mirror of
https://github.com/nillerusr/source-engine.git
synced 2024-12-30 18:13:00 +00:00
109 lines
3.4 KiB
Plaintext
109 lines
3.4 KiB
Plaintext
=pod
|
|
|
|
=head1 NAME
|
|
|
|
BIO_set_callback, BIO_get_callback, BIO_set_callback_arg, BIO_get_callback_arg,
|
|
BIO_debug_callback - BIO callback functions
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
#include <openssl/bio.h>
|
|
|
|
#define BIO_set_callback(b,cb) ((b)->callback=(cb))
|
|
#define BIO_get_callback(b) ((b)->callback)
|
|
#define BIO_set_callback_arg(b,arg) ((b)->cb_arg=(char *)(arg))
|
|
#define BIO_get_callback_arg(b) ((b)->cb_arg)
|
|
|
|
long BIO_debug_callback(BIO *bio,int cmd,const char *argp,int argi,
|
|
long argl,long ret);
|
|
|
|
typedef long (*callback)(BIO *b, int oper, const char *argp,
|
|
int argi, long argl, long retvalue);
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
BIO_set_callback() and BIO_get_callback() set and retrieve the BIO callback,
|
|
they are both macros. The callback is called during most high level BIO
|
|
operations. It can be used for debugging purposes to trace operations on
|
|
a BIO or to modify its operation.
|
|
|
|
BIO_set_callback_arg() and BIO_get_callback_arg() are macros which can be
|
|
used to set and retrieve an argument for use in the callback.
|
|
|
|
BIO_debug_callback() is a standard debugging callback which prints
|
|
out information relating to each BIO operation. If the callback
|
|
argument is set if is interpreted as a BIO to send the information
|
|
to, otherwise stderr is used.
|
|
|
|
callback() is the callback function itself. The meaning of each
|
|
argument is described below.
|
|
|
|
The BIO the callback is attached to is passed in B<b>.
|
|
|
|
B<oper> is set to the operation being performed. For some operations
|
|
the callback is called twice, once before and once after the actual
|
|
operation, the latter case has B<oper> or'ed with BIO_CB_RETURN.
|
|
|
|
The meaning of the arguments B<argp>, B<argi> and B<argl> depends on
|
|
the value of B<oper>, that is the operation being performed.
|
|
|
|
B<retvalue> is the return value that would be returned to the
|
|
application if no callback were present. The actual value returned
|
|
is the return value of the callback itself. In the case of callbacks
|
|
called before the actual BIO operation 1 is placed in retvalue, if
|
|
the return value is not positive it will be immediately returned to
|
|
the application and the BIO operation will not be performed.
|
|
|
|
The callback should normally simply return B<retvalue> when it has
|
|
finished processing, unless if specifically wishes to modify the
|
|
value returned to the application.
|
|
|
|
=head1 CALLBACK OPERATIONS
|
|
|
|
=over 4
|
|
|
|
=item B<BIO_free(b)>
|
|
|
|
callback(b, BIO_CB_FREE, NULL, 0L, 0L, 1L) is called before the
|
|
free operation.
|
|
|
|
=item B<BIO_read(b, out, outl)>
|
|
|
|
callback(b, BIO_CB_READ, out, outl, 0L, 1L) is called before
|
|
the read and callback(b, BIO_CB_READ|BIO_CB_RETURN, out, outl, 0L, retvalue)
|
|
after.
|
|
|
|
=item B<BIO_write(b, in, inl)>
|
|
|
|
callback(b, BIO_CB_WRITE, in, inl, 0L, 1L) is called before
|
|
the write and callback(b, BIO_CB_WRITE|BIO_CB_RETURN, in, inl, 0L, retvalue)
|
|
after.
|
|
|
|
=item B<BIO_gets(b, out, outl)>
|
|
|
|
callback(b, BIO_CB_GETS, out, outl, 0L, 1L) is called before
|
|
the operation and callback(b, BIO_CB_GETS|BIO_CB_RETURN, out, outl, 0L, retvalue)
|
|
after.
|
|
|
|
=item B<BIO_puts(b, in)>
|
|
|
|
callback(b, BIO_CB_WRITE, in, 0, 0L, 1L) is called before
|
|
the operation and callback(b, BIO_CB_WRITE|BIO_CB_RETURN, in, 0, 0L, retvalue)
|
|
after.
|
|
|
|
=item B<BIO_ctrl(BIO *b, int cmd, long larg, void *parg)>
|
|
|
|
callback(b,BIO_CB_CTRL,parg,cmd,larg,1L) is called before the call and
|
|
callback(b,BIO_CB_CTRL|BIO_CB_RETURN,parg,cmd, larg,ret) after.
|
|
|
|
=back
|
|
|
|
=head1 EXAMPLE
|
|
|
|
The BIO_debug_callback() function is a good example, its source is
|
|
in crypto/bio/bio_cb.c
|
|
|
|
=head1 SEE ALSO
|
|
|
|
TBA
|