From aae0b82b46cb5004bdf82a000c004d69a0885c33 Mon Sep 17 00:00:00 2001 From: Adrian Moreno Date: Thu, 4 Jul 2024 10:56:56 +0200 Subject: net: openvswitch: add psample action 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. Reviewed-by: Michal Kubiak Reviewed-by: Aaron Conole Reviewed-by: Ilya Maximets Acked-by: Eelco Chaudron Signed-off-by: Adrian Moreno Link: https://patch.msgid.link/20240704085710.353845-6-amorenoz@redhat.com Signed-off-by: Jakub Kicinski --- Documentation/netlink/specs/ovs_flow.yaml | 17 +++++++++++ include/uapi/linux/openvswitch.h | 28 ++++++++++++++++++ net/openvswitch/Kconfig | 1 + net/openvswitch/actions.c | 48 +++++++++++++++++++++++++++++++ net/openvswitch/flow_netlink.c | 32 ++++++++++++++++++++- 5 files changed, 125 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..892d7e48fc5b 100644 --- a/net/openvswitch/actions.c +++ b/net/openvswitch/actions.c @@ -24,6 +24,11 @@ #include #include #include + +#if IS_ENABLED(CONFIG_PSAMPLE) +#include +#endif + #include #include "datapath.h" @@ -1299,6 +1304,40 @@ 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 void execute_psample(struct datapath *dp, struct sk_buff *skb, + const struct nlattr *attr) +{} +#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 +1541,15 @@ 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; + 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; -- cgit v1.2.3-58-ga151