xref: /dragonfly/sys/netgraph7/tee/ng_tee.c (revision 678e8cc6)
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  *
41  * $FreeBSD: src/sys/netgraph/ng_tee.c,v 1.35 2008/02/24 10:13:32 mav Exp $
42  * $DragonFly: src/sys/netgraph7/ng_tee.c,v 1.2 2008/06/26 23:05:35 dillon Exp $
43  * $Whistle: ng_tee.c,v 1.18 1999/11/01 09:24:52 julian Exp $
44  */
45 
46 /*
47  * This node is like the tee(1) command and is useful for ``snooping.''
48  * It has 4 hooks: left, right, left2right, and right2left. Data
49  * entering from the right is passed to the left and duplicated on
50  * right2left, and data entering from the left is passed to the right
51  * and duplicated on left2right. Data entering from left2right is
52  * sent to left, and data from right2left to right.
53  */
54 
55 #include <sys/param.h>
56 #include <sys/systm.h>
57 #include <sys/errno.h>
58 #include <sys/kernel.h>
59 #include <sys/malloc.h>
60 #include <sys/mbuf.h>
61 #include <netgraph7/ng_message.h>
62 #include <netgraph7/netgraph.h>
63 #include <netgraph7/ng_parse.h>
64 #include "ng_tee.h"
65 
66 /* Per hook info */
67 struct hookinfo {
68 	hook_p			hook;
69 	struct hookinfo		*dest, *dup;
70 	struct ng_tee_hookstat	stats;
71 };
72 typedef struct hookinfo *hi_p;
73 
74 /* Per node info */
75 struct privdata {
76 	struct hookinfo		left;
77 	struct hookinfo		right;
78 	struct hookinfo		left2right;
79 	struct hookinfo		right2left;
80 };
81 typedef struct privdata *sc_p;
82 
83 /* Netgraph methods */
84 static ng_constructor_t	ng_tee_constructor;
85 static ng_rcvmsg_t	ng_tee_rcvmsg;
86 static ng_close_t	ng_tee_close;
87 static ng_shutdown_t	ng_tee_shutdown;
88 static ng_newhook_t	ng_tee_newhook;
89 static ng_rcvdata_t	ng_tee_rcvdata;
90 static ng_disconnect_t	ng_tee_disconnect;
91 
92 /* Parse type for struct ng_tee_hookstat */
93 static const struct ng_parse_struct_field ng_tee_hookstat_type_fields[]
94 	= NG_TEE_HOOKSTAT_INFO;
95 static const struct ng_parse_type ng_tee_hookstat_type = {
96 	&ng_parse_struct_type,
97 	&ng_tee_hookstat_type_fields
98 };
99 
100 /* Parse type for struct ng_tee_stats */
101 static const struct ng_parse_struct_field ng_tee_stats_type_fields[]
102 	= NG_TEE_STATS_INFO(&ng_tee_hookstat_type);
103 static const struct ng_parse_type ng_tee_stats_type = {
104 	&ng_parse_struct_type,
105 	&ng_tee_stats_type_fields
106 };
107 
108 /* List of commands and how to convert arguments to/from ASCII */
109 static const struct ng_cmdlist ng_tee_cmds[] = {
110 	{
111 	  NGM_TEE_COOKIE,
112 	  NGM_TEE_GET_STATS,
113 	  "getstats",
114 	  NULL,
115 	  &ng_tee_stats_type
116 	},
117 	{
118 	  NGM_TEE_COOKIE,
119 	  NGM_TEE_CLR_STATS,
120 	  "clrstats",
121 	  NULL,
122 	  NULL
123 	},
124 	{
125 	  NGM_TEE_COOKIE,
126 	  NGM_TEE_GETCLR_STATS,
127 	  "getclrstats",
128 	  NULL,
129 	  &ng_tee_stats_type
130 	},
131 	{ 0 }
132 };
133 
134 /* Netgraph type descriptor */
135 static struct ng_type ng_tee_typestruct = {
136 	.version =	NG_ABI_VERSION,
137 	.name =		NG_TEE_NODE_TYPE,
138 	.constructor =  ng_tee_constructor,
139 	.rcvmsg =	ng_tee_rcvmsg,
140 	.close =	ng_tee_close,
141 	.shutdown =	ng_tee_shutdown,
142 	.newhook =	ng_tee_newhook,
143 	.rcvdata =	ng_tee_rcvdata,
144 	.disconnect =	ng_tee_disconnect,
145 	.cmdlist =	ng_tee_cmds,
146 };
147 NETGRAPH_INIT(tee, &ng_tee_typestruct);
148 
149 /*
150  * Node constructor
151  */
152 static int
153 ng_tee_constructor(node_p node)
154 {
155 	sc_p privdata;
156 
157 	privdata = kmalloc(sizeof(*privdata), M_NETGRAPH,
158 			   M_WAITOK | M_NULLOK | M_ZERO);
159 	if (privdata == NULL)
160 		return (ENOMEM);
161 
162 	NG_NODE_SET_PRIVATE(node, privdata);
163 	return (0);
164 }
165 
166 /*
167  * Add a hook
168  */
169 static int
170 ng_tee_newhook(node_p node, hook_p hook, const char *name)
171 {
172 	sc_p	privdata = NG_NODE_PRIVATE(node);
173 	hi_p	hinfo;
174 
175 	/* Precalculate internal pathes. */
176 	if (strcmp(name, NG_TEE_HOOK_RIGHT) == 0) {
177 		hinfo = &privdata->right;
178 		if (privdata->left.dest)
179 			privdata->left.dup = privdata->left.dest;
180 		privdata->left.dest = hinfo;
181 		privdata->right2left.dest = hinfo;
182 	} else if (strcmp(name, NG_TEE_HOOK_LEFT) == 0) {
183 		hinfo = &privdata->left;
184 		if (privdata->right.dest)
185 			privdata->right.dup = privdata->right.dest;
186 		privdata->right.dest = hinfo;
187 		privdata->left2right.dest = hinfo;
188 	} else if (strcmp(name, NG_TEE_HOOK_RIGHT2LEFT) == 0) {
189 		hinfo = &privdata->right2left;
190 		if (privdata->right.dest)
191 			privdata->right.dup = hinfo;
192 		else
193 			privdata->right.dest = hinfo;
194 	} else if (strcmp(name, NG_TEE_HOOK_LEFT2RIGHT) == 0) {
195 		hinfo = &privdata->left2right;
196 		if (privdata->left.dest)
197 			privdata->left.dup = hinfo;
198 		else
199 			privdata->left.dest = hinfo;
200 	} else
201 		return (EINVAL);
202 	hinfo->hook = hook;
203 	bzero(&hinfo->stats, sizeof(hinfo->stats));
204 	NG_HOOK_SET_PRIVATE(hook, hinfo);
205 	return (0);
206 }
207 
208 /*
209  * Receive a control message
210  */
211 static int
212 ng_tee_rcvmsg(node_p node, item_p item, hook_p lasthook)
213 {
214 	const sc_p sc = NG_NODE_PRIVATE(node);
215 	struct ng_mesg *resp = NULL;
216 	int error = 0;
217 	struct ng_mesg *msg;
218 
219 	NGI_GET_MSG(item, msg);
220 	switch (msg->header.typecookie) {
221 	case NGM_TEE_COOKIE:
222 		switch (msg->header.cmd) {
223 		case NGM_TEE_GET_STATS:
224 		case NGM_TEE_CLR_STATS:
225 		case NGM_TEE_GETCLR_STATS:
226                     {
227 			struct ng_tee_stats *stats;
228 
229                         if (msg->header.cmd != NGM_TEE_CLR_STATS) {
230                                 NG_MKRESPONSE(resp, msg,
231                                     sizeof(*stats), M_WAITOK | M_NULLOK);
232 				if (resp == NULL) {
233 					error = ENOMEM;
234 					goto done;
235 				}
236 				stats = (struct ng_tee_stats *)resp->data;
237 				bcopy(&sc->right.stats, &stats->right,
238 				    sizeof(stats->right));
239 				bcopy(&sc->left.stats, &stats->left,
240 				    sizeof(stats->left));
241 				bcopy(&sc->right2left.stats, &stats->right2left,
242 				    sizeof(stats->right2left));
243 				bcopy(&sc->left2right.stats, &stats->left2right,
244 				    sizeof(stats->left2right));
245                         }
246                         if (msg->header.cmd != NGM_TEE_GET_STATS) {
247 				bzero(&sc->right.stats,
248 				    sizeof(sc->right.stats));
249 				bzero(&sc->left.stats,
250 				    sizeof(sc->left.stats));
251 				bzero(&sc->right2left.stats,
252 				    sizeof(sc->right2left.stats));
253 				bzero(&sc->left2right.stats,
254 				    sizeof(sc->left2right.stats));
255 			}
256                         break;
257 		    }
258 		default:
259 			error = EINVAL;
260 			break;
261 		}
262 		break;
263 	case NGM_FLOW_COOKIE:
264 		if (lasthook == sc->left.hook || lasthook == sc->right.hook)  {
265 			hi_p const hinfo = NG_HOOK_PRIVATE(lasthook);
266 			if (hinfo && hinfo->dest) {
267 				NGI_MSG(item) = msg;
268 				NG_FWD_ITEM_HOOK(error, item, hinfo->dest->hook);
269 				return (error);
270 			}
271 		}
272 		break;
273 	default:
274 		error = EINVAL;
275 		break;
276 	}
277 done:
278 	NG_RESPOND_MSG(error, node, item, resp);
279 	NG_FREE_MSG(msg);
280 	return (error);
281 }
282 
283 /*
284  * Receive data on a hook
285  *
286  * If data comes in the right link send a copy out right2left, and then
287  * send the original onwards out through the left link.
288  * Do the opposite for data coming in from the left link.
289  * Data coming in right2left or left2right is forwarded
290  * on through the appropriate destination hook as if it had come
291  * from the other side.
292  */
293 static int
294 ng_tee_rcvdata(hook_p hook, item_p item)
295 {
296 	const hi_p hinfo = NG_HOOK_PRIVATE(hook);
297 	hi_p	h;
298 	int	error = 0;
299 	struct mbuf *m;
300 
301 	m = NGI_M(item);
302 
303 	/* Update stats on incoming hook */
304 	hinfo->stats.inOctets += m->m_pkthdr.len;
305 	hinfo->stats.inFrames++;
306 
307 	/* Duplicate packet if requried */
308 	if (hinfo->dup) {
309 		struct mbuf *m2;
310 
311 		/* Copy packet (failure will not stop the original)*/
312 		m2 = m_dup(m, MB_DONTWAIT);
313 		if (m2) {
314 			/* Deliver duplicate */
315 			h = hinfo->dup;
316 			NG_SEND_DATA_ONLY(error, h->hook, m2);
317 			if (error == 0) {
318 				h->stats.outOctets += m->m_pkthdr.len;
319 				h->stats.outFrames++;
320 			}
321 		}
322 	}
323 	/* Deliver frame out destination hook */
324 	if (hinfo->dest) {
325 		h = hinfo->dest;
326 		h->stats.outOctets += m->m_pkthdr.len;
327 		h->stats.outFrames++;
328 		NG_FWD_ITEM_HOOK(error, item, h->hook);
329 	} else
330 		NG_FREE_ITEM(item);
331 	return (error);
332 }
333 
334 /*
335  * We are going to be shut down soon
336  *
337  * If we have both a left and right hook, then we probably want to extricate
338  * ourselves and leave the two peers still linked to each other. Otherwise we
339  * should just shut down as a normal node would.
340  */
341 static int
342 ng_tee_close(node_p node)
343 {
344 	const sc_p privdata = NG_NODE_PRIVATE(node);
345 
346 	if (privdata->left.hook && privdata->right.hook)
347 		ng_bypass(privdata->left.hook, privdata->right.hook);
348 
349 	return (0);
350 }
351 
352 /*
353  * Shutdown processing
354  */
355 static int
356 ng_tee_shutdown(node_p node)
357 {
358 	const sc_p privdata = NG_NODE_PRIVATE(node);
359 
360 	NG_NODE_SET_PRIVATE(node, NULL);
361 	kfree(privdata, M_NETGRAPH);
362 	NG_NODE_UNREF(node);
363 	return (0);
364 }
365 
366 /*
367  * Hook disconnection
368  */
369 static int
370 ng_tee_disconnect(hook_p hook)
371 {
372 	sc_p	sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
373 	hi_p const hinfo = NG_HOOK_PRIVATE(hook);
374 
375 	KASSERT(hinfo != NULL, ("%s: null info", __func__));
376 	hinfo->hook = NULL;
377 
378 	/* Recalculate internal pathes. */
379 	if (sc->left.dest == hinfo) {
380 		sc->left.dest = sc->left.dup;
381 		sc->left.dup = NULL;
382 	} else if (sc->left.dup == hinfo)
383 		sc->left.dup = NULL;
384 	if (sc->right.dest == hinfo) {
385 		sc->right.dest = sc->right.dup;
386 		sc->right.dup = NULL;
387 	} else if (sc->right.dup == hinfo)
388 		sc->right.dup = NULL;
389 	if (sc->left2right.dest == hinfo)
390 		sc->left2right.dest = NULL;
391 	if (sc->right2left.dest == hinfo)
392 		sc->right2left.dest = NULL;
393 
394 	/* Die when last hook disconnected. */
395 	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) &&
396 	    NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
397 		ng_rmnode_self(NG_HOOK_NODE(hook));
398 	return (0);
399 }
400