/*-

 * Copyright (c) 2003-2010 Tim Kientzle

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#include "archive_platform.h"

#ifdef HAVE_SYS_TYPES_H

#include <sys/types.h>

#endif

#include <stdio.h>

#include <errno.h>

#ifdef HAVE_STDLIB_H

#include <stdlib.h>

#endif

#ifdef HAVE_STRING_H

#include <string.h>

#endif

#ifdef HAVE_UNISTD_H

#include <unistd.h>

#endif

#if defined(_WIN32) && !defined(__CYGWIN__)

#include <windows.h>

#include <winbase.h>

#endif

#include "archive_private.h"

static void

errmsg(const char *m)

{

  size_t s = strlen(m);

  ssize_t written;

  while (s > 0) {

    written = write(2, m, s);

    if (written == 0)

      return;

    if (written < 0)

    {

      if (errno == EINTR)

        continue;

      return;

    }

    m += written;

    s -= written;

  }

}

static __LA_NORETURN void

diediedie(void)

{

#if defined(_WIN32) && !defined(__CYGWIN__) && defined(_DEBUG)

  /* Cause a breakpoint exception  */

  DebugBreak();

#endif

  abort();        /* Terminate the program abnormally. */

}

static const char *

state_name(unsigned s)

{

  switch (s) {

  case ARCHIVE_STATE_NEW:   return ("new");

  case ARCHIVE_STATE_HEADER: return ("header");

  case ARCHIVE_STATE_DATA: return ("data");

  case ARCHIVE_STATE_EOF:   return ("eof");

  case ARCHIVE_STATE_CLOSED: return ("closed");

  case ARCHIVE_STATE_FATAL: return ("fatal");

  default:      return ("??");

  }

}

static const char *

archive_handle_type_name(unsigned m)

{

  switch (m) {

  case ARCHIVE_WRITE_MAGIC: return ("archive_write");

  case ARCHIVE_READ_MAGIC: return ("archive_read");

  case ARCHIVE_WRITE_DISK_MAGIC: return ("archive_write_disk");

  case ARCHIVE_READ_DISK_MAGIC: return ("archive_read_disk");

  case ARCHIVE_MATCH_MAGIC: return ("archive_match");

  default:      return NULL;

  }

}

static void

write_all_states(char *buff, unsigned int states)

{

  unsigned int lowbit;

  *buff = '\0';

  /* A trick for computing the lowest set bit. */

  while ((lowbit = states & (1 + ~states)) != 0) {

    states &= ~lowbit;    /* Clear the low bit. */

    strcat(buff, state_name(lowbit));

    if (states != 0)

      strcat(buff, "/");

  }

}

/*

 * Check magic value and current state.

 *   Magic value mismatches are fatal and result in calls to abort().

 *   State mismatches return ARCHIVE_FATAL.

 *   Otherwise, returns ARCHIVE_OK.

 *

 * This is designed to catch serious programming errors that violate

 * the libarchive API.

 */

int

__archive_check_magic(struct archive *a, unsigned int magic,

    unsigned int state, const char *function)

{

  char states1[64];

  char states2[64];

  const char *handle_type;

  /*

   * If this isn't some form of archive handle,

   * then the library user has screwed up so bad that

   * we don't even have a reliable way to report an error.

   */

  handle_type = archive_handle_type_name(a->magic);

  if (!handle_type) {

    errmsg("PROGRAMMER ERROR: Function ");

    errmsg(function);

    errmsg(" invoked with invalid archive handle.\n");

    diediedie();

  }

  if (a->magic != magic) {

    archive_set_error(a, -1,

        "PROGRAMMER ERROR: Function '%s' invoked"

        " on '%s' archive object, which is not supported.",

        function,

        handle_type);

    a->state = ARCHIVE_STATE_FATAL;

    return (ARCHIVE_FATAL);

  }

  if ((a->state & state) == 0) {

    /* If we're already FATAL, don't overwrite the error. */

    if (a->state != ARCHIVE_STATE_FATAL) {

      write_all_states(states1, a->state);

      write_all_states(states2, state);

      archive_set_error(a, -1,

          "INTERNAL ERROR: Function '%s' invoked with"

          " archive structure in state '%s',"

          " should be in state '%s'",

          function,

          states1,

          states2);

    }

    a->state = ARCHIVE_STATE_FATAL;

    return (ARCHIVE_FATAL);

  }

  return (ARCHIVE_OK);

}