batadv_mcast_forw_want_rtr(9)

📦 version 7.3.1, in nixpkgs unstable

💅 batadv_mcast_forw_want_rtr — Kernel API Manual realness

Okay so bestie, buckle up, because we're diving into batadv_mcast_forw_want_rtr from the Kernel API Manual, fr fr. This is a batman-adv multicast forwarding function and it's giving "quietly important" main character energy, iykyk. 🦋

✨ NAME ✨

batadv_mcast_forw_want_rtr — forward packet to nodes in a want-all-rtr list

No cap, that's literally the whole vibe. It forwards a packet to the nodes chillin' on the want-all-rtr list. 💖

🌸 SYNOPSIS 🌸

int batadv_mcast_forw_want_rtr (struct batadv_priv *bat_priv , struct
       sk_buff *skb , unsigned short vid );

Three args, one int coming back. Slay. ✨

🎀 ARGUMENTS 🎀

  • bat_priv — the bat priv with all the mesh interface information. Like, it's the whole registry of mesh interface tea. 👑
  • skb — the multicast packet to transmit. This is the actual cargo we're shipping out. 📦
  • vid — the vlan identifier. Yep, need to know which VLAN we're repping. 🏷️

🦋 DESCRIPTION 🦋

So here's what's happening: this function sends copies of a frame with a multicast destination to any node with a BATADV_MCAST_WANT_NO_RTR4 or BATADV_MCAST_WANT_NO_RTR6 flag unset. Read that again — unset. Those are the nodes that actually want it. 🙈

And the way it does it? A transmission is performed via a batman-adv unicast packet for each such destination node. One copy, one unicast packet, per node. Periodt. 💅

Not me making sure you caught the "unset" part — if the flag were set, they'd be saying "no thanks, I don't want the router stuff," and they wouldn't be getting a copy. Vibe check passed. ✅

🔥 RETURN 🔥

  • NET_XMIT_DROP — returned on memory allocation failure 😭, or if the protocol family is neither IPv4 nor IPv6. Like, if it's not one of those two, we're not doing it, bestie. 💀
  • NET_XMIT_SUCCESS — returned otherwise. That's the win. 🌈⭐

💜 SEE ALSO 💜

Kernel file ./net/batman-adv/multicast.c, plus this absolute constellation of friends:

Okay that's the page!! 🫶 This one came out of ./net/batman-adv in October 2026, and the whole thing is filed under batadv_mcast_forw_want_rtr(9) — go read the friends list, it's lowkey iconic. Go off, kernel docs. 👑✨

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