441 lines
13 KiB
C
441 lines
13 KiB
C
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/*
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* ng_sample.c
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*
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* Copyright (c) 1996-1999 Whistle Communications, Inc.
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* All rights reserved.
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*
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* Subject to the following obligations and disclaimer of warranty, use and
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* redistribution of this software, in source or object code forms, with or
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* without modifications are expressly permitted by Whistle Communications;
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* provided, however, that:
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* 1. Any and all reproductions of the source or object code must include the
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* copyright notice above and the following disclaimer of warranties; and
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* 2. No rights are granted, in any manner or form, to use Whistle
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* Communications, Inc. trademarks, including the mark "WHISTLE
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* COMMUNICATIONS" on advertising, endorsements, or otherwise except as
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* such appears in the above copyright notice or in the software.
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*
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* THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
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* TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
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* REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
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* INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
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* WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
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* REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
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* SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
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* IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
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* RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
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* WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
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* PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
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* OF SUCH DAMAGE.
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*
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* Author: Julian Elischer <julian@whistle.com>
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*
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* $FreeBSD$
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* $Whistle: ng_sample.c,v 1.13 1999/11/01 09:24:52 julian Exp $
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/mbuf.h>
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#include <sys/malloc.h>
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#include <sys/errno.h>
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#include <sys/syslog.h>
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#include <netgraph/ng_message.h>
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#include <netgraph/ng_sample.h>
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#include <netgraph/netgraph.h>
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/*
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* This section contains the netgraph method declarations for the
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* sample node. These methods define the netgraph 'type'.
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*/
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static ng_constructor_t ng_xxx_constructor;
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static ng_rcvmsg_t ng_xxx_rcvmsg;
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static ng_shutdown_t ng_xxx_rmnode;
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static ng_newhook_t ng_xxx_newhook;
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static ng_connect_t ng_xxx_connect;
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static ng_rcvdata_t ng_xxx_rcvdata; /* note these are both ng_rcvdata_t */
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static ng_rcvdata_t ng_xxx_rcvdataq; /* note these are both ng_rcvdata_t */
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static ng_disconnect_t ng_xxx_disconnect;
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/* Netgraph node type descriptor */
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static struct ng_type typestruct = {
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NG_VERSION,
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NG_XXX_NODE_TYPE,
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NULL,
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ng_xxx_constructor,
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ng_xxx_rcvmsg,
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ng_xxx_rmnode,
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ng_xxx_newhook,
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NULL,
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ng_xxx_connect,
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ng_xxx_rcvdata,
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ng_xxx_rcvdataq,
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ng_xxx_disconnect
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};
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NETGRAPH_INIT(xxx, &typestruct);
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/* Information we store for each hook on each node */
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struct XXX_hookinfo {
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int dlci; /* The DLCI it represents, -1 == downstream */
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int channel; /* The channel representing this DLCI */
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hook_p hook;
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};
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/* Information we store for each node */
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struct XXX {
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struct XXX_hookinfo channel[XXX_NUM_DLCIS];
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struct XXX_hookinfo downstream_hook;
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node_p node; /* back pointer to node */
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hook_p debughook;
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u_int packets_in; /* packets in from downstream */
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u_int packets_out; /* packets out towards downstream */
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u_int32_t flags;
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};
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typedef struct XXX *xxx_p;
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/*
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* Allocate the private data structure and the generic node
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* and link them together.
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*
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* ng_make_node_common() returns with a generic node struct
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* with a single reference for us.. we transfer it to the
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* private structure.. when we free the private struct we must
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* unref the node so it gets freed too.
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*
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* If this were a device node than this work would be done in the attach()
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* routine and the constructor would return EINVAL as you should not be able
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* to creatednodes that depend on hardware (unless you can add the hardware :)
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*/
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static int
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ng_xxx_constructor(node_p *nodep)
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{
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xxx_p privdata;
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int i, error;
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/* Initialize private descriptor */
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MALLOC(privdata, xxx_p, sizeof(*privdata), M_NETGRAPH, M_WAITOK);
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if (privdata == NULL)
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return (ENOMEM);
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bzero(privdata, sizeof(struct XXX));
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for (i = 0; i < XXX_NUM_DLCIS; i++) {
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privdata->channel[i].dlci = -2;
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privdata->channel[i].channel = i;
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}
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/* Call the 'generic' (ie, superclass) node constructor */
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if ((error = ng_make_node_common(&typestruct, nodep))) {
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FREE(privdata, M_NETGRAPH);
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return (error);
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}
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/* Link structs together; this counts as our one reference to *nodep */
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(*nodep)->private = privdata;
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privdata->node = *nodep;
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return (0);
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}
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/*
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* Give our ok for a hook to be added...
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* If we are not running this might kick a device into life.
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* Possibly decode information out of the hook name.
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* Add the hook's private info to the hook structure.
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* (if we had some). In this example, we assume that there is a
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* an array of structs, called 'channel' in the private info,
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* one for each active channel. The private
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* pointer of each hook points to the appropriate XXX_hookinfo struct
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* so that the source of an input packet is easily identified.
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* (a dlci is a frame relay channel)
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*/
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static int
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ng_xxx_newhook(node_p node, hook_p hook, const char *name)
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{
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const xxx_p xxxp = node->private;
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const char *cp;
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char c = '\0';
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int digits = 0;
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int dlci = 0;
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int chan;
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#if 0
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/* Possibly start up the device if it's not already going */
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if ((xxxp->flags & SCF_RUNNING) == 0) {
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ng_xxx_start_hardware(xxxp);
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}
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#endif
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/* Example of how one might use hooks with embedded numbers: All
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* hooks start with 'dlci' and have a decimal trailing channel
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* number up to 4 digits Use the leadin defined int he associated .h
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* file. */
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if (strncmp(name,
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NG_XXX_HOOK_DLCI_LEADIN, strlen(NG_XXX_HOOK_DLCI_LEADIN)) == 0) {
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const char *eptr;
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cp = name + sizeof(NG_XXX_HOOK_DLCI_LEADIN);
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if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0'))
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return (EINVAL);
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dlci = (int)strtoul(cp, &eptr, 10);
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if (*eptr != '\0' || dlci < 0 || dlci > 1023)
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return (EINVAL);
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/* We have a dlci, now either find it, or allocate it */
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for (chan = 0; chan < XXX_NUM_DLCIS; chan++)
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if (xxxp->channel[chan].dlci == dlci)
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break;
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if (chan == XXX_NUM_DLCIS) {
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for (chan = 0; chan < XXX_NUM_DLCIS; chan++)
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if (xxxp->channel[chan].dlci != -2)
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continue;
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if (chan == XXX_NUM_DLCIS)
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return (ENOBUFS);
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}
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if (xxxp->channel[chan].hook != NULL)
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return (EADDRINUSE);
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hook->private = xxxp->channel + chan;
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xxxp->channel[chan].hook = hook;
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return (0);
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} else if (strcmp(name, NG_XXX_HOOK_DOWNSTREAM) == 0) {
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/* Example of simple predefined hooks. */
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/* do something specific to the downstream connection */
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xxxp->downstream_hook.hook = hook;
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hook->private = &xxxp->downstream_hook;
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} else if (strcmp(name, NG_XXX_HOOK_DEBUG) == 0) {
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/* do something specific to a debug connection */
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xxxp->debughook = hook;
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hook->private = NULL;
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} else
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return (EINVAL); /* not a hook we know about */
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return(0);
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}
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/*
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* Get a netgraph control message.
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* Check it is one we understand. If needed, send a response.
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* We could save the address for an async action later, but don't here.
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* Always free the message.
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* The response should be in a malloc'd region that the caller can 'free'.
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* A response is not required.
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* Theoretically you could respond defferently to old message types if
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* the cookie in the header didn't match what we consider to be current
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* (so that old userland programs could continue to work).
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*/
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static int
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ng_xxx_rcvmsg(node_p node,
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struct ng_mesg *msg, const char *retaddr, struct ng_mesg **rptr)
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{
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const xxx_p xxxp = node->private;
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struct ng_mesg *resp = NULL;
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int error = 0;
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/* Deal with message according to cookie and command */
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switch (msg->header.typecookie) {
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case NGM_XXX_COOKIE:
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switch (msg->header.cmd) {
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case NGM_XXX_GET_STATUS:
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{
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struct ngxxxstat *stats;
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NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT);
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if (!resp) {
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error = ENOMEM;
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break;
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}
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stats = (struct ngxxxstat *) resp->data;
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stats->packets_in = xxxp->packets_in;
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stats->packets_out = xxxp->packets_out;
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break;
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}
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case NGM_XXX_SET_FLAG:
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if (msg->header.arglen != sizeof(u_int32_t)) {
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error = EINVAL;
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break;
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}
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xxxp->flags = *((u_int32_t *) msg->data);
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break;
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default:
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error = EINVAL; /* unknown command */
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break;
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}
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break;
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default:
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error = EINVAL; /* unknown cookie type */
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break;
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}
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/* Take care of synchronous response, if any */
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if (rptr)
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*rptr = resp;
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else if (resp)
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FREE(resp, M_NETGRAPH);
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/* Free the message and return */
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FREE(msg, M_NETGRAPH);
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return(error);
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}
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/*
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* Receive data, and do something with it.
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* Possibly send it out on another link after processing.
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* Possibly do something different if it comes from different
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* hooks. the caller will never free m or meta, so
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* if we use up this data or abort we must free BOTH of these.
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*
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* If we want, we may decide to force this data to be queued and reprocessed
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* at the netgraph NETISR time. (at which time it will be entered using ng_xxx_rcvdataq().
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*/
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static int
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ng_xxx_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
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{
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int dlci = -2;
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int error;
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if (hook->private) {
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/*
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* If it's dlci 1023, requeue it so that it's handled at a lower priority.
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* This is how a node decides to defer a data message.
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*/
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dlci = ((struct XXX_hookinfo *) hook->private)->dlci;
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if (dlci == 1023) {
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return(ng_queue_data(hook->peer, m, meta));
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}
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}
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return(ng_xxx_rcvdataq(hook, m, meta));
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}
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/*
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* Always accept the data. This version of rcvdata is called from the dequeueing routine.
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*/
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static int
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ng_xxx_rcvdataq(hook_p hook, struct mbuf *m, meta_p meta)
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{
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const xxx_p xxxp = hook->node->private;
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int chan = -2;
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int dlci = -2;
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int error;
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if (hook->private) {
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dlci = ((struct XXX_hookinfo *) hook->private)->dlci;
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chan = ((struct XXX_hookinfo *) hook->private)->channel;
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if (dlci != -1) {
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/* If received on a DLCI hook process for this
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* channel and pass it to the downstream module.
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* Normally one would add a multiplexing header at
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* the front here */
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/* M_PREPEND(....) ; */
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/* mtod(m, xxxxxx)->dlci = dlci; */
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error = ng_send_data(xxxp->downstream_hook.hook,
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m, meta);
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xxxp->packets_out++;
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} else {
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/* data came from the multiplexed link */
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dlci = 1; /* get dlci from header */
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/* madjust(....) *//* chop off header */
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for (chan = 0; chan < XXX_NUM_DLCIS; chan++)
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if (xxxp->channel[chan].dlci == dlci)
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break;
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if (chan == XXX_NUM_DLCIS) {
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NG_FREE_DATA(m, meta);
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return (ENETUNREACH);
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}
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/* If we were called at splnet, use the following:
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* NG_SEND_DATA(error, otherhook, m, meta); if this
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* node is running at some SPL other than SPLNET
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* then you should use instead: error =
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* ng_queueit(otherhook, m, meta); m = NULL: meta =
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* NULL; this queues the data using the standard
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* NETISR system and schedules the data to be picked
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* up again once the system has moved to SPLNET and
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* the processing of the data can continue. after
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* these are run 'm' and 'meta' should be considered
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* as invalid and NG_SEND_DATA actually zaps them. */
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NG_SEND_DATA(error, xxxp->channel[chan].hook, m, meta);
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xxxp->packets_in++;
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}
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} else {
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/* It's the debug hook, throw it away.. */
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if (hook == xxxp->downstream_hook.hook)
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NG_FREE_DATA(m, meta);
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}
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return 0;
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}
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#if 0
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/*
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* If this were a device node, the data may have been received in response
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* to some interrupt.
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* in which case it would probably look as follows:
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*/
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devintr()
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{
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meta_p meta = NULL; /* whatever metadata we might imagine goes
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* here */
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/* get packet from device and send on */
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m = MGET(blah blah)
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error = ng_queueit(upstream, m, meta); /* see note above in
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* xxx_rcvdata() */
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}
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#endif /* 0 */
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/*
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* Do local shutdown processing..
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* If we are a persistant device, we might refuse to go away, and
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* we'd only remove our links and reset ourself.
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*/
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static int
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ng_xxx_rmnode(node_p node)
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{
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const xxx_p privdata = node->private;
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node->flags |= NG_INVALID;
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ng_cutlinks(node);
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#ifndef PERSISTANT_NODE
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ng_unname(node);
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node->private = NULL;
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ng_unref(privdata->node);
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FREE(privdata, M_NETGRAPH);
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#else
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privdata->packets_in = 0; /* reset stats */
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privdata->packets_out = 0;
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node->flags &= ~NG_INVALID; /* reset invalid flag */
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#endif /* PERSISTANT_NODE */
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return (0);
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}
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/*
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* This is called once we've already connected a new hook to the other node.
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* It gives us a chance to balk at the last minute.
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*/
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static int
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ng_xxx_connect(hook_p hook)
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{
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/* be really amiable and just say "YUP that's OK by me! " */
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return (0);
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}
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/*
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* Dook disconnection
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*
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* For this type, removal of the last link destroys the node
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*/
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static int
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ng_xxx_disconnect(hook_p hook)
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{
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if (hook->private)
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((struct XXX_hookinfo *) (hook->private))->hook == NULL;
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if (hook->node->numhooks == 0)
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ng_rmnode(hook->node);
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return (0);
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}
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