Add support for a new action: emit_sample. 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. Signed-off-by: Adrian Moreno <amore...@redhat.com> --- Documentation/netlink/specs/ovs_flow.yaml | 17 ++++++++ include/uapi/linux/openvswitch.h | 25 ++++++++++++ net/openvswitch/actions.c | 50 +++++++++++++++++++++++ net/openvswitch/flow_netlink.c | 33 ++++++++++++++- 4 files changed, 124 insertions(+), 1 deletion(-) diff --git a/Documentation/netlink/specs/ovs_flow.yaml b/Documentation/netlink/specs/ovs_flow.yaml index 4fdfc6b5cae9..a7ab5593a24f 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: emit-sample + type: nest + nested-attributes: emit-sample-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: emit-sample-attrs + enum-name: ovs-emit-sample-attr + name-prefix: ovs-emit-sample-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..a0e9dde0584a 100644 --- a/include/uapi/linux/openvswitch.h +++ b/include/uapi/linux/openvswitch.h @@ -914,6 +914,30 @@ struct check_pkt_len_arg { }; #endif +#define OVS_EMIT_SAMPLE_COOKIE_MAX_SIZE 16 +/** + * enum ovs_emit_sample_attr - Attributes for %OVS_ACTION_ATTR_EMIT_SAMPLE + * action. + * + * @OVS_EMIT_SAMPLE_ATTR_GROUP: 32-bit number to identify the source of the + * sample. + * @OVS_EMIT_SAMPLE_ATTR_COOKIE: A variable-length binary cookie that contains + * user-defined metadata. The maximum length is 16 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 packet being emitted. + */ +enum ovs_emit_sample_attr { + OVS_EMIT_SAMPLE_ATTR_UNPSEC, + OVS_EMIT_SAMPLE_ATTR_GROUP, /* u32 number. */ + OVS_EMIT_SAMPLE_ATTR_COOKIE, /* Optional, user specified cookie. */ + __OVS_EMIT_SAMPLE_ATTR_MAX +}; + +#define OVS_EMIT_SAMPLE_ATTR_MAX (__OVS_EMIT_SAMPLE_ATTR_MAX - 1) + + /** * enum ovs_action_attr - Action types. * @@ -1004,6 +1028,7 @@ 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_EMIT_SAMPLE, /* Nested OVS_EMIT_SAMPLE_ATTR_*. */ __OVS_ACTION_ATTR_MAX, /* Nothing past this will be accepted * from userspace. */ diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c index 964225580824..3b4dba0ded59 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 +1304,46 @@ static int execute_dec_ttl(struct sk_buff *skb, struct sw_flow_key *key) return 0; } +static int execute_emit_sample(struct datapath *dp, struct sk_buff *skb, + const struct sw_flow_key *key, + const struct nlattr *attr) +{ +#if IS_ENABLED(CONFIG_PSAMPLE) + struct psample_group psample_group = {}; + struct psample_metadata md = {}; + struct vport *input_vport; + const struct nlattr *a; + int rem; + + for (a = nla_data(attr), rem = nla_len(attr); rem > 0; + a = nla_next(a, &rem)) { + switch (nla_type(a)) { + case OVS_EMIT_SAMPLE_ATTR_GROUP: + psample_group.group_num = nla_get_u32(a); + break; + + case OVS_EMIT_SAMPLE_ATTR_COOKIE: + md.user_cookie = nla_data(a); + md.user_cookie_len = nla_len(a); + break; + } + } + + psample_group.net = ovs_dp_get_net(dp); + + input_vport = ovs_vport_rcu(dp, key->phy.in_port); + if (!input_vport) + input_vport = ovs_vport_rcu(dp, OVSP_LOCAL); + + md.in_ifindex = input_vport->dev->ifindex; + md.trunc_size = skb->len - OVS_CB(skb)->cutlen; + + psample_sample_packet(&psample_group, skb, 0, &md); +#endif + + return 0; +} + /* 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 +1547,11 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb, ovs_kfree_skb_reason(skb, reason); return 0; } + + case OVS_ACTION_ATTR_EMIT_SAMPLE: + err = execute_emit_sample(dp, skb, key, a); + OVS_CB(skb)->cutlen = 0; + break; } if (unlikely(err)) { diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c index f224d9bcea5e..eb59ff9c8154 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_EMIT_SAMPLE: 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 +3158,29 @@ static int validate_and_copy_check_pkt_len(struct net *net, return 0; } +static int validate_emit_sample(const struct nlattr *attr) +{ + static const struct nla_policy policy[OVS_EMIT_SAMPLE_ATTR_MAX + 1] = { + [OVS_EMIT_SAMPLE_ATTR_GROUP] = { .type = NLA_U32 }, + [OVS_EMIT_SAMPLE_ATTR_COOKIE] = { + .type = NLA_BINARY, + .len = OVS_EMIT_SAMPLE_COOKIE_MAX_SIZE + }, + }; + struct nlattr *a[OVS_EMIT_SAMPLE_ATTR_MAX + 1]; + int err; + + if (!IS_ENABLED(CONFIG_PSAMPLE)) + return -EOPNOTSUPP; + + err = nla_parse_nested(a, OVS_EMIT_SAMPLE_ATTR_MAX, attr, policy, + NULL); + if (err) + return err; + + return a[OVS_EMIT_SAMPLE_ATTR_GROUP] ? 0 : -EINVAL; +} + static int copy_action(const struct nlattr *from, struct sw_flow_actions **sfa, bool log) { @@ -3212,6 +3236,7 @@ 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_EMIT_SAMPLE] = (u32)-1, }; const struct ovs_action_push_vlan *vlan; int type = nla_type(a); @@ -3490,6 +3515,12 @@ static int __ovs_nla_copy_actions(struct net *net, const struct nlattr *attr, return -EINVAL; break; + case OVS_ACTION_ATTR_EMIT_SAMPLE: + err = validate_emit_sample(a); + if (err) + return err; + break; + default: OVS_NLERR(log, "Unknown Action type %d", type); return -EINVAL; -- 2.45.1 _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev