1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (C) 2003-2013 Jozsef Kadlecsik <kadlec@netfilter.org> */
3 
4 /* Kernel module implementing an IP set type: the hash:net type */
5 
6 #include <linux/jhash.h>
7 #include <linux/module.h>
8 #include <linux/ip.h>
9 #include <linux/skbuff.h>
10 #include <linux/errno.h>
11 #include <linux/random.h>
12 #include <net/ip.h>
13 #include <net/ipv6.h>
14 #include <net/netlink.h>
15 
16 #include <linux/netfilter.h>
17 #include <linux/netfilter/ipset/pfxlen.h>
18 #include <linux/netfilter/ipset/ip_set.h>
19 #include <linux/netfilter/ipset/ip_set_hash.h>
20 
21 #define IPSET_TYPE_REV_MIN	0
22 /*				1    Range as input support for IPv4 added */
23 /*				2    nomatch flag support added */
24 /*				3    Counters support added */
25 /*				4    Comments support added */
26 /*				5    Forceadd support added */
27 /*				6    skbinfo support added */
28 #define IPSET_TYPE_REV_MAX	7 /* bucketsize, initval support added */
29 
30 MODULE_LICENSE("GPL");
31 MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@netfilter.org>");
32 IP_SET_MODULE_DESC("hash:net", IPSET_TYPE_REV_MIN, IPSET_TYPE_REV_MAX);
33 MODULE_ALIAS("ip_set_hash:net");
34 
35 /* Type specific function prefix */
36 #define HTYPE		hash_net
37 #define IP_SET_HASH_WITH_NETS
38 
39 /* IPv4 variant */
40 
41 /* Member elements  */
42 struct hash_net4_elem {
43 	__be32 ip;
44 	u16 padding0;
45 	u8 nomatch;
46 	u8 cidr;
47 };
48 
49 /* Common functions */
50 
51 static bool
52 hash_net4_data_equal(const struct hash_net4_elem *ip1,
53 		     const struct hash_net4_elem *ip2,
54 		     u32 *multi)
55 {
56 	return ip1->ip == ip2->ip &&
57 	       ip1->cidr == ip2->cidr;
58 }
59 
60 static int
61 hash_net4_do_data_match(const struct hash_net4_elem *elem)
62 {
63 	return elem->nomatch ? -ENOTEMPTY : 1;
64 }
65 
66 static void
67 hash_net4_data_set_flags(struct hash_net4_elem *elem, u32 flags)
68 {
69 	elem->nomatch = (flags >> 16) & IPSET_FLAG_NOMATCH;
70 }
71 
72 static void
73 hash_net4_data_reset_flags(struct hash_net4_elem *elem, u8 *flags)
74 {
75 	swap(*flags, elem->nomatch);
76 }
77 
78 static void
79 hash_net4_data_netmask(struct hash_net4_elem *elem, u8 cidr)
80 {
81 	elem->ip &= ip_set_netmask(cidr);
82 	elem->cidr = cidr;
83 }
84 
85 static bool
86 hash_net4_data_list(struct sk_buff *skb, const struct hash_net4_elem *data)
87 {
88 	u32 flags = data->nomatch ? IPSET_FLAG_NOMATCH : 0;
89 
90 	if (nla_put_ipaddr4(skb, IPSET_ATTR_IP, data->ip) ||
91 	    nla_put_u8(skb, IPSET_ATTR_CIDR, data->cidr) ||
92 	    (flags &&
93 	     nla_put_net32(skb, IPSET_ATTR_CADT_FLAGS, htonl(flags))))
94 		goto nla_put_failure;
95 	return false;
96 
97 nla_put_failure:
98 	return true;
99 }
100 
101 static void
102 hash_net4_data_next(struct hash_net4_elem *next,
103 		    const struct hash_net4_elem *d)
104 {
105 	next->ip = d->ip;
106 }
107 
108 #define MTYPE		hash_net4
109 #define HOST_MASK	32
110 #include "ip_set_hash_gen.h"
111 
112 static int
113 hash_net4_kadt(struct ip_set *set, const struct sk_buff *skb,
114 	       const struct xt_action_param *par,
115 	       enum ipset_adt adt, struct ip_set_adt_opt *opt)
116 {
117 	const struct hash_net4 *h = set->data;
118 	ipset_adtfn adtfn = set->variant->adt[adt];
119 	struct hash_net4_elem e = {
120 		.cidr = INIT_CIDR(h->nets[0].cidr[0], HOST_MASK),
121 	};
122 	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
123 
124 	if (e.cidr == 0)
125 		return -EINVAL;
126 	if (adt == IPSET_TEST)
127 		e.cidr = HOST_MASK;
128 
129 	ip4addrptr(skb, opt->flags & IPSET_DIM_ONE_SRC, &e.ip);
130 	e.ip &= ip_set_netmask(e.cidr);
131 
132 	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
133 }
134 
135 static int
136 hash_net4_uadt(struct ip_set *set, struct nlattr *tb[],
137 	       enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
138 {
139 	struct hash_net4 *h = set->data;
140 	ipset_adtfn adtfn = set->variant->adt[adt];
141 	struct hash_net4_elem e = { .cidr = HOST_MASK };
142 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
143 	u32 ip = 0, ip_to = 0, i = 0;
144 	int ret;
145 
146 	if (tb[IPSET_ATTR_LINENO])
147 		*lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
148 
149 	if (unlikely(!tb[IPSET_ATTR_IP] ||
150 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_CADT_FLAGS)))
151 		return -IPSET_ERR_PROTOCOL;
152 
153 	ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP], &ip);
154 	if (ret)
155 		return ret;
156 
157 	ret = ip_set_get_extensions(set, tb, &ext);
158 	if (ret)
159 		return ret;
160 
161 	if (tb[IPSET_ATTR_CIDR]) {
162 		e.cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
163 		if (!e.cidr || e.cidr > HOST_MASK)
164 			return -IPSET_ERR_INVALID_CIDR;
165 	}
166 
167 	if (tb[IPSET_ATTR_CADT_FLAGS]) {
168 		u32 cadt_flags = ip_set_get_h32(tb[IPSET_ATTR_CADT_FLAGS]);
169 
170 		if (cadt_flags & IPSET_FLAG_NOMATCH)
171 			flags |= (IPSET_FLAG_NOMATCH << 16);
172 	}
173 
174 	if (adt == IPSET_TEST || !tb[IPSET_ATTR_IP_TO]) {
175 		e.ip = htonl(ip & ip_set_hostmask(e.cidr));
176 		ret = adtfn(set, &e, &ext, &ext, flags);
177 		return ip_set_enomatch(ret, flags, adt, set) ? -ret :
178 		       ip_set_eexist(ret, flags) ? 0 : ret;
179 	}
180 
181 	ip_to = ip;
182 	if (tb[IPSET_ATTR_IP_TO]) {
183 		ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP_TO], &ip_to);
184 		if (ret)
185 			return ret;
186 		if (ip_to < ip)
187 			swap(ip, ip_to);
188 		if (ip + UINT_MAX == ip_to)
189 			return -IPSET_ERR_HASH_RANGE;
190 	}
191 
192 	if (retried)
193 		ip = ntohl(h->next.ip);
194 	do {
195 		i++;
196 		e.ip = htonl(ip);
197 		if (i > IPSET_MAX_RANGE) {
198 			hash_net4_data_next(&h->next, &e);
199 			return -ERANGE;
200 		}
201 		ip = ip_set_range_to_cidr(ip, ip_to, &e.cidr);
202 		ret = adtfn(set, &e, &ext, &ext, flags);
203 		if (ret && !ip_set_eexist(ret, flags))
204 			return ret;
205 
206 		ret = 0;
207 	} while (ip++ < ip_to);
208 	return ret;
209 }
210 
211 /* IPv6 variant */
212 
213 struct hash_net6_elem {
214 	union nf_inet_addr ip;
215 	u16 padding0;
216 	u8 nomatch;
217 	u8 cidr;
218 };
219 
220 /* Common functions */
221 
222 static bool
223 hash_net6_data_equal(const struct hash_net6_elem *ip1,
224 		     const struct hash_net6_elem *ip2,
225 		     u32 *multi)
226 {
227 	return ipv6_addr_equal(&ip1->ip.in6, &ip2->ip.in6) &&
228 	       ip1->cidr == ip2->cidr;
229 }
230 
231 static int
232 hash_net6_do_data_match(const struct hash_net6_elem *elem)
233 {
234 	return elem->nomatch ? -ENOTEMPTY : 1;
235 }
236 
237 static void
238 hash_net6_data_set_flags(struct hash_net6_elem *elem, u32 flags)
239 {
240 	elem->nomatch = (flags >> 16) & IPSET_FLAG_NOMATCH;
241 }
242 
243 static void
244 hash_net6_data_reset_flags(struct hash_net6_elem *elem, u8 *flags)
245 {
246 	swap(*flags, elem->nomatch);
247 }
248 
249 static void
250 hash_net6_data_netmask(struct hash_net6_elem *elem, u8 cidr)
251 {
252 	ip6_netmask(&elem->ip, cidr);
253 	elem->cidr = cidr;
254 }
255 
256 static bool
257 hash_net6_data_list(struct sk_buff *skb, const struct hash_net6_elem *data)
258 {
259 	u32 flags = data->nomatch ? IPSET_FLAG_NOMATCH : 0;
260 
261 	if (nla_put_ipaddr6(skb, IPSET_ATTR_IP, &data->ip.in6) ||
262 	    nla_put_u8(skb, IPSET_ATTR_CIDR, data->cidr) ||
263 	    (flags &&
264 	     nla_put_net32(skb, IPSET_ATTR_CADT_FLAGS, htonl(flags))))
265 		goto nla_put_failure;
266 	return false;
267 
268 nla_put_failure:
269 	return true;
270 }
271 
272 static void
273 hash_net6_data_next(struct hash_net6_elem *next,
274 		    const struct hash_net6_elem *d)
275 {
276 }
277 
278 #undef MTYPE
279 #undef HOST_MASK
280 
281 #define MTYPE		hash_net6
282 #define HOST_MASK	128
283 #define IP_SET_EMIT_CREATE
284 #include "ip_set_hash_gen.h"
285 
286 static int
287 hash_net6_kadt(struct ip_set *set, const struct sk_buff *skb,
288 	       const struct xt_action_param *par,
289 	       enum ipset_adt adt, struct ip_set_adt_opt *opt)
290 {
291 	const struct hash_net6 *h = set->data;
292 	ipset_adtfn adtfn = set->variant->adt[adt];
293 	struct hash_net6_elem e = {
294 		.cidr = INIT_CIDR(h->nets[0].cidr[0], HOST_MASK),
295 	};
296 	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
297 
298 	if (e.cidr == 0)
299 		return -EINVAL;
300 	if (adt == IPSET_TEST)
301 		e.cidr = HOST_MASK;
302 
303 	ip6addrptr(skb, opt->flags & IPSET_DIM_ONE_SRC, &e.ip.in6);
304 	ip6_netmask(&e.ip, e.cidr);
305 
306 	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
307 }
308 
309 static int
310 hash_net6_uadt(struct ip_set *set, struct nlattr *tb[],
311 	       enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
312 {
313 	ipset_adtfn adtfn = set->variant->adt[adt];
314 	struct hash_net6_elem e = { .cidr = HOST_MASK };
315 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
316 	int ret;
317 
318 	if (tb[IPSET_ATTR_LINENO])
319 		*lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
320 
321 	if (unlikely(!tb[IPSET_ATTR_IP] ||
322 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_CADT_FLAGS)))
323 		return -IPSET_ERR_PROTOCOL;
324 	if (unlikely(tb[IPSET_ATTR_IP_TO]))
325 		return -IPSET_ERR_HASH_RANGE_UNSUPPORTED;
326 
327 	ret = ip_set_get_ipaddr6(tb[IPSET_ATTR_IP], &e.ip);
328 	if (ret)
329 		return ret;
330 
331 	ret = ip_set_get_extensions(set, tb, &ext);
332 	if (ret)
333 		return ret;
334 
335 	if (tb[IPSET_ATTR_CIDR]) {
336 		e.cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
337 		if (!e.cidr || e.cidr > HOST_MASK)
338 			return -IPSET_ERR_INVALID_CIDR;
339 	}
340 
341 	ip6_netmask(&e.ip, e.cidr);
342 
343 	if (tb[IPSET_ATTR_CADT_FLAGS]) {
344 		u32 cadt_flags = ip_set_get_h32(tb[IPSET_ATTR_CADT_FLAGS]);
345 
346 		if (cadt_flags & IPSET_FLAG_NOMATCH)
347 			flags |= (IPSET_FLAG_NOMATCH << 16);
348 	}
349 
350 	ret = adtfn(set, &e, &ext, &ext, flags);
351 
352 	return ip_set_enomatch(ret, flags, adt, set) ? -ret :
353 	       ip_set_eexist(ret, flags) ? 0 : ret;
354 }
355 
356 static struct ip_set_type hash_net_type __read_mostly = {
357 	.name		= "hash:net",
358 	.protocol	= IPSET_PROTOCOL,
359 	.features	= IPSET_TYPE_IP | IPSET_TYPE_NOMATCH,
360 	.dimension	= IPSET_DIM_ONE,
361 	.family		= NFPROTO_UNSPEC,
362 	.revision_min	= IPSET_TYPE_REV_MIN,
363 	.revision_max	= IPSET_TYPE_REV_MAX,
364 	.create_flags[IPSET_TYPE_REV_MAX] = IPSET_CREATE_FLAG_BUCKETSIZE,
365 	.create		= hash_net_create,
366 	.create_policy	= {
367 		[IPSET_ATTR_HASHSIZE]	= { .type = NLA_U32 },
368 		[IPSET_ATTR_MAXELEM]	= { .type = NLA_U32 },
369 		[IPSET_ATTR_INITVAL]	= { .type = NLA_U32 },
370 		[IPSET_ATTR_BUCKETSIZE]	= { .type = NLA_U8 },
371 		[IPSET_ATTR_RESIZE]	= { .type = NLA_U8  },
372 		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
373 		[IPSET_ATTR_CADT_FLAGS]	= { .type = NLA_U32 },
374 	},
375 	.adt_policy	= {
376 		[IPSET_ATTR_IP]		= { .type = NLA_NESTED },
377 		[IPSET_ATTR_IP_TO]	= { .type = NLA_NESTED },
378 		[IPSET_ATTR_CIDR]	= { .type = NLA_U8 },
379 		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
380 		[IPSET_ATTR_LINENO]	= { .type = NLA_U32 },
381 		[IPSET_ATTR_CADT_FLAGS]	= { .type = NLA_U32 },
382 		[IPSET_ATTR_BYTES]	= { .type = NLA_U64 },
383 		[IPSET_ATTR_PACKETS]	= { .type = NLA_U64 },
384 		[IPSET_ATTR_COMMENT]	= { .type = NLA_NUL_STRING,
385 					    .len  = IPSET_MAX_COMMENT_SIZE },
386 		[IPSET_ATTR_SKBMARK]	= { .type = NLA_U64 },
387 		[IPSET_ATTR_SKBPRIO]	= { .type = NLA_U32 },
388 		[IPSET_ATTR_SKBQUEUE]	= { .type = NLA_U16 },
389 	},
390 	.me		= THIS_MODULE,
391 };
392 
393 static int __init
394 hash_net_init(void)
395 {
396 	return ip_set_type_register(&hash_net_type);
397 }
398 
399 static void __exit
400 hash_net_fini(void)
401 {
402 	rcu_barrier();
403 	ip_set_type_unregister(&hash_net_type);
404 }
405 
406 module_init(hash_net_init);
407 module_exit(hash_net_fini);
408