session tls: improve app transports tx scheduling

Type: improvement

- allow apps to request rescheduling of tx events via
SESSION_F_CUSTOM_TX flag
- limit max burst per session custom tx dispatch

In tls
- use the new infra to reschedule tx events
- use max burst bytes as upper limit to number of bytes to be encrypted

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: I544a5a3337af7ebdff3406b776adf30cf96ebf3c

1 files changed, 7 insertions, 10 deletions

diff --git a/src/plugins/tlsopenssl/tls_openssl.c b/src/plugins/tlsopenssl/tls_openssl.c
index 43bb13ff967..935e0147e30 100644
--- a/src/plugins/tlsopenssl/tls_openssl.c
+++ b/src/plugins/tlsopenssl/tls_openssl.c
@@ -413,7 +413,7 @@ openssl_confirm_app_close (tls_ctx_t * ctx)
 }
 
 static inline int
-openssl_ctx_write (tls_ctx_t * ctx, session_t * app_session)
+openssl_ctx_write (tls_ctx_t * ctx, session_t * app_session, u32 max_write)
 {
   openssl_ctx_t *oc = (openssl_ctx_t *) ctx;
   int wrote = 0, read, max_buf = 4 * TLS_CHUNK_SIZE, max_space;
@@ -427,6 +427,8 @@ openssl_ctx_write (tls_ctx_t * ctx, session_t * app_session)
   if (!deq_max)
     goto check_tls_fifo;
 
+  deq_max = clib_min (deq_max, max_write);
+
   /* Figure out how much data to write */
   max_space = max_buf - BIO_ctrl_pending (oc->rbio);
   max_space = (max_space < 0) ? 0 : max_space;
@@ -434,17 +436,11 @@ openssl_ctx_write (tls_ctx_t * ctx, session_t * app_session)
 
   wrote = openssl_write_from_fifo_into_ssl (f, oc->ssl, to_write);
   if (!wrote)
-    {
-      tls_add_vpp_q_builtin_tx_evt (app_session);
-      goto check_tls_fifo;
-    }
+    goto check_tls_fifo;
 
   if (svm_fifo_needs_deq_ntf (f, wrote))
     session_dequeue_notify (app_session);
 
-  if (svm_fifo_max_dequeue_cons (f))
-    tls_add_vpp_q_builtin_tx_evt (app_session);
-
 check_tls_fifo:
 
   if (BIO_ctrl_pending (oc->rbio) <= 0)
@@ -455,14 +451,15 @@ check_tls_fifo:
   read = openssl_read_from_bio_into_fifo (tls_session->tx_fifo, oc->rbio);
   if (!read)
     {
-      tls_add_vpp_q_builtin_tx_evt (app_session);
+      /* Request tx reschedule of the app session */
+      app_session->flags |= SESSION_F_CUSTOM_TX;
       return wrote;
     }
 
   tls_add_vpp_q_tx_evt (tls_session);
 
   if (BIO_ctrl_pending (oc->rbio) > 0)
-    tls_add_vpp_q_builtin_tx_evt (app_session);
+    app_session->flags |= SESSION_F_CUSTOM_TX;
   else if (ctx->app_closed)
     openssl_confirm_app_close (ctx);