xref: /dragonfly/tools/tools/netrate/pktgen/pktgen.c (revision cfd1aba3) 
1 /*
2  * Copyright (c) 2012 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Sepherosa Ziehau <sepherosa@gmail.com>
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  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * $DragonFly: src/tools/tools/netrate/pktgen/pktgen.c,v 1.4 2008/04/02 14:18:55 sephe Exp $
35  */
36 
37 #define _IP_VHL
38 
39 #include <sys/param.h>
40 #include <sys/conf.h>
41 #include <sys/device.h>
42 #include <sys/in_cksum.h>
43 #include <sys/kernel.h>
44 #include <sys/malloc.h>
45 #include <sys/mbuf.h>
46 #include <sys/proc.h>
47 #include <sys/priv.h>
48 #include <sys/queue.h>
49 #include <sys/socket.h>
50 #include <sys/systm.h>
51 #include <sys/serialize.h>
52 
53 #include <net/if.h>
54 #include <net/if_dl.h>
55 #include <net/if_var.h>
56 #include <net/ifq_var.h>
57 #include <net/ethernet.h>
58 #include <net/netmsg2.h>
59 #include <net/netisr2.h>
60 
61 #include <netinet/in.h>
62 #include <netinet/ip.h>
63 #include <netinet/udp_var.h>
64 
65 #include "pktgen.h"
66 
67 #define CDEV_NAME	"pktg"
68 
69 #define PKTGEN_BUFSZ	2048
70 
71 #ifndef PKTGEN_DEVCNT
72 #define PKTGEN_DEVCNT	4
73 #endif
74 
75 struct pktgen;
76 
77 struct netmsg_pktgen {
78 	struct netmsg_base	np_base;
79 	struct pktgen		*np_pktg;
80 	struct ifaltq_subque	*np_ifsq;
81 };
82 
83 struct pktgen_buf {
84 	struct netmsg_base	pb_nmsg;	/* MUST BE THE FIRST */
85 	void			*pb_buf;
86 	volatile int		pb_done;
87 	int			pb_inuse;
88 	struct ifnet		*pb_ifp;
89 	struct ifaltq_subque	*pb_ifsq;
90 	int			pb_len;
91 	int			pb_cpuid;
92 	struct pktgen		*pb_pktg;
93 	LIST_ENTRY(pktgen_buf)	pb_link;
94 };
95 
96 struct pktgen_pcpu {
97 	struct callout		pktg_stop;
98 	LIST_HEAD(, pktgen_buf)	pktg_buflist;
99 };
100 
101 struct pktgen {
102 	uint32_t		pktg_flags;	/* PKTG_F_ */
103 	int			pktg_refcnt;
104 
105 	int			pktg_duration;
106 
107 	int			pktg_datalen;
108 	struct ifnet		*pktg_ifp;
109 
110 	int			pktg_pktenq;
111 
112 	struct sockaddr_in	pktg_src;
113 	int			pktg_ndst;
114 	struct sockaddr_in	*pktg_dst;
115 	uint8_t			pktg_dst_lladdr[ETHER_ADDR_LEN];
116 
117 	struct pktgen_pcpu	pktg_pcpu[MAXCPU];
118 };
119 
120 #define PKTG_F_CONFIG	0x1
121 #define PKTG_F_RUNNING	0x4
122 
123 static int 		pktgen_modevent(module_t, int, void *);
124 
125 static void		pktgen_buf_free(void *);
126 static void		pktgen_buf_ref(void *);
127 static void		pktgen_buf_send(netmsg_t);
128 
129 static int		pktgen_config(struct pktgen *,
130 			    const struct pktgen_conf *);
131 static int		pktgen_start(struct pktgen *, int);
132 static void		pktgen_free(struct pktgen *);
133 static void		pktgen_ref(struct pktgen *);
134 static void		pktgen_pcpu_stop_cb(void *);
135 static void		pktgen_mbuf(struct pktgen_buf *, struct mbuf *);
136 static void		pktgen_start_ifsq(struct pktgen *,
137 			    struct ifaltq_subque *);
138 static void		pktgen_start_ifsq_handler(netmsg_t);
139 
140 static d_open_t		pktgen_open;
141 static d_close_t	pktgen_close;
142 static d_ioctl_t	pktgen_ioctl;
143 
144 static struct dev_ops	pktgen_ops = {
145 	{ CDEV_NAME, 0, D_MPSAFE },
146 	.d_open =	pktgen_open,
147 	.d_close =	pktgen_close,
148 	.d_ioctl =	pktgen_ioctl,
149 };
150 
151 static volatile int		pktgen_refcnt;
152 static struct lwkt_token pktgen_tok = LWKT_TOKEN_INITIALIZER(pktgen_token);
153 
154 MALLOC_DECLARE(M_PKTGEN);
155 MALLOC_DEFINE(M_PKTGEN, CDEV_NAME, "Packet generator");
156 
157 DEV_MODULE(pktgen, pktgen_modevent, NULL);
158 
159 static int
160 pktgen_modevent(module_t mod, int type, void *data)
161 {
162 	int error = 0, i;
163 
164 	switch (type) {
165 	case MOD_LOAD:
166 		for (i = 0; i < PKTGEN_DEVCNT; ++i) {
167 			make_dev(&pktgen_ops, 0, UID_ROOT, GID_WHEEL, 0600,
168 			    CDEV_NAME"%d", i);
169 		}
170 		break;
171 
172 	case MOD_UNLOAD:
173 		if (pktgen_refcnt > 0)
174 			return EBUSY;
175 		dev_ops_remove_all(&pktgen_ops);
176 		break;
177 
178 	default:
179 		error = EOPNOTSUPP;
180 		break;
181 	}
182 	return error;
183 }
184 
185 static int
186 pktgen_open(struct dev_open_args *ap)
187 {
188 	cdev_t dev = ap->a_head.a_dev;
189 	struct pktgen *pktg;
190 	int error, i;
191 
192 	error = priv_check_cred(ap->a_cred, PRIV_ROOT, 0);
193 	if (error)
194 		return error;
195 
196 	lwkt_gettoken(&pktgen_tok);
197 
198 	if (dev->si_drv1 != NULL) {
199 		lwkt_reltoken(&pktgen_tok);
200 		return EBUSY;
201 	}
202 
203 	pktg = kmalloc(sizeof(*pktg), M_PKTGEN, M_ZERO | M_WAITOK);
204 	for (i = 0; i < ncpus; ++i) {
205 		struct pktgen_pcpu *p = &pktg->pktg_pcpu[i];
206 
207 		callout_init_mp(&p->pktg_stop);
208 		LIST_INIT(&p->pktg_buflist);
209 	}
210 
211 	dev->si_drv1 = pktg;
212 	pktg->pktg_refcnt = 1;
213 
214 	atomic_add_int(&pktgen_refcnt, 1);
215 
216 	lwkt_reltoken(&pktgen_tok);
217 	return 0;
218 }
219 
220 static int
221 pktgen_close(struct dev_close_args *ap)
222 {
223 	cdev_t dev = ap->a_head.a_dev;
224 	struct pktgen *pktg = dev->si_drv1;
225 
226 	lwkt_gettoken(&pktgen_tok);
227 	dev->si_drv1 = NULL;
228 	lwkt_reltoken(&pktgen_tok);
229 
230 	pktgen_free(pktg);
231 
232 	return 0;
233 }
234 
235 static int
236 pktgen_ioctl(struct dev_ioctl_args *ap __unused)
237 {
238 	cdev_t dev = ap->a_head.a_dev;
239 	caddr_t data = ap->a_data;
240 	struct pktgen *pktg = dev->si_drv1;
241 	int error;
242 
243 	lwkt_gettoken(&pktgen_tok);
244 
245 	switch (ap->a_cmd) {
246 	case PKTGENSTART:
247 		error = pktgen_start(pktg, 0);
248 		break;
249 
250 	case PKTGENMQSTART:
251 		error = pktgen_start(pktg, 1);
252 		break;
253 
254 	case PKTGENSCONF:
255 		error = pktgen_config(pktg, (const struct pktgen_conf *)data);
256 		break;
257 
258 	default:
259 		error = EOPNOTSUPP;
260 		break;
261 	}
262 
263 	lwkt_reltoken(&pktgen_tok);
264 	return error;
265 }
266 
267 static int
268 pktgen_config(struct pktgen *pktg, const struct pktgen_conf *conf)
269 {
270 	const struct sockaddr_in *sin;
271 	struct sockaddr_in *dst = NULL;
272 	const struct sockaddr *sa;
273 	struct ifnet *ifp;
274 	size_t dst_size;
275 	int i, error, pktenq;
276 
277 	if (pktg->pktg_flags & (PKTG_F_RUNNING | PKTG_F_CONFIG))
278 		return EBUSY;
279 
280 	if (conf->pc_datalen <= 0 ||
281 	    conf->pc_datalen > ETHERMTU - sizeof(struct udpiphdr))
282 		return EINVAL;
283 	if (conf->pc_duration <= 0)
284 		return EINVAL;
285 
286 	sin = &conf->pc_src;
287 	if (sin->sin_family != AF_INET)
288 		return EPROTONOSUPPORT;
289 	if (sin->sin_port == 0)
290 		return EINVAL;
291 
292 	if (conf->pc_ndst <= 0)
293 		return EINVAL;
294 	dst_size = conf->pc_ndst * sizeof(struct sockaddr_in);
295 
296 	dst = kmalloc(dst_size, M_PKTGEN, M_WAITOK | M_NULLOK);
297 	if (dst == NULL)
298 		return ENOMEM;
299 
300 	error = copyin(conf->pc_dst, dst, dst_size);
301 	if (error)
302 		goto failed;
303 
304 	for (i = 0; i < conf->pc_ndst; ++i) {
305 		sin = &dst[i];
306 		if (sin->sin_family != AF_INET) {
307 			error = EPROTONOSUPPORT;
308 			goto failed;
309 		}
310 		if (sin->sin_port == 0) {
311 			error = EINVAL;
312 			goto failed;
313 		}
314 	}
315 
316 	ifp = ifunit(conf->pc_ifname);
317 	if (ifp == NULL) {
318 		error = ENXIO;
319 		goto failed;
320 	}
321 
322 	pktenq = conf->pc_pktenq;
323 	if (pktenq < 0 || pktenq > ifp->if_snd.altq_maxlen) {
324 		error = ENOBUFS;
325 		goto failed;
326 	} else if (pktenq == 0) {
327 		pktenq = (ifp->if_snd.altq_maxlen * 3) / 4;
328 	}
329 
330 	sa = &conf->pc_dst_lladdr;
331 	if (sa->sa_family != AF_LINK) {
332 		error = EPROTONOSUPPORT;
333 		goto failed;
334 	}
335 	if (sa->sa_len != ETHER_ADDR_LEN) {
336 		error = EPROTONOSUPPORT;
337 		goto failed;
338 	}
339 	if (ETHER_IS_MULTICAST(sa->sa_data) ||
340 	    bcmp(sa->sa_data, ifp->if_broadcastaddr, ifp->if_addrlen) == 0) {
341 		error = EADDRNOTAVAIL;
342 		goto failed;
343 	}
344 
345 	/*
346 	 * Accept the config
347 	 */
348 	pktg->pktg_flags |= PKTG_F_CONFIG;
349 
350 	pktg->pktg_duration = conf->pc_duration;
351 	pktg->pktg_datalen = conf->pc_datalen;
352 	pktg->pktg_pktenq = pktenq;
353 	pktg->pktg_ifp = ifp;
354 	pktg->pktg_src = conf->pc_src;
355 	pktg->pktg_ndst = conf->pc_ndst;
356 	KKASSERT(pktg->pktg_dst == NULL);
357 	pktg->pktg_dst = dst;
358 	bcopy(sa->sa_data, pktg->pktg_dst_lladdr, ETHER_ADDR_LEN);
359 
360 	return 0;
361 
362 failed:
363 	if (dst != NULL)
364 		kfree(dst, M_PKTGEN);
365 	return error;
366 }
367 
368 static void
369 pktgen_start_ifsq(struct pktgen *pktg, struct ifaltq_subque *ifsq)
370 {
371 	struct netmsg_pktgen *np;
372 
373 	np = kmalloc(sizeof(*np), M_LWKTMSG, M_WAITOK);
374 	netmsg_init(&np->np_base, NULL, &netisr_afree_rport, 0,
375 	    pktgen_start_ifsq_handler);
376 	np->np_pktg = pktg;
377 	np->np_ifsq = ifsq;
378 
379 	lwkt_sendmsg(netisr_cpuport(ifsq_get_cpuid(ifsq)), &np->np_base.lmsg);
380 }
381 
382 static int
383 pktgen_start(struct pktgen *pktg, int mq)
384 {
385 	struct ifaltq *ifq;
386 
387 	if ((pktg->pktg_flags & PKTG_F_CONFIG) == 0)
388 		return EINVAL;
389 	if (pktg->pktg_flags & PKTG_F_RUNNING)
390 		return EBUSY;
391 	pktg->pktg_flags |= PKTG_F_RUNNING;
392 
393 	ifq = &pktg->pktg_ifp->if_snd;
394 	if (!mq) {
395 		pktgen_ref(pktg);
396 		pktgen_start_ifsq(pktg, ifq_get_subq_default(ifq));
397 	} else {
398 		int i;
399 
400 		for (i = 0; i < ifq->altq_subq_cnt; ++i)
401 			pktgen_ref(pktg);
402 		for (i = 0; i < ifq->altq_subq_cnt; ++i)
403 			pktgen_start_ifsq(pktg, ifq_get_subq(ifq, i));
404 	}
405 	return 0;
406 }
407 
408 static void
409 pktgen_start_ifsq_handler(netmsg_t nmsg)
410 {
411 	struct netmsg_pktgen *np = (struct netmsg_pktgen *)nmsg;
412 	struct pktgen *pktg = np->np_pktg;
413 	struct ifaltq_subque *ifsq = np->np_ifsq;
414 
415 	struct mbuf *m, *head = NULL, **next;
416 	struct ifnet *ifp;
417 	struct pktgen_pcpu *p;
418 	int cpuid, i, alloc_cnt, keep_cnt;
419 
420 	u_short ulen, psum;
421 	int len, ip_len;
422 
423 	/* Reply ASAP */
424 	lwkt_replymsg(&np->np_base.lmsg, 0);
425 
426 	ifp = pktg->pktg_ifp;
427 
428 	cpuid = ifsq_get_cpuid(ifsq);
429 	KKASSERT(cpuid == mycpuid);
430 
431 	p = &pktg->pktg_pcpu[cpuid];
432 
433 	keep_cnt = pktg->pktg_pktenq;
434 	alloc_cnt = keep_cnt * 2;
435 
436 	/*
437 	 * Prefault enough mbuf into mbuf objcache
438 	 */
439 	next = &head;
440 	for (i = 0; i < alloc_cnt; ++i) {
441 		MGETHDR(m, MB_WAIT, MT_DATA);
442 		*next = m;
443 		next = &m->m_nextpkt;
444 	}
445 
446 	for (i = 0; i < alloc_cnt - keep_cnt; ++i) {
447 		m = head;
448 		head = m->m_nextpkt;
449 		m->m_nextpkt = NULL;
450 		m_freem(m);
451 	}
452 	KKASSERT(head != NULL);
453 
454 	/*
455 	 * Setup the packets' data
456 	 */
457 	ip_len = pktg->pktg_datalen + sizeof(struct udpiphdr);
458 	len = ip_len + ETHER_HDR_LEN;
459 
460 	psum = htons((u_short)pktg->pktg_datalen + sizeof(struct udphdr) +
461 	    IPPROTO_UDP);
462 	ulen = htons(pktg->pktg_datalen + sizeof(struct udphdr));
463 
464 	m = head;
465 	i = 0;
466 	while (m != NULL) {
467 		struct mbuf *nextm;
468 		const struct sockaddr_in *dst;
469 		struct pktgen_buf *pb;
470 		struct ip *ip;
471 		struct udpiphdr *ui;
472 		struct ether_header *eh;
473 
474 		pktgen_ref(pktg);
475 
476 		pb = kmalloc(sizeof(*pb), M_PKTGEN, M_WAITOK | M_ZERO);
477 		pb->pb_ifp = ifp;
478 		pb->pb_ifsq = ifsq;
479 		pb->pb_inuse = 1;
480 		pb->pb_buf = kmalloc(PKTGEN_BUFSZ, M_PKTGEN, M_WAITOK);
481 		pb->pb_len = len;
482 		pb->pb_cpuid = cpuid;
483 		pb->pb_pktg = pktg;
484 		netmsg_init(&pb->pb_nmsg, NULL, &netisr_adone_rport, 0,
485 		    pktgen_buf_send);
486 		LIST_INSERT_HEAD(&p->pktg_buflist, pb, pb_link);
487 
488 		dst = &pktg->pktg_dst[i % pktg->pktg_ndst];
489 		++i;
490 
491 		m->m_ext.ext_arg = pb;
492 		m->m_ext.ext_buf = pb->pb_buf;
493 		m->m_ext.ext_free = pktgen_buf_free;
494 		m->m_ext.ext_ref = pktgen_buf_ref;
495 		m->m_ext.ext_size = PKTGEN_BUFSZ;
496 
497 		m->m_data = m->m_ext.ext_buf;
498 		m->m_flags |= M_EXT;
499 		m->m_len = m->m_pkthdr.len = len;
500 
501 		m->m_data += ETHER_HDR_LEN;
502 		m->m_len -= ETHER_HDR_LEN;
503 		m->m_pkthdr.len -= ETHER_HDR_LEN;
504 
505 		ui = mtod(m, struct udpiphdr *);
506 		ui->ui_pr = IPPROTO_UDP;
507 		ui->ui_src.s_addr = pktg->pktg_src.sin_addr.s_addr;
508 		ui->ui_dst.s_addr = dst->sin_addr.s_addr;
509 		ui->ui_sport = pktg->pktg_src.sin_port;
510 		ui->ui_dport = dst->sin_port;
511 		ui->ui_ulen = ulen;
512 		ui->ui_sum = in_pseudo(ui->ui_src.s_addr, ui->ui_dst.s_addr,
513 		    psum);
514 		m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
515 
516 		ip = (struct ip *)ui;
517 		ip->ip_len = ip_len;
518 		ip->ip_ttl = 64;	/* XXX */
519 		ip->ip_tos = 0;		/* XXX */
520 		ip->ip_vhl = IP_VHL_BORING;
521 		ip->ip_off = 0;
522 		ip->ip_sum = 0;
523 		ip->ip_id = ip_newid();
524 
525 		in_delayed_cksum(m);
526 
527 		ip->ip_len = htons(ip->ip_len);
528 		ip->ip_sum = in_cksum_hdr(ip);
529 
530 		m->m_data -= ETHER_HDR_LEN;
531 		m->m_len += ETHER_HDR_LEN;
532 		m->m_pkthdr.len += ETHER_HDR_LEN;
533 
534 		eh = mtod(m, struct ether_header *);
535 		bcopy(pktg->pktg_dst_lladdr, eh->ether_dhost, ETHER_ADDR_LEN);
536 		bcopy(IF_LLADDR(ifp), eh->ether_shost, ETHER_ADDR_LEN);
537 		eh->ether_type = htons(ETHERTYPE_IP);
538 
539 		nextm = m->m_nextpkt;
540 		m->m_nextpkt = NULL;
541 
542 		ifq_dispatch(ifp, m, NULL);
543 
544 		m = nextm;
545 	}
546 
547 	callout_reset(&p->pktg_stop, pktg->pktg_duration * hz,
548 	    pktgen_pcpu_stop_cb, p);
549 
550 	pktgen_free(pktg);
551 }
552 
553 static void
554 pktgen_mbuf(struct pktgen_buf *pb, struct mbuf *m)
555 {
556 	m->m_ext.ext_arg = pb;
557 	m->m_ext.ext_buf = pb->pb_buf;
558 	m->m_ext.ext_free = pktgen_buf_free;
559 	m->m_ext.ext_ref = pktgen_buf_ref;
560 	m->m_ext.ext_size = PKTGEN_BUFSZ;
561 
562 	m->m_data = m->m_ext.ext_buf;
563 	m->m_flags |= M_EXT;
564 	m->m_len = m->m_pkthdr.len = pb->pb_len;
565 }
566 
567 static void
568 pktgen_buf_send(netmsg_t msg)
569 {
570 	struct pktgen_buf *pb = (struct pktgen_buf *)msg;
571 	struct mbuf *m;
572 
573 	KKASSERT(&curthread->td_msgport == netisr_cpuport(pb->pb_cpuid));
574 
575 	crit_enter();
576 	lwkt_replymsg(&pb->pb_nmsg.lmsg, 0);
577 	crit_exit();
578 
579 	MGETHDR(m, MB_WAIT, MT_DATA);
580 	pktgen_mbuf(pb, m);
581 	ifq_dispatch(pb->pb_ifp, m, NULL);
582 }
583 
584 static void
585 pktgen_buf_free(void *arg)
586 {
587 	struct pktgen_buf *pb = arg;
588 	struct mbuf *m;
589 
590 	KKASSERT(pb->pb_inuse > 0);
591 	if (pb->pb_done) {
592 		if (atomic_fetchadd_int(&pb->pb_inuse, -1) == 1) {
593 			struct pktgen *pktg;
594 
595 			pktg = pb->pb_pktg;
596 			crit_enter();
597 			LIST_REMOVE(pb, pb_link);
598 			crit_exit();
599 			kfree(pb->pb_buf, M_PKTGEN);
600 			kfree(pb, M_PKTGEN);
601 
602 			pktgen_free(pktg);
603 		}
604 		return;
605 	}
606 
607 	if (&curthread->td_msgport != netisr_cpuport(pb->pb_cpuid)) {
608 		KKASSERT(pb->pb_cpuid == mycpuid);
609 		crit_enter();
610 		KKASSERT(pb->pb_nmsg.lmsg.ms_flags & MSGF_DONE);
611 		lwkt_sendmsg(netisr_cpuport(pb->pb_cpuid), &pb->pb_nmsg.lmsg);
612 		crit_exit();
613 		return;
614 	}
615 
616 	MGETHDR(m, MB_WAIT, MT_DATA);
617 	pktgen_mbuf(pb, m);
618 	ifsq_enqueue(pb->pb_ifsq, m, NULL);
619 }
620 
621 static void
622 pktgen_buf_ref(void *arg)
623 {
624 	struct pktgen_buf *pb = arg;
625 
626 	panic("%s should never be called\n", __func__);
627 
628 	KKASSERT(pb->pb_inuse > 0);
629 	atomic_add_int(&pb->pb_inuse, 1);
630 }
631 
632 static void
633 pktgen_free(struct pktgen *pktg)
634 {
635 	KKASSERT(pktg->pktg_refcnt > 0);
636 	if (atomic_fetchadd_int(&pktg->pktg_refcnt, -1) == 1) {
637 		int i;
638 
639 		if (pktg->pktg_dst != NULL)
640 			kfree(pktg->pktg_dst, M_PKTGEN);
641 
642 		for (i = 0; i < ncpus; ++i)
643 			KKASSERT(LIST_EMPTY(&pktg->pktg_pcpu[i].pktg_buflist));
644 		kfree(pktg, M_PKTGEN);
645 	}
646 
647 	KKASSERT(pktgen_refcnt > 0);
648 	atomic_subtract_int(&pktgen_refcnt, 1);
649 }
650 
651 static void
652 pktgen_pcpu_stop_cb(void *arg)
653 {
654 	struct pktgen_pcpu *p = arg;
655 	struct pktgen_buf *pb;
656 
657 	crit_enter();
658 	LIST_FOREACH(pb, &p->pktg_buflist, pb_link)
659 		pb->pb_done = 1;
660 	crit_exit();
661 }
662 
663 static void
664 pktgen_ref(struct pktgen *pktg)
665 {
666 	atomic_add_int(&pktg->pktg_refcnt, 1);
667 	atomic_add_int(&pktgen_refcnt, 1);
668 }
669