1
2/*
3 * ng_tee.c
4 */
5
6/*-
7 * Copyright (c) 1996-1999 Whistle Communications, Inc.
8 * All rights reserved.
9 *
10 * Subject to the following obligations and disclaimer of warranty, use and
11 * redistribution of this software, in source or object code forms, with or
12 * without modifications are expressly permitted by Whistle Communications;
13 * provided, however, that:
14 * 1. Any and all reproductions of the source or object code must include the
15 *    copyright notice above and the following disclaimer of warranties; and
16 * 2. No rights are granted, in any manner or form, to use Whistle
17 *    Communications, Inc. trademarks, including the mark "WHISTLE
18 *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
19 *    such appears in the above copyright notice or in the software.
20 *
21 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
22 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
23 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
24 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
26 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
27 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
28 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
29 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
30 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
31 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
32 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
33 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
34 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
35 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
36 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
37 * OF SUCH DAMAGE.
38 *
39 * Author: Julian Elischer <julian@freebsd.org>
40 * $Whistle: ng_tee.c,v 1.18 1999/11/01 09:24:52 julian Exp $
41 */
42
43/*
44 * This node is like the tee(1) command and is useful for ``snooping.''
45 * It has 4 hooks: left, right, left2right, and right2left. Data
46 * entering from the right is passed to the left and duplicated on
47 * right2left, and data entering from the left is passed to the right
48 * and duplicated on left2right. Data entering from left2right is
49 * sent to left, and data from right2left to right.
50 */
51
52#include <sys/param.h>
53#include <sys/systm.h>
54#include <sys/errno.h>
55#include <sys/kernel.h>
56#include <sys/malloc.h>
57#include <sys/mbuf.h>
58#include <netgraph/ng_message.h>
59#include <netgraph/netgraph.h>
60#include <netgraph/ng_parse.h>
61#include <netgraph/ng_tee.h>
62
63/* Per hook info */
64struct hookinfo {
65	hook_p			hook;
66	struct hookinfo		*dest, *dup;
67	struct ng_tee_hookstat	stats;
68};
69typedef struct hookinfo *hi_p;
70
71/* Per node info */
72struct privdata {
73	struct hookinfo		left;
74	struct hookinfo		right;
75	struct hookinfo		left2right;
76	struct hookinfo		right2left;
77};
78typedef struct privdata *sc_p;
79
80/* Netgraph methods */
81static ng_constructor_t	ng_tee_constructor;
82static ng_rcvmsg_t	ng_tee_rcvmsg;
83static ng_close_t	ng_tee_close;
84static ng_shutdown_t	ng_tee_shutdown;
85static ng_newhook_t	ng_tee_newhook;
86static ng_rcvdata_t	ng_tee_rcvdata;
87static ng_disconnect_t	ng_tee_disconnect;
88
89/* Parse type for struct ng_tee_hookstat */
90static const struct ng_parse_struct_field ng_tee_hookstat_type_fields[]
91	= NG_TEE_HOOKSTAT_INFO;
92static const struct ng_parse_type ng_tee_hookstat_type = {
93	&ng_parse_struct_type,
94	&ng_tee_hookstat_type_fields
95};
96
97/* Parse type for struct ng_tee_stats */
98static const struct ng_parse_struct_field ng_tee_stats_type_fields[]
99	= NG_TEE_STATS_INFO(&ng_tee_hookstat_type);
100static const struct ng_parse_type ng_tee_stats_type = {
101	&ng_parse_struct_type,
102	&ng_tee_stats_type_fields
103};
104
105/* List of commands and how to convert arguments to/from ASCII */
106static const struct ng_cmdlist ng_tee_cmds[] = {
107	{
108	  NGM_TEE_COOKIE,
109	  NGM_TEE_GET_STATS,
110	  "getstats",
111	  NULL,
112	  &ng_tee_stats_type
113	},
114	{
115	  NGM_TEE_COOKIE,
116	  NGM_TEE_CLR_STATS,
117	  "clrstats",
118	  NULL,
119	  NULL
120	},
121	{
122	  NGM_TEE_COOKIE,
123	  NGM_TEE_GETCLR_STATS,
124	  "getclrstats",
125	  NULL,
126	  &ng_tee_stats_type
127	},
128	{ 0 }
129};
130
131/* Netgraph type descriptor */
132static struct ng_type ng_tee_typestruct = {
133	.version =	NG_ABI_VERSION,
134	.name =		NG_TEE_NODE_TYPE,
135	.constructor =  ng_tee_constructor,
136	.rcvmsg =	ng_tee_rcvmsg,
137	.close =	ng_tee_close,
138	.shutdown =	ng_tee_shutdown,
139	.newhook =	ng_tee_newhook,
140	.rcvdata =	ng_tee_rcvdata,
141	.disconnect =	ng_tee_disconnect,
142	.cmdlist =	ng_tee_cmds,
143};
144NETGRAPH_INIT(tee, &ng_tee_typestruct);
145
146/*
147 * Node constructor
148 */
149static int
150ng_tee_constructor(node_p node)
151{
152	sc_p privdata;
153
154	privdata = malloc(sizeof(*privdata), M_NETGRAPH, M_WAITOK | M_ZERO);
155
156	NG_NODE_SET_PRIVATE(node, privdata);
157	return (0);
158}
159
160/*
161 * Add a hook
162 */
163static int
164ng_tee_newhook(node_p node, hook_p hook, const char *name)
165{
166	sc_p	privdata = NG_NODE_PRIVATE(node);
167	hi_p	hinfo;
168
169	/* Precalculate internal paths. */
170	if (strcmp(name, NG_TEE_HOOK_RIGHT) == 0) {
171		hinfo = &privdata->right;
172		if (privdata->left.dest)
173			privdata->left.dup = privdata->left.dest;
174		privdata->left.dest = hinfo;
175		privdata->right2left.dest = hinfo;
176	} else if (strcmp(name, NG_TEE_HOOK_LEFT) == 0) {
177		hinfo = &privdata->left;
178		if (privdata->right.dest)
179			privdata->right.dup = privdata->right.dest;
180		privdata->right.dest = hinfo;
181		privdata->left2right.dest = hinfo;
182	} else if (strcmp(name, NG_TEE_HOOK_RIGHT2LEFT) == 0) {
183		hinfo = &privdata->right2left;
184		if (privdata->right.dest)
185			privdata->right.dup = hinfo;
186		else
187			privdata->right.dest = hinfo;
188	} else if (strcmp(name, NG_TEE_HOOK_LEFT2RIGHT) == 0) {
189		hinfo = &privdata->left2right;
190		if (privdata->left.dest)
191			privdata->left.dup = hinfo;
192		else
193			privdata->left.dest = hinfo;
194	} else
195		return (EINVAL);
196	hinfo->hook = hook;
197	bzero(&hinfo->stats, sizeof(hinfo->stats));
198	NG_HOOK_SET_PRIVATE(hook, hinfo);
199	return (0);
200}
201
202/*
203 * Receive a control message
204 */
205static int
206ng_tee_rcvmsg(node_p node, item_p item, hook_p lasthook)
207{
208	const sc_p sc = NG_NODE_PRIVATE(node);
209	struct ng_mesg *resp = NULL;
210	int error = 0;
211	struct ng_mesg *msg;
212
213	NGI_GET_MSG(item, msg);
214	switch (msg->header.typecookie) {
215	case NGM_TEE_COOKIE:
216		switch (msg->header.cmd) {
217		case NGM_TEE_GET_STATS:
218		case NGM_TEE_CLR_STATS:
219		case NGM_TEE_GETCLR_STATS:
220                    {
221			struct ng_tee_stats *stats;
222
223                        if (msg->header.cmd != NGM_TEE_CLR_STATS) {
224                                NG_MKRESPONSE(resp, msg,
225                                    sizeof(*stats), M_NOWAIT);
226				if (resp == NULL) {
227					error = ENOMEM;
228					goto done;
229				}
230				stats = (struct ng_tee_stats *)resp->data;
231				bcopy(&sc->right.stats, &stats->right,
232				    sizeof(stats->right));
233				bcopy(&sc->left.stats, &stats->left,
234				    sizeof(stats->left));
235				bcopy(&sc->right2left.stats, &stats->right2left,
236				    sizeof(stats->right2left));
237				bcopy(&sc->left2right.stats, &stats->left2right,
238				    sizeof(stats->left2right));
239                        }
240                        if (msg->header.cmd != NGM_TEE_GET_STATS) {
241				bzero(&sc->right.stats,
242				    sizeof(sc->right.stats));
243				bzero(&sc->left.stats,
244				    sizeof(sc->left.stats));
245				bzero(&sc->right2left.stats,
246				    sizeof(sc->right2left.stats));
247				bzero(&sc->left2right.stats,
248				    sizeof(sc->left2right.stats));
249			}
250                        break;
251		    }
252		default:
253			error = EINVAL;
254			break;
255		}
256		break;
257	case NGM_FLOW_COOKIE:
258		if (lasthook == sc->left.hook || lasthook == sc->right.hook)  {
259			hi_p const hinfo = NG_HOOK_PRIVATE(lasthook);
260			if (hinfo && hinfo->dest) {
261				NGI_MSG(item) = msg;
262				NG_FWD_ITEM_HOOK(error, item, hinfo->dest->hook);
263				return (error);
264			}
265		}
266		break;
267	default:
268		error = EINVAL;
269		break;
270	}
271done:
272	NG_RESPOND_MSG(error, node, item, resp);
273	NG_FREE_MSG(msg);
274	return (error);
275}
276
277/*
278 * Receive data on a hook
279 *
280 * If data comes in the right link send a copy out right2left, and then
281 * send the original onwards out through the left link.
282 * Do the opposite for data coming in from the left link.
283 * Data coming in right2left or left2right is forwarded
284 * on through the appropriate destination hook as if it had come
285 * from the other side.
286 */
287static int
288ng_tee_rcvdata(hook_p hook, item_p item)
289{
290	const hi_p hinfo = NG_HOOK_PRIVATE(hook);
291	hi_p	h;
292	int	error = 0;
293	struct mbuf *m;
294
295	m = NGI_M(item);
296
297	/* Update stats on incoming hook */
298	hinfo->stats.inOctets += m->m_pkthdr.len;
299	hinfo->stats.inFrames++;
300
301	/* Duplicate packet if requried */
302	if (hinfo->dup) {
303		struct mbuf *m2;
304
305		/* Copy packet (failure will not stop the original)*/
306		m2 = m_dup(m, M_NOWAIT);
307		if (m2) {
308			/* Deliver duplicate */
309			h = hinfo->dup;
310			NG_SEND_DATA_ONLY(error, h->hook, m2);
311			if (error == 0) {
312				h->stats.outOctets += m->m_pkthdr.len;
313				h->stats.outFrames++;
314			}
315		}
316	}
317	/* Deliver frame out destination hook */
318	if (hinfo->dest) {
319		h = hinfo->dest;
320		h->stats.outOctets += m->m_pkthdr.len;
321		h->stats.outFrames++;
322		NG_FWD_ITEM_HOOK(error, item, h->hook);
323	} else
324		NG_FREE_ITEM(item);
325	return (error);
326}
327
328/*
329 * We are going to be shut down soon
330 *
331 * If we have both a left and right hook, then we probably want to extricate
332 * ourselves and leave the two peers still linked to each other. Otherwise we
333 * should just shut down as a normal node would.
334 */
335static int
336ng_tee_close(node_p node)
337{
338	const sc_p privdata = NG_NODE_PRIVATE(node);
339
340	if (privdata->left.hook && privdata->right.hook)
341		ng_bypass(privdata->left.hook, privdata->right.hook);
342
343	return (0);
344}
345
346/*
347 * Shutdown processing
348 */
349static int
350ng_tee_shutdown(node_p node)
351{
352	const sc_p privdata = NG_NODE_PRIVATE(node);
353
354	NG_NODE_SET_PRIVATE(node, NULL);
355	free(privdata, M_NETGRAPH);
356	NG_NODE_UNREF(node);
357	return (0);
358}
359
360/*
361 * Hook disconnection
362 */
363static int
364ng_tee_disconnect(hook_p hook)
365{
366	sc_p	sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
367	hi_p const hinfo = NG_HOOK_PRIVATE(hook);
368
369	KASSERT(hinfo != NULL, ("%s: null info", __func__));
370	hinfo->hook = NULL;
371
372	/* Recalculate internal paths. */
373	if (sc->left.dest == hinfo) {
374		sc->left.dest = sc->left.dup;
375		sc->left.dup = NULL;
376	} else if (sc->left.dup == hinfo)
377		sc->left.dup = NULL;
378	if (sc->right.dest == hinfo) {
379		sc->right.dest = sc->right.dup;
380		sc->right.dup = NULL;
381	} else if (sc->right.dup == hinfo)
382		sc->right.dup = NULL;
383	if (sc->left2right.dest == hinfo)
384		sc->left2right.dest = NULL;
385	if (sc->right2left.dest == hinfo)
386		sc->right2left.dest = NULL;
387
388	/* Die when last hook disconnected. */
389	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) &&
390	    NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
391		ng_rmnode_self(NG_HOOK_NODE(hook));
392	return (0);
393}
394