STRUCT EFX_NEIGH_BINDER(9)

💖 NAME 💖

struct efx_neigh_binder — driver state for a neighbour entry

okay so bestie, welcome to the Kernel API Manual, section 9 — this page is all about struct efx_neigh_binder, and we're gonna make it make sense 💅

✨ SYNOPSIS ✨

       struct efx_neigh_binder {
           struct net *net;
           __be32 dst_ip;
           struct in6_addr dst_ip6;
           char ha[ETH_ALEN];
           bool n_valid;
           rwlock_t lock;
           u8 ttl;
           bool dying;
           struct net_device *egdev;
           netdevice_tracker dev_tracker;
           netns_tracker ns_tracker;
           refcount_t ref;
           unsigned long used;
           struct list_head users;
           struct rhash_head linkage;
           struct work_struct work;
           struct efx_nic *efx;
        };

🫶 Members 🫶

• net — the network namespace in which this neigh resides
• dst_ip — the IPv4 destination address resolved by this neigh
• dst_ip6 — the IPv6 destination address resolved by this neigh
• ha — the hardware (Ethernet) address of the neighbour
• n_valid — true if the neighbour is in NUD_VALID state
• lock — protects ha and n_valid
• ttl — Time To Live associated with the route used
• dying — set when egdev is going away, to skip further updates
• egdev — egress device from the route lookup. Holds a reference (yes, that's literally the whole sentence — don't @ me 😭)
• dev_tracker — reference tracker entry for egdev
• ns_tracker — reference tracker entry for ns
• ref — counts encap actions referencing this entry
• used — jiffies of last time traffic hit any encap action using this. When counter reads update this, a new neighbour event is sent to indicate that the neighbour entry is still in use.
• users — list of struct efx_tc_encap_action
• linkage — entry in efx->neigh_ht (keys are net, dst_ip, dst_ip6).
• work — processes neighbour state changes, updates the encap actions
• efx — owning NIC instance.

🌸 DESCRIPTION 🌸

okay so picture this: struct efx_neigh_binder associates a neighbour entry with the encap actions that are interested in it, and that lets the latter get updated when the neighbour details change. That's the whole vibe. Whichever of dst_ip and dst_ip6 is not in use will be all-zeroes — and this distinguishes IPv4 from IPv6 entries. no cap, that all-zeroes check is the IPv4/IPv6 vibe check 🦋

🔥 SEE ALSO 🔥

go peek at the kernel file: ./drivers/net/ethernet/sfc/tc_encap_actions.h

made with 💖 from source/version ./drivers/net/ethernet/sfc, dated October 2026, for struct efx_neigh_binder(9) — bye bestie 🫶