lwIP on ethernet: examples (#8395)

* ethernet: examples

* remove duplicate

* styling

* fix comment restyle + comment eth.setdefault()

* comment and add comments about eth.setDefault()

* update comments when using interface::setDefault()

* repair bad merge

* fix default interface case

* factorize

* change comment

Author: d-a-v

cores/esp8266/LwipIntfDev.h

@@ -59,20 +59,36 @@ class LwipIntfDev: public LwipIntf, public RawDev
         return IPAddress(ip4_addr_get_u32(ip_2_ip4(&_netif.gw)));
     }
 
-    void setDefault();
+    // 1. Currently when no default is set, esp8266-Arduino uses the first
+    //    DHCP client interface receiving a valid address and gateway to
+    //    become the new lwIP default interface.
+    // 2. Otherwise - when using static addresses - lwIP for every packets by
+    //    defaults selects automatically the best suited output interface
+    //    matching the destination address.  If several interfaces match,
+    //    the first one is picked.  On esp8266/Arduno: WiFi interfaces are
+    //    checked first.
+    // 3. Or, use `::setDefault(true)` to force using this interface's gateway
+    //    as default router.
+    void setDefault(bool deflt = true);
 
     // true if interface has a valid IPv4 address
     bool connected()
     {
         return !!ip4_addr_get_u32(ip_2_ip4(&_netif.ip_addr));
     }
 
+    bool routable()
+    {
+        return !ip_addr_isany(&_netif.gw);
+    }
+
     // ESP8266WiFi API compatibility
 
     wl_status_t status();
 
 protected:
     err_t netif_init();
+    void  check_route();
     void  netif_status_callback();
 
     static err_t netif_init_s(netif* netif);
@@ -184,10 +200,10 @@ boolean LwipIntfDev<RawDev>::begin(const uint8_t* macAddress, const uint16_t mtu
         return false;
     }
 
-    _netif.flags |= NETIF_FLAG_UP;
-
     if (localIP().v4() == 0)
     {
+        // IP not set, starting DHCP
+        _netif.flags |= NETIF_FLAG_UP;
         switch (dhcp_start(&_netif))
         {
         case ERR_OK:
@@ -201,6 +217,12 @@ boolean LwipIntfDev<RawDev>::begin(const uint8_t* macAddress, const uint16_t mtu
             return false;
         }
     }
+    else
+    {
+        // IP is set, static config
+        netif_set_link_up(&_netif);
+        netif_set_up(&_netif);
+    }
 
     _started = true;
 
@@ -301,16 +323,25 @@ err_t LwipIntfDev<RawDev>::netif_init()
 template<class RawDev>
 void LwipIntfDev<RawDev>::netif_status_callback()
 {
+    check_route();
     if (connected())
     {
-        if (_default || (netif_default == nullptr && !ip_addr_isany(&_netif.gw)))
+        sntp_stop();
+        sntp_init();
+    }
+}
+
+template<class RawDev>
+void LwipIntfDev<RawDev>::check_route()
+{
+    if (connected())
+    {
+        if (_default || (netif_default == nullptr && routable()))
         {
             // on user request,
-            // or if there is no current default interface, but a gateway is valid
+            // or if there is no current default interface, but our gateway is valid
             netif_set_default(&_netif);
         }
-        sntp_stop();
-        sntp_init();
     }
     else if (netif_default == &_netif)
     {
@@ -386,13 +417,10 @@ err_t LwipIntfDev<RawDev>::handlePackets()
 }
 
 template<class RawDev>
-void LwipIntfDev<RawDev>::setDefault()
+void LwipIntfDev<RawDev>::setDefault(bool deflt)
 {
-    _default = true;
-    if (connected())
-    {
-        netif_set_default(&_netif);
-    }
+    _default = deflt;
+    check_route();
 }
 
 #endif  // _LWIPINTFDEV_H

libraries/ESP8266mDNS/src/LEAmDNS_Transfer.cpp

@@ -1766,11 +1766,13 @@ namespace MDNSImplementation
         stcMDNS_RRAttributes attributes(DNS_RRTYPE_AAAA,
                                         ((p_rSendParameter.m_bCacheFlush ? 0x8000 : 0)
                                          | DNS_RRCLASS_IN));  // Cache flush? & INternet
-        bool    bResult = ((_writeMDNSHostDomain(m_pcHostname, false, p_rSendParameter)) && // esp8266.local
-                       (_writeMDNSRRAttributes(attributes, p_rSendParameter)) &&            // TYPE & CLASS
-                       (_write32((p_rSendParameter.m_bUnannounce ? 0 : MDNS_HOST_TTL), p_rSendParameter)) &&    // TTL
-                       (_write16(MDNS_IP6_SIZE, p_rSendParameter)) &&                       // RDLength
-                       (false /*TODO: IP6 version of: _udpAppendBuffer((uint32_t)p_IPAddress, MDNS_IP4_SIZE)*/));   // RData
+        bool                 bResult
+            = ((_writeMDNSHostDomain(m_pcHostname, false, p_rSendParameter)) &&  // esp8266.local
+               (_writeMDNSRRAttributes(attributes, p_rSendParameter)) &&         // TYPE & CLASS
+               (_write32((p_rSendParameter.m_bUnannounce ? 0 : MDNS_HOST_TTL), p_rSendParameter))
+               &&                                              // TTL
+               (_write16(MDNS_IP6_SIZE, p_rSendParameter)) &&  // RDLength
+               (false /*TODO: IP6 version of: _udpAppendBuffer((uint32_t)p_IPAddress, MDNS_IP4_SIZE)*/));  // RData
 
         DEBUG_EX_ERR(if (!bResult) {
             DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _writeMDNSAnswer_AAAA: FAILED!\n"));
@@ -1855,7 +1857,7 @@ namespace MDNSImplementation
                                                             p_rSendParameter.m_u16Offset))
                        && (_writeMDNSRRDomain(hostDomain,
                                               p_rSendParameter)))  // Host, eg. esp8266.local
-                    // Cache available for domain
+                                                                   // Cache available for domain
                     : ((MDNS_DOMAIN_COMPRESS_MARK
                         > ((u16CachedDomainOffset >> 8) & ~MDNS_DOMAIN_COMPRESS_MARK))
                        &&                                      // Valid offset

libraries/lwIP_Ethernet/examples/EthClient/EthClient.ino

@@ -0,0 +1,89 @@
+/*
+    This sketch establishes a TCP connection to a "quote of the day" service.
+    It sends a "hello" message, and then prints received data.
+
+    This is Ethernet version of:
+    https://github.com/esp8266/Arduino/blob/master/libraries/ESP8266WiFi/examples/WiFiClient/WiFiClient.ino
+*/
+
+#include <LwipEthernet.h>
+
+Wiznet5500lwIP eth(/*SS*/ 16);  // <== adapt to your hardware
+
+const char* host = "djxmmx.net";
+const uint16_t port = 17;
+
+void setup() {
+  Serial.begin(115200);
+
+  Serial.println("\nEthernet\n");
+
+  // 1. Currently when no default is set, esp8266-Arduino uses the first
+  //    DHCP client interface receiving a valid address and gateway to
+  //    become the new lwIP default interface.
+  // 2. Otherwise - when using static addresses - lwIP for every packets by
+  //    defaults selects automatically the best suited output interface
+  //    matching the destination address.  If several interfaces match,
+  //    the first one is picked.  On esp8266/Arduno: WiFi interfaces are
+  //    checked first.
+  // 3. Or, use `::setDefault()` to force routing through this interface.
+  // eth.setDefault(); // default route set through this interface
+
+  if (!ethInitDHCP(eth)) {
+    Serial.printf("no hardware found\n");
+    while (1) {
+      delay(1000);
+    }
+  }
+
+  while (!eth.connected()) {
+    Serial.printf(".");
+    delay(1000);
+  }
+
+  Serial.printf("Ethernet: IP Address: %s\n",
+                eth.localIP().toString().c_str());
+}
+
+void loop() {
+
+  Serial.print("connecting to ");
+  Serial.print(host);
+  Serial.print(':');
+  Serial.println(port);
+
+  // Use WiFiClient class to create TCP connections
+  // (this class could have been named TCPClient)
+  WiFiClient client;
+  if (!client.connect(host, port)) {
+    Serial.println("connection failed");
+    delay(5000);
+    return;
+  }
+
+  // This will send a string to the server
+  Serial.println("sending data to server");
+  if (client.connected()) { client.println("hello from ESP8266"); }
+
+  // wait for data to be available
+  unsigned long timeout = millis();
+  while (client.available() == 0) {
+    if (millis() - timeout > 5000) {
+      Serial.println(">>> Client Timeout !");
+      client.stop();
+      delay(60000);
+      return;
+    }
+  }
+
+  // Read all the lines of the reply from server and print them to Serial
+  Serial.println("receiving from remote server");
+  client.sendAll(Serial);  // this peer closes once all data are sent
+
+  // Close the connection
+  Serial.println();
+  Serial.println("closing connection");
+  client.stop();
+
+  delay(300000);  // execute once every 5 minutes, don't flood remote service
+}

libraries/lwIP_Ethernet/examples/EthClientStatic/EthClientStatic.ino

@@ -0,0 +1,92 @@
+/*
+    This sketch establishes a TCP connection to a "quote of the day" service.
+    It sends a "hello" message, and then prints received data.
+
+    This is Ethernet version of:
+    https://github.com/esp8266/Arduino/blob/master/libraries/ESP8266WiFi/examples/WiFiClient/WiFiClient.ino
+*/
+
+#include <LwipEthernet.h>
+
+#define LOCAL_IP IPAddress(192, 168, 0, 233)
+#define LOCAL_GW IPAddress(192, 168, 0, 254)  // <== adapt to your network
+#define LOCAL_MASK IPAddress(255, 255, 255, 0)
+#define DNS IPAddress(8, 8, 8, 8)
+
+Wiznet5500lwIP eth(/*SS*/ 16);  // <== adapt to your hardware
+
+const char* host = "djxmmx.net";
+const uint16_t port = 17;
+
+void setup() {
+  Serial.begin(115200);
+
+  Serial.println("\nEthernet\n");
+
+  // 1. Currently when no default is set, esp8266-Arduino uses the first
+  //    DHCP client interface receiving a valid address and gateway to
+  //    become the new lwIP default interface.
+  // 2. Otherwise - when using static addresses - lwIP for every packets by
+  //    defaults selects automatically the best suited output interface
+  //    matching the destination address.  If several interfaces match,
+  //    the first one is picked.  On esp8266/Arduno: WiFi interfaces are
+  //    checked first.
+  // 3. Or, use `::setDefault()` to force routing through this interface.
+  // eth.setDefault(true); // default route set through this interface
+
+  if (!ethInitStatic(eth, LOCAL_IP, LOCAL_GW, LOCAL_MASK, DNS)) {
+    // enabling debug message will show the real cause
+    Serial.printf("no hardware found or bad network configuration\n");
+    while (1) {
+      delay(1000);
+    }
+  }
+
+  Serial.printf("Ethernet: IP Address: %s\n",
+                eth.localIP().toString().c_str());
+}
+
+void loop() {
+
+  Serial.print("connecting to ");
+  Serial.print(host);
+  Serial.print(':');
+  Serial.println(port);
+
+  // Use WiFiClient class to create TCP connections
+  // (this class could have been named TCPClient)
+  WiFiClient client;
+  if (!client.connect(host, port)) {
+    Serial.println("connection failed");
+    delay(5000);
+    return;
+  }
+
+  // This will send a string to the server
+  Serial.println("sending data to server");
+  if (client.connected()) {
+    client.println("hello from ESP8266");
+  }
+
+  // wait for data to be available
+  unsigned long timeout = millis();
+  while (client.available() == 0) {
+    if (millis() - timeout > 5000) {
+      Serial.println(">>> Client Timeout !");
+      client.stop();
+      delay(60000);
+      return;
+    }
+  }
+
+  // Read all the lines of the reply from server and print them to Serial
+  Serial.println("receiving from remote server");
+  client.sendAll(Serial);  // this peer closes once all data are sent
+
+  // Close the connection
+  Serial.println();
+  Serial.println("closing connection");
+  client.stop();
+
+  delay(600000);  // execute once every 10 minutes, don't flood remote service
+}