From 90b03e1746a7d19dc5ca2b17a7228231315f9839 Mon Sep 17 00:00:00 2001
From: patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3>
Date: Mon, 6 Jun 2011 15:06:08 +0000
Subject: [PATCH] Fix minimum MTU... must be at lest 576
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3674 42af7a65-404d-4744-a932-0658087f49c3
---
TODO | 15 +++++++++++++--
arch/arm/src/lpc17xx/lpc17_emacram.h | 2 +-
arch/arm/src/lpc17xx/lpc17_ethernet.c | 3 ++-
configs/olimex-lpc1766stk/ftpc/defconfig | 4 ++--
include/net/uip/uip-arch.h | 2 +-
include/net/uip/uipopt.h | 12 ++++++++++++
6 files changed, 31 insertions(+), 7 deletions(-)
diff --git a/TODO b/TODO
index 4752637277..7345d5b608 100644
--- a/TODO
+++ b/TODO
@@ -1,4 +1,4 @@
-NuttX TODO List (Last updated May 31, 2011)
+NuttX TODO List (Last updated June 6, 2011)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
nuttx/
@@ -10,7 +10,7 @@ nuttx/
(1) pthreads (sched/)
(1) C++ Support
(5) Binary loaders (binfmt/)
- (15) Network (net/, drivers/net)
+ (16) Network (net/, drivers/net)
(2) USB (drivers/usbdev, drivers/usbhost)
(6) Libraries (lib/)
(13) File system/Generic drivers (fs/, drivers/)
@@ -333,6 +333,17 @@ o Network (net/, drivers/net)
the mechanism for leaving and joining groups is hidden behind a wrapper
function so that little of this incompatibilities need be exposed.
+ Description: Many configurations have the MTU (CONFIG_NET_BUFSIZE) set to very small
+ numbers, less then the minimum MTU size that must be supported -- 576.
+ This can cause problems in some networks: CONFIG_NET_BUFSIZE should
+ be set to at least 576 in all defconfig files.
+
+ The symptoms of using very small MTU sizes can be very strange. With
+ Ubuntu 9.x and vsFtpd was that the total packet size did *not match* the
+ packet size in the IP header. This then caused a TCP checksum failure
+ and the packet was rejected.
+ Status: Open
+ Priority: Low... fix defconfig files as necessary.
o USB (drivers/usbdev, drivers/usbhost)
^^^^^^^^^^^^^^^^^^^^
diff --git a/arch/arm/src/lpc17xx/lpc17_emacram.h b/arch/arm/src/lpc17xx/lpc17_emacram.h
index 98eaa91b97..3561b72ba8 100755
--- a/arch/arm/src/lpc17xx/lpc17_emacram.h
+++ b/arch/arm/src/lpc17xx/lpc17_emacram.h
@@ -209,7 +209,7 @@
#define LPC17_PKTMEM_SIZE (LPC17_EMACRAM_SIZE-LPC17_DESCTAB_SIZE)
#define LPC17_PKTMEM_END (LPC17_EMACRAM_BASE+LPC17_PKTMEM_SIZE)
-#define LPC17_MAXPACKET_SIZE ((CONFIG_NET_BUFSIZE + 3 + 2) & ~3)
+#define LPC17_MAXPACKET_SIZE ((CONFIG_NET_BUFSIZE + CONFIG_NET_GUARDSIZE + 3) & ~3)
#define LPC17_NTXPKTS CONFIG_NET_NTXDESC
#define LPC17_NRXPKTS CONFIG_NET_NRXDESC
diff --git a/arch/arm/src/lpc17xx/lpc17_ethernet.c b/arch/arm/src/lpc17xx/lpc17_ethernet.c
index 3efa3df03b..de015bcb94 100644
--- a/arch/arm/src/lpc17xx/lpc17_ethernet.c
+++ b/arch/arm/src/lpc17xx/lpc17_ethernet.c
@@ -53,6 +53,7 @@
#include <nuttx/mii.h>
#include <net/uip/uip.h>
+#include <net/uip/uipopt.h>
#include <net/uip/uip-arp.h>
#include <net/uip/uip-arch.h>
@@ -809,7 +810,7 @@ static void lpc17_rxdone(struct lpc17_driver_s *priv)
* imply that the packet is too big.
*/
- /* else */ if (pktlen > CONFIG_NET_BUFSIZE+2)
+ /* else */ if (pktlen > CONFIG_NET_BUFSIZE + CONFIG_NET_GUARDSIZE)
{
nlldbg("Too big. considx: %08x prodidx: %08x pktlen: %d rxstat: %08x\n",
considx, prodidx, pktlen, *rxstat);
diff --git a/configs/olimex-lpc1766stk/ftpc/defconfig b/configs/olimex-lpc1766stk/ftpc/defconfig
index 2ba0a0277e..5d01d7e86d 100755
--- a/configs/olimex-lpc1766stk/ftpc/defconfig
+++ b/configs/olimex-lpc1766stk/ftpc/defconfig
@@ -207,7 +207,7 @@ CONFIG_PHY_KS8721=y
CONFIG_PHY_AUTONEG=y
CONFIG_PHY_SPEED100=n
CONFIG_PHY_FDUPLEX=y
-CONFIG_NET_EMACRAM_SIZE=8192
+CONFIG_NET_EMACRAM_SIZE=8448
CONFIG_NET_NTXDESC=7
CONFIG_NET_NRXDESC=7
CONFIG_NET_REGDEBUG=n
@@ -551,7 +551,7 @@ CONFIG_NET=y
CONFIG_NET_IPv6=n
CONFIG_NSOCKET_DESCRIPTORS=16
CONFIG_NET_SOCKOPTS=y
-CONFIG_NET_BUFSIZE=562
+CONFIG_NET_BUFSIZE=576
CONFIG_NET_TCP=y
CONFIG_NET_TCP_CONNS=16
CONFIG_NET_NTCP_READAHEAD_BUFFERS=16
diff --git a/include/net/uip/uip-arch.h b/include/net/uip/uip-arch.h
index 2cbe7239c6..3cb2904ea3 100644
--- a/include/net/uip/uip-arch.h
+++ b/include/net/uip/uip-arch.h
@@ -117,7 +117,7 @@ struct uip_driver_s
#ifdef CONFIG_NET_MULTIBUFFER
uint8_t *d_buf;
#else
- uint8_t d_buf[CONFIG_NET_BUFSIZE + 2];
+ uint8_t d_buf[CONFIG_NET_BUFSIZE + CONFIG_NET_GUARDSIZE];
#endif
/* d_appdata points to the location where application data can be read from
diff --git a/include/net/uip/uipopt.h b/include/net/uip/uipopt.h
index f6aff58bd3..a0ba62ee10 100644
--- a/include/net/uip/uipopt.h
+++ b/include/net/uip/uipopt.h
@@ -134,6 +134,18 @@
#define UIP_REASS_MAXAGE (20*10) /* 20 seconds */
+/* Network drivers often receive packets with garbage at the end
+ * and are longer than the size of packet in the TCP header. The
+ * following "fudge" factor increases the size of the I/O buffering
+ * by a small amount to allocate slightly oversize packets. After
+ * receipt, the packet size will be chopped down to the size indicated
+ * in the TCP header.
+ */
+
+#ifndef CONFIG_NET_GUARDSIZE
+# define CONFIG_NET_GUARDSIZE 2
+#endif
+
/* ICMP configuration options */
#if !defined(CONFIG_NET_ICMP) || defined(CONFIG_DISABLE_CLOCK)
--
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