kernel/git/stable/linux-stable.git/drivers/net/veth.c, branch linux-4.9.y

veth: Ensure eth header is in skb's linear part

2022-04-20T07:06:45+00:00

[ Upstream commit 726e2c5929de841fdcef4e2bf995680688ae1b87 ] After feeding a decapsulated packet to a veth device with act_mirred, skb_headlen() may be 0. But veth_xmit() calls __dev_forward_skb(), which expects at least ETH_HLEN byte of linear data (as __dev_forward_skb2() calls eth_type_trans(), which pulls ETH_HLEN bytes unconditionally). Use pskb_may_pull() to ensure veth_xmit() respects this constraint. kernel BUG at include/linux/skbuff.h:2328! RIP: 0010:eth_type_trans+0xcf/0x140 Call Trace: __dev_forward_skb2+0xe3/0x160 veth_xmit+0x6e/0x250 [veth] dev_hard_start_xmit+0xc7/0x200 __dev_queue_xmit+0x47f/0x520 ? skb_ensure_writable+0x85/0xa0 ? skb_mpls_pop+0x98/0x1c0 tcf_mirred_act+0x442/0x47e [act_mirred] tcf_action_exec+0x86/0x140 fl_classify+0x1d8/0x1e0 [cls_flower] ? dma_pte_clear_level+0x129/0x1a0 ? dma_pte_clear_level+0x129/0x1a0 ? prb_fill_curr_block+0x2f/0xc0 ? skb_copy_bits+0x11a/0x220 __tcf_classify+0x58/0x110 tcf_classify_ingress+0x6b/0x140 __netif_receive_skb_core.constprop.0+0x47d/0xfd0 ? __iommu_dma_unmap_swiotlb+0x44/0x90 __netif_receive_skb_one_core+0x3d/0xa0 netif_receive_skb+0x116/0x170 be_process_rx+0x22f/0x330 [be2net] be_poll+0x13c/0x370 [be2net] __napi_poll+0x2a/0x170 net_rx_action+0x22f/0x2f0 __do_softirq+0xca/0x2a8 __irq_exit_rcu+0xc1/0xe0 common_interrupt+0x83/0xa0 Fixes: e314dbdc1c0d ("[NET]: Virtual ethernet device driver.") Signed-off-by: Guillaume Nault Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

veth: set peer GSO values

2018-03-22T08:17:57+00:00

[ Upstream commit 72d24955b44a4039db54a1c252b5031969eeaac3 ] When new veth is created, and GSO values have been configured on one device, clone those values to the peer. For example: # ip link add dev vm1 gso_max_size 65530 type veth peer name vm2 This should create vm1 <--> vm2 with both having GSO maximum size set to 65530. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

net: veth: Set features for MPLS

2016-08-31T05:27:18+00:00

veth does not really transmit packets only moves the skb from one netdev to another so gso and checksum is not really needed. Add the features to mpls_features to get the same benefit and performance with MPLS as without it. Reported-by: Lennert Buytenhek Signed-off-by: David Ahern Signed-off-by: David S. Miller

veth: sctp: add NETIF_F_SCTP_CRC to device features

2016-08-26T18:43:03+00:00

Commit b17c706987fa ("loopback: sctp: add NETIF_F_SCTP_CSUM to device features") added NETIF_F_SCTP_CRC to device features for lo device to improve the performance of sctp over lo. This patch is to add NETIF_F_SCTP_CRC to device features for veth to improve the performance of sctp over veth. Before this patch: ip netns exec cs_client netperf -H 10.167.12.2 -t SCTP_STREAM -- -m 10K Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 212992 212992 10240 10.00 1117.16 After this patch: ip netns exec cs_client netperf -H 10.167.12.2 -t SCTP_STREAM -- -m 10K Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 212992 212992 10240 10.20 1415.22 Tested-by: Li Shuang Signed-off-by: Xin Long Signed-off-by: David S. Miller

veth: Update features to include all tunnel GSO types

2016-04-21T18:14:59+00:00

This patch adds support for the checksum enabled versions of UDP and GRE tunnels. With this change we should be able to send and receive GSO frames of these types over the veth pair without needing to segment the packets. Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller

veth: implement ndo_set_rx_headroom

2016-03-01T20:54:31+00:00

The rx headroom for veth dev is the peer device needed_headroom. Avoid ping-pong updates setting the private flag IFF_PHONY_HEADROOM. This avoids skb head reallocation when forwarding from a veth dev towards a device adding some kind of encapsulation. When transmitting frames below the MTU size towards a vxlan device, this gives about 10% performance speed-up when OVS is used to connect the veth and the vxlan device and a little more when using a plain Linux bridge. Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller

veth: don’t modify ip_summed; doing so treats packets with bad checksums as good.

2015-12-22T20:15:34+00:00

Packets that arrive from real hardware devices have ip_summed == CHECKSUM_UNNECESSARY if the hardware verified the checksums, or CHECKSUM_NONE if the packet is bad or it was unable to verify it. The current version of veth will replace CHECKSUM_NONE with CHECKSUM_UNNECESSARY, which causes corrupt packets routed from hardware to a veth device to be delivered to the application. This caused applications at Twitter to receive corrupt data when network hardware was corrupting packets. We believe this was added as an optimization to skip computing and verifying checksums for communication between containers. However, locally generated packets have ip_summed == CHECKSUM_PARTIAL, so the code as written does nothing for them. As far as we can tell, after removing this code, these packets are transmitted from one stack to another unmodified (tcpdump shows invalid checksums on both sides, as expected), and they are delivered correctly to applications. We didn’t test every possible network configuration, but we tried a few common ones such as bridging containers, using NAT between the host and a container, and routing from hardware devices to containers. We have effectively deployed this in production at Twitter (by disabling RX checksum offloading on veth devices). This code dates back to the first version of the driver, commit ("[NET]: Virtual ethernet device driver"), so I suspect this bug occurred mostly because the driver API has evolved significantly since then. Commit <0b7967503dc97864f283a> ("net/veth: Fix packet checksumming") (in December 2010) fixed this for packets that get created locally and sent to hardware devices, by not changing CHECKSUM_PARTIAL. However, the same issue still occurs for packets coming in from hardware devices. Co-authored-by: Evan Jones Signed-off-by: Evan Jones Cc: Nicolas Dichtel Cc: Phil Sutter Cc: Toshiaki Makita Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Vijay Pandurangan Acked-by: Cong Wang Signed-off-by: David S. Miller

net: veth: enable noqueue operation by default

2015-08-18T18:55:04+00:00

Signed-off-by: Phil Sutter Cc: Pavel Emelyanov Signed-off-by: David S. Miller

veth: Don't segment multiple tagged packets on veth device

2015-08-03T21:24:50+00:00

Veth devices don't need to segment multiple tagged packets. Signed-off-by: Toshiaki Makita Signed-off-by: David S. Miller

veth: set iflink to the peer veth

2015-04-02T18:05:01+00:00

Now that the peer netns is advertised in rtnl messages, we can set this property so that IFLA_LINK will advertise the peer ifindex. It allows the userland to get the full veth configuration. Signed-off-by: Nicolas Dichtel Signed-off-by: David S. Miller