ip_set_bitmap_ip.c

  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
 30MODULE_LICENSE("GPL");
 31MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@netfilter.org>");
 32IP_SET_MODULE_DESC("bitmap:ip", IPSET_TYPE_REV_MIN, IPSET_TYPE_REV_MAX);
 33MODULE_ALIAS("ip_set_bitmap:ip");
 34
 35#define MTYPE		bitmap_ip
 36#define HOST_MASK	32
 37
 38/* Type structure */
 39struct 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 */
 54struct bitmap_ip_adt_elem {
 55	u16 id;
 56};
 57
 58static u32
 59ip_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
 66static int
 67bitmap_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
 73static int
 74bitmap_ip_gc_test(u16 id, const struct bitmap_ip *map, size_t dsize)
 75{
 76	return !!test_bit(id, map->members);
 77}
 78
 79static int
 80bitmap_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
 86static int
 87bitmap_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
 92static int
 93bitmap_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
100static int
101bitmap_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
109static int
110bitmap_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
129static int
130bitmap_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	} else if (tb[IPSET_ATTR_CIDR]) {
169		u8 cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
170
171		if (!cidr || cidr > HOST_MASK)
172			return -IPSET_ERR_INVALID_CIDR;
173		ip_set_mask_from_to(ip, ip_to, cidr);
174	} else {
175		ip_to = ip;
176	}
177
178	if (ip < map->first_ip || ip_to > map->last_ip)
179		return -IPSET_ERR_BITMAP_RANGE;
180
181	for (; !before(ip_to, ip); ip += map->hosts) {
182		e.id = ip_to_id(map, ip);
183		ret = adtfn(set, &e, &ext, &ext, flags);
184
185		if (ret && !ip_set_eexist(ret, flags))
186			return ret;
187
188		ret = 0;
189	}
190	return ret;
191}
192
193static bool
194bitmap_ip_same_set(const struct ip_set *a, const struct ip_set *b)
195{
196	const struct bitmap_ip *x = a->data;
197	const struct bitmap_ip *y = b->data;
198
199	return x->first_ip == y->first_ip &&
200	       x->last_ip == y->last_ip &&
201	       x->netmask == y->netmask &&
202	       a->timeout == b->timeout &&
203	       a->extensions == b->extensions;
204}
205
206/* Plain variant */
207
208struct bitmap_ip_elem {
209};
210
211#include "ip_set_bitmap_gen.h"
212
213/* Create bitmap:ip type of sets */
214
215static bool
216init_map_ip(struct ip_set *set, struct bitmap_ip *map,
217	    u32 first_ip, u32 last_ip,
218	    u32 elements, u32 hosts, u8 netmask)
219{
220	map->members = bitmap_zalloc(elements, GFP_KERNEL | __GFP_NOWARN);
221	if (!map->members)
222		return false;
223	map->first_ip = first_ip;
224	map->last_ip = last_ip;
225	map->elements = elements;
226	map->hosts = hosts;
227	map->netmask = netmask;
228	set->timeout = IPSET_NO_TIMEOUT;
229
230	map->set = set;
231	set->data = map;
232	set->family = NFPROTO_IPV4;
233
234	return true;
235}
236
237static u32
238range_to_mask(u32 from, u32 to, u8 *bits)
239{
240	u32 mask = 0xFFFFFFFE;
241
242	*bits = 32;
243	while (--(*bits) > 0 && mask && (to & mask) != from)
244		mask <<= 1;
245
246	return mask;
247}
248
249static int
250bitmap_ip_create(struct net *net, struct ip_set *set, struct nlattr *tb[],
251		 u32 flags)
252{
253	struct bitmap_ip *map;
254	u32 first_ip = 0, last_ip = 0, hosts;
255	u64 elements;
256	u8 netmask = 32;
257	int ret;
258
259	if (unlikely(!tb[IPSET_ATTR_IP] ||
260		     !ip_set_optattr_netorder(tb, IPSET_ATTR_TIMEOUT) ||
261		     !ip_set_optattr_netorder(tb, IPSET_ATTR_CADT_FLAGS)))
262		return -IPSET_ERR_PROTOCOL;
263
264	ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP], &first_ip);
265	if (ret)
266		return ret;
267
268	if (tb[IPSET_ATTR_IP_TO]) {
269		ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP_TO], &last_ip);
270		if (ret)
271			return ret;
272		if (first_ip > last_ip)
273			swap(first_ip, last_ip);
274	} else if (tb[IPSET_ATTR_CIDR]) {
275		u8 cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
276
277		if (cidr >= HOST_MASK)
278			return -IPSET_ERR_INVALID_CIDR;
279		ip_set_mask_from_to(first_ip, last_ip, cidr);
280	} else {
281		return -IPSET_ERR_PROTOCOL;
282	}
283
284	if (tb[IPSET_ATTR_NETMASK]) {
285		netmask = nla_get_u8(tb[IPSET_ATTR_NETMASK]);
286
287		if (netmask > HOST_MASK)
288			return -IPSET_ERR_INVALID_NETMASK;
289
290		first_ip &= ip_set_hostmask(netmask);
291		last_ip |= ~ip_set_hostmask(netmask);
292	}
293
294	if (netmask == 32) {
295		hosts = 1;
296		elements = (u64)last_ip - first_ip + 1;
297	} else {
298		u8 mask_bits;
299		u32 mask;
300
301		mask = range_to_mask(first_ip, last_ip, &mask_bits);
302
303		if ((!mask && (first_ip || last_ip != 0xFFFFFFFF)) ||
304		    netmask <= mask_bits)
305			return -IPSET_ERR_BITMAP_RANGE;
306
307		pr_debug("mask_bits %u, netmask %u\n", mask_bits, netmask);
308		hosts = 2U << (32 - netmask - 1);
309		elements = 2UL << (netmask - mask_bits - 1);
310	}
311	if (elements > IPSET_BITMAP_MAX_RANGE + 1)
312		return -IPSET_ERR_BITMAP_RANGE_SIZE;
313
314	pr_debug("hosts %u, elements %llu\n",
315		 hosts, (unsigned long long)elements);
316
317	set->dsize = ip_set_elem_len(set, tb, 0, 0);
318	map = ip_set_alloc(sizeof(*map) + elements * set->dsize);
319	if (!map)
320		return -ENOMEM;
321
322	map->memsize = BITS_TO_LONGS(elements) * sizeof(unsigned long);
323	set->variant = &bitmap_ip;
324	if (!init_map_ip(set, map, first_ip, last_ip,
325			 elements, hosts, netmask)) {
326		ip_set_free(map);
327		return -ENOMEM;
328	}
329	if (tb[IPSET_ATTR_TIMEOUT]) {
330		set->timeout = ip_set_timeout_uget(tb[IPSET_ATTR_TIMEOUT]);
331		bitmap_ip_gc_init(set, bitmap_ip_gc);
332	}
333	return 0;
334}
335
336static struct ip_set_type bitmap_ip_type __read_mostly = {
337	.name		= "bitmap:ip",
338	.protocol	= IPSET_PROTOCOL,
339	.features	= IPSET_TYPE_IP,
340	.dimension	= IPSET_DIM_ONE,
341	.family		= NFPROTO_IPV4,
342	.revision_min	= IPSET_TYPE_REV_MIN,
343	.revision_max	= IPSET_TYPE_REV_MAX,
344	.create		= bitmap_ip_create,
345	.create_policy	= {
346		[IPSET_ATTR_IP]		= { .type = NLA_NESTED },
347		[IPSET_ATTR_IP_TO]	= { .type = NLA_NESTED },
348		[IPSET_ATTR_CIDR]	= { .type = NLA_U8 },
349		[IPSET_ATTR_NETMASK]	= { .type = NLA_U8  },
350		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
351		[IPSET_ATTR_CADT_FLAGS]	= { .type = NLA_U32 },
352	},
353	.adt_policy	= {
354		[IPSET_ATTR_IP]		= { .type = NLA_NESTED },
355		[IPSET_ATTR_IP_TO]	= { .type = NLA_NESTED },
356		[IPSET_ATTR_CIDR]	= { .type = NLA_U8 },
357		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
358		[IPSET_ATTR_LINENO]	= { .type = NLA_U32 },
359		[IPSET_ATTR_BYTES]	= { .type = NLA_U64 },
360		[IPSET_ATTR_PACKETS]	= { .type = NLA_U64 },
361		[IPSET_ATTR_COMMENT]	= { .type = NLA_NUL_STRING,
362					    .len  = IPSET_MAX_COMMENT_SIZE },
363		[IPSET_ATTR_SKBMARK]	= { .type = NLA_U64 },
364		[IPSET_ATTR_SKBPRIO]	= { .type = NLA_U32 },
365		[IPSET_ATTR_SKBQUEUE]	= { .type = NLA_U16 },
366	},
367	.me		= THIS_MODULE,
368};
369
370static int __init
371bitmap_ip_init(void)
372{
373	return ip_set_type_register(&bitmap_ip_type);
374}
375
376static void __exit
377bitmap_ip_fini(void)
378{
379	rcu_barrier();
380	ip_set_type_unregister(&bitmap_ip_type);
381}
382
383module_init(bitmap_ip_init);
384module_exit(bitmap_ip_fini);