net/netfilter/ipset/ip_set_hash_mac.c

   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
  25 MODULE_LICENSE("GPL");
  26 MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>");
  27 IP_SET_MODULE_DESC("hash:mac", IPSET_TYPE_REV_MIN, IPSET_TYPE_REV_MAX);
  28 MODULE_ALIAS("ip_set_hash:mac");
  29
  30 /* Type specific function prefix */
  31 #define HTYPE           hash_mac
  32
  33 /* Member elements */
  34 struct 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
  44 static inline bool
  45 hash_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
  52 static inline bool
  53 hash_mac4_data_list(struct sk_buff *skb, const struct hash_mac4_elem *e)
  54 {
  55         if (nla_put(skb, IPSET_ATTR_ETHER, ETH_ALEN, e->ether))
  56                 goto nla_put_failure;
  57         return false;
  58
  59 nla_put_failure:
  60         return true;
  61 }
  62
  63 static inline void
  64 hash_mac4_data_next(struct hash_mac4_elem *next,
  65                     const struct hash_mac4_elem *e)
  66 {
  67 }
  68
  69 #define MTYPE           hash_mac4
  70 #define HOST_MASK       32
  71 #define IP_SET_EMIT_CREATE
  72 #define IP_SET_PROTO_UNDEF
  73 #include "ip_set_hash_gen.h"
  74
  75 /* Zero valued element is not supported */
  76 static const unsigned char invalid_ether[ETH_ALEN] = { 0 };
  77
  78 static int
  79 hash_mac4_kadt(struct ip_set *set, const struct sk_buff *skb,
  80                const struct xt_action_param *par,
  81                enum ipset_adt adt, struct ip_set_adt_opt *opt)
  82 {
  83         ipset_adtfn adtfn = set->variant->adt[adt];
  84         struct hash_mac4_elem e = { { .foo[0] = 0, .foo[1] = 0 } };
  85         struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
  86
  87          /* MAC can be src only */
  88         if (!(opt->flags & IPSET_DIM_ONE_SRC))
  89                 return 0;
  90
  91         if (skb_mac_header(skb) < skb->head ||
  92             (skb_mac_header(skb) + ETH_HLEN) > skb->data)
  93                 return -EINVAL;
  94
  95         ether_addr_copy(e.ether, eth_hdr(skb)->h_source);
  96         if (memcmp(e.ether, invalid_ether, ETH_ALEN) == 0)
  97                 return -EINVAL;
  98         return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
  99 }
 100
 101 static int
 102 hash_mac4_uadt(struct ip_set *set, struct nlattr *tb[],
 103                enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
 104 {
 105         ipset_adtfn adtfn = set->variant->adt[adt];
 106         struct hash_mac4_elem e = { { .foo[0] = 0, .foo[1] = 0 } };
 107         struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
 108         int ret;
 109
 110         if (tb[IPSET_ATTR_LINENO])
 111                 *lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
 112
 113         if (unlikely(!tb[IPSET_ATTR_ETHER] ||
 114                      nla_len(tb[IPSET_ATTR_ETHER]) != ETH_ALEN))
 115                 return -IPSET_ERR_PROTOCOL;
 116
 117         ret = ip_set_get_extensions(set, tb, &ext);
 118         if (ret)
 119                 return ret;
 120         ether_addr_copy(e.ether, nla_data(tb[IPSET_ATTR_ETHER]));
 121         if (memcmp(e.ether, invalid_ether, ETH_ALEN) == 0)
 122                 return -IPSET_ERR_HASH_ELEM;
 123
 124         return adtfn(set, &e, &ext, &ext, flags);
 125 }
 126
 127 static struct ip_set_type hash_mac_type __read_mostly = {
 128         .name           = "hash:mac",
 129         .protocol       = IPSET_PROTOCOL,
 130         .features       = IPSET_TYPE_MAC,
 131         .dimension      = IPSET_DIM_ONE,
 132         .family         = NFPROTO_UNSPEC,
 133         .revision_min   = IPSET_TYPE_REV_MIN,
 134         .revision_max   = IPSET_TYPE_REV_MAX,
 135         .create         = hash_mac_create,
 136         .create_policy  = {
 137                 [IPSET_ATTR_HASHSIZE]   = { .type = NLA_U32 },
 138                 [IPSET_ATTR_MAXELEM]    = { .type = NLA_U32 },
 139                 [IPSET_ATTR_PROBES]     = { .type = NLA_U8 },
 140                 [IPSET_ATTR_RESIZE]     = { .type = NLA_U8  },
 141                 [IPSET_ATTR_TIMEOUT]    = { .type = NLA_U32 },
 142                 [IPSET_ATTR_CADT_FLAGS] = { .type = NLA_U32 },
 143         },
 144         .adt_policy     = {
 145                 [IPSET_ATTR_ETHER]      = { .type = NLA_BINARY,
 146                                             .len  = ETH_ALEN },
 147                 [IPSET_ATTR_TIMEOUT]    = { .type = NLA_U32 },
 148                 [IPSET_ATTR_LINENO]     = { .type = NLA_U32 },
 149                 [IPSET_ATTR_BYTES]      = { .type = NLA_U64 },
 150                 [IPSET_ATTR_PACKETS]    = { .type = NLA_U64 },
 151                 [IPSET_ATTR_COMMENT]    = { .type = NLA_NUL_STRING,
 152                                             .len  = IPSET_MAX_COMMENT_SIZE },
 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
 160 static int __init
 161 hash_mac_init(void)
 162 {
 163         return ip_set_type_register(&hash_mac_type);
 164 }
 165
 166 static void __exit
 167 hash_mac_fini(void)
 168 {
 169         rcu_barrier();
 170         ip_set_type_unregister(&hash_mac_type);
 171 }
 172
 173 module_init(hash_mac_init);
 174 module_exit(hash_mac_fini);