lkml.org 
[lkml]   [2019]   [May]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.1 010/122] rtnetlink: always put IFLA_LINK for links with a link-netnsid
    Date
    From: Sabrina Dubroca <sd@queasysnail.net>

    [ Upstream commit feadc4b6cf42a53a8a93c918a569a0b7e62bd350 ]

    Currently, nla_put_iflink() doesn't put the IFLA_LINK attribute when
    iflink == ifindex.

    In some cases, a device can be created in a different netns with the
    same ifindex as its parent. That device will not dump its IFLA_LINK
    attribute, which can confuse some userspace software that expects it.
    For example, if the last ifindex created in init_net and foo are both
    8, these commands will trigger the issue:

    ip link add parent type dummy # ifindex 9
    ip link add link parent netns foo type macvlan # ifindex 9 in ns foo

    So, in case a device puts the IFLA_LINK_NETNSID attribute in a dump,
    always put the IFLA_LINK attribute as well.

    Thanks to Dan Winship for analyzing the original OpenShift bug down to
    the missing netlink attribute.

    v2: change Fixes tag, it's been here forever, as Nicolas Dichtel said
    add Nicolas' ack
    v3: change Fixes tag
    fix subject typo, spotted by Edward Cree

    Analyzed-by: Dan Winship <danw@redhat.com>
    Fixes: d8a5ec672768 ("[NET]: netlink support for moving devices between network namespaces.")
    Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
    Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    net/core/rtnetlink.c | 16 ++++++++++------
    1 file changed, 10 insertions(+), 6 deletions(-)

    --- a/net/core/rtnetlink.c
    +++ b/net/core/rtnetlink.c
    @@ -1496,14 +1496,15 @@ static int put_master_ifindex(struct sk_
    return ret;
    }

    -static int nla_put_iflink(struct sk_buff *skb, const struct net_device *dev)
    +static int nla_put_iflink(struct sk_buff *skb, const struct net_device *dev,
    + bool force)
    {
    int ifindex = dev_get_iflink(dev);

    - if (dev->ifindex == ifindex)
    - return 0;
    + if (force || dev->ifindex != ifindex)
    + return nla_put_u32(skb, IFLA_LINK, ifindex);

    - return nla_put_u32(skb, IFLA_LINK, ifindex);
    + return 0;
    }

    static noinline_for_stack int nla_put_ifalias(struct sk_buff *skb,
    @@ -1520,6 +1521,8 @@ static int rtnl_fill_link_netnsid(struct
    const struct net_device *dev,
    struct net *src_net)
    {
    + bool put_iflink = false;
    +
    if (dev->rtnl_link_ops && dev->rtnl_link_ops->get_link_net) {
    struct net *link_net = dev->rtnl_link_ops->get_link_net(dev);

    @@ -1528,10 +1531,12 @@ static int rtnl_fill_link_netnsid(struct

    if (nla_put_s32(skb, IFLA_LINK_NETNSID, id))
    return -EMSGSIZE;
    +
    + put_iflink = true;
    }
    }

    - return 0;
    + return nla_put_iflink(skb, dev, put_iflink);
    }

    static int rtnl_fill_link_af(struct sk_buff *skb,
    @@ -1617,7 +1622,6 @@ static int rtnl_fill_ifinfo(struct sk_bu
    #ifdef CONFIG_RPS
    nla_put_u32(skb, IFLA_NUM_RX_QUEUES, dev->num_rx_queues) ||
    #endif
    - nla_put_iflink(skb, dev) ||
    put_master_ifindex(skb, dev) ||
    nla_put_u8(skb, IFLA_CARRIER, netif_carrier_ok(dev)) ||
    (dev->qdisc &&

    \
     
     \ /
      Last update: 2019-05-23 21:39    [W:2.240 / U:0.112 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site