linux/net/openvswitch/vport.c

582 lines
14 KiB

net: openvswitch: fix upcall counter access before allocation Currently, the per cpu upcall counters are allocated after the vport is created and inserted into the system. This could lead to the datapath accessing the counters before they are allocated resulting in a kernel Oops. Here is an example: PID: 59693 TASK: ffff0005f4f51500 CPU: 0 COMMAND: "ovs-vswitchd" #0 [ffff80000a39b5b0] __switch_to at ffffb70f0629f2f4 #1 [ffff80000a39b5d0] __schedule at ffffb70f0629f5cc #2 [ffff80000a39b650] preempt_schedule_common at ffffb70f0629fa60 #3 [ffff80000a39b670] dynamic_might_resched at ffffb70f0629fb58 #4 [ffff80000a39b680] mutex_lock_killable at ffffb70f062a1388 #5 [ffff80000a39b6a0] pcpu_alloc at ffffb70f0594460c #6 [ffff80000a39b750] __alloc_percpu_gfp at ffffb70f05944e68 #7 [ffff80000a39b760] ovs_vport_cmd_new at ffffb70ee6961b90 [openvswitch] ... PID: 58682 TASK: ffff0005b2f0bf00 CPU: 0 COMMAND: "kworker/0:3" #0 [ffff80000a5d2f40] machine_kexec at ffffb70f056a0758 #1 [ffff80000a5d2f70] __crash_kexec at ffffb70f057e2994 #2 [ffff80000a5d3100] crash_kexec at ffffb70f057e2ad8 #3 [ffff80000a5d3120] die at ffffb70f0628234c #4 [ffff80000a5d31e0] die_kernel_fault at ffffb70f062828a8 #5 [ffff80000a5d3210] __do_kernel_fault at ffffb70f056a31f4 #6 [ffff80000a5d3240] do_bad_area at ffffb70f056a32a4 #7 [ffff80000a5d3260] do_translation_fault at ffffb70f062a9710 #8 [ffff80000a5d3270] do_mem_abort at ffffb70f056a2f74 #9 [ffff80000a5d32a0] el1_abort at ffffb70f06297dac #10 [ffff80000a5d32d0] el1h_64_sync_handler at ffffb70f06299b24 #11 [ffff80000a5d3410] el1h_64_sync at ffffb70f056812dc #12 [ffff80000a5d3430] ovs_dp_upcall at ffffb70ee6963c84 [openvswitch] #13 [ffff80000a5d3470] ovs_dp_process_packet at ffffb70ee6963fdc [openvswitch] #14 [ffff80000a5d34f0] ovs_vport_receive at ffffb70ee6972c78 [openvswitch] #15 [ffff80000a5d36f0] netdev_port_receive at ffffb70ee6973948 [openvswitch] #16 [ffff80000a5d3720] netdev_frame_hook at ffffb70ee6973a28 [openvswitch] #17 [ffff80000a5d3730] __netif_receive_skb_core.constprop.0 at ffffb70f06079f90 We moved the per cpu upcall counter allocation to the existing vport alloc and free functions to solve this. Fixes: 95637d91fefd ("net: openvswitch: release vport resources on failure") Fixes: 1933ea365aa7 ("net: openvswitch: Add support to count upcall packets") Signed-off-by: Eelco Chaudron <echaudro@redhat.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Acked-by: Aaron Conole <aconole@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-06-06 13:56:35 +02:00
net: openvswitch: fix upcall counter access before allocation Currently, the per cpu upcall counters are allocated after the vport is created and inserted into the system. This could lead to the datapath accessing the counters before they are allocated resulting in a kernel Oops. Here is an example: PID: 59693 TASK: ffff0005f4f51500 CPU: 0 COMMAND: "ovs-vswitchd" #0 [ffff80000a39b5b0] __switch_to at ffffb70f0629f2f4 #1 [ffff80000a39b5d0] __schedule at ffffb70f0629f5cc #2 [ffff80000a39b650] preempt_schedule_common at ffffb70f0629fa60 #3 [ffff80000a39b670] dynamic_might_resched at ffffb70f0629fb58 #4 [ffff80000a39b680] mutex_lock_killable at ffffb70f062a1388 #5 [ffff80000a39b6a0] pcpu_alloc at ffffb70f0594460c #6 [ffff80000a39b750] __alloc_percpu_gfp at ffffb70f05944e68 #7 [ffff80000a39b760] ovs_vport_cmd_new at ffffb70ee6961b90 [openvswitch] ... PID: 58682 TASK: ffff0005b2f0bf00 CPU: 0 COMMAND: "kworker/0:3" #0 [ffff80000a5d2f40] machine_kexec at ffffb70f056a0758 #1 [ffff80000a5d2f70] __crash_kexec at ffffb70f057e2994 #2 [ffff80000a5d3100] crash_kexec at ffffb70f057e2ad8 #3 [ffff80000a5d3120] die at ffffb70f0628234c #4 [ffff80000a5d31e0] die_kernel_fault at ffffb70f062828a8 #5 [ffff80000a5d3210] __do_kernel_fault at ffffb70f056a31f4 #6 [ffff80000a5d3240] do_bad_area at ffffb70f056a32a4 #7 [ffff80000a5d3260] do_translation_fault at ffffb70f062a9710 #8 [ffff80000a5d3270] do_mem_abort at ffffb70f056a2f74 #9 [ffff80000a5d32a0] el1_abort at ffffb70f06297dac #10 [ffff80000a5d32d0] el1h_64_sync_handler at ffffb70f06299b24 #11 [ffff80000a5d3410] el1h_64_sync at ffffb70f056812dc #12 [ffff80000a5d3430] ovs_dp_upcall at ffffb70ee6963c84 [openvswitch] #13 [ffff80000a5d3470] ovs_dp_process_packet at ffffb70ee6963fdc [openvswitch] #14 [ffff80000a5d34f0] ovs_vport_receive at ffffb70ee6972c78 [openvswitch] #15 [ffff80000a5d36f0] netdev_port_receive at ffffb70ee6973948 [openvswitch] #16 [ffff80000a5d3720] netdev_frame_hook at ffffb70ee6973a28 [openvswitch] #17 [ffff80000a5d3730] __netif_receive_skb_core.constprop.0 at ffffb70f06079f90 We moved the per cpu upcall counter allocation to the existing vport alloc and free functions to solve this. Fixes: 95637d91fefd ("net: openvswitch: release vport resources on failure") Fixes: 1933ea365aa7 ("net: openvswitch: Add support to count upcall packets") Signed-off-by: Eelco Chaudron <echaudro@redhat.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Acked-by: Aaron Conole <aconole@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-06-06 13:56:35 +02:00
net: openvswitch: fix upcall counter access before allocation Currently, the per cpu upcall counters are allocated after the vport is created and inserted into the system. This could lead to the datapath accessing the counters before they are allocated resulting in a kernel Oops. Here is an example: PID: 59693 TASK: ffff0005f4f51500 CPU: 0 COMMAND: "ovs-vswitchd" #0 [ffff80000a39b5b0] __switch_to at ffffb70f0629f2f4 #1 [ffff80000a39b5d0] __schedule at ffffb70f0629f5cc #2 [ffff80000a39b650] preempt_schedule_common at ffffb70f0629fa60 #3 [ffff80000a39b670] dynamic_might_resched at ffffb70f0629fb58 #4 [ffff80000a39b680] mutex_lock_killable at ffffb70f062a1388 #5 [ffff80000a39b6a0] pcpu_alloc at ffffb70f0594460c #6 [ffff80000a39b750] __alloc_percpu_gfp at ffffb70f05944e68 #7 [ffff80000a39b760] ovs_vport_cmd_new at ffffb70ee6961b90 [openvswitch] ... PID: 58682 TASK: ffff0005b2f0bf00 CPU: 0 COMMAND: "kworker/0:3" #0 [ffff80000a5d2f40] machine_kexec at ffffb70f056a0758 #1 [ffff80000a5d2f70] __crash_kexec at ffffb70f057e2994 #2 [ffff80000a5d3100] crash_kexec at ffffb70f057e2ad8 #3 [ffff80000a5d3120] die at ffffb70f0628234c #4 [ffff80000a5d31e0] die_kernel_fault at ffffb70f062828a8 #5 [ffff80000a5d3210] __do_kernel_fault at ffffb70f056a31f4 #6 [ffff80000a5d3240] do_bad_area at ffffb70f056a32a4 #7 [ffff80000a5d3260] do_translation_fault at ffffb70f062a9710 #8 [ffff80000a5d3270] do_mem_abort at ffffb70f056a2f74 #9 [ffff80000a5d32a0] el1_abort at ffffb70f06297dac #10 [ffff80000a5d32d0] el1h_64_sync_handler at ffffb70f06299b24 #11 [ffff80000a5d3410] el1h_64_sync at ffffb70f056812dc #12 [ffff80000a5d3430] ovs_dp_upcall at ffffb70ee6963c84 [openvswitch] #13 [ffff80000a5d3470] ovs_dp_process_packet at ffffb70ee6963fdc [openvswitch] #14 [ffff80000a5d34f0] ovs_vport_receive at ffffb70ee6972c78 [openvswitch] #15 [ffff80000a5d36f0] netdev_port_receive at ffffb70ee6973948 [openvswitch] #16 [ffff80000a5d3720] netdev_frame_hook at ffffb70ee6973a28 [openvswitch] #17 [ffff80000a5d3730] __netif_receive_skb_core.constprop.0 at ffffb70f06079f90 We moved the per cpu upcall counter allocation to the existing vport alloc and free functions to solve this. Fixes: 95637d91fefd ("net: openvswitch: release vport resources on failure") Fixes: 1933ea365aa7 ("net: openvswitch: Add support to count upcall packets") Signed-off-by: Eelco Chaudron <echaudro@redhat.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Acked-by: Aaron Conole <aconole@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-06-06 13:56:35 +02:00
net: openvswitch: fix upcall counter access before allocation Currently, the per cpu upcall counters are allocated after the vport is created and inserted into the system. This could lead to the datapath accessing the counters before they are allocated resulting in a kernel Oops. Here is an example: PID: 59693 TASK: ffff0005f4f51500 CPU: 0 COMMAND: "ovs-vswitchd" #0 [ffff80000a39b5b0] __switch_to at ffffb70f0629f2f4 #1 [ffff80000a39b5d0] __schedule at ffffb70f0629f5cc #2 [ffff80000a39b650] preempt_schedule_common at ffffb70f0629fa60 #3 [ffff80000a39b670] dynamic_might_resched at ffffb70f0629fb58 #4 [ffff80000a39b680] mutex_lock_killable at ffffb70f062a1388 #5 [ffff80000a39b6a0] pcpu_alloc at ffffb70f0594460c #6 [ffff80000a39b750] __alloc_percpu_gfp at ffffb70f05944e68 #7 [ffff80000a39b760] ovs_vport_cmd_new at ffffb70ee6961b90 [openvswitch] ... PID: 58682 TASK: ffff0005b2f0bf00 CPU: 0 COMMAND: "kworker/0:3" #0 [ffff80000a5d2f40] machine_kexec at ffffb70f056a0758 #1 [ffff80000a5d2f70] __crash_kexec at ffffb70f057e2994 #2 [ffff80000a5d3100] crash_kexec at ffffb70f057e2ad8 #3 [ffff80000a5d3120] die at ffffb70f0628234c #4 [ffff80000a5d31e0] die_kernel_fault at ffffb70f062828a8 #5 [ffff80000a5d3210] __do_kernel_fault at ffffb70f056a31f4 #6 [ffff80000a5d3240] do_bad_area at ffffb70f056a32a4 #7 [ffff80000a5d3260] do_translation_fault at ffffb70f062a9710 #8 [ffff80000a5d3270] do_mem_abort at ffffb70f056a2f74 #9 [ffff80000a5d32a0] el1_abort at ffffb70f06297dac #10 [ffff80000a5d32d0] el1h_64_sync_handler at ffffb70f06299b24 #11 [ffff80000a5d3410] el1h_64_sync at ffffb70f056812dc #12 [ffff80000a5d3430] ovs_dp_upcall at ffffb70ee6963c84 [openvswitch] #13 [ffff80000a5d3470] ovs_dp_process_packet at ffffb70ee6963fdc [openvswitch] #14 [ffff80000a5d34f0] ovs_vport_receive at ffffb70ee6972c78 [openvswitch] #15 [ffff80000a5d36f0] netdev_port_receive at ffffb70ee6973948 [openvswitch] #16 [ffff80000a5d3720] netdev_frame_hook at ffffb70ee6973a28 [openvswitch] #17 [ffff80000a5d3730] __netif_receive_skb_core.constprop.0 at ffffb70f06079f90 We moved the per cpu upcall counter allocation to the existing vport alloc and free functions to solve this. Fixes: 95637d91fefd ("net: openvswitch: release vport resources on failure") Fixes: 1933ea365aa7 ("net: openvswitch: Add support to count upcall packets") Signed-off-by: Eelco Chaudron <echaudro@redhat.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Acked-by: Aaron Conole <aconole@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-06-06 13:56:35 +02:00
net: openvswitch: fix upcall counter access before allocation Currently, the per cpu upcall counters are allocated after the vport is created and inserted into the system. This could lead to the datapath accessing the counters before they are allocated resulting in a kernel Oops. Here is an example: PID: 59693 TASK: ffff0005f4f51500 CPU: 0 COMMAND: "ovs-vswitchd" #0 [ffff80000a39b5b0] __switch_to at ffffb70f0629f2f4 #1 [ffff80000a39b5d0] __schedule at ffffb70f0629f5cc #2 [ffff80000a39b650] preempt_schedule_common at ffffb70f0629fa60 #3 [ffff80000a39b670] dynamic_might_resched at ffffb70f0629fb58 #4 [ffff80000a39b680] mutex_lock_killable at ffffb70f062a1388 #5 [ffff80000a39b6a0] pcpu_alloc at ffffb70f0594460c #6 [ffff80000a39b750] __alloc_percpu_gfp at ffffb70f05944e68 #7 [ffff80000a39b760] ovs_vport_cmd_new at ffffb70ee6961b90 [openvswitch] ... PID: 58682 TASK: ffff0005b2f0bf00 CPU: 0 COMMAND: "kworker/0:3" #0 [ffff80000a5d2f40] machine_kexec at ffffb70f056a0758 #1 [ffff80000a5d2f70] __crash_kexec at ffffb70f057e2994 #2 [ffff80000a5d3100] crash_kexec at ffffb70f057e2ad8 #3 [ffff80000a5d3120] die at ffffb70f0628234c #4 [ffff80000a5d31e0] die_kernel_fault at ffffb70f062828a8 #5 [ffff80000a5d3210] __do_kernel_fault at ffffb70f056a31f4 #6 [ffff80000a5d3240] do_bad_area at ffffb70f056a32a4 #7 [ffff80000a5d3260] do_translation_fault at ffffb70f062a9710 #8 [ffff80000a5d3270] do_mem_abort at ffffb70f056a2f74 #9 [ffff80000a5d32a0] el1_abort at ffffb70f06297dac #10 [ffff80000a5d32d0] el1h_64_sync_handler at ffffb70f06299b24 #11 [ffff80000a5d3410] el1h_64_sync at ffffb70f056812dc #12 [ffff80000a5d3430] ovs_dp_upcall at ffffb70ee6963c84 [openvswitch] #13 [ffff80000a5d3470] ovs_dp_process_packet at ffffb70ee6963fdc [openvswitch] #14 [ffff80000a5d34f0] ovs_vport_receive at ffffb70ee6972c78 [openvswitch] #15 [ffff80000a5d36f0] netdev_port_receive at ffffb70ee6973948 [openvswitch] #16 [ffff80000a5d3720] netdev_frame_hook at ffffb70ee6973a28 [openvswitch] #17 [ffff80000a5d3730] __netif_receive_skb_core.constprop.0 at ffffb70f06079f90 We moved the per cpu upcall counter allocation to the existing vport alloc and free functions to solve this. Fixes: 95637d91fefd ("net: openvswitch: release vport resources on failure") Fixes: 1933ea365aa7 ("net: openvswitch: Add support to count upcall packets") Signed-off-by: Eelco Chaudron <echaudro@redhat.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Acked-by: Aaron Conole <aconole@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-06-06 13:56:35 +02:00
openvswitch: Fix ovs_vport_get_stats() Not every device has dev->tstats set. So when OVS tries to calculate vport stats it causes kernel panic. Following patch fixes it by using standard API to get net-device stats. ---8<--- Unable to handle kernel paging request at virtual address 766b4008 Internal error: Oops: 96000005 [#1] PREEMPT SMP Modules linked in: vport_vxlan vxlan ip6_udp_tunnel udp_tunnel tun bridge stp llc openvswitch ipv6 CPU: 7 PID: 1108 Comm: ovs-vswitchd Not tainted 4.3.0-rc3+ #82 PC is at ovs_vport_get_stats+0x150/0x1f8 [openvswitch] <snip> Call trace: [<ffffffbffc0859f8>] ovs_vport_get_stats+0x150/0x1f8 [openvswitch] [<ffffffbffc07cdb0>] ovs_vport_cmd_fill_info+0x140/0x1e0 [openvswitch] [<ffffffbffc07cf0c>] ovs_vport_cmd_dump+0xbc/0x138 [openvswitch] [<ffffffc00045a5ac>] netlink_dump+0xb8/0x258 [<ffffffc00045ace0>] __netlink_dump_start+0x120/0x178 [<ffffffc00045dd9c>] genl_family_rcv_msg+0x2d4/0x308 [<ffffffc00045de58>] genl_rcv_msg+0x88/0xc4 [<ffffffc00045cf24>] netlink_rcv_skb+0xd4/0x100 [<ffffffc00045dab0>] genl_rcv+0x30/0x48 [<ffffffc00045c830>] netlink_unicast+0x154/0x200 [<ffffffc00045cc9c>] netlink_sendmsg+0x308/0x364 [<ffffffc00041e10c>] sock_sendmsg+0x14/0x2c [<ffffffc000420d58>] SyS_sendto+0xbc/0xf0 Code: aa1603e1 f94037a4 aa1303e2 aa1703e0 (f9400465) Reported-by: Tomasz Sawicki <tomasz.sawicki@objectiveintegration.uk> Fixes: 8c876639c98 ("openvswitch: Remove vport stats.") Signed-off-by: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-02 14:56:34 -07:00
openvswitch: Fix ovs_vport_get_stats() Not every device has dev->tstats set. So when OVS tries to calculate vport stats it causes kernel panic. Following patch fixes it by using standard API to get net-device stats. ---8<--- Unable to handle kernel paging request at virtual address 766b4008 Internal error: Oops: 96000005 [#1] PREEMPT SMP Modules linked in: vport_vxlan vxlan ip6_udp_tunnel udp_tunnel tun bridge stp llc openvswitch ipv6 CPU: 7 PID: 1108 Comm: ovs-vswitchd Not tainted 4.3.0-rc3+ #82 PC is at ovs_vport_get_stats+0x150/0x1f8 [openvswitch] <snip> Call trace: [<ffffffbffc0859f8>] ovs_vport_get_stats+0x150/0x1f8 [openvswitch] [<ffffffbffc07cdb0>] ovs_vport_cmd_fill_info+0x140/0x1e0 [openvswitch] [<ffffffbffc07cf0c>] ovs_vport_cmd_dump+0xbc/0x138 [openvswitch] [<ffffffc00045a5ac>] netlink_dump+0xb8/0x258 [<ffffffc00045ace0>] __netlink_dump_start+0x120/0x178 [<ffffffc00045dd9c>] genl_family_rcv_msg+0x2d4/0x308 [<ffffffc00045de58>] genl_rcv_msg+0x88/0xc4 [<ffffffc00045cf24>] netlink_rcv_skb+0xd4/0x100 [<ffffffc00045dab0>] genl_rcv+0x30/0x48 [<ffffffc00045c830>] netlink_unicast+0x154/0x200 [<ffffffc00045cc9c>] netlink_sendmsg+0x308/0x364 [<ffffffc00041e10c>] sock_sendmsg+0x14/0x2c [<ffffffc000420d58>] SyS_sendto+0xbc/0xf0 Code: aa1603e1 f94037a4 aa1303e2 aa1703e0 (f9400465) Reported-by: Tomasz Sawicki <tomasz.sawicki@objectiveintegration.uk> Fixes: 8c876639c98 ("openvswitch: Remove vport stats.") Signed-off-by: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-02 14:56:34 -07:00
openvswitch: Fix ovs_vport_get_stats() Not every device has dev->tstats set. So when OVS tries to calculate vport stats it causes kernel panic. Following patch fixes it by using standard API to get net-device stats. ---8<--- Unable to handle kernel paging request at virtual address 766b4008 Internal error: Oops: 96000005 [#1] PREEMPT SMP Modules linked in: vport_vxlan vxlan ip6_udp_tunnel udp_tunnel tun bridge stp llc openvswitch ipv6 CPU: 7 PID: 1108 Comm: ovs-vswitchd Not tainted 4.3.0-rc3+ #82 PC is at ovs_vport_get_stats+0x150/0x1f8 [openvswitch] <snip> Call trace: [<ffffffbffc0859f8>] ovs_vport_get_stats+0x150/0x1f8 [openvswitch] [<ffffffbffc07cdb0>] ovs_vport_cmd_fill_info+0x140/0x1e0 [openvswitch] [<ffffffbffc07cf0c>] ovs_vport_cmd_dump+0xbc/0x138 [openvswitch] [<ffffffc00045a5ac>] netlink_dump+0xb8/0x258 [<ffffffc00045ace0>] __netlink_dump_start+0x120/0x178 [<ffffffc00045dd9c>] genl_family_rcv_msg+0x2d4/0x308 [<ffffffc00045de58>] genl_rcv_msg+0x88/0xc4 [<ffffffc00045cf24>] netlink_rcv_skb+0xd4/0x100 [<ffffffc00045dab0>] genl_rcv+0x30/0x48 [<ffffffc00045c830>] netlink_unicast+0x154/0x200 [<ffffffc00045cc9c>] netlink_sendmsg+0x308/0x364 [<ffffffc00041e10c>] sock_sendmsg+0x14/0x2c [<ffffffc000420d58>] SyS_sendto+0xbc/0xf0 Code: aa1603e1 f94037a4 aa1303e2 aa1703e0 (f9400465) Reported-by: Tomasz Sawicki <tomasz.sawicki@objectiveintegration.uk> Fixes: 8c876639c98 ("openvswitch: Remove vport stats.") Signed-off-by: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-02 14:56:34 -07:00
openvswitch: Add conntrack action Expose the kernel connection tracker via OVS. Userspace components can make use of the CT action to populate the connection state (ct_state) field for a flow. This state can be subsequently matched. Exposed connection states are OVS_CS_F_*: - NEW (0x01) - Beginning of a new connection. - ESTABLISHED (0x02) - Part of an existing connection. - RELATED (0x04) - Related to an established connection. - INVALID (0x20) - Could not track the connection for this packet. - REPLY_DIR (0x40) - This packet is in the reply direction for the flow. - TRACKED (0x80) - This packet has been sent through conntrack. When the CT action is executed by itself, it will send the packet through the connection tracker and populate the ct_state field with one or more of the connection state flags above. The CT action will always set the TRACKED bit. When the COMMIT flag is passed to the conntrack action, this specifies that information about the connection should be stored. This allows subsequent packets for the same (or related) connections to be correlated with this connection. Sending subsequent packets for the connection through conntrack allows the connection tracker to consider the packets as ESTABLISHED, RELATED, and/or REPLY_DIR. The CT action may optionally take a zone to track the flow within. This allows connections with the same 5-tuple to be kept logically separate from connections in other zones. If the zone is specified, then the "ct_zone" match field will be subsequently populated with the zone id. IP fragments are handled by transparently assembling them as part of the CT action. The maximum received unit (MRU) size is tracked so that refragmentation can occur during output. IP frag handling contributed by Andy Zhou. Based on original design by Justin Pettit. Signed-off-by: Joe Stringer <joestringer@nicira.com> Signed-off-by: Justin Pettit <jpettit@nicira.com> Signed-off-by: Andy Zhou <azhou@nicira.com> Acked-by: Thomas Graf <tgraf@suug.ch> Acked-by: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-26 11:31:48 -07:00
net: openvswitch: allow providing upcall pid for the 'execute' command When a packet enters OVS datapath and there is no flow to handle it, packet goes to userspace through a MISS upcall. With per-CPU upcall dispatch mechanism, we're using the current CPU id to select the Netlink PID on which to send this packet. This allows us to send packets from the same traffic flow through the same handler. The handler will process the packet, install required flow into the kernel and re-inject the original packet via OVS_PACKET_CMD_EXECUTE. While handling OVS_PACKET_CMD_EXECUTE, however, we may hit a recirculation action that will pass the (likely modified) packet through the flow lookup again. And if the flow is not found, the packet will be sent to userspace again through another MISS upcall. However, the handler thread in userspace is likely running on a different CPU core, and the OVS_PACKET_CMD_EXECUTE request is handled in the syscall context of that thread. So, when the time comes to send the packet through another upcall, the per-CPU dispatch will choose a different Netlink PID, and this packet will end up processed by a different handler thread on a different CPU. The process continues as long as there are new recirculations, each time the packet goes to a different handler thread before it is sent out of the OVS datapath to the destination port. In real setups the number of recirculations can go up to 4 or 5, sometimes more. There is always a chance to re-order packets while processing upcalls, because userspace will first install the flow and then re-inject the original packet. So, there is a race window when the flow is already installed and the second packet can match it and be forwarded to the destination before the first packet is re-injected. But the fact that packets are going through multiple upcalls handled by different userspace threads makes the reordering noticeably more likely, because we not only have a race between the kernel and a userspace handler (which is hard to avoid), but also between multiple userspace handlers. For example, let's assume that 10 packets got enqueued through a MISS upcall for handler-1, it will start processing them, will install the flow into the kernel and start re-injecting packets back, from where they will go through another MISS to handler-2. Handler-2 will install the flow into the kernel and start re-injecting the packets, while handler-1 continues to re-inject the last of the 10 packets, they will hit the flow installed by handler-2 and be forwarded without going to the handler-2, while handler-2 still re-injects the first of these 10 packets. Given multiple recirculations and misses, these 10 packets may end up completely mixed up on the output from the datapath. Let's allow userspace to specify on which Netlink PID the packets should be upcalled while processing OVS_PACKET_CMD_EXECUTE. This makes it possible to ensure that all the packets are processed by the same handler thread in the userspace even with them being upcalled multiple times in the process. Packets will remain in order since they will be enqueued to the same socket and re-injected in the same order. This doesn't eliminate re-ordering as stated above, since we still have a race between kernel and the userspace thread, but it allows to eliminate races between multiple userspace threads. Userspace knows the PID of the socket on which the original upcall is received, so there is no need to send it up from the kernel. Solution requires storing the value somewhere for the duration of the packet processing. There are two potential places for this: our skb extension or the per-CPU storage. It's not clear which is better, so just following currently used scheme of storing this kind of things along the skb. We still have a decent amount of space in the cb. Signed-off-by: Ilya Maximets <i.maximets@ovn.org> Acked-by: Flavio Leitner <fbl@sysclose.org> Acked-by: Eelco Chaudron <echaudro@redhat.com> Acked-by: Aaron Conole <aconole@redhat.com> Link: https://patch.msgid.link/20250702155043.2331772-1-i.maximets@ovn.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-02 17:50:34 +02:00