lkml.org 
[lkml]   [2022]   [Oct]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 6.0 305/862] flow_dissector: Do not count vlan tags inside tunnel payload
    Date
    From: Qingqing Yang <qingqing.yang@broadcom.com>

    [ Upstream commit 9f87eb4246994e32a4e4ea88476b20ab3b412840 ]

    We've met the problem that when there is a vlan tag inside
    GRE encapsulation, the match of num_of_vlans fails.
    It is caused by the vlan tag inside GRE payload has been
    counted into num_of_vlans, which is not expected.

    One example packet is like this:
    Ethernet II, Src: Broadcom_68:56:07 (00:10:18:68:56:07)
    Dst: Broadcom_68:56:08 (00:10:18:68:56:08)
    802.1Q Virtual LAN, PRI: 0, DEI: 0, ID: 100
    Internet Protocol Version 4, Src: 192.168.1.4, Dst: 192.168.1.200
    Generic Routing Encapsulation (Transparent Ethernet bridging)
    Ethernet II, Src: Broadcom_68:58:07 (00:10:18:68:58:07)
    Dst: Broadcom_68:58:08 (00:10:18:68:58:08)
    802.1Q Virtual LAN, PRI: 0, DEI: 0, ID: 200
    ...
    It should match the (num_of_vlans 1) rule, but it matches
    the (num_of_vlans 2) rule.

    The vlan tags inside the GRE or other tunnel encapsulated payload
    should not be taken into num_of_vlans.
    The fix is to stop counting the vlan number when the encapsulation
    bit is set.

    Fixes: 34951fcf26c5 ("flow_dissector: Add number of vlan tags dissector")
    Signed-off-by: Qingqing Yang <qingqing.yang@broadcom.com>
    Reviewed-by: Boris Sukholitko <boris.sukholitko@broadcom.com>
    Link: https://lore.kernel.org/r/20220919074808.136640-1-qingqing.yang@broadcom.com
    Signed-off-by: Jakub Kicinski <kuba@kernel.org>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    net/core/flow_dissector.c | 4 ++--
    1 file changed, 2 insertions(+), 2 deletions(-)

    diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
    index 5dc3860e9fc7..7105529abb0f 100644
    --- a/net/core/flow_dissector.c
    +++ b/net/core/flow_dissector.c
    @@ -1173,8 +1173,8 @@ bool __skb_flow_dissect(const struct net *net,
    nhoff += sizeof(*vlan);
    }

    - if (dissector_uses_key(flow_dissector,
    - FLOW_DISSECTOR_KEY_NUM_OF_VLANS)) {
    + if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_NUM_OF_VLANS) &&
    + !(key_control->flags & FLOW_DIS_ENCAPSULATION)) {
    struct flow_dissector_key_num_of_vlans *key_nvs;

    key_nvs = skb_flow_dissector_target(flow_dissector,
    --
    2.35.1


    \
     
     \ /
      Last update: 2022-10-19 11:07    [W:4.031 / U:0.024 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site