1.\" Copyright (c) 2004-2005 Gleb Smirnoff <glebius@FreeBSD.org> 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 December 10, 2012 28.Dt NG_NETFLOW 4 29.Os 30.Sh NAME 31.Nm ng_netflow 32.Nd Cisco's NetFlow implementation 33.Sh SYNOPSIS 34.In sys/types.h 35.In netinet/in.h 36.In netgraph/netflow/ng_netflow.h 37.Sh DESCRIPTION 38The 39.Nm 40node implements Cisco's NetFlow export protocol on a router running 41.Fx . 42The 43.Nm 44node listens for incoming traffic and identifies unique flows in it. 45Flows are distinguished by endpoint IP addresses, TCP/UDP port numbers, 46ToS and input interface. 47Expired flows are exported out of the node in NetFlow version 5/9 UDP datagrams. 48Expiration reason can be one of the following: 49.Bl -dash 50.It 51RST or FIN TCP segment. 52.It 53Active timeout. 54Flows cannot live more than the specified period of time. 55The default is 1800 seconds (30 minutes). 56.It 57Inactive timeout. 58A flow was inactive for the specified period of time. 59The default is 15 seconds. 60.El 61.Pp 62Node supports IPv6 accounting (NetFlow v9 only) and is aware of multiple fibs. 63Different fibs are mapped to different domain_id in NetFlow V9 and different engine_id in NetFlow V5. 64.Sh HOOKS 65This node type supports up to 66.Dv NG_NETFLOW_MAXIFACES 67(default 65536) hooks named 68.Va iface0 , iface1 , 69etc., 70and the same number of hooks named 71.Va out0 , out1 , 72etc., 73plus two export hooks: 74.Va export 75(for NetFlow version 5) and 76.Va export9 77(for NetFlow version 9). 78Export can be done simultaneously for all supported export hooks. 79By default (ingress NetFlow enabled) node does NetFlow accounting of data 80received on 81.Va iface* 82hooks. 83If corresponding 84.Va out 85hook is connected, unmodified data is bypassed to it, otherwise data is freed. 86If data is received on 87.Va out 88hook, it is bypassed to corresponding 89.Va iface 90hook without any processing (egress NetFlow disabled by default). 91When full export datagram for an export protocol is built it is sent to the 92.Va export 93or 94.Va export9 95hook. 96In normal operation, one (or more) export hook is connected to the 97.Va inet/dgram/udp 98hook of the 99.Xr ng_ksocket 4 100node. 101.Sh CONTROL MESSAGES 102This node type supports the generic control messages, plus the following: 103.Bl -tag -width foo 104.It Dv NGM_NETFLOW_INFO Pq Ic info 105Returns some node statistics and the current timeout values in a 106.Vt "struct ng_netflow_info" . 107.It Dv NGM_NETFLOW_IFINFO Pq Ic ifinfo 108Returns information about the 109.Va iface Ns Ar N 110hook. 111The hook number is passed as an argument. 112.It Dv NGM_NETFLOW_SETDLT Pq Ic setdlt 113Sets data link type on the 114.Va iface Ns Ar N 115hook. 116Currently, supported types are 117.Cm DLT_RAW 118(raw IP datagrams) and 119.Cm DLT_EN10MB 120(Ethernet). 121DLT_ definitions can be found in 122.In net/bpf.h 123header. 124Currently used values are 1 for 125.Cm DLT_EN10MB 126and 12 for 127.Cm DLT_RAW . 128This message type uses 129.Vt "struct ng_netflow_setdlt" 130as an argument: 131.Bd -literal -offset 4n 132struct ng_netflow_setdlt { 133 uint16_t iface; /* which iface dlt change */ 134 uint8_t dlt; /* DLT_XXX from bpf.h */ 135}; 136.Ed 137.Pp 138The requested 139.Va iface Ns Ar N 140hook must already be connected, otherwise message send operation will 141return an error. 142.It Dv NGM_NETFLOW_SETIFINDEX Pq Ic setifindex 143In some cases, 144.Nm 145may be unable to determine the input interface index of a packet. 146This can happen if traffic enters the 147.Nm 148node before it comes to the system interface's input queue. 149An example of such a setup is capturing a traffic 150.Em between 151synchronous data line and 152.Xr ng_iface 4 . 153In this case, the input index should be associated with a given hook. 154The interface's index can be determined via 155.Xr if_nametoindex 3 156from userland. 157This message requires 158.Vt "struct ng_netflow_setifindex" 159as an argument: 160.Bd -literal -offset 4n 161struct ng_netflow_setifindex { 162 uint16_t iface; /* which iface index change */ 163 uint16_t index; /* new index */ 164}; 165.Ed 166.Pp 167The requested 168.Va iface Ns Ar N 169hook must already be connected, otherwise the message 170send operation will return an error. 171.It Dv NGM_NETFLOW_SETTIMEOUTS Pq Ic settimeouts 172Sets values in seconds for NetFlow active/inactive timeouts. 173This message requires 174.Vt "struct ng_netflow_settimeouts" 175as an argument: 176.Bd -literal -offset 4n 177struct ng_netflow_settimeouts { 178 uint32_t inactive_timeout; /* flow inactive timeout */ 179 uint32_t active_timeout; /* flow active timeout */ 180}; 181.Ed 182.It Dv NGM_NETFLOW_SETCONFIG Pq Ic setconfig 183Sets configuration for the specified interface. 184This message requires 185.Vt "struct ng_netflow_setconfig" 186as an argument: 187.Bd -literal -offset 4n 188struct ng_netflow_setconfig { 189 uint16_t iface; /* which iface config change */ 190 uint32_t conf; /* new config */ 191#define NG_NETFLOW_CONF_INGRESS 1 192#define NG_NETFLOW_CONF_EGRESS 2 193#define NG_NETFLOW_CONF_ONCE 4 194#define NG_NETFLOW_CONF_THISONCE 8 195#define NG_NETFLOW_CONF_NOSRCLOOKUP 16 196#define NG_NETFLOW_CONF_NODSTLOOKUP 32 197}; 198.Ed 199.Pp 200Configuration is a bitmask of several options. 201Option NG_NETFLOW_CONF_INGRESS 202enabled by default enables ingress NetFlow generation (for data coming from 203ifaceX hook). 204Option 205.Va NG_NETFLOW_CONF_EGRESS 206enables egress NetFlow (for data coming from outX hook). 207Option 208.Va NG_NETFLOW_CONF_ONCE 209defines that packet should be accounted only once if it several times passes 210via netflow node. 211Option 212.Va NG_NETFLOW_CONF_THISONCE 213defines that packet should be accounted only once if it several times passes 214via exactly this netflow node. 215These two options are important to avoid duplicate accounting when both ingress 216and egress NetFlow are enabled. 217Option 218.Va NG_NETFLOW_CONF_NOSRCLOOKUP 219skips radix lookup on flow source address used to fill in network mask. 220Option 221.Va NG_NETFLOW_CONF_NODSTLOOKUP 222skips radix lookup on destination (which fills egress interface id, destination 223mask and gateway). 224If one doesn't need data provided by lookups, he/she can disable them, to reduce 225load on routers. 226.It Dv NGM_NETFLOW_SETTEMPLATE Pq Ic settemplate 227Sets various timeouts to announce data flow templates 228(NetFlow v9-specific). This message requires 229.Vt "struct ng_netflow_settemplate" 230as an argument: 231.Bd -literal -offset 4n 232struct ng_netflow_settemplate { 233 uint16_t time; /* max time between announce */ 234 uint16_t packets; /* max packets between announce */ 235}; 236.Ed 237.Pp 238Value of time field represents time in seconds to re-announce data templates. 239Value of packets field represents maximum packets count between 240re-announcing data templates. 241.It Dv NGM_NETFLOW_SETMTU Pq Ic setmtu 242Sets export interface MTU to build packets of specified size (NetFlow v9-specific). 243This message requires 244.Vt "struct ng_netflow_setmtu" 245as an argument: 246.Bd -literal -offset 4n 247struct ng_netflow_setemtu { 248 uint16_t mtu; /* MTU for packet */ 249}; 250.Ed 251.Pp 252Default is 1500 bytes. 253.It Dv NGM_NETFLOW_SHOW 254This control message asks a node to dump the entire contents of the flow cache. 255It is called from 256.Xr flowctl 8 , 257not directly from 258.Xr ngctl 8 . 259.It Dv NGM_NETFLOW_V9INFO Pq Ic v9info 260Returns some NetFlow v9 related values in a 261.Bd -literal -offset 4n 262struct ng_netflow_v9info { 263 uint16_t templ_packets; /* v9 template packets */ 264 uint16_t templ_time; /* v9 template time */ 265 uint16_t mtu; /* v9 MTU */ 266}; 267.Ed 268.El 269.Sh SHUTDOWN 270This node shuts down upon receipt of a 271.Dv NGM_SHUTDOWN 272control message, or when all hooks have been disconnected. 273.Sh EXAMPLES 274The simplest possible configuration is one Ethernet interface, where 275flow collecting is enabled. 276.Bd -literal -offset indent 277/usr/sbin/ngctl -f- <<-SEQ 278 mkpeer fxp0: netflow lower iface0 279 name fxp0:lower netflow 280 connect fxp0: netflow: upper out0 281 mkpeer netflow: ksocket export inet/dgram/udp 282 msg netflow:export connect inet/10.0.0.1:4444 283SEQ 284.Ed 285.Pp 286This is a more complicated example of a router with 2 NetFlow-enabled 287interfaces 288.Li fxp0 289and 290.Li ng0 . 291Note that the 292.Va ng0: 293node in this example is connected to 294.Xr ng_tee 4 . 295The latter sends us a copy of IP packets, which we analyze and free. 296On 297.Va fxp0: 298we do not use tee, but send packets back to either node. 299.Bd -literal -offset indent 300/usr/sbin/ngctl -f- <<-SEQ 301 # connect ng0's tee to iface0 hook 302 mkpeer ng0:inet netflow right2left iface0 303 name ng0:inet.right2left netflow 304 # set DLT to raw mode 305 msg netflow: setdlt { iface=0 dlt=12 } 306 # set interface index (5 in this example) 307 msg netflow: setifindex { iface=0 index=5 } 308 309 # Connect fxp0: to iface1 and out1 hook 310 connect fxp0: netflow: lower iface1 311 connect fxp0: netflow: upper out1 312 313 # Create ksocket node on export hook, and configure it 314 # to send exports to proper destination 315 mkpeer netflow: ksocket export inet/dgram/udp 316 msg netflow:export connect inet/10.0.0.1:4444 317SEQ 318.Ed 319.Sh SEE ALSO 320.Xr setfib 2 , 321.Xr netgraph 4 , 322.Xr ng_ether 4 , 323.Xr ng_iface 4 , 324.Xr ng_ksocket 4 , 325.Xr ng_tee 4 , 326.Xr flowctl 8 , 327.Xr ngctl 8 328.Rs 329.%A B. Claise, Ed 330.%T "Cisco Systems NetFlow Services Export Version 9" 331.%O RFC 3954 332.Re 333.Pp 334.Pa http://www.cisco.com/en/US/docs/ios/solutions_docs/netflow/nfwhite.html 335.Sh AUTHORS 336.An -nosplit 337The 338.Nm 339node type was written by 340.An Gleb Smirnoff Aq Mt glebius@FreeBSD.org , 341.An Alexander Motin Aq Mt mav@FreeBSD.org , 342.An Alexander Chernikov Aq Mt melifaro@ipfw.ru . 343The initial code was based on 344.Nm ng_ipacct 345written by 346.An Roman V. Palagin Aq Mt romanp@unshadow.net . 347.Sh BUGS 348Cache snapshot obtained via 349.Dv NGM_NETFLOW_SHOW 350command may lack some percentage of entries under severe load. 351.Pp 352The 353.Nm 354node type does not fill in AS numbers. 355This is due to the lack of necessary information in the kernel routing table. 356However, this information can be injected into the kernel from a routing daemon 357such as GNU Zebra. 358This functionality may become available in future releases. 359