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_ip *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_ip *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 
127 	if (adt == IPSET_TEST) {
128 		e.ip = htonl(ip);
129 		if (e.ip == 0)
130 			return -IPSET_ERR_HASH_ELEM;
131 		return adtfn(set, &e, &ext, &ext, flags);
132 	}
133 
134 	ip_to = ip;
135 	if (tb[IPSET_ATTR_IP_TO]) {
136 		ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP_TO], &ip_to);
137 		if (ret)
138 			return ret;
139 		if (ip > ip_to)
140 			swap(ip, ip_to);
141 	} else if (tb[IPSET_ATTR_CIDR]) {
142 		u8 cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
143 
144 		if (!cidr || cidr > HOST_MASK)
145 			return -IPSET_ERR_INVALID_CIDR;
146 		ip_set_mask_from_to(ip, ip_to, cidr);
147 	}
148 
149 	hosts = h->netmask == 32 ? 1 : 2 << (32 - h->netmask - 1);
150 
151 	if (retried)
152 		ip = ntohl(h->next.ip);
153 	for (; !before(ip_to, ip); ip += hosts) {
154 		e.ip = htonl(ip);
155 		if (e.ip == 0)
156 			return -IPSET_ERR_HASH_ELEM;
157 		ret = adtfn(set, &e, &ext, &ext, flags);
158 
159 		if (ret && !ip_set_eexist(ret, flags))
160 			return ret;
161 
162 		ret = 0;
163 	}
164 	return ret;
165 }
166 
167 /* IPv6 variant */
168 
169 /* Member elements */
170 struct hash_ip6_elem {
171 	union nf_inet_addr ip;
172 };
173 
174 /* Common functions */
175 
176 static inline bool
177 hash_ip6_data_equal(const struct hash_ip6_elem *ip1,
178 		    const struct hash_ip6_elem *ip2,
179 		    u32 *multi)
180 {
181 	return ipv6_addr_equal(&ip1->ip.in6, &ip2->ip.in6);
182 }
183 
184 static inline void
185 hash_ip6_netmask(union nf_inet_addr *ip, u8 prefix)
186 {
187 	ip6_netmask(ip, prefix);
188 }
189 
190 static bool
191 hash_ip6_data_list(struct sk_buff *skb, const struct hash_ip6_elem *e)
192 {
193 	if (nla_put_ipaddr6(skb, IPSET_ATTR_IP, &e->ip.in6))
194 		goto nla_put_failure;
195 	return false;
196 
197 nla_put_failure:
198 	return true;
199 }
200 
201 static inline void
202 hash_ip6_data_next(struct hash_ip4_elem *next, const struct hash_ip6_elem *e)
203 {
204 }
205 
206 #undef MTYPE
207 #undef HOST_MASK
208 
209 #define MTYPE		hash_ip6
210 #define HOST_MASK	128
211 
212 #define IP_SET_EMIT_CREATE
213 #include "ip_set_hash_gen.h"
214 
215 static int
216 hash_ip6_kadt(struct ip_set *set, const struct sk_buff *skb,
217 	      const struct xt_action_param *par,
218 	      enum ipset_adt adt, struct ip_set_adt_opt *opt)
219 {
220 	const struct hash_ip *h = set->data;
221 	ipset_adtfn adtfn = set->variant->adt[adt];
222 	struct hash_ip6_elem e = { { .all = { 0 } } };
223 	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
224 
225 	ip6addrptr(skb, opt->flags & IPSET_DIM_ONE_SRC, &e.ip.in6);
226 	hash_ip6_netmask(&e.ip, h->netmask);
227 	if (ipv6_addr_any(&e.ip.in6))
228 		return -EINVAL;
229 
230 	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
231 }
232 
233 static int
234 hash_ip6_uadt(struct ip_set *set, struct nlattr *tb[],
235 	      enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
236 {
237 	const struct hash_ip *h = set->data;
238 	ipset_adtfn adtfn = set->variant->adt[adt];
239 	struct hash_ip6_elem e = { { .all = { 0 } } };
240 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
241 	int ret;
242 
243 	if (tb[IPSET_ATTR_LINENO])
244 		*lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
245 
246 	if (unlikely(!tb[IPSET_ATTR_IP]))
247 		return -IPSET_ERR_PROTOCOL;
248 	if (unlikely(tb[IPSET_ATTR_IP_TO]))
249 		return -IPSET_ERR_HASH_RANGE_UNSUPPORTED;
250 	if (unlikely(tb[IPSET_ATTR_CIDR])) {
251 		u8 cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
252 
253 		if (cidr != HOST_MASK)
254 			return -IPSET_ERR_INVALID_CIDR;
255 	}
256 
257 	ret = ip_set_get_ipaddr6(tb[IPSET_ATTR_IP], &e.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 	hash_ip6_netmask(&e.ip, h->netmask);
266 	if (ipv6_addr_any(&e.ip.in6))
267 		return -IPSET_ERR_HASH_ELEM;
268 
269 	ret = adtfn(set, &e, &ext, &ext, flags);
270 
271 	return ip_set_eexist(ret, flags) ? 0 : ret;
272 }
273 
274 static struct ip_set_type hash_ip_type __read_mostly = {
275 	.name		= "hash:ip",
276 	.protocol	= IPSET_PROTOCOL,
277 	.features	= IPSET_TYPE_IP,
278 	.dimension	= IPSET_DIM_ONE,
279 	.family		= NFPROTO_UNSPEC,
280 	.revision_min	= IPSET_TYPE_REV_MIN,
281 	.revision_max	= IPSET_TYPE_REV_MAX,
282 	.create		= hash_ip_create,
283 	.create_policy	= {
284 		[IPSET_ATTR_HASHSIZE]	= { .type = NLA_U32 },
285 		[IPSET_ATTR_MAXELEM]	= { .type = NLA_U32 },
286 		[IPSET_ATTR_PROBES]	= { .type = NLA_U8 },
287 		[IPSET_ATTR_RESIZE]	= { .type = NLA_U8  },
288 		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
289 		[IPSET_ATTR_NETMASK]	= { .type = NLA_U8  },
290 		[IPSET_ATTR_CADT_FLAGS]	= { .type = NLA_U32 },
291 	},
292 	.adt_policy	= {
293 		[IPSET_ATTR_IP]		= { .type = NLA_NESTED },
294 		[IPSET_ATTR_IP_TO]	= { .type = NLA_NESTED },
295 		[IPSET_ATTR_CIDR]	= { .type = NLA_U8 },
296 		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
297 		[IPSET_ATTR_LINENO]	= { .type = NLA_U32 },
298 		[IPSET_ATTR_BYTES]	= { .type = NLA_U64 },
299 		[IPSET_ATTR_PACKETS]	= { .type = NLA_U64 },
300 		[IPSET_ATTR_COMMENT]	= { .type = NLA_NUL_STRING,
301 					    .len  = IPSET_MAX_COMMENT_SIZE },
302 		[IPSET_ATTR_SKBMARK]	= { .type = NLA_U64 },
303 		[IPSET_ATTR_SKBPRIO]	= { .type = NLA_U32 },
304 		[IPSET_ATTR_SKBQUEUE]	= { .type = NLA_U16 },
305 	},
306 	.me		= THIS_MODULE,
307 };
308 
309 static int __init
310 hash_ip_init(void)
311 {
312 	return ip_set_type_register(&hash_ip_type);
313 }
314 
315 static void __exit
316 hash_ip_fini(void)
317 {
318 	rcu_barrier();
319 	ip_set_type_unregister(&hash_ip_type);
320 }
321 
322 module_init(hash_ip_init);
323 module_exit(hash_ip_fini);
324