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ng_pppoe(4)

NAME

     ng_pppoe -- RFC 2516 PPPoE protocol netgraph node type

SYNOPSIS

     #include <net/ethernet.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 it's 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 it's 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
	  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
	  The ng_pppoe node can operate in two different modes: standard mode
	  described in RFC 2516, and in a non-standard mode compatible with
	  equipment from 3Com.	When ng_pppoe is a client node, it initiates a
	  ple, 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.

SYSCTL VARIABLES

     The variable net.graph.nonstandard_pppoe is a deprecated way to set
     ng_pppoe client mode.  Consider using NGM_PPPOE_SETMODE or an appropriate
     option in your client software instead.

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 {
		     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)

		     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);
	     }
	     /*
	     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 5.4			 July 27, 2004			   FreeBSD 5.4

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