1 /* Copyright (C) 2016 Tomasz Chilinski <tomasz.chilinski@chilan.com>
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,mac type */
9 
10 #include <linux/jhash.h>
11 #include <linux/module.h>
12 #include <linux/ip.h>
13 #include <linux/etherdevice.h>
14 #include <linux/skbuff.h>
15 #include <linux/errno.h>
16 #include <linux/random.h>
17 #include <linux/if_ether.h>
18 #include <net/ip.h>
19 #include <net/ipv6.h>
20 #include <net/netlink.h>
21 #include <net/tcp.h>
22 
23 #include <linux/netfilter.h>
24 #include <linux/netfilter/ipset/pfxlen.h>
25 #include <linux/netfilter/ipset/ip_set.h>
26 #include <linux/netfilter/ipset/ip_set_hash.h>
27 
28 #define IPSET_TYPE_REV_MIN	0
29 #define IPSET_TYPE_REV_MAX	0
30 
31 MODULE_LICENSE("GPL");
32 MODULE_AUTHOR("Tomasz Chilinski <tomasz.chilinski@chilan.com>");
33 IP_SET_MODULE_DESC("hash:ip,mac", IPSET_TYPE_REV_MIN, IPSET_TYPE_REV_MAX);
34 MODULE_ALIAS("ip_set_hash:ip,mac");
35 
36 /* Type specific function prefix */
37 #define HTYPE		hash_ipmac
38 
39 /* Zero valued element is not supported */
40 static const unsigned char invalid_ether[ETH_ALEN] = { 0 };
41 
42 /* IPv4 variant */
43 
44 /* Member elements */
45 struct hash_ipmac4_elem {
46 	/* Zero valued IP addresses cannot be stored */
47 	__be32 ip;
48 	union {
49 		unsigned char ether[ETH_ALEN];
50 		__be32 foo[2];
51 	};
52 };
53 
54 /* Common functions */
55 
56 static inline bool
57 hash_ipmac4_data_equal(const struct hash_ipmac4_elem *e1,
58 		       const struct hash_ipmac4_elem *e2,
59 		       u32 *multi)
60 {
61 	return e1->ip == e2->ip && ether_addr_equal(e1->ether, e2->ether);
62 }
63 
64 static bool
65 hash_ipmac4_data_list(struct sk_buff *skb, const struct hash_ipmac4_elem *e)
66 {
67 	if (nla_put_ipaddr4(skb, IPSET_ATTR_IP, e->ip) ||
68 	    nla_put(skb, IPSET_ATTR_ETHER, ETH_ALEN, e->ether))
69 		goto nla_put_failure;
70 	return false;
71 
72 nla_put_failure:
73 	return true;
74 }
75 
76 static inline void
77 hash_ipmac4_data_next(struct hash_ipmac4_elem *next,
78 		      const struct hash_ipmac4_elem *e)
79 {
80 	next->ip = e->ip;
81 }
82 
83 #define MTYPE		hash_ipmac4
84 #define PF		4
85 #define HOST_MASK	32
86 #define HKEY_DATALEN	sizeof(struct hash_ipmac4_elem)
87 #include "ip_set_hash_gen.h"
88 
89 static int
90 hash_ipmac4_kadt(struct ip_set *set, const struct sk_buff *skb,
91 		 const struct xt_action_param *par,
92 		 enum ipset_adt adt, struct ip_set_adt_opt *opt)
93 {
94 	ipset_adtfn adtfn = set->variant->adt[adt];
95 	struct hash_ipmac4_elem e = { .ip = 0, { .foo[0] = 0, .foo[1] = 0 } };
96 	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
97 
98 	 /* MAC can be src only */
99 	if (!(opt->flags & IPSET_DIM_TWO_SRC))
100 		return 0;
101 
102 	if (skb_mac_header(skb) < skb->head ||
103 	    (skb_mac_header(skb) + ETH_HLEN) > skb->data)
104 		return -EINVAL;
105 
106 	memcpy(e.ether, eth_hdr(skb)->h_source, ETH_ALEN);
107 	if (ether_addr_equal(e.ether, invalid_ether))
108 		return -EINVAL;
109 
110 	ip4addrptr(skb, opt->flags & IPSET_DIM_ONE_SRC, &e.ip);
111 
112 	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
113 }
114 
115 static int
116 hash_ipmac4_uadt(struct ip_set *set, struct nlattr *tb[],
117 		 enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
118 {
119 	ipset_adtfn adtfn = set->variant->adt[adt];
120 	struct hash_ipmac4_elem e = { .ip = 0, { .foo[0] = 0, .foo[1] = 0 } };
121 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
122 	int ret;
123 
124 	if (unlikely(!tb[IPSET_ATTR_IP] ||
125 		     !tb[IPSET_ATTR_ETHER] ||
126 		     nla_len(tb[IPSET_ATTR_ETHER]) != ETH_ALEN ||
127 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_TIMEOUT) ||
128 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_PACKETS) ||
129 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_BYTES)   ||
130 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_SKBMARK) ||
131 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_SKBPRIO) ||
132 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_SKBQUEUE)))
133 		return -IPSET_ERR_PROTOCOL;
134 
135 	if (tb[IPSET_ATTR_LINENO])
136 		*lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
137 
138 	ret = ip_set_get_ipaddr4(tb[IPSET_ATTR_IP], &e.ip) ||
139 		ip_set_get_extensions(set, tb, &ext);
140 	if (ret)
141 		return ret;
142 	memcpy(e.ether, nla_data(tb[IPSET_ATTR_ETHER]), ETH_ALEN);
143 	if (ether_addr_equal(e.ether, invalid_ether))
144 		return -IPSET_ERR_HASH_ELEM;
145 
146 	return adtfn(set, &e, &ext, &ext, flags);
147 }
148 
149 /* IPv6 variant */
150 
151 /* Member elements */
152 struct hash_ipmac6_elem {
153 	/* Zero valued IP addresses cannot be stored */
154 	union nf_inet_addr ip;
155 	union {
156 		unsigned char ether[ETH_ALEN];
157 		__be32 foo[2];
158 	};
159 };
160 
161 /* Common functions */
162 
163 static inline bool
164 hash_ipmac6_data_equal(const struct hash_ipmac6_elem *e1,
165 		       const struct hash_ipmac6_elem *e2,
166 		       u32 *multi)
167 {
168 	return ipv6_addr_equal(&e1->ip.in6, &e2->ip.in6) &&
169 		ether_addr_equal(e1->ether, e2->ether);
170 }
171 
172 static bool
173 hash_ipmac6_data_list(struct sk_buff *skb, const struct hash_ipmac6_elem *e)
174 {
175 	if (nla_put_ipaddr6(skb, IPSET_ATTR_IP, &e->ip.in6) ||
176 	    nla_put(skb, IPSET_ATTR_ETHER, ETH_ALEN, e->ether))
177 		goto nla_put_failure;
178 	return false;
179 
180 nla_put_failure:
181 	return true;
182 }
183 
184 static inline void
185 hash_ipmac6_data_next(struct hash_ipmac6_elem *next,
186 		      const struct hash_ipmac6_elem *e)
187 {
188 }
189 
190 #undef MTYPE
191 #undef PF
192 #undef HOST_MASK
193 #undef HKEY_DATALEN
194 
195 #define MTYPE		hash_ipmac6
196 #define PF		6
197 #define HOST_MASK	128
198 #define HKEY_DATALEN	sizeof(struct hash_ipmac6_elem)
199 #define IP_SET_EMIT_CREATE
200 #include "ip_set_hash_gen.h"
201 
202 static int
203 hash_ipmac6_kadt(struct ip_set *set, const struct sk_buff *skb,
204 		 const struct xt_action_param *par,
205 		 enum ipset_adt adt, struct ip_set_adt_opt *opt)
206 {
207 	ipset_adtfn adtfn = set->variant->adt[adt];
208 	struct hash_ipmac6_elem e = {
209 		{ .all = { 0 } },
210 		{ .foo[0] = 0, .foo[1] = 0 }
211 	};
212 	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
213 
214 	 /* MAC can be src only */
215 	if (!(opt->flags & IPSET_DIM_TWO_SRC))
216 		return 0;
217 
218 	if (skb_mac_header(skb) < skb->head ||
219 	    (skb_mac_header(skb) + ETH_HLEN) > skb->data)
220 		return -EINVAL;
221 
222 	memcpy(e.ether, eth_hdr(skb)->h_source, ETH_ALEN);
223 	if (ether_addr_equal(e.ether, invalid_ether))
224 		return -EINVAL;
225 
226 	ip6addrptr(skb, opt->flags & IPSET_DIM_ONE_SRC, &e.ip.in6);
227 
228 	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
229 }
230 
231 static int
232 hash_ipmac6_uadt(struct ip_set *set, struct nlattr *tb[],
233 		 enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
234 {
235 	ipset_adtfn adtfn = set->variant->adt[adt];
236 	struct hash_ipmac6_elem e = {
237 		{ .all = { 0 } },
238 		{ .foo[0] = 0, .foo[1] = 0 }
239 	};
240 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
241 	int ret;
242 
243 	if (unlikely(!tb[IPSET_ATTR_IP] ||
244 		     !tb[IPSET_ATTR_ETHER] ||
245 		     nla_len(tb[IPSET_ATTR_ETHER]) != ETH_ALEN ||
246 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_TIMEOUT) ||
247 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_PACKETS) ||
248 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_BYTES)   ||
249 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_SKBMARK) ||
250 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_SKBPRIO) ||
251 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_SKBQUEUE)))
252 		return -IPSET_ERR_PROTOCOL;
253 
254 	if (tb[IPSET_ATTR_LINENO])
255 		*lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
256 
257 	ret = ip_set_get_ipaddr6(tb[IPSET_ATTR_IP], &e.ip) ||
258 		ip_set_get_extensions(set, tb, &ext);
259 	if (ret)
260 		return ret;
261 
262 	memcpy(e.ether, nla_data(tb[IPSET_ATTR_ETHER]), ETH_ALEN);
263 	if (ether_addr_equal(e.ether, invalid_ether))
264 		return -IPSET_ERR_HASH_ELEM;
265 
266 	return adtfn(set, &e, &ext, &ext, flags);
267 }
268 
269 static struct ip_set_type hash_ipmac_type __read_mostly = {
270 	.name		= "hash:ip,mac",
271 	.protocol	= IPSET_PROTOCOL,
272 	.features	= IPSET_TYPE_IP | IPSET_TYPE_MAC,
273 	.dimension	= IPSET_DIM_TWO,
274 	.family		= NFPROTO_UNSPEC,
275 	.revision_min	= IPSET_TYPE_REV_MIN,
276 	.revision_max	= IPSET_TYPE_REV_MAX,
277 	.create		= hash_ipmac_create,
278 	.create_policy	= {
279 		[IPSET_ATTR_HASHSIZE]	= { .type = NLA_U32 },
280 		[IPSET_ATTR_MAXELEM]	= { .type = NLA_U32 },
281 		[IPSET_ATTR_PROBES]	= { .type = NLA_U8 },
282 		[IPSET_ATTR_RESIZE]	= { .type = NLA_U8  },
283 		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
284 		[IPSET_ATTR_CADT_FLAGS]	= { .type = NLA_U32 },
285 	},
286 	.adt_policy	= {
287 		[IPSET_ATTR_IP]		= { .type = NLA_NESTED },
288 		[IPSET_ATTR_ETHER]	= { .type = NLA_BINARY,
289 				.len  = ETH_ALEN },
290 		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
291 		[IPSET_ATTR_LINENO]	= { .type = NLA_U32 },
292 		[IPSET_ATTR_BYTES]	= { .type = NLA_U64 },
293 		[IPSET_ATTR_PACKETS]	= { .type = NLA_U64 },
294 		[IPSET_ATTR_COMMENT]	= { .type = NLA_NUL_STRING },
295 		[IPSET_ATTR_SKBMARK]	= { .type = NLA_U64 },
296 		[IPSET_ATTR_SKBPRIO]	= { .type = NLA_U32 },
297 		[IPSET_ATTR_SKBQUEUE]	= { .type = NLA_U16 },
298 	},
299 	.me		= THIS_MODULE,
300 };
301 
302 static int __init
303 hash_ipmac_init(void)
304 {
305 	return ip_set_type_register(&hash_ipmac_type);
306 }
307 
308 static void __exit
309 hash_ipmac_fini(void)
310 {
311 	ip_set_type_unregister(&hash_ipmac_type);
312 }
313 
314 module_init(hash_ipmac_init);
315 module_exit(hash_ipmac_fini);
316