net/netlabel/netlabel_unlabeled.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * NetLabel Unlabeled Support
   4  *
   5  * This file defines functions for dealing with unlabeled packets for the
   6  * NetLabel system.  The NetLabel system manages static and dynamic label
   7  * mappings for network protocols such as CIPSO and RIPSO.
   8  *
   9  * Author: Paul Moore <paul@paul-moore.com>
  10  */
  11
  12 /*
  13  * (c) Copyright Hewlett-Packard Development Company, L.P., 2006 - 2008
  14  */
  15
  16 #include <linux/types.h>
  17 #include <linux/rcupdate.h>
  18 #include <linux/list.h>
  19 #include <linux/spinlock.h>
  20 #include <linux/socket.h>
  21 #include <linux/string.h>
  22 #include <linux/skbuff.h>
  23 #include <linux/audit.h>
  24 #include <linux/in.h>
  25 #include <linux/in6.h>
  26 #include <linux/ip.h>
  27 #include <linux/ipv6.h>
  28 #include <linux/notifier.h>
  29 #include <linux/netdevice.h>
  30 #include <linux/security.h>
  31 #include <linux/slab.h>
  32 #include <net/sock.h>
  33 #include <net/netlink.h>
  34 #include <net/genetlink.h>
  35 #include <net/ip.h>
  36 #include <net/ipv6.h>
  37 #include <net/net_namespace.h>
  38 #include <net/netlabel.h>
  39 #include <asm/bug.h>
  40 #include <linux/atomic.h>
  41
  42 #include "netlabel_user.h"
  43 #include "netlabel_addrlist.h"
  44 #include "netlabel_domainhash.h"
  45 #include "netlabel_unlabeled.h"
  46 #include "netlabel_mgmt.h"
  47
  48 /* NOTE: at present we always use init's network namespace since we don't
  49  *       presently support different namespaces even though the majority of
  50  *       the functions in this file are "namespace safe" */
  51
  52 /* The unlabeled connection hash table which we use to map network interfaces
  53  * and addresses of unlabeled packets to a user specified secid value for the
  54  * LSM.  The hash table is used to lookup the network interface entry
  55  * (struct netlbl_unlhsh_iface) and then the interface entry is used to
  56  * lookup an IP address match from an ordered list.  If a network interface
  57  * match can not be found in the hash table then the default entry
  58  * (netlbl_unlhsh_def) is used.  The IP address entry list
  59  * (struct netlbl_unlhsh_addr) is ordered such that the entries with a
  60  * larger netmask come first.
  61  */
  62 struct netlbl_unlhsh_tbl {
  63         struct list_head *tbl;
  64         u32 size;
  65 };
  66 #define netlbl_unlhsh_addr4_entry(iter) \
  67         container_of(iter, struct netlbl_unlhsh_addr4, list)
  68 struct netlbl_unlhsh_addr4 {
  69         u32 secid;
  70
  71         struct netlbl_af4list list;
  72         struct rcu_head rcu;
  73 };
  74 #define netlbl_unlhsh_addr6_entry(iter) \
  75         container_of(iter, struct netlbl_unlhsh_addr6, list)
  76 struct netlbl_unlhsh_addr6 {
  77         u32 secid;
  78
  79         struct netlbl_af6list list;
  80         struct rcu_head rcu;
  81 };
  82 struct netlbl_unlhsh_iface {
  83         int ifindex;
  84         struct list_head addr4_list;
  85         struct list_head addr6_list;
  86
  87         u32 valid;
  88         struct list_head list;
  89         struct rcu_head rcu;
  90 };
  91
  92 /* Argument struct for netlbl_unlhsh_walk() */
  93 struct netlbl_unlhsh_walk_arg {
  94         struct netlink_callback *nl_cb;
  95         struct sk_buff *skb;
  96         u32 seq;
  97 };
  98
  99 /* Unlabeled connection hash table */
 100 /* updates should be so rare that having one spinlock for the entire
 101  * hash table should be okay */
 102 static DEFINE_SPINLOCK(netlbl_unlhsh_lock);
 103 #define netlbl_unlhsh_rcu_deref(p) \
 104         rcu_dereference_check(p, lockdep_is_held(&netlbl_unlhsh_lock))
 105 static struct netlbl_unlhsh_tbl __rcu *netlbl_unlhsh;
 106 static struct netlbl_unlhsh_iface __rcu *netlbl_unlhsh_def;
 107
 108 /* Accept unlabeled packets flag */
 109 static u8 netlabel_unlabel_acceptflg;
 110
 111 /* NetLabel Generic NETLINK unlabeled family */
 112 static struct genl_family netlbl_unlabel_gnl_family;
 113
 114 /* NetLabel Netlink attribute policy */
 115 static const struct nla_policy netlbl_unlabel_genl_policy[NLBL_UNLABEL_A_MAX + 1] = {
 116         [NLBL_UNLABEL_A_ACPTFLG] = { .type = NLA_U8 },
 117         [NLBL_UNLABEL_A_IPV6ADDR] = { .type = NLA_BINARY,
 118                                       .len = sizeof(struct in6_addr) },
 119         [NLBL_UNLABEL_A_IPV6MASK] = { .type = NLA_BINARY,
 120                                       .len = sizeof(struct in6_addr) },
 121         [NLBL_UNLABEL_A_IPV4ADDR] = { .type = NLA_BINARY,
 122                                       .len = sizeof(struct in_addr) },
 123         [NLBL_UNLABEL_A_IPV4MASK] = { .type = NLA_BINARY,
 124                                       .len = sizeof(struct in_addr) },
 125         [NLBL_UNLABEL_A_IFACE] = { .type = NLA_NUL_STRING,
 126                                    .len = IFNAMSIZ - 1 },
 127         [NLBL_UNLABEL_A_SECCTX] = { .type = NLA_BINARY }
 128 };
 129
 130 /*
 131  * Unlabeled Connection Hash Table Functions
 132  */
 133
 134 /**
 135  * netlbl_unlhsh_free_iface - Frees an interface entry from the hash table
 136  * @entry: the entry's RCU field
 137  *
 138  * Description:
 139  * This function is designed to be used as a callback to the call_rcu()
 140  * function so that memory allocated to a hash table interface entry can be
 141  * released safely.  It is important to note that this function does not free
 142  * the IPv4 and IPv6 address lists contained as part of an interface entry.  It
 143  * is up to the rest of the code to make sure an interface entry is only freed
 144  * once it's address lists are empty.
 145  *
 146  */
 147 static void netlbl_unlhsh_free_iface(struct rcu_head *entry)
 148 {
 149         struct netlbl_unlhsh_iface *iface;
 150         struct netlbl_af4list *iter4;
 151         struct netlbl_af4list *tmp4;
 152 #if IS_ENABLED(CONFIG_IPV6)
 153         struct netlbl_af6list *iter6;
 154         struct netlbl_af6list *tmp6;
 155 #endif /* IPv6 */
 156
 157         iface = container_of(entry, struct netlbl_unlhsh_iface, rcu);
 158
 159         /* no need for locks here since we are the only one with access to this
 160          * structure */
 161
 162         netlbl_af4list_foreach_safe(iter4, tmp4, &iface->addr4_list) {
 163                 netlbl_af4list_remove_entry(iter4);
 164                 kfree(netlbl_unlhsh_addr4_entry(iter4));
 165         }
 166 #if IS_ENABLED(CONFIG_IPV6)
 167         netlbl_af6list_foreach_safe(iter6, tmp6, &iface->addr6_list) {
 168                 netlbl_af6list_remove_entry(iter6);
 169                 kfree(netlbl_unlhsh_addr6_entry(iter6));
 170         }
 171 #endif /* IPv6 */
 172         kfree(iface);
 173 }
 174
 175 /**
 176  * netlbl_unlhsh_hash - Hashing function for the hash table
 177  * @ifindex: the network interface/device to hash
 178  *
 179  * Description:
 180  * This is the hashing function for the unlabeled hash table, it returns the
 181  * bucket number for the given device/interface.  The caller is responsible for
 182  * ensuring that the hash table is protected with either a RCU read lock or
 183  * the hash table lock.
 184  *
 185  */
 186 static u32 netlbl_unlhsh_hash(int ifindex)
 187 {
 188         return ifindex & (netlbl_unlhsh_rcu_deref(netlbl_unlhsh)->size - 1);
 189 }
 190
 191 /**
 192  * netlbl_unlhsh_search_iface - Search for a matching interface entry
 193  * @ifindex: the network interface
 194  *
 195  * Description:
 196  * Searches the unlabeled connection hash table and returns a pointer to the
 197  * interface entry which matches @ifindex, otherwise NULL is returned.  The
 198  * caller is responsible for ensuring that the hash table is protected with
 199  * either a RCU read lock or the hash table lock.
 200  *
 201  */
 202 static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex)
 203 {
 204         u32 bkt;
 205         struct list_head *bkt_list;
 206         struct netlbl_unlhsh_iface *iter;
 207
 208         bkt = netlbl_unlhsh_hash(ifindex);
 209         bkt_list = &netlbl_unlhsh_rcu_deref(netlbl_unlhsh)->tbl[bkt];
 210         list_for_each_entry_rcu(iter, bkt_list, list,
 211                                 lockdep_is_held(&netlbl_unlhsh_lock))
 212                 if (iter->valid && iter->ifindex == ifindex)
 213                         return iter;
 214
 215         return NULL;
 216 }
 217
 218 /**
 219  * netlbl_unlhsh_add_addr4 - Add a new IPv4 address entry to the hash table
 220  * @iface: the associated interface entry
 221  * @addr: IPv4 address in network byte order
 222  * @mask: IPv4 address mask in network byte order
 223  * @secid: LSM secid value for entry
 224  *
 225  * Description:
 226  * Add a new address entry into the unlabeled connection hash table using the
 227  * interface entry specified by @iface.  On success zero is returned, otherwise
 228  * a negative value is returned.
 229  *
 230  */
 231 static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
 232                                    const struct in_addr *addr,
 233                                    const struct in_addr *mask,
 234                                    u32 secid)
 235 {
 236         int ret_val;
 237         struct netlbl_unlhsh_addr4 *entry;
 238
 239         entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
 240         if (entry == NULL)
 241                 return -ENOMEM;
 242
 243         entry->list.addr = addr->s_addr & mask->s_addr;
 244         entry->list.mask = mask->s_addr;
 245         entry->list.valid = 1;
 246         entry->secid = secid;
 247
 248         spin_lock(&netlbl_unlhsh_lock);
 249         ret_val = netlbl_af4list_add(&entry->list, &iface->addr4_list);
 250         spin_unlock(&netlbl_unlhsh_lock);
 251
 252         if (ret_val != 0)
 253                 kfree(entry);
 254         return ret_val;
 255 }
 256
 257 #if IS_ENABLED(CONFIG_IPV6)
 258 /**
 259  * netlbl_unlhsh_add_addr6 - Add a new IPv6 address entry to the hash table
 260  * @iface: the associated interface entry
 261  * @addr: IPv6 address in network byte order
 262  * @mask: IPv6 address mask in network byte order
 263  * @secid: LSM secid value for entry
 264  *
 265  * Description:
 266  * Add a new address entry into the unlabeled connection hash table using the
 267  * interface entry specified by @iface.  On success zero is returned, otherwise
 268  * a negative value is returned.
 269  *
 270  */
 271 static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface,
 272                                    const struct in6_addr *addr,
 273                                    const struct in6_addr *mask,
 274                                    u32 secid)
 275 {
 276         int ret_val;
 277         struct netlbl_unlhsh_addr6 *entry;
 278
 279         entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
 280         if (entry == NULL)
 281                 return -ENOMEM;
 282
 283         entry->list.addr = *addr;
 284         entry->list.addr.s6_addr32[0] &= mask->s6_addr32[0];
 285         entry->list.addr.s6_addr32[1] &= mask->s6_addr32[1];
 286         entry->list.addr.s6_addr32[2] &= mask->s6_addr32[2];
 287         entry->list.addr.s6_addr32[3] &= mask->s6_addr32[3];
 288         entry->list.mask = *mask;
 289         entry->list.valid = 1;
 290         entry->secid = secid;
 291
 292         spin_lock(&netlbl_unlhsh_lock);
 293         ret_val = netlbl_af6list_add(&entry->list, &iface->addr6_list);
 294         spin_unlock(&netlbl_unlhsh_lock);
 295
 296         if (ret_val != 0)
 297                 kfree(entry);
 298         return 0;
 299 }
 300 #endif /* IPv6 */
 301
 302 /**
 303  * netlbl_unlhsh_add_iface - Adds a new interface entry to the hash table
 304  * @ifindex: network interface
 305  *
 306  * Description:
 307  * Add a new, empty, interface entry into the unlabeled connection hash table.
 308  * On success a pointer to the new interface entry is returned, on failure NULL
 309  * is returned.
 310  *
 311  */
 312 static struct netlbl_unlhsh_iface *netlbl_unlhsh_add_iface(int ifindex)
 313 {
 314         u32 bkt;
 315         struct netlbl_unlhsh_iface *iface;
 316
 317         iface = kzalloc(sizeof(*iface), GFP_ATOMIC);
 318         if (iface == NULL)
 319                 return NULL;
 320
 321         iface->ifindex = ifindex;
 322         INIT_LIST_HEAD(&iface->addr4_list);
 323         INIT_LIST_HEAD(&iface->addr6_list);
 324         iface->valid = 1;
 325
 326         spin_lock(&netlbl_unlhsh_lock);
 327         if (ifindex > 0) {
 328                 bkt = netlbl_unlhsh_hash(ifindex);
 329                 if (netlbl_unlhsh_search_iface(ifindex) != NULL)
 330                         goto add_iface_failure;
 331                 list_add_tail_rcu(&iface->list,
 332                              &netlbl_unlhsh_rcu_deref(netlbl_unlhsh)->tbl[bkt]);
 333         } else {
 334                 INIT_LIST_HEAD(&iface->list);
 335                 if (netlbl_unlhsh_rcu_deref(netlbl_unlhsh_def) != NULL)
 336                         goto add_iface_failure;
 337                 rcu_assign_pointer(netlbl_unlhsh_def, iface);
 338         }
 339         spin_unlock(&netlbl_unlhsh_lock);
 340
 341         return iface;
 342
 343 add_iface_failure:
 344         spin_unlock(&netlbl_unlhsh_lock);
 345         kfree(iface);
 346         return NULL;
 347 }
 348
 349 /**
 350  * netlbl_unlhsh_add - Adds a new entry to the unlabeled connection hash table
 351  * @net: network namespace
 352  * @dev_name: interface name
 353  * @addr: IP address in network byte order
 354  * @mask: address mask in network byte order
 355  * @addr_len: length of address/mask (4 for IPv4, 16 for IPv6)
 356  * @secid: LSM secid value for the entry
 357  * @audit_info: NetLabel audit information
 358  *
 359  * Description:
 360  * Adds a new entry to the unlabeled connection hash table.  Returns zero on
 361  * success, negative values on failure.
 362  *
 363  */
 364 int netlbl_unlhsh_add(struct net *net,
 365                       const char *dev_name,
 366                       const void *addr,
 367                       const void *mask,
 368                       u32 addr_len,
 369                       u32 secid,
 370                       struct netlbl_audit *audit_info)
 371 {
 372         int ret_val;
 373         int ifindex;
 374         struct net_device *dev;
 375         struct netlbl_unlhsh_iface *iface;
 376         struct audit_buffer *audit_buf = NULL;
 377         char *secctx = NULL;
 378         u32 secctx_len;
 379
 380         if (addr_len != sizeof(struct in_addr) &&
 381             addr_len != sizeof(struct in6_addr))
 382                 return -EINVAL;
 383
 384         rcu_read_lock();
 385         if (dev_name != NULL) {
 386                 dev = dev_get_by_name_rcu(net, dev_name);
 387                 if (dev == NULL) {
 388                         ret_val = -ENODEV;
 389                         goto unlhsh_add_return;
 390                 }
 391                 ifindex = dev->ifindex;
 392                 iface = netlbl_unlhsh_search_iface(ifindex);
 393         } else {
 394                 ifindex = 0;
 395                 iface = rcu_dereference(netlbl_unlhsh_def);
 396         }
 397         if (iface == NULL) {
 398                 iface = netlbl_unlhsh_add_iface(ifindex);
 399                 if (iface == NULL) {
 400                         ret_val = -ENOMEM;
 401                         goto unlhsh_add_return;
 402                 }
 403         }
 404         audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_STCADD,
 405                                               audit_info);
 406         switch (addr_len) {
 407         case sizeof(struct in_addr): {
 408                 const struct in_addr *addr4 = addr;
 409                 const struct in_addr *mask4 = mask;
 410
 411                 ret_val = netlbl_unlhsh_add_addr4(iface, addr4, mask4, secid);
 412                 if (audit_buf != NULL)
 413                         netlbl_af4list_audit_addr(audit_buf, 1,
 414                                                   dev_name,
 415                                                   addr4->s_addr,
 416                                                   mask4->s_addr);
 417                 break;
 418         }
 419 #if IS_ENABLED(CONFIG_IPV6)
 420         case sizeof(struct in6_addr): {
 421                 const struct in6_addr *addr6 = addr;
 422                 const struct in6_addr *mask6 = mask;
 423
 424                 ret_val = netlbl_unlhsh_add_addr6(iface, addr6, mask6, secid);
 425                 if (audit_buf != NULL)
 426                         netlbl_af6list_audit_addr(audit_buf, 1,
 427                                                   dev_name,
 428                                                   addr6, mask6);
 429                 break;
 430         }
 431 #endif /* IPv6 */
 432         default:
 433                 ret_val = -EINVAL;
 434         }
 435         if (ret_val == 0)
 436                 atomic_inc(&netlabel_mgmt_protocount);
 437
 438 unlhsh_add_return:
 439         rcu_read_unlock();
 440         if (audit_buf != NULL) {
 441                 if (security_secid_to_secctx(secid,
 442                                              &secctx,
 443                                              &secctx_len) == 0) {
 444                         audit_log_format(audit_buf, " sec_obj=%s", secctx);
 445                         security_release_secctx(secctx, secctx_len);
 446                 }
 447                 audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
 448                 audit_log_end(audit_buf);
 449         }
 450         return ret_val;
 451 }
 452
 453 /**
 454  * netlbl_unlhsh_remove_addr4 - Remove an IPv4 address entry
 455  * @net: network namespace
 456  * @iface: interface entry
 457  * @addr: IP address
 458  * @mask: IP address mask
 459  * @audit_info: NetLabel audit information
 460  *
 461  * Description:
 462  * Remove an IP address entry from the unlabeled connection hash table.
 463  * Returns zero on success, negative values on failure.
 464  *
 465  */
 466 static int netlbl_unlhsh_remove_addr4(struct net *net,
 467                                       struct netlbl_unlhsh_iface *iface,
 468                                       const struct in_addr *addr,
 469                                       const struct in_addr *mask,
 470                                       struct netlbl_audit *audit_info)
 471 {
 472         struct netlbl_af4list *list_entry;
 473         struct netlbl_unlhsh_addr4 *entry;
 474         struct audit_buffer *audit_buf;
 475         struct net_device *dev;
 476         char *secctx;
 477         u32 secctx_len;
 478
 479         spin_lock(&netlbl_unlhsh_lock);
 480         list_entry = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
 481                                            &iface->addr4_list);
 482         spin_unlock(&netlbl_unlhsh_lock);
 483         if (list_entry != NULL)
 484                 entry = netlbl_unlhsh_addr4_entry(list_entry);
 485         else
 486                 entry = NULL;
 487
 488         audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_STCDEL,
 489                                               audit_info);
 490         if (audit_buf != NULL) {
 491                 dev = dev_get_by_index(net, iface->ifindex);
 492                 netlbl_af4list_audit_addr(audit_buf, 1,
 493                                           (dev != NULL ? dev->name : NULL),
 494                                           addr->s_addr, mask->s_addr);
 495                 dev_put(dev);
 496                 if (entry != NULL &&
 497                     security_secid_to_secctx(entry->secid,
 498                                              &secctx, &secctx_len) == 0) {
 499                         audit_log_format(audit_buf, " sec_obj=%s", secctx);
 500                         security_release_secctx(secctx, secctx_len);
 501                 }
 502                 audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
 503                 audit_log_end(audit_buf);
 504         }
 505
 506         if (entry == NULL)
 507                 return -ENOENT;
 508
 509         kfree_rcu(entry, rcu);
 510         return 0;
 511 }
 512
 513 #if IS_ENABLED(CONFIG_IPV6)
 514 /**
 515  * netlbl_unlhsh_remove_addr6 - Remove an IPv6 address entry
 516  * @net: network namespace
 517  * @iface: interface entry
 518  * @addr: IP address
 519  * @mask: IP address mask
 520  * @audit_info: NetLabel audit information
 521  *
 522  * Description:
 523  * Remove an IP address entry from the unlabeled connection hash table.
 524  * Returns zero on success, negative values on failure.
 525  *
 526  */
 527 static int netlbl_unlhsh_remove_addr6(struct net *net,
 528                                       struct netlbl_unlhsh_iface *iface,
 529                                       const struct in6_addr *addr,
 530                                       const struct in6_addr *mask,
 531                                       struct netlbl_audit *audit_info)
 532 {
 533         struct netlbl_af6list *list_entry;
 534         struct netlbl_unlhsh_addr6 *entry;
 535         struct audit_buffer *audit_buf;
 536         struct net_device *dev;
 537         char *secctx;
 538         u32 secctx_len;
 539
 540         spin_lock(&netlbl_unlhsh_lock);
 541         list_entry = netlbl_af6list_remove(addr, mask, &iface->addr6_list);
 542         spin_unlock(&netlbl_unlhsh_lock);
 543         if (list_entry != NULL)
 544                 entry = netlbl_unlhsh_addr6_entry(list_entry);
 545         else
 546                 entry = NULL;
 547
 548         audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_STCDEL,
 549                                               audit_info);
 550         if (audit_buf != NULL) {
 551                 dev = dev_get_by_index(net, iface->ifindex);
 552                 netlbl_af6list_audit_addr(audit_buf, 1,
 553                                           (dev != NULL ? dev->name : NULL),
 554                                           addr, mask);
 555                 dev_put(dev);
 556                 if (entry != NULL &&
 557                     security_secid_to_secctx(entry->secid,
 558                                              &secctx, &secctx_len) == 0) {
 559                         audit_log_format(audit_buf, " sec_obj=%s", secctx);
 560                         security_release_secctx(secctx, secctx_len);
 561                 }
 562                 audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
 563                 audit_log_end(audit_buf);
 564         }
 565
 566         if (entry == NULL)
 567                 return -ENOENT;
 568
 569         kfree_rcu(entry, rcu);
 570         return 0;
 571 }
 572 #endif /* IPv6 */
 573
 574 /**
 575  * netlbl_unlhsh_condremove_iface - Remove an interface entry
 576  * @iface: the interface entry
 577  *
 578  * Description:
 579  * Remove an interface entry from the unlabeled connection hash table if it is
 580  * empty.  An interface entry is considered to be empty if there are no
 581  * address entries assigned to it.
 582  *
 583  */
 584 static void netlbl_unlhsh_condremove_iface(struct netlbl_unlhsh_iface *iface)
 585 {
 586         struct netlbl_af4list *iter4;
 587 #if IS_ENABLED(CONFIG_IPV6)
 588         struct netlbl_af6list *iter6;
 589 #endif /* IPv6 */
 590
 591         spin_lock(&netlbl_unlhsh_lock);
 592         netlbl_af4list_foreach_rcu(iter4, &iface->addr4_list)
 593                 goto unlhsh_condremove_failure;
 594 #if IS_ENABLED(CONFIG_IPV6)
 595         netlbl_af6list_foreach_rcu(iter6, &iface->addr6_list)
 596                 goto unlhsh_condremove_failure;
 597 #endif /* IPv6 */
 598         iface->valid = 0;
 599         if (iface->ifindex > 0)
 600                 list_del_rcu(&iface->list);
 601         else
 602                 RCU_INIT_POINTER(netlbl_unlhsh_def, NULL);
 603         spin_unlock(&netlbl_unlhsh_lock);
 604
 605         call_rcu(&iface->rcu, netlbl_unlhsh_free_iface);
 606         return;
 607
 608 unlhsh_condremove_failure:
 609         spin_unlock(&netlbl_unlhsh_lock);
 610 }
 611
 612 /**
 613  * netlbl_unlhsh_remove - Remove an entry from the unlabeled hash table
 614  * @net: network namespace
 615  * @dev_name: interface name
 616  * @addr: IP address in network byte order
 617  * @mask: address mask in network byte order
 618  * @addr_len: length of address/mask (4 for IPv4, 16 for IPv6)
 619  * @audit_info: NetLabel audit information
 620  *
 621  * Description:
 622  * Removes and existing entry from the unlabeled connection hash table.
 623  * Returns zero on success, negative values on failure.
 624  *
 625  */
 626 int netlbl_unlhsh_remove(struct net *net,
 627                          const char *dev_name,
 628                          const void *addr,
 629                          const void *mask,
 630                          u32 addr_len,
 631                          struct netlbl_audit *audit_info)
 632 {
 633         int ret_val;
 634         struct net_device *dev;
 635         struct netlbl_unlhsh_iface *iface;
 636
 637         if (addr_len != sizeof(struct in_addr) &&
 638             addr_len != sizeof(struct in6_addr))
 639                 return -EINVAL;
 640
 641         rcu_read_lock();
 642         if (dev_name != NULL) {
 643                 dev = dev_get_by_name_rcu(net, dev_name);
 644                 if (dev == NULL) {
 645                         ret_val = -ENODEV;
 646                         goto unlhsh_remove_return;
 647                 }
 648                 iface = netlbl_unlhsh_search_iface(dev->ifindex);
 649         } else
 650                 iface = rcu_dereference(netlbl_unlhsh_def);
 651         if (iface == NULL) {
 652                 ret_val = -ENOENT;
 653                 goto unlhsh_remove_return;
 654         }
 655         switch (addr_len) {
 656         case sizeof(struct in_addr):
 657                 ret_val = netlbl_unlhsh_remove_addr4(net,
 658                                                      iface, addr, mask,
 659                                                      audit_info);
 660                 break;
 661 #if IS_ENABLED(CONFIG_IPV6)
 662         case sizeof(struct in6_addr):
 663                 ret_val = netlbl_unlhsh_remove_addr6(net,
 664                                                      iface, addr, mask,
 665                                                      audit_info);
 666                 break;
 667 #endif /* IPv6 */
 668         default:
 669                 ret_val = -EINVAL;
 670         }
 671         if (ret_val == 0) {
 672                 netlbl_unlhsh_condremove_iface(iface);
 673                 atomic_dec(&netlabel_mgmt_protocount);
 674         }
 675
 676 unlhsh_remove_return:
 677         rcu_read_unlock();
 678         return ret_val;
 679 }
 680
 681 /*
 682  * General Helper Functions
 683  */
 684
 685 /**
 686  * netlbl_unlhsh_netdev_handler - Network device notification handler
 687  * @this: notifier block
 688  * @event: the event
 689  * @ptr: the netdevice notifier info (cast to void)
 690  *
 691  * Description:
 692  * Handle network device events, although at present all we care about is a
 693  * network device going away.  In the case of a device going away we clear any
 694  * related entries from the unlabeled connection hash table.
 695  *
 696  */
 697 static int netlbl_unlhsh_netdev_handler(struct notifier_block *this,
 698                                         unsigned long event, void *ptr)
 699 {
 700         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 701         struct netlbl_unlhsh_iface *iface = NULL;
 702
 703         if (!net_eq(dev_net(dev), &init_net))
 704                 return NOTIFY_DONE;
 705
 706         /* XXX - should this be a check for NETDEV_DOWN or _UNREGISTER? */
 707         if (event == NETDEV_DOWN) {
 708                 spin_lock(&netlbl_unlhsh_lock);
 709                 iface = netlbl_unlhsh_search_iface(dev->ifindex);
 710                 if (iface != NULL && iface->valid) {
 711                         iface->valid = 0;
 712                         list_del_rcu(&iface->list);
 713                 } else
 714                         iface = NULL;
 715                 spin_unlock(&netlbl_unlhsh_lock);
 716         }
 717
 718         if (iface != NULL)
 719                 call_rcu(&iface->rcu, netlbl_unlhsh_free_iface);
 720
 721         return NOTIFY_DONE;
 722 }
 723
 724 /**
 725  * netlbl_unlabel_acceptflg_set - Set the unlabeled accept flag
 726  * @value: desired value
 727  * @audit_info: NetLabel audit information
 728  *
 729  * Description:
 730  * Set the value of the unlabeled accept flag to @value.
 731  *
 732  */
 733 static void netlbl_unlabel_acceptflg_set(u8 value,
 734                                          struct netlbl_audit *audit_info)
 735 {
 736         struct audit_buffer *audit_buf;
 737         u8 old_val;
 738
 739         old_val = netlabel_unlabel_acceptflg;
 740         netlabel_unlabel_acceptflg = value;
 741         audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_ALLOW,
 742                                               audit_info);
 743         if (audit_buf != NULL) {
 744                 audit_log_format(audit_buf,
 745                                  " unlbl_accept=%u old=%u", value, old_val);
 746                 audit_log_end(audit_buf);
 747         }
 748 }
 749
 750 /**
 751  * netlbl_unlabel_addrinfo_get - Get the IPv4/6 address information
 752  * @info: the Generic NETLINK info block
 753  * @addr: the IP address
 754  * @mask: the IP address mask
 755  * @len: the address length
 756  *
 757  * Description:
 758  * Examine the Generic NETLINK message and extract the IP address information.
 759  * Returns zero on success, negative values on failure.
 760  *
 761  */
 762 static int netlbl_unlabel_addrinfo_get(struct genl_info *info,
 763                                        void **addr,
 764                                        void **mask,
 765                                        u32 *len)
 766 {
 767         u32 addr_len;
 768
 769         if (info->attrs[NLBL_UNLABEL_A_IPV4ADDR] &&
 770             info->attrs[NLBL_UNLABEL_A_IPV4MASK]) {
 771                 addr_len = nla_len(info->attrs[NLBL_UNLABEL_A_IPV4ADDR]);
 772                 if (addr_len != sizeof(struct in_addr) &&
 773                     addr_len != nla_len(info->attrs[NLBL_UNLABEL_A_IPV4MASK]))
 774                         return -EINVAL;
 775                 *len = addr_len;
 776                 *addr = nla_data(info->attrs[NLBL_UNLABEL_A_IPV4ADDR]);
 777                 *mask = nla_data(info->attrs[NLBL_UNLABEL_A_IPV4MASK]);
 778                 return 0;
 779         } else if (info->attrs[NLBL_UNLABEL_A_IPV6ADDR]) {
 780                 addr_len = nla_len(info->attrs[NLBL_UNLABEL_A_IPV6ADDR]);
 781                 if (addr_len != sizeof(struct in6_addr) &&
 782                     addr_len != nla_len(info->attrs[NLBL_UNLABEL_A_IPV6MASK]))
 783                         return -EINVAL;
 784                 *len = addr_len;
 785                 *addr = nla_data(info->attrs[NLBL_UNLABEL_A_IPV6ADDR]);
 786                 *mask = nla_data(info->attrs[NLBL_UNLABEL_A_IPV6MASK]);
 787                 return 0;
 788         }
 789
 790         return -EINVAL;
 791 }
 792
 793 /*
 794  * NetLabel Command Handlers
 795  */
 796
 797 /**
 798  * netlbl_unlabel_accept - Handle an ACCEPT message
 799  * @skb: the NETLINK buffer
 800  * @info: the Generic NETLINK info block
 801  *
 802  * Description:
 803  * Process a user generated ACCEPT message and set the accept flag accordingly.
 804  * Returns zero on success, negative values on failure.
 805  *
 806  */
 807 static int netlbl_unlabel_accept(struct sk_buff *skb, struct genl_info *info)
 808 {
 809         u8 value;
 810         struct netlbl_audit audit_info;
 811
 812         if (info->attrs[NLBL_UNLABEL_A_ACPTFLG]) {
 813                 value = nla_get_u8(info->attrs[NLBL_UNLABEL_A_ACPTFLG]);
 814                 if (value == 1 || value == 0) {
 815                         netlbl_netlink_auditinfo(&audit_info);
 816                         netlbl_unlabel_acceptflg_set(value, &audit_info);
 817                         return 0;
 818                 }
 819         }
 820
 821         return -EINVAL;
 822 }
 823
 824 /**
 825  * netlbl_unlabel_list - Handle a LIST message
 826  * @skb: the NETLINK buffer
 827  * @info: the Generic NETLINK info block
 828  *
 829  * Description:
 830  * Process a user generated LIST message and respond with the current status.
 831  * Returns zero on success, negative values on failure.
 832  *
 833  */
 834 static int netlbl_unlabel_list(struct sk_buff *skb, struct genl_info *info)
 835 {
 836         int ret_val = -EINVAL;
 837         struct sk_buff *ans_skb;
 838         void *data;
 839
 840         ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 841         if (ans_skb == NULL)
 842                 goto list_failure;
 843         data = genlmsg_put_reply(ans_skb, info, &netlbl_unlabel_gnl_family,
 844                                  0, NLBL_UNLABEL_C_LIST);
 845         if (data == NULL) {
 846                 ret_val = -ENOMEM;
 847                 goto list_failure;
 848         }
 849
 850         ret_val = nla_put_u8(ans_skb,
 851                              NLBL_UNLABEL_A_ACPTFLG,
 852                              netlabel_unlabel_acceptflg);
 853         if (ret_val != 0)
 854                 goto list_failure;
 855
 856         genlmsg_end(ans_skb, data);
 857         return genlmsg_reply(ans_skb, info);
 858
 859 list_failure:
 860         kfree_skb(ans_skb);
 861         return ret_val;
 862 }
 863
 864 /**
 865  * netlbl_unlabel_staticadd - Handle a STATICADD message
 866  * @skb: the NETLINK buffer
 867  * @info: the Generic NETLINK info block
 868  *
 869  * Description:
 870  * Process a user generated STATICADD message and add a new unlabeled
 871  * connection entry to the hash table.  Returns zero on success, negative
 872  * values on failure.
 873  *
 874  */
 875 static int netlbl_unlabel_staticadd(struct sk_buff *skb,
 876                                     struct genl_info *info)
 877 {
 878         int ret_val;
 879         char *dev_name;
 880         void *addr;
 881         void *mask;
 882         u32 addr_len;
 883         u32 secid;
 884         struct netlbl_audit audit_info;
 885
 886         /* Don't allow users to add both IPv4 and IPv6 addresses for a
 887          * single entry.  However, allow users to create two entries, one each
 888          * for IPv4 and IPv4, with the same LSM security context which should
 889          * achieve the same result. */
 890         if (!info->attrs[NLBL_UNLABEL_A_SECCTX] ||
 891             !info->attrs[NLBL_UNLABEL_A_IFACE] ||
 892             !((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] ||
 893                !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^
 894               (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] ||
 895                !info->attrs[NLBL_UNLABEL_A_IPV6MASK])))
 896                 return -EINVAL;
 897
 898         netlbl_netlink_auditinfo(&audit_info);
 899
 900         ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len);
 901         if (ret_val != 0)
 902                 return ret_val;
 903         dev_name = nla_data(info->attrs[NLBL_UNLABEL_A_IFACE]);
 904         ret_val = security_secctx_to_secid(
 905                                   nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
 906                                   nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
 907                                   &secid);
 908         if (ret_val != 0)
 909                 return ret_val;
 910
 911         return netlbl_unlhsh_add(&init_net,
 912                                  dev_name, addr, mask, addr_len, secid,
 913                                  &audit_info);
 914 }
 915
 916 /**
 917  * netlbl_unlabel_staticadddef - Handle a STATICADDDEF message
 918  * @skb: the NETLINK buffer
 919  * @info: the Generic NETLINK info block
 920  *
 921  * Description:
 922  * Process a user generated STATICADDDEF message and add a new default
 923  * unlabeled connection entry.  Returns zero on success, negative values on
 924  * failure.
 925  *
 926  */
 927 static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
 928                                        struct genl_info *info)
 929 {
 930         int ret_val;
 931         void *addr;
 932         void *mask;
 933         u32 addr_len;
 934         u32 secid;
 935         struct netlbl_audit audit_info;
 936
 937         /* Don't allow users to add both IPv4 and IPv6 addresses for a
 938          * single entry.  However, allow users to create two entries, one each
 939          * for IPv4 and IPv6, with the same LSM security context which should
 940          * achieve the same result. */
 941         if (!info->attrs[NLBL_UNLABEL_A_SECCTX] ||
 942             !((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] ||
 943                !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^
 944               (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] ||
 945                !info->attrs[NLBL_UNLABEL_A_IPV6MASK])))
 946                 return -EINVAL;
 947
 948         netlbl_netlink_auditinfo(&audit_info);
 949
 950         ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len);
 951         if (ret_val != 0)
 952                 return ret_val;
 953         ret_val = security_secctx_to_secid(
 954                                   nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
 955                                   nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
 956                                   &secid);
 957         if (ret_val != 0)
 958                 return ret_val;
 959
 960         return netlbl_unlhsh_add(&init_net,
 961                                  NULL, addr, mask, addr_len, secid,
 962                                  &audit_info);
 963 }
 964
 965 /**
 966  * netlbl_unlabel_staticremove - Handle a STATICREMOVE message
 967  * @skb: the NETLINK buffer
 968  * @info: the Generic NETLINK info block
 969  *
 970  * Description:
 971  * Process a user generated STATICREMOVE message and remove the specified
 972  * unlabeled connection entry.  Returns zero on success, negative values on
 973  * failure.
 974  *
 975  */
 976 static int netlbl_unlabel_staticremove(struct sk_buff *skb,
 977                                        struct genl_info *info)
 978 {
 979         int ret_val;
 980         char *dev_name;
 981         void *addr;
 982         void *mask;
 983         u32 addr_len;
 984         struct netlbl_audit audit_info;
 985
 986         /* See the note in netlbl_unlabel_staticadd() about not allowing both
 987          * IPv4 and IPv6 in the same entry. */
 988         if (!info->attrs[NLBL_UNLABEL_A_IFACE] ||
 989             !((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] ||
 990                !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^
 991               (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] ||
 992                !info->attrs[NLBL_UNLABEL_A_IPV6MASK])))
 993                 return -EINVAL;
 994
 995         netlbl_netlink_auditinfo(&audit_info);
 996
 997         ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len);
 998         if (ret_val != 0)
 999                 return ret_val;
1000         dev_name = nla_data(info->attrs[NLBL_UNLABEL_A_IFACE]);
1001
1002         return netlbl_unlhsh_remove(&init_net,
1003                                     dev_name, addr, mask, addr_len,
1004                                     &audit_info);
1005 }
1006
1007 /**
1008  * netlbl_unlabel_staticremovedef - Handle a STATICREMOVEDEF message
1009  * @skb: the NETLINK buffer
1010  * @info: the Generic NETLINK info block
1011  *
1012  * Description:
1013  * Process a user generated STATICREMOVEDEF message and remove the default
1014  * unlabeled connection entry.  Returns zero on success, negative values on
1015  * failure.
1016  *
1017  */
1018 static int netlbl_unlabel_staticremovedef(struct sk_buff *skb,
1019                                           struct genl_info *info)
1020 {
1021         int ret_val;
1022         void *addr;
1023         void *mask;
1024         u32 addr_len;
1025         struct netlbl_audit audit_info;
1026
1027         /* See the note in netlbl_unlabel_staticadd() about not allowing both
1028          * IPv4 and IPv6 in the same entry. */
1029         if (!((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] ||
1030                !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^
1031               (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] ||
1032                !info->attrs[NLBL_UNLABEL_A_IPV6MASK])))
1033                 return -EINVAL;
1034
1035         netlbl_netlink_auditinfo(&audit_info);
1036
1037         ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len);
1038         if (ret_val != 0)
1039                 return ret_val;
1040
1041         return netlbl_unlhsh_remove(&init_net,
1042                                     NULL, addr, mask, addr_len,
1043                                     &audit_info);
1044 }
1045
1046
1047 /**
1048  * netlbl_unlabel_staticlist_gen - Generate messages for STATICLIST[DEF]
1049  * @cmd: command/message
1050  * @iface: the interface entry
1051  * @addr4: the IPv4 address entry
1052  * @addr6: the IPv6 address entry
1053  * @arg: the netlbl_unlhsh_walk_arg structure
1054  *
1055  * Description:
1056  * This function is designed to be used to generate a response for a
1057  * STATICLIST or STATICLISTDEF message.  When called either @addr4 or @addr6
1058  * can be specified, not both, the other unspecified entry should be set to
1059  * NULL by the caller.  Returns the size of the message on success, negative
1060  * values on failure.
1061  *
1062  */
1063 static int netlbl_unlabel_staticlist_gen(u32 cmd,
1064                                        const struct netlbl_unlhsh_iface *iface,
1065                                        const struct netlbl_unlhsh_addr4 *addr4,
1066                                        const struct netlbl_unlhsh_addr6 *addr6,
1067                                        void *arg)
1068 {
1069         int ret_val = -ENOMEM;
1070         struct netlbl_unlhsh_walk_arg *cb_arg = arg;
1071         struct net_device *dev;
1072         void *data;
1073         u32 secid;
1074         char *secctx;
1075         u32 secctx_len;
1076
1077         data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
1078                            cb_arg->seq, &netlbl_unlabel_gnl_family,
1079                            NLM_F_MULTI, cmd);
1080         if (data == NULL)
1081                 goto list_cb_failure;
1082
1083         if (iface->ifindex > 0) {
1084                 dev = dev_get_by_index(&init_net, iface->ifindex);
1085                 if (!dev) {
1086                         ret_val = -ENODEV;
1087                         goto list_cb_failure;
1088                 }
1089                 ret_val = nla_put_string(cb_arg->skb,
1090                                          NLBL_UNLABEL_A_IFACE, dev->name);
1091                 dev_put(dev);
1092                 if (ret_val != 0)
1093                         goto list_cb_failure;
1094         }
1095
1096         if (addr4) {
1097                 struct in_addr addr_struct;
1098
1099                 addr_struct.s_addr = addr4->list.addr;
1100                 ret_val = nla_put_in_addr(cb_arg->skb,
1101                                           NLBL_UNLABEL_A_IPV4ADDR,
1102                                           addr_struct.s_addr);
1103                 if (ret_val != 0)
1104                         goto list_cb_failure;
1105
1106                 addr_struct.s_addr = addr4->list.mask;
1107                 ret_val = nla_put_in_addr(cb_arg->skb,
1108                                           NLBL_UNLABEL_A_IPV4MASK,
1109                                           addr_struct.s_addr);
1110                 if (ret_val != 0)
1111                         goto list_cb_failure;
1112
1113                 secid = addr4->secid;
1114         } else {
1115                 ret_val = nla_put_in6_addr(cb_arg->skb,
1116                                            NLBL_UNLABEL_A_IPV6ADDR,
1117                                            &addr6->list.addr);
1118                 if (ret_val != 0)
1119                         goto list_cb_failure;
1120
1121                 ret_val = nla_put_in6_addr(cb_arg->skb,
1122                                            NLBL_UNLABEL_A_IPV6MASK,
1123                                            &addr6->list.mask);
1124                 if (ret_val != 0)
1125                         goto list_cb_failure;
1126
1127                 secid = addr6->secid;
1128         }
1129
1130         ret_val = security_secid_to_secctx(secid, &secctx, &secctx_len);
1131         if (ret_val != 0)
1132                 goto list_cb_failure;
1133         ret_val = nla_put(cb_arg->skb,
1134                           NLBL_UNLABEL_A_SECCTX,
1135                           secctx_len,
1136                           secctx);
1137         security_release_secctx(secctx, secctx_len);
1138         if (ret_val != 0)
1139                 goto list_cb_failure;
1140
1141         cb_arg->seq++;
1142         genlmsg_end(cb_arg->skb, data);
1143         return 0;
1144
1145 list_cb_failure:
1146         genlmsg_cancel(cb_arg->skb, data);
1147         return ret_val;
1148 }
1149
1150 /**
1151  * netlbl_unlabel_staticlist - Handle a STATICLIST message
1152  * @skb: the NETLINK buffer
1153  * @cb: the NETLINK callback
1154  *
1155  * Description:
1156  * Process a user generated STATICLIST message and dump the unlabeled
1157  * connection hash table in a form suitable for use in a kernel generated
1158  * STATICLIST message.  Returns the length of @skb.
1159  *
1160  */
1161 static int netlbl_unlabel_staticlist(struct sk_buff *skb,
1162                                      struct netlink_callback *cb)
1163 {
1164         struct netlbl_unlhsh_walk_arg cb_arg;
1165         u32 skip_bkt = cb->args[0];
1166         u32 skip_chain = cb->args[1];
1167         u32 skip_addr4 = cb->args[2];
1168         u32 iter_bkt, iter_chain = 0, iter_addr4 = 0, iter_addr6 = 0;
1169         struct netlbl_unlhsh_iface *iface;
1170         struct list_head *iter_list;
1171         struct netlbl_af4list *addr4;
1172 #if IS_ENABLED(CONFIG_IPV6)
1173         u32 skip_addr6 = cb->args[3];
1174         struct netlbl_af6list *addr6;
1175 #endif
1176
1177         cb_arg.nl_cb = cb;
1178         cb_arg.skb = skb;
1179         cb_arg.seq = cb->nlh->nlmsg_seq;
1180
1181         rcu_read_lock();
1182         for (iter_bkt = skip_bkt;
1183              iter_bkt < rcu_dereference(netlbl_unlhsh)->size;
1184              iter_bkt++) {
1185                 iter_list = &rcu_dereference(netlbl_unlhsh)->tbl[iter_bkt];
1186                 list_for_each_entry_rcu(iface, iter_list, list) {
1187                         if (!iface->valid ||
1188                             iter_chain++ < skip_chain)
1189                                 continue;
1190                         netlbl_af4list_foreach_rcu(addr4,
1191                                                    &iface->addr4_list) {
1192                                 if (iter_addr4++ < skip_addr4)
1193                                         continue;
1194                                 if (netlbl_unlabel_staticlist_gen(
1195                                               NLBL_UNLABEL_C_STATICLIST,
1196                                               iface,
1197                                               netlbl_unlhsh_addr4_entry(addr4),
1198                                               NULL,
1199                                               &cb_arg) < 0) {
1200                                         iter_addr4--;
1201                                         iter_chain--;
1202                                         goto unlabel_staticlist_return;
1203                                 }
1204                         }
1205                         iter_addr4 = 0;
1206                         skip_addr4 = 0;
1207 #if IS_ENABLED(CONFIG_IPV6)
1208                         netlbl_af6list_foreach_rcu(addr6,
1209                                                    &iface->addr6_list) {
1210                                 if (iter_addr6++ < skip_addr6)
1211                                         continue;
1212                                 if (netlbl_unlabel_staticlist_gen(
1213                                               NLBL_UNLABEL_C_STATICLIST,
1214                                               iface,
1215                                               NULL,
1216                                               netlbl_unlhsh_addr6_entry(addr6),
1217                                               &cb_arg) < 0) {
1218                                         iter_addr6--;
1219                                         iter_chain--;
1220                                         goto unlabel_staticlist_return;
1221                                 }
1222                         }
1223                         iter_addr6 = 0;
1224                         skip_addr6 = 0;
1225 #endif /* IPv6 */
1226                 }
1227                 iter_chain = 0;
1228                 skip_chain = 0;
1229         }
1230
1231 unlabel_staticlist_return:
1232         rcu_read_unlock();
1233         cb->args[0] = iter_bkt;
1234         cb->args[1] = iter_chain;
1235         cb->args[2] = iter_addr4;
1236         cb->args[3] = iter_addr6;
1237         return skb->len;
1238 }
1239
1240 /**
1241  * netlbl_unlabel_staticlistdef - Handle a STATICLISTDEF message
1242  * @skb: the NETLINK buffer
1243  * @cb: the NETLINK callback
1244  *
1245  * Description:
1246  * Process a user generated STATICLISTDEF message and dump the default
1247  * unlabeled connection entry in a form suitable for use in a kernel generated
1248  * STATICLISTDEF message.  Returns the length of @skb.
1249  *
1250  */
1251 static int netlbl_unlabel_staticlistdef(struct sk_buff *skb,
1252                                         struct netlink_callback *cb)
1253 {
1254         struct netlbl_unlhsh_walk_arg cb_arg;
1255         struct netlbl_unlhsh_iface *iface;
1256         u32 iter_addr4 = 0, iter_addr6 = 0;
1257         struct netlbl_af4list *addr4;
1258 #if IS_ENABLED(CONFIG_IPV6)
1259         struct netlbl_af6list *addr6;
1260 #endif
1261
1262         cb_arg.nl_cb = cb;
1263         cb_arg.skb = skb;
1264         cb_arg.seq = cb->nlh->nlmsg_seq;
1265
1266         rcu_read_lock();
1267         iface = rcu_dereference(netlbl_unlhsh_def);
1268         if (iface == NULL || !iface->valid)
1269                 goto unlabel_staticlistdef_return;
1270
1271         netlbl_af4list_foreach_rcu(addr4, &iface->addr4_list) {
1272                 if (iter_addr4++ < cb->args[0])
1273                         continue;
1274                 if (netlbl_unlabel_staticlist_gen(NLBL_UNLABEL_C_STATICLISTDEF,
1275                                               iface,
1276                                               netlbl_unlhsh_addr4_entry(addr4),
1277                                               NULL,
1278                                               &cb_arg) < 0) {
1279                         iter_addr4--;
1280                         goto unlabel_staticlistdef_return;
1281                 }
1282         }
1283 #if IS_ENABLED(CONFIG_IPV6)
1284         netlbl_af6list_foreach_rcu(addr6, &iface->addr6_list) {
1285                 if (iter_addr6++ < cb->args[1])
1286                         continue;
1287                 if (netlbl_unlabel_staticlist_gen(NLBL_UNLABEL_C_STATICLISTDEF,
1288                                               iface,
1289                                               NULL,
1290                                               netlbl_unlhsh_addr6_entry(addr6),
1291                                               &cb_arg) < 0) {
1292                         iter_addr6--;
1293                         goto unlabel_staticlistdef_return;
1294                 }
1295         }
1296 #endif /* IPv6 */
1297
1298 unlabel_staticlistdef_return:
1299         rcu_read_unlock();
1300         cb->args[0] = iter_addr4;
1301         cb->args[1] = iter_addr6;
1302         return skb->len;
1303 }
1304
1305 /*
1306  * NetLabel Generic NETLINK Command Definitions
1307  */
1308
1309 static const struct genl_small_ops netlbl_unlabel_genl_ops[] = {
1310         {
1311         .cmd = NLBL_UNLABEL_C_STATICADD,
1312         .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1313         .flags = GENL_ADMIN_PERM,
1314         .doit = netlbl_unlabel_staticadd,
1315         .dumpit = NULL,
1316         },
1317         {
1318         .cmd = NLBL_UNLABEL_C_STATICREMOVE,
1319         .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1320         .flags = GENL_ADMIN_PERM,
1321         .doit = netlbl_unlabel_staticremove,
1322         .dumpit = NULL,
1323         },
1324         {
1325         .cmd = NLBL_UNLABEL_C_STATICLIST,
1326         .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1327         .flags = 0,
1328         .doit = NULL,
1329         .dumpit = netlbl_unlabel_staticlist,
1330         },
1331         {
1332         .cmd = NLBL_UNLABEL_C_STATICADDDEF,
1333         .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1334         .flags = GENL_ADMIN_PERM,
1335         .doit = netlbl_unlabel_staticadddef,
1336         .dumpit = NULL,
1337         },
1338         {
1339         .cmd = NLBL_UNLABEL_C_STATICREMOVEDEF,
1340         .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1341         .flags = GENL_ADMIN_PERM,
1342         .doit = netlbl_unlabel_staticremovedef,
1343         .dumpit = NULL,
1344         },
1345         {
1346         .cmd = NLBL_UNLABEL_C_STATICLISTDEF,
1347         .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1348         .flags = 0,
1349         .doit = NULL,
1350         .dumpit = netlbl_unlabel_staticlistdef,
1351         },
1352         {
1353         .cmd = NLBL_UNLABEL_C_ACCEPT,
1354         .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1355         .flags = GENL_ADMIN_PERM,
1356         .doit = netlbl_unlabel_accept,
1357         .dumpit = NULL,
1358         },
1359         {
1360         .cmd = NLBL_UNLABEL_C_LIST,
1361         .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1362         .flags = 0,
1363         .doit = netlbl_unlabel_list,
1364         .dumpit = NULL,
1365         },
1366 };
1367
1368 static struct genl_family netlbl_unlabel_gnl_family __ro_after_init = {
1369         .hdrsize = 0,
1370         .name = NETLBL_NLTYPE_UNLABELED_NAME,
1371         .version = NETLBL_PROTO_VERSION,
1372         .maxattr = NLBL_UNLABEL_A_MAX,
1373         .policy = netlbl_unlabel_genl_policy,
1374         .module = THIS_MODULE,
1375         .small_ops = netlbl_unlabel_genl_ops,
1376         .n_small_ops = ARRAY_SIZE(netlbl_unlabel_genl_ops),
1377 };
1378
1379 /*
1380  * NetLabel Generic NETLINK Protocol Functions
1381  */
1382
1383 /**
1384  * netlbl_unlabel_genl_init - Register the Unlabeled NetLabel component
1385  *
1386  * Description:
1387  * Register the unlabeled packet NetLabel component with the Generic NETLINK
1388  * mechanism.  Returns zero on success, negative values on failure.
1389  *
1390  */
1391 int __init netlbl_unlabel_genl_init(void)
1392 {
1393         return genl_register_family(&netlbl_unlabel_gnl_family);
1394 }
1395
1396 /*
1397  * NetLabel KAPI Hooks
1398  */
1399
1400 static struct notifier_block netlbl_unlhsh_netdev_notifier = {
1401         .notifier_call = netlbl_unlhsh_netdev_handler,
1402 };
1403
1404 /**
1405  * netlbl_unlabel_init - Initialize the unlabeled connection hash table
1406  * @size: the number of bits to use for the hash buckets
1407  *
1408  * Description:
1409  * Initializes the unlabeled connection hash table and registers a network
1410  * device notification handler.  This function should only be called by the
1411  * NetLabel subsystem itself during initialization.  Returns zero on success,
1412  * non-zero values on error.
1413  *
1414  */
1415 int __init netlbl_unlabel_init(u32 size)
1416 {
1417         u32 iter;
1418         struct netlbl_unlhsh_tbl *hsh_tbl;
1419
1420         if (size == 0)
1421                 return -EINVAL;
1422
1423         hsh_tbl = kmalloc(sizeof(*hsh_tbl), GFP_KERNEL);
1424         if (hsh_tbl == NULL)
1425                 return -ENOMEM;
1426         hsh_tbl->size = 1 << size;
1427         hsh_tbl->tbl = kcalloc(hsh_tbl->size,
1428                                sizeof(struct list_head),
1429                                GFP_KERNEL);
1430         if (hsh_tbl->tbl == NULL) {
1431                 kfree(hsh_tbl);
1432                 return -ENOMEM;
1433         }
1434         for (iter = 0; iter < hsh_tbl->size; iter++)
1435                 INIT_LIST_HEAD(&hsh_tbl->tbl[iter]);
1436
1437         spin_lock(&netlbl_unlhsh_lock);
1438         rcu_assign_pointer(netlbl_unlhsh, hsh_tbl);
1439         spin_unlock(&netlbl_unlhsh_lock);
1440
1441         register_netdevice_notifier(&netlbl_unlhsh_netdev_notifier);
1442
1443         return 0;
1444 }
1445
1446 /**
1447  * netlbl_unlabel_getattr - Get the security attributes for an unlabled packet
1448  * @skb: the packet
1449  * @family: protocol family
1450  * @secattr: the security attributes
1451  *
1452  * Description:
1453  * Determine the security attributes, if any, for an unlabled packet and return
1454  * them in @secattr.  Returns zero on success and negative values on failure.
1455  *
1456  */
1457 int netlbl_unlabel_getattr(const struct sk_buff *skb,
1458                            u16 family,
1459                            struct netlbl_lsm_secattr *secattr)
1460 {
1461         struct netlbl_unlhsh_iface *iface;
1462
1463         rcu_read_lock();
1464         iface = netlbl_unlhsh_search_iface(skb->skb_iif);
1465         if (iface == NULL)
1466                 iface = rcu_dereference(netlbl_unlhsh_def);
1467         if (iface == NULL || !iface->valid)
1468                 goto unlabel_getattr_nolabel;
1469
1470 #if IS_ENABLED(CONFIG_IPV6)
1471         /* When resolving a fallback label, check the sk_buff version as
1472          * it is possible (e.g. SCTP) to have family = PF_INET6 while
1473          * receiving ip_hdr(skb)->version = 4.
1474          */
1475         if (family == PF_INET6 && ip_hdr(skb)->version == 4)
1476                 family = PF_INET;
1477 #endif /* IPv6 */
1478
1479         switch (family) {
1480         case PF_INET: {
1481                 struct iphdr *hdr4;
1482                 struct netlbl_af4list *addr4;
1483
1484                 hdr4 = ip_hdr(skb);
1485                 addr4 = netlbl_af4list_search(hdr4->saddr,
1486                                               &iface->addr4_list);
1487                 if (addr4 == NULL)
1488                         goto unlabel_getattr_nolabel;
1489                 secattr->attr.secid = netlbl_unlhsh_addr4_entry(addr4)->secid;
1490                 break;
1491         }
1492 #if IS_ENABLED(CONFIG_IPV6)
1493         case PF_INET6: {
1494                 struct ipv6hdr *hdr6;
1495                 struct netlbl_af6list *addr6;
1496
1497                 hdr6 = ipv6_hdr(skb);
1498                 addr6 = netlbl_af6list_search(&hdr6->saddr,
1499                                               &iface->addr6_list);
1500                 if (addr6 == NULL)
1501                         goto unlabel_getattr_nolabel;
1502                 secattr->attr.secid = netlbl_unlhsh_addr6_entry(addr6)->secid;
1503                 break;
1504         }
1505 #endif /* IPv6 */
1506         default:
1507                 goto unlabel_getattr_nolabel;
1508         }
1509         rcu_read_unlock();
1510
1511         secattr->flags |= NETLBL_SECATTR_SECID;
1512         secattr->type = NETLBL_NLTYPE_UNLABELED;
1513         return 0;
1514
1515 unlabel_getattr_nolabel:
1516         rcu_read_unlock();
1517         if (netlabel_unlabel_acceptflg == 0)
1518                 return -ENOMSG;
1519         secattr->type = NETLBL_NLTYPE_UNLABELED;
1520         return 0;
1521 }
1522
1523 /**
1524  * netlbl_unlabel_defconf - Set the default config to allow unlabeled packets
1525  *
1526  * Description:
1527  * Set the default NetLabel configuration to allow incoming unlabeled packets
1528  * and to send unlabeled network traffic by default.
1529  *
1530  */
1531 int __init netlbl_unlabel_defconf(void)
1532 {
1533         int ret_val;
1534         struct netlbl_dom_map *entry;
1535         struct netlbl_audit audit_info;
1536
1537         /* Only the kernel is allowed to call this function and the only time
1538          * it is called is at bootup before the audit subsystem is reporting
1539          * messages so don't worry to much about these values. */
1540         security_task_getsecid_subj(current, &audit_info.secid);
1541         audit_info.loginuid = GLOBAL_ROOT_UID;
1542         audit_info.sessionid = 0;
1543
1544         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
1545         if (entry == NULL)
1546                 return -ENOMEM;
1547         entry->family = AF_UNSPEC;
1548         entry->def.type = NETLBL_NLTYPE_UNLABELED;
1549         ret_val = netlbl_domhsh_add_default(entry, &audit_info);
1550         if (ret_val != 0)
1551                 return ret_val;
1552
1553         netlbl_unlabel_acceptflg_set(1, &audit_info);
1554
1555         return 0;
1556 }