dlls/crypt32/context.c

   1 /*
   2  * Copyright 2006 Juan Lang
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  17  */
  18 #include <assert.h>
  19 #include <stdarg.h>
  20 #include "windef.h"
  21 #include "winbase.h"
  22 #include "wincrypt.h"
  23 #include "wine/debug.h"
  24 #include "wine/list.h"
  25 #include "crypt32_private.h"
  26
  27 WINE_DEFAULT_DEBUG_CHANNEL(crypt);
  28
  29 typedef enum _ContextType {
  30     ContextTypeData,
  31     ContextTypeLink,
  32 } ContextType;
  33
  34 typedef struct _BASE_CONTEXT
  35 {
  36     LONG        ref;
  37     ContextType type;
  38 } BASE_CONTEXT, *PBASE_CONTEXT;
  39
  40 typedef struct _DATA_CONTEXT
  41 {
  42     LONG                   ref;
  43     ContextType            type; /* always ContextTypeData */
  44     PCONTEXT_PROPERTY_LIST properties;
  45 } DATA_CONTEXT, *PDATA_CONTEXT;
  46
  47 typedef struct _LINK_CONTEXT
  48 {
  49     LONG          ref;
  50     ContextType   type; /* always ContextTypeLink */
  51     PBASE_CONTEXT linked;
  52 } LINK_CONTEXT, *PLINK_CONTEXT;
  53
  54 #define CONTEXT_FROM_BASE_CONTEXT(p, s) ((LPBYTE)(p) - (s))
  55 #define BASE_CONTEXT_FROM_CONTEXT(p, s) (PBASE_CONTEXT)((LPBYTE)(p) + (s))
  56
  57 void *Context_CreateDataContext(size_t contextSize)
  58 {
  59     void *ret = CryptMemAlloc(contextSize + sizeof(DATA_CONTEXT));
  60
  61     if (ret)
  62     {
  63         PDATA_CONTEXT context = (PDATA_CONTEXT)((LPBYTE)ret + contextSize);
  64
  65         context->ref = 1;
  66         context->type = ContextTypeData;
  67         context->properties = ContextPropertyList_Create();
  68         if (!context->properties)
  69         {
  70             CryptMemFree(ret);
  71             ret = NULL;
  72         }
  73     }
  74     return ret;
  75 }
  76
  77 void *Context_CreateLinkContext(unsigned int contextSize, void *linked, unsigned int extra,
  78  BOOL addRef)
  79 {
  80     void *context = CryptMemAlloc(contextSize + sizeof(LINK_CONTEXT) + extra);
  81
  82     TRACE("(%d, %p, %d)\n", contextSize, linked, extra);
  83
  84     if (context)
  85     {
  86         PLINK_CONTEXT linkContext = (PLINK_CONTEXT)BASE_CONTEXT_FROM_CONTEXT(
  87          context, contextSize);
  88         PBASE_CONTEXT linkedBase = BASE_CONTEXT_FROM_CONTEXT(linked,
  89          contextSize);
  90
  91         memcpy(context, linked, contextSize);
  92         linkContext->ref = 1;
  93         linkContext->type = ContextTypeLink;
  94         linkContext->linked = linkedBase;
  95         if (addRef)
  96             InterlockedIncrement(&linkedBase->ref);
  97         TRACE("%p's ref count is %ld\n", context, linkContext->ref);
  98     }
  99     return context;
 100 }
 101
 102 void Context_AddRef(void *context, size_t contextSize)
 103 {
 104     PBASE_CONTEXT baseContext = BASE_CONTEXT_FROM_CONTEXT(context, contextSize);
 105
 106     InterlockedIncrement(&baseContext->ref);
 107 }
 108
 109 void *Context_GetExtra(const void *context, size_t contextSize)
 110 {
 111     PBASE_CONTEXT baseContext = BASE_CONTEXT_FROM_CONTEXT(context, contextSize);
 112
 113     assert(baseContext->type == ContextTypeLink);
 114     return (LPBYTE)baseContext + sizeof(LINK_CONTEXT);
 115 }
 116
 117 void *Context_GetLinkedContext(void *context, size_t contextSize)
 118 {
 119     PBASE_CONTEXT baseContext = BASE_CONTEXT_FROM_CONTEXT(context, contextSize);
 120
 121     assert(baseContext->type == ContextTypeLink);
 122     return CONTEXT_FROM_BASE_CONTEXT(((PLINK_CONTEXT)baseContext)->linked,
 123      contextSize);
 124 }
 125
 126 PCONTEXT_PROPERTY_LIST Context_GetProperties(void *context, size_t contextSize)
 127 {
 128     PBASE_CONTEXT ptr = BASE_CONTEXT_FROM_CONTEXT(context, contextSize);
 129
 130     while (ptr && ptr->type == ContextTypeLink)
 131         ptr = ((PLINK_CONTEXT)ptr)->linked;
 132     return (ptr && ptr->type == ContextTypeData) ?
 133      ((PDATA_CONTEXT)ptr)->properties : NULL;
 134 }
 135
 136 void Context_Release(void *context, size_t contextSize,
 137  ContextFreeFunc dataContextFree)
 138 {
 139     PBASE_CONTEXT base = BASE_CONTEXT_FROM_CONTEXT(context, contextSize);
 140
 141     if (InterlockedDecrement(&base->ref) == 0)
 142     {
 143         TRACE("freeing %p\n", context);
 144         switch (base->type)
 145         {
 146         case ContextTypeData:
 147             ContextPropertyList_Free(((PDATA_CONTEXT)base)->properties);
 148             dataContextFree(context);
 149             break;
 150         case ContextTypeLink:
 151             /* The linked context is of the same type as this, so release
 152              * it as well, using the same offset and data free function.
 153              */
 154             Context_Release(CONTEXT_FROM_BASE_CONTEXT(
 155              ((PLINK_CONTEXT)base)->linked, contextSize), contextSize,
 156              dataContextFree);
 157             break;
 158         default:
 159             assert(0);
 160         }
 161         CryptMemFree(context);
 162     }
 163     else
 164         TRACE("%p's ref count is %ld\n", context, base->ref);
 165 }
 166
 167 void Context_CopyProperties(const void *to, const void *from,
 168  size_t contextSize)
 169 {
 170     PCONTEXT_PROPERTY_LIST toProperties, fromProperties;
 171
 172     toProperties = Context_GetProperties((void *)to, contextSize);
 173     fromProperties = Context_GetProperties((void *)from, contextSize);
 174     ContextPropertyList_Copy(toProperties, fromProperties);
 175 }
 176
 177 struct ContextList
 178 {
 179     PCWINE_CONTEXT_INTERFACE contextInterface;
 180     size_t contextSize;
 181     CRITICAL_SECTION cs;
 182     struct list contexts;
 183 };
 184
 185 struct ContextList *ContextList_Create(
 186  PCWINE_CONTEXT_INTERFACE contextInterface, size_t contextSize)
 187 {
 188     struct ContextList *list = CryptMemAlloc(sizeof(struct ContextList));
 189
 190     if (list)
 191     {
 192         list->contextInterface = contextInterface;
 193         list->contextSize = contextSize;
 194         InitializeCriticalSection(&list->cs);
 195         list_init(&list->contexts);
 196     }
 197     return list;
 198 }
 199
 200 static inline struct list *ContextList_ContextToEntry(struct ContextList *list,
 201  const void *context)
 202 {
 203     struct list *ret;
 204
 205     if (context)
 206         ret = (struct list *)Context_GetExtra(context, list->contextSize);
 207     else
 208         ret = NULL;
 209     return ret;
 210 }
 211
 212 static inline void *ContextList_EntryToContext(struct ContextList *list,
 213  struct list *entry)
 214 {
 215     return (LPBYTE)entry - sizeof(LINK_CONTEXT) - list->contextSize;
 216 }
 217
 218 void *ContextList_Add(struct ContextList *list, void *toLink, void *toReplace)
 219 {
 220     void *context;
 221
 222     TRACE("(%p, %p, %p)\n", list, toLink, toReplace);
 223
 224     context = Context_CreateLinkContext(list->contextSize, toLink,
 225      sizeof(struct list), TRUE);
 226     if (context)
 227     {
 228         struct list *entry = ContextList_ContextToEntry(list, context);
 229
 230         TRACE("adding %p\n", context);
 231         EnterCriticalSection(&list->cs);
 232         if (toReplace)
 233         {
 234             struct list *existing = ContextList_ContextToEntry(list, toReplace);
 235
 236             entry->prev = existing->prev;
 237             entry->next = existing->next;
 238             entry->prev->next = entry;
 239             entry->next->prev = entry;
 240             existing->prev = existing->next = existing;
 241             list->contextInterface->free(toReplace);
 242         }
 243         else
 244             list_add_tail(&list->contexts, entry);
 245         LeaveCriticalSection(&list->cs);
 246     }
 247     return context;
 248 }
 249
 250 void *ContextList_Enum(struct ContextList *list, void *pPrev)
 251 {
 252     struct list *listNext;
 253     void *ret;
 254
 255     EnterCriticalSection(&list->cs);
 256     if (pPrev)
 257     {
 258         struct list *prevEntry = ContextList_ContextToEntry(list, pPrev);
 259
 260         listNext = list_next(&list->contexts, prevEntry);
 261         list->contextInterface->free(pPrev);
 262     }
 263     else
 264         listNext = list_next(&list->contexts, &list->contexts);
 265     LeaveCriticalSection(&list->cs);
 266
 267     if (listNext)
 268     {
 269         ret = ContextList_EntryToContext(list, listNext);
 270         list->contextInterface->duplicate(ret);
 271     }
 272     else
 273         ret = NULL;
 274     return ret;
 275 }
 276
 277 void ContextList_Delete(struct ContextList *list, void *context)
 278 {
 279     struct list *entry = ContextList_ContextToEntry(list, context);
 280
 281     EnterCriticalSection(&list->cs);
 282     list_remove(entry);
 283     LeaveCriticalSection(&list->cs);
 284     list->contextInterface->free(context);
 285 }
 286
 287 void ContextList_Empty(struct ContextList *list)
 288 {
 289     struct list *entry, *next;
 290
 291     EnterCriticalSection(&list->cs);
 292     LIST_FOR_EACH_SAFE(entry, next, &list->contexts)
 293     {
 294         const void *context = ContextList_EntryToContext(list, entry);
 295
 296         TRACE("removing %p\n", context);
 297         list_remove(entry);
 298         list->contextInterface->free(context);
 299     }
 300     LeaveCriticalSection(&list->cs);
 301 }
 302
 303 void ContextList_Free(struct ContextList *list)
 304 {
 305     ContextList_Empty(list);
 306     DeleteCriticalSection(&list->cs);
 307     CryptMemFree(list);
 308 }