3 files changed, 31 insertions, 17 deletions

diff --git a/src/vnet/session/application_local.c b/src/vnet/session/application_local.c
index d54d1119ce6..0e1f6db19fb 100644
--- a/src/vnet/session/application_local.c
+++ b/src/vnet/session/application_local.c
@@ -470,7 +470,7 @@ format_ct_connection_id (u8 * s, va_list * args)
 }
 
 static int
-ct_custom_tx (void *session, u32 max_burst_size)
+ct_custom_tx (void *session, transport_send_params_t * sp)
 {
   session_t *s = (session_t *) session;
   if (session_has_transport (s))
diff --git a/src/vnet/session/session_node.c b/src/vnet/session/session_node.c
index 30eca1e6577..f023a95c98c 100644
--- a/src/vnet/session/session_node.c
+++ b/src/vnet/session/session_node.c
@@ -872,7 +872,8 @@ session_tx_fifo_read_and_snd_i (session_worker_t * wrk,
     {
       u32 n_custom_tx;
       ctx->s->flags &= ~SESSION_F_CUSTOM_TX;
-      n_custom_tx = ctx->transport_vft->custom_tx (ctx->tc, max_burst);
+      ctx->sp.max_burst_size = max_burst;
+      n_custom_tx = ctx->transport_vft->custom_tx (ctx->tc, &ctx->sp);
       *n_tx_packets += n_custom_tx;
       if (PREDICT_FALSE
 	  (ctx->s->session_state >= SESSION_STATE_TRANSPORT_CLOSED))
@@ -1068,8 +1069,9 @@ session_tx_fifo_dequeue_internal (session_worker_t * wrk,
 				  vlib_node_runtime_t * node,
 				  session_evt_elt_t * elt, int *n_tx_packets)
 {
+  transport_send_params_t *sp = &wrk->ctx.sp;
   session_t *s = wrk->ctx.s;
-  u32 n_packets, max_pkts;
+  u32 n_packets;
 
   if (PREDICT_FALSE (s->session_state >= SESSION_STATE_TRANSPORT_CLOSED))
     return 0;
@@ -1077,18 +1079,17 @@ session_tx_fifo_dequeue_internal (session_worker_t * wrk,
   /* Clear custom-tx flag used to request reschedule for tx */
   s->flags &= ~SESSION_F_CUSTOM_TX;
 
-  max_pkts = clib_min (VLIB_FRAME_SIZE - *n_tx_packets,
-		       TRANSPORT_PACER_MAX_BURST_PKTS);
-  n_packets = transport_custom_tx (session_get_transport_proto (s), s,
-				   max_pkts);
-  *n_tx_packets -= n_packets;
+  sp->max_burst_size = clib_min (VLIB_FRAME_SIZE - *n_tx_packets,
+				 TRANSPORT_PACER_MAX_BURST_PKTS);
 
-  if (svm_fifo_max_dequeue_cons (s->tx_fifo)
-      || (s->flags & SESSION_F_CUSTOM_TX))
+  n_packets = transport_custom_tx (session_get_transport_proto (s), s, sp);
+  *n_tx_packets += n_packets;
+
+  if (s->flags & SESSION_F_CUSTOM_TX)
     {
       session_evt_add_old (wrk, elt);
     }
-  else
+  else if (!(sp->flags & TRANSPORT_SND_F_DESCHED))
     {
       svm_fifo_unset_event (s->tx_fifo);
       if (svm_fifo_max_dequeue_cons (s->tx_fifo))
diff --git a/src/vnet/session/transport.h b/src/vnet/session/transport.h
index 6dc6984cdf4..eb98032b1e4 100644
--- a/src/vnet/session/transport.h
+++ b/src/vnet/session/transport.h
@@ -44,9 +44,21 @@ typedef enum transport_snd_flags_
 
 typedef struct transport_send_params_
 {
-  u32 snd_space;
-  u32 tx_offset;
-  u16 snd_mss;
+  union
+  {
+    /* Used to retrieve snd params from transports */
+    struct
+    {
+      u32 snd_space;
+      u32 tx_offset;
+      u16 snd_mss;
+    };
+    /* Used by custom tx functions */
+    struct
+    {
+      u32 max_burst_size;
+    };
+  };
   transport_snd_flags_t flags;
 } transport_send_params_t;
 
@@ -76,7 +88,7 @@ typedef struct _transport_proto_vft
 		      transport_send_params_t *sp);
   void (*update_time) (f64 time_now, u8 thread_index);
   void (*flush_data) (transport_connection_t *tconn);
-  int (*custom_tx) (void *session, u32 max_burst_size);
+  int (*custom_tx) (void *session, transport_send_params_t *sp);
   int (*app_rx_evt) (transport_connection_t *tconn);
 
   /*
@@ -152,9 +164,10 @@ transport_get_half_open (transport_proto_t tp, u32 conn_index)
 }
 
 static inline int
-transport_custom_tx (transport_proto_t tp, void *s, u32 max_burst_size)
+transport_custom_tx (transport_proto_t tp, void *s,
+		     transport_send_params_t * sp)
 {
-  return tp_vfts[tp].custom_tx (s, max_burst_size);
+  return tp_vfts[tp].custom_tx (s, sp);
 }
 
 static inline int