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 *			   Martin Josefsson <gandalf@wlug.westbo.se>
5 */
6
7/* Kernel module implementing an IP set type: the bitmap:ip,mac type */
8
9#include <linux/module.h>
10#include <linux/ip.h>
11#include <linux/etherdevice.h>
12#include <linux/skbuff.h>
13#include <linux/errno.h>
14#include <linux/if_ether.h>
15#include <linux/netlink.h>
16#include <linux/jiffies.h>
17#include <linux/timer.h>
18#include <net/netlink.h>
19
20#include <linux/netfilter/ipset/pfxlen.h>
21#include <linux/netfilter/ipset/ip_set.h>
22#include <linux/netfilter/ipset/ip_set_bitmap.h>
23
24#define IPSET_TYPE_REV_MIN	0
25/*				1	   Counter support added */
26/*				2	   Comment support added */
27#define IPSET_TYPE_REV_MAX	3	/* skbinfo support added */
28
29MODULE_LICENSE("GPL");
30MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@netfilter.org>");
31IP_SET_MODULE_DESC("bitmap:ip,mac", IPSET_TYPE_REV_MIN, IPSET_TYPE_REV_MAX);
32MODULE_ALIAS("ip_set_bitmap:ip,mac");
33
34#define MTYPE		bitmap_ipmac
35#define HOST_MASK	32
36#define IP_SET_BITMAP_STORED_TIMEOUT
37
38enum {
39	MAC_UNSET,		/* element is set, without MAC */
40	MAC_FILLED,		/* element is set with MAC */
41};
42
43/* Type structure */
44struct bitmap_ipmac {
45	unsigned long *members;	/* the set members */
46	u32 first_ip;		/* host byte order, included in range */
47	u32 last_ip;		/* host byte order, included in range */
48	u32 elements;		/* number of max elements in the set */
49	size_t memsize;		/* members size */
50	struct timer_list gc;	/* garbage collector */
51	struct ip_set *set;	/* attached to this ip_set */
52	unsigned char extensions[]	/* MAC + data extensions */
53		__aligned(__alignof__(u64));
54};
55
56/* ADT structure for generic function args */
57struct bitmap_ipmac_adt_elem {
58	unsigned char ether[ETH_ALEN] __aligned(2);
59	u16 id;
60	u16 add_mac;
61};
62
63struct bitmap_ipmac_elem {
64	unsigned char ether[ETH_ALEN];
65	unsigned char filled;
66} __aligned(__alignof__(u64));
67
68static u32
69ip_to_id(const struct bitmap_ipmac *m, u32 ip)
70{
71	return ip - m->first_ip;
72}
73
74#define get_elem(extensions, id, dsize)		\
75	(struct bitmap_ipmac_elem *)(extensions + (id) * (dsize))
76
77#define get_const_elem(extensions, id, dsize)	\
78	(const struct bitmap_ipmac_elem *)(extensions + (id) * (dsize))
79
80/* Common functions */
81
82static int
83bitmap_ipmac_do_test(const struct bitmap_ipmac_adt_elem *e,
84		     const struct bitmap_ipmac *map, size_t dsize)
85{
86	const struct bitmap_ipmac_elem *elem;
87
88	if (!test_bit(e->id, map->members))
89		return 0;
90	elem = get_const_elem(map->extensions, e->id, dsize);
91	if (e->add_mac && elem->filled == MAC_FILLED)
92		return ether_addr_equal(e->ether, elem->ether);
93	/* Trigger kernel to fill out the ethernet address */
94	return -EAGAIN;
95}
96
97static int
98bitmap_ipmac_gc_test(u16 id, const struct bitmap_ipmac *map, size_t dsize)
99{
100	const struct bitmap_ipmac_elem *elem;
101
102	if (!test_bit(id, map->members))
103		return 0;
104	elem = get_const_elem(map->extensions, id, dsize);
105	/* Timer not started for the incomplete elements */
106	return elem->filled == MAC_FILLED;
107}
108
109static int
110bitmap_ipmac_is_filled(const struct bitmap_ipmac_elem *elem)
111{
112	return elem->filled == MAC_FILLED;
113}
114
115static int
116bitmap_ipmac_add_timeout(unsigned long *timeout,
117			 const struct bitmap_ipmac_adt_elem *e,
118			 const struct ip_set_ext *ext, struct ip_set *set,
119			 struct bitmap_ipmac *map, int mode)
120{
121	u32 t = ext->timeout;
122
123	if (mode == IPSET_ADD_START_STORED_TIMEOUT) {
124		if (t == set->timeout)
125			/* Timeout was not specified, get stored one */
126			t = *timeout;
127		ip_set_timeout_set(timeout, t);
128	} else {
129		/* If MAC is unset yet, we store plain timeout value
130		 * because the timer is not activated yet
131		 * and we can reuse it later when MAC is filled out,
132		 * possibly by the kernel
133		 */
134		if (e->add_mac)
135			ip_set_timeout_set(timeout, t);
136		else
137			*timeout = t;
138	}
139	return 0;
140}
141
142static int
143bitmap_ipmac_do_add(const struct bitmap_ipmac_adt_elem *e,
144		    struct bitmap_ipmac *map, u32 flags, size_t dsize)
145{
146	struct bitmap_ipmac_elem *elem;
147
148	elem = get_elem(map->extensions, e->id, dsize);
149	if (test_bit(e->id, map->members)) {
150		if (elem->filled == MAC_FILLED) {
151			if (e->add_mac &&
152			    (flags & IPSET_FLAG_EXIST) &&
153			    !ether_addr_equal(e->ether, elem->ether)) {
154				/* memcpy isn't atomic */
155				clear_bit(e->id, map->members);
156				smp_mb__after_atomic();
157				ether_addr_copy(elem->ether, e->ether);
158			}
159			return IPSET_ADD_FAILED;
160		} else if (!e->add_mac)
161			/* Already added without ethernet address */
162			return IPSET_ADD_FAILED;
163		/* Fill the MAC address and trigger the timer activation */
164		clear_bit(e->id, map->members);
165		smp_mb__after_atomic();
166		ether_addr_copy(elem->ether, e->ether);
167		elem->filled = MAC_FILLED;
168		return IPSET_ADD_START_STORED_TIMEOUT;
169	} else if (e->add_mac) {
170		/* We can store MAC too */
171		ether_addr_copy(elem->ether, e->ether);
172		elem->filled = MAC_FILLED;
173		return 0;
174	}
175	elem->filled = MAC_UNSET;
176	/* MAC is not stored yet, don't start timer */
177	return IPSET_ADD_STORE_PLAIN_TIMEOUT;
178}
179
180static int
181bitmap_ipmac_do_del(const struct bitmap_ipmac_adt_elem *e,
182		    struct bitmap_ipmac *map)
183{
184	return !test_and_clear_bit(e->id, map->members);
185}
186
187static int
188bitmap_ipmac_do_list(struct sk_buff *skb, const struct bitmap_ipmac *map,
189		     u32 id, size_t dsize)
190{
191	const struct bitmap_ipmac_elem *elem =
192		get_const_elem(map->extensions, id, dsize);
193
194	return nla_put_ipaddr4(skb, IPSET_ATTR_IP,
195			       htonl(map->first_ip + id)) ||
196	       (elem->filled == MAC_FILLED &&
197		nla_put(skb, IPSET_ATTR_ETHER, ETH_ALEN, elem->ether));
198}
199
200static int
201bitmap_ipmac_do_head(struct sk_buff *skb, const struct bitmap_ipmac *map)
202{
203	return nla_put_ipaddr4(skb, IPSET_ATTR_IP, htonl(map->first_ip)) ||
204	       nla_put_ipaddr4(skb, IPSET_ATTR_IP_TO, htonl(map->last_ip));
205}
206
207static int
208bitmap_ipmac_kadt(struct ip_set *set, const struct sk_buff *skb,
209		  const struct xt_action_param *par,
210		  enum ipset_adt adt, struct ip_set_adt_opt *opt)
211{
212	struct bitmap_ipmac *map = set->data;
213	ipset_adtfn adtfn = set->variant->adt[adt];
214	struct bitmap_ipmac_adt_elem e = { .id = 0, .add_mac = 1 };
215	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
216	u32 ip;
217
218	ip = ntohl(ip4addr(skb, opt->flags & IPSET_DIM_ONE_SRC));
219	if (ip < map->first_ip || ip > map->last_ip)
220		return -IPSET_ERR_BITMAP_RANGE;
221
222	/* Backward compatibility: we don't check the second flag */
223	if (skb_mac_header(skb) < skb->head ||
224	    (skb_mac_header(skb) + ETH_HLEN) > skb->data)
225		return -EINVAL;
226
227	e.id = ip_to_id(map, ip);
228
229	if (opt->flags & IPSET_DIM_TWO_SRC)
230		ether_addr_copy(e.ether, eth_hdr(skb)->h_source);
231	else
232		ether_addr_copy(e.ether, eth_hdr(skb)->h_dest);
233
234	if (is_zero_ether_addr(e.ether))
235		return -EINVAL;
236
237	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
238}
239
240static int
241bitmap_ipmac_uadt(struct ip_set *set, struct nlattr *tb[],
242		  enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
243{
244	const struct bitmap_ipmac *map = set->data;
245	ipset_adtfn adtfn = set->variant->adt[adt];
246	struct bitmap_ipmac_adt_elem e = { .id = 0 };
247	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
248	u32 ip = 0;
249	int ret = 0;
250
251	if (tb[IPSET_ATTR_LINENO])
252		*lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
253
254	if (unlikely(!tb[IPSET_ATTR_IP]))
255		return -IPSET_ERR_PROTOCOL;
256
257	ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP], &ip);
258	if (ret)
259		return ret;
260
261	ret = ip_set_get_extensions(set, tb, &ext);
262	if (ret)
263		return ret;
264
265	if (ip < map->first_ip || ip > map->last_ip)
266		return -IPSET_ERR_BITMAP_RANGE;
267
268	e.id = ip_to_id(map, ip);
269	if (tb[IPSET_ATTR_ETHER]) {
270		if (nla_len(tb[IPSET_ATTR_ETHER]) != ETH_ALEN)
271			return -IPSET_ERR_PROTOCOL;
272		memcpy(e.ether, nla_data(tb[IPSET_ATTR_ETHER]), ETH_ALEN);
273		e.add_mac = 1;
274	}
275	ret = adtfn(set, &e, &ext, &ext, flags);
276
277	return ip_set_eexist(ret, flags) ? 0 : ret;
278}
279
280static bool
281bitmap_ipmac_same_set(const struct ip_set *a, const struct ip_set *b)
282{
283	const struct bitmap_ipmac *x = a->data;
284	const struct bitmap_ipmac *y = b->data;
285
286	return x->first_ip == y->first_ip &&
287	       x->last_ip == y->last_ip &&
288	       a->timeout == b->timeout &&
289	       a->extensions == b->extensions;
290}
291
292/* Plain variant */
293
294#include "ip_set_bitmap_gen.h"
295
296/* Create bitmap:ip,mac type of sets */
297
298static bool
299init_map_ipmac(struct ip_set *set, struct bitmap_ipmac *map,
300	       u32 first_ip, u32 last_ip, u32 elements)
301{
302	map->members = bitmap_zalloc(elements, GFP_KERNEL | __GFP_NOWARN);
303	if (!map->members)
304		return false;
305	map->first_ip = first_ip;
306	map->last_ip = last_ip;
307	map->elements = elements;
308	set->timeout = IPSET_NO_TIMEOUT;
309
310	map->set = set;
311	set->data = map;
312	set->family = NFPROTO_IPV4;
313
314	return true;
315}
316
317static int
318bitmap_ipmac_create(struct net *net, struct ip_set *set, struct nlattr *tb[],
319		    u32 flags)
320{
321	u32 first_ip = 0, last_ip = 0;
322	u64 elements;
323	struct bitmap_ipmac *map;
324	int ret;
325
326	if (unlikely(!tb[IPSET_ATTR_IP] ||
327		     !ip_set_optattr_netorder(tb, IPSET_ATTR_TIMEOUT) ||
328		     !ip_set_optattr_netorder(tb, IPSET_ATTR_CADT_FLAGS)))
329		return -IPSET_ERR_PROTOCOL;
330
331	ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP], &first_ip);
332	if (ret)
333		return ret;
334
335	if (tb[IPSET_ATTR_IP_TO]) {
336		ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP_TO], &last_ip);
337		if (ret)
338			return ret;
339		if (first_ip > last_ip)
340			swap(first_ip, last_ip);
341	} else if (tb[IPSET_ATTR_CIDR]) {
342		u8 cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
343
344		if (cidr >= HOST_MASK)
345			return -IPSET_ERR_INVALID_CIDR;
346		ip_set_mask_from_to(first_ip, last_ip, cidr);
347	} else {
348		return -IPSET_ERR_PROTOCOL;
349	}
350
351	elements = (u64)last_ip - first_ip + 1;
352
353	if (elements > IPSET_BITMAP_MAX_RANGE + 1)
354		return -IPSET_ERR_BITMAP_RANGE_SIZE;
355
356	set->dsize = ip_set_elem_len(set, tb,
357				     sizeof(struct bitmap_ipmac_elem),
358				     __alignof__(struct bitmap_ipmac_elem));
359	map = ip_set_alloc(sizeof(*map) + elements * set->dsize);
360	if (!map)
361		return -ENOMEM;
362
363	map->memsize = BITS_TO_LONGS(elements) * sizeof(unsigned long);
364	set->variant = &bitmap_ipmac;
365	if (!init_map_ipmac(set, map, first_ip, last_ip, elements)) {
366		ip_set_free(map);
367		return -ENOMEM;
368	}
369	if (tb[IPSET_ATTR_TIMEOUT]) {
370		set->timeout = ip_set_timeout_uget(tb[IPSET_ATTR_TIMEOUT]);
371		bitmap_ipmac_gc_init(set, bitmap_ipmac_gc);
372	}
373	return 0;
374}
375
376static struct ip_set_type bitmap_ipmac_type = {
377	.name		= "bitmap:ip,mac",
378	.protocol	= IPSET_PROTOCOL,
379	.features	= IPSET_TYPE_IP | IPSET_TYPE_MAC,
380	.dimension	= IPSET_DIM_TWO,
381	.family		= NFPROTO_IPV4,
382	.revision_min	= IPSET_TYPE_REV_MIN,
383	.revision_max	= IPSET_TYPE_REV_MAX,
384	.create		= bitmap_ipmac_create,
385	.create_policy	= {
386		[IPSET_ATTR_IP]		= { .type = NLA_NESTED },
387		[IPSET_ATTR_IP_TO]	= { .type = NLA_NESTED },
388		[IPSET_ATTR_CIDR]	= { .type = NLA_U8 },
389		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
390		[IPSET_ATTR_CADT_FLAGS]	= { .type = NLA_U32 },
391	},
392	.adt_policy	= {
393		[IPSET_ATTR_IP]		= { .type = NLA_NESTED },
394		[IPSET_ATTR_ETHER]	= { .type = NLA_BINARY,
395					    .len  = ETH_ALEN },
396		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
397		[IPSET_ATTR_LINENO]	= { .type = NLA_U32 },
398		[IPSET_ATTR_BYTES]	= { .type = NLA_U64 },
399		[IPSET_ATTR_PACKETS]	= { .type = NLA_U64 },
400		[IPSET_ATTR_COMMENT]	= { .type = NLA_NUL_STRING,
401					    .len  = IPSET_MAX_COMMENT_SIZE },
402		[IPSET_ATTR_SKBMARK]	= { .type = NLA_U64 },
403		[IPSET_ATTR_SKBPRIO]	= { .type = NLA_U32 },
404		[IPSET_ATTR_SKBQUEUE]	= { .type = NLA_U16 },
405	},
406	.me		= THIS_MODULE,
407};
408
409static int __init
410bitmap_ipmac_init(void)
411{
412	return ip_set_type_register(&bitmap_ipmac_type);
413}
414
415static void __exit
416bitmap_ipmac_fini(void)
417{
418	rcu_barrier();
419	ip_set_type_unregister(&bitmap_ipmac_type);
420}
421
422module_init(bitmap_ipmac_init);
423module_exit(bitmap_ipmac_fini);
424