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.Dd December 10, 2012 26.Dt NG_NETFLOW 4 27.Os 28.Sh NAME 29.Nm ng_netflow 30.Nd Cisco's NetFlow implementation 31.Sh SYNOPSIS 32.In sys/types.h 33.In netinet/in.h 34.In netgraph/netflow/ng_netflow.h 35.Sh DESCRIPTION 36The 37.Nm 38node implements Cisco's NetFlow export protocol on a router running 39.Fx . 40The 41.Nm 42node listens for incoming traffic and identifies unique flows in it. 43Flows are distinguished by endpoint IP addresses, TCP/UDP port numbers, 44ToS and input interface. 45Expired flows are exported out of the node in NetFlow version 5/9 UDP datagrams. 46Expiration reason can be one of the following: 47.Bl -dash 48.It 49RST or FIN TCP segment. 50.It 51Active timeout. 52Flows cannot live more than the specified period of time. 53The default is 1800 seconds (30 minutes). 54.It 55Inactive timeout. 56A flow was inactive for the specified period of time. 57The default is 15 seconds. 58.El 59.Pp 60Node supports IPv6 accounting (NetFlow v9 only) and is aware of multiple fibs. 61Different fibs are mapped to different domain_id in NetFlow V9 and different engine_id in NetFlow V5. 62.Sh HOOKS 63This node type supports up to 64.Dv NG_NETFLOW_MAXIFACES 65(default 65536) hooks named 66.Va iface0 , iface1 , 67etc., 68and the same number of hooks named 69.Va out0 , out1 , 70etc., 71plus two export hooks: 72.Va export 73(for NetFlow version 5) and 74.Va export9 75(for NetFlow version 9). 76Export can be done simultaneously for all supported export hooks. 77By default (ingress NetFlow enabled) node does NetFlow accounting of data 78received on 79.Va iface* 80hooks. 81If corresponding 82.Va out 83hook is connected, unmodified data is bypassed to it, otherwise data is freed. 84If data is received on 85.Va out 86hook, it is bypassed to corresponding 87.Va iface 88hook without any processing (egress NetFlow disabled by default). 89When full export datagram for an export protocol is built it is sent to the 90.Va export 91or 92.Va export9 93hook. 94In normal operation, one (or more) export hook is connected to the 95.Va inet/dgram/udp 96hook of the 97.Xr ng_ksocket 4 98node. 99.Sh CONTROL MESSAGES 100This node type supports the generic control messages, plus the following: 101.Bl -tag -width foo 102.It Dv NGM_NETFLOW_INFO Pq Ic info 103Returns some node statistics and the current timeout values in a 104.Vt "struct ng_netflow_info" . 105.It Dv NGM_NETFLOW_IFINFO Pq Ic ifinfo 106Returns information about the 107.Va iface Ns Ar N 108hook. 109The hook number is passed as an argument. 110.It Dv NGM_NETFLOW_SETDLT Pq Ic setdlt 111Sets data link type on the 112.Va iface Ns Ar N 113hook. 114Currently, supported types are 115.Cm DLT_RAW 116(raw IP datagrams) and 117.Cm DLT_EN10MB 118(Ethernet). 119DLT_ definitions can be found in 120.In net/bpf.h 121header. 122Currently used values are 1 for 123.Cm DLT_EN10MB 124and 12 for 125.Cm DLT_RAW . 126This message type uses 127.Vt "struct ng_netflow_setdlt" 128as an argument: 129.Bd -literal -offset 4n 130struct ng_netflow_setdlt { 131 uint16_t iface; /* which iface dlt change */ 132 uint8_t dlt; /* DLT_XXX from bpf.h */ 133}; 134.Ed 135.Pp 136The requested 137.Va iface Ns Ar N 138hook must already be connected, otherwise message send operation will 139return an error. 140.It Dv NGM_NETFLOW_SETIFINDEX Pq Ic setifindex 141In some cases, 142.Nm 143may be unable to determine the input interface index of a packet. 144This can happen if traffic enters the 145.Nm 146node before it comes to the system interface's input queue. 147An example of such a setup is capturing a traffic 148.Em between 149synchronous data line and 150.Xr ng_iface 4 . 151In this case, the input index should be associated with a given hook. 152The interface's index can be determined via 153.Xr if_nametoindex 3 154from userland. 155This message requires 156.Vt "struct ng_netflow_setifindex" 157as an argument: 158.Bd -literal -offset 4n 159struct ng_netflow_setifindex { 160 uint16_t iface; /* which iface index change */ 161 uint16_t index; /* new index */ 162}; 163.Ed 164.Pp 165The requested 166.Va iface Ns Ar N 167hook must already be connected, otherwise the message 168send operation will return an error. 169.It Dv NGM_NETFLOW_SETTIMEOUTS Pq Ic settimeouts 170Sets values in seconds for NetFlow active/inactive timeouts. 171This message requires 172.Vt "struct ng_netflow_settimeouts" 173as an argument: 174.Bd -literal -offset 4n 175struct ng_netflow_settimeouts { 176 uint32_t inactive_timeout; /* flow inactive timeout */ 177 uint32_t active_timeout; /* flow active timeout */ 178}; 179.Ed 180.It Dv NGM_NETFLOW_SETCONFIG Pq Ic setconfig 181Sets configuration for the specified interface. 182This message requires 183.Vt "struct ng_netflow_setconfig" 184as an argument: 185.Bd -literal -offset 4n 186struct ng_netflow_setconfig { 187 uint16_t iface; /* which iface config change */ 188 uint32_t conf; /* new config */ 189#define NG_NETFLOW_CONF_INGRESS 1 190#define NG_NETFLOW_CONF_EGRESS 2 191#define NG_NETFLOW_CONF_ONCE 4 192#define NG_NETFLOW_CONF_THISONCE 8 193#define NG_NETFLOW_CONF_NOSRCLOOKUP 16 194#define NG_NETFLOW_CONF_NODSTLOOKUP 32 195}; 196.Ed 197.Pp 198Configuration is a bitmask of several options. 199Option 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 setfib 2 , 319.Xr netgraph 4 , 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 Mt glebius@FreeBSD.org , 339.An Alexander Motin Aq Mt mav@FreeBSD.org , 340.An Alexander Chernikov Aq Mt melifaro@ipfw.ru . 341The initial code was based on 342.Nm ng_ipacct 343written by 344.An Roman V. Palagin Aq Mt 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