linux/net/core/dev.c, branch v3.13

net: core: explicitly select a txq before doing l2 forwarding

2014-01-10T18:23:08Z

Currently, the tx queue were selected implicitly in ndo_dfwd_start_xmit(). The will cause several issues: - NETIF_F_LLTX were removed for macvlan, so txq lock were done for macvlan instead of lower device which misses the necessary txq synchronization for lower device such as txq stopping or frozen required by dev watchdog or control path. - dev_hard_start_xmit() was called with NULL txq which bypasses the net device watchdog. - dev_hard_start_xmit() does not check txq everywhere which will lead a crash when tso is disabled for lower device. Fix this by explicitly introducing a new param for .ndo_select_queue() for just selecting queues in the case of l2 forwarding offload. netdev_pick_tx() was also extended to accept this parameter and dev_queue_xmit_accel() was used to do l2 forwarding transmission. With this fixes, NETIF_F_LLTX could be preserved for macvlan and there's no need to check txq against NULL in dev_hard_start_xmit(). Also there's no need to keep a dedicated ndo_dfwd_start_xmit() and we can just reuse the code of dev_queue_xmit() to do the transmission. In the future, it was also required for macvtap l2 forwarding support since it provides a necessary synchronization method. Cc: John Fastabend Cc: Neil Horman Cc: e1000-devel@lists.sourceforge.net Signed-off-by: Jason Wang Acked-by: Neil Horman Acked-by: John Fastabend Signed-off-by: David S. Miller

net: allow netdev_all_upper_get_next_dev_rcu with rtnl lock held

2013-12-18T05:19:08Z

It is useful to be able to walk all upper devices when bringing a device online where the RTNL lock is held. In this case it is safe to walk the all_adj_list because the RTNL lock is used to protect the write side as well. This patch adds a check to see if the rtnl lock is held before throwing a warning in netdev_all_upper_get_next_dev_rcu(). Also because we now have a call site for lockdep_rtnl_is_held() outside COFIG_LOCK_PROVING an inline definition returning 1 is needed. Similar to the rcu_read_lock_is_held(). Fixes: 2a47fa45d4df ("ixgbe: enable l2 forwarding acceleration for macvlans") CC: Veaceslav Falico Reported-by: Yuanhan Liu Signed-off-by: John Fastabend Tested-by: Phil Schmitt Signed-off-by: Jeff Kirsher

net: core: Always propagate flag changes to interfaces

2013-11-20T20:29:56Z

The following commit: b6c40d68ff6498b7f63ddf97cf0aa818d748dee7 net: only invoke dev->change_rx_flags when device is UP tried to fix a problem with VLAN devices and promiscuouse flag setting. The issue was that VLAN device was setting a flag on an interface that was down, thus resulting in bad promiscuity count. This commit blocked flag propagation to any device that is currently down. A later commit: deede2fabe24e00bd7e246eb81cd5767dc6fcfc7 vlan: Don't propagate flag changes on down interfaces fixed VLAN code to only propagate flags when the VLAN interface is up, thus fixing the same issue as above, only localized to VLAN. The problem we have now is that if we have create a complex stack involving multiple software devices like bridges, bonds, and vlans, then it is possible that the flags would not propagate properly to the physical devices. A simple examle of the scenario is the following: eth0----> bond0 ----> bridge0 ---> vlan50 If bond0 or eth0 happen to be down at the time bond0 is added to the bridge, then eth0 will never have promisc mode set which is currently required for operation as part of the bridge. As a result, packets with vlan50 will be dropped by the interface. The only 2 devices that implement the special flag handling are VLAN and DSA and they both have required code to prevent incorrect flag propagation. As a result we can remove the generic solution introduced in b6c40d68ff6498b7f63ddf97cf0aa818d748dee7 and leave it to the individual devices to decide whether they will block flag propagation or not. Reported-by: Stefan Priebe Suggested-by: Veaceslav Falico Signed-off-by: Vlad Yasevich Signed-off-by: David S. Miller

macvlan: disable LRO on lower device instead of macvlan

2013-11-15T22:55:48Z

A macvlan device has always LRO disabled so that calling dev_disable_lro() on it does nothing. If we need to disable LRO e.g. because - the macvlan device is inserted into a bridge - IPv6 forwarding is enabled for it - it is in a different namespace than lowerdev and IPv4 forwarding is enabled in it we need to disable LRO on its underlying device instead (as we do for 802.1q VLAN devices). v2: use newly introduced netif_is_macvlan() Signed-off-by: Michal Kubecek Signed-off-by: David S. Miller

core/dev: do not ignore dmac in dev_forward_skb()

2013-11-14T07:39:53Z

commit 06a23fe31ca3 ("core/dev: set pkt_type after eth_type_trans() in dev_forward_skb()") and refactoring 64261f230a91 ("dev: move skb_scrub_packet() after eth_type_trans()") are forcing pkt_type to be PACKET_HOST when skb traverses veth. which means that ip forwarding will kick in inside netns even if skb->eth->h_dest != dev->dev_addr Fix order of eth_type_trans() and skb_scrub_packet() in dev_forward_skb() and in ip_tunnel_rcv() Fixes: 06a23fe31ca3 ("core/dev: set pkt_type after eth_type_trans() in dev_forward_skb()") CC: Isaku Yamahata CC: Maciej Zenczykowski CC: Nicolas Dichtel Signed-off-by: Alexei Starovoitov Signed-off-by: David S. Miller

net: Add layer 2 hardware acceleration operations for macvlan devices

2013-11-08T00:11:41Z

Add a operations structure that allows a network interface to export the fact that it supports package forwarding in hardware between physical interfaces and other mac layer devices assigned to it (such as macvlans). This operaions structure can be used by virtual mac devices to bypass software switching so that forwarding can be done in hardware more efficiently. Signed-off-by: John Fastabend Signed-off-by: Neil Horman CC: Andy Gospodarek CC: "David S. Miller" Signed-off-by: David S. Miller

net: extend net_device allocation to vmalloc()

2013-11-04T04:19:00Z

Joby Poriyath provided a xen-netback patch to reduce the size of xenvif structure as some netdev allocation could fail under memory pressure/fragmentation. This patch is handling the problem at the core level, allowing any netdev structures to use vmalloc() if kmalloc() failed. As vmalloc() adds overhead on a critical network path, add __GFP_REPEAT to kzalloc() flags to do this fallback only when really needed. Signed-off-by: Eric Dumazet Reported-by: Joby Poriyath Cc: Ben Hutchings Signed-off-by: David S. Miller

net: fix rtnl notification in atomic context

2013-10-25T23:03:45Z

commit 991fb3f74c "dev: always advertise rx_flags changes via netlink" introduced rtnl notification from __dev_set_promiscuity(), which can be called in atomic context. Steps to reproduce: ip tuntap add dev tap1 mode tap ifconfig tap1 up tcpdump -nei tap1 & ip tuntap del dev tap1 mode tap [ 271.627994] device tap1 left promiscuous mode [ 271.639897] BUG: sleeping function called from invalid context at mm/slub.c:940 [ 271.664491] in_atomic(): 1, irqs_disabled(): 0, pid: 3394, name: ip [ 271.677525] INFO: lockdep is turned off. [ 271.690503] CPU: 0 PID: 3394 Comm: ip Tainted: G W 3.12.0-rc3+ #73 [ 271.703996] Hardware name: System manufacturer System Product Name/P8Z77 WS, BIOS 3007 07/26/2012 [ 271.731254] ffffffff81a58506 ffff8807f0d57a58 ffffffff817544e5 ffff88082fa0f428 [ 271.760261] ffff8808071f5f40 ffff8807f0d57a88 ffffffff8108bad1 ffffffff81110ff8 [ 271.790683] 0000000000000010 00000000000000d0 00000000000000d0 ffff8807f0d57af8 [ 271.822332] Call Trace: [ 271.838234] [] dump_stack+0x55/0x76 [ 271.854446] [] __might_sleep+0x181/0x240 [ 271.870836] [] ? rcu_irq_exit+0x68/0xb0 [ 271.887076] [] kmem_cache_alloc_node+0x4e/0x2a0 [ 271.903368] [] ? vprintk_emit+0x1dc/0x5a0 [ 271.919716] [] ? __alloc_skb+0x57/0x2a0 [ 271.936088] [] ? vprintk_emit+0x1e0/0x5a0 [ 271.952504] [] __alloc_skb+0x57/0x2a0 [ 271.968902] [] rtmsg_ifinfo+0x52/0x100 [ 271.985302] [] __dev_notify_flags+0xad/0xc0 [ 272.001642] [] __dev_set_promiscuity+0x8c/0x1c0 [ 272.017917] [] ? packet_notifier+0x5/0x380 [ 272.033961] [] dev_set_promiscuity+0x29/0x50 [ 272.049855] [] packet_dev_mc+0x87/0xc0 [ 272.065494] [] packet_notifier+0x1b2/0x380 [ 272.080915] [] ? packet_notifier+0x5/0x380 [ 272.096009] [] notifier_call_chain+0x66/0x150 [ 272.110803] [] __raw_notifier_call_chain+0xe/0x10 [ 272.125468] [] raw_notifier_call_chain+0x16/0x20 [ 272.139984] [] call_netdevice_notifiers_info+0x40/0x70 [ 272.154523] [] call_netdevice_notifiers+0x16/0x20 [ 272.168552] [] rollback_registered_many+0x145/0x240 [ 272.182263] [] rollback_registered+0x31/0x40 [ 272.195369] [] unregister_netdevice_queue+0x58/0x90 [ 272.208230] [] __tun_detach+0x140/0x340 [ 272.220686] [] tun_chr_close+0x36/0x60 Signed-off-by: Alexei Starovoitov Acked-by: Nicolas Dichtel Signed-off-by: David S. Miller

net: add missing dev_put() in __netdev_adjacent_dev_insert

2013-10-25T23:03:39Z

I think that a dev_put() is needed in the error path to preserve the proper dev refcount. CC: Veaceslav Falico Signed-off-by: Nikolay Aleksandrov Acked-by: Veaceslav Falico Signed-off-by: David S. Miller

ipv4: gso: make inet_gso_segment() stackable

2013-10-19T23:36:18Z

In order to support GSO on IPIP, we need to make inet_gso_segment() stackable. It should not assume network header starts right after mac header. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller