Question regarding SSL code in backend and frontend

Hi,

While looking into SSL code in secure_read() of be-secure.c and
pqsecure_read() of fe-secure.c, I noticed subtle difference between
them.

In secure_read:
----------------------------------------------------------
case SSL_ERROR_WANT_READ:
case SSL_ERROR_WANT_WRITE:
if (port->noblock)
{
errno = EWOULDBLOCK;
n = -1;
break;
}
#ifdef WIN32
pgwin32_waitforsinglesocket(SSL_get_fd(port->ssl),
(err == SSL_ERROR_WANT_READ) ?
FD_READ | FD_CLOSE : FD_WRITE | FD_CLOSE,
INFINITE);
#endif
goto rloop;
----------------------------------------------------------

while in pqsecure_read:
----------------------------------------------------------
case SSL_ERROR_WANT_READ:
n = 0;
break;
case SSL_ERROR_WANT_WRITE:

/*
* Returning 0 here would cause caller to wait for read-ready,
* which is not correct since what SSL wants is wait for
* write-ready. The former could get us stuck in an infinite
* wait, so don't risk it; busy-loop instead.
*/
goto rloop;
----------------------------------------------------------

Those code fragment judges the return value from
SSL_read(). secure_read() does retrying when SSL_ERROR_WANT_READ *and*
SSL_ERROR_WANT_WRITE returned. However, pqsecure_read() does not retry
when SSL_ERROR_WANT_READ. It seems they are not consistent. Comments?
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese: http://www.sraoss.co.jp