xref: /freebsd/sys/netgraph/netflow/ng_netflow.c (revision 145992504973bd16cf3518af9ba5ce185fefa82a)
1 /*-
2  * Copyright (c) 2010-2011 Alexander V. Chernikov <melifaro@ipfw.ru>
3  * Copyright (c) 2004-2005 Gleb Smirnoff <glebius@FreeBSD.org>
4  * Copyright (c) 2001-2003 Roman V. Palagin <romanp@unshadow.net>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * $SourceForge: ng_netflow.c,v 1.30 2004/09/05 11:37:43 glebius Exp $
29  */
30 
31 static const char rcs_id[] =
32     "@(#) $FreeBSD$";
33 
34 #include "opt_inet6.h"
35 #include "opt_route.h"
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/kernel.h>
40 #include <sys/limits.h>
41 #include <sys/mbuf.h>
42 #include <sys/socket.h>
43 #include <sys/syslog.h>
44 #include <sys/ctype.h>
45 
46 #include <net/if.h>
47 #include <net/ethernet.h>
48 #include <net/route.h>
49 #include <net/if_arp.h>
50 #include <net/if_var.h>
51 #include <net/if_vlan_var.h>
52 #include <net/bpf.h>
53 #include <netinet/in.h>
54 #include <netinet/in_systm.h>
55 #include <netinet/ip.h>
56 #include <netinet/ip6.h>
57 #include <netinet/tcp.h>
58 #include <netinet/udp.h>
59 #include <netinet/sctp.h>
60 
61 #include <netgraph/ng_message.h>
62 #include <netgraph/ng_parse.h>
63 #include <netgraph/netgraph.h>
64 #include <netgraph/netflow/netflow.h>
65 #include <netgraph/netflow/netflow_v9.h>
66 #include <netgraph/netflow/ng_netflow.h>
67 
68 /* Netgraph methods */
69 static ng_constructor_t	ng_netflow_constructor;
70 static ng_rcvmsg_t	ng_netflow_rcvmsg;
71 static ng_close_t	ng_netflow_close;
72 static ng_shutdown_t	ng_netflow_rmnode;
73 static ng_newhook_t	ng_netflow_newhook;
74 static ng_rcvdata_t	ng_netflow_rcvdata;
75 static ng_disconnect_t	ng_netflow_disconnect;
76 
77 /* Parse type for struct ng_netflow_info */
78 static const struct ng_parse_struct_field ng_netflow_info_type_fields[]
79 	= NG_NETFLOW_INFO_TYPE;
80 static const struct ng_parse_type ng_netflow_info_type = {
81 	&ng_parse_struct_type,
82 	&ng_netflow_info_type_fields
83 };
84 
85 /*  Parse type for struct ng_netflow_ifinfo */
86 static const struct ng_parse_struct_field ng_netflow_ifinfo_type_fields[]
87 	= NG_NETFLOW_IFINFO_TYPE;
88 static const struct ng_parse_type ng_netflow_ifinfo_type = {
89 	&ng_parse_struct_type,
90 	&ng_netflow_ifinfo_type_fields
91 };
92 
93 /* Parse type for struct ng_netflow_setdlt */
94 static const struct ng_parse_struct_field ng_netflow_setdlt_type_fields[]
95 	= NG_NETFLOW_SETDLT_TYPE;
96 static const struct ng_parse_type ng_netflow_setdlt_type = {
97 	&ng_parse_struct_type,
98 	&ng_netflow_setdlt_type_fields
99 };
100 
101 /* Parse type for ng_netflow_setifindex */
102 static const struct ng_parse_struct_field ng_netflow_setifindex_type_fields[]
103 	= NG_NETFLOW_SETIFINDEX_TYPE;
104 static const struct ng_parse_type ng_netflow_setifindex_type = {
105 	&ng_parse_struct_type,
106 	&ng_netflow_setifindex_type_fields
107 };
108 
109 /* Parse type for ng_netflow_settimeouts */
110 static const struct ng_parse_struct_field ng_netflow_settimeouts_type_fields[]
111 	= NG_NETFLOW_SETTIMEOUTS_TYPE;
112 static const struct ng_parse_type ng_netflow_settimeouts_type = {
113 	&ng_parse_struct_type,
114 	&ng_netflow_settimeouts_type_fields
115 };
116 
117 /* Parse type for ng_netflow_setconfig */
118 static const struct ng_parse_struct_field ng_netflow_setconfig_type_fields[]
119 	= NG_NETFLOW_SETCONFIG_TYPE;
120 static const struct ng_parse_type ng_netflow_setconfig_type = {
121 	&ng_parse_struct_type,
122 	&ng_netflow_setconfig_type_fields
123 };
124 
125 /* Parse type for ng_netflow_settemplate */
126 static const struct ng_parse_struct_field ng_netflow_settemplate_type_fields[]
127 	= NG_NETFLOW_SETTEMPLATE_TYPE;
128 static const struct ng_parse_type ng_netflow_settemplate_type = {
129 	&ng_parse_struct_type,
130 	&ng_netflow_settemplate_type_fields
131 };
132 
133 /* Parse type for ng_netflow_setmtu */
134 static const struct ng_parse_struct_field ng_netflow_setmtu_type_fields[]
135 	= NG_NETFLOW_SETMTU_TYPE;
136 static const struct ng_parse_type ng_netflow_setmtu_type = {
137 	&ng_parse_struct_type,
138 	&ng_netflow_setmtu_type_fields
139 };
140 
141 /* Parse type for struct ng_netflow_v9info */
142 static const struct ng_parse_struct_field ng_netflow_v9info_type_fields[]
143 	= NG_NETFLOW_V9INFO_TYPE;
144 static const struct ng_parse_type ng_netflow_v9info_type = {
145 	&ng_parse_struct_type,
146 	&ng_netflow_v9info_type_fields
147 };
148 
149 /* List of commands and how to convert arguments to/from ASCII */
150 static const struct ng_cmdlist ng_netflow_cmds[] = {
151        {
152 	 NGM_NETFLOW_COOKIE,
153 	 NGM_NETFLOW_INFO,
154 	 "info",
155 	 NULL,
156 	 &ng_netflow_info_type
157        },
158        {
159 	NGM_NETFLOW_COOKIE,
160 	NGM_NETFLOW_IFINFO,
161 	"ifinfo",
162 	&ng_parse_uint16_type,
163 	&ng_netflow_ifinfo_type
164        },
165        {
166 	NGM_NETFLOW_COOKIE,
167 	NGM_NETFLOW_SETDLT,
168 	"setdlt",
169 	&ng_netflow_setdlt_type,
170 	NULL
171        },
172        {
173 	NGM_NETFLOW_COOKIE,
174 	NGM_NETFLOW_SETIFINDEX,
175 	"setifindex",
176 	&ng_netflow_setifindex_type,
177 	NULL
178        },
179        {
180 	NGM_NETFLOW_COOKIE,
181 	NGM_NETFLOW_SETTIMEOUTS,
182 	"settimeouts",
183 	&ng_netflow_settimeouts_type,
184 	NULL
185        },
186        {
187 	NGM_NETFLOW_COOKIE,
188 	NGM_NETFLOW_SETCONFIG,
189 	"setconfig",
190 	&ng_netflow_setconfig_type,
191 	NULL
192        },
193        {
194 	NGM_NETFLOW_COOKIE,
195 	NGM_NETFLOW_SETTEMPLATE,
196 	"settemplate",
197 	&ng_netflow_settemplate_type,
198 	NULL
199        },
200        {
201 	NGM_NETFLOW_COOKIE,
202 	NGM_NETFLOW_SETMTU,
203 	"setmtu",
204 	&ng_netflow_setmtu_type,
205 	NULL
206        },
207        {
208 	 NGM_NETFLOW_COOKIE,
209 	 NGM_NETFLOW_V9INFO,
210 	 "v9info",
211 	 NULL,
212 	 &ng_netflow_v9info_type
213        },
214        { 0 }
215 };
216 
217 
218 /* Netgraph node type descriptor */
219 static struct ng_type ng_netflow_typestruct = {
220 	.version =	NG_ABI_VERSION,
221 	.name =		NG_NETFLOW_NODE_TYPE,
222 	.constructor =	ng_netflow_constructor,
223 	.rcvmsg =	ng_netflow_rcvmsg,
224 	.close =	ng_netflow_close,
225 	.shutdown =	ng_netflow_rmnode,
226 	.newhook =	ng_netflow_newhook,
227 	.rcvdata =	ng_netflow_rcvdata,
228 	.disconnect =	ng_netflow_disconnect,
229 	.cmdlist =	ng_netflow_cmds,
230 };
231 NETGRAPH_INIT(netflow, &ng_netflow_typestruct);
232 
233 /* Called at node creation */
234 static int
235 ng_netflow_constructor(node_p node)
236 {
237 	priv_p priv;
238 	int i;
239 
240 	/* Initialize private data */
241 	priv = malloc(sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO);
242 
243 	/* Initialize fib data */
244 	priv->maxfibs = rt_numfibs;
245 	priv->fib_data = malloc(sizeof(fib_export_p) * priv->maxfibs,
246 	    M_NETGRAPH, M_WAITOK | M_ZERO);
247 
248 	/* Make node and its data point at each other */
249 	NG_NODE_SET_PRIVATE(node, priv);
250 	priv->node = node;
251 
252 	/* Initialize timeouts to default values */
253 	priv->info.nfinfo_inact_t = INACTIVE_TIMEOUT;
254 	priv->info.nfinfo_act_t = ACTIVE_TIMEOUT;
255 
256 	/* Set default config */
257 	for (i = 0; i < NG_NETFLOW_MAXIFACES; i++)
258 		priv->ifaces[i].info.conf = NG_NETFLOW_CONF_INGRESS;
259 
260 	/* Initialize callout handle */
261 	callout_init(&priv->exp_callout, CALLOUT_MPSAFE);
262 
263 	/* Allocate memory and set up flow cache */
264 	ng_netflow_cache_init(priv);
265 
266 	return (0);
267 }
268 
269 /*
270  * ng_netflow supports two hooks: data and export.
271  * Incoming traffic is expected on data, and expired
272  * netflow datagrams are sent to export.
273  */
274 static int
275 ng_netflow_newhook(node_p node, hook_p hook, const char *name)
276 {
277 	const priv_p priv = NG_NODE_PRIVATE(node);
278 
279 	if (strncmp(name, NG_NETFLOW_HOOK_DATA,	/* an iface hook? */
280 	    strlen(NG_NETFLOW_HOOK_DATA)) == 0) {
281 		iface_p iface;
282 		int ifnum = -1;
283 		const char *cp;
284 		char *eptr;
285 
286 		cp = name + strlen(NG_NETFLOW_HOOK_DATA);
287 		if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0'))
288 			return (EINVAL);
289 
290 		ifnum = (int)strtoul(cp, &eptr, 10);
291 		if (*eptr != '\0' || ifnum < 0 || ifnum >= NG_NETFLOW_MAXIFACES)
292 			return (EINVAL);
293 
294 		/* See if hook is already connected */
295 		if (priv->ifaces[ifnum].hook != NULL)
296 			return (EISCONN);
297 
298 		iface = &priv->ifaces[ifnum];
299 
300 		/* Link private info and hook together */
301 		NG_HOOK_SET_PRIVATE(hook, iface);
302 		iface->hook = hook;
303 
304 		/*
305 		 * In most cases traffic accounting is done on an
306 		 * Ethernet interface, so default data link type
307 		 * will be DLT_EN10MB.
308 		 */
309 		iface->info.ifinfo_dlt = DLT_EN10MB;
310 
311 	} else if (strncmp(name, NG_NETFLOW_HOOK_OUT,
312 	    strlen(NG_NETFLOW_HOOK_OUT)) == 0) {
313 		iface_p iface;
314 		int ifnum = -1;
315 		const char *cp;
316 		char *eptr;
317 
318 		cp = name + strlen(NG_NETFLOW_HOOK_OUT);
319 		if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0'))
320 			return (EINVAL);
321 
322 		ifnum = (int)strtoul(cp, &eptr, 10);
323 		if (*eptr != '\0' || ifnum < 0 || ifnum >= NG_NETFLOW_MAXIFACES)
324 			return (EINVAL);
325 
326 		/* See if hook is already connected */
327 		if (priv->ifaces[ifnum].out != NULL)
328 			return (EISCONN);
329 
330 		iface = &priv->ifaces[ifnum];
331 
332 		/* Link private info and hook together */
333 		NG_HOOK_SET_PRIVATE(hook, iface);
334 		iface->out = hook;
335 
336 	} else if (strcmp(name, NG_NETFLOW_HOOK_EXPORT) == 0) {
337 
338 		if (priv->export != NULL)
339 			return (EISCONN);
340 
341 		/* Netflow version 5 supports 32-bit counters only */
342 		if (CNTR_MAX == UINT64_MAX)
343 			return (EINVAL);
344 
345 		priv->export = hook;
346 
347 		/* Exporter is ready. Let's schedule expiry. */
348 		callout_reset(&priv->exp_callout, (1*hz), &ng_netflow_expire,
349 		    (void *)priv);
350 	} else if (strcmp(name, NG_NETFLOW_HOOK_EXPORT9) == 0) {
351 
352 		if (priv->export9 != NULL)
353 			return (EISCONN);
354 
355 		priv->export9 = hook;
356 
357 		/* Exporter is ready. Let's schedule expiry. */
358 		callout_reset(&priv->exp_callout, (1*hz), &ng_netflow_expire,
359 		    (void *)priv);
360 	} else
361 		return (EINVAL);
362 
363 	return (0);
364 }
365 
366 /* Get a netgraph control message. */
367 static int
368 ng_netflow_rcvmsg (node_p node, item_p item, hook_p lasthook)
369 {
370 	const priv_p priv = NG_NODE_PRIVATE(node);
371 	struct ng_mesg *resp = NULL;
372 	int error = 0;
373 	struct ng_mesg *msg;
374 
375 	NGI_GET_MSG(item, msg);
376 
377 	/* Deal with message according to cookie and command */
378 	switch (msg->header.typecookie) {
379 	case NGM_NETFLOW_COOKIE:
380 		switch (msg->header.cmd) {
381 		case NGM_NETFLOW_INFO:
382 		{
383 			struct ng_netflow_info *i;
384 
385 			NG_MKRESPONSE(resp, msg, sizeof(struct ng_netflow_info),
386 			    M_NOWAIT);
387 			i = (struct ng_netflow_info *)resp->data;
388 			ng_netflow_copyinfo(priv, i);
389 
390 			break;
391 		}
392 		case NGM_NETFLOW_IFINFO:
393 		{
394 			struct ng_netflow_ifinfo *i;
395 			const uint16_t *index;
396 
397 			if (msg->header.arglen != sizeof(uint16_t))
398 				 ERROUT(EINVAL);
399 
400 			index  = (uint16_t *)msg->data;
401 			if (*index >= NG_NETFLOW_MAXIFACES)
402 				ERROUT(EINVAL);
403 
404 			/* connected iface? */
405 			if (priv->ifaces[*index].hook == NULL)
406 				 ERROUT(EINVAL);
407 
408 			NG_MKRESPONSE(resp, msg,
409 			     sizeof(struct ng_netflow_ifinfo), M_NOWAIT);
410 			i = (struct ng_netflow_ifinfo *)resp->data;
411 			memcpy((void *)i, (void *)&priv->ifaces[*index].info,
412 			    sizeof(priv->ifaces[*index].info));
413 
414 			break;
415 		}
416 		case NGM_NETFLOW_SETDLT:
417 		{
418 			struct ng_netflow_setdlt *set;
419 			struct ng_netflow_iface *iface;
420 
421 			if (msg->header.arglen != sizeof(struct ng_netflow_setdlt))
422 				ERROUT(EINVAL);
423 
424 			set = (struct ng_netflow_setdlt *)msg->data;
425 			if (set->iface >= NG_NETFLOW_MAXIFACES)
426 				ERROUT(EINVAL);
427 			iface = &priv->ifaces[set->iface];
428 
429 			/* connected iface? */
430 			if (iface->hook == NULL)
431 				ERROUT(EINVAL);
432 
433 			switch (set->dlt) {
434 			case	DLT_EN10MB:
435 				iface->info.ifinfo_dlt = DLT_EN10MB;
436 				break;
437 			case	DLT_RAW:
438 				iface->info.ifinfo_dlt = DLT_RAW;
439 				break;
440 			default:
441 				ERROUT(EINVAL);
442 			}
443 			break;
444 		}
445 		case NGM_NETFLOW_SETIFINDEX:
446 		{
447 			struct ng_netflow_setifindex *set;
448 			struct ng_netflow_iface *iface;
449 
450 			if (msg->header.arglen != sizeof(struct ng_netflow_setifindex))
451 				ERROUT(EINVAL);
452 
453 			set = (struct ng_netflow_setifindex *)msg->data;
454 			if (set->iface >= NG_NETFLOW_MAXIFACES)
455 				ERROUT(EINVAL);
456 			iface = &priv->ifaces[set->iface];
457 
458 			/* connected iface? */
459 			if (iface->hook == NULL)
460 				ERROUT(EINVAL);
461 
462 			iface->info.ifinfo_index = set->index;
463 
464 			break;
465 		}
466 		case NGM_NETFLOW_SETTIMEOUTS:
467 		{
468 			struct ng_netflow_settimeouts *set;
469 
470 			if (msg->header.arglen != sizeof(struct ng_netflow_settimeouts))
471 				ERROUT(EINVAL);
472 
473 			set = (struct ng_netflow_settimeouts *)msg->data;
474 
475 			priv->info.nfinfo_inact_t = set->inactive_timeout;
476 			priv->info.nfinfo_act_t = set->active_timeout;
477 
478 			break;
479 		}
480 		case NGM_NETFLOW_SETCONFIG:
481 		{
482 			struct ng_netflow_setconfig *set;
483 
484 			if (msg->header.arglen != sizeof(struct ng_netflow_setconfig))
485 				ERROUT(EINVAL);
486 
487 			set = (struct ng_netflow_setconfig *)msg->data;
488 
489 			if (set->iface >= NG_NETFLOW_MAXIFACES)
490 				ERROUT(EINVAL);
491 
492 			priv->ifaces[set->iface].info.conf = set->conf;
493 
494 			break;
495 		}
496 		case NGM_NETFLOW_SETTEMPLATE:
497 		{
498 			struct ng_netflow_settemplate *set;
499 
500 			if (msg->header.arglen != sizeof(struct ng_netflow_settemplate))
501 				ERROUT(EINVAL);
502 
503 			set = (struct ng_netflow_settemplate *)msg->data;
504 
505 			priv->templ_packets = set->packets;
506 			priv->templ_time = set->time;
507 
508 			break;
509 		}
510 		case NGM_NETFLOW_SETMTU:
511 		{
512 			struct ng_netflow_setmtu *set;
513 
514 			if (msg->header.arglen != sizeof(struct ng_netflow_setmtu))
515 				ERROUT(EINVAL);
516 
517 			set = (struct ng_netflow_setmtu *)msg->data;
518 			if ((set->mtu < MIN_MTU) || (set->mtu > MAX_MTU))
519 				ERROUT(EINVAL);
520 
521 			priv->mtu = set->mtu;
522 
523 			break;
524 		}
525 		case NGM_NETFLOW_SHOW:
526 		{
527 			if (msg->header.arglen != sizeof(struct ngnf_show_header))
528 				ERROUT(EINVAL);
529 
530 			NG_MKRESPONSE(resp, msg, NGRESP_SIZE, M_NOWAIT);
531 
532 			if (!resp)
533 				ERROUT(ENOMEM);
534 
535 			error = ng_netflow_flow_show(priv,
536 			    (struct ngnf_show_header *)msg->data,
537 			    (struct ngnf_show_header *)resp->data);
538 
539 			if (error)
540 				NG_FREE_MSG(resp);
541 
542 			break;
543 		}
544 		case NGM_NETFLOW_V9INFO:
545 		{
546 			struct ng_netflow_v9info *i;
547 
548 			NG_MKRESPONSE(resp, msg, sizeof(struct ng_netflow_v9info),
549 			    M_NOWAIT);
550 			i = (struct ng_netflow_v9info *)resp->data;
551 			ng_netflow_copyv9info(priv, i);
552 
553 			break;
554 		}
555 		default:
556 			ERROUT(EINVAL);		/* unknown command */
557 			break;
558 		}
559 		break;
560 	default:
561 		ERROUT(EINVAL);		/* incorrect cookie */
562 		break;
563 	}
564 
565 	/*
566 	 * Take care of synchronous response, if any.
567 	 * Free memory and return.
568 	 */
569 done:
570 	NG_RESPOND_MSG(error, node, item, resp);
571 	NG_FREE_MSG(msg);
572 
573 	return (error);
574 }
575 
576 /* Receive data on hook. */
577 static int
578 ng_netflow_rcvdata (hook_p hook, item_p item)
579 {
580 	const node_p node = NG_HOOK_NODE(hook);
581 	const priv_p priv = NG_NODE_PRIVATE(node);
582 	const iface_p iface = NG_HOOK_PRIVATE(hook);
583 	hook_p out;
584 	struct mbuf *m = NULL, *m_old = NULL;
585 	struct ip *ip = NULL;
586 	struct ip6_hdr *ip6 = NULL;
587 	struct m_tag *mtag;
588 	int pullup_len = 0, off;
589 	uint8_t acct = 0, bypass = 0, flags = 0, upper_proto = 0;
590 	int error = 0, l3_off = 0;
591 	unsigned int src_if_index;
592 	caddr_t upper_ptr = NULL;
593 	fib_export_p fe;
594 	uint32_t fib;
595 
596 	if ((hook == priv->export) || (hook == priv->export9)) {
597 		/*
598 		 * Data arrived on export hook.
599 		 * This must not happen.
600 		 */
601 		log(LOG_ERR, "ng_netflow: incoming data on export hook!\n");
602 		ERROUT(EINVAL);
603 	};
604 
605 	if (hook == iface->hook) {
606 		if ((iface->info.conf & NG_NETFLOW_CONF_INGRESS) == 0)
607 			bypass = 1;
608 		out = iface->out;
609 	} else if (hook == iface->out) {
610 		if ((iface->info.conf & NG_NETFLOW_CONF_EGRESS) == 0)
611 			bypass = 1;
612 		out = iface->hook;
613 	} else
614 		ERROUT(EINVAL);
615 
616 	if ((!bypass) &&
617 	    (iface->info.conf & (NG_NETFLOW_CONF_ONCE | NG_NETFLOW_CONF_THISONCE))) {
618 		mtag = m_tag_locate(NGI_M(item), MTAG_NETFLOW,
619 		    MTAG_NETFLOW_CALLED, NULL);
620 		while (mtag != NULL) {
621 			if ((iface->info.conf & NG_NETFLOW_CONF_ONCE) ||
622 			    ((ng_ID_t *)(mtag + 1))[0] == NG_NODE_ID(node)) {
623 				bypass = 1;
624 				break;
625 			}
626 			mtag = m_tag_locate(NGI_M(item), MTAG_NETFLOW,
627 			    MTAG_NETFLOW_CALLED, mtag);
628 		}
629 	}
630 
631 	if (bypass) {
632 		if (out == NULL)
633 			ERROUT(ENOTCONN);
634 
635 		NG_FWD_ITEM_HOOK(error, item, out);
636 		return (error);
637 	}
638 
639 	if (iface->info.conf & (NG_NETFLOW_CONF_ONCE | NG_NETFLOW_CONF_THISONCE)) {
640 		mtag = m_tag_alloc(MTAG_NETFLOW, MTAG_NETFLOW_CALLED,
641 		    sizeof(ng_ID_t), M_NOWAIT);
642 		if (mtag) {
643 			((ng_ID_t *)(mtag + 1))[0] = NG_NODE_ID(node);
644 			m_tag_prepend(NGI_M(item), mtag);
645 		}
646 	}
647 
648 	/* Import configuration flags related to flow creation */
649 	flags = iface->info.conf & NG_NETFLOW_FLOW_FLAGS;
650 
651 	NGI_GET_M(item, m);
652 	m_old = m;
653 
654 	/* Increase counters. */
655 	iface->info.ifinfo_packets++;
656 
657 	/*
658 	 * Depending on interface data link type and packet contents
659 	 * we pullup enough data, so that ng_netflow_flow_add() does not
660 	 * need to know about mbuf at all. We keep current length of data
661 	 * needed to be contiguous in pullup_len. mtod() is done at the
662 	 * very end one more time, since m can had changed after pulluping.
663 	 *
664 	 * In case of unrecognized data we don't return error, but just
665 	 * pass data to downstream hook, if it is available.
666 	 */
667 
668 #define	M_CHECK(length)	do {					\
669 	pullup_len += length;					\
670 	if (((m)->m_pkthdr.len < (pullup_len)) ||		\
671 	   ((pullup_len) > MHLEN)) {				\
672 		error = EINVAL;					\
673 		goto bypass;					\
674 	} 							\
675 	if ((m)->m_len < (pullup_len) &&			\
676 	   (((m) = m_pullup((m),(pullup_len))) == NULL)) {	\
677 		error = ENOBUFS;				\
678 		goto done;					\
679 	}							\
680 } while (0)
681 
682 	switch (iface->info.ifinfo_dlt) {
683 	case DLT_EN10MB:	/* Ethernet */
684 	    {
685 		struct ether_header *eh;
686 		uint16_t etype;
687 
688 		M_CHECK(sizeof(struct ether_header));
689 		eh = mtod(m, struct ether_header *);
690 
691 		/* Make sure this is IP frame. */
692 		etype = ntohs(eh->ether_type);
693 		switch (etype) {
694 		case ETHERTYPE_IP:
695 			M_CHECK(sizeof(struct ip));
696 			eh = mtod(m, struct ether_header *);
697 			ip = (struct ip *)(eh + 1);
698 			l3_off = sizeof(struct ether_header);
699 			break;
700 #ifdef INET6
701 		case ETHERTYPE_IPV6:
702 			/*
703 			 * m_pullup() called by M_CHECK() pullups
704 			 * kern.ipc.max_protohdr (default 60 bytes) which is enough
705 			 */
706 			M_CHECK(sizeof(struct ip6_hdr));
707 			eh = mtod(m, struct ether_header *);
708 			ip6 = (struct ip6_hdr *)(eh + 1);
709 			l3_off = sizeof(struct ether_header);
710 			break;
711 #endif
712 		case ETHERTYPE_VLAN:
713 		    {
714 			struct ether_vlan_header *evh;
715 
716 			M_CHECK(sizeof(struct ether_vlan_header) -
717 			    sizeof(struct ether_header));
718 			evh = mtod(m, struct ether_vlan_header *);
719 			etype = ntohs(evh->evl_proto);
720 			l3_off = sizeof(struct ether_vlan_header);
721 
722 			if (etype == ETHERTYPE_IP) {
723 				M_CHECK(sizeof(struct ip));
724 				ip = (struct ip *)(evh + 1);
725 				break;
726 #ifdef INET6
727 			} else if (etype == ETHERTYPE_IPV6) {
728 				M_CHECK(sizeof(struct ip6_hdr));
729 				ip6 = (struct ip6_hdr *)(evh + 1);
730 				break;
731 #endif
732 			}
733 		    }
734 		default:
735 			goto bypass;	/* pass this frame */
736 		}
737 		break;
738 	    }
739 	case DLT_RAW:		/* IP packets */
740 		M_CHECK(sizeof(struct ip));
741 		ip = mtod(m, struct ip *);
742 		/* l3_off is already zero */
743 #ifdef INET6
744 		/* If INET6 is not defined IPv6 packets will be discarded in ng_netflow_flow_add() */
745 		if (ip->ip_v == IP6VERSION) {
746 			/* IPv6 packet */
747 			ip = NULL;
748 			M_CHECK(sizeof(struct ip6_hdr) - sizeof(struct ip));
749 			ip6 = mtod(m, struct ip6_hdr *);
750 		}
751 #endif
752 		break;
753 	default:
754 		goto bypass;
755 		break;
756 	}
757 
758 	off = pullup_len;
759 
760 	if ((ip != NULL) && ((ip->ip_off & htons(IP_OFFMASK)) == 0)) {
761 		if ((ip->ip_v != IPVERSION) ||
762 		    ((ip->ip_hl << 2) < sizeof(struct ip)))
763 			goto bypass;
764 		/*
765 		 * In case of IPv4 header with options, we haven't pulled
766 		 * up enough, yet.
767 		 */
768 		M_CHECK((ip->ip_hl << 2) - sizeof(struct ip));
769 
770 		/* Save upper layer offset and proto */
771 		off = pullup_len;
772 		upper_proto = ip->ip_p;
773 
774 		/*
775 		 * XXX: in case of wrong upper layer header we will forward this packet
776 		 * but skip this record in netflow
777 		 */
778 		switch (ip->ip_p) {
779 		case IPPROTO_TCP:
780 			M_CHECK(sizeof(struct tcphdr));
781 			break;
782 		case IPPROTO_UDP:
783 			M_CHECK(sizeof(struct udphdr));
784 			break;
785 		case IPPROTO_SCTP:
786 			M_CHECK(sizeof(struct sctphdr));
787 			break;
788 		}
789 	} else if (ip != NULL) {
790 		/* Nothing to save except upper layer proto, since this is packet fragment */
791 		flags |= NG_NETFLOW_IS_FRAG;
792 		upper_proto = ip->ip_p;
793 		if ((ip->ip_v != IPVERSION) ||
794 		    ((ip->ip_hl << 2) < sizeof(struct ip)))
795 			goto bypass;
796 #ifdef INET6
797 	} else if (ip6 != NULL) {
798 		/* Check if we can export */
799 		if (priv->export9 == NULL)
800 			goto bypass;
801 
802 		/* Loop thru IPv6 extended headers to get upper layer header / frag */
803 		int cur = ip6->ip6_nxt, hdr_off = 0;
804 		struct ip6_ext *ip6e;
805 		struct ip6_frag *ip6f;
806 
807 		/* Save upper layer info */
808 		off = pullup_len;
809 		upper_proto = cur;
810 
811 		if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION)
812 			goto bypass;
813 
814 		while (42) {
815 			switch (cur) {
816 			/*
817 			 * Same as in IPv4, we can forward 'bad' packet without accounting
818 			 */
819 			case IPPROTO_TCP:
820 				M_CHECK(sizeof(struct tcphdr));
821 				goto loopend;
822 			case IPPROTO_UDP:
823 				M_CHECK(sizeof(struct udphdr));
824 				goto loopend;
825 			case IPPROTO_SCTP:
826 				M_CHECK(sizeof(struct sctphdr));
827 				goto loopend;
828 
829 			/* Loop until 'real' upper layer headers */
830 			case IPPROTO_HOPOPTS:
831 			case IPPROTO_ROUTING:
832 			case IPPROTO_DSTOPTS:
833 				M_CHECK(sizeof(struct ip6_ext));
834 				ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
835 				upper_proto = ip6e->ip6e_nxt;
836 				hdr_off = (ip6e->ip6e_len + 1) << 3;
837 				break;
838 
839 			/* RFC4302, can be before DSTOPTS */
840 			case IPPROTO_AH:
841 				M_CHECK(sizeof(struct ip6_ext));
842 				ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
843 				upper_proto = ip6e->ip6e_nxt;
844 				hdr_off = (ip6e->ip6e_len + 2) << 2;
845 				break;
846 
847 			case IPPROTO_FRAGMENT:
848 				M_CHECK(sizeof(struct ip6_frag));
849 				ip6f = (struct ip6_frag *)(mtod(m, caddr_t) + off);
850 				upper_proto = ip6f->ip6f_nxt;
851 				hdr_off = sizeof(struct ip6_frag);
852 				off += hdr_off;
853 				flags |= NG_NETFLOW_IS_FRAG;
854 				goto loopend;
855 
856 #if 0
857 			case IPPROTO_NONE:
858 				goto loopend;
859 #endif
860 			/*
861 			 * Any unknown header (new extension or IPv6/IPv4
862 			 * header for tunnels) ends loop.
863 			 */
864 			default:
865 				goto loopend;
866 			}
867 
868 			off += hdr_off;
869 			cur = upper_proto;
870 		}
871 #endif
872 	}
873 #undef	M_CHECK
874 
875 #ifdef INET6
876 loopend:
877 #endif
878 	/* Just in case of real reallocation in M_CHECK() / m_pullup() */
879 	if (m != m_old) {
880 		atomic_fetchadd_32(&priv->info.nfinfo_realloc_mbuf, 1);
881 		/* Restore ip/ipv6 pointer */
882 		if (ip != NULL)
883 			ip = (struct ip *)(mtod(m, caddr_t) + l3_off);
884 		else if (ip6 != NULL)
885 			ip6 = (struct ip6_hdr *)(mtod(m, caddr_t) + l3_off);
886  	}
887 
888 	upper_ptr = (caddr_t)(mtod(m, caddr_t) + off);
889 
890 	/* Determine packet input interface. Prefer configured. */
891 	src_if_index = 0;
892 	if (hook == iface->out || iface->info.ifinfo_index == 0) {
893 		if (m->m_pkthdr.rcvif != NULL)
894 			src_if_index = m->m_pkthdr.rcvif->if_index;
895 	} else
896 		src_if_index = iface->info.ifinfo_index;
897 
898 	/* Check packet FIB */
899 	fib = M_GETFIB(m);
900 	if (fib >= priv->maxfibs) {
901 		CTR2(KTR_NET, "ng_netflow_rcvdata(): packet fib %d is out of "
902 		    "range of available fibs: 0 .. %d",
903 		    fib, priv->maxfibs);
904 		goto bypass;
905 	}
906 
907 	if ((fe = priv_to_fib(priv, fib)) == NULL) {
908 		/* Setup new FIB */
909 		if (ng_netflow_fib_init(priv, fib) != 0) {
910 			/* malloc() failed */
911 			goto bypass;
912 		}
913 
914 		fe = priv_to_fib(priv, fib);
915 	}
916 
917 	if (ip != NULL)
918 		error = ng_netflow_flow_add(priv, fe, ip, upper_ptr, upper_proto, flags, src_if_index);
919 #ifdef INET6
920 	else if (ip6 != NULL)
921 		error = ng_netflow_flow6_add(priv, fe, ip6, upper_ptr, upper_proto, flags, src_if_index);
922 #endif
923 	else
924 		goto bypass;
925 
926 	acct = 1;
927 bypass:
928 	if (out != NULL) {
929 		if (acct == 0) {
930 			/* Accounting failure */
931 			if (ip != NULL) {
932 				atomic_fetchadd_32(&priv->info.nfinfo_spackets, 1);
933 				priv->info.nfinfo_sbytes += m_length(m, NULL);
934 			} else if (ip6 != NULL) {
935 				atomic_fetchadd_32(&priv->info.nfinfo_spackets6, 1);
936 				priv->info.nfinfo_sbytes6 += m_length(m, NULL);
937 			}
938 		}
939 
940 		/* XXX: error gets overwritten here */
941 		NG_FWD_NEW_DATA(error, item, out, m);
942 		return (error);
943 	}
944 done:
945 	if (item)
946 		NG_FREE_ITEM(item);
947 	if (m)
948 		NG_FREE_M(m);
949 
950 	return (error);
951 }
952 
953 /* We will be shut down in a moment */
954 static int
955 ng_netflow_close(node_p node)
956 {
957 	const priv_p priv = NG_NODE_PRIVATE(node);
958 
959 	callout_drain(&priv->exp_callout);
960 	ng_netflow_cache_flush(priv);
961 
962 	return (0);
963 }
964 
965 /* Do local shutdown processing. */
966 static int
967 ng_netflow_rmnode(node_p node)
968 {
969 	const priv_p priv = NG_NODE_PRIVATE(node);
970 
971 	NG_NODE_SET_PRIVATE(node, NULL);
972 	NG_NODE_UNREF(priv->node);
973 
974 	free(priv->fib_data, M_NETGRAPH);
975 	free(priv, M_NETGRAPH);
976 
977 	return (0);
978 }
979 
980 /* Hook disconnection. */
981 static int
982 ng_netflow_disconnect(hook_p hook)
983 {
984 	node_p node = NG_HOOK_NODE(hook);
985 	priv_p priv = NG_NODE_PRIVATE(node);
986 	iface_p iface = NG_HOOK_PRIVATE(hook);
987 
988 	if (iface != NULL) {
989 		if (iface->hook == hook)
990 			iface->hook = NULL;
991 		if (iface->out == hook)
992 			iface->out = NULL;
993 	}
994 
995 	/* if export hook disconnected stop running expire(). */
996 	if (hook == priv->export) {
997 		if (priv->export9 == NULL)
998 			callout_drain(&priv->exp_callout);
999 		priv->export = NULL;
1000 	}
1001 
1002 	if (hook == priv->export9) {
1003 		if (priv->export == NULL)
1004 			callout_drain(&priv->exp_callout);
1005 		priv->export9 = NULL;
1006 	}
1007 
1008 	/* Removal of the last link destroys the node. */
1009 	if (NG_NODE_NUMHOOKS(node) == 0)
1010 		ng_rmnode_self(node);
1011 
1012 	return (0);
1013 }
1014