[ovs-dev] [PATCH branch-2.7 08/25] datapath: use core MTU range checking in core net infra
Jarno Rajahalme
jarno at ovn.org
Wed Mar 15 23:31:12 UTC 2017
From: Jarod Wilson <jarod at redhat.com>
Upstream commit:
commit 61e84623ace35ce48975e8f90bbbac7557c43d61
Author: Jarod Wilson <jarod at redhat.com>
Date: Fri Oct 7 22:04:33 2016 -0400
net: centralize net_device min/max MTU checking
While looking into an MTU issue with sfc, I started noticing that almost
every NIC driver with an ndo_change_mtu function implemented almost
exactly the same range checks, and in many cases, that was the only
practical thing their ndo_change_mtu function was doing. Quite a few
drivers have either 68, 64, 60 or 46 as their minimum MTU value checked,
and then various sizes from 1500 to 65535 for their maximum MTU value. We
can remove a whole lot of redundant code here if we simple store min_mtu
and max_mtu in net_device, and check against those in net/core/dev.c's
dev_set_mtu().
In theory, there should be zero functional change with this patch, it just
puts the infrastructure in place. Subsequent patches will attempt to start
using said infrastructure, with theoretically zero change in
functionality.
CC: netdev at vger.kernel.org
Signed-off-by: Jarod Wilson <jarod at redhat.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Upstream commit:
commit 91572088e3fdbf4fe31cf397926d8b890fdb3237
Author: Jarod Wilson <jarod at redhat.com>
Date: Thu Oct 20 13:55:20 2016 -0400
net: use core MTU range checking in core net infra
...
openvswitch:
- set min/max_mtu, remove internal_dev_change_mtu
- note: max_mtu wasn't checked previously, it's been set to 65535, which
is the largest possible size supported
...
Signed-off-by: Jarod Wilson <jarod at redhat.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Jarno Rajahalme <jarno at ovn.org>
Upstream commit:
commit 425df17ce3a26d98f76e2b6b0af2acf4aeb0b026
Author: Jarno Rajahalme <jarno at ovn.org>
Date: Tue Feb 14 21:16:28 2017 -0800
openvswitch: Set internal device max mtu to ETH_MAX_MTU.
Commit 91572088e3fd ("net: use core MTU range checking in core net
infra") changed the openvswitch internal device to use the core net
infra for controlling the MTU range, but failed to actually set the
max_mtu as described in the commit message, which now defaults to
ETH_DATA_LEN.
This patch fixes this by setting max_mtu to ETH_MAX_MTU after
ether_setup() call.
Fixes: 91572088e3fd ("net: use core MTU range checking in core net infra")
Signed-off-by: Jarno Rajahalme <jarno at ovn.org>
Signed-off-by: David S. Miller <davem at davemloft.net>
This backport detects the new max_mtu field in the struct netdevice
and uses the upstream code if it exists, and local backport code if
not. The latter case is amended with bounds checks with new upstream
macros ETH_MIN_MTU and ETH_MAX_MTU and the corresponding error
messages from the upstream commit.
Signed-off-by: Jarno Rajahalme <jarno at ovn.org>
Signed-off-by: Joe Stringer <joe at ovn.org>
---
acinclude.m4 | 2 ++
datapath/linux/compat/include/linux/if_ether.h | 8 ++++++++
datapath/vport-internal_dev.c | 22 +++++++++++++++++++---
3 files changed, 29 insertions(+), 3 deletions(-)
diff --git a/acinclude.m4 b/acinclude.m4
index e8b64b5..052a18f 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -510,6 +510,8 @@ AC_DEFUN([OVS_CHECK_LINUX_COMPAT], [
OVS_FIND_PARAM_IFELSE([$KSRC/include/linux/netdevice.h],
[netdev_master_upper_dev_link], [upper_priv],
[OVS_DEFINE([HAVE_NETDEV_MASTER_UPPER_DEV_LINK_PRIV])])
+ OVS_FIND_FIELD_IFELSE([$KSRC/include/linux/netdevice.h], [net_device],
+ [max_mtu])
OVS_GREP_IFELSE([$KSRC/include/linux/netfilter.h], [nf_hook_state])
OVS_GREP_IFELSE([$KSRC/include/linux/netfilter.h], [nf_register_net_hook])
diff --git a/datapath/linux/compat/include/linux/if_ether.h b/datapath/linux/compat/include/linux/if_ether.h
index ac0f1ed..5eb99bc 100644
--- a/datapath/linux/compat/include/linux/if_ether.h
+++ b/datapath/linux/compat/include/linux/if_ether.h
@@ -3,6 +3,14 @@
#include_next <linux/if_ether.h>
+#ifndef ETH_MIN_MTU
+#define ETH_MIN_MTU 68 /* Min IPv4 MTU per RFC791 */
+#endif
+
+#ifndef ETH_MAX_MTU
+#define ETH_MAX_MTU 0xFFFFU /* 65535, same as IP_MAX_MTU */
+#endif
+
#ifndef ETH_P_802_3_MIN
#define ETH_P_802_3_MIN 0x0600
#endif
diff --git a/datapath/vport-internal_dev.c b/datapath/vport-internal_dev.c
index f0542a5..2988e8c 100644
--- a/datapath/vport-internal_dev.c
+++ b/datapath/vport-internal_dev.c
@@ -89,14 +89,25 @@ static const struct ethtool_ops internal_dev_ethtool_ops = {
.get_link = ethtool_op_get_link,
};
-static int internal_dev_change_mtu(struct net_device *netdev, int new_mtu)
+#ifndef HAVE_NET_DEVICE_WITH_MAX_MTU
+static int internal_dev_change_mtu(struct net_device *dev, int new_mtu)
{
- if (new_mtu < 68)
+ if (new_mtu < ETH_MIN_MTU) {
+ net_err_ratelimited("%s: Invalid MTU %d requested, hw min %d\n",
+ dev->name, new_mtu, ETH_MIN_MTU);
return -EINVAL;
+ }
+
+ if (new_mtu > ETH_MAX_MTU) {
+ net_err_ratelimited("%s: Invalid MTU %d requested, hw max %d\n",
+ dev->name, new_mtu, ETH_MAX_MTU);
+ return -EINVAL;
+ }
- netdev->mtu = new_mtu;
+ dev->mtu = new_mtu;
return 0;
}
+#endif
static void internal_dev_destructor(struct net_device *dev)
{
@@ -150,7 +161,9 @@ static const struct net_device_ops internal_dev_netdev_ops = {
.ndo_stop = internal_dev_stop,
.ndo_start_xmit = internal_dev_xmit,
.ndo_set_mac_address = eth_mac_addr,
+#ifndef HAVE_NET_DEVICE_WITH_MAX_MTU
.ndo_change_mtu = internal_dev_change_mtu,
+#endif
.ndo_get_stats64 = internal_get_stats,
#ifdef HAVE_IFF_PHONY_HEADROOM
#ifndef HAVE_NET_DEVICE_OPS_WITH_EXTENDED
@@ -169,6 +182,9 @@ static void do_setup(struct net_device *netdev)
{
ether_setup(netdev);
+#ifdef HAVE_NET_DEVICE_WITH_MAX_MTU
+ netdev->max_mtu = ETH_MAX_MTU;
+#endif
netdev->netdev_ops = &internal_dev_netdev_ops;
netdev->priv_flags &= ~IFF_TX_SKB_SHARING;
--
2.1.4
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