summaryrefslogtreecommitdiffstats
path: root/kernel/ip_set_hash_net.c
blob: e3b09e0cc52c37ed953faaa6271f0c30431e700c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
/* Copyright (C) 2003-2008 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

/* Kernel module implementing a cidr nethash set */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/ip.h>
#include <linux/skbuff.h>
#include <linux/netfilter_ipv4/ip_set_jhash.h>
#include <linux/errno.h>
#include <asm/uaccess.h>
#include <asm/bitops.h>
#include <linux/spinlock.h>
#include <linux/random.h>

#include <net/ip.h>

#include <linux/netfilter_ipv4/ip_set_nethash.h>

static int limit = MAX_RANGE;

static inline __u32
nethash_id_cidr(const struct ip_set_nethash *map,
		ip_set_ip_t ip,
		uint8_t cidr)
{
	__u32 id;
	u_int16_t i;
	ip_set_ip_t *elem;

	ip = pack_ip_cidr(ip, cidr);
	if (!ip)
		return MAX_RANGE;
	
	for (i = 0; i < map->probes; i++) {
		id = jhash_ip(map, i, ip) % map->hashsize;
	   	DP("hash key: %u", id);
		elem = HARRAY_ELEM(map->members, ip_set_ip_t *, id);
	   	if (*elem == ip)
			return id;
		/* No shortcut - there can be deleted entries. */
	}
	return UINT_MAX;
}

static inline __u32
nethash_id(struct ip_set *set, ip_set_ip_t ip)
{
	const struct ip_set_nethash *map = set->data;
	__u32 id = UINT_MAX;
	int i;

	for (i = 0; i < 30 && map->cidr[i]; i++) {
		id = nethash_id_cidr(map, ip, map->cidr[i]);
		if (id != UINT_MAX)
			break;
	}
	return id;
}

static inline int
nethash_test_cidr(struct ip_set *set, ip_set_ip_t ip, uint8_t cidr)
{
	const struct ip_set_nethash *map = set->data;

	return (nethash_id_cidr(map, ip, cidr) != UINT_MAX);
}

static inline int
nethash_test(struct ip_set *set, ip_set_ip_t ip)
{
	return (nethash_id(set, ip) != UINT_MAX);
}

static int
nethash_utest(struct ip_set *set, const void *data, u_int32_t size)
{
	const struct ip_set_req_nethash *req = data;

	if (req->cidr <= 0 || req->cidr > 32)
		return -EINVAL;
	return (req->cidr == 32 ? nethash_test(set, req->ip)
		: nethash_test_cidr(set, req->ip, req->cidr));
}

#define KADT_CONDITION

KADT(nethash, test, ipaddr)

static inline int
__nethash_add(struct ip_set_nethash *map, ip_set_ip_t *ip)
{
	__u32 probe;
	u_int16_t i;
	ip_set_ip_t *elem, *slot = NULL;
	
	for (i = 0; i < map->probes; i++) {
		probe = jhash_ip(map, i, *ip) % map->hashsize;
		elem = HARRAY_ELEM(map->members, ip_set_ip_t *, probe);
		if (*elem == *ip)
			return -EEXIST;
		if (!(slot || *elem))
			slot = elem;
		/* There can be deleted entries, must check all slots */
	}
	if (slot) {
		*slot = *ip;
		map->elements++;
		return 0;
	}
	/* Trigger rehashing */
	return -EAGAIN;
}

static inline int
nethash_add(struct ip_set *set, ip_set_ip_t ip, uint8_t cidr)
{
	struct ip_set_nethash *map = set->data;
	int ret;
	
	if (map->elements >= limit || map->nets[cidr-1] == UINT16_MAX)
		return -ERANGE;	
	if (cidr <= 0 || cidr >= 32)
		return -EINVAL;

	ip = pack_ip_cidr(ip, cidr);
	if (!ip)
		return -ERANGE;
	
	ret = __nethash_add(map, &ip);
	if (ret == 0) {
		if (!map->nets[cidr-1]++)
			add_cidr_size(map->cidr, cidr);
	}
	
	return ret;
}

#undef KADT_CONDITION
#define KADT_CONDITION							\
	struct ip_set_nethash *map = set->data;				\
	uint8_t cidr = map->cidr[0] ? map->cidr[0] : 31;

UADT(nethash, add, req->cidr)
KADT(nethash, add, ipaddr, cidr)

static inline void
__nethash_retry(struct ip_set_nethash *tmp, struct ip_set_nethash *map)
{
	memcpy(tmp->cidr, map->cidr, sizeof(tmp->cidr));
	memcpy(tmp->nets, map->nets, sizeof(tmp->nets));
}

HASH_RETRY(nethash, ip_set_ip_t)

static inline int
nethash_del(struct ip_set *set, ip_set_ip_t ip, uint8_t cidr)
{
	struct ip_set_nethash *map = set->data;
	ip_set_ip_t id, *elem;

	if (cidr <= 0 || cidr >= 32)
		return -EINVAL;	
	
	id = nethash_id_cidr(map, ip, cidr);
	if (id == UINT_MAX)
		return -EEXIST;
		
	elem = HARRAY_ELEM(map->members, ip_set_ip_t *, id);
	*elem = 0;
	map->elements--;
	if (!map->nets[cidr-1]--)
		del_cidr_size(map->cidr, cidr);
	return 0;
}

UADT(nethash, del, req->cidr)
KADT(nethash, del, ipaddr, cidr)

static inline int
__nethash_create(const struct ip_set_req_nethash_create *req,
		 struct ip_set_nethash *map)
{
	memset(map->cidr, 0, sizeof(map->cidr));
	memset(map->nets, 0, sizeof(map->nets));
	
	return 0;
}

HASH_CREATE(nethash, ip_set_ip_t)
HASH_DESTROY(nethash)

HASH_FLUSH_CIDR(nethash, ip_set_ip_t)

static inline void
__nethash_list_header(const struct ip_set_nethash *map,
		      struct ip_set_req_nethash_create *header)
{    
}

HASH_LIST_HEADER(nethash)
HASH_LIST_MEMBERS_SIZE(nethash, ip_set_ip_t)
HASH_LIST_MEMBERS(nethash, ip_set_ip_t)

IP_SET_RTYPE(nethash, IPSET_TYPE_IP | IPSET_DATA_SINGLE)

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>");
MODULE_DESCRIPTION("nethash type of IP sets");
module_param(limit, int, 0600);
MODULE_PARM_DESC(limit, "maximal number of elements stored in the sets");

REGISTER_MODULE(nethash)