kernel/linux.git/drivers/net/ifb.c, branch v4.17.1

net: Do not take net_rwsem in __rtnl_link_unregister()

2018-04-01T02:24:58+00:00

This function calls call_netdevice_notifier(), which also may take net_rwsem. So, we can't use net_rwsem here. This patch makes callers of this functions take pernet_ops_rwsem, like register_netdevice_notifier() does. This will protect the modifications of net_namespace_list, and allows notifiers to take it (they won't have to care about context). Since __rtnl_link_unregister() is used on module load and unload (which are not frequent operations), this looks for me better, than make all call_netdevice_notifier() always executing in "protected net_namespace_list" context. Also, this fixes the problem we had a deal in 328fbe747ad4 "Close race between {un, }register_netdevice_notifier and ...", and guarantees __rtnl_link_unregister() does not skip exitting net. Signed-off-by: Kirill Tkhai Signed-off-by: David S. Miller

net: remove MTU limits for dummy and ifb device

2017-09-25T23:26:09+00:00

These two drivers (dummy and ifb) call ether_setup(), after commit 61e84623ace3 ("net: centralize net_device min/max MTU checking"), the range of mtu is [min_mtu, max_mtu], which is [68, 1500] by default. These two devices should not have limits on MTU. This patch set their min_mtu/max_mtu to 0. So that dev_set_mtu() will not check the mtu range, and can be set with any value. CC: Eric Dumazet CC: Sabrina Dubroca Signed-off-by: Zhang Shengju Signed-off-by: David S. Miller

net: add netlink_ext_ack argument to rtnl_link_ops.validate

2017-06-27T03:13:22+00:00

Add support for extended error reporting. Signed-off-by: Matthias Schiffer Acked-by: David Ahern Signed-off-by: David S. Miller

net: Fix inconsistent teardown and release of private netdev state.

2017-06-07T19:53:24+00:00

Network devices can allocate reasources and private memory using netdev_ops->ndo_init(). However, the release of these resources can occur in one of two different places. Either netdev_ops->ndo_uninit() or netdev->destructor(). The decision of which operation frees the resources depends upon whether it is necessary for all netdev refs to be released before it is safe to perform the freeing. netdev_ops->ndo_uninit() presumably can occur right after the NETDEV_UNREGISTER notifier completes and the unicast and multicast address lists are flushed. netdev->destructor(), on the other hand, does not run until the netdev references all go away. Further complicating the situation is that netdev->destructor() almost universally does also a free_netdev(). This creates a problem for the logic in register_netdevice(). Because all callers of register_netdevice() manage the freeing of the netdev, and invoke free_netdev(dev) if register_netdevice() fails. If netdev_ops->ndo_init() succeeds, but something else fails inside of register_netdevice(), it does call ndo_ops->ndo_uninit(). But it is not able to invoke netdev->destructor(). This is because netdev->destructor() will do a free_netdev() and then the caller of register_netdevice() will do the same. However, this means that the resources that would normally be released by netdev->destructor() will not be. Over the years drivers have added local hacks to deal with this, by invoking their destructor parts by hand when register_netdevice() fails. Many drivers do not try to deal with this, and instead we have leaks. Let's close this hole by formalizing the distinction between what private things need to be freed up by netdev->destructor() and whether the driver needs unregister_netdevice() to perform the free_netdev(). netdev->priv_destructor() performs all actions to free up the private resources that used to be freed by netdev->destructor(), except for free_netdev(). netdev->needs_free_netdev is a boolean that indicates whether free_netdev() should be done at the end of unregister_netdevice(). Now, register_netdevice() can sanely release all resources after ndo_ops->ndo_init() succeeds, by invoking both ndo_ops->ndo_uninit() and netdev->priv_destructor(). And at the end of unregister_netdevice(), we invoke netdev->priv_destructor() and optionally call free_netdev(). Signed-off-by: David S. Miller

net-tc: convert tc_from to tc_from_ingress and tc_redirected

2017-01-09T01:58:52+00:00

The tc_from field fulfills two roles. It encodes whether a packet was redirected by an act_mirred device and, if so, whether act_mirred was called on ingress or egress. Split it into separate fields. The information is needed by the special IFB loop, where packets are taken out of the normal path by act_mirred, forwarded to IFB, then reinjected at their original location (ingress or egress) by IFB. The IFB device cannot use skb->tc_at_ingress, because that may have been overwritten as the packet travels from act_mirred to ifb_xmit, when it passes through tc_classify on the IFB egress path. Cache this value in skb->tc_from_ingress. That field is valid only if a packet arriving at ifb_xmit came from act_mirred. Other packets can be crafted to reach ifb_xmit. These must be dropped. Set tc_redirected on redirection and drop all packets that do not have this bit set. Both fields are set only on cloned skbs in tc actions, so original packet sources do not have to clear the bit when reusing packets (notably, pktgen and octeon). Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller

net-tc: convert tc_verd to integer bitfields

2017-01-09T01:58:52+00:00

Extract the remaining two fields from tc_verd and remove the __u16 completely. TC_AT and TC_FROM are converted to equivalent two-bit integer fields tc_at and tc_from. Where possible, use existing helper skb_at_tc_ingress when reading tc_at. Introduce helper skb_reset_tc to clear fields. Not documenting tc_from and tc_at, because they will be replaced with single bit fields in follow-on patches. Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller

net-tc: extract skip classify bit from tc_verd

2017-01-09T01:58:52+00:00

Packets sent by the IFB device skip subsequent tc classification. A single bit governs this state. Move it out of tc_verd in anticipation of removing that __u16 completely. The new bitfield tc_skip_classify temporarily uses one bit of a hole, until tc_verd is removed completely in a follow-up patch. Remove the bit hole comment. It could be 2, 3, 4 or 5 bits long. With that many options, little value in documenting it. Introduce a helper function to deduplicate the logic in the two sites that check this bit. The field tc_skip_classify is set only in IFB on skbs cloned in act_mirred, so original packet sources do not have to clear the bit when reusing packets (notably, pktgen and octeon). Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller

net: make ndo_get_stats64 a void function

2017-01-08T22:51:44+00:00

The network device operation for reading statistics is only called in one place, and it ignores the return value. Having a structure return value is potentially confusing because some future driver could incorrectly assume that the return value was used. Fix all drivers with ndo_get_stats64 to have a void function. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller

ifb: support more features

2016-05-09T04:00:28+00:00

When using ifb+netem on ingress on SIT/IPIP/GRE traffic, GRO packets are not properly processed. Segmentation should not be forced, since ifb is already adding quite a performance hit. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

ifb: add multiqueue operation

2015-07-08T23:00:09+00:00

Add multiqueue capabilities to ifb netdevice. This removes last bottleneck for ingress when mq qdisc can be used to shard load from multiple RX queues on physical device. Tested: # netem based setup, installed at receiver side ETH=eth0 IFB=ifb10 EST="est 1sec 4sec" # Optional rate estimator RTT_HALF=2ms #REORDER=20us #LOSS="loss 1" TXQ=8 ip link add ifb10 numtxqueues $TXQ type ifb ip link set dev $IFB up tc qdisc add dev $ETH ingress 2>/dev/null tc filter add dev $ETH parent ffff: \ protocol ip u32 match u32 0 0 flowid 1:1 \ action mirred egress redirect dev $IFB tc qdisc del dev $IFB root 2>/dev/null tc qdisc add dev $IFB root handle 1: mq for i in `seq 1 $TXQ` do slot=$( printf %x $(( i )) ) tc qd add dev $IFB parent 1:$slot $EST netem \ limit 100000 delay $RTT_HALF $REORDER $LOSS done lpaa24:~# tc -s -d qd sh dev ifb10 qdisc mq 1: root Sent 316544766 bytes 5265927 pkt (dropped 0, overlimits 0 requeues 0) backlog 98880b 1648p requeues 0 qdisc netem 8002: parent 1:1 limit 100000 delay 2.0ms Sent 39601416 bytes 658721 pkt (dropped 0, overlimits 0 requeues 0) rate 38235Kbit 79657pps backlog 12240b 204p requeues 0 qdisc netem 8003: parent 1:2 limit 100000 delay 2.0ms Sent 39472866 bytes 657227 pkt (dropped 0, overlimits 0 requeues 0) rate 38234Kbit 79655pps backlog 10620b 176p requeues 0 qdisc netem 8004: parent 1:3 limit 100000 delay 2.0ms Sent 39703417 bytes 659699 pkt (dropped 0, overlimits 0 requeues 0) rate 38320Kbit 79831pps backlog 12780b 213p requeues 0 qdisc netem 8005: parent 1:4 limit 100000 delay 2.0ms Sent 39565149 bytes 658011 pkt (dropped 0, overlimits 0 requeues 0) rate 38174Kbit 79530pps backlog 11880b 198p requeues 0 qdisc netem 8006: parent 1:5 limit 100000 delay 2.0ms Sent 39506078 bytes 657354 pkt (dropped 0, overlimits 0 requeues 0) rate 38195Kbit 79571pps backlog 12480b 208p requeues 0 qdisc netem 8007: parent 1:6 limit 100000 delay 2.0ms Sent 39675994 bytes 658849 pkt (dropped 0, overlimits 0 requeues 0) rate 38323Kbit 79838pps backlog 12600b 210p requeues 0 qdisc netem 8008: parent 1:7 limit 100000 delay 2.0ms Sent 39532042 bytes 658367 pkt (dropped 0, overlimits 0 requeues 0) rate 38177Kbit 79536pps backlog 13140b 219p requeues 0 qdisc netem 8009: parent 1:8 limit 100000 delay 2.0ms Sent 39488164 bytes 657705 pkt (dropped 0, overlimits 0 requeues 0) rate 38192Kbit 79568pps backlog 13Kb 222p requeues 0 Signed-off-by: Eric Dumazet Cc: Alexei Starovoitov Cc: Jamal Hadi Salim Cc: John Fastabend Acked-by: Alexei Starovoitov Acked-by: Jamal Hadi Salim Signed-off-by: David S. Miller