1 /* Copyright (C) 2003-2013 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
2  *
3  * This program is free software; you can redistribute it and/or modify
4  * it under the terms of the GNU General Public License version 2 as
5  * published by the Free Software Foundation.
6  */
7 
8 /* Kernel module implementing an IP set type: the hash:ip type */
9 
10 #include <linux/jhash.h>
11 #include <linux/module.h>
12 #include <linux/ip.h>
13 #include <linux/skbuff.h>
14 #include <linux/errno.h>
15 #include <linux/random.h>
16 #include <net/ip.h>
17 #include <net/ipv6.h>
18 #include <net/netlink.h>
19 #include <net/tcp.h>
20 
21 #include <linux/netfilter.h>
22 #include <linux/netfilter/ipset/pfxlen.h>
23 #include <linux/netfilter/ipset/ip_set.h>
24 #include <linux/netfilter/ipset/ip_set_hash.h>
25 
26 #define IPSET_TYPE_REV_MIN	0
27 /*				1	   Counters support */
28 /*				2	   Comments support */
29 /*				3	   Forceadd support */
30 #define IPSET_TYPE_REV_MAX	4	/* skbinfo support  */
31 
32 MODULE_LICENSE("GPL");
33 MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>");
34 IP_SET_MODULE_DESC("hash:ip", IPSET_TYPE_REV_MIN, IPSET_TYPE_REV_MAX);
35 MODULE_ALIAS("ip_set_hash:ip");
36 
37 /* Type specific function prefix */
38 #define HTYPE		hash_ip
39 #define IP_SET_HASH_WITH_NETMASK
40 
41 /* IPv4 variant */
42 
43 /* Member elements */
44 struct hash_ip4_elem {
45 	/* Zero valued IP addresses cannot be stored */
46 	__be32 ip;
47 };
48 
49 /* Common functions */
50 
51 static inline bool
52 hash_ip4_data_equal(const struct hash_ip4_elem *e1,
53 		    const struct hash_ip4_elem *e2,
54 		    u32 *multi)
55 {
56 	return e1->ip == e2->ip;
57 }
58 
59 static bool
60 hash_ip4_data_list(struct sk_buff *skb, const struct hash_ip4_elem *e)
61 {
62 	if (nla_put_ipaddr4(skb, IPSET_ATTR_IP, e->ip))
63 		goto nla_put_failure;
64 	return false;
65 
66 nla_put_failure:
67 	return true;
68 }
69 
70 static inline void
71 hash_ip4_data_next(struct hash_ip4_elem *next, const struct hash_ip4_elem *e)
72 {
73 	next->ip = e->ip;
74 }
75 
76 #define MTYPE		hash_ip4
77 #define HOST_MASK	32
78 #include "ip_set_hash_gen.h"
79 
80 static int
81 hash_ip4_kadt(struct ip_set *set, const struct sk_buff *skb,
82 	      const struct xt_action_param *par,
83 	      enum ipset_adt adt, struct ip_set_adt_opt *opt)
84 {
85 	const struct hash_ip4 *h = set->data;
86 	ipset_adtfn adtfn = set->variant->adt[adt];
87 	struct hash_ip4_elem e = { 0 };
88 	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
89 	__be32 ip;
90 
91 	ip4addrptr(skb, opt->flags & IPSET_DIM_ONE_SRC, &ip);
92 	ip &= ip_set_netmask(h->netmask);
93 	if (ip == 0)
94 		return -EINVAL;
95 
96 	e.ip = ip;
97 	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
98 }
99 
100 static int
101 hash_ip4_uadt(struct ip_set *set, struct nlattr *tb[],
102 	      enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
103 {
104 	const struct hash_ip4 *h = set->data;
105 	ipset_adtfn adtfn = set->variant->adt[adt];
106 	struct hash_ip4_elem e = { 0 };
107 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
108 	u32 ip = 0, ip_to = 0, hosts;
109 	int ret = 0;
110 
111 	if (tb[IPSET_ATTR_LINENO])
112 		*lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
113 
114 	if (unlikely(!tb[IPSET_ATTR_IP]))
115 		return -IPSET_ERR_PROTOCOL;
116 
117 	ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP], &ip);
118 	if (ret)
119 		return ret;
120 
121 	ret = ip_set_get_extensions(set, tb, &ext);
122 	if (ret)
123 		return ret;
124 
125 	ip &= ip_set_hostmask(h->netmask);
126 	e.ip = htonl(ip);
127 	if (e.ip == 0)
128 		return -IPSET_ERR_HASH_ELEM;
129 
130 	if (adt == IPSET_TEST)
131 		return adtfn(set, &e, &ext, &ext, flags);
132 
133 	ip_to = ip;
134 	if (tb[IPSET_ATTR_IP_TO]) {
135 		ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP_TO], &ip_to);
136 		if (ret)
137 			return ret;
138 		if (ip > ip_to)
139 			swap(ip, ip_to);
140 	} else if (tb[IPSET_ATTR_CIDR]) {
141 		u8 cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
142 
143 		if (!cidr || cidr > HOST_MASK)
144 			return -IPSET_ERR_INVALID_CIDR;
145 		ip_set_mask_from_to(ip, ip_to, cidr);
146 	}
147 
148 	hosts = h->netmask == 32 ? 1 : 2 << (32 - h->netmask - 1);
149 
150 	if (retried) {
151 		ip = ntohl(h->next.ip);
152 		e.ip = htonl(ip);
153 	}
154 	for (; ip <= ip_to;) {
155 		ret = adtfn(set, &e, &ext, &ext, flags);
156 		if (ret && !ip_set_eexist(ret, flags))
157 			return ret;
158 
159 		ip += hosts;
160 		e.ip = htonl(ip);
161 		if (e.ip == 0)
162 			return 0;
163 
164 		ret = 0;
165 	}
166 	return ret;
167 }
168 
169 /* IPv6 variant */
170 
171 /* Member elements */
172 struct hash_ip6_elem {
173 	union nf_inet_addr ip;
174 };
175 
176 /* Common functions */
177 
178 static inline bool
179 hash_ip6_data_equal(const struct hash_ip6_elem *ip1,
180 		    const struct hash_ip6_elem *ip2,
181 		    u32 *multi)
182 {
183 	return ipv6_addr_equal(&ip1->ip.in6, &ip2->ip.in6);
184 }
185 
186 static inline void
187 hash_ip6_netmask(union nf_inet_addr *ip, u8 prefix)
188 {
189 	ip6_netmask(ip, prefix);
190 }
191 
192 static bool
193 hash_ip6_data_list(struct sk_buff *skb, const struct hash_ip6_elem *e)
194 {
195 	if (nla_put_ipaddr6(skb, IPSET_ATTR_IP, &e->ip.in6))
196 		goto nla_put_failure;
197 	return false;
198 
199 nla_put_failure:
200 	return true;
201 }
202 
203 static inline void
204 hash_ip6_data_next(struct hash_ip6_elem *next, const struct hash_ip6_elem *e)
205 {
206 }
207 
208 #undef MTYPE
209 #undef HOST_MASK
210 
211 #define MTYPE		hash_ip6
212 #define HOST_MASK	128
213 
214 #define IP_SET_EMIT_CREATE
215 #include "ip_set_hash_gen.h"
216 
217 static int
218 hash_ip6_kadt(struct ip_set *set, const struct sk_buff *skb,
219 	      const struct xt_action_param *par,
220 	      enum ipset_adt adt, struct ip_set_adt_opt *opt)
221 {
222 	const struct hash_ip6 *h = set->data;
223 	ipset_adtfn adtfn = set->variant->adt[adt];
224 	struct hash_ip6_elem e = { { .all = { 0 } } };
225 	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
226 
227 	ip6addrptr(skb, opt->flags & IPSET_DIM_ONE_SRC, &e.ip.in6);
228 	hash_ip6_netmask(&e.ip, h->netmask);
229 	if (ipv6_addr_any(&e.ip.in6))
230 		return -EINVAL;
231 
232 	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
233 }
234 
235 static int
236 hash_ip6_uadt(struct ip_set *set, struct nlattr *tb[],
237 	      enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
238 {
239 	const struct hash_ip6 *h = set->data;
240 	ipset_adtfn adtfn = set->variant->adt[adt];
241 	struct hash_ip6_elem e = { { .all = { 0 } } };
242 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
243 	int ret;
244 
245 	if (tb[IPSET_ATTR_LINENO])
246 		*lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
247 
248 	if (unlikely(!tb[IPSET_ATTR_IP]))
249 		return -IPSET_ERR_PROTOCOL;
250 	if (unlikely(tb[IPSET_ATTR_IP_TO]))
251 		return -IPSET_ERR_HASH_RANGE_UNSUPPORTED;
252 	if (unlikely(tb[IPSET_ATTR_CIDR])) {
253 		u8 cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
254 
255 		if (cidr != HOST_MASK)
256 			return -IPSET_ERR_INVALID_CIDR;
257 	}
258 
259 	ret = ip_set_get_ipaddr6(tb[IPSET_ATTR_IP], &e.ip);
260 	if (ret)
261 		return ret;
262 
263 	ret = ip_set_get_extensions(set, tb, &ext);
264 	if (ret)
265 		return ret;
266 
267 	hash_ip6_netmask(&e.ip, h->netmask);
268 	if (ipv6_addr_any(&e.ip.in6))
269 		return -IPSET_ERR_HASH_ELEM;
270 
271 	ret = adtfn(set, &e, &ext, &ext, flags);
272 
273 	return ip_set_eexist(ret, flags) ? 0 : ret;
274 }
275 
276 static struct ip_set_type hash_ip_type __read_mostly = {
277 	.name		= "hash:ip",
278 	.protocol	= IPSET_PROTOCOL,
279 	.features	= IPSET_TYPE_IP,
280 	.dimension	= IPSET_DIM_ONE,
281 	.family		= NFPROTO_UNSPEC,
282 	.revision_min	= IPSET_TYPE_REV_MIN,
283 	.revision_max	= IPSET_TYPE_REV_MAX,
284 	.create		= hash_ip_create,
285 	.create_policy	= {
286 		[IPSET_ATTR_HASHSIZE]	= { .type = NLA_U32 },
287 		[IPSET_ATTR_MAXELEM]	= { .type = NLA_U32 },
288 		[IPSET_ATTR_PROBES]	= { .type = NLA_U8 },
289 		[IPSET_ATTR_RESIZE]	= { .type = NLA_U8  },
290 		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
291 		[IPSET_ATTR_NETMASK]	= { .type = NLA_U8  },
292 		[IPSET_ATTR_CADT_FLAGS]	= { .type = NLA_U32 },
293 	},
294 	.adt_policy	= {
295 		[IPSET_ATTR_IP]		= { .type = NLA_NESTED },
296 		[IPSET_ATTR_IP_TO]	= { .type = NLA_NESTED },
297 		[IPSET_ATTR_CIDR]	= { .type = NLA_U8 },
298 		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
299 		[IPSET_ATTR_LINENO]	= { .type = NLA_U32 },
300 		[IPSET_ATTR_BYTES]	= { .type = NLA_U64 },
301 		[IPSET_ATTR_PACKETS]	= { .type = NLA_U64 },
302 		[IPSET_ATTR_COMMENT]	= { .type = NLA_NUL_STRING,
303 					    .len  = IPSET_MAX_COMMENT_SIZE },
304 		[IPSET_ATTR_SKBMARK]	= { .type = NLA_U64 },
305 		[IPSET_ATTR_SKBPRIO]	= { .type = NLA_U32 },
306 		[IPSET_ATTR_SKBQUEUE]	= { .type = NLA_U16 },
307 	},
308 	.me		= THIS_MODULE,
309 };
310 
311 static int __init
312 hash_ip_init(void)
313 {
314 	return ip_set_type_register(&hash_ip_type);
315 }
316 
317 static void __exit
318 hash_ip_fini(void)
319 {
320 	rcu_barrier();
321 	ip_set_type_unregister(&hash_ip_type);
322 }
323 
324 module_init(hash_ip_init);
325 module_exit(hash_ip_fini);
326