/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include <string.h>
#include <stdlib.h>
#include "primpl.h"
#include "prmem.h"

#if defined(XP_UNIX)
#  include <unistd.h>
#  if defined(DARWIN)
#    if defined(HAVE_CRT_EXTERNS_H)
#      include <crt_externs.h>
#    endif /* HAVE_CRT_EXTERNS_H */
#  else    /* DARWIN */
PR_IMPORT_DATA(char**) environ;
#  endif   /* DARWIN */
#endif     /* XP_UNIX */

#if !defined(HAVE_SECURE_GETENV) && defined(HAVE___SECURE_GETENV)
#  define secure_getenv __secure_getenv
#  define HAVE_SECURE_GETENV 1
#endif

/* Lock used to lock the environment */
#if defined(_PR_NO_PREEMPT)
#  define _PR_NEW_LOCK_ENV()
#  define _PR_DELETE_LOCK_ENV()
#  define _PR_LOCK_ENV()
#  define _PR_UNLOCK_ENV()
#elif defined(_PR_LOCAL_THREADS_ONLY)
extern _PRCPU* _pr_primordialCPU;
static PRIntn _is;
#  define _PR_NEW_LOCK_ENV()
#  define _PR_DELETE_LOCK_ENV()
#  define _PR_LOCK_ENV() \
    if (_pr_primordialCPU) _PR_INTSOFF(_is);
#  define _PR_UNLOCK_ENV() \
    if (_pr_primordialCPU) _PR_INTSON(_is);
#else
static PRLock* _pr_envLock = NULL;
#  define _PR_NEW_LOCK_ENV() \
    { _pr_envLock = PR_NewLock(); }
#  define _PR_DELETE_LOCK_ENV()      \
    {                                \
      if (_pr_envLock) {             \
        PR_DestroyLock(_pr_envLock); \
        _pr_envLock = NULL;          \
      }                              \
    }
#  define _PR_LOCK_ENV()                     \
    {                                        \
      if (_pr_envLock) PR_Lock(_pr_envLock); \
    }
#  define _PR_UNLOCK_ENV()                     \
    {                                          \
      if (_pr_envLock) PR_Unlock(_pr_envLock); \
    }
#endif

/************************************************************************/

void _PR_InitEnv(void) { _PR_NEW_LOCK_ENV(); }

void _PR_CleanupEnv(void) { _PR_DELETE_LOCK_ENV(); }

PR_IMPLEMENT(char*) PR_GetEnv(const char* var) {
  char* ev;

  if (!_pr_initialized) {
    _PR_ImplicitInitialization();
  }

  _PR_LOCK_ENV();
  ev = _PR_MD_GET_ENV(var);
  _PR_UNLOCK_ENV();
  return ev;
}

PR_IMPLEMENT(char*) PR_GetEnvSecure(const char* var) {
#ifdef HAVE_SECURE_GETENV
  char* ev;

  if (!_pr_initialized) {
    _PR_ImplicitInitialization();
  }

  _PR_LOCK_ENV();
  ev = secure_getenv(var);
  _PR_UNLOCK_ENV();

  return ev;
#else
#  ifdef XP_UNIX
  /*
  ** Fall back to checking uids and gids.  This won't detect any other
  ** privilege-granting mechanisms the platform may have.  This also
  ** can't detect the case where the process already called
  ** setuid(geteuid()) and/or setgid(getegid()).
  */
  if (getuid() != geteuid() || getgid() != getegid()) {
    return NULL;
  }
#  endif /* XP_UNIX */
  return PR_GetEnv(var);
#endif   /* HAVE_SECURE_GETENV */
}

PR_IMPLEMENT(PRStatus) PR_SetEnv(const char* string) {
  PRIntn result;

  if (!_pr_initialized) {
    _PR_ImplicitInitialization();
  }

  if (!strchr(string, '=')) {
    return (PR_FAILURE);
  }

  _PR_LOCK_ENV();
  result = _PR_MD_PUT_ENV((char*)string);
  _PR_UNLOCK_ENV();
  return result ? PR_FAILURE : PR_SUCCESS;
}

#if defined(XP_UNIX) && (!defined(DARWIN) || defined(HAVE_CRT_EXTERNS_H))
PR_IMPLEMENT(char**) PR_DuplicateEnvironment(void) {
  char **the_environ, **result, **end, **src, **dst;

  _PR_LOCK_ENV();
#  ifdef DARWIN
  the_environ = *(_NSGetEnviron());
#  else
  the_environ = environ;
#  endif

  for (end = the_environ; *end != NULL; end++) /* empty loop body */;

  result = (char**)PR_Malloc(sizeof(char*) * (end - the_environ + 1));
  if (result != NULL) {
    for (src = the_environ, dst = result; src != end; src++, dst++) {
      size_t len;

      len = strlen(*src) + 1;
      *dst = PR_Malloc(len);
      if (*dst == NULL) {
        /* Allocation failed.  Must clean up the half-copied env. */
        char** to_delete;

        for (to_delete = result; to_delete != dst; to_delete++) {
          PR_Free(*to_delete);
        }
        PR_Free(result);
        result = NULL;
        goto out;
      }
      memcpy(*dst, *src, len);
    }
    *dst = NULL;
  }
out:
  _PR_UNLOCK_ENV();
  return result;
}
#else
/* This platform doesn't support raw access to the environ block. */
PR_IMPLEMENT(char**) PR_DuplicateEnvironment(void) { return NULL; }
#endif