lwip2 updates: no more git sub-sub-module deps, faster checksum, backlog limitation and other fixes

libraries/ESP8266WiFi/src/WiFiServer.cpp

@@ -35,12 +35,17 @@ extern "C" {
 #include "lwip/opt.h"
 #include "lwip/tcp.h"
 #include "lwip/inet.h"
+#include "lwip/init.h" // LWIP_VERSION_
 #include <include/ClientContext.h>
 
+#ifndef MAX_DEFAULT_SIMULTANEOUS_CLIENTS_PER_PORT
+#define MAX_DEFAULT_SIMULTANEOUS_CLIENTS_PER_PORT 5
+#endif
+
 WiFiServer::WiFiServer(const IPAddress& addr, uint16_t port)
 : _port(port)
 , _addr(addr)
-, _pcb(nullptr)
+, _listen_pcb(nullptr)
 , _unclaimed(nullptr)
 , _discarded(nullptr)
 {
@@ -49,7 +54,7 @@ WiFiServer::WiFiServer(const IPAddress& addr, uint16_t port)
 WiFiServer::WiFiServer(uint16_t port)
 : _port(port)
 , _addr(IP_ANY_TYPE)
-, _pcb(nullptr)
+, _listen_pcb(nullptr)
 , _unclaimed(nullptr)
 , _discarded(nullptr)
 {
@@ -59,7 +64,7 @@ void WiFiServer::begin() {
 	begin(_port);
 }
 
-void WiFiServer::begin(uint16_t port) {
+void WiFiServer::begin(uint16_t port, uint8_t backlog) {
     close();
     _port = port;
     err_t err;
@@ -77,13 +82,21 @@ void WiFiServer::begin(uint16_t port) {
         return;
     }
 
+#if LWIP_VERSION_MAJOR == 1
+    (void)backlog;
     tcp_pcb* listen_pcb = tcp_listen(pcb);
+#else
+    if (backlog == 0)
+        backlog = MAX_DEFAULT_SIMULTANEOUS_CLIENTS_PER_PORT;
+    tcp_pcb* listen_pcb = tcp_listen_with_backlog(pcb, backlog);
+#endif
+
     if (!listen_pcb) {
         tcp_close(pcb);
         return;
     }
-    _pcb = listen_pcb;
-    _port = _pcb->local_port;
+    _listen_pcb = listen_pcb;
+    _port = _listen_pcb->local_port;
     tcp_accept(listen_pcb, &WiFiServer::_s_accept);
     tcp_arg(listen_pcb, (void*) this);
 }
@@ -122,21 +135,21 @@ WiFiClient WiFiServer::available(byte* status) {
 }
 
 uint8_t WiFiServer::status()  {
-    if (!_pcb)
+    if (!_listen_pcb)
         return CLOSED;
-    return _pcb->state;
+    return _listen_pcb->state;
 }
 
 uint16_t WiFiServer::port() const {
     return _port;
 }
 
 void WiFiServer::close() {
-    if (!_pcb) {
+    if (!_listen_pcb) {
       return;
     }
-    tcp_close(_pcb);
-    _pcb = nullptr;
+    tcp_close(_listen_pcb);
+    _listen_pcb = nullptr;
 }
 
 void WiFiServer::stop() {
@@ -171,7 +184,16 @@ long WiFiServer::_accept(tcp_pcb* apcb, long err) {
     DEBUGV("WS:ac\r\n");
     ClientContext* client = new ClientContext(apcb, &WiFiServer::_s_discard, this);
     _unclaimed = slist_append_tail(_unclaimed, client);
-    tcp_accepted(_pcb);
+#if LWIP_VERSION_MAJOR == 1
+    tcp_accepted(_listen_pcb);
+#else
+    tcp_backlog_delayed(apcb);
+    // tcp_backlog_accepted() has to be called on this ClientContext's pcb (here = acpb)
+    // just before tcp_close() (but not needed before tcp_abort()).
+    // http://lwip.100.n7.nabble.com/Problem-re-opening-listening-pbc-tt32484.html#a32494
+    // https://www.nongnu.org/lwip/2_1_x/group__tcp__raw.html#gaeff14f321d1eecd0431611f382fcd338
+    client->write((const uint8_t*)"gotit",5);
+#endif
     return ERR_OK;
 }
 

libraries/ESP8266WiFi/src/WiFiServer.h

@@ -31,6 +31,42 @@ extern "C" {
 #include "Server.h"
 #include "IPAddress.h"
 
+// lwIP-v2 backlog facility allows to keep memory safe by limiting the
+// maximum number of simultaneously accepted clients.  Default number of
+// possibly simultaneously accepted client is defined in WiFiServer.cpp,
+// user can overide it at runtime from sketch:
+//      WiFiServer::begin(port, max-simultaneous-clients-per-port);
+// New incoming clients to this server will be delayed until an already
+// connected one leaves.
+// By "delayed", it is meant that WiFiServer will not answer to the SYN
+// packet until there is room for a new one: The server (tcp on that port)
+// will be invisible.  When a connected client leaves, the server will
+// accept a newcomer at the moment when one of them retries to connect by
+// sending another SYN (which will not immediately happen), and before it
+// times-out trying to connect.
+//
+// Back to Arduino scenario:
+//
+// Usually only one client is used at a time: The client (like a http
+// browser) is accepted, served then closed.  The ESP8266WebServer cannot
+// answer to another client during that time even if it is tcp-accepted
+// (syn-acked), until the current one has been served.
+//
+// Now that backlog is enabled, at most
+// MAX_DEFAULT_SIMULTANEOUS_CLIENTS_PER_PORT clients will be tcp-accepted by
+// a WiFiServer even if it is currently busy serving one client (ie: busy
+// and not checking WiFiServer::available()/hasClient()).  But next clients
+// will be kept out and will have to tcp-retry (as if they were trying to
+// connect through a mute firewall):
+// - Then eventually one of the connected clients leaves
+// - Then a while *after* that moment a waiting/potential client say hello
+//   if it has not given up waiting (72 seconds on windows for the connect
+//   timeout).
+//
+// Note that ESPAsync servers may serve more than one client at a time so
+// the default setting is not 1 or 2.  It was 0xff by default.  It can be
+// overriden at runtime in WiFiServer::begin().
+
 class ClientContext;
 class WiFiClient;
 
@@ -39,7 +75,7 @@ class WiFiServer : public Server {
 protected:
   uint16_t _port;
   IPAddress _addr;
-  tcp_pcb* _pcb;
+  tcp_pcb* _listen_pcb;
 
   ClientContext* _unclaimed;
   ClientContext* _discarded;
@@ -52,7 +88,8 @@ class WiFiServer : public Server {
   WiFiClient available(uint8_t* status = NULL);
   bool hasClient();
   void begin();
-  void begin(uint16_t port);
+  void begin(uint16_t port) { begin(port, 0); }
+  void begin(uint16_t port, uint8_t backlog);
   void setNoDelay(bool nodelay);
   bool getNoDelay();
   virtual size_t write(uint8_t);

libraries/ESP8266WiFi/src/include/ClientContext.h

@@ -76,6 +76,11 @@ class ClientContext
             tcp_recv(_pcb, NULL);
             tcp_err(_pcb, NULL);
             tcp_poll(_pcb, NULL, 0);
+#if LWIP_VERSION_MAJOR != 1
+            // needed for clients from WiFiServer
+            // harmless for other clients
+            tcp_backlog_accepted(_pcb);
+#endif
             err = tcp_close(_pcb);
             if(err != ERR_OK) {
                 DEBUGV(":tc err %d\r\n", (int) err);

tests/host/common/MockWiFiServer.cpp

@@ -59,7 +59,7 @@ WiFiClient WiFiServer::available (uint8_t* status)
 {
 	(void)status;
 	if (hasClient())
-		return WiFiClient(new ClientContext(serverAccept(pcb2int(_pcb))));
+		return WiFiClient(new ClientContext(serverAccept(pcb2int(_listen_pcb))));
 	return WiFiClient();
 }
 

tests/host/common/MockWiFiServerSocket.cpp

@@ -58,8 +58,9 @@ int serverAccept (int srvsock)
 	return mockSockSetup(clisock);
 }
 
-void WiFiServer::begin (uint16_t port)
+void WiFiServer::begin (uint16_t port, uint8_t backlog)
 {
+	(void)backlog;
 	_port = port;
 	return begin();
 }
@@ -109,13 +110,13 @@ void WiFiServer::begin ()
 
 
 	// store int into pointer
-	_pcb = int2pcb(sock);
+	_listen_pcb = int2pcb(sock);
 }
 
 bool WiFiServer::hasClient ()
 {
 	struct pollfd p;
-	p.fd = pcb2int(_pcb);
+	p.fd = pcb2int(_listen_pcb);
 	p.events = POLLIN;
 	return poll(&p, 1, 0) && p.revents == POLLIN;
 }
@@ -134,7 +135,7 @@ size_t WiFiServer::write (const uint8_t *buf, size_t size)
 
 void WiFiServer::close ()
 {
-	if (pcb2int(_pcb) >= 0)
-		::close(pcb2int(_pcb));
-	_pcb = int2pcb(-1);
+	if (pcb2int(_listen_pcb) >= 0)
+		::close(pcb2int(_listen_pcb));
+	_listen_pcb = int2pcb(-1);
 }

tools/sdk/lwip2/include/lwip-git-hash.h

@@ -1,5 +1,5 @@
 // generated by makefiles/make-lwip2-hash
 #ifndef LWIP_HASH_H
 #define LWIP_HASH_H
-#define LWIP_HASH_STR "STABLE-2_1_2_RELEASE/glue:1.2-16-ge23a07e"
+#define LWIP_HASH_STR "STABLE-2_1_2_RELEASE/glue:1.2-29-gb543b1f"
 #endif // LWIP_HASH_H

tools/sdk/lwip2/include/lwip/priv/tcp_priv.h

@@ -357,7 +357,7 @@ extern struct tcp_pcb ** const tcp_pcb_lists[NUM_TCP_PCB_LISTS];
 #if TCP_DEBUG_PCB_LISTS
 #define TCP_REG(pcbs, npcb) do {\
                             struct tcp_pcb *tcp_tmp_pcb; \
-                            LWIP_DEBUGF(TCP_DEBUG, ("TCP_REG %p local port %"U16_F"\n", (void *)(npcb), (npcb)->local_port)); \
+                            LWIP_DEBUGF(TCP_DEBUG, ("TCP_REG %p local port %" U16_F "\n", (void *)(npcb), (npcb)->local_port)); \
                             for (tcp_tmp_pcb = *(pcbs); \
           tcp_tmp_pcb != NULL; \
         tcp_tmp_pcb = tcp_tmp_pcb->next) { \

tools/sdk/lwip2/include/lwipopts.h

@@ -1402,7 +1402,7 @@
  * TCP_LISTEN_BACKLOG: Enable the backlog option for tcp listen pcb.
  */
 #if !defined TCP_LISTEN_BACKLOG || defined __DOXYGEN__
-#define TCP_LISTEN_BACKLOG              0
+#define TCP_LISTEN_BACKLOG              LWIP_FEATURES // 0
 #endif
 
 /**
@@ -2278,6 +2278,12 @@
  * @ingroup lwip_opts_infrastructure
  * @{
  */
+/**
+ * LWIP_CHKSUM_ALGORITHM==3: Checksum algorithm fastest for ESP8266
+ */
+#if !defined LWIP_CHKSUM_ALGORITHM || defined __DOXYGEN__
+#define LWIP_CHKSUM_ALGORITHM           3 // 2
+#endif
 /**
  * LWIP_CHECKSUM_CTRL_PER_NETIF==1: Checksum generation/check can be enabled/disabled
  * per netif.
@@ -3573,7 +3579,7 @@ extern "C" {
 #define SNTP_SUPPRESS_DELAY_CHECK 1
 #define SNTP_UPDATE_DELAY_DEFAULT 3600000   // update delay defined by a default weak function
 #define SNTP_UPDATE_DELAY sntp_update_delay_MS_rfc_not_less_than_15000()
-extern uint32_t SNTP_UPDATE_DELAY;
+uint32_t SNTP_UPDATE_DELAY;
 
 #if LWIP_FEATURES
 // esp8266/arduino/lwip-1.4 had 3 possible SNTP servers (constant was harcoded)
@@ -3591,7 +3597,7 @@ extern uint32_t SNTP_UPDATE_DELAY;
 #define SNTP_STARTUP_DELAY 1                // enable startup delay
 #define SNTP_STARTUP_DELAY_FUNC_DEFAULT 0   // to 0 by default via a default weak function
 #define SNTP_STARTUP_DELAY_FUNC sntp_startup_delay_MS_rfc_not_less_than_60000()
-extern uint32_t SNTP_STARTUP_DELAY_FUNC;
+uint32_t SNTP_STARTUP_DELAY_FUNC;
 
 /*
    --------------------------------------------------
@@ -3611,7 +3617,7 @@ struct netif;
 #error LWIP_ERR_T definition should come from lwip1.4 from espressif
 #endif
 //#define LWIP_ERR_T s8
-LWIP_ERR_T lwip_unhandled_packet (struct pbuf* pbuf, struct netif* netif) __attribute__((weak));
+LWIP_ERR_T lwip_unhandled_packet (struct pbuf* pbuf, struct netif* netif);
 
 /*
    --------------------------------------------------