MdeModulePkg/UdfDxe: Update GetInfo() for FS VolumeLabel info request

[mirror_edk2.git] / MdeModulePkg / Universal / Disk / UdfDxe / FileSystemOperations.c

diff --git a/MdeModulePkg/Universal/Disk/UdfDxe/FileSystemOperations.c b/MdeModulePkg/Universal/Disk/UdfDxe/FileSystemOperations.c
index c55dcf1301768039171ef3a96b435d05b17640d2..f1205bbb8eed2b890367beabbe563ece04a71292 100644 (file)
--- a/MdeModulePkg/Universal/Disk/UdfDxe/FileSystemOperations.c
+++ b/MdeModulePkg/Universal/Disk/UdfDxe/FileSystemOperations.c
@@ -2530,6 +2530,90 @@ SetFileInfo (
   return EFI_SUCCESS;\r
 }\r
 \r
+/**\r
+  Get volume label of an UDF volume.\r
+\r
+  @attention This is boundary function that may receive untrusted input.\r
+  @attention The input is from FileSystem.\r
+\r
+  The File Set Descriptor is external input, so this routine will do basic\r
+  validation for File Set Descriptor and report status.\r
+\r
+  @param[in]   Volume   Volume information pointer.\r
+  @param[in]   CharMax  The maximum number of Unicode char in String,\r
+                        including terminating null char.\r
+  @param[out]  String   String buffer pointer to store the volume label.\r
+\r
+  @retval EFI_SUCCESS           Volume label is returned.\r
+  @retval EFI_VOLUME_CORRUPTED  The file system structures are corrupted.\r
+  @retval EFI_BUFFER_TOO_SMALL  The string buffer String cannot hold the\r
+                                volume label.\r
+\r
+**/\r
+EFI_STATUS\r
+GetVolumeLabel (\r
+  IN   UDF_VOLUME_INFO  *Volume,\r
+  IN   UINTN            CharMax,\r
+  OUT  CHAR16           *String\r
+  )\r
+{\r
+  UDF_FILE_SET_DESCRIPTOR  *FileSetDesc;\r
+  UINTN                    Index;\r
+  UINT8                    *OstaCompressed;\r
+  UINT8                    CompressionId;\r
+  CHAR16                   *StringBak;\r
+\r
+  FileSetDesc = &Volume->FileSetDesc;\r
+\r
+  OstaCompressed = &FileSetDesc->LogicalVolumeIdentifier[0];\r
+\r
+  CompressionId = OstaCompressed[0];\r
+  if (!IS_VALID_COMPRESSION_ID (CompressionId)) {\r
+    return EFI_VOLUME_CORRUPTED;\r
+  }\r
+\r
+  StringBak = String;\r
+  for (Index = 1; Index < 128; Index++) {\r
+    if (CompressionId == 16) {\r
+      if ((Index >> 1) > CharMax) {\r
+        return EFI_BUFFER_TOO_SMALL;\r
+      }\r
+\r
+      *String = *(UINT8 *)(OstaCompressed + Index) << 8;\r
+      Index++;\r
+    } else {\r
+      if (Index > CharMax) {\r
+        return EFI_BUFFER_TOO_SMALL;\r
+      }\r
+\r
+      *String = 0;\r
+    }\r
+\r
+    if (Index < 128) {\r
+      *String |= (CHAR16)(*(UINT8 *)(OstaCompressed + Index));\r
+    }\r
+\r
+    //\r
+    // Unlike FID Identifiers, Logical Volume Identifier is stored in a\r
+    // NULL-terminated OSTA compressed format, so we must check for the NULL\r
+    // character.\r
+    //\r
+    if (*String == L'\0') {\r
+      break;\r
+    }\r
+\r
+    String++;\r
+  }\r
+\r
+  Index = ((UINTN)String - (UINTN)StringBak) / sizeof (CHAR16);\r
+  if (Index > CharMax - 1) {\r
+    Index = CharMax - 1;\r
+  }\r
+  StringBak[Index] = L'\0';\r
+\r
+  return EFI_SUCCESS;\r
+}\r
+\r
 /**\r
   Get volume and free space size information of an UDF volume.\r
 \r