1.\" Copyright (c) 2015 Dmitry Vagin <daemon.hammer@ya.ru> 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd October 29, 2015 28.Dt NG_CHECKSUM 4 29.Os 30.Sh NAME 31.Nm ng_checksum 32.Nd reconstructing IP checksums node type 33.Sh SYNOPSIS 34.In netgraph/ng_checksum.h 35.Sh DESCRIPTION 36The 37.Nm checksum 38node can calculate, or prepare for calculation in hardware, 39IPv4 header, TCP and UDP checksums. 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 the 46.Ar out 47hook, if it exists and is connected. 48Otherwise they are reflected back to the 49.Ar in 50hook. 51.It Va out 52Packets received on this hook are forwarded to the 53.Ar in 54hook without any changes. 55.El 56.Sh CONTROL MESSAGES 57This node type supports the generic control messages, plus the following: 58.Bl -tag -width foo 59.It Dv NGM_CHECKSUM_SETDLT Pq Ic setdlt 60Sets the data link type on the 61.Va in 62hook. 63Currently, supported types are 64.Cm DLT_RAW 65(raw IP datagrams) and 66.Cm DLT_EN10MB 67(Ethernet). DLT_ definitions can be found in the 68.In net/bpf.h 69header. 70Currently used values are 71.Cm DLT_EN10MB 72= 1 and 73.Cm DLT_RAW 74= 12. 75.It Dv NGM_CHECKSUM_GETDLT Pq Ic getdlt 76This control message obtains the data link type on the 77.Va in 78hook. 79.It Dv NGM_CHECKSUM_SETCONFIG Pq Ic setconfig 80Sets the node configuration. 81The following 82.Vt "struct ng_checksum_config" 83must be supplied as an argument: 84.Bd -literal -offset 4n 85struct ng_checksum_config { 86 uint64_t csum_flags; 87 uint64_t csum_offload; 88}; 89.Ed 90.Pp 91The 92.Va csum_flags 93can be set to any combination of CSUM_IP, CSUM_TCP, CSUM_UDP, CSUM_TCP_IPV6 and CSUM_UDP_IPV6 94(other values are ignored) for instructing the node to calculate the corresponding checksum. 95.Pp 96The 97.Va csum_offload 98value can be set to any combination of CSUM_IP, CSUM_TCP, CSUM_UDP, CSUM_TCP_IPV6 and CSUM_UDP_IPV6 99(other values are ignored) for instructing the node what checksums should be requested from the hardware. 100.Pp 101The node also takes into account any combination of 102CSUM_IP, CSUM_TCP, CSUM_UDP, CSUM_TCP_IPV6 and CSUM_UDP_IPV6 already 103flagged on the mbuf. 104.It Dv NGM_CHECKSUM_GETCONFIG Pq Ic getconfig 105This control message obtains the current node configuration returned as a 106.Vt "struct ng_checksum_config" . 107.It Dv NGM_CHECKSUM_GET_STATS Pq Ic getstats 108Returns node statistics as a 109.Vt "struct ng_checksum_stats" . 110.It Dv NGM_CHECKSUM_CLR_STATS Pq Ic clrstats 111Clear the node statistics. 112.It Dv NGM_CHECKSUM_GETCLR_STATS Pq Ic getclrstats 113This command is identical to 114.Dv NGM_CHECKSUM_GET_STATS , 115except that the statistics are also atomically cleared. 116.El 117.Sh SHUTDOWN 118This node shuts down upon receipt of a 119.Dv NGM_SHUTDOWN 120control message, or when all hooks have been disconnected. 121.Sh EXAMPLES 122.Xr ngctl 8 123script: 124.Bd -literal -offset 4n 125/usr/sbin/ngctl -f- <<-SEQ 126 msg checksum-1: setdlt 1 127 msg checksum-1: setconfig { csum_flags=0 csum_offload=6 } 128SEQ 129.Ed 130.Pp 131Set the data link type to 132.Cm DLT_EN10MB 133(Ethernet), do not set additional checksum flags 134and request that the hardware calculate CSUM_IP_UDP|CSUM_IP_TCP. 135.Sh SEE ALSO 136.Xr netgraph 4 , 137.Xr ng_patch 4 , 138.Xr ngctl 8 139.Sh HISTORY 140The 141.Nm 142node type was implemented in 143.Fx 10.2 144and first submitted in 145.Fx 12.0 . 146.Sh AUTHORS 147.An "Dmitry Vagin" Aq daemon.hammer@ya.ru . 148