Improve general TCP stability

libraries/ESP8266WiFi/src/WiFiClient.cpp

@@ -41,6 +41,8 @@ extern "C"
 #include "include/ClientContext.h"
 #include "c_types.h"
 
+char lwip_bufferize = 1;
+
 uint16_t WiFiClient::_localPort = 0;
 
 template<>
@@ -163,6 +165,10 @@ bool WiFiClient::getNoDelay() {
     return _client->getNoDelay();
 }
 
+size_t WiFiClient::ESPWriteAvailable() {
+    return _client->writeAvailable();
+}
+
 size_t WiFiClient::write(uint8_t b)
 {
     return write(&b, 1);

libraries/ESP8266WiFi/src/WiFiClient.h

@@ -30,6 +30,8 @@
 
 #define WIFICLIENT_MAX_PACKET_SIZE 1460
 
+extern char lwip_bufferize;
+
 class ClientContext;
 class WiFiServer;
 
@@ -75,6 +77,8 @@ class WiFiClient : public Client, public SList<WiFiClient> {
   void setNoDelay(bool nodelay);
   static void setLocalPortStart(uint16_t port) { _localPort = port; }
 
+  size_t ESPWriteAvailable();
+
   friend class WiFiServer;
 
   using Print::write;

libraries/ESP8266WiFi/src/include/ClientContext.h

@@ -36,6 +36,9 @@ typedef int32_t recv_ret_t;
 #endif
 
 #include "DataSource.h"
+#include "cbuf.h"
+
+extern char lwip_bufferize;
 
 class ClientContext
 {
@@ -49,6 +52,12 @@ class ClientContext
         tcp_sent(pcb, &_s_sent);
         tcp_err(pcb, &_s_error);
         tcp_poll(pcb, &_s_poll, 1);
+
+	if(lwip_bufferize) {
+            /* cbuf impl. handles size-1 bytes at most,
+               we want the whole TCP_WND at least */
+            _rx_full_buf = new cbuf(TCP_WND + 1);
+        }
     }
 
     err_t abort()
@@ -89,6 +98,13 @@ class ClientContext
 
     ~ClientContext()
     {
+        if(_rx_full_buf)
+            delete _rx_full_buf;
+    }
+
+    uint16_t writeAvailable ()
+    {
+        return _pcb? tcp_sndbuf(_pcb): 0;
     }
 
     ClientContext* next() const
@@ -192,6 +208,9 @@ class ClientContext
 
     size_t getSize() const
     {
+        if(_rx_full_buf) {
+            return _rx_full_buf->available();
+        }
         if(!_rx_buf) {
             return 0;
         }
@@ -201,6 +220,15 @@ class ClientContext
 
     char read()
     {
+        if(_rx_full_buf) {
+            if(!_rx_full_buf->available())
+                return 0;
+            if(_pcb) {
+                tcp_recved(_pcb, 1);
+            }
+            return (char)_rx_full_buf->read();
+        }
+
         if(!_rx_buf) {
             return 0;
         }
@@ -212,6 +240,15 @@ class ClientContext
 
     size_t read(char* dst, size_t size)
     {
+        if(_rx_full_buf) {
+            DEBUGV(":rdifb %d\r\n", size);
+            size_t size_read = _rx_full_buf->read(dst, size);
+            if(_pcb) {
+                tcp_recved(_pcb, size_read);
+            }
+            return size_read;
+        }
+
         if(!_rx_buf) {
             return 0;
         }
@@ -236,6 +273,9 @@ class ClientContext
 
     char peek()
     {
+        if(_rx_full_buf) {
+            return _rx_full_buf->available()? (char)_rx_full_buf->peek(): 0;
+        }
         if(!_rx_buf) {
             return 0;
         }
@@ -245,6 +285,10 @@ class ClientContext
 
     size_t peekBytes(char *dst, size_t size)
     {
+	if(_rx_full_buf) {
+	    return _rx_full_buf->peek(dst, size);
+	}
+
         if(!_rx_buf) {
             return 0;
         }
@@ -262,6 +306,13 @@ class ClientContext
 
     void flush()
     {
+        if(_rx_full_buf) {
+            if(_pcb) {
+                tcp_recved(_pcb, _rx_full_buf->available());
+            }
+            return _rx_full_buf->flush();
+        }
+
         if(!_rx_buf) {
             return;
         }
@@ -353,6 +404,7 @@ class ClientContext
             err_t err = tcp_write(_pcb, buf, next_chunk, TCP_WRITE_FLAG_COPY);
             _datasource->release_buffer(buf, next_chunk);
             if (err == ERR_OK) {
+		DEBUGV(":w %d\r\n", next_chunk);
                 _written += next_chunk;
                 did_write = true;
             }
@@ -420,7 +472,24 @@ class ClientContext
             return ERR_ABRT;
         }
 
-        if(_rx_buf) {
+        if(_rx_full_buf) {
+            DEBUGV(":rfb0\r\n");
+            for (pbuf* p = pb; p; p = p->next) {
+                /* cbuf does not like null pointer and 0 size */
+                if(p->len) {
+	            DEBUGV(":rfb %d, %d\r\n", _rx_full_buf->available(), p->len);
+                    size_t test = _rx_full_buf->write((const char*)p->payload, p->len);
+                    if(test != p->len) {
+                        /* internal error, cbuf is supposed to contain all receivable data (TCP_WND) */
+                        printf/*DEBUGV*/(":rfbe %d %d %d !IntErr!\r\n", test, p->len, _rx_full_buf->available());
+                        pbuf_free(pb);
+                        return ERR_ABRT;
+                    }
+                }
+            }
+            pbuf_free(pb);
+        }
+        else if(_rx_buf) {
             DEBUGV(":rch %d, %d\r\n", _rx_buf->tot_len, pb->tot_len);
             pbuf_cat(_rx_buf, pb);
         } else {
@@ -481,6 +550,8 @@ class ClientContext
     int _refcnt;
     ClientContext* _next;
 
+    cbuf* _rx_full_buf = nullptr;
+
     DataSource* _datasource = nullptr;
     size_t _written = 0;
     size_t _write_chunk_size = 256;

tools/sdk/lwip/src/LWIP-CHANGE-MSS

@@ -0,0 +1,21 @@
+#!/bin/sh
+
+set -e
+
+mss=$1
+
+[ -z "$mss" ] && { echo "syntax: $0 <mss>    (try with 256)"; exit 1; }
+
+[ -f ../include/lwipopts.h.orig ] || mv ../include/lwipopts.h ../include/lwipopts.h.orig
+
+< ../include/lwipopts.h.orig \
+> ../include/lwipopts.h \
+sed "s,^[ \t]*#define[ \t]*TCP_MSS\(.*\)$,#define TCP_MSS $mss //\1,g"
+
+make clean
+make
+for i in liblwip_gcc.a liblwip.a liblwip_536.a; do 
+    test -f ../../lib/${i}.orig || mv ../../lib/${i} ../../lib/${i}.orig
+done
+
+ln -sf ../lwip/src/liblwip_src.a ../../lib/liblwip_gcc.a