xref: /openbsd/share/man/man9/ifiq_input.9 (revision 905646f0)
1.\" $OpenBSD: ifiq_input.9,v 1.3 2020/06/05 05:33:58 jmc Exp $
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3.\" Copyright (c) 2020 David Gwynne <dlg@openbsd.org>
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17.Dd $Mdocdate: June 5 2020 $
18.Dt IFIQ_INPUT 9
19.Os
20.Sh NAME
21.Nm ifiq_input ,
22.Nm ifiq_enqueue
23.Nd network interface input queue (ifiqueue) API
24.Sh SYNOPSIS
25.In net/if_var.h
26.Ft int
27.Fn ifiq_input "struct ifiqueue *ifiq" "struct mbuf_list *ml"
28.Ft void
29.Fn ifiq_enqueue "struct ifiqueue *ifiq" "struct mbuf *m"
30.Sh DESCRIPTION
31The network interface input queue (ifiqueue) API provides functions
32for network drivers to queue received packets for processing by the
33network stack.
34.Bl -tag -width Ds
35.It Fn ifiq_input "struct ifiqueue *ifq" "struct mbuf_list *ml"
36Enqueue the list of mbufs in
37.Fa ml
38on the
39.Fa ifiq
40interface input queue and notify the network stack to process them.
41If the queue rejects the packets they will be freed
42and counted as drops.
43.It Fn ifiq_enqueue "struct ifiqueue *ifq" "struct mbuf *m"
44Enqueue the mbuf
45.Fa m
46on the
47.Fa ifiq
48interface input queue and notify the network stack to process it.
49.El
50.Sh CONTEXT
51.Fn ifiq_input
52and
53.Fn ifiq_enqueue
54can be called during autoconf, from process context, or from interrupt context.
55.Sh RETURN VALUES
56.Fn ifiq_input
57returns a non-zero value if mbufs are queued too rapidly for the
58stack to process.
59If possible, the caller should attempt to reduce the number of mbufs
60being generated in the future.
61For example, if mbufs are being received from
62hardware managed with the interface RX ring API,
63.Xr if_rxr_livelocked 9
64can be called to indicate to the hardware that backpressure is required.
65.Sh SEE ALSO
66.Xr if_rxr_livelocked 9
67