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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 tcf_csum_init(struct net *n, struct nlattr *nla, struct nlattr *est,
46 struct tc_action *a, int ovr, int bind)
47{
48 struct nlattr *tb[TCA_CSUM_MAX + 1];
49 struct tc_csum *parm;
50 struct tcf_csum *p;
51 int ret = 0, err;
52
53 if (nla == NULL)
54 return -EINVAL;
55
56 err = nla_parse_nested(tb, TCA_CSUM_MAX, nla, csum_policy);
57 if (err < 0)
58 return err;
59
60 if (tb[TCA_CSUM_PARMS] == NULL)
61 return -EINVAL;
62 parm = nla_data(tb[TCA_CSUM_PARMS]);
63
64 if (!tcf_hash_check(parm->index, a, bind)) {
65 ret = tcf_hash_create(parm->index, est, a, sizeof(*p), bind);
66 if (ret)
67 return ret;
68 ret = ACT_P_CREATED;
69 } else {
70 if (bind)/* dont override defaults */
71 return 0;
72 tcf_hash_release(a, bind);
73 if (!ovr)
74 return -EEXIST;
75 }
76
77 p = to_tcf_csum(a);
78 spin_lock_bh(&p->tcf_lock);
79 p->tcf_action = parm->action;
80 p->update_flags = parm->update_flags;
81 spin_unlock_bh(&p->tcf_lock);
82
83 if (ret == ACT_P_CREATED)
84 tcf_hash_insert(a);
85
86 return ret;
87}
88
89/**
90 * tcf_csum_skb_nextlayer - Get next layer pointer
91 * @skb: sk_buff to use
92 * @ihl: previous summed headers length
93 * @ipl: complete packet length
94 * @jhl: next header length
95 *
96 * Check the expected next layer availability in the specified sk_buff.
97 * Return the next layer pointer if pass, NULL otherwise.
98 */
99static void *tcf_csum_skb_nextlayer(struct sk_buff *skb,
100 unsigned int ihl, unsigned int ipl,
101 unsigned int jhl)
102{
103 int ntkoff = skb_network_offset(skb);
104 int hl = ihl + jhl;
105
106 if (!pskb_may_pull(skb, ipl + ntkoff) || (ipl < hl) ||
107 (skb_cloned(skb) &&
108 !skb_clone_writable(skb, hl + ntkoff) &&
109 pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
110 return NULL;
111 else
112 return (void *)(skb_network_header(skb) + ihl);
113}
114
115static int tcf_csum_ipv4_icmp(struct sk_buff *skb,
116 unsigned int ihl, unsigned int ipl)
117{
118 struct icmphdr *icmph;
119
120 icmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmph));
121 if (icmph == NULL)
122 return 0;
123
124 icmph->checksum = 0;
125 skb->csum = csum_partial(icmph, ipl - ihl, 0);
126 icmph->checksum = csum_fold(skb->csum);
127
128 skb->ip_summed = CHECKSUM_NONE;
129
130 return 1;
131}
132
133static int tcf_csum_ipv4_igmp(struct sk_buff *skb,
134 unsigned int ihl, unsigned int ipl)
135{
136 struct igmphdr *igmph;
137
138 igmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*igmph));
139 if (igmph == NULL)
140 return 0;
141
142 igmph->csum = 0;
143 skb->csum = csum_partial(igmph, ipl - ihl, 0);
144 igmph->csum = csum_fold(skb->csum);
145
146 skb->ip_summed = CHECKSUM_NONE;
147
148 return 1;
149}
150
151static int tcf_csum_ipv6_icmp(struct sk_buff *skb,
152 unsigned int ihl, unsigned int ipl)
153{
154 struct icmp6hdr *icmp6h;
155 const struct ipv6hdr *ip6h;
156
157 icmp6h = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmp6h));
158 if (icmp6h == NULL)
159 return 0;
160
161 ip6h = ipv6_hdr(skb);
162 icmp6h->icmp6_cksum = 0;
163 skb->csum = csum_partial(icmp6h, ipl - ihl, 0);
164 icmp6h->icmp6_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
165 ipl - ihl, IPPROTO_ICMPV6,
166 skb->csum);
167
168 skb->ip_summed = CHECKSUM_NONE;
169
170 return 1;
171}
172
173static int tcf_csum_ipv4_tcp(struct sk_buff *skb,
174 unsigned int ihl, unsigned int ipl)
175{
176 struct tcphdr *tcph;
177 const struct iphdr *iph;
178
179 tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
180 if (tcph == NULL)
181 return 0;
182
183 iph = ip_hdr(skb);
184 tcph->check = 0;
185 skb->csum = csum_partial(tcph, ipl - ihl, 0);
186 tcph->check = tcp_v4_check(ipl - ihl,
187 iph->saddr, iph->daddr, skb->csum);
188
189 skb->ip_summed = CHECKSUM_NONE;
190
191 return 1;
192}
193
194static int tcf_csum_ipv6_tcp(struct sk_buff *skb,
195 unsigned int ihl, unsigned int ipl)
196{
197 struct tcphdr *tcph;
198 const struct ipv6hdr *ip6h;
199
200 tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
201 if (tcph == NULL)
202 return 0;
203
204 ip6h = ipv6_hdr(skb);
205 tcph->check = 0;
206 skb->csum = csum_partial(tcph, ipl - ihl, 0);
207 tcph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
208 ipl - ihl, IPPROTO_TCP,
209 skb->csum);
210
211 skb->ip_summed = CHECKSUM_NONE;
212
213 return 1;
214}
215
216static int tcf_csum_ipv4_udp(struct sk_buff *skb,
217 unsigned int ihl, unsigned int ipl, int udplite)
218{
219 struct udphdr *udph;
220 const struct iphdr *iph;
221 u16 ul;
222
223 /*
224 * Support both UDP and UDPLITE checksum algorithms, Don't use
225 * udph->len to get the real length without any protocol check,
226 * UDPLITE uses udph->len for another thing,
227 * Use iph->tot_len, or just ipl.
228 */
229
230 udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
231 if (udph == NULL)
232 return 0;
233
234 iph = ip_hdr(skb);
235 ul = ntohs(udph->len);
236
237 if (udplite || udph->check) {
238
239 udph->check = 0;
240
241 if (udplite) {
242 if (ul == 0)
243 skb->csum = csum_partial(udph, ipl - ihl, 0);
244 else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
245 skb->csum = csum_partial(udph, ul, 0);
246 else
247 goto ignore_obscure_skb;
248 } else {
249 if (ul != ipl - ihl)
250 goto ignore_obscure_skb;
251
252 skb->csum = csum_partial(udph, ul, 0);
253 }
254
255 udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
256 ul, iph->protocol,
257 skb->csum);
258
259 if (!udph->check)
260 udph->check = CSUM_MANGLED_0;
261 }
262
263 skb->ip_summed = CHECKSUM_NONE;
264
265ignore_obscure_skb:
266 return 1;
267}
268
269static int tcf_csum_ipv6_udp(struct sk_buff *skb,
270 unsigned int ihl, unsigned int ipl, int udplite)
271{
272 struct udphdr *udph;
273 const struct ipv6hdr *ip6h;
274 u16 ul;
275
276 /*
277 * Support both UDP and UDPLITE checksum algorithms, Don't use
278 * udph->len to get the real length without any protocol check,
279 * UDPLITE uses udph->len for another thing,
280 * Use ip6h->payload_len + sizeof(*ip6h) ... , or just ipl.
281 */
282
283 udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
284 if (udph == NULL)
285 return 0;
286
287 ip6h = ipv6_hdr(skb);
288 ul = ntohs(udph->len);
289
290 udph->check = 0;
291
292 if (udplite) {
293 if (ul == 0)
294 skb->csum = csum_partial(udph, ipl - ihl, 0);
295
296 else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
297 skb->csum = csum_partial(udph, ul, 0);
298
299 else
300 goto ignore_obscure_skb;
301 } else {
302 if (ul != ipl - ihl)
303 goto ignore_obscure_skb;
304
305 skb->csum = csum_partial(udph, ul, 0);
306 }
307
308 udph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, ul,
309 udplite ? IPPROTO_UDPLITE : IPPROTO_UDP,
310 skb->csum);
311
312 if (!udph->check)
313 udph->check = CSUM_MANGLED_0;
314
315 skb->ip_summed = CHECKSUM_NONE;
316
317ignore_obscure_skb:
318 return 1;
319}
320
321static int tcf_csum_ipv4(struct sk_buff *skb, u32 update_flags)
322{
323 const struct iphdr *iph;
324 int ntkoff;
325
326 ntkoff = skb_network_offset(skb);
327
328 if (!pskb_may_pull(skb, sizeof(*iph) + ntkoff))
329 goto fail;
330
331 iph = ip_hdr(skb);
332
333 switch (iph->frag_off & htons(IP_OFFSET) ? 0 : iph->protocol) {
334 case IPPROTO_ICMP:
335 if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
336 if (!tcf_csum_ipv4_icmp(skb, iph->ihl * 4,
337 ntohs(iph->tot_len)))
338 goto fail;
339 break;
340 case IPPROTO_IGMP:
341 if (update_flags & TCA_CSUM_UPDATE_FLAG_IGMP)
342 if (!tcf_csum_ipv4_igmp(skb, iph->ihl * 4,
343 ntohs(iph->tot_len)))
344 goto fail;
345 break;
346 case IPPROTO_TCP:
347 if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
348 if (!tcf_csum_ipv4_tcp(skb, iph->ihl * 4,
349 ntohs(iph->tot_len)))
350 goto fail;
351 break;
352 case IPPROTO_UDP:
353 if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
354 if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
355 ntohs(iph->tot_len), 0))
356 goto fail;
357 break;
358 case IPPROTO_UDPLITE:
359 if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
360 if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
361 ntohs(iph->tot_len), 1))
362 goto fail;
363 break;
364 }
365
366 if (update_flags & TCA_CSUM_UPDATE_FLAG_IPV4HDR) {
367 if (skb_cloned(skb) &&
368 !skb_clone_writable(skb, sizeof(*iph) + ntkoff) &&
369 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
370 goto fail;
371
372 ip_send_check(ip_hdr(skb));
373 }
374
375 return 1;
376
377fail:
378 return 0;
379}
380
381static int tcf_csum_ipv6_hopopts(struct ipv6_opt_hdr *ip6xh,
382 unsigned int ixhl, unsigned int *pl)
383{
384 int off, len, optlen;
385 unsigned char *xh = (void *)ip6xh;
386
387 off = sizeof(*ip6xh);
388 len = ixhl - off;
389
390 while (len > 1) {
391 switch (xh[off]) {
392 case IPV6_TLV_PAD1:
393 optlen = 1;
394 break;
395 case IPV6_TLV_JUMBO:
396 optlen = xh[off + 1] + 2;
397 if (optlen != 6 || len < 6 || (off & 3) != 2)
398 /* wrong jumbo option length/alignment */
399 return 0;
400 *pl = ntohl(*(__be32 *)(xh + off + 2));
401 goto done;
402 default:
403 optlen = xh[off + 1] + 2;
404 if (optlen > len)
405 /* ignore obscure options */
406 goto done;
407 break;
408 }
409 off += optlen;
410 len -= optlen;
411 }
412
413done:
414 return 1;
415}
416
417static int tcf_csum_ipv6(struct sk_buff *skb, u32 update_flags)
418{
419 struct ipv6hdr *ip6h;
420 struct ipv6_opt_hdr *ip6xh;
421 unsigned int hl, ixhl;
422 unsigned int pl;
423 int ntkoff;
424 u8 nexthdr;
425
426 ntkoff = skb_network_offset(skb);
427
428 hl = sizeof(*ip6h);
429
430 if (!pskb_may_pull(skb, hl + ntkoff))
431 goto fail;
432
433 ip6h = ipv6_hdr(skb);
434
435 pl = ntohs(ip6h->payload_len);
436 nexthdr = ip6h->nexthdr;
437
438 do {
439 switch (nexthdr) {
440 case NEXTHDR_FRAGMENT:
441 goto ignore_skb;
442 case NEXTHDR_ROUTING:
443 case NEXTHDR_HOP:
444 case NEXTHDR_DEST:
445 if (!pskb_may_pull(skb, hl + sizeof(*ip6xh) + ntkoff))
446 goto fail;
447 ip6xh = (void *)(skb_network_header(skb) + hl);
448 ixhl = ipv6_optlen(ip6xh);
449 if (!pskb_may_pull(skb, hl + ixhl + ntkoff))
450 goto fail;
451 ip6xh = (void *)(skb_network_header(skb) + hl);
452 if ((nexthdr == NEXTHDR_HOP) &&
453 !(tcf_csum_ipv6_hopopts(ip6xh, ixhl, &pl)))
454 goto fail;
455 nexthdr = ip6xh->nexthdr;
456 hl += ixhl;
457 break;
458 case IPPROTO_ICMPV6:
459 if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
460 if (!tcf_csum_ipv6_icmp(skb,
461 hl, pl + sizeof(*ip6h)))
462 goto fail;
463 goto done;
464 case IPPROTO_TCP:
465 if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
466 if (!tcf_csum_ipv6_tcp(skb,
467 hl, pl + sizeof(*ip6h)))
468 goto fail;
469 goto done;
470 case IPPROTO_UDP:
471 if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
472 if (!tcf_csum_ipv6_udp(skb, hl,
473 pl + sizeof(*ip6h), 0))
474 goto fail;
475 goto done;
476 case IPPROTO_UDPLITE:
477 if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
478 if (!tcf_csum_ipv6_udp(skb, hl,
479 pl + sizeof(*ip6h), 1))
480 goto fail;
481 goto done;
482 default:
483 goto ignore_skb;
484 }
485 } while (pskb_may_pull(skb, hl + 1 + ntkoff));
486
487done:
488ignore_skb:
489 return 1;
490
491fail:
492 return 0;
493}
494
495static int tcf_csum(struct sk_buff *skb,
496 const struct tc_action *a, struct tcf_result *res)
497{
498 struct tcf_csum *p = a->priv;
499 int action;
500 u32 update_flags;
501
502 spin_lock(&p->tcf_lock);
503 p->tcf_tm.lastuse = jiffies;
504 bstats_update(&p->tcf_bstats, skb);
505 action = p->tcf_action;
506 update_flags = p->update_flags;
507 spin_unlock(&p->tcf_lock);
508
509 if (unlikely(action == TC_ACT_SHOT))
510 goto drop;
511
512 switch (skb->protocol) {
513 case cpu_to_be16(ETH_P_IP):
514 if (!tcf_csum_ipv4(skb, update_flags))
515 goto drop;
516 break;
517 case cpu_to_be16(ETH_P_IPV6):
518 if (!tcf_csum_ipv6(skb, update_flags))
519 goto drop;
520 break;
521 }
522
523 return action;
524
525drop:
526 spin_lock(&p->tcf_lock);
527 p->tcf_qstats.drops++;
528 spin_unlock(&p->tcf_lock);
529 return TC_ACT_SHOT;
530}
531
532static int tcf_csum_dump(struct sk_buff *skb,
533 struct tc_action *a, int bind, int ref)
534{
535 unsigned char *b = skb_tail_pointer(skb);
536 struct tcf_csum *p = a->priv;
537 struct tc_csum opt = {
538 .update_flags = p->update_flags,
539 .index = p->tcf_index,
540 .action = p->tcf_action,
541 .refcnt = p->tcf_refcnt - ref,
542 .bindcnt = p->tcf_bindcnt - bind,
543 };
544 struct tcf_t t;
545
546 if (nla_put(skb, TCA_CSUM_PARMS, sizeof(opt), &opt))
547 goto nla_put_failure;
548 t.install = jiffies_to_clock_t(jiffies - p->tcf_tm.install);
549 t.lastuse = jiffies_to_clock_t(jiffies - p->tcf_tm.lastuse);
550 t.expires = jiffies_to_clock_t(p->tcf_tm.expires);
551 if (nla_put(skb, TCA_CSUM_TM, sizeof(t), &t))
552 goto nla_put_failure;
553
554 return skb->len;
555
556nla_put_failure:
557 nlmsg_trim(skb, b);
558 return -1;
559}
560
561static struct tc_action_ops act_csum_ops = {
562 .kind = "csum",
563 .type = TCA_ACT_CSUM,
564 .owner = THIS_MODULE,
565 .act = tcf_csum,
566 .dump = tcf_csum_dump,
567 .init = tcf_csum_init,
568};
569
570MODULE_DESCRIPTION("Checksum updating actions");
571MODULE_LICENSE("GPL");
572
573static int __init csum_init_module(void)
574{
575 return tcf_register_action(&act_csum_ops, CSUM_TAB_MASK);
576}
577
578static void __exit csum_cleanup_module(void)
579{
580 tcf_unregister_action(&act_csum_ops);
581}
582
583module_init(csum_init_module);
584module_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#include <net/tc_wrapper.h>
36
37static const struct nla_policy csum_policy[TCA_CSUM_MAX + 1] = {
38 [TCA_CSUM_PARMS] = { .len = sizeof(struct tc_csum), },
39};
40
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,
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 0;
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(sizeof(*params_new), GFP_KERNEL);
97 if (unlikely(!params_new)) {
98 err = -ENOMEM;
99 goto put_chain;
100 }
101 params_new->update_flags = parm->update_flags;
102
103 spin_lock_bh(&p->tcf_lock);
104 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
105 params_new = rcu_replace_pointer(p->params, params_new,
106 lockdep_is_held(&p->tcf_lock));
107 spin_unlock_bh(&p->tcf_lock);
108
109 if (goto_ch)
110 tcf_chain_put_by_act(goto_ch);
111 if (params_new)
112 kfree_rcu(params_new, rcu);
113
114 return ret;
115put_chain:
116 if (goto_ch)
117 tcf_chain_put_by_act(goto_ch);
118release_idr:
119 tcf_idr_release(*a, bind);
120 return err;
121}
122
123/**
124 * tcf_csum_skb_nextlayer - Get next layer pointer
125 * @skb: sk_buff to use
126 * @ihl: previous summed headers length
127 * @ipl: complete packet length
128 * @jhl: next header length
129 *
130 * Check the expected next layer availability in the specified sk_buff.
131 * Return the next layer pointer if pass, NULL otherwise.
132 */
133static void *tcf_csum_skb_nextlayer(struct sk_buff *skb,
134 unsigned int ihl, unsigned int ipl,
135 unsigned int jhl)
136{
137 int ntkoff = skb_network_offset(skb);
138 int hl = ihl + jhl;
139
140 if (!pskb_may_pull(skb, ipl + ntkoff) || (ipl < hl) ||
141 skb_try_make_writable(skb, hl + ntkoff))
142 return NULL;
143 else
144 return (void *)(skb_network_header(skb) + ihl);
145}
146
147static int tcf_csum_ipv4_icmp(struct sk_buff *skb, unsigned int ihl,
148 unsigned int ipl)
149{
150 struct icmphdr *icmph;
151
152 icmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmph));
153 if (icmph == NULL)
154 return 0;
155
156 icmph->checksum = 0;
157 skb->csum = csum_partial(icmph, ipl - ihl, 0);
158 icmph->checksum = csum_fold(skb->csum);
159
160 skb->ip_summed = CHECKSUM_NONE;
161
162 return 1;
163}
164
165static int tcf_csum_ipv4_igmp(struct sk_buff *skb,
166 unsigned int ihl, unsigned int ipl)
167{
168 struct igmphdr *igmph;
169
170 igmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*igmph));
171 if (igmph == NULL)
172 return 0;
173
174 igmph->csum = 0;
175 skb->csum = csum_partial(igmph, ipl - ihl, 0);
176 igmph->csum = csum_fold(skb->csum);
177
178 skb->ip_summed = CHECKSUM_NONE;
179
180 return 1;
181}
182
183static int tcf_csum_ipv6_icmp(struct sk_buff *skb, unsigned int ihl,
184 unsigned int ipl)
185{
186 struct icmp6hdr *icmp6h;
187 const struct ipv6hdr *ip6h;
188
189 icmp6h = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmp6h));
190 if (icmp6h == NULL)
191 return 0;
192
193 ip6h = ipv6_hdr(skb);
194 icmp6h->icmp6_cksum = 0;
195 skb->csum = csum_partial(icmp6h, ipl - ihl, 0);
196 icmp6h->icmp6_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
197 ipl - ihl, IPPROTO_ICMPV6,
198 skb->csum);
199
200 skb->ip_summed = CHECKSUM_NONE;
201
202 return 1;
203}
204
205static int tcf_csum_ipv4_tcp(struct sk_buff *skb, unsigned int ihl,
206 unsigned int ipl)
207{
208 struct tcphdr *tcph;
209 const struct iphdr *iph;
210
211 if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
212 return 1;
213
214 tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
215 if (tcph == NULL)
216 return 0;
217
218 iph = ip_hdr(skb);
219 tcph->check = 0;
220 skb->csum = csum_partial(tcph, ipl - ihl, 0);
221 tcph->check = tcp_v4_check(ipl - ihl,
222 iph->saddr, iph->daddr, skb->csum);
223
224 skb->ip_summed = CHECKSUM_NONE;
225
226 return 1;
227}
228
229static int tcf_csum_ipv6_tcp(struct sk_buff *skb, unsigned int ihl,
230 unsigned int ipl)
231{
232 struct tcphdr *tcph;
233 const struct ipv6hdr *ip6h;
234
235 if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
236 return 1;
237
238 tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
239 if (tcph == NULL)
240 return 0;
241
242 ip6h = ipv6_hdr(skb);
243 tcph->check = 0;
244 skb->csum = csum_partial(tcph, ipl - ihl, 0);
245 tcph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
246 ipl - ihl, IPPROTO_TCP,
247 skb->csum);
248
249 skb->ip_summed = CHECKSUM_NONE;
250
251 return 1;
252}
253
254static int tcf_csum_ipv4_udp(struct sk_buff *skb, unsigned int ihl,
255 unsigned int ipl, int udplite)
256{
257 struct udphdr *udph;
258 const struct iphdr *iph;
259 u16 ul;
260
261 if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
262 return 1;
263
264 /*
265 * Support both UDP and UDPLITE checksum algorithms, Don't use
266 * udph->len to get the real length without any protocol check,
267 * UDPLITE uses udph->len for another thing,
268 * Use iph->tot_len, or just ipl.
269 */
270
271 udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
272 if (udph == NULL)
273 return 0;
274
275 iph = ip_hdr(skb);
276 ul = ntohs(udph->len);
277
278 if (udplite || udph->check) {
279
280 udph->check = 0;
281
282 if (udplite) {
283 if (ul == 0)
284 skb->csum = csum_partial(udph, ipl - ihl, 0);
285 else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
286 skb->csum = csum_partial(udph, ul, 0);
287 else
288 goto ignore_obscure_skb;
289 } else {
290 if (ul != ipl - ihl)
291 goto ignore_obscure_skb;
292
293 skb->csum = csum_partial(udph, ul, 0);
294 }
295
296 udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
297 ul, iph->protocol,
298 skb->csum);
299
300 if (!udph->check)
301 udph->check = CSUM_MANGLED_0;
302 }
303
304 skb->ip_summed = CHECKSUM_NONE;
305
306ignore_obscure_skb:
307 return 1;
308}
309
310static int tcf_csum_ipv6_udp(struct sk_buff *skb, unsigned int ihl,
311 unsigned int ipl, int udplite)
312{
313 struct udphdr *udph;
314 const struct ipv6hdr *ip6h;
315 u16 ul;
316
317 if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
318 return 1;
319
320 /*
321 * Support both UDP and UDPLITE checksum algorithms, Don't use
322 * udph->len to get the real length without any protocol check,
323 * UDPLITE uses udph->len for another thing,
324 * Use ip6h->payload_len + sizeof(*ip6h) ... , or just ipl.
325 */
326
327 udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
328 if (udph == NULL)
329 return 0;
330
331 ip6h = ipv6_hdr(skb);
332 ul = ntohs(udph->len);
333
334 udph->check = 0;
335
336 if (udplite) {
337 if (ul == 0)
338 skb->csum = csum_partial(udph, ipl - ihl, 0);
339
340 else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
341 skb->csum = csum_partial(udph, ul, 0);
342
343 else
344 goto ignore_obscure_skb;
345 } else {
346 if (ul != ipl - ihl)
347 goto ignore_obscure_skb;
348
349 skb->csum = csum_partial(udph, ul, 0);
350 }
351
352 udph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, ul,
353 udplite ? IPPROTO_UDPLITE : IPPROTO_UDP,
354 skb->csum);
355
356 if (!udph->check)
357 udph->check = CSUM_MANGLED_0;
358
359 skb->ip_summed = CHECKSUM_NONE;
360
361ignore_obscure_skb:
362 return 1;
363}
364
365static int tcf_csum_sctp(struct sk_buff *skb, unsigned int ihl,
366 unsigned int ipl)
367{
368 struct sctphdr *sctph;
369
370 if (skb_is_gso(skb) && skb_is_gso_sctp(skb))
371 return 1;
372
373 sctph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*sctph));
374 if (!sctph)
375 return 0;
376
377 sctph->checksum = sctp_compute_cksum(skb,
378 skb_network_offset(skb) + ihl);
379 skb->ip_summed = CHECKSUM_NONE;
380 skb->csum_not_inet = 0;
381
382 return 1;
383}
384
385static int tcf_csum_ipv4(struct sk_buff *skb, u32 update_flags)
386{
387 const struct iphdr *iph;
388 int ntkoff;
389
390 ntkoff = skb_network_offset(skb);
391
392 if (!pskb_may_pull(skb, sizeof(*iph) + ntkoff))
393 goto fail;
394
395 iph = ip_hdr(skb);
396
397 switch (iph->frag_off & htons(IP_OFFSET) ? 0 : iph->protocol) {
398 case IPPROTO_ICMP:
399 if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
400 if (!tcf_csum_ipv4_icmp(skb, iph->ihl * 4,
401 ntohs(iph->tot_len)))
402 goto fail;
403 break;
404 case IPPROTO_IGMP:
405 if (update_flags & TCA_CSUM_UPDATE_FLAG_IGMP)
406 if (!tcf_csum_ipv4_igmp(skb, iph->ihl * 4,
407 ntohs(iph->tot_len)))
408 goto fail;
409 break;
410 case IPPROTO_TCP:
411 if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
412 if (!tcf_csum_ipv4_tcp(skb, iph->ihl * 4,
413 ntohs(iph->tot_len)))
414 goto fail;
415 break;
416 case IPPROTO_UDP:
417 if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
418 if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
419 ntohs(iph->tot_len), 0))
420 goto fail;
421 break;
422 case IPPROTO_UDPLITE:
423 if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
424 if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
425 ntohs(iph->tot_len), 1))
426 goto fail;
427 break;
428 case IPPROTO_SCTP:
429 if ((update_flags & TCA_CSUM_UPDATE_FLAG_SCTP) &&
430 !tcf_csum_sctp(skb, iph->ihl * 4, ntohs(iph->tot_len)))
431 goto fail;
432 break;
433 }
434
435 if (update_flags & TCA_CSUM_UPDATE_FLAG_IPV4HDR) {
436 if (skb_try_make_writable(skb, sizeof(*iph) + ntkoff))
437 goto fail;
438
439 ip_send_check(ip_hdr(skb));
440 }
441
442 return 1;
443
444fail:
445 return 0;
446}
447
448static int tcf_csum_ipv6_hopopts(struct ipv6_opt_hdr *ip6xh, unsigned int ixhl,
449 unsigned int *pl)
450{
451 int off, len, optlen;
452 unsigned char *xh = (void *)ip6xh;
453
454 off = sizeof(*ip6xh);
455 len = ixhl - off;
456
457 while (len > 1) {
458 switch (xh[off]) {
459 case IPV6_TLV_PAD1:
460 optlen = 1;
461 break;
462 case IPV6_TLV_JUMBO:
463 optlen = xh[off + 1] + 2;
464 if (optlen != 6 || len < 6 || (off & 3) != 2)
465 /* wrong jumbo option length/alignment */
466 return 0;
467 *pl = ntohl(*(__be32 *)(xh + off + 2));
468 goto done;
469 default:
470 optlen = xh[off + 1] + 2;
471 if (optlen > len)
472 /* ignore obscure options */
473 goto done;
474 break;
475 }
476 off += optlen;
477 len -= optlen;
478 }
479
480done:
481 return 1;
482}
483
484static int tcf_csum_ipv6(struct sk_buff *skb, u32 update_flags)
485{
486 struct ipv6hdr *ip6h;
487 struct ipv6_opt_hdr *ip6xh;
488 unsigned int hl, ixhl;
489 unsigned int pl;
490 int ntkoff;
491 u8 nexthdr;
492
493 ntkoff = skb_network_offset(skb);
494
495 hl = sizeof(*ip6h);
496
497 if (!pskb_may_pull(skb, hl + ntkoff))
498 goto fail;
499
500 ip6h = ipv6_hdr(skb);
501
502 pl = ntohs(ip6h->payload_len);
503 nexthdr = ip6h->nexthdr;
504
505 do {
506 switch (nexthdr) {
507 case NEXTHDR_FRAGMENT:
508 goto ignore_skb;
509 case NEXTHDR_ROUTING:
510 case NEXTHDR_HOP:
511 case NEXTHDR_DEST:
512 if (!pskb_may_pull(skb, hl + sizeof(*ip6xh) + ntkoff))
513 goto fail;
514 ip6xh = (void *)(skb_network_header(skb) + hl);
515 ixhl = ipv6_optlen(ip6xh);
516 if (!pskb_may_pull(skb, hl + ixhl + ntkoff))
517 goto fail;
518 ip6xh = (void *)(skb_network_header(skb) + hl);
519 if ((nexthdr == NEXTHDR_HOP) &&
520 !(tcf_csum_ipv6_hopopts(ip6xh, ixhl, &pl)))
521 goto fail;
522 nexthdr = ip6xh->nexthdr;
523 hl += ixhl;
524 break;
525 case IPPROTO_ICMPV6:
526 if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
527 if (!tcf_csum_ipv6_icmp(skb,
528 hl, pl + sizeof(*ip6h)))
529 goto fail;
530 goto done;
531 case IPPROTO_TCP:
532 if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
533 if (!tcf_csum_ipv6_tcp(skb,
534 hl, pl + sizeof(*ip6h)))
535 goto fail;
536 goto done;
537 case IPPROTO_UDP:
538 if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
539 if (!tcf_csum_ipv6_udp(skb, hl,
540 pl + sizeof(*ip6h), 0))
541 goto fail;
542 goto done;
543 case IPPROTO_UDPLITE:
544 if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
545 if (!tcf_csum_ipv6_udp(skb, hl,
546 pl + sizeof(*ip6h), 1))
547 goto fail;
548 goto done;
549 case IPPROTO_SCTP:
550 if ((update_flags & TCA_CSUM_UPDATE_FLAG_SCTP) &&
551 !tcf_csum_sctp(skb, hl, pl + sizeof(*ip6h)))
552 goto fail;
553 goto done;
554 default:
555 goto ignore_skb;
556 }
557 } while (pskb_may_pull(skb, hl + 1 + ntkoff));
558
559done:
560ignore_skb:
561 return 1;
562
563fail:
564 return 0;
565}
566
567TC_INDIRECT_SCOPE int tcf_csum_act(struct sk_buff *skb,
568 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 tcf_action_update_bstats(&p->common, 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 = skb_protocol(skb, false);
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 fallthrough;
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 tcf_action_inc_drop_qstats(&p->common);
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 size_t tcf_csum_get_fill_size(const struct tc_action *act)
678{
679 return nla_total_size(sizeof(struct tc_csum));
680}
681
682static int tcf_csum_offload_act_setup(struct tc_action *act, void *entry_data,
683 u32 *index_inc, bool bind,
684 struct netlink_ext_ack *extack)
685{
686 if (bind) {
687 struct flow_action_entry *entry = entry_data;
688
689 entry->id = FLOW_ACTION_CSUM;
690 entry->csum_flags = tcf_csum_update_flags(act);
691 *index_inc = 1;
692 } else {
693 struct flow_offload_action *fl_action = entry_data;
694
695 fl_action->id = FLOW_ACTION_CSUM;
696 }
697
698 return 0;
699}
700
701static struct tc_action_ops act_csum_ops = {
702 .kind = "csum",
703 .id = TCA_ID_CSUM,
704 .owner = THIS_MODULE,
705 .act = tcf_csum_act,
706 .dump = tcf_csum_dump,
707 .init = tcf_csum_init,
708 .cleanup = tcf_csum_cleanup,
709 .get_fill_size = tcf_csum_get_fill_size,
710 .offload_act_setup = tcf_csum_offload_act_setup,
711 .size = sizeof(struct tcf_csum),
712};
713
714static __net_init int csum_init_net(struct net *net)
715{
716 struct tc_action_net *tn = net_generic(net, act_csum_ops.net_id);
717
718 return tc_action_net_init(net, tn, &act_csum_ops);
719}
720
721static void __net_exit csum_exit_net(struct list_head *net_list)
722{
723 tc_action_net_exit(net_list, act_csum_ops.net_id);
724}
725
726static struct pernet_operations csum_net_ops = {
727 .init = csum_init_net,
728 .exit_batch = csum_exit_net,
729 .id = &act_csum_ops.net_id,
730 .size = sizeof(struct tc_action_net),
731};
732
733MODULE_DESCRIPTION("Checksum updating actions");
734MODULE_LICENSE("GPL");
735
736static int __init csum_init_module(void)
737{
738 return tcf_register_action(&act_csum_ops, &csum_net_ops);
739}
740
741static void __exit csum_cleanup_module(void)
742{
743 tcf_unregister_action(&act_csum_ops, &csum_net_ops);
744}
745
746module_init(csum_init_module);
747module_exit(csum_cleanup_module);