xref: /linux/net/netfilter/ipset/ip_set_bitmap_ip.c (revision 42874e4eb35bdfc54f8514685e50434098ba4f6c) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (C) 2000-2002 Joakim Axelsson <gozem@linux.nu>
3  *                         Patrick Schaaf <bof@bof.de>
4  * Copyright (C) 2003-2013 Jozsef Kadlecsik <kadlec@netfilter.org>
5  */
6 
7 /* Kernel module implementing an IP set type: the bitmap:ip type */
8 
9 #include <linux/module.h>
10 #include <linux/ip.h>
11 #include <linux/skbuff.h>
12 #include <linux/errno.h>
13 #include <linux/bitops.h>
14 #include <linux/spinlock.h>
15 #include <linux/netlink.h>
16 #include <linux/jiffies.h>
17 #include <linux/timer.h>
18 #include <net/netlink.h>
19 #include <net/tcp.h>
20 
21 #include <linux/netfilter/ipset/pfxlen.h>
22 #include <linux/netfilter/ipset/ip_set.h>
23 #include <linux/netfilter/ipset/ip_set_bitmap.h>
24 
25 #define IPSET_TYPE_REV_MIN	0
26 /*				1	   Counter support added */
27 /*				2	   Comment support added */
28 #define IPSET_TYPE_REV_MAX	3	/* skbinfo support added */
29 
30 MODULE_LICENSE("GPL");
31 MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@netfilter.org>");
32 IP_SET_MODULE_DESC("bitmap:ip", IPSET_TYPE_REV_MIN, IPSET_TYPE_REV_MAX);
33 MODULE_ALIAS("ip_set_bitmap:ip");
34 
35 #define MTYPE		bitmap_ip
36 #define HOST_MASK	32
37 
38 /* Type structure */
39 struct bitmap_ip {
40 	unsigned long *members;	/* the set members */
41 	u32 first_ip;		/* host byte order, included in range */
42 	u32 last_ip;		/* host byte order, included in range */
43 	u32 elements;		/* number of max elements in the set */
44 	u32 hosts;		/* number of hosts in a subnet */
45 	size_t memsize;		/* members size */
46 	u8 netmask;		/* subnet netmask */
47 	struct timer_list gc;	/* garbage collection */
48 	struct ip_set *set;	/* attached to this ip_set */
49 	unsigned char extensions[]	/* data extensions */
50 		__aligned(__alignof__(u64));
51 };
52 
53 /* ADT structure for generic function args */
54 struct bitmap_ip_adt_elem {
55 	u16 id;
56 };
57 
58 static u32
59 ip_to_id(const struct bitmap_ip *m, u32 ip)
60 {
61 	return ((ip & ip_set_hostmask(m->netmask)) - m->first_ip) / m->hosts;
62 }
63 
64 /* Common functions */
65 
66 static int
67 bitmap_ip_do_test(const struct bitmap_ip_adt_elem *e,
68 		  struct bitmap_ip *map, size_t dsize)
69 {
70 	return !!test_bit(e->id, map->members);
71 }
72 
73 static int
74 bitmap_ip_gc_test(u16 id, const struct bitmap_ip *map, size_t dsize)
75 {
76 	return !!test_bit(id, map->members);
77 }
78 
79 static int
80 bitmap_ip_do_add(const struct bitmap_ip_adt_elem *e, struct bitmap_ip *map,
81 		 u32 flags, size_t dsize)
82 {
83 	return !!test_bit(e->id, map->members);
84 }
85 
86 static int
87 bitmap_ip_do_del(const struct bitmap_ip_adt_elem *e, struct bitmap_ip *map)
88 {
89 	return !test_and_clear_bit(e->id, map->members);
90 }
91 
92 static int
93 bitmap_ip_do_list(struct sk_buff *skb, const struct bitmap_ip *map, u32 id,
94 		  size_t dsize)
95 {
96 	return nla_put_ipaddr4(skb, IPSET_ATTR_IP,
97 			htonl(map->first_ip + id * map->hosts));
98 }
99 
100 static int
101 bitmap_ip_do_head(struct sk_buff *skb, const struct bitmap_ip *map)
102 {
103 	return nla_put_ipaddr4(skb, IPSET_ATTR_IP, htonl(map->first_ip)) ||
104 	       nla_put_ipaddr4(skb, IPSET_ATTR_IP_TO, htonl(map->last_ip)) ||
105 	       (map->netmask != 32 &&
106 		nla_put_u8(skb, IPSET_ATTR_NETMASK, map->netmask));
107 }
108 
109 static int
110 bitmap_ip_kadt(struct ip_set *set, const struct sk_buff *skb,
111 	       const struct xt_action_param *par,
112 	       enum ipset_adt adt, struct ip_set_adt_opt *opt)
113 {
114 	struct bitmap_ip *map = set->data;
115 	ipset_adtfn adtfn = set->variant->adt[adt];
116 	struct bitmap_ip_adt_elem e = { .id = 0 };
117 	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
118 	u32 ip;
119 
120 	ip = ntohl(ip4addr(skb, opt->flags & IPSET_DIM_ONE_SRC));
121 	if (ip < map->first_ip || ip > map->last_ip)
122 		return -IPSET_ERR_BITMAP_RANGE;
123 
124 	e.id = ip_to_id(map, ip);
125 
126 	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
127 }
128 
129 static int
130 bitmap_ip_uadt(struct ip_set *set, struct nlattr *tb[],
131 	       enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
132 {
133 	struct bitmap_ip *map = set->data;
134 	ipset_adtfn adtfn = set->variant->adt[adt];
135 	u32 ip = 0, ip_to = 0;
136 	struct bitmap_ip_adt_elem e = { .id = 0 };
137 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
138 	int ret = 0;
139 
140 	if (tb[IPSET_ATTR_LINENO])
141 		*lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
142 
143 	if (unlikely(!tb[IPSET_ATTR_IP]))
144 		return -IPSET_ERR_PROTOCOL;
145 
146 	ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP], &ip);
147 	if (ret)
148 		return ret;
149 
150 	ret = ip_set_get_extensions(set, tb, &ext);
151 	if (ret)
152 		return ret;
153 
154 	if (ip < map->first_ip || ip > map->last_ip)
155 		return -IPSET_ERR_BITMAP_RANGE;
156 
157 	if (adt == IPSET_TEST) {
158 		e.id = ip_to_id(map, ip);
159 		return adtfn(set, &e, &ext, &ext, flags);
160 	}
161 
162 	if (tb[IPSET_ATTR_IP_TO]) {
163 		ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP_TO], &ip_to);
164 		if (ret)
165 			return ret;
166 		if (ip > ip_to) {
167 			swap(ip, ip_to);
168 			if (ip < map->first_ip)
169 				return -IPSET_ERR_BITMAP_RANGE;
170 		}
171 	} else if (tb[IPSET_ATTR_CIDR]) {
172 		u8 cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
173 
174 		if (!cidr || cidr > HOST_MASK)
175 			return -IPSET_ERR_INVALID_CIDR;
176 		ip_set_mask_from_to(ip, ip_to, cidr);
177 	} else {
178 		ip_to = ip;
179 	}
180 
181 	if (ip_to > map->last_ip)
182 		return -IPSET_ERR_BITMAP_RANGE;
183 
184 	for (; !before(ip_to, ip); ip += map->hosts) {
185 		e.id = ip_to_id(map, ip);
186 		ret = adtfn(set, &e, &ext, &ext, flags);
187 
188 		if (ret && !ip_set_eexist(ret, flags))
189 			return ret;
190 
191 		ret = 0;
192 	}
193 	return ret;
194 }
195 
196 static bool
197 bitmap_ip_same_set(const struct ip_set *a, const struct ip_set *b)
198 {
199 	const struct bitmap_ip *x = a->data;
200 	const struct bitmap_ip *y = b->data;
201 
202 	return x->first_ip == y->first_ip &&
203 	       x->last_ip == y->last_ip &&
204 	       x->netmask == y->netmask &&
205 	       a->timeout == b->timeout &&
206 	       a->extensions == b->extensions;
207 }
208 
209 /* Plain variant */
210 
211 struct bitmap_ip_elem {
212 };
213 
214 #include "ip_set_bitmap_gen.h"
215 
216 /* Create bitmap:ip type of sets */
217 
218 static bool
219 init_map_ip(struct ip_set *set, struct bitmap_ip *map,
220 	    u32 first_ip, u32 last_ip,
221 	    u32 elements, u32 hosts, u8 netmask)
222 {
223 	map->members = bitmap_zalloc(elements, GFP_KERNEL | __GFP_NOWARN);
224 	if (!map->members)
225 		return false;
226 	map->first_ip = first_ip;
227 	map->last_ip = last_ip;
228 	map->elements = elements;
229 	map->hosts = hosts;
230 	map->netmask = netmask;
231 	set->timeout = IPSET_NO_TIMEOUT;
232 
233 	map->set = set;
234 	set->data = map;
235 	set->family = NFPROTO_IPV4;
236 
237 	return true;
238 }
239 
240 static u32
241 range_to_mask(u32 from, u32 to, u8 *bits)
242 {
243 	u32 mask = 0xFFFFFFFE;
244 
245 	*bits = 32;
246 	while (--(*bits) > 0 && mask && (to & mask) != from)
247 		mask <<= 1;
248 
249 	return mask;
250 }
251 
252 static int
253 bitmap_ip_create(struct net *net, struct ip_set *set, struct nlattr *tb[],
254 		 u32 flags)
255 {
256 	struct bitmap_ip *map;
257 	u32 first_ip = 0, last_ip = 0, hosts;
258 	u64 elements;
259 	u8 netmask = 32;
260 	int ret;
261 
262 	if (unlikely(!tb[IPSET_ATTR_IP] ||
263 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_TIMEOUT) ||
264 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_CADT_FLAGS)))
265 		return -IPSET_ERR_PROTOCOL;
266 
267 	ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP], &first_ip);
268 	if (ret)
269 		return ret;
270 
271 	if (tb[IPSET_ATTR_IP_TO]) {
272 		ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP_TO], &last_ip);
273 		if (ret)
274 			return ret;
275 		if (first_ip > last_ip)
276 			swap(first_ip, last_ip);
277 	} else if (tb[IPSET_ATTR_CIDR]) {
278 		u8 cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
279 
280 		if (cidr >= HOST_MASK)
281 			return -IPSET_ERR_INVALID_CIDR;
282 		ip_set_mask_from_to(first_ip, last_ip, cidr);
283 	} else {
284 		return -IPSET_ERR_PROTOCOL;
285 	}
286 
287 	if (tb[IPSET_ATTR_NETMASK]) {
288 		netmask = nla_get_u8(tb[IPSET_ATTR_NETMASK]);
289 
290 		if (netmask > HOST_MASK)
291 			return -IPSET_ERR_INVALID_NETMASK;
292 
293 		first_ip &= ip_set_hostmask(netmask);
294 		last_ip |= ~ip_set_hostmask(netmask);
295 	}
296 
297 	if (netmask == 32) {
298 		hosts = 1;
299 		elements = (u64)last_ip - first_ip + 1;
300 	} else {
301 		u8 mask_bits;
302 		u32 mask;
303 
304 		mask = range_to_mask(first_ip, last_ip, &mask_bits);
305 
306 		if ((!mask && (first_ip || last_ip != 0xFFFFFFFF)) ||
307 		    netmask <= mask_bits)
308 			return -IPSET_ERR_BITMAP_RANGE;
309 
310 		pr_debug("mask_bits %u, netmask %u\n", mask_bits, netmask);
311 		hosts = 2U << (32 - netmask - 1);
312 		elements = 2UL << (netmask - mask_bits - 1);
313 	}
314 	if (elements > IPSET_BITMAP_MAX_RANGE + 1)
315 		return -IPSET_ERR_BITMAP_RANGE_SIZE;
316 
317 	pr_debug("hosts %u, elements %llu\n",
318 		 hosts, (unsigned long long)elements);
319 
320 	set->dsize = ip_set_elem_len(set, tb, 0, 0);
321 	map = ip_set_alloc(sizeof(*map) + elements * set->dsize);
322 	if (!map)
323 		return -ENOMEM;
324 
325 	map->memsize = BITS_TO_LONGS(elements) * sizeof(unsigned long);
326 	set->variant = &bitmap_ip;
327 	if (!init_map_ip(set, map, first_ip, last_ip,
328 			 elements, hosts, netmask)) {
329 		ip_set_free(map);
330 		return -ENOMEM;
331 	}
332 	if (tb[IPSET_ATTR_TIMEOUT]) {
333 		set->timeout = ip_set_timeout_uget(tb[IPSET_ATTR_TIMEOUT]);
334 		bitmap_ip_gc_init(set, bitmap_ip_gc);
335 	}
336 	return 0;
337 }
338 
339 static struct ip_set_type bitmap_ip_type __read_mostly = {
340 	.name		= "bitmap:ip",
341 	.protocol	= IPSET_PROTOCOL,
342 	.features	= IPSET_TYPE_IP,
343 	.dimension	= IPSET_DIM_ONE,
344 	.family		= NFPROTO_IPV4,
345 	.revision_min	= IPSET_TYPE_REV_MIN,
346 	.revision_max	= IPSET_TYPE_REV_MAX,
347 	.create		= bitmap_ip_create,
348 	.create_policy	= {
349 		[IPSET_ATTR_IP]		= { .type = NLA_NESTED },
350 		[IPSET_ATTR_IP_TO]	= { .type = NLA_NESTED },
351 		[IPSET_ATTR_CIDR]	= { .type = NLA_U8 },
352 		[IPSET_ATTR_NETMASK]	= { .type = NLA_U8  },
353 		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
354 		[IPSET_ATTR_CADT_FLAGS]	= { .type = NLA_U32 },
355 	},
356 	.adt_policy	= {
357 		[IPSET_ATTR_IP]		= { .type = NLA_NESTED },
358 		[IPSET_ATTR_IP_TO]	= { .type = NLA_NESTED },
359 		[IPSET_ATTR_CIDR]	= { .type = NLA_U8 },
360 		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
361 		[IPSET_ATTR_LINENO]	= { .type = NLA_U32 },
362 		[IPSET_ATTR_BYTES]	= { .type = NLA_U64 },
363 		[IPSET_ATTR_PACKETS]	= { .type = NLA_U64 },
364 		[IPSET_ATTR_COMMENT]	= { .type = NLA_NUL_STRING,
365 					    .len  = IPSET_MAX_COMMENT_SIZE },
366 		[IPSET_ATTR_SKBMARK]	= { .type = NLA_U64 },
367 		[IPSET_ATTR_SKBPRIO]	= { .type = NLA_U32 },
368 		[IPSET_ATTR_SKBQUEUE]	= { .type = NLA_U16 },
369 	},
370 	.me		= THIS_MODULE,
371 };
372 
373 static int __init
374 bitmap_ip_init(void)
375 {
376 	return ip_set_type_register(&bitmap_ip_type);
377 }
378 
379 static void __exit
380 bitmap_ip_fini(void)
381 {
382 	rcu_barrier();
383 	ip_set_type_unregister(&bitmap_ip_type);
384 }
385 
386 module_init(bitmap_ip_init);
387 module_exit(bitmap_ip_fini);
388