[ovs-dev] [PATCH v2 ovn] northd: set packet length in check_pkt_larger()

Numan Siddique numans at ovn.org
Mon Jun 22 07:18:51 UTC 2020


On Thu, Jun 18, 2020 at 10:21 PM Lorenzo Bianconi <
lorenzo.bianconi at redhat.com> wrote:

> Set packet length in lr_in_chk_pkt_len router pipeline instead of
> gw interface MTU since ovs kernel datapath usually works on L2 frames
>
> Fixes: 7d42c146be ("ovn: Generate ICMPv4 packet in router pipeline for
> larger packets")
> Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi at redhat.com>
>

Thanks Lorenzo. I applied this patch to master, branch-20.06 and
branch-20.03.

Numan


> ---
> Changes since v1:
> - rely on macros for L2 header size
> - fix comment
> ---
>  northd/ovn-northd.c |  7 +++----
>  tests/ovn.at        | 33 ++++++++++++++++++---------------
>  2 files changed, 21 insertions(+), 19 deletions(-)
>
> diff --git a/northd/ovn-northd.c b/northd/ovn-northd.c
> index 6a9b097e5..40aeb0a58 100644
> --- a/northd/ovn-northd.c
> +++ b/northd/ovn-northd.c
> @@ -10082,7 +10082,7 @@ build_lrouter_flows(struct hmap *datapaths, struct
> hmap *ports,
>              ds_clear(&actions);
>              ds_put_format(&actions,
>                            REGBIT_PKT_LARGER" = check_pkt_larger(%d);"
> -                          " next;", gw_mtu);
> +                          " next;", gw_mtu + VLAN_ETH_HEADER_LEN);
>              ovn_lflow_add_with_hint(lflows, od, S_ROUTER_IN_CHK_PKT_LEN,
> 50,
>                                      ds_cstr(&match), ds_cstr(&actions),
>                                      &od->l3dgw_port->nbrp->header_);
> @@ -10100,8 +10100,7 @@ build_lrouter_flows(struct hmap *datapaths, struct
> hmap *ports,
>                                rp->json_key, od->l3dgw_port->json_key);
>
>                  ds_clear(&actions);
> -                /* Set icmp4.frag_mtu to gw_mtu - 58. 58 is the Geneve
> tunnel
> -                 * overhead. */
> +                /* Set icmp4.frag_mtu to gw_mtu */
>                  ds_put_format(&actions,
>                      "icmp4_error {"
>                      REGBIT_EGRESS_LOOPBACK" = 1; "
> @@ -10115,7 +10114,7 @@ build_lrouter_flows(struct hmap *datapaths, struct
> hmap *ports,
>                      "next(pipeline=ingress, table=0); };",
>                      rp->lrp_networks.ea_s,
>                      rp->lrp_networks.ipv4_addrs[0].addr_s,
> -                    gw_mtu - 18);
> +                    gw_mtu);
>                  ovn_lflow_add_with_hint(lflows, od,
> S_ROUTER_IN_LARGER_PKTS,
>                                          50, ds_cstr(&match),
> ds_cstr(&actions),
>                                          &rp->nbrp->header_);
> diff --git a/tests/ovn.at b/tests/ovn.at
> index 7622b745b..8ee348397 100644
> --- a/tests/ovn.at
> +++ b/tests/ovn.at
> @@ -14873,14 +14873,16 @@ test_ip_packet_larger() {
>      dst_mac="00000000ff01" # sw0-lr0 mac (internal router leg)
>      src_ip=`ip_to_hex 10 0 0 3`
>      dst_ip=`ip_to_hex 172 168 0 3`
> -    # Set the packet length to 100.
> -    pkt_len=0064
> -    packet=${dst_mac}${src_mac}08004500${pkt_len}0000000040010000
> +    # Set the packet length to 118.
> +    pkt_len=0076
> +    packet=${dst_mac}${src_mac}08004500${pkt_len}000000004001c3d9
>      orig_packet_l3=${src_ip}${dst_ip}0304000000000000
>      orig_packet_l3=${orig_packet_l3}000000000000000000000000000000000000
>      orig_packet_l3=${orig_packet_l3}000000000000000000000000000000000000
>      orig_packet_l3=${orig_packet_l3}000000000000000000000000000000000000
>      orig_packet_l3=${orig_packet_l3}000000000000000000000000000000000000
> +    orig_packet_l3=${orig_packet_l3}000000000000000000000000000000000000
> +
>      packet=${packet}${orig_packet_l3}
>
>
>  gw_ip_garp=ffffffffffff00002020121308060001080006040001000020201213aca80064000000000000aca80064
> @@ -14890,32 +14892,33 @@ test_ip_packet_larger() {
>      # localnet port.
>      # If icmp_pmtu_reply_expected is 1, it means the packet is larger than
>      # the gateway mtu and ovn-controller should drop the packet and
> instead
> -    # generate ICMPv4  Destination Unreachable message with pmtu set to
> 42.
> +    # generate ICMPv4  Destination Unreachable message with pmtu set to
> 100.
>      if test $icmp_pmtu_reply_expected = 0; then
>          # Packet to expect at br-phys.
>          src_mac="000020201213"
>          dst_mac="00000012af11"
>          src_ip=`ip_to_hex 10 0 0 3`
>          dst_ip=`ip_to_hex 172 168 0 3`
> -        expected=${dst_mac}${src_mac}08004500${pkt_len}000000003f010100
> +        expected=${dst_mac}${src_mac}08004500${pkt_len}000000003f01c4d9
>          expected=${expected}${src_ip}${dst_ip}0304000000000000
>          expected=${expected}000000000000000000000000000000000000
>          expected=${expected}000000000000000000000000000000000000
>          expected=${expected}000000000000000000000000000000000000
>          expected=${expected}000000000000000000000000000000000000
> +        expected=${expected}000000000000000000000000000000000000
>          echo $expected > br_phys_n1.expected
>          echo $gw_ip_garp >> br_phys_n1.expected
>      else
> -        # MTU would be 100 - 18 = 82 (hex 0052)
> -        mtu=0052
> +        # MTU would be 118 - 18 = 100 (hex 0064)
> +        mtu=0064
>          src_ip=`ip_to_hex 10 0 0 1`
>          dst_ip=`ip_to_hex 10 0 0 3`
> -        # pkt len should be 128 (28 (icmp packet) + 100 (orig ip +
> payload))
> -        reply_pkt_len=0080
> -        ip_csum=bd91
> -
> icmp_reply=${src_mac}${dst_mac}08004500${reply_pkt_len}00004000fe016879
> +        # pkt len should be 146 (28 (icmp packet) + 118 (orig ip +
> payload))
> +        reply_pkt_len=0092
> +        ip_csum=f993
> +
> icmp_reply=${src_mac}${dst_mac}08004500${reply_pkt_len}00004000fe016867
>          icmp_reply=${icmp_reply}${src_ip}${dst_ip}0304${ip_csum}0000${mtu}
> -        icmp_reply=${icmp_reply}4500${pkt_len}000000003f010100
> +        icmp_reply=${icmp_reply}4500${pkt_len}000000003f01c4d9
>          icmp_reply=${icmp_reply}${orig_packet_l3}
>          echo $icmp_reply > hv1-vif1.expected
>      fi
> @@ -14955,12 +14958,12 @@ awk '{print $3}')
>  ovn-sbctl create MAC_Binding ip=172.168.0.3 datapath=$dp_uuid \
>  logical_port=lr0-public mac="00\:00\:00\:12\:af\:11"
>
> -# Set the gateway mtu to 100. If the packet length is > 100,
> ovn-controller
> +# Set the gateway mtu to 100. If the packet length is > 118,
> ovn-controller
>  # should send icmp host not reachable with pmtu set to 100.
>  ovn-nbctl --wait=hv set logical_router_port lr0-public
> options:gateway_mtu=100
>  as hv3 ovs-appctl netdev-dummy/receive hv3-vif1 $arp_reply
>  OVS_WAIT_UNTIL([
> -    test `as hv1 ovs-ofctl dump-flows br-int | grep
> "check_pkt_larger(100)" | \
> +    test `as hv1 ovs-ofctl dump-flows br-int | grep
> "check_pkt_larger(118)" | \
>      wc -l` -eq 1
>  ])
>
> @@ -14971,7 +14974,7 @@ test_ip_packet_larger $icmp_reply_expected
>  ovn-nbctl --wait=hv set logical_router_port lr0-public
> options:gateway_mtu=500
>  as hv3 ovs-appctl netdev-dummy/receive hv3-vif1 $arp_reply
>  OVS_WAIT_UNTIL([
> -    test `as hv1 ovs-ofctl dump-flows br-int | grep
> "check_pkt_larger(500)" | \
> +    test `as hv1 ovs-ofctl dump-flows br-int | grep
> "check_pkt_larger(518)" | \
>      wc -l` -eq 1
>  ])
>
> --
> 2.26.2
>
> _______________________________________________
> dev mailing list
> dev at openvswitch.org
> https://mail.openvswitch.org/mailman/listinfo/ovs-dev
>
>


More information about the dev mailing list