xref: /freebsd/sys/netgraph/ng_tee.c (revision 41466b50c1d5bfd1cf6adaae547a579a75d7c04e)
1 
2 /*
3  * ng_tee.c
4  *
5  * Copyright (c) 1996-1999 Whistle Communications, Inc.
6  * All rights reserved.
7  *
8  * Subject to the following obligations and disclaimer of warranty, use and
9  * redistribution of this software, in source or object code forms, with or
10  * without modifications are expressly permitted by Whistle Communications;
11  * provided, however, that:
12  * 1. Any and all reproductions of the source or object code must include the
13  *    copyright notice above and the following disclaimer of warranties; and
14  * 2. No rights are granted, in any manner or form, to use Whistle
15  *    Communications, Inc. trademarks, including the mark "WHISTLE
16  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
17  *    such appears in the above copyright notice or in the software.
18  *
19  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
20  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
21  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
22  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
23  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
24  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
25  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
26  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
27  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
28  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
29  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
30  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
31  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
35  * OF SUCH DAMAGE.
36  *
37  * Author: Julian Elischer <julian@freebsd.org>
38  *
39  * $FreeBSD$
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 right, and data from right2left to left.
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 */
64 struct hookinfo {
65 	hook_p			hook;
66 	struct ng_tee_hookstat	stats;
67 };
68 
69 /* Per node info */
70 struct privdata {
71 	node_p			node;
72 	struct hookinfo		left;
73 	struct hookinfo		right;
74 	struct hookinfo		left2right;
75 	struct hookinfo		right2left;
76 };
77 typedef struct privdata *sc_p;
78 
79 /* Netgraph methods */
80 static ng_constructor_t	ngt_constructor;
81 static ng_rcvmsg_t	ngt_rcvmsg;
82 static ng_shutdown_t	ngt_shutdown;
83 static ng_newhook_t	ngt_newhook;
84 static ng_rcvdata_t	ngt_rcvdata;
85 static ng_disconnect_t	ngt_disconnect;
86 
87 /* Parse type for struct ng_tee_hookstat */
88 static const struct ng_parse_struct_info
89 	ng_tee_hookstat_type_info = NG_TEE_HOOKSTAT_INFO;
90 static const struct ng_parse_type ng_tee_hookstat_type = {
91 	&ng_parse_struct_type,
92 	&ng_tee_hookstat_type_info,
93 };
94 
95 /* Parse type for struct ng_tee_stats */
96 static const struct ng_parse_struct_info
97 	ng_tee_stats_type_info = NG_TEE_STATS_INFO(&ng_tee_hookstat_type);
98 static const struct ng_parse_type ng_tee_stats_type = {
99 	&ng_parse_struct_type,
100 	&ng_tee_stats_type_info,
101 };
102 
103 /* List of commands and how to convert arguments to/from ASCII */
104 static const struct ng_cmdlist ng_tee_cmds[] = {
105 	{
106 	  NGM_TEE_COOKIE,
107 	  NGM_TEE_GET_STATS,
108 	  "getstats",
109 	  NULL,
110 	  &ng_tee_stats_type
111 	},
112 	{
113 	  NGM_TEE_COOKIE,
114 	  NGM_TEE_CLR_STATS,
115 	  "clrstats",
116 	  NULL,
117 	  NULL
118 	},
119 	{
120 	  NGM_TEE_COOKIE,
121 	  NGM_TEE_GETCLR_STATS,
122 	  "getclrstats",
123 	  NULL,
124 	  &ng_tee_stats_type
125 	},
126 	{ 0 }
127 };
128 
129 /* Netgraph type descriptor */
130 static struct ng_type ng_tee_typestruct = {
131 	NG_ABI_VERSION,
132 	NG_TEE_NODE_TYPE,
133 	NULL,
134 	ngt_constructor,
135 	ngt_rcvmsg,
136 	ngt_shutdown,
137 	ngt_newhook,
138 	NULL,
139 	NULL,
140 	ngt_rcvdata,
141 	ngt_disconnect,
142 	ng_tee_cmds
143 };
144 NETGRAPH_INIT(tee, &ng_tee_typestruct);
145 
146 /*
147  * Node constructor
148  */
149 static int
150 ngt_constructor(node_p node)
151 {
152 	sc_p privdata;
153 
154 	MALLOC(privdata, sc_p, sizeof(*privdata), M_NETGRAPH, M_NOWAIT|M_ZERO);
155 	if (privdata == NULL)
156 		return (ENOMEM);
157 
158 	NG_NODE_SET_PRIVATE(node, privdata);
159 	privdata->node = node;
160 	return (0);
161 }
162 
163 /*
164  * Add a hook
165  */
166 static int
167 ngt_newhook(node_p node, hook_p hook, const char *name)
168 {
169 	const sc_p sc = NG_NODE_PRIVATE(node);
170 
171 	if (strcmp(name, NG_TEE_HOOK_RIGHT) == 0) {
172 		sc->right.hook = hook;
173 		bzero(&sc->right.stats, sizeof(sc->right.stats));
174 		NG_HOOK_SET_PRIVATE(hook, &sc->right);
175 	} else if (strcmp(name, NG_TEE_HOOK_LEFT) == 0) {
176 		sc->left.hook = hook;
177 		bzero(&sc->left.stats, sizeof(sc->left.stats));
178 		NG_HOOK_SET_PRIVATE(hook, &sc->left);
179 	} else if (strcmp(name, NG_TEE_HOOK_RIGHT2LEFT) == 0) {
180 		sc->right2left.hook = hook;
181 		bzero(&sc->right2left.stats, sizeof(sc->right2left.stats));
182 		NG_HOOK_SET_PRIVATE(hook, &sc->right2left);
183 	} else if (strcmp(name, NG_TEE_HOOK_LEFT2RIGHT) == 0) {
184 		sc->left2right.hook = hook;
185 		bzero(&sc->left2right.stats, sizeof(sc->left2right.stats));
186 		NG_HOOK_SET_PRIVATE(hook, &sc->left2right);
187 	} else
188 		return (EINVAL);
189 	return (0);
190 }
191 
192 /*
193  * Receive a control message
194  */
195 static int
196 ngt_rcvmsg(node_p node, item_p item, hook_p lasthook)
197 {
198 	const sc_p sc = NG_NODE_PRIVATE(node);
199 	struct ng_mesg *resp = NULL;
200 	int error = 0;
201 	struct ng_mesg *msg;
202 
203 	NGI_GET_MSG(item, msg);
204 	switch (msg->header.typecookie) {
205 	case NGM_TEE_COOKIE:
206 		switch (msg->header.cmd) {
207 		case NGM_TEE_GET_STATS:
208 		case NGM_TEE_CLR_STATS:
209 		case NGM_TEE_GETCLR_STATS:
210                     {
211 			struct ng_tee_stats *stats;
212 
213                         if (msg->header.cmd != NGM_TEE_CLR_STATS) {
214                                 NG_MKRESPONSE(resp, msg,
215                                     sizeof(*stats), M_NOWAIT);
216 				if (resp == NULL) {
217 					error = ENOMEM;
218 					goto done;
219 				}
220 				stats = (struct ng_tee_stats *)resp->data;
221 				bcopy(&sc->right.stats, &stats->right,
222 				    sizeof(stats->right));
223 				bcopy(&sc->left.stats, &stats->left,
224 				    sizeof(stats->left));
225 				bcopy(&sc->right2left.stats, &stats->right2left,
226 				    sizeof(stats->right2left));
227 				bcopy(&sc->left2right.stats, &stats->left2right,
228 				    sizeof(stats->left2right));
229                         }
230                         if (msg->header.cmd != NGM_TEE_GET_STATS) {
231 				bzero(&sc->right.stats,
232 				    sizeof(sc->right.stats));
233 				bzero(&sc->left.stats,
234 				    sizeof(sc->left.stats));
235 				bzero(&sc->right2left.stats,
236 				    sizeof(sc->right2left.stats));
237 				bzero(&sc->left2right.stats,
238 				    sizeof(sc->left2right.stats));
239 			}
240                         break;
241 		    }
242 		default:
243 			error = EINVAL;
244 			break;
245 		}
246 		break;
247 	case NGM_FLOW_COOKIE:
248 		if (lasthook)  {
249 			if (lasthook == sc->left.hook) {
250 				if (sc->right.hook) {
251 					NGI_MSG(item) = msg;
252 					NG_FWD_ITEM_HOOK(error, item,
253 							sc->right.hook);
254 					return (error);
255 				}
256 			} else {
257 				if (sc->left.hook) {
258 					NGI_MSG(item) = msg;
259 					NG_FWD_ITEM_HOOK(error, item,
260 							sc->left.hook);
261 					return (error);
262 				}
263 			}
264 		}
265 		break;
266 	default:
267 		error = EINVAL;
268 		break;
269 	}
270 done:
271 	NG_RESPOND_MSG(error, node, item, resp);
272 	NG_FREE_MSG(msg);
273 	return (error);
274 }
275 
276 /*
277  * Receive data on a hook
278  *
279  * If data comes in the right link send a copy out right2left, and then
280  * send the original onwards out through the left link.
281  * Do the opposite for data coming in from the left link.
282  * Data coming in right2left or left2right is forwarded
283  * on through the appropriate destination hook as if it had come
284  * from the other side.
285  */
286 static int
287 ngt_rcvdata(hook_p hook, item_p item)
288 {
289 	const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
290 	struct hookinfo *const hinfo = NG_HOOK_PRIVATE(hook);
291 	struct hookinfo *dest;
292 	struct hookinfo *dup;
293 	int error = 0;
294 	struct mbuf *m;
295 	meta_p meta;
296 
297 	m = NGI_M(item);
298 	meta = NGI_META(item); /* leave these owned by the item */
299 	/* Which hook? */
300 	if (hinfo == &sc->left) {
301 		dup = &sc->left2right;
302 		dest = &sc->right;
303 	} else if (hinfo == &sc->right) {
304 		dup = &sc->right2left;
305 		dest = &sc->left;
306 	} else if (hinfo == &sc->right2left) {
307 		dup = NULL;
308 		dest = &sc->right;
309 	} else if (hinfo == &sc->left2right) {
310 		dup = NULL;
311 		dest = &sc->left;
312 	} else {
313 		panic("%s: no hook!", __FUNCTION__);
314 #ifdef	RESTARTABLE_PANICS
315 		return(EINVAL);
316 #endif
317 	}
318 
319 	/* Update stats on incoming hook */
320 	hinfo->stats.inOctets += m->m_pkthdr.len;
321 	hinfo->stats.inFrames++;
322 
323 	/*
324 	 * Don't make a copy if only the dup hook exists.
325 	 */
326 	if ((dup && dup->hook) && (dest->hook == NULL)) {
327 		dest = dup;
328 		dup = NULL;
329 	}
330 
331 	/* Duplicate packet and meta info if requried */
332 	if (dup != NULL) {
333 		struct mbuf *m2;
334 		meta_p meta2;
335 
336 		/* Copy packet (failure will not stop the original)*/
337 		m2 = m_dup(m, M_NOWAIT);
338 		if (m2) {
339 
340 			/* Copy meta info */
341 			/* If we can't get a copy, tough.. */
342 			if (meta != NULL) {
343 				meta2 = ng_copy_meta(meta);
344 			} else
345 				meta2 = NULL;
346 
347 			/* Deliver duplicate */
348 			dup->stats.outOctets += m->m_pkthdr.len;
349 			dup->stats.outFrames++;
350 			NG_SEND_DATA(error, dup->hook, m2, meta2);
351 		}
352 	}
353 	/* Deliver frame out destination hook */
354 	dest->stats.outOctets += m->m_pkthdr.len;
355 	dest->stats.outFrames++;
356 	if (dest->hook)
357 		NG_FWD_ITEM_HOOK(error, item, dest->hook);
358 	else
359 		NG_FREE_ITEM(item);
360 	return (0);
361 }
362 
363 /*
364  * Shutdown processing
365  *
366  * This is tricky. If we have both a left and right hook, then we
367  * probably want to extricate ourselves and leave the two peers
368  * still linked to each other. Otherwise we should just shut down as
369  * a normal node would.
370  *
371  * To keep the scope of info correct the routine to "extract" a node
372  * from two links is in ng_base.c.
373  */
374 static int
375 ngt_shutdown(node_p node)
376 {
377 	const sc_p privdata = NG_NODE_PRIVATE(node);
378 
379 #if 0 /* can never happen as cutlinks is already called */
380 	if (privdata->left.hook && privdata->right.hook)
381 		ng_bypass(privdata->left.hook, privdata->right.hook);
382 #endif
383 	NG_NODE_SET_PRIVATE(node, NULL);
384 	NG_NODE_UNREF(privdata->node);
385 	FREE(privdata, M_NETGRAPH);
386 	return (0);
387 }
388 
389 /*
390  * Hook disconnection
391  */
392 static int
393 ngt_disconnect(hook_p hook)
394 {
395 	struct hookinfo *const hinfo = NG_HOOK_PRIVATE(hook);
396 
397 	KASSERT(hinfo != NULL, ("%s: null info", __FUNCTION__));
398 	hinfo->hook = NULL;
399 	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
400 	&& (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
401 		ng_rmnode_self(NG_HOOK_NODE(hook));
402 	return (0);
403 }
404 
405