.\" Copyright (c) 2004-2005 Gleb Smirnoff .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" $FreeBSD$ .\" .Dd October 8, 2008 .Os .Dt NG_NETFLOW 4 .Sh NAME .Nm ng_netflow .Nd Cisco's NetFlow implementation .Sh SYNOPSIS .In sys/types.h .In netinet/in.h .In netgraph/netflow/ng_netflow.h .Sh DESCRIPTION The .Nm node implements Cisco's NetFlow export protocol on a router running .Fx . The .Nm node listens for incoming traffic and identifies unique flows in it. Flows are distinguished by endpoint IP addresses, TCP/UDP port numbers, ToS and input interface. Expired flows are exported out of the node in NetFlow version 5 UDP datagrams. Expiration reason can be one of the following: .Bl -dash .It RST or FIN TCP segment. .It Active timeout. Flows cannot live more than the specified period of time. The default is 1800 seconds (30 minutes). .It Inactive timeout. A flow was inactive for the specified period of time. The default is 15 seconds. .El .Pp Export information is stored in NetFlow version 5 datagrams. .Sh HOOKS This node type supports up to .Dv NG_NETFLOW_MAXIFACES hooks named .Va iface0 , iface1 , etc., and the same number of hooks named .Va out0 , out1 , etc., plus a single hook named .Va export . By default (ingress NetFlow enabled) node does NetFlow accounting of data received on .Va iface* hooks. If corresponding .Va out hook is connected, unmodified data is bypassed to it, otherwise data is freed. If data is received on .Va out hook, it is bypassed to corresponding .Va iface hook without any processing (egress NetFlow disabled by default). When full export datagram is built it is sent to the .Va export hook. In normal operation, the .Va export hook is connected to the .Va inet/dgram/udp hook of the .Xr ng_ksocket 4 node. .Sh CONTROL MESSAGES This node type supports the generic control messages, plus the following: .Bl -tag -width indent .It Dv NGM_NETFLOW_INFO Returns some node statistics and the current timeout values in a .Vt "struct ng_netflow_info" . .It Dv NGM_NETFLOW_IFINFO Returns information about the .Va iface Ns Ar N hook. The hook number is passed as an argument. .It Dv NGM_NETFLOW_SETDLT Sets data link type on the .Va iface Ns Ar N hook. Currently, supported types are raw IP datagrams and Ethernet. This message type uses .Vt "struct ng_netflow_setdlt" as an argument: .Bd -literal -offset 4n struct ng_netflow_setdlt { uint16_t iface; /* which iface to operate on */ uint8_t dlt; /* DLT_XXX from bpf.h */ }; .Ed .Pp The requested .Va iface Ns Ar N hook must already be connected, otherwise message send operation will return an error. .It Dv NGM_NETFLOW_SETIFINDEX In some cases, .Nm may be unable to determine the input interface index of a packet. This can happen if traffic enters the .Nm node before it comes to the system interface's input queue. An example of such a setup is capturing a traffic .Em between synchronous data line and .Xr ng_iface 4 . In this case, the input index should be associated with a given hook. The interface's index can be determined via .Xr if_nametoindex 3 from userland. This message requires .Vt "struct ng_netflow_setifindex" as an argument: .Bd -literal -offset 4n struct ng_netflow_setifindex { u_int16_t iface; /* which iface to operate on */ u_int16_t index; /* new index */ }; .Ed .Pp The requested .Va iface Ns Ar N hook must already be connected, otherwise the message send operation will return an error. .It Dv NGM_NETFLOW_SETTIMEOUTS Sets values in seconds for NetFlow active/inactive timeouts. This message requires .Vt "struct ng_netflow_settimeouts" as an argument: .Bd -literal -offset 4n struct ng_netflow_settimeouts { uint32_t inactive_timeout; uint32_t active_timeout; }; .Ed .It Dv NGM_NETFLOW_SETCONFIG Sets configuration for the specified interface. This message requires .Vt "struct ng_netflow_setconfig" as an argument: .Bd -literal -offset 4n struct ng_netflow_setconfig { u_int16_t iface; u_int32_t conf; #define NG_NETFLOW_CONF_INGRESS 1 #define NG_NETFLOW_CONF_EGRESS 2 #define NG_NETFLOW_CONF_ONCE 4 #define NG_NETFLOW_CONF_THISONCE 8 }; .Ed .Pp Configuration is a bitmask of several options. Option NG_NETFLOW_CONF_INGRESS enabled by default enables ingress NetFlow generation (for data coming from ifaceX hook). Option NG_NETFLOW_CONF_EGRESS enables egress NetFlow (for data coming from outX hook). Option NG_NETFLOW_CONF_ONCE defines that packet should be accounted only once if it several times passes via netflow node. Option NG_NETFLOW_CONF_THISONCE defines that packet should be accounted only once if it several times passes via exactly this netflow node. Last two options are important to avoid duplicate accounting when both ingress and egress NetFlow are enabled. .It Dv NGM_NETFLOW_SHOW This control message asks a node to dump the entire contents of the flow cache. It is called from .Xr flowctl 8 , not directly from .Xr ngctl 8 . See also .Sx BUGS section. .El .Sh ASCII CONTROL MESSAGES Most binary control messages have an .Tn ASCII equivalent. The supported .Tn ASCII commands are: .Pp .Bl -tag -width ".Dv NGM_NETFLOW_SETTIMEOUTS" -compact .It Dv NGM_NETFLOW_INFO .Qq Li info .It Dv NGM_NETFLOW_IFINFO .Qq Li "ifinfo %u" .It Dv NGM_NETFLOW_SETDLT .Qq Li "setdlt { iface = %u dlt = %u }" .It Dv NGM_NETFLOW_SETIFINDEX .Qq Li "setifindex { iface = %u index = %u }" .It Dv NGM_NETFLOW_SETTIMEOUTS .Qq Li "settimeouts { inactive = %u active = %u }" .It Dv NGM_NETFLOW_SETCONFIG .Qq Li "setconfig { iface = %u conf = %u }" .El .Sh SHUTDOWN This node shuts down upon receipt of a .Dv NGM_SHUTDOWN control message, or when all hooks have been disconnected. .Sh EXAMPLES The simplest possible configuration is one Ethernet interface, where flow collecting is enabled. .Bd -literal -offset indent /usr/sbin/ngctl -f- <<-SEQ mkpeer fxp0: netflow lower iface0 name fxp0:lower netflow connect fxp0: netflow: upper out0 mkpeer netflow: ksocket export inet/dgram/udp msg netflow:export connect inet/10.0.0.1:4444 SEQ .Ed .Pp This is a more complicated example of a router with 2 NetFlow-enabled interfaces .Li fxp0 and .Li ng0 . Note that the .Va ng0: node in this example is connected to .Xr ng_tee 4 . The latter sends us a copy of IP packets, which we analyze and free. On .Va fxp0: we do not use tee, but send packets back to ether node. .Bd -literal -offset indent /usr/sbin/ngctl -f- <<-SEQ # connect ng0's tee to iface0 hook mkpeer ng0:inet netflow right2left iface0 name ng0:inet.right2left netflow # set DLT to raw mode msg netflow: setdlt { iface=0 dlt=12 } # set interface index (5 in this example) msg netflow: setifindex { iface=0 index=5 } # Connect fxp0: to iface1 and out1 hook connect fxp0: netflow: lower iface1 connect fxp0: netflow: upper out1 # Create ksocket node on export hook, and configure it # to send exports to proper destination mkpeer netflow: ksocket export inet/dgram/udp msg netflow:export connect inet/10.0.0.1:4444 SEQ .Ed .Sh SEE ALSO .Xr netgraph 4 , .Xr ng_ether 4 , .Xr ng_iface 4 , .Xr ng_ksocket 4 , .Xr ng_tee 4 , .Xr flowctl 8 , .Xr ngctl 8 .Pp .Pa http://www.cisco.com/univercd/cc/td/doc/cisintwk/intsolns/netflsol/\:nfwhite.htm .Sh AUTHORS .An -nosplit The .Nm node type was written by .An Gleb Smirnoff Aq glebius@FreeBSD.org , based on .Nm ng_ipacct written by .An Roman V. Palagin Aq romanp@unshadow.net . .Sh BUGS Cache snapshot obtained via .Dv NGM_NETFLOW_SHOW command may lack some percentage of entries under severe load. .Pp The .Nm node type does not fill in AS numbers. This is due to the lack of necessary information in the kernel routing table. However, this information can be injected into the kernel from a routing daemon such as GNU Zebra. This functionality may become available in future releases.