+long BIO_callback_ctrl(BIO *b, int cmd, void (*fp)(struct bio_st *, int, const char *, int, long, long))
+ {
+ long ret;
+ long (*cb)();
+
+ if (b == NULL) return(0);
+
+ if ((b->method == NULL) || (b->method->callback_ctrl == NULL))
+ {
+ BIOerr(BIO_F_BIO_CTRL,BIO_R_UNSUPPORTED_METHOD);
+ return(-2);
+ }
+
+ cb=b->callback;
+
+ if ((cb != NULL) &&
+ ((ret=cb(b,BIO_CB_CTRL,(void *)&fp,cmd,0,1L)) <= 0))
+ return(ret);
+
+ ret=b->method->callback_ctrl(b,cmd,fp);
+
+ if (cb != NULL)
+ ret=cb(b,BIO_CB_CTRL|BIO_CB_RETURN,(void *)&fp,cmd,
+ 0,ret);
+ return(ret);
+ }
+
+/* It is unfortunate to duplicate in functions what the BIO_(w)pending macros
+ * do; but those macros have inappropriate return type, and for interfacing
+ * from other programming languages, C macros aren't much of a help anyway. */
+size_t BIO_ctrl_pending(BIO *bio)
+ {
+ return BIO_ctrl(bio, BIO_CTRL_PENDING, 0, NULL);
+ }
+
+size_t BIO_ctrl_wpending(BIO *bio)
+ {
+ return BIO_ctrl(bio, BIO_CTRL_WPENDING, 0, NULL);
+ }
+
+