1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (C) 2003-2013 Jozsef Kadlecsik <kadlec@netfilter.org> */
3 
4 /* Kernel module implementing an IP set type: the hash:ip type */
5 
6 #include <linux/jhash.h>
7 #include <linux/module.h>
8 #include <linux/ip.h>
9 #include <linux/skbuff.h>
10 #include <linux/errno.h>
11 #include <linux/random.h>
12 #include <net/ip.h>
13 #include <net/ipv6.h>
14 #include <net/netlink.h>
15 #include <net/tcp.h>
16 
17 #include <linux/netfilter.h>
18 #include <linux/netfilter/ipset/pfxlen.h>
19 #include <linux/netfilter/ipset/ip_set.h>
20 #include <linux/netfilter/ipset/ip_set_hash.h>
21 
22 #define IPSET_TYPE_REV_MIN	0
23 /*				1	   Counters support */
24 /*				2	   Comments support */
25 /*				3	   Forceadd support */
26 /*				4	   skbinfo support */
27 #define IPSET_TYPE_REV_MAX	5	/* bucketsize, initval support  */
28 
29 MODULE_LICENSE("GPL");
30 MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@netfilter.org>");
31 IP_SET_MODULE_DESC("hash:ip", IPSET_TYPE_REV_MIN, IPSET_TYPE_REV_MAX);
32 MODULE_ALIAS("ip_set_hash:ip");
33 
34 /* Type specific function prefix */
35 #define HTYPE		hash_ip
36 #define IP_SET_HASH_WITH_NETMASK
37 
38 /* IPv4 variant */
39 
40 /* Member elements */
41 struct hash_ip4_elem {
42 	/* Zero valued IP addresses cannot be stored */
43 	__be32 ip;
44 };
45 
46 /* Common functions */
47 
48 static bool
49 hash_ip4_data_equal(const struct hash_ip4_elem *e1,
50 		    const struct hash_ip4_elem *e2,
51 		    u32 *multi)
52 {
53 	return e1->ip == e2->ip;
54 }
55 
56 static bool
57 hash_ip4_data_list(struct sk_buff *skb, const struct hash_ip4_elem *e)
58 {
59 	if (nla_put_ipaddr4(skb, IPSET_ATTR_IP, e->ip))
60 		goto nla_put_failure;
61 	return false;
62 
63 nla_put_failure:
64 	return true;
65 }
66 
67 static void
68 hash_ip4_data_next(struct hash_ip4_elem *next, const struct hash_ip4_elem *e)
69 {
70 	next->ip = e->ip;
71 }
72 
73 #define MTYPE		hash_ip4
74 #define HOST_MASK	32
75 #include "ip_set_hash_gen.h"
76 
77 static int
78 hash_ip4_kadt(struct ip_set *set, const struct sk_buff *skb,
79 	      const struct xt_action_param *par,
80 	      enum ipset_adt adt, struct ip_set_adt_opt *opt)
81 {
82 	const struct hash_ip4 *h = set->data;
83 	ipset_adtfn adtfn = set->variant->adt[adt];
84 	struct hash_ip4_elem e = { 0 };
85 	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
86 	__be32 ip;
87 
88 	ip4addrptr(skb, opt->flags & IPSET_DIM_ONE_SRC, &ip);
89 	ip &= ip_set_netmask(h->netmask);
90 	if (ip == 0)
91 		return -EINVAL;
92 
93 	e.ip = ip;
94 	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
95 }
96 
97 static int
98 hash_ip4_uadt(struct ip_set *set, struct nlattr *tb[],
99 	      enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
100 {
101 	const struct hash_ip4 *h = set->data;
102 	ipset_adtfn adtfn = set->variant->adt[adt];
103 	struct hash_ip4_elem e = { 0 };
104 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
105 	u32 ip = 0, ip_to = 0, hosts;
106 	int ret = 0;
107 
108 	if (tb[IPSET_ATTR_LINENO])
109 		*lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
110 
111 	if (unlikely(!tb[IPSET_ATTR_IP]))
112 		return -IPSET_ERR_PROTOCOL;
113 
114 	ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP], &ip);
115 	if (ret)
116 		return ret;
117 
118 	ret = ip_set_get_extensions(set, tb, &ext);
119 	if (ret)
120 		return ret;
121 
122 	ip &= ip_set_hostmask(h->netmask);
123 	e.ip = htonl(ip);
124 	if (e.ip == 0)
125 		return -IPSET_ERR_HASH_ELEM;
126 
127 	if (adt == IPSET_TEST)
128 		return adtfn(set, &e, &ext, &ext, flags);
129 
130 	ip_to = ip;
131 	if (tb[IPSET_ATTR_IP_TO]) {
132 		ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP_TO], &ip_to);
133 		if (ret)
134 			return ret;
135 		if (ip > ip_to)
136 			swap(ip, ip_to);
137 	} else if (tb[IPSET_ATTR_CIDR]) {
138 		u8 cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
139 
140 		if (!cidr || cidr > HOST_MASK)
141 			return -IPSET_ERR_INVALID_CIDR;
142 		ip_set_mask_from_to(ip, ip_to, cidr);
143 	}
144 
145 	hosts = h->netmask == 32 ? 1 : 2 << (32 - h->netmask - 1);
146 
147 	if (retried) {
148 		ip = ntohl(h->next.ip);
149 		e.ip = htonl(ip);
150 	}
151 	for (; ip <= ip_to;) {
152 		ret = adtfn(set, &e, &ext, &ext, flags);
153 		if (ret && !ip_set_eexist(ret, flags))
154 			return ret;
155 
156 		ip += hosts;
157 		e.ip = htonl(ip);
158 		if (e.ip == 0)
159 			return 0;
160 
161 		ret = 0;
162 	}
163 	return ret;
164 }
165 
166 /* IPv6 variant */
167 
168 /* Member elements */
169 struct hash_ip6_elem {
170 	union nf_inet_addr ip;
171 };
172 
173 /* Common functions */
174 
175 static bool
176 hash_ip6_data_equal(const struct hash_ip6_elem *ip1,
177 		    const struct hash_ip6_elem *ip2,
178 		    u32 *multi)
179 {
180 	return ipv6_addr_equal(&ip1->ip.in6, &ip2->ip.in6);
181 }
182 
183 static void
184 hash_ip6_netmask(union nf_inet_addr *ip, u8 prefix)
185 {
186 	ip6_netmask(ip, prefix);
187 }
188 
189 static bool
190 hash_ip6_data_list(struct sk_buff *skb, const struct hash_ip6_elem *e)
191 {
192 	if (nla_put_ipaddr6(skb, IPSET_ATTR_IP, &e->ip.in6))
193 		goto nla_put_failure;
194 	return false;
195 
196 nla_put_failure:
197 	return true;
198 }
199 
200 static void
201 hash_ip6_data_next(struct hash_ip6_elem *next, const struct hash_ip6_elem *e)
202 {
203 }
204 
205 #undef MTYPE
206 #undef HOST_MASK
207 
208 #define MTYPE		hash_ip6
209 #define HOST_MASK	128
210 
211 #define IP_SET_EMIT_CREATE
212 #include "ip_set_hash_gen.h"
213 
214 static int
215 hash_ip6_kadt(struct ip_set *set, const struct sk_buff *skb,
216 	      const struct xt_action_param *par,
217 	      enum ipset_adt adt, struct ip_set_adt_opt *opt)
218 {
219 	const struct hash_ip6 *h = set->data;
220 	ipset_adtfn adtfn = set->variant->adt[adt];
221 	struct hash_ip6_elem e = { { .all = { 0 } } };
222 	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
223 
224 	ip6addrptr(skb, opt->flags & IPSET_DIM_ONE_SRC, &e.ip.in6);
225 	hash_ip6_netmask(&e.ip, h->netmask);
226 	if (ipv6_addr_any(&e.ip.in6))
227 		return -EINVAL;
228 
229 	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
230 }
231 
232 static int
233 hash_ip6_uadt(struct ip_set *set, struct nlattr *tb[],
234 	      enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
235 {
236 	const struct hash_ip6 *h = set->data;
237 	ipset_adtfn adtfn = set->variant->adt[adt];
238 	struct hash_ip6_elem e = { { .all = { 0 } } };
239 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
240 	int ret;
241 
242 	if (tb[IPSET_ATTR_LINENO])
243 		*lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
244 
245 	if (unlikely(!tb[IPSET_ATTR_IP]))
246 		return -IPSET_ERR_PROTOCOL;
247 	if (unlikely(tb[IPSET_ATTR_IP_TO]))
248 		return -IPSET_ERR_HASH_RANGE_UNSUPPORTED;
249 	if (unlikely(tb[IPSET_ATTR_CIDR])) {
250 		u8 cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
251 
252 		if (cidr != HOST_MASK)
253 			return -IPSET_ERR_INVALID_CIDR;
254 	}
255 
256 	ret = ip_set_get_ipaddr6(tb[IPSET_ATTR_IP], &e.ip);
257 	if (ret)
258 		return ret;
259 
260 	ret = ip_set_get_extensions(set, tb, &ext);
261 	if (ret)
262 		return ret;
263 
264 	hash_ip6_netmask(&e.ip, h->netmask);
265 	if (ipv6_addr_any(&e.ip.in6))
266 		return -IPSET_ERR_HASH_ELEM;
267 
268 	ret = adtfn(set, &e, &ext, &ext, flags);
269 
270 	return ip_set_eexist(ret, flags) ? 0 : ret;
271 }
272 
273 static struct ip_set_type hash_ip_type __read_mostly = {
274 	.name		= "hash:ip",
275 	.protocol	= IPSET_PROTOCOL,
276 	.features	= IPSET_TYPE_IP,
277 	.dimension	= IPSET_DIM_ONE,
278 	.family		= NFPROTO_UNSPEC,
279 	.revision_min	= IPSET_TYPE_REV_MIN,
280 	.revision_max	= IPSET_TYPE_REV_MAX,
281 	.create_flags[IPSET_TYPE_REV_MAX] = IPSET_CREATE_FLAG_BUCKETSIZE,
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_INITVAL]	= { .type = NLA_U32 },
287 		[IPSET_ATTR_BUCKETSIZE]	= { .type = NLA_U8 },
288 		[IPSET_ATTR_RESIZE]	= { .type = NLA_U8  },
289 		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
290 		[IPSET_ATTR_NETMASK]	= { .type = NLA_U8  },
291 		[IPSET_ATTR_CADT_FLAGS]	= { .type = NLA_U32 },
292 	},
293 	.adt_policy	= {
294 		[IPSET_ATTR_IP]		= { .type = NLA_NESTED },
295 		[IPSET_ATTR_IP_TO]	= { .type = NLA_NESTED },
296 		[IPSET_ATTR_CIDR]	= { .type = NLA_U8 },
297 		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
298 		[IPSET_ATTR_LINENO]	= { .type = NLA_U32 },
299 		[IPSET_ATTR_BYTES]	= { .type = NLA_U64 },
300 		[IPSET_ATTR_PACKETS]	= { .type = NLA_U64 },
301 		[IPSET_ATTR_COMMENT]	= { .type = NLA_NUL_STRING,
302 					    .len  = IPSET_MAX_COMMENT_SIZE },
303 		[IPSET_ATTR_SKBMARK]	= { .type = NLA_U64 },
304 		[IPSET_ATTR_SKBPRIO]	= { .type = NLA_U32 },
305 		[IPSET_ATTR_SKBQUEUE]	= { .type = NLA_U16 },
306 	},
307 	.me		= THIS_MODULE,
308 };
309 
310 static int __init
311 hash_ip_init(void)
312 {
313 	return ip_set_type_register(&hash_ip_type);
314 }
315 
316 static void __exit
317 hash_ip_fini(void)
318 {
319 	rcu_barrier();
320 	ip_set_type_unregister(&hash_ip_type);
321 }
322 
323 module_init(hash_ip_init);
324 module_exit(hash_ip_fini);
325