ShellPkg/Dp: Add null pointer check

[mirror_edk2.git] / ShellPkg / Library / UefiShellLevel1CommandsLib / UefiShellLevel1CommandsLib.c

/** @file\r
  Main file for NULL named library for level 1 shell command functions.\r
\r
  (C) Copyright 2013 Hewlett-Packard Development Company, L.P.<BR>\r
  Copyright (c) 2009 - 2011, Intel Corporation. All rights reserved.<BR>\r
  This program and the accompanying materials\r
  are licensed and made available under the terms and conditions of the BSD License\r
  which accompanies this distribution.  The full text of the license may be found at\r
  http://opensource.org/licenses/bsd-license.php\r
\r
  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
\r
**/\r
\r
#include "UefiShellLevel1CommandsLib.h"\r
\r
STATIC CONST CHAR16 mFileName[] = L"ShellCommands";\r
EFI_HANDLE gShellLevel1HiiHandle = NULL;\r
\r
/**\r
  Return the help text filename.  Only used if no HII information found.\r
\r
  @retval the filename.\r
**/\r
CONST CHAR16*\r
EFIAPI\r
ShellCommandGetManFileNameLevel1 (\r
  VOID\r
  )\r
{\r
  return (mFileName);\r
}\r
\r
/**\r
  Constructor for the Shell Level 1 Commands library.\r
\r
  Install the handlers for level 1 UEFI Shell 2.0 commands.\r
\r
  @param ImageHandle    the image handle of the process\r
  @param SystemTable    the EFI System Table pointer\r
\r
  @retval EFI_SUCCESS        the shell command handlers were installed sucessfully\r
  @retval EFI_UNSUPPORTED    the shell level required was not found.\r
**/\r
EFI_STATUS\r
EFIAPI\r
ShellLevel1CommandsLibConstructor (\r
  IN EFI_HANDLE        ImageHandle,\r
  IN EFI_SYSTEM_TABLE  *SystemTable\r
  )\r
{\r
  //\r
  // if shell level is less than 2 do nothing\r
  //\r
  if (PcdGet8(PcdShellSupportLevel) < 1) {\r
    return (EFI_SUCCESS);\r
  }\r
\r
  gShellLevel1HiiHandle = HiiAddPackages (&gShellLevel1HiiGuid, gImageHandle, UefiShellLevel1CommandsLibStrings, NULL);\r
  if (gShellLevel1HiiHandle == NULL) {\r
    return (EFI_DEVICE_ERROR);\r
  }\r
\r
  //\r
  // install our shell command handlers that are always installed\r
  //\r
  ShellCommandRegisterCommandName(L"stall",  ShellCommandRunStall   , ShellCommandGetManFileNameLevel1, 1, L"", FALSE, gShellLevel1HiiHandle, (EFI_STRING_ID)(PcdGet8(PcdShellSupportLevel) < 3 ? 0 : STRING_TOKEN(STR_GET_HELP_STALL) ));\r
  ShellCommandRegisterCommandName(L"for",    ShellCommandRunFor     , ShellCommandGetManFileNameLevel1, 1, L"", FALSE, gShellLevel1HiiHandle, (EFI_STRING_ID)(PcdGet8(PcdShellSupportLevel) < 3 ? 0 : STRING_TOKEN(STR_GET_HELP_FOR)   ));\r
  ShellCommandRegisterCommandName(L"goto",   ShellCommandRunGoto    , ShellCommandGetManFileNameLevel1, 1, L"", FALSE, gShellLevel1HiiHandle, (EFI_STRING_ID)(PcdGet8(PcdShellSupportLevel) < 3 ? 0 : STRING_TOKEN(STR_GET_HELP_GOTO)  ));\r
  ShellCommandRegisterCommandName(L"if",     ShellCommandRunIf      , ShellCommandGetManFileNameLevel1, 1, L"", FALSE, gShellLevel1HiiHandle, (EFI_STRING_ID)(PcdGet8(PcdShellSupportLevel) < 3 ? 0 : STRING_TOKEN(STR_GET_HELP_IF)    ));\r
  ShellCommandRegisterCommandName(L"shift",  ShellCommandRunShift   , ShellCommandGetManFileNameLevel1, 1, L"", FALSE, gShellLevel1HiiHandle, (EFI_STRING_ID)(PcdGet8(PcdShellSupportLevel) < 3 ? 0 : STRING_TOKEN(STR_GET_HELP_SHIFT) ));\r
  ShellCommandRegisterCommandName(L"exit",   ShellCommandRunExit    , ShellCommandGetManFileNameLevel1, 1, L"", TRUE , gShellLevel1HiiHandle, (EFI_STRING_ID)(PcdGet8(PcdShellSupportLevel) < 3 ? 0 : STRING_TOKEN(STR_GET_HELP_EXIT)  ));\r
  ShellCommandRegisterCommandName(L"else",   ShellCommandRunElse    , ShellCommandGetManFileNameLevel1, 1, L"", FALSE, gShellLevel1HiiHandle, (EFI_STRING_ID)(PcdGet8(PcdShellSupportLevel) < 3 ? 0 : STRING_TOKEN(STR_GET_HELP_ELSE)  ));\r
  ShellCommandRegisterCommandName(L"endif",  ShellCommandRunEndIf   , ShellCommandGetManFileNameLevel1, 1, L"", FALSE, gShellLevel1HiiHandle, (EFI_STRING_ID)(PcdGet8(PcdShellSupportLevel) < 3 ? 0 : STRING_TOKEN(STR_GET_HELP_ENDIF) ));\r
  ShellCommandRegisterCommandName(L"endfor", ShellCommandRunEndFor  , ShellCommandGetManFileNameLevel1, 1, L"", FALSE, gShellLevel1HiiHandle, (EFI_STRING_ID)(PcdGet8(PcdShellSupportLevel) < 3 ? 0 : STRING_TOKEN(STR_GET_HELP_ENDFOR)));\r
\r
  return (EFI_SUCCESS);\r
}\r
\r
/**\r
  Destructor for the library.  free any resources.\r
\r
  @param ImageHandle            The image handle of the process.\r
  @param SystemTable            The EFI System Table pointer.\r
**/\r
EFI_STATUS\r
EFIAPI\r
ShellLevel1CommandsLibDestructor (\r
  IN EFI_HANDLE        ImageHandle,\r
  IN EFI_SYSTEM_TABLE  *SystemTable\r
  )\r
{\r
  if (gShellLevel1HiiHandle != NULL) {\r
    HiiRemovePackages(gShellLevel1HiiHandle);\r
  }\r
  return (EFI_SUCCESS);\r
}\r
\r
/**\r
  Test a node to see if meets the criterion.\r
\r
  It functions so that count starts at 1 and it increases or decreases when it\r
  hits the specified tags.  when it hits zero the location has been found.\r
\r
  DecrementerTag and IncrementerTag are used to get around for/endfor and \r
  similar paired types where the entire middle should be ignored.\r
\r
  If label is used it will be used instead of the count.\r
\r
  @param[in] Function          The function to use to enumerate through the \r
                               list.  Normally GetNextNode or GetPreviousNode.\r
  @param[in] DecrementerTag    The tag to decrement the count at.\r
  @param[in] IncrementerTag    The tag to increment the count at.\r
  @param[in] Label             A label to look for.\r
  @param[in, out] ScriptFile   The pointer to the current script file structure.\r
  @param[in] MovePast          TRUE makes function return 1 past the found \r
                               location.\r
  @param[in] FindOnly          TRUE to not change the ScriptFile.\r
  @param[in] CommandNode       The pointer to the Node to test.\r
  @param[in, out] TargetCount  The pointer to the current count.\r
**/\r
BOOLEAN\r
TestNodeForMove (\r
  IN CONST LIST_MANIP_FUNC      Function,\r
  IN CONST CHAR16               *DecrementerTag,\r
  IN CONST CHAR16               *IncrementerTag,\r
  IN CONST CHAR16               *Label OPTIONAL,\r
  IN OUT SCRIPT_FILE            *ScriptFile,\r
  IN CONST BOOLEAN              MovePast,\r
  IN CONST BOOLEAN              FindOnly,\r
  IN CONST SCRIPT_COMMAND_LIST  *CommandNode,\r
  IN OUT UINTN                  *TargetCount\r
  )\r
{\r
  BOOLEAN             Found;\r
  CHAR16              *CommandName;\r
  CHAR16              *CommandNameWalker;\r
  CHAR16              *TempLocation;\r
\r
  Found = FALSE;\r
\r
  //\r
  // get just the first part of the command line...\r
  //\r
  CommandName   = NULL;\r
  CommandName   = StrnCatGrow(&CommandName, NULL, CommandNode->Cl, 0);\r
  if (CommandName == NULL) {\r
    return (FALSE);\r
  }\r
\r
  CommandNameWalker = CommandName;\r
\r
  //\r
  // Skip leading spaces and tabs.\r
  //\r
  while ((CommandNameWalker[0] == L' ') || (CommandNameWalker[0] == L'\t')) {\r
    CommandNameWalker++;\r
  }\r
  TempLocation  = StrStr(CommandNameWalker, L" ");\r
\r
  if (TempLocation != NULL) {\r
    *TempLocation = CHAR_NULL;\r
  }\r
\r
  //\r
  // did we find a nested item ?\r
  //\r
  if (gUnicodeCollation->StriColl(\r
      gUnicodeCollation,\r
      (CHAR16*)CommandNameWalker,\r
      (CHAR16*)IncrementerTag) == 0) {\r
    (*TargetCount)++;\r
  } else if (gUnicodeCollation->StriColl(\r
      gUnicodeCollation,\r
      (CHAR16*)CommandNameWalker,\r
      (CHAR16*)DecrementerTag) == 0) {\r
    if (*TargetCount > 0) {\r
      (*TargetCount)--;\r
    }\r
  }\r
\r
  //\r
  // did we find the matching one...\r
  //\r
  if (Label == NULL) {\r
    if (*TargetCount == 0) {\r
      Found = TRUE;\r
      if (!FindOnly) {\r
        if (MovePast) {\r
          ScriptFile->CurrentCommand = (SCRIPT_COMMAND_LIST *)(*Function)(&ScriptFile->CommandList, &CommandNode->Link);\r
        } else {\r
          ScriptFile->CurrentCommand = (SCRIPT_COMMAND_LIST *)CommandNode;\r
        }\r
      }\r
    }\r
  } else {\r
    if (gUnicodeCollation->StriColl(\r
      gUnicodeCollation,\r
      (CHAR16*)CommandNameWalker,\r
      (CHAR16*)Label) == 0\r
      && (*TargetCount) == 0) {\r
      Found = TRUE;\r
      if (!FindOnly) {\r
        //\r
        // we found the target label without loops\r
        //\r
        if (MovePast) {\r
          ScriptFile->CurrentCommand = (SCRIPT_COMMAND_LIST *)(*Function)(&ScriptFile->CommandList, &CommandNode->Link);\r
        } else {\r
          ScriptFile->CurrentCommand = (SCRIPT_COMMAND_LIST *)CommandNode;\r
        }\r
      }\r
    }\r
  }\r
\r
  //\r
  // Free the memory for this loop...\r
  //\r
  FreePool(CommandName);\r
  return (Found);\r
}\r
\r
/**\r
  Move the script pointer from 1 tag (line) to another.\r
\r
  It functions so that count starts at 1 and it increases or decreases when it\r
  hits the specified tags.  when it hits zero the location has been found.\r
\r
  DecrementerTag and IncrementerTag are used to get around for/endfor and \r
  similar paired types where the entire middle should be ignored.\r
\r
  If label is used it will be used instead of the count.\r
\r
  @param[in] Function          The function to use to enumerate through the \r
                               list.  Normally GetNextNode or GetPreviousNode.\r
  @param[in] DecrementerTag    The tag to decrement the count at.\r
  @param[in] IncrementerTag    The tag to increment the count at.\r
  @param[in] Label             A label to look for.\r
  @param[in, out] ScriptFile   The pointer to the current script file structure.\r
  @param[in] MovePast          TRUE makes function return 1 past the found \r
                               location.\r
  @param[in] FindOnly          TRUE to not change the ScriptFile.\r
  @param[in] WrapAroundScript  TRUE to wrap end-to-begining or vise versa in \r
                               searching.\r
**/\r
BOOLEAN\r
MoveToTag (\r
  IN CONST LIST_MANIP_FUNC      Function,\r
  IN CONST CHAR16               *DecrementerTag,\r
  IN CONST CHAR16               *IncrementerTag,\r
  IN CONST CHAR16               *Label OPTIONAL,\r
  IN OUT SCRIPT_FILE            *ScriptFile,\r
  IN CONST BOOLEAN              MovePast,\r
  IN CONST BOOLEAN              FindOnly,\r
  IN CONST BOOLEAN              WrapAroundScript\r
  )\r
{\r
  SCRIPT_COMMAND_LIST *CommandNode;\r
  BOOLEAN             Found;\r
  UINTN               TargetCount;\r
\r
  if (Label == NULL) {\r
    TargetCount       = 1;\r
  } else {\r
    TargetCount       = 0;\r
  }\r
\r
  if (ScriptFile == NULL) {\r
    return FALSE;\r
  }\r
\r
  for (CommandNode = (SCRIPT_COMMAND_LIST *)(*Function)(&ScriptFile->CommandList, &ScriptFile->CurrentCommand->Link), Found = FALSE\r
    ;  !IsNull(&ScriptFile->CommandList, &CommandNode->Link)&& !Found\r
    ;  CommandNode = (SCRIPT_COMMAND_LIST *)(*Function)(&ScriptFile->CommandList, &CommandNode->Link)\r
   ){\r
    Found = TestNodeForMove(\r
      Function,\r
      DecrementerTag,\r
      IncrementerTag,\r
      Label,\r
      ScriptFile,\r
      MovePast,\r
      FindOnly,\r
      CommandNode,\r
      &TargetCount);\r
  }\r
\r
  if (WrapAroundScript && !Found) {\r
    for (CommandNode = (SCRIPT_COMMAND_LIST *)GetFirstNode(&ScriptFile->CommandList), Found = FALSE\r
      ;  CommandNode != ScriptFile->CurrentCommand && !Found\r
      ;  CommandNode = (SCRIPT_COMMAND_LIST *)(*Function)(&ScriptFile->CommandList, &CommandNode->Link)\r
     ){\r
      Found = TestNodeForMove(\r
        Function,\r
        DecrementerTag,\r
        IncrementerTag,\r
        Label,\r
        ScriptFile,\r
        MovePast,\r
        FindOnly,\r
        CommandNode,\r
        &TargetCount);\r
    }\r
  }\r
  return (Found);\r
}\r
\r