improved persist mode, we now clear everything we can in the PPP control block structure, ensuring we start a new session from a clean state

src/netif/ppp/lcp.c

@@ -1494,7 +1494,7 @@ static int lcp_nakci(fsm *f, u_char *p, int len, int treat_as_reject) {
      */
     if (f->state != PPP_FSM_OPENED) {
 	if (looped_back) {
-	    if (++try.numloops >= pcb->lcp_loopbackfail) {
+	    if (++try.numloops >= pcb->settings.lcp_loopbackfail) {
 		int errcode = PPPERR_LOOPBACK;
 		notice("Serial line is looped back.");
 		ppp_ioctl(pcb, PPPCTLS_ERRCODE, &errcode);

src/netif/ppp/ppp.c

@@ -187,6 +187,7 @@ struct protent *protocols[] = {
 #endif /* PPPOS_SUPPORT */
 
 /* Prototypes for procedures local to this file. */
+static void ppp_clear(ppp_pcb *pcb);
 
 static void ppp_start(ppp_pcb *pcb);	/** Initiate LCP open request */
 
@@ -248,24 +249,16 @@ int ppp_init(void) {
 
 /* Create a new PPP session. */
 ppp_pcb *ppp_new(void) {
-    int i;
     ppp_pcb *pcb;
-    struct protent *protp;
 
     pcb = (ppp_pcb*)memp_malloc(MEMP_PPP_PCB);
     if (pcb == NULL)
       return NULL;
 
-#if PPP_STATS_SUPPORT
-    link_stats_valid = 0;
-#endif /* PPP_STATS_SUPPORT */
-
     memset(pcb, 0, sizeof(ppp_pcb));
 #if PPP_DEBUG
     pcb->num = ppp_num++;
 #endif /* PPP_DEBUG */
-    IP4_ADDR(&pcb->addrs.netmask, 255,255,255,255);
-    pcb->lcp_loopbackfail = DEFLOOPBACKFAIL;
 
     /* default configuration */
     pcb->settings.usepeerdns = 1;
@@ -275,14 +268,11 @@ ppp_pcb *ppp_new(void) {
     pcb->settings.chap_timeout_time = 3;
     pcb->settings.chap_max_transmits = 10;
 #endif /* CHAP_SUPPPORT */
+    pcb->settings.lcp_loopbackfail = DEFLOOPBACKFAIL;
     pcb->settings.lcp_echo_interval = LCP_ECHOINTERVAL;
     pcb->settings.lcp_echo_fails = LCP_MAXECHOFAILS;
 
-    /*
+    ppp_clear(pcb);
-     * Initialize each protocol.
-     */
-    for (i = 0; (protp = protocols[i]) != NULL; ++i)
-        (*protp->init)(pcb);
 
     if (!netif_add(&pcb->netif, &pcb->addrs.our_ipaddr, &pcb->addrs.netmask,
                   &pcb->addrs.his_ipaddr, (void *)pcb, ppp_netif_init_cb, NULL)) {
@@ -294,6 +284,25 @@ ppp_pcb *ppp_new(void) {
     return pcb;
 }
 
+/* Set a PPP PCB to its initial state */
+static void ppp_clear(ppp_pcb *pcb) {
+  struct protent *protp;
+  int i;
+
+#if PPP_STATS_SUPPORTs
+  link_stats_valid = 0;
+#endif /* PPP_STATS_SUPPORT */
+
+  memset(&pcb->phase, 0, sizeof(ppp_pcb) - ( (char*)&((ppp_pcb*)0)->phase - (char*)0 ) );
+  IP4_ADDR(&pcb->addrs.netmask, 255,255,255,255);
+
+  /*
+   * Initialize each protocol.
+   */
+  for (i = 0; (protp = protocols[i]) != NULL; ++i)
+      (*protp->init)(pcb);
+}
+
 void ppp_set_default(ppp_pcb *pcb) {
   netif_set_default(&pcb->netif);
 }
@@ -371,7 +380,6 @@ int ppp_over_serial_open(ppp_pcb *pcb, sio_fd_t fd, ppp_link_status_cb_fn link_s
    * Start the connection and handle incoming events (packet or timeout).
    */
   PPPDEBUG(LOG_INFO, ("ppp_over_serial_open: unit %d: Connecting\n", pcb->num));
-  new_phase(pcb, PHASE_INITIALIZE);
   ppp_start(pcb);
 #if PPP_INPROC_OWNTHREAD
   sys_thread_new(PPP_THREAD_NAME, ppp_input_thread, (void*)&pcb->rx, PPP_THREAD_STACKSIZE, PPP_THREAD_PRIO);
@@ -430,7 +438,6 @@ int ppp_over_ethernet_open(ppp_pcb *pcb, struct netif *ethif, const char *servic
     return PPPERR_OPEN;
   }
 
-  new_phase(pcb, PHASE_INITIALIZE);
   pppoe_connect(pcb->pppoe_sc);
   return PPPERR_NONE;
 }
@@ -454,12 +461,12 @@ int ppp_over_l2tp_open(ppp_pcb *pcb, struct netif *netif, ip_addr_t *ipaddr, u16
   pcb->link_status_cb  = link_status_cb;
   pcb->link_status_ctx = link_status_ctx;
 
-  wo->mru = 1500; /* FIXME: MTU depends we support IP fragmentation or not */
+  wo->mru = 1500; /* FIXME: MTU depends if we support IP fragmentation or not */
   wo->neg_asyncmap = 0;
   wo->neg_pcompression = 0;
   wo->neg_accompression = 0;
 
-  ao->mru = 1500; /* FIXME: MTU depends we support IP fragmentation or not */
+  ao->mru = 1500; /* FIXME: MTU depends if we support IP fragmentation or not */
   ao->neg_asyncmap = 0;
   ao->neg_pcompression = 0;
   ao->neg_accompression = 0;
@@ -468,7 +475,6 @@ int ppp_over_l2tp_open(ppp_pcb *pcb, struct netif *netif, ip_addr_t *ipaddr, u16
     return PPPERR_OPEN;
   }
 
-  new_phase(pcb, PHASE_INITIALIZE);
   if(!pppol2tp_connect(pcb->l2tp_pcb, netif, ipaddr, port) != ERR_OK) {
     return PPPERR_OPEN;
   }
@@ -525,6 +531,7 @@ ppp_sighup(ppp_pcb *pcb)
 /** Initiate LCP open request */
 static void ppp_start(ppp_pcb *pcb) {
   PPPDEBUG(LOG_DEBUG, ("ppp_start: unit %d\n", pcb->num));
+  new_phase(pcb, PHASE_INITIALIZE);
   lcp_open(pcb); /* Start protocol */
   lcp_lowerup(pcb);
   PPPDEBUG(LOG_DEBUG, ("ppp_start: finished\n"));
@@ -1817,9 +1824,24 @@ static void ppp_over_ethernet_link_status_cb(ppp_pcb *pcb, int state) {
 
   /* Reconnect if persist mode is enabled */
   if(pcb->settings.persist) {
+    lcp_options *wo = &pcb->lcp_wantoptions;
+    lcp_options *ao = &pcb->lcp_allowoptions;
+
     if(pcb->link_status_cb)
       pcb->link_status_cb(pcb, pcb->err_code ? pcb->err_code : pppoe_err_code, pcb->link_status_ctx);
-    new_phase(pcb, PHASE_INITIALIZE);
+
+    ppp_clear(pcb);
+
+    wo->mru = pcb->ethif->mtu-PPPOE_HEADERLEN-2; /* two byte PPP protocol discriminator, then IP data */
+    wo->neg_asyncmap = 0;
+    wo->neg_pcompression = 0;
+    wo->neg_accompression = 0;
+
+    ao->mru = pcb->ethif->mtu-PPPOE_HEADERLEN-2; /* two byte PPP protocol discriminator, then IP data */
+    ao->neg_asyncmap = 0;
+    ao->neg_pcompression = 0;
+    ao->neg_accompression = 0;
+
     pppoe_reconnect(pcb->pppoe_sc);
     return;
   }
@@ -1860,9 +1882,24 @@ static void ppp_over_l2tp_link_status_cb(ppp_pcb *pcb, int state) {
 
   /* Reconnect if persist mode is enabled */
   if(pcb->settings.persist) {
+    lcp_options *wo = &pcb->lcp_wantoptions;
+    lcp_options *ao = &pcb->lcp_allowoptions;
+
     if(pcb->link_status_cb)
       pcb->link_status_cb(pcb, pcb->err_code ? pcb->err_code : pppol2tp_err_code, pcb->link_status_ctx);
-    new_phase(pcb, PHASE_INITIALIZE);
+
+    ppp_clear(pcb);
+
+    wo->mru = 1500; /* FIXME: MTU depends if we support IP fragmentation or not */
+    wo->neg_asyncmap = 0;
+    wo->neg_pcompression = 0;
+    wo->neg_accompression = 0;
+
+    ao->mru = 1500; /* FIXME: MTU depends if we support IP fragmentation or not */
+    ao->neg_asyncmap = 0;
+    ao->neg_pcompression = 0;
+    ao->neg_accompression = 0;
+
     pppol2tp_reconnect(pcb->l2tp_pcb);
     return;
   }

src/netif/ppp/ppp.h

@@ -231,6 +231,8 @@ typedef struct ppp_settings_s {
   u8_t  chap_rechallenge_time;
 #endif /* CHAP_SUPPPORT */
 
+  u8_t  lcp_loopbackfail;     /* Number of times we receive our magic number from the peer
+                                 before deciding the link is looped-back. */
   u8_t  lcp_echo_interval;    /* Interval between LCP echo-requests */
   u8_t  lcp_echo_fails;       /* Tolerance to unanswered echo-requests */
 
@@ -281,7 +283,7 @@ typedef struct ppp_pcb_rx_s {
 
   u16_t in_protocol;             /* The input protocol code. */
   u16_t in_fcs;                  /* Input Frame Check Sequence value. */
-  ppp_dev_states in_state;         /* The input process state. */
+  ppp_dev_states in_state;       /* The input process state. */
   char in_escaped;               /* Escape next character. */
   ext_accm in_accm;              /* Async-Ctl-Char-Map for input. */
 } ppp_pcb_rx;
@@ -291,6 +293,35 @@ typedef struct ppp_pcb_rx_s {
  * PPP interface control block.
  */
 struct ppp_pcb_s {
+  /* -- below are data that will NOT be cleared between two sessions if persist mode is enabled */
+#if PPP_DEBUG
+  u8_t num;                      /* Interface number - only useful for debugging */
+#endif /* PPP_DEBUG */
+  ppp_settings settings;
+#if PPPOS_SUPPORT
+  sio_fd_t fd;                   /* File device ID of port. */
+#endif /* PPPOS_SUPPORT */
+#if PPPOE_SUPPORT
+  struct netif *ethif;
+  struct pppoe_softc *pppoe_sc;
+#endif /* PPPOE_SUPPORT */
+#if PPPOL2TP_SUPPORT
+  pppol2tp_pcb *l2tp_pcb;
+#endif /* PPPOL2TP_SUPPORT */
+  void (*link_status_cb)(ppp_pcb *pcb, int err_code, void *ctx);  /* Status change callback */
+  void *link_status_ctx;                                          /* Status change callback optional pointer */
+  struct netif netif;            /* PPP interface */
+
+  /* -- below are data that will be cleared between two sessions if persist mode is enabled */
+
+  /*
+   * phase must be the first member of cleared members, because it is used to know
+   * which part must not be cleared.
+   */
+  u8_t phase;                    /* where the link is at */
+  u8_t err_code;                 /* Code indicating why interface is down. */
+
+  /* flags */
   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? */
@@ -311,14 +342,7 @@ struct ppp_pcb_s {
 #endif /* PPPOS_SUPPORT && VJ_SUPPORT */
   unsigned int                         :6; /* 5 bits of padding to round out to 16 bits */
 
-  ppp_settings settings;
-
-#if PPP_DEBUG
-  u8_t num;                      /* Interface number - only useful for debugging */
-#endif /* PPP_DEBUG */
-
 #if PPPOS_SUPPORT
-  sio_fd_t fd;                   /* File device ID of port. */
 /* FIXME: there is probably one superfluous */
   ext_accm out_accm;             /* Async-Ctl-Char-Map for output. */
   ext_accm xmit_accm;            /* extended transmit ACCM */
@@ -328,18 +352,6 @@ struct ppp_pcb_s {
 #endif /* VJ_SUPPORT */
 #endif /* PPPOS_SUPPORT */
 
-#if PPPOE_SUPPORT
-  struct netif *ethif;
-  struct pppoe_softc *pppoe_sc;
-#endif /* PPPOE_SUPPORT */
-
-#if PPPOL2TP_SUPPORT
-  pppol2tp_pcb *l2tp_pcb;
-#endif /* PPPOL2TP_SUPPORT */
-
-  u8_t phase;                    /* where the link is at */
-  u8_t err_code;                 /* Code indicating why interface is down. */
-
   /* FIXME: maybe we should cleanup one of those MTU variables */
   u16_t mtu;                     /* Peer's mru */
   u16_t peer_mru;                /* currently negotiated peer MRU */
@@ -347,10 +359,6 @@ struct ppp_pcb_s {
   u32_t last_xmit;               /* Time of last transmission. */
 
   struct ppp_addrs addrs;        /* PPP addresses */
-  struct netif netif;            /* PPP interface */
-
-  void (*link_status_cb)(ppp_pcb *pcb, int err_code, void *ctx);  /* Status change callback */
-  void *link_status_ctx;                                       /* Status change callback optional pointer */
 
   /* auth data */
 #if PPP_SERVER
@@ -358,11 +366,11 @@ struct ppp_pcb_s {
 #endif /* PPP_SERVER */
   u16_t auth_pending;        /* Records which authentication operations haven't completed yet. */
   u16_t auth_done;           /* Records which authentication operations have been completed. */
-  u8_t num_np_open;         /* Number of network protocols which we have opened. */
+  u8_t num_np_open;          /* Number of network protocols which we have opened. */
-  u8_t num_np_up;           /* Number of network protocols which have come up. */
+  u8_t num_np_up;            /* Number of network protocols which have come up. */
 
 #if PAP_SUPPORT
-  upap_state upap;          /* PAP data */
+  upap_state upap;           /* PAP data */
 #endif /* PAP_SUPPORT */
 
 #if CHAP_SUPPORT
@@ -383,7 +391,6 @@ struct ppp_pcb_s {
   lcp_options lcp_hisoptions;    /* Options that we ack'd */
   u8_t lcp_echos_pending;        /* Number of outstanding echo msgs */
   u8_t lcp_echo_number;          /* ID number of next echo frame */
-  u8_t lcp_loopbackfail;
 
   fsm ipcp_fsm;                   /* IPCP fsm structure */
   ipcp_options ipcp_wantoptions;  /* Options that we want to request */