_start_process );
 }
 
diff --git a/include/winternl.h b/include/winternl.h
index 8efdaf31193..2ed26e397c4 100644
--- a/include/winternl.h
+++ b/include/winternl.h
@@ -2672,8 +2672,8 @@ typedef struct _LDR_DATA_TABLE_ENTRY
     ULONG               Flags;
     SHORT               LoadCount;
     SHORT               TlsIndex;
-    HANDLE              SectionHandle;
     ULONG               CheckSum;
+    LIST_ENTRY          HashLinks;
     ULONG               TimeDateStamp;
     HANDLE              ActivationContext;
     void*               Lock;
-- 
2.27.0

