1 /* Copyright (C) 2000-2002 Joakim Axelsson <gozem@linux.nu>
2  *                         Patrick Schaaf <bof@bof.de>
3  * Copyright (C) 2003-2013 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  */
9 
10 /* Kernel module for IP set management */
11 
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/moduleparam.h>
15 #include <linux/ip.h>
16 #include <linux/skbuff.h>
17 #include <linux/spinlock.h>
18 #include <linux/rculist.h>
19 #include <net/netlink.h>
20 #include <net/net_namespace.h>
21 #include <net/netns/generic.h>
22 
23 #include <linux/netfilter.h>
24 #include <linux/netfilter/x_tables.h>
25 #include <linux/netfilter/nfnetlink.h>
26 #include <linux/netfilter/ipset/ip_set.h>
27 
28 static LIST_HEAD(ip_set_type_list);		/* all registered set types */
29 static DEFINE_MUTEX(ip_set_type_mutex);		/* protects ip_set_type_list */
30 static DEFINE_RWLOCK(ip_set_ref_lock);		/* protects the set refs */
31 
32 struct ip_set_net {
33 	struct ip_set * __rcu *ip_set_list;	/* all individual sets */
34 	ip_set_id_t	ip_set_max;	/* max number of sets */
35 	bool		is_deleted;	/* deleted by ip_set_net_exit */
36 	bool		is_destroyed;	/* all sets are destroyed */
37 };
38 
39 static unsigned int ip_set_net_id __read_mostly;
40 
41 static inline struct ip_set_net *ip_set_pernet(struct net *net)
42 {
43 	return net_generic(net, ip_set_net_id);
44 }
45 
46 #define IP_SET_INC	64
47 #define STRNCMP(a, b)	(strncmp(a, b, IPSET_MAXNAMELEN) == 0)
48 
49 static unsigned int max_sets;
50 
51 module_param(max_sets, int, 0600);
52 MODULE_PARM_DESC(max_sets, "maximal number of sets");
53 MODULE_LICENSE("GPL");
54 MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>");
55 MODULE_DESCRIPTION("core IP set support");
56 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_IPSET);
57 
58 /* When the nfnl mutex is held: */
59 #define ip_set_dereference(p)		\
60 	rcu_dereference_protected(p, lockdep_nfnl_is_held(NFNL_SUBSYS_IPSET))
61 #define ip_set(inst, id)		\
62 	ip_set_dereference((inst)->ip_set_list)[id]
63 
64 /* The set types are implemented in modules and registered set types
65  * can be found in ip_set_type_list. Adding/deleting types is
66  * serialized by ip_set_type_mutex.
67  */
68 
69 static inline void
70 ip_set_type_lock(void)
71 {
72 	mutex_lock(&ip_set_type_mutex);
73 }
74 
75 static inline void
76 ip_set_type_unlock(void)
77 {
78 	mutex_unlock(&ip_set_type_mutex);
79 }
80 
81 /* Register and deregister settype */
82 
83 static struct ip_set_type *
84 find_set_type(const char *name, u8 family, u8 revision)
85 {
86 	struct ip_set_type *type;
87 
88 	list_for_each_entry_rcu(type, &ip_set_type_list, list)
89 		if (STRNCMP(type->name, name) &&
90 		    (type->family == family ||
91 		     type->family == NFPROTO_UNSPEC) &&
92 		    revision >= type->revision_min &&
93 		    revision <= type->revision_max)
94 			return type;
95 	return NULL;
96 }
97 
98 /* Unlock, try to load a set type module and lock again */
99 static bool
100 load_settype(const char *name)
101 {
102 	nfnl_unlock(NFNL_SUBSYS_IPSET);
103 	pr_debug("try to load ip_set_%s\n", name);
104 	if (request_module("ip_set_%s", name) < 0) {
105 		pr_warn("Can't find ip_set type %s\n", name);
106 		nfnl_lock(NFNL_SUBSYS_IPSET);
107 		return false;
108 	}
109 	nfnl_lock(NFNL_SUBSYS_IPSET);
110 	return true;
111 }
112 
113 /* Find a set type and reference it */
114 #define find_set_type_get(name, family, revision, found)	\
115 	__find_set_type_get(name, family, revision, found, false)
116 
117 static int
118 __find_set_type_get(const char *name, u8 family, u8 revision,
119 		    struct ip_set_type **found, bool retry)
120 {
121 	struct ip_set_type *type;
122 	int err;
123 
124 	if (retry && !load_settype(name))
125 		return -IPSET_ERR_FIND_TYPE;
126 
127 	rcu_read_lock();
128 	*found = find_set_type(name, family, revision);
129 	if (*found) {
130 		err = !try_module_get((*found)->me) ? -EFAULT : 0;
131 		goto unlock;
132 	}
133 	/* Make sure the type is already loaded
134 	 * but we don't support the revision
135 	 */
136 	list_for_each_entry_rcu(type, &ip_set_type_list, list)
137 		if (STRNCMP(type->name, name)) {
138 			err = -IPSET_ERR_FIND_TYPE;
139 			goto unlock;
140 		}
141 	rcu_read_unlock();
142 
143 	return retry ? -IPSET_ERR_FIND_TYPE :
144 		__find_set_type_get(name, family, revision, found, true);
145 
146 unlock:
147 	rcu_read_unlock();
148 	return err;
149 }
150 
151 /* Find a given set type by name and family.
152  * If we succeeded, the supported minimal and maximum revisions are
153  * filled out.
154  */
155 #define find_set_type_minmax(name, family, min, max) \
156 	__find_set_type_minmax(name, family, min, max, false)
157 
158 static int
159 __find_set_type_minmax(const char *name, u8 family, u8 *min, u8 *max,
160 		       bool retry)
161 {
162 	struct ip_set_type *type;
163 	bool found = false;
164 
165 	if (retry && !load_settype(name))
166 		return -IPSET_ERR_FIND_TYPE;
167 
168 	*min = 255; *max = 0;
169 	rcu_read_lock();
170 	list_for_each_entry_rcu(type, &ip_set_type_list, list)
171 		if (STRNCMP(type->name, name) &&
172 		    (type->family == family ||
173 		     type->family == NFPROTO_UNSPEC)) {
174 			found = true;
175 			if (type->revision_min < *min)
176 				*min = type->revision_min;
177 			if (type->revision_max > *max)
178 				*max = type->revision_max;
179 		}
180 	rcu_read_unlock();
181 	if (found)
182 		return 0;
183 
184 	return retry ? -IPSET_ERR_FIND_TYPE :
185 		__find_set_type_minmax(name, family, min, max, true);
186 }
187 
188 #define family_name(f)	((f) == NFPROTO_IPV4 ? "inet" : \
189 			 (f) == NFPROTO_IPV6 ? "inet6" : "any")
190 
191 /* Register a set type structure. The type is identified by
192  * the unique triple of name, family and revision.
193  */
194 int
195 ip_set_type_register(struct ip_set_type *type)
196 {
197 	int ret = 0;
198 
199 	if (type->protocol != IPSET_PROTOCOL) {
200 		pr_warn("ip_set type %s, family %s, revision %u:%u uses wrong protocol version %u (want %u)\n",
201 			type->name, family_name(type->family),
202 			type->revision_min, type->revision_max,
203 			type->protocol, IPSET_PROTOCOL);
204 		return -EINVAL;
205 	}
206 
207 	ip_set_type_lock();
208 	if (find_set_type(type->name, type->family, type->revision_min)) {
209 		/* Duplicate! */
210 		pr_warn("ip_set type %s, family %s with revision min %u already registered!\n",
211 			type->name, family_name(type->family),
212 			type->revision_min);
213 		ip_set_type_unlock();
214 		return -EINVAL;
215 	}
216 	list_add_rcu(&type->list, &ip_set_type_list);
217 	pr_debug("type %s, family %s, revision %u:%u registered.\n",
218 		 type->name, family_name(type->family),
219 		 type->revision_min, type->revision_max);
220 	ip_set_type_unlock();
221 
222 	return ret;
223 }
224 EXPORT_SYMBOL_GPL(ip_set_type_register);
225 
226 /* Unregister a set type. There's a small race with ip_set_create */
227 void
228 ip_set_type_unregister(struct ip_set_type *type)
229 {
230 	ip_set_type_lock();
231 	if (!find_set_type(type->name, type->family, type->revision_min)) {
232 		pr_warn("ip_set type %s, family %s with revision min %u not registered\n",
233 			type->name, family_name(type->family),
234 			type->revision_min);
235 		ip_set_type_unlock();
236 		return;
237 	}
238 	list_del_rcu(&type->list);
239 	pr_debug("type %s, family %s with revision min %u unregistered.\n",
240 		 type->name, family_name(type->family), type->revision_min);
241 	ip_set_type_unlock();
242 
243 	synchronize_rcu();
244 }
245 EXPORT_SYMBOL_GPL(ip_set_type_unregister);
246 
247 /* Utility functions */
248 void *
249 ip_set_alloc(size_t size)
250 {
251 	void *members = NULL;
252 
253 	if (size < KMALLOC_MAX_SIZE)
254 		members = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
255 
256 	if (members) {
257 		pr_debug("%p: allocated with kmalloc\n", members);
258 		return members;
259 	}
260 
261 	members = vzalloc(size);
262 	if (!members)
263 		return NULL;
264 	pr_debug("%p: allocated with vmalloc\n", members);
265 
266 	return members;
267 }
268 EXPORT_SYMBOL_GPL(ip_set_alloc);
269 
270 void
271 ip_set_free(void *members)
272 {
273 	pr_debug("%p: free with %s\n", members,
274 		 is_vmalloc_addr(members) ? "vfree" : "kfree");
275 	kvfree(members);
276 }
277 EXPORT_SYMBOL_GPL(ip_set_free);
278 
279 static inline bool
280 flag_nested(const struct nlattr *nla)
281 {
282 	return nla->nla_type & NLA_F_NESTED;
283 }
284 
285 static const struct nla_policy ipaddr_policy[IPSET_ATTR_IPADDR_MAX + 1] = {
286 	[IPSET_ATTR_IPADDR_IPV4]	= { .type = NLA_U32 },
287 	[IPSET_ATTR_IPADDR_IPV6]	= { .type = NLA_BINARY,
288 					    .len = sizeof(struct in6_addr) },
289 };
290 
291 int
292 ip_set_get_ipaddr4(struct nlattr *nla,  __be32 *ipaddr)
293 {
294 	struct nlattr *tb[IPSET_ATTR_IPADDR_MAX + 1];
295 
296 	if (unlikely(!flag_nested(nla)))
297 		return -IPSET_ERR_PROTOCOL;
298 	if (nla_parse_nested(tb, IPSET_ATTR_IPADDR_MAX, nla,
299 			     ipaddr_policy, NULL))
300 		return -IPSET_ERR_PROTOCOL;
301 	if (unlikely(!ip_set_attr_netorder(tb, IPSET_ATTR_IPADDR_IPV4)))
302 		return -IPSET_ERR_PROTOCOL;
303 
304 	*ipaddr = nla_get_be32(tb[IPSET_ATTR_IPADDR_IPV4]);
305 	return 0;
306 }
307 EXPORT_SYMBOL_GPL(ip_set_get_ipaddr4);
308 
309 int
310 ip_set_get_ipaddr6(struct nlattr *nla, union nf_inet_addr *ipaddr)
311 {
312 	struct nlattr *tb[IPSET_ATTR_IPADDR_MAX + 1];
313 
314 	if (unlikely(!flag_nested(nla)))
315 		return -IPSET_ERR_PROTOCOL;
316 
317 	if (nla_parse_nested(tb, IPSET_ATTR_IPADDR_MAX, nla,
318 			     ipaddr_policy, NULL))
319 		return -IPSET_ERR_PROTOCOL;
320 	if (unlikely(!ip_set_attr_netorder(tb, IPSET_ATTR_IPADDR_IPV6)))
321 		return -IPSET_ERR_PROTOCOL;
322 
323 	memcpy(ipaddr, nla_data(tb[IPSET_ATTR_IPADDR_IPV6]),
324 	       sizeof(struct in6_addr));
325 	return 0;
326 }
327 EXPORT_SYMBOL_GPL(ip_set_get_ipaddr6);
328 
329 typedef void (*destroyer)(struct ip_set *, void *);
330 /* ipset data extension types, in size order */
331 
332 const struct ip_set_ext_type ip_set_extensions[] = {
333 	[IPSET_EXT_ID_COUNTER] = {
334 		.type	= IPSET_EXT_COUNTER,
335 		.flag	= IPSET_FLAG_WITH_COUNTERS,
336 		.len	= sizeof(struct ip_set_counter),
337 		.align	= __alignof__(struct ip_set_counter),
338 	},
339 	[IPSET_EXT_ID_TIMEOUT] = {
340 		.type	= IPSET_EXT_TIMEOUT,
341 		.len	= sizeof(unsigned long),
342 		.align	= __alignof__(unsigned long),
343 	},
344 	[IPSET_EXT_ID_SKBINFO] = {
345 		.type	= IPSET_EXT_SKBINFO,
346 		.flag	= IPSET_FLAG_WITH_SKBINFO,
347 		.len	= sizeof(struct ip_set_skbinfo),
348 		.align	= __alignof__(struct ip_set_skbinfo),
349 	},
350 	[IPSET_EXT_ID_COMMENT] = {
351 		.type	 = IPSET_EXT_COMMENT | IPSET_EXT_DESTROY,
352 		.flag	 = IPSET_FLAG_WITH_COMMENT,
353 		.len	 = sizeof(struct ip_set_comment),
354 		.align	 = __alignof__(struct ip_set_comment),
355 		.destroy = (destroyer) ip_set_comment_free,
356 	},
357 };
358 EXPORT_SYMBOL_GPL(ip_set_extensions);
359 
360 static inline bool
361 add_extension(enum ip_set_ext_id id, u32 flags, struct nlattr *tb[])
362 {
363 	return ip_set_extensions[id].flag ?
364 		(flags & ip_set_extensions[id].flag) :
365 		!!tb[IPSET_ATTR_TIMEOUT];
366 }
367 
368 size_t
369 ip_set_elem_len(struct ip_set *set, struct nlattr *tb[], size_t len,
370 		size_t align)
371 {
372 	enum ip_set_ext_id id;
373 	u32 cadt_flags = 0;
374 
375 	if (tb[IPSET_ATTR_CADT_FLAGS])
376 		cadt_flags = ip_set_get_h32(tb[IPSET_ATTR_CADT_FLAGS]);
377 	if (cadt_flags & IPSET_FLAG_WITH_FORCEADD)
378 		set->flags |= IPSET_CREATE_FLAG_FORCEADD;
379 	if (!align)
380 		align = 1;
381 	for (id = 0; id < IPSET_EXT_ID_MAX; id++) {
382 		if (!add_extension(id, cadt_flags, tb))
383 			continue;
384 		len = ALIGN(len, ip_set_extensions[id].align);
385 		set->offset[id] = len;
386 		set->extensions |= ip_set_extensions[id].type;
387 		len += ip_set_extensions[id].len;
388 	}
389 	return ALIGN(len, align);
390 }
391 EXPORT_SYMBOL_GPL(ip_set_elem_len);
392 
393 int
394 ip_set_get_extensions(struct ip_set *set, struct nlattr *tb[],
395 		      struct ip_set_ext *ext)
396 {
397 	u64 fullmark;
398 
399 	if (unlikely(!ip_set_optattr_netorder(tb, IPSET_ATTR_TIMEOUT) ||
400 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_PACKETS) ||
401 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_BYTES) ||
402 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_SKBMARK) ||
403 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_SKBPRIO) ||
404 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_SKBQUEUE)))
405 		return -IPSET_ERR_PROTOCOL;
406 
407 	if (tb[IPSET_ATTR_TIMEOUT]) {
408 		if (!SET_WITH_TIMEOUT(set))
409 			return -IPSET_ERR_TIMEOUT;
410 		ext->timeout = ip_set_timeout_uget(tb[IPSET_ATTR_TIMEOUT]);
411 	}
412 	if (tb[IPSET_ATTR_BYTES] || tb[IPSET_ATTR_PACKETS]) {
413 		if (!SET_WITH_COUNTER(set))
414 			return -IPSET_ERR_COUNTER;
415 		if (tb[IPSET_ATTR_BYTES])
416 			ext->bytes = be64_to_cpu(nla_get_be64(
417 						 tb[IPSET_ATTR_BYTES]));
418 		if (tb[IPSET_ATTR_PACKETS])
419 			ext->packets = be64_to_cpu(nla_get_be64(
420 						   tb[IPSET_ATTR_PACKETS]));
421 	}
422 	if (tb[IPSET_ATTR_COMMENT]) {
423 		if (!SET_WITH_COMMENT(set))
424 			return -IPSET_ERR_COMMENT;
425 		ext->comment = ip_set_comment_uget(tb[IPSET_ATTR_COMMENT]);
426 	}
427 	if (tb[IPSET_ATTR_SKBMARK]) {
428 		if (!SET_WITH_SKBINFO(set))
429 			return -IPSET_ERR_SKBINFO;
430 		fullmark = be64_to_cpu(nla_get_be64(tb[IPSET_ATTR_SKBMARK]));
431 		ext->skbinfo.skbmark = fullmark >> 32;
432 		ext->skbinfo.skbmarkmask = fullmark & 0xffffffff;
433 	}
434 	if (tb[IPSET_ATTR_SKBPRIO]) {
435 		if (!SET_WITH_SKBINFO(set))
436 			return -IPSET_ERR_SKBINFO;
437 		ext->skbinfo.skbprio =
438 			be32_to_cpu(nla_get_be32(tb[IPSET_ATTR_SKBPRIO]));
439 	}
440 	if (tb[IPSET_ATTR_SKBQUEUE]) {
441 		if (!SET_WITH_SKBINFO(set))
442 			return -IPSET_ERR_SKBINFO;
443 		ext->skbinfo.skbqueue =
444 			be16_to_cpu(nla_get_be16(tb[IPSET_ATTR_SKBQUEUE]));
445 	}
446 	return 0;
447 }
448 EXPORT_SYMBOL_GPL(ip_set_get_extensions);
449 
450 int
451 ip_set_put_extensions(struct sk_buff *skb, const struct ip_set *set,
452 		      const void *e, bool active)
453 {
454 	if (SET_WITH_TIMEOUT(set)) {
455 		unsigned long *timeout = ext_timeout(e, set);
456 
457 		if (nla_put_net32(skb, IPSET_ATTR_TIMEOUT,
458 			htonl(active ? ip_set_timeout_get(timeout)
459 				: *timeout)))
460 			return -EMSGSIZE;
461 	}
462 	if (SET_WITH_COUNTER(set) &&
463 	    ip_set_put_counter(skb, ext_counter(e, set)))
464 		return -EMSGSIZE;
465 	if (SET_WITH_COMMENT(set) &&
466 	    ip_set_put_comment(skb, ext_comment(e, set)))
467 		return -EMSGSIZE;
468 	if (SET_WITH_SKBINFO(set) &&
469 	    ip_set_put_skbinfo(skb, ext_skbinfo(e, set)))
470 		return -EMSGSIZE;
471 	return 0;
472 }
473 EXPORT_SYMBOL_GPL(ip_set_put_extensions);
474 
475 bool
476 ip_set_match_extensions(struct ip_set *set, const struct ip_set_ext *ext,
477 			struct ip_set_ext *mext, u32 flags, void *data)
478 {
479 	if (SET_WITH_TIMEOUT(set) &&
480 	    ip_set_timeout_expired(ext_timeout(data, set)))
481 		return false;
482 	if (SET_WITH_COUNTER(set)) {
483 		struct ip_set_counter *counter = ext_counter(data, set);
484 
485 		if (flags & IPSET_FLAG_MATCH_COUNTERS &&
486 		    !(ip_set_match_counter(ip_set_get_packets(counter),
487 				mext->packets, mext->packets_op) &&
488 		      ip_set_match_counter(ip_set_get_bytes(counter),
489 				mext->bytes, mext->bytes_op)))
490 			return false;
491 		ip_set_update_counter(counter, ext, flags);
492 	}
493 	if (SET_WITH_SKBINFO(set))
494 		ip_set_get_skbinfo(ext_skbinfo(data, set),
495 				   ext, mext, flags);
496 	return true;
497 }
498 EXPORT_SYMBOL_GPL(ip_set_match_extensions);
499 
500 /* Creating/destroying/renaming/swapping affect the existence and
501  * the properties of a set. All of these can be executed from userspace
502  * only and serialized by the nfnl mutex indirectly from nfnetlink.
503  *
504  * Sets are identified by their index in ip_set_list and the index
505  * is used by the external references (set/SET netfilter modules).
506  *
507  * The set behind an index may change by swapping only, from userspace.
508  */
509 
510 static inline void
511 __ip_set_get(struct ip_set *set)
512 {
513 	write_lock_bh(&ip_set_ref_lock);
514 	set->ref++;
515 	write_unlock_bh(&ip_set_ref_lock);
516 }
517 
518 static inline void
519 __ip_set_put(struct ip_set *set)
520 {
521 	write_lock_bh(&ip_set_ref_lock);
522 	BUG_ON(set->ref == 0);
523 	set->ref--;
524 	write_unlock_bh(&ip_set_ref_lock);
525 }
526 
527 /* set->ref can be swapped out by ip_set_swap, netlink events (like dump) need
528  * a separate reference counter
529  */
530 static inline void
531 __ip_set_put_netlink(struct ip_set *set)
532 {
533 	write_lock_bh(&ip_set_ref_lock);
534 	BUG_ON(set->ref_netlink == 0);
535 	set->ref_netlink--;
536 	write_unlock_bh(&ip_set_ref_lock);
537 }
538 
539 /* Add, del and test set entries from kernel.
540  *
541  * The set behind the index must exist and must be referenced
542  * so it can't be destroyed (or changed) under our foot.
543  */
544 
545 static inline struct ip_set *
546 ip_set_rcu_get(struct net *net, ip_set_id_t index)
547 {
548 	struct ip_set *set;
549 	struct ip_set_net *inst = ip_set_pernet(net);
550 
551 	rcu_read_lock();
552 	/* ip_set_list itself needs to be protected */
553 	set = rcu_dereference(inst->ip_set_list)[index];
554 	rcu_read_unlock();
555 
556 	return set;
557 }
558 
559 int
560 ip_set_test(ip_set_id_t index, const struct sk_buff *skb,
561 	    const struct xt_action_param *par, struct ip_set_adt_opt *opt)
562 {
563 	struct ip_set *set = ip_set_rcu_get(xt_net(par), index);
564 	int ret = 0;
565 
566 	BUG_ON(!set);
567 	pr_debug("set %s, index %u\n", set->name, index);
568 
569 	if (opt->dim < set->type->dimension ||
570 	    !(opt->family == set->family || set->family == NFPROTO_UNSPEC))
571 		return 0;
572 
573 	rcu_read_lock_bh();
574 	ret = set->variant->kadt(set, skb, par, IPSET_TEST, opt);
575 	rcu_read_unlock_bh();
576 
577 	if (ret == -EAGAIN) {
578 		/* Type requests element to be completed */
579 		pr_debug("element must be completed, ADD is triggered\n");
580 		spin_lock_bh(&set->lock);
581 		set->variant->kadt(set, skb, par, IPSET_ADD, opt);
582 		spin_unlock_bh(&set->lock);
583 		ret = 1;
584 	} else {
585 		/* --return-nomatch: invert matched element */
586 		if ((opt->cmdflags & IPSET_FLAG_RETURN_NOMATCH) &&
587 		    (set->type->features & IPSET_TYPE_NOMATCH) &&
588 		    (ret > 0 || ret == -ENOTEMPTY))
589 			ret = -ret;
590 	}
591 
592 	/* Convert error codes to nomatch */
593 	return (ret < 0 ? 0 : ret);
594 }
595 EXPORT_SYMBOL_GPL(ip_set_test);
596 
597 int
598 ip_set_add(ip_set_id_t index, const struct sk_buff *skb,
599 	   const struct xt_action_param *par, struct ip_set_adt_opt *opt)
600 {
601 	struct ip_set *set = ip_set_rcu_get(xt_net(par), index);
602 	int ret;
603 
604 	BUG_ON(!set);
605 	pr_debug("set %s, index %u\n", set->name, index);
606 
607 	if (opt->dim < set->type->dimension ||
608 	    !(opt->family == set->family || set->family == NFPROTO_UNSPEC))
609 		return -IPSET_ERR_TYPE_MISMATCH;
610 
611 	spin_lock_bh(&set->lock);
612 	ret = set->variant->kadt(set, skb, par, IPSET_ADD, opt);
613 	spin_unlock_bh(&set->lock);
614 
615 	return ret;
616 }
617 EXPORT_SYMBOL_GPL(ip_set_add);
618 
619 int
620 ip_set_del(ip_set_id_t index, const struct sk_buff *skb,
621 	   const struct xt_action_param *par, struct ip_set_adt_opt *opt)
622 {
623 	struct ip_set *set = ip_set_rcu_get(xt_net(par), index);
624 	int ret = 0;
625 
626 	BUG_ON(!set);
627 	pr_debug("set %s, index %u\n", set->name, index);
628 
629 	if (opt->dim < set->type->dimension ||
630 	    !(opt->family == set->family || set->family == NFPROTO_UNSPEC))
631 		return -IPSET_ERR_TYPE_MISMATCH;
632 
633 	spin_lock_bh(&set->lock);
634 	ret = set->variant->kadt(set, skb, par, IPSET_DEL, opt);
635 	spin_unlock_bh(&set->lock);
636 
637 	return ret;
638 }
639 EXPORT_SYMBOL_GPL(ip_set_del);
640 
641 /* Find set by name, reference it once. The reference makes sure the
642  * thing pointed to, does not go away under our feet.
643  *
644  */
645 ip_set_id_t
646 ip_set_get_byname(struct net *net, const char *name, struct ip_set **set)
647 {
648 	ip_set_id_t i, index = IPSET_INVALID_ID;
649 	struct ip_set *s;
650 	struct ip_set_net *inst = ip_set_pernet(net);
651 
652 	rcu_read_lock();
653 	for (i = 0; i < inst->ip_set_max; i++) {
654 		s = rcu_dereference(inst->ip_set_list)[i];
655 		if (s && STRNCMP(s->name, name)) {
656 			__ip_set_get(s);
657 			index = i;
658 			*set = s;
659 			break;
660 		}
661 	}
662 	rcu_read_unlock();
663 
664 	return index;
665 }
666 EXPORT_SYMBOL_GPL(ip_set_get_byname);
667 
668 /* If the given set pointer points to a valid set, decrement
669  * reference count by 1. The caller shall not assume the index
670  * to be valid, after calling this function.
671  *
672  */
673 
674 static inline void
675 __ip_set_put_byindex(struct ip_set_net *inst, ip_set_id_t index)
676 {
677 	struct ip_set *set;
678 
679 	rcu_read_lock();
680 	set = rcu_dereference(inst->ip_set_list)[index];
681 	if (set)
682 		__ip_set_put(set);
683 	rcu_read_unlock();
684 }
685 
686 void
687 ip_set_put_byindex(struct net *net, ip_set_id_t index)
688 {
689 	struct ip_set_net *inst = ip_set_pernet(net);
690 
691 	__ip_set_put_byindex(inst, index);
692 }
693 EXPORT_SYMBOL_GPL(ip_set_put_byindex);
694 
695 /* Get the name of a set behind a set index.
696  * We assume the set is referenced, so it does exist and
697  * can't be destroyed. The set cannot be renamed due to
698  * the referencing either.
699  *
700  */
701 const char *
702 ip_set_name_byindex(struct net *net, ip_set_id_t index)
703 {
704 	const struct ip_set *set = ip_set_rcu_get(net, index);
705 
706 	BUG_ON(!set);
707 	BUG_ON(set->ref == 0);
708 
709 	/* Referenced, so it's safe */
710 	return set->name;
711 }
712 EXPORT_SYMBOL_GPL(ip_set_name_byindex);
713 
714 /* Routines to call by external subsystems, which do not
715  * call nfnl_lock for us.
716  */
717 
718 /* Find set by index, reference it once. The reference makes sure the
719  * thing pointed to, does not go away under our feet.
720  *
721  * The nfnl mutex is used in the function.
722  */
723 ip_set_id_t
724 ip_set_nfnl_get_byindex(struct net *net, ip_set_id_t index)
725 {
726 	struct ip_set *set;
727 	struct ip_set_net *inst = ip_set_pernet(net);
728 
729 	if (index >= inst->ip_set_max)
730 		return IPSET_INVALID_ID;
731 
732 	nfnl_lock(NFNL_SUBSYS_IPSET);
733 	set = ip_set(inst, index);
734 	if (set)
735 		__ip_set_get(set);
736 	else
737 		index = IPSET_INVALID_ID;
738 	nfnl_unlock(NFNL_SUBSYS_IPSET);
739 
740 	return index;
741 }
742 EXPORT_SYMBOL_GPL(ip_set_nfnl_get_byindex);
743 
744 /* If the given set pointer points to a valid set, decrement
745  * reference count by 1. The caller shall not assume the index
746  * to be valid, after calling this function.
747  *
748  * The nfnl mutex is used in the function.
749  */
750 void
751 ip_set_nfnl_put(struct net *net, ip_set_id_t index)
752 {
753 	struct ip_set *set;
754 	struct ip_set_net *inst = ip_set_pernet(net);
755 
756 	nfnl_lock(NFNL_SUBSYS_IPSET);
757 	if (!inst->is_deleted) { /* already deleted from ip_set_net_exit() */
758 		set = ip_set(inst, index);
759 		if (set)
760 			__ip_set_put(set);
761 	}
762 	nfnl_unlock(NFNL_SUBSYS_IPSET);
763 }
764 EXPORT_SYMBOL_GPL(ip_set_nfnl_put);
765 
766 /* Communication protocol with userspace over netlink.
767  *
768  * The commands are serialized by the nfnl mutex.
769  */
770 
771 static inline bool
772 protocol_failed(const struct nlattr * const tb[])
773 {
774 	return !tb[IPSET_ATTR_PROTOCOL] ||
775 	       nla_get_u8(tb[IPSET_ATTR_PROTOCOL]) != IPSET_PROTOCOL;
776 }
777 
778 static inline u32
779 flag_exist(const struct nlmsghdr *nlh)
780 {
781 	return nlh->nlmsg_flags & NLM_F_EXCL ? 0 : IPSET_FLAG_EXIST;
782 }
783 
784 static struct nlmsghdr *
785 start_msg(struct sk_buff *skb, u32 portid, u32 seq, unsigned int flags,
786 	  enum ipset_cmd cmd)
787 {
788 	struct nlmsghdr *nlh;
789 	struct nfgenmsg *nfmsg;
790 
791 	nlh = nlmsg_put(skb, portid, seq, nfnl_msg_type(NFNL_SUBSYS_IPSET, cmd),
792 			sizeof(*nfmsg), flags);
793 	if (!nlh)
794 		return NULL;
795 
796 	nfmsg = nlmsg_data(nlh);
797 	nfmsg->nfgen_family = NFPROTO_IPV4;
798 	nfmsg->version = NFNETLINK_V0;
799 	nfmsg->res_id = 0;
800 
801 	return nlh;
802 }
803 
804 /* Create a set */
805 
806 static const struct nla_policy ip_set_create_policy[IPSET_ATTR_CMD_MAX + 1] = {
807 	[IPSET_ATTR_PROTOCOL]	= { .type = NLA_U8 },
808 	[IPSET_ATTR_SETNAME]	= { .type = NLA_NUL_STRING,
809 				    .len = IPSET_MAXNAMELEN - 1 },
810 	[IPSET_ATTR_TYPENAME]	= { .type = NLA_NUL_STRING,
811 				    .len = IPSET_MAXNAMELEN - 1},
812 	[IPSET_ATTR_REVISION]	= { .type = NLA_U8 },
813 	[IPSET_ATTR_FAMILY]	= { .type = NLA_U8 },
814 	[IPSET_ATTR_DATA]	= { .type = NLA_NESTED },
815 };
816 
817 static struct ip_set *
818 find_set_and_id(struct ip_set_net *inst, const char *name, ip_set_id_t *id)
819 {
820 	struct ip_set *set = NULL;
821 	ip_set_id_t i;
822 
823 	*id = IPSET_INVALID_ID;
824 	for (i = 0; i < inst->ip_set_max; i++) {
825 		set = ip_set(inst, i);
826 		if (set && STRNCMP(set->name, name)) {
827 			*id = i;
828 			break;
829 		}
830 	}
831 	return (*id == IPSET_INVALID_ID ? NULL : set);
832 }
833 
834 static inline struct ip_set *
835 find_set(struct ip_set_net *inst, const char *name)
836 {
837 	ip_set_id_t id;
838 
839 	return find_set_and_id(inst, name, &id);
840 }
841 
842 static int
843 find_free_id(struct ip_set_net *inst, const char *name, ip_set_id_t *index,
844 	     struct ip_set **set)
845 {
846 	struct ip_set *s;
847 	ip_set_id_t i;
848 
849 	*index = IPSET_INVALID_ID;
850 	for (i = 0;  i < inst->ip_set_max; i++) {
851 		s = ip_set(inst, i);
852 		if (!s) {
853 			if (*index == IPSET_INVALID_ID)
854 				*index = i;
855 		} else if (STRNCMP(name, s->name)) {
856 			/* Name clash */
857 			*set = s;
858 			return -EEXIST;
859 		}
860 	}
861 	if (*index == IPSET_INVALID_ID)
862 		/* No free slot remained */
863 		return -IPSET_ERR_MAX_SETS;
864 	return 0;
865 }
866 
867 static int ip_set_none(struct net *net, struct sock *ctnl, struct sk_buff *skb,
868 		       const struct nlmsghdr *nlh,
869 		       const struct nlattr * const attr[],
870 		       struct netlink_ext_ack *extack)
871 {
872 	return -EOPNOTSUPP;
873 }
874 
875 static int ip_set_create(struct net *net, struct sock *ctnl,
876 			 struct sk_buff *skb, const struct nlmsghdr *nlh,
877 			 const struct nlattr * const attr[],
878 			 struct netlink_ext_ack *extack)
879 {
880 	struct ip_set_net *inst = ip_set_pernet(net);
881 	struct ip_set *set, *clash = NULL;
882 	ip_set_id_t index = IPSET_INVALID_ID;
883 	struct nlattr *tb[IPSET_ATTR_CREATE_MAX + 1] = {};
884 	const char *name, *typename;
885 	u8 family, revision;
886 	u32 flags = flag_exist(nlh);
887 	int ret = 0;
888 
889 	if (unlikely(protocol_failed(attr) ||
890 		     !attr[IPSET_ATTR_SETNAME] ||
891 		     !attr[IPSET_ATTR_TYPENAME] ||
892 		     !attr[IPSET_ATTR_REVISION] ||
893 		     !attr[IPSET_ATTR_FAMILY] ||
894 		     (attr[IPSET_ATTR_DATA] &&
895 		      !flag_nested(attr[IPSET_ATTR_DATA]))))
896 		return -IPSET_ERR_PROTOCOL;
897 
898 	name = nla_data(attr[IPSET_ATTR_SETNAME]);
899 	typename = nla_data(attr[IPSET_ATTR_TYPENAME]);
900 	family = nla_get_u8(attr[IPSET_ATTR_FAMILY]);
901 	revision = nla_get_u8(attr[IPSET_ATTR_REVISION]);
902 	pr_debug("setname: %s, typename: %s, family: %s, revision: %u\n",
903 		 name, typename, family_name(family), revision);
904 
905 	/* First, and without any locks, allocate and initialize
906 	 * a normal base set structure.
907 	 */
908 	set = kzalloc(sizeof(*set), GFP_KERNEL);
909 	if (!set)
910 		return -ENOMEM;
911 	spin_lock_init(&set->lock);
912 	strlcpy(set->name, name, IPSET_MAXNAMELEN);
913 	set->family = family;
914 	set->revision = revision;
915 
916 	/* Next, check that we know the type, and take
917 	 * a reference on the type, to make sure it stays available
918 	 * while constructing our new set.
919 	 *
920 	 * After referencing the type, we try to create the type
921 	 * specific part of the set without holding any locks.
922 	 */
923 	ret = find_set_type_get(typename, family, revision, &set->type);
924 	if (ret)
925 		goto out;
926 
927 	/* Without holding any locks, create private part. */
928 	if (attr[IPSET_ATTR_DATA] &&
929 	    nla_parse_nested(tb, IPSET_ATTR_CREATE_MAX, attr[IPSET_ATTR_DATA],
930 			     set->type->create_policy, NULL)) {
931 		ret = -IPSET_ERR_PROTOCOL;
932 		goto put_out;
933 	}
934 
935 	ret = set->type->create(net, set, tb, flags);
936 	if (ret != 0)
937 		goto put_out;
938 
939 	/* BTW, ret==0 here. */
940 
941 	/* Here, we have a valid, constructed set and we are protected
942 	 * by the nfnl mutex. Find the first free index in ip_set_list
943 	 * and check clashing.
944 	 */
945 	ret = find_free_id(inst, set->name, &index, &clash);
946 	if (ret == -EEXIST) {
947 		/* If this is the same set and requested, ignore error */
948 		if ((flags & IPSET_FLAG_EXIST) &&
949 		    STRNCMP(set->type->name, clash->type->name) &&
950 		    set->type->family == clash->type->family &&
951 		    set->type->revision_min == clash->type->revision_min &&
952 		    set->type->revision_max == clash->type->revision_max &&
953 		    set->variant->same_set(set, clash))
954 			ret = 0;
955 		goto cleanup;
956 	} else if (ret == -IPSET_ERR_MAX_SETS) {
957 		struct ip_set **list, **tmp;
958 		ip_set_id_t i = inst->ip_set_max + IP_SET_INC;
959 
960 		if (i < inst->ip_set_max || i == IPSET_INVALID_ID)
961 			/* Wraparound */
962 			goto cleanup;
963 
964 		list = kcalloc(i, sizeof(struct ip_set *), GFP_KERNEL);
965 		if (!list)
966 			goto cleanup;
967 		/* nfnl mutex is held, both lists are valid */
968 		tmp = ip_set_dereference(inst->ip_set_list);
969 		memcpy(list, tmp, sizeof(struct ip_set *) * inst->ip_set_max);
970 		rcu_assign_pointer(inst->ip_set_list, list);
971 		/* Make sure all current packets have passed through */
972 		synchronize_net();
973 		/* Use new list */
974 		index = inst->ip_set_max;
975 		inst->ip_set_max = i;
976 		kfree(tmp);
977 		ret = 0;
978 	} else if (ret) {
979 		goto cleanup;
980 	}
981 
982 	/* Finally! Add our shiny new set to the list, and be done. */
983 	pr_debug("create: '%s' created with index %u!\n", set->name, index);
984 	ip_set(inst, index) = set;
985 
986 	return ret;
987 
988 cleanup:
989 	set->variant->destroy(set);
990 put_out:
991 	module_put(set->type->me);
992 out:
993 	kfree(set);
994 	return ret;
995 }
996 
997 /* Destroy sets */
998 
999 static const struct nla_policy
1000 ip_set_setname_policy[IPSET_ATTR_CMD_MAX + 1] = {
1001 	[IPSET_ATTR_PROTOCOL]	= { .type = NLA_U8 },
1002 	[IPSET_ATTR_SETNAME]	= { .type = NLA_NUL_STRING,
1003 				    .len = IPSET_MAXNAMELEN - 1 },
1004 };
1005 
1006 static void
1007 ip_set_destroy_set(struct ip_set *set)
1008 {
1009 	pr_debug("set: %s\n",  set->name);
1010 
1011 	/* Must call it without holding any lock */
1012 	set->variant->destroy(set);
1013 	module_put(set->type->me);
1014 	kfree(set);
1015 }
1016 
1017 static int ip_set_destroy(struct net *net, struct sock *ctnl,
1018 			  struct sk_buff *skb, const struct nlmsghdr *nlh,
1019 			  const struct nlattr * const attr[],
1020 			  struct netlink_ext_ack *extack)
1021 {
1022 	struct ip_set_net *inst = ip_set_pernet(net);
1023 	struct ip_set *s;
1024 	ip_set_id_t i;
1025 	int ret = 0;
1026 
1027 	if (unlikely(protocol_failed(attr)))
1028 		return -IPSET_ERR_PROTOCOL;
1029 
1030 	/* Must wait for flush to be really finished in list:set */
1031 	rcu_barrier();
1032 
1033 	/* Commands are serialized and references are
1034 	 * protected by the ip_set_ref_lock.
1035 	 * External systems (i.e. xt_set) must call
1036 	 * ip_set_put|get_nfnl_* functions, that way we
1037 	 * can safely check references here.
1038 	 *
1039 	 * list:set timer can only decrement the reference
1040 	 * counter, so if it's already zero, we can proceed
1041 	 * without holding the lock.
1042 	 */
1043 	read_lock_bh(&ip_set_ref_lock);
1044 	if (!attr[IPSET_ATTR_SETNAME]) {
1045 		for (i = 0; i < inst->ip_set_max; i++) {
1046 			s = ip_set(inst, i);
1047 			if (s && (s->ref || s->ref_netlink)) {
1048 				ret = -IPSET_ERR_BUSY;
1049 				goto out;
1050 			}
1051 		}
1052 		inst->is_destroyed = true;
1053 		read_unlock_bh(&ip_set_ref_lock);
1054 		for (i = 0; i < inst->ip_set_max; i++) {
1055 			s = ip_set(inst, i);
1056 			if (s) {
1057 				ip_set(inst, i) = NULL;
1058 				ip_set_destroy_set(s);
1059 			}
1060 		}
1061 		/* Modified by ip_set_destroy() only, which is serialized */
1062 		inst->is_destroyed = false;
1063 	} else {
1064 		s = find_set_and_id(inst, nla_data(attr[IPSET_ATTR_SETNAME]),
1065 				    &i);
1066 		if (!s) {
1067 			ret = -ENOENT;
1068 			goto out;
1069 		} else if (s->ref || s->ref_netlink) {
1070 			ret = -IPSET_ERR_BUSY;
1071 			goto out;
1072 		}
1073 		ip_set(inst, i) = NULL;
1074 		read_unlock_bh(&ip_set_ref_lock);
1075 
1076 		ip_set_destroy_set(s);
1077 	}
1078 	return 0;
1079 out:
1080 	read_unlock_bh(&ip_set_ref_lock);
1081 	return ret;
1082 }
1083 
1084 /* Flush sets */
1085 
1086 static void
1087 ip_set_flush_set(struct ip_set *set)
1088 {
1089 	pr_debug("set: %s\n",  set->name);
1090 
1091 	spin_lock_bh(&set->lock);
1092 	set->variant->flush(set);
1093 	spin_unlock_bh(&set->lock);
1094 }
1095 
1096 static int ip_set_flush(struct net *net, struct sock *ctnl, struct sk_buff *skb,
1097 			const struct nlmsghdr *nlh,
1098 			const struct nlattr * const attr[],
1099 			struct netlink_ext_ack *extack)
1100 {
1101 	struct ip_set_net *inst = ip_set_pernet(net);
1102 	struct ip_set *s;
1103 	ip_set_id_t i;
1104 
1105 	if (unlikely(protocol_failed(attr)))
1106 		return -IPSET_ERR_PROTOCOL;
1107 
1108 	if (!attr[IPSET_ATTR_SETNAME]) {
1109 		for (i = 0; i < inst->ip_set_max; i++) {
1110 			s = ip_set(inst, i);
1111 			if (s)
1112 				ip_set_flush_set(s);
1113 		}
1114 	} else {
1115 		s = find_set(inst, nla_data(attr[IPSET_ATTR_SETNAME]));
1116 		if (!s)
1117 			return -ENOENT;
1118 
1119 		ip_set_flush_set(s);
1120 	}
1121 
1122 	return 0;
1123 }
1124 
1125 /* Rename a set */
1126 
1127 static const struct nla_policy
1128 ip_set_setname2_policy[IPSET_ATTR_CMD_MAX + 1] = {
1129 	[IPSET_ATTR_PROTOCOL]	= { .type = NLA_U8 },
1130 	[IPSET_ATTR_SETNAME]	= { .type = NLA_NUL_STRING,
1131 				    .len = IPSET_MAXNAMELEN - 1 },
1132 	[IPSET_ATTR_SETNAME2]	= { .type = NLA_NUL_STRING,
1133 				    .len = IPSET_MAXNAMELEN - 1 },
1134 };
1135 
1136 static int ip_set_rename(struct net *net, struct sock *ctnl,
1137 			 struct sk_buff *skb, const struct nlmsghdr *nlh,
1138 			 const struct nlattr * const attr[],
1139 			 struct netlink_ext_ack *extack)
1140 {
1141 	struct ip_set_net *inst = ip_set_pernet(net);
1142 	struct ip_set *set, *s;
1143 	const char *name2;
1144 	ip_set_id_t i;
1145 	int ret = 0;
1146 
1147 	if (unlikely(protocol_failed(attr) ||
1148 		     !attr[IPSET_ATTR_SETNAME] ||
1149 		     !attr[IPSET_ATTR_SETNAME2]))
1150 		return -IPSET_ERR_PROTOCOL;
1151 
1152 	set = find_set(inst, nla_data(attr[IPSET_ATTR_SETNAME]));
1153 	if (!set)
1154 		return -ENOENT;
1155 
1156 	read_lock_bh(&ip_set_ref_lock);
1157 	if (set->ref != 0) {
1158 		ret = -IPSET_ERR_REFERENCED;
1159 		goto out;
1160 	}
1161 
1162 	name2 = nla_data(attr[IPSET_ATTR_SETNAME2]);
1163 	for (i = 0; i < inst->ip_set_max; i++) {
1164 		s = ip_set(inst, i);
1165 		if (s && STRNCMP(s->name, name2)) {
1166 			ret = -IPSET_ERR_EXIST_SETNAME2;
1167 			goto out;
1168 		}
1169 	}
1170 	strncpy(set->name, name2, IPSET_MAXNAMELEN);
1171 
1172 out:
1173 	read_unlock_bh(&ip_set_ref_lock);
1174 	return ret;
1175 }
1176 
1177 /* Swap two sets so that name/index points to the other.
1178  * References and set names are also swapped.
1179  *
1180  * The commands are serialized by the nfnl mutex and references are
1181  * protected by the ip_set_ref_lock. The kernel interfaces
1182  * do not hold the mutex but the pointer settings are atomic
1183  * so the ip_set_list always contains valid pointers to the sets.
1184  */
1185 
1186 static int ip_set_swap(struct net *net, struct sock *ctnl, struct sk_buff *skb,
1187 		       const struct nlmsghdr *nlh,
1188 		       const struct nlattr * const attr[],
1189 		       struct netlink_ext_ack *extack)
1190 {
1191 	struct ip_set_net *inst = ip_set_pernet(net);
1192 	struct ip_set *from, *to;
1193 	ip_set_id_t from_id, to_id;
1194 	char from_name[IPSET_MAXNAMELEN];
1195 
1196 	if (unlikely(protocol_failed(attr) ||
1197 		     !attr[IPSET_ATTR_SETNAME] ||
1198 		     !attr[IPSET_ATTR_SETNAME2]))
1199 		return -IPSET_ERR_PROTOCOL;
1200 
1201 	from = find_set_and_id(inst, nla_data(attr[IPSET_ATTR_SETNAME]),
1202 			       &from_id);
1203 	if (!from)
1204 		return -ENOENT;
1205 
1206 	to = find_set_and_id(inst, nla_data(attr[IPSET_ATTR_SETNAME2]),
1207 			     &to_id);
1208 	if (!to)
1209 		return -IPSET_ERR_EXIST_SETNAME2;
1210 
1211 	/* Features must not change.
1212 	 * Not an artifical restriction anymore, as we must prevent
1213 	 * possible loops created by swapping in setlist type of sets.
1214 	 */
1215 	if (!(from->type->features == to->type->features &&
1216 	      from->family == to->family))
1217 		return -IPSET_ERR_TYPE_MISMATCH;
1218 
1219 	write_lock_bh(&ip_set_ref_lock);
1220 
1221 	if (from->ref_netlink || to->ref_netlink) {
1222 		write_unlock_bh(&ip_set_ref_lock);
1223 		return -EBUSY;
1224 	}
1225 
1226 	strncpy(from_name, from->name, IPSET_MAXNAMELEN);
1227 	strncpy(from->name, to->name, IPSET_MAXNAMELEN);
1228 	strncpy(to->name, from_name, IPSET_MAXNAMELEN);
1229 
1230 	swap(from->ref, to->ref);
1231 	ip_set(inst, from_id) = to;
1232 	ip_set(inst, to_id) = from;
1233 	write_unlock_bh(&ip_set_ref_lock);
1234 
1235 	return 0;
1236 }
1237 
1238 /* List/save set data */
1239 
1240 #define DUMP_INIT	0
1241 #define DUMP_ALL	1
1242 #define DUMP_ONE	2
1243 #define DUMP_LAST	3
1244 
1245 #define DUMP_TYPE(arg)		(((u32)(arg)) & 0x0000FFFF)
1246 #define DUMP_FLAGS(arg)		(((u32)(arg)) >> 16)
1247 
1248 static int
1249 ip_set_dump_done(struct netlink_callback *cb)
1250 {
1251 	if (cb->args[IPSET_CB_ARG0]) {
1252 		struct ip_set_net *inst =
1253 			(struct ip_set_net *)cb->args[IPSET_CB_NET];
1254 		ip_set_id_t index = (ip_set_id_t)cb->args[IPSET_CB_INDEX];
1255 		struct ip_set *set = ip_set(inst, index);
1256 
1257 		if (set->variant->uref)
1258 			set->variant->uref(set, cb, false);
1259 		pr_debug("release set %s\n", set->name);
1260 		__ip_set_put_netlink(set);
1261 	}
1262 	return 0;
1263 }
1264 
1265 static inline void
1266 dump_attrs(struct nlmsghdr *nlh)
1267 {
1268 	const struct nlattr *attr;
1269 	int rem;
1270 
1271 	pr_debug("dump nlmsg\n");
1272 	nlmsg_for_each_attr(attr, nlh, sizeof(struct nfgenmsg), rem) {
1273 		pr_debug("type: %u, len %u\n", nla_type(attr), attr->nla_len);
1274 	}
1275 }
1276 
1277 static int
1278 dump_init(struct netlink_callback *cb, struct ip_set_net *inst)
1279 {
1280 	struct nlmsghdr *nlh = nlmsg_hdr(cb->skb);
1281 	int min_len = nlmsg_total_size(sizeof(struct nfgenmsg));
1282 	struct nlattr *cda[IPSET_ATTR_CMD_MAX + 1];
1283 	struct nlattr *attr = (void *)nlh + min_len;
1284 	u32 dump_type;
1285 	ip_set_id_t index;
1286 
1287 	/* Second pass, so parser can't fail */
1288 	nla_parse(cda, IPSET_ATTR_CMD_MAX, attr, nlh->nlmsg_len - min_len,
1289 		  ip_set_setname_policy, NULL);
1290 
1291 	if (cda[IPSET_ATTR_SETNAME]) {
1292 		struct ip_set *set;
1293 
1294 		set = find_set_and_id(inst, nla_data(cda[IPSET_ATTR_SETNAME]),
1295 				      &index);
1296 		if (!set)
1297 			return -ENOENT;
1298 
1299 		dump_type = DUMP_ONE;
1300 		cb->args[IPSET_CB_INDEX] = index;
1301 	} else {
1302 		dump_type = DUMP_ALL;
1303 	}
1304 
1305 	if (cda[IPSET_ATTR_FLAGS]) {
1306 		u32 f = ip_set_get_h32(cda[IPSET_ATTR_FLAGS]);
1307 
1308 		dump_type |= (f << 16);
1309 	}
1310 	cb->args[IPSET_CB_NET] = (unsigned long)inst;
1311 	cb->args[IPSET_CB_DUMP] = dump_type;
1312 
1313 	return 0;
1314 }
1315 
1316 static int
1317 ip_set_dump_start(struct sk_buff *skb, struct netlink_callback *cb)
1318 {
1319 	ip_set_id_t index = IPSET_INVALID_ID, max;
1320 	struct ip_set *set = NULL;
1321 	struct nlmsghdr *nlh = NULL;
1322 	unsigned int flags = NETLINK_CB(cb->skb).portid ? NLM_F_MULTI : 0;
1323 	struct ip_set_net *inst = ip_set_pernet(sock_net(skb->sk));
1324 	u32 dump_type, dump_flags;
1325 	bool is_destroyed;
1326 	int ret = 0;
1327 
1328 	if (!cb->args[IPSET_CB_DUMP]) {
1329 		ret = dump_init(cb, inst);
1330 		if (ret < 0) {
1331 			nlh = nlmsg_hdr(cb->skb);
1332 			/* We have to create and send the error message
1333 			 * manually :-(
1334 			 */
1335 			if (nlh->nlmsg_flags & NLM_F_ACK)
1336 				netlink_ack(cb->skb, nlh, ret, NULL);
1337 			return ret;
1338 		}
1339 	}
1340 
1341 	if (cb->args[IPSET_CB_INDEX] >= inst->ip_set_max)
1342 		goto out;
1343 
1344 	dump_type = DUMP_TYPE(cb->args[IPSET_CB_DUMP]);
1345 	dump_flags = DUMP_FLAGS(cb->args[IPSET_CB_DUMP]);
1346 	max = dump_type == DUMP_ONE ? cb->args[IPSET_CB_INDEX] + 1
1347 				    : inst->ip_set_max;
1348 dump_last:
1349 	pr_debug("dump type, flag: %u %u index: %ld\n",
1350 		 dump_type, dump_flags, cb->args[IPSET_CB_INDEX]);
1351 	for (; cb->args[IPSET_CB_INDEX] < max; cb->args[IPSET_CB_INDEX]++) {
1352 		index = (ip_set_id_t)cb->args[IPSET_CB_INDEX];
1353 		write_lock_bh(&ip_set_ref_lock);
1354 		set = ip_set(inst, index);
1355 		is_destroyed = inst->is_destroyed;
1356 		if (!set || is_destroyed) {
1357 			write_unlock_bh(&ip_set_ref_lock);
1358 			if (dump_type == DUMP_ONE) {
1359 				ret = -ENOENT;
1360 				goto out;
1361 			}
1362 			if (is_destroyed) {
1363 				/* All sets are just being destroyed */
1364 				ret = 0;
1365 				goto out;
1366 			}
1367 			continue;
1368 		}
1369 		/* When dumping all sets, we must dump "sorted"
1370 		 * so that lists (unions of sets) are dumped last.
1371 		 */
1372 		if (dump_type != DUMP_ONE &&
1373 		    ((dump_type == DUMP_ALL) ==
1374 		     !!(set->type->features & IPSET_DUMP_LAST))) {
1375 			write_unlock_bh(&ip_set_ref_lock);
1376 			continue;
1377 		}
1378 		pr_debug("List set: %s\n", set->name);
1379 		if (!cb->args[IPSET_CB_ARG0]) {
1380 			/* Start listing: make sure set won't be destroyed */
1381 			pr_debug("reference set\n");
1382 			set->ref_netlink++;
1383 		}
1384 		write_unlock_bh(&ip_set_ref_lock);
1385 		nlh = start_msg(skb, NETLINK_CB(cb->skb).portid,
1386 				cb->nlh->nlmsg_seq, flags,
1387 				IPSET_CMD_LIST);
1388 		if (!nlh) {
1389 			ret = -EMSGSIZE;
1390 			goto release_refcount;
1391 		}
1392 		if (nla_put_u8(skb, IPSET_ATTR_PROTOCOL, IPSET_PROTOCOL) ||
1393 		    nla_put_string(skb, IPSET_ATTR_SETNAME, set->name))
1394 			goto nla_put_failure;
1395 		if (dump_flags & IPSET_FLAG_LIST_SETNAME)
1396 			goto next_set;
1397 		switch (cb->args[IPSET_CB_ARG0]) {
1398 		case 0:
1399 			/* Core header data */
1400 			if (nla_put_string(skb, IPSET_ATTR_TYPENAME,
1401 					   set->type->name) ||
1402 			    nla_put_u8(skb, IPSET_ATTR_FAMILY,
1403 				       set->family) ||
1404 			    nla_put_u8(skb, IPSET_ATTR_REVISION,
1405 				       set->revision))
1406 				goto nla_put_failure;
1407 			ret = set->variant->head(set, skb);
1408 			if (ret < 0)
1409 				goto release_refcount;
1410 			if (dump_flags & IPSET_FLAG_LIST_HEADER)
1411 				goto next_set;
1412 			if (set->variant->uref)
1413 				set->variant->uref(set, cb, true);
1414 			/* fall through */
1415 		default:
1416 			ret = set->variant->list(set, skb, cb);
1417 			if (!cb->args[IPSET_CB_ARG0])
1418 				/* Set is done, proceed with next one */
1419 				goto next_set;
1420 			goto release_refcount;
1421 		}
1422 	}
1423 	/* If we dump all sets, continue with dumping last ones */
1424 	if (dump_type == DUMP_ALL) {
1425 		dump_type = DUMP_LAST;
1426 		cb->args[IPSET_CB_DUMP] = dump_type | (dump_flags << 16);
1427 		cb->args[IPSET_CB_INDEX] = 0;
1428 		if (set && set->variant->uref)
1429 			set->variant->uref(set, cb, false);
1430 		goto dump_last;
1431 	}
1432 	goto out;
1433 
1434 nla_put_failure:
1435 	ret = -EFAULT;
1436 next_set:
1437 	if (dump_type == DUMP_ONE)
1438 		cb->args[IPSET_CB_INDEX] = IPSET_INVALID_ID;
1439 	else
1440 		cb->args[IPSET_CB_INDEX]++;
1441 release_refcount:
1442 	/* If there was an error or set is done, release set */
1443 	if (ret || !cb->args[IPSET_CB_ARG0]) {
1444 		set = ip_set(inst, index);
1445 		if (set->variant->uref)
1446 			set->variant->uref(set, cb, false);
1447 		pr_debug("release set %s\n", set->name);
1448 		__ip_set_put_netlink(set);
1449 		cb->args[IPSET_CB_ARG0] = 0;
1450 	}
1451 out:
1452 	if (nlh) {
1453 		nlmsg_end(skb, nlh);
1454 		pr_debug("nlmsg_len: %u\n", nlh->nlmsg_len);
1455 		dump_attrs(nlh);
1456 	}
1457 
1458 	return ret < 0 ? ret : skb->len;
1459 }
1460 
1461 static int ip_set_dump(struct net *net, struct sock *ctnl, struct sk_buff *skb,
1462 		       const struct nlmsghdr *nlh,
1463 		       const struct nlattr * const attr[],
1464 		       struct netlink_ext_ack *extack)
1465 {
1466 	if (unlikely(protocol_failed(attr)))
1467 		return -IPSET_ERR_PROTOCOL;
1468 
1469 	{
1470 		struct netlink_dump_control c = {
1471 			.dump = ip_set_dump_start,
1472 			.done = ip_set_dump_done,
1473 		};
1474 		return netlink_dump_start(ctnl, skb, nlh, &c);
1475 	}
1476 }
1477 
1478 /* Add, del and test */
1479 
1480 static const struct nla_policy ip_set_adt_policy[IPSET_ATTR_CMD_MAX + 1] = {
1481 	[IPSET_ATTR_PROTOCOL]	= { .type = NLA_U8 },
1482 	[IPSET_ATTR_SETNAME]	= { .type = NLA_NUL_STRING,
1483 				    .len = IPSET_MAXNAMELEN - 1 },
1484 	[IPSET_ATTR_LINENO]	= { .type = NLA_U32 },
1485 	[IPSET_ATTR_DATA]	= { .type = NLA_NESTED },
1486 	[IPSET_ATTR_ADT]	= { .type = NLA_NESTED },
1487 };
1488 
1489 static int
1490 call_ad(struct sock *ctnl, struct sk_buff *skb, struct ip_set *set,
1491 	struct nlattr *tb[], enum ipset_adt adt,
1492 	u32 flags, bool use_lineno)
1493 {
1494 	int ret;
1495 	u32 lineno = 0;
1496 	bool eexist = flags & IPSET_FLAG_EXIST, retried = false;
1497 
1498 	do {
1499 		spin_lock_bh(&set->lock);
1500 		ret = set->variant->uadt(set, tb, adt, &lineno, flags, retried);
1501 		spin_unlock_bh(&set->lock);
1502 		retried = true;
1503 	} while (ret == -EAGAIN &&
1504 		 set->variant->resize &&
1505 		 (ret = set->variant->resize(set, retried)) == 0);
1506 
1507 	if (!ret || (ret == -IPSET_ERR_EXIST && eexist))
1508 		return 0;
1509 	if (lineno && use_lineno) {
1510 		/* Error in restore/batch mode: send back lineno */
1511 		struct nlmsghdr *rep, *nlh = nlmsg_hdr(skb);
1512 		struct sk_buff *skb2;
1513 		struct nlmsgerr *errmsg;
1514 		size_t payload = min(SIZE_MAX,
1515 				     sizeof(*errmsg) + nlmsg_len(nlh));
1516 		int min_len = nlmsg_total_size(sizeof(struct nfgenmsg));
1517 		struct nlattr *cda[IPSET_ATTR_CMD_MAX + 1];
1518 		struct nlattr *cmdattr;
1519 		u32 *errline;
1520 
1521 		skb2 = nlmsg_new(payload, GFP_KERNEL);
1522 		if (!skb2)
1523 			return -ENOMEM;
1524 		rep = __nlmsg_put(skb2, NETLINK_CB(skb).portid,
1525 				  nlh->nlmsg_seq, NLMSG_ERROR, payload, 0);
1526 		errmsg = nlmsg_data(rep);
1527 		errmsg->error = ret;
1528 		memcpy(&errmsg->msg, nlh, nlh->nlmsg_len);
1529 		cmdattr = (void *)&errmsg->msg + min_len;
1530 
1531 		nla_parse(cda, IPSET_ATTR_CMD_MAX, cmdattr,
1532 			  nlh->nlmsg_len - min_len, ip_set_adt_policy, NULL);
1533 
1534 		errline = nla_data(cda[IPSET_ATTR_LINENO]);
1535 
1536 		*errline = lineno;
1537 
1538 		netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid,
1539 				MSG_DONTWAIT);
1540 		/* Signal netlink not to send its ACK/errmsg.  */
1541 		return -EINTR;
1542 	}
1543 
1544 	return ret;
1545 }
1546 
1547 static int ip_set_uadd(struct net *net, struct sock *ctnl, struct sk_buff *skb,
1548 		       const struct nlmsghdr *nlh,
1549 		       const struct nlattr * const attr[],
1550 		       struct netlink_ext_ack *extack)
1551 {
1552 	struct ip_set_net *inst = ip_set_pernet(net);
1553 	struct ip_set *set;
1554 	struct nlattr *tb[IPSET_ATTR_ADT_MAX + 1] = {};
1555 	const struct nlattr *nla;
1556 	u32 flags = flag_exist(nlh);
1557 	bool use_lineno;
1558 	int ret = 0;
1559 
1560 	if (unlikely(protocol_failed(attr) ||
1561 		     !attr[IPSET_ATTR_SETNAME] ||
1562 		     !((attr[IPSET_ATTR_DATA] != NULL) ^
1563 		       (attr[IPSET_ATTR_ADT] != NULL)) ||
1564 		     (attr[IPSET_ATTR_DATA] &&
1565 		      !flag_nested(attr[IPSET_ATTR_DATA])) ||
1566 		     (attr[IPSET_ATTR_ADT] &&
1567 		      (!flag_nested(attr[IPSET_ATTR_ADT]) ||
1568 		       !attr[IPSET_ATTR_LINENO]))))
1569 		return -IPSET_ERR_PROTOCOL;
1570 
1571 	set = find_set(inst, nla_data(attr[IPSET_ATTR_SETNAME]));
1572 	if (!set)
1573 		return -ENOENT;
1574 
1575 	use_lineno = !!attr[IPSET_ATTR_LINENO];
1576 	if (attr[IPSET_ATTR_DATA]) {
1577 		if (nla_parse_nested(tb, IPSET_ATTR_ADT_MAX,
1578 				     attr[IPSET_ATTR_DATA],
1579 				     set->type->adt_policy, NULL))
1580 			return -IPSET_ERR_PROTOCOL;
1581 		ret = call_ad(ctnl, skb, set, tb, IPSET_ADD, flags,
1582 			      use_lineno);
1583 	} else {
1584 		int nla_rem;
1585 
1586 		nla_for_each_nested(nla, attr[IPSET_ATTR_ADT], nla_rem) {
1587 			memset(tb, 0, sizeof(tb));
1588 			if (nla_type(nla) != IPSET_ATTR_DATA ||
1589 			    !flag_nested(nla) ||
1590 			    nla_parse_nested(tb, IPSET_ATTR_ADT_MAX, nla,
1591 					     set->type->adt_policy, NULL))
1592 				return -IPSET_ERR_PROTOCOL;
1593 			ret = call_ad(ctnl, skb, set, tb, IPSET_ADD,
1594 				      flags, use_lineno);
1595 			if (ret < 0)
1596 				return ret;
1597 		}
1598 	}
1599 	return ret;
1600 }
1601 
1602 static int ip_set_udel(struct net *net, struct sock *ctnl, struct sk_buff *skb,
1603 		       const struct nlmsghdr *nlh,
1604 		       const struct nlattr * const attr[],
1605 		       struct netlink_ext_ack *extack)
1606 {
1607 	struct ip_set_net *inst = ip_set_pernet(net);
1608 	struct ip_set *set;
1609 	struct nlattr *tb[IPSET_ATTR_ADT_MAX + 1] = {};
1610 	const struct nlattr *nla;
1611 	u32 flags = flag_exist(nlh);
1612 	bool use_lineno;
1613 	int ret = 0;
1614 
1615 	if (unlikely(protocol_failed(attr) ||
1616 		     !attr[IPSET_ATTR_SETNAME] ||
1617 		     !((attr[IPSET_ATTR_DATA] != NULL) ^
1618 		       (attr[IPSET_ATTR_ADT] != NULL)) ||
1619 		     (attr[IPSET_ATTR_DATA] &&
1620 		      !flag_nested(attr[IPSET_ATTR_DATA])) ||
1621 		     (attr[IPSET_ATTR_ADT] &&
1622 		      (!flag_nested(attr[IPSET_ATTR_ADT]) ||
1623 		       !attr[IPSET_ATTR_LINENO]))))
1624 		return -IPSET_ERR_PROTOCOL;
1625 
1626 	set = find_set(inst, nla_data(attr[IPSET_ATTR_SETNAME]));
1627 	if (!set)
1628 		return -ENOENT;
1629 
1630 	use_lineno = !!attr[IPSET_ATTR_LINENO];
1631 	if (attr[IPSET_ATTR_DATA]) {
1632 		if (nla_parse_nested(tb, IPSET_ATTR_ADT_MAX,
1633 				     attr[IPSET_ATTR_DATA],
1634 				     set->type->adt_policy, NULL))
1635 			return -IPSET_ERR_PROTOCOL;
1636 		ret = call_ad(ctnl, skb, set, tb, IPSET_DEL, flags,
1637 			      use_lineno);
1638 	} else {
1639 		int nla_rem;
1640 
1641 		nla_for_each_nested(nla, attr[IPSET_ATTR_ADT], nla_rem) {
1642 			memset(tb, 0, sizeof(*tb));
1643 			if (nla_type(nla) != IPSET_ATTR_DATA ||
1644 			    !flag_nested(nla) ||
1645 			    nla_parse_nested(tb, IPSET_ATTR_ADT_MAX, nla,
1646 					     set->type->adt_policy, NULL))
1647 				return -IPSET_ERR_PROTOCOL;
1648 			ret = call_ad(ctnl, skb, set, tb, IPSET_DEL,
1649 				      flags, use_lineno);
1650 			if (ret < 0)
1651 				return ret;
1652 		}
1653 	}
1654 	return ret;
1655 }
1656 
1657 static int ip_set_utest(struct net *net, struct sock *ctnl, struct sk_buff *skb,
1658 			const struct nlmsghdr *nlh,
1659 			const struct nlattr * const attr[],
1660 			struct netlink_ext_ack *extack)
1661 {
1662 	struct ip_set_net *inst = ip_set_pernet(net);
1663 	struct ip_set *set;
1664 	struct nlattr *tb[IPSET_ATTR_ADT_MAX + 1] = {};
1665 	int ret = 0;
1666 
1667 	if (unlikely(protocol_failed(attr) ||
1668 		     !attr[IPSET_ATTR_SETNAME] ||
1669 		     !attr[IPSET_ATTR_DATA] ||
1670 		     !flag_nested(attr[IPSET_ATTR_DATA])))
1671 		return -IPSET_ERR_PROTOCOL;
1672 
1673 	set = find_set(inst, nla_data(attr[IPSET_ATTR_SETNAME]));
1674 	if (!set)
1675 		return -ENOENT;
1676 
1677 	if (nla_parse_nested(tb, IPSET_ATTR_ADT_MAX, attr[IPSET_ATTR_DATA],
1678 			     set->type->adt_policy, NULL))
1679 		return -IPSET_ERR_PROTOCOL;
1680 
1681 	rcu_read_lock_bh();
1682 	ret = set->variant->uadt(set, tb, IPSET_TEST, NULL, 0, 0);
1683 	rcu_read_unlock_bh();
1684 	/* Userspace can't trigger element to be re-added */
1685 	if (ret == -EAGAIN)
1686 		ret = 1;
1687 
1688 	return ret > 0 ? 0 : -IPSET_ERR_EXIST;
1689 }
1690 
1691 /* Get headed data of a set */
1692 
1693 static int ip_set_header(struct net *net, struct sock *ctnl,
1694 			 struct sk_buff *skb, const struct nlmsghdr *nlh,
1695 			 const struct nlattr * const attr[],
1696 			 struct netlink_ext_ack *extack)
1697 {
1698 	struct ip_set_net *inst = ip_set_pernet(net);
1699 	const struct ip_set *set;
1700 	struct sk_buff *skb2;
1701 	struct nlmsghdr *nlh2;
1702 	int ret = 0;
1703 
1704 	if (unlikely(protocol_failed(attr) ||
1705 		     !attr[IPSET_ATTR_SETNAME]))
1706 		return -IPSET_ERR_PROTOCOL;
1707 
1708 	set = find_set(inst, nla_data(attr[IPSET_ATTR_SETNAME]));
1709 	if (!set)
1710 		return -ENOENT;
1711 
1712 	skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1713 	if (!skb2)
1714 		return -ENOMEM;
1715 
1716 	nlh2 = start_msg(skb2, NETLINK_CB(skb).portid, nlh->nlmsg_seq, 0,
1717 			 IPSET_CMD_HEADER);
1718 	if (!nlh2)
1719 		goto nlmsg_failure;
1720 	if (nla_put_u8(skb2, IPSET_ATTR_PROTOCOL, IPSET_PROTOCOL) ||
1721 	    nla_put_string(skb2, IPSET_ATTR_SETNAME, set->name) ||
1722 	    nla_put_string(skb2, IPSET_ATTR_TYPENAME, set->type->name) ||
1723 	    nla_put_u8(skb2, IPSET_ATTR_FAMILY, set->family) ||
1724 	    nla_put_u8(skb2, IPSET_ATTR_REVISION, set->revision))
1725 		goto nla_put_failure;
1726 	nlmsg_end(skb2, nlh2);
1727 
1728 	ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid, MSG_DONTWAIT);
1729 	if (ret < 0)
1730 		return ret;
1731 
1732 	return 0;
1733 
1734 nla_put_failure:
1735 	nlmsg_cancel(skb2, nlh2);
1736 nlmsg_failure:
1737 	kfree_skb(skb2);
1738 	return -EMSGSIZE;
1739 }
1740 
1741 /* Get type data */
1742 
1743 static const struct nla_policy ip_set_type_policy[IPSET_ATTR_CMD_MAX + 1] = {
1744 	[IPSET_ATTR_PROTOCOL]	= { .type = NLA_U8 },
1745 	[IPSET_ATTR_TYPENAME]	= { .type = NLA_NUL_STRING,
1746 				    .len = IPSET_MAXNAMELEN - 1 },
1747 	[IPSET_ATTR_FAMILY]	= { .type = NLA_U8 },
1748 };
1749 
1750 static int ip_set_type(struct net *net, struct sock *ctnl, struct sk_buff *skb,
1751 		       const struct nlmsghdr *nlh,
1752 		       const struct nlattr * const attr[],
1753 		       struct netlink_ext_ack *extack)
1754 {
1755 	struct sk_buff *skb2;
1756 	struct nlmsghdr *nlh2;
1757 	u8 family, min, max;
1758 	const char *typename;
1759 	int ret = 0;
1760 
1761 	if (unlikely(protocol_failed(attr) ||
1762 		     !attr[IPSET_ATTR_TYPENAME] ||
1763 		     !attr[IPSET_ATTR_FAMILY]))
1764 		return -IPSET_ERR_PROTOCOL;
1765 
1766 	family = nla_get_u8(attr[IPSET_ATTR_FAMILY]);
1767 	typename = nla_data(attr[IPSET_ATTR_TYPENAME]);
1768 	ret = find_set_type_minmax(typename, family, &min, &max);
1769 	if (ret)
1770 		return ret;
1771 
1772 	skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1773 	if (!skb2)
1774 		return -ENOMEM;
1775 
1776 	nlh2 = start_msg(skb2, NETLINK_CB(skb).portid, nlh->nlmsg_seq, 0,
1777 			 IPSET_CMD_TYPE);
1778 	if (!nlh2)
1779 		goto nlmsg_failure;
1780 	if (nla_put_u8(skb2, IPSET_ATTR_PROTOCOL, IPSET_PROTOCOL) ||
1781 	    nla_put_string(skb2, IPSET_ATTR_TYPENAME, typename) ||
1782 	    nla_put_u8(skb2, IPSET_ATTR_FAMILY, family) ||
1783 	    nla_put_u8(skb2, IPSET_ATTR_REVISION, max) ||
1784 	    nla_put_u8(skb2, IPSET_ATTR_REVISION_MIN, min))
1785 		goto nla_put_failure;
1786 	nlmsg_end(skb2, nlh2);
1787 
1788 	pr_debug("Send TYPE, nlmsg_len: %u\n", nlh2->nlmsg_len);
1789 	ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid, MSG_DONTWAIT);
1790 	if (ret < 0)
1791 		return ret;
1792 
1793 	return 0;
1794 
1795 nla_put_failure:
1796 	nlmsg_cancel(skb2, nlh2);
1797 nlmsg_failure:
1798 	kfree_skb(skb2);
1799 	return -EMSGSIZE;
1800 }
1801 
1802 /* Get protocol version */
1803 
1804 static const struct nla_policy
1805 ip_set_protocol_policy[IPSET_ATTR_CMD_MAX + 1] = {
1806 	[IPSET_ATTR_PROTOCOL]	= { .type = NLA_U8 },
1807 };
1808 
1809 static int ip_set_protocol(struct net *net, struct sock *ctnl,
1810 			   struct sk_buff *skb, const struct nlmsghdr *nlh,
1811 			   const struct nlattr * const attr[],
1812 			   struct netlink_ext_ack *extack)
1813 {
1814 	struct sk_buff *skb2;
1815 	struct nlmsghdr *nlh2;
1816 	int ret = 0;
1817 
1818 	if (unlikely(!attr[IPSET_ATTR_PROTOCOL]))
1819 		return -IPSET_ERR_PROTOCOL;
1820 
1821 	skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1822 	if (!skb2)
1823 		return -ENOMEM;
1824 
1825 	nlh2 = start_msg(skb2, NETLINK_CB(skb).portid, nlh->nlmsg_seq, 0,
1826 			 IPSET_CMD_PROTOCOL);
1827 	if (!nlh2)
1828 		goto nlmsg_failure;
1829 	if (nla_put_u8(skb2, IPSET_ATTR_PROTOCOL, IPSET_PROTOCOL))
1830 		goto nla_put_failure;
1831 	nlmsg_end(skb2, nlh2);
1832 
1833 	ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid, MSG_DONTWAIT);
1834 	if (ret < 0)
1835 		return ret;
1836 
1837 	return 0;
1838 
1839 nla_put_failure:
1840 	nlmsg_cancel(skb2, nlh2);
1841 nlmsg_failure:
1842 	kfree_skb(skb2);
1843 	return -EMSGSIZE;
1844 }
1845 
1846 static const struct nfnl_callback ip_set_netlink_subsys_cb[IPSET_MSG_MAX] = {
1847 	[IPSET_CMD_NONE]	= {
1848 		.call		= ip_set_none,
1849 		.attr_count	= IPSET_ATTR_CMD_MAX,
1850 	},
1851 	[IPSET_CMD_CREATE]	= {
1852 		.call		= ip_set_create,
1853 		.attr_count	= IPSET_ATTR_CMD_MAX,
1854 		.policy		= ip_set_create_policy,
1855 	},
1856 	[IPSET_CMD_DESTROY]	= {
1857 		.call		= ip_set_destroy,
1858 		.attr_count	= IPSET_ATTR_CMD_MAX,
1859 		.policy		= ip_set_setname_policy,
1860 	},
1861 	[IPSET_CMD_FLUSH]	= {
1862 		.call		= ip_set_flush,
1863 		.attr_count	= IPSET_ATTR_CMD_MAX,
1864 		.policy		= ip_set_setname_policy,
1865 	},
1866 	[IPSET_CMD_RENAME]	= {
1867 		.call		= ip_set_rename,
1868 		.attr_count	= IPSET_ATTR_CMD_MAX,
1869 		.policy		= ip_set_setname2_policy,
1870 	},
1871 	[IPSET_CMD_SWAP]	= {
1872 		.call		= ip_set_swap,
1873 		.attr_count	= IPSET_ATTR_CMD_MAX,
1874 		.policy		= ip_set_setname2_policy,
1875 	},
1876 	[IPSET_CMD_LIST]	= {
1877 		.call		= ip_set_dump,
1878 		.attr_count	= IPSET_ATTR_CMD_MAX,
1879 		.policy		= ip_set_setname_policy,
1880 	},
1881 	[IPSET_CMD_SAVE]	= {
1882 		.call		= ip_set_dump,
1883 		.attr_count	= IPSET_ATTR_CMD_MAX,
1884 		.policy		= ip_set_setname_policy,
1885 	},
1886 	[IPSET_CMD_ADD]	= {
1887 		.call		= ip_set_uadd,
1888 		.attr_count	= IPSET_ATTR_CMD_MAX,
1889 		.policy		= ip_set_adt_policy,
1890 	},
1891 	[IPSET_CMD_DEL]	= {
1892 		.call		= ip_set_udel,
1893 		.attr_count	= IPSET_ATTR_CMD_MAX,
1894 		.policy		= ip_set_adt_policy,
1895 	},
1896 	[IPSET_CMD_TEST]	= {
1897 		.call		= ip_set_utest,
1898 		.attr_count	= IPSET_ATTR_CMD_MAX,
1899 		.policy		= ip_set_adt_policy,
1900 	},
1901 	[IPSET_CMD_HEADER]	= {
1902 		.call		= ip_set_header,
1903 		.attr_count	= IPSET_ATTR_CMD_MAX,
1904 		.policy		= ip_set_setname_policy,
1905 	},
1906 	[IPSET_CMD_TYPE]	= {
1907 		.call		= ip_set_type,
1908 		.attr_count	= IPSET_ATTR_CMD_MAX,
1909 		.policy		= ip_set_type_policy,
1910 	},
1911 	[IPSET_CMD_PROTOCOL]	= {
1912 		.call		= ip_set_protocol,
1913 		.attr_count	= IPSET_ATTR_CMD_MAX,
1914 		.policy		= ip_set_protocol_policy,
1915 	},
1916 };
1917 
1918 static struct nfnetlink_subsystem ip_set_netlink_subsys __read_mostly = {
1919 	.name		= "ip_set",
1920 	.subsys_id	= NFNL_SUBSYS_IPSET,
1921 	.cb_count	= IPSET_MSG_MAX,
1922 	.cb		= ip_set_netlink_subsys_cb,
1923 };
1924 
1925 /* Interface to iptables/ip6tables */
1926 
1927 static int
1928 ip_set_sockfn_get(struct sock *sk, int optval, void __user *user, int *len)
1929 {
1930 	unsigned int *op;
1931 	void *data;
1932 	int copylen = *len, ret = 0;
1933 	struct net *net = sock_net(sk);
1934 	struct ip_set_net *inst = ip_set_pernet(net);
1935 
1936 	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1937 		return -EPERM;
1938 	if (optval != SO_IP_SET)
1939 		return -EBADF;
1940 	if (*len < sizeof(unsigned int))
1941 		return -EINVAL;
1942 
1943 	data = vmalloc(*len);
1944 	if (!data)
1945 		return -ENOMEM;
1946 	if (copy_from_user(data, user, *len) != 0) {
1947 		ret = -EFAULT;
1948 		goto done;
1949 	}
1950 	op = data;
1951 
1952 	if (*op < IP_SET_OP_VERSION) {
1953 		/* Check the version at the beginning of operations */
1954 		struct ip_set_req_version *req_version = data;
1955 
1956 		if (*len < sizeof(struct ip_set_req_version)) {
1957 			ret = -EINVAL;
1958 			goto done;
1959 		}
1960 
1961 		if (req_version->version != IPSET_PROTOCOL) {
1962 			ret = -EPROTO;
1963 			goto done;
1964 		}
1965 	}
1966 
1967 	switch (*op) {
1968 	case IP_SET_OP_VERSION: {
1969 		struct ip_set_req_version *req_version = data;
1970 
1971 		if (*len != sizeof(struct ip_set_req_version)) {
1972 			ret = -EINVAL;
1973 			goto done;
1974 		}
1975 
1976 		req_version->version = IPSET_PROTOCOL;
1977 		ret = copy_to_user(user, req_version,
1978 				   sizeof(struct ip_set_req_version));
1979 		goto done;
1980 	}
1981 	case IP_SET_OP_GET_BYNAME: {
1982 		struct ip_set_req_get_set *req_get = data;
1983 		ip_set_id_t id;
1984 
1985 		if (*len != sizeof(struct ip_set_req_get_set)) {
1986 			ret = -EINVAL;
1987 			goto done;
1988 		}
1989 		req_get->set.name[IPSET_MAXNAMELEN - 1] = '\0';
1990 		nfnl_lock(NFNL_SUBSYS_IPSET);
1991 		find_set_and_id(inst, req_get->set.name, &id);
1992 		req_get->set.index = id;
1993 		nfnl_unlock(NFNL_SUBSYS_IPSET);
1994 		goto copy;
1995 	}
1996 	case IP_SET_OP_GET_FNAME: {
1997 		struct ip_set_req_get_set_family *req_get = data;
1998 		ip_set_id_t id;
1999 
2000 		if (*len != sizeof(struct ip_set_req_get_set_family)) {
2001 			ret = -EINVAL;
2002 			goto done;
2003 		}
2004 		req_get->set.name[IPSET_MAXNAMELEN - 1] = '\0';
2005 		nfnl_lock(NFNL_SUBSYS_IPSET);
2006 		find_set_and_id(inst, req_get->set.name, &id);
2007 		req_get->set.index = id;
2008 		if (id != IPSET_INVALID_ID)
2009 			req_get->family = ip_set(inst, id)->family;
2010 		nfnl_unlock(NFNL_SUBSYS_IPSET);
2011 		goto copy;
2012 	}
2013 	case IP_SET_OP_GET_BYINDEX: {
2014 		struct ip_set_req_get_set *req_get = data;
2015 		struct ip_set *set;
2016 
2017 		if (*len != sizeof(struct ip_set_req_get_set) ||
2018 		    req_get->set.index >= inst->ip_set_max) {
2019 			ret = -EINVAL;
2020 			goto done;
2021 		}
2022 		nfnl_lock(NFNL_SUBSYS_IPSET);
2023 		set = ip_set(inst, req_get->set.index);
2024 		strncpy(req_get->set.name, set ? set->name : "",
2025 			IPSET_MAXNAMELEN);
2026 		nfnl_unlock(NFNL_SUBSYS_IPSET);
2027 		goto copy;
2028 	}
2029 	default:
2030 		ret = -EBADMSG;
2031 		goto done;
2032 	}	/* end of switch(op) */
2033 
2034 copy:
2035 	ret = copy_to_user(user, data, copylen);
2036 
2037 done:
2038 	vfree(data);
2039 	if (ret > 0)
2040 		ret = 0;
2041 	return ret;
2042 }
2043 
2044 static struct nf_sockopt_ops so_set __read_mostly = {
2045 	.pf		= PF_INET,
2046 	.get_optmin	= SO_IP_SET,
2047 	.get_optmax	= SO_IP_SET + 1,
2048 	.get		= ip_set_sockfn_get,
2049 	.owner		= THIS_MODULE,
2050 };
2051 
2052 static int __net_init
2053 ip_set_net_init(struct net *net)
2054 {
2055 	struct ip_set_net *inst = ip_set_pernet(net);
2056 	struct ip_set **list;
2057 
2058 	inst->ip_set_max = max_sets ? max_sets : CONFIG_IP_SET_MAX;
2059 	if (inst->ip_set_max >= IPSET_INVALID_ID)
2060 		inst->ip_set_max = IPSET_INVALID_ID - 1;
2061 
2062 	list = kcalloc(inst->ip_set_max, sizeof(struct ip_set *), GFP_KERNEL);
2063 	if (!list)
2064 		return -ENOMEM;
2065 	inst->is_deleted = false;
2066 	inst->is_destroyed = false;
2067 	rcu_assign_pointer(inst->ip_set_list, list);
2068 	return 0;
2069 }
2070 
2071 static void __net_exit
2072 ip_set_net_exit(struct net *net)
2073 {
2074 	struct ip_set_net *inst = ip_set_pernet(net);
2075 
2076 	struct ip_set *set = NULL;
2077 	ip_set_id_t i;
2078 
2079 	inst->is_deleted = true; /* flag for ip_set_nfnl_put */
2080 
2081 	nfnl_lock(NFNL_SUBSYS_IPSET);
2082 	for (i = 0; i < inst->ip_set_max; i++) {
2083 		set = ip_set(inst, i);
2084 		if (set) {
2085 			ip_set(inst, i) = NULL;
2086 			ip_set_destroy_set(set);
2087 		}
2088 	}
2089 	nfnl_unlock(NFNL_SUBSYS_IPSET);
2090 	kfree(rcu_dereference_protected(inst->ip_set_list, 1));
2091 }
2092 
2093 static struct pernet_operations ip_set_net_ops = {
2094 	.init	= ip_set_net_init,
2095 	.exit   = ip_set_net_exit,
2096 	.id	= &ip_set_net_id,
2097 	.size	= sizeof(struct ip_set_net)
2098 };
2099 
2100 static int __init
2101 ip_set_init(void)
2102 {
2103 	int ret = register_pernet_subsys(&ip_set_net_ops);
2104 
2105 	if (ret) {
2106 		pr_err("ip_set: cannot register pernet_subsys.\n");
2107 		return ret;
2108 	}
2109 
2110 	ret = nfnetlink_subsys_register(&ip_set_netlink_subsys);
2111 	if (ret != 0) {
2112 		pr_err("ip_set: cannot register with nfnetlink.\n");
2113 		unregister_pernet_subsys(&ip_set_net_ops);
2114 		return ret;
2115 	}
2116 
2117 	ret = nf_register_sockopt(&so_set);
2118 	if (ret != 0) {
2119 		pr_err("SO_SET registry failed: %d\n", ret);
2120 		nfnetlink_subsys_unregister(&ip_set_netlink_subsys);
2121 		unregister_pernet_subsys(&ip_set_net_ops);
2122 		return ret;
2123 	}
2124 
2125 	return 0;
2126 }
2127 
2128 static void __exit
2129 ip_set_fini(void)
2130 {
2131 	nf_unregister_sockopt(&so_set);
2132 	nfnetlink_subsys_unregister(&ip_set_netlink_subsys);
2133 
2134 	unregister_pernet_subsys(&ip_set_net_ops);
2135 	pr_debug("these are the famous last words\n");
2136 }
2137 
2138 module_init(ip_set_init);
2139 module_exit(ip_set_fini);
2140 
2141 MODULE_DESCRIPTION("ip_set: protocol " __stringify(IPSET_PROTOCOL));
2142