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