PPP, CORE, compile out auth support if none of auth protocols are enabled

Added macro PPP_AUTH_SUPPORT, if none of auth protocols are enabled
(PAP, CHAP, EAP) we reduce PPP memory usage by compiling out all
struct fields and source code used for authentication.

src/include/netif/ppp/ppp.h

@@ -140,6 +140,9 @@
 #define PPPCTLG_ERRCODE  102 /* Get the error code */
 #define PPPCTLG_FD       103 /* Get the fd associated with the ppp */
 
+/* Whether auth support is enabled at all */
+#define PPP_AUTH_SUPPORT (PAP_SUPPORT || CHAP_SUPPORT || EAP_SUPPORT)
+
 /************************
 *** PUBLIC DATA TYPES ***
 ************************/
@@ -187,12 +190,12 @@ typedef void (*ppp_link_status_cb_fn)(ppp_pcb *pcb, int err_code, void *ctx);
  */
 typedef struct ppp_settings_s {
 
-#if PPP_SERVER
+#if PPP_SERVER && PPP_AUTH_SUPPORT
   unsigned int  auth_required     : 1;       /* Peer is required to authenticate */
   unsigned int  null_login        : 1;       /* Username of "" and a password of "" are acceptable */
 #else
     unsigned int                   :2;       /* 2 bits of padding */
-#endif /* PPP_SERVER */
+#endif /* PPP_SERVER && PPP_AUTH_SUPPORT */
 #if PPP_REMOTENAME
   unsigned int  explicit_remote   : 1;       /* remote_name specified with remotename opt */
 #else
@@ -245,6 +248,7 @@ typedef struct ppp_settings_s {
   u32_t  maxconnect;                  /* Maximum connect time (seconds) */
 #endif /* PPP_MAXCONNECT */
 
+#if PPP_AUTH_SUPPORT
   /* auth data */
   const char  *user;                   /* Username for PAP */
   const char  *passwd;                 /* Password for PAP, secret for CHAP */
@@ -280,6 +284,8 @@ typedef struct ppp_settings_s {
 #endif /* PPP_SERVER */
 #endif /* EAP_SUPPORT */
 
+#endif /* PPP_AUTH_SUPPORT */
+
   u8_t  fsm_timeout_time;            /* Timeout time in seconds */
   u8_t  fsm_max_conf_req_transmits;  /* Maximum Configure-Request transmissions */
   u8_t  fsm_max_term_transmits;      /* Maximum Terminate-Request transmissions */

src/include/netif/ppp/ppp_impl.h

@@ -544,6 +544,7 @@ void upper_layers_down(ppp_pcb *pcb); /* take all NCPs down */
 void link_established(ppp_pcb *pcb);  /* the link is up; authenticate now */
 void start_networks(ppp_pcb *pcb);    /* start all the network control protos */
 void continue_networks(ppp_pcb *pcb); /* start network [ip, etc] control protos */
+#if PPP_AUTH_SUPPORT
 #if PPP_SERVER
 void auth_peer_fail(ppp_pcb *pcb, int protocol);
 				/* peer failed to authenticate itself */
@@ -554,12 +555,15 @@ void auth_withpeer_fail(ppp_pcb *pcb, int protocol);
 				/* we failed to authenticate ourselves */
 void auth_withpeer_success(ppp_pcb *pcb, int protocol, int prot_flavor);
 				/* we successfully authenticated ourselves */
+#endif /* PPP_AUTH_SUPPORT */
 void np_up(ppp_pcb *pcb, int proto);    /* a network protocol has come up */
 void np_down(ppp_pcb *pcb, int proto);  /* a network protocol has gone down */
 void np_finished(ppp_pcb *pcb, int proto); /* a network protocol no longer needs link */
+#if PPP_AUTH_SUPPORT
 void auth_reset(ppp_pcb *pcb);	/* check what secrets we have */
 int get_secret(ppp_pcb *pcb, const char *client, const char *server, char *secret, int *secret_len, int am_server);
 				/* get "secret" for chap */
+#endif /* PPP_AUTH_SUPPORT */
 
 /* Procedures exported from ipcp.c */
 /* int parse_dotted_ip (char *, u32_t *); */

src/netif/ppp/auth.c

@@ -725,17 +725,17 @@ void upper_layers_down(ppp_pcb *pcb) {
  * Proceed to the Dead, Authenticate or Network phase as appropriate.
  */
 void link_established(ppp_pcb *pcb) {
+#if PPP_AUTH_SUPPORT
     int auth;
 #if PPP_SERVER
+    int errcode;
     lcp_options *wo = &pcb->lcp_wantoptions;
     lcp_options *go = &pcb->lcp_gotoptions;
 #endif /* PPP_SERVER */
     lcp_options *ho = &pcb->lcp_hisoptions;
+#endif /* PPP_AUTH_SUPPORT */
     int i;
     const struct protent *protp;
-#if PPP_SERVER
-    int errcode;
-#endif /* PPP_SERVER */
 
     /*
      * Tell higher-level protocols that LCP is up.
@@ -747,6 +747,7 @@ void link_established(ppp_pcb *pcb) {
 		(*protp->lowerup)(pcb);
     }
 
+#if PPP_AUTH_SUPPORT
 #if PPP_SERVER
 #if PPP_ALLOWED_ADDRS
     if (!auth_required && noauth_addrs != NULL)
@@ -838,7 +839,7 @@ void link_established(ppp_pcb *pcb) {
     pcb->auth_done = 0;
 
     if (!auth)
-
+#endif /* PPP_AUTH_SUPPORT */
 	network_phase(pcb);
 }
 
@@ -994,6 +995,7 @@ void continue_networks(ppp_pcb *pcb) {
 	lcp_close(pcb, "No network protocols running");
 }
 
+#if PPP_AUTH_SUPPORT
 #if PPP_SERVER
 /*
  * The peer has failed to authenticate himself using `protocol'.
@@ -1156,6 +1158,7 @@ void auth_withpeer_success(ppp_pcb *pcb, int protocol, int prot_flavor) {
     if ((pcb->auth_pending &= ~bit) == 0)
 	network_phase(pcb);
 }
+#endif /* PPP_AUTH_SUPPORT */
 
 
 /*
@@ -1469,6 +1472,7 @@ auth_check_options()
 }
 #endif /* PPP_OPTIONS */
 
+#if PPP_AUTH_SUPPORT
 /*
  * auth_reset - called when LCP is starting negotiations to recheck
  * authentication options, i.e. whether we have appropriate secrets
@@ -1581,6 +1585,7 @@ void auth_reset(ppp_pcb *pcb) {
 	go->neg_eap = 0;
 #endif
 }
+#endif /* PPP_AUTH_SUPPORT */
 
 #if 0 /* UNUSED */
 /*
@@ -1934,6 +1939,7 @@ have_srp_secret(client, server, need_ip, lacks_ipp)
 }
 #endif /* UNUSED */
 
+#if PPP_AUTH_SUPPORT
 /*
  * get_secret - open the CHAP secret file and return the secret
  * for authenticating the given client on the given server.
@@ -2024,6 +2030,7 @@ int get_secret(ppp_pcb *pcb, const char *client, const char *server, char *secre
     return 1;
 #endif
 }
+#endif /* PPP_AUTH_SUPPORT */
 
 
 #if 0 /* UNUSED */

src/netif/ppp/lcp.c

@@ -665,7 +665,9 @@ static void lcp_resetci(fsm *f) {
     if (pcb->settings.noendpoint)
 	ao->neg_endpoint = 0;
     pcb->peer_mru = PPP_MRU;
+#if PPP_AUTH_SUPPORT
     auth_reset(pcb);
+#endif /* PPP_AUTH_SUPPORT */
 }
 
 

src/netif/ppp/ppp.c

@@ -187,6 +187,8 @@ static err_t ppp_netif_output(struct netif *netif, struct pbuf *pb, u_short prot
 /***********************************/
 void ppp_set_auth(ppp_pcb *pcb, u8_t authtype, const char *user, const char *passwd) {
 
+#if PPP_AUTH_SUPPORT
+
 #if PAP_SUPPORT
   if (authtype & PPPAUTHTYPE_PAP) {
     pcb->settings.refuse_pap = 0;
@@ -227,6 +229,13 @@ void ppp_set_auth(ppp_pcb *pcb, u8_t authtype, const char *user, const char *pas
   if (passwd) {
     pcb->settings.passwd = passwd;
   }
+
+#else /* PPP_AUTH_SUPPORT */
+  LWIP_UNUSED_ARG(pcb);
+  LWIP_UNUSED_ARG(authtype);
+  LWIP_UNUSED_ARG(user);
+  LWIP_UNUSED_ARG(passwd);
+#endif /* PPP_AUTH_SUPPORT */
 }
 
 #if PPP_NOTIFY_PHASE