From a1555e061550edc523475d20bb11d72b53523080 Mon Sep 17 00:00:00 2001
From: Sylvain Rochet <gradator@gradator.net>
Date: Tue, 23 Apr 2013 00:19:07 +0200
Subject: [PATCH] PPP, added ppp_free()

Free the control block, clean everything except the PPP PCB itself
and the netif, it allows you to change the underlying PPP protocol
(eg. from PPPoE to PPPoS to switch from DSL to GPRS) without losing
your PPP and netif handlers.
---
 src/include/netif/ppp/ppp.h | 15 +++++++++
 src/netif/ppp/ppp.c         | 63 +++++++++++++++++++++++++++----------
 2 files changed, 62 insertions(+), 16 deletions(-)

diff --git a/src/include/netif/ppp/ppp.h b/src/include/netif/ppp/ppp.h
index fc4d2c91..a2389cd8 100644
--- a/src/include/netif/ppp/ppp.h
+++ b/src/include/netif/ppp/ppp.h
@@ -539,6 +539,21 @@ int ppp_close(ppp_pcb *pcb);
  */
 void ppp_sighup(ppp_pcb *pcb);
 
+/*
+ * Free the control block, clean everything except the PPP PCB itself
+ * and the netif, it allows you to change the underlying PPP protocol
+ * (eg. from PPPoE to PPPoS to switch from DSL to GPRS) without losing
+ * your PPP and netif handlers.
+ *
+ * This can only be called if PPP is in the dead phase.
+ *
+ * You must use ppp_close() before if you wish to terminate
+ * an established PPP session.
+ *
+ * Return 0 on success, an error code on failure.
+ */
+int ppp_free(ppp_pcb *pcb);
+
 /*
  * Release the control block.
  *
diff --git a/src/netif/ppp/ppp.c b/src/netif/ppp/ppp.c
index c00a129a..cc0fc121 100644
--- a/src/netif/ppp/ppp.c
+++ b/src/netif/ppp/ppp.c
@@ -519,6 +519,48 @@ ppp_sighup(ppp_pcb *pcb)
   ppp_hup(pcb);
 }
 
+/*
+ * Free the control block, clean everything except the PPP PCB itself
+ * and the netif, it allows you to change the underlying PPP protocol
+ * (eg. from PPPoE to PPPoS to switch from DSL to GPRS) without losing
+ * your PPP and netif handlers.
+ *
+ * This can only be called if PPP is in the dead phase.
+ *
+ * You must use ppp_close() before if you wish to terminate
+ * an established PPP session.
+ *
+ * Return 0 on success, an error code on failure.
+ */
+int ppp_free(ppp_pcb *pcb) {
+  if (pcb->phase != PHASE_DEAD) {
+    return PPPERR_PARAM;
+  }
+
+  PPPDEBUG(LOG_DEBUG, ("ppp_free: unit %d\n", pcb->num));
+
+#if PPPOE_SUPPORT
+  if (pcb->pppoe_sc) {
+    pppoe_destroy(&pcb->netif);
+    pcb->pppoe_sc = NULL;
+  }
+#endif /* PPPOE_SUPPORT */
+
+#if PPPOL2TP_SUPPORT
+  if (pcb->l2tp_pcb) {
+    pppol2tp_destroy(pcb->l2tp_pcb);
+    pcb->l2tp_pcb = NULL;
+  }
+#endif /* PPPOL2TP_SUPPORT */
+
+#if PPPOS_SUPPORT
+  /* input pbuf left ? */
+  ppp_free_current_input_packet(&pcb->rx);
+#endif /* PPPOS_SUPPORT */
+
+  return 0;
+}
+
 /*
  * Release the control block.
  *
@@ -530,29 +572,18 @@ ppp_sighup(ppp_pcb *pcb)
  * Return 0 on success, an error code on failure.
  */
 int ppp_delete(ppp_pcb *pcb) {
+  int err;
+
   if (pcb->phase != PHASE_DEAD) {
     return PPPERR_PARAM;
   }
 
   PPPDEBUG(LOG_DEBUG, ("ppp_delete: unit %d\n", pcb->num));
+
   netif_remove(&pcb->netif);
-
-#if PPPOE_SUPPORT
-  if (pcb->pppoe_sc) {
-    pppoe_destroy(&pcb->netif);
+  if( (err = ppp_free(pcb)) != PPPERR_NONE) {
+    return err;
   }
-#endif /* PPPOE_SUPPORT */
-
-#if PPPOL2TP_SUPPORT
-  if (pcb->l2tp_pcb) {
-    pppol2tp_destroy(pcb->l2tp_pcb);
-  }
-#endif /* PPPOL2TP_SUPPORT */
-
-#if PPPOS_SUPPORT
-  /* input pbuf left ? */
-  ppp_free_current_input_packet(&pcb->rx);
-#endif /* PPPOS_SUPPORT */
 
   memp_free(MEMP_PPP_PCB, pcb);
   return 0;