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.Dd October 29, 2015 26.Dt NG_CHECKSUM 4 27.Os 28.Sh NAME 29.Nm ng_checksum 30.Nd reconstructing IP checksums node type 31.Sh SYNOPSIS 32.In netgraph/ng_checksum.h 33.Sh DESCRIPTION 34The 35.Nm checksum 36node can calculate, or prepare for calculation in hardware, 37IPv4 header, TCP and UDP checksums. 38.Sh HOOKS 39This node type has two hooks: 40.Bl -tag -width ".Va out" 41.It Va in 42Packets received on this hook are processed according to settings specified 43in config and then forwarded to the 44.Ar out 45hook, if it exists and is connected. 46Otherwise they are reflected back to the 47.Ar in 48hook. 49.It Va out 50Packets received on this hook are forwarded to the 51.Ar in 52hook without any changes. 53.El 54.Sh CONTROL MESSAGES 55This node type supports the generic control messages, plus the following: 56.Bl -tag -width foo 57.It Dv NGM_CHECKSUM_SETDLT Pq Ic setdlt 58Sets the data link type on the 59.Va in 60hook. 61Currently, supported types are 62.Cm DLT_RAW 63(raw IP datagrams) and 64.Cm DLT_EN10MB 65(Ethernet). DLT_ definitions can be found in the 66.In net/bpf.h 67header. 68Currently used values are 69.Cm DLT_EN10MB 70= 1 and 71.Cm DLT_RAW 72= 12. 73.It Dv NGM_CHECKSUM_GETDLT Pq Ic getdlt 74This control message obtains the data link type on the 75.Va in 76hook. 77.It Dv NGM_CHECKSUM_SETCONFIG Pq Ic setconfig 78Sets the node configuration. 79The following 80.Vt "struct ng_checksum_config" 81must be supplied as an argument: 82.Bd -literal -offset 4n 83struct ng_checksum_config { 84 uint64_t csum_flags; 85 uint64_t csum_offload; 86}; 87.Ed 88.Pp 89The 90.Va csum_flags 91can be set to any combination of CSUM_IP, CSUM_TCP, CSUM_UDP, CSUM_TCP_IPV6 and CSUM_UDP_IPV6 92(other values are ignored) for instructing the node to calculate the corresponding checksum. 93.Pp 94The 95.Va csum_offload 96value can be set to any combination of CSUM_IP, CSUM_TCP, CSUM_UDP, CSUM_TCP_IPV6 and CSUM_UDP_IPV6 97(other values are ignored) for instructing the node what checksums should be requested from the hardware. 98.Pp 99The node also takes into account any combination of 100CSUM_IP, CSUM_TCP, CSUM_UDP, CSUM_TCP_IPV6 and CSUM_UDP_IPV6 already 101flagged on the mbuf. 102.It Dv NGM_CHECKSUM_GETCONFIG Pq Ic getconfig 103This control message obtains the current node configuration returned as a 104.Vt "struct ng_checksum_config" . 105.It Dv NGM_CHECKSUM_GET_STATS Pq Ic getstats 106Returns node statistics as a 107.Vt "struct ng_checksum_stats" . 108.It Dv NGM_CHECKSUM_CLR_STATS Pq Ic clrstats 109Clear the node statistics. 110.It Dv NGM_CHECKSUM_GETCLR_STATS Pq Ic getclrstats 111This command is identical to 112.Dv NGM_CHECKSUM_GET_STATS , 113except that the statistics are also atomically cleared. 114.El 115.Sh SHUTDOWN 116This node shuts down upon receipt of a 117.Dv NGM_SHUTDOWN 118control message, or when all hooks have been disconnected. 119.Sh EXAMPLES 120.Xr ngctl 8 121script: 122.Bd -literal -offset 4n 123/usr/sbin/ngctl -f- <<-SEQ 124 msg checksum-1: setdlt 1 125 msg checksum-1: setconfig { csum_flags=0 csum_offload=6 } 126SEQ 127.Ed 128.Pp 129Set the data link type to 130.Cm DLT_EN10MB 131(Ethernet), do not set additional checksum flags 132and request that the hardware calculate CSUM_IP_UDP|CSUM_IP_TCP. 133.Sh SEE ALSO 134.Xr netgraph 4 , 135.Xr ng_patch 4 , 136.Xr ngctl 8 137.Sh HISTORY 138The 139.Nm 140node type was implemented in 141.Fx 10.2 142and first submitted in 143.Fx 12.0 . 144.Sh AUTHORS 145.An "Dmitry Vagin" Aq daemon.hammer@ya.ru . 146