proto_media_preout

Declaration

typedef errno_t (*proto_media_preout)(ifnet_t ifp, protocol_family_t protocol, mbuf_t *packet, const struct sockaddr *dest, void *route, char *frame_type, char *link_layer_dest);

Parameters

• ifp:

  The interface the packet will be sent on.

• protocol_family:

  The protocol of the packet being sent (PF_INET/etc...).

• packet:

  The packet being sent.

• dest:

  The protocol level destination address.

• route:

  A pointer to the routing structure for the packet.

• frame_type:

  The media specific frame type.

• link_layer_dest:

  The media specific destination.

Return Value

If the result is zero, processing will continue normally. If the result is non-zero, processing will stop. If the result is non-zero and not EJUSTRETURN, the packet will be freed by the caller.

Discussion

proto_media_preout is called just before the packet is transmitted. This gives the proto_media_preout function an opportunity to specify the media specific frame type and destination.