190 lines
7.0 KiB
Plaintext
190 lines
7.0 KiB
Plaintext
|
=pod
|
||
|
|
|
||
|
|
=head1 NAME
|
||
|
|
|
||
|
|
BIO_ctrl, BIO_callback_ctrl, BIO_ptr_ctrl, BIO_int_ctrl, BIO_reset,
|
||
|
|
BIO_seek, BIO_tell, BIO_flush, BIO_eof, BIO_set_close, BIO_get_close,
|
||
|
|
BIO_pending, BIO_wpending, BIO_ctrl_pending, BIO_ctrl_wpending,
|
||
|
|
BIO_get_info_callback, BIO_set_info_callback, BIO_info_cb, BIO_get_ktls_send,
|
||
|
|
BIO_get_ktls_recv, BIO_set_conn_mode, BIO_get_conn_mode, BIO_set_tfo
|
||
|
|
- BIO control operations
|
||
|
|
|
||
|
|
=head1 SYNOPSIS
|
||
|
|
|
||
|
|
#include <openssl/bio.h>
|
||
|
|
|
||
|
|
typedef int BIO_info_cb(BIO *b, int state, int res);
|
||
|
|
|
||
|
|
long BIO_ctrl(BIO *bp, int cmd, long larg, void *parg);
|
||
|
|
long BIO_callback_ctrl(BIO *b, int cmd, BIO_info_cb *cb);
|
||
|
|
void *BIO_ptr_ctrl(BIO *bp, int cmd, long larg);
|
||
|
|
long BIO_int_ctrl(BIO *bp, int cmd, long larg, int iarg);
|
||
|
|
|
||
|
|
int BIO_reset(BIO *b);
|
||
|
|
int BIO_seek(BIO *b, int ofs);
|
||
|
|
int BIO_tell(BIO *b);
|
||
|
|
int BIO_flush(BIO *b);
|
||
|
|
int BIO_eof(BIO *b);
|
||
|
|
int BIO_set_close(BIO *b, long flag);
|
||
|
|
int BIO_get_close(BIO *b);
|
||
|
|
int BIO_pending(BIO *b);
|
||
|
|
int BIO_wpending(BIO *b);
|
||
|
|
size_t BIO_ctrl_pending(BIO *b);
|
||
|
|
size_t BIO_ctrl_wpending(BIO *b);
|
||
|
|
|
||
|
|
int BIO_get_info_callback(BIO *b, BIO_info_cb **cbp);
|
||
|
|
int BIO_set_info_callback(BIO *b, BIO_info_cb *cb);
|
||
|
|
|
||
|
|
int BIO_get_ktls_send(BIO *b);
|
||
|
|
int BIO_get_ktls_recv(BIO *b);
|
||
|
|
|
||
|
|
int BIO_set_conn_mode(BIO *b, int mode);
|
||
|
|
int BIO_get_conn_mode(BIO *b);
|
||
|
|
|
||
|
|
int BIO_set_tfo(BIO *b, int onoff);
|
||
|
|
|
||
|
|
=head1 DESCRIPTION
|
||
|
|
|
||
|
|
BIO_ctrl(), BIO_callback_ctrl(), BIO_ptr_ctrl() and BIO_int_ctrl()
|
||
|
|
are BIO "control" operations taking arguments of various types.
|
||
|
|
These functions are not normally called directly, various macros
|
||
|
|
are used instead. The standard macros are described below, macros
|
||
|
|
specific to a particular type of BIO are described in the specific
|
||
|
|
BIOs manual page as well as any special features of the standard
|
||
|
|
calls.
|
||
|
|
|
||
|
|
BIO_reset() typically resets a BIO to some initial state, in the case
|
||
|
|
of file related BIOs for example it rewinds the file pointer to the
|
||
|
|
start of the file.
|
||
|
|
|
||
|
|
BIO_seek() resets a file related BIO's (that is file descriptor and
|
||
|
|
FILE BIOs) file position pointer to B<ofs> bytes from start of file.
|
||
|
|
|
||
|
|
BIO_tell() returns the current file position of a file related BIO.
|
||
|
|
|
||
|
|
BIO_flush() normally writes out any internally buffered data, in some
|
||
|
|
cases it is used to signal EOF and that no more data will be written.
|
||
|
|
|
||
|
|
BIO_eof() returns 1 if the BIO has read EOF, the precise meaning of
|
||
|
|
"EOF" varies according to the BIO type.
|
||
|
|
|
||
|
|
BIO_set_close() sets the BIO B<b> close flag to B<flag>. B<flag> can
|
||
|
|
take the value BIO_CLOSE or BIO_NOCLOSE. Typically BIO_CLOSE is used
|
||
|
|
in a source/sink BIO to indicate that the underlying I/O stream should
|
||
|
|
be closed when the BIO is freed.
|
||
|
|
|
||
|
|
BIO_get_close() returns the BIOs close flag.
|
||
|
|
|
||
|
|
BIO_pending(), BIO_ctrl_pending(), BIO_wpending() and BIO_ctrl_wpending()
|
||
|
|
return the number of pending characters in the BIOs read and write buffers.
|
||
|
|
Not all BIOs support these calls. BIO_ctrl_pending() and BIO_ctrl_wpending()
|
||
|
|
return a size_t type and are functions, BIO_pending() and BIO_wpending() are
|
||
|
|
macros which call BIO_ctrl().
|
||
|
|
|
||
|
|
BIO_get_ktls_send() returns 1 if the BIO is using the Kernel TLS data-path for
|
||
|
|
sending. Otherwise, it returns zero.
|
||
|
|
BIO_get_ktls_recv() returns 1 if the BIO is using the Kernel TLS data-path for
|
||
|
|
receiving. Otherwise, it returns zero.
|
||
|
|
|
||
|
|
BIO_get_conn_mode() returns the BIO connection mode. BIO_set_conn_mode() sets
|
||
|
|
the BIO connection mode.
|
||
|
|
|
||
|
|
BIO_set_tfo() disables TCP Fast Open when B<onoff> is 0, and enables TCP Fast
|
||
|
|
Open when B<onoff> is nonzero. Setting the value to 1 is equivalent to setting
|
||
|
|
B<BIO_SOCK_TFO> in BIO_set_conn_mode().
|
||
|
|
|
||
|
|
=head1 RETURN VALUES
|
||
|
|
|
||
|
|
BIO_reset() normally returns 1 for success and <=0 for failure. File
|
||
|
|
BIOs are an exception, they return 0 for success and -1 for failure.
|
||
|
|
|
||
|
|
BIO_seek() and BIO_tell() both return the current file position on success
|
||
|
|
and -1 for failure, except file BIOs which for BIO_seek() always return 0
|
||
|
|
for success and -1 for failure.
|
||
|
|
|
||
|
|
BIO_flush() returns 1 for success and <=0 for failure.
|
||
|
|
|
||
|
|
BIO_eof() returns 1 if EOF has been reached, 0 if not, or negative values for failure.
|
||
|
|
|
||
|
|
BIO_set_close() returns 1 on success or <=0 for failure.
|
||
|
|
|
||
|
|
BIO_get_close() returns the close flag value: BIO_CLOSE or BIO_NOCLOSE. It also
|
||
|
|
returns other negative values if an error occurs.
|
||
|
|
|
||
|
|
BIO_pending(), BIO_ctrl_pending(), BIO_wpending() and BIO_ctrl_wpending()
|
||
|
|
return the amount of pending data. BIO_pending() and BIO_wpending() return
|
||
|
|
negative value or 0 on error. BIO_ctrl_pending() and BIO_ctrl_wpending() return
|
||
|
|
0 on error.
|
||
|
|
|
||
|
|
BIO_get_ktls_send() returns 1 if the BIO is using the Kernel TLS data-path for
|
||
|
|
sending. Otherwise, it returns zero.
|
||
|
|
BIO_get_ktls_recv() returns 1 if the BIO is using the Kernel TLS data-path for
|
||
|
|
receiving. Otherwise, it returns zero.
|
||
|
|
|
||
|
|
BIO_set_conn_mode() returns 1 for success and 0 for failure. BIO_get_conn_mode()
|
||
|
|
returns the current connection mode. Which may contain the bitwise-or of the
|
||
|
|
following flags:
|
||
|
|
|
||
|
|
BIO_SOCK_REUSEADDR
|
||
|
|
BIO_SOCK_V6_ONLY
|
||
|
|
BIO_SOCK_KEEPALIVE
|
||
|
|
BIO_SOCK_NONBLOCK
|
||
|
|
BIO_SOCK_NODELAY
|
||
|
|
BIO_SOCK_TFO
|
||
|
|
|
||
|
|
BIO_set_tfo() returns 1 for success, and 0 for failure.
|
||
|
|
|
||
|
|
=head1 NOTES
|
||
|
|
|
||
|
|
BIO_flush(), because it can write data may return 0 or -1 indicating
|
||
|
|
that the call should be retried later in a similar manner to BIO_write_ex().
|
||
|
|
The BIO_should_retry() call should be used and appropriate action taken
|
||
|
|
is the call fails.
|
||
|
|
|
||
|
|
The return values of BIO_pending() and BIO_wpending() may not reliably
|
||
|
|
determine the amount of pending data in all cases. For example in the
|
||
|
|
case of a file BIO some data may be available in the FILE structures
|
||
|
|
internal buffers but it is not possible to determine this in a
|
||
|
|
portably way. For other types of BIO they may not be supported.
|
||
|
|
|
||
|
|
Filter BIOs if they do not internally handle a particular BIO_ctrl()
|
||
|
|
operation usually pass the operation to the next BIO in the chain.
|
||
|
|
This often means there is no need to locate the required BIO for
|
||
|
|
a particular operation, it can be called on a chain and it will
|
||
|
|
be automatically passed to the relevant BIO. However, this can cause
|
||
|
|
unexpected results: for example no current filter BIOs implement
|
||
|
|
BIO_seek(), but this may still succeed if the chain ends in a FILE
|
||
|
|
or file descriptor BIO.
|
||
|
|
|
||
|
|
Source/sink BIOs return an 0 if they do not recognize the BIO_ctrl()
|
||
|
|
operation.
|
||
|
|
|
||
|
|
=head1 BUGS
|
||
|
|
|
||
|
|
Some of the return values are ambiguous and care should be taken. In
|
||
|
|
particular a return value of 0 can be returned if an operation is not
|
||
|
|
supported, if an error occurred, if EOF has not been reached and in
|
||
|
|
the case of BIO_seek() on a file BIO for a successful operation.
|
||
|
|
|
||
|
|
In older versions of OpenSSL the BIO_ctrl_pending() and
|
||
|
|
BIO_ctrl_wpending() could return values greater than INT_MAX on error.
|
||
|
|
|
||
|
|
=head1 HISTORY
|
||
|
|
|
||
|
|
The BIO_get_ktls_send() and BIO_get_ktls_recv() macros were added in
|
||
|
|
OpenSSL 3.0. They were modified to never return -1 in OpenSSL 3.0.4.
|
||
|
|
|
||
|
|
The BIO_get_conn_mode(), BIO_set_conn_mode() and BIO_set_tfo() functions
|
||
|
|
were added in OpenSSL 3.2.
|
||
|
|
|
||
|
|
=head1 COPYRIGHT
|
||
|
|
|
||
|
|
Copyright 2000-2022 The OpenSSL Project Authors. All Rights Reserved.
|
||
|
|
|
||
|
|
Licensed under the Apache License 2.0 (the "License"). You may not use
|
||
|
|
this file except in compliance with the License. You can obtain a copy
|
||
|
|
in the file LICENSE in the source distribution or at
|
||
|
|
L<https://www.openssl.org/source/license.html>.
|
||
|
|
|
||
|
|
=cut
|