net/netlabel/netlabel_unlabeled.c

   1 /*
   2  * NetLabel Unlabeled Support
   3  *
   4  * This file defines functions for dealing with unlabeled packets for the
   5  * NetLabel system.  The NetLabel system manages static and dynamic label
   6  * mappings for network protocols such as CIPSO and RIPSO.
   7  *
   8  * Author: Paul Moore <paul@paul-moore.com>
   9  *
  10  */
  11
  12 /*
  13  * (c) Copyright Hewlett-Packard Development Company, L.P., 2006 - 2008
  14  *
  15  * This program is free software;  you can redistribute it and/or modify
  16  * it under the terms of the GNU General Public License as published by
  17  * the Free Software Foundation; either version 2 of the License, or
  18  * (at your option) any later version.
  19  *
  20  * This program is distributed in the hope that it will be useful,
  21  * but WITHOUT ANY WARRANTY;  without even the implied warranty of
  22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  23  * the GNU General Public License for more details.
  24  *
  25  * You should have received a copy of the GNU General Public License
  26  * along with this program;  if not, see <http://www.gnu.org/licenses/>.
  27  *
  28  */
  29
  30 #include <linux/types.h>
  31 #include <linux/rcupdate.h>
  32 #include <linux/list.h>
  33 #include <linux/spinlock.h>
  34 #include <linux/socket.h>
  35 #include <linux/string.h>
  36 #include <linux/skbuff.h>
  37 #include <linux/audit.h>
  38 #include <linux/in.h>
  39 #include <linux/in6.h>
  40 #include <linux/ip.h>
  41 #include <linux/ipv6.h>
  42 #include <linux/notifier.h>
  43 #include <linux/netdevice.h>
  44 #include <linux/security.h>
  45 #include <linux/slab.h>
  46 #include <net/sock.h>
  47 #include <net/netlink.h>
  48 #include <net/genetlink.h>
  49 #include <net/ip.h>
  50 #include <net/ipv6.h>
  51 #include <net/net_namespace.h>
  52 #include <net/netlabel.h>
  53 #include <asm/bug.h>
  54 #include <linux/atomic.h>
  55
  56 #include "netlabel_user.h"
  57 #include "netlabel_addrlist.h"
  58 #include "netlabel_domainhash.h"
  59 #include "netlabel_unlabeled.h"
  60 #include "netlabel_mgmt.h"
  61
  62 /* NOTE: at present we always use init's network namespace since we don't
  63  *       presently support different namespaces even though the majority of
  64  *       the functions in this file are "namespace safe" */
  65
  66 /* The unlabeled connection hash table which we use to map network interfaces
  67  * and addresses of unlabeled packets to a user specified secid value for the
  68  * LSM.  The hash table is used to lookup the network interface entry
  69  * (struct netlbl_unlhsh_iface) and then the interface entry is used to
  70  * lookup an IP address match from an ordered list.  If a network interface
  71  * match can not be found in the hash table then the default entry
  72  * (netlbl_unlhsh_def) is used.  The IP address entry list
  73  * (struct netlbl_unlhsh_addr) is ordered such that the entries with a
  74  * larger netmask come first.
  75  */
  76 struct netlbl_unlhsh_tbl {
  77         struct list_head *tbl;
  78         u32 size;
  79 };
  80 #define netlbl_unlhsh_addr4_entry(iter) \
  81         container_of(iter, struct netlbl_unlhsh_addr4, list)
  82 struct netlbl_unlhsh_addr4 {
  83         u32 secid;
  84
  85         struct netlbl_af4list list;
  86         struct rcu_head rcu;
  87 };
  88 #define netlbl_unlhsh_addr6_entry(iter) \
  89         container_of(iter, struct netlbl_unlhsh_addr6, list)
  90 struct netlbl_unlhsh_addr6 {
  91         u32 secid;
  92
  93         struct netlbl_af6list list;
  94         struct rcu_head rcu;
  95 };
  96 struct netlbl_unlhsh_iface {
  97         int ifindex;
  98         struct list_head addr4_list;
  99         struct list_head addr6_list;
 100
 101         u32 valid;
 102         struct list_head list;
 103         struct rcu_head rcu;
 104 };
 105
 106 /* Argument struct for netlbl_unlhsh_walk() */
 107 struct netlbl_unlhsh_walk_arg {
 108         struct netlink_callback *nl_cb;
 109         struct sk_buff *skb;
 110         u32 seq;
 111 };
 112
 113 /* Unlabeled connection hash table */
 114 /* updates should be so rare that having one spinlock for the entire
 115  * hash table should be okay */
 116 static DEFINE_SPINLOCK(netlbl_unlhsh_lock);
 117 #define netlbl_unlhsh_rcu_deref(p) \
 118         rcu_dereference_check(p, lockdep_is_held(&netlbl_unlhsh_lock))
 119 static struct netlbl_unlhsh_tbl __rcu *netlbl_unlhsh;
 120 static struct netlbl_unlhsh_iface __rcu *netlbl_unlhsh_def;
 121
 122 /* Accept unlabeled packets flag */
 123 static u8 netlabel_unlabel_acceptflg;
 124
 125 /* NetLabel Generic NETLINK unlabeled family */
 126 static struct genl_family netlbl_unlabel_gnl_family = {
 127         .id = GENL_ID_GENERATE,
 128         .hdrsize = 0,
 129         .name = NETLBL_NLTYPE_UNLABELED_NAME,
 130         .version = NETLBL_PROTO_VERSION,
 131         .maxattr = NLBL_UNLABEL_A_MAX,
 132 };
 133
 134 /* NetLabel Netlink attribute policy */
 135 static const struct nla_policy netlbl_unlabel_genl_policy[NLBL_UNLABEL_A_MAX + 1] = {
 136         [NLBL_UNLABEL_A_ACPTFLG] = { .type = NLA_U8 },
 137         [NLBL_UNLABEL_A_IPV6ADDR] = { .type = NLA_BINARY,
 138                                       .len = sizeof(struct in6_addr) },
 139         [NLBL_UNLABEL_A_IPV6MASK] = { .type = NLA_BINARY,
 140                                       .len = sizeof(struct in6_addr) },
 141         [NLBL_UNLABEL_A_IPV4ADDR] = { .type = NLA_BINARY,
 142                                       .len = sizeof(struct in_addr) },
 143         [NLBL_UNLABEL_A_IPV4MASK] = { .type = NLA_BINARY,
 144                                       .len = sizeof(struct in_addr) },
 145         [NLBL_UNLABEL_A_IFACE] = { .type = NLA_NUL_STRING,
 146                                    .len = IFNAMSIZ - 1 },
 147         [NLBL_UNLABEL_A_SECCTX] = { .type = NLA_BINARY }
 148 };
 149
 150 /*
 151  * Unlabeled Connection Hash Table Functions
 152  */
 153
 154 /**
 155  * netlbl_unlhsh_free_iface - Frees an interface entry from the hash table
 156  * @entry: the entry's RCU field
 157  *
 158  * Description:
 159  * This function is designed to be used as a callback to the call_rcu()
 160  * function so that memory allocated to a hash table interface entry can be
 161  * released safely.  It is important to note that this function does not free
 162  * the IPv4 and IPv6 address lists contained as part of an interface entry.  It
 163  * is up to the rest of the code to make sure an interface entry is only freed
 164  * once it's address lists are empty.
 165  *
 166  */
 167 static void netlbl_unlhsh_free_iface(struct rcu_head *entry)
 168 {
 169         struct netlbl_unlhsh_iface *iface;
 170         struct netlbl_af4list *iter4;
 171         struct netlbl_af4list *tmp4;
 172 #if IS_ENABLED(CONFIG_IPV6)
 173         struct netlbl_af6list *iter6;
 174         struct netlbl_af6list *tmp6;
 175 #endif /* IPv6 */
 176
 177         iface = container_of(entry, struct netlbl_unlhsh_iface, rcu);
 178
 179         /* no need for locks here since we are the only one with access to this
 180          * structure */
 181
 182         netlbl_af4list_foreach_safe(iter4, tmp4, &iface->addr4_list) {
 183                 netlbl_af4list_remove_entry(iter4);
 184                 kfree(netlbl_unlhsh_addr4_entry(iter4));
 185         }
 186 #if IS_ENABLED(CONFIG_IPV6)
 187         netlbl_af6list_foreach_safe(iter6, tmp6, &iface->addr6_list) {
 188                 netlbl_af6list_remove_entry(iter6);
 189                 kfree(netlbl_unlhsh_addr6_entry(iter6));
 190         }
 191 #endif /* IPv6 */
 192         kfree(iface);
 193 }
 194
 195 /**
 196  * netlbl_unlhsh_hash - Hashing function for the hash table
 197  * @ifindex: the network interface/device to hash
 198  *
 199  * Description:
 200  * This is the hashing function for the unlabeled hash table, it returns the
 201  * bucket number for the given device/interface.  The caller is responsible for
 202  * ensuring that the hash table is protected with either a RCU read lock or
 203  * the hash table lock.
 204  *
 205  */
 206 static u32 netlbl_unlhsh_hash(int ifindex)
 207 {
 208         return ifindex & (netlbl_unlhsh_rcu_deref(netlbl_unlhsh)->size - 1);
 209 }
 210
 211 /**
 212  * netlbl_unlhsh_search_iface - Search for a matching interface entry
 213  * @ifindex: the network interface
 214  *
 215  * Description:
 216  * Searches the unlabeled connection hash table and returns a pointer to the
 217  * interface entry which matches @ifindex, otherwise NULL is returned.  The
 218  * caller is responsible for ensuring that the hash table is protected with
 219  * either a RCU read lock or the hash table lock.
 220  *
 221  */
 222 static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex)
 223 {
 224         u32 bkt;
 225         struct list_head *bkt_list;
 226         struct netlbl_unlhsh_iface *iter;
 227
 228         bkt = netlbl_unlhsh_hash(ifindex);
 229         bkt_list = &netlbl_unlhsh_rcu_deref(netlbl_unlhsh)->tbl[bkt];
 230         list_for_each_entry_rcu(iter, bkt_list, list)
 231                 if (iter->valid && iter->ifindex == ifindex)
 232                         return iter;
 233
 234         return NULL;
 235 }
 236
 237 /**
 238  * netlbl_unlhsh_add_addr4 - Add a new IPv4 address entry to the hash table
 239  * @iface: the associated interface entry
 240  * @addr: IPv4 address in network byte order
 241  * @mask: IPv4 address mask in network byte order
 242  * @secid: LSM secid value for entry
 243  *
 244  * Description:
 245  * Add a new address entry into the unlabeled connection hash table using the
 246  * interface entry specified by @iface.  On success zero is returned, otherwise
 247  * a negative value is returned.
 248  *
 249  */
 250 static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
 251                                    const struct in_addr *addr,
 252                                    const struct in_addr *mask,
 253                                    u32 secid)
 254 {
 255         int ret_val;
 256         struct netlbl_unlhsh_addr4 *entry;
 257
 258         entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
 259         if (entry == NULL)
 260                 return -ENOMEM;
 261
 262         entry->list.addr = addr->s_addr & mask->s_addr;
 263         entry->list.mask = mask->s_addr;
 264         entry->list.valid = 1;
 265         entry->secid = secid;
 266
 267         spin_lock(&netlbl_unlhsh_lock);
 268         ret_val = netlbl_af4list_add(&entry->list, &iface->addr4_list);
 269         spin_unlock(&netlbl_unlhsh_lock);
 270
 271         if (ret_val != 0)
 272                 kfree(entry);
 273         return ret_val;
 274 }
 275
 276 #if IS_ENABLED(CONFIG_IPV6)
 277 /**
 278  * netlbl_unlhsh_add_addr6 - Add a new IPv6 address entry to the hash table
 279  * @iface: the associated interface entry
 280  * @addr: IPv6 address in network byte order
 281  * @mask: IPv6 address mask in network byte order
 282  * @secid: LSM secid value for entry
 283  *
 284  * Description:
 285  * Add a new address entry into the unlabeled connection hash table using the
 286  * interface entry specified by @iface.  On success zero is returned, otherwise
 287  * a negative value is returned.
 288  *
 289  */
 290 static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface,
 291                                    const struct in6_addr *addr,
 292                                    const struct in6_addr *mask,
 293                                    u32 secid)
 294 {
 295         int ret_val;
 296         struct netlbl_unlhsh_addr6 *entry;
 297
 298         entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
 299         if (entry == NULL)
 300                 return -ENOMEM;
 301
 302         entry->list.addr = *addr;
 303         entry->list.addr.s6_addr32[0] &= mask->s6_addr32[0];
 304         entry->list.addr.s6_addr32[1] &= mask->s6_addr32[1];
 305         entry->list.addr.s6_addr32[2] &= mask->s6_addr32[2];
 306         entry->list.addr.s6_addr32[3] &= mask->s6_addr32[3];
 307         entry->list.mask = *mask;
 308         entry->list.valid = 1;
 309         entry->secid = secid;
 310
 311         spin_lock(&netlbl_unlhsh_lock);
 312         ret_val = netlbl_af6list_add(&entry->list, &iface->addr6_list);
 313         spin_unlock(&netlbl_unlhsh_lock);
 314
 315         if (ret_val != 0)
 316                 kfree(entry);
 317         return 0;
 318 }
 319 #endif /* IPv6 */
 320
 321 /**
 322  * netlbl_unlhsh_add_iface - Adds a new interface entry to the hash table
 323  * @ifindex: network interface
 324  *
 325  * Description:
 326  * Add a new, empty, interface entry into the unlabeled connection hash table.
 327  * On success a pointer to the new interface entry is returned, on failure NULL
 328  * is returned.
 329  *
 330  */
 331 static struct netlbl_unlhsh_iface *netlbl_unlhsh_add_iface(int ifindex)
 332 {
 333         u32 bkt;
 334         struct netlbl_unlhsh_iface *iface;
 335
 336         iface = kzalloc(sizeof(*iface), GFP_ATOMIC);
 337         if (iface == NULL)
 338                 return NULL;
 339
 340         iface->ifindex = ifindex;
 341         INIT_LIST_HEAD(&iface->addr4_list);
 342         INIT_LIST_HEAD(&iface->addr6_list);
 343         iface->valid = 1;
 344
 345         spin_lock(&netlbl_unlhsh_lock);
 346         if (ifindex > 0) {
 347                 bkt = netlbl_unlhsh_hash(ifindex);
 348                 if (netlbl_unlhsh_search_iface(ifindex) != NULL)
 349                         goto add_iface_failure;
 350                 list_add_tail_rcu(&iface->list,
 351                              &netlbl_unlhsh_rcu_deref(netlbl_unlhsh)->tbl[bkt]);
 352         } else {
 353                 INIT_LIST_HEAD(&iface->list);
 354                 if (netlbl_unlhsh_rcu_deref(netlbl_unlhsh_def) != NULL)
 355                         goto add_iface_failure;
 356                 rcu_assign_pointer(netlbl_unlhsh_def, iface);
 357         }
 358         spin_unlock(&netlbl_unlhsh_lock);
 359
 360         return iface;
 361
 362 add_iface_failure:
 363         spin_unlock(&netlbl_unlhsh_lock);
 364         kfree(iface);
 365         return NULL;
 366 }
 367
 368 /**
 369  * netlbl_unlhsh_add - Adds a new entry to the unlabeled connection hash table
 370  * @net: network namespace
 371  * @dev_name: interface name
 372  * @addr: IP address in network byte order
 373  * @mask: address mask in network byte order
 374  * @addr_len: length of address/mask (4 for IPv4, 16 for IPv6)
 375  * @secid: LSM secid value for the entry
 376  * @audit_info: NetLabel audit information
 377  *
 378  * Description:
 379  * Adds a new entry to the unlabeled connection hash table.  Returns zero on
 380  * success, negative values on failure.
 381  *
 382  */
 383 int netlbl_unlhsh_add(struct net *net,
 384                       const char *dev_name,
 385                       const void *addr,
 386                       const void *mask,
 387                       u32 addr_len,
 388                       u32 secid,
 389                       struct netlbl_audit *audit_info)
 390 {
 391         int ret_val;
 392         int ifindex;
 393         struct net_device *dev;
 394         struct netlbl_unlhsh_iface *iface;
 395         struct audit_buffer *audit_buf = NULL;
 396         char *secctx = NULL;
 397         u32 secctx_len;
 398
 399         if (addr_len != sizeof(struct in_addr) &&
 400             addr_len != sizeof(struct in6_addr))
 401                 return -EINVAL;
 402
 403         rcu_read_lock();
 404         if (dev_name != NULL) {
 405                 dev = dev_get_by_name_rcu(net, dev_name);
 406                 if (dev == NULL) {
 407                         ret_val = -ENODEV;
 408                         goto unlhsh_add_return;
 409                 }
 410                 ifindex = dev->ifindex;
 411                 iface = netlbl_unlhsh_search_iface(ifindex);
 412         } else {
 413                 ifindex = 0;
 414                 iface = rcu_dereference(netlbl_unlhsh_def);
 415         }
 416         if (iface == NULL) {
 417                 iface = netlbl_unlhsh_add_iface(ifindex);
 418                 if (iface == NULL) {
 419                         ret_val = -ENOMEM;
 420                         goto unlhsh_add_return;
 421                 }
 422         }
 423         audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_STCADD,
 424                                               audit_info);
 425         switch (addr_len) {
 426         case sizeof(struct in_addr): {
 427                 const struct in_addr *addr4 = addr;
 428                 const struct in_addr *mask4 = mask;
 429
 430                 ret_val = netlbl_unlhsh_add_addr4(iface, addr4, mask4, secid);
 431                 if (audit_buf != NULL)
 432                         netlbl_af4list_audit_addr(audit_buf, 1,
 433                                                   dev_name,
 434                                                   addr4->s_addr,
 435                                                   mask4->s_addr);
 436                 break;
 437         }
 438 #if IS_ENABLED(CONFIG_IPV6)
 439         case sizeof(struct in6_addr): {
 440                 const struct in6_addr *addr6 = addr;
 441                 const struct in6_addr *mask6 = mask;
 442
 443                 ret_val = netlbl_unlhsh_add_addr6(iface, addr6, mask6, secid);
 444                 if (audit_buf != NULL)
 445                         netlbl_af6list_audit_addr(audit_buf, 1,
 446                                                   dev_name,
 447                                                   addr6, mask6);
 448                 break;
 449         }
 450 #endif /* IPv6 */
 451         default:
 452                 ret_val = -EINVAL;
 453         }
 454         if (ret_val == 0)
 455                 atomic_inc(&netlabel_mgmt_protocount);
 456
 457 unlhsh_add_return:
 458         rcu_read_unlock();
 459         if (audit_buf != NULL) {
 460                 if (security_secid_to_secctx(secid,
 461                                              &secctx,
 462                                              &secctx_len) == 0) {
 463                         audit_log_format(audit_buf, " sec_obj=%s", secctx);
 464                         security_release_secctx(secctx, secctx_len);
 465                 }
 466                 audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
 467                 audit_log_end(audit_buf);
 468         }
 469         return ret_val;
 470 }
 471
 472 /**
 473  * netlbl_unlhsh_remove_addr4 - Remove an IPv4 address entry
 474  * @net: network namespace
 475  * @iface: interface entry
 476  * @addr: IP address
 477  * @mask: IP address mask
 478  * @audit_info: NetLabel audit information
 479  *
 480  * Description:
 481  * Remove an IP address entry from the unlabeled connection hash table.
 482  * Returns zero on success, negative values on failure.
 483  *
 484  */
 485 static int netlbl_unlhsh_remove_addr4(struct net *net,
 486                                       struct netlbl_unlhsh_iface *iface,
 487                                       const struct in_addr *addr,
 488                                       const struct in_addr *mask,
 489                                       struct netlbl_audit *audit_info)
 490 {
 491         struct netlbl_af4list *list_entry;
 492         struct netlbl_unlhsh_addr4 *entry;
 493         struct audit_buffer *audit_buf;
 494         struct net_device *dev;
 495         char *secctx;
 496         u32 secctx_len;
 497
 498         spin_lock(&netlbl_unlhsh_lock);
 499         list_entry = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
 500                                            &iface->addr4_list);
 501         spin_unlock(&netlbl_unlhsh_lock);
 502         if (list_entry != NULL)
 503                 entry = netlbl_unlhsh_addr4_entry(list_entry);
 504         else
 505                 entry = NULL;
 506
 507         audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_STCDEL,
 508                                               audit_info);
 509         if (audit_buf != NULL) {
 510                 dev = dev_get_by_index(net, iface->ifindex);
 511                 netlbl_af4list_audit_addr(audit_buf, 1,
 512                                           (dev != NULL ? dev->name : NULL),
 513                                           addr->s_addr, mask->s_addr);
 514                 if (dev != NULL)
 515                         dev_put(dev);
 516                 if (entry != NULL &&
 517                     security_secid_to_secctx(entry->secid,
 518                                              &secctx, &secctx_len) == 0) {
 519                         audit_log_format(audit_buf, " sec_obj=%s", secctx);
 520                         security_release_secctx(secctx, secctx_len);
 521                 }
 522                 audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
 523                 audit_log_end(audit_buf);
 524         }
 525
 526         if (entry == NULL)
 527                 return -ENOENT;
 528
 529         kfree_rcu(entry, rcu);
 530         return 0;
 531 }
 532
 533 #if IS_ENABLED(CONFIG_IPV6)
 534 /**
 535  * netlbl_unlhsh_remove_addr6 - Remove an IPv6 address entry
 536  * @net: network namespace
 537  * @iface: interface entry
 538  * @addr: IP address
 539  * @mask: IP address mask
 540  * @audit_info: NetLabel audit information
 541  *
 542  * Description:
 543  * Remove an IP address entry from the unlabeled connection hash table.
 544  * Returns zero on success, negative values on failure.
 545  *
 546  */
 547 static int netlbl_unlhsh_remove_addr6(struct net *net,
 548                                       struct netlbl_unlhsh_iface *iface,
 549                                       const struct in6_addr *addr,
 550                                       const struct in6_addr *mask,
 551                                       struct netlbl_audit *audit_info)
 552 {
 553         struct netlbl_af6list *list_entry;
 554         struct netlbl_unlhsh_addr6 *entry;
 555         struct audit_buffer *audit_buf;
 556         struct net_device *dev;
 557         char *secctx;
 558         u32 secctx_len;
 559
 560         spin_lock(&netlbl_unlhsh_lock);
 561         list_entry = netlbl_af6list_remove(addr, mask, &iface->addr6_list);
 562         spin_unlock(&netlbl_unlhsh_lock);
 563         if (list_entry != NULL)
 564                 entry = netlbl_unlhsh_addr6_entry(list_entry);
 565         else
 566                 entry = NULL;
 567
 568         audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_STCDEL,
 569                                               audit_info);
 570         if (audit_buf != NULL) {
 571                 dev = dev_get_by_index(net, iface->ifindex);
 572                 netlbl_af6list_audit_addr(audit_buf, 1,
 573                                           (dev != NULL ? dev->name : NULL),
 574                                           addr, mask);
 575                 if (dev != NULL)
 576                         dev_put(dev);
 577                 if (entry != NULL &&
 578                     security_secid_to_secctx(entry->secid,
 579                                              &secctx, &secctx_len) == 0) {
 580                         audit_log_format(audit_buf, " sec_obj=%s", secctx);
 581                         security_release_secctx(secctx, secctx_len);
 582                 }
 583                 audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
 584                 audit_log_end(audit_buf);
 585         }
 586
 587         if (entry == NULL)
 588                 return -ENOENT;
 589
 590         kfree_rcu(entry, rcu);
 591         return 0;
 592 }
 593 #endif /* IPv6 */
 594
 595 /**
 596  * netlbl_unlhsh_condremove_iface - Remove an interface entry
 597  * @iface: the interface entry
 598  *
 599  * Description:
 600  * Remove an interface entry from the unlabeled connection hash table if it is
 601  * empty.  An interface entry is considered to be empty if there are no
 602  * address entries assigned to it.
 603  *
 604  */
 605 static void netlbl_unlhsh_condremove_iface(struct netlbl_unlhsh_iface *iface)
 606 {
 607         struct netlbl_af4list *iter4;
 608 #if IS_ENABLED(CONFIG_IPV6)
 609         struct netlbl_af6list *iter6;
 610 #endif /* IPv6 */
 611
 612         spin_lock(&netlbl_unlhsh_lock);
 613         netlbl_af4list_foreach_rcu(iter4, &iface->addr4_list)
 614                 goto unlhsh_condremove_failure;
 615 #if IS_ENABLED(CONFIG_IPV6)
 616         netlbl_af6list_foreach_rcu(iter6, &iface->addr6_list)
 617                 goto unlhsh_condremove_failure;
 618 #endif /* IPv6 */
 619         iface->valid = 0;
 620         if (iface->ifindex > 0)
 621                 list_del_rcu(&iface->list);
 622         else
 623                 RCU_INIT_POINTER(netlbl_unlhsh_def, NULL);
 624         spin_unlock(&netlbl_unlhsh_lock);
 625
 626         call_rcu(&iface->rcu, netlbl_unlhsh_free_iface);
 627         return;
 628
 629 unlhsh_condremove_failure:
 630         spin_unlock(&netlbl_unlhsh_lock);
 631 }
 632
 633 /**
 634  * netlbl_unlhsh_remove - Remove an entry from the unlabeled hash table
 635  * @net: network namespace
 636  * @dev_name: interface name
 637  * @addr: IP address in network byte order
 638  * @mask: address mask in network byte order
 639  * @addr_len: length of address/mask (4 for IPv4, 16 for IPv6)
 640  * @audit_info: NetLabel audit information
 641  *
 642  * Description:
 643  * Removes and existing entry from the unlabeled connection hash table.
 644  * Returns zero on success, negative values on failure.
 645  *
 646  */
 647 int netlbl_unlhsh_remove(struct net *net,
 648                          const char *dev_name,
 649                          const void *addr,
 650                          const void *mask,
 651                          u32 addr_len,
 652                          struct netlbl_audit *audit_info)
 653 {
 654         int ret_val;
 655         struct net_device *dev;
 656         struct netlbl_unlhsh_iface *iface;
 657
 658         if (addr_len != sizeof(struct in_addr) &&
 659             addr_len != sizeof(struct in6_addr))
 660                 return -EINVAL;
 661
 662         rcu_read_lock();
 663         if (dev_name != NULL) {
 664                 dev = dev_get_by_name_rcu(net, dev_name);
 665                 if (dev == NULL) {
 666                         ret_val = -ENODEV;
 667                         goto unlhsh_remove_return;
 668                 }
 669                 iface = netlbl_unlhsh_search_iface(dev->ifindex);
 670         } else
 671                 iface = rcu_dereference(netlbl_unlhsh_def);
 672         if (iface == NULL) {
 673                 ret_val = -ENOENT;
 674                 goto unlhsh_remove_return;
 675         }
 676         switch (addr_len) {
 677         case sizeof(struct in_addr):
 678                 ret_val = netlbl_unlhsh_remove_addr4(net,
 679                                                      iface, addr, mask,
 680                                                      audit_info);
 681                 break;
 682 #if IS_ENABLED(CONFIG_IPV6)
 683         case sizeof(struct in6_addr):
 684                 ret_val = netlbl_unlhsh_remove_addr6(net,
 685                                                      iface, addr, mask,
 686                                                      audit_info);
 687                 break;
 688 #endif /* IPv6 */
 689         default:
 690                 ret_val = -EINVAL;
 691         }
 692         if (ret_val == 0) {
 693                 netlbl_unlhsh_condremove_iface(iface);
 694                 atomic_dec(&netlabel_mgmt_protocount);
 695         }
 696
 697 unlhsh_remove_return:
 698         rcu_read_unlock();
 699         return ret_val;
 700 }
 701
 702 /*
 703  * General Helper Functions
 704  */
 705
 706 /**
 707  * netlbl_unlhsh_netdev_handler - Network device notification handler
 708  * @this: notifier block
 709  * @event: the event
 710  * @ptr: the netdevice notifier info (cast to void)
 711  *
 712  * Description:
 713  * Handle network device events, although at present all we care about is a
 714  * network device going away.  In the case of a device going away we clear any
 715  * related entries from the unlabeled connection hash table.
 716  *
 717  */
 718 static int netlbl_unlhsh_netdev_handler(struct notifier_block *this,
 719                                         unsigned long event, void *ptr)
 720 {
 721         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 722         struct netlbl_unlhsh_iface *iface = NULL;
 723
 724         if (!net_eq(dev_net(dev), &init_net))
 725                 return NOTIFY_DONE;
 726
 727         /* XXX - should this be a check for NETDEV_DOWN or _UNREGISTER? */
 728         if (event == NETDEV_DOWN) {
 729                 spin_lock(&netlbl_unlhsh_lock);
 730                 iface = netlbl_unlhsh_search_iface(dev->ifindex);
 731                 if (iface != NULL && iface->valid) {
 732                         iface->valid = 0;
 733                         list_del_rcu(&iface->list);
 734                 } else
 735                         iface = NULL;
 736                 spin_unlock(&netlbl_unlhsh_lock);
 737         }
 738
 739         if (iface != NULL)
 740                 call_rcu(&iface->rcu, netlbl_unlhsh_free_iface);
 741
 742         return NOTIFY_DONE;
 743 }
 744
 745 /**
 746  * netlbl_unlabel_acceptflg_set - Set the unlabeled accept flag
 747  * @value: desired value
 748  * @audit_info: NetLabel audit information
 749  *
 750  * Description:
 751  * Set the value of the unlabeled accept flag to @value.
 752  *
 753  */
 754 static void netlbl_unlabel_acceptflg_set(u8 value,
 755                                          struct netlbl_audit *audit_info)
 756 {
 757         struct audit_buffer *audit_buf;
 758         u8 old_val;
 759
 760         old_val = netlabel_unlabel_acceptflg;
 761         netlabel_unlabel_acceptflg = value;
 762         audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_ALLOW,
 763                                               audit_info);
 764         if (audit_buf != NULL) {
 765                 audit_log_format(audit_buf,
 766                                  " unlbl_accept=%u old=%u", value, old_val);
 767                 audit_log_end(audit_buf);
 768         }
 769 }
 770
 771 /**
 772  * netlbl_unlabel_addrinfo_get - Get the IPv4/6 address information
 773  * @info: the Generic NETLINK info block
 774  * @addr: the IP address
 775  * @mask: the IP address mask
 776  * @len: the address length
 777  *
 778  * Description:
 779  * Examine the Generic NETLINK message and extract the IP address information.
 780  * Returns zero on success, negative values on failure.
 781  *
 782  */
 783 static int netlbl_unlabel_addrinfo_get(struct genl_info *info,
 784                                        void **addr,
 785                                        void **mask,
 786                                        u32 *len)
 787 {
 788         u32 addr_len;
 789
 790         if (info->attrs[NLBL_UNLABEL_A_IPV4ADDR] &&
 791             info->attrs[NLBL_UNLABEL_A_IPV4MASK]) {
 792                 addr_len = nla_len(info->attrs[NLBL_UNLABEL_A_IPV4ADDR]);
 793                 if (addr_len != sizeof(struct in_addr) &&
 794                     addr_len != nla_len(info->attrs[NLBL_UNLABEL_A_IPV4MASK]))
 795                         return -EINVAL;
 796                 *len = addr_len;
 797                 *addr = nla_data(info->attrs[NLBL_UNLABEL_A_IPV4ADDR]);
 798                 *mask = nla_data(info->attrs[NLBL_UNLABEL_A_IPV4MASK]);
 799                 return 0;
 800         } else if (info->attrs[NLBL_UNLABEL_A_IPV6ADDR]) {
 801                 addr_len = nla_len(info->attrs[NLBL_UNLABEL_A_IPV6ADDR]);
 802                 if (addr_len != sizeof(struct in6_addr) &&
 803                     addr_len != nla_len(info->attrs[NLBL_UNLABEL_A_IPV6MASK]))
 804                         return -EINVAL;
 805                 *len = addr_len;
 806                 *addr = nla_data(info->attrs[NLBL_UNLABEL_A_IPV6ADDR]);
 807                 *mask = nla_data(info->attrs[NLBL_UNLABEL_A_IPV6MASK]);
 808                 return 0;
 809         }
 810
 811         return -EINVAL;
 812 }
 813
 814 /*
 815  * NetLabel Command Handlers
 816  */
 817
 818 /**
 819  * netlbl_unlabel_accept - Handle an ACCEPT message
 820  * @skb: the NETLINK buffer
 821  * @info: the Generic NETLINK info block
 822  *
 823  * Description:
 824  * Process a user generated ACCEPT message and set the accept flag accordingly.
 825  * Returns zero on success, negative values on failure.
 826  *
 827  */
 828 static int netlbl_unlabel_accept(struct sk_buff *skb, struct genl_info *info)
 829 {
 830         u8 value;
 831         struct netlbl_audit audit_info;
 832
 833         if (info->attrs[NLBL_UNLABEL_A_ACPTFLG]) {
 834                 value = nla_get_u8(info->attrs[NLBL_UNLABEL_A_ACPTFLG]);
 835                 if (value == 1 || value == 0) {
 836                         netlbl_netlink_auditinfo(skb, &audit_info);
 837                         netlbl_unlabel_acceptflg_set(value, &audit_info);
 838                         return 0;
 839                 }
 840         }
 841
 842         return -EINVAL;
 843 }
 844
 845 /**
 846  * netlbl_unlabel_list - Handle a LIST message
 847  * @skb: the NETLINK buffer
 848  * @info: the Generic NETLINK info block
 849  *
 850  * Description:
 851  * Process a user generated LIST message and respond with the current status.
 852  * Returns zero on success, negative values on failure.
 853  *
 854  */
 855 static int netlbl_unlabel_list(struct sk_buff *skb, struct genl_info *info)
 856 {
 857         int ret_val = -EINVAL;
 858         struct sk_buff *ans_skb;
 859         void *data;
 860
 861         ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 862         if (ans_skb == NULL)
 863                 goto list_failure;
 864         data = genlmsg_put_reply(ans_skb, info, &netlbl_unlabel_gnl_family,
 865                                  0, NLBL_UNLABEL_C_LIST);
 866         if (data == NULL) {
 867                 ret_val = -ENOMEM;
 868                 goto list_failure;
 869         }
 870
 871         ret_val = nla_put_u8(ans_skb,
 872                              NLBL_UNLABEL_A_ACPTFLG,
 873                              netlabel_unlabel_acceptflg);
 874         if (ret_val != 0)
 875                 goto list_failure;
 876
 877         genlmsg_end(ans_skb, data);
 878         return genlmsg_reply(ans_skb, info);
 879
 880 list_failure:
 881         kfree_skb(ans_skb);
 882         return ret_val;
 883 }
 884
 885 /**
 886  * netlbl_unlabel_staticadd - Handle a STATICADD message
 887  * @skb: the NETLINK buffer
 888  * @info: the Generic NETLINK info block
 889  *
 890  * Description:
 891  * Process a user generated STATICADD message and add a new unlabeled
 892  * connection entry to the hash table.  Returns zero on success, negative
 893  * values on failure.
 894  *
 895  */
 896 static int netlbl_unlabel_staticadd(struct sk_buff *skb,
 897                                     struct genl_info *info)
 898 {
 899         int ret_val;
 900         char *dev_name;
 901         void *addr;
 902         void *mask;
 903         u32 addr_len;
 904         u32 secid;
 905         struct netlbl_audit audit_info;
 906
 907         /* Don't allow users to add both IPv4 and IPv6 addresses for a
 908          * single entry.  However, allow users to create two entries, one each
 909          * for IPv4 and IPv4, with the same LSM security context which should
 910          * achieve the same result. */
 911         if (!info->attrs[NLBL_UNLABEL_A_SECCTX] ||
 912             !info->attrs[NLBL_UNLABEL_A_IFACE] ||
 913             !((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] ||
 914                !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^
 915               (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] ||
 916                !info->attrs[NLBL_UNLABEL_A_IPV6MASK])))
 917                 return -EINVAL;
 918
 919         netlbl_netlink_auditinfo(skb, &audit_info);
 920
 921         ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len);
 922         if (ret_val != 0)
 923                 return ret_val;
 924         dev_name = nla_data(info->attrs[NLBL_UNLABEL_A_IFACE]);
 925         ret_val = security_secctx_to_secid(
 926                                   nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
 927                                   nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
 928                                   &secid);
 929         if (ret_val != 0)
 930                 return ret_val;
 931
 932         return netlbl_unlhsh_add(&init_net,
 933                                  dev_name, addr, mask, addr_len, secid,
 934                                  &audit_info);
 935 }
 936
 937 /**
 938  * netlbl_unlabel_staticadddef - Handle a STATICADDDEF message
 939  * @skb: the NETLINK buffer
 940  * @info: the Generic NETLINK info block
 941  *
 942  * Description:
 943  * Process a user generated STATICADDDEF message and add a new default
 944  * unlabeled connection entry.  Returns zero on success, negative values on
 945  * failure.
 946  *
 947  */
 948 static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
 949                                        struct genl_info *info)
 950 {
 951         int ret_val;
 952         void *addr;
 953         void *mask;
 954         u32 addr_len;
 955         u32 secid;
 956         struct netlbl_audit audit_info;
 957
 958         /* Don't allow users to add both IPv4 and IPv6 addresses for a
 959          * single entry.  However, allow users to create two entries, one each
 960          * for IPv4 and IPv6, with the same LSM security context which should
 961          * achieve the same result. */
 962         if (!info->attrs[NLBL_UNLABEL_A_SECCTX] ||
 963             !((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] ||
 964                !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^
 965               (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] ||
 966                !info->attrs[NLBL_UNLABEL_A_IPV6MASK])))
 967                 return -EINVAL;
 968
 969         netlbl_netlink_auditinfo(skb, &audit_info);
 970
 971         ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len);
 972         if (ret_val != 0)
 973                 return ret_val;
 974         ret_val = security_secctx_to_secid(
 975                                   nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
 976                                   nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
 977                                   &secid);
 978         if (ret_val != 0)
 979                 return ret_val;
 980
 981         return netlbl_unlhsh_add(&init_net,
 982                                  NULL, addr, mask, addr_len, secid,
 983                                  &audit_info);
 984 }
 985
 986 /**
 987  * netlbl_unlabel_staticremove - Handle a STATICREMOVE message
 988  * @skb: the NETLINK buffer
 989  * @info: the Generic NETLINK info block
 990  *
 991  * Description:
 992  * Process a user generated STATICREMOVE message and remove the specified
 993  * unlabeled connection entry.  Returns zero on success, negative values on
 994  * failure.
 995  *
 996  */
 997 static int netlbl_unlabel_staticremove(struct sk_buff *skb,
 998                                        struct genl_info *info)
 999 {
1000         int ret_val;
1001         char *dev_name;
1002         void *addr;
1003         void *mask;
1004         u32 addr_len;
1005         struct netlbl_audit audit_info;
1006
1007         /* See the note in netlbl_unlabel_staticadd() about not allowing both
1008          * IPv4 and IPv6 in the same entry. */
1009         if (!info->attrs[NLBL_UNLABEL_A_IFACE] ||
1010             !((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] ||
1011                !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^
1012               (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] ||
1013                !info->attrs[NLBL_UNLABEL_A_IPV6MASK])))
1014                 return -EINVAL;
1015
1016         netlbl_netlink_auditinfo(skb, &audit_info);
1017
1018         ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len);
1019         if (ret_val != 0)
1020                 return ret_val;
1021         dev_name = nla_data(info->attrs[NLBL_UNLABEL_A_IFACE]);
1022
1023         return netlbl_unlhsh_remove(&init_net,
1024                                     dev_name, addr, mask, addr_len,
1025                                     &audit_info);
1026 }
1027
1028 /**
1029  * netlbl_unlabel_staticremovedef - Handle a STATICREMOVEDEF message
1030  * @skb: the NETLINK buffer
1031  * @info: the Generic NETLINK info block
1032  *
1033  * Description:
1034  * Process a user generated STATICREMOVEDEF message and remove the default
1035  * unlabeled connection entry.  Returns zero on success, negative values on
1036  * failure.
1037  *
1038  */
1039 static int netlbl_unlabel_staticremovedef(struct sk_buff *skb,
1040                                           struct genl_info *info)
1041 {
1042         int ret_val;
1043         void *addr;
1044         void *mask;
1045         u32 addr_len;
1046         struct netlbl_audit audit_info;
1047
1048         /* See the note in netlbl_unlabel_staticadd() about not allowing both
1049          * IPv4 and IPv6 in the same entry. */
1050         if (!((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] ||
1051                !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^
1052               (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] ||
1053                !info->attrs[NLBL_UNLABEL_A_IPV6MASK])))
1054                 return -EINVAL;
1055
1056         netlbl_netlink_auditinfo(skb, &audit_info);
1057
1058         ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len);
1059         if (ret_val != 0)
1060                 return ret_val;
1061
1062         return netlbl_unlhsh_remove(&init_net,
1063                                     NULL, addr, mask, addr_len,
1064                                     &audit_info);
1065 }
1066
1067
1068 /**
1069  * netlbl_unlabel_staticlist_gen - Generate messages for STATICLIST[DEF]
1070  * @cmd: command/message
1071  * @iface: the interface entry
1072  * @addr4: the IPv4 address entry
1073  * @addr6: the IPv6 address entry
1074  * @arg: the netlbl_unlhsh_walk_arg structure
1075  *
1076  * Description:
1077  * This function is designed to be used to generate a response for a
1078  * STATICLIST or STATICLISTDEF message.  When called either @addr4 or @addr6
1079  * can be specified, not both, the other unspecified entry should be set to
1080  * NULL by the caller.  Returns the size of the message on success, negative
1081  * values on failure.
1082  *
1083  */
1084 static int netlbl_unlabel_staticlist_gen(u32 cmd,
1085                                        const struct netlbl_unlhsh_iface *iface,
1086                                        const struct netlbl_unlhsh_addr4 *addr4,
1087                                        const struct netlbl_unlhsh_addr6 *addr6,
1088                                        void *arg)
1089 {
1090         int ret_val = -ENOMEM;
1091         struct netlbl_unlhsh_walk_arg *cb_arg = arg;
1092         struct net_device *dev;
1093         void *data;
1094         u32 secid;
1095         char *secctx;
1096         u32 secctx_len;
1097
1098         data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
1099                            cb_arg->seq, &netlbl_unlabel_gnl_family,
1100                            NLM_F_MULTI, cmd);
1101         if (data == NULL)
1102                 goto list_cb_failure;
1103
1104         if (iface->ifindex > 0) {
1105                 dev = dev_get_by_index(&init_net, iface->ifindex);
1106                 if (!dev) {
1107                         ret_val = -ENODEV;
1108                         goto list_cb_failure;
1109                 }
1110                 ret_val = nla_put_string(cb_arg->skb,
1111                                          NLBL_UNLABEL_A_IFACE, dev->name);
1112                 dev_put(dev);
1113                 if (ret_val != 0)
1114                         goto list_cb_failure;
1115         }
1116
1117         if (addr4) {
1118                 struct in_addr addr_struct;
1119
1120                 addr_struct.s_addr = addr4->list.addr;
1121                 ret_val = nla_put_in_addr(cb_arg->skb,
1122                                           NLBL_UNLABEL_A_IPV4ADDR,
1123                                           addr_struct.s_addr);
1124                 if (ret_val != 0)
1125                         goto list_cb_failure;
1126
1127                 addr_struct.s_addr = addr4->list.mask;
1128                 ret_val = nla_put_in_addr(cb_arg->skb,
1129                                           NLBL_UNLABEL_A_IPV4MASK,
1130                                           addr_struct.s_addr);
1131                 if (ret_val != 0)
1132                         goto list_cb_failure;
1133
1134                 secid = addr4->secid;
1135         } else {
1136                 ret_val = nla_put_in6_addr(cb_arg->skb,
1137                                            NLBL_UNLABEL_A_IPV6ADDR,
1138                                            &addr6->list.addr);
1139                 if (ret_val != 0)
1140                         goto list_cb_failure;
1141
1142                 ret_val = nla_put_in6_addr(cb_arg->skb,
1143                                            NLBL_UNLABEL_A_IPV6MASK,
1144                                            &addr6->list.mask);
1145                 if (ret_val != 0)
1146                         goto list_cb_failure;
1147
1148                 secid = addr6->secid;
1149         }
1150
1151         ret_val = security_secid_to_secctx(secid, &secctx, &secctx_len);
1152         if (ret_val != 0)
1153                 goto list_cb_failure;
1154         ret_val = nla_put(cb_arg->skb,
1155                           NLBL_UNLABEL_A_SECCTX,
1156                           secctx_len,
1157                           secctx);
1158         security_release_secctx(secctx, secctx_len);
1159         if (ret_val != 0)
1160                 goto list_cb_failure;
1161
1162         cb_arg->seq++;
1163         genlmsg_end(cb_arg->skb, data);
1164         return 0;
1165
1166 list_cb_failure:
1167         genlmsg_cancel(cb_arg->skb, data);
1168         return ret_val;
1169 }
1170
1171 /**
1172  * netlbl_unlabel_staticlist - Handle a STATICLIST message
1173  * @skb: the NETLINK buffer
1174  * @cb: the NETLINK callback
1175  *
1176  * Description:
1177  * Process a user generated STATICLIST message and dump the unlabeled
1178  * connection hash table in a form suitable for use in a kernel generated
1179  * STATICLIST message.  Returns the length of @skb.
1180  *
1181  */
1182 static int netlbl_unlabel_staticlist(struct sk_buff *skb,
1183                                      struct netlink_callback *cb)
1184 {
1185         struct netlbl_unlhsh_walk_arg cb_arg;
1186         u32 skip_bkt = cb->args[0];
1187         u32 skip_chain = cb->args[1];
1188         u32 skip_addr4 = cb->args[2];
1189         u32 iter_bkt, iter_chain = 0, iter_addr4 = 0, iter_addr6 = 0;
1190         struct netlbl_unlhsh_iface *iface;
1191         struct list_head *iter_list;
1192         struct netlbl_af4list *addr4;
1193 #if IS_ENABLED(CONFIG_IPV6)
1194         u32 skip_addr6 = cb->args[3];
1195         struct netlbl_af6list *addr6;
1196 #endif
1197
1198         cb_arg.nl_cb = cb;
1199         cb_arg.skb = skb;
1200         cb_arg.seq = cb->nlh->nlmsg_seq;
1201
1202         rcu_read_lock();
1203         for (iter_bkt = skip_bkt;
1204              iter_bkt < rcu_dereference(netlbl_unlhsh)->size;
1205              iter_bkt++) {
1206                 iter_list = &rcu_dereference(netlbl_unlhsh)->tbl[iter_bkt];
1207                 list_for_each_entry_rcu(iface, iter_list, list) {
1208                         if (!iface->valid ||
1209                             iter_chain++ < skip_chain)
1210                                 continue;
1211                         netlbl_af4list_foreach_rcu(addr4,
1212                                                    &iface->addr4_list) {
1213                                 if (iter_addr4++ < skip_addr4)
1214                                         continue;
1215                                 if (netlbl_unlabel_staticlist_gen(
1216                                               NLBL_UNLABEL_C_STATICLIST,
1217                                               iface,
1218                                               netlbl_unlhsh_addr4_entry(addr4),
1219                                               NULL,
1220                                               &cb_arg) < 0) {
1221                                         iter_addr4--;
1222                                         iter_chain--;
1223                                         goto unlabel_staticlist_return;
1224                                 }
1225                         }
1226                         iter_addr4 = 0;
1227                         skip_addr4 = 0;
1228 #if IS_ENABLED(CONFIG_IPV6)
1229                         netlbl_af6list_foreach_rcu(addr6,
1230                                                    &iface->addr6_list) {
1231                                 if (iter_addr6++ < skip_addr6)
1232                                         continue;
1233                                 if (netlbl_unlabel_staticlist_gen(
1234                                               NLBL_UNLABEL_C_STATICLIST,
1235                                               iface,
1236                                               NULL,
1237                                               netlbl_unlhsh_addr6_entry(addr6),
1238                                               &cb_arg) < 0) {
1239                                         iter_addr6--;
1240                                         iter_chain--;
1241                                         goto unlabel_staticlist_return;
1242                                 }
1243                         }
1244                         iter_addr6 = 0;
1245                         skip_addr6 = 0;
1246 #endif /* IPv6 */
1247                 }
1248                 iter_chain = 0;
1249                 skip_chain = 0;
1250         }
1251
1252 unlabel_staticlist_return:
1253         rcu_read_unlock();
1254         cb->args[0] = iter_bkt;
1255         cb->args[1] = iter_chain;
1256         cb->args[2] = iter_addr4;
1257         cb->args[3] = iter_addr6;
1258         return skb->len;
1259 }
1260
1261 /**
1262  * netlbl_unlabel_staticlistdef - Handle a STATICLISTDEF message
1263  * @skb: the NETLINK buffer
1264  * @cb: the NETLINK callback
1265  *
1266  * Description:
1267  * Process a user generated STATICLISTDEF message and dump the default
1268  * unlabeled connection entry in a form suitable for use in a kernel generated
1269  * STATICLISTDEF message.  Returns the length of @skb.
1270  *
1271  */
1272 static int netlbl_unlabel_staticlistdef(struct sk_buff *skb,
1273                                         struct netlink_callback *cb)
1274 {
1275         struct netlbl_unlhsh_walk_arg cb_arg;
1276         struct netlbl_unlhsh_iface *iface;
1277         u32 iter_addr4 = 0, iter_addr6 = 0;
1278         struct netlbl_af4list *addr4;
1279 #if IS_ENABLED(CONFIG_IPV6)
1280         struct netlbl_af6list *addr6;
1281 #endif
1282
1283         cb_arg.nl_cb = cb;
1284         cb_arg.skb = skb;
1285         cb_arg.seq = cb->nlh->nlmsg_seq;
1286
1287         rcu_read_lock();
1288         iface = rcu_dereference(netlbl_unlhsh_def);
1289         if (iface == NULL || !iface->valid)
1290                 goto unlabel_staticlistdef_return;
1291
1292         netlbl_af4list_foreach_rcu(addr4, &iface->addr4_list) {
1293                 if (iter_addr4++ < cb->args[0])
1294                         continue;
1295                 if (netlbl_unlabel_staticlist_gen(NLBL_UNLABEL_C_STATICLISTDEF,
1296                                               iface,
1297                                               netlbl_unlhsh_addr4_entry(addr4),
1298                                               NULL,
1299                                               &cb_arg) < 0) {
1300                         iter_addr4--;
1301                         goto unlabel_staticlistdef_return;
1302                 }
1303         }
1304 #if IS_ENABLED(CONFIG_IPV6)
1305         netlbl_af6list_foreach_rcu(addr6, &iface->addr6_list) {
1306                 if (iter_addr6++ < cb->args[1])
1307                         continue;
1308                 if (netlbl_unlabel_staticlist_gen(NLBL_UNLABEL_C_STATICLISTDEF,
1309                                               iface,
1310                                               NULL,
1311                                               netlbl_unlhsh_addr6_entry(addr6),
1312                                               &cb_arg) < 0) {
1313                         iter_addr6--;
1314                         goto unlabel_staticlistdef_return;
1315                 }
1316         }
1317 #endif /* IPv6 */
1318
1319 unlabel_staticlistdef_return:
1320         rcu_read_unlock();
1321         cb->args[0] = iter_addr4;
1322         cb->args[1] = iter_addr6;
1323         return skb->len;
1324 }
1325
1326 /*
1327  * NetLabel Generic NETLINK Command Definitions
1328  */
1329
1330 static const struct genl_ops netlbl_unlabel_genl_ops[] = {
1331         {
1332         .cmd = NLBL_UNLABEL_C_STATICADD,
1333         .flags = GENL_ADMIN_PERM,
1334         .policy = netlbl_unlabel_genl_policy,
1335         .doit = netlbl_unlabel_staticadd,
1336         .dumpit = NULL,
1337         },
1338         {
1339         .cmd = NLBL_UNLABEL_C_STATICREMOVE,
1340         .flags = GENL_ADMIN_PERM,
1341         .policy = netlbl_unlabel_genl_policy,
1342         .doit = netlbl_unlabel_staticremove,
1343         .dumpit = NULL,
1344         },
1345         {
1346         .cmd = NLBL_UNLABEL_C_STATICLIST,
1347         .flags = 0,
1348         .policy = netlbl_unlabel_genl_policy,
1349         .doit = NULL,
1350         .dumpit = netlbl_unlabel_staticlist,
1351         },
1352         {
1353         .cmd = NLBL_UNLABEL_C_STATICADDDEF,
1354         .flags = GENL_ADMIN_PERM,
1355         .policy = netlbl_unlabel_genl_policy,
1356         .doit = netlbl_unlabel_staticadddef,
1357         .dumpit = NULL,
1358         },
1359         {
1360         .cmd = NLBL_UNLABEL_C_STATICREMOVEDEF,
1361         .flags = GENL_ADMIN_PERM,
1362         .policy = netlbl_unlabel_genl_policy,
1363         .doit = netlbl_unlabel_staticremovedef,
1364         .dumpit = NULL,
1365         },
1366         {
1367         .cmd = NLBL_UNLABEL_C_STATICLISTDEF,
1368         .flags = 0,
1369         .policy = netlbl_unlabel_genl_policy,
1370         .doit = NULL,
1371         .dumpit = netlbl_unlabel_staticlistdef,
1372         },
1373         {
1374         .cmd = NLBL_UNLABEL_C_ACCEPT,
1375         .flags = GENL_ADMIN_PERM,
1376         .policy = netlbl_unlabel_genl_policy,
1377         .doit = netlbl_unlabel_accept,
1378         .dumpit = NULL,
1379         },
1380         {
1381         .cmd = NLBL_UNLABEL_C_LIST,
1382         .flags = 0,
1383         .policy = netlbl_unlabel_genl_policy,
1384         .doit = netlbl_unlabel_list,
1385         .dumpit = NULL,
1386         },
1387 };
1388
1389 /*
1390  * NetLabel Generic NETLINK Protocol Functions
1391  */
1392
1393 /**
1394  * netlbl_unlabel_genl_init - Register the Unlabeled NetLabel component
1395  *
1396  * Description:
1397  * Register the unlabeled packet NetLabel component with the Generic NETLINK
1398  * mechanism.  Returns zero on success, negative values on failure.
1399  *
1400  */
1401 int __init netlbl_unlabel_genl_init(void)
1402 {
1403         return genl_register_family_with_ops(&netlbl_unlabel_gnl_family,
1404                                              netlbl_unlabel_genl_ops);
1405 }
1406
1407 /*
1408  * NetLabel KAPI Hooks
1409  */
1410
1411 static struct notifier_block netlbl_unlhsh_netdev_notifier = {
1412         .notifier_call = netlbl_unlhsh_netdev_handler,
1413 };
1414
1415 /**
1416  * netlbl_unlabel_init - Initialize the unlabeled connection hash table
1417  * @size: the number of bits to use for the hash buckets
1418  *
1419  * Description:
1420  * Initializes the unlabeled connection hash table and registers a network
1421  * device notification handler.  This function should only be called by the
1422  * NetLabel subsystem itself during initialization.  Returns zero on success,
1423  * non-zero values on error.
1424  *
1425  */
1426 int __init netlbl_unlabel_init(u32 size)
1427 {
1428         u32 iter;
1429         struct netlbl_unlhsh_tbl *hsh_tbl;
1430
1431         if (size == 0)
1432                 return -EINVAL;
1433
1434         hsh_tbl = kmalloc(sizeof(*hsh_tbl), GFP_KERNEL);
1435         if (hsh_tbl == NULL)
1436                 return -ENOMEM;
1437         hsh_tbl->size = 1 << size;
1438         hsh_tbl->tbl = kcalloc(hsh_tbl->size,
1439                                sizeof(struct list_head),
1440                                GFP_KERNEL);
1441         if (hsh_tbl->tbl == NULL) {
1442                 kfree(hsh_tbl);
1443                 return -ENOMEM;
1444         }
1445         for (iter = 0; iter < hsh_tbl->size; iter++)
1446                 INIT_LIST_HEAD(&hsh_tbl->tbl[iter]);
1447
1448         spin_lock(&netlbl_unlhsh_lock);
1449         rcu_assign_pointer(netlbl_unlhsh, hsh_tbl);
1450         spin_unlock(&netlbl_unlhsh_lock);
1451
1452         register_netdevice_notifier(&netlbl_unlhsh_netdev_notifier);
1453
1454         return 0;
1455 }
1456
1457 /**
1458  * netlbl_unlabel_getattr - Get the security attributes for an unlabled packet
1459  * @skb: the packet
1460  * @family: protocol family
1461  * @secattr: the security attributes
1462  *
1463  * Description:
1464  * Determine the security attributes, if any, for an unlabled packet and return
1465  * them in @secattr.  Returns zero on success and negative values on failure.
1466  *
1467  */
1468 int netlbl_unlabel_getattr(const struct sk_buff *skb,
1469                            u16 family,
1470                            struct netlbl_lsm_secattr *secattr)
1471 {
1472         struct netlbl_unlhsh_iface *iface;
1473
1474         rcu_read_lock();
1475         iface = netlbl_unlhsh_search_iface(skb->skb_iif);
1476         if (iface == NULL)
1477                 iface = rcu_dereference(netlbl_unlhsh_def);
1478         if (iface == NULL || !iface->valid)
1479                 goto unlabel_getattr_nolabel;
1480
1481 #if IS_ENABLED(CONFIG_IPV6)
1482         /* When resolving a fallback label, check the sk_buff version as
1483          * it is possible (e.g. SCTP) to have family = PF_INET6 while
1484          * receiving ip_hdr(skb)->version = 4.
1485          */
1486         if (family == PF_INET6 && ip_hdr(skb)->version == 4)
1487                 family = PF_INET;
1488 #endif /* IPv6 */
1489
1490         switch (family) {
1491         case PF_INET: {
1492                 struct iphdr *hdr4;
1493                 struct netlbl_af4list *addr4;
1494
1495                 hdr4 = ip_hdr(skb);
1496                 addr4 = netlbl_af4list_search(hdr4->saddr,
1497                                               &iface->addr4_list);
1498                 if (addr4 == NULL)
1499                         goto unlabel_getattr_nolabel;
1500                 secattr->attr.secid = netlbl_unlhsh_addr4_entry(addr4)->secid;
1501                 break;
1502         }
1503 #if IS_ENABLED(CONFIG_IPV6)
1504         case PF_INET6: {
1505                 struct ipv6hdr *hdr6;
1506                 struct netlbl_af6list *addr6;
1507
1508                 hdr6 = ipv6_hdr(skb);
1509                 addr6 = netlbl_af6list_search(&hdr6->saddr,
1510                                               &iface->addr6_list);
1511                 if (addr6 == NULL)
1512                         goto unlabel_getattr_nolabel;
1513                 secattr->attr.secid = netlbl_unlhsh_addr6_entry(addr6)->secid;
1514                 break;
1515         }
1516 #endif /* IPv6 */
1517         default:
1518                 goto unlabel_getattr_nolabel;
1519         }
1520         rcu_read_unlock();
1521
1522         secattr->flags |= NETLBL_SECATTR_SECID;
1523         secattr->type = NETLBL_NLTYPE_UNLABELED;
1524         return 0;
1525
1526 unlabel_getattr_nolabel:
1527         rcu_read_unlock();
1528         if (netlabel_unlabel_acceptflg == 0)
1529                 return -ENOMSG;
1530         secattr->type = NETLBL_NLTYPE_UNLABELED;
1531         return 0;
1532 }
1533
1534 /**
1535  * netlbl_unlabel_defconf - Set the default config to allow unlabeled packets
1536  *
1537  * Description:
1538  * Set the default NetLabel configuration to allow incoming unlabeled packets
1539  * and to send unlabeled network traffic by default.
1540  *
1541  */
1542 int __init netlbl_unlabel_defconf(void)
1543 {
1544         int ret_val;
1545         struct netlbl_dom_map *entry;
1546         struct netlbl_audit audit_info;
1547
1548         /* Only the kernel is allowed to call this function and the only time
1549          * it is called is at bootup before the audit subsystem is reporting
1550          * messages so don't worry to much about these values. */
1551         security_task_getsecid(current, &audit_info.secid);
1552         audit_info.loginuid = GLOBAL_ROOT_UID;
1553         audit_info.sessionid = 0;
1554
1555         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
1556         if (entry == NULL)
1557                 return -ENOMEM;
1558         entry->family = AF_UNSPEC;
1559         entry->def.type = NETLBL_NLTYPE_UNLABELED;
1560         ret_val = netlbl_domhsh_add_default(entry, &audit_info);
1561         if (ret_val != 0)
1562                 return ret_val;
1563
1564         netlbl_unlabel_acceptflg_set(1, &audit_info);
1565
1566         return 0;
1567 }