From 3f74a7f6f909124df49886ef7bfa54f37ed72cd8 Mon Sep 17 00:00:00 2001
From: Ari Parkkila <ari.parkkila@arm.com>
Date: Mon, 5 Aug 2019 03:11:06 -0700
Subject: [PATCH 1/2] Fix nsapi_dns_add_server to add a server just once

---
 features/netsocket/nsapi_dns.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/features/netsocket/nsapi_dns.cpp b/features/netsocket/nsapi_dns.cpp
index e8f245b7ca..d9030450bf 100644
--- a/features/netsocket/nsapi_dns.cpp
+++ b/features/netsocket/nsapi_dns.cpp
@@ -131,6 +131,13 @@ static bool dns_timer_running = false;
 // DNS server configuration
 extern "C" nsapi_error_t nsapi_dns_add_server(nsapi_addr_t addr, const char *interface_name)
 {
+    // check if addr was already added
+    for (int i = 0; i < DNS_SERVERS_SIZE; i++) {
+        if (memcmp(&addr, &dns_servers[i], sizeof(nsapi_addr_t)) == 0) {
+            return NSAPI_ERROR_OK;
+        }
+    }
+
     memmove(&dns_servers[1], &dns_servers[0],
             (DNS_SERVERS_SIZE - 1)*sizeof(nsapi_addr_t));
 

From e1124668dbbaf376467207822e4a891d1a26180c Mon Sep 17 00:00:00 2001
From: Ari Parkkila <ari.parkkila@arm.com>
Date: Mon, 5 Aug 2019 03:11:37 -0700
Subject: [PATCH 2/2] Cellular: Add DNS servers from PDP contexts to nsapi_dns

---
 .../AT/at_cellularcontext/unittest.cmake      |  1 +
 UNITTESTS/stubs/AT_CellularContext_stub.cpp   |  5 +++
 .../framework/AT/AT_CellularContext.cpp       | 35 ++++++++++++++++++-
 .../framework/AT/AT_CellularContext.h         |  1 +
 4 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/UNITTESTS/features/cellular/framework/AT/at_cellularcontext/unittest.cmake b/UNITTESTS/features/cellular/framework/AT/at_cellularcontext/unittest.cmake
index 761d1ee357..dae0f2e268 100644
--- a/UNITTESTS/features/cellular/framework/AT/at_cellularcontext/unittest.cmake
+++ b/UNITTESTS/features/cellular/framework/AT/at_cellularcontext/unittest.cmake
@@ -41,4 +41,5 @@ set(unittest-test-sources
   stubs/SerialBase_stub.cpp
   stubs/CellularContext_stub.cpp
   stubs/CellularUtil_stub.cpp
+  stubs/SocketAddress_stub.cpp
 )
diff --git a/UNITTESTS/stubs/AT_CellularContext_stub.cpp b/UNITTESTS/stubs/AT_CellularContext_stub.cpp
index 87bc66765b..4f89449efa 100644
--- a/UNITTESTS/stubs/AT_CellularContext_stub.cpp
+++ b/UNITTESTS/stubs/AT_CellularContext_stub.cpp
@@ -287,3 +287,8 @@ void AT_CellularContext::do_connect_with_retry()
 {
 
 }
+
+char *AT_CellularContext::get_interface_name(char *interface_name)
+{
+    return NULL;
+}
diff --git a/features/cellular/framework/AT/AT_CellularContext.cpp b/features/cellular/framework/AT/AT_CellularContext.cpp
index ec3b93d993..3342e006c6 100644
--- a/features/cellular/framework/AT/AT_CellularContext.cpp
+++ b/features/cellular/framework/AT/AT_CellularContext.cpp
@@ -239,6 +239,16 @@ const char *AT_CellularContext::get_ip_address()
 #endif
 }
 
+char *AT_CellularContext::get_interface_name(char *interface_name)
+{
+    if (_cid < 0) {
+        return NULL;
+    }
+    MBED_ASSERT(interface_name);
+    sprintf(interface_name, "ce%02d", _cid);
+    return interface_name;
+}
+
 void AT_CellularContext::attach(Callback<void(nsapi_event_t, intptr_t)> status_cb)
 {
     _status_cb = status_cb;
@@ -458,7 +468,30 @@ nsapi_error_t AT_CellularContext::do_activate_context()
 
 nsapi_error_t AT_CellularContext::activate_ip_context()
 {
-    return find_and_activate_context();
+    nsapi_error_t ret = find_and_activate_context();
+#if !NSAPI_PPP_AVAILABLE
+    if (ret == NSAPI_ERROR_OK) {
+        pdpContextList_t params_list;
+        if (get_pdpcontext_params(params_list) == NSAPI_ERROR_OK) {
+            pdpcontext_params_t *pdp = params_list.get_head();
+            while (pdp) {
+                SocketAddress addr;
+                if (addr.set_ip_address(pdp->dns_secondary_addr)) {
+                    tr_info("DNS secondary %s", pdp->dns_secondary_addr);
+                    char ifn[5]; // "ce" + two digit _cid + zero
+                    add_dns_server(addr, get_interface_name(ifn));
+                }
+                if (addr.set_ip_address(pdp->dns_primary_addr)) {
+                    tr_info("DNS primary %s", pdp->dns_primary_addr);
+                    char ifn[5]; // "ce" + two digit _cid + zero
+                    add_dns_server(addr, get_interface_name(ifn));
+                }
+                pdp = pdp->next;
+            }
+        }
+    }
+#endif
+    return ret;
 }
 
 nsapi_error_t AT_CellularContext::activate_non_ip_context()
diff --git a/features/cellular/framework/AT/AT_CellularContext.h b/features/cellular/framework/AT/AT_CellularContext.h
index a5da94daa9..9831d9b9fa 100644
--- a/features/cellular/framework/AT/AT_CellularContext.h
+++ b/features/cellular/framework/AT/AT_CellularContext.h
@@ -36,6 +36,7 @@ public:
     virtual nsapi_error_t set_blocking(bool blocking);
     virtual NetworkStack *get_stack();
     virtual const char *get_ip_address();
+    virtual char *get_interface_name(char *interface_name);
     virtual void attach(mbed::Callback<void(nsapi_event_t, intptr_t)> status_cb);
     virtual nsapi_error_t connect();
     virtual nsapi_error_t disconnect();