xref: /freebsd/sys/netgraph/netflow/ng_netflow.c (revision fe6060f10f634930ff71b7c50291ddc610da2475)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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 __FBSDID("$FreeBSD$");
35 
36 #include "opt_inet.h"
37 #include "opt_inet6.h"
38 #include "opt_route.h"
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/counter.h>
43 #include <sys/kernel.h>
44 #include <sys/ktr.h>
45 #include <sys/limits.h>
46 #include <sys/malloc.h>
47 #include <sys/mbuf.h>
48 #include <sys/socket.h>
49 #include <sys/syslog.h>
50 #include <sys/ctype.h>
51 #include <vm/uma.h>
52 
53 #include <net/if.h>
54 #include <net/ethernet.h>
55 #include <net/route.h>
56 #include <net/if_arp.h>
57 #include <net/if_var.h>
58 #include <net/if_vlan_var.h>
59 #include <net/bpf.h>
60 #include <netinet/in.h>
61 #include <netinet/in_systm.h>
62 #include <netinet/ip.h>
63 #include <netinet/ip6.h>
64 #include <netinet/tcp.h>
65 #include <netinet/udp.h>
66 #include <netinet/sctp.h>
67 
68 #include <netgraph/ng_message.h>
69 #include <netgraph/ng_parse.h>
70 #include <netgraph/netgraph.h>
71 #include <netgraph/netflow/netflow.h>
72 #include <netgraph/netflow/netflow_v9.h>
73 #include <netgraph/netflow/ng_netflow.h>
74 
75 /* Netgraph methods */
76 static ng_constructor_t	ng_netflow_constructor;
77 static ng_rcvmsg_t	ng_netflow_rcvmsg;
78 static ng_close_t	ng_netflow_close;
79 static ng_shutdown_t	ng_netflow_rmnode;
80 static ng_newhook_t	ng_netflow_newhook;
81 static ng_rcvdata_t	ng_netflow_rcvdata;
82 static ng_disconnect_t	ng_netflow_disconnect;
83 
84 /* Parse type for struct ng_netflow_info */
85 static const struct ng_parse_struct_field ng_netflow_info_type_fields[]
86 	= NG_NETFLOW_INFO_TYPE;
87 static const struct ng_parse_type ng_netflow_info_type = {
88 	&ng_parse_struct_type,
89 	&ng_netflow_info_type_fields
90 };
91 
92 /*  Parse type for struct ng_netflow_ifinfo */
93 static const struct ng_parse_struct_field ng_netflow_ifinfo_type_fields[]
94 	= NG_NETFLOW_IFINFO_TYPE;
95 static const struct ng_parse_type ng_netflow_ifinfo_type = {
96 	&ng_parse_struct_type,
97 	&ng_netflow_ifinfo_type_fields
98 };
99 
100 /* Parse type for struct ng_netflow_setdlt */
101 static const struct ng_parse_struct_field ng_netflow_setdlt_type_fields[]
102 	= NG_NETFLOW_SETDLT_TYPE;
103 static const struct ng_parse_type ng_netflow_setdlt_type = {
104 	&ng_parse_struct_type,
105 	&ng_netflow_setdlt_type_fields
106 };
107 
108 /* Parse type for ng_netflow_setifindex */
109 static const struct ng_parse_struct_field ng_netflow_setifindex_type_fields[]
110 	= NG_NETFLOW_SETIFINDEX_TYPE;
111 static const struct ng_parse_type ng_netflow_setifindex_type = {
112 	&ng_parse_struct_type,
113 	&ng_netflow_setifindex_type_fields
114 };
115 
116 /* Parse type for ng_netflow_settimeouts */
117 static const struct ng_parse_struct_field ng_netflow_settimeouts_type_fields[]
118 	= NG_NETFLOW_SETTIMEOUTS_TYPE;
119 static const struct ng_parse_type ng_netflow_settimeouts_type = {
120 	&ng_parse_struct_type,
121 	&ng_netflow_settimeouts_type_fields
122 };
123 
124 /* Parse type for ng_netflow_setconfig */
125 static const struct ng_parse_struct_field ng_netflow_setconfig_type_fields[]
126 	= NG_NETFLOW_SETCONFIG_TYPE;
127 static const struct ng_parse_type ng_netflow_setconfig_type = {
128 	&ng_parse_struct_type,
129 	&ng_netflow_setconfig_type_fields
130 };
131 
132 /* Parse type for ng_netflow_settemplate */
133 static const struct ng_parse_struct_field ng_netflow_settemplate_type_fields[]
134 	= NG_NETFLOW_SETTEMPLATE_TYPE;
135 static const struct ng_parse_type ng_netflow_settemplate_type = {
136 	&ng_parse_struct_type,
137 	&ng_netflow_settemplate_type_fields
138 };
139 
140 /* Parse type for ng_netflow_setmtu */
141 static const struct ng_parse_struct_field ng_netflow_setmtu_type_fields[]
142 	= NG_NETFLOW_SETMTU_TYPE;
143 static const struct ng_parse_type ng_netflow_setmtu_type = {
144 	&ng_parse_struct_type,
145 	&ng_netflow_setmtu_type_fields
146 };
147 
148 /* Parse type for struct ng_netflow_v9info */
149 static const struct ng_parse_struct_field ng_netflow_v9info_type_fields[]
150 	= NG_NETFLOW_V9INFO_TYPE;
151 static const struct ng_parse_type ng_netflow_v9info_type = {
152 	&ng_parse_struct_type,
153 	&ng_netflow_v9info_type_fields
154 };
155 
156 /* List of commands and how to convert arguments to/from ASCII */
157 static const struct ng_cmdlist ng_netflow_cmds[] = {
158        {
159 	 NGM_NETFLOW_COOKIE,
160 	 NGM_NETFLOW_INFO,
161 	 "info",
162 	 NULL,
163 	 &ng_netflow_info_type
164        },
165        {
166 	NGM_NETFLOW_COOKIE,
167 	NGM_NETFLOW_IFINFO,
168 	"ifinfo",
169 	&ng_parse_uint16_type,
170 	&ng_netflow_ifinfo_type
171        },
172        {
173 	NGM_NETFLOW_COOKIE,
174 	NGM_NETFLOW_SETDLT,
175 	"setdlt",
176 	&ng_netflow_setdlt_type,
177 	NULL
178        },
179        {
180 	NGM_NETFLOW_COOKIE,
181 	NGM_NETFLOW_SETIFINDEX,
182 	"setifindex",
183 	&ng_netflow_setifindex_type,
184 	NULL
185        },
186        {
187 	NGM_NETFLOW_COOKIE,
188 	NGM_NETFLOW_SETTIMEOUTS,
189 	"settimeouts",
190 	&ng_netflow_settimeouts_type,
191 	NULL
192        },
193        {
194 	NGM_NETFLOW_COOKIE,
195 	NGM_NETFLOW_SETCONFIG,
196 	"setconfig",
197 	&ng_netflow_setconfig_type,
198 	NULL
199        },
200        {
201 	NGM_NETFLOW_COOKIE,
202 	NGM_NETFLOW_SETTEMPLATE,
203 	"settemplate",
204 	&ng_netflow_settemplate_type,
205 	NULL
206        },
207        {
208 	NGM_NETFLOW_COOKIE,
209 	NGM_NETFLOW_SETMTU,
210 	"setmtu",
211 	&ng_netflow_setmtu_type,
212 	NULL
213        },
214        {
215 	 NGM_NETFLOW_COOKIE,
216 	 NGM_NETFLOW_V9INFO,
217 	 "v9info",
218 	 NULL,
219 	 &ng_netflow_v9info_type
220        },
221        { 0 }
222 };
223 
224 /* Netgraph node type descriptor */
225 static struct ng_type ng_netflow_typestruct = {
226 	.version =	NG_ABI_VERSION,
227 	.name =		NG_NETFLOW_NODE_TYPE,
228 	.constructor =	ng_netflow_constructor,
229 	.rcvmsg =	ng_netflow_rcvmsg,
230 	.close =	ng_netflow_close,
231 	.shutdown =	ng_netflow_rmnode,
232 	.newhook =	ng_netflow_newhook,
233 	.rcvdata =	ng_netflow_rcvdata,
234 	.disconnect =	ng_netflow_disconnect,
235 	.cmdlist =	ng_netflow_cmds,
236 };
237 NETGRAPH_INIT(netflow, &ng_netflow_typestruct);
238 
239 /* Called at node creation */
240 static int
241 ng_netflow_constructor(node_p node)
242 {
243 	priv_p priv;
244 	int i;
245 
246 	/* Initialize private data */
247 	priv = malloc(sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO);
248 
249 	/* Initialize fib data */
250 	priv->maxfibs = rt_numfibs;
251 	priv->fib_data = malloc(sizeof(fib_export_p) * priv->maxfibs,
252 	    M_NETGRAPH, M_WAITOK | M_ZERO);
253 
254 	/* Make node and its data point at each other */
255 	NG_NODE_SET_PRIVATE(node, priv);
256 	priv->node = node;
257 
258 	/* Initialize timeouts to default values */
259 	priv->nfinfo_inact_t = INACTIVE_TIMEOUT;
260 	priv->nfinfo_act_t = ACTIVE_TIMEOUT;
261 
262 	/* Set default config */
263 	for (i = 0; i < NG_NETFLOW_MAXIFACES; i++)
264 		priv->ifaces[i].info.conf = NG_NETFLOW_CONF_INGRESS;
265 
266 	/* Initialize callout handle */
267 	callout_init(&priv->exp_callout, 1);
268 
269 	/* Allocate memory and set up flow cache */
270 	ng_netflow_cache_init(priv);
271 
272 	return (0);
273 }
274 
275 /*
276  * ng_netflow supports two hooks: data and export.
277  * Incoming traffic is expected on data, and expired
278  * netflow datagrams are sent to export.
279  */
280 static int
281 ng_netflow_newhook(node_p node, hook_p hook, const char *name)
282 {
283 	const priv_p priv = NG_NODE_PRIVATE(node);
284 
285 	if (strncmp(name, NG_NETFLOW_HOOK_DATA,	/* an iface hook? */
286 	    strlen(NG_NETFLOW_HOOK_DATA)) == 0) {
287 		iface_p iface;
288 		int ifnum = -1;
289 		const char *cp;
290 		char *eptr;
291 
292 		cp = name + strlen(NG_NETFLOW_HOOK_DATA);
293 		if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0'))
294 			return (EINVAL);
295 
296 		ifnum = (int)strtoul(cp, &eptr, 10);
297 		if (*eptr != '\0' || ifnum < 0 || ifnum >= NG_NETFLOW_MAXIFACES)
298 			return (EINVAL);
299 
300 		/* See if hook is already connected */
301 		if (priv->ifaces[ifnum].hook != NULL)
302 			return (EISCONN);
303 
304 		iface = &priv->ifaces[ifnum];
305 
306 		/* Link private info and hook together */
307 		NG_HOOK_SET_PRIVATE(hook, iface);
308 		iface->hook = hook;
309 
310 		/*
311 		 * In most cases traffic accounting is done on an
312 		 * Ethernet interface, so default data link type
313 		 * will be DLT_EN10MB.
314 		 */
315 		iface->info.ifinfo_dlt = DLT_EN10MB;
316 
317 	} else if (strncmp(name, NG_NETFLOW_HOOK_OUT,
318 	    strlen(NG_NETFLOW_HOOK_OUT)) == 0) {
319 		iface_p iface;
320 		int ifnum = -1;
321 		const char *cp;
322 		char *eptr;
323 
324 		cp = name + strlen(NG_NETFLOW_HOOK_OUT);
325 		if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0'))
326 			return (EINVAL);
327 
328 		ifnum = (int)strtoul(cp, &eptr, 10);
329 		if (*eptr != '\0' || ifnum < 0 || ifnum >= NG_NETFLOW_MAXIFACES)
330 			return (EINVAL);
331 
332 		/* See if hook is already connected */
333 		if (priv->ifaces[ifnum].out != NULL)
334 			return (EISCONN);
335 
336 		iface = &priv->ifaces[ifnum];
337 
338 		/* Link private info and hook together */
339 		NG_HOOK_SET_PRIVATE(hook, iface);
340 		iface->out = hook;
341 
342 	} else if (strcmp(name, NG_NETFLOW_HOOK_EXPORT) == 0) {
343 		if (priv->export != NULL)
344 			return (EISCONN);
345 
346 		/* Netflow version 5 supports 32-bit counters only */
347 		if (CNTR_MAX == UINT64_MAX)
348 			return (EINVAL);
349 
350 		priv->export = hook;
351 
352 		/* Exporter is ready. Let's schedule expiry. */
353 		callout_reset(&priv->exp_callout, (1*hz), &ng_netflow_expire,
354 		    (void *)priv);
355 	} else if (strcmp(name, NG_NETFLOW_HOOK_EXPORT9) == 0) {
356 		if (priv->export9 != NULL)
357 			return (EISCONN);
358 
359 		priv->export9 = hook;
360 
361 		/* Exporter is ready. Let's schedule expiry. */
362 		callout_reset(&priv->exp_callout, (1*hz), &ng_netflow_expire,
363 		    (void *)priv);
364 	} else
365 		return (EINVAL);
366 
367 	return (0);
368 }
369 
370 /* Get a netgraph control message. */
371 static int
372 ng_netflow_rcvmsg (node_p node, item_p item, hook_p lasthook)
373 {
374 	const priv_p priv = NG_NODE_PRIVATE(node);
375 	struct ng_mesg *resp = NULL;
376 	int error = 0;
377 	struct ng_mesg *msg;
378 
379 	NGI_GET_MSG(item, msg);
380 
381 	/* Deal with message according to cookie and command */
382 	switch (msg->header.typecookie) {
383 	case NGM_NETFLOW_COOKIE:
384 		switch (msg->header.cmd) {
385 		case NGM_NETFLOW_INFO:
386 		    {
387 			struct ng_netflow_info *i;
388 
389 			NG_MKRESPONSE(resp, msg, sizeof(struct ng_netflow_info),
390 			    M_NOWAIT);
391 			i = (struct ng_netflow_info *)resp->data;
392 			ng_netflow_copyinfo(priv, i);
393 
394 			break;
395 		    }
396 		case NGM_NETFLOW_IFINFO:
397 		    {
398 			struct ng_netflow_ifinfo *i;
399 			const uint16_t *index;
400 
401 			if (msg->header.arglen != sizeof(uint16_t))
402 				 ERROUT(EINVAL);
403 
404 			index  = (uint16_t *)msg->data;
405 			if (*index >= NG_NETFLOW_MAXIFACES)
406 				ERROUT(EINVAL);
407 
408 			/* connected iface? */
409 			if (priv->ifaces[*index].hook == NULL)
410 				 ERROUT(EINVAL);
411 
412 			NG_MKRESPONSE(resp, msg,
413 			     sizeof(struct ng_netflow_ifinfo), M_NOWAIT);
414 			i = (struct ng_netflow_ifinfo *)resp->data;
415 			memcpy((void *)i, (void *)&priv->ifaces[*index].info,
416 			    sizeof(priv->ifaces[*index].info));
417 
418 			break;
419 		    }
420 		case NGM_NETFLOW_SETDLT:
421 		    {
422 			struct ng_netflow_setdlt *set;
423 			struct ng_netflow_iface *iface;
424 
425 			if (msg->header.arglen !=
426 			    sizeof(struct ng_netflow_setdlt))
427 				ERROUT(EINVAL);
428 
429 			set = (struct ng_netflow_setdlt *)msg->data;
430 			if (set->iface >= NG_NETFLOW_MAXIFACES)
431 				ERROUT(EINVAL);
432 			iface = &priv->ifaces[set->iface];
433 
434 			/* connected iface? */
435 			if (iface->hook == NULL)
436 				ERROUT(EINVAL);
437 
438 			switch (set->dlt) {
439 			case	DLT_EN10MB:
440 				iface->info.ifinfo_dlt = DLT_EN10MB;
441 				break;
442 			case	DLT_RAW:
443 				iface->info.ifinfo_dlt = DLT_RAW;
444 				break;
445 			default:
446 				ERROUT(EINVAL);
447 			}
448 			break;
449 		    }
450 		case NGM_NETFLOW_SETIFINDEX:
451 		    {
452 			struct ng_netflow_setifindex *set;
453 			struct ng_netflow_iface *iface;
454 
455 			if (msg->header.arglen !=
456 			    sizeof(struct ng_netflow_setifindex))
457 				ERROUT(EINVAL);
458 
459 			set = (struct ng_netflow_setifindex *)msg->data;
460 			if (set->iface >= NG_NETFLOW_MAXIFACES)
461 				ERROUT(EINVAL);
462 			iface = &priv->ifaces[set->iface];
463 
464 			/* connected iface? */
465 			if (iface->hook == NULL)
466 				ERROUT(EINVAL);
467 
468 			iface->info.ifinfo_index = set->index;
469 
470 			break;
471 		    }
472 		case NGM_NETFLOW_SETTIMEOUTS:
473 		    {
474 			struct ng_netflow_settimeouts *set;
475 
476 			if (msg->header.arglen !=
477 			    sizeof(struct ng_netflow_settimeouts))
478 				ERROUT(EINVAL);
479 
480 			set = (struct ng_netflow_settimeouts *)msg->data;
481 
482 			priv->nfinfo_inact_t = set->inactive_timeout;
483 			priv->nfinfo_act_t = set->active_timeout;
484 
485 			break;
486 		    }
487 		case NGM_NETFLOW_SETCONFIG:
488 		    {
489 			struct ng_netflow_setconfig *set;
490 
491 			if (msg->header.arglen !=
492 			    sizeof(struct ng_netflow_setconfig))
493 				ERROUT(EINVAL);
494 
495 			set = (struct ng_netflow_setconfig *)msg->data;
496 
497 			if (set->iface >= NG_NETFLOW_MAXIFACES)
498 				ERROUT(EINVAL);
499 
500 			priv->ifaces[set->iface].info.conf = set->conf;
501 
502 			break;
503 		    }
504 		case NGM_NETFLOW_SETTEMPLATE:
505 		    {
506 			struct ng_netflow_settemplate *set;
507 
508 			if (msg->header.arglen !=
509 			    sizeof(struct ng_netflow_settemplate))
510 				ERROUT(EINVAL);
511 
512 			set = (struct ng_netflow_settemplate *)msg->data;
513 
514 			priv->templ_packets = set->packets;
515 			priv->templ_time = set->time;
516 
517 			break;
518 		    }
519 		case NGM_NETFLOW_SETMTU:
520 		    {
521 			struct ng_netflow_setmtu *set;
522 
523 			if (msg->header.arglen !=
524 			    sizeof(struct ng_netflow_setmtu))
525 				ERROUT(EINVAL);
526 
527 			set = (struct ng_netflow_setmtu *)msg->data;
528 			if ((set->mtu < MIN_MTU) || (set->mtu > MAX_MTU))
529 				ERROUT(EINVAL);
530 
531 			priv->mtu = set->mtu;
532 
533 			break;
534 		    }
535 		case NGM_NETFLOW_SHOW:
536 			if (msg->header.arglen !=
537 			    sizeof(struct ngnf_show_header))
538 				ERROUT(EINVAL);
539 
540 			NG_MKRESPONSE(resp, msg, NGRESP_SIZE, M_NOWAIT);
541 
542 			if (!resp)
543 				ERROUT(ENOMEM);
544 
545 			error = ng_netflow_flow_show(priv,
546 			    (struct ngnf_show_header *)msg->data,
547 			    (struct ngnf_show_header *)resp->data);
548 
549 			if (error)
550 				NG_FREE_MSG(resp);
551 
552 			break;
553 		case NGM_NETFLOW_V9INFO:
554 		    {
555 			struct ng_netflow_v9info *i;
556 
557 			NG_MKRESPONSE(resp, msg,
558 			    sizeof(struct ng_netflow_v9info), M_NOWAIT);
559 			i = (struct ng_netflow_v9info *)resp->data;
560 			ng_netflow_copyv9info(priv, i);
561 
562 			break;
563 		    }
564 		default:
565 			ERROUT(EINVAL);		/* unknown command */
566 			break;
567 		}
568 		break;
569 	default:
570 		ERROUT(EINVAL);		/* incorrect cookie */
571 		break;
572 	}
573 
574 	/*
575 	 * Take care of synchronous response, if any.
576 	 * Free memory and return.
577 	 */
578 done:
579 	NG_RESPOND_MSG(error, node, item, resp);
580 	NG_FREE_MSG(msg);
581 
582 	return (error);
583 }
584 
585 /* Receive data on hook. */
586 static int
587 ng_netflow_rcvdata (hook_p hook, item_p item)
588 {
589 	const node_p node = NG_HOOK_NODE(hook);
590 	const priv_p priv = NG_NODE_PRIVATE(node);
591 	const iface_p iface = NG_HOOK_PRIVATE(hook);
592 	hook_p out;
593 	struct mbuf *m = NULL, *m_old = NULL;
594 	struct ip *ip = NULL;
595 	struct ip6_hdr *ip6 = NULL;
596 	struct m_tag *mtag;
597 	int pullup_len = 0, off;
598 	uint8_t acct = 0, bypass = 0, flags = 0, upper_proto = 0;
599 	int error = 0, l3_off = 0;
600 	unsigned int src_if_index;
601 	caddr_t upper_ptr = NULL;
602 	fib_export_p fe;
603 	uint32_t fib;
604 
605 	if ((hook == priv->export) || (hook == priv->export9)) {
606 		/*
607 		 * Data arrived on export hook.
608 		 * This must not happen.
609 		 */
610 		log(LOG_ERR, "ng_netflow: incoming data on export hook!\n");
611 		ERROUT(EINVAL);
612 	}
613 
614 	if (hook == iface->hook) {
615 		if ((iface->info.conf & NG_NETFLOW_CONF_INGRESS) == 0)
616 			bypass = 1;
617 		out = iface->out;
618 	} else if (hook == iface->out) {
619 		if ((iface->info.conf & NG_NETFLOW_CONF_EGRESS) == 0)
620 			bypass = 1;
621 		out = iface->hook;
622 	} else
623 		ERROUT(EINVAL);
624 
625 	if ((!bypass) && (iface->info.conf &
626 	    (NG_NETFLOW_CONF_ONCE | NG_NETFLOW_CONF_THISONCE))) {
627 		mtag = m_tag_locate(NGI_M(item), MTAG_NETFLOW,
628 		    MTAG_NETFLOW_CALLED, NULL);
629 		while (mtag != NULL) {
630 			if ((iface->info.conf & NG_NETFLOW_CONF_ONCE) ||
631 			    ((ng_ID_t *)(mtag + 1))[0] == NG_NODE_ID(node)) {
632 				bypass = 1;
633 				break;
634 			}
635 			mtag = m_tag_locate(NGI_M(item), MTAG_NETFLOW,
636 			    MTAG_NETFLOW_CALLED, mtag);
637 		}
638 	}
639 
640 	if (bypass) {
641 		if (out == NULL)
642 			ERROUT(ENOTCONN);
643 
644 		NG_FWD_ITEM_HOOK(error, item, out);
645 		return (error);
646 	}
647 
648 	if (iface->info.conf &
649 	    (NG_NETFLOW_CONF_ONCE | NG_NETFLOW_CONF_THISONCE)) {
650 		mtag = m_tag_alloc(MTAG_NETFLOW, MTAG_NETFLOW_CALLED,
651 		    sizeof(ng_ID_t), M_NOWAIT);
652 		if (mtag) {
653 			((ng_ID_t *)(mtag + 1))[0] = NG_NODE_ID(node);
654 			m_tag_prepend(NGI_M(item), mtag);
655 		}
656 	}
657 
658 	/* Import configuration flags related to flow creation */
659 	flags = iface->info.conf & NG_NETFLOW_FLOW_FLAGS;
660 
661 	NGI_GET_M(item, m);
662 	m_old = m;
663 
664 	/* Increase counters. */
665 	iface->info.ifinfo_packets++;
666 
667 	/*
668 	 * Depending on interface data link type and packet contents
669 	 * we pullup enough data, so that ng_netflow_flow_add() does not
670 	 * need to know about mbuf at all. We keep current length of data
671 	 * needed to be contiguous in pullup_len. mtod() is done at the
672 	 * very end one more time, since m can had changed after pulluping.
673 	 *
674 	 * In case of unrecognized data we don't return error, but just
675 	 * pass data to downstream hook, if it is available.
676 	 */
677 
678 #define	M_CHECK(length)	do {					\
679 	pullup_len += length;					\
680 	if (((m)->m_pkthdr.len < (pullup_len)) ||		\
681 	   ((pullup_len) > MHLEN)) {				\
682 		error = EINVAL;					\
683 		goto bypass;					\
684 	} 							\
685 	if ((m)->m_len < (pullup_len) &&			\
686 	   (((m) = m_pullup((m),(pullup_len))) == NULL)) {	\
687 		error = ENOBUFS;				\
688 		goto done;					\
689 	}							\
690 } while (0)
691 
692 	switch (iface->info.ifinfo_dlt) {
693 	case DLT_EN10MB:	/* Ethernet */
694 	    {
695 		struct ether_header *eh;
696 		uint16_t etype;
697 
698 		M_CHECK(sizeof(struct ether_header));
699 		eh = mtod(m, struct ether_header *);
700 
701 		/* Make sure this is IP frame. */
702 		etype = ntohs(eh->ether_type);
703 		switch (etype) {
704 #ifdef INET
705 		case ETHERTYPE_IP:
706 			M_CHECK(sizeof(struct ip));
707 			eh = mtod(m, struct ether_header *);
708 			ip = (struct ip *)(eh + 1);
709 			l3_off = sizeof(struct ether_header);
710 			break;
711 #endif
712 #ifdef INET6
713 		case ETHERTYPE_IPV6:
714 			/*
715 			 * m_pullup() called by M_CHECK() pullups
716 			 * kern.ipc.max_protohdr (default 60 bytes)
717 			 * which is enough.
718 			 */
719 			M_CHECK(sizeof(struct ip6_hdr));
720 			eh = mtod(m, struct ether_header *);
721 			ip6 = (struct ip6_hdr *)(eh + 1);
722 			l3_off = sizeof(struct ether_header);
723 			break;
724 #endif
725 		case ETHERTYPE_VLAN:
726 		    {
727 			struct ether_vlan_header *evh;
728 
729 			M_CHECK(sizeof(struct ether_vlan_header) -
730 			    sizeof(struct ether_header));
731 			evh = mtod(m, struct ether_vlan_header *);
732 			etype = ntohs(evh->evl_proto);
733 			l3_off = sizeof(struct ether_vlan_header);
734 
735 			if (etype == ETHERTYPE_IP) {
736 #ifdef INET
737 				M_CHECK(sizeof(struct ip));
738 				ip = (struct ip *)(evh + 1);
739 				break;
740 #endif
741 #ifdef INET6
742 			} else if (etype == ETHERTYPE_IPV6) {
743 				M_CHECK(sizeof(struct ip6_hdr));
744 				ip6 = (struct ip6_hdr *)(evh + 1);
745 				break;
746 #endif
747 			}
748 		    }
749 		default:
750 			goto bypass;	/* pass this frame */
751 		}
752 		break;
753 	    }
754 	case DLT_RAW:		/* IP packets */
755 		M_CHECK(sizeof(struct ip));
756 		ip = mtod(m, struct ip *);
757 		/* l3_off is already zero */
758 #ifdef INET6
759 		/*
760 		 * If INET6 is not defined IPv6 packets
761 		 * will be discarded in ng_netflow_flow_add().
762 		 */
763 		if (ip->ip_v == IP6VERSION) {
764 			ip = NULL;
765 			M_CHECK(sizeof(struct ip6_hdr) - sizeof(struct ip));
766 			ip6 = mtod(m, struct ip6_hdr *);
767 		}
768 #endif
769 #ifndef INET
770 		ip = NULL;
771 #endif
772 		break;
773 	default:
774 		goto bypass;
775 		break;
776 	}
777 
778 	off = pullup_len;
779 
780 	if ((ip != NULL) && ((ip->ip_off & htons(IP_OFFMASK)) == 0)) {
781 		if ((ip->ip_v != IPVERSION) ||
782 		    ((ip->ip_hl << 2) < sizeof(struct ip)))
783 			goto bypass;
784 		/*
785 		 * In case of IPv4 header with options, we haven't pulled
786 		 * up enough, yet.
787 		 */
788 		M_CHECK((ip->ip_hl << 2) - sizeof(struct ip));
789 
790 		/* Save upper layer offset and proto */
791 		off = pullup_len;
792 		upper_proto = ip->ip_p;
793 
794 		/*
795 		 * XXX: in case of wrong upper layer header we will
796 		 * forward this packet but skip this record in netflow.
797 		 */
798 		switch (ip->ip_p) {
799 		case IPPROTO_TCP:
800 			M_CHECK(sizeof(struct tcphdr));
801 			break;
802 		case IPPROTO_UDP:
803 			M_CHECK(sizeof(struct udphdr));
804 			break;
805 		case IPPROTO_SCTP:
806 			M_CHECK(sizeof(struct sctphdr));
807 			break;
808 		}
809 	} else if (ip != NULL) {
810 		/*
811 		 * Nothing to save except upper layer proto,
812 		 * since this is a packet fragment.
813 		 */
814 		flags |= NG_NETFLOW_IS_FRAG;
815 		upper_proto = ip->ip_p;
816 		if ((ip->ip_v != IPVERSION) ||
817 		    ((ip->ip_hl << 2) < sizeof(struct ip)))
818 			goto bypass;
819 #ifdef INET6
820 	} else if (ip6 != NULL) {
821 		int cur = ip6->ip6_nxt, hdr_off = 0;
822 		struct ip6_ext *ip6e;
823 		struct ip6_frag *ip6f;
824 
825 		if (priv->export9 == NULL)
826 			goto bypass;
827 
828 		/* Save upper layer info. */
829 		off = pullup_len;
830 		upper_proto = cur;
831 
832 		if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION)
833 			goto bypass;
834 
835 		/*
836 		 * Loop through IPv6 extended headers to get upper
837 		 * layer header / frag.
838 		 */
839 		for (;;) {
840 			switch (cur) {
841 			/*
842 			 * Same as in IPv4, we can forward a 'bad'
843 			 * packet without accounting.
844 			 */
845 			case IPPROTO_TCP:
846 				M_CHECK(sizeof(struct tcphdr));
847 				goto loopend;
848 			case IPPROTO_UDP:
849 				M_CHECK(sizeof(struct udphdr));
850 				goto loopend;
851 			case IPPROTO_SCTP:
852 				M_CHECK(sizeof(struct sctphdr));
853 				goto loopend;
854 
855 			/* Loop until 'real' upper layer headers */
856 			case IPPROTO_HOPOPTS:
857 			case IPPROTO_ROUTING:
858 			case IPPROTO_DSTOPTS:
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 + 1) << 3;
864 				break;
865 
866 			/* RFC4302, can be before DSTOPTS */
867 			case IPPROTO_AH:
868 				M_CHECK(sizeof(struct ip6_ext));
869 				ip6e = (struct ip6_ext *)(mtod(m, caddr_t) +
870 				    off);
871 				upper_proto = ip6e->ip6e_nxt;
872 				hdr_off = (ip6e->ip6e_len + 2) << 2;
873 				break;
874 
875 			case IPPROTO_FRAGMENT:
876 				M_CHECK(sizeof(struct ip6_frag));
877 				ip6f = (struct ip6_frag *)(mtod(m, caddr_t) +
878 				    off);
879 				upper_proto = ip6f->ip6f_nxt;
880 				hdr_off = sizeof(struct ip6_frag);
881 				off += hdr_off;
882 				flags |= NG_NETFLOW_IS_FRAG;
883 				goto loopend;
884 
885 #if 0
886 			case IPPROTO_NONE:
887 				goto loopend;
888 #endif
889 			/*
890 			 * Any unknown header (new extension or IPv6/IPv4
891 			 * header for tunnels) ends loop.
892 			 */
893 			default:
894 				goto loopend;
895 			}
896 
897 			off += hdr_off;
898 			cur = upper_proto;
899 		}
900 #endif
901 	}
902 #undef	M_CHECK
903 
904 #ifdef INET6
905 loopend:
906 #endif
907 	/* Just in case of real reallocation in M_CHECK() / m_pullup() */
908 	if (m != m_old) {
909 		priv->nfinfo_realloc_mbuf++;
910 		/* Restore ip/ipv6 pointer */
911 		if (ip != NULL)
912 			ip = (struct ip *)(mtod(m, caddr_t) + l3_off);
913 		else if (ip6 != NULL)
914 			ip6 = (struct ip6_hdr *)(mtod(m, caddr_t) + l3_off);
915  	}
916 
917 	upper_ptr = (caddr_t)(mtod(m, caddr_t) + off);
918 
919 	/* Determine packet input interface. Prefer configured. */
920 	src_if_index = 0;
921 	if (hook == iface->out || iface->info.ifinfo_index == 0) {
922 		if (m->m_pkthdr.rcvif != NULL)
923 			src_if_index = m->m_pkthdr.rcvif->if_index;
924 	} else
925 		src_if_index = iface->info.ifinfo_index;
926 
927 	/* Check packet FIB */
928 	fib = M_GETFIB(m);
929 	if (fib >= priv->maxfibs) {
930 		CTR2(KTR_NET, "ng_netflow_rcvdata(): packet fib %d is out of "
931 		    "range of available fibs: 0 .. %d",
932 		    fib, priv->maxfibs);
933 		goto bypass;
934 	}
935 
936 	if ((fe = priv_to_fib(priv, fib)) == NULL) {
937 		/* Setup new FIB */
938 		if (ng_netflow_fib_init(priv, fib) != 0) {
939 			/* malloc() failed */
940 			goto bypass;
941 		}
942 
943 		fe = priv_to_fib(priv, fib);
944 	}
945 
946 #ifdef INET
947 	if (ip != NULL)
948 		error = ng_netflow_flow_add(priv, fe, ip, upper_ptr,
949 		    upper_proto, flags, src_if_index);
950 #endif
951 #if defined(INET6) && defined(INET)
952 	else
953 #endif
954 #ifdef INET6
955 	if (ip6 != NULL)
956 		error = ng_netflow_flow6_add(priv, fe, ip6, upper_ptr,
957 		    upper_proto, flags, src_if_index);
958 #endif
959 	else
960 		goto bypass;
961 
962 	acct = 1;
963 bypass:
964 	if (out != NULL) {
965 		if (acct == 0) {
966 			/* Accounting failure */
967 			if (ip != NULL) {
968 				counter_u64_add(priv->nfinfo_spackets, 1);
969 				counter_u64_add(priv->nfinfo_sbytes,
970 				    m->m_pkthdr.len);
971 			} else if (ip6 != NULL) {
972 				counter_u64_add(priv->nfinfo_spackets6, 1);
973 				counter_u64_add(priv->nfinfo_sbytes6,
974 				    m->m_pkthdr.len);
975 			}
976 		}
977 
978 		/* XXX: error gets overwritten here */
979 		NG_FWD_NEW_DATA(error, item, out, m);
980 		return (error);
981 	}
982 done:
983 	if (item)
984 		NG_FREE_ITEM(item);
985 	if (m)
986 		NG_FREE_M(m);
987 
988 	return (error);
989 }
990 
991 /* We will be shut down in a moment */
992 static int
993 ng_netflow_close(node_p node)
994 {
995 	const priv_p priv = NG_NODE_PRIVATE(node);
996 
997 	callout_drain(&priv->exp_callout);
998 	ng_netflow_cache_flush(priv);
999 
1000 	return (0);
1001 }
1002 
1003 /* Do local shutdown processing. */
1004 static int
1005 ng_netflow_rmnode(node_p node)
1006 {
1007 	const priv_p priv = NG_NODE_PRIVATE(node);
1008 
1009 	NG_NODE_SET_PRIVATE(node, NULL);
1010 	NG_NODE_UNREF(priv->node);
1011 
1012 	free(priv->fib_data, M_NETGRAPH);
1013 	free(priv, M_NETGRAPH);
1014 
1015 	return (0);
1016 }
1017 
1018 /* Hook disconnection. */
1019 static int
1020 ng_netflow_disconnect(hook_p hook)
1021 {
1022 	node_p node = NG_HOOK_NODE(hook);
1023 	priv_p priv = NG_NODE_PRIVATE(node);
1024 	iface_p iface = NG_HOOK_PRIVATE(hook);
1025 
1026 	if (iface != NULL) {
1027 		if (iface->hook == hook)
1028 			iface->hook = NULL;
1029 		if (iface->out == hook)
1030 			iface->out = NULL;
1031 	}
1032 
1033 	/* if export hook disconnected stop running expire(). */
1034 	if (hook == priv->export) {
1035 		if (priv->export9 == NULL)
1036 			callout_drain(&priv->exp_callout);
1037 		priv->export = NULL;
1038 	}
1039 
1040 	if (hook == priv->export9) {
1041 		if (priv->export == NULL)
1042 			callout_drain(&priv->exp_callout);
1043 		priv->export9 = NULL;
1044 	}
1045 
1046 	/* Removal of the last link destroys the node. */
1047 	if (NG_NODE_NUMHOOKS(node) == 0)
1048 		ng_rmnode_self(node);
1049 
1050 	return (0);
1051 }
1052