1 /* Copyright (C) 2003-2013 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:net 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 
20 #include <linux/netfilter.h>
21 #include <linux/netfilter/ipset/pfxlen.h>
22 #include <linux/netfilter/ipset/ip_set.h>
23 #include <linux/netfilter/ipset/ip_set_hash.h>
24 
25 #define IPSET_TYPE_REV_MIN	0
26 /*				1    Range as input support for IPv4 added */
27 /*				2    nomatch flag support added */
28 /*				3    Counters support added */
29 /*				4    Comments support added */
30 /*				5    Forceadd support added */
31 #define IPSET_TYPE_REV_MAX	6 /* skbinfo mapping support added */
32 
33 MODULE_LICENSE("GPL");
34 MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>");
35 IP_SET_MODULE_DESC("hash:net", IPSET_TYPE_REV_MIN, IPSET_TYPE_REV_MAX);
36 MODULE_ALIAS("ip_set_hash:net");
37 
38 /* Type specific function prefix */
39 #define HTYPE		hash_net
40 #define IP_SET_HASH_WITH_NETS
41 
42 /* IPv4 variant */
43 
44 /* Member elements  */
45 struct hash_net4_elem {
46 	__be32 ip;
47 	u16 padding0;
48 	u8 nomatch;
49 	u8 cidr;
50 };
51 
52 /* Common functions */
53 
54 static inline bool
55 hash_net4_data_equal(const struct hash_net4_elem *ip1,
56 		     const struct hash_net4_elem *ip2,
57 		     u32 *multi)
58 {
59 	return ip1->ip == ip2->ip &&
60 	       ip1->cidr == ip2->cidr;
61 }
62 
63 static inline int
64 hash_net4_do_data_match(const struct hash_net4_elem *elem)
65 {
66 	return elem->nomatch ? -ENOTEMPTY : 1;
67 }
68 
69 static inline void
70 hash_net4_data_set_flags(struct hash_net4_elem *elem, u32 flags)
71 {
72 	elem->nomatch = (flags >> 16) & IPSET_FLAG_NOMATCH;
73 }
74 
75 static inline void
76 hash_net4_data_reset_flags(struct hash_net4_elem *elem, u8 *flags)
77 {
78 	swap(*flags, elem->nomatch);
79 }
80 
81 static inline void
82 hash_net4_data_netmask(struct hash_net4_elem *elem, u8 cidr)
83 {
84 	elem->ip &= ip_set_netmask(cidr);
85 	elem->cidr = cidr;
86 }
87 
88 static bool
89 hash_net4_data_list(struct sk_buff *skb, const struct hash_net4_elem *data)
90 {
91 	u32 flags = data->nomatch ? IPSET_FLAG_NOMATCH : 0;
92 
93 	if (nla_put_ipaddr4(skb, IPSET_ATTR_IP, data->ip) ||
94 	    nla_put_u8(skb, IPSET_ATTR_CIDR, data->cidr) ||
95 	    (flags &&
96 	     nla_put_net32(skb, IPSET_ATTR_CADT_FLAGS, htonl(flags))))
97 		goto nla_put_failure;
98 	return false;
99 
100 nla_put_failure:
101 	return true;
102 }
103 
104 static inline void
105 hash_net4_data_next(struct hash_net4_elem *next,
106 		    const struct hash_net4_elem *d)
107 {
108 	next->ip = d->ip;
109 }
110 
111 #define MTYPE		hash_net4
112 #define HOST_MASK	32
113 #include "ip_set_hash_gen.h"
114 
115 static int
116 hash_net4_kadt(struct ip_set *set, const struct sk_buff *skb,
117 	       const struct xt_action_param *par,
118 	       enum ipset_adt adt, struct ip_set_adt_opt *opt)
119 {
120 	const struct hash_net *h = set->data;
121 	ipset_adtfn adtfn = set->variant->adt[adt];
122 	struct hash_net4_elem e = {
123 		.cidr = INIT_CIDR(h->nets[0].cidr[0], HOST_MASK),
124 	};
125 	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
126 
127 	if (e.cidr == 0)
128 		return -EINVAL;
129 	if (adt == IPSET_TEST)
130 		e.cidr = HOST_MASK;
131 
132 	ip4addrptr(skb, opt->flags & IPSET_DIM_ONE_SRC, &e.ip);
133 	e.ip &= ip_set_netmask(e.cidr);
134 
135 	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
136 }
137 
138 static int
139 hash_net4_uadt(struct ip_set *set, struct nlattr *tb[],
140 	       enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
141 {
142 	const struct hash_net *h = set->data;
143 	ipset_adtfn adtfn = set->variant->adt[adt];
144 	struct hash_net4_elem e = { .cidr = HOST_MASK };
145 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
146 	u32 ip = 0, ip_to = 0, last;
147 	int ret;
148 
149 	if (tb[IPSET_ATTR_LINENO])
150 		*lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
151 
152 	if (unlikely(!tb[IPSET_ATTR_IP] ||
153 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_CADT_FLAGS)))
154 		return -IPSET_ERR_PROTOCOL;
155 
156 	ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP], &ip);
157 	if (ret)
158 		return ret;
159 
160 	ret = ip_set_get_extensions(set, tb, &ext);
161 	if (ret)
162 		return ret;
163 
164 	if (tb[IPSET_ATTR_CIDR]) {
165 		e.cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
166 		if (!e.cidr || e.cidr > HOST_MASK)
167 			return -IPSET_ERR_INVALID_CIDR;
168 	}
169 
170 	if (tb[IPSET_ATTR_CADT_FLAGS]) {
171 		u32 cadt_flags = ip_set_get_h32(tb[IPSET_ATTR_CADT_FLAGS]);
172 
173 		if (cadt_flags & IPSET_FLAG_NOMATCH)
174 			flags |= (IPSET_FLAG_NOMATCH << 16);
175 	}
176 
177 	if (adt == IPSET_TEST || !tb[IPSET_ATTR_IP_TO]) {
178 		e.ip = htonl(ip & ip_set_hostmask(e.cidr));
179 		ret = adtfn(set, &e, &ext, &ext, flags);
180 		return ip_set_enomatch(ret, flags, adt, set) ? -ret :
181 		       ip_set_eexist(ret, flags) ? 0 : ret;
182 	}
183 
184 	ip_to = ip;
185 	if (tb[IPSET_ATTR_IP_TO]) {
186 		ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP_TO], &ip_to);
187 		if (ret)
188 			return ret;
189 		if (ip_to < ip)
190 			swap(ip, ip_to);
191 		if (ip + UINT_MAX == ip_to)
192 			return -IPSET_ERR_HASH_RANGE;
193 	}
194 	if (retried)
195 		ip = ntohl(h->next.ip);
196 	while (!after(ip, ip_to)) {
197 		e.ip = htonl(ip);
198 		last = ip_set_range_to_cidr(ip, ip_to, &e.cidr);
199 		ret = adtfn(set, &e, &ext, &ext, flags);
200 		if (ret && !ip_set_eexist(ret, flags))
201 			return ret;
202 
203 		ret = 0;
204 		ip = last + 1;
205 	}
206 	return ret;
207 }
208 
209 /* IPv6 variant */
210 
211 struct hash_net6_elem {
212 	union nf_inet_addr ip;
213 	u16 padding0;
214 	u8 nomatch;
215 	u8 cidr;
216 };
217 
218 /* Common functions */
219 
220 static inline bool
221 hash_net6_data_equal(const struct hash_net6_elem *ip1,
222 		     const struct hash_net6_elem *ip2,
223 		     u32 *multi)
224 {
225 	return ipv6_addr_equal(&ip1->ip.in6, &ip2->ip.in6) &&
226 	       ip1->cidr == ip2->cidr;
227 }
228 
229 static inline int
230 hash_net6_do_data_match(const struct hash_net6_elem *elem)
231 {
232 	return elem->nomatch ? -ENOTEMPTY : 1;
233 }
234 
235 static inline void
236 hash_net6_data_set_flags(struct hash_net6_elem *elem, u32 flags)
237 {
238 	elem->nomatch = (flags >> 16) & IPSET_FLAG_NOMATCH;
239 }
240 
241 static inline void
242 hash_net6_data_reset_flags(struct hash_net6_elem *elem, u8 *flags)
243 {
244 	swap(*flags, elem->nomatch);
245 }
246 
247 static inline void
248 hash_net6_data_netmask(struct hash_net6_elem *elem, u8 cidr)
249 {
250 	ip6_netmask(&elem->ip, cidr);
251 	elem->cidr = cidr;
252 }
253 
254 static bool
255 hash_net6_data_list(struct sk_buff *skb, const struct hash_net6_elem *data)
256 {
257 	u32 flags = data->nomatch ? IPSET_FLAG_NOMATCH : 0;
258 
259 	if (nla_put_ipaddr6(skb, IPSET_ATTR_IP, &data->ip.in6) ||
260 	    nla_put_u8(skb, IPSET_ATTR_CIDR, data->cidr) ||
261 	    (flags &&
262 	     nla_put_net32(skb, IPSET_ATTR_CADT_FLAGS, htonl(flags))))
263 		goto nla_put_failure;
264 	return false;
265 
266 nla_put_failure:
267 	return true;
268 }
269 
270 static inline void
271 hash_net6_data_next(struct hash_net4_elem *next,
272 		    const struct hash_net6_elem *d)
273 {
274 }
275 
276 #undef MTYPE
277 #undef HOST_MASK
278 
279 #define MTYPE		hash_net6
280 #define HOST_MASK	128
281 #define IP_SET_EMIT_CREATE
282 #include "ip_set_hash_gen.h"
283 
284 static int
285 hash_net6_kadt(struct ip_set *set, const struct sk_buff *skb,
286 	       const struct xt_action_param *par,
287 	       enum ipset_adt adt, struct ip_set_adt_opt *opt)
288 {
289 	const struct hash_net *h = set->data;
290 	ipset_adtfn adtfn = set->variant->adt[adt];
291 	struct hash_net6_elem e = {
292 		.cidr = INIT_CIDR(h->nets[0].cidr[0], HOST_MASK),
293 	};
294 	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
295 
296 	if (e.cidr == 0)
297 		return -EINVAL;
298 	if (adt == IPSET_TEST)
299 		e.cidr = HOST_MASK;
300 
301 	ip6addrptr(skb, opt->flags & IPSET_DIM_ONE_SRC, &e.ip.in6);
302 	ip6_netmask(&e.ip, e.cidr);
303 
304 	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
305 }
306 
307 static int
308 hash_net6_uadt(struct ip_set *set, struct nlattr *tb[],
309 	       enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
310 {
311 	ipset_adtfn adtfn = set->variant->adt[adt];
312 	struct hash_net6_elem e = { .cidr = HOST_MASK };
313 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
314 	int ret;
315 
316 	if (tb[IPSET_ATTR_LINENO])
317 		*lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
318 
319 	if (unlikely(!tb[IPSET_ATTR_IP] ||
320 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_CADT_FLAGS)))
321 		return -IPSET_ERR_PROTOCOL;
322 	if (unlikely(tb[IPSET_ATTR_IP_TO]))
323 		return -IPSET_ERR_HASH_RANGE_UNSUPPORTED;
324 
325 	ret = ip_set_get_ipaddr6(tb[IPSET_ATTR_IP], &e.ip);
326 	if (ret)
327 		return ret;
328 
329 	ret = ip_set_get_extensions(set, tb, &ext);
330 	if (ret)
331 		return ret;
332 
333 	if (tb[IPSET_ATTR_CIDR]) {
334 		e.cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
335 		if (!e.cidr || e.cidr > HOST_MASK)
336 			return -IPSET_ERR_INVALID_CIDR;
337 	}
338 
339 	ip6_netmask(&e.ip, e.cidr);
340 
341 	if (tb[IPSET_ATTR_CADT_FLAGS]) {
342 		u32 cadt_flags = ip_set_get_h32(tb[IPSET_ATTR_CADT_FLAGS]);
343 
344 		if (cadt_flags & IPSET_FLAG_NOMATCH)
345 			flags |= (IPSET_FLAG_NOMATCH << 16);
346 	}
347 
348 	ret = adtfn(set, &e, &ext, &ext, flags);
349 
350 	return ip_set_enomatch(ret, flags, adt, set) ? -ret :
351 	       ip_set_eexist(ret, flags) ? 0 : ret;
352 }
353 
354 static struct ip_set_type hash_net_type __read_mostly = {
355 	.name		= "hash:net",
356 	.protocol	= IPSET_PROTOCOL,
357 	.features	= IPSET_TYPE_IP | IPSET_TYPE_NOMATCH,
358 	.dimension	= IPSET_DIM_ONE,
359 	.family		= NFPROTO_UNSPEC,
360 	.revision_min	= IPSET_TYPE_REV_MIN,
361 	.revision_max	= IPSET_TYPE_REV_MAX,
362 	.create		= hash_net_create,
363 	.create_policy	= {
364 		[IPSET_ATTR_HASHSIZE]	= { .type = NLA_U32 },
365 		[IPSET_ATTR_MAXELEM]	= { .type = NLA_U32 },
366 		[IPSET_ATTR_PROBES]	= { .type = NLA_U8 },
367 		[IPSET_ATTR_RESIZE]	= { .type = NLA_U8  },
368 		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
369 		[IPSET_ATTR_CADT_FLAGS]	= { .type = NLA_U32 },
370 	},
371 	.adt_policy	= {
372 		[IPSET_ATTR_IP]		= { .type = NLA_NESTED },
373 		[IPSET_ATTR_IP_TO]	= { .type = NLA_NESTED },
374 		[IPSET_ATTR_CIDR]	= { .type = NLA_U8 },
375 		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
376 		[IPSET_ATTR_CADT_FLAGS]	= { .type = NLA_U32 },
377 		[IPSET_ATTR_BYTES]	= { .type = NLA_U64 },
378 		[IPSET_ATTR_PACKETS]	= { .type = NLA_U64 },
379 		[IPSET_ATTR_COMMENT]	= { .type = NLA_NUL_STRING,
380 					    .len  = IPSET_MAX_COMMENT_SIZE },
381 		[IPSET_ATTR_SKBMARK]	= { .type = NLA_U64 },
382 		[IPSET_ATTR_SKBPRIO]	= { .type = NLA_U32 },
383 		[IPSET_ATTR_SKBQUEUE]	= { .type = NLA_U16 },
384 	},
385 	.me		= THIS_MODULE,
386 };
387 
388 static int __init
389 hash_net_init(void)
390 {
391 	return ip_set_type_register(&hash_net_type);
392 }
393 
394 static void __exit
395 hash_net_fini(void)
396 {
397 	rcu_barrier();
398 	ip_set_type_unregister(&hash_net_type);
399 }
400 
401 module_init(hash_net_init);
402 module_exit(hash_net_fini);
403