lkml.org 
[lkml]   [2022]   [Mar]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    SubjectRe: [PATCH net-next 1/3] net: bridge: add fdb flag to extent locked port feature
    On Thu, Mar 10, 2022 at 03:23:18PM +0100, Hans Schultz wrote:
    > Add an intermediate state for clients behind a locked port to allow for
    > possible opening of the port for said clients. This feature corresponds
    > to the Mac-Auth and MAC Authentication Bypass (MAB) named features. The
    > latter defined by Cisco.
    >
    > Signed-off-by: Hans Schultz <schultz.hans+netdev@gmail.com>
    > ---
    > include/uapi/linux/neighbour.h | 1 +
    > net/bridge/br_fdb.c | 6 ++++++
    > net/bridge/br_input.c | 11 ++++++++++-
    > net/bridge/br_private.h | 3 ++-
    > 4 files changed, 19 insertions(+), 2 deletions(-)
    >
    > diff --git a/include/uapi/linux/neighbour.h b/include/uapi/linux/neighbour.h
    > index db05fb55055e..83115a592d58 100644
    > --- a/include/uapi/linux/neighbour.h
    > +++ b/include/uapi/linux/neighbour.h
    > @@ -208,6 +208,7 @@ enum {
    > NFEA_UNSPEC,
    > NFEA_ACTIVITY_NOTIFY,
    > NFEA_DONT_REFRESH,
    > + NFEA_LOCKED,
    > __NFEA_MAX
    > };
    > #define NFEA_MAX (__NFEA_MAX - 1)
    > diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
    > index 6ccda68bd473..396dcf3084cf 100644
    > --- a/net/bridge/br_fdb.c
    > +++ b/net/bridge/br_fdb.c
    > @@ -105,6 +105,7 @@ static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
    > struct nda_cacheinfo ci;
    > struct nlmsghdr *nlh;
    > struct ndmsg *ndm;
    > + u8 ext_flags = 0;
    >
    > nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
    > if (nlh == NULL)
    > @@ -125,11 +126,16 @@ static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
    > ndm->ndm_flags |= NTF_EXT_LEARNED;
    > if (test_bit(BR_FDB_STICKY, &fdb->flags))
    > ndm->ndm_flags |= NTF_STICKY;
    > + if (test_bit(BR_FDB_ENTRY_LOCKED, &fdb->flags))
    > + ext_flags |= 1 << NFEA_LOCKED;
    >
    > if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->key.addr))
    > goto nla_put_failure;
    > if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
    > goto nla_put_failure;
    > + if (nla_put_u8(skb, NDA_FDB_EXT_ATTRS, ext_flags))
    > + goto nla_put_failure;
    > +
    > ci.ndm_used = jiffies_to_clock_t(now - fdb->used);
    > ci.ndm_confirmed = 0;
    > ci.ndm_updated = jiffies_to_clock_t(now - fdb->updated);
    > diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
    > index e0c13fcc50ed..897908484b18 100644
    > --- a/net/bridge/br_input.c
    > +++ b/net/bridge/br_input.c
    > @@ -75,6 +75,7 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
    > struct net_bridge_mcast *brmctx;
    > struct net_bridge_vlan *vlan;
    > struct net_bridge *br;
    > + unsigned long flags = 0;
    > u16 vid = 0;
    > u8 state;
    >
    > @@ -94,8 +95,16 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
    > br_fdb_find_rcu(br, eth_hdr(skb)->h_source, vid);
    >
    > if (!fdb_src || READ_ONCE(fdb_src->dst) != p ||
    > - test_bit(BR_FDB_LOCAL, &fdb_src->flags))
    > + test_bit(BR_FDB_LOCAL, &fdb_src->flags)) {
    > + if (!fdb_src) {
    > + set_bit(BR_FDB_ENTRY_LOCKED, &flags);

    This flag is read-only for user space, right? That is, the kernel needs
    to reject it during netlink policy validation.

    > + br_fdb_update(br, p, eth_hdr(skb)->h_source, vid, flags);
    > + }
    > goto drop;
    > + } else {

    IIUC, we get here in case there is a non-local FDB entry with the SA
    that points to our port. Can you write it as:

    if (!fdb_src || READ_ONCE(fdb_src->dst) != p ||
    test_bit(BR_FDB_LOCAL, &fdb_src->flags) ||
    test_bit(BR_FDB_ENTRY_LOCKED, &fdb_src->flags)) {
    if (!fdb_src) {
    ...
    }
    goto drop;
    }

    > + if (test_bit(BR_FDB_ENTRY_LOCKED, &fdb_src->flags))
    > + goto drop;
    > + }
    > }
    >
    > nbp_switchdev_frame_mark(p, skb);
    > diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
    > index 48bc61ebc211..f5a0b68c4857 100644
    > --- a/net/bridge/br_private.h
    > +++ b/net/bridge/br_private.h
    > @@ -248,7 +248,8 @@ enum {
    > BR_FDB_ADDED_BY_EXT_LEARN,
    > BR_FDB_OFFLOADED,
    > BR_FDB_NOTIFY,
    > - BR_FDB_NOTIFY_INACTIVE
    > + BR_FDB_NOTIFY_INACTIVE,
    > + BR_FDB_ENTRY_LOCKED,
    > };
    >
    > struct net_bridge_fdb_key {
    > --
    > 2.30.2
    >

    \
     
     \ /
      Last update: 2022-03-14 16:32    [W:3.830 / U:0.052 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site