/* Network-related functions for internal library use.

   Copyright (C) 2016-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#ifndef _NET_INTERNAL_H

#define _NET_INTERNAL_H 1

#include <arpa/inet.h>

#include <stdbool.h>

#include <stdint.h>

#include <sys/time.h>

int __inet6_scopeid_pton (const struct in6_addr *address,

                          const char *scope, uint32_t *result);

libc_hidden_proto (__inet6_scopeid_pton)

/* IDNA conversion.  These functions convert domain names between the

   current multi-byte character set and the IDNA encoding.  On

   success, the result string is written to *RESULT (which the caller

   has to free), and zero is returned.  On error, an EAI_* error code

   is returned (see <netdb.h>), and *RESULT is not changed.  */

int __idna_to_dns_encoding (const char *name, char **result);

libc_hidden_proto (__idna_to_dns_encoding)

int __idna_from_dns_encoding (const char *name, char **result);

libc_hidden_proto (__idna_from_dns_encoding)

/* Return value of __idna_name_classify below.  */

enum idna_name_classification

{

  idna_name_ascii,          /* No non-ASCII characters.  */

  idna_name_nonascii,       /* Non-ASCII characters, no backslash.  */

  idna_name_nonascii_backslash, /* Non-ASCII characters with backslash.  */

  idna_name_encoding_error, /* Decoding error.  */

  idna_name_memory_error,   /* Memory allocation failure.  */

  idna_name_error,          /* Other error during decoding.  Check errno.  */

};

/* Check the specified name for non-ASCII characters and backslashes

   or encoding errors.  */

enum idna_name_classification __idna_name_classify (const char *name)

  attribute_hidden;

/* Deadline handling for enforcing timeouts.

   Code should call __deadline_current_time to obtain the current time

   and cache it locally.  The cache needs updating after every

   long-running or potentially blocking operation.  Deadlines relative

   to the current time can be computed using __deadline_from_timeval.

   The deadlines may have to be recomputed in response to certain

   events (such as an incoming packet), but they are absolute (not

   relative to the current time).  A timeout suitable for use with the

   poll function can be computed from such a deadline using

   __deadline_to_ms.

   The fields in the structs defined belowed should only be used

   within the implementation.  */

/* Cache of the current time.  Used to compute deadlines from relative

   timeouts and vice versa.  */

struct deadline_current_time

{

  struct timespec current;

};

/* Return the current time.  Terminates the process if the current

   time is not available.  */

struct deadline_current_time __deadline_current_time (void) attribute_hidden;

/* Computed absolute deadline.  */

struct deadline

{

  struct timespec absolute;

};

/* For internal use only.  */

static inline bool

__deadline_is_infinite (struct deadline deadline)

{

  return deadline.absolute.tv_nsec < 0;

}

/* Return true if the current time is at the deadline or past it.  */

static inline bool

__deadline_elapsed (struct deadline_current_time current,

                    struct deadline deadline)

{

  return !__deadline_is_infinite (deadline)

    && (current.current.tv_sec > deadline.absolute.tv_sec

        || (current.current.tv_sec == deadline.absolute.tv_sec

            && current.current.tv_nsec >= deadline.absolute.tv_nsec));

}

/* Return the deadline which occurs first.  */

static inline struct deadline

__deadline_first (struct deadline left, struct deadline right)

{

  if (__deadline_is_infinite (right)

      || left.absolute.tv_sec < right.absolute.tv_sec

      || (left.absolute.tv_sec == right.absolute.tv_sec

          && left.absolute.tv_nsec < right.absolute.tv_nsec))

    return left;

  else

    return right;

}

/* Add TV to the current time and return it.  Returns a special

   infinite absolute deadline on overflow.  */

struct deadline __deadline_from_timeval (struct deadline_current_time,

                                         struct timeval tv) attribute_hidden;

/* Compute the number of milliseconds until the specified deadline,

   from the current time in the argument.  The result is mainly for

   use with poll.  If the deadline has already passed, return 0.  If

   the result would overflow an int, return INT_MAX.  */

int __deadline_to_ms (struct deadline_current_time, struct deadline)

  attribute_hidden;

/* Return true if TV.tv_sec is non-negative and TV.tv_usec is in the

   interval [0, 999999].  */

static inline bool

__is_timeval_valid_timeout (struct timeval tv)

{

  return tv.tv_sec >= 0 && tv.tv_usec >= 0 && tv.tv_usec < 1000 * 1000;

}

#endif /* _NET_INTERNAL_H */