Corrected lwip to enable disabling of ipcp and ipv6cp protocols

features/FEATURE_LWIP/lwip-interface/lwip/src/include/netif/ppp/ppp.h

@@ -336,6 +336,10 @@ struct ppp_pcb_s {
   unsigned int ipv6cp_is_up            :1; /* have called ip6cp_up() */
   unsigned int if6_up                  :1; /* True when the IPv6 interface is up. */
 #endif /* PPP_IPV6_SUPPORT */
+#if PPP_IPV4_SUPPORT && PPP_IPV6_SUPPORT
+  unsigned int ipcp_disabled           :1; /* disable ipcp */
+  unsigned int ipv6cp_disabled         :1; /* disable ipv6cp */
+#endif
   unsigned int lcp_echo_timer_running  :1; /* set if a timer is running */
 #if VJ_SUPPORT
   unsigned int vj_enabled              :1; /* Flag indicating VJ compression enabled. */

features/FEATURE_LWIP/lwip-interface/lwip/src/netif/ppp/lwip_ipcp.c

@@ -671,6 +671,11 @@ static void ipcp_close(ppp_pcb *pcb, const char *reason) {
  * ipcp_lowerup - The lower layer is up.
  */
 static void ipcp_lowerup(ppp_pcb *pcb) {
+#if PPP_IPV4_SUPPORT && PPP_IPV6_SUPPORT
+    if (pcb->ipcp_disabled) {
+        return;
+    }
+#endif
     fsm *f = &pcb->ipcp_fsm;
     fsm_lowerup(f);
 }

features/FEATURE_LWIP/lwip-interface/lwip/src/netif/ppp/lwip_ipv6cp.c

@@ -473,6 +473,11 @@ static void ipv6cp_close(ppp_pcb *pcb, const char *reason) {
  * ipv6cp_lowerup - The lower layer is up.
  */
 static void ipv6cp_lowerup(ppp_pcb *pcb) {
+#if PPP_IPV4_SUPPORT && PPP_IPV6_SUPPORT
+    if (pcb->ipv6cp_disabled) {
+        return;
+    }
+#endif
     fsm_lowerup(&pcb->ipv6cp_fsm);
 }
 

features/FEATURE_LWIP/lwip-interface/ppp_lwip.cpp

@@ -335,11 +335,13 @@ extern "C" nsapi_error_t ppp_lwip_if_init(struct netif *netif, const nsapi_ip_st
     }
 #endif
 
+#if LWIP_IPV4 && LWIP_IPV6
     if (stack == IPV4_STACK) {
         my_ppp_pcb->ipv6cp_disabled = true;
     } else if (stack == IPV6_STACK) {
         my_ppp_pcb->ipcp_disabled = true;
     }
+#endif
 
     return NSAPI_ERROR_OK;
 }