kernel.git/drivers/net/veth.c, branch linux-5.4.y

veth: Fixing transmit return status for dropped packets

2023-09-23T08:59:58Z

[ Upstream commit 151e887d8ff97e2e42110ffa1fb1e6a2128fb364 ] The veth_xmit function returns NETDEV_TX_OK even when packets are dropped. This behavior leads to incorrect calculations of statistics counts, as well as things like txq->trans_start updates. Fixes: e314dbdc1c0d ("[NET]: Virtual ethernet device driver.") Signed-off-by: Liang Chen Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: validate veth and vxcan peer ifindexes

2023-08-30T14:27:24Z

[ Upstream commit f534f6581ec084fe94d6759f7672bd009794b07e ] veth and vxcan need to make sure the ifindexes of the peer are not negative, core does not validate this. Using iproute2 with user-space-level checking removed: Before: # ./ip link add index 10 type veth peer index -1 # ip link show 1: lo: mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 2: enp1s0: mtu 1500 qdisc fq_codel state UP mode DEFAULT group default qlen 1000 link/ether 52:54:00:74:b2:03 brd ff:ff:ff:ff:ff:ff 10: veth1@veth0: mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000 link/ether 8a:90:ff:57:6d:5d brd ff:ff:ff:ff:ff:ff -1: veth0@veth1: mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000 link/ether ae:ed:18:e6:fa:7f brd ff:ff:ff:ff:ff:ff Now: $ ./ip link add index 10 type veth peer index -1 Error: ifindex can't be negative. This problem surfaced in net-next because an explicit WARN() was added, the root cause is older. Fixes: e6f8f1a739b6 ("veth: Allow to create peer link with given ifindex") Fixes: a8f820a380a2 ("can: add Virtual CAN Tunnel driver (vxcan)") Reported-by: syzbot+5ba06978f34abb058571@syzkaller.appspotmail.com Signed-off-by: Jakub Kicinski Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

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

2022-04-20T07:19:34Z

[ 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: fix races around rq->rx_notify_masked

2022-02-16T11:52:51Z

[ Upstream commit 68468d8c4cd4222a4ca1f185ab5a1c14480d078c ] veth being NETIF_F_LLTX enabled, we need to be more careful whenever we read/write rq->rx_notify_masked. BUG: KCSAN: data-race in veth_xmit / veth_xmit write to 0xffff888133d9a9f8 of 1 bytes by task 23552 on cpu 0: __veth_xdp_flush drivers/net/veth.c:269 [inline] veth_xmit+0x307/0x470 drivers/net/veth.c:350 __netdev_start_xmit include/linux/netdevice.h:4683 [inline] netdev_start_xmit include/linux/netdevice.h:4697 [inline] xmit_one+0x105/0x2f0 net/core/dev.c:3473 dev_hard_start_xmit net/core/dev.c:3489 [inline] __dev_queue_xmit+0x86d/0xf90 net/core/dev.c:4116 dev_queue_xmit+0x13/0x20 net/core/dev.c:4149 br_dev_queue_push_xmit+0x3ce/0x430 net/bridge/br_forward.c:53 NF_HOOK include/linux/netfilter.h:307 [inline] br_forward_finish net/bridge/br_forward.c:66 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] __br_forward+0x2e4/0x400 net/bridge/br_forward.c:115 br_flood+0x521/0x5c0 net/bridge/br_forward.c:242 br_dev_xmit+0x8b6/0x960 __netdev_start_xmit include/linux/netdevice.h:4683 [inline] netdev_start_xmit include/linux/netdevice.h:4697 [inline] xmit_one+0x105/0x2f0 net/core/dev.c:3473 dev_hard_start_xmit net/core/dev.c:3489 [inline] __dev_queue_xmit+0x86d/0xf90 net/core/dev.c:4116 dev_queue_xmit+0x13/0x20 net/core/dev.c:4149 neigh_hh_output include/net/neighbour.h:525 [inline] neigh_output include/net/neighbour.h:539 [inline] ip_finish_output2+0x6f8/0xb70 net/ipv4/ip_output.c:228 ip_finish_output+0xfb/0x240 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip_output+0xf3/0x1a0 net/ipv4/ip_output.c:430 dst_output include/net/dst.h:451 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] ip_send_skb+0x6e/0xe0 net/ipv4/ip_output.c:1570 udp_send_skb+0x641/0x880 net/ipv4/udp.c:967 udp_sendmsg+0x12ea/0x14c0 net/ipv4/udp.c:1254 inet_sendmsg+0x5f/0x80 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg net/socket.c:725 [inline] ____sys_sendmsg+0x39a/0x510 net/socket.c:2413 ___sys_sendmsg net/socket.c:2467 [inline] __sys_sendmmsg+0x267/0x4c0 net/socket.c:2553 __do_sys_sendmmsg net/socket.c:2582 [inline] __se_sys_sendmmsg net/socket.c:2579 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2579 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff888133d9a9f8 of 1 bytes by task 23563 on cpu 1: __veth_xdp_flush drivers/net/veth.c:268 [inline] veth_xmit+0x2d6/0x470 drivers/net/veth.c:350 __netdev_start_xmit include/linux/netdevice.h:4683 [inline] netdev_start_xmit include/linux/netdevice.h:4697 [inline] xmit_one+0x105/0x2f0 net/core/dev.c:3473 dev_hard_start_xmit net/core/dev.c:3489 [inline] __dev_queue_xmit+0x86d/0xf90 net/core/dev.c:4116 dev_queue_xmit+0x13/0x20 net/core/dev.c:4149 br_dev_queue_push_xmit+0x3ce/0x430 net/bridge/br_forward.c:53 NF_HOOK include/linux/netfilter.h:307 [inline] br_forward_finish net/bridge/br_forward.c:66 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] __br_forward+0x2e4/0x400 net/bridge/br_forward.c:115 br_flood+0x521/0x5c0 net/bridge/br_forward.c:242 br_dev_xmit+0x8b6/0x960 __netdev_start_xmit include/linux/netdevice.h:4683 [inline] netdev_start_xmit include/linux/netdevice.h:4697 [inline] xmit_one+0x105/0x2f0 net/core/dev.c:3473 dev_hard_start_xmit net/core/dev.c:3489 [inline] __dev_queue_xmit+0x86d/0xf90 net/core/dev.c:4116 dev_queue_xmit+0x13/0x20 net/core/dev.c:4149 neigh_hh_output include/net/neighbour.h:525 [inline] neigh_output include/net/neighbour.h:539 [inline] ip_finish_output2+0x6f8/0xb70 net/ipv4/ip_output.c:228 ip_finish_output+0xfb/0x240 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip_output+0xf3/0x1a0 net/ipv4/ip_output.c:430 dst_output include/net/dst.h:451 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] ip_send_skb+0x6e/0xe0 net/ipv4/ip_output.c:1570 udp_send_skb+0x641/0x880 net/ipv4/udp.c:967 udp_sendmsg+0x12ea/0x14c0 net/ipv4/udp.c:1254 inet_sendmsg+0x5f/0x80 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg net/socket.c:725 [inline] ____sys_sendmsg+0x39a/0x510 net/socket.c:2413 ___sys_sendmsg net/socket.c:2467 [inline] __sys_sendmmsg+0x267/0x4c0 net/socket.c:2553 __do_sys_sendmmsg net/socket.c:2582 [inline] __se_sys_sendmmsg net/socket.c:2579 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2579 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x00 -> 0x01 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 23563 Comm: syz-executor.5 Not tainted 5.17.0-rc2-syzkaller-00064-gc36c04c2e132 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: 948d4f214fde ("veth: Add driver XDP") Signed-off-by: Eric Dumazet Cc: Toshiaki Makita Reported-by: syzbot Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

veth: Do not record rx queue hint in veth_xmit

2022-01-16T08:15:38Z

commit 710ad98c363a66a0cd8526465426c5c5f8377ee0 upstream. Laurent reported that they have seen a significant amount of TCP retransmissions at high throughput from applications residing in network namespaces talking to the outside world via veths. The drops were seen on the qdisc layer (fq_codel, as per systemd default) of the phys device such as ena or virtio_net due to all traffic hitting a _single_ TX queue _despite_ multi-queue device. (Note that the setup was _not_ using XDP on veths as the issue is generic.) More specifically, after edbea9220251 ("veth: Store queue_mapping independently of XDP prog presence") which made it all the way back to v4.19.184+, skb_record_rx_queue() would set skb->queue_mapping to 1 (given 1 RX and 1 TX queue by default for veths) instead of leaving at 0. This is eventually retained and callbacks like ena_select_queue() will also pick single queue via netdev_core_pick_tx()'s ndo_select_queue() once all the traffic is forwarded to that device via upper stack or other means. Similarly, for others not implementing ndo_select_queue() if XPS is disabled, netdev_pick_tx() might call into the skb_tx_hash() and check for prior skb_rx_queue_recorded() as well. In general, it is a _bad_ idea for virtual devices like veth to mess around with queue selection [by default]. Given dev->real_num_tx_queues is by default 1, the skb->queue_mapping was left untouched, and so prior to edbea9220251 the netdev_core_pick_tx() could do its job upon __dev_queue_xmit() on the phys device. Unbreak this and restore prior behavior by removing the skb_record_rx_queue() from veth_xmit() altogether. If the veth peer has an XDP program attached, then it would return the first RX queue index in xdp_md->rx_queue_index (unless configured in non-default manner). However, this is still better than breaking the generic case. Fixes: edbea9220251 ("veth: Store queue_mapping independently of XDP prog presence") Fixes: 638264dc9022 ("veth: Support per queue XDP ring") Reported-by: Laurent Bernaille Signed-off-by: Daniel Borkmann Cc: Maciej Fijalkowski Cc: Toshiaki Makita Cc: Eric Dumazet Cc: Paolo Abeni Cc: John Fastabend Cc: Willem de Bruijn Acked-by: John Fastabend Reviewed-by: Eric Dumazet Acked-by: Toshiaki Makita Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

veth: Store queue_mapping independently of XDP prog presence

2021-03-30T12:35:24Z

[ Upstream commit edbea922025169c0e5cdca5ebf7bf5374cc5566c ] Currently, veth_xmit() would call the skb_record_rx_queue() only when there is XDP program loaded on peer interface in native mode. If peer has XDP prog in generic mode, then netif_receive_generic_xdp() has a call to netif_get_rxqueue(skb), so for multi-queue veth it will not be possible to grab a correct rxq. To fix that, store queue_mapping independently of XDP prog presence on peer interface. Fixes: 638264dc9022 ("veth: Support per queue XDP ring") Signed-off-by: Maciej Fijalkowski Signed-off-by: Daniel Borkmann Acked-by: Toshiaki Makita Link: https://lore.kernel.org/bpf/20210303152903.11172-1-maciej.fijalkowski@intel.com Signed-off-by: Sasha Levin

veth: Adjust hard_start offset on redirect XDP frames

2020-06-22T07:31:06Z

[ Upstream commit 5c8572251fabc5bb49fd623c064e95a9daf6a3e3 ] When native XDP redirect into a veth device, the frame arrives in the xdp_frame structure. It is then processed in veth_xdp_rcv_one(), which can run a new XDP bpf_prog on the packet. Doing so requires converting xdp_frame to xdp_buff, but the tricky part is that xdp_frame memory area is located in the top (data_hard_start) memory area that xdp_buff will point into. The current code tried to protect the xdp_frame area, by assigning xdp_buff.data_hard_start past this memory. This results in 32 bytes less headroom to expand into via BPF-helper bpf_xdp_adjust_head(). This protect step is actually not needed, because BPF-helper bpf_xdp_adjust_head() already reserve this area, and don't allow BPF-prog to expand into it. Thus, it is safe to point data_hard_start directly at xdp_frame memory area. Fixes: 9fc8d518d9d5 ("veth: Handle xdp_frames in xdp napi ring") Reported-by: Mao Wenan Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Alexei Starovoitov Acked-by: Toshiaki Makita Acked-by: Toke Høiland-Jørgensen Link: https://lore.kernel.org/bpf/158945338331.97035.5923525383710752178.stgit@firesoul Signed-off-by: Sasha Levin

veth: Support bulk XDP_TX

2019-06-25T12:26:54Z

XDP_TX is similar to XDP_REDIRECT as it essentially redirects packets to the device itself. XDP_REDIRECT has bulk transmit mechanism to avoid the heavy cost of indirect call but it also reduces lock acquisition on the destination device that needs locks like veth and tun. XDP_TX does not use indirect calls but drivers which require locks can benefit from the bulk transmit for XDP_TX as well. This patch introduces bulk transmit mechanism in veth using bulk queue on stack, and improves XDP_TX performance by about 9%. Here are single-core/single-flow XDP_TX test results. CPU consumptions are taken from "perf report --no-child". - Before: 7.26 Mpps _raw_spin_lock 7.83% veth_xdp_xmit 12.23% - After: 7.94 Mpps _raw_spin_lock 1.08% veth_xdp_xmit 6.10% v2: - Use stack for bulk queue instead of a global variable. Signed-off-by: Toshiaki Makita Acked-by: Jesper Dangaard Brouer Signed-off-by: Daniel Borkmann

veth: use xdp_release_frame for XDP_PASS

2019-06-19T15:23:13Z

Like cpumap use xdp_release_frame() when an xdp_frame got converted into an SKB and send towars the network stack. Signed-off-by: Jesper Dangaard Brouer Signed-off-by: David S. Miller

treewide: Add SPDX license identifier for more missed files

2019-05-21T08:50:45Z

Add SPDX license identifiers to all files which: - Have no license information of any form - Have MODULE_LICENCE("GPL*") inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman