net/netfilter/ipset/ip_set_bitmap_ipmac.c

   1 /* Copyright (C) 2000-2002 Joakim Axelsson <gozem@linux.nu>
   2  *                         Patrick Schaaf <bof@bof.de>
   3  *                         Martin Josefsson <gandalf@wlug.westbo.se>
   4  * Copyright (C) 2003-2013 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 /* Kernel module implementing an IP set type: the bitmap:ip,mac type */
  12
  13 #include <linux/module.h>
  14 #include <linux/ip.h>
  15 #include <linux/etherdevice.h>
  16 #include <linux/skbuff.h>
  17 #include <linux/errno.h>
  18 #include <linux/if_ether.h>
  19 #include <linux/netlink.h>
  20 #include <linux/jiffies.h>
  21 #include <linux/timer.h>
  22 #include <net/netlink.h>
  23
  24 #include <linux/netfilter/ipset/pfxlen.h>
  25 #include <linux/netfilter/ipset/ip_set.h>
  26 #include <linux/netfilter/ipset/ip_set_bitmap.h>
  27
  28 #define IPSET_TYPE_REV_MIN      0
  29 /*                              1          Counter support added */
  30 /*                              2          Comment support added */
  31 #define IPSET_TYPE_REV_MAX      3       /* skbinfo support added */
  32
  33 MODULE_LICENSE("GPL");
  34 MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>");
  35 IP_SET_MODULE_DESC("bitmap:ip,mac", IPSET_TYPE_REV_MIN, IPSET_TYPE_REV_MAX);
  36 MODULE_ALIAS("ip_set_bitmap:ip,mac");
  37
  38 #define MTYPE           bitmap_ipmac
  39 #define HOST_MASK       32
  40 #define IP_SET_BITMAP_STORED_TIMEOUT
  41
  42 enum {
  43         MAC_UNSET,              /* element is set, without MAC */
  44         MAC_FILLED,             /* element is set with MAC */
  45 };
  46
  47 /* Type structure */
  48 struct bitmap_ipmac {
  49         unsigned long *members; /* the set members */
  50         u32 first_ip;           /* host byte order, included in range */
  51         u32 last_ip;            /* host byte order, included in range */
  52         u32 elements;           /* number of max elements in the set */
  53         size_t memsize;         /* members size */
  54         struct timer_list gc;   /* garbage collector */
  55         struct ip_set *set;     /* attached to this ip_set */
  56         unsigned char extensions[0]     /* MAC + data extensions */
  57                 __aligned(__alignof__(u64));
  58 };
  59
  60 /* ADT structure for generic function args */
  61 struct bitmap_ipmac_adt_elem {
  62         unsigned char ether[ETH_ALEN] __aligned(2);
  63         u16 id;
  64         u16 add_mac;
  65 };
  66
  67 struct bitmap_ipmac_elem {
  68         unsigned char ether[ETH_ALEN];
  69         unsigned char filled;
  70 } __aligned(__alignof__(u64));
  71
  72 static inline u32
  73 ip_to_id(const struct bitmap_ipmac *m, u32 ip)
  74 {
  75         return ip - m->first_ip;
  76 }
  77
  78 #define get_elem(extensions, id, dsize)         \
  79         (struct bitmap_ipmac_elem *)(extensions + (id) * (dsize))
  80
  81 #define get_const_elem(extensions, id, dsize)   \
  82         (const struct bitmap_ipmac_elem *)(extensions + (id) * (dsize))
  83
  84 /* Common functions */
  85
  86 static inline int
  87 bitmap_ipmac_do_test(const struct bitmap_ipmac_adt_elem *e,
  88                      const struct bitmap_ipmac *map, size_t dsize)
  89 {
  90         const struct bitmap_ipmac_elem *elem;
  91
  92         if (!test_bit(e->id, map->members))
  93                 return 0;
  94         elem = get_const_elem(map->extensions, e->id, dsize);
  95         if (e->add_mac && elem->filled == MAC_FILLED)
  96                 return ether_addr_equal(e->ether, elem->ether);
  97         /* Trigger kernel to fill out the ethernet address */
  98         return -EAGAIN;
  99 }
 100
 101 static inline int
 102 bitmap_ipmac_gc_test(u16 id, const struct bitmap_ipmac *map, size_t dsize)
 103 {
 104         const struct bitmap_ipmac_elem *elem;
 105
 106         if (!test_bit(id, map->members))
 107                 return 0;
 108         elem = get_const_elem(map->extensions, id, dsize);
 109         /* Timer not started for the incomplete elements */
 110         return elem->filled == MAC_FILLED;
 111 }
 112
 113 static inline int
 114 bitmap_ipmac_is_filled(const struct bitmap_ipmac_elem *elem)
 115 {
 116         return elem->filled == MAC_FILLED;
 117 }
 118
 119 static inline int
 120 bitmap_ipmac_add_timeout(unsigned long *timeout,
 121                          const struct bitmap_ipmac_adt_elem *e,
 122                          const struct ip_set_ext *ext, struct ip_set *set,
 123                          struct bitmap_ipmac *map, int mode)
 124 {
 125         u32 t = ext->timeout;
 126
 127         if (mode == IPSET_ADD_START_STORED_TIMEOUT) {
 128                 if (t == set->timeout)
 129                         /* Timeout was not specified, get stored one */
 130                         t = *timeout;
 131                 ip_set_timeout_set(timeout, t);
 132         } else {
 133                 /* If MAC is unset yet, we store plain timeout value
 134                  * because the timer is not activated yet
 135                  * and we can reuse it later when MAC is filled out,
 136                  * possibly by the kernel
 137                  */
 138                 if (e->add_mac)
 139                         ip_set_timeout_set(timeout, t);
 140                 else
 141                         *timeout = t;
 142         }
 143         return 0;
 144 }
 145
 146 static inline int
 147 bitmap_ipmac_do_add(const struct bitmap_ipmac_adt_elem *e,
 148                     struct bitmap_ipmac *map, u32 flags, size_t dsize)
 149 {
 150         struct bitmap_ipmac_elem *elem;
 151
 152         elem = get_elem(map->extensions, e->id, dsize);
 153         if (test_bit(e->id, map->members)) {
 154                 if (elem->filled == MAC_FILLED) {
 155                         if (e->add_mac &&
 156                             (flags & IPSET_FLAG_EXIST) &&
 157                             !ether_addr_equal(e->ether, elem->ether)) {
 158                                 /* memcpy isn't atomic */
 159                                 clear_bit(e->id, map->members);
 160                                 smp_mb__after_atomic();
 161                                 ether_addr_copy(elem->ether, e->ether);
 162                         }
 163                         return IPSET_ADD_FAILED;
 164                 } else if (!e->add_mac)
 165                         /* Already added without ethernet address */
 166                         return IPSET_ADD_FAILED;
 167                 /* Fill the MAC address and trigger the timer activation */
 168                 clear_bit(e->id, map->members);
 169                 smp_mb__after_atomic();
 170                 ether_addr_copy(elem->ether, e->ether);
 171                 elem->filled = MAC_FILLED;
 172                 return IPSET_ADD_START_STORED_TIMEOUT;
 173         } else if (e->add_mac) {
 174                 /* We can store MAC too */
 175                 ether_addr_copy(elem->ether, e->ether);
 176                 elem->filled = MAC_FILLED;
 177                 return 0;
 178         }
 179         elem->filled = MAC_UNSET;
 180         /* MAC is not stored yet, don't start timer */
 181         return IPSET_ADD_STORE_PLAIN_TIMEOUT;
 182 }
 183
 184 static inline int
 185 bitmap_ipmac_do_del(const struct bitmap_ipmac_adt_elem *e,
 186                     struct bitmap_ipmac *map)
 187 {
 188         return !test_and_clear_bit(e->id, map->members);
 189 }
 190
 191 static inline int
 192 bitmap_ipmac_do_list(struct sk_buff *skb, const struct bitmap_ipmac *map,
 193                      u32 id, size_t dsize)
 194 {
 195         const struct bitmap_ipmac_elem *elem =
 196                 get_const_elem(map->extensions, id, dsize);
 197
 198         return nla_put_ipaddr4(skb, IPSET_ATTR_IP,
 199                                htonl(map->first_ip + id)) ||
 200                (elem->filled == MAC_FILLED &&
 201                 nla_put(skb, IPSET_ATTR_ETHER, ETH_ALEN, elem->ether));
 202 }
 203
 204 static inline int
 205 bitmap_ipmac_do_head(struct sk_buff *skb, const struct bitmap_ipmac *map)
 206 {
 207         return nla_put_ipaddr4(skb, IPSET_ATTR_IP, htonl(map->first_ip)) ||
 208                nla_put_ipaddr4(skb, IPSET_ATTR_IP_TO, htonl(map->last_ip));
 209 }
 210
 211 static int
 212 bitmap_ipmac_kadt(struct ip_set *set, const struct sk_buff *skb,
 213                   const struct xt_action_param *par,
 214                   enum ipset_adt adt, struct ip_set_adt_opt *opt)
 215 {
 216         struct bitmap_ipmac *map = set->data;
 217         ipset_adtfn adtfn = set->variant->adt[adt];
 218         struct bitmap_ipmac_adt_elem e = { .id = 0, .add_mac = 1 };
 219         struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
 220         u32 ip;
 221
 222         ip = ntohl(ip4addr(skb, opt->flags & IPSET_DIM_ONE_SRC));
 223         if (ip < map->first_ip || ip > map->last_ip)
 224                 return -IPSET_ERR_BITMAP_RANGE;
 225
 226         /* Backward compatibility: we don't check the second flag */
 227         if (skb_mac_header(skb) < skb->head ||
 228             (skb_mac_header(skb) + ETH_HLEN) > skb->data)
 229                 return -EINVAL;
 230
 231         e.id = ip_to_id(map, ip);
 232
 233         if (opt->flags & IPSET_DIM_TWO_SRC)
 234                 ether_addr_copy(e.ether, eth_hdr(skb)->h_source);
 235         else
 236                 ether_addr_copy(e.ether, eth_hdr(skb)->h_dest);
 237
 238         if (is_zero_ether_addr(e.ether))
 239                 return -EINVAL;
 240
 241         return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
 242 }
 243
 244 static int
 245 bitmap_ipmac_uadt(struct ip_set *set, struct nlattr *tb[],
 246                   enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
 247 {
 248         const struct bitmap_ipmac *map = set->data;
 249         ipset_adtfn adtfn = set->variant->adt[adt];
 250         struct bitmap_ipmac_adt_elem e = { .id = 0 };
 251         struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
 252         u32 ip = 0;
 253         int ret = 0;
 254
 255         if (tb[IPSET_ATTR_LINENO])
 256                 *lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
 257
 258         if (unlikely(!tb[IPSET_ATTR_IP]))
 259                 return -IPSET_ERR_PROTOCOL;
 260
 261         ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP], &ip);
 262         if (ret)
 263                 return ret;
 264
 265         ret = ip_set_get_extensions(set, tb, &ext);
 266         if (ret)
 267                 return ret;
 268
 269         if (ip < map->first_ip || ip > map->last_ip)
 270                 return -IPSET_ERR_BITMAP_RANGE;
 271
 272         e.id = ip_to_id(map, ip);
 273         if (tb[IPSET_ATTR_ETHER]) {
 274                 if (nla_len(tb[IPSET_ATTR_ETHER]) != ETH_ALEN)
 275                         return -IPSET_ERR_PROTOCOL;
 276                 memcpy(e.ether, nla_data(tb[IPSET_ATTR_ETHER]), ETH_ALEN);
 277                 e.add_mac = 1;
 278         }
 279         ret = adtfn(set, &e, &ext, &ext, flags);
 280
 281         return ip_set_eexist(ret, flags) ? 0 : ret;
 282 }
 283
 284 static bool
 285 bitmap_ipmac_same_set(const struct ip_set *a, const struct ip_set *b)
 286 {
 287         const struct bitmap_ipmac *x = a->data;
 288         const struct bitmap_ipmac *y = b->data;
 289
 290         return x->first_ip == y->first_ip &&
 291                x->last_ip == y->last_ip &&
 292                a->timeout == b->timeout &&
 293                a->extensions == b->extensions;
 294 }
 295
 296 /* Plain variant */
 297
 298 #include "ip_set_bitmap_gen.h"
 299
 300 /* Create bitmap:ip,mac type of sets */
 301
 302 static bool
 303 init_map_ipmac(struct ip_set *set, struct bitmap_ipmac *map,
 304                u32 first_ip, u32 last_ip, u32 elements)
 305 {
 306         map->members = bitmap_zalloc(elements, GFP_KERNEL | __GFP_NOWARN);
 307         if (!map->members)
 308                 return false;
 309         map->first_ip = first_ip;
 310         map->last_ip = last_ip;
 311         map->elements = elements;
 312         set->timeout = IPSET_NO_TIMEOUT;
 313
 314         map->set = set;
 315         set->data = map;
 316         set->family = NFPROTO_IPV4;
 317
 318         return true;
 319 }
 320
 321 static int
 322 bitmap_ipmac_create(struct net *net, struct ip_set *set, struct nlattr *tb[],
 323                     u32 flags)
 324 {
 325         u32 first_ip = 0, last_ip = 0;
 326         u64 elements;
 327         struct bitmap_ipmac *map;
 328         int ret;
 329
 330         if (unlikely(!tb[IPSET_ATTR_IP] ||
 331                      !ip_set_optattr_netorder(tb, IPSET_ATTR_TIMEOUT) ||
 332                      !ip_set_optattr_netorder(tb, IPSET_ATTR_CADT_FLAGS)))
 333                 return -IPSET_ERR_PROTOCOL;
 334
 335         ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP], &first_ip);
 336         if (ret)
 337                 return ret;
 338
 339         if (tb[IPSET_ATTR_IP_TO]) {
 340                 ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP_TO], &last_ip);
 341                 if (ret)
 342                         return ret;
 343                 if (first_ip > last_ip) {
 344                         u32 tmp = first_ip;
 345
 346                         first_ip = last_ip;
 347                         last_ip = tmp;
 348                 }
 349         } else if (tb[IPSET_ATTR_CIDR]) {
 350                 u8 cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
 351
 352                 if (cidr >= HOST_MASK)
 353                         return -IPSET_ERR_INVALID_CIDR;
 354                 ip_set_mask_from_to(first_ip, last_ip, cidr);
 355         } else {
 356                 return -IPSET_ERR_PROTOCOL;
 357         }
 358
 359         elements = (u64)last_ip - first_ip + 1;
 360
 361         if (elements > IPSET_BITMAP_MAX_RANGE + 1)
 362                 return -IPSET_ERR_BITMAP_RANGE_SIZE;
 363
 364         set->dsize = ip_set_elem_len(set, tb,
 365                                      sizeof(struct bitmap_ipmac_elem),
 366                                      __alignof__(struct bitmap_ipmac_elem));
 367         map = ip_set_alloc(sizeof(*map) + elements * set->dsize);
 368         if (!map)
 369                 return -ENOMEM;
 370
 371         map->memsize = BITS_TO_LONGS(elements) * sizeof(unsigned long);
 372         set->variant = &bitmap_ipmac;
 373         if (!init_map_ipmac(set, map, first_ip, last_ip, elements)) {
 374                 kfree(map);
 375                 return -ENOMEM;
 376         }
 377         if (tb[IPSET_ATTR_TIMEOUT]) {
 378                 set->timeout = ip_set_timeout_uget(tb[IPSET_ATTR_TIMEOUT]);
 379                 bitmap_ipmac_gc_init(set, bitmap_ipmac_gc);
 380         }
 381         return 0;
 382 }
 383
 384 static struct ip_set_type bitmap_ipmac_type = {
 385         .name           = "bitmap:ip,mac",
 386         .protocol       = IPSET_PROTOCOL,
 387         .features       = IPSET_TYPE_IP | IPSET_TYPE_MAC,
 388         .dimension      = IPSET_DIM_TWO,
 389         .family         = NFPROTO_IPV4,
 390         .revision_min   = IPSET_TYPE_REV_MIN,
 391         .revision_max   = IPSET_TYPE_REV_MAX,
 392         .create         = bitmap_ipmac_create,
 393         .create_policy  = {
 394                 [IPSET_ATTR_IP]         = { .type = NLA_NESTED },
 395                 [IPSET_ATTR_IP_TO]      = { .type = NLA_NESTED },
 396                 [IPSET_ATTR_CIDR]       = { .type = NLA_U8 },
 397                 [IPSET_ATTR_TIMEOUT]    = { .type = NLA_U32 },
 398                 [IPSET_ATTR_CADT_FLAGS] = { .type = NLA_U32 },
 399         },
 400         .adt_policy     = {
 401                 [IPSET_ATTR_IP]         = { .type = NLA_NESTED },
 402                 [IPSET_ATTR_ETHER]      = { .type = NLA_BINARY,
 403                                             .len  = ETH_ALEN },
 404                 [IPSET_ATTR_TIMEOUT]    = { .type = NLA_U32 },
 405                 [IPSET_ATTR_LINENO]     = { .type = NLA_U32 },
 406                 [IPSET_ATTR_BYTES]      = { .type = NLA_U64 },
 407                 [IPSET_ATTR_PACKETS]    = { .type = NLA_U64 },
 408                 [IPSET_ATTR_COMMENT]    = { .type = NLA_NUL_STRING,
 409                                             .len  = IPSET_MAX_COMMENT_SIZE },
 410                 [IPSET_ATTR_SKBMARK]    = { .type = NLA_U64 },
 411                 [IPSET_ATTR_SKBPRIO]    = { .type = NLA_U32 },
 412                 [IPSET_ATTR_SKBQUEUE]   = { .type = NLA_U16 },
 413         },
 414         .me             = THIS_MODULE,
 415 };
 416
 417 static int __init
 418 bitmap_ipmac_init(void)
 419 {
 420         return ip_set_type_register(&bitmap_ipmac_type);
 421 }
 422
 423 static void __exit
 424 bitmap_ipmac_fini(void)
 425 {
 426         rcu_barrier();
 427         ip_set_type_unregister(&bitmap_ipmac_type);
 428 }
 429
 430 module_init(bitmap_ipmac_init);
 431 module_exit(bitmap_ipmac_fini);