Daniele Lacamera / PicoTCP Featured

Free (GPLv2) TCP/IP stack developed by TASS Belgium

Dependents:   lpc1768-picotcp-demo ZeroMQ_PicoTCP_Publisher_demo TCPSocket_HelloWorld_PicoTCP Pico_TCP_UDP_Test ... more

PicoTCP. Copyright (c) 2013 TASS Belgium NV.

Released under the GNU General Public License, version 2.

Different licensing models may exist, at the sole discretion of the Copyright holders.

Official homepage: http://www.picotcp.com

Bug tracker: https://github.com/tass-belgium/picotcp/issues

Development steps:

  • initial integration with mbed RTOS
  • generic mbed Ethernet driver
  • high performance NXP LPC1768 specific Ethernet driver
  • Multi-threading support for mbed RTOS
  • Berkeley sockets and integration with the New Socket API
  • Fork of the apps running on top of the New Socket API
  • Scheduling optimizations
  • Debugging/benchmarking/testing

Demo application (measuring TCP sender performance):

Import programlpc1768-picotcp-demo

A PicoTCP demo app testing the ethernet throughput on the lpc1768 mbed board.

Last commit 17 May 2013 by TASS Belgium

Diff: modules/pico_tcp.c

Revision:
31:d3b2dfcc358f
Parent:
10:dd7111d4279f
--- a/modules/pico_tcp.c	Tue Jun 11 23:28:50 2013 +0000
+++ b/modules/pico_tcp.c	Wed Jun 12 13:35:01 2013 +0000
@@ -61,6 +61,7 @@
 #endif
 
 
+
 static inline int seq_compare(uint32_t a, uint32_t b)
 {
   uint32_t thresh = ((uint32_t)(-1))>>1;
@@ -213,8 +214,11 @@
   uint8_t  x_mode;
   uint8_t  dupacks;
   uint8_t  backoff;
+  /* Close wait flag */
+  uint8_t closing;
+};
 
-};
+static void checkIfQueueEmptyAndFin(struct pico_socket_tcp * t);
 
 /* Queues */
 static struct pico_queue tcp_in = {};
@@ -710,7 +714,7 @@
     if (in_frame_len > f->payload_len - in_frame_off)
       in_frame_len = f->payload_len - in_frame_off;
 
-    memcpy(buf + tot_rd_len, f->payload + in_frame_off, in_frame_len);
+    memcpy((uint8_t *)buf + tot_rd_len, f->payload + in_frame_off, in_frame_len);
     tot_rd_len += in_frame_len;
     t->rcv_processed += in_frame_len;
 
@@ -1041,6 +1045,44 @@
   t->snd_nxt++;
 }
 
+/*****/
+static inline void checkIfQueueEmptyAndFin(struct pico_socket_tcp * t)
+{
+    struct pico_socket *s =(struct pico_socket *)&t->sock;
+    if(t->closing && t->tcpq_out.frames==0)
+    {
+        s->state &= 0x00FFU;
+        /* set SHUT_REMOTE */
+        s->state |= PICO_SOCKET_STATE_SHUT_REMOTE;
+        s->state |= PICO_SOCKET_STATE_TCP_CLOSE_WAIT;
+        tcp_dbg("TCP> Close-wait\n");
+        if (s->wakeup)
+        {
+                s->wakeup(PICO_SOCK_EV_CLOSE, s);
+        }
+        t->closing = 0;
+    }
+
+    if ((t->tcpq_out.frames == 0) && (s->state & PICO_SOCKET_STATE_SHUT_LOCAL)) {    /* if no more packets in queue, XXX replacled !f by tcpq check */
+        if ((s->state & PICO_SOCKET_STATE_TCP) == PICO_SOCKET_STATE_TCP_ESTABLISHED) {
+            tcp_dbg("TCP> buffer empty, shutdown established ...\n");
+            /* send fin if queue empty and in state shut local (write) */
+            tcp_send_fin(t);
+            /* change tcp state to FIN_WAIT1 */
+            s->state &= 0x00FFU;
+            s->state |= PICO_SOCKET_STATE_TCP_FIN_WAIT1;
+        } else if ((s->state & PICO_SOCKET_STATE_TCP) == PICO_SOCKET_STATE_TCP_CLOSE_WAIT) {
+            /* send fin if queue empty and in state shut local (write) */
+            tcp_send_fin(t);
+            /* change tcp state to LAST_ACK */
+            s->state &= 0x00FFU;
+            s->state |= PICO_SOCKET_STATE_TCP_LAST_ACK;
+            tcp_dbg("TCP> STATE: LAST_ACK.\n");
+        }
+    }
+}
+/*****/
+
 static void tcp_sack_prepare(struct pico_socket_tcp *t)
 {
   struct pico_frame *pkt;
@@ -1280,6 +1322,7 @@
         add_retransmission_timer(t, 0);
         if (t->tcpq_out.size < t->tcpq_out.max_size)
              t->sock.ev_pending |= PICO_SOCK_EV_WR;
+        checkIfQueueEmptyAndFin(t);
         return;
     }
 }
@@ -1739,19 +1782,31 @@
   if (f->flags & PICO_TCP_ACK)
     tcp_ack(s,f);
   if (seq_compare(SEQN(f), t->rcv_nxt) == 0) {
-    /* received FIN, increase ACK nr */
-    t->rcv_nxt = long_be(hdr->seq) + 1;
-    s->state &= 0x00FFU;
-    s->state |= PICO_SOCKET_STATE_TCP_CLOSE_WAIT;
-    /* set SHUT_REMOTE */
-    s->state |= PICO_SOCKET_STATE_SHUT_REMOTE;
-      tcp_dbg("TCP> Close-wait\n");
-    if (s->wakeup){
-      if(f->payload_len>0){
-        struct pico_socket_tcp *t = (struct pico_socket_tcp *)s;
-        t->sock.ev_pending |=PICO_SOCK_EV_CLOSE;
-      }else
-        s->wakeup(PICO_SOCK_EV_CLOSE, s);
+    if(t->tcpq_out.frames == 0)
+    {
+            /* received FIN, increase ACK nr */
+            t->rcv_nxt = long_be(hdr->seq) + 1;
+            s->state &= 0x00FFU;
+            s->state |= PICO_SOCKET_STATE_TCP_CLOSE_WAIT;
+            /* set SHUT_REMOTE */
+            s->state |= PICO_SOCKET_STATE_SHUT_REMOTE;
+                tcp_dbg("TCP> Close-wait\n");
+            if (s->wakeup){
+                if(f->payload_len>0){
+                    struct pico_socket_tcp *t = (struct pico_socket_tcp *)s;
+                    t->sock.ev_pending |=PICO_SOCK_EV_CLOSE;
+                }else
+                    s->wakeup(PICO_SOCK_EV_CLOSE, s);
+            }
+    }
+    else
+    {
+        if(!t->closing)
+        {
+            /* Update ACK for the first FIN */
+            t->rcv_nxt = long_be(hdr->seq) + 1;
+        }
+        t->closing = 1;
     }
   } else {
     tcp_send_ack(t);  /* return ACK */
@@ -2032,23 +2087,9 @@
     // no packets in queue ??
   }
 
-  if ((t->tcpq_out.frames == 0) && (s->state & PICO_SOCKET_STATE_SHUT_LOCAL)) {    /* if no more packets in queue, XXX replacled !f by tcpq check */
-    if ((s->state & PICO_SOCKET_STATE_TCP) == PICO_SOCKET_STATE_TCP_ESTABLISHED) {
-      tcp_dbg("TCP> buffer empty, shutdown established ...\n");
-      /* send fin if queue empty and in state shut local (write) */
-      tcp_send_fin(t);
-      /* change tcp state to FIN_WAIT1 */
-      s->state &= 0x00FFU;
-      s->state |= PICO_SOCKET_STATE_TCP_FIN_WAIT1;
-    } else if ((s->state & PICO_SOCKET_STATE_TCP) == PICO_SOCKET_STATE_TCP_CLOSE_WAIT) {
-      /* send fin if queue empty and in state shut local (write) */
-      tcp_send_fin(t);
-      /* change tcp state to LAST_ACK */
-      s->state &= 0x00FFU;
-      s->state |= PICO_SOCKET_STATE_TCP_LAST_ACK;
-      tcp_dbg("TCP> STATE: LAST_ACK.\n");
-    }
-  }
+  // check to see if we are in the case where FIN was received
+  // but we still had data in the queue (tcpq_out)
+  checkIfQueueEmptyAndFin(t);
   return loop_score;
 }