xref: /openbmc/linux/net/sched/act_csum.c (revision e3b9f1e8) 
1 /*
2  * Checksum updating actions
3  *
4  * Copyright (c) 2010 Gregoire Baron <baronchon@n7mm.org>
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License as published by the Free
8  * Software Foundation; either version 2 of the License, or (at your option)
9  * any later version.
10  *
11  */
12 
13 #include <linux/types.h>
14 #include <linux/init.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/spinlock.h>
18 
19 #include <linux/netlink.h>
20 #include <net/netlink.h>
21 #include <linux/rtnetlink.h>
22 
23 #include <linux/skbuff.h>
24 
25 #include <net/ip.h>
26 #include <net/ipv6.h>
27 #include <net/icmp.h>
28 #include <linux/icmpv6.h>
29 #include <linux/igmp.h>
30 #include <net/tcp.h>
31 #include <net/udp.h>
32 #include <net/ip6_checksum.h>
33 #include <net/sctp/checksum.h>
34 
35 #include <net/act_api.h>
36 
37 #include <linux/tc_act/tc_csum.h>
38 #include <net/tc_act/tc_csum.h>
39 
40 static const struct nla_policy csum_policy[TCA_CSUM_MAX + 1] = {
41 	[TCA_CSUM_PARMS] = { .len = sizeof(struct tc_csum), },
42 };
43 
44 static unsigned int csum_net_id;
45 static struct tc_action_ops act_csum_ops;
46 
47 static int tcf_csum_init(struct net *net, struct nlattr *nla,
48 			 struct nlattr *est, struct tc_action **a, int ovr,
49 			 int bind)
50 {
51 	struct tc_action_net *tn = net_generic(net, csum_net_id);
52 	struct tcf_csum_params *params_old, *params_new;
53 	struct nlattr *tb[TCA_CSUM_MAX + 1];
54 	struct tc_csum *parm;
55 	struct tcf_csum *p;
56 	int ret = 0, err;
57 
58 	if (nla == NULL)
59 		return -EINVAL;
60 
61 	err = nla_parse_nested(tb, TCA_CSUM_MAX, nla, csum_policy, NULL);
62 	if (err < 0)
63 		return err;
64 
65 	if (tb[TCA_CSUM_PARMS] == NULL)
66 		return -EINVAL;
67 	parm = nla_data(tb[TCA_CSUM_PARMS]);
68 
69 	if (!tcf_idr_check(tn, parm->index, a, bind)) {
70 		ret = tcf_idr_create(tn, parm->index, est, a,
71 				     &act_csum_ops, bind, true);
72 		if (ret)
73 			return ret;
74 		ret = ACT_P_CREATED;
75 	} else {
76 		if (bind)/* dont override defaults */
77 			return 0;
78 		tcf_idr_release(*a, bind);
79 		if (!ovr)
80 			return -EEXIST;
81 	}
82 
83 	p = to_tcf_csum(*a);
84 	ASSERT_RTNL();
85 
86 	params_new = kzalloc(sizeof(*params_new), GFP_KERNEL);
87 	if (unlikely(!params_new)) {
88 		if (ret == ACT_P_CREATED)
89 			tcf_idr_release(*a, bind);
90 		return -ENOMEM;
91 	}
92 	params_old = rtnl_dereference(p->params);
93 
94 	params_new->action = parm->action;
95 	params_new->update_flags = parm->update_flags;
96 	rcu_assign_pointer(p->params, params_new);
97 	if (params_old)
98 		kfree_rcu(params_old, rcu);
99 
100 	if (ret == ACT_P_CREATED)
101 		tcf_idr_insert(tn, *a);
102 
103 	return ret;
104 }
105 
106 /**
107  * tcf_csum_skb_nextlayer - Get next layer pointer
108  * @skb: sk_buff to use
109  * @ihl: previous summed headers length
110  * @ipl: complete packet length
111  * @jhl: next header length
112  *
113  * Check the expected next layer availability in the specified sk_buff.
114  * Return the next layer pointer if pass, NULL otherwise.
115  */
116 static void *tcf_csum_skb_nextlayer(struct sk_buff *skb,
117 				    unsigned int ihl, unsigned int ipl,
118 				    unsigned int jhl)
119 {
120 	int ntkoff = skb_network_offset(skb);
121 	int hl = ihl + jhl;
122 
123 	if (!pskb_may_pull(skb, ipl + ntkoff) || (ipl < hl) ||
124 	    skb_try_make_writable(skb, hl + ntkoff))
125 		return NULL;
126 	else
127 		return (void *)(skb_network_header(skb) + ihl);
128 }
129 
130 static int tcf_csum_ipv4_icmp(struct sk_buff *skb, unsigned int ihl,
131 			      unsigned int ipl)
132 {
133 	struct icmphdr *icmph;
134 
135 	icmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmph));
136 	if (icmph == NULL)
137 		return 0;
138 
139 	icmph->checksum = 0;
140 	skb->csum = csum_partial(icmph, ipl - ihl, 0);
141 	icmph->checksum = csum_fold(skb->csum);
142 
143 	skb->ip_summed = CHECKSUM_NONE;
144 
145 	return 1;
146 }
147 
148 static int tcf_csum_ipv4_igmp(struct sk_buff *skb,
149 			      unsigned int ihl, unsigned int ipl)
150 {
151 	struct igmphdr *igmph;
152 
153 	igmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*igmph));
154 	if (igmph == NULL)
155 		return 0;
156 
157 	igmph->csum = 0;
158 	skb->csum = csum_partial(igmph, ipl - ihl, 0);
159 	igmph->csum = csum_fold(skb->csum);
160 
161 	skb->ip_summed = CHECKSUM_NONE;
162 
163 	return 1;
164 }
165 
166 static int tcf_csum_ipv6_icmp(struct sk_buff *skb, unsigned int ihl,
167 			      unsigned int ipl)
168 {
169 	struct icmp6hdr *icmp6h;
170 	const struct ipv6hdr *ip6h;
171 
172 	icmp6h = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmp6h));
173 	if (icmp6h == NULL)
174 		return 0;
175 
176 	ip6h = ipv6_hdr(skb);
177 	icmp6h->icmp6_cksum = 0;
178 	skb->csum = csum_partial(icmp6h, ipl - ihl, 0);
179 	icmp6h->icmp6_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
180 					      ipl - ihl, IPPROTO_ICMPV6,
181 					      skb->csum);
182 
183 	skb->ip_summed = CHECKSUM_NONE;
184 
185 	return 1;
186 }
187 
188 static int tcf_csum_ipv4_tcp(struct sk_buff *skb, unsigned int ihl,
189 			     unsigned int ipl)
190 {
191 	struct tcphdr *tcph;
192 	const struct iphdr *iph;
193 
194 	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
195 		return 1;
196 
197 	tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
198 	if (tcph == NULL)
199 		return 0;
200 
201 	iph = ip_hdr(skb);
202 	tcph->check = 0;
203 	skb->csum = csum_partial(tcph, ipl - ihl, 0);
204 	tcph->check = tcp_v4_check(ipl - ihl,
205 				   iph->saddr, iph->daddr, skb->csum);
206 
207 	skb->ip_summed = CHECKSUM_NONE;
208 
209 	return 1;
210 }
211 
212 static int tcf_csum_ipv6_tcp(struct sk_buff *skb, unsigned int ihl,
213 			     unsigned int ipl)
214 {
215 	struct tcphdr *tcph;
216 	const struct ipv6hdr *ip6h;
217 
218 	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
219 		return 1;
220 
221 	tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
222 	if (tcph == NULL)
223 		return 0;
224 
225 	ip6h = ipv6_hdr(skb);
226 	tcph->check = 0;
227 	skb->csum = csum_partial(tcph, ipl - ihl, 0);
228 	tcph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
229 				      ipl - ihl, IPPROTO_TCP,
230 				      skb->csum);
231 
232 	skb->ip_summed = CHECKSUM_NONE;
233 
234 	return 1;
235 }
236 
237 static int tcf_csum_ipv4_udp(struct sk_buff *skb, unsigned int ihl,
238 			     unsigned int ipl, int udplite)
239 {
240 	struct udphdr *udph;
241 	const struct iphdr *iph;
242 	u16 ul;
243 
244 	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
245 		return 1;
246 
247 	/*
248 	 * Support both UDP and UDPLITE checksum algorithms, Don't use
249 	 * udph->len to get the real length without any protocol check,
250 	 * UDPLITE uses udph->len for another thing,
251 	 * Use iph->tot_len, or just ipl.
252 	 */
253 
254 	udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
255 	if (udph == NULL)
256 		return 0;
257 
258 	iph = ip_hdr(skb);
259 	ul = ntohs(udph->len);
260 
261 	if (udplite || udph->check) {
262 
263 		udph->check = 0;
264 
265 		if (udplite) {
266 			if (ul == 0)
267 				skb->csum = csum_partial(udph, ipl - ihl, 0);
268 			else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
269 				skb->csum = csum_partial(udph, ul, 0);
270 			else
271 				goto ignore_obscure_skb;
272 		} else {
273 			if (ul != ipl - ihl)
274 				goto ignore_obscure_skb;
275 
276 			skb->csum = csum_partial(udph, ul, 0);
277 		}
278 
279 		udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
280 						ul, iph->protocol,
281 						skb->csum);
282 
283 		if (!udph->check)
284 			udph->check = CSUM_MANGLED_0;
285 	}
286 
287 	skb->ip_summed = CHECKSUM_NONE;
288 
289 ignore_obscure_skb:
290 	return 1;
291 }
292 
293 static int tcf_csum_ipv6_udp(struct sk_buff *skb, unsigned int ihl,
294 			     unsigned int ipl, int udplite)
295 {
296 	struct udphdr *udph;
297 	const struct ipv6hdr *ip6h;
298 	u16 ul;
299 
300 	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
301 		return 1;
302 
303 	/*
304 	 * Support both UDP and UDPLITE checksum algorithms, Don't use
305 	 * udph->len to get the real length without any protocol check,
306 	 * UDPLITE uses udph->len for another thing,
307 	 * Use ip6h->payload_len + sizeof(*ip6h) ... , or just ipl.
308 	 */
309 
310 	udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
311 	if (udph == NULL)
312 		return 0;
313 
314 	ip6h = ipv6_hdr(skb);
315 	ul = ntohs(udph->len);
316 
317 	udph->check = 0;
318 
319 	if (udplite) {
320 		if (ul == 0)
321 			skb->csum = csum_partial(udph, ipl - ihl, 0);
322 
323 		else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
324 			skb->csum = csum_partial(udph, ul, 0);
325 
326 		else
327 			goto ignore_obscure_skb;
328 	} else {
329 		if (ul != ipl - ihl)
330 			goto ignore_obscure_skb;
331 
332 		skb->csum = csum_partial(udph, ul, 0);
333 	}
334 
335 	udph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, ul,
336 				      udplite ? IPPROTO_UDPLITE : IPPROTO_UDP,
337 				      skb->csum);
338 
339 	if (!udph->check)
340 		udph->check = CSUM_MANGLED_0;
341 
342 	skb->ip_summed = CHECKSUM_NONE;
343 
344 ignore_obscure_skb:
345 	return 1;
346 }
347 
348 static int tcf_csum_sctp(struct sk_buff *skb, unsigned int ihl,
349 			 unsigned int ipl)
350 {
351 	struct sctphdr *sctph;
352 
353 	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_SCTP)
354 		return 1;
355 
356 	sctph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*sctph));
357 	if (!sctph)
358 		return 0;
359 
360 	sctph->checksum = sctp_compute_cksum(skb,
361 					     skb_network_offset(skb) + ihl);
362 	skb->ip_summed = CHECKSUM_NONE;
363 	skb->csum_not_inet = 0;
364 
365 	return 1;
366 }
367 
368 static int tcf_csum_ipv4(struct sk_buff *skb, u32 update_flags)
369 {
370 	const struct iphdr *iph;
371 	int ntkoff;
372 
373 	ntkoff = skb_network_offset(skb);
374 
375 	if (!pskb_may_pull(skb, sizeof(*iph) + ntkoff))
376 		goto fail;
377 
378 	iph = ip_hdr(skb);
379 
380 	switch (iph->frag_off & htons(IP_OFFSET) ? 0 : iph->protocol) {
381 	case IPPROTO_ICMP:
382 		if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
383 			if (!tcf_csum_ipv4_icmp(skb, iph->ihl * 4,
384 						ntohs(iph->tot_len)))
385 				goto fail;
386 		break;
387 	case IPPROTO_IGMP:
388 		if (update_flags & TCA_CSUM_UPDATE_FLAG_IGMP)
389 			if (!tcf_csum_ipv4_igmp(skb, iph->ihl * 4,
390 						ntohs(iph->tot_len)))
391 				goto fail;
392 		break;
393 	case IPPROTO_TCP:
394 		if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
395 			if (!tcf_csum_ipv4_tcp(skb, iph->ihl * 4,
396 					       ntohs(iph->tot_len)))
397 				goto fail;
398 		break;
399 	case IPPROTO_UDP:
400 		if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
401 			if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
402 					       ntohs(iph->tot_len), 0))
403 				goto fail;
404 		break;
405 	case IPPROTO_UDPLITE:
406 		if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
407 			if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
408 					       ntohs(iph->tot_len), 1))
409 				goto fail;
410 		break;
411 	case IPPROTO_SCTP:
412 		if ((update_flags & TCA_CSUM_UPDATE_FLAG_SCTP) &&
413 		    !tcf_csum_sctp(skb, iph->ihl * 4, ntohs(iph->tot_len)))
414 			goto fail;
415 		break;
416 	}
417 
418 	if (update_flags & TCA_CSUM_UPDATE_FLAG_IPV4HDR) {
419 		if (skb_try_make_writable(skb, sizeof(*iph) + ntkoff))
420 			goto fail;
421 
422 		ip_send_check(ip_hdr(skb));
423 	}
424 
425 	return 1;
426 
427 fail:
428 	return 0;
429 }
430 
431 static int tcf_csum_ipv6_hopopts(struct ipv6_opt_hdr *ip6xh, unsigned int ixhl,
432 				 unsigned int *pl)
433 {
434 	int off, len, optlen;
435 	unsigned char *xh = (void *)ip6xh;
436 
437 	off = sizeof(*ip6xh);
438 	len = ixhl - off;
439 
440 	while (len > 1) {
441 		switch (xh[off]) {
442 		case IPV6_TLV_PAD1:
443 			optlen = 1;
444 			break;
445 		case IPV6_TLV_JUMBO:
446 			optlen = xh[off + 1] + 2;
447 			if (optlen != 6 || len < 6 || (off & 3) != 2)
448 				/* wrong jumbo option length/alignment */
449 				return 0;
450 			*pl = ntohl(*(__be32 *)(xh + off + 2));
451 			goto done;
452 		default:
453 			optlen = xh[off + 1] + 2;
454 			if (optlen > len)
455 				/* ignore obscure options */
456 				goto done;
457 			break;
458 		}
459 		off += optlen;
460 		len -= optlen;
461 	}
462 
463 done:
464 	return 1;
465 }
466 
467 static int tcf_csum_ipv6(struct sk_buff *skb, u32 update_flags)
468 {
469 	struct ipv6hdr *ip6h;
470 	struct ipv6_opt_hdr *ip6xh;
471 	unsigned int hl, ixhl;
472 	unsigned int pl;
473 	int ntkoff;
474 	u8 nexthdr;
475 
476 	ntkoff = skb_network_offset(skb);
477 
478 	hl = sizeof(*ip6h);
479 
480 	if (!pskb_may_pull(skb, hl + ntkoff))
481 		goto fail;
482 
483 	ip6h = ipv6_hdr(skb);
484 
485 	pl = ntohs(ip6h->payload_len);
486 	nexthdr = ip6h->nexthdr;
487 
488 	do {
489 		switch (nexthdr) {
490 		case NEXTHDR_FRAGMENT:
491 			goto ignore_skb;
492 		case NEXTHDR_ROUTING:
493 		case NEXTHDR_HOP:
494 		case NEXTHDR_DEST:
495 			if (!pskb_may_pull(skb, hl + sizeof(*ip6xh) + ntkoff))
496 				goto fail;
497 			ip6xh = (void *)(skb_network_header(skb) + hl);
498 			ixhl = ipv6_optlen(ip6xh);
499 			if (!pskb_may_pull(skb, hl + ixhl + ntkoff))
500 				goto fail;
501 			ip6xh = (void *)(skb_network_header(skb) + hl);
502 			if ((nexthdr == NEXTHDR_HOP) &&
503 			    !(tcf_csum_ipv6_hopopts(ip6xh, ixhl, &pl)))
504 				goto fail;
505 			nexthdr = ip6xh->nexthdr;
506 			hl += ixhl;
507 			break;
508 		case IPPROTO_ICMPV6:
509 			if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
510 				if (!tcf_csum_ipv6_icmp(skb,
511 							hl, pl + sizeof(*ip6h)))
512 					goto fail;
513 			goto done;
514 		case IPPROTO_TCP:
515 			if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
516 				if (!tcf_csum_ipv6_tcp(skb,
517 						       hl, pl + sizeof(*ip6h)))
518 					goto fail;
519 			goto done;
520 		case IPPROTO_UDP:
521 			if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
522 				if (!tcf_csum_ipv6_udp(skb, hl,
523 						       pl + sizeof(*ip6h), 0))
524 					goto fail;
525 			goto done;
526 		case IPPROTO_UDPLITE:
527 			if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
528 				if (!tcf_csum_ipv6_udp(skb, hl,
529 						       pl + sizeof(*ip6h), 1))
530 					goto fail;
531 			goto done;
532 		case IPPROTO_SCTP:
533 			if ((update_flags & TCA_CSUM_UPDATE_FLAG_SCTP) &&
534 			    !tcf_csum_sctp(skb, hl, pl + sizeof(*ip6h)))
535 				goto fail;
536 			goto done;
537 		default:
538 			goto ignore_skb;
539 		}
540 	} while (pskb_may_pull(skb, hl + 1 + ntkoff));
541 
542 done:
543 ignore_skb:
544 	return 1;
545 
546 fail:
547 	return 0;
548 }
549 
550 static int tcf_csum(struct sk_buff *skb, const struct tc_action *a,
551 		    struct tcf_result *res)
552 {
553 	struct tcf_csum *p = to_tcf_csum(a);
554 	struct tcf_csum_params *params;
555 	u32 update_flags;
556 	int action;
557 
558 	rcu_read_lock();
559 	params = rcu_dereference(p->params);
560 
561 	tcf_lastuse_update(&p->tcf_tm);
562 	bstats_cpu_update(this_cpu_ptr(p->common.cpu_bstats), skb);
563 
564 	action = params->action;
565 	if (unlikely(action == TC_ACT_SHOT))
566 		goto drop_stats;
567 
568 	update_flags = params->update_flags;
569 	switch (tc_skb_protocol(skb)) {
570 	case cpu_to_be16(ETH_P_IP):
571 		if (!tcf_csum_ipv4(skb, update_flags))
572 			goto drop;
573 		break;
574 	case cpu_to_be16(ETH_P_IPV6):
575 		if (!tcf_csum_ipv6(skb, update_flags))
576 			goto drop;
577 		break;
578 	}
579 
580 unlock:
581 	rcu_read_unlock();
582 	return action;
583 
584 drop:
585 	action = TC_ACT_SHOT;
586 
587 drop_stats:
588 	qstats_drop_inc(this_cpu_ptr(p->common.cpu_qstats));
589 	goto unlock;
590 }
591 
592 static int tcf_csum_dump(struct sk_buff *skb, struct tc_action *a, int bind,
593 			 int ref)
594 {
595 	unsigned char *b = skb_tail_pointer(skb);
596 	struct tcf_csum *p = to_tcf_csum(a);
597 	struct tcf_csum_params *params;
598 	struct tc_csum opt = {
599 		.index   = p->tcf_index,
600 		.refcnt  = p->tcf_refcnt - ref,
601 		.bindcnt = p->tcf_bindcnt - bind,
602 	};
603 	struct tcf_t t;
604 
605 	params = rtnl_dereference(p->params);
606 	opt.action = params->action;
607 	opt.update_flags = params->update_flags;
608 
609 	if (nla_put(skb, TCA_CSUM_PARMS, sizeof(opt), &opt))
610 		goto nla_put_failure;
611 
612 	tcf_tm_dump(&t, &p->tcf_tm);
613 	if (nla_put_64bit(skb, TCA_CSUM_TM, sizeof(t), &t, TCA_CSUM_PAD))
614 		goto nla_put_failure;
615 
616 	return skb->len;
617 
618 nla_put_failure:
619 	nlmsg_trim(skb, b);
620 	return -1;
621 }
622 
623 static void tcf_csum_cleanup(struct tc_action *a)
624 {
625 	struct tcf_csum *p = to_tcf_csum(a);
626 	struct tcf_csum_params *params;
627 
628 	params = rcu_dereference_protected(p->params, 1);
629 	kfree_rcu(params, rcu);
630 }
631 
632 static int tcf_csum_walker(struct net *net, struct sk_buff *skb,
633 			   struct netlink_callback *cb, int type,
634 			   const struct tc_action_ops *ops)
635 {
636 	struct tc_action_net *tn = net_generic(net, csum_net_id);
637 
638 	return tcf_generic_walker(tn, skb, cb, type, ops);
639 }
640 
641 static int tcf_csum_search(struct net *net, struct tc_action **a, u32 index)
642 {
643 	struct tc_action_net *tn = net_generic(net, csum_net_id);
644 
645 	return tcf_idr_search(tn, a, index);
646 }
647 
648 static struct tc_action_ops act_csum_ops = {
649 	.kind		= "csum",
650 	.type		= TCA_ACT_CSUM,
651 	.owner		= THIS_MODULE,
652 	.act		= tcf_csum,
653 	.dump		= tcf_csum_dump,
654 	.init		= tcf_csum_init,
655 	.cleanup	= tcf_csum_cleanup,
656 	.walk		= tcf_csum_walker,
657 	.lookup		= tcf_csum_search,
658 	.size		= sizeof(struct tcf_csum),
659 };
660 
661 static __net_init int csum_init_net(struct net *net)
662 {
663 	struct tc_action_net *tn = net_generic(net, csum_net_id);
664 
665 	return tc_action_net_init(tn, &act_csum_ops);
666 }
667 
668 static void __net_exit csum_exit_net(struct list_head *net_list)
669 {
670 	tc_action_net_exit(net_list, csum_net_id);
671 }
672 
673 static struct pernet_operations csum_net_ops = {
674 	.init = csum_init_net,
675 	.exit_batch = csum_exit_net,
676 	.id   = &csum_net_id,
677 	.size = sizeof(struct tc_action_net),
678 };
679 
680 MODULE_DESCRIPTION("Checksum updating actions");
681 MODULE_LICENSE("GPL");
682 
683 static int __init csum_init_module(void)
684 {
685 	return tcf_register_action(&act_csum_ops, &csum_net_ops);
686 }
687 
688 static void __exit csum_cleanup_module(void)
689 {
690 	tcf_unregister_action(&act_csum_ops, &csum_net_ops);
691 }
692 
693 module_init(csum_init_module);
694 module_exit(csum_cleanup_module);
695