Adrian Moreno <amore...@redhat.com> writes: > Create a new drop reason subsystem for openvswitch and add the first > drop reason to represent last-action drops. > > Last-action drops happen when a flow has an empty action list or there > is no action that consumes the packet (output, userspace, recirc, etc). > It is the most common way in which OVS drops packets. > > Implementation-wise, most of these skb-consuming actions already call > "consume_skb" internally and return directly from within the > do_execute_actions() loop so with minimal changes we can assume that > any skb that exits the loop normally is a packet drop. > > Signed-off-by: Adrian Moreno <amore...@redhat.com> > ---
Overall, looks good. I did a build with this and got some warnings. I think they can be resolved in the same way the mac80211 drops are resolved by using (__force u32) to pass the reason argument. > include/net/dropreason.h | 6 ++++++ > net/openvswitch/actions.c | 12 ++++++++++-- > net/openvswitch/datapath.c | 16 ++++++++++++++++ > net/openvswitch/drop.h | 24 ++++++++++++++++++++++++ > 4 files changed, 56 insertions(+), 2 deletions(-) > create mode 100644 net/openvswitch/drop.h > > diff --git a/include/net/dropreason.h b/include/net/dropreason.h > index 685fb37df8e8..56cb7be92244 100644 > --- a/include/net/dropreason.h > +++ b/include/net/dropreason.h > @@ -23,6 +23,12 @@ enum skb_drop_reason_subsys { > */ > SKB_DROP_REASON_SUBSYS_MAC80211_MONITOR, > > + /** > + * @SKB_DROP_REASON_SUBSYS_OPENVSWITCH: openvswitch drop reasons, > + * see net/openvswitch/drop.h > + */ > + SKB_DROP_REASON_SUBSYS_OPENVSWITCH, > + > /** @SKB_DROP_REASON_SUBSYS_NUM: number of subsystems defined */ > SKB_DROP_REASON_SUBSYS_NUM > }; > diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c > index cab1e02b63e0..1234e95a9ce8 100644 > --- a/net/openvswitch/actions.c > +++ b/net/openvswitch/actions.c > @@ -27,6 +27,7 @@ > #include <net/sctp/checksum.h> > > #include "datapath.h" > +#include "drop.h" > #include "flow.h" > #include "conntrack.h" > #include "vport.h" > @@ -1036,7 +1037,7 @@ static int sample(struct datapath *dp, struct sk_buff > *skb, > if ((arg->probability != U32_MAX) && > (!arg->probability || get_random_u32() > arg->probability)) { > if (last) > - consume_skb(skb); > + kfree_skb_reason(skb, OVS_DROP_LAST_ACTION); > return 0; > } > > @@ -1297,6 +1298,9 @@ static int do_execute_actions(struct datapath *dp, > struct sk_buff *skb, > if (trace_ovs_do_execute_action_enabled()) > trace_ovs_do_execute_action(dp, skb, key, a, rem); > > + /* Actions that rightfully have to consume the skb should do it > + * and return directly. > + */ > switch (nla_type(a)) { > case OVS_ACTION_ATTR_OUTPUT: { > int port = nla_get_u32(a); > @@ -1332,6 +1336,10 @@ static int do_execute_actions(struct datapath *dp, > struct sk_buff *skb, > output_userspace(dp, skb, key, a, attr, > len, OVS_CB(skb)->cutlen); > OVS_CB(skb)->cutlen = 0; > + if (nla_is_last(a, rem)) { > + consume_skb(skb); > + return 0; > + } > break; > > case OVS_ACTION_ATTR_HASH: > @@ -1485,7 +1493,7 @@ static int do_execute_actions(struct datapath *dp, > struct sk_buff *skb, > } > } > > - consume_skb(skb); > + kfree_skb_reason(skb, OVS_DROP_LAST_ACTION); > return 0; > } > > diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c > index a6d2a0b1aa21..d33cb739883f 100644 > --- a/net/openvswitch/datapath.c > +++ b/net/openvswitch/datapath.c > @@ -41,6 +41,7 @@ > #include <net/pkt_cls.h> > > #include "datapath.h" > +#include "drop.h" > #include "flow.h" > #include "flow_table.h" > #include "flow_netlink.h" > @@ -2702,6 +2703,17 @@ static struct pernet_operations ovs_net_ops = { > .size = sizeof(struct ovs_net), > }; > > +static const char * const ovs_drop_reasons[] = { > +#define S(x) (#x), > + OVS_DROP_REASONS(S) > +#undef S > +}; > + > +static struct drop_reason_list drop_reason_list_ovs = { > + .reasons = ovs_drop_reasons, > + .n_reasons = ARRAY_SIZE(ovs_drop_reasons), > +}; > + > static int __init dp_init(void) > { > int err; > @@ -2743,6 +2755,9 @@ static int __init dp_init(void) > if (err < 0) > goto error_unreg_netdev; > > + drop_reasons_register_subsys(SKB_DROP_REASON_SUBSYS_OPENVSWITCH, > + &drop_reason_list_ovs); > + > return 0; > > error_unreg_netdev: > @@ -2769,6 +2784,7 @@ static void dp_cleanup(void) > ovs_netdev_exit(); > unregister_netdevice_notifier(&ovs_dp_device_notifier); > unregister_pernet_device(&ovs_net_ops); > + drop_reasons_unregister_subsys(SKB_DROP_REASON_SUBSYS_OPENVSWITCH); > rcu_barrier(); > ovs_vport_exit(); > ovs_flow_exit(); > diff --git a/net/openvswitch/drop.h b/net/openvswitch/drop.h > new file mode 100644 > index 000000000000..ffdb8ab045bd > --- /dev/null > +++ b/net/openvswitch/drop.h > @@ -0,0 +1,24 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > +/* > + * OpenvSwitch drop reason list. > + */ > + > +#ifndef OPENVSWITCH_DROP_H > +#define OPENVSWITCH_DROP_H > +#include <net/dropreason.h> > + > +#define OVS_DROP_REASONS(R) \ > + R(OVS_DROP_LAST_ACTION) \ > + /* deliberate comment for trailing \ */ > + > +enum ovs_drop_reason { > + __OVS_DROP_REASON = SKB_DROP_REASON_SUBSYS_OPENVSWITCH << > + SKB_DROP_REASON_SUBSYS_SHIFT, > +#define ENUM(x) x, > + OVS_DROP_REASONS(ENUM) > +#undef ENUM > + > + OVS_DROP_MAX, > +}; > + > +#endif /* OPENVSWITCH_DROP_H */ _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev