117 lines
4.0 KiB
C
117 lines
4.0 KiB
C
/* Network-related functions for internal library use.
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Copyright (C) 2016-2017 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#ifndef _NET_INTERNAL_H
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#define _NET_INTERNAL_H 1
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#include <arpa/inet.h>
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#include <stdbool.h>
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#include <stdint.h>
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#include <sys/time.h>
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int __inet6_scopeid_pton (const struct in6_addr *address,
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const char *scope, uint32_t *result);
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libc_hidden_proto (__inet6_scopeid_pton)
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/* Deadline handling for enforcing timeouts.
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Code should call __deadline_current_time to obtain the current time
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and cache it locally. The cache needs updating after every
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long-running or potentially blocking operation. Deadlines relative
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to the current time can be computed using __deadline_from_timeval.
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The deadlines may have to be recomputed in response to certain
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events (such as an incoming packet), but they are absolute (not
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relative to the current time). A timeout suitable for use with the
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poll function can be computed from such a deadline using
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__deadline_to_ms.
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The fields in the structs defined belowed should only be used
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within the implementation. */
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/* Cache of the current time. Used to compute deadlines from relative
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timeouts and vice versa. */
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struct deadline_current_time
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{
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struct timespec current;
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};
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/* Return the current time. Terminates the process if the current
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time is not available. */
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struct deadline_current_time __deadline_current_time (void) attribute_hidden;
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/* Computed absolute deadline. */
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struct deadline
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{
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struct timespec absolute;
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};
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/* For internal use only. */
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static inline bool
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__deadline_is_infinite (struct deadline deadline)
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{
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return deadline.absolute.tv_nsec < 0;
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}
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/* Return true if the current time is at the deadline or past it. */
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static inline bool
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__deadline_elapsed (struct deadline_current_time current,
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struct deadline deadline)
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{
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return !__deadline_is_infinite (deadline)
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&& (current.current.tv_sec > deadline.absolute.tv_sec
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|| (current.current.tv_sec == deadline.absolute.tv_sec
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&& current.current.tv_nsec >= deadline.absolute.tv_nsec));
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}
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/* Return the deadline which occurs first. */
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static inline struct deadline
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__deadline_first (struct deadline left, struct deadline right)
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{
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if (__deadline_is_infinite (right)
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|| left.absolute.tv_sec < right.absolute.tv_sec
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|| (left.absolute.tv_sec == right.absolute.tv_sec
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&& left.absolute.tv_nsec < right.absolute.tv_nsec))
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return left;
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else
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return right;
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}
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/* Add TV to the current time and return it. Returns a special
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infinite absolute deadline on overflow. */
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struct deadline __deadline_from_timeval (struct deadline_current_time,
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struct timeval tv) attribute_hidden;
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/* Compute the number of milliseconds until the specified deadline,
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from the current time in the argument. The result is mainly for
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use with poll. If the deadline has already passed, return 0. If
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the result would overflow an int, return INT_MAX. */
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int __deadline_to_ms (struct deadline_current_time, struct deadline)
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attribute_hidden;
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/* Return true if TV.tv_sec is non-negative and TV.tv_usec is in the
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interval [0, 999999]. */
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static inline bool
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__is_timeval_valid_timeout (struct timeval tv)
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{
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return tv.tv_sec >= 0 && tv.tv_usec >= 0 && tv.tv_usec < 1000 * 1000;
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}
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#endif /* _NET_INTERNAL_H */
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