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dmnetbridge API Reference

See dmnetbridge.md for the architecture and rationale behind this API's shape.

Send

Function	Description
`dmnetbridge_send(dst_ip, ethertype, payload, payload_len, arp_timeout_ms, out_iface)`	Route, resolve, frame and transmit `payload` to `dst_ip`. Returns `0`, `-EINVAL`, `-ENETUNREACH`, `-ENODEV`, `-EHOSTUNREACH`, `-ENOMEM`, or `-EIO`. `out_iface` is optional.
`dmnetbridge_send_on_iface(iface, dst_ip, ethertype, payload, payload_len, arp_timeout_ms)`	Like `dmnetbridge_send()`, but treats `dst_ip` as on-link on `iface` (next-hop = `dst_ip`) instead of calling `dmroute_lookup()` - use when the caller already knows the interface and there may be no route yet (e.g. a DHCP client's pre-lease broadcast). Returns `0` or a negative errno.
`dmnetbridge_get_source_address(dst, out_src)`	The source address `dmnetbridge_send()` would use to reach `dst` (egress interface's own IP).
`dmnetbridge_get_mtu(dst, out_mtu)`	The MTU `dmnetbridge_send()` would transmit through to reach `dst`. `*out_mtu` is left untouched on failure.

Receive

Function	Description
`dmnetbridge_handle_netif_rx(iface)`	Blocking pump loop for one interface - reads frames and dispatches them (`dmarp_note_frame()` + every `packet_received` DIF implementor) until the interface is gone. Run one per interface, in its own thread.
`packet_received(iface, frame, frame_len)` (DIF)	Declared here, implemented by `dmip`. Delivers one raw received frame to an interested protocol module.

Lifecycle

Function	Description
`dmnetbridge_reset(void)`	Clears dmnetbridge's own "which interfaces are being pumped" bookkeeping - call before spawning pump threads on a (re)start.

All addresses use dmroute_addr_t from dmroute; interfaces use dmnetif_iface_t from dmnetif.