1/* Copyright (C) 2014 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:mac type */
9
10#include <linux/jhash.h>
11#include <linux/module.h>
12#include <linux/etherdevice.h>
13#include <linux/skbuff.h>
14#include <linux/errno.h>
15#include <linux/if_ether.h>
16#include <net/netlink.h>
17
18#include <linux/netfilter.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#define IPSET_TYPE_REV_MAX	0
24
25MODULE_LICENSE("GPL");
26MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>");
27IP_SET_MODULE_DESC("hash:mac", IPSET_TYPE_REV_MIN, IPSET_TYPE_REV_MAX);
28MODULE_ALIAS("ip_set_hash:mac");
29
30/* Type specific function prefix */
31#define HTYPE		hash_mac
32
33/* Member elements */
34struct hash_mac4_elem {
35	/* Zero valued IP addresses cannot be stored */
36	union {
37		unsigned char ether[ETH_ALEN];
38		__be32 foo[2];
39	};
40};
41
42/* Common functions */
43
44static inline bool
45hash_mac4_data_equal(const struct hash_mac4_elem *e1,
46		     const struct hash_mac4_elem *e2,
47		     u32 *multi)
48{
49	return ether_addr_equal(e1->ether, e2->ether);
50}
51
52static inline bool
53hash_mac4_data_list(struct sk_buff *skb, const struct hash_mac4_elem *e)
54{
55	return nla_put(skb, IPSET_ATTR_ETHER, ETH_ALEN, e->ether);
56}
57
58static inline void
59hash_mac4_data_next(struct hash_mac4_elem *next,
60		    const struct hash_mac4_elem *e)
61{
62}
63
64#define MTYPE		hash_mac4
65#define PF		4
66#define HOST_MASK	32
67#define IP_SET_EMIT_CREATE
68#define IP_SET_PROTO_UNDEF
69#include "ip_set_hash_gen.h"
70
71/* Zero valued element is not supported */
72static const unsigned char invalid_ether[ETH_ALEN] = { 0 };
73
74static int
75hash_mac4_kadt(struct ip_set *set, const struct sk_buff *skb,
76	       const struct xt_action_param *par,
77	       enum ipset_adt adt, struct ip_set_adt_opt *opt)
78{
79	ipset_adtfn adtfn = set->variant->adt[adt];
80	struct hash_mac4_elem e = { { .foo[0] = 0, .foo[1] = 0 } };
81	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
82
83	 /* MAC can be src only */
84	if (!(opt->flags & IPSET_DIM_ONE_SRC))
85		return 0;
86
87	if (skb_mac_header(skb) < skb->head ||
88	     (skb_mac_header(skb) + ETH_HLEN) > skb->data)
89		return -EINVAL;
90
91	memcpy(e.ether, eth_hdr(skb)->h_source, ETH_ALEN);
92	if (memcmp(e.ether, invalid_ether, ETH_ALEN) == 0)
93		return -EINVAL;
94	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
95}
96
97static int
98hash_mac4_uadt(struct ip_set *set, struct nlattr *tb[],
99	       enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
100{
101	ipset_adtfn adtfn = set->variant->adt[adt];
102	struct hash_mac4_elem e = { { .foo[0] = 0, .foo[1] = 0 } };
103	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
104	int ret;
105
106	if (unlikely(!tb[IPSET_ATTR_ETHER] ||
107		     !ip_set_optattr_netorder(tb, IPSET_ATTR_TIMEOUT) ||
108		     !ip_set_optattr_netorder(tb, IPSET_ATTR_PACKETS) ||
109		     !ip_set_optattr_netorder(tb, IPSET_ATTR_BYTES)   ||
110		     !ip_set_optattr_netorder(tb, IPSET_ATTR_SKBMARK) ||
111		     !ip_set_optattr_netorder(tb, IPSET_ATTR_SKBPRIO) ||
112		     !ip_set_optattr_netorder(tb, IPSET_ATTR_SKBQUEUE)))
113		return -IPSET_ERR_PROTOCOL;
114
115	if (tb[IPSET_ATTR_LINENO])
116		*lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
117
118	ret = ip_set_get_extensions(set, tb, &ext);
119	if (ret)
120		return ret;
121	memcpy(e.ether, nla_data(tb[IPSET_ATTR_ETHER]), ETH_ALEN);
122	if (memcmp(e.ether, invalid_ether, ETH_ALEN) == 0)
123		return -IPSET_ERR_HASH_ELEM;
124
125	return adtfn(set, &e, &ext, &ext, flags);
126}
127
128static struct ip_set_type hash_mac_type __read_mostly = {
129	.name		= "hash:mac",
130	.protocol	= IPSET_PROTOCOL,
131	.features	= IPSET_TYPE_MAC,
132	.dimension	= IPSET_DIM_ONE,
133	.family		= NFPROTO_UNSPEC,
134	.revision_min	= IPSET_TYPE_REV_MIN,
135	.revision_max	= IPSET_TYPE_REV_MAX,
136	.create		= hash_mac_create,
137	.create_policy	= {
138		[IPSET_ATTR_HASHSIZE]	= { .type = NLA_U32 },
139		[IPSET_ATTR_MAXELEM]	= { .type = NLA_U32 },
140		[IPSET_ATTR_PROBES]	= { .type = NLA_U8 },
141		[IPSET_ATTR_RESIZE]	= { .type = NLA_U8  },
142		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
143		[IPSET_ATTR_CADT_FLAGS]	= { .type = NLA_U32 },
144	},
145	.adt_policy	= {
146		[IPSET_ATTR_ETHER]	= { .type = NLA_BINARY,
147					    .len  = ETH_ALEN },
148		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
149		[IPSET_ATTR_LINENO]	= { .type = NLA_U32 },
150		[IPSET_ATTR_BYTES]	= { .type = NLA_U64 },
151		[IPSET_ATTR_PACKETS]	= { .type = NLA_U64 },
152		[IPSET_ATTR_COMMENT]	= { .type = NLA_NUL_STRING },
153		[IPSET_ATTR_SKBMARK]	= { .type = NLA_U64 },
154		[IPSET_ATTR_SKBPRIO]	= { .type = NLA_U32 },
155		[IPSET_ATTR_SKBQUEUE]	= { .type = NLA_U16 },
156	},
157	.me		= THIS_MODULE,
158};
159
160static int __init
161hash_mac_init(void)
162{
163	return ip_set_type_register(&hash_mac_type);
164}
165
166static void __exit
167hash_mac_fini(void)
168{
169	ip_set_type_unregister(&hash_mac_type);
170}
171
172module_init(hash_mac_init);
173module_exit(hash_mac_fini);
174