On Tue, Jul 02, 2024 at 03:05:02AM GMT, Adrián Moreno wrote: > On Mon, Jul 01, 2024 at 02:23:12PM GMT, Aaron Conole wrote: > > Adrian Moreno <amore...@redhat.com> writes: > > > > > Add support for a new action: psample. > > > > > > This action accepts a u32 group id and a variable-length cookie and uses > > > the psample multicast group to make the packet available for > > > observability. > > > > > > The maximum length of the user-defined cookie is set to 16, same as > > > tc_cookie, to discourage using cookies that will not be offloadable. > > > > > > Acked-by: Eelco Chaudron <echau...@redhat.com> > > > Signed-off-by: Adrian Moreno <amore...@redhat.com> > > > --- > > > > Hi Adrian, > > > > Just some nits below. > > > > > Documentation/netlink/specs/ovs_flow.yaml | 17 ++++++++ > > > include/uapi/linux/openvswitch.h | 28 ++++++++++++++ > > > net/openvswitch/Kconfig | 1 + > > > net/openvswitch/actions.c | 47 +++++++++++++++++++++++ > > > net/openvswitch/flow_netlink.c | 32 ++++++++++++++- > > > 5 files changed, 124 insertions(+), 1 deletion(-) > > > > > > diff --git a/Documentation/netlink/specs/ovs_flow.yaml > > > b/Documentation/netlink/specs/ovs_flow.yaml > > > index 4fdfc6b5cae9..46f5d1cd8a5f 100644 > > > --- a/Documentation/netlink/specs/ovs_flow.yaml > > > +++ b/Documentation/netlink/specs/ovs_flow.yaml > > > @@ -727,6 +727,12 @@ attribute-sets: > > > name: dec-ttl > > > type: nest > > > nested-attributes: dec-ttl-attrs > > > + - > > > + name: psample > > > + type: nest > > > + nested-attributes: psample-attrs > > > + doc: | > > > + Sends a packet sample to psample for external observation. > > > - > > > name: tunnel-key-attrs > > > enum-name: ovs-tunnel-key-attr > > > @@ -938,6 +944,17 @@ attribute-sets: > > > - > > > name: gbp > > > type: u32 > > > + - > > > + name: psample-attrs > > > + enum-name: ovs-psample-attr > > > + name-prefix: ovs-psample-attr- > > > + attributes: > > > + - > > > + name: group > > > + type: u32 > > > + - > > > + name: cookie > > > + type: binary > > > > > > operations: > > > name-prefix: ovs-flow-cmd- > > > diff --git a/include/uapi/linux/openvswitch.h > > > b/include/uapi/linux/openvswitch.h > > > index efc82c318fa2..3dd653748725 100644 > > > --- a/include/uapi/linux/openvswitch.h > > > +++ b/include/uapi/linux/openvswitch.h > > > @@ -914,6 +914,31 @@ struct check_pkt_len_arg { > > > }; > > > #endif > > > > > > +#define OVS_PSAMPLE_COOKIE_MAX_SIZE 16 > > > +/** > > > + * enum ovs_psample_attr - Attributes for %OVS_ACTION_ATTR_PSAMPLE > > > + * action. > > > + * > > > + * @OVS_PSAMPLE_ATTR_GROUP: 32-bit number to identify the source of the > > > + * sample. > > > + * @OVS_PSAMPLE_ATTR_COOKIE: An optional variable-length binary cookie > > > that > > > + * contains user-defined metadata. The maximum length is > > > + * OVS_PSAMPLE_COOKIE_MAX_SIZE bytes. > > > + * > > > + * Sends the packet to the psample multicast group with the specified > > > group and > > > + * cookie. It is possible to combine this action with the > > > + * %OVS_ACTION_ATTR_TRUNC action to limit the size of the sample. > > > + */ > > > +enum ovs_psample_attr { > > > + OVS_PSAMPLE_ATTR_GROUP = 1, /* u32 number. */ > > > + OVS_PSAMPLE_ATTR_COOKIE, /* Optional, user specified cookie. */ > > > + > > > + /* private: */ > > > + __OVS_PSAMPLE_ATTR_MAX > > > +}; > > > + > > > +#define OVS_PSAMPLE_ATTR_MAX (__OVS_PSAMPLE_ATTR_MAX - 1) > > > + > > > /** > > > * enum ovs_action_attr - Action types. > > > * > > > @@ -966,6 +991,8 @@ struct check_pkt_len_arg { > > > * of l3 tunnel flag in the tun_flags field of OVS_ACTION_ATTR_ADD_MPLS > > > * argument. > > > * @OVS_ACTION_ATTR_DROP: Explicit drop action. > > > + * @OVS_ACTION_ATTR_PSAMPLE: Send a sample of the packet to external > > > observers > > > + * via psample. > > > * > > > * Only a single header can be set with a single %OVS_ACTION_ATTR_SET. > > > Not all > > > * fields within a header are modifiable, e.g. the IPv4 protocol and > > > fragment > > > @@ -1004,6 +1031,7 @@ enum ovs_action_attr { > > > OVS_ACTION_ATTR_ADD_MPLS, /* struct ovs_action_add_mpls. */ > > > OVS_ACTION_ATTR_DEC_TTL, /* Nested OVS_DEC_TTL_ATTR_*. */ > > > OVS_ACTION_ATTR_DROP, /* u32 error code. */ > > > + OVS_ACTION_ATTR_PSAMPLE, /* Nested OVS_PSAMPLE_ATTR_*. */ > > > > > > __OVS_ACTION_ATTR_MAX, /* Nothing past this will be accepted > > > * from userspace. */ > > > diff --git a/net/openvswitch/Kconfig b/net/openvswitch/Kconfig > > > index 29a7081858cd..2535f3f9f462 100644 > > > --- a/net/openvswitch/Kconfig > > > +++ b/net/openvswitch/Kconfig > > > @@ -10,6 +10,7 @@ config OPENVSWITCH > > > (NF_CONNTRACK && ((!NF_DEFRAG_IPV6 || NF_DEFRAG_IPV6) && \ > > > (!NF_NAT || NF_NAT) && \ > > > (!NETFILTER_CONNCOUNT || > > > NETFILTER_CONNCOUNT))) > > > + depends on PSAMPLE || !PSAMPLE > > > select LIBCRC32C > > > select MPLS > > > select NET_MPLS_GSO > > > diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c > > > index 964225580824..a035b7e677dd 100644 > > > --- a/net/openvswitch/actions.c > > > +++ b/net/openvswitch/actions.c > > > @@ -24,6 +24,11 @@ > > > #include <net/checksum.h> > > > #include <net/dsfield.h> > > > #include <net/mpls.h> > > > + > > > +#if IS_ENABLED(CONFIG_PSAMPLE) > > > +#include <net/psample.h> > > > +#endif > > > + > > > #include <net/sctp/checksum.h> > > > > > > #include "datapath.h" > > > @@ -1299,6 +1304,39 @@ static int execute_dec_ttl(struct sk_buff *skb, > > > struct sw_flow_key *key) > > > return 0; > > > } > > > > > > +#if IS_ENABLED(CONFIG_PSAMPLE) > > > +static void execute_psample(struct datapath *dp, struct sk_buff *skb, > > > + const struct nlattr *attr) > > > +{ > > > + struct psample_group psample_group = {}; > > > + struct psample_metadata md = {}; > > > + const struct nlattr *a; > > > + int rem; > > > + > > > + nla_for_each_attr(a, nla_data(attr), nla_len(attr), rem) { > > > + switch (nla_type(a)) { > > > + case OVS_PSAMPLE_ATTR_GROUP: > > > + psample_group.group_num = nla_get_u32(a); > > > + break; > > > + > > > + case OVS_PSAMPLE_ATTR_COOKIE: > > > + md.user_cookie = nla_data(a); > > > + md.user_cookie_len = nla_len(a); > > > + break; > > > + } > > > + } > > > + > > > + psample_group.net = ovs_dp_get_net(dp); > > > + md.in_ifindex = OVS_CB(skb)->input_vport->dev->ifindex; > > > + md.trunc_size = skb->len - OVS_CB(skb)->cutlen; > > > + > > > + psample_sample_packet(&psample_group, skb, 0, &md); > > > +} > > > +#else > > > +static inline void execute_psample(struct datapath *dp, struct sk_buff > > > *skb, > > > + const struct nlattr *attr) {} > > > > I noticed that this got flagged in patchwork since it is 'static inline' > > while being part of a complete translation unit - but I also see some > > other places where that has been done. I guess it should be just > > 'static' though. I don't feel very strongly about it. > > > > We had a bit of discussion about this with Ilya. It seems "static > inline" is a common pattern around the kernel. The coding style > documentation says: > "Generally, inline functions are preferable to macros resembling functions." > > So I think this "inline" is correct but I might be missing something. > > > > +#endif > > > + > > > /* Execute a list of actions against 'skb'. */ > > > static int do_execute_actions(struct datapath *dp, struct sk_buff *skb, > > > struct sw_flow_key *key, > > > @@ -1502,6 +1540,15 @@ static int do_execute_actions(struct datapath *dp, > > > struct sk_buff *skb, > > > ovs_kfree_skb_reason(skb, reason); > > > return 0; > > > } > > > + > > > + case OVS_ACTION_ATTR_PSAMPLE: > > > + execute_psample(dp, skb, a); > > > + OVS_CB(skb)->cutlen = 0; > > > > We may want to document that trunc is also impacted by psample calls. > > Right now, it is only mentioned for a single OUTPUT action. > > Alternatively, we could either ignore trunc, or not reset here. > > The uAPI header says: > > " > Sends the packet to the psample multicast group with the specified group and > cookie. It is possible to combine this action with the > %OVS_ACTION_ATTR_TRUNC action to limit the size of the sample. > " > > Isn't this enough? What else would you add to make it even more clear? >
BTW trunc also affects userspace and it's not explicitly documented. > > > > > + if (nla_is_last(a, rem)) { > > > + consume_skb(skb); > > > + return 0; > > > + } > > > + break; > > > } > > > > > > if (unlikely(err)) { > > > diff --git a/net/openvswitch/flow_netlink.c > > > b/net/openvswitch/flow_netlink.c > > > index f224d9bcea5e..c92bdc4dfe19 100644 > > > --- a/net/openvswitch/flow_netlink.c > > > +++ b/net/openvswitch/flow_netlink.c > > > @@ -64,6 +64,7 @@ static bool actions_may_change_flow(const struct nlattr > > > *actions) > > > case OVS_ACTION_ATTR_TRUNC: > > > case OVS_ACTION_ATTR_USERSPACE: > > > case OVS_ACTION_ATTR_DROP: > > > + case OVS_ACTION_ATTR_PSAMPLE: > > > break; > > > > > > case OVS_ACTION_ATTR_CT: > > > @@ -2409,7 +2410,7 @@ static void ovs_nla_free_nested_actions(const > > > struct nlattr *actions, int len) > > > /* Whenever new actions are added, the need to update this > > > * function should be considered. > > > */ > > > - BUILD_BUG_ON(OVS_ACTION_ATTR_MAX != 24); > > > + BUILD_BUG_ON(OVS_ACTION_ATTR_MAX != 25); > > > > > > if (!actions) > > > return; > > > @@ -3157,6 +3158,28 @@ static int validate_and_copy_check_pkt_len(struct > > > net *net, > > > return 0; > > > } > > > > > > +static int validate_psample(const struct nlattr *attr) > > > +{ > > > + static const struct nla_policy policy[OVS_PSAMPLE_ATTR_MAX + 1] = { > > > + [OVS_PSAMPLE_ATTR_GROUP] = { .type = NLA_U32 }, > > > + [OVS_PSAMPLE_ATTR_COOKIE] = { > > > + .type = NLA_BINARY, > > > + .len = OVS_PSAMPLE_COOKIE_MAX_SIZE, > > > + }, > > > + }; > > > + struct nlattr *a[OVS_PSAMPLE_ATTR_MAX + 1]; > > > + int err; > > > + > > > + if (!IS_ENABLED(CONFIG_PSAMPLE)) > > > + return -EOPNOTSUPP; > > > + > > > + err = nla_parse_nested(a, OVS_PSAMPLE_ATTR_MAX, attr, policy, NULL); > > > + if (err) > > > + return err; > > > + > > > + return a[OVS_PSAMPLE_ATTR_GROUP] ? 0 : -EINVAL; > > > +} > > > + > > > static int copy_action(const struct nlattr *from, > > > struct sw_flow_actions **sfa, bool log) > > > { > > > @@ -3212,6 +3235,7 @@ static int __ovs_nla_copy_actions(struct net *net, > > > const struct nlattr *attr, > > > [OVS_ACTION_ATTR_ADD_MPLS] = sizeof(struct > > > ovs_action_add_mpls), > > > [OVS_ACTION_ATTR_DEC_TTL] = (u32)-1, > > > [OVS_ACTION_ATTR_DROP] = sizeof(u32), > > > + [OVS_ACTION_ATTR_PSAMPLE] = (u32)-1, > > > }; > > > const struct ovs_action_push_vlan *vlan; > > > int type = nla_type(a); > > > @@ -3490,6 +3514,12 @@ static int __ovs_nla_copy_actions(struct net *net, > > > const struct nlattr *attr, > > > return -EINVAL; > > > break; > > > > > > + case OVS_ACTION_ATTR_PSAMPLE: > > > + err = validate_psample(a); > > > + if (err) > > > + return err; > > > + break; > > > + > > > default: > > > OVS_NLERR(log, "Unknown Action type %d", type); > > > return -EINVAL; > > _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev