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