25b8ac3c90
This fixes a bug where if the original packet was modified downstream of the tee node, then the copy could get modified too.
338 lines
8.9 KiB
C
338 lines
8.9 KiB
C
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/*
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* ng_tee.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_tee.c,v 1.18 1999/11/01 09:24:52 julian Exp $
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*/
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/*
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* This node is like the tee(1) command and is useful for ``snooping.''
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* It has 4 hooks: left, right, left2right, and right2left. Data
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* entering from the right is passed to the left and duplicated on
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* right2left, and data entering from the left is passed to the right
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* and duplicated on left2right. Data entering from left2right is
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* sent to right, and data from right2left to left.
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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/errno.h>
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#include <sys/kernel.h>
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#include <sys/malloc.h>
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#include <sys/mbuf.h>
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#include <netgraph/ng_message.h>
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#include <netgraph/netgraph.h>
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#include <netgraph/ng_tee.h>
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/* Per hook info */
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struct hookinfo {
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hook_p hook;
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struct ng_tee_hookstat stats;
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};
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/* Per node info */
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struct privdata {
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node_p node;
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struct hookinfo left;
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struct hookinfo right;
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struct hookinfo left2right;
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struct hookinfo right2left;
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};
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typedef struct privdata *sc_p;
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/* Netgraph methods */
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static ng_constructor_t ngt_constructor;
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static ng_rcvmsg_t ngt_rcvmsg;
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static ng_shutdown_t ngt_rmnode;
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static ng_newhook_t ngt_newhook;
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static ng_rcvdata_t ngt_rcvdata;
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static ng_disconnect_t ngt_disconnect;
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/* Netgraph type descriptor */
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static struct ng_type typestruct = {
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NG_VERSION,
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NG_TEE_NODE_TYPE,
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NULL,
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ngt_constructor,
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ngt_rcvmsg,
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ngt_rmnode,
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ngt_newhook,
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NULL,
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NULL,
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ngt_rcvdata,
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ngt_rcvdata,
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ngt_disconnect,
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NULL
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};
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NETGRAPH_INIT(tee, &typestruct);
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/*
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* Node constructor
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*/
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static int
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ngt_constructor(node_p *nodep)
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{
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sc_p privdata;
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int error = 0;
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MALLOC(privdata, sc_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(*privdata));
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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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(*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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* Add a hook
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*/
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static int
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ngt_newhook(node_p node, hook_p hook, const char *name)
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{
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const sc_p sc = node->private;
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if (strcmp(name, NG_TEE_HOOK_RIGHT) == 0) {
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sc->right.hook = hook;
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bzero(&sc->right.stats, sizeof(sc->right.stats));
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hook->private = &sc->right;
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} else if (strcmp(name, NG_TEE_HOOK_LEFT) == 0) {
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sc->left.hook = hook;
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bzero(&sc->left.stats, sizeof(sc->left.stats));
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hook->private = &sc->left;
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} else if (strcmp(name, NG_TEE_HOOK_RIGHT2LEFT) == 0) {
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sc->right2left.hook = hook;
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bzero(&sc->right2left.stats, sizeof(sc->right2left.stats));
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hook->private = &sc->right2left;
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} else if (strcmp(name, NG_TEE_HOOK_LEFT2RIGHT) == 0) {
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sc->left2right.hook = hook;
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bzero(&sc->left2right.stats, sizeof(sc->left2right.stats));
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hook->private = &sc->left2right;
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} else
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return (EINVAL);
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return (0);
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}
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/*
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* Receive a control message
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*/
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static int
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ngt_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr,
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struct ng_mesg **rptr)
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{
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const sc_p sc = node->private;
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struct ng_mesg *resp = NULL;
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int error = 0;
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switch (msg->header.typecookie) {
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case NGM_TEE_COOKIE:
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switch (msg->header.cmd) {
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case NGM_TEE_GET_STATS:
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{
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struct ng_tee_stats *stats;
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NG_MKRESPONSE(resp, msg,
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sizeof(struct ng_tee_stats), M_NOWAIT);
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if (resp == NULL) {
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error = ENOMEM;
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goto done;
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}
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stats = (struct ng_tee_stats *) resp->data;
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bcopy(&sc->right.stats,
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&stats->right, sizeof(stats->right));
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bcopy(&sc->left.stats,
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&stats->left, sizeof(stats->left));
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bcopy(&sc->right2left.stats,
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&stats->right2left, sizeof(stats->right2left));
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bcopy(&sc->left2right.stats,
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&stats->left2right, sizeof(stats->left2right));
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break;
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}
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case NGM_TEE_CLR_STATS:
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bzero(&sc->right.stats, sizeof(sc->right.stats));
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bzero(&sc->left.stats, sizeof(sc->left.stats));
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bzero(&sc->right2left.stats,
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sizeof(sc->right2left.stats));
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bzero(&sc->left2right.stats,
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sizeof(sc->left2right.stats));
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break;
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default:
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error = EINVAL;
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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;
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break;
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}
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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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done:
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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 on a hook
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*
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* If data comes in the right link send a copy out right2left, and then
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* send the original onwards out through the left link.
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* Do the opposite for data coming in from the left link.
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* Data coming in right2left or left2right is forwarded
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* on through the appropriate destination hook as if it had come
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* from the other side.
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*/
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static int
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ngt_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
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{
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const sc_p sc = hook->node->private;
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struct hookinfo *const hinfo = (struct hookinfo *) hook->private;
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struct hookinfo *dest;
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struct hookinfo *dup;
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int error = 0;
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/* Which hook? */
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if (hinfo == &sc->left) {
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dup = &sc->left2right;
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dest = &sc->right;
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} else if (hinfo == &sc->right) {
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dup = &sc->right2left;
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dest = &sc->left;
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} else if (hinfo == &sc->right2left) {
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dup = NULL;
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dest = &sc->left;
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} else if (hinfo == &sc->left2right) {
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dup = NULL;
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dest = &sc->right;
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} else
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panic("%s: no hook!", __FUNCTION__);
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/* Update stats on incoming hook */
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hinfo->stats.inOctets += m->m_pkthdr.len;
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hinfo->stats.inFrames++;
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/* Duplicate packet and meta info if requried */
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if (dup != NULL) {
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struct mbuf *m2;
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meta_p meta2;
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/* Copy packet */
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m2 = m_dup(m, M_NOWAIT);
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if (m2 == NULL) {
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NG_FREE_DATA(m, meta);
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return (ENOBUFS);
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}
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/* Copy meta info */
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if (meta != NULL) {
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MALLOC(meta2, meta_p,
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meta->used_len, M_NETGRAPH, M_NOWAIT);
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if (meta2 == NULL) {
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m_freem(m2);
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NG_FREE_DATA(m, meta);
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return (ENOMEM);
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}
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bcopy(meta, meta2, meta->used_len);
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meta2->allocated_len = meta->used_len;
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} else
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meta2 = NULL;
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/* Deliver duplicate */
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dup->stats.outOctets += m->m_pkthdr.len;
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dup->stats.outFrames++;
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NG_SEND_DATA(error, dup->hook, m2, meta2);
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}
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/* Deliver frame out destination hook */
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dest->stats.outOctets += m->m_pkthdr.len;
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dest->stats.outFrames++;
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NG_SEND_DATA(error, dest->hook, m, meta);
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return (0);
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}
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/*
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* Shutdown processing
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*
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* This is tricky. If we have both a left and right hook, then we
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* probably want to extricate ourselves and leave the two peers
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* still linked to each other. Otherwise we should just shut down as
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* a normal node would.
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*
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* To keep the scope of info correct the routine to "extract" a node
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* from two links is in ng_base.c.
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*/
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static int
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ngt_rmnode(node_p node)
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{
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const sc_p privdata = node->private;
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node->flags |= NG_INVALID;
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if (privdata->left.hook && privdata->right.hook)
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ng_bypass(privdata->left.hook, privdata->right.hook);
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ng_cutlinks(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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return (0);
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}
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/*
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* Hook disconnection
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*/
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static int
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ngt_disconnect(hook_p hook)
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{
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struct hookinfo *const hinfo = (struct hookinfo *) hook->private;
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KASSERT(hinfo != NULL, ("%s: null info", __FUNCTION__));
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hinfo->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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