xref: /freebsd/sys/netgraph/netflow/ng_netflow.c (revision 031beb4e239bfce798af17f5fe8dba8bcaf13d99)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2010-2011 Alexander V. Chernikov <melifaro@ipfw.ru>
5  * Copyright (c) 2004-2005 Gleb Smirnoff <glebius@FreeBSD.org>
6  * Copyright (c) 2001-2003 Roman V. Palagin <romanp@unshadow.net>
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  * $SourceForge: ng_netflow.c,v 1.30 2004/09/05 11:37:43 glebius Exp $
31  */
32 
33 #include <sys/cdefs.h>
34 #include "opt_inet.h"
35 #include "opt_inet6.h"
36 #include "opt_route.h"
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/counter.h>
41 #include <sys/kernel.h>
42 #include <sys/ktr.h>
43 #include <sys/limits.h>
44 #include <sys/malloc.h>
45 #include <sys/mbuf.h>
46 #include <sys/socket.h>
47 #include <sys/syslog.h>
48 #include <sys/ctype.h>
49 #include <vm/uma.h>
50 
51 #include <net/if.h>
52 #include <net/ethernet.h>
53 #include <net/route.h>
54 #include <net/if_arp.h>
55 #include <net/if_var.h>
56 #include <net/if_private.h>
57 #include <net/if_vlan_var.h>
58 #include <net/bpf.h>
59 #include <netinet/in.h>
60 #include <netinet/in_systm.h>
61 #include <netinet/ip.h>
62 #include <netinet/ip6.h>
63 #include <netinet/tcp.h>
64 #include <netinet/udp.h>
65 #include <netinet/sctp.h>
66 
67 #include <netgraph/ng_message.h>
68 #include <netgraph/ng_parse.h>
69 #include <netgraph/netgraph.h>
70 #include <netgraph/netflow/netflow.h>
71 #include <netgraph/netflow/netflow_v9.h>
72 #include <netgraph/netflow/ng_netflow.h>
73 
74 /* Netgraph methods */
75 static ng_constructor_t	ng_netflow_constructor;
76 static ng_rcvmsg_t	ng_netflow_rcvmsg;
77 static ng_close_t	ng_netflow_close;
78 static ng_shutdown_t	ng_netflow_rmnode;
79 static ng_newhook_t	ng_netflow_newhook;
80 static ng_rcvdata_t	ng_netflow_rcvdata;
81 static ng_disconnect_t	ng_netflow_disconnect;
82 
83 /* Parse type for struct ng_netflow_info */
84 static const struct ng_parse_struct_field ng_netflow_info_type_fields[]
85 	= NG_NETFLOW_INFO_TYPE;
86 static const struct ng_parse_type ng_netflow_info_type = {
87 	&ng_parse_struct_type,
88 	&ng_netflow_info_type_fields
89 };
90 
91 /*  Parse type for struct ng_netflow_ifinfo */
92 static const struct ng_parse_struct_field ng_netflow_ifinfo_type_fields[]
93 	= NG_NETFLOW_IFINFO_TYPE;
94 static const struct ng_parse_type ng_netflow_ifinfo_type = {
95 	&ng_parse_struct_type,
96 	&ng_netflow_ifinfo_type_fields
97 };
98 
99 /* Parse type for struct ng_netflow_setdlt */
100 static const struct ng_parse_struct_field ng_netflow_setdlt_type_fields[]
101 	= NG_NETFLOW_SETDLT_TYPE;
102 static const struct ng_parse_type ng_netflow_setdlt_type = {
103 	&ng_parse_struct_type,
104 	&ng_netflow_setdlt_type_fields
105 };
106 
107 /* Parse type for ng_netflow_setifindex */
108 static const struct ng_parse_struct_field ng_netflow_setifindex_type_fields[]
109 	= NG_NETFLOW_SETIFINDEX_TYPE;
110 static const struct ng_parse_type ng_netflow_setifindex_type = {
111 	&ng_parse_struct_type,
112 	&ng_netflow_setifindex_type_fields
113 };
114 
115 /* Parse type for ng_netflow_settimeouts */
116 static const struct ng_parse_struct_field ng_netflow_settimeouts_type_fields[]
117 	= NG_NETFLOW_SETTIMEOUTS_TYPE;
118 static const struct ng_parse_type ng_netflow_settimeouts_type = {
119 	&ng_parse_struct_type,
120 	&ng_netflow_settimeouts_type_fields
121 };
122 
123 /* Parse type for ng_netflow_setconfig */
124 static const struct ng_parse_struct_field ng_netflow_setconfig_type_fields[]
125 	= NG_NETFLOW_SETCONFIG_TYPE;
126 static const struct ng_parse_type ng_netflow_setconfig_type = {
127 	&ng_parse_struct_type,
128 	&ng_netflow_setconfig_type_fields
129 };
130 
131 /* Parse type for ng_netflow_settemplate */
132 static const struct ng_parse_struct_field ng_netflow_settemplate_type_fields[]
133 	= NG_NETFLOW_SETTEMPLATE_TYPE;
134 static const struct ng_parse_type ng_netflow_settemplate_type = {
135 	&ng_parse_struct_type,
136 	&ng_netflow_settemplate_type_fields
137 };
138 
139 /* Parse type for ng_netflow_setmtu */
140 static const struct ng_parse_struct_field ng_netflow_setmtu_type_fields[]
141 	= NG_NETFLOW_SETMTU_TYPE;
142 static const struct ng_parse_type ng_netflow_setmtu_type = {
143 	&ng_parse_struct_type,
144 	&ng_netflow_setmtu_type_fields
145 };
146 
147 /* Parse type for struct ng_netflow_v9info */
148 static const struct ng_parse_struct_field ng_netflow_v9info_type_fields[]
149 	= NG_NETFLOW_V9INFO_TYPE;
150 static const struct ng_parse_type ng_netflow_v9info_type = {
151 	&ng_parse_struct_type,
152 	&ng_netflow_v9info_type_fields
153 };
154 
155 /* List of commands and how to convert arguments to/from ASCII */
156 static const struct ng_cmdlist ng_netflow_cmds[] = {
157        {
158 	 NGM_NETFLOW_COOKIE,
159 	 NGM_NETFLOW_INFO,
160 	 "info",
161 	 NULL,
162 	 &ng_netflow_info_type
163        },
164        {
165 	NGM_NETFLOW_COOKIE,
166 	NGM_NETFLOW_IFINFO,
167 	"ifinfo",
168 	&ng_parse_uint16_type,
169 	&ng_netflow_ifinfo_type
170        },
171        {
172 	NGM_NETFLOW_COOKIE,
173 	NGM_NETFLOW_SETDLT,
174 	"setdlt",
175 	&ng_netflow_setdlt_type,
176 	NULL
177        },
178        {
179 	NGM_NETFLOW_COOKIE,
180 	NGM_NETFLOW_SETIFINDEX,
181 	"setifindex",
182 	&ng_netflow_setifindex_type,
183 	NULL
184        },
185        {
186 	NGM_NETFLOW_COOKIE,
187 	NGM_NETFLOW_SETTIMEOUTS,
188 	"settimeouts",
189 	&ng_netflow_settimeouts_type,
190 	NULL
191        },
192        {
193 	NGM_NETFLOW_COOKIE,
194 	NGM_NETFLOW_SETCONFIG,
195 	"setconfig",
196 	&ng_netflow_setconfig_type,
197 	NULL
198        },
199        {
200 	NGM_NETFLOW_COOKIE,
201 	NGM_NETFLOW_SETTEMPLATE,
202 	"settemplate",
203 	&ng_netflow_settemplate_type,
204 	NULL
205        },
206        {
207 	NGM_NETFLOW_COOKIE,
208 	NGM_NETFLOW_SETMTU,
209 	"setmtu",
210 	&ng_netflow_setmtu_type,
211 	NULL
212        },
213        {
214 	 NGM_NETFLOW_COOKIE,
215 	 NGM_NETFLOW_V9INFO,
216 	 "v9info",
217 	 NULL,
218 	 &ng_netflow_v9info_type
219        },
220        { 0 }
221 };
222 
223 /* Netgraph node type descriptor */
224 static struct ng_type ng_netflow_typestruct = {
225 	.version =	NG_ABI_VERSION,
226 	.name =		NG_NETFLOW_NODE_TYPE,
227 	.constructor =	ng_netflow_constructor,
228 	.rcvmsg =	ng_netflow_rcvmsg,
229 	.close =	ng_netflow_close,
230 	.shutdown =	ng_netflow_rmnode,
231 	.newhook =	ng_netflow_newhook,
232 	.rcvdata =	ng_netflow_rcvdata,
233 	.disconnect =	ng_netflow_disconnect,
234 	.cmdlist =	ng_netflow_cmds,
235 };
236 NETGRAPH_INIT(netflow, &ng_netflow_typestruct);
237 
238 /* Called at node creation */
239 static int
240 ng_netflow_constructor(node_p node)
241 {
242 	priv_p priv;
243 	int i;
244 
245 	/* Initialize private data */
246 	priv = malloc(sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO);
247 
248 	/* Initialize fib data */
249 	priv->maxfibs = rt_numfibs;
250 	priv->fib_data = malloc(sizeof(fib_export_p) * priv->maxfibs,
251 	    M_NETGRAPH, M_WAITOK | M_ZERO);
252 
253 	/* Make node and its data point at each other */
254 	NG_NODE_SET_PRIVATE(node, priv);
255 	priv->node = node;
256 
257 	/* Initialize timeouts to default values */
258 	priv->nfinfo_inact_t = INACTIVE_TIMEOUT;
259 	priv->nfinfo_act_t = ACTIVE_TIMEOUT;
260 
261 	/* Set default config */
262 	for (i = 0; i < NG_NETFLOW_MAXIFACES; i++)
263 		priv->ifaces[i].info.conf = NG_NETFLOW_CONF_INGRESS;
264 
265 	/* Initialize callout handle */
266 	callout_init(&priv->exp_callout, 1);
267 
268 	/* Allocate memory and set up flow cache */
269 	ng_netflow_cache_init(priv);
270 
271 	return (0);
272 }
273 
274 /*
275  * ng_netflow supports two hooks: data and export.
276  * Incoming traffic is expected on data, and expired
277  * netflow datagrams are sent to export.
278  */
279 static int
280 ng_netflow_newhook(node_p node, hook_p hook, const char *name)
281 {
282 	const priv_p priv = NG_NODE_PRIVATE(node);
283 
284 	if (strncmp(name, NG_NETFLOW_HOOK_DATA,	/* an iface hook? */
285 	    strlen(NG_NETFLOW_HOOK_DATA)) == 0) {
286 		iface_p iface;
287 		int ifnum = -1;
288 		const char *cp;
289 		char *eptr;
290 
291 		cp = name + strlen(NG_NETFLOW_HOOK_DATA);
292 		if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0'))
293 			return (EINVAL);
294 
295 		ifnum = (int)strtoul(cp, &eptr, 10);
296 		if (*eptr != '\0' || ifnum < 0 || ifnum >= NG_NETFLOW_MAXIFACES)
297 			return (EINVAL);
298 
299 		/* See if hook is already connected */
300 		if (priv->ifaces[ifnum].hook != NULL)
301 			return (EISCONN);
302 
303 		iface = &priv->ifaces[ifnum];
304 
305 		/* Link private info and hook together */
306 		NG_HOOK_SET_PRIVATE(hook, iface);
307 		iface->hook = hook;
308 
309 		/*
310 		 * In most cases traffic accounting is done on an
311 		 * Ethernet interface, so default data link type
312 		 * will be DLT_EN10MB.
313 		 */
314 		iface->info.ifinfo_dlt = DLT_EN10MB;
315 
316 	} else if (strncmp(name, NG_NETFLOW_HOOK_OUT,
317 	    strlen(NG_NETFLOW_HOOK_OUT)) == 0) {
318 		iface_p iface;
319 		int ifnum = -1;
320 		const char *cp;
321 		char *eptr;
322 
323 		cp = name + strlen(NG_NETFLOW_HOOK_OUT);
324 		if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0'))
325 			return (EINVAL);
326 
327 		ifnum = (int)strtoul(cp, &eptr, 10);
328 		if (*eptr != '\0' || ifnum < 0 || ifnum >= NG_NETFLOW_MAXIFACES)
329 			return (EINVAL);
330 
331 		/* See if hook is already connected */
332 		if (priv->ifaces[ifnum].out != NULL)
333 			return (EISCONN);
334 
335 		iface = &priv->ifaces[ifnum];
336 
337 		/* Link private info and hook together */
338 		NG_HOOK_SET_PRIVATE(hook, iface);
339 		iface->out = hook;
340 
341 	} else if (strcmp(name, NG_NETFLOW_HOOK_EXPORT) == 0) {
342 		if (priv->export != NULL)
343 			return (EISCONN);
344 
345 		/* Netflow version 5 supports 32-bit counters only */
346 		if (CNTR_MAX == UINT64_MAX)
347 			return (EINVAL);
348 
349 		priv->export = hook;
350 
351 		/* Exporter is ready. Let's schedule expiry. */
352 		callout_reset(&priv->exp_callout, (1*hz), &ng_netflow_expire,
353 		    (void *)priv);
354 	} else if (strcmp(name, NG_NETFLOW_HOOK_EXPORT9) == 0) {
355 		if (priv->export9 != NULL)
356 			return (EISCONN);
357 
358 		priv->export9 = hook;
359 
360 		/* Exporter is ready. Let's schedule expiry. */
361 		callout_reset(&priv->exp_callout, (1*hz), &ng_netflow_expire,
362 		    (void *)priv);
363 	} else
364 		return (EINVAL);
365 
366 	return (0);
367 }
368 
369 /* Get a netgraph control message. */
370 static int
371 ng_netflow_rcvmsg (node_p node, item_p item, hook_p lasthook)
372 {
373 	const priv_p priv = NG_NODE_PRIVATE(node);
374 	struct ng_mesg *resp = NULL;
375 	int error = 0;
376 	struct ng_mesg *msg;
377 
378 	NGI_GET_MSG(item, msg);
379 
380 	/* Deal with message according to cookie and command */
381 	switch (msg->header.typecookie) {
382 	case NGM_NETFLOW_COOKIE:
383 		switch (msg->header.cmd) {
384 		case NGM_NETFLOW_INFO:
385 		    {
386 			struct ng_netflow_info *i;
387 
388 			NG_MKRESPONSE(resp, msg, sizeof(struct ng_netflow_info),
389 			    M_NOWAIT);
390 			i = (struct ng_netflow_info *)resp->data;
391 			ng_netflow_copyinfo(priv, i);
392 
393 			break;
394 		    }
395 		case NGM_NETFLOW_IFINFO:
396 		    {
397 			struct ng_netflow_ifinfo *i;
398 			const uint16_t *index;
399 
400 			if (msg->header.arglen != sizeof(uint16_t))
401 				 ERROUT(EINVAL);
402 
403 			index  = (uint16_t *)msg->data;
404 			if (*index >= NG_NETFLOW_MAXIFACES)
405 				ERROUT(EINVAL);
406 
407 			/* connected iface? */
408 			if (priv->ifaces[*index].hook == NULL)
409 				 ERROUT(EINVAL);
410 
411 			NG_MKRESPONSE(resp, msg,
412 			     sizeof(struct ng_netflow_ifinfo), M_NOWAIT);
413 			i = (struct ng_netflow_ifinfo *)resp->data;
414 			memcpy((void *)i, (void *)&priv->ifaces[*index].info,
415 			    sizeof(priv->ifaces[*index].info));
416 
417 			break;
418 		    }
419 		case NGM_NETFLOW_SETDLT:
420 		    {
421 			struct ng_netflow_setdlt *set;
422 			struct ng_netflow_iface *iface;
423 
424 			if (msg->header.arglen !=
425 			    sizeof(struct ng_netflow_setdlt))
426 				ERROUT(EINVAL);
427 
428 			set = (struct ng_netflow_setdlt *)msg->data;
429 			if (set->iface >= NG_NETFLOW_MAXIFACES)
430 				ERROUT(EINVAL);
431 			iface = &priv->ifaces[set->iface];
432 
433 			/* connected iface? */
434 			if (iface->hook == NULL)
435 				ERROUT(EINVAL);
436 
437 			switch (set->dlt) {
438 			case	DLT_EN10MB:
439 				iface->info.ifinfo_dlt = DLT_EN10MB;
440 				break;
441 			case	DLT_RAW:
442 				iface->info.ifinfo_dlt = DLT_RAW;
443 				break;
444 			default:
445 				ERROUT(EINVAL);
446 			}
447 			break;
448 		    }
449 		case NGM_NETFLOW_SETIFINDEX:
450 		    {
451 			struct ng_netflow_setifindex *set;
452 			struct ng_netflow_iface *iface;
453 
454 			if (msg->header.arglen !=
455 			    sizeof(struct ng_netflow_setifindex))
456 				ERROUT(EINVAL);
457 
458 			set = (struct ng_netflow_setifindex *)msg->data;
459 			if (set->iface >= NG_NETFLOW_MAXIFACES)
460 				ERROUT(EINVAL);
461 			iface = &priv->ifaces[set->iface];
462 
463 			/* connected iface? */
464 			if (iface->hook == NULL)
465 				ERROUT(EINVAL);
466 
467 			iface->info.ifinfo_index = set->index;
468 
469 			break;
470 		    }
471 		case NGM_NETFLOW_SETTIMEOUTS:
472 		    {
473 			struct ng_netflow_settimeouts *set;
474 
475 			if (msg->header.arglen !=
476 			    sizeof(struct ng_netflow_settimeouts))
477 				ERROUT(EINVAL);
478 
479 			set = (struct ng_netflow_settimeouts *)msg->data;
480 
481 			priv->nfinfo_inact_t = set->inactive_timeout;
482 			priv->nfinfo_act_t = set->active_timeout;
483 
484 			break;
485 		    }
486 		case NGM_NETFLOW_SETCONFIG:
487 		    {
488 			struct ng_netflow_setconfig *set;
489 
490 			if (msg->header.arglen !=
491 			    sizeof(struct ng_netflow_setconfig))
492 				ERROUT(EINVAL);
493 
494 			set = (struct ng_netflow_setconfig *)msg->data;
495 
496 			if (set->iface >= NG_NETFLOW_MAXIFACES)
497 				ERROUT(EINVAL);
498 
499 			priv->ifaces[set->iface].info.conf = set->conf;
500 
501 			break;
502 		    }
503 		case NGM_NETFLOW_SETTEMPLATE:
504 		    {
505 			struct ng_netflow_settemplate *set;
506 
507 			if (msg->header.arglen !=
508 			    sizeof(struct ng_netflow_settemplate))
509 				ERROUT(EINVAL);
510 
511 			set = (struct ng_netflow_settemplate *)msg->data;
512 
513 			priv->templ_packets = set->packets;
514 			priv->templ_time = set->time;
515 
516 			break;
517 		    }
518 		case NGM_NETFLOW_SETMTU:
519 		    {
520 			struct ng_netflow_setmtu *set;
521 
522 			if (msg->header.arglen !=
523 			    sizeof(struct ng_netflow_setmtu))
524 				ERROUT(EINVAL);
525 
526 			set = (struct ng_netflow_setmtu *)msg->data;
527 			if ((set->mtu < MIN_MTU) || (set->mtu > MAX_MTU))
528 				ERROUT(EINVAL);
529 
530 			priv->mtu = set->mtu;
531 
532 			break;
533 		    }
534 		case NGM_NETFLOW_SHOW:
535 			if (msg->header.arglen !=
536 			    sizeof(struct ngnf_show_header))
537 				ERROUT(EINVAL);
538 
539 			NG_MKRESPONSE(resp, msg, NGRESP_SIZE, M_NOWAIT);
540 
541 			if (!resp)
542 				ERROUT(ENOMEM);
543 
544 			error = ng_netflow_flow_show(priv,
545 			    (struct ngnf_show_header *)msg->data,
546 			    (struct ngnf_show_header *)resp->data);
547 
548 			if (error)
549 				NG_FREE_MSG(resp);
550 
551 			break;
552 		case NGM_NETFLOW_V9INFO:
553 		    {
554 			struct ng_netflow_v9info *i;
555 
556 			NG_MKRESPONSE(resp, msg,
557 			    sizeof(struct ng_netflow_v9info), M_NOWAIT);
558 			i = (struct ng_netflow_v9info *)resp->data;
559 			ng_netflow_copyv9info(priv, i);
560 
561 			break;
562 		    }
563 		default:
564 			ERROUT(EINVAL);		/* unknown command */
565 			break;
566 		}
567 		break;
568 	default:
569 		ERROUT(EINVAL);		/* incorrect cookie */
570 		break;
571 	}
572 
573 	/*
574 	 * Take care of synchronous response, if any.
575 	 * Free memory and return.
576 	 */
577 done:
578 	NG_RESPOND_MSG(error, node, item, resp);
579 	NG_FREE_MSG(msg);
580 
581 	return (error);
582 }
583 
584 /* Receive data on hook. */
585 static int
586 ng_netflow_rcvdata (hook_p hook, item_p item)
587 {
588 	const node_p node = NG_HOOK_NODE(hook);
589 	const priv_p priv = NG_NODE_PRIVATE(node);
590 	const iface_p iface = NG_HOOK_PRIVATE(hook);
591 	hook_p out;
592 	struct mbuf *m = NULL, *m_old = NULL;
593 	struct ip *ip = NULL;
594 	struct ip6_hdr *ip6 = NULL;
595 	struct m_tag *mtag;
596 	int pullup_len = 0;
597 	uint8_t acct = 0, bypass = 0;
598 	int error = 0, l3_off = 0;
599 #if defined(INET) || defined(INET6)
600 	int off;
601 	uint8_t flags = 0, upper_proto = 0;
602 	unsigned int src_if_index;
603 	caddr_t upper_ptr = NULL;
604 #endif
605 	fib_export_p fe;
606 	uint32_t fib;
607 
608 	if ((hook == priv->export) || (hook == priv->export9)) {
609 		/*
610 		 * Data arrived on export hook.
611 		 * This must not happen.
612 		 */
613 		log(LOG_ERR, "ng_netflow: incoming data on export hook!\n");
614 		ERROUT(EINVAL);
615 	}
616 
617 	if (hook == iface->hook) {
618 		if ((iface->info.conf & NG_NETFLOW_CONF_INGRESS) == 0)
619 			bypass = 1;
620 		out = iface->out;
621 	} else if (hook == iface->out) {
622 		if ((iface->info.conf & NG_NETFLOW_CONF_EGRESS) == 0)
623 			bypass = 1;
624 		out = iface->hook;
625 	} else
626 		ERROUT(EINVAL);
627 
628 	if ((!bypass) && (iface->info.conf &
629 	    (NG_NETFLOW_CONF_ONCE | NG_NETFLOW_CONF_THISONCE))) {
630 		mtag = m_tag_locate(NGI_M(item), MTAG_NETFLOW,
631 		    MTAG_NETFLOW_CALLED, NULL);
632 		while (mtag != NULL) {
633 			if ((iface->info.conf & NG_NETFLOW_CONF_ONCE) ||
634 			    ((ng_ID_t *)(mtag + 1))[0] == NG_NODE_ID(node)) {
635 				bypass = 1;
636 				break;
637 			}
638 			mtag = m_tag_locate(NGI_M(item), MTAG_NETFLOW,
639 			    MTAG_NETFLOW_CALLED, mtag);
640 		}
641 	}
642 
643 	if (bypass) {
644 		if (out == NULL)
645 			ERROUT(ENOTCONN);
646 
647 		NG_FWD_ITEM_HOOK(error, item, out);
648 		return (error);
649 	}
650 
651 	if (iface->info.conf &
652 	    (NG_NETFLOW_CONF_ONCE | NG_NETFLOW_CONF_THISONCE)) {
653 		mtag = m_tag_alloc(MTAG_NETFLOW, MTAG_NETFLOW_CALLED,
654 		    sizeof(ng_ID_t), M_NOWAIT);
655 		if (mtag) {
656 			((ng_ID_t *)(mtag + 1))[0] = NG_NODE_ID(node);
657 			m_tag_prepend(NGI_M(item), mtag);
658 		}
659 	}
660 
661 #if defined(INET) || defined(INET6)
662 	/* Import configuration flags related to flow creation */
663 	flags = iface->info.conf & NG_NETFLOW_FLOW_FLAGS;
664 #endif
665 
666 	NGI_GET_M(item, m);
667 	m_old = m;
668 
669 	/* Increase counters. */
670 	iface->info.ifinfo_packets++;
671 
672 	/*
673 	 * Depending on interface data link type and packet contents
674 	 * we pullup enough data, so that ng_netflow_flow_add() does not
675 	 * need to know about mbuf at all. We keep current length of data
676 	 * needed to be contiguous in pullup_len. mtod() is done at the
677 	 * very end one more time, since m can had changed after pulluping.
678 	 *
679 	 * In case of unrecognized data we don't return error, but just
680 	 * pass data to downstream hook, if it is available.
681 	 */
682 
683 #define	M_CHECK(length)	do {					\
684 	pullup_len += length;					\
685 	if (((m)->m_pkthdr.len < (pullup_len)) ||		\
686 	   ((pullup_len) > MHLEN)) {				\
687 		error = EINVAL;					\
688 		goto bypass;					\
689 	} 							\
690 	if ((m)->m_len < (pullup_len) &&			\
691 	   (((m) = m_pullup((m),(pullup_len))) == NULL)) {	\
692 		error = ENOBUFS;				\
693 		goto done;					\
694 	}							\
695 } while (0)
696 
697 	switch (iface->info.ifinfo_dlt) {
698 	case DLT_EN10MB:	/* Ethernet */
699 	    {
700 		struct ether_header *eh;
701 		uint16_t etype;
702 
703 		M_CHECK(sizeof(struct ether_header));
704 		eh = mtod(m, struct ether_header *);
705 
706 		/* Make sure this is IP frame. */
707 		etype = ntohs(eh->ether_type);
708 		switch (etype) {
709 #ifdef INET
710 		case ETHERTYPE_IP:
711 			M_CHECK(sizeof(struct ip));
712 			eh = mtod(m, struct ether_header *);
713 			ip = (struct ip *)(eh + 1);
714 			l3_off = sizeof(struct ether_header);
715 			break;
716 #endif
717 #ifdef INET6
718 		case ETHERTYPE_IPV6:
719 			/*
720 			 * m_pullup() called by M_CHECK() pullups
721 			 * kern.ipc.max_protohdr (default 60 bytes)
722 			 * which is enough.
723 			 */
724 			M_CHECK(sizeof(struct ip6_hdr));
725 			eh = mtod(m, struct ether_header *);
726 			ip6 = (struct ip6_hdr *)(eh + 1);
727 			l3_off = sizeof(struct ether_header);
728 			break;
729 #endif
730 		case ETHERTYPE_VLAN:
731 		    {
732 			struct ether_vlan_header *evh;
733 
734 			M_CHECK(sizeof(struct ether_vlan_header) -
735 			    sizeof(struct ether_header));
736 			evh = mtod(m, struct ether_vlan_header *);
737 			etype = ntohs(evh->evl_proto);
738 			l3_off = sizeof(struct ether_vlan_header);
739 
740 			if (etype == ETHERTYPE_IP) {
741 #ifdef INET
742 				M_CHECK(sizeof(struct ip));
743 				ip = (struct ip *)(evh + 1);
744 				break;
745 #endif
746 #ifdef INET6
747 			} else if (etype == ETHERTYPE_IPV6) {
748 				M_CHECK(sizeof(struct ip6_hdr));
749 				ip6 = (struct ip6_hdr *)(evh + 1);
750 				break;
751 #endif
752 			}
753 		    }
754 		default:
755 			goto bypass;	/* pass this frame */
756 		}
757 		break;
758 	    }
759 	case DLT_RAW:		/* IP packets */
760 		M_CHECK(sizeof(struct ip));
761 		ip = mtod(m, struct ip *);
762 		/* l3_off is already zero */
763 #ifdef INET6
764 		/*
765 		 * If INET6 is not defined IPv6 packets
766 		 * will be discarded in ng_netflow_flow_add().
767 		 */
768 		if (ip->ip_v == IP6VERSION) {
769 			ip = NULL;
770 			M_CHECK(sizeof(struct ip6_hdr) - sizeof(struct ip));
771 			ip6 = mtod(m, struct ip6_hdr *);
772 		}
773 #endif
774 #ifndef INET
775 		ip = NULL;
776 #endif
777 		break;
778 	default:
779 		goto bypass;
780 		break;
781 	}
782 
783 #if defined(INET) || defined(INET6)
784 	off = pullup_len;
785 #endif
786 
787 	if ((ip != NULL) && ((ip->ip_off & htons(IP_OFFMASK)) == 0)) {
788 		if ((ip->ip_v != IPVERSION) ||
789 		    ((ip->ip_hl << 2) < sizeof(struct ip)))
790 			goto bypass;
791 		/*
792 		 * In case of IPv4 header with options, we haven't pulled
793 		 * up enough, yet.
794 		 */
795 		M_CHECK((ip->ip_hl << 2) - sizeof(struct ip));
796 
797 #if defined(INET) || defined(INET6)
798 		/* Save upper layer offset and proto */
799 		off = pullup_len;
800 		upper_proto = ip->ip_p;
801 #endif
802 
803 		/*
804 		 * XXX: in case of wrong upper layer header we will
805 		 * forward this packet but skip this record in netflow.
806 		 */
807 		switch (ip->ip_p) {
808 		case IPPROTO_TCP:
809 			M_CHECK(sizeof(struct tcphdr));
810 			break;
811 		case IPPROTO_UDP:
812 			M_CHECK(sizeof(struct udphdr));
813 			break;
814 		case IPPROTO_SCTP:
815 			M_CHECK(sizeof(struct sctphdr));
816 			break;
817 		}
818 	} else if (ip != NULL) {
819 		/*
820 		 * Nothing to save except upper layer proto,
821 		 * since this is a packet fragment.
822 		 */
823 #if defined(INET) || defined(INET6)
824 		flags |= NG_NETFLOW_IS_FRAG;
825 		upper_proto = ip->ip_p;
826 #endif
827 		if ((ip->ip_v != IPVERSION) ||
828 		    ((ip->ip_hl << 2) < sizeof(struct ip)))
829 			goto bypass;
830 #ifdef INET6
831 	} else if (ip6 != NULL) {
832 		int cur = ip6->ip6_nxt, hdr_off = 0;
833 		struct ip6_ext *ip6e;
834 		struct ip6_frag *ip6f;
835 
836 		if (priv->export9 == NULL)
837 			goto bypass;
838 
839 		/* Save upper layer info. */
840 		off = pullup_len;
841 		upper_proto = cur;
842 
843 		if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION)
844 			goto bypass;
845 
846 		/*
847 		 * Loop through IPv6 extended headers to get upper
848 		 * layer header / frag.
849 		 */
850 		for (;;) {
851 			switch (cur) {
852 			/*
853 			 * Same as in IPv4, we can forward a 'bad'
854 			 * packet without accounting.
855 			 */
856 			case IPPROTO_TCP:
857 				M_CHECK(sizeof(struct tcphdr));
858 				goto loopend;
859 			case IPPROTO_UDP:
860 				M_CHECK(sizeof(struct udphdr));
861 				goto loopend;
862 			case IPPROTO_SCTP:
863 				M_CHECK(sizeof(struct sctphdr));
864 				goto loopend;
865 
866 			/* Loop until 'real' upper layer headers */
867 			case IPPROTO_HOPOPTS:
868 			case IPPROTO_ROUTING:
869 			case IPPROTO_DSTOPTS:
870 				M_CHECK(sizeof(struct ip6_ext));
871 				ip6e = (struct ip6_ext *)(mtod(m, caddr_t) +
872 				    off);
873 				upper_proto = ip6e->ip6e_nxt;
874 				hdr_off = (ip6e->ip6e_len + 1) << 3;
875 				break;
876 
877 			/* RFC4302, can be before DSTOPTS */
878 			case IPPROTO_AH:
879 				M_CHECK(sizeof(struct ip6_ext));
880 				ip6e = (struct ip6_ext *)(mtod(m, caddr_t) +
881 				    off);
882 				upper_proto = ip6e->ip6e_nxt;
883 				hdr_off = (ip6e->ip6e_len + 2) << 2;
884 				break;
885 
886 			case IPPROTO_FRAGMENT:
887 				M_CHECK(sizeof(struct ip6_frag));
888 				ip6f = (struct ip6_frag *)(mtod(m, caddr_t) +
889 				    off);
890 				upper_proto = ip6f->ip6f_nxt;
891 				hdr_off = sizeof(struct ip6_frag);
892 				off += hdr_off;
893 				flags |= NG_NETFLOW_IS_FRAG;
894 				goto loopend;
895 
896 #if 0
897 			case IPPROTO_NONE:
898 				goto loopend;
899 #endif
900 			/*
901 			 * Any unknown header (new extension or IPv6/IPv4
902 			 * header for tunnels) ends loop.
903 			 */
904 			default:
905 				goto loopend;
906 			}
907 
908 			off += hdr_off;
909 			cur = upper_proto;
910 		}
911 #endif
912 	}
913 #undef	M_CHECK
914 
915 #ifdef INET6
916 loopend:
917 #endif
918 	/* Just in case of real reallocation in M_CHECK() / m_pullup() */
919 	if (m != m_old) {
920 		priv->nfinfo_realloc_mbuf++;
921 		/* Restore ip/ipv6 pointer */
922 		if (ip != NULL)
923 			ip = (struct ip *)(mtod(m, caddr_t) + l3_off);
924 		else if (ip6 != NULL)
925 			ip6 = (struct ip6_hdr *)(mtod(m, caddr_t) + l3_off);
926  	}
927 
928 #if defined(INET) || defined(INET6)
929 	upper_ptr = (caddr_t)(mtod(m, caddr_t) + off);
930 
931 	/* Determine packet input interface. Prefer configured. */
932 	src_if_index = 0;
933 	if (hook == iface->out || iface->info.ifinfo_index == 0) {
934 		if (m->m_pkthdr.rcvif != NULL)
935 			src_if_index = m->m_pkthdr.rcvif->if_index;
936 	} else
937 		src_if_index = iface->info.ifinfo_index;
938 #endif
939 
940 	/* Check packet FIB */
941 	fib = M_GETFIB(m);
942 	if (fib >= priv->maxfibs) {
943 		CTR2(KTR_NET, "ng_netflow_rcvdata(): packet fib %d is out of "
944 		    "range of available fibs: 0 .. %d",
945 		    fib, priv->maxfibs);
946 		goto bypass;
947 	}
948 
949 	if ((fe = priv_to_fib(priv, fib)) == NULL) {
950 		/* Setup new FIB */
951 		if (ng_netflow_fib_init(priv, fib) != 0) {
952 			/* malloc() failed */
953 			goto bypass;
954 		}
955 
956 		fe = priv_to_fib(priv, fib);
957 	}
958 
959 #ifdef INET
960 	if (ip != NULL)
961 		error = ng_netflow_flow_add(priv, fe, ip, upper_ptr,
962 		    upper_proto, flags, src_if_index);
963 #endif
964 #if defined(INET6) && defined(INET)
965 	else
966 #endif
967 #ifdef INET6
968 	if (ip6 != NULL)
969 		error = ng_netflow_flow6_add(priv, fe, ip6, upper_ptr,
970 		    upper_proto, flags, src_if_index);
971 #endif
972 	else
973 		goto bypass;
974 
975 	acct = 1;
976 bypass:
977 	if (out != NULL) {
978 		if (acct == 0) {
979 			/* Accounting failure */
980 			if (ip != NULL) {
981 				counter_u64_add(priv->nfinfo_spackets, 1);
982 				counter_u64_add(priv->nfinfo_sbytes,
983 				    m->m_pkthdr.len);
984 			} else if (ip6 != NULL) {
985 				counter_u64_add(priv->nfinfo_spackets6, 1);
986 				counter_u64_add(priv->nfinfo_sbytes6,
987 				    m->m_pkthdr.len);
988 			}
989 		}
990 
991 		/* XXX: error gets overwritten here */
992 		NG_FWD_NEW_DATA(error, item, out, m);
993 		return (error);
994 	}
995 done:
996 	if (item)
997 		NG_FREE_ITEM(item);
998 	if (m)
999 		NG_FREE_M(m);
1000 
1001 	return (error);
1002 }
1003 
1004 /* We will be shut down in a moment */
1005 static int
1006 ng_netflow_close(node_p node)
1007 {
1008 	const priv_p priv = NG_NODE_PRIVATE(node);
1009 
1010 	callout_drain(&priv->exp_callout);
1011 	ng_netflow_cache_flush(priv);
1012 
1013 	return (0);
1014 }
1015 
1016 /* Do local shutdown processing. */
1017 static int
1018 ng_netflow_rmnode(node_p node)
1019 {
1020 	const priv_p priv = NG_NODE_PRIVATE(node);
1021 
1022 	NG_NODE_SET_PRIVATE(node, NULL);
1023 	NG_NODE_UNREF(priv->node);
1024 
1025 	free(priv->fib_data, M_NETGRAPH);
1026 	free(priv, M_NETGRAPH);
1027 
1028 	return (0);
1029 }
1030 
1031 /* Hook disconnection. */
1032 static int
1033 ng_netflow_disconnect(hook_p hook)
1034 {
1035 	node_p node = NG_HOOK_NODE(hook);
1036 	priv_p priv = NG_NODE_PRIVATE(node);
1037 	iface_p iface = NG_HOOK_PRIVATE(hook);
1038 
1039 	if (iface != NULL) {
1040 		if (iface->hook == hook)
1041 			iface->hook = NULL;
1042 		if (iface->out == hook)
1043 			iface->out = NULL;
1044 	}
1045 
1046 	/* if export hook disconnected stop running expire(). */
1047 	if (hook == priv->export) {
1048 		if (priv->export9 == NULL)
1049 			callout_drain(&priv->exp_callout);
1050 		priv->export = NULL;
1051 	}
1052 
1053 	if (hook == priv->export9) {
1054 		if (priv->export == NULL)
1055 			callout_drain(&priv->exp_callout);
1056 		priv->export9 = NULL;
1057 	}
1058 
1059 	/* Removal of the last link destroys the node. */
1060 	if (NG_NODE_NUMHOOKS(node) == 0)
1061 		ng_rmnode_self(node);
1062 
1063 	return (0);
1064 }
1065