From b38468d49f77c3ef4cadf6b0d24c70699cce67b4 Mon Sep 17 00:00:00 2001
From: Gregory Nutt <gnutt@nuttx.org>
Date: Thu, 17 Oct 2013 09:54:48 -0600
Subject: [PATCH] net_sendfile:  Let the ACK callback handle the REXMIT flag
 and don't return until all data has been ACK'd. From Max Holtzberg

---
 ChangeLog          |  6 ++++--
 net/net_sendfile.c | 47 +++++++++++++++++++++++++---------------------
 2 files changed, 30 insertions(+), 23 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 7760eecbfd..ac87c9a833 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -5787,5 +5787,7 @@
 	  Max Holtzberg (2013-10-17).
 	* net/uip/uip_tcpinput.c:  Move tcp connection into SYN_RCVD state
 	  after aception instead of bypassing and moving directly into ESTABLISHED.
-	  From Max Holtzber (2013-10-17).
-
+	  From Max Holtzberg (2013-10-17).
+	* net/net_sendfile.c:  Let the ACK callback handle the REXMIT flag and
+	  don't return until all data has been ACK'd. From Max Holtzberg
+	  (2013-10-17).
diff --git a/net/net_sendfile.c b/net/net_sendfile.c
index 2b5f6b2116..17189ae0f1 100644
--- a/net/net_sendfile.c
+++ b/net/net_sendfile.c
@@ -170,12 +170,18 @@ static uint16_t ack_interrupt(FAR struct uip_driver_s *dev, FAR void *pvconn,
 
       dev->d_sndlen = 0;
 
-      /* Wake up the waiting thread */
-
-      sem_post(&pstate->snd_sem);
-
       flags &= ~UIP_ACKDATA;
     }
+  else if ((flags & UIP_REXMIT) != 0)
+    {
+      nlldbg("REXMIT\n");
+
+      /* Yes.. in this case, reset the number of bytes that have been sent
+       * to the number of bytes that have been ACKed.
+       */
+
+      pstate->snd_sent = pstate->snd_acked;
+    }
 
   /* Check for a loss of connection */
 
@@ -187,10 +193,12 @@ static uint16_t ack_interrupt(FAR struct uip_driver_s *dev, FAR void *pvconn,
 
       net_lostconnection(pstate->snd_sock, flags);
       pstate->snd_sent = -ENOTCONN;
-
-      sem_post(&pstate->snd_sem);
     }
 
+  /* Wake up the waiting thread */
+
+  sem_post(&pstate->snd_sem);
+
   return flags;
 }
 
@@ -224,20 +232,9 @@ static uint16_t sendfile_interrupt(FAR struct uip_driver_s *dev, FAR void *pvcon
   nllvdbg("flags: %04x acked: %d sent: %d\n",
           flags, pstate->snd_acked, pstate->snd_sent);
 
-  if ((flags & UIP_REXMIT) != 0)
-    {
-      /* Yes.. in this case, reset the number of bytes that have been sent
-       * to the number of bytes that have been ACKed.
-       */
-
-      pstate->snd_sent = pstate->snd_acked;
-
-      /* Fall through to re-send data from the last that was ACKed */
-    }
-
   /* Check for a loss of connection */
 
-  else if ((flags & (UIP_CLOSE|UIP_ABORT|UIP_TIMEDOUT)) != 0)
+  if ((flags & (UIP_CLOSE|UIP_ABORT|UIP_TIMEDOUT)) != 0)
     {
       /* Report not connected */
 
@@ -356,6 +353,14 @@ static uint16_t sendfile_interrupt(FAR struct uip_driver_s *dev, FAR void *pvcon
     }
 #endif /* CONFIG_NET_SOCKOPTS && !CONFIG_DISABLE_CLOCK */
 
+  if (pstate->snd_sent >= pstate->snd_flen
+      && pstate->snd_acked < pstate->snd_flen)
+    {
+      /* All data has been sent, but there are outstanding ACK's */
+
+      goto wait;
+    }
+
 end_wait:
 
   /* Do not allow any further callbacks */
@@ -521,7 +526,7 @@ ssize_t net_sendfile(int outfd, struct file *infile, off_t *offset,
 
   /* Set up the ACK callback in the connection */
 
-  state.snd_ackcb->flags = UIP_ACKDATA|UIP_CLOSE|UIP_ABORT|UIP_TIMEDOUT;
+  state.snd_ackcb->flags = UIP_ACKDATA|UIP_REXMIT|UIP_CLOSE|UIP_ABORT|UIP_TIMEDOUT;
   state.snd_ackcb->priv  = (void*)&state;
   state.snd_ackcb->event = ack_interrupt;
 
@@ -529,7 +534,7 @@ ssize_t net_sendfile(int outfd, struct file *infile, off_t *offset,
 
   do
     {
-      state.snd_datacb->flags = UIP_REXMIT|UIP_POLL;
+      state.snd_datacb->flags = UIP_POLL;
       state.snd_datacb->priv  = (void*)&state;
       state.snd_datacb->event = sendfile_interrupt;
 
@@ -539,7 +544,7 @@ ssize_t net_sendfile(int outfd, struct file *infile, off_t *offset,
 
       uip_lockedwait(&state.snd_sem);
     }
-  while (state.snd_sent > 0 && state.snd_acked < state.snd_flen);
+  while (state.snd_sent >= 0 && state.snd_acked < state.snd_flen);
 
   /* Set the socket state to idle */