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