enum netdev_priv_flags

/**
 * enum netdev_priv_flags - &struct net_device priv_flags
 *
 * These are the &struct net_device, they are only set internally
 * by drivers and used in the kernel. These flags are invisible to
 * userspace; this means that the order of these flags can change
 * during any kernel release.
 *
 * You should add bitfield booleans after either net_device::priv_flags
 * (hotpath) or ::threaded (slowpath) instead of extending these flags.
 *
 * @IFF_802_1Q_VLAN: 802.1Q VLAN device
 * @IFF_EBRIDGE: Ethernet bridging device
 * @IFF_BONDING: bonding master or slave
 * @IFF_ISATAP: ISATAP interface (RFC4214)
 * @IFF_WAN_HDLC: WAN HDLC device
 * @IFF_XMIT_DST_RELEASE: dev_hard_start_xmit() is allowed to
 *	release skb->dst
 * @IFF_DONT_BRIDGE: disallow bridging this ether dev
 * @IFF_DISABLE_NETPOLL: disable netpoll at run-time
 * @IFF_MACVLAN_PORT: device used as macvlan port
 * @IFF_BRIDGE_PORT: device used as bridge port
 * @IFF_OVS_DATAPATH: device used as Open vSwitch datapath port
 * @IFF_TX_SKB_SHARING: The interface supports sharing skbs on transmit
 * @IFF_UNICAST_FLT: Supports unicast filtering
 * @IFF_TEAM_PORT: device used as team port
 * @IFF_SUPP_NOFCS: device supports sending custom FCS
 * @IFF_LIVE_ADDR_CHANGE: device supports hardware address
 *	change when it's running
 * @IFF_MACVLAN: Macvlan device
 * @IFF_XMIT_DST_RELEASE_PERM: IFF_XMIT_DST_RELEASE not taking into account
 *	underlying stacked devices
 * @IFF_L3MDEV_MASTER: device is an L3 master device
 * @IFF_NO_QUEUE: device can run without qdisc attached
 * @IFF_OPENVSWITCH: device is a Open vSwitch master
 * @IFF_L3MDEV_SLAVE: device is enslaved to an L3 master device
 * @IFF_TEAM: device is a team device
 * @IFF_RXFH_CONFIGURED: device has had Rx Flow indirection table configured
 * @IFF_PHONY_HEADROOM: the headroom value is controlled by an external
 *	entity (i.e. the master device for bridged veth)
 * @IFF_MACSEC: device is a MACsec device
 * @IFF_NO_RX_HANDLER: device doesn't support the rx_handler hook
 * @IFF_FAILOVER: device is a failover master device
 * @IFF_FAILOVER_SLAVE: device is lower dev of a failover master device
 * @IFF_L3MDEV_RX_HANDLER: only invoke the rx handler of L3 master device
 * @IFF_NO_ADDRCONF: prevent ipv6 addrconf
 * @IFF_TX_SKB_NO_LINEAR: device/driver is capable of xmitting frames with
 *	skb_headlen(skb) == 0 (data starts from frag0)
 */
enum netdev_priv_flags {
	IFF_802_1Q_VLAN			= 1<<0,
	IFF_EBRIDGE			= 1<<1,
	IFF_BONDING			= 1<<2,
	IFF_ISATAP			= 1<<3,
	IFF_WAN_HDLC			= 1<<4,
	IFF_XMIT_DST_RELEASE		= 1<<5,
	IFF_DONT_BRIDGE			= 1<<6,
	IFF_DISABLE_NETPOLL		= 1<<7,
	IFF_MACVLAN_PORT		= 1<<8,
	IFF_BRIDGE_PORT			= 1<<9,
	IFF_OVS_DATAPATH		= 1<<10,
	IFF_TX_SKB_SHARING		= 1<<11,
	IFF_UNICAST_FLT			= 1<<12,
	IFF_TEAM_PORT			= 1<<13,
	IFF_SUPP_NOFCS			= 1<<14,
	IFF_LIVE_ADDR_CHANGE		= 1<<15,
	IFF_MACVLAN			= 1<<16,
	IFF_XMIT_DST_RELEASE_PERM	= 1<<17,
	IFF_L3MDEV_MASTER		= 1<<18,
	IFF_NO_QUEUE			= 1<<19,
	IFF_OPENVSWITCH			= 1<<20,
	IFF_L3MDEV_SLAVE		= 1<<21,
	IFF_TEAM			= 1<<22,
	IFF_RXFH_CONFIGURED		= 1<<23,
	IFF_PHONY_HEADROOM		= 1<<24,
	IFF_MACSEC			= 1<<25,
	IFF_NO_RX_HANDLER		= 1<<26,
	IFF_FAILOVER			= 1<<27,
	IFF_FAILOVER_SLAVE		= 1<<28,
	IFF_L3MDEV_RX_HANDLER		= 1<<29,
	IFF_NO_ADDRCONF			= BIT_ULL(30),
	IFF_TX_SKB_NO_LINEAR		= BIT_ULL(31),
};

不过的确有一个问题，这些 flags 设置的产生的效果到底是什么样子的？

例如如果这样修改的话?

 net/ipv4/ip_gre.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 0ac652fef06d..edb025970bbf 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -1577,7 +1577,7 @@ static void erspan_setup(struct net_device *dev)
 	dev->max_mtu = 0;
 	dev->netdev_ops = &erspan_netdev_ops;
 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
-	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
+	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE;
 	ip_tunnel_setup(dev, erspan_net_id);
 	t->erspan_ver = 1;
 }

本站所有文章转发 CSDN 将按侵权追究法律责任，其它情况随意。