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NG_PPPOE(4)	       FreeBSD Kernel Interfaces Manual		   NG_PPPOE(4)

NAME
     ng_pppoe -- RFC 2516 PPPoE	protocol netgraph node type

SYNOPSIS
     #include <sys/types.h>
     #include <net/ethernet.h>
     #include <netgraph.h>
     #include <netgraph/ng_pppoe.h>

DESCRIPTION
     The pppoe node type performs the PPPoE protocol.  It is used in conjunc-
     tion with the netgraph(4) extensions to the Ethernet framework to divert
     and inject	Ethernet packets to and	from a PPP agent (which	is not speci-
     fied).

     The NGM_PPPOE_GET_STATUS control message can be used at any time to query
     the current status	of the PPPoE module.  The only statistics presently
     available are the total packet counts for input and output.  This node
     does not yet support the NGM_TEXT_STATUS control message.

HOOKS
     This node type supports the following hooks:

     ethernet	    The	hook that should normally be connected to an Ethernet
		    node.

     debug	    Presently no use.

     [unspecified]  Any	other name is assumed to be a session hook that	will
		    be connected to a PPP client agent,	or a PPP server	agent.

CONTROL	MESSAGES
     This node type supports the generic control messages, plus	the following:

     NGM_PPPOE_GET_STATUS
	  This command returns status information in a struct ngpppoestat:

	      struct ngpppoestat {
		  u_int	  packets_in;	  /* packets in	from Ethernet */
		  u_int	  packets_out;	  /* packets out towards Ethernet */
	      };

     NGM_TEXT_STATUS
	  This generic message returns is a human-readable version of the node
	  status.  (not	yet)

     NGM_PPPOE_CONNECT
	  Tell a nominated newly created hook that its session should enter
	  the state machine in a manner	to become a client.  It	must be	newly
	  created and a	service	name can be given as an	argument.  It is legal
	  to specify a zero length service name.  This is common on some DSL
	  setups.  A session request packet will be broadcast on the Ethernet.
	  This command uses the	ngpppoe_init_data structure shown below.

     NGM_PPPOE_LISTEN
	  Tell a nominated newly created hook that its session should enter
	  the state machine in a manner	to become a server listener.  The
	  argument given is the	name of	the service to listen on behalf	of a
	  zero length service length will match	all requests for service.  A
	  matching service request packet will be passed unmodified back to
	  the process responsible for starting the service.  It	can then exam-
	  ine it and pass it on	to the session that is started to answer the
	  request.  This command uses the ngpppoe_init_data structure shown
	  below.

     NGM_PPPOE_OFFER
	  Tell a nominated newly created hook that its session should enter
	  the state machine in a manner	to become a server.  The argument
	  given	is the name of the service to offer.  A	zero length service is
	  legal.  The State machine will progress to a state where it will
	  await	a request packet to be forwarded to it from the	startup
	  server, which	in turn	probably received it from a LISTEN mode	hook (
	  see above).  This is so that information that	is required for	the
	  session that is embedded in the original session request packet, is
	  made available to the	state machine that eventually answers the
	  request.  When the Session request packet is received, the session
	  negotiation will proceed.  This command uses the ngpppoe_init_data
	  structure shown below.

     The three commands	above use a common data	structure:

	 struct	ngpppoe_init_data {
	     char	hook[NG_HOOKSIZ];	/* hook	to monitor on */
	     u_int16_t	data_len;		/* service name	length */
	     char	data[0];		/* init	data goes here */
	 };

     NGM_PPPOE_SUCCESS
	  This command is sent to the node that	started	this session with one
	  of the above messages, and reports a state change.  This message
	  reports successful Session negotiation.  It uses the structure shown
	  below, and reports back the hook name	corresponding to the success-
	  ful session.

     NGM_NGM_PPPOE_FAIL
	  This command is sent to the node that	started	this session with one
	  of the above messages, and reports a state change.  This message
	  reports failed Session negotiation.  It uses the structure shown
	  below, and reports back the hook name	corresponding to the failed
	  session.  The	hook will probably have	been removed immediately after
	  sending this message

     NGM_NGM_PPPOE_CLOSE
	  This command is sent to the node that	started	this session with one
	  of the above messages, and reports a state change.  This message
	  reports a request to close a session.	 It uses the structure shown
	  below, and reports back the hook name	corresponding to the closed
	  session.  The	hook will probably have	been removed immediately after
	  sending this message.	 At present this message is not	yet used and a
	  'failed' message will	be received at closure instead.

     NGM_PPPOE_ACNAME
	  This command is sent to the node that	started	this session with one
	  of the above messages, and reports the Access	Concentrator Name.

     The four commands above use a common data structure:

	 struct	ngpppoe_sts {
	     char    hook[NG_HOOKSIZ];	  /* hook associated with event	session	*/
	 };

     NGM_PPPOE_GETMODE
	  This command returns the current compatibility mode of the node as a
	  string.  ASCII form of this message is "pppoe_getmode".  The follow-
	  ing keywords are can be returned:

	  "standard"
	       The node	operates according to RFC 2516.

	  "3Com"
	       When ng_pppoe is	a PPPoE	client,	it initiates a session encap-
	       sulating	packets	into incorrect 3Com ethertypes.	 This compati-
	       bility option doesn't affect server mode.  In server mode
	       ng_pppoe	supports both modes simultaneously, depending on the
	       ethertype, the client used when connecting.

	  "D-Link"
	       When ng_pppoe is	a PPPoE	server serving only specific Service-
	       Name(s),	it will	respond	to a PADI requests with	empty Service-
	       Name tag, returning all available Service-Name(s) on node.
	       This option is necessary	for compatibility with D-Link DI-614+
	       and DI-624+ SOHO	routers	as clients, when serving only specific
	       Service-Name.  This compatibility option	doesn't	affect client
	       mode.

     NGM_PPPOE_SETMODE
	  Configure node to the	specified mode.	 The string argument is
	  required.  This command understands same keywords, that are returned
	  by NGM_PPPOE_GETMODE command.	 ASCII form of this message is
	  "pppoe_setmode".  For	example, the following command will configure
	  the node to initiate the next	session	in the proprietary 3Com	mode:

		ngctl msg fxp0:orphans pppoe_setmode '"3Com"'

SHUTDOWN
     This node shuts down upon receipt of a NGM_SHUTDOWN control message, when
     all session have been disconnected	or when	the ethernet hook is discon-
     nected.

EXAMPLES
     The following code	uses libnetgraph to set	up a ng_pppoe node and connect
     it	to both	a socket node and an Ethernet node.  It	can handle the case of
     when a ng_pppoe node is already attached to the Ethernet.	It then	starts
     a client session.

     #include <stdio.h>
     #include <stdlib.h>
     #include <string.h>
     #include <ctype.h>
     #include <unistd.h>
     #include <sysexits.h>
     #include <errno.h>
     #include <err.h>

     #include <sys/types.h>
     #include <sys/socket.h>
     #include <sys/select.h>
     #include <net/ethernet.h>

     #include <netgraph.h>
     #include <netgraph/ng_ether.h>
     #include <netgraph/ng_pppoe.h>
     #include <netgraph/ng_socket.h>
     static int	setup(char *ethername, char *service, char *sessname,
				     int *dfd, int *cfd);

     int
     main()
     {
	     int  fd1, fd2;
	     setup("xl0", NULL,	"fred",	&fd1, &fd2);
	     sleep (30);
     }

     static int
     setup(char	*ethername, char *service, char	*sessname,
			     int *dfd, int *cfd)
     {
	     struct ngm_connect	ngc; /*	connect	*/
	     struct ngm_mkpeer mkp;  /*	mkpeer */
	     /******** nodeinfo	stuff **********/
	     u_char	     rbuf[2 * 1024];
	     struct ng_mesg *const resp	= (struct ng_mesg *) rbuf;
	     struct hooklist *const hlist
			     = (struct hooklist	*) resp->data;
	     struct nodeinfo *const ninfo = &hlist->nodeinfo;
	     int	     ch, no_hooks = 0;
	     struct linkinfo *link;
	     struct nodeinfo *peer;
	     /****message to connect PPPoE session*****/
	     struct {
		     struct ngpppoe_init_data idata;
		     char	     service[100];
	     }		     message;
	     /********tracking our little graph	********/
	     char	     path[100];
	     char	     source_ID[NG_NODESIZ];
	     char	     pppoe_node_name[100];
	     int	     k;

	     /*
	      *	Create the data	and control sockets
	      */
	     if	(NgMkSockNode(NULL, cfd, dfd) <	0) {
		     return (errno);
	     }
	     /*
	      *	find the ether node of the name	requested by asking it for
	      *	it's inquiry information.
	      */
	     if	(strlen(ethername) > 16)
		     return (EINVAL);
	     sprintf(path, "%s:", ethername);
	     if	(NgSendMsg(*cfd, path, NGM_GENERIC_COOKIE,
			   NGM_LISTHOOKS, NULL,	0) < 0)	{
		     return (errno);
	     }
	     /*
	      *	the command was	accepted so it exists. Await the reply (It's
	      *	almost certainly already waiting).
	      */
	     if	(NgRecvMsg(*cfd, resp, sizeof(rbuf), NULL) < 0)	{
		     return (errno);
	     }
	     /**
	      *	The following is available about the node:
	      *	ninfo->name	     (string)
	      *	ninfo->type	     (string)
	      *	ninfo->id	     (u_int32_t)
	      *	ninfo->hooks	     (u_int32_t) (count	of hooks)
	      *	check it is the	correct	type. and get it's ID for use
	      *	with mkpeer later.
	      */
	     if	(strncmp(ninfo->type, NG_ETHER_NODE_TYPE,
			 strlen(NG_ETHER_NODE_TYPE)) !=	0) {
		     return (EPROTOTYPE);
	     }
	     sprintf(source_ID,	"[%08x]:", ninfo->id);

	     /*
	      *	look for a hook	already	attached.
	      */
	     for (k = 0; k < ninfo->hooks; k++)	{
		     /**
		      *	The following are available about each hook.
		      *	link->ourhook	     (string)
		      *	link->peerhook	     (string)
		      *	peer->name	     (string)
		      *	peer->type	     (string)
		      *	peer->id	     (u_int32_t)
		      *	peer->hooks	     (u_int32_t)
		      */
		     link = &hlist->link[k];
		     peer = &hlist->link[k].nodeinfo;

		     /*	Ignore debug hooks */
		     if	(strcmp("debug", link->ourhook)	== 0)
			     continue;

		     /*	If the orphans hook is attached, use that */
		     if	(strcmp(NG_ETHER_HOOK_ORPHAN,
			 link->ourhook)	== 0) {
			     break;
		     }
		     /*	the other option is the	'divert' hook */
		     if	(strcmp("NG_ETHER_HOOK_DIVERT",
			 link->ourhook)	== 0) {
			     break;
		     }
	     }

	     /*
	      *	See if we found	a hook there.
	      */
	     if	(k < ninfo->hooks) {
		     if	(strcmp(peer->type, NG_PPPOE_NODE_TYPE)	== 0) {
			     /*
			      *	If it's	a type PPPoE, we skip making one
			      *	ourself, but we	continue, using
			      *	the existing one.
			      */
			     sprintf(pppoe_node_name, "[%08x]:", peer->id);
		     } else {
			     /*
			      *	There is already someone hogging the data,
			      *	return an error. Some day we'll	try
			      *	daisy-chaining..
			      */
			     return (EBUSY);
		     }
	     } else {

		     /*
		      *	Try make a node	of type	PPPoE against node "ID"
		      *	On hook	NG_ETHER_HOOK_ORPHAN.
		      */
		     snprintf(mkp.type,	sizeof(mkp.type),
			      "%s", NG_PPPOE_NODE_TYPE);
		     snprintf(mkp.ourhook, sizeof(mkp.ourhook),
			      "%s", NG_ETHER_HOOK_ORPHAN);
		     snprintf(mkp.peerhook, sizeof(mkp.peerhook),
			      "%s", NG_PPPOE_HOOK_ETHERNET);
		     /*	Send message */
		     if	(NgSendMsg(*cfd, source_ID, NGM_GENERIC_COOKIE,
				   NGM_MKPEER, &mkp, sizeof(mkp)) < 0) {
			     return (errno);
		     }
		     /*
		      *	Work out a name	for the	new node.
		      */
		     sprintf(pppoe_node_name, "%s:%s",
			     source_ID,	NG_ETHER_HOOK_ORPHAN);
	     }
	     /*
	      *	We now have a PPPoE node attached to the Ethernet
	      *	card. The Ethernet is addressed	as ethername: The PPPoE
	      *	node is	addressed as pppoe_node_name: attach to	it.
	      *	Connect	socket node to specified node Use the same hook
	      *	name on	both ends of the link.
	      */
	     snprintf(ngc.path,	sizeof(ngc.path), "%s",	pppoe_node_name);
	     snprintf(ngc.ourhook, sizeof(ngc.ourhook),	"%s", sessname);
	     snprintf(ngc.peerhook, sizeof(ngc.peerhook), "%s",	sessname);

	     if	(NgSendMsg(*cfd, ".:", NGM_GENERIC_COOKIE,
			   NGM_CONNECT,	&ngc, sizeof(ngc)) < 0)	{
		     return (errno);
	     }

     #ifdef  NONSTANDARD
	     /*
	      *	In some	cases we are speaking to 3Com hardware,	so
	      *	configure node to non-standard mode.
	      */
	     if	(NgSendMsg(*cfd, ngc.path, NGM_PPPOE_COOKIE,
			     NGM_PPPOE_SETMODE,	NG_PPPOE_NONSTANDARD,
			     strlen(NG_PPPOE_NONSTANDARD) + 1) == -1) {
		     return (errno);
	     }
     #endif

	     /*
	      *	Send it	a message telling it to	start up.
	      */
	     bzero(&message, sizeof(message));
	     snprintf(message.idata.hook, sizeof(message.idata.hook),
				     "%s", sessname);
	     if	(service == NULL) {
		     message.idata.data_len = 0;
	     } else {
		     snprintf(message.idata.data,
			      sizeof(message.idata.data), "%s",	service);
		     message.idata.data_len = strlen(service);
	     }
	     /*	Tell session/hook to start up as a client */
	     if	(NgSendMsg(*cfd, ngc.path,
			   NGM_PPPOE_COOKIE, NGM_PPPOE_CONNECT,	&message.idata,
			   sizeof(message.idata) + message.idata.data_len) < 0)	{
		     return (errno);
	     }
	     return (0);
     }

SEE ALSO
     netgraph(3), netgraph(4), ng_ppp(4), ng_socket(4),	ngctl(8), ppp(8)

     L.	Mamakos, K. Lidl, J. Evarts, D.	Carrel,	D. Simone, and R. Wheeler, A
     Method for	transmitting PPP over Ethernet (PPPoE),	RFC 2516.

HISTORY
     The ng_pppoe node type was	implemented in FreeBSD 4.0.

AUTHORS
     Julian Elischer <julian@FreeBSD.org>

FreeBSD	9.2		       January 27, 2006			   FreeBSD 9.2

NAME | SYNOPSIS | DESCRIPTION | HOOKS | CONTROL MESSAGES | SHUTDOWN | EXAMPLES | SEE ALSO | HISTORY | AUTHORS

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