Commit | Line | Data |
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eb4d4065 GB |
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 | ||
33 | #include <net/act_api.h> | |
34 | ||
35 | #include <linux/tc_act/tc_csum.h> | |
36 | #include <net/tc_act/tc_csum.h> | |
37 | ||
38 | #define CSUM_TAB_MASK 15 | |
39 | static struct tcf_common *tcf_csum_ht[CSUM_TAB_MASK + 1]; | |
40 | static u32 csum_idx_gen; | |
41 | static DEFINE_RWLOCK(csum_lock); | |
42 | ||
43 | static struct tcf_hashinfo csum_hash_info = { | |
44 | .htab = tcf_csum_ht, | |
45 | .hmask = CSUM_TAB_MASK, | |
46 | .lock = &csum_lock, | |
47 | }; | |
48 | ||
49 | static const struct nla_policy csum_policy[TCA_CSUM_MAX + 1] = { | |
50 | [TCA_CSUM_PARMS] = { .len = sizeof(struct tc_csum), }, | |
51 | }; | |
52 | ||
53 | static int tcf_csum_init(struct nlattr *nla, struct nlattr *est, | |
54 | struct tc_action *a, int ovr, int bind) | |
55 | { | |
56 | struct nlattr *tb[TCA_CSUM_MAX + 1]; | |
57 | struct tc_csum *parm; | |
58 | struct tcf_common *pc; | |
59 | struct tcf_csum *p; | |
60 | int ret = 0, err; | |
61 | ||
62 | if (nla == NULL) | |
63 | return -EINVAL; | |
64 | ||
65 | err = nla_parse_nested(tb, TCA_CSUM_MAX, nla,csum_policy); | |
66 | if (err < 0) | |
67 | return err; | |
68 | ||
69 | if (tb[TCA_CSUM_PARMS] == NULL) | |
70 | return -EINVAL; | |
71 | parm = nla_data(tb[TCA_CSUM_PARMS]); | |
72 | ||
73 | pc = tcf_hash_check(parm->index, a, bind, &csum_hash_info); | |
74 | if (!pc) { | |
75 | pc = tcf_hash_create(parm->index, est, a, sizeof(*p), bind, &csum_idx_gen, &csum_hash_info); | |
76 | if (IS_ERR(pc)) | |
77 | return PTR_ERR(pc); | |
78 | p = to_tcf_csum(pc); | |
79 | ret = ACT_P_CREATED; | |
80 | } else { | |
81 | p = to_tcf_csum(pc); | |
82 | if (!ovr) { | |
83 | tcf_hash_release(pc, bind, &csum_hash_info); | |
84 | return -EEXIST; | |
85 | } | |
86 | } | |
87 | ||
88 | spin_lock_bh(&p->tcf_lock); | |
89 | p->tcf_action = parm->action; | |
90 | p->update_flags = parm->update_flags; | |
91 | spin_unlock_bh(&p->tcf_lock); | |
92 | ||
93 | if (ret == ACT_P_CREATED) | |
94 | tcf_hash_insert(pc, &csum_hash_info); | |
95 | ||
96 | return ret; | |
97 | } | |
98 | ||
99 | static int tcf_csum_cleanup(struct tc_action *a, int bind) | |
100 | { | |
101 | struct tcf_csum *p = a->priv; | |
102 | return tcf_hash_release(&p->common, bind, &csum_hash_info); | |
103 | } | |
104 | ||
105 | /** | |
106 | * tcf_csum_skb_nextlayer - Get next layer pointer | |
107 | * @skb: sk_buff to use | |
108 | * @ihl: previous summed headers length | |
109 | * @ipl: complete packet length | |
110 | * @jhl: next header length | |
111 | * | |
112 | * Check the expected next layer availability in the specified sk_buff. | |
113 | * Return the next layer pointer if pass, NULL otherwise. | |
114 | */ | |
115 | static void *tcf_csum_skb_nextlayer(struct sk_buff *skb, | |
116 | unsigned int ihl, unsigned int ipl, | |
117 | unsigned int jhl) | |
118 | { | |
119 | int ntkoff = skb_network_offset(skb); | |
120 | int hl = ihl + jhl; | |
121 | ||
122 | if (!pskb_may_pull(skb, ipl + ntkoff) || (ipl < hl) || | |
123 | (skb_cloned(skb) && | |
124 | !skb_clone_writable(skb, hl + ntkoff) && | |
125 | pskb_expand_head(skb, 0, 0, GFP_ATOMIC))) | |
126 | return NULL; | |
127 | else | |
128 | return (void *)(skb_network_header(skb) + ihl); | |
129 | } | |
130 | ||
131 | static int tcf_csum_ipv4_icmp(struct sk_buff *skb, | |
132 | unsigned int ihl, unsigned int ipl) | |
133 | { | |
134 | struct icmphdr *icmph; | |
135 | ||
136 | icmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmph)); | |
137 | if (icmph == NULL) | |
138 | return 0; | |
139 | ||
140 | icmph->checksum = 0; | |
141 | skb->csum = csum_partial(icmph, ipl - ihl, 0); | |
142 | icmph->checksum = csum_fold(skb->csum); | |
143 | ||
144 | skb->ip_summed = CHECKSUM_NONE; | |
145 | ||
146 | return 1; | |
147 | } | |
148 | ||
149 | static int tcf_csum_ipv4_igmp(struct sk_buff *skb, | |
150 | unsigned int ihl, unsigned int ipl) | |
151 | { | |
152 | struct igmphdr *igmph; | |
153 | ||
154 | igmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*igmph)); | |
155 | if (igmph == NULL) | |
156 | return 0; | |
157 | ||
158 | igmph->csum = 0; | |
159 | skb->csum = csum_partial(igmph, ipl - ihl, 0); | |
160 | igmph->csum = csum_fold(skb->csum); | |
161 | ||
162 | skb->ip_summed = CHECKSUM_NONE; | |
163 | ||
164 | return 1; | |
165 | } | |
166 | ||
167 | static int tcf_csum_ipv6_icmp(struct sk_buff *skb, struct ipv6hdr *ip6h, | |
168 | unsigned int ihl, unsigned int ipl) | |
169 | { | |
170 | struct icmp6hdr *icmp6h; | |
171 | ||
172 | icmp6h = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmp6h)); | |
173 | if (icmp6h == NULL) | |
174 | return 0; | |
175 | ||
176 | icmp6h->icmp6_cksum = 0; | |
177 | skb->csum = csum_partial(icmp6h, ipl - ihl, 0); | |
178 | icmp6h->icmp6_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, | |
179 | ipl - ihl, IPPROTO_ICMPV6, | |
180 | skb->csum); | |
181 | ||
182 | skb->ip_summed = CHECKSUM_NONE; | |
183 | ||
184 | return 1; | |
185 | } | |
186 | ||
187 | static int tcf_csum_ipv4_tcp(struct sk_buff *skb, struct iphdr *iph, | |
188 | unsigned int ihl, unsigned int ipl) | |
189 | { | |
190 | struct tcphdr *tcph; | |
191 | ||
192 | tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph)); | |
193 | if (tcph == NULL) | |
194 | return 0; | |
195 | ||
196 | tcph->check = 0; | |
197 | skb->csum = csum_partial(tcph, ipl - ihl, 0); | |
198 | tcph->check = tcp_v4_check(ipl - ihl, | |
199 | iph->saddr, iph->daddr, skb->csum); | |
200 | ||
201 | skb->ip_summed = CHECKSUM_NONE; | |
202 | ||
203 | return 1; | |
204 | } | |
205 | ||
206 | static int tcf_csum_ipv6_tcp(struct sk_buff *skb, struct ipv6hdr *ip6h, | |
207 | unsigned int ihl, unsigned int ipl) | |
208 | { | |
209 | struct tcphdr *tcph; | |
210 | ||
211 | tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph)); | |
212 | if (tcph == NULL) | |
213 | return 0; | |
214 | ||
215 | tcph->check = 0; | |
216 | skb->csum = csum_partial(tcph, ipl - ihl, 0); | |
217 | tcph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, | |
218 | ipl - ihl, IPPROTO_TCP, | |
219 | skb->csum); | |
220 | ||
221 | skb->ip_summed = CHECKSUM_NONE; | |
222 | ||
223 | return 1; | |
224 | } | |
225 | ||
226 | static int tcf_csum_ipv4_udp(struct sk_buff *skb, struct iphdr *iph, | |
227 | unsigned int ihl, unsigned int ipl, int udplite) | |
228 | { | |
229 | struct udphdr *udph; | |
230 | u16 ul; | |
231 | ||
232 | /* Support both UDP and UDPLITE checksum algorithms, | |
233 | * Don't use udph->len to get the real length without any protocol check, | |
234 | * UDPLITE uses udph->len for another thing, | |
235 | * Use iph->tot_len, or just ipl. | |
236 | */ | |
237 | ||
238 | udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph)); | |
239 | if (udph == NULL) | |
240 | return 0; | |
241 | ||
242 | ul = ntohs(udph->len); | |
243 | ||
244 | if (udplite || udph->check) { | |
245 | ||
246 | udph->check = 0; | |
247 | ||
248 | if (udplite) { | |
249 | if (ul == 0) | |
250 | skb->csum = csum_partial(udph, ipl - ihl, 0); | |
251 | ||
252 | else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl)) | |
253 | skb->csum = csum_partial(udph, ul, 0); | |
254 | ||
255 | else | |
256 | goto ignore_obscure_skb; | |
257 | } else { | |
258 | if (ul != ipl - ihl) | |
259 | goto ignore_obscure_skb; | |
260 | ||
261 | skb->csum = csum_partial(udph, ul, 0); | |
262 | } | |
263 | ||
264 | udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr, | |
265 | ul, iph->protocol, | |
266 | skb->csum); | |
267 | ||
268 | if (!udph->check) | |
269 | udph->check = CSUM_MANGLED_0; | |
270 | } | |
271 | ||
272 | skb->ip_summed = CHECKSUM_NONE; | |
273 | ||
274 | ignore_obscure_skb: | |
275 | return 1; | |
276 | } | |
277 | ||
278 | static int tcf_csum_ipv6_udp(struct sk_buff *skb, struct ipv6hdr *ip6h, | |
279 | unsigned int ihl, unsigned int ipl, int udplite) | |
280 | { | |
281 | struct udphdr *udph; | |
282 | u16 ul; | |
283 | ||
284 | /* Support both UDP and UDPLITE checksum algorithms, | |
285 | * Don't use udph->len to get the real length without any protocol check, | |
286 | * UDPLITE uses udph->len for another thing, | |
287 | * Use ip6h->payload_len + sizeof(*ip6h) ... , or just ipl. | |
288 | */ | |
289 | ||
290 | udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph)); | |
291 | if (udph == NULL) | |
292 | return 0; | |
293 | ||
294 | ul = ntohs(udph->len); | |
295 | ||
296 | udph->check = 0; | |
297 | ||
298 | if (udplite) { | |
299 | if (ul == 0) | |
300 | skb->csum = csum_partial(udph, ipl - ihl, 0); | |
301 | ||
302 | else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl)) | |
303 | skb->csum = csum_partial(udph, ul, 0); | |
304 | ||
305 | else | |
306 | goto ignore_obscure_skb; | |
307 | } else { | |
308 | if (ul != ipl - ihl) | |
309 | goto ignore_obscure_skb; | |
310 | ||
311 | skb->csum = csum_partial(udph, ul, 0); | |
312 | } | |
313 | ||
314 | udph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, ul, | |
315 | udplite ? IPPROTO_UDPLITE : IPPROTO_UDP, | |
316 | skb->csum); | |
317 | ||
318 | if (!udph->check) | |
319 | udph->check = CSUM_MANGLED_0; | |
320 | ||
321 | skb->ip_summed = CHECKSUM_NONE; | |
322 | ||
323 | ignore_obscure_skb: | |
324 | return 1; | |
325 | } | |
326 | ||
327 | static int tcf_csum_ipv4(struct sk_buff *skb, u32 update_flags) | |
328 | { | |
329 | struct iphdr *iph; | |
330 | int ntkoff; | |
331 | ||
332 | ntkoff = skb_network_offset(skb); | |
333 | ||
334 | if (!pskb_may_pull(skb, sizeof(*iph) + ntkoff)) | |
335 | goto fail; | |
336 | ||
337 | iph = ip_hdr(skb); | |
338 | ||
339 | switch (iph->frag_off & htons(IP_OFFSET) ? 0 : iph->protocol) { | |
340 | case IPPROTO_ICMP: | |
341 | if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP) | |
342 | if (!tcf_csum_ipv4_icmp(skb, | |
343 | iph->ihl * 4, ntohs(iph->tot_len))) | |
344 | goto fail; | |
345 | break; | |
346 | case IPPROTO_IGMP: | |
347 | if (update_flags & TCA_CSUM_UPDATE_FLAG_IGMP) | |
348 | if (!tcf_csum_ipv4_igmp(skb, | |
349 | iph->ihl * 4, ntohs(iph->tot_len))) | |
350 | goto fail; | |
351 | break; | |
352 | case IPPROTO_TCP: | |
353 | if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP) | |
354 | if (!tcf_csum_ipv4_tcp(skb, iph, | |
355 | iph->ihl * 4, ntohs(iph->tot_len))) | |
356 | goto fail; | |
357 | break; | |
358 | case IPPROTO_UDP: | |
359 | if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP) | |
360 | if (!tcf_csum_ipv4_udp(skb, iph, | |
361 | iph->ihl * 4, ntohs(iph->tot_len), 0)) | |
362 | goto fail; | |
363 | break; | |
364 | case IPPROTO_UDPLITE: | |
365 | if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE) | |
366 | if (!tcf_csum_ipv4_udp(skb, iph, | |
367 | iph->ihl * 4, ntohs(iph->tot_len), 1)) | |
368 | goto fail; | |
369 | break; | |
370 | } | |
371 | ||
372 | if (update_flags & TCA_CSUM_UPDATE_FLAG_IPV4HDR) { | |
373 | if (skb_cloned(skb) && | |
374 | !skb_clone_writable(skb, sizeof(*iph) + ntkoff) && | |
375 | pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) | |
376 | goto fail; | |
377 | ||
378 | ip_send_check(iph); | |
379 | } | |
380 | ||
381 | return 1; | |
382 | ||
383 | fail: | |
384 | return 0; | |
385 | } | |
386 | ||
387 | static int tcf_csum_ipv6_hopopts(struct ipv6_opt_hdr *ip6xh, | |
388 | unsigned int ixhl, unsigned int *pl) | |
389 | { | |
390 | int off, len, optlen; | |
391 | unsigned char *xh = (void *)ip6xh; | |
392 | ||
393 | off = sizeof(*ip6xh); | |
394 | len = ixhl - off; | |
395 | ||
396 | while (len > 1) { | |
397 | switch (xh[off]) | |
398 | { | |
399 | case IPV6_TLV_PAD0: | |
400 | optlen = 1; | |
401 | break; | |
402 | case IPV6_TLV_JUMBO: | |
403 | optlen = xh[off + 1] + 2; | |
404 | if (optlen != 6 || len < 6 || (off & 3) != 2) | |
405 | /* wrong jumbo option length/alignment */ | |
406 | return 0; | |
407 | *pl = ntohl(*(__be32 *)(xh + off + 2)); | |
408 | goto done; | |
409 | default: | |
410 | optlen = xh[off + 1] + 2; | |
411 | if (optlen > len) | |
412 | /* ignore obscure options */ | |
413 | goto done; | |
414 | break; | |
415 | } | |
416 | off += optlen; | |
417 | len -= optlen; | |
418 | } | |
419 | ||
420 | done: | |
421 | return 1; | |
422 | } | |
423 | ||
424 | static int tcf_csum_ipv6(struct sk_buff *skb, u32 update_flags) | |
425 | { | |
426 | struct ipv6hdr *ip6h; | |
427 | struct ipv6_opt_hdr *ip6xh; | |
428 | unsigned int hl, ixhl; | |
429 | unsigned int pl; | |
430 | int ntkoff; | |
431 | u8 nexthdr; | |
432 | ||
433 | ntkoff = skb_network_offset(skb); | |
434 | ||
435 | hl = sizeof(*ip6h); | |
436 | ||
437 | if (!pskb_may_pull(skb, hl + ntkoff)) | |
438 | goto fail; | |
439 | ||
440 | ip6h = ipv6_hdr(skb); | |
441 | ||
442 | pl = ntohs(ip6h->payload_len); | |
443 | nexthdr = ip6h->nexthdr; | |
444 | ||
445 | do { | |
446 | switch (nexthdr) { | |
447 | case NEXTHDR_FRAGMENT: | |
448 | goto ignore_skb; | |
449 | case NEXTHDR_ROUTING: | |
450 | case NEXTHDR_HOP: | |
451 | case NEXTHDR_DEST: | |
452 | if (!pskb_may_pull(skb, hl + sizeof(*ip6xh) + ntkoff)) | |
453 | goto fail; | |
454 | ip6xh = (void *)(skb_network_header(skb) + hl); | |
455 | ixhl = ipv6_optlen(ip6xh); | |
456 | if (!pskb_may_pull(skb, hl + ixhl + ntkoff)) | |
457 | goto fail; | |
458 | if ((nexthdr == NEXTHDR_HOP) && | |
459 | !(tcf_csum_ipv6_hopopts(ip6xh, ixhl, &pl))) | |
460 | goto fail; | |
461 | nexthdr = ip6xh->nexthdr; | |
462 | hl += ixhl; | |
463 | break; | |
464 | case IPPROTO_ICMPV6: | |
465 | if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP) | |
466 | if (!tcf_csum_ipv6_icmp(skb, ip6h, | |
467 | hl, pl + sizeof(*ip6h))) | |
468 | goto fail; | |
469 | goto done; | |
470 | case IPPROTO_TCP: | |
471 | if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP) | |
472 | if (!tcf_csum_ipv6_tcp(skb, ip6h, | |
473 | hl, pl + sizeof(*ip6h))) | |
474 | goto fail; | |
475 | goto done; | |
476 | case IPPROTO_UDP: | |
477 | if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP) | |
478 | if (!tcf_csum_ipv6_udp(skb, ip6h, | |
479 | hl, pl + sizeof(*ip6h), 0)) | |
480 | goto fail; | |
481 | goto done; | |
482 | case IPPROTO_UDPLITE: | |
483 | if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE) | |
484 | if (!tcf_csum_ipv6_udp(skb, ip6h, | |
485 | hl, pl + sizeof(*ip6h), 1)) | |
486 | goto fail; | |
487 | goto done; | |
488 | default: | |
489 | goto ignore_skb; | |
490 | } | |
491 | } while (pskb_may_pull(skb, hl + 1 + ntkoff)); | |
492 | ||
493 | done: | |
494 | ignore_skb: | |
495 | return 1; | |
496 | ||
497 | fail: | |
498 | return 0; | |
499 | } | |
500 | ||
501 | static int tcf_csum(struct sk_buff *skb, | |
502 | struct tc_action *a, struct tcf_result *res) | |
503 | { | |
504 | struct tcf_csum *p = a->priv; | |
505 | int action; | |
506 | u32 update_flags; | |
507 | ||
508 | spin_lock(&p->tcf_lock); | |
509 | p->tcf_tm.lastuse = jiffies; | |
510 | p->tcf_bstats.bytes += qdisc_pkt_len(skb); | |
511 | p->tcf_bstats.packets++; | |
512 | action = p->tcf_action; | |
513 | update_flags = p->update_flags; | |
514 | spin_unlock(&p->tcf_lock); | |
515 | ||
516 | if (unlikely(action == TC_ACT_SHOT)) | |
517 | goto drop; | |
518 | ||
519 | switch (skb->protocol) { | |
520 | case cpu_to_be16(ETH_P_IP): | |
521 | if (!tcf_csum_ipv4(skb, update_flags)) | |
522 | goto drop; | |
523 | break; | |
524 | case cpu_to_be16(ETH_P_IPV6): | |
525 | if (!tcf_csum_ipv6(skb, update_flags)) | |
526 | goto drop; | |
527 | break; | |
528 | } | |
529 | ||
530 | return action; | |
531 | ||
532 | drop: | |
533 | spin_lock(&p->tcf_lock); | |
534 | p->tcf_qstats.drops++; | |
535 | spin_unlock(&p->tcf_lock); | |
536 | return TC_ACT_SHOT; | |
537 | } | |
538 | ||
539 | static int tcf_csum_dump(struct sk_buff *skb, | |
540 | struct tc_action *a, int bind, int ref) | |
541 | { | |
542 | unsigned char *b = skb_tail_pointer(skb); | |
543 | struct tcf_csum *p = a->priv; | |
544 | struct tc_csum opt = { | |
545 | .update_flags = p->update_flags, | |
546 | ||
547 | .index = p->tcf_index, | |
548 | .action = p->tcf_action, | |
549 | .refcnt = p->tcf_refcnt - ref, | |
550 | .bindcnt = p->tcf_bindcnt - bind, | |
551 | }; | |
552 | struct tcf_t t; | |
553 | ||
554 | NLA_PUT(skb, TCA_CSUM_PARMS, sizeof(opt), &opt); | |
555 | t.install = jiffies_to_clock_t(jiffies - p->tcf_tm.install); | |
556 | t.lastuse = jiffies_to_clock_t(jiffies - p->tcf_tm.lastuse); | |
557 | t.expires = jiffies_to_clock_t(p->tcf_tm.expires); | |
558 | NLA_PUT(skb, TCA_CSUM_TM, sizeof(t), &t); | |
559 | ||
560 | return skb->len; | |
561 | ||
562 | nla_put_failure: | |
563 | nlmsg_trim(skb, b); | |
564 | return -1; | |
565 | } | |
566 | ||
567 | static struct tc_action_ops act_csum_ops = { | |
568 | .kind = "csum", | |
569 | .hinfo = &csum_hash_info, | |
570 | .type = TCA_ACT_CSUM, | |
571 | .capab = TCA_CAP_NONE, | |
572 | .owner = THIS_MODULE, | |
573 | .act = tcf_csum, | |
574 | .dump = tcf_csum_dump, | |
575 | .cleanup = tcf_csum_cleanup, | |
576 | .lookup = tcf_hash_search, | |
577 | .init = tcf_csum_init, | |
578 | .walk = tcf_generic_walker | |
579 | }; | |
580 | ||
581 | MODULE_DESCRIPTION("Checksum updating actions"); | |
582 | MODULE_LICENSE("GPL"); | |
583 | ||
584 | static int __init csum_init_module(void) | |
585 | { | |
586 | return tcf_register_action(&act_csum_ops); | |
587 | } | |
588 | ||
589 | static void __exit csum_cleanup_module(void) | |
590 | { | |
591 | tcf_unregister_action(&act_csum_ops); | |
592 | } | |
593 | ||
594 | module_init(csum_init_module); | |
595 | module_exit(csum_cleanup_module); |