Re: [PATCH 1/1] tun: change speed from 10M to dynamically configured

I would like to propose this is as a more complete alternative.

From: Stephen Hemminger <redacted>
Subject: [PATCH] tun: support overriding ethtool information

Extensions to allow masqurade of ethtool info and device statistics.
This is useful to provide correct information to SNMP and OSPF routing
daemons when doing hw/sw offload of network device.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

---
  drivers/net/tun.c              | 139 +++++++++++++++++++++++++++++++++++++----
  include/uapi/linux/if_tunnel.h |   9 +++
  2 files changed, 135 insertions(+), 13 deletions(-)

--- a/drivers/net/tun.c	2015-02-16 11:58:00.651506008 -0500
+++ b/drivers/net/tun.c	2015-02-16 11:59:15.560842558 -0500

@@ -60,6 +60,7 @@
  #include <linux/if_arp.h>
  #include <linux/if_ether.h>
  #include <linux/if_tun.h>
+#include <linux/if_tunnel.h>
  #include <linux/if_vlan.h>
  #include <linux/crc32.h>
  #include <linux/nsproxy.h>

@@ -204,6 +205,9 @@ struct tun_struct {
  	struct list_head disabled;
  	void *security;
  	u32 flow_count;
+	u8 duplex;
+	u32 speed;
+	struct ip_tunnel_info	info;
  };
  
  static inline u16 tun16_to_cpu(struct tun_struct *tun, __virtio16 val)

@@ -866,6 +870,33 @@ static netdev_features_t tun_net_fix_fea
  
  	return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
  }
+
+static int
+tun_net_set_info(struct net_device *dev, const void __user *data)
+{
+	struct tun_struct *tun = netdev_priv(dev);
+	struct ip_tunnel_info info;
+
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
+	if (copy_from_user(&info, data, sizeof(info)))
+		return -EFAULT;
+
+	strlcpy(tun->info.driver, info.driver, sizeof(tun->info.driver));
+	strlcpy(tun->info.bus, info.bus, sizeof(tun->info.bus));
+	return 0;
+}
+
+static int
+tun_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+	if (cmd != SIOCDRVINFO)
+		return -EOPNOTSUPP;
+
+	return tun_net_set_info(dev, ifr->ifr_ifru.ifru_data);
+}
+

  #ifdef CONFIG_NET_POLL_CONTROLLER
  static void tun_poll_controller(struct net_device *dev)
  {

@@ -904,6 +935,7 @@ static const struct net_device_ops tap_n
  	.ndo_change_mtu		= tun_net_change_mtu,
  	.ndo_fix_features	= tun_net_fix_features,
  	.ndo_set_rx_mode	= tun_net_mclist,
+	.ndo_do_ioctl		= tun_net_ioctl,
  	.ndo_set_mac_address	= eth_mac_addr,
  	.ndo_validate_addr	= eth_validate_addr,
  	.ndo_select_queue	= tun_select_queue,

@@ -1408,6 +1440,8 @@ static void tun_setup(struct net_device
  
  	tun->owner = INVALID_UID;
  	tun->group = INVALID_GID;
+	tun->speed = SPEED_10;
+	tun->duplex = DUPLEX_FULL;
  
  	dev->ethtool_ops = &tun_ethtool_ops;
  	dev->destructor = tun_free_netdev;

@@ -1654,6 +1688,11 @@ static int tun_set_iff(struct net *net,
  
  		spin_lock_init(&tun->lock);
  
+		strlcpy(tun->info.driver, DRV_NAME, sizeof(tun->info.driver));
+		strlcpy(tun->info.bus,
+			(ifr->ifr_flags & IFF_TUN) ? "tun" : "tap",
+			sizeof(tun->info.bus));
+
  		err = security_tun_dev_alloc_security(&tun->security);
  		if (err < 0)
  			goto err_free_dev;

@@ -2253,10 +2292,12 @@ static struct miscdevice tun_miscdev = {
  
  static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
  {
+	struct tun_struct *tun = netdev_priv(dev);
+
  	cmd->supported		= 0;
  	cmd->advertising	= 0;
-	ethtool_cmd_speed_set(cmd, SPEED_10);
-	cmd->duplex		= DUPLEX_FULL;
+	ethtool_cmd_speed_set(cmd, tun->speed);
+	cmd->duplex		= tun->duplex;
  	cmd->port		= PORT_TP;
  	cmd->phy_address	= 0;
  	cmd->transceiver	= XCVR_INTERNAL;

@@ -2266,21 +2307,24 @@ static int tun_get_settings(struct net_d
  	return 0;
  }
  
+static int tun_set_settings(struct net_device *dev, struct ethtool_cmd *ecmd)
+{
+	struct tun_struct *tun = netdev_priv(dev);
+
+	tun->speed = ethtool_cmd_speed(ecmd);
+	tun->duplex = ecmd->duplex;
+
+	return 0;
+}
+
  static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
  {
  	struct tun_struct *tun = netdev_priv(dev);
  
-	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
+	strlcpy(info->driver, tun->info.driver, sizeof(info->driver));
  	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
  
-	switch (tun->flags & TUN_TYPE_MASK) {
-	case IFF_TUN:
-		strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
-		break;
-	case IFF_TAP:
-		strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
-		break;
-	}
+	strlcpy(info->bus_info, tun->info.bus, sizeof(info->bus_info));
  }
  
  static u32 tun_get_msglevel(struct net_device *dev)

@@ -2303,6 +2347,7 @@ static void tun_set_msglevel(struct net_
  
  static const struct ethtool_ops tun_ethtool_ops = {
  	.get_settings	= tun_get_settings,
+	.set_settings	= tun_set_settings,
  	.get_drvinfo	= tun_get_drvinfo,
  	.get_msglevel	= tun_get_msglevel,
  	.set_msglevel	= tun_set_msglevel,
--- a/include/uapi/linux/if_tunnel.h	2015-02-16 11:58:00.651506008 -0500
+++ b/include/uapi/linux/if_tunnel.h	2015-02-16 11:58:00.651506008 -0500

@@ -17,6 +17,12 @@
  #define SIOCADD6RD      (SIOCDEVPRIVATE + 9)
  #define SIOCDEL6RD      (SIOCDEVPRIVATE + 10)
  #define SIOCCHG6RD      (SIOCDEVPRIVATE + 11)
+#define SIOCDRVINFO	(SIOCDEVPRIVATE + 12)
+
+struct ip_tunnel_info {
+	char driver[32];
+	char bus[32];
+};