freebsd-dev/sys/netgraph/ng_sample.c
Julian Elischer 1acb27c64a Implement direct support for semipersistant nodes.
(e.g. ethernet nodes are persistent until you rip out the hardware)
Use this support in the ethernet and sample nodes.
Add some more abstraction on the 'item's so that  node and
hook reference counting can be checked easier.
Slight man page correction.
Make pppoe type dependent on ethernet type.
Clean up node shutdown a little.
Move a mutex from MTX_SPIN to MTX_DEF (oops)
Fix small ref-counting bug.
remove warning on one2many type.
2001-01-30 20:51:52 +00:00

503 lines
15 KiB
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>
*
* $FreeBSD$
* $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_info
ng_xxx_stat_type_info = NG_XXX_STATS_TYPE_INFO;
static const struct ng_parse_type ng_xxx_stat_type = {
&ng_parse_struct_type,
&ng_xxx_stat_type_info
};
/* 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 = {
NG_ABI_VERSION,
NG_XXX_NODE_TYPE,
NULL,
ng_xxx_constructor,
ng_xxx_rcvmsg,
ng_xxx_shutdown,
ng_xxx_newhook,
NULL,
ng_xxx_connect,
ng_xxx_rcvdata,
ng_xxx_disconnect,
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, error;
/* 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_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 wil also froo the data and metadata unless
* we have previously disassociated them using the NGI_GET_xxx() macros.
* 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 or meta, so
* if we use up this data or abort we must free BOTH of these.
*
* 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;
meta_p meta;
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(error, otherhook, m, meta); if this
* node is running at some SPL other than SPLNET
* then you should use instead: error =
* ng_queueit(otherhook, m, meta); m = NULL: meta =
* 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' and 'meta' 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 NG_INVALID bit. However
* If we find the NG_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);
int error;
#ifndef PERSISTANT_NODE
NG_NODE_SET_PRIVATE(node, NULL);
NG_NODE_UNREF(privdata->node);
FREE(privdata, M_NETGRAPH);
#else
if (node->nd_flags & NG_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);
}
node->nd_flags &= ~NG_INVALID; /* reset invalid flag */
#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);
}
/*
* Dook 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);
}