FreeBSD-5.3/sys/netgraph/ng_sample.c
/*
* ng_sample.c
*
* Copyright (c) 1996-1999 Whistle Communications, Inc.
* All rights reserved.
*
* Subject to the following obligations and disclaimer of warranty, use and
* redistribution of this software, in source or object code forms, with or
* without modifications are expressly permitted by Whistle Communications;
* provided, however, that:
* 1. Any and all reproductions of the source or object code must include the
* copyright notice above and the following disclaimer of warranties; and
* 2. No rights are granted, in any manner or form, to use Whistle
* Communications, Inc. trademarks, including the mark "WHISTLE
* COMMUNICATIONS" on advertising, endorsements, or otherwise except as
* such appears in the above copyright notice or in the software.
*
* THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
* TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
* REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
* INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
* WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
* REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
* SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
* IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
* RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
* WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
* PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*
* Author: Julian Elischer <julian@freebsd.org>
*
* $FreeBSD: src/sys/netgraph/ng_sample.c,v 1.24 2004/07/29 08:05:02 glebius Exp $
* $Whistle: ng_sample.c,v 1.13 1999/11/01 09:24:52 julian Exp $
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/ctype.h>
#include <sys/errno.h>
#include <sys/syslog.h>
#include <netgraph/ng_message.h>
#include <netgraph/ng_parse.h>
#include <netgraph/ng_sample.h>
#include <netgraph/netgraph.h>
/* If you do complicated mallocs you may want to do this */
/* and use it for your mallocs */
#ifdef NG_SEPARATE_MALLOC
MALLOC_DEFINE(M_NETGRAPH_XXX, "netgraph_xxx", "netgraph xxx node ");
#else
#define M_NETGRAPH_XXX M_NETGRAPH
#endif
/*
* This section contains the netgraph method declarations for the
* sample node. These methods define the netgraph 'type'.
*/
static ng_constructor_t ng_xxx_constructor;
static ng_rcvmsg_t ng_xxx_rcvmsg;
static ng_shutdown_t ng_xxx_shutdown;
static ng_newhook_t ng_xxx_newhook;
static ng_connect_t ng_xxx_connect;
static ng_rcvdata_t ng_xxx_rcvdata; /* note these are both ng_rcvdata_t */
static ng_disconnect_t ng_xxx_disconnect;
/* Parse type for struct ngxxxstat */
static const struct ng_parse_struct_field ng_xxx_stat_type_fields[]
= NG_XXX_STATS_TYPE_INFO;
static const struct ng_parse_type ng_xxx_stat_type = {
&ng_parse_struct_type,
&ng_xxx_stat_type_fields
};
/* List of commands and how to convert arguments to/from ASCII */
static const struct ng_cmdlist ng_xxx_cmdlist[] = {
{
NGM_XXX_COOKIE,
NGM_XXX_GET_STATUS,
"getstatus",
NULL,
&ng_xxx_stat_type,
},
{
NGM_XXX_COOKIE,
NGM_XXX_SET_FLAG,
"setflag",
&ng_parse_int32_type,
NULL
},
{ 0 }
};
/* Netgraph node type descriptor */
static struct ng_type typestruct = {
.version = NG_ABI_VERSION,
.name = NG_XXX_NODE_TYPE,
.constructor = ng_xxx_constructor,
.rcvmsg = ng_xxx_rcvmsg,
.shutdown = ng_xxx_shutdown,
.newhook = ng_xxx_newhook,
/* .findhook = ng_xxx_findhook, */
.connect = ng_xxx_connect,
.rcvdata = ng_xxx_rcvdata,
.disconnect = ng_xxx_disconnect,
.cmdlist = ng_xxx_cmdlist,
};
NETGRAPH_INIT(xxx, &typestruct);
/* Information we store for each hook on each node */
struct XXX_hookinfo {
int dlci; /* The DLCI it represents, -1 == downstream */
int channel; /* The channel representing this DLCI */
hook_p hook;
};
/* Information we store for each node */
struct XXX {
struct XXX_hookinfo channel[XXX_NUM_DLCIS];
struct XXX_hookinfo downstream_hook;
node_p node; /* back pointer to node */
hook_p debughook;
u_int packets_in; /* packets in from downstream */
u_int packets_out; /* packets out towards downstream */
u_int32_t flags;
};
typedef struct XXX *xxx_p;
/*
* Allocate the private data structure. The generic node has already
* been created. Link them together. We arrive with a reference to the node
* i.e. the reference count is incremented for us already.
*
* If this were a device node than this work would be done in the attach()
* routine and the constructor would return EINVAL as you should not be able
* to creatednodes that depend on hardware (unless you can add the hardware :)
*/
static int
ng_xxx_constructor(node_p node)
{
xxx_p privdata;
int i;
/* Initialize private descriptor */
MALLOC(privdata, xxx_p, sizeof(*privdata), M_NETGRAPH,
M_NOWAIT | M_ZERO);
if (privdata == NULL)
return (ENOMEM);
for (i = 0; i < XXX_NUM_DLCIS; i++) {
privdata->channel[i].dlci = -2;
privdata->channel[i].channel = i;
}
/* Link structs together; this counts as our one reference to *nodep */
NG_NODE_SET_PRIVATE(node, privdata);
privdata->node = node;
return (0);
}
/*
* Give our ok for a hook to be added...
* If we are not running this might kick a device into life.
* Possibly decode information out of the hook name.
* Add the hook's private info to the hook structure.
* (if we had some). In this example, we assume that there is a
* an array of structs, called 'channel' in the private info,
* one for each active channel. The private
* pointer of each hook points to the appropriate XXX_hookinfo struct
* so that the source of an input packet is easily identified.
* (a dlci is a frame relay channel)
*/
static int
ng_xxx_newhook(node_p node, hook_p hook, const char *name)
{
const xxx_p xxxp = NG_NODE_PRIVATE(node);
const char *cp;
int dlci = 0;
int chan;
#if 0
/* Possibly start up the device if it's not already going */
if ((xxxp->flags & SCF_RUNNING) == 0) {
ng_xxx_start_hardware(xxxp);
}
#endif
/* Example of how one might use hooks with embedded numbers: All
* hooks start with 'dlci' and have a decimal trailing channel
* number up to 4 digits Use the leadin defined int he associated .h
* file. */
if (strncmp(name,
NG_XXX_HOOK_DLCI_LEADIN, strlen(NG_XXX_HOOK_DLCI_LEADIN)) == 0) {
char *eptr;
cp = name + sizeof(NG_XXX_HOOK_DLCI_LEADIN);
if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0'))
return (EINVAL);
dlci = (int)strtoul(cp, &eptr, 10);
if (*eptr != '\0' || dlci < 0 || dlci > 1023)
return (EINVAL);
/* We have a dlci, now either find it, or allocate it */
for (chan = 0; chan < XXX_NUM_DLCIS; chan++)
if (xxxp->channel[chan].dlci == dlci)
break;
if (chan == XXX_NUM_DLCIS) {
for (chan = 0; chan < XXX_NUM_DLCIS; chan++)
if (xxxp->channel[chan].dlci != -2)
continue;
if (chan == XXX_NUM_DLCIS)
return (ENOBUFS);
}
if (xxxp->channel[chan].hook != NULL)
return (EADDRINUSE);
NG_HOOK_SET_PRIVATE(hook, xxxp->channel + chan);
xxxp->channel[chan].hook = hook;
return (0);
} else if (strcmp(name, NG_XXX_HOOK_DOWNSTREAM) == 0) {
/* Example of simple predefined hooks. */
/* do something specific to the downstream connection */
xxxp->downstream_hook.hook = hook;
NG_HOOK_SET_PRIVATE(hook, &xxxp->downstream_hook);
} else if (strcmp(name, NG_XXX_HOOK_DEBUG) == 0) {
/* do something specific to a debug connection */
xxxp->debughook = hook;
NG_HOOK_SET_PRIVATE(hook, NULL);
} else
return (EINVAL); /* not a hook we know about */
return(0);
}
/*
* Get a netgraph control message.
* We actually recieve a queue item that has a pointer to the message.
* If we free the item, the message will be freed too, unless we remove
* it from the item using NGI_GET_MSG();
* The return address is also stored in the item, as an ng_ID_t,
* accessible as NGI_RETADDR(item);
* Check it is one we understand. If needed, send a response.
* We could save the address for an async action later, but don't here.
* Always free the message.
* The response should be in a malloc'd region that the caller can 'free'.
* A response is not required.
* Theoretically you could respond defferently to old message types if
* the cookie in the header didn't match what we consider to be current
* (so that old userland programs could continue to work).
*/
static int
ng_xxx_rcvmsg(node_p node, item_p item, hook_p lasthook)
{
const xxx_p xxxp = NG_NODE_PRIVATE(node);
struct ng_mesg *resp = NULL;
int error = 0;
struct ng_mesg *msg;
NGI_GET_MSG(item, msg);
/* Deal with message according to cookie and command */
switch (msg->header.typecookie) {
case NGM_XXX_COOKIE:
switch (msg->header.cmd) {
case NGM_XXX_GET_STATUS:
{
struct ngxxxstat *stats;
NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT);
if (!resp) {
error = ENOMEM;
break;
}
stats = (struct ngxxxstat *) resp->data;
stats->packets_in = xxxp->packets_in;
stats->packets_out = xxxp->packets_out;
break;
}
case NGM_XXX_SET_FLAG:
if (msg->header.arglen != sizeof(u_int32_t)) {
error = EINVAL;
break;
}
xxxp->flags = *((u_int32_t *) msg->data);
break;
default:
error = EINVAL; /* unknown command */
break;
}
break;
default:
error = EINVAL; /* unknown cookie type */
break;
}
/* Take care of synchronous response, if any */
NG_RESPOND_MSG(error, node, item, resp);
/* Free the message and return */
NG_FREE_MSG(msg);
return(error);
}
/*
* Receive data, and do something with it.
* Actually we receive a queue item which holds the data.
* If we free the item it will also free the data unless we have
* previously disassociated it using the NGI_GET_M() macro.
* Possibly send it out on another link after processing.
* Possibly do something different if it comes from different
* hooks. The caller will never free m, so if we use up this data or
* abort we must free it.
*
* If we want, we may decide to force this data to be queued and reprocessed
* at the netgraph NETISR time.
* We would do that by setting the HK_QUEUE flag on our hook. We would do that
* in the connect() method.
*/
static int
ng_xxx_rcvdata(hook_p hook, item_p item )
{
const xxx_p xxxp = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
int chan = -2;
int dlci = -2;
int error;
struct mbuf *m;
NGI_GET_M(item, m);
if (NG_HOOK_PRIVATE(hook)) {
dlci = ((struct XXX_hookinfo *) NG_HOOK_PRIVATE(hook))->dlci;
chan = ((struct XXX_hookinfo *) NG_HOOK_PRIVATE(hook))->channel;
if (dlci != -1) {
/* If received on a DLCI hook process for this
* channel and pass it to the downstream module.
* Normally one would add a multiplexing header at
* the front here */
/* M_PREPEND(....) ; */
/* mtod(m, xxxxxx)->dlci = dlci; */
NG_FWD_NEW_DATA(error, item,
xxxp->downstream_hook.hook, m);
xxxp->packets_out++;
} else {
/* data came from the multiplexed link */
dlci = 1; /* get dlci from header */
/* madjust(....) *//* chop off header */
for (chan = 0; chan < XXX_NUM_DLCIS; chan++)
if (xxxp->channel[chan].dlci == dlci)
break;
if (chan == XXX_NUM_DLCIS) {
NG_FREE_ITEM(item);
NG_FREE_M(m);
return (ENETUNREACH);
}
/* If we were called at splnet, use the following:
* NG_SEND_DATA_ONLY(error, otherhook, m); if this
* node is running at some SPL other than SPLNET
* then you should use instead: error =
* ng_queueit(otherhook, m, NULL); m = NULL;
* This queues the data using the standard NETISR
* system and schedules the data to be picked
* up again once the system has moved to SPLNET and
* the processing of the data can continue. After
* these are run 'm' should be considered
* as invalid and NG_SEND_DATA actually zaps them. */
NG_FWD_NEW_DATA(error, item,
xxxp->channel[chan].hook, m);
xxxp->packets_in++;
}
} else {
/* It's the debug hook, throw it away.. */
if (hook == xxxp->downstream_hook.hook) {
NG_FREE_ITEM(item);
NG_FREE_M(m);
}
}
return 0;
}
#if 0
/*
* If this were a device node, the data may have been received in response
* to some interrupt.
* in which case it would probably look as follows:
*/
devintr()
{
int error;
* here */
/* get packet from device and send on */
m = MGET(blah blah)
NG_SEND_DATA_ONLY(error, xxxp->upstream_hook.hook, m);
/* see note above in xxx_rcvdata() */
/* and ng_xxx_connect() */
}
#endif /* 0 */
/*
* Do local shutdown processing..
* All our links and the name have already been removed.
* If we are a persistant device, we might refuse to go away.
* In the case of a persistant node we signal the framework that we
* are still in business by clearing the NGF_INVALID bit. However
* If we find the NGF_REALLY_DIE bit set, this means that
* we REALLY need to die (e.g. hardware removed).
* This would have been set using the NG_NODE_REALLY_DIE(node)
* macro in some device dependent function (not shown here) before
* calling ng_rmnode_self().
*/
static int
ng_xxx_shutdown(node_p node)
{
const xxx_p privdata = NG_NODE_PRIVATE(node);
#ifndef PERSISTANT_NODE
NG_NODE_SET_PRIVATE(node, NULL);
NG_NODE_UNREF(node);
FREE(privdata, M_NETGRAPH);
#else
if (node->nd_flags & NGF_REALLY_DIE) {
/*
* WE came here because the widget card is being unloaded,
* so stop being persistant.
* Actually undo all the things we did on creation.
*/
NG_NODE_SET_PRIVATE(node, NULL);
NG_NODE_UNREF(privdata->node);
FREE(privdata, M_NETGRAPH);
return (0);
}
NG_NODE_REVIVE(node); /* tell ng_rmnode() we will persist */
#endif /* PERSISTANT_NODE */
return (0);
}
/*
* This is called once we've already connected a new hook to the other node.
* It gives us a chance to balk at the last minute.
*/
static int
ng_xxx_connect(hook_p hook)
{
#if 0
/*
* If we were a driver running at other than splnet then
* we should set the QUEUE bit on the edge so that we
* will deliver by queing.
*/
if /*it is the upstream hook */
NG_HOOK_FORCE_QUEUE(NG_HOOK_PEER(hook));
#endif
#if 0
/*
* If for some reason we want incoming date to be queued
* by the NETISR system and delivered later we can set the same bit on
* OUR hook. (maybe to allow unwinding of the stack)
*/
if (NG_HOOK_PRIVATE(hook)) {
int dlci;
/*
* If it's dlci 1023, requeue it so that it's handled
* at a lower priority. This is how a node decides to
* defer a data message.
*/
dlci = ((struct XXX_hookinfo *) NG_HOOK_PRIVATE(hook))->dlci;
if (dlci == 1023) {
NG_HOOK_FORCE_QUEUE(hook);
}
#endif
/* otherwise be really amiable and just say "YUP that's OK by me! " */
return (0);
}
/*
* Hook disconnection
*
* For this type, removal of the last link destroys the node
*/
static int
ng_xxx_disconnect(hook_p hook)
{
if (NG_HOOK_PRIVATE(hook))
((struct XXX_hookinfo *) (NG_HOOK_PRIVATE(hook)))->hook = NULL;
if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
&& (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) /* already shutting down? */
ng_rmnode_self(NG_HOOK_NODE(hook));
return (0);
}