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Merge tag 'xfs-5.4-merge-8' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
[linux-2.6-block.git] / net / netfilter / nfnetlink_cthelper.c
CommitLineData
e97150df 1// SPDX-License-Identifier: GPL-2.0-or-later
12f7a505
PNA		 2/*
3 * (C) 2012 Pablo Neira Ayuso <pablo@netfilter.org>
4 *
12f7a505
PNA		 5 * This software has been sponsored by Vyatta Inc. <http://www.vyatta.com>
6 */
7#include <linux/init.h>
8#include <linux/module.h>
9#include <linux/kernel.h>
10#include <linux/skbuff.h>
11#include <linux/netlink.h>
12#include <linux/rculist.h>
13#include <linux/slab.h>
14#include <linux/types.h>
15#include <linux/list.h>
16#include <linux/errno.h>
4b380c42 17#include <linux/capability.h>
12f7a505
PNA		 18#include <net/netlink.h>
19#include <net/sock.h>
20
21#include <net/netfilter/nf_conntrack_helper.h>
22#include <net/netfilter/nf_conntrack_expect.h>
23#include <net/netfilter/nf_conntrack_ecache.h>
24
25#include <linux/netfilter/nfnetlink.h>
26#include <linux/netfilter/nfnetlink_conntrack.h>
27#include <linux/netfilter/nfnetlink_cthelper.h>
28
29MODULE_LICENSE("GPL");
30MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
31MODULE_DESCRIPTION("nfnl_cthelper: User-space connection tracking helpers");
32
83d90219
LZ		 33struct nfnl_cthelper {
34 struct list_head list;
35 struct nf_conntrack_helper helper;
36};
37
38static LIST_HEAD(nfnl_cthelper_list);
39
12f7a505
PNA		 40static int
41nfnl_userspace_cthelper(struct sk_buff *skb, unsigned int protoff,
42 struct nf_conn *ct, enum ip_conntrack_info ctinfo)
43{
44 const struct nf_conn_help *help;
45 struct nf_conntrack_helper *helper;
46
47 help = nfct_help(ct);
48 if (help == NULL)
49 return NF_DROP;
50
e2361cb9 51 /* rcu_read_lock()ed by nf_hook_thresh */
12f7a505
PNA		 52 helper = rcu_dereference(help->helper);
53 if (helper == NULL)
54 return NF_DROP;
55
9332ef9d 56 /* This is a user-space helper not yet configured, skip. */
12f7a505
PNA		 57 if ((helper->flags &
58 (NF_CT_HELPER_F_USERSPACE | NF_CT_HELPER_F_CONFIGURED)) ==
59 NF_CT_HELPER_F_USERSPACE)
60 return NF_ACCEPT;
61
62 /* If the user-space helper is not available, don't block traffic. */
63 return NF_QUEUE_NR(helper->queue_num) | NF_VERDICT_FLAG_QUEUE_BYPASS;
64}
65
66static const struct nla_policy nfnl_cthelper_tuple_pol[NFCTH_TUPLE_MAX+1] = {
67 [NFCTH_TUPLE_L3PROTONUM] = { .type = NLA_U16, },
68 [NFCTH_TUPLE_L4PROTONUM] = { .type = NLA_U8, },
69};
70
71static int
72nfnl_cthelper_parse_tuple(struct nf_conntrack_tuple *tuple,
73 const struct nlattr *attr)
74{
130ffbc2 75 int err;
12f7a505
PNA		 76 struct nlattr *tb[NFCTH_TUPLE_MAX+1];
77
8cb08174
JB		 78 err = nla_parse_nested_deprecated(tb, NFCTH_TUPLE_MAX, attr,
79 nfnl_cthelper_tuple_pol, NULL);
130ffbc2
DB		 80 if (err < 0)
81 return err;
12f7a505
PNA		 82
83 if (!tb[NFCTH_TUPLE_L3PROTONUM] || !tb[NFCTH_TUPLE_L4PROTONUM])
84 return -EINVAL;
85
78146572
IW		 86 /* Not all fields are initialized so first zero the tuple */
87 memset(tuple, 0, sizeof(struct nf_conntrack_tuple));
88
fe31d1a8 89 tuple->src.l3num = ntohs(nla_get_be16(tb[NFCTH_TUPLE_L3PROTONUM]));
12f7a505
PNA		 90 tuple->dst.protonum = nla_get_u8(tb[NFCTH_TUPLE_L4PROTONUM]);
91
92 return 0;
93}
94
95static int
96nfnl_cthelper_from_nlattr(struct nlattr *attr, struct nf_conn *ct)
97{
b18c5d15 98 struct nf_conn_help *help = nfct_help(ct);
12f7a505 99
7be54ca4
PNA		 100 if (attr == NULL)
101 return -EINVAL;
102
12f7a505
PNA		 103 if (help->helper->data_len == 0)
104 return -EINVAL;
105
157ffffe 106 nla_memcpy(help->data, nla_data(attr), sizeof(help->data));
12f7a505
PNA		 107 return 0;
108}
109
110static int
111nfnl_cthelper_to_nlattr(struct sk_buff *skb, const struct nf_conn *ct)
112{
113 const struct nf_conn_help *help = nfct_help(ct);
114
115 if (help->helper->data_len &&
116 nla_put(skb, CTA_HELP_INFO, help->helper->data_len, &help->data))
117 goto nla_put_failure;
118
119 return 0;
120
121nla_put_failure:
122 return -ENOSPC;
123}
124
125static const struct nla_policy nfnl_cthelper_expect_pol[NFCTH_POLICY_MAX+1] = {
126 [NFCTH_POLICY_NAME] = { .type = NLA_NUL_STRING,
127 .len = NF_CT_HELPER_NAME_LEN-1 },
128 [NFCTH_POLICY_EXPECT_MAX] = { .type = NLA_U32, },
129 [NFCTH_POLICY_EXPECT_TIMEOUT] = { .type = NLA_U32, },
130};
131
132static int
133nfnl_cthelper_expect_policy(struct nf_conntrack_expect_policy *expect_policy,
134 const struct nlattr *attr)
135{
130ffbc2 136 int err;
12f7a505
PNA		 137 struct nlattr *tb[NFCTH_POLICY_MAX+1];
138
8cb08174
JB		 139 err = nla_parse_nested_deprecated(tb, NFCTH_POLICY_MAX, attr,
140 nfnl_cthelper_expect_pol, NULL);
130ffbc2
DB		 141 if (err < 0)
142 return err;
12f7a505
PNA		 143
144 if (!tb[NFCTH_POLICY_NAME] ||
145 !tb[NFCTH_POLICY_EXPECT_MAX] ||
146 !tb[NFCTH_POLICY_EXPECT_TIMEOUT])
147 return -EINVAL;
148
4e09fc87 149 nla_strlcpy(expect_policy->name,
4b83a904 150 tb[NFCTH_POLICY_NAME], NF_CT_HELPER_NAME_LEN);
12f7a505
PNA		 151 expect_policy->max_expected =
152 ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX]));
92f73221
GF		 153 if (expect_policy->max_expected > NF_CT_EXPECT_MAX_CNT)
154 return -EINVAL;
155
12f7a505
PNA		 156 expect_policy->timeout =
157 ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT]));
158
159 return 0;
160}
161
162static const struct nla_policy
163nfnl_cthelper_expect_policy_set[NFCTH_POLICY_SET_MAX+1] = {
164 [NFCTH_POLICY_SET_NUM] = { .type = NLA_U32, },
165};
166
167static int
168nfnl_cthelper_parse_expect_policy(struct nf_conntrack_helper *helper,
169 const struct nlattr *attr)
170{
171 int i, ret;
172 struct nf_conntrack_expect_policy *expect_policy;
173 struct nlattr *tb[NFCTH_POLICY_SET_MAX+1];
ae5c6821 174 unsigned int class_max;
12f7a505 175
8cb08174
JB		 176 ret = nla_parse_nested_deprecated(tb, NFCTH_POLICY_SET_MAX, attr,
177 nfnl_cthelper_expect_policy_set,
178 NULL);
130ffbc2
DB		 179 if (ret < 0)
180 return ret;
12f7a505
PNA		 181
182 if (!tb[NFCTH_POLICY_SET_NUM])
183 return -EINVAL;
184
ae5c6821
LZ		 185 class_max = ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM]));
186 if (class_max == 0)
187 return -EINVAL;
188 if (class_max > NF_CT_MAX_EXPECT_CLASSES)
12f7a505
PNA		 189 return -EOVERFLOW;
190
6396bb22
KC		 191 expect_policy = kcalloc(class_max,
192 sizeof(struct nf_conntrack_expect_policy),
193 GFP_KERNEL);
12f7a505
PNA		 194 if (expect_policy == NULL)
195 return -ENOMEM;
196
ae5c6821 197 for (i = 0; i < class_max; i++) {
12f7a505
PNA		 198 if (!tb[NFCTH_POLICY_SET+i])
199 goto err;
200
201 ret = nfnl_cthelper_expect_policy(&expect_policy[i],
202 tb[NFCTH_POLICY_SET+i]);
203 if (ret < 0)
204 goto err;
205 }
ae5c6821
LZ		 206
207 helper->expect_class_max = class_max - 1;
12f7a505
PNA		 208 helper->expect_policy = expect_policy;
209 return 0;
210err:
211 kfree(expect_policy);
212 return -EINVAL;
213}
214
215static int
216nfnl_cthelper_create(const struct nlattr * const tb[],
217 struct nf_conntrack_tuple *tuple)
218{
219 struct nf_conntrack_helper *helper;
83d90219 220 struct nfnl_cthelper *nfcth;
157ffffe 221 unsigned int size;
12f7a505
PNA		 222 int ret;
223
224 if (!tb[NFCTH_TUPLE] || !tb[NFCTH_POLICY] || !tb[NFCTH_PRIV_DATA_LEN])
225 return -EINVAL;
226
83d90219
LZ		 227 nfcth = kzalloc(sizeof(*nfcth), GFP_KERNEL);
228 if (nfcth == NULL)
12f7a505 229 return -ENOMEM;
83d90219 230 helper = &nfcth->helper;
12f7a505
PNA		 231
232 ret = nfnl_cthelper_parse_expect_policy(helper, tb[NFCTH_POLICY]);
233 if (ret < 0)
f83bf8da 234 goto err1;
12f7a505 235
4e09fc87 236 nla_strlcpy(helper->name,
4b83a904 237 tb[NFCTH_NAME], NF_CT_HELPER_NAME_LEN);
157ffffe
FW		 238 size = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN]));
239 if (size > FIELD_SIZEOF(struct nf_conn_help, data)) {
240 ret = -ENOMEM;
241 goto err2;
242 }
243
12f7a505
PNA		 244 helper->flags |= NF_CT_HELPER_F_USERSPACE;
245 memcpy(&helper->tuple, tuple, sizeof(struct nf_conntrack_tuple));
246
247 helper->me = THIS_MODULE;
248 helper->help = nfnl_userspace_cthelper;
249 helper->from_nlattr = nfnl_cthelper_from_nlattr;
250 helper->to_nlattr = nfnl_cthelper_to_nlattr;
251
252 /* Default to queue number zero, this can be updated at any time. */
253 if (tb[NFCTH_QUEUE_NUM])
254 helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM]));
255
256 if (tb[NFCTH_STATUS]) {
257 int status = ntohl(nla_get_be32(tb[NFCTH_STATUS]));
258
259 switch(status) {
260 case NFCT_HELPER_STATUS_ENABLED:
261 helper->flags |= NF_CT_HELPER_F_CONFIGURED;
262 break;
263 case NFCT_HELPER_STATUS_DISABLED:
264 helper->flags &= ~NF_CT_HELPER_F_CONFIGURED;
265 break;
266 }
267 }
268
269 ret = nf_conntrack_helper_register(helper);
270 if (ret < 0)
f83bf8da 271 goto err2;
12f7a505 272
83d90219 273 list_add_tail(&nfcth->list, &nfnl_cthelper_list);
12f7a505 274 return 0;
f83bf8da
JC		 275err2:
276 kfree(helper->expect_policy);
277err1:
83d90219 278 kfree(nfcth);
12f7a505
PNA		 279 return ret;
280}
281
2c422257
PNA		 282static int
283nfnl_cthelper_update_policy_one(const struct nf_conntrack_expect_policy *policy,
284 struct nf_conntrack_expect_policy *new_policy,
285 const struct nlattr *attr)
286{
287 struct nlattr *tb[NFCTH_POLICY_MAX + 1];
288 int err;
289
8cb08174
JB		 290 err = nla_parse_nested_deprecated(tb, NFCTH_POLICY_MAX, attr,
291 nfnl_cthelper_expect_pol, NULL);
2c422257
PNA		 292 if (err < 0)
293 return err;
294
295 if (!tb[NFCTH_POLICY_NAME] ||
296 !tb[NFCTH_POLICY_EXPECT_MAX] ||
297 !tb[NFCTH_POLICY_EXPECT_TIMEOUT])
298 return -EINVAL;
299
300 if (nla_strcmp(tb[NFCTH_POLICY_NAME], policy->name))
301 return -EBUSY;
302
303 new_policy->max_expected =
304 ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX]));
92f73221
GF		 305 if (new_policy->max_expected > NF_CT_EXPECT_MAX_CNT)
306 return -EINVAL;
307
2c422257
PNA		 308 new_policy->timeout =
309 ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT]));
310
311 return 0;
312}
313
314static int nfnl_cthelper_update_policy_all(struct nlattr *tb[],
315 struct nf_conntrack_helper *helper)
316{
14463859 317 struct nf_conntrack_expect_policy *new_policy;
2c422257 318 struct nf_conntrack_expect_policy *policy;
14463859
GS		 319 int i, ret = 0;
320
321 new_policy = kmalloc_array(helper->expect_class_max + 1,
322 sizeof(*new_policy), GFP_KERNEL);
323 if (!new_policy)
324 return -ENOMEM;
2c422257
PNA		 325
326 /* Check first that all policy attributes are well-formed, so we don't
327 * leave things in inconsistent state on errors.
328 */
329 for (i = 0; i < helper->expect_class_max + 1; i++) {
330
14463859
GS		 331 if (!tb[NFCTH_POLICY_SET + i]) {
332 ret = -EINVAL;
333 goto err;
334 }
2c422257 335
14463859 336 ret = nfnl_cthelper_update_policy_one(&helper->expect_policy[i],
2c422257
PNA		 337 &new_policy[i],
338 tb[NFCTH_POLICY_SET + i]);
14463859
GS		 339 if (ret < 0)
340 goto err;
2c422257
PNA		 341 }
342 /* Now we can safely update them. */
343 for (i = 0; i < helper->expect_class_max + 1; i++) {
344 policy = (struct nf_conntrack_expect_policy *)
345 &helper->expect_policy[i];
346 policy->max_expected = new_policy->max_expected;
347 policy->timeout = new_policy->timeout;
348 }
349
14463859
GS		 350err:
351 kfree(new_policy);
352 return ret;
2c422257
PNA		 353}
354
355static int nfnl_cthelper_update_policy(struct nf_conntrack_helper *helper,
356 const struct nlattr *attr)
357{
358 struct nlattr *tb[NFCTH_POLICY_SET_MAX + 1];
359 unsigned int class_max;
360 int err;
361
8cb08174
JB		 362 err = nla_parse_nested_deprecated(tb, NFCTH_POLICY_SET_MAX, attr,
363 nfnl_cthelper_expect_policy_set,
364 NULL);
2c422257
PNA		 365 if (err < 0)
366 return err;
367
368 if (!tb[NFCTH_POLICY_SET_NUM])
369 return -EINVAL;
370
371 class_max = ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM]));
372 if (helper->expect_class_max + 1 != class_max)
373 return -EBUSY;
374
375 return nfnl_cthelper_update_policy_all(tb, helper);
376}
377
12f7a505
PNA		 378static int
379nfnl_cthelper_update(const struct nlattr * const tb[],
380 struct nf_conntrack_helper *helper)
381{
382 int ret;
383
384 if (tb[NFCTH_PRIV_DATA_LEN])
385 return -EBUSY;
386
387 if (tb[NFCTH_POLICY]) {
2c422257 388 ret = nfnl_cthelper_update_policy(helper, tb[NFCTH_POLICY]);
12f7a505
PNA		 389 if (ret < 0)
390 return ret;
391 }
392 if (tb[NFCTH_QUEUE_NUM])
393 helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM]));
394
395 if (tb[NFCTH_STATUS]) {
396 int status = ntohl(nla_get_be32(tb[NFCTH_STATUS]));
397
398 switch(status) {
399 case NFCT_HELPER_STATUS_ENABLED:
400 helper->flags |= NF_CT_HELPER_F_CONFIGURED;
401 break;
402 case NFCT_HELPER_STATUS_DISABLED:
403 helper->flags &= ~NF_CT_HELPER_F_CONFIGURED;
404 break;
405 }
406 }
407 return 0;
408}
409
7b8002a1
PNA		 410static int nfnl_cthelper_new(struct net *net, struct sock *nfnl,
411 struct sk_buff *skb, const struct nlmsghdr *nlh,
04ba724b
PNA		 412 const struct nlattr * const tb[],
413 struct netlink_ext_ack *extack)
12f7a505
PNA		 414{
415 const char *helper_name;
416 struct nf_conntrack_helper *cur, *helper = NULL;
417 struct nf_conntrack_tuple tuple;
83d90219
LZ		 418 struct nfnl_cthelper *nlcth;
419 int ret = 0;
12f7a505 420
4b380c42
KC		 421 if (!capable(CAP_NET_ADMIN))
422 return -EPERM;
423
12f7a505
PNA		 424 if (!tb[NFCTH_NAME] || !tb[NFCTH_TUPLE])
425 return -EINVAL;
426
427 helper_name = nla_data(tb[NFCTH_NAME]);
428
429 ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
430 if (ret < 0)
431 return ret;
432
83d90219
LZ		 433 list_for_each_entry(nlcth, &nfnl_cthelper_list, list) {
434 cur = &nlcth->helper;
12f7a505 435
83d90219
LZ		 436 if (strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN))
437 continue;
12f7a505 438
83d90219
LZ		 439 if ((tuple.src.l3num != cur->tuple.src.l3num ||
440 tuple.dst.protonum != cur->tuple.dst.protonum))
441 continue;
12f7a505 442
83d90219
LZ		 443 if (nlh->nlmsg_flags & NLM_F_EXCL)
444 return -EEXIST;
12f7a505 445
83d90219
LZ		 446 helper = cur;
447 break;
12f7a505 448 }
12f7a505
PNA		 449
450 if (helper == NULL)
451 ret = nfnl_cthelper_create(tb, &tuple);
452 else
453 ret = nfnl_cthelper_update(tb, helper);
454
455 return ret;
12f7a505
PNA		 456}
457
458static int
459nfnl_cthelper_dump_tuple(struct sk_buff *skb,
460 struct nf_conntrack_helper *helper)
461{
462 struct nlattr *nest_parms;
463
ae0be8de 464 nest_parms = nla_nest_start(skb, NFCTH_TUPLE);
12f7a505
PNA		 465 if (nest_parms == NULL)
466 goto nla_put_failure;
467
468 if (nla_put_be16(skb, NFCTH_TUPLE_L3PROTONUM,
469 htons(helper->tuple.src.l3num)))
470 goto nla_put_failure;
471
472 if (nla_put_u8(skb, NFCTH_TUPLE_L4PROTONUM, helper->tuple.dst.protonum))
473 goto nla_put_failure;
474
475 nla_nest_end(skb, nest_parms);
476 return 0;
477
478nla_put_failure:
479 return -1;
480}
481
482static int
483nfnl_cthelper_dump_policy(struct sk_buff *skb,
484 struct nf_conntrack_helper *helper)
485{
486 int i;
487 struct nlattr *nest_parms1, *nest_parms2;
488
ae0be8de 489 nest_parms1 = nla_nest_start(skb, NFCTH_POLICY);
12f7a505
PNA		 490 if (nest_parms1 == NULL)
491 goto nla_put_failure;
492
493 if (nla_put_be32(skb, NFCTH_POLICY_SET_NUM,
ae5c6821 494 htonl(helper->expect_class_max + 1)))
12f7a505
PNA		 495 goto nla_put_failure;
496
ae5c6821 497 for (i = 0; i < helper->expect_class_max + 1; i++) {
ae0be8de 498 nest_parms2 = nla_nest_start(skb, (NFCTH_POLICY_SET + i));
12f7a505
PNA		 499 if (nest_parms2 == NULL)
500 goto nla_put_failure;
501
502 if (nla_put_string(skb, NFCTH_POLICY_NAME,
503 helper->expect_policy[i].name))
504 goto nla_put_failure;
505
506 if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_MAX,
507 htonl(helper->expect_policy[i].max_expected)))
508 goto nla_put_failure;
509
510 if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_TIMEOUT,
511 htonl(helper->expect_policy[i].timeout)))
512 goto nla_put_failure;
513
514 nla_nest_end(skb, nest_parms2);
515 }
516 nla_nest_end(skb, nest_parms1);
517 return 0;
518
519nla_put_failure:
520 return -1;
521}
522
523static int
15e47304 524nfnl_cthelper_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
12f7a505
PNA		 525 int event, struct nf_conntrack_helper *helper)
526{
527 struct nlmsghdr *nlh;
528 struct nfgenmsg *nfmsg;
15e47304 529 unsigned int flags = portid ? NLM_F_MULTI : 0;
12f7a505
PNA		 530 int status;
531
dedb67c4 532 event = nfnl_msg_type(NFNL_SUBSYS_CTHELPER, event);
15e47304 533 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
12f7a505
PNA		 534 if (nlh == NULL)
535 goto nlmsg_failure;
536
537 nfmsg = nlmsg_data(nlh);
538 nfmsg->nfgen_family = AF_UNSPEC;
539 nfmsg->version = NFNETLINK_V0;
540 nfmsg->res_id = 0;
541
542 if (nla_put_string(skb, NFCTH_NAME, helper->name))
543 goto nla_put_failure;
544
545 if (nla_put_be32(skb, NFCTH_QUEUE_NUM, htonl(helper->queue_num)))
546 goto nla_put_failure;
547
548 if (nfnl_cthelper_dump_tuple(skb, helper) < 0)
549 goto nla_put_failure;
550
551 if (nfnl_cthelper_dump_policy(skb, helper) < 0)
552 goto nla_put_failure;
553
554 if (nla_put_be32(skb, NFCTH_PRIV_DATA_LEN, htonl(helper->data_len)))
555 goto nla_put_failure;
556
557 if (helper->flags & NF_CT_HELPER_F_CONFIGURED)
558 status = NFCT_HELPER_STATUS_ENABLED;
559 else
560 status = NFCT_HELPER_STATUS_DISABLED;
561
562 if (nla_put_be32(skb, NFCTH_STATUS, htonl(status)))
563 goto nla_put_failure;
564
565 nlmsg_end(skb, nlh);
566 return skb->len;
567
568nlmsg_failure:
569nla_put_failure:
570 nlmsg_cancel(skb, nlh);
571 return -1;
572}
573
574static int
575nfnl_cthelper_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
576{
577 struct nf_conntrack_helper *cur, *last;
12f7a505
PNA		 578
579 rcu_read_lock();
580 last = (struct nf_conntrack_helper *)cb->args[1];
581 for (; cb->args[0] < nf_ct_helper_hsize; cb->args[0]++) {
582restart:
b67bfe0d 583 hlist_for_each_entry_rcu(cur,
12f7a505
PNA		 584 &nf_ct_helper_hash[cb->args[0]], hnode) {
585
586 /* skip non-userspace conntrack helpers. */
587 if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
588 continue;
589
590 if (cb->args[1]) {
591 if (cur != last)
592 continue;
593 cb->args[1] = 0;
594 }
595 if (nfnl_cthelper_fill_info(skb,
15e47304 596 NETLINK_CB(cb->skb).portid,
12f7a505
PNA		 597 cb->nlh->nlmsg_seq,
598 NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
599 NFNL_MSG_CTHELPER_NEW, cur) < 0) {
600 cb->args[1] = (unsigned long)cur;
601 goto out;
602 }
603 }
604 }
605 if (cb->args[1]) {
606 cb->args[1] = 0;
607 goto restart;
608 }
609out:
610 rcu_read_unlock();
611 return skb->len;
612}
613
7b8002a1
PNA		 614static int nfnl_cthelper_get(struct net *net, struct sock *nfnl,
615 struct sk_buff *skb, const struct nlmsghdr *nlh,
04ba724b
PNA		 616 const struct nlattr * const tb[],
617 struct netlink_ext_ack *extack)
12f7a505 618{
83d90219 619 int ret = -ENOENT;
12f7a505 620 struct nf_conntrack_helper *cur;
12f7a505
PNA		 621 struct sk_buff *skb2;
622 char *helper_name = NULL;
623 struct nf_conntrack_tuple tuple;
83d90219 624 struct nfnl_cthelper *nlcth;
12f7a505
PNA		 625 bool tuple_set = false;
626
4b380c42
KC		 627 if (!capable(CAP_NET_ADMIN))
628 return -EPERM;
629
12f7a505
PNA		 630 if (nlh->nlmsg_flags & NLM_F_DUMP) {
631 struct netlink_dump_control c = {
632 .dump = nfnl_cthelper_dump_table,
633 };
634 return netlink_dump_start(nfnl, skb, nlh, &c);
635 }
636
637 if (tb[NFCTH_NAME])
638 helper_name = nla_data(tb[NFCTH_NAME]);
639
640 if (tb[NFCTH_TUPLE]) {
641 ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
642 if (ret < 0)
643 return ret;
644
645 tuple_set = true;
646 }
647
83d90219
LZ		 648 list_for_each_entry(nlcth, &nfnl_cthelper_list, list) {
649 cur = &nlcth->helper;
650 if (helper_name &&
651 strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN))
652 continue;
12f7a505 653
83d90219
LZ		 654 if (tuple_set &&
655 (tuple.src.l3num != cur->tuple.src.l3num ||
656 tuple.dst.protonum != cur->tuple.dst.protonum))
657 continue;
12f7a505 658
83d90219
LZ		 659 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
660 if (skb2 == NULL) {
661 ret = -ENOMEM;
662 break;
663 }
12f7a505 664
83d90219
LZ		 665 ret = nfnl_cthelper_fill_info(skb2, NETLINK_CB(skb).portid,
666 nlh->nlmsg_seq,
667 NFNL_MSG_TYPE(nlh->nlmsg_type),
668 NFNL_MSG_CTHELPER_NEW, cur);
669 if (ret <= 0) {
670 kfree_skb(skb2);
671 break;
672 }
12f7a505 673
83d90219
LZ		 674 ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
675 MSG_DONTWAIT);
676 if (ret > 0)
677 ret = 0;
12f7a505 678
83d90219
LZ		 679 /* this avoids a loop in nfnetlink. */
680 return ret == -EAGAIN ? -ENOBUFS : ret;
12f7a505
PNA		 681 }
682 return ret;
683}
684
7b8002a1
PNA		 685static int nfnl_cthelper_del(struct net *net, struct sock *nfnl,
686 struct sk_buff *skb, const struct nlmsghdr *nlh,
04ba724b
PNA		 687 const struct nlattr * const tb[],
688 struct netlink_ext_ack *extack)
12f7a505
PNA		 689{
690 char *helper_name = NULL;
691 struct nf_conntrack_helper *cur;
12f7a505
PNA		 692 struct nf_conntrack_tuple tuple;
693 bool tuple_set = false, found = false;
83d90219
LZ		 694 struct nfnl_cthelper *nlcth, *n;
695 int j = 0, ret;
12f7a505 696
4b380c42
KC		 697 if (!capable(CAP_NET_ADMIN))
698 return -EPERM;
699
12f7a505
PNA		 700 if (tb[NFCTH_NAME])
701 helper_name = nla_data(tb[NFCTH_NAME]);
702
703 if (tb[NFCTH_TUPLE]) {
704 ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
705 if (ret < 0)
706 return ret;
707
708 tuple_set = true;
709 }
710
9338d7b4 711 ret = -ENOENT;
83d90219
LZ		 712 list_for_each_entry_safe(nlcth, n, &nfnl_cthelper_list, list) {
713 cur = &nlcth->helper;
714 j++;
12f7a505 715
83d90219
LZ		 716 if (helper_name &&
717 strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN))
718 continue;
12f7a505 719
83d90219
LZ		 720 if (tuple_set &&
721 (tuple.src.l3num != cur->tuple.src.l3num ||
722 tuple.dst.protonum != cur->tuple.dst.protonum))
723 continue;
12f7a505 724
9338d7b4
LZ		 725 if (refcount_dec_if_one(&cur->refcnt)) {
726 found = true;
727 nf_conntrack_helper_unregister(cur);
728 kfree(cur->expect_policy);
83d90219 729
9338d7b4
LZ		 730 list_del(&nlcth->list);
731 kfree(nlcth);
732 } else {
733 ret = -EBUSY;
734 }
12f7a505 735 }
83d90219 736
12f7a505 737 /* Make sure we return success if we flush and there is no helpers */
9338d7b4 738 return (found || j == 0) ? 0 : ret;
12f7a505
PNA		 739}
740
741static const struct nla_policy nfnl_cthelper_policy[NFCTH_MAX+1] = {
742 [NFCTH_NAME] = { .type = NLA_NUL_STRING,
743 .len = NF_CT_HELPER_NAME_LEN-1 },
744 [NFCTH_QUEUE_NUM] = { .type = NLA_U32, },
745};
746
747static const struct nfnl_callback nfnl_cthelper_cb[NFNL_MSG_CTHELPER_MAX] = {
748 [NFNL_MSG_CTHELPER_NEW] = { .call = nfnl_cthelper_new,
749 .attr_count = NFCTH_MAX,
750 .policy = nfnl_cthelper_policy },
751 [NFNL_MSG_CTHELPER_GET] = { .call = nfnl_cthelper_get,
752 .attr_count = NFCTH_MAX,
753 .policy = nfnl_cthelper_policy },
754 [NFNL_MSG_CTHELPER_DEL] = { .call = nfnl_cthelper_del,
755 .attr_count = NFCTH_MAX,
756 .policy = nfnl_cthelper_policy },
757};
758
759static const struct nfnetlink_subsystem nfnl_cthelper_subsys = {
760 .name = "cthelper",
761 .subsys_id = NFNL_SUBSYS_CTHELPER,
762 .cb_count = NFNL_MSG_CTHELPER_MAX,
763 .cb = nfnl_cthelper_cb,
764};
765
766MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTHELPER);
767
768static int __init nfnl_cthelper_init(void)
769{
770 int ret;
771
772 ret = nfnetlink_subsys_register(&nfnl_cthelper_subsys);
773 if (ret < 0) {
774 pr_err("nfnl_cthelper: cannot register with nfnetlink.\n");
775 goto err_out;
776 }
777 return 0;
778err_out:
779 return ret;
780}
781
782static void __exit nfnl_cthelper_exit(void)
783{
784 struct nf_conntrack_helper *cur;
83d90219 785 struct nfnl_cthelper *nlcth, *n;
12f7a505
PNA		 786
787 nfnetlink_subsys_unregister(&nfnl_cthelper_subsys);
788
83d90219
LZ		 789 list_for_each_entry_safe(nlcth, n, &nfnl_cthelper_list, list) {
790 cur = &nlcth->helper;
12f7a505 791
83d90219
LZ		 792 nf_conntrack_helper_unregister(cur);
793 kfree(cur->expect_policy);
794 kfree(nlcth);
12f7a505
PNA		 795 }
796}
797
798module_init(nfnl_cthelper_init);
799module_exit(nfnl_cthelper_exit);
Linux 6.x block layer and io_uring tree(s)