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 conjunction with the netgraph(4) extensions to the Ethernet frame
work to divert and inject Ethernet packets to and from a PPP agent (which
is not specified).
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 Eth

ernet */
u_int packets_out; /* packets out towards

Ethernet */

};
NGM_TEXT_STATUS: This generic message returns is a human-readable ver; sion 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 lis; tener. 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 unmodi; fied back to
the process responsible for starting the service. It; can then examine 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 LIS; TEN mode hook (
see above). This is so that information that is re; quired for the
session that is embedded in the original session re; quest packet, is
made available to the state machine that eventually an; swers the
request. When the Session request packet is received,; the session
negotiation will proceed. This command uses the ngpp; poe_init_data
structure shown below.
The three commands above use a common data structure:: struct ngpppoe_init_data {
char hook[NG_HOOKSIZ]; /* hook to moni

tor 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 ses; sion 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 successful session.
NGM_NGM_PPPOE_FAIL: This command is sent to the node that started this ses; sion with one
of the above messages, and reports a state change.; This message
reports failed Session negotiation. It uses the struc; ture shown
below, and reports back the hook name corresponding to; the failed
session. The hook will probably have been removed im; mediately after
sending this message
NGM_NGM_PPPOE_CLOSE: This command is sent to the node that started this ses; sion 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 im; mediately 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 ses; sion with one
of the above messages, and reports the Access Concen; trator 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 following 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 encapsulating packets into incorrect 3Com ethertypes.

This compatibility option doesn't affect server mode. In

server mode
ng_pppoe supports both modes simultaneously, de

pending on the
ethertype, the client used when connecting.; "D-Link"
When ng_pppoe is a PPPoE server serving only spe

cific ServiceName(s), it will respond to a PADI requests with

empty ServiceName 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 argu; ment is
required. This command understands same keywords, that; are returned
by NGM_PPPOE_GETMODE command. ASCII form of this mes; sage is
"pppoe_setmode". For example, the following command; will configure
the node to initiate the next session in the propri; etary 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 disconnected.

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 han
dle 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 *sess
name,: 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 ask

ing 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_GENER

IC_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", pp; poe_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_NONSTAN

DARD,
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.ida; ta.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.ida

ta.data_len) < 0) {; return (errno);
} return (0);
}

HISTORY

The ng_pppoe node type was implemented in FreeBSD 4.0.

AUTHORS

Julian Elischer <julian@FreeBSD.org>
BSD January 27, 2006

docs.sk

comprehensive documentation repository

See also

ng_pppoe(4)

NAME

SYNOPSIS

DESCRIPTION

HOOKS

CONTROL MESSAGES

SHUTDOWN

EXAMPLES

SEE ALSO

HISTORY

AUTHORS