environment.c

 
#include <winpr/config.h>
 
#include <winpr/crt.h>
#include <winpr/platform.h>
#include <winpr/error.h>
#include <winpr/file.h>
#include <winpr/string.h>
 
#include <winpr/environment.h>
 
#ifndef _WIN32
 
#include <errno.h>
 
#ifdef WINPR_HAVE_UNISTD_H
#include <unistd.h>
#endif
 
#if defined(__IOS__)
 
#elif defined(__MACOSX__)
#include <crt_externs.h>
#define environ (*_NSGetEnviron())
#endif
 
DWORD GetCurrentDirectoryA(DWORD nBufferLength, LPSTR lpBuffer)
{
  size_t length = 0;
  char* cwd = NULL;
  char* ccwd = NULL;
 
  do
  {
    length += MAX_PATH;
    char* tmp = realloc(cwd, length);
    if (!tmp)
    {
      free(cwd);
      return 0;
    }
    cwd = tmp;
 
    ccwd = getcwd(cwd, length);
  } while (!ccwd && (errno == ERANGE));
 
  if (!ccwd)
  {
    free(cwd);
    return 0;
  }
 
  length = strnlen(cwd, length);
 
  if ((nBufferLength == 0) && (lpBuffer == NULL))
  {
    free(cwd);
    return (DWORD)length;
  }
  else
  {
    if (lpBuffer == NULL)
    {
      free(cwd);
      return 0;
    }
 
    if ((length + 1) > nBufferLength)
    {
      free(cwd);
      return (DWORD)(length + 1);
    }
 
    memcpy(lpBuffer, cwd, length + 1);
    free(cwd);
    return (DWORD)length;
  }
}
 
DWORD GetCurrentDirectoryW(DWORD nBufferLength, LPWSTR lpBuffer)
{
  return 0;
}
 
BOOL SetCurrentDirectoryA(LPCSTR lpPathName)
{
  return TRUE;
}
 
BOOL SetCurrentDirectoryW(LPCWSTR lpPathName)
{
  return TRUE;
}
 
DWORD SearchPathA(LPCSTR lpPath, LPCSTR lpFileName, LPCSTR lpExtension, DWORD nBufferLength,
                  LPSTR lpBuffer, LPSTR* lpFilePart)
{
  return 0;
}
 
DWORD SearchPathW(LPCWSTR lpPath, LPCWSTR lpFileName, LPCWSTR lpExtension, DWORD nBufferLength,
                  LPWSTR lpBuffer, LPWSTR* lpFilePart)
{
  return 0;
}
 
LPSTR GetCommandLineA(VOID)
{
  return NULL;
}
 
LPWSTR GetCommandLineW(VOID)
{
  return NULL;
}
 
BOOL NeedCurrentDirectoryForExePathA(LPCSTR ExeName)
{
  return TRUE;
}
 
BOOL NeedCurrentDirectoryForExePathW(LPCWSTR ExeName)
{
  return TRUE;
}
 
#endif
 
#if !defined(_WIN32) || defined(_UWP)
 
DWORD GetEnvironmentVariableA(LPCSTR lpName, LPSTR lpBuffer, DWORD nSize)
{
#if !defined(_UWP)
  size_t length = 0;
  char* env = NULL;
 
  env = getenv(lpName);
 
  if (!env)
  {
    SetLastError(ERROR_ENVVAR_NOT_FOUND);
    return 0;
  }
 
  length = strlen(env);
 
  if ((length + 1 > nSize) || (!lpBuffer))
    return (DWORD)length + 1;
 
  CopyMemory(lpBuffer, env, length);
  lpBuffer[length] = '\0';
 
  return (DWORD)length;
#else
  SetLastError(ERROR_ENVVAR_NOT_FOUND);
  return 0;
#endif
}
 
DWORD GetEnvironmentVariableW(LPCWSTR lpName, LPWSTR lpBuffer, DWORD nSize)
{
  SetLastError(ERROR_ENVVAR_NOT_FOUND);
  return 0;
}
 
BOOL SetEnvironmentVariableA(LPCSTR lpName, LPCSTR lpValue)
{
#if !defined(_UWP)
  if (!lpName)
    return FALSE;
 
  if (lpValue)
  {
    if (0 != setenv(lpName, lpValue, 1))
      return FALSE;
  }
  else
  {
    if (0 != unsetenv(lpName))
      return FALSE;
  }
 
  return TRUE;
#else
  return FALSE;
#endif
}
 
BOOL SetEnvironmentVariableW(LPCWSTR lpName, LPCWSTR lpValue)
{
  return FALSE;
}
 
extern char** environ;
 
LPCH GetEnvironmentStringsA(VOID)
{
#if !defined(_UWP)
  char* p = NULL;
  size_t offset = 0;
  size_t length = 0;
  char** envp = NULL;
  DWORD cchEnvironmentBlock = 0;
  LPCH lpszEnvironmentBlock = NULL;
 
  offset = 0;
  envp = environ;
 
  cchEnvironmentBlock = 128;
  lpszEnvironmentBlock = (LPCH)calloc(cchEnvironmentBlock, sizeof(CHAR));
  if (!lpszEnvironmentBlock)
    return NULL;
 
  while (*envp)
  {
    length = strlen(*envp);
 
    while ((offset + length + 8) > cchEnvironmentBlock)
    {
      DWORD new_size = 0;
      LPCH new_blk = NULL;
 
      new_size = cchEnvironmentBlock * 2;
      new_blk = (LPCH)realloc(lpszEnvironmentBlock, new_size * sizeof(CHAR));
      if (!new_blk)
      {
        free(lpszEnvironmentBlock);
        return NULL;
      }
 
      lpszEnvironmentBlock = new_blk;
      cchEnvironmentBlock = new_size;
    }
 
    p = &(lpszEnvironmentBlock[offset]);
 
    CopyMemory(p, *envp, length * sizeof(CHAR));
    p[length] = '\0';
 
    offset += (length + 1);
    envp++;
  }
 
  lpszEnvironmentBlock[offset] = '\0';
 
  return lpszEnvironmentBlock;
#else
  return NULL;
#endif
}
 
LPWCH GetEnvironmentStringsW(VOID)
{
  return NULL;
}
 
BOOL SetEnvironmentStringsA(LPCH NewEnvironment)
{
  return TRUE;
}
 
BOOL SetEnvironmentStringsW(LPWCH NewEnvironment)
{
  return TRUE;
}
 
DWORD ExpandEnvironmentStringsA(LPCSTR lpSrc, LPSTR lpDst, DWORD nSize)
{
  return 0;
}
 
DWORD ExpandEnvironmentStringsW(LPCWSTR lpSrc, LPWSTR lpDst, DWORD nSize)
{
  return 0;
}
 
BOOL FreeEnvironmentStringsA(LPCH lpszEnvironmentBlock)
{
  free(lpszEnvironmentBlock);
 
  return TRUE;
}
 
BOOL FreeEnvironmentStringsW(LPWCH lpszEnvironmentBlock)
{
  free(lpszEnvironmentBlock);
 
  return TRUE;
}
 
#endif
 
LPCH MergeEnvironmentStrings(PCSTR original, PCSTR merge)
{
  const char* cp = NULL;
  char* p = NULL;
  size_t offset = 0;
  size_t length = 0;
  const char* envp = NULL;
  DWORD cchEnvironmentBlock = 0;
  LPCH lpszEnvironmentBlock = NULL;
  const char** mergeStrings = NULL;
  size_t mergeStringLength = 0;
  size_t mergeArraySize = 128;
  size_t mergeLength = 0;
  size_t foundMerge = 0;
  char* foundEquals = NULL;
 
  mergeStrings = (LPCSTR*)calloc(mergeArraySize, sizeof(char*));
 
  if (!mergeStrings)
    return NULL;
 
  mergeStringLength = 0;
 
  cp = merge;
 
  while (*cp && *(cp + 1))
  {
    length = strlen(cp);
 
    if (mergeStringLength == mergeArraySize)
    {
      const char** new_str = NULL;
 
      mergeArraySize += 128;
      new_str = (const char**)realloc((void*)mergeStrings, mergeArraySize * sizeof(char*));
 
      if (!new_str)
      {
        free((void*)mergeStrings);
        return NULL;
      }
      mergeStrings = new_str;
    }
 
    mergeStrings[mergeStringLength] = cp;
    cp += length + 1;
    mergeStringLength++;
  }
 
  offset = 0;
 
  cchEnvironmentBlock = 128;
  lpszEnvironmentBlock = (LPCH)calloc(cchEnvironmentBlock, sizeof(CHAR));
 
  if (!lpszEnvironmentBlock)
  {
    free((void*)mergeStrings);
    return NULL;
  }
 
  envp = original;
 
  while ((original != NULL) && (*envp && *(envp + 1)))
  {
    size_t old_offset = offset;
    length = strlen(envp);
 
    while ((offset + length + 8) > cchEnvironmentBlock)
    {
      cchEnvironmentBlock *= 2;
      LPCH tmp = (LPCH)realloc(lpszEnvironmentBlock, cchEnvironmentBlock * sizeof(CHAR));
 
      if (!tmp)
      {
        free((void*)lpszEnvironmentBlock);
        free((void*)mergeStrings);
        return NULL;
      }
      lpszEnvironmentBlock = tmp;
    }
 
    p = &(lpszEnvironmentBlock[offset]);
 
    // check if this value is in the mergeStrings
    foundMerge = 0;
    for (size_t run = 0; run < mergeStringLength; run++)
    {
      if (!mergeStrings[run])
        continue;
 
      mergeLength = strlen(mergeStrings[run]);
      foundEquals = strstr(mergeStrings[run], "=");
 
      if (!foundEquals)
        continue;
 
      if (strncmp(envp, mergeStrings[run], foundEquals - mergeStrings[run] + 1) == 0)
      {
        // found variable in merge list ... use this ....
        if (*(foundEquals + 1) == '\0')
        {
          // check if the argument is set ... if not remove variable ...
          foundMerge = 1;
        }
        else
        {
          while ((offset + mergeLength + 8) > cchEnvironmentBlock)
          {
            cchEnvironmentBlock *= 2;
            LPCH tmp =
                (LPCH)realloc(lpszEnvironmentBlock, cchEnvironmentBlock * sizeof(CHAR));
 
            if (!tmp)
            {
              free((void*)lpszEnvironmentBlock);
              free((void*)mergeStrings);
              return NULL;
            }
            lpszEnvironmentBlock = tmp;
            p = &(lpszEnvironmentBlock[old_offset]);
          }
 
          foundMerge = 1;
          CopyMemory(p, mergeStrings[run], mergeLength);
          mergeStrings[run] = NULL;
          p[mergeLength] = '\0';
          offset += (mergeLength + 1);
        }
      }
    }
 
    if (foundMerge == 0)
    {
      CopyMemory(p, envp, length * sizeof(CHAR));
      p[length] = '\0';
      offset += (length + 1);
    }
 
    envp += (length + 1);
  }
 
  // now merge the not already merged env
  for (size_t run = 0; run < mergeStringLength; run++)
  {
    if (!mergeStrings[run])
      continue;
 
    mergeLength = strlen(mergeStrings[run]);
 
    while ((offset + mergeLength + 8) > cchEnvironmentBlock)
    {
      cchEnvironmentBlock *= 2;
      LPCH tmp = (LPCH)realloc(lpszEnvironmentBlock, cchEnvironmentBlock * sizeof(CHAR));
 
      if (!tmp)
      {
        free((void*)lpszEnvironmentBlock);
        free((void*)mergeStrings);
        return NULL;
      }
 
      lpszEnvironmentBlock = tmp;
    }
 
    p = &(lpszEnvironmentBlock[offset]);
 
    CopyMemory(p, mergeStrings[run], mergeLength);
    mergeStrings[run] = NULL;
    p[mergeLength] = '\0';
    offset += (mergeLength + 1);
  }
 
  lpszEnvironmentBlock[offset] = '\0';
 
  free((void*)mergeStrings);
 
  return lpszEnvironmentBlock;
}
 
DWORD GetEnvironmentVariableEBA(LPCSTR envBlock, LPCSTR lpName, LPSTR lpBuffer, DWORD nSize)
{
  size_t vLength = 0;
  char* env = NULL;
  char* foundEquals = NULL;
  const char* penvb = envBlock;
  size_t nLength = 0;
  size_t fLength = 0;
  size_t lpNameLength = 0;
 
  if (!lpName || NULL == envBlock)
    return 0;
 
  lpNameLength = strlen(lpName);
 
  if (lpNameLength < 1)
    return 0;
 
  while (*penvb && *(penvb + 1))
  {
    fLength = strlen(penvb);
    foundEquals = strstr(penvb, "=");
 
    if (!foundEquals)
    {
      /* if no = sign is found the envBlock is broken */
      return 0;
    }
 
    nLength = (foundEquals - penvb);
 
    if (nLength != lpNameLength)
    {
      penvb += (fLength + 1);
      continue;
    }
 
    if (strncmp(penvb, lpName, nLength) == 0)
    {
      env = foundEquals + 1;
      break;
    }
 
    penvb += (fLength + 1);
  }
 
  if (!env)
    return 0;
 
  vLength = strlen(env);
  if (vLength >= UINT32_MAX)
    return 0;
 
  if ((vLength + 1 > nSize) || (!lpBuffer))
    return (DWORD)vLength + 1;
 
  CopyMemory(lpBuffer, env, vLength + 1);
 
  return (DWORD)vLength;
}
 
BOOL SetEnvironmentVariableEBA(LPSTR* envBlock, LPCSTR lpName, LPCSTR lpValue)
{
  size_t length = 0;
  char* envstr = NULL;
  char* newEB = NULL;
 
  if (!lpName)
    return FALSE;
 
  if (lpValue)
  {
    length = (strlen(lpName) + strlen(lpValue) + 2); /* +2 because of = and \0 */
    envstr = (char*)malloc(length + 1);              /* +1 because of closing \0 */
 
    if (!envstr)
      return FALSE;
 
    (void)sprintf_s(envstr, length, "%s=%s", lpName, lpValue);
  }
  else
  {
    length = strlen(lpName) + 2;        /* +2 because of = and \0 */
    envstr = (char*)malloc(length + 1); /* +1 because of closing \0 */
 
    if (!envstr)
      return FALSE;
 
    (void)sprintf_s(envstr, length, "%s=", lpName);
  }
 
  envstr[length] = '\0';
 
  newEB = MergeEnvironmentStrings((LPCSTR)*envBlock, envstr);
 
  free(envstr);
  free(*envBlock);
 
  *envBlock = newEB;
 
  return TRUE;
}
 
char** EnvironmentBlockToEnvpA(LPCH lpszEnvironmentBlock)
{
  char* p = NULL;
  SSIZE_T index = 0;
  size_t count = 0;
  size_t length = 0;
  char** envp = NULL;
 
  count = 0;
  if (!lpszEnvironmentBlock)
    return NULL;
 
  p = (char*)lpszEnvironmentBlock;
 
  while (p[0] && p[1])
  {
    length = strlen(p);
    p += (length + 1);
    count++;
  }
 
  index = 0;
  p = (char*)lpszEnvironmentBlock;
 
  envp = (char**)calloc(count + 1, sizeof(char*));
  if (!envp)
    return NULL;
  envp[count] = NULL;
 
  while (p[0] && p[1])
  {
    length = strlen(p);
    envp[index] = _strdup(p);
    if (!envp[index])
    {
      for (index -= 1; index >= 0; --index)
      {
        free(envp[index]);
      }
      free(envp);
      return NULL;
    }
    p += (length + 1);
    index++;
  }
 
  return envp;
}
 
#ifdef _WIN32
 
// https://devblogs.microsoft.com/oldnewthing/20100203-00/?p=15083
#define WINPR_MAX_ENVIRONMENT_LENGTH 2048
 
DWORD GetEnvironmentVariableX(const char* lpName, char* lpBuffer, DWORD nSize)
{
  DWORD result = 0;
  DWORD nSizeW = 0;
  LPWSTR lpNameW = NULL;
  LPWSTR lpBufferW = NULL;
  LPSTR lpBufferA = lpBuffer;
 
  lpNameW = ConvertUtf8ToWCharAlloc(lpName, NULL);
  if (!lpNameW)
    goto cleanup;
 
  if (!lpBuffer)
  {
    char lpBufferMaxA[WINPR_MAX_ENVIRONMENT_LENGTH] = { 0 };
    WCHAR lpBufferMaxW[WINPR_MAX_ENVIRONMENT_LENGTH] = { 0 };
    LPSTR lpTmpBuffer = lpBufferMaxA;
 
    nSizeW = ARRAYSIZE(lpBufferMaxW);
 
    result = GetEnvironmentVariableW(lpNameW, lpBufferMaxW, nSizeW);
 
    SSIZE_T rc =
        ConvertWCharNToUtf8(lpBufferMaxW, nSizeW, lpTmpBuffer, ARRAYSIZE(lpBufferMaxA));
    if ((rc < 0) || (rc >= UINT32_MAX))
      goto cleanup;
 
    result = (DWORD)rc + 1;
  }
  else
  {
    nSizeW = nSize;
    lpBufferW = calloc(nSizeW + 1, sizeof(WCHAR));
 
    if (!lpBufferW)
      goto cleanup;
 
    result = GetEnvironmentVariableW(lpNameW, lpBufferW, nSizeW);
 
    if (result == 0)
      goto cleanup;
 
    SSIZE_T rc = ConvertWCharNToUtf8(lpBufferW, nSizeW, lpBufferA, nSize);
    if ((rc < 0) || (rc > UINT32_MAX))
      goto cleanup;
 
    result = (DWORD)rc;
  }
 
cleanup:
  free(lpBufferW);
  free(lpNameW);
 
  return result;
}
 
#else
 
DWORD GetEnvironmentVariableX(const char* lpName, char* lpBuffer, DWORD nSize)
{
  return GetEnvironmentVariableA(lpName, lpBuffer, nSize);
}
 
#endif