table of contents
NG_PPPOE(4) | Device Drivers Manual | NG_PPPOE(4) |
NAME¶
ng_pppoe — RFC 2516 PPPoE protocol netgraph node typeSYNOPSIS¶
#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 framework to divert and inject Ethernet packets to and from a PPP agent (which is not specified). TheNGM_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 ng_ether(4) node. Once connected, ng_pppoe will send a message down this hook to determine Ethernet address of the underlying node. Obtained address will be stored and then used for outgoing datagrams.
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 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 as 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. It is
possible to request a connection to a specific access concentrator by its
name using the "AC-Name\Service-Name" syntax. A session request
packet will be broadcasted 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 as a server listener. The argument given is the
name of the service to listen for. A zero-length service name 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 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 as 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.
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 successful session.
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_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
NGM_PPPOE_FAIL
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.
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 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 does not 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 does not affect client mode.
NGM_PPPOE_SETMODE
- Configure node to the specified mode. The string argument
is required. This command understands the same keywords that are returned
by the
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"'
NGM_PPPOE_SETENADDR
- Set the node Ethernet address for outgoing datagrams. This
message is important when a node has failed to obtain an Ethernet address
from its peer on the
ethernet
hook, or when user wants to override this address with another one. ASCII form of this message is “setenaddr
”.
SHUTDOWN¶
This node shuts down upon receipt of aNGM_SHUTDOWN
control message, when all session have been disconnected or when the
ethernet
hook is disconnected.
EXAMPLES¶
The following code useslibnetgraph
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_ether(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⟩December 27, 2007 | Debian |