Legacy BIO callback invoked immediately before and after I/O operations (deprecated).
Declared in <openssl/bio.h>
typedef long(* BIO_callback_fn)(BIO*, int, char const*, int, long, long);Post-call return value (usually ret unchanged).
| Name | Description |
|---|---|
| b | BIO performing the operation. |
| oper | BIO_CB_* operation code OR'd with BIO_CB_RETURN after the call. |
| argp | Pointer argument (buffer or ctrl pointer), or NULL. |
| argi | Integer argument for ctrl-style operations. |
| argl | Long argument for ctrl-style operations. |
| ret | Return value from the underlying operation (post-call only). |