[nginx] SSL: corrected SSL_ERROR_WANT_WRITE / SSL_ERROR_WANT_READ logging.

[Maxim Dounin]

details:   http://hg.nginx.org/nginx/rev/0de0b16a551c
branches:  
changeset: 7352:0de0b16a551c
user:      Maxim Dounin <mdounin at mdounin.ru>
date:      Mon Sep 10 18:57:19 2018 +0300
description:
SSL: corrected SSL_ERROR_WANT_WRITE / SSL_ERROR_WANT_READ logging.

While SSL_read() most likely to return SSL_ERROR_WANT_WRITE (and SSL_write()
accordingly SSL_ERROR_WANT_READ) during an SSL renegotiation, it is
not necessary mean that a renegotiation was started.  In particular,
it can never happen during a renegotiation or can happen multiple times
during a renegotiation.

Because of the above, misleading "peer started SSL renegotiation" info
messages were replaced with "SSL_read: want write" and "SSL_write: want read"
debug ones.

Additionally, "SSL write handler" and "SSL read handler" are now logged
by the SSL write and read handlers, to make it easier to understand that
temporary SSL handlers are called instead of normal handlers.

diffstat:

 src/event/ngx_event_openssl.c |  12 ++++++++----
 1 files changed, 8 insertions(+), 4 deletions(-)

diffs (43 lines):

diff --git a/src/event/ngx_event_openssl.c b/src/event/ngx_event_openssl.c
--- a/src/event/ngx_event_openssl.c
+++ b/src/event/ngx_event_openssl.c
@@ -1681,8 +1681,8 @@ ngx_ssl_handle_recv(ngx_connection_t *c,
 
     if (sslerr == SSL_ERROR_WANT_WRITE) {
 
-        ngx_log_error(NGX_LOG_INFO, c->log, 0,
-                      "peer started SSL renegotiation");
+        ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0,
+                       "SSL_read: want write");
 
         c->write->ready = 0;
 
@@ -1724,6 +1724,8 @@ ngx_ssl_write_handler(ngx_event_t *wev)
 
     c = wev->data;
 
+    ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0, "SSL write handler");
+
     c->read->handler(c->read);
 }
 
@@ -1938,8 +1940,8 @@ ngx_ssl_write(ngx_connection_t *c, u_cha
 
     if (sslerr == SSL_ERROR_WANT_READ) {
 
-        ngx_log_error(NGX_LOG_INFO, c->log, 0,
-                      "peer started SSL renegotiation");
+        ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0,
+                       "SSL_write: want read");
 
         c->read->ready = 0;
 
@@ -1977,6 +1979,8 @@ ngx_ssl_read_handler(ngx_event_t *rev)
 
     c = rev->data;
 
+    ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0, "SSL read handler");
+
     c->write->handler(c->write);
 }