From 6f21f489377a0830cb790a35a1eb21f9e63268de Mon Sep 17 00:00:00 2001
From: Sylvain Rochet <gradator@gradator.net>
Date: Tue, 5 Jun 2012 23:10:38 +0200
Subject: [PATCH] added MTU support (using MRU from the peer)

---
 src/netif/ppp/ppp.c      | 42 +++++++++++++++++-----------------------
 src/netif/ppp/ppp.h      |  6 ------
 src/netif/ppp/ppp_impl.h |  2 +-
 3 files changed, 19 insertions(+), 31 deletions(-)

diff --git a/src/netif/ppp/ppp.c b/src/netif/ppp/ppp.c
index ea8fabaa..937a46a7 100644
--- a/src/netif/ppp/ppp.c
+++ b/src/netif/ppp/ppp.c
@@ -1088,7 +1088,7 @@ static err_t ppp_netif_init_cb(struct netif *netif) {
   netif->name[0] = 'p';
   netif->name[1] = 'p';
   netif->output = ppp_netif_output;
-  netif->mtu = ppp_mtu((int)(size_t)netif->state);
+  netif->mtu = netif_get_mtu((int)(size_t)netif->state);
   netif->flags = NETIF_FLAG_POINTTOPOINT | NETIF_FLAG_LINK_UP;
 #if LWIP_NETIF_HOSTNAME
   /* @todo: Initialize interface hostname */
@@ -1381,24 +1381,6 @@ static err_t ppp_netif_output_over_ethernet(int pd, struct pbuf *p) {
 #endif /* PPPOE_SUPPORT */
 
 
-/*
- * Return the Maximum Transmission Unit for the given PPP connection.
- */
-u_short ppp_mtu(int pd) {
-  ppp_control *pc = &ppp_control_list[pd];
-  u_short st;
-
-  /* Validate parameters. */
-  if (pd < 0 || pd >= NUM_PPP || !pc->open_flag) {
-    st = 0;
-  } else {
-    st = pc->mtu;
-  }
-
-  return st;
-}
-
-
 /* Get and set parameters for the given connection.
  * Return 0 on success, an error code on failure. */
 int
@@ -1976,7 +1958,7 @@ int ppp_send_config(int unit, int mtu, u_int32_t accm, int pcomp, int accomp) {
   int i;
 #endif /* PPPOS_SUPPORT */
 
-  pc->mtu = mtu;
+  /* pc->mtu = mtu; -- set correctly with netif_set_mtu */
   pc->pcomp = pcomp;
   pc->accomp = accomp;
 
@@ -2190,14 +2172,26 @@ int sifnpmode(int u, int proto, enum NPmode mode) {
  * netif_set_mtu - set the MTU on the PPP network interface.
  */
 void netif_set_mtu(int unit, int mtu) {
-  /* FIXME: set lwIP MTU */
+  ppp_control *pc = &ppp_control_list[unit];
+
+  /* Validate parameters. */
+  if (unit < 0 || unit >= NUM_PPP || !pc->open_flag)
+    return;
+
+  pc->mtu = mtu;
 }
+
 /*
  * netif_get_mtu - get PPP interface MTU
  */
-int netif_get_mtu(int mtu) {
-  /* FIXME: get lwIP MTU */
-  return 1492;
+int netif_get_mtu(int unit) {
+  ppp_control *pc = &ppp_control_list[unit];
+
+  /* Validate parameters. */
+  if (unit < 0 || unit >= NUM_PPP || !pc->open_flag)
+    return  0;
+
+  return pc->mtu;
 }
 
 /********************************************************************
diff --git a/src/netif/ppp/ppp.h b/src/netif/ppp/ppp.h
index 57d29485..06c425a9 100644
--- a/src/netif/ppp/ppp.h
+++ b/src/netif/ppp/ppp.h
@@ -176,12 +176,6 @@ void ppp_sighup(int pd);
  */
 int ppp_ioctl(int pd, int cmd, void *arg);
 
-/*
- * Return the Maximum Transmission Unit for the given PPP connection.
- */
-/* FIXME: demystify MTU support */
-u_short ppp_mtu(int pd);
-
 #if PPPOS_SUPPORT && !PPP_INPROC_OWNTHREAD
 /*
  * PPP over Serial: this is the input function to be called for received data.
diff --git a/src/netif/ppp/ppp_impl.h b/src/netif/ppp/ppp_impl.h
index a05ce7c2..cfb4cd72 100644
--- a/src/netif/ppp/ppp_impl.h
+++ b/src/netif/ppp/ppp_impl.h
@@ -493,7 +493,7 @@ int sifdown (int u);
 int sifnpmode(int u, int proto, enum NPmode mode);
 
 void netif_set_mtu(int unit, int mtu);
-int netif_get_mtu(int mtu);
+int netif_get_mtu(int unit);
 
 int sifdefaultroute (int unit, u_int32_t ouraddr, u_int32_t gateway, bool replace);
 int cifdefaultroute (int unit, u_int32_t ouraddr, u_int32_t gateway);