ENUM OVS_PACKET_ATTR(9)

💅 enum ovs_packet_attr — the Kernel API Manual moment ✨

okay so bestie, welcome to the enum ovs_packet_attr(9) page — it's the one all about the attributes for %OVS_PACKET_* commands. lowkey iconic, highkey essential. let's get into it 🫶

🌸 SYNOPSIS 🌸

enum ovs_packet_attr {
    OVS_PACKET_ATTR_PACKET ,
    OVS_PACKET_ATTR_KEY ,
    OVS_PACKET_ATTR_ACTIONS ,
    OVS_PACKET_ATTR_USERDATA ,
    OVS_PACKET_ATTR_EGRESS_TUN_KEY ,
    OVS_PACKET_ATTR_PROBE ,
    OVS_PACKET_ATTR_MRU ,
    OVS_PACKET_ATTR_LEN ,
    OVS_PACKET_ATTR_HASH ,
    OVS_PACKET_ATTR_UPCALL_PID

};

🎀 Constants 🎀

• OVS_PACKET_ATTR_PACKET — the main character 💫 present for all notifications, no cap. it holds the entire packet as received, from the start of the Ethernet header onward. and like, for OVS_PACKET_CMD_ACTION, OVS_PACKET_ATTR_PACKET reflects changes made by actions preceding OVS_ACTION_ATTR_USERSPACE, but OVS_PACKET_ATTR_KEY is the flow key extracted from the packet as originally received. so they're giving two different energies, periodt.
• OVS_PACKET_ATTR_KEY — also present for all notifications 🗝️ contains the flow key extracted from the packet as nested OVS_KEY_ATTR_* attributes. this lets userspace adapt its flow setup strategy by comparing its notion of the flow key against the kernel's. it's giving vibe check between userspace and kernel, iykyk.
• OVS_PACKET_ATTR_ACTIONS — contains actions for the packet 🎬 used for OVS_PACKET_CMD_EXECUTE, and it has nested OVS_ACTION_ATTR_* attributes. also used in upcall when OVS_ACTION_ATTR_USERSPACE has the optional OVS_USERSPACE_ATTR_ACTIONS attribute. multitasking queen.
• OVS_PACKET_ATTR_USERDATA — present for an OVS_PACKET_CMD_ACTION notification if the OVS_ACTION_ATTR_USERSPACE action specified an OVS_USERSPACE_ATTR_USERDATA attribute, with the same length and content specified there 🍓 literally same length, same content, matching set.
• OVS_PACKET_ATTR_EGRESS_TUN_KEY — present for an OVS_PACKET_CMD_ACTION notification if the OVS_ACTION_ATTR_USERSPACE action specified an OVS_USERSPACE_ATTR_EGRESS_TUN_PORT attribute — which is sent only if the output port is actually a tunnel port 🚇 contains the output tunnel key extracted from the packet as nested OVS_TUNNEL_KEY_ATTR_* attributes. conditional queen.
• OVS_PACKET_ATTR_PROBE — packet operation is a feature probe 🔍 just out here checking the vibes.
• OVS_PACKET_ATTR_MRU — present for an OVS_PACKET_CMD_ACTION and
• OVS_PACKET_ATTR_LEN — packet size before truncation 📏 the OVS_PACKET_ATTR_USERSPACE action specify the Maximum received fragment size.
• OVS_PACKET_ATTR_HASH — packet hash info (e.g. hash, sw_hash and l4_hash in skb) 🔥
• OVS_PACKET_ATTR_UPCALL_PID — Netlink PID to use for upcalls while processing OVS_PACKET_CMD_EXECUTE 👑 takes precedence over all other ways to determine the Netlink PID, including OVS_USERSPACE_ATTR_PID, OVS_DP_ATTR_UPCALL_PID, OVS_DP_ATTR_PER_CPU_PIDS and the OVS_VPORT_ATTR_UPCALL_PID. main character energy fr fr, everybody else is supporting cast.

🦋 Description 🦋

these attributes follow the struct ovs_header within the Generic Netlink payload for OVS_PACKET_* commands 💖 so like, they know their place and their place is right after struct ovs_header.

✨ SEE ALSO ✨

• Kernel file ./include/uapi/linux/openvswitch.h
• struct ovs_header(9)
• enum ovs_datapath_attr(9)
• enum ovs_vport_type(9)
• enum ovs_vport_attr(9)
• enum ovs_vport_upcall_attr(9)
• enum ovs_frag_type(9)
• enum ovs_flow_attr(9)
• enum ovs_sample_attr(9)
• enum ovs_userspace_attr(9)
• struct ovs_action_push_mpls(9)
• struct ovs_action_add_mpls(9)
• struct ovs_action_push_vlan(9)
• enum ovs_ct_attr(9)
• enum ovs_nat_attr(9)
• struct ovs_action_push_eth(9)
• enum ovs_check_pkt_len_attr(9)
• enum ovs_psample_attr(9)
• enum ovs_action_attr(9)

and that's the whole page, bestie, you ate that 💅 mwah 💋

sign-off szn: this lil masterpiece lives in ./include/uapi/linux, dated October 2026, and it's literally the enum ovs_packet_attr(9) page from the Kernel API Manual 🌈⭐ go forth and slay 🎀💜