improved PPP default interface management, added ppp_set_default() API call

src/api/pppapi.c

@@ -58,6 +58,26 @@ ppp_pcb *pppapi_new(void) {
 }
 
 
+/**
+ * Call ppp_set_default() inside the tcpip_thread context.
+ */
+static void pppapi_do_ppp_set_default(struct pppapi_msg_msg *msg) {
+  ppp_set_default(msg->ppp);
+  TCPIP_PPPAPI_ACK(msg);
+}
+
+/**
+ * Call ppp_set_default() in a thread-safe way by running that function inside the
+ * tcpip_thread context.
+ */
+void pppapi_set_default(ppp_pcb *pcb) {
+  struct pppapi_msg msg;
+  msg.function = pppapi_do_ppp_set_default;
+  msg.msg.ppp = pcb;
+  TCPIP_PPPAPI(&msg);
+}
+
+
 /**
  * Call ppp_set_auth() inside the tcpip_thread context.
  */

src/include/lwip/pppapi.h

@@ -110,6 +110,7 @@ struct pppapi_msg {
 
 /* API for application */
 ppp_pcb *pppapi_new(void);
+void pppapi_set_default(ppp_pcb *pcb);
 void pppapi_set_auth(ppp_pcb *pcb, u8_t authtype, char *user, char *passwd);
 #if PPPOS_SUPPORT
 int pppapi_over_serial_open(ppp_pcb *pcb, sio_fd_t fd, ppp_link_status_cb_fn link_status_cb, void *link_status_ctx);

src/netif/ppp/ipcp.c

@@ -619,9 +619,10 @@ static void ipcp_init(ppp_pcb *pcb) {
     wo->maxslotindex = MAX_STATES - 1; /* really max index */
     wo->cflag = 1;
 
+#if 0 /* UNUSED */
     /* wanting default route by default */
-    /* FIXME: should be configurable */
     wo->default_route = 1;
+#endif /* UNUSED */
 
     /* max slots and slot-id compression are currently hardwired in */
     /* ppp_if.c to 16 and 1, this needs to be changed (among other */
@@ -632,12 +633,14 @@ static void ipcp_init(ppp_pcb *pcb) {
     ao->maxslotindex = MAX_STATES - 1;
     ao->cflag = 1;
 
+#if 0 /* UNUSED */
     /*
      * XXX These control whether the user may use the proxyarp
      * and defaultroute options.
      */
     ao->proxy_arp = 1;
     ao->default_route = 1;
+#endif /* UNUSED */
 }
 
 
@@ -1737,10 +1740,12 @@ ip_demand_conf(u)
 	return 0;
     if (!sifnpmode(pcb, PPP_IP, NPMODE_QUEUE))
 	return 0;
+#if 0 /* UNUSED */
     if (wo->default_route)
 	if (sifdefaultroute(pcb, wo->ouraddr, wo->hisaddr,
 		wo->replace_default_route))
 	    default_route_set[u] = 1;
+#endif /* UNUSED */
     if (wo->proxy_arp)
 	if (sifproxyarp(pcb, wo->hisaddr))
 	    proxy_arp_set[u] = 1;
@@ -1914,11 +1919,13 @@ static void ipcp_up(fsm *f) {
 #endif
 	sifnpmode(pcb, PPP_IP, NPMODE_PASS);
 
+#if 0 /* UNUSED */
 	/* assign a default route through the interface if required */
 	if (wo->default_route)
 	    if (sifdefaultroute(pcb, go->ouraddr, ho->hisaddr,
 		    wo->replace_default_route))
 		    pcb->default_route_set = 1;
+#endif /* UNUSED */
 
 	/* Make a proxy ARP entry if requested. */
 	if (ho->hisaddr != 0 && wo->proxy_arp)
@@ -2020,6 +2027,7 @@ static void ipcp_clear_addrs(ppp_pcb *pcb, u32_t ouraddr, u32_t hisaddr, u8_t re
 	cifproxyarp(pcb, hisaddr);
 	pcb->proxy_arp_set = 0;
     }
+#if 0 /* UNUSED */
     /* If replacedefaultroute, sifdefaultroute will be called soon
      * with replacedefaultroute set and that will overwrite the current
      * default route. This is the case only when doing demand, otherwise
@@ -2032,6 +2040,7 @@ static void ipcp_clear_addrs(ppp_pcb *pcb, u32_t ouraddr, u32_t hisaddr, u8_t re
 	cifdefaultroute(pcb, ouraddr, hisaddr);
 	pcb->default_route_set = 0;
     }
+#endif /* UNUSED */
     cifaddr(pcb, ouraddr, hisaddr);
 }
 

src/netif/ppp/ipcp.h

@@ -75,8 +75,10 @@ typedef struct ipcp_options {
     unsigned int neg_addr               :1; /* Negotiate IP Address? */
     unsigned int old_addrs              :1; /* Use old (IP-Addresses) option? */
     unsigned int req_addr               :1; /* Ask peer to send IP address? */
+#if 0 /* UNUSED */
     unsigned int default_route          :1; /* Assign default route through interface? */
     unsigned int replace_default_route  :1; /* Replace default route through interface? */
+#endif /* UNUSED */
     unsigned int proxy_arp              :1; /* Make proxy ARP entry for peer? */
     unsigned int neg_vj                 :1; /* Van Jacobson Compression? */
     unsigned int old_vj                 :1; /* use old (short) form of VJ option? */
@@ -85,7 +87,7 @@ typedef struct ipcp_options {
     unsigned int req_dns1               :1; /* Ask peer to send primary DNS address? */
     unsigned int req_dns2               :1; /* Ask peer to send secondary DNS address? */
     unsigned int cflag                  :1;
-    unsigned int                        :3; /* 3 bits of padding to round out to 16 bits */
+    unsigned int                        :5; /* 3 bits of padding to round out to 16 bits */
 
     u32_t ouraddr, hisaddr;	/* Addresses in NETWORK BYTE ORDER */
     u32_t dnsaddr[2];	/* Primary and secondary MS DNS entries */

src/netif/ppp/ppp.c

@@ -294,6 +294,10 @@ ppp_pcb *ppp_new(void) {
     return pcb;
 }
 
+void ppp_set_default(ppp_pcb *pcb) {
+  netif_set_default(&pcb->netif);
+}
+
 void ppp_set_auth(ppp_pcb *pcb, u8_t authtype, char *user, char *passwd) {
 
 #if PAP_SUPPORT
@@ -2190,41 +2194,6 @@ int netif_get_mtu(ppp_pcb *pcb) {
   return pcb->mtu;
 }
 
-/********************************************************************
- *
- * sifdefaultroute - assign a default route through the address given.
- *
- * If the global default_rt_repl_rest flag is set, then this function
- * already replaced the original system defaultroute with some other
- * route and it should just replace the current defaultroute with
- * another one, without saving the current route. Use: demand mode,
- * when pppd sets first a defaultroute it it's temporary ppp0 addresses
- * and then changes the temporary addresses to the addresses for the real
- * ppp connection when it has come up.
- */
-int sifdefaultroute(ppp_pcb *pcb, u32_t ouraddr, u32_t gateway, u8_t replace) {
-
-  LWIP_UNUSED_ARG(ouraddr);
-  LWIP_UNUSED_ARG(gateway);
-  LWIP_UNUSED_ARG(replace);
-
-  netif_set_default(&pcb->netif);
-  return 1;
-}
-
-/********************************************************************
- *
- * cifdefaultroute - delete a default route through the address given.
- */
-int cifdefaultroute(ppp_pcb *pcb, u32_t ouraddr, u32_t gateway) {
-
-  LWIP_UNUSED_ARG(ouraddr);
-  LWIP_UNUSED_ARG(gateway);
-
-  netif_set_default(NULL);
-  return 1;
-}
-
 /********************************************************************
  *
  * sifproxyarp - Make a proxy ARP entry for the peer.

src/netif/ppp/ppp.h

@@ -294,7 +294,6 @@ struct ppp_pcb_s {
   unsigned int if_up                   :1; /* True when the interface is up. */
   unsigned int pcomp                   :1; /* Does peer accept protocol compression? */
   unsigned int accomp                  :1; /* Does peer accept addr/ctl compression? */
-  unsigned int default_route_set       :1; /* Have set up a default route */
   unsigned int proxy_arp_set           :1; /* Have created proxy arp entry */
   unsigned int ipcp_is_open            :1; /* haven't called np_finished() */
   unsigned int ipcp_is_up              :1; /* have called ipcp_up() */
@@ -310,7 +309,7 @@ struct ppp_pcb_s {
 #else
   unsigned int                         :1; /* 1 bit of padding */
 #endif /* PPPOS_SUPPORT && VJ_SUPPORT */
-  unsigned int                         :5; /* 5 bits of padding to round out to 16 bits */
+  unsigned int                         :6; /* 5 bits of padding to round out to 16 bits */
 
   ppp_settings settings;
 
@@ -421,6 +420,12 @@ int ppp_init(void);
  */
 ppp_pcb *ppp_new(void);
 
+/*
+ * Set a PPP interface as the default network interface
+ * (used to output all packets for which no specific route is found).
+ */
+void ppp_set_default(ppp_pcb *pcb);
+
 /*
  * Set auth helper, optional, you can either fill ppp_pcb->settings.
  *

src/netif/ppp/ppp_impl.h

@@ -416,9 +416,6 @@ int sifnpmode(ppp_pcb *pcb, int proto, enum NPmode mode);
 void netif_set_mtu(ppp_pcb *pcb, int mtu);
 int netif_get_mtu(ppp_pcb *pcb);
 
-int sifdefaultroute(ppp_pcb *pcb, u32_t ouraddr, u32_t gateway, u8_t replace);
-int cifdefaultroute(ppp_pcb *pcb, u32_t ouraddr, u32_t gateway);
-
 int sifproxyarp(ppp_pcb *pcb, u32_t his_adr);
 int cifproxyarp(ppp_pcb *pcb, u32_t his_adr);