1.\" Copyright (c) 1996-1999 Whistle Communications, Inc. 2.\" All rights reserved. 3.\" 4.\" Subject to the following obligations and disclaimer of warranty, use and 5.\" redistribution of this software, in source or object code forms, with or 6.\" without modifications are expressly permitted by Whistle Communications; 7.\" provided, however, that: 8.\" 1. Any and all reproductions of the source or object code must include the 9.\" copyright notice above and the following disclaimer of warranties; and 10.\" 2. No rights are granted, in any manner or form, to use Whistle 11.\" Communications, Inc. trademarks, including the mark "WHISTLE 12.\" COMMUNICATIONS" on advertising, endorsements, or otherwise except as 13.\" such appears in the above copyright notice or in the software. 14.\" 15.\" THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND 16.\" TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO 17.\" REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE, 18.\" INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF 19.\" MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. 20.\" WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY 21.\" REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS 22.\" SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE. 23.\" IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES 24.\" RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING 25.\" WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 26.\" PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR 27.\" SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY 28.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30.\" THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY 31.\" OF SUCH DAMAGE. 32.\" 33.\" Author: Archie Cobbs <archie@FreeBSD.org> 34.\" 35.\" $FreeBSD$ 36.\" $Whistle: ng_pptpgre.8,v 1.2 1999/12/08 00:20:53 archie Exp $ 37.\" 38.Dd November 29, 1999 39.Dt NG_PPTPGRE 4 40.Os 41.Sh NAME 42.Nm ng_pptpgre 43.Nd PPTP GRE protocol netgraph node type 44.Sh SYNOPSIS 45.In netgraph/ng_pptpgre.h 46.Sh DESCRIPTION 47The 48.Nm pptpgre 49node type performs Generic Routing Encapsulation (GRE) over IP 50for the PPTP protocol as specified by RFC 2637. This involves packet 51encapsulation, sequencing, acknowlegement, and an adaptive timeout 52sliding window mechanism. This node type does not handle any of 53the TCP control protocol or call negotiation defined by PPTP. 54.Pp 55This node type expects to receive complete IP packets, 56including the IP header, on the 57.Dv lower 58hook, but it transmits outgoing frames without any IP header. 59The typical use for this node type would be to connect the 60.Dv upper 61hook to one of the link hooks of a 62.Xr ng_ppp 4 63node, and the 64.Dv lower 65hook to the 66.Dv "inet/raw/gre" 67hook of a 68.Xr ng_ksocket 4 69node. 70.Sh HOOKS 71This node type supports the following hooks: 72.Pp 73.Bl -tag -compact -width vjc_vjuncomp 74.It Dv upper 75Connection to the upper protocol layers 76.It Dv lower 77Connection to the lower protocol layers 78.El 79.Sh CONTROL MESSAGES 80This node type supports the generic control messages, plus the following: 81.Bl -tag -width foo 82.It Dv NGM_PPTPGRE_SET_CONFIG 83This command resets and configures the node for a session. 84This command takes a 85.Dv "struct ng_pptpgre_conf" 86as an argument: 87.Bd -literal -offset 0n 88/* Configuration for a session */ 89struct ng_pptpgre_conf { 90 u_char enabled; /* enables traffic flow */ 91 u_char enableDelayedAck; /* enables delayed acks */ 92 u_int16_t cid; /* my call id */ 93 u_int16_t peerCid; /* peer call id */ 94 u_int16_t recvWin; /* peer recv window size */ 95 u_int16_t peerPpd; /* peer packet processing delay 96 (in 1/10 of a second) */ 97}; 98 99.Ed 100The 101.Dv enabled 102field enables traffic flow through the node. The 103.Dv enableDelayedAck 104field enables delayed acknowledgement (maximum 250 miliseconds), which 105is a useful optimization and should generally be turned on. 106The remaining fields are as supplied by the PPTP virtual call setup process. 107.It Dv NGM_PPTPGRE_GET_CONFIG 108Returns the current configuration as a 109.Dv "struct ng_pptpgre_conf" . 110.It Dv NGM_PPTPGRE_GET_STATS 111This command returns a 112.Dv "struct ng_pptpgre_stats" 113containing various node statistics. 114.It Dv NGM_PPTPGRE_CLR_STATS 115This command resets the node statistics. 116.It Dv NGM_PPTPGRE_GETCLR_STATS 117This command atomically gets and resets the node statistics, returning a 118.Dv "struct ng_pptpgre_stats" . 119.El 120.Sh SHUTDOWN 121This node shuts down upon receipt of a 122.Dv NGM_SHUTDOWN 123control message, or when both hooks have been disconnected. 124.Sh SEE ALSO 125.Xr netgraph 4 , 126.Xr ng_ksocket 4 , 127.Xr ng_ppp 4 , 128.Xr ngctl 8 129.Rs 130.%A K. Hamzeh 131.%A G. Pall 132.%A W. Verthein 133.%A J. Taarud 134.%A W. Little 135.%A G. Zorn 136.%T "Point-to-Point Tunneling Protocol (PPTP)" 137.%O RFC 2637 138.Re 139.Rs 140.%A S. Hanks 141.%A T. \&Li 142.%A D. Farinacci 143.%A P. Traina 144.%T "Generic Routing Encapsulation over IPv4 networks" 145.%O RFC 1702 146.Re 147.Sh BUGS 148The node should not expect incoming GRE packets to have an IP header. 149This behavior is inherited from the (converse) behavior of raw IP sockets. 150An intermediate node that strips IP headers in one direction 151should be used instead. 152.Sh HISTORY 153The 154.Nm 155node type was implemented in 156.Fx 4.0 . 157.Sh AUTHORS 158.An Archie Cobbs Aq archie@FreeBSD.org 159