xref: /freebsd/sys/netgraph/netflow/ng_netflow.c (revision abac203368a6069d3d557a71a60a843707694d65)
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 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
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/counter.h>
40 #include <sys/kernel.h>
41 #include <sys/ktr.h>
42 #include <sys/limits.h>
43 #include <sys/mbuf.h>
44 #include <sys/socket.h>
45 #include <sys/syslog.h>
46 #include <sys/ctype.h>
47 
48 #include <net/if.h>
49 #include <net/ethernet.h>
50 #include <net/route.h>
51 #include <net/if_arp.h>
52 #include <net/if_var.h>
53 #include <net/if_vlan_var.h>
54 #include <net/bpf.h>
55 #include <netinet/in.h>
56 #include <netinet/in_systm.h>
57 #include <netinet/ip.h>
58 #include <netinet/ip6.h>
59 #include <netinet/tcp.h>
60 #include <netinet/udp.h>
61 #include <netinet/sctp.h>
62 
63 #include <netgraph/ng_message.h>
64 #include <netgraph/ng_parse.h>
65 #include <netgraph/netgraph.h>
66 #include <netgraph/netflow/netflow.h>
67 #include <netgraph/netflow/netflow_v9.h>
68 #include <netgraph/netflow/ng_netflow.h>
69 
70 /* Netgraph methods */
71 static ng_constructor_t	ng_netflow_constructor;
72 static ng_rcvmsg_t	ng_netflow_rcvmsg;
73 static ng_close_t	ng_netflow_close;
74 static ng_shutdown_t	ng_netflow_rmnode;
75 static ng_newhook_t	ng_netflow_newhook;
76 static ng_rcvdata_t	ng_netflow_rcvdata;
77 static ng_disconnect_t	ng_netflow_disconnect;
78 
79 /* Parse type for struct ng_netflow_info */
80 static const struct ng_parse_struct_field ng_netflow_info_type_fields[]
81 	= NG_NETFLOW_INFO_TYPE;
82 static const struct ng_parse_type ng_netflow_info_type = {
83 	&ng_parse_struct_type,
84 	&ng_netflow_info_type_fields
85 };
86 
87 /*  Parse type for struct ng_netflow_ifinfo */
88 static const struct ng_parse_struct_field ng_netflow_ifinfo_type_fields[]
89 	= NG_NETFLOW_IFINFO_TYPE;
90 static const struct ng_parse_type ng_netflow_ifinfo_type = {
91 	&ng_parse_struct_type,
92 	&ng_netflow_ifinfo_type_fields
93 };
94 
95 /* Parse type for struct ng_netflow_setdlt */
96 static const struct ng_parse_struct_field ng_netflow_setdlt_type_fields[]
97 	= NG_NETFLOW_SETDLT_TYPE;
98 static const struct ng_parse_type ng_netflow_setdlt_type = {
99 	&ng_parse_struct_type,
100 	&ng_netflow_setdlt_type_fields
101 };
102 
103 /* Parse type for ng_netflow_setifindex */
104 static const struct ng_parse_struct_field ng_netflow_setifindex_type_fields[]
105 	= NG_NETFLOW_SETIFINDEX_TYPE;
106 static const struct ng_parse_type ng_netflow_setifindex_type = {
107 	&ng_parse_struct_type,
108 	&ng_netflow_setifindex_type_fields
109 };
110 
111 /* Parse type for ng_netflow_settimeouts */
112 static const struct ng_parse_struct_field ng_netflow_settimeouts_type_fields[]
113 	= NG_NETFLOW_SETTIMEOUTS_TYPE;
114 static const struct ng_parse_type ng_netflow_settimeouts_type = {
115 	&ng_parse_struct_type,
116 	&ng_netflow_settimeouts_type_fields
117 };
118 
119 /* Parse type for ng_netflow_setconfig */
120 static const struct ng_parse_struct_field ng_netflow_setconfig_type_fields[]
121 	= NG_NETFLOW_SETCONFIG_TYPE;
122 static const struct ng_parse_type ng_netflow_setconfig_type = {
123 	&ng_parse_struct_type,
124 	&ng_netflow_setconfig_type_fields
125 };
126 
127 /* Parse type for ng_netflow_settemplate */
128 static const struct ng_parse_struct_field ng_netflow_settemplate_type_fields[]
129 	= NG_NETFLOW_SETTEMPLATE_TYPE;
130 static const struct ng_parse_type ng_netflow_settemplate_type = {
131 	&ng_parse_struct_type,
132 	&ng_netflow_settemplate_type_fields
133 };
134 
135 /* Parse type for ng_netflow_setmtu */
136 static const struct ng_parse_struct_field ng_netflow_setmtu_type_fields[]
137 	= NG_NETFLOW_SETMTU_TYPE;
138 static const struct ng_parse_type ng_netflow_setmtu_type = {
139 	&ng_parse_struct_type,
140 	&ng_netflow_setmtu_type_fields
141 };
142 
143 /* Parse type for struct ng_netflow_v9info */
144 static const struct ng_parse_struct_field ng_netflow_v9info_type_fields[]
145 	= NG_NETFLOW_V9INFO_TYPE;
146 static const struct ng_parse_type ng_netflow_v9info_type = {
147 	&ng_parse_struct_type,
148 	&ng_netflow_v9info_type_fields
149 };
150 
151 /* List of commands and how to convert arguments to/from ASCII */
152 static const struct ng_cmdlist ng_netflow_cmds[] = {
153        {
154 	 NGM_NETFLOW_COOKIE,
155 	 NGM_NETFLOW_INFO,
156 	 "info",
157 	 NULL,
158 	 &ng_netflow_info_type
159        },
160        {
161 	NGM_NETFLOW_COOKIE,
162 	NGM_NETFLOW_IFINFO,
163 	"ifinfo",
164 	&ng_parse_uint16_type,
165 	&ng_netflow_ifinfo_type
166        },
167        {
168 	NGM_NETFLOW_COOKIE,
169 	NGM_NETFLOW_SETDLT,
170 	"setdlt",
171 	&ng_netflow_setdlt_type,
172 	NULL
173        },
174        {
175 	NGM_NETFLOW_COOKIE,
176 	NGM_NETFLOW_SETIFINDEX,
177 	"setifindex",
178 	&ng_netflow_setifindex_type,
179 	NULL
180        },
181        {
182 	NGM_NETFLOW_COOKIE,
183 	NGM_NETFLOW_SETTIMEOUTS,
184 	"settimeouts",
185 	&ng_netflow_settimeouts_type,
186 	NULL
187        },
188        {
189 	NGM_NETFLOW_COOKIE,
190 	NGM_NETFLOW_SETCONFIG,
191 	"setconfig",
192 	&ng_netflow_setconfig_type,
193 	NULL
194        },
195        {
196 	NGM_NETFLOW_COOKIE,
197 	NGM_NETFLOW_SETTEMPLATE,
198 	"settemplate",
199 	&ng_netflow_settemplate_type,
200 	NULL
201        },
202        {
203 	NGM_NETFLOW_COOKIE,
204 	NGM_NETFLOW_SETMTU,
205 	"setmtu",
206 	&ng_netflow_setmtu_type,
207 	NULL
208        },
209        {
210 	 NGM_NETFLOW_COOKIE,
211 	 NGM_NETFLOW_V9INFO,
212 	 "v9info",
213 	 NULL,
214 	 &ng_netflow_v9info_type
215        },
216        { 0 }
217 };
218 
219 
220 /* Netgraph node type descriptor */
221 static struct ng_type ng_netflow_typestruct = {
222 	.version =	NG_ABI_VERSION,
223 	.name =		NG_NETFLOW_NODE_TYPE,
224 	.constructor =	ng_netflow_constructor,
225 	.rcvmsg =	ng_netflow_rcvmsg,
226 	.close =	ng_netflow_close,
227 	.shutdown =	ng_netflow_rmnode,
228 	.newhook =	ng_netflow_newhook,
229 	.rcvdata =	ng_netflow_rcvdata,
230 	.disconnect =	ng_netflow_disconnect,
231 	.cmdlist =	ng_netflow_cmds,
232 };
233 NETGRAPH_INIT(netflow, &ng_netflow_typestruct);
234 
235 /* Called at node creation */
236 static int
237 ng_netflow_constructor(node_p node)
238 {
239 	priv_p priv;
240 	int i;
241 
242 	/* Initialize private data */
243 	priv = malloc(sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO);
244 
245 	/* Initialize fib data */
246 	priv->maxfibs = rt_numfibs;
247 	priv->fib_data = malloc(sizeof(fib_export_p) * priv->maxfibs,
248 	    M_NETGRAPH, M_WAITOK | M_ZERO);
249 
250 	/* Make node and its data point at each other */
251 	NG_NODE_SET_PRIVATE(node, priv);
252 	priv->node = node;
253 
254 	/* Initialize timeouts to default values */
255 	priv->nfinfo_inact_t = INACTIVE_TIMEOUT;
256 	priv->nfinfo_act_t = ACTIVE_TIMEOUT;
257 
258 	/* Set default config */
259 	for (i = 0; i < NG_NETFLOW_MAXIFACES; i++)
260 		priv->ifaces[i].info.conf = NG_NETFLOW_CONF_INGRESS;
261 
262 	/* Initialize callout handle */
263 	callout_init(&priv->exp_callout, 1);
264 
265 	/* Allocate memory and set up flow cache */
266 	ng_netflow_cache_init(priv);
267 
268 	return (0);
269 }
270 
271 /*
272  * ng_netflow supports two hooks: data and export.
273  * Incoming traffic is expected on data, and expired
274  * netflow datagrams are sent to export.
275  */
276 static int
277 ng_netflow_newhook(node_p node, hook_p hook, const char *name)
278 {
279 	const priv_p priv = NG_NODE_PRIVATE(node);
280 
281 	if (strncmp(name, NG_NETFLOW_HOOK_DATA,	/* an iface hook? */
282 	    strlen(NG_NETFLOW_HOOK_DATA)) == 0) {
283 		iface_p iface;
284 		int ifnum = -1;
285 		const char *cp;
286 		char *eptr;
287 
288 		cp = name + strlen(NG_NETFLOW_HOOK_DATA);
289 		if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0'))
290 			return (EINVAL);
291 
292 		ifnum = (int)strtoul(cp, &eptr, 10);
293 		if (*eptr != '\0' || ifnum < 0 || ifnum >= NG_NETFLOW_MAXIFACES)
294 			return (EINVAL);
295 
296 		/* See if hook is already connected */
297 		if (priv->ifaces[ifnum].hook != NULL)
298 			return (EISCONN);
299 
300 		iface = &priv->ifaces[ifnum];
301 
302 		/* Link private info and hook together */
303 		NG_HOOK_SET_PRIVATE(hook, iface);
304 		iface->hook = hook;
305 
306 		/*
307 		 * In most cases traffic accounting is done on an
308 		 * Ethernet interface, so default data link type
309 		 * will be DLT_EN10MB.
310 		 */
311 		iface->info.ifinfo_dlt = DLT_EN10MB;
312 
313 	} else if (strncmp(name, NG_NETFLOW_HOOK_OUT,
314 	    strlen(NG_NETFLOW_HOOK_OUT)) == 0) {
315 		iface_p iface;
316 		int ifnum = -1;
317 		const char *cp;
318 		char *eptr;
319 
320 		cp = name + strlen(NG_NETFLOW_HOOK_OUT);
321 		if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0'))
322 			return (EINVAL);
323 
324 		ifnum = (int)strtoul(cp, &eptr, 10);
325 		if (*eptr != '\0' || ifnum < 0 || ifnum >= NG_NETFLOW_MAXIFACES)
326 			return (EINVAL);
327 
328 		/* See if hook is already connected */
329 		if (priv->ifaces[ifnum].out != NULL)
330 			return (EISCONN);
331 
332 		iface = &priv->ifaces[ifnum];
333 
334 		/* Link private info and hook together */
335 		NG_HOOK_SET_PRIVATE(hook, iface);
336 		iface->out = hook;
337 
338 	} else if (strcmp(name, NG_NETFLOW_HOOK_EXPORT) == 0) {
339 
340 		if (priv->export != NULL)
341 			return (EISCONN);
342 
343 		/* Netflow version 5 supports 32-bit counters only */
344 		if (CNTR_MAX == UINT64_MAX)
345 			return (EINVAL);
346 
347 		priv->export = hook;
348 
349 		/* Exporter is ready. Let's schedule expiry. */
350 		callout_reset(&priv->exp_callout, (1*hz), &ng_netflow_expire,
351 		    (void *)priv);
352 	} else if (strcmp(name, NG_NETFLOW_HOOK_EXPORT9) == 0) {
353 
354 		if (priv->export9 != NULL)
355 			return (EISCONN);
356 
357 		priv->export9 = hook;
358 
359 		/* Exporter is ready. Let's schedule expiry. */
360 		callout_reset(&priv->exp_callout, (1*hz), &ng_netflow_expire,
361 		    (void *)priv);
362 	} else
363 		return (EINVAL);
364 
365 	return (0);
366 }
367 
368 /* Get a netgraph control message. */
369 static int
370 ng_netflow_rcvmsg (node_p node, item_p item, hook_p lasthook)
371 {
372 	const priv_p priv = NG_NODE_PRIVATE(node);
373 	struct ng_mesg *resp = NULL;
374 	int error = 0;
375 	struct ng_mesg *msg;
376 
377 	NGI_GET_MSG(item, msg);
378 
379 	/* Deal with message according to cookie and command */
380 	switch (msg->header.typecookie) {
381 	case NGM_NETFLOW_COOKIE:
382 		switch (msg->header.cmd) {
383 		case NGM_NETFLOW_INFO:
384 		    {
385 			struct ng_netflow_info *i;
386 
387 			NG_MKRESPONSE(resp, msg, sizeof(struct ng_netflow_info),
388 			    M_NOWAIT);
389 			i = (struct ng_netflow_info *)resp->data;
390 			ng_netflow_copyinfo(priv, i);
391 
392 			break;
393 		    }
394 		case NGM_NETFLOW_IFINFO:
395 		    {
396 			struct ng_netflow_ifinfo *i;
397 			const uint16_t *index;
398 
399 			if (msg->header.arglen != sizeof(uint16_t))
400 				 ERROUT(EINVAL);
401 
402 			index  = (uint16_t *)msg->data;
403 			if (*index >= NG_NETFLOW_MAXIFACES)
404 				ERROUT(EINVAL);
405 
406 			/* connected iface? */
407 			if (priv->ifaces[*index].hook == NULL)
408 				 ERROUT(EINVAL);
409 
410 			NG_MKRESPONSE(resp, msg,
411 			     sizeof(struct ng_netflow_ifinfo), M_NOWAIT);
412 			i = (struct ng_netflow_ifinfo *)resp->data;
413 			memcpy((void *)i, (void *)&priv->ifaces[*index].info,
414 			    sizeof(priv->ifaces[*index].info));
415 
416 			break;
417 		    }
418 		case NGM_NETFLOW_SETDLT:
419 		    {
420 			struct ng_netflow_setdlt *set;
421 			struct ng_netflow_iface *iface;
422 
423 			if (msg->header.arglen !=
424 			    sizeof(struct ng_netflow_setdlt))
425 				ERROUT(EINVAL);
426 
427 			set = (struct ng_netflow_setdlt *)msg->data;
428 			if (set->iface >= NG_NETFLOW_MAXIFACES)
429 				ERROUT(EINVAL);
430 			iface = &priv->ifaces[set->iface];
431 
432 			/* connected iface? */
433 			if (iface->hook == NULL)
434 				ERROUT(EINVAL);
435 
436 			switch (set->dlt) {
437 			case	DLT_EN10MB:
438 				iface->info.ifinfo_dlt = DLT_EN10MB;
439 				break;
440 			case	DLT_RAW:
441 				iface->info.ifinfo_dlt = DLT_RAW;
442 				break;
443 			default:
444 				ERROUT(EINVAL);
445 			}
446 			break;
447 		    }
448 		case NGM_NETFLOW_SETIFINDEX:
449 		    {
450 			struct ng_netflow_setifindex *set;
451 			struct ng_netflow_iface *iface;
452 
453 			if (msg->header.arglen !=
454 			    sizeof(struct ng_netflow_setifindex))
455 				ERROUT(EINVAL);
456 
457 			set = (struct ng_netflow_setifindex *)msg->data;
458 			if (set->iface >= NG_NETFLOW_MAXIFACES)
459 				ERROUT(EINVAL);
460 			iface = &priv->ifaces[set->iface];
461 
462 			/* connected iface? */
463 			if (iface->hook == NULL)
464 				ERROUT(EINVAL);
465 
466 			iface->info.ifinfo_index = set->index;
467 
468 			break;
469 		    }
470 		case NGM_NETFLOW_SETTIMEOUTS:
471 		    {
472 			struct ng_netflow_settimeouts *set;
473 
474 			if (msg->header.arglen !=
475 			    sizeof(struct ng_netflow_settimeouts))
476 				ERROUT(EINVAL);
477 
478 			set = (struct ng_netflow_settimeouts *)msg->data;
479 
480 			priv->nfinfo_inact_t = set->inactive_timeout;
481 			priv->nfinfo_act_t = set->active_timeout;
482 
483 			break;
484 		    }
485 		case NGM_NETFLOW_SETCONFIG:
486 		    {
487 			struct ng_netflow_setconfig *set;
488 
489 			if (msg->header.arglen !=
490 			    sizeof(struct ng_netflow_setconfig))
491 				ERROUT(EINVAL);
492 
493 			set = (struct ng_netflow_setconfig *)msg->data;
494 
495 			if (set->iface >= NG_NETFLOW_MAXIFACES)
496 				ERROUT(EINVAL);
497 
498 			priv->ifaces[set->iface].info.conf = set->conf;
499 
500 			break;
501 		    }
502 		case NGM_NETFLOW_SETTEMPLATE:
503 		    {
504 			struct ng_netflow_settemplate *set;
505 
506 			if (msg->header.arglen !=
507 			    sizeof(struct ng_netflow_settemplate))
508 				ERROUT(EINVAL);
509 
510 			set = (struct ng_netflow_settemplate *)msg->data;
511 
512 			priv->templ_packets = set->packets;
513 			priv->templ_time = set->time;
514 
515 			break;
516 		    }
517 		case NGM_NETFLOW_SETMTU:
518 		    {
519 			struct ng_netflow_setmtu *set;
520 
521 			if (msg->header.arglen !=
522 			    sizeof(struct ng_netflow_setmtu))
523 				ERROUT(EINVAL);
524 
525 			set = (struct ng_netflow_setmtu *)msg->data;
526 			if ((set->mtu < MIN_MTU) || (set->mtu > MAX_MTU))
527 				ERROUT(EINVAL);
528 
529 			priv->mtu = set->mtu;
530 
531 			break;
532 		    }
533 		case NGM_NETFLOW_SHOW:
534 			if (msg->header.arglen !=
535 			    sizeof(struct ngnf_show_header))
536 				ERROUT(EINVAL);
537 
538 			NG_MKRESPONSE(resp, msg, NGRESP_SIZE, M_NOWAIT);
539 
540 			if (!resp)
541 				ERROUT(ENOMEM);
542 
543 			error = ng_netflow_flow_show(priv,
544 			    (struct ngnf_show_header *)msg->data,
545 			    (struct ngnf_show_header *)resp->data);
546 
547 			if (error)
548 				NG_FREE_MSG(resp);
549 
550 			break;
551 		case NGM_NETFLOW_V9INFO:
552 		    {
553 			struct ng_netflow_v9info *i;
554 
555 			NG_MKRESPONSE(resp, msg,
556 			    sizeof(struct ng_netflow_v9info), M_NOWAIT);
557 			i = (struct ng_netflow_v9info *)resp->data;
558 			ng_netflow_copyv9info(priv, i);
559 
560 			break;
561 		    }
562 		default:
563 			ERROUT(EINVAL);		/* unknown command */
564 			break;
565 		}
566 		break;
567 	default:
568 		ERROUT(EINVAL);		/* incorrect cookie */
569 		break;
570 	}
571 
572 	/*
573 	 * Take care of synchronous response, if any.
574 	 * Free memory and return.
575 	 */
576 done:
577 	NG_RESPOND_MSG(error, node, item, resp);
578 	NG_FREE_MSG(msg);
579 
580 	return (error);
581 }
582 
583 /* Receive data on hook. */
584 static int
585 ng_netflow_rcvdata (hook_p hook, item_p item)
586 {
587 	const node_p node = NG_HOOK_NODE(hook);
588 	const priv_p priv = NG_NODE_PRIVATE(node);
589 	const iface_p iface = NG_HOOK_PRIVATE(hook);
590 	hook_p out;
591 	struct mbuf *m = NULL, *m_old = NULL;
592 	struct ip *ip = NULL;
593 	struct ip6_hdr *ip6 = NULL;
594 	struct m_tag *mtag;
595 	int pullup_len = 0, off;
596 	uint8_t acct = 0, bypass = 0, flags = 0, upper_proto = 0;
597 	int error = 0, l3_off = 0;
598 	unsigned int src_if_index;
599 	caddr_t upper_ptr = NULL;
600 	fib_export_p fe;
601 	uint32_t fib;
602 
603 	if ((hook == priv->export) || (hook == priv->export9)) {
604 		/*
605 		 * Data arrived on export hook.
606 		 * This must not happen.
607 		 */
608 		log(LOG_ERR, "ng_netflow: incoming data on export hook!\n");
609 		ERROUT(EINVAL);
610 	};
611 
612 	if (hook == iface->hook) {
613 		if ((iface->info.conf & NG_NETFLOW_CONF_INGRESS) == 0)
614 			bypass = 1;
615 		out = iface->out;
616 	} else if (hook == iface->out) {
617 		if ((iface->info.conf & NG_NETFLOW_CONF_EGRESS) == 0)
618 			bypass = 1;
619 		out = iface->hook;
620 	} else
621 		ERROUT(EINVAL);
622 
623 	if ((!bypass) && (iface->info.conf &
624 	    (NG_NETFLOW_CONF_ONCE | NG_NETFLOW_CONF_THISONCE))) {
625 		mtag = m_tag_locate(NGI_M(item), MTAG_NETFLOW,
626 		    MTAG_NETFLOW_CALLED, NULL);
627 		while (mtag != NULL) {
628 			if ((iface->info.conf & NG_NETFLOW_CONF_ONCE) ||
629 			    ((ng_ID_t *)(mtag + 1))[0] == NG_NODE_ID(node)) {
630 				bypass = 1;
631 				break;
632 			}
633 			mtag = m_tag_locate(NGI_M(item), MTAG_NETFLOW,
634 			    MTAG_NETFLOW_CALLED, mtag);
635 		}
636 	}
637 
638 	if (bypass) {
639 		if (out == NULL)
640 			ERROUT(ENOTCONN);
641 
642 		NG_FWD_ITEM_HOOK(error, item, out);
643 		return (error);
644 	}
645 
646 	if (iface->info.conf &
647 	    (NG_NETFLOW_CONF_ONCE | NG_NETFLOW_CONF_THISONCE)) {
648 		mtag = m_tag_alloc(MTAG_NETFLOW, MTAG_NETFLOW_CALLED,
649 		    sizeof(ng_ID_t), M_NOWAIT);
650 		if (mtag) {
651 			((ng_ID_t *)(mtag + 1))[0] = NG_NODE_ID(node);
652 			m_tag_prepend(NGI_M(item), mtag);
653 		}
654 	}
655 
656 	/* Import configuration flags related to flow creation */
657 	flags = iface->info.conf & NG_NETFLOW_FLOW_FLAGS;
658 
659 	NGI_GET_M(item, m);
660 	m_old = m;
661 
662 	/* Increase counters. */
663 	iface->info.ifinfo_packets++;
664 
665 	/*
666 	 * Depending on interface data link type and packet contents
667 	 * we pullup enough data, so that ng_netflow_flow_add() does not
668 	 * need to know about mbuf at all. We keep current length of data
669 	 * needed to be contiguous in pullup_len. mtod() is done at the
670 	 * very end one more time, since m can had changed after pulluping.
671 	 *
672 	 * In case of unrecognized data we don't return error, but just
673 	 * pass data to downstream hook, if it is available.
674 	 */
675 
676 #define	M_CHECK(length)	do {					\
677 	pullup_len += length;					\
678 	if (((m)->m_pkthdr.len < (pullup_len)) ||		\
679 	   ((pullup_len) > MHLEN)) {				\
680 		error = EINVAL;					\
681 		goto bypass;					\
682 	} 							\
683 	if ((m)->m_len < (pullup_len) &&			\
684 	   (((m) = m_pullup((m),(pullup_len))) == NULL)) {	\
685 		error = ENOBUFS;				\
686 		goto done;					\
687 	}							\
688 } while (0)
689 
690 	switch (iface->info.ifinfo_dlt) {
691 	case DLT_EN10MB:	/* Ethernet */
692 	    {
693 		struct ether_header *eh;
694 		uint16_t etype;
695 
696 		M_CHECK(sizeof(struct ether_header));
697 		eh = mtod(m, struct ether_header *);
698 
699 		/* Make sure this is IP frame. */
700 		etype = ntohs(eh->ether_type);
701 		switch (etype) {
702 		case ETHERTYPE_IP:
703 			M_CHECK(sizeof(struct ip));
704 			eh = mtod(m, struct ether_header *);
705 			ip = (struct ip *)(eh + 1);
706 			l3_off = sizeof(struct ether_header);
707 			break;
708 #ifdef INET6
709 		case ETHERTYPE_IPV6:
710 			/*
711 			 * m_pullup() called by M_CHECK() pullups
712 			 * kern.ipc.max_protohdr (default 60 bytes)
713 			 * which is enough.
714 			 */
715 			M_CHECK(sizeof(struct ip6_hdr));
716 			eh = mtod(m, struct ether_header *);
717 			ip6 = (struct ip6_hdr *)(eh + 1);
718 			l3_off = sizeof(struct ether_header);
719 			break;
720 #endif
721 		case ETHERTYPE_VLAN:
722 		    {
723 			struct ether_vlan_header *evh;
724 
725 			M_CHECK(sizeof(struct ether_vlan_header) -
726 			    sizeof(struct ether_header));
727 			evh = mtod(m, struct ether_vlan_header *);
728 			etype = ntohs(evh->evl_proto);
729 			l3_off = sizeof(struct ether_vlan_header);
730 
731 			if (etype == ETHERTYPE_IP) {
732 				M_CHECK(sizeof(struct ip));
733 				ip = (struct ip *)(evh + 1);
734 				break;
735 #ifdef INET6
736 			} else if (etype == ETHERTYPE_IPV6) {
737 				M_CHECK(sizeof(struct ip6_hdr));
738 				ip6 = (struct ip6_hdr *)(evh + 1);
739 				break;
740 #endif
741 			}
742 		    }
743 		default:
744 			goto bypass;	/* pass this frame */
745 		}
746 		break;
747 	    }
748 	case DLT_RAW:		/* IP packets */
749 		M_CHECK(sizeof(struct ip));
750 		ip = mtod(m, struct ip *);
751 		/* l3_off is already zero */
752 #ifdef INET6
753 		/*
754 		 * If INET6 is not defined IPv6 packets
755 		 * will be discarded in ng_netflow_flow_add().
756 		 */
757 		if (ip->ip_v == IP6VERSION) {
758 			ip = NULL;
759 			M_CHECK(sizeof(struct ip6_hdr) - sizeof(struct ip));
760 			ip6 = mtod(m, struct ip6_hdr *);
761 		}
762 #endif
763 		break;
764 	default:
765 		goto bypass;
766 		break;
767 	}
768 
769 	off = pullup_len;
770 
771 	if ((ip != NULL) && ((ip->ip_off & htons(IP_OFFMASK)) == 0)) {
772 		if ((ip->ip_v != IPVERSION) ||
773 		    ((ip->ip_hl << 2) < sizeof(struct ip)))
774 			goto bypass;
775 		/*
776 		 * In case of IPv4 header with options, we haven't pulled
777 		 * up enough, yet.
778 		 */
779 		M_CHECK((ip->ip_hl << 2) - sizeof(struct ip));
780 
781 		/* Save upper layer offset and proto */
782 		off = pullup_len;
783 		upper_proto = ip->ip_p;
784 
785 		/*
786 		 * XXX: in case of wrong upper layer header we will
787 		 * forward this packet but skip this record in netflow.
788 		 */
789 		switch (ip->ip_p) {
790 		case IPPROTO_TCP:
791 			M_CHECK(sizeof(struct tcphdr));
792 			break;
793 		case IPPROTO_UDP:
794 			M_CHECK(sizeof(struct udphdr));
795 			break;
796 		case IPPROTO_SCTP:
797 			M_CHECK(sizeof(struct sctphdr));
798 			break;
799 		}
800 	} else if (ip != NULL) {
801 		/*
802 		 * Nothing to save except upper layer proto,
803 		 * since this is a packet fragment.
804 		 */
805 		flags |= NG_NETFLOW_IS_FRAG;
806 		upper_proto = ip->ip_p;
807 		if ((ip->ip_v != IPVERSION) ||
808 		    ((ip->ip_hl << 2) < sizeof(struct ip)))
809 			goto bypass;
810 #ifdef INET6
811 	} else if (ip6 != NULL) {
812 		int cur = ip6->ip6_nxt, hdr_off = 0;
813 		struct ip6_ext *ip6e;
814 		struct ip6_frag *ip6f;
815 
816 		if (priv->export9 == NULL)
817 			goto bypass;
818 
819 		/* Save upper layer info. */
820 		off = pullup_len;
821 		upper_proto = cur;
822 
823 		if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION)
824 			goto bypass;
825 
826 		/*
827 		 * Loop thru IPv6 extended headers to get upper
828 		 * layer header / frag.
829 		 */
830 		for (;;) {
831 			switch (cur) {
832 			/*
833 			 * Same as in IPv4, we can forward a 'bad'
834 			 * packet without accounting.
835 			 */
836 			case IPPROTO_TCP:
837 				M_CHECK(sizeof(struct tcphdr));
838 				goto loopend;
839 			case IPPROTO_UDP:
840 				M_CHECK(sizeof(struct udphdr));
841 				goto loopend;
842 			case IPPROTO_SCTP:
843 				M_CHECK(sizeof(struct sctphdr));
844 				goto loopend;
845 
846 			/* Loop until 'real' upper layer headers */
847 			case IPPROTO_HOPOPTS:
848 			case IPPROTO_ROUTING:
849 			case IPPROTO_DSTOPTS:
850 				M_CHECK(sizeof(struct ip6_ext));
851 				ip6e = (struct ip6_ext *)(mtod(m, caddr_t) +
852 				    off);
853 				upper_proto = ip6e->ip6e_nxt;
854 				hdr_off = (ip6e->ip6e_len + 1) << 3;
855 				break;
856 
857 			/* RFC4302, can be before DSTOPTS */
858 			case IPPROTO_AH:
859 				M_CHECK(sizeof(struct ip6_ext));
860 				ip6e = (struct ip6_ext *)(mtod(m, caddr_t) +
861 				    off);
862 				upper_proto = ip6e->ip6e_nxt;
863 				hdr_off = (ip6e->ip6e_len + 2) << 2;
864 				break;
865 
866 			case IPPROTO_FRAGMENT:
867 				M_CHECK(sizeof(struct ip6_frag));
868 				ip6f = (struct ip6_frag *)(mtod(m, caddr_t) +
869 				    off);
870 				upper_proto = ip6f->ip6f_nxt;
871 				hdr_off = sizeof(struct ip6_frag);
872 				off += hdr_off;
873 				flags |= NG_NETFLOW_IS_FRAG;
874 				goto loopend;
875 
876 #if 0
877 			case IPPROTO_NONE:
878 				goto loopend;
879 #endif
880 			/*
881 			 * Any unknown header (new extension or IPv6/IPv4
882 			 * header for tunnels) ends loop.
883 			 */
884 			default:
885 				goto loopend;
886 			}
887 
888 			off += hdr_off;
889 			cur = upper_proto;
890 		}
891 #endif
892 	}
893 #undef	M_CHECK
894 
895 #ifdef INET6
896 loopend:
897 #endif
898 	/* Just in case of real reallocation in M_CHECK() / m_pullup() */
899 	if (m != m_old) {
900 		priv->nfinfo_realloc_mbuf++;
901 		/* Restore ip/ipv6 pointer */
902 		if (ip != NULL)
903 			ip = (struct ip *)(mtod(m, caddr_t) + l3_off);
904 		else if (ip6 != NULL)
905 			ip6 = (struct ip6_hdr *)(mtod(m, caddr_t) + l3_off);
906  	}
907 
908 	upper_ptr = (caddr_t)(mtod(m, caddr_t) + off);
909 
910 	/* Determine packet input interface. Prefer configured. */
911 	src_if_index = 0;
912 	if (hook == iface->out || iface->info.ifinfo_index == 0) {
913 		if (m->m_pkthdr.rcvif != NULL)
914 			src_if_index = m->m_pkthdr.rcvif->if_index;
915 	} else
916 		src_if_index = iface->info.ifinfo_index;
917 
918 	/* Check packet FIB */
919 	fib = M_GETFIB(m);
920 	if (fib >= priv->maxfibs) {
921 		CTR2(KTR_NET, "ng_netflow_rcvdata(): packet fib %d is out of "
922 		    "range of available fibs: 0 .. %d",
923 		    fib, priv->maxfibs);
924 		goto bypass;
925 	}
926 
927 	if ((fe = priv_to_fib(priv, fib)) == NULL) {
928 		/* Setup new FIB */
929 		if (ng_netflow_fib_init(priv, fib) != 0) {
930 			/* malloc() failed */
931 			goto bypass;
932 		}
933 
934 		fe = priv_to_fib(priv, fib);
935 	}
936 
937 	if (ip != NULL)
938 		error = ng_netflow_flow_add(priv, fe, ip, upper_ptr,
939 		    upper_proto, flags, src_if_index);
940 #ifdef INET6
941 	else if (ip6 != NULL)
942 		error = ng_netflow_flow6_add(priv, fe, ip6, upper_ptr,
943 		    upper_proto, flags, src_if_index);
944 #endif
945 	else
946 		goto bypass;
947 
948 	acct = 1;
949 bypass:
950 	if (out != NULL) {
951 		if (acct == 0) {
952 			/* Accounting failure */
953 			if (ip != NULL) {
954 				counter_u64_add(priv->nfinfo_spackets, 1);
955 				counter_u64_add(priv->nfinfo_sbytes,
956 				    m->m_pkthdr.len);
957 			} else if (ip6 != NULL) {
958 				counter_u64_add(priv->nfinfo_spackets6, 1);
959 				counter_u64_add(priv->nfinfo_sbytes6,
960 				    m->m_pkthdr.len);
961 			}
962 		}
963 
964 		/* XXX: error gets overwritten here */
965 		NG_FWD_NEW_DATA(error, item, out, m);
966 		return (error);
967 	}
968 done:
969 	if (item)
970 		NG_FREE_ITEM(item);
971 	if (m)
972 		NG_FREE_M(m);
973 
974 	return (error);
975 }
976 
977 /* We will be shut down in a moment */
978 static int
979 ng_netflow_close(node_p node)
980 {
981 	const priv_p priv = NG_NODE_PRIVATE(node);
982 
983 	callout_drain(&priv->exp_callout);
984 	ng_netflow_cache_flush(priv);
985 
986 	return (0);
987 }
988 
989 /* Do local shutdown processing. */
990 static int
991 ng_netflow_rmnode(node_p node)
992 {
993 	const priv_p priv = NG_NODE_PRIVATE(node);
994 
995 	NG_NODE_SET_PRIVATE(node, NULL);
996 	NG_NODE_UNREF(priv->node);
997 
998 	free(priv->fib_data, M_NETGRAPH);
999 	free(priv, M_NETGRAPH);
1000 
1001 	return (0);
1002 }
1003 
1004 /* Hook disconnection. */
1005 static int
1006 ng_netflow_disconnect(hook_p hook)
1007 {
1008 	node_p node = NG_HOOK_NODE(hook);
1009 	priv_p priv = NG_NODE_PRIVATE(node);
1010 	iface_p iface = NG_HOOK_PRIVATE(hook);
1011 
1012 	if (iface != NULL) {
1013 		if (iface->hook == hook)
1014 			iface->hook = NULL;
1015 		if (iface->out == hook)
1016 			iface->out = NULL;
1017 	}
1018 
1019 	/* if export hook disconnected stop running expire(). */
1020 	if (hook == priv->export) {
1021 		if (priv->export9 == NULL)
1022 			callout_drain(&priv->exp_callout);
1023 		priv->export = NULL;
1024 	}
1025 
1026 	if (hook == priv->export9) {
1027 		if (priv->export == NULL)
1028 			callout_drain(&priv->exp_callout);
1029 		priv->export9 = NULL;
1030 	}
1031 
1032 	/* Removal of the last link destroys the node. */
1033 	if (NG_NODE_NUMHOOKS(node) == 0)
1034 		ng_rmnode_self(node);
1035 
1036 	return (0);
1037 }
1038