xref: /linux/net/sched/act_csum.c (revision 18f65355e112dfc87d5e2e8a299119afd2e65e7e)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Checksum updating actions
4  *
5  * Copyright (c) 2010 Gregoire Baron <baronchon@n7mm.org>
6  */
7 
8 #include <linux/types.h>
9 #include <linux/init.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/spinlock.h>
13 
14 #include <linux/netlink.h>
15 #include <net/netlink.h>
16 #include <linux/rtnetlink.h>
17 
18 #include <linux/skbuff.h>
19 
20 #include <net/ip.h>
21 #include <net/ipv6.h>
22 #include <net/icmp.h>
23 #include <linux/icmpv6.h>
24 #include <linux/igmp.h>
25 #include <net/tcp.h>
26 #include <net/udp.h>
27 #include <net/ip6_checksum.h>
28 #include <net/sctp/checksum.h>
29 
30 #include <net/act_api.h>
31 #include <net/pkt_cls.h>
32 
33 #include <linux/tc_act/tc_csum.h>
34 #include <net/tc_act/tc_csum.h>
35 #include <net/tc_wrapper.h>
36 
37 static const struct nla_policy csum_policy[TCA_CSUM_MAX + 1] = {
38 	[TCA_CSUM_PARMS] = { .len = sizeof(struct tc_csum), },
39 };
40 
41 static struct tc_action_ops act_csum_ops;
42 
43 static int tcf_csum_init(struct net *net, struct nlattr *nla,
44 			 struct nlattr *est, struct tc_action **a,
45 			 struct tcf_proto *tp,
46 			 u32 flags, struct netlink_ext_ack *extack)
47 {
48 	struct tc_action_net *tn = net_generic(net, act_csum_ops.net_id);
49 	bool bind = flags & TCA_ACT_FLAGS_BIND;
50 	struct tcf_csum_params *params_new;
51 	struct nlattr *tb[TCA_CSUM_MAX + 1];
52 	struct tcf_chain *goto_ch = NULL;
53 	struct tc_csum *parm;
54 	struct tcf_csum *p;
55 	int ret = 0, err;
56 	u32 index;
57 
58 	if (nla == NULL)
59 		return -EINVAL;
60 
61 	err = nla_parse_nested_deprecated(tb, TCA_CSUM_MAX, nla, csum_policy,
62 					  NULL);
63 	if (err < 0)
64 		return err;
65 
66 	if (tb[TCA_CSUM_PARMS] == NULL)
67 		return -EINVAL;
68 	parm = nla_data(tb[TCA_CSUM_PARMS]);
69 	index = parm->index;
70 	err = tcf_idr_check_alloc(tn, &index, a, bind);
71 	if (!err) {
72 		ret = tcf_idr_create_from_flags(tn, index, est, a,
73 						&act_csum_ops, bind, flags);
74 		if (ret) {
75 			tcf_idr_cleanup(tn, index);
76 			return ret;
77 		}
78 		ret = ACT_P_CREATED;
79 	} else if (err > 0) {
80 		if (bind) /* dont override defaults */
81 			return ACT_P_BOUND;
82 		if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
83 			tcf_idr_release(*a, bind);
84 			return -EEXIST;
85 		}
86 	} else {
87 		return err;
88 	}
89 
90 	err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
91 	if (err < 0)
92 		goto release_idr;
93 
94 	p = to_tcf_csum(*a);
95 
96 	params_new = kzalloc_obj(*params_new);
97 	if (unlikely(!params_new)) {
98 		err = -ENOMEM;
99 		goto put_chain;
100 	}
101 	params_new->update_flags = parm->update_flags;
102 	params_new->action = parm->action;
103 
104 	spin_lock_bh(&p->tcf_lock);
105 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
106 	params_new = rcu_replace_pointer(p->params, params_new,
107 					 lockdep_is_held(&p->tcf_lock));
108 	spin_unlock_bh(&p->tcf_lock);
109 
110 	if (goto_ch)
111 		tcf_chain_put_by_act(goto_ch);
112 	if (params_new)
113 		kfree_rcu(params_new, rcu);
114 
115 	return ret;
116 put_chain:
117 	if (goto_ch)
118 		tcf_chain_put_by_act(goto_ch);
119 release_idr:
120 	tcf_idr_release(*a, bind);
121 	return err;
122 }
123 
124 /**
125  * tcf_csum_skb_nextlayer - Get next layer pointer
126  * @skb: sk_buff to use
127  * @ihl: previous summed headers length
128  * @ipl: complete packet length
129  * @jhl: next header length
130  *
131  * Check the expected next layer availability in the specified sk_buff.
132  * Return the next layer pointer if pass, NULL otherwise.
133  */
134 static void *tcf_csum_skb_nextlayer(struct sk_buff *skb,
135 				    unsigned int ihl, unsigned int ipl,
136 				    unsigned int jhl)
137 {
138 	int ntkoff = skb_network_offset(skb);
139 	int hl = ihl + jhl;
140 
141 	if (!pskb_may_pull(skb, ipl + ntkoff) || (ipl < hl) ||
142 	    skb_try_make_writable(skb, hl + ntkoff))
143 		return NULL;
144 	else
145 		return (void *)(skb_network_header(skb) + ihl);
146 }
147 
148 static int tcf_csum_ipv4_icmp(struct sk_buff *skb, unsigned int ihl,
149 			      unsigned int ipl)
150 {
151 	struct icmphdr *icmph;
152 
153 	icmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmph));
154 	if (icmph == NULL)
155 		return 0;
156 
157 	icmph->checksum = 0;
158 	skb->csum = csum_partial(icmph, ipl - ihl, 0);
159 	icmph->checksum = csum_fold(skb->csum);
160 
161 	skb->ip_summed = CHECKSUM_NONE;
162 
163 	return 1;
164 }
165 
166 static int tcf_csum_ipv4_igmp(struct sk_buff *skb,
167 			      unsigned int ihl, unsigned int ipl)
168 {
169 	struct igmphdr *igmph;
170 
171 	igmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*igmph));
172 	if (igmph == NULL)
173 		return 0;
174 
175 	igmph->csum = 0;
176 	skb->csum = csum_partial(igmph, ipl - ihl, 0);
177 	igmph->csum = csum_fold(skb->csum);
178 
179 	skb->ip_summed = CHECKSUM_NONE;
180 
181 	return 1;
182 }
183 
184 static int tcf_csum_ipv6_icmp(struct sk_buff *skb, unsigned int ihl,
185 			      unsigned int ipl)
186 {
187 	struct icmp6hdr *icmp6h;
188 	const struct ipv6hdr *ip6h;
189 
190 	icmp6h = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmp6h));
191 	if (icmp6h == NULL)
192 		return 0;
193 
194 	ip6h = ipv6_hdr(skb);
195 	icmp6h->icmp6_cksum = 0;
196 	skb->csum = csum_partial(icmp6h, ipl - ihl, 0);
197 	icmp6h->icmp6_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
198 					      ipl - ihl, IPPROTO_ICMPV6,
199 					      skb->csum);
200 
201 	skb->ip_summed = CHECKSUM_NONE;
202 
203 	return 1;
204 }
205 
206 static int tcf_csum_ipv4_tcp(struct sk_buff *skb, unsigned int ihl,
207 			     unsigned int ipl)
208 {
209 	struct tcphdr *tcph;
210 	const struct iphdr *iph;
211 
212 	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
213 		return 1;
214 
215 	tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
216 	if (tcph == NULL)
217 		return 0;
218 
219 	iph = ip_hdr(skb);
220 	tcph->check = 0;
221 	skb->csum = csum_partial(tcph, ipl - ihl, 0);
222 	tcph->check = tcp_v4_check(ipl - ihl,
223 				   iph->saddr, iph->daddr, skb->csum);
224 
225 	skb->ip_summed = CHECKSUM_NONE;
226 
227 	return 1;
228 }
229 
230 static int tcf_csum_ipv6_tcp(struct sk_buff *skb, unsigned int ihl,
231 			     unsigned int ipl)
232 {
233 	struct tcphdr *tcph;
234 	const struct ipv6hdr *ip6h;
235 
236 	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
237 		return 1;
238 
239 	tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
240 	if (tcph == NULL)
241 		return 0;
242 
243 	ip6h = ipv6_hdr(skb);
244 	tcph->check = 0;
245 	skb->csum = csum_partial(tcph, ipl - ihl, 0);
246 	tcph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
247 				      ipl - ihl, IPPROTO_TCP,
248 				      skb->csum);
249 
250 	skb->ip_summed = CHECKSUM_NONE;
251 
252 	return 1;
253 }
254 
255 static int tcf_csum_ipv4_udp(struct sk_buff *skb, unsigned int ihl,
256 			     unsigned int ipl, int udplite)
257 {
258 	struct udphdr *udph;
259 	const struct iphdr *iph;
260 	u16 ul;
261 
262 	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type &
263 	    (SKB_GSO_UDP | SKB_GSO_UDP_L4 |
264 	     SKB_GSO_UDP_TUNNEL | SKB_GSO_UDP_TUNNEL_CSUM))
265 		return 1;
266 
267 	/*
268 	 * Support both UDP and UDPLITE checksum algorithms, Don't use
269 	 * udph->len to get the real length without any protocol check,
270 	 * UDPLITE uses udph->len for another thing,
271 	 * Use iph->tot_len, or just ipl.
272 	 */
273 
274 	udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
275 	if (udph == NULL)
276 		return 0;
277 
278 	iph = ip_hdr(skb);
279 	ul = ntohs(udph->len);
280 
281 	if (udplite || udph->check) {
282 
283 		udph->check = 0;
284 
285 		if (udplite) {
286 			if (ul == 0)
287 				skb->csum = csum_partial(udph, ipl - ihl, 0);
288 			else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
289 				skb->csum = csum_partial(udph, ul, 0);
290 			else
291 				goto ignore_obscure_skb;
292 		} else {
293 			if (ul != ipl - ihl)
294 				goto ignore_obscure_skb;
295 
296 			skb->csum = csum_partial(udph, ul, 0);
297 		}
298 
299 		udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
300 						ul, iph->protocol,
301 						skb->csum);
302 
303 		if (!udph->check)
304 			udph->check = CSUM_MANGLED_0;
305 	}
306 
307 	skb->ip_summed = CHECKSUM_NONE;
308 
309 ignore_obscure_skb:
310 	return 1;
311 }
312 
313 static int tcf_csum_ipv6_udp(struct sk_buff *skb, unsigned int ihl,
314 			     unsigned int ipl, int udplite)
315 {
316 	struct udphdr *udph;
317 	const struct ipv6hdr *ip6h;
318 	u16 ul;
319 
320 	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type &
321 	    (SKB_GSO_UDP | SKB_GSO_UDP_L4 |
322 	     SKB_GSO_UDP_TUNNEL | SKB_GSO_UDP_TUNNEL_CSUM))
323 		return 1;
324 
325 	/*
326 	 * Support both UDP and UDPLITE checksum algorithms, Don't use
327 	 * udph->len to get the real length without any protocol check,
328 	 * UDPLITE uses udph->len for another thing,
329 	 * Use ip6h->payload_len + sizeof(*ip6h) ... , or just ipl.
330 	 */
331 
332 	udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
333 	if (udph == NULL)
334 		return 0;
335 
336 	ip6h = ipv6_hdr(skb);
337 	ul = ntohs(udph->len);
338 
339 	udph->check = 0;
340 
341 	if (udplite) {
342 		if (ul == 0)
343 			skb->csum = csum_partial(udph, ipl - ihl, 0);
344 
345 		else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
346 			skb->csum = csum_partial(udph, ul, 0);
347 
348 		else
349 			goto ignore_obscure_skb;
350 	} else {
351 		if (ul != ipl - ihl)
352 			goto ignore_obscure_skb;
353 
354 		skb->csum = csum_partial(udph, ul, 0);
355 	}
356 
357 	udph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, ul,
358 				      udplite ? IPPROTO_UDPLITE : IPPROTO_UDP,
359 				      skb->csum);
360 
361 	if (!udph->check)
362 		udph->check = CSUM_MANGLED_0;
363 
364 	skb->ip_summed = CHECKSUM_NONE;
365 
366 ignore_obscure_skb:
367 	return 1;
368 }
369 
370 static int tcf_csum_sctp(struct sk_buff *skb, unsigned int ihl,
371 			 unsigned int ipl)
372 {
373 	struct sctphdr *sctph;
374 
375 	if (skb_is_gso(skb) && skb_is_gso_sctp(skb))
376 		return 1;
377 
378 	sctph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*sctph));
379 	if (!sctph)
380 		return 0;
381 
382 	sctph->checksum = sctp_compute_cksum(skb,
383 					     skb_network_offset(skb) + ihl);
384 	skb_reset_csum_not_inet(skb);
385 
386 	return 1;
387 }
388 
389 static int tcf_csum_ipv4(struct sk_buff *skb, u32 update_flags)
390 {
391 	const struct iphdr *iph;
392 	int ntkoff;
393 
394 	ntkoff = skb_network_offset(skb);
395 
396 	if (!pskb_may_pull(skb, sizeof(*iph) + ntkoff))
397 		goto fail;
398 
399 	iph = ip_hdr(skb);
400 
401 	switch (iph->frag_off & htons(IP_OFFSET) ? 0 : iph->protocol) {
402 	case IPPROTO_ICMP:
403 		if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
404 			if (!tcf_csum_ipv4_icmp(skb, iph->ihl * 4,
405 						ntohs(iph->tot_len)))
406 				goto fail;
407 		break;
408 	case IPPROTO_IGMP:
409 		if (update_flags & TCA_CSUM_UPDATE_FLAG_IGMP)
410 			if (!tcf_csum_ipv4_igmp(skb, iph->ihl * 4,
411 						ntohs(iph->tot_len)))
412 				goto fail;
413 		break;
414 	case IPPROTO_TCP:
415 		if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
416 			if (!tcf_csum_ipv4_tcp(skb, iph->ihl * 4,
417 					       ntohs(iph->tot_len)))
418 				goto fail;
419 		break;
420 	case IPPROTO_UDP:
421 		if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
422 			if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
423 					       ntohs(iph->tot_len), 0))
424 				goto fail;
425 		break;
426 	case IPPROTO_UDPLITE:
427 		if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
428 			if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
429 					       ntohs(iph->tot_len), 1))
430 				goto fail;
431 		break;
432 	case IPPROTO_SCTP:
433 		if ((update_flags & TCA_CSUM_UPDATE_FLAG_SCTP) &&
434 		    !tcf_csum_sctp(skb, iph->ihl * 4, ntohs(iph->tot_len)))
435 			goto fail;
436 		break;
437 	}
438 
439 	if (update_flags & TCA_CSUM_UPDATE_FLAG_IPV4HDR) {
440 		if (skb_try_make_writable(skb, sizeof(*iph) + ntkoff))
441 			goto fail;
442 
443 		ip_send_check(ip_hdr(skb));
444 	}
445 
446 	return 1;
447 
448 fail:
449 	return 0;
450 }
451 
452 static int tcf_csum_ipv6_hopopts(struct ipv6_opt_hdr *ip6xh, unsigned int ixhl,
453 				 unsigned int *pl)
454 {
455 	int off, len, optlen;
456 	unsigned char *xh = (void *)ip6xh;
457 
458 	off = sizeof(*ip6xh);
459 	len = ixhl - off;
460 
461 	while (len > 1) {
462 		switch (xh[off]) {
463 		case IPV6_TLV_PAD1:
464 			optlen = 1;
465 			break;
466 		case IPV6_TLV_JUMBO:
467 			optlen = xh[off + 1] + 2;
468 			if (optlen != 6 || len < 6 || (off & 3) != 2)
469 				/* wrong jumbo option length/alignment */
470 				return 0;
471 			*pl = ntohl(*(__be32 *)(xh + off + 2));
472 			goto done;
473 		default:
474 			optlen = xh[off + 1] + 2;
475 			if (optlen > len)
476 				/* ignore obscure options */
477 				goto done;
478 			break;
479 		}
480 		off += optlen;
481 		len -= optlen;
482 	}
483 
484 done:
485 	return 1;
486 }
487 
488 static int tcf_csum_ipv6(struct sk_buff *skb, u32 update_flags)
489 {
490 	struct ipv6hdr *ip6h;
491 	struct ipv6_opt_hdr *ip6xh;
492 	unsigned int hl, ixhl;
493 	unsigned int pl;
494 	int ntkoff;
495 	u8 nexthdr;
496 
497 	ntkoff = skb_network_offset(skb);
498 
499 	hl = sizeof(*ip6h);
500 
501 	if (!pskb_may_pull(skb, hl + ntkoff))
502 		goto fail;
503 
504 	ip6h = ipv6_hdr(skb);
505 
506 	pl = ntohs(ip6h->payload_len);
507 	nexthdr = ip6h->nexthdr;
508 
509 	do {
510 		switch (nexthdr) {
511 		case NEXTHDR_FRAGMENT:
512 			goto ignore_skb;
513 		case NEXTHDR_ROUTING:
514 		case NEXTHDR_HOP:
515 		case NEXTHDR_DEST:
516 			if (!pskb_may_pull(skb, hl + sizeof(*ip6xh) + ntkoff))
517 				goto fail;
518 			ip6xh = (void *)(skb_network_header(skb) + hl);
519 			ixhl = ipv6_optlen(ip6xh);
520 			if (!pskb_may_pull(skb, hl + ixhl + ntkoff))
521 				goto fail;
522 			ip6xh = (void *)(skb_network_header(skb) + hl);
523 			if ((nexthdr == NEXTHDR_HOP) &&
524 			    !(tcf_csum_ipv6_hopopts(ip6xh, ixhl, &pl)))
525 				goto fail;
526 			nexthdr = ip6xh->nexthdr;
527 			hl += ixhl;
528 			break;
529 		case IPPROTO_ICMPV6:
530 			if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
531 				if (!tcf_csum_ipv6_icmp(skb,
532 							hl, pl + sizeof(*ip6h)))
533 					goto fail;
534 			goto done;
535 		case IPPROTO_TCP:
536 			if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
537 				if (!tcf_csum_ipv6_tcp(skb,
538 						       hl, pl + sizeof(*ip6h)))
539 					goto fail;
540 			goto done;
541 		case IPPROTO_UDP:
542 			if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
543 				if (!tcf_csum_ipv6_udp(skb, hl,
544 						       pl + sizeof(*ip6h), 0))
545 					goto fail;
546 			goto done;
547 		case IPPROTO_UDPLITE:
548 			if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
549 				if (!tcf_csum_ipv6_udp(skb, hl,
550 						       pl + sizeof(*ip6h), 1))
551 					goto fail;
552 			goto done;
553 		case IPPROTO_SCTP:
554 			if ((update_flags & TCA_CSUM_UPDATE_FLAG_SCTP) &&
555 			    !tcf_csum_sctp(skb, hl, pl + sizeof(*ip6h)))
556 				goto fail;
557 			goto done;
558 		default:
559 			goto ignore_skb;
560 		}
561 	} while (pskb_may_pull(skb, hl + 1 + ntkoff));
562 
563 done:
564 ignore_skb:
565 	return 1;
566 
567 fail:
568 	return 0;
569 }
570 
571 TC_INDIRECT_SCOPE int tcf_csum_act(struct sk_buff *skb,
572 				   const struct tc_action *a,
573 				   struct tcf_result *res)
574 {
575 	struct tcf_csum *p = to_tcf_csum(a);
576 	bool orig_vlan_tag_present = false;
577 	unsigned int vlan_hdr_count = 0;
578 	struct tcf_csum_params *params;
579 	u32 update_flags;
580 	__be16 protocol;
581 	int action;
582 
583 	params = rcu_dereference_bh(p->params);
584 
585 	tcf_lastuse_update(&p->tcf_tm);
586 	tcf_action_update_bstats(&p->common, skb);
587 
588 	action = params->action;
589 	if (unlikely(action == TC_ACT_SHOT))
590 		goto drop;
591 
592 	update_flags = params->update_flags;
593 	protocol = skb_protocol(skb, false);
594 again:
595 	switch (protocol) {
596 	case cpu_to_be16(ETH_P_IP):
597 		if (!tcf_csum_ipv4(skb, update_flags))
598 			goto drop;
599 		break;
600 	case cpu_to_be16(ETH_P_IPV6):
601 		if (!tcf_csum_ipv6(skb, update_flags))
602 			goto drop;
603 		break;
604 	case cpu_to_be16(ETH_P_8021AD):
605 		fallthrough;
606 	case cpu_to_be16(ETH_P_8021Q):
607 		if (skb_vlan_tag_present(skb) && !orig_vlan_tag_present) {
608 			protocol = skb->protocol;
609 			orig_vlan_tag_present = true;
610 		} else {
611 			struct vlan_hdr *vlan;
612 
613 			if (!pskb_may_pull(skb, VLAN_HLEN))
614 				goto drop;
615 
616 			vlan = (struct vlan_hdr *)skb->data;
617 			protocol = vlan->h_vlan_encapsulated_proto;
618 			skb_pull(skb, VLAN_HLEN);
619 			skb_reset_network_header(skb);
620 			vlan_hdr_count++;
621 		}
622 		goto again;
623 	}
624 
625 out:
626 	/* Restore the skb for the pulled VLAN tags */
627 	while (vlan_hdr_count--) {
628 		skb_push(skb, VLAN_HLEN);
629 		skb_reset_network_header(skb);
630 	}
631 
632 	return action;
633 
634 drop:
635 	tcf_action_inc_drop_qstats(&p->common);
636 	action = TC_ACT_SHOT;
637 	goto out;
638 }
639 
640 static int tcf_csum_dump(struct sk_buff *skb, struct tc_action *a, int bind,
641 			 int ref)
642 {
643 	const struct tcf_csum *p = to_tcf_csum(a);
644 	unsigned char *b = skb_tail_pointer(skb);
645 	const struct tcf_csum_params *params;
646 	struct tc_csum opt = {
647 		.index   = p->tcf_index,
648 		.refcnt  = refcount_read(&p->tcf_refcnt) - ref,
649 		.bindcnt = atomic_read(&p->tcf_bindcnt) - bind,
650 	};
651 	struct tcf_t t;
652 
653 	rcu_read_lock();
654 	params = rcu_dereference(p->params);
655 	opt.action = params->action;
656 	opt.update_flags = params->update_flags;
657 
658 	if (nla_put(skb, TCA_CSUM_PARMS, sizeof(opt), &opt))
659 		goto nla_put_failure;
660 
661 	tcf_tm_dump(&t, &p->tcf_tm);
662 	if (nla_put_64bit(skb, TCA_CSUM_TM, sizeof(t), &t, TCA_CSUM_PAD))
663 		goto nla_put_failure;
664 	rcu_read_unlock();
665 
666 	return skb->len;
667 
668 nla_put_failure:
669 	rcu_read_unlock();
670 	nlmsg_trim(skb, b);
671 	return -1;
672 }
673 
674 static void tcf_csum_cleanup(struct tc_action *a)
675 {
676 	struct tcf_csum *p = to_tcf_csum(a);
677 	struct tcf_csum_params *params;
678 
679 	params = rcu_dereference_protected(p->params, 1);
680 	if (params)
681 		kfree_rcu(params, rcu);
682 }
683 
684 static size_t tcf_csum_get_fill_size(const struct tc_action *act)
685 {
686 	return nla_total_size(sizeof(struct tc_csum));
687 }
688 
689 static int tcf_csum_offload_act_setup(struct tc_action *act, void *entry_data,
690 				      u32 *index_inc, bool bind,
691 				      struct netlink_ext_ack *extack)
692 {
693 	if (bind) {
694 		struct flow_action_entry *entry = entry_data;
695 
696 		entry->id = FLOW_ACTION_CSUM;
697 		entry->csum_flags = tcf_csum_update_flags(act);
698 		*index_inc = 1;
699 	} else {
700 		struct flow_offload_action *fl_action = entry_data;
701 
702 		fl_action->id = FLOW_ACTION_CSUM;
703 	}
704 
705 	return 0;
706 }
707 
708 static struct tc_action_ops act_csum_ops = {
709 	.kind		= "csum",
710 	.id		= TCA_ID_CSUM,
711 	.owner		= THIS_MODULE,
712 	.act		= tcf_csum_act,
713 	.dump		= tcf_csum_dump,
714 	.init		= tcf_csum_init,
715 	.cleanup	= tcf_csum_cleanup,
716 	.get_fill_size  = tcf_csum_get_fill_size,
717 	.offload_act_setup = tcf_csum_offload_act_setup,
718 	.size		= sizeof(struct tcf_csum),
719 };
720 MODULE_ALIAS_NET_ACT("csum");
721 
722 static __net_init int csum_init_net(struct net *net)
723 {
724 	struct tc_action_net *tn = net_generic(net, act_csum_ops.net_id);
725 
726 	return tc_action_net_init(net, tn, &act_csum_ops);
727 }
728 
729 static void __net_exit csum_exit_net(struct list_head *net_list)
730 {
731 	tc_action_net_exit(net_list, act_csum_ops.net_id);
732 }
733 
734 static struct pernet_operations csum_net_ops = {
735 	.init = csum_init_net,
736 	.exit_batch = csum_exit_net,
737 	.id   = &act_csum_ops.net_id,
738 	.size = sizeof(struct tc_action_net),
739 };
740 
741 MODULE_DESCRIPTION("Checksum updating actions");
742 MODULE_LICENSE("GPL");
743 
744 static int __init csum_init_module(void)
745 {
746 	return tcf_register_action(&act_csum_ops, &csum_net_ops);
747 }
748 
749 static void __exit csum_cleanup_module(void)
750 {
751 	tcf_unregister_action(&act_csum_ops, &csum_net_ops);
752 }
753 
754 module_init(csum_init_module);
755 module_exit(csum_cleanup_module);
756