Cellular.resolve()

docs/reference/firmware.md

@@ -2166,6 +2166,36 @@ else {
 }
 ```
 
+### resolve()
+_Since 0.6.1_
+
+`Cellular.resolve()` finds the IP address for a domain name.
+
+```cpp
+// SYNTAX
+IPAddress ip = Cellular.resolve(name);
+```
+
+Parameters:
+
+- `name`: the domain name to resolve (string)
+
+It returns the IP address if the domain name is found, otherwise a blank IP address.
+
+```cpp
+// EXAMPLE USAGE
+
+IPAddress ip;
+void setup() {
+   ip = Cellular.resolve("www.google.com");
+   if(ip) {
+     // IP address was resolved
+   } else {
+     // name resolution failed
+   }
+}
+```
+
 ### localIP()
 _Since 0.5.0_
 

user/tests/wiring/api/cellular.cpp

@@ -132,4 +132,10 @@ test(api_cellular_band_select) {
     (void)result; // avoid unused warning
 }
 
+test(api_cellular_resolve) {
+    IPAddress ip;
+    API_COMPILE(ip = Cellular.resolve("www.google.com"));
+    (void)ip;
+}
+
 #endif

user/tests/wiring/no_fixture/cellular.cpp

@@ -108,6 +108,11 @@ test(CELLULAR_04_local_ip_cellular_config)
     checkIPAddress("local", Cellular.localIP());
 }
 
+test(CELLULAR_05_resolve) {
+    connect_to_cloud(6*60*1000);
+    checkIPAddress("www.google.com", Cellular.resolve("www.google.com"));
+}
+
 int how_many_band_options_are_available(void)
 {
     CellularBand band_avail;

wiring/inc/spark_wiring_cellular.h

@@ -27,6 +27,7 @@
 #if Wiring_Cellular
 
 #include "cellular_hal.h"
+#include "inet_hal.h"
 #include "spark_wiring_cellular_printable.h"
 
 namespace spark {
@@ -124,6 +125,13 @@ class CellularClass : public NetworkClass
     {
         return cellular_command((_CALLBACKPTR_MDM)cb, (void*)param, timeout_ms, format, Fargs...);
     }
+
+    IPAddress resolve(const char* name)
+    {
+        HAL_IPAddress ip;
+        return (inet_gethostbyname(name, strlen(name), &ip, *this, NULL)<0) ?
+                IPAddress(uint32_t(0)) : IPAddress(ip);
+    }
 };