1=pod 2 3=head1 NAME 4 5BIO_socket_wait, 6BIO_wait, 7BIO_do_connect_retry 8- BIO connection utility functions 9 10=head1 SYNOPSIS 11 12 #include <openssl/bio.h> 13 14 #ifndef OPENSSL_NO_SOCK 15 int BIO_socket_wait(int fd, int for_read, time_t max_time); 16 #endif 17 int BIO_wait(BIO *bio, time_t max_time, unsigned int nap_milliseconds); 18 int BIO_do_connect_retry(BIO *bio, int timeout, int nap_milliseconds); 19 20=head1 DESCRIPTION 21 22BIO_socket_wait() waits on the socket B<fd> for reading if B<for_read> is not 0, 23else for writing, at most until B<max_time>. 24It succeeds immediately if B<max_time> == 0 (which means no timeout given). 25 26BIO_wait() waits at most until B<max_time> on the given (typically socket-based) 27B<bio>, for reading if B<bio> is supposed to read, else for writing. 28It is used by BIO_do_connect_retry() and can be used together L<BIO_read(3)>. 29It succeeds immediately if B<max_time> == 0 (which means no timeout given). 30If sockets are not available it supports polling by succeeding after sleeping 31at most the given B<nap_milliseconds> in order to avoid a tight busy loop. 32Via B<nap_milliseconds> the caller determines the polling granularity. 33 34BIO_do_connect_retry() connects via the given B<bio>. 35It retries BIO_do_connect() as far as needed to reach a definite outcome, 36i.e., connection succeeded, timeout has been reached, or an error occurred. 37For nonblocking and potentially even non-socket BIOs it polls 38every B<nap_milliseconds> and sleeps in between using BIO_wait(). 39If B<nap_milliseconds> is < 0 then a default value of 100 ms is used. 40If the B<timeout> parameter is > 0 this indicates the maximum number of seconds 41to wait until the connection is established or a definite error occurred. 42A value of 0 enables waiting indefinitely (i.e, no timeout), 43while a value < 0 means that BIO_do_connect() is tried only once. 44The function may, directly or indirectly, invoke ERR_clear_error(). 45 46=head1 RETURN VALUES 47 48BIO_socket_wait(), BIO_wait(), and BIO_do_connect_retry() 49return -1 on error, 0 on timeout, and 1 on success. 50 51=head1 SEE ALSO 52 53L<BIO_do_connect(3)>, L<BIO_read(3)> 54 55=head1 HISTORY 56 57BIO_socket_wait(), BIO_wait(), and BIO_do_connect_retry() 58were added in OpenSSL 3.0. 59 60=head1 COPYRIGHT 61 62Copyright 2019-2020 The OpenSSL Project Authors. All Rights Reserved. 63 64Licensed under the Apache License 2.0 (the "License"). You may not use 65this file except in compliance with the License. You can obtain a copy 66in the file LICENSE in the source distribution or at 67L<https://www.openssl.org/source/license.html>. 68 69=cut 70
