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@whistle.com> 34.\" 35.\" $FreeBSD$ 36.\" $Whistle: netgraph.3,v 1.7 1999/01/25 07:14:06 archie Exp $ 37.\" 38.Dd January 19, 1999 39.Dt NETGRAPH 3 40.Os FreeBSD 3 41.Sh NAME 42.Nm NgMkSockNode , 43.Nm NgNameNode , 44.Nm NgSendMsg , 45.Nm NgRecvMsg , 46.Nm NgSendData , 47.Nm NgRecvData , 48.Nm NgSetDebug , 49.Nm NgSetErrLog 50.Nd Netgraph user library 51.Sh SYNOPSIS 52.Fd #include <netgraph.h> 53.Ft int 54.Fn NgMkSockNode "const char *name" "int *csp" "int *dsp" 55.Ft int 56.Fn NgNameNode "int cs" "const char *path" "const char *fmt" "..." 57.Ft int 58.Fn NgSendMsg "int cs" "const char *path" "int cookie" "int cmd" "const void *arg" "size_t arglen" 59.Ft int 60.Fn NgSendMsgReply "int cs" "const char *path" "struct ng_mesg *msg" "const void *arg" "size_t arglen" 61.Ft int 62.Fn NgRecvMsg "int cs" "struct ng_mesg *rep" "size_t replen" "char *path" 63.Ft int 64.Fn NgSendData "int ds" "const char *hook" "const u_char *buf" "size_t len" 65.Ft int 66.Fn NgRecvData "int ds" "u_char *buf" "size_t len" "char *hook" 67.Ft int 68.Fn NgSetDebug "int level" 69.Ft void 70.Fn NgSetErrLog "void (*log)(const char *fmt, ...)" "void (*logx)(const char *fmt, ...)" 71.Sh DESCRIPTION 72These functions facilitate user-mode program participation in the kernel 73.Xr netgraph 4 74graph-based networking system, by utilizing the netgraph 75.Em socket 76node type (see 77.Xr ng_socket 8 ")." 78.Pp 79.Fn NgMkSockNode 80should be called first, to create a new 81.Em socket 82type netgraph node with associated control and data sockets. If 83.Fa name 84is non-NULL, the node will have that global name assigned to it. 85.Fa "*csp" 86and 87.Fa "*dsp" 88will be set to the newly opened control and data sockets 89associated with the node; either 90.Fa "csp" 91or 92.Fa "dsp" 93may be NULL if only one socket is desired. 94.Pp 95.Fn NgNameNode 96assigns a global name to the node addressed by 97.Fa path . 98.Pp 99.Fn NgSendMsg 100sends a control message from the socket node associated with control socket 101.Fa cs 102to the node addressed by 103.Fa path . 104The 105.Fa cookie 106indicates how to interpret 107.Fa cmd , 108which indicates a specific command. 109Extra argument data (if any) is specified by 110.Fa arg 111and 112.Fa arglen . 113The 114.Fa cookie , 115.Fa cmd , 116and argument data are defined by the header file corresponding 117to the type of the node being addressed. 118.Pp 119Use 120.Fn NgSendMsgReply 121to send reply to a previously received control message. 122The original message header should be pointed to by 123.Fa msg . 124.Pp 125.Fn NgRecvMsg 126reads the next control message received by the node associated with 127control socket 128.Fa cs . 129The message and any extra argument data must fit in 130.Fa replen 131bytes. 132If 133.Fa "path" 134is non-NULL, it must point to a buffer of at least 135.Dv "NG_PATHLEN + 1" 136bytes, which will be filled in (and NUL terminated) with the path to 137the node from which the message was received. 138.Pp 139.Fn NgSendData 140writes a data packet out on the specified hook of the node corresponding 141to data socket 142.Fa ds . 143The node must already be connected to some other node via that hook. 144.Pp 145.Fn NgRecvData 146reads the next data packet (of up to 147.Fa len 148bytes) received by the node corresponding to data socket 149.Fa ds 150and stores it in 151.Fa buf , 152which must be large enough to hold the entire packet. If 153.Fa "hook" 154is non-NULL, it must point to a buffer of at least 155.Dv "NG_HOOKLEN + 1" 156bytes, which will be filled in (and NUL terminated) with the name of 157the hook on which the data was received. 158.Pp 159.Fn NgSetDebug 160and 161.Fn NgSetErrLog 162are used for debugging. 163.Fn NgSetDebug 164sets the debug level (if non-negative), and returns the old setting. 165Higher debug levels result in more verbosity. The default is zero. 166All debug and error messages are logged via the functions 167specified in the most recent call to 168.Fn NgSetErrLog . 169The default logging functions are 170.Xr vwarn 3 171and 172.Xr vwarnx 3 . 173.Pp 174Note that 175.Xr select 2 176can be used on the data and the control sockets to detect the presence of 177incoming data and control messages, respectively. 178Data and control packets are always written and read atomically, i.e., 179in one whole piece. 180.Pp 181User mode programs must be linked with the 182.Dv -lnetgraph 183flag to link in this library. 184.Sh INITIALIZATION 185Netgraph is not part of the standard FreeBSD kernel. To enable it, 186either your kernel must be compiled with ``options NETGRAPH'' 187in the kernel configuration file, or else the 188.Xr netgraph 4 189and 190.Xr ng_socket 8 191KLD modules must have been loaded via 192.Xr kldload 8 . 193.Sh DIAGNOSTICS 194All functions except 195.Fn NgSetDebug 196and 197.Fn NgSetErrLog 198return -1 if there was an error and set errno accordingly. 199.Sh SEE ALSO 200.Xr netgraph 4 , 201.Xr socket 2 , 202.Xr select 2 , 203.Xr warnx 3 , 204.Xr ng_socket 8 . 205.Sh HISTORY 206The 207.Em netgraph 208system was designed and first implemented at Whistle Communications, Inc. 209in a version FreeBSD 2.2 customized for the Whistle InterJet. 210.Sh AUTHOR 211.An Archie Cobbs <archie@whistle.com> 212