xref: /freebsd/share/man/man4/ng_checksum.4 (revision 5dae51da3da0cc94d17bd67b308fad304ebec7e0)
1.\" Copyright (c) 2015 Dmitry Vagin <daemon.hammer@ya.ru>
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25.\" $FreeBSD$
26.\"
27.Dd October 29, 2015
28.Dt NG_CHECKSUM 4
29.Os
30.Sh NAME
31.Nm ng_checksum
32.Nd IP checksum node type
33.Sh SYNOPSIS
34.In netgraph/ng_checksum.h
35.Sh DESCRIPTION
36The
37.Nm checksum
38node can calculate and prepare for calculation in hardware
39IPv4 header, TCP, UDP checksum.
40.Sh HOOKS
41This node type has two hooks:
42.Bl -tag -width ".Va out"
43.It Va in
44Packets received on this hook are processed according to settings specified
45in config and then forwarded to
46.Ar out
47hook, if it exists and connected. Otherwise they are reflected back to the
48.Ar in
49hook.
50.It Va out
51Packets received on this hook are forwarded to
52.Ar in
53hook without any changes.
54.El
55.Sh CONTROL MESSAGES
56This node type supports the generic control messages, plus the following:
57.Bl -tag -width foo
58.It Dv NGM_CHECKSUM_SETDLT Pq Ic setdlt
59Sets data link type on the
60.Va in
61hook. Currently, supported types are
62.Cm DLT_RAW
63(raw IP datagrams) and
64.Cm DLT_EN10MB
65(Ethernet). DLT_ definitions can be found in
66.In net/bpf.h
67header. Currently used values are
68.Cm DLT_EN10MB
69= 1 and
70.Cm DLT_RAW
71= 12.
72.It Dv NGM_CHECKSUM_GETDLT Pq Ic getdlt
73This control message obtains data link type on the
74.Va in
75hook.
76.It Dv NGM_CHECKSUM_SETCONFIG Pq Ic setconfig
77Sets node configuration. The following
78.Vt "struct ng_checksum_config"
79must be supplied as an argument:
80.Bd -literal -offset 4n
81struct ng_checksum_config {
82	uint64_t	csum_flags;
83	uint64_t	csum_offload;
84};
85.Ed
86.Pp
87The
88.Va csum_flags
89can be set to any combination of CSUM_IP, CSUM_TCP, CSUM_UDP, CSUM_TCP_IPV6 and CSUM_UDP_IPV6
90(other values are ignored) for instructing node need calculate the corresponding checksum.
91.Pp
92The
93.Va csum_offload
94can be set to any combination of CSUM_IP, CSUM_TCP, CSUM_UDP, CSUM_TCP_IPV6 and CSUM_UDP_IPV6
95(other values are ignored) for instructing node what checksum can calculate in hardware.
96.Pp
97Also processed any combination of CSUM_IP, CSUM_TCP, CSUM_UDP, CSUM_TCP_IPV6 and CSUM_UDP_IPV6 sets before on mbuf.
98.It Dv NGM_CHECKSUM_GETCONFIG Pq Ic getconfig
99This control message obtains current node configuration,
100returned as
101.Vt "struct ng_checksum_config" .
102.It Dv NGM_CHECKSUM_GET_STATS Pq Ic getstats
103Returns node statistics as a
104.Vt "struct ng_checksum_stats" .
105.It Dv NGM_CHECKSUM_CLR_STATS Pq Ic clrstats
106Clear node statistics.
107.It Dv NGM_CHECKSUM_GETCLR_STATS Pq Ic getclrstats
108This command is identical to
109.Dv NGM_CHECKSUM_GET_STATS ,
110except that the statistics are also atomically cleared.
111.El
112.Sh SHUTDOWN
113This node shuts down upon receipt of a
114.Dv NGM_SHUTDOWN
115control message, or when all hooks have been disconnected.
116.Sh EXAMPLES
117.Xr ngctl 8
118script:
119.Bd -literal -offset 4n
120/usr/sbin/ngctl -f- <<-SEQ
121	msg checksum-1: "setdlt 1"
122	ngctl msg checksum-1: "setconfig { csum_flags=0 csum_offload=6 }"
123.Ed
124.Pp
125Set data link type to
126.Cm DLT_EN10MB
127(Ethernet), not set additional checksum flags, set hardware
128can calculate CSUM_IP_UDP|CSUM_IP_TCP.
129.Sh SEE ALSO
130.Xr netgraph 4 ,
131.Xr ng_patch 4 ,
132.Xr ngctl 8
133.Sh HISTORY
134The
135.Nm
136node type was implemented in
137.Fx 10.2
138and first submitted in
139.Fx 12.0 .
140.Sh AUTHORS
141.An "Dmitry Vagin" Aq daemon.hammer@ya.ru .
142