xref: /freebsd/sys/netgraph/ng_patch.c (revision 2b15cb3d0922bd70ea592f0da9b4a5b167f4d53f)
1 /*-
2  * Copyright (C) 2010 by Maxim Ignatenko <gelraen.ua@gmail.com>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/kernel.h>
34 #include <sys/endian.h>
35 #include <sys/malloc.h>
36 #include <sys/mbuf.h>
37 #include <netgraph/ng_message.h>
38 #include <netgraph/ng_parse.h>
39 #include <netgraph/ng_patch.h>
40 #include <netgraph/netgraph.h>
41 
42 static ng_constructor_t	ng_patch_constructor;
43 static ng_rcvmsg_t	ng_patch_rcvmsg;
44 static ng_shutdown_t	ng_patch_shutdown;
45 static ng_newhook_t	ng_patch_newhook;
46 static ng_rcvdata_t	ng_patch_rcvdata;
47 static ng_disconnect_t	ng_patch_disconnect;
48 
49 static int
50 ng_patch_config_getlen(const struct ng_parse_type *type,
51     const u_char *start, const u_char *buf)
52 {
53 	const struct ng_patch_config *p;
54 
55 	p = (const struct ng_patch_config *)(buf -
56 	    offsetof(struct ng_patch_config, ops));
57 	return (p->count);
58 }
59 
60 static const struct ng_parse_struct_field ng_patch_op_type_fields[]
61 	= NG_PATCH_OP_TYPE_INFO;
62 static const struct ng_parse_type ng_patch_op_type = {
63 	&ng_parse_struct_type,
64 	&ng_patch_op_type_fields
65 };
66 
67 static const struct ng_parse_array_info ng_patch_confarr_info = {
68 	&ng_patch_op_type,
69 	&ng_patch_config_getlen
70 };
71 static const struct ng_parse_type ng_patch_confarr_type = {
72 	&ng_parse_array_type,
73 	&ng_patch_confarr_info
74 };
75 
76 static const struct ng_parse_struct_field ng_patch_config_type_fields[]
77 	= NG_PATCH_CONFIG_TYPE_INFO;
78 static const struct ng_parse_type ng_patch_config_type = {
79 	&ng_parse_struct_type,
80 	&ng_patch_config_type_fields
81 };
82 
83 static const struct ng_parse_struct_field ng_patch_stats_fields[]
84 	= NG_PATCH_STATS_TYPE_INFO;
85 static const struct ng_parse_type ng_patch_stats_type = {
86 	&ng_parse_struct_type,
87 	&ng_patch_stats_fields
88 };
89 
90 static const struct ng_cmdlist ng_patch_cmdlist[] = {
91 	{
92 		NGM_PATCH_COOKIE,
93 		NGM_PATCH_GETCONFIG,
94 		"getconfig",
95 		NULL,
96 		&ng_patch_config_type
97 	},
98 	{
99 		NGM_PATCH_COOKIE,
100 		NGM_PATCH_SETCONFIG,
101 		"setconfig",
102 		&ng_patch_config_type,
103 		NULL
104 	},
105 	{
106 		NGM_PATCH_COOKIE,
107 		NGM_PATCH_GET_STATS,
108 		"getstats",
109 		NULL,
110 		&ng_patch_stats_type
111 	},
112 	{
113 		NGM_PATCH_COOKIE,
114 		NGM_PATCH_CLR_STATS,
115 		"clrstats",
116 		NULL,
117 		NULL
118 	},
119 	{
120 		NGM_PATCH_COOKIE,
121 		NGM_PATCH_GETCLR_STATS,
122 		"getclrstats",
123 		NULL,
124 		&ng_patch_stats_type
125 	},
126 	{ 0 }
127 };
128 
129 static struct ng_type typestruct = {
130 	.version =	NG_ABI_VERSION,
131 	.name =		NG_PATCH_NODE_TYPE,
132 	.constructor =	ng_patch_constructor,
133 	.rcvmsg =	ng_patch_rcvmsg,
134 	.shutdown =	ng_patch_shutdown,
135 	.newhook =	ng_patch_newhook,
136 	.rcvdata =	ng_patch_rcvdata,
137 	.disconnect =	ng_patch_disconnect,
138 	.cmdlist =	ng_patch_cmdlist,
139 };
140 NETGRAPH_INIT(patch, &typestruct);
141 
142 union patch_val {
143 	uint8_t		v1;
144 	uint16_t	v2;
145 	uint32_t	v4;
146 	uint64_t	v8;
147 };
148 
149 struct ng_patch_priv {
150 	hook_p		in;
151 	hook_p		out;
152 	struct ng_patch_config *config;
153 	union patch_val *val;
154 	struct ng_patch_stats stats;
155 };
156 typedef struct ng_patch_priv *priv_p;
157 
158 #define	NG_PATCH_CONF_SIZE(count)	(sizeof(struct ng_patch_config) + \
159 		(count) * sizeof(struct ng_patch_op))
160 
161 static void do_patch(priv_p conf, struct mbuf *m);
162 
163 static int
164 ng_patch_constructor(node_p node)
165 {
166 	priv_p privdata;
167 
168 	privdata = malloc(sizeof(*privdata), M_NETGRAPH, M_WAITOK | M_ZERO);
169 	NG_NODE_SET_PRIVATE(node, privdata);
170 	privdata->in = NULL;
171 	privdata->out = NULL;
172 	privdata->config = NULL;
173 	return (0);
174 }
175 
176 static int
177 ng_patch_newhook(node_p node, hook_p hook, const char *name)
178 {
179 	const priv_p privp = NG_NODE_PRIVATE(node);
180 
181 	if (strncmp(name, NG_PATCH_HOOK_IN, strlen(NG_PATCH_HOOK_IN)) == 0) {
182 		privp->in = hook;
183 	} else if (strncmp(name, NG_PATCH_HOOK_OUT,
184 	    strlen(NG_PATCH_HOOK_OUT)) == 0) {
185 		privp->out = hook;
186 	} else
187 		return (EINVAL);
188 	return(0);
189 }
190 
191 static int
192 ng_patch_rcvmsg(node_p node, item_p item, hook_p lasthook)
193 {
194 	const priv_p privp = NG_NODE_PRIVATE(node);
195 	struct ng_patch_config *conf, *newconf;
196 	union patch_val *newval;
197 	struct ng_mesg *msg;
198 	struct ng_mesg *resp;
199 	int i, clear, error;
200 
201 	clear = error = 0;
202 	resp = NULL;
203 	NGI_GET_MSG(item, msg);
204 	switch (msg->header.typecookie) {
205 	case NGM_PATCH_COOKIE:
206 		switch (msg->header.cmd) {
207 		case NGM_PATCH_GETCONFIG:
208 			if (privp->config == NULL)
209 				break;
210 			NG_MKRESPONSE(resp, msg,
211 			    NG_PATCH_CONF_SIZE(privp->config->count),
212 			    M_WAITOK);
213 			bcopy(privp->config, resp->data,
214 			    NG_PATCH_CONF_SIZE(privp->config->count));
215 			break;
216 		case NGM_PATCH_SETCONFIG:
217 		    {
218 			if (msg->header.arglen <
219 			    sizeof(struct ng_patch_config)) {
220 				error = EINVAL;
221 				break;
222 			}
223 
224 			conf = (struct ng_patch_config *)msg->data;
225 			if (msg->header.arglen <
226 			    NG_PATCH_CONF_SIZE(conf->count)) {
227 				error = EINVAL;
228 				break;
229 			}
230 
231 			for(i = 0; i < conf->count; i++) {
232 				switch(conf->ops[i].length) {
233 				case 1:
234 				case 2:
235 				case 4:
236 				case 8:
237 					break;
238 				default:
239 					error = EINVAL;
240 					break;
241 				}
242 				if (error != 0)
243 					break;
244 			}
245 
246 			conf->csum_flags &= CSUM_IP | CSUM_TCP | CSUM_UDP |
247 			    CSUM_SCTP;
248 
249 			if (error == 0) {
250 				newconf = malloc(
251 				    NG_PATCH_CONF_SIZE(conf->count),
252 				    M_NETGRAPH, M_WAITOK);
253 				newval = malloc(conf->count *
254 				    sizeof(union patch_val), M_NETGRAPH,
255 				    M_WAITOK);
256 				for(i = 0; i < conf->count; i++) {
257 					switch (conf->ops[i].length) {
258 					case 1:
259 						newval[i].v1 =
260 						    conf->ops[i].value;
261 						break;
262 					case 2:
263 						newval[i].v2 =
264 						    conf->ops[i].value;
265 						break;
266 					case 4:
267 						newval[i].v4 =
268 						    conf->ops[i].value;
269 						break;
270 					case 8:
271 						newval[i].v8 =
272 						    conf->ops[i].value;
273 						break;
274 					}
275 				}
276 				bcopy(conf, newconf,
277 				    NG_PATCH_CONF_SIZE(conf->count));
278 				if (privp->val != NULL)
279 					free(privp->val, M_NETGRAPH);
280 				privp->val = newval;
281 				if (privp->config != NULL)
282 					free(privp->config, M_NETGRAPH);
283 				privp->config = newconf;
284 			}
285 			break;
286 		    }
287 		case NGM_PATCH_GETCLR_STATS:
288 			clear = 1;
289 			/* FALLTHROUGH */
290 		case NGM_PATCH_GET_STATS:
291 			NG_MKRESPONSE(resp, msg, sizeof(struct ng_patch_stats),
292 			    M_WAITOK);
293 			bcopy(&(privp->stats), resp->data,
294 			    sizeof(struct ng_patch_stats));
295 			if (clear == 0)
296 				break;
297 			/* else FALLTHROUGH */
298 		case NGM_PATCH_CLR_STATS:
299 			bzero(&(privp->stats), sizeof(struct ng_patch_stats));
300 			break;
301 		default:
302 			error = EINVAL;
303 			break;
304 		}
305 		break;
306 	default:
307 		error = EINVAL;
308 		break;
309 	}
310 
311 	NG_RESPOND_MSG(error, node, item, resp);
312 	NG_FREE_MSG(msg);
313 	return(error);
314 }
315 
316 static void
317 do_patch(priv_p privp, struct mbuf *m)
318 {
319 	struct ng_patch_config *conf;
320 	uint64_t buf;
321 	int i, patched;
322 
323 	conf = privp->config;
324 	patched = 0;
325 	for(i = 0; i < conf->count; i++) {
326 		if (conf->ops[i].offset + conf->ops[i].length >
327 		    m->m_pkthdr.len)
328 			continue;
329 
330 		/* for "=" operation we don't need to copy data from mbuf */
331 		if (conf->ops[i].mode != NG_PATCH_MODE_SET) {
332 			m_copydata(m, conf->ops[i].offset,
333 			    conf->ops[i].length, (caddr_t)&buf);
334 		}
335 
336 		switch (conf->ops[i].length) {
337 		case 1:
338 			switch (conf->ops[i].mode) {
339 			case NG_PATCH_MODE_SET:
340 				*((uint8_t *)&buf) = privp->val[i].v1;
341 				break;
342 			case NG_PATCH_MODE_ADD:
343 				*((uint8_t *)&buf) += privp->val[i].v1;
344 				break;
345 			case NG_PATCH_MODE_SUB:
346 				*((uint8_t *)&buf) -= privp->val[i].v1;
347 				break;
348 			case NG_PATCH_MODE_MUL:
349 				*((uint8_t *)&buf) *= privp->val[i].v1;
350 				break;
351 			case NG_PATCH_MODE_DIV:
352 				*((uint8_t *)&buf) /= privp->val[i].v1;
353 				break;
354 			case NG_PATCH_MODE_NEG:
355 				*((int8_t *)&buf) = - *((int8_t *)&buf);
356 				break;
357 			case NG_PATCH_MODE_AND:
358 				*((uint8_t *)&buf) &= privp->val[i].v1;
359 				break;
360 			case NG_PATCH_MODE_OR:
361 				*((uint8_t *)&buf) |= privp->val[i].v1;
362 				break;
363 			case NG_PATCH_MODE_XOR:
364 				*((uint8_t *)&buf) ^= privp->val[i].v1;
365 				break;
366 			case NG_PATCH_MODE_SHL:
367 				*((uint8_t *)&buf) <<= privp->val[i].v1;
368 				break;
369 			case NG_PATCH_MODE_SHR:
370 				*((uint8_t *)&buf) >>= privp->val[i].v1;
371 				break;
372 			}
373 			break;
374 		case 2:
375 			*((int16_t *)&buf) =  ntohs(*((int16_t *)&buf));
376 			switch (conf->ops[i].mode) {
377 			case NG_PATCH_MODE_SET:
378 				*((uint16_t *)&buf) = privp->val[i].v2;
379 				break;
380 			case NG_PATCH_MODE_ADD:
381 				*((uint16_t *)&buf) += privp->val[i].v2;
382 				break;
383 			case NG_PATCH_MODE_SUB:
384 				*((uint16_t *)&buf) -= privp->val[i].v2;
385 				break;
386 			case NG_PATCH_MODE_MUL:
387 				*((uint16_t *)&buf) *= privp->val[i].v2;
388 				break;
389 			case NG_PATCH_MODE_DIV:
390 				*((uint16_t *)&buf) /= privp->val[i].v2;
391 				break;
392 			case NG_PATCH_MODE_NEG:
393 				*((int16_t *)&buf) = - *((int16_t *)&buf);
394 				break;
395 			case NG_PATCH_MODE_AND:
396 				*((uint16_t *)&buf) &= privp->val[i].v2;
397 				break;
398 			case NG_PATCH_MODE_OR:
399 				*((uint16_t *)&buf) |= privp->val[i].v2;
400 				break;
401 			case NG_PATCH_MODE_XOR:
402 				*((uint16_t *)&buf) ^= privp->val[i].v2;
403 				break;
404 			case NG_PATCH_MODE_SHL:
405 				*((uint16_t *)&buf) <<= privp->val[i].v2;
406 				break;
407 			case NG_PATCH_MODE_SHR:
408 				*((uint16_t *)&buf) >>= privp->val[i].v2;
409 				break;
410 			}
411 			*((int16_t *)&buf) =  htons(*((int16_t *)&buf));
412 			break;
413 		case 4:
414 			*((int32_t *)&buf) =  ntohl(*((int32_t *)&buf));
415 			switch (conf->ops[i].mode) {
416 			case NG_PATCH_MODE_SET:
417 				*((uint32_t *)&buf) = privp->val[i].v4;
418 				break;
419 			case NG_PATCH_MODE_ADD:
420 				*((uint32_t *)&buf) += privp->val[i].v4;
421 				break;
422 			case NG_PATCH_MODE_SUB:
423 				*((uint32_t *)&buf) -= privp->val[i].v4;
424 				break;
425 			case NG_PATCH_MODE_MUL:
426 				*((uint32_t *)&buf) *= privp->val[i].v4;
427 				break;
428 			case NG_PATCH_MODE_DIV:
429 				*((uint32_t *)&buf) /= privp->val[i].v4;
430 				break;
431 			case NG_PATCH_MODE_NEG:
432 				*((int32_t *)&buf) = - *((int32_t *)&buf);
433 				break;
434 			case NG_PATCH_MODE_AND:
435 				*((uint32_t *)&buf) &= privp->val[i].v4;
436 				break;
437 			case NG_PATCH_MODE_OR:
438 				*((uint32_t *)&buf) |= privp->val[i].v4;
439 				break;
440 			case NG_PATCH_MODE_XOR:
441 				*((uint32_t *)&buf) ^= privp->val[i].v4;
442 				break;
443 			case NG_PATCH_MODE_SHL:
444 				*((uint32_t *)&buf) <<= privp->val[i].v4;
445 				break;
446 			case NG_PATCH_MODE_SHR:
447 				*((uint32_t *)&buf) >>= privp->val[i].v4;
448 				break;
449 			}
450 			*((int32_t *)&buf) =  htonl(*((int32_t *)&buf));
451 			break;
452 		case 8:
453 			*((int64_t *)&buf) =  be64toh(*((int64_t *)&buf));
454 			switch (conf->ops[i].mode) {
455 			case NG_PATCH_MODE_SET:
456 				*((uint64_t *)&buf) = privp->val[i].v8;
457 				break;
458 			case NG_PATCH_MODE_ADD:
459 				*((uint64_t *)&buf) += privp->val[i].v8;
460 				break;
461 			case NG_PATCH_MODE_SUB:
462 				*((uint64_t *)&buf) -= privp->val[i].v8;
463 				break;
464 			case NG_PATCH_MODE_MUL:
465 				*((uint64_t *)&buf) *= privp->val[i].v8;
466 				break;
467 			case NG_PATCH_MODE_DIV:
468 				*((uint64_t *)&buf) /= privp->val[i].v8;
469 				break;
470 			case NG_PATCH_MODE_NEG:
471 				*((int64_t *)&buf) = - *((int64_t *)&buf);
472 				break;
473 			case NG_PATCH_MODE_AND:
474 				*((uint64_t *)&buf) &= privp->val[i].v8;
475 				break;
476 			case NG_PATCH_MODE_OR:
477 				*((uint64_t *)&buf) |= privp->val[i].v8;
478 				break;
479 			case NG_PATCH_MODE_XOR:
480 				*((uint64_t *)&buf) ^= privp->val[i].v8;
481 				break;
482 			case NG_PATCH_MODE_SHL:
483 				*((uint64_t *)&buf) <<= privp->val[i].v8;
484 				break;
485 			case NG_PATCH_MODE_SHR:
486 				*((uint64_t *)&buf) >>= privp->val[i].v8;
487 				break;
488 			}
489 			*((int64_t *)&buf) =  htobe64(*((int64_t *)&buf));
490 			break;
491 		}
492 
493 		m_copyback(m, conf->ops[i].offset, conf->ops[i].length,
494 		    (caddr_t)&buf);
495 		patched = 1;
496 	}
497 	if (patched > 0)
498 		privp->stats.patched++;
499 }
500 
501 static int
502 ng_patch_rcvdata(hook_p hook, item_p item)
503 {
504 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
505 	struct mbuf *m;
506 	hook_p target;
507 	int error;
508 
509 	priv->stats.received++;
510 	NGI_GET_M(item, m);
511 	if (priv->config != NULL && hook == priv->in &&
512 	    (m->m_flags & M_PKTHDR) != 0) {
513 		m = m_unshare(m,M_NOWAIT);
514 		if (m == NULL) {
515 			priv->stats.dropped++;
516 			NG_FREE_ITEM(item);
517 			return (ENOMEM);
518 		}
519 		do_patch(priv, m);
520 		m->m_pkthdr.csum_flags |= priv->config->csum_flags;
521 	}
522 
523 	target = NULL;
524 	if (hook == priv->in) {
525 		/* return frames on 'in' hook if 'out' not connected */
526 		if (priv->out != NULL)
527 			target = priv->out;
528 		else
529 			target = priv->in;
530 	}
531 	if (hook == priv->out && priv->in != NULL)
532 		target = priv->in;
533 
534 	if (target == NULL) {
535 		priv->stats.dropped++;
536 		NG_FREE_ITEM(item);
537 		NG_FREE_M(m);
538 		return (0);
539 	}
540 	NG_FWD_NEW_DATA(error, item, target, m);
541 	return (error);
542 }
543 
544 static int
545 ng_patch_shutdown(node_p node)
546 {
547 	const priv_p privdata = NG_NODE_PRIVATE(node);
548 
549 	if (privdata->val != NULL)
550 		free(privdata->val, M_NETGRAPH);
551 	if (privdata->config != NULL)
552 		free(privdata->config, M_NETGRAPH);
553 	NG_NODE_SET_PRIVATE(node, NULL);
554 	NG_NODE_UNREF(node);
555 	free(privdata, M_NETGRAPH);
556 	return (0);
557 }
558 
559 static int
560 ng_patch_disconnect(hook_p hook)
561 {
562 	priv_p priv;
563 
564 	priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
565 	if (hook == priv->in) {
566 		priv->in = NULL;
567 	}
568 	if (hook == priv->out) {
569 		priv->out = NULL;
570 	}
571 	if (NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0 &&
572 	    NG_NODE_IS_VALID(NG_HOOK_NODE(hook))) /* already shutting down? */
573 		ng_rmnode_self(NG_HOOK_NODE(hook));
574 	return (0);
575 }
576 
577