Either ipv4 or ipv4v6 PPP and IP stacks are enabled based on 3GPP context

features/FEATURE_LWIP/lwip-interface/EthernetInterface.cpp

@@ -49,7 +49,8 @@ nsapi_error_t EthernetInterface::connect()
     return mbed_lwip_bringup_2(_dhcp, false,
             _ip_address[0] ? _ip_address : 0,
             _netmask[0] ? _netmask : 0,
-            _gateway[0] ? _gateway : 0);
+            _gateway[0] ? _gateway : 0,
+            DEFAULT_STACK);
 }
 
 nsapi_error_t EthernetInterface::disconnect()

features/FEATURE_LWIP/lwip-interface/lwip_stack.c

@@ -511,10 +511,10 @@ nsapi_error_t mbed_lwip_init(emac_interface_t *emac)
 // Backwards compatibility with people using DEVICE_EMAC
 nsapi_error_t mbed_lwip_bringup(bool dhcp, const char *ip, const char *netmask, const char *gw)
 {
-    return mbed_lwip_bringup_2(dhcp, false, ip, netmask, gw);
+    return mbed_lwip_bringup_2(dhcp, false, ip, netmask, gw, DEFAULT_STACK);
 }
 
-nsapi_error_t mbed_lwip_bringup_2(bool dhcp, bool ppp, const char *ip, const char *netmask, const char *gw)
+nsapi_error_t mbed_lwip_bringup_2(bool dhcp, bool ppp, const char *ip, const char *netmask, const char *gw, const nsapi_ip_stack_t stack)
 {
     // Check if we've already connected
     if (lwip_connected) {
@@ -533,7 +533,7 @@ nsapi_error_t mbed_lwip_bringup_2(bool dhcp, bool ppp, const char *ip, const cha
         }
     } else {
         if (ppp) {
-            ret = ppp_lwip_if_init(&lwip_netif);
+            ret = ppp_lwip_if_init(&lwip_netif, stack);
         } else {
             ret = mbed_lwip_emac_init(NULL);
         }
@@ -553,6 +553,7 @@ nsapi_error_t mbed_lwip_bringup_2(bool dhcp, bool ppp, const char *ip, const cha
     netif_set_status_callback(&lwip_netif, mbed_lwip_netif_status_irq);
 
 #if LWIP_IPV6
+    if (stack != IPV4_STACK) {
         if (lwip_netif.hwaddr_len == ETH_HWADDR_LEN) {
             netif_create_ip6_linklocal_address(&lwip_netif, 1/*from MAC*/);
         }
@@ -573,11 +574,15 @@ nsapi_error_t mbed_lwip_bringup_2(bool dhcp, bool ppp, const char *ip, const cha
 #if LWIP_IPV6_AUTOCONFIG
         /* IPv6 address autoconfiguration not enabled by default */
         lwip_netif.ip6_autoconfig_enabled = 1;
+    } else {
+        // Disable router solidifications
+        lwip_netif.rs_count = 0;
+    }
 #endif /* LWIP_IPV6_AUTOCONFIG */
 #endif // LWIP_IPV6
 
-
 #if LWIP_IPV4
+    if (stack != IPV6_STACK) {
         if (!dhcp && !ppp) {
             ip4_addr_t ip_addr;
             ip4_addr_t netmask_addr;
@@ -591,6 +596,7 @@ nsapi_error_t mbed_lwip_bringup_2(bool dhcp, bool ppp, const char *ip, const cha
 
             netif_set_addr(&lwip_netif, &ip_addr, &netmask_addr, &gw_addr);
         }
+    }
 #endif
 
     if (ppp) {
@@ -614,6 +620,7 @@ nsapi_error_t mbed_lwip_bringup_2(bool dhcp, bool ppp, const char *ip, const cha
     }
 
 #if LWIP_DHCP
+    if (stack != IPV6_STACK) {
         // Connect to the network
         lwip_dhcp = dhcp;
 
@@ -623,6 +630,7 @@ nsapi_error_t mbed_lwip_bringup_2(bool dhcp, bool ppp, const char *ip, const cha
                 return NSAPI_ERROR_DHCP_FAILURE;
             }
         }
+    }
 #endif
 
     // If doesn't have address
@@ -636,18 +644,22 @@ nsapi_error_t mbed_lwip_bringup_2(bool dhcp, bool ppp, const char *ip, const cha
     }
 
 #if PREF_ADDR_TIMEOUT
+    if (stack != IPV4_STACK && stack != IPV6_STACK) {
         // If address is not for preferred stack waits a while to see
         // if preferred stack address is acquired
         if (!mbed_lwip_get_ip_addr(false, &lwip_netif)) {
             sys_arch_sem_wait(&lwip_netif_has_pref_addr, PREF_ADDR_TIMEOUT * 1000);
         }
+    }
 #endif
 #if BOTH_ADDR_TIMEOUT
+    if (stack != IPV4_STACK && stack != IPV6_STACK) {
         // If addresses for both stacks are not available waits a while to
         // see if address for both stacks are acquired
         if (!(mbed_lwip_get_ipv4_addr(&lwip_netif) && mbed_lwip_get_ipv6_addr(&lwip_netif))) {
             sys_arch_sem_wait(&lwip_netif_has_both_addr, BOTH_ADDR_TIMEOUT * 1000);
         }
+    }
 #endif
 
     add_dns_addr(&lwip_netif);

features/FEATURE_LWIP/lwip-interface/lwip_stack.h

@@ -29,7 +29,7 @@ extern "C" {
 nsapi_error_t mbed_lwip_init(emac_interface_t *emac);
 nsapi_error_t mbed_lwip_emac_init(emac_interface_t *emac);
 nsapi_error_t mbed_lwip_bringup(bool dhcp, const char *ip, const char *netmask, const char *gw);
-nsapi_error_t mbed_lwip_bringup_2(bool dhcp, bool ppp, const char *ip, const char *netmask, const char *gw);
+nsapi_error_t mbed_lwip_bringup_2(bool dhcp, bool ppp, const char *ip, const char *netmask, const char *gw, const nsapi_ip_stack_t stack);
 nsapi_error_t mbed_lwip_bringdown(void);
 nsapi_error_t mbed_lwip_bringdown_2(bool ppp);
 

features/FEATURE_LWIP/lwip-interface/mbed_lib.json

@@ -34,6 +34,16 @@
             "value": false,
             "macro_name": "NSAPI_PPP_AVAILABLE"
         },
+        "ppp-ipv4-enabled": {
+            "help": "Enable support for ipv4 PPP interface",
+            "value": true,
+            "macro_name": "NSAPI_PPP_IPV4_AVAILABLE"
+        },
+        "ppp-ipv6-enabled": {
+            "help": "Enable support for ipv6 PPP interface",
+            "value": false,
+            "macro_name": "NSAPI_PPP_IPV6_AVAILABLE"
+        },
         "use-mbed-trace": {
             "help": "Use mbed trace for debug, rather than printf",
             "value": false

features/FEATURE_LWIP/lwip-interface/ppp_lwip.cpp

@@ -313,7 +313,7 @@ extern "C" err_t ppp_lwip_disconnect()
     return ret;
 }
 
-extern "C" nsapi_error_t ppp_lwip_if_init(struct netif *netif)
+extern "C" nsapi_error_t ppp_lwip_if_init(struct netif *netif, const nsapi_ip_stack_t stack)
 {
     if (!prepare_event_queue()) {
         return NSAPI_ERROR_NO_MEMORY;
@@ -330,9 +330,17 @@ extern "C" nsapi_error_t ppp_lwip_if_init(struct netif *netif)
     }
 
 #if LWIP_IPV4
+    if (stack != IPV6_STACK) {
         ppp_set_usepeerdns(my_ppp_pcb, true);
+    }
 #endif
 
+    if (stack == IPV4_STACK) {
+        my_ppp_pcb->ipv6cp_disabled = true;
+    } else if (stack == IPV6_STACK) {
+        my_ppp_pcb->ipcp_disabled = true;
+    }
+
     return NSAPI_ERROR_OK;
 }
 
@@ -341,7 +349,7 @@ nsapi_error_t nsapi_ppp_error_code()
     return connect_error_code;
 }
 
-nsapi_error_t nsapi_ppp_connect(FileHandle *stream, Callback<void(nsapi_error_t)> cb, const char *uname, const char *password)
+nsapi_error_t nsapi_ppp_connect(FileHandle *stream, Callback<void(nsapi_error_t)> cb, const char *uname, const char *password, const nsapi_ip_stack_t stack)
 {
     if (my_stream) {
         return NSAPI_ERROR_PARAMETER;
@@ -354,7 +362,7 @@ nsapi_error_t nsapi_ppp_connect(FileHandle *stream, Callback<void(nsapi_error_t)
 
     // mustn't start calling input until after connect -
     // attach deferred until ppp_lwip_connect, called from mbed_lwip_bringup
-    nsapi_error_t retcode = mbed_lwip_bringup_2(false, true, NULL, NULL, NULL);
+    nsapi_error_t retcode = mbed_lwip_bringup_2(false, true, NULL, NULL, NULL, stack);
 
     if (retcode != NSAPI_ERROR_OK && connect_error_code != NSAPI_ERROR_OK) {
         return connect_error_code;
@@ -388,7 +396,7 @@ const char *nsapi_ppp_get_ip_addr(FileHandle *stream)
 }
 const char *nsapi_ppp_get_netmask(FileHandle *stream)
 {
-#if LWIP_IPV6
+#if !LWIP_IPV4
     return NULL;
 #endif
 
@@ -403,7 +411,7 @@ const char *nsapi_ppp_get_netmask(FileHandle *stream)
 }
 const char *nsapi_ppp_get_gw_addr(FileHandle *stream)
 {
-#if LWIP_IPV6
+#if !LWIP_IPV4
     return NULL;
 #endif
 

features/FEATURE_LWIP/lwip-interface/ppp_lwip.h

@@ -30,7 +30,7 @@ extern "C" {
  *
  *  @return 0 for success and negative error codes for failure
  */
-nsapi_error_t ppp_lwip_if_init(struct netif *netif);
+nsapi_error_t ppp_lwip_if_init(struct netif *netif, const nsapi_ip_stack_t stack);
 
 /** Connects to a PPP pipe
  *
@@ -53,7 +53,7 @@ err_t ppp_lwip_disconnect(void);
 /**
  * Stubs in case LWIP PPP is not enabled
  */
-#define ppp_lwip_if_init(netif)     NSAPI_ERROR_UNSUPPORTED
+#define ppp_lwip_if_init(netif, stack)     NSAPI_ERROR_UNSUPPORTED
 #define ppp_lwip_connect()                 ERR_IF
 #define ppp_lwip_disconnect()              ERR_IF
 #endif //LWIP_PPP_API

features/netsocket/cellular/generic_modem_driver/PPPCellularInterface.cpp

@@ -262,6 +262,7 @@ PPPCellularInterface::PPPCellularInterface(FileHandle *fh, bool debug)
     _pwd = NULL;
     _fh = fh;
     _debug_trace_on = debug;
+    _stack = DEFAULT_STACK;
     dev_info.reg_status_csd = CSD_NOT_REGISTERED_NOT_SEARCHING;
     dev_info.reg_status_psd = PSD_NOT_REGISTERED_NOT_SEARCHING;
     dev_info.ppp_connection_up = false;
@@ -451,21 +452,38 @@ nsapi_error_t PPPCellularInterface::setup_context_and_credentials()
         return NSAPI_ERROR_PARAMETER;
     }
 
-    bool try_ipv6 = false;
+#if NSAPI_PPP_IPV4_AVAILABLE && NSAPI_PPP_IPV6_AVAILABLE
+    const char ipv4v6_pdp_type[] = {"IPV4V6"};
+    const char ipv4_pdp_type[] = {"IP"};
+    const char *pdp_type = ipv4v6_pdp_type;
+    _stack = IPV4V6_STACK;
+#elif NSAPI_PPP_IPV6_AVAILABLE
+    const char pdp_type[] = {"IPV6"};
+#elif NSAPI_PPP_IPV4_AVAILABLE
+    const char pdp_type[] = {"IP"};
+#endif
     const char *auth = _uname && _pwd ? "CHAP:" : "";
 
-retry_without_ipv6:
+#if NSAPI_PPP_IPV4_AVAILABLE && NSAPI_PPP_IPV6_AVAILABLE
+retry_without_dual_stack:
+#endif
     success = _at->send("AT"
                           "+FCLASS=0;" // set to connection (ATD) to data mode
                           "+CGDCONT="CTX",\"%s\",\"%s%s\"",
-                          try_ipv6 ? "IPV4V6" : "IP", auth, _apn
+                          pdp_type, auth, _apn
                          )
                    && _at->recv("OK");
 
-    if (!success && try_ipv6) {
+#if NSAPI_PPP_IPV4_AVAILABLE && NSAPI_PPP_IPV6_AVAILABLE
-        try_ipv6 = false;
+    if (_stack == IPV4V6_STACK) {
-        goto retry_without_ipv6;
+        if (!success) {
+            // fallback to ipv4
+            pdp_type = ipv4_pdp_type;
+            _stack = IPV4_STACK;
+            goto retry_without_dual_stack;
         }
+    }
+#endif
 
     if (!success) {
         _at->recv("OK");
@@ -662,7 +680,7 @@ nsapi_error_t PPPCellularInterface::connect()
         /* Initialize PPP
          * mbed_ppp_init() is a blocking call, it will block until
          * connected, or timeout after 30 seconds*/
-        retcode = nsapi_ppp_connect(_fh, _connection_status_cb, _uname, _pwd);
+        retcode = nsapi_ppp_connect(_fh, _connection_status_cb, _uname, _pwd, _stack);
         if (retcode == NSAPI_ERROR_OK) {
             dev_info.ppp_connection_up = true;
         }

features/netsocket/cellular/generic_modem_driver/PPPCellularInterface.h

@@ -252,6 +252,7 @@ private:
     const char *_uname;
     const char *_pwd;
     bool _debug_trace_on;
+    nsapi_ip_stack_t _stack;
     Callback<void(nsapi_error_t)> _connection_status_cb;
     void base_initialization();
     void setup_at_parser();

features/netsocket/nsapi_ppp.h

@@ -36,10 +36,11 @@ NetworkStack *nsapi_ppp_get_stack();
  *  @param status_cb    Optional, user provided callback for connection status
  *  @param uname        Optional, username for the connection
  *  @param pwd          Optional, password for the connection
+ *  @param stack        Optional, stack for the connection
  *
  *  @return             0 on success, negative error code on failure
  */
-nsapi_error_t nsapi_ppp_connect(FileHandle *stream, Callback<void(nsapi_error_t)> status_cb=0, const char *uname=0, const char *pwd=0);
+nsapi_error_t nsapi_ppp_connect(FileHandle *stream, Callback<void(nsapi_error_t)> status_cb=0, const char *uname=0, const char *pwd=0, const nsapi_ip_stack_t stack=DEFAULT_STACK);
 
 /** Close a PPP connection
  *

features/netsocket/nsapi_types.h

@@ -216,6 +216,17 @@ typedef enum nsapi_socket_option {
     NSAPI_RCVBUF,    /*!< Sets recv buffer size */
 } nsapi_socket_option_t;
 
+/** Supported IP protocol versions of IP stack
+ *
+ *  @enum nsapi_ip_stack
+ */
+typedef enum nsapi_ip_stack {
+    DEFAULT_STACK = 0,
+    IPV4_STACK,
+    IPV6_STACK,
+    IPV4V6_STACK
+} nsapi_ip_stack_t;
+
 /* Backwards compatibility - previously didn't distinguish stack and socket options */
 typedef nsapi_socket_level_t nsapi_level_t;
 typedef nsapi_socket_option_t nsapi_option_t;