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32 .Nd reconstructing IP checksums node type
34 .In netgraph/ng_checksum.h
38 node can calculate, or prepare for calculation in hardware,
39 IPv4 header, TCP and UDP checksums.
41 This node type has two hooks:
42 .Bl -tag -width ".Va out"
44 Packets received on this hook are processed according to settings specified
45 in config and then forwarded to the
47 hook, if it exists and is connected.
48 Otherwise they are reflected back to the
52 Packets received on this hook are forwarded to the
54 hook without any changes.
57 This node type supports the generic control messages, plus the following:
59 .It Dv NGM_CHECKSUM_SETDLT Pq Ic setdlt
60 Sets the data link type on the
63 Currently, supported types are
65 (raw IP datagrams) and
67 (Ethernet). DLT_ definitions can be found in the
70 Currently used values are
75 .It Dv NGM_CHECKSUM_GETDLT Pq Ic getdlt
76 This control message obtains the data link type on the
79 .It Dv NGM_CHECKSUM_SETCONFIG Pq Ic setconfig
80 Sets the node configuration.
82 .Vt "struct ng_checksum_config"
83 must be supplied as an argument:
84 .Bd -literal -offset 4n
85 struct ng_checksum_config {
87 uint64_t csum_offload;
93 can 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.
98 value 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.
101 The node also takes into account any combination of
102 CSUM_IP, CSUM_TCP, CSUM_UDP, CSUM_TCP_IPV6 and CSUM_UDP_IPV6 already
104 .It Dv NGM_CHECKSUM_GETCONFIG Pq Ic getconfig
105 This 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
108 Returns node statistics as a
109 .Vt "struct ng_checksum_stats" .
110 .It Dv NGM_CHECKSUM_CLR_STATS Pq Ic clrstats
111 Clear the node statistics.
112 .It Dv NGM_CHECKSUM_GETCLR_STATS Pq Ic getclrstats
113 This command is identical to
114 .Dv NGM_CHECKSUM_GET_STATS ,
115 except that the statistics are also atomically cleared.
118 This node shuts down upon receipt of a
120 control message, or when all hooks have been disconnected.
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 }
131 Set the data link type to
133 (Ethernet), do not set additional checksum flags
134 and request that the hardware calculate CSUM_IP_UDP|CSUM_IP_TCP.
142 node type was implemented in
144 and first submitted in
147 .An "Dmitry Vagin" Aq daemon.hammer@ya.ru .