OpenCorePkg/Library/OcBootManagementLib/BootArguments.c

/** @file
  Copyright (C) 2019, vit9696. All rights reserved.

  All rights reserved.

  This program and the accompanying materials
  are licensed and made available under the terms and conditions of the BSD License
  which accompanies this distribution.  The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/

#include <Library/BaseMemoryLib.h>
#include <Library/DebugLib.h>
#include <Library/OcBootManagementLib.h>
#include <Library/OcMiscLib.h>
#include <Library/UefiLib.h>

VOID
OcParseBootArgs (
  OUT OC_BOOT_ARGUMENTS *Arguments,
  IN  VOID              *BootArgs
  )
{
  BootArgs1  *BA1 = (BootArgs1 *) BootArgs;
  BootArgs2  *BA2 = (BootArgs2 *) BootArgs;

  ZeroMem (Arguments, sizeof (*Arguments));

  if (BA1->Version == kBootArgsVersion1) {
    //
    // Pre Lion
    //
    Arguments->MemoryMap = &BA1->MemoryMap;
    Arguments->MemoryMapSize = &BA1->MemoryMapSize;
    Arguments->MemoryMapDescriptorSize = &BA1->MemoryMapDescriptorSize;
    Arguments->MemoryMapDescriptorVersion = &BA1->MemoryMapDescriptorVersion;

    Arguments->CommandLine = &BA1->CommandLine[0];

    Arguments->DeviceTreeP = &BA1->deviceTreeP;
    Arguments->DeviceTreeLength = &BA1->deviceTreeLength;
  } else {
    //
    // Lion and newer
    //
    Arguments->MemoryMap = &BA2->MemoryMap;
    Arguments->MemoryMapSize = &BA2->MemoryMapSize;
    Arguments->MemoryMapDescriptorSize = &BA2->MemoryMapDescriptorSize;
    Arguments->MemoryMapDescriptorVersion = &BA2->MemoryMapDescriptorVersion;

    Arguments->CommandLine = &BA2->CommandLine[0];

    Arguments->DeviceTreeP = &BA2->deviceTreeP;
    Arguments->DeviceTreeLength = &BA2->deviceTreeLength;

    if (BA2->flags & kBootArgsFlagCSRActiveConfig) {
      Arguments->CsrActiveConfig = &BA2->csrActiveConfig;
    }
  }
}

CONST CHAR8 *
OcGetArgumentFromCmd (
  IN CONST CHAR8  *CommandLine,
  IN CONST CHAR8  *Argument,
  IN CONST UINTN  ArgumentLength
  )
{
  CHAR8 *Str;

  Str = AsciiStrStr (CommandLine, Argument);

  //
  // Invalidate found boot arg if:
  // - it is neither the beginning of Cmd, nor has space prefix            -> boot arg is a suffix of another arg
  // - it has neither space suffix, nor \0 suffix, and does not end with = -> boot arg is a prefix of another arg
  //
  if (!Str || (Str != CommandLine && *(Str - 1) != ' ') ||
      (Str[ArgumentLength] != ' ' && Str[ArgumentLength] != '\0' &&
       Str[ArgumentLength - 1] != '=')) {
    return NULL;
  }

  return Str + ArgumentLength;
}

VOID
OcRemoveArgumentFromCmd (
  IN OUT CHAR8        *CommandLine,
  IN     CONST CHAR8  *Argument
  )
{
  CHAR8 *Match;

  Match = NULL;

  do {
    Match = AsciiStrStr (CommandLine, Argument);
    if (Match && (Match == CommandLine || *(Match - 1) == ' ')) {
      while (*Match != ' ' && *Match != '\0') {
        *Match++ = ' ';
      }
    }
  } while (Match != NULL);

  //
  // Write zeroes to reduce data leak
  //
  CHAR8 *Updated = CommandLine;

  while (CommandLine[0] == ' ') {
    CommandLine++;
  }

  while (CommandLine[0] != '\0') {
    while (CommandLine[0] == ' ' && CommandLine[1] == ' ') {
      CommandLine++;
    }

    *Updated++ = *CommandLine++;
  }

  ZeroMem (Updated, CommandLine - Updated);
}

BOOLEAN
OcAppendArgumentToCmd (
  IN OUT CHAR8        *CommandLine,
  IN     CONST CHAR8  *Argument,
  IN     CONST UINTN  ArgumentLength
  )
{
  UINTN Len = AsciiStrLen (CommandLine);

  //
  // Account for extra space.
  //
  if (Len + (Len > 0 ? 1 : 0) + ArgumentLength >= BOOT_LINE_LENGTH) {
    DEBUG ((DEBUG_INFO, "OCBM: boot-args are invalid, ignoring\n"));
    return FALSE;
  }

  if (Len > 0) {
    CommandLine   += Len;
    *CommandLine++ = ' ';
  }

  AsciiStrnCpyS (CommandLine, ArgumentLength + 1, Argument, ArgumentLength + 1);
  return TRUE;
}