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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
36static const struct nla_policy csum_policy[TCA_CSUM_MAX + 1] = {
37 [TCA_CSUM_PARMS] = { .len = sizeof(struct tc_csum), },
38};
39
40static unsigned int csum_net_id;
41static struct tc_action_ops act_csum_ops;
42
43static int tcf_csum_init(struct net *net, struct nlattr *nla,
44 struct nlattr *est, struct tc_action **a, int ovr,
45 int bind, bool rtnl_held, struct tcf_proto *tp,
46 struct netlink_ext_ack *extack)
47{
48 struct tc_action_net *tn = net_generic(net, csum_net_id);
49 struct tcf_csum_params *params_new;
50 struct nlattr *tb[TCA_CSUM_MAX + 1];
51 struct tcf_chain *goto_ch = NULL;
52 struct tc_csum *parm;
53 struct tcf_csum *p;
54 int ret = 0, err;
55
56 if (nla == NULL)
57 return -EINVAL;
58
59 err = nla_parse_nested_deprecated(tb, TCA_CSUM_MAX, nla, csum_policy,
60 NULL);
61 if (err < 0)
62 return err;
63
64 if (tb[TCA_CSUM_PARMS] == NULL)
65 return -EINVAL;
66 parm = nla_data(tb[TCA_CSUM_PARMS]);
67
68 err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
69 if (!err) {
70 ret = tcf_idr_create(tn, parm->index, est, a,
71 &act_csum_ops, bind, true);
72 if (ret) {
73 tcf_idr_cleanup(tn, parm->index);
74 return ret;
75 }
76 ret = ACT_P_CREATED;
77 } else if (err > 0) {
78 if (bind)
79 return 0;
80 if (!ovr) {
81 tcf_idr_release(*a, bind);
82 return -EEXIST;
83 }
84 } else {
85 return err;
86 }
87
88 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
89 if (err < 0)
90 goto release_idr;
91
92 p = to_tcf_csum(*a);
93
94 params_new = kzalloc(sizeof(*params_new), GFP_KERNEL);
95 if (unlikely(!params_new)) {
96 err = -ENOMEM;
97 goto put_chain;
98 }
99 params_new->update_flags = parm->update_flags;
100
101 spin_lock_bh(&p->tcf_lock);
102 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
103 rcu_swap_protected(p->params, params_new,
104 lockdep_is_held(&p->tcf_lock));
105 spin_unlock_bh(&p->tcf_lock);
106
107 if (goto_ch)
108 tcf_chain_put_by_act(goto_ch);
109 if (params_new)
110 kfree_rcu(params_new, rcu);
111
112 if (ret == ACT_P_CREATED)
113 tcf_idr_insert(tn, *a);
114
115 return ret;
116put_chain:
117 if (goto_ch)
118 tcf_chain_put_by_act(goto_ch);
119release_idr:
120 tcf_idr_release(*a, bind);
121 return err;
122}
123
124
125
126
127
128
129
130
131
132
133
134static 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
148static 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
166static 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
184static 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
206static 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
230static 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
255static 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 & SKB_GSO_UDP)
263 return 1;
264
265
266
267
268
269
270
271
272 udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
273 if (udph == NULL)
274 return 0;
275
276 iph = ip_hdr(skb);
277 ul = ntohs(udph->len);
278
279 if (udplite || udph->check) {
280
281 udph->check = 0;
282
283 if (udplite) {
284 if (ul == 0)
285 skb->csum = csum_partial(udph, ipl - ihl, 0);
286 else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
287 skb->csum = csum_partial(udph, ul, 0);
288 else
289 goto ignore_obscure_skb;
290 } else {
291 if (ul != ipl - ihl)
292 goto ignore_obscure_skb;
293
294 skb->csum = csum_partial(udph, ul, 0);
295 }
296
297 udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
298 ul, iph->protocol,
299 skb->csum);
300
301 if (!udph->check)
302 udph->check = CSUM_MANGLED_0;
303 }
304
305 skb->ip_summed = CHECKSUM_NONE;
306
307ignore_obscure_skb:
308 return 1;
309}
310
311static int tcf_csum_ipv6_udp(struct sk_buff *skb, unsigned int ihl,
312 unsigned int ipl, int udplite)
313{
314 struct udphdr *udph;
315 const struct ipv6hdr *ip6h;
316 u16 ul;
317
318 if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
319 return 1;
320
321
322
323
324
325
326
327
328 udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
329 if (udph == NULL)
330 return 0;
331
332 ip6h = ipv6_hdr(skb);
333 ul = ntohs(udph->len);
334
335 udph->check = 0;
336
337 if (udplite) {
338 if (ul == 0)
339 skb->csum = csum_partial(udph, ipl - ihl, 0);
340
341 else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
342 skb->csum = csum_partial(udph, ul, 0);
343
344 else
345 goto ignore_obscure_skb;
346 } else {
347 if (ul != ipl - ihl)
348 goto ignore_obscure_skb;
349
350 skb->csum = csum_partial(udph, ul, 0);
351 }
352
353 udph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, ul,
354 udplite ? IPPROTO_UDPLITE : IPPROTO_UDP,
355 skb->csum);
356
357 if (!udph->check)
358 udph->check = CSUM_MANGLED_0;
359
360 skb->ip_summed = CHECKSUM_NONE;
361
362ignore_obscure_skb:
363 return 1;
364}
365
366static int tcf_csum_sctp(struct sk_buff *skb, unsigned int ihl,
367 unsigned int ipl)
368{
369 struct sctphdr *sctph;
370
371 if (skb_is_gso(skb) && skb_is_gso_sctp(skb))
372 return 1;
373
374 sctph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*sctph));
375 if (!sctph)
376 return 0;
377
378 sctph->checksum = sctp_compute_cksum(skb,
379 skb_network_offset(skb) + ihl);
380 skb->ip_summed = CHECKSUM_NONE;
381 skb->csum_not_inet = 0;
382
383 return 1;
384}
385
386static int tcf_csum_ipv4(struct sk_buff *skb, u32 update_flags)
387{
388 const struct iphdr *iph;
389 int ntkoff;
390
391 ntkoff = skb_network_offset(skb);
392
393 if (!pskb_may_pull(skb, sizeof(*iph) + ntkoff))
394 goto fail;
395
396 iph = ip_hdr(skb);
397
398 switch (iph->frag_off & htons(IP_OFFSET) ? 0 : iph->protocol) {
399 case IPPROTO_ICMP:
400 if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
401 if (!tcf_csum_ipv4_icmp(skb, iph->ihl * 4,
402 ntohs(iph->tot_len)))
403 goto fail;
404 break;
405 case IPPROTO_IGMP:
406 if (update_flags & TCA_CSUM_UPDATE_FLAG_IGMP)
407 if (!tcf_csum_ipv4_igmp(skb, iph->ihl * 4,
408 ntohs(iph->tot_len)))
409 goto fail;
410 break;
411 case IPPROTO_TCP:
412 if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
413 if (!tcf_csum_ipv4_tcp(skb, iph->ihl * 4,
414 ntohs(iph->tot_len)))
415 goto fail;
416 break;
417 case IPPROTO_UDP:
418 if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
419 if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
420 ntohs(iph->tot_len), 0))
421 goto fail;
422 break;
423 case IPPROTO_UDPLITE:
424 if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
425 if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
426 ntohs(iph->tot_len), 1))
427 goto fail;
428 break;
429 case IPPROTO_SCTP:
430 if ((update_flags & TCA_CSUM_UPDATE_FLAG_SCTP) &&
431 !tcf_csum_sctp(skb, iph->ihl * 4, ntohs(iph->tot_len)))
432 goto fail;
433 break;
434 }
435
436 if (update_flags & TCA_CSUM_UPDATE_FLAG_IPV4HDR) {
437 if (skb_try_make_writable(skb, sizeof(*iph) + ntkoff))
438 goto fail;
439
440 ip_send_check(ip_hdr(skb));
441 }
442
443 return 1;
444
445fail:
446 return 0;
447}
448
449static int tcf_csum_ipv6_hopopts(struct ipv6_opt_hdr *ip6xh, unsigned int ixhl,
450 unsigned int *pl)
451{
452 int off, len, optlen;
453 unsigned char *xh = (void *)ip6xh;
454
455 off = sizeof(*ip6xh);
456 len = ixhl - off;
457
458 while (len > 1) {
459 switch (xh[off]) {
460 case IPV6_TLV_PAD1:
461 optlen = 1;
462 break;
463 case IPV6_TLV_JUMBO:
464 optlen = xh[off + 1] + 2;
465 if (optlen != 6 || len < 6 || (off & 3) != 2)
466
467 return 0;
468 *pl = ntohl(*(__be32 *)(xh + off + 2));
469 goto done;
470 default:
471 optlen = xh[off + 1] + 2;
472 if (optlen > len)
473
474 goto done;
475 break;
476 }
477 off += optlen;
478 len -= optlen;
479 }
480
481done:
482 return 1;
483}
484
485static int tcf_csum_ipv6(struct sk_buff *skb, u32 update_flags)
486{
487 struct ipv6hdr *ip6h;
488 struct ipv6_opt_hdr *ip6xh;
489 unsigned int hl, ixhl;
490 unsigned int pl;
491 int ntkoff;
492 u8 nexthdr;
493
494 ntkoff = skb_network_offset(skb);
495
496 hl = sizeof(*ip6h);
497
498 if (!pskb_may_pull(skb, hl + ntkoff))
499 goto fail;
500
501 ip6h = ipv6_hdr(skb);
502
503 pl = ntohs(ip6h->payload_len);
504 nexthdr = ip6h->nexthdr;
505
506 do {
507 switch (nexthdr) {
508 case NEXTHDR_FRAGMENT:
509 goto ignore_skb;
510 case NEXTHDR_ROUTING:
511 case NEXTHDR_HOP:
512 case NEXTHDR_DEST:
513 if (!pskb_may_pull(skb, hl + sizeof(*ip6xh) + ntkoff))
514 goto fail;
515 ip6xh = (void *)(skb_network_header(skb) + hl);
516 ixhl = ipv6_optlen(ip6xh);
517 if (!pskb_may_pull(skb, hl + ixhl + ntkoff))
518 goto fail;
519 ip6xh = (void *)(skb_network_header(skb) + hl);
520 if ((nexthdr == NEXTHDR_HOP) &&
521 !(tcf_csum_ipv6_hopopts(ip6xh, ixhl, &pl)))
522 goto fail;
523 nexthdr = ip6xh->nexthdr;
524 hl += ixhl;
525 break;
526 case IPPROTO_ICMPV6:
527 if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
528 if (!tcf_csum_ipv6_icmp(skb,
529 hl, pl + sizeof(*ip6h)))
530 goto fail;
531 goto done;
532 case IPPROTO_TCP:
533 if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
534 if (!tcf_csum_ipv6_tcp(skb,
535 hl, pl + sizeof(*ip6h)))
536 goto fail;
537 goto done;
538 case IPPROTO_UDP:
539 if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
540 if (!tcf_csum_ipv6_udp(skb, hl,
541 pl + sizeof(*ip6h), 0))
542 goto fail;
543 goto done;
544 case IPPROTO_UDPLITE:
545 if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
546 if (!tcf_csum_ipv6_udp(skb, hl,
547 pl + sizeof(*ip6h), 1))
548 goto fail;
549 goto done;
550 case IPPROTO_SCTP:
551 if ((update_flags & TCA_CSUM_UPDATE_FLAG_SCTP) &&
552 !tcf_csum_sctp(skb, hl, pl + sizeof(*ip6h)))
553 goto fail;
554 goto done;
555 default:
556 goto ignore_skb;
557 }
558 } while (pskb_may_pull(skb, hl + 1 + ntkoff));
559
560done:
561ignore_skb:
562 return 1;
563
564fail:
565 return 0;
566}
567
568static int tcf_csum_act(struct sk_buff *skb, const struct tc_action *a,
569 struct tcf_result *res)
570{
571 struct tcf_csum *p = to_tcf_csum(a);
572 bool orig_vlan_tag_present = false;
573 unsigned int vlan_hdr_count = 0;
574 struct tcf_csum_params *params;
575 u32 update_flags;
576 __be16 protocol;
577 int action;
578
579 params = rcu_dereference_bh(p->params);
580
581 tcf_lastuse_update(&p->tcf_tm);
582 bstats_cpu_update(this_cpu_ptr(p->common.cpu_bstats), skb);
583
584 action = READ_ONCE(p->tcf_action);
585 if (unlikely(action == TC_ACT_SHOT))
586 goto drop;
587
588 update_flags = params->update_flags;
589 protocol = tc_skb_protocol(skb);
590again:
591 switch (protocol) {
592 case cpu_to_be16(ETH_P_IP):
593 if (!tcf_csum_ipv4(skb, update_flags))
594 goto drop;
595 break;
596 case cpu_to_be16(ETH_P_IPV6):
597 if (!tcf_csum_ipv6(skb, update_flags))
598 goto drop;
599 break;
600 case cpu_to_be16(ETH_P_8021AD):
601 case cpu_to_be16(ETH_P_8021Q):
602 if (skb_vlan_tag_present(skb) && !orig_vlan_tag_present) {
603 protocol = skb->protocol;
604 orig_vlan_tag_present = true;
605 } else {
606 struct vlan_hdr *vlan = (struct vlan_hdr *)skb->data;
607
608 protocol = vlan->h_vlan_encapsulated_proto;
609 skb_pull(skb, VLAN_HLEN);
610 skb_reset_network_header(skb);
611 vlan_hdr_count++;
612 }
613 goto again;
614 }
615
616out:
617
618 while (vlan_hdr_count--) {
619 skb_push(skb, VLAN_HLEN);
620 skb_reset_network_header(skb);
621 }
622
623 return action;
624
625drop:
626 qstats_drop_inc(this_cpu_ptr(p->common.cpu_qstats));
627 action = TC_ACT_SHOT;
628 goto out;
629}
630
631static int tcf_csum_dump(struct sk_buff *skb, struct tc_action *a, int bind,
632 int ref)
633{
634 unsigned char *b = skb_tail_pointer(skb);
635 struct tcf_csum *p = to_tcf_csum(a);
636 struct tcf_csum_params *params;
637 struct tc_csum opt = {
638 .index = p->tcf_index,
639 .refcnt = refcount_read(&p->tcf_refcnt) - ref,
640 .bindcnt = atomic_read(&p->tcf_bindcnt) - bind,
641 };
642 struct tcf_t t;
643
644 spin_lock_bh(&p->tcf_lock);
645 params = rcu_dereference_protected(p->params,
646 lockdep_is_held(&p->tcf_lock));
647 opt.action = p->tcf_action;
648 opt.update_flags = params->update_flags;
649
650 if (nla_put(skb, TCA_CSUM_PARMS, sizeof(opt), &opt))
651 goto nla_put_failure;
652
653 tcf_tm_dump(&t, &p->tcf_tm);
654 if (nla_put_64bit(skb, TCA_CSUM_TM, sizeof(t), &t, TCA_CSUM_PAD))
655 goto nla_put_failure;
656 spin_unlock_bh(&p->tcf_lock);
657
658 return skb->len;
659
660nla_put_failure:
661 spin_unlock_bh(&p->tcf_lock);
662 nlmsg_trim(skb, b);
663 return -1;
664}
665
666static void tcf_csum_cleanup(struct tc_action *a)
667{
668 struct tcf_csum *p = to_tcf_csum(a);
669 struct tcf_csum_params *params;
670
671 params = rcu_dereference_protected(p->params, 1);
672 if (params)
673 kfree_rcu(params, rcu);
674}
675
676static int tcf_csum_walker(struct net *net, struct sk_buff *skb,
677 struct netlink_callback *cb, int type,
678 const struct tc_action_ops *ops,
679 struct netlink_ext_ack *extack)
680{
681 struct tc_action_net *tn = net_generic(net, csum_net_id);
682
683 return tcf_generic_walker(tn, skb, cb, type, ops, extack);
684}
685
686static int tcf_csum_search(struct net *net, struct tc_action **a, u32 index)
687{
688 struct tc_action_net *tn = net_generic(net, csum_net_id);
689
690 return tcf_idr_search(tn, a, index);
691}
692
693static size_t tcf_csum_get_fill_size(const struct tc_action *act)
694{
695 return nla_total_size(sizeof(struct tc_csum));
696}
697
698static struct tc_action_ops act_csum_ops = {
699 .kind = "csum",
700 .id = TCA_ID_CSUM,
701 .owner = THIS_MODULE,
702 .act = tcf_csum_act,
703 .dump = tcf_csum_dump,
704 .init = tcf_csum_init,
705 .cleanup = tcf_csum_cleanup,
706 .walk = tcf_csum_walker,
707 .lookup = tcf_csum_search,
708 .get_fill_size = tcf_csum_get_fill_size,
709 .size = sizeof(struct tcf_csum),
710};
711
712static __net_init int csum_init_net(struct net *net)
713{
714 struct tc_action_net *tn = net_generic(net, csum_net_id);
715
716 return tc_action_net_init(tn, &act_csum_ops);
717}
718
719static void __net_exit csum_exit_net(struct list_head *net_list)
720{
721 tc_action_net_exit(net_list, csum_net_id);
722}
723
724static struct pernet_operations csum_net_ops = {
725 .init = csum_init_net,
726 .exit_batch = csum_exit_net,
727 .id = &csum_net_id,
728 .size = sizeof(struct tc_action_net),
729};
730
731MODULE_DESCRIPTION("Checksum updating actions");
732MODULE_LICENSE("GPL");
733
734static int __init csum_init_module(void)
735{
736 return tcf_register_action(&act_csum_ops, &csum_net_ops);
737}
738
739static void __exit csum_cleanup_module(void)
740{
741 tcf_unregister_action(&act_csum_ops, &csum_net_ops);
742}
743
744module_init(csum_init_module);
745module_exit(csum_cleanup_module);
746
