1 /* Copyright (C) 2003-2011 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
2  *
3  * This program is free software; you can redistribute it and/or modify
4  * it under the terms of the GNU General Public License version 2 as
5  * published by the Free Software Foundation.
6  */
7 
8 /* Kernel module implementing an IP set type: the hash:ip type */
9 
10 #include <linux/jhash.h>
11 #include <linux/module.h>
12 #include <linux/ip.h>
13 #include <linux/skbuff.h>
14 #include <linux/errno.h>
15 #include <linux/random.h>
16 #include <net/ip.h>
17 #include <net/ipv6.h>
18 #include <net/netlink.h>
19 #include <net/tcp.h>
20 
21 #include <linux/netfilter.h>
22 #include <linux/netfilter/ipset/pfxlen.h>
23 #include <linux/netfilter/ipset/ip_set.h>
24 #include <linux/netfilter/ipset/ip_set_timeout.h>
25 #include <linux/netfilter/ipset/ip_set_hash.h>
26 
27 MODULE_LICENSE("GPL");
28 MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>");
29 MODULE_DESCRIPTION("hash:ip type of IP sets");
30 MODULE_ALIAS("ip_set_hash:ip");
31 
32 /* Type specific function prefix */
33 #define TYPE		hash_ip
34 
35 static bool
36 hash_ip_same_set(const struct ip_set *a, const struct ip_set *b);
37 
38 #define hash_ip4_same_set	hash_ip_same_set
39 #define hash_ip6_same_set	hash_ip_same_set
40 
41 /* The type variant functions: IPv4 */
42 
43 /* Member elements without timeout */
44 struct hash_ip4_elem {
45 	__be32 ip;
46 };
47 
48 /* Member elements with timeout support */
49 struct hash_ip4_telem {
50 	__be32 ip;
51 	unsigned long timeout;
52 };
53 
54 static inline bool
hash_ip4_data_equal(const struct hash_ip4_elem * ip1,const struct hash_ip4_elem * ip2,u32 * multi)55 hash_ip4_data_equal(const struct hash_ip4_elem *ip1,
56 		    const struct hash_ip4_elem *ip2,
57 		    u32 *multi)
58 {
59 	return ip1->ip == ip2->ip;
60 }
61 
62 static inline bool
hash_ip4_data_isnull(const struct hash_ip4_elem * elem)63 hash_ip4_data_isnull(const struct hash_ip4_elem *elem)
64 {
65 	return elem->ip == 0;
66 }
67 
68 static inline void
hash_ip4_data_copy(struct hash_ip4_elem * dst,const struct hash_ip4_elem * src)69 hash_ip4_data_copy(struct hash_ip4_elem *dst, const struct hash_ip4_elem *src)
70 {
71 	dst->ip = src->ip;
72 }
73 
74 /* Zero valued IP addresses cannot be stored */
75 static inline void
hash_ip4_data_zero_out(struct hash_ip4_elem * elem)76 hash_ip4_data_zero_out(struct hash_ip4_elem *elem)
77 {
78 	elem->ip = 0;
79 }
80 
81 static inline bool
hash_ip4_data_list(struct sk_buff * skb,const struct hash_ip4_elem * data)82 hash_ip4_data_list(struct sk_buff *skb, const struct hash_ip4_elem *data)
83 {
84 	NLA_PUT_IPADDR4(skb, IPSET_ATTR_IP, data->ip);
85 	return 0;
86 
87 nla_put_failure:
88 	return 1;
89 }
90 
91 static bool
hash_ip4_data_tlist(struct sk_buff * skb,const struct hash_ip4_elem * data)92 hash_ip4_data_tlist(struct sk_buff *skb, const struct hash_ip4_elem *data)
93 {
94 	const struct hash_ip4_telem *tdata =
95 		(const struct hash_ip4_telem *)data;
96 
97 	NLA_PUT_IPADDR4(skb, IPSET_ATTR_IP, tdata->ip);
98 	NLA_PUT_NET32(skb, IPSET_ATTR_TIMEOUT,
99 		      htonl(ip_set_timeout_get(tdata->timeout)));
100 
101 	return 0;
102 
103 nla_put_failure:
104 	return 1;
105 }
106 
107 #define IP_SET_HASH_WITH_NETMASK
108 #define PF		4
109 #define HOST_MASK	32
110 #include <linux/netfilter/ipset/ip_set_ahash.h>
111 
112 static inline void
hash_ip4_data_next(struct ip_set_hash * h,const struct hash_ip4_elem * d)113 hash_ip4_data_next(struct ip_set_hash *h, const struct hash_ip4_elem *d)
114 {
115 	h->next.ip = ntohl(d->ip);
116 }
117 
118 static int
hash_ip4_kadt(struct ip_set * set,const struct sk_buff * skb,const struct xt_action_param * par,enum ipset_adt adt,const struct ip_set_adt_opt * opt)119 hash_ip4_kadt(struct ip_set *set, const struct sk_buff *skb,
120 	      const struct xt_action_param *par,
121 	      enum ipset_adt adt, const struct ip_set_adt_opt *opt)
122 {
123 	const struct ip_set_hash *h = set->data;
124 	ipset_adtfn adtfn = set->variant->adt[adt];
125 	__be32 ip;
126 
127 	ip4addrptr(skb, opt->flags & IPSET_DIM_ONE_SRC, &ip);
128 	ip &= ip_set_netmask(h->netmask);
129 	if (ip == 0)
130 		return -EINVAL;
131 
132 	return adtfn(set, &ip, opt_timeout(opt, h), opt->cmdflags);
133 }
134 
135 static int
hash_ip4_uadt(struct ip_set * set,struct nlattr * tb[],enum ipset_adt adt,u32 * lineno,u32 flags,bool retried)136 hash_ip4_uadt(struct ip_set *set, struct nlattr *tb[],
137 	      enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
138 {
139 	const struct ip_set_hash *h = set->data;
140 	ipset_adtfn adtfn = set->variant->adt[adt];
141 	u32 ip, ip_to, hosts, timeout = h->timeout;
142 	__be32 nip;
143 	int ret = 0;
144 
145 	if (unlikely(!tb[IPSET_ATTR_IP] ||
146 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_TIMEOUT)))
147 		return -IPSET_ERR_PROTOCOL;
148 
149 	if (tb[IPSET_ATTR_LINENO])
150 		*lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
151 
152 	ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP], &ip);
153 	if (ret)
154 		return ret;
155 
156 	ip &= ip_set_hostmask(h->netmask);
157 
158 	if (tb[IPSET_ATTR_TIMEOUT]) {
159 		if (!with_timeout(h->timeout))
160 			return -IPSET_ERR_TIMEOUT;
161 		timeout = ip_set_timeout_uget(tb[IPSET_ATTR_TIMEOUT]);
162 	}
163 
164 	if (adt == IPSET_TEST) {
165 		nip = htonl(ip);
166 		if (nip == 0)
167 			return -IPSET_ERR_HASH_ELEM;
168 		return adtfn(set, &nip, timeout, flags);
169 	}
170 
171 	if (tb[IPSET_ATTR_IP_TO]) {
172 		ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP_TO], &ip_to);
173 		if (ret)
174 			return ret;
175 		if (ip > ip_to)
176 			swap(ip, ip_to);
177 	} else if (tb[IPSET_ATTR_CIDR]) {
178 		u8 cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
179 
180 		if (cidr > 32)
181 			return -IPSET_ERR_INVALID_CIDR;
182 		ip_set_mask_from_to(ip, ip_to, cidr);
183 	} else
184 		ip_to = ip;
185 
186 	hosts = h->netmask == 32 ? 1 : 2 << (32 - h->netmask - 1);
187 
188 	if (retried)
189 		ip = h->next.ip;
190 	for (; !before(ip_to, ip); ip += hosts) {
191 		nip = htonl(ip);
192 		if (nip == 0)
193 			return -IPSET_ERR_HASH_ELEM;
194 		ret = adtfn(set, &nip, timeout, flags);
195 
196 		if (ret && !ip_set_eexist(ret, flags))
197 			return ret;
198 		else
199 			ret = 0;
200 	}
201 	return ret;
202 }
203 
204 static bool
hash_ip_same_set(const struct ip_set * a,const struct ip_set * b)205 hash_ip_same_set(const struct ip_set *a, const struct ip_set *b)
206 {
207 	const struct ip_set_hash *x = a->data;
208 	const struct ip_set_hash *y = b->data;
209 
210 	/* Resizing changes htable_bits, so we ignore it */
211 	return x->maxelem == y->maxelem &&
212 	       x->timeout == y->timeout &&
213 	       x->netmask == y->netmask;
214 }
215 
216 /* The type variant functions: IPv6 */
217 
218 struct hash_ip6_elem {
219 	union nf_inet_addr ip;
220 };
221 
222 struct hash_ip6_telem {
223 	union nf_inet_addr ip;
224 	unsigned long timeout;
225 };
226 
227 static inline bool
hash_ip6_data_equal(const struct hash_ip6_elem * ip1,const struct hash_ip6_elem * ip2,u32 * multi)228 hash_ip6_data_equal(const struct hash_ip6_elem *ip1,
229 		    const struct hash_ip6_elem *ip2,
230 		    u32 *multi)
231 {
232 	return ipv6_addr_cmp(&ip1->ip.in6, &ip2->ip.in6) == 0;
233 }
234 
235 static inline bool
hash_ip6_data_isnull(const struct hash_ip6_elem * elem)236 hash_ip6_data_isnull(const struct hash_ip6_elem *elem)
237 {
238 	return ipv6_addr_any(&elem->ip.in6);
239 }
240 
241 static inline void
hash_ip6_data_copy(struct hash_ip6_elem * dst,const struct hash_ip6_elem * src)242 hash_ip6_data_copy(struct hash_ip6_elem *dst, const struct hash_ip6_elem *src)
243 {
244 	dst->ip.in6 = src->ip.in6;
245 }
246 
247 static inline void
hash_ip6_data_zero_out(struct hash_ip6_elem * elem)248 hash_ip6_data_zero_out(struct hash_ip6_elem *elem)
249 {
250 	ipv6_addr_set(&elem->ip.in6, 0, 0, 0, 0);
251 }
252 
253 static inline void
ip6_netmask(union nf_inet_addr * ip,u8 prefix)254 ip6_netmask(union nf_inet_addr *ip, u8 prefix)
255 {
256 	ip->ip6[0] &= ip_set_netmask6(prefix)[0];
257 	ip->ip6[1] &= ip_set_netmask6(prefix)[1];
258 	ip->ip6[2] &= ip_set_netmask6(prefix)[2];
259 	ip->ip6[3] &= ip_set_netmask6(prefix)[3];
260 }
261 
262 static bool
hash_ip6_data_list(struct sk_buff * skb,const struct hash_ip6_elem * data)263 hash_ip6_data_list(struct sk_buff *skb, const struct hash_ip6_elem *data)
264 {
265 	NLA_PUT_IPADDR6(skb, IPSET_ATTR_IP, &data->ip);
266 	return 0;
267 
268 nla_put_failure:
269 	return 1;
270 }
271 
272 static bool
hash_ip6_data_tlist(struct sk_buff * skb,const struct hash_ip6_elem * data)273 hash_ip6_data_tlist(struct sk_buff *skb, const struct hash_ip6_elem *data)
274 {
275 	const struct hash_ip6_telem *e =
276 		(const struct hash_ip6_telem *)data;
277 
278 	NLA_PUT_IPADDR6(skb, IPSET_ATTR_IP, &e->ip);
279 	NLA_PUT_NET32(skb, IPSET_ATTR_TIMEOUT,
280 		      htonl(ip_set_timeout_get(e->timeout)));
281 	return 0;
282 
283 nla_put_failure:
284 	return 1;
285 }
286 
287 #undef PF
288 #undef HOST_MASK
289 
290 #define PF		6
291 #define HOST_MASK	128
292 #include <linux/netfilter/ipset/ip_set_ahash.h>
293 
294 static inline void
hash_ip6_data_next(struct ip_set_hash * h,const struct hash_ip6_elem * d)295 hash_ip6_data_next(struct ip_set_hash *h, const struct hash_ip6_elem *d)
296 {
297 }
298 
299 static int
hash_ip6_kadt(struct ip_set * set,const struct sk_buff * skb,const struct xt_action_param * par,enum ipset_adt adt,const struct ip_set_adt_opt * opt)300 hash_ip6_kadt(struct ip_set *set, const struct sk_buff *skb,
301 	      const struct xt_action_param *par,
302 	      enum ipset_adt adt, const struct ip_set_adt_opt *opt)
303 {
304 	const struct ip_set_hash *h = set->data;
305 	ipset_adtfn adtfn = set->variant->adt[adt];
306 	union nf_inet_addr ip;
307 
308 	ip6addrptr(skb, opt->flags & IPSET_DIM_ONE_SRC, &ip.in6);
309 	ip6_netmask(&ip, h->netmask);
310 	if (ipv6_addr_any(&ip.in6))
311 		return -EINVAL;
312 
313 	return adtfn(set, &ip, opt_timeout(opt, h), opt->cmdflags);
314 }
315 
316 static const struct nla_policy hash_ip6_adt_policy[IPSET_ATTR_ADT_MAX + 1] = {
317 	[IPSET_ATTR_IP]		= { .type = NLA_NESTED },
318 	[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
319 	[IPSET_ATTR_LINENO]	= { .type = NLA_U32 },
320 };
321 
322 static int
hash_ip6_uadt(struct ip_set * set,struct nlattr * tb[],enum ipset_adt adt,u32 * lineno,u32 flags,bool retried)323 hash_ip6_uadt(struct ip_set *set, struct nlattr *tb[],
324 	      enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
325 {
326 	const struct ip_set_hash *h = set->data;
327 	ipset_adtfn adtfn = set->variant->adt[adt];
328 	union nf_inet_addr ip;
329 	u32 timeout = h->timeout;
330 	int ret;
331 
332 	if (unlikely(!tb[IPSET_ATTR_IP] ||
333 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_TIMEOUT) ||
334 		     tb[IPSET_ATTR_IP_TO] ||
335 		     tb[IPSET_ATTR_CIDR]))
336 		return -IPSET_ERR_PROTOCOL;
337 
338 	if (tb[IPSET_ATTR_LINENO])
339 		*lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
340 
341 	ret = ip_set_get_ipaddr6(tb[IPSET_ATTR_IP], &ip);
342 	if (ret)
343 		return ret;
344 
345 	ip6_netmask(&ip, h->netmask);
346 	if (ipv6_addr_any(&ip.in6))
347 		return -IPSET_ERR_HASH_ELEM;
348 
349 	if (tb[IPSET_ATTR_TIMEOUT]) {
350 		if (!with_timeout(h->timeout))
351 			return -IPSET_ERR_TIMEOUT;
352 		timeout = ip_set_timeout_uget(tb[IPSET_ATTR_TIMEOUT]);
353 	}
354 
355 	ret = adtfn(set, &ip, timeout, flags);
356 
357 	return ip_set_eexist(ret, flags) ? 0 : ret;
358 }
359 
360 /* Create hash:ip type of sets */
361 
362 static int
hash_ip_create(struct ip_set * set,struct nlattr * tb[],u32 flags)363 hash_ip_create(struct ip_set *set, struct nlattr *tb[], u32 flags)
364 {
365 	u32 hashsize = IPSET_DEFAULT_HASHSIZE, maxelem = IPSET_DEFAULT_MAXELEM;
366 	u8 netmask, hbits;
367 	struct ip_set_hash *h;
368 
369 	if (!(set->family == AF_INET || set->family == AF_INET6))
370 		return -IPSET_ERR_INVALID_FAMILY;
371 	netmask = set->family == AF_INET ? 32 : 128;
372 	pr_debug("Create set %s with family %s\n",
373 		 set->name, set->family == AF_INET ? "inet" : "inet6");
374 
375 	if (unlikely(!ip_set_optattr_netorder(tb, IPSET_ATTR_HASHSIZE) ||
376 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_MAXELEM) ||
377 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_TIMEOUT)))
378 		return -IPSET_ERR_PROTOCOL;
379 
380 	if (tb[IPSET_ATTR_HASHSIZE]) {
381 		hashsize = ip_set_get_h32(tb[IPSET_ATTR_HASHSIZE]);
382 		if (hashsize < IPSET_MIMINAL_HASHSIZE)
383 			hashsize = IPSET_MIMINAL_HASHSIZE;
384 	}
385 
386 	if (tb[IPSET_ATTR_MAXELEM])
387 		maxelem = ip_set_get_h32(tb[IPSET_ATTR_MAXELEM]);
388 
389 	if (tb[IPSET_ATTR_NETMASK]) {
390 		netmask = nla_get_u8(tb[IPSET_ATTR_NETMASK]);
391 
392 		if ((set->family == AF_INET && netmask > 32) ||
393 		    (set->family == AF_INET6 && netmask > 128) ||
394 		    netmask == 0)
395 			return -IPSET_ERR_INVALID_NETMASK;
396 	}
397 
398 	h = kzalloc(sizeof(*h), GFP_KERNEL);
399 	if (!h)
400 		return -ENOMEM;
401 
402 	h->maxelem = maxelem;
403 	h->netmask = netmask;
404 	get_random_bytes(&h->initval, sizeof(h->initval));
405 	h->timeout = IPSET_NO_TIMEOUT;
406 
407 	hbits = htable_bits(hashsize);
408 	h->table = ip_set_alloc(
409 			sizeof(struct htable)
410 			+ jhash_size(hbits) * sizeof(struct hbucket));
411 	if (!h->table) {
412 		kfree(h);
413 		return -ENOMEM;
414 	}
415 	h->table->htable_bits = hbits;
416 
417 	set->data = h;
418 
419 	if (tb[IPSET_ATTR_TIMEOUT]) {
420 		h->timeout = ip_set_timeout_uget(tb[IPSET_ATTR_TIMEOUT]);
421 
422 		set->variant = set->family == AF_INET
423 			? &hash_ip4_tvariant : &hash_ip6_tvariant;
424 
425 		if (set->family == AF_INET)
426 			hash_ip4_gc_init(set);
427 		else
428 			hash_ip6_gc_init(set);
429 	} else {
430 		set->variant = set->family == AF_INET
431 			? &hash_ip4_variant : &hash_ip6_variant;
432 	}
433 
434 	pr_debug("create %s hashsize %u (%u) maxelem %u: %p(%p)\n",
435 		 set->name, jhash_size(h->table->htable_bits),
436 		 h->table->htable_bits, h->maxelem, set->data, h->table);
437 
438 	return 0;
439 }
440 
441 static struct ip_set_type hash_ip_type __read_mostly = {
442 	.name		= "hash:ip",
443 	.protocol	= IPSET_PROTOCOL,
444 	.features	= IPSET_TYPE_IP,
445 	.dimension	= IPSET_DIM_ONE,
446 	.family		= AF_UNSPEC,
447 	.revision_min	= 0,
448 	.revision_max	= 0,
449 	.create		= hash_ip_create,
450 	.create_policy	= {
451 		[IPSET_ATTR_HASHSIZE]	= { .type = NLA_U32 },
452 		[IPSET_ATTR_MAXELEM]	= { .type = NLA_U32 },
453 		[IPSET_ATTR_PROBES]	= { .type = NLA_U8 },
454 		[IPSET_ATTR_RESIZE]	= { .type = NLA_U8  },
455 		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
456 		[IPSET_ATTR_NETMASK]	= { .type = NLA_U8  },
457 	},
458 	.adt_policy	= {
459 		[IPSET_ATTR_IP]		= { .type = NLA_NESTED },
460 		[IPSET_ATTR_IP_TO]	= { .type = NLA_NESTED },
461 		[IPSET_ATTR_CIDR]	= { .type = NLA_U8 },
462 		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
463 		[IPSET_ATTR_LINENO]	= { .type = NLA_U32 },
464 	},
465 	.me		= THIS_MODULE,
466 };
467 
468 static int __init
hash_ip_init(void)469 hash_ip_init(void)
470 {
471 	return ip_set_type_register(&hash_ip_type);
472 }
473 
474 static void __exit
hash_ip_fini(void)475 hash_ip_fini(void)
476 {
477 	ip_set_type_unregister(&hash_ip_type);
478 }
479 
480 module_init(hash_ip_init);
481 module_exit(hash_ip_fini);
482