src/libsystemd-network/sd-ipv4ll.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright (C) 2014 Axis Communications AB. All rights reserved.
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <stdlib.h>
  21 #include <errno.h>
  22 #include <string.h>
  23 #include <stdio.h>
  24 #include <arpa/inet.h>
  25
  26 #include "util.h"
  27 #include "siphash24.h"
  28 #include "list.h"
  29 #include "random-util.h"
  30
  31 #include "ipv4ll-internal.h"
  32 #include "sd-ipv4ll.h"
  33
  34 /* Constants from the RFC */
  35 #define PROBE_WAIT 1
  36 #define PROBE_NUM 3
  37 #define PROBE_MIN 1
  38 #define PROBE_MAX 2
  39 #define ANNOUNCE_WAIT 2
  40 #define ANNOUNCE_NUM 2
  41 #define ANNOUNCE_INTERVAL 2
  42 #define MAX_CONFLICTS 10
  43 #define RATE_LIMIT_INTERVAL 60
  44 #define DEFEND_INTERVAL 10
  45
  46 #define IPV4LL_NETWORK 0xA9FE0000L
  47 #define IPV4LL_NETMASK 0xFFFF0000L
  48
  49 typedef enum IPv4LLTrigger{
  50         IPV4LL_TRIGGER_NULL,
  51         IPV4LL_TRIGGER_PACKET,
  52         IPV4LL_TRIGGER_TIMEOUT,
  53         _IPV4LL_TRIGGER_MAX,
  54         _IPV4LL_TRIGGER_INVALID = -1
  55 } IPv4LLTrigger;
  56
  57 typedef enum IPv4LLState {
  58         IPV4LL_STATE_INIT,
  59         IPV4LL_STATE_WAITING_PROBE,
  60         IPV4LL_STATE_PROBING,
  61         IPV4LL_STATE_WAITING_ANNOUNCE,
  62         IPV4LL_STATE_ANNOUNCING,
  63         IPV4LL_STATE_RUNNING,
  64         IPV4LL_STATE_STOPPED,
  65         _IPV4LL_STATE_MAX,
  66         _IPV4LL_STATE_INVALID = -1
  67 } IPv4LLState;
  68
  69 struct sd_ipv4ll {
  70         unsigned n_ref;
  71
  72         IPv4LLState state;
  73         int index;
  74         int fd;
  75         union sockaddr_union link;
  76         int iteration;
  77         int conflict;
  78         sd_event_source *receive_message;
  79         sd_event_source *timer;
  80         usec_t next_wakeup;
  81         usec_t defend_window;
  82         int next_wakeup_valid;
  83         be32_t address;
  84         struct random_data *random_data;
  85         char *random_data_state;
  86         /* External */
  87         be32_t claimed_address;
  88         struct ether_addr mac_addr;
  89         sd_event *event;
  90         int event_priority;
  91         sd_ipv4ll_cb_t cb;
  92         void* userdata;
  93 };
  94
  95 static void ipv4ll_run_state_machine(sd_ipv4ll *ll, IPv4LLTrigger trigger, void *trigger_data);
  96
  97 static void ipv4ll_set_state(sd_ipv4ll *ll, IPv4LLState st, int reset_counter) {
  98
  99         assert(ll);
 100         assert(st < _IPV4LL_STATE_MAX);
 101
 102         if (st == ll->state && !reset_counter) {
 103                 ll->iteration++;
 104         } else {
 105                 ll->state = st;
 106                 ll->iteration = 0;
 107         }
 108 }
 109
 110 static sd_ipv4ll *ipv4ll_client_notify(sd_ipv4ll *ll, int event) {
 111         assert(ll);
 112
 113         if (ll->cb) {
 114                 ll = sd_ipv4ll_ref(ll);
 115                 ll->cb(ll, event, ll->userdata);
 116                 ll = sd_ipv4ll_unref(ll);
 117         }
 118
 119         return ll;
 120 }
 121
 122 static sd_ipv4ll *ipv4ll_stop(sd_ipv4ll *ll, int event) {
 123         assert(ll);
 124
 125         ll->receive_message = sd_event_source_unref(ll->receive_message);
 126         ll->fd = safe_close(ll->fd);
 127
 128         ll->timer = sd_event_source_unref(ll->timer);
 129
 130         log_ipv4ll(ll, "STOPPED");
 131
 132         ll = ipv4ll_client_notify(ll, event);
 133
 134         if (ll) {
 135                 ll->claimed_address = 0;
 136                 ipv4ll_set_state (ll, IPV4LL_STATE_INIT, 1);
 137         }
 138
 139         return ll;
 140 }
 141
 142 static int ipv4ll_pick_address(sd_ipv4ll *ll, be32_t *address) {
 143         be32_t addr;
 144         int r;
 145         int32_t random;
 146
 147         assert(ll);
 148         assert(address);
 149         assert(ll->random_data);
 150
 151         do {
 152                 r = random_r(ll->random_data, &random);
 153                 if (r < 0)
 154                         return r;
 155                 addr = htonl((random & 0x0000FFFF) | IPV4LL_NETWORK);
 156         } while (addr == ll->address ||
 157                 (ntohl(addr) & IPV4LL_NETMASK) != IPV4LL_NETWORK ||
 158                 (ntohl(addr) & 0x0000FF00) == 0x0000 ||
 159                 (ntohl(addr) & 0x0000FF00) == 0xFF00);
 160
 161         *address = addr;
 162         return 0;
 163 }
 164
 165 static int ipv4ll_timer(sd_event_source *s, uint64_t usec, void *userdata) {
 166         sd_ipv4ll *ll = (sd_ipv4ll*)userdata;
 167
 168         assert(ll);
 169
 170         ll->next_wakeup_valid = 0;
 171         ipv4ll_run_state_machine(ll, IPV4LL_TRIGGER_TIMEOUT, NULL);
 172
 173         return 0;
 174 }
 175
 176 static void ipv4ll_set_next_wakeup(sd_ipv4ll *ll, int sec, int random_sec) {
 177         usec_t next_timeout = 0;
 178         usec_t time_now = 0;
 179
 180         assert(sec >= 0);
 181         assert(random_sec >= 0);
 182         assert(ll);
 183
 184         next_timeout = sec * USEC_PER_SEC;
 185
 186         if (random_sec)
 187                 next_timeout += random_u32() % (random_sec * USEC_PER_SEC);
 188
 189         assert_se(sd_event_now(ll->event, clock_boottime_or_monotonic(), &time_now) >= 0);
 190
 191         ll->next_wakeup = time_now + next_timeout;
 192         ll->next_wakeup_valid = 1;
 193 }
 194
 195 static bool ipv4ll_arp_conflict (sd_ipv4ll *ll, struct ether_arp *arp) {
 196         assert(ll);
 197         assert(arp);
 198
 199         if (memcmp(arp->arp_spa, &ll->address, sizeof(ll->address)) == 0 &&
 200             memcmp(arp->arp_sha, &ll->mac_addr, ETH_ALEN) != 0)
 201                 return true;
 202
 203         return false;
 204 }
 205
 206 static bool ipv4ll_arp_probe_conflict (sd_ipv4ll *ll, struct ether_arp *arp) {
 207         assert(ll);
 208         assert(arp);
 209
 210         if (ipv4ll_arp_conflict(ll, arp))
 211                 return true;
 212
 213         if (memcmp(arp->arp_tpa, &ll->address, sizeof(ll->address)) == 0 &&
 214             memcmp(arp->arp_sha, &ll->mac_addr, ETH_ALEN))
 215                 return true;
 216
 217         return false;
 218 }
 219
 220 static void ipv4ll_run_state_machine(sd_ipv4ll *ll, IPv4LLTrigger trigger, void *trigger_data) {
 221         struct ether_arp out_packet;
 222         int out_packet_ready = 0;
 223         int r = 0;
 224
 225         assert(ll);
 226         assert(trigger < _IPV4LL_TRIGGER_MAX);
 227
 228         if (ll->state == IPV4LL_STATE_INIT) {
 229
 230                 log_ipv4ll(ll, "PROBE");
 231                 ipv4ll_set_state(ll, IPV4LL_STATE_WAITING_PROBE, 1);
 232                 ipv4ll_set_next_wakeup(ll, 0, PROBE_WAIT);
 233
 234         } else if ((ll->state == IPV4LL_STATE_WAITING_PROBE && trigger == IPV4LL_TRIGGER_TIMEOUT) ||
 235                 (ll->state == IPV4LL_STATE_PROBING && trigger == IPV4LL_TRIGGER_TIMEOUT && ll->iteration < PROBE_NUM-2)) {
 236
 237                 /* Send a probe */
 238                 arp_packet_probe(&out_packet, ll->address, &ll->mac_addr);
 239                 out_packet_ready = 1;
 240                 ipv4ll_set_state(ll, IPV4LL_STATE_PROBING, 0);
 241
 242                 ipv4ll_set_next_wakeup(ll, PROBE_MIN, (PROBE_MAX-PROBE_MIN));
 243
 244         } else if (ll->state == IPV4LL_STATE_PROBING && trigger == IPV4LL_TRIGGER_TIMEOUT && ll->iteration >= PROBE_NUM-2) {
 245
 246                 /* Send the last probe */
 247                 arp_packet_probe(&out_packet, ll->address, &ll->mac_addr);
 248                 out_packet_ready = 1;
 249                 ipv4ll_set_state(ll, IPV4LL_STATE_WAITING_ANNOUNCE, 1);
 250
 251                 ipv4ll_set_next_wakeup(ll, ANNOUNCE_WAIT, 0);
 252
 253         } else if ((ll->state == IPV4LL_STATE_WAITING_ANNOUNCE && trigger == IPV4LL_TRIGGER_TIMEOUT) ||
 254                 (ll->state == IPV4LL_STATE_ANNOUNCING && trigger == IPV4LL_TRIGGER_TIMEOUT && ll->iteration < ANNOUNCE_NUM-1)) {
 255
 256                 /* Send announcement packet */
 257                 arp_packet_announcement(&out_packet, ll->address, &ll->mac_addr);
 258                 out_packet_ready = 1;
 259                 ipv4ll_set_state(ll, IPV4LL_STATE_ANNOUNCING, 0);
 260
 261                 ipv4ll_set_next_wakeup(ll, ANNOUNCE_INTERVAL, 0);
 262
 263                 if (ll->iteration == 0) {
 264                         log_ipv4ll(ll, "ANNOUNCE");
 265                         ll->claimed_address = ll->address;
 266                         ll = ipv4ll_client_notify(ll, IPV4LL_EVENT_BIND);
 267                         if (!ll || ll->state == IPV4LL_STATE_STOPPED)
 268                                 goto out;
 269
 270                         ll->conflict = 0;
 271                 }
 272
 273         } else if ((ll->state == IPV4LL_STATE_ANNOUNCING && trigger == IPV4LL_TRIGGER_TIMEOUT &&
 274                     ll->iteration >= ANNOUNCE_NUM-1)) {
 275
 276                 ipv4ll_set_state(ll, IPV4LL_STATE_RUNNING, 0);
 277                 ll->next_wakeup_valid = 0;
 278
 279         } else if (trigger == IPV4LL_TRIGGER_PACKET) {
 280
 281                 int conflicted = 0;
 282                 usec_t time_now;
 283                 struct ether_arp* in_packet = (struct ether_arp*)trigger_data;
 284
 285                 assert(in_packet);
 286
 287                 if (IN_SET(ll->state, IPV4LL_STATE_ANNOUNCING, IPV4LL_STATE_RUNNING)) {
 288
 289                         if (ipv4ll_arp_conflict(ll, in_packet)) {
 290
 291                                 r = sd_event_now(ll->event, clock_boottime_or_monotonic(), &time_now);
 292                                 if (r < 0)
 293                                         goto out;
 294
 295                                 /* Defend address */
 296                                 if (time_now > ll->defend_window) {
 297                                         ll->defend_window = time_now + DEFEND_INTERVAL * USEC_PER_SEC;
 298                                         arp_packet_announcement(&out_packet, ll->address, &ll->mac_addr);
 299                                         out_packet_ready = 1;
 300                                 } else
 301                                         conflicted = 1;
 302                         }
 303
 304                 } else if (IN_SET(ll->state, IPV4LL_STATE_WAITING_PROBE,
 305                                              IPV4LL_STATE_PROBING,
 306                                              IPV4LL_STATE_WAITING_ANNOUNCE)) {
 307
 308                         conflicted = ipv4ll_arp_probe_conflict(ll, in_packet);
 309                 }
 310
 311                 if (conflicted) {
 312                         log_ipv4ll(ll, "CONFLICT");
 313                         ll = ipv4ll_client_notify(ll, IPV4LL_EVENT_CONFLICT);
 314                         if (!ll || ll->state == IPV4LL_STATE_STOPPED)
 315                                 goto out;
 316
 317                         ll->claimed_address = 0;
 318
 319                         /* Pick a new address */
 320                         r = ipv4ll_pick_address(ll, &ll->address);
 321                         if (r < 0)
 322                                 goto out;
 323                         ll->conflict++;
 324                         ll->defend_window = 0;
 325                         ipv4ll_set_state(ll, IPV4LL_STATE_WAITING_PROBE, 1);
 326
 327                         if (ll->conflict >= MAX_CONFLICTS) {
 328                                 log_ipv4ll(ll, "MAX_CONFLICTS");
 329                                 ipv4ll_set_next_wakeup(ll, RATE_LIMIT_INTERVAL, PROBE_WAIT);
 330                         } else
 331                                 ipv4ll_set_next_wakeup(ll, 0, PROBE_WAIT);
 332
 333                 }
 334         }
 335
 336         if (out_packet_ready) {
 337                 r = arp_network_send_raw_socket(ll->fd, &ll->link, &out_packet);
 338                 if (r < 0) {
 339                         log_ipv4ll(ll, "failed to send arp packet out");
 340                         goto out;
 341                 }
 342         }
 343
 344         if (ll->next_wakeup_valid) {
 345                 ll->timer = sd_event_source_unref(ll->timer);
 346                 r = sd_event_add_time(ll->event, &ll->timer, clock_boottime_or_monotonic(),
 347                                       ll->next_wakeup, 0, ipv4ll_timer, ll);
 348                 if (r < 0)
 349                         goto out;
 350
 351                 r = sd_event_source_set_priority(ll->timer, ll->event_priority);
 352                 if (r < 0)
 353                         goto out;
 354
 355                 r = sd_event_source_set_description(ll->timer, "ipv4ll-timer");
 356                 if (r < 0)
 357                         goto out;
 358         }
 359
 360 out:
 361         if (r < 0 && ll)
 362                 ipv4ll_stop(ll, r);
 363 }
 364
 365 static int ipv4ll_receive_message(sd_event_source *s, int fd,
 366                                   uint32_t revents, void *userdata) {
 367         int r;
 368         struct ether_arp arp;
 369         sd_ipv4ll *ll = (sd_ipv4ll*)userdata;
 370
 371         assert(ll);
 372
 373         r = read(fd, &arp, sizeof(struct ether_arp));
 374         if (r < (int) sizeof(struct ether_arp))
 375                 return 0;
 376
 377         r = arp_packet_verify_headers(&arp);
 378         if (r < 0)
 379                 return 0;
 380
 381         ipv4ll_run_state_machine(ll, IPV4LL_TRIGGER_PACKET, &arp);
 382
 383         return 0;
 384 }
 385
 386 int sd_ipv4ll_set_index(sd_ipv4ll *ll, int interface_index) {
 387         assert_return(ll, -EINVAL);
 388         assert_return(interface_index > 0, -EINVAL);
 389         assert_return(IN_SET(ll->state, IPV4LL_STATE_INIT,
 390                              IPV4LL_STATE_STOPPED), -EBUSY);
 391
 392         ll->index = interface_index;
 393
 394         return 0;
 395 }
 396
 397 int sd_ipv4ll_set_mac(sd_ipv4ll *ll, const struct ether_addr *addr) {
 398         bool need_restart = false;
 399
 400         assert_return(ll, -EINVAL);
 401         assert_return(addr, -EINVAL);
 402
 403         if (memcmp(&ll->mac_addr, addr, ETH_ALEN) == 0)
 404                 return 0;
 405
 406         if (!IN_SET(ll->state, IPV4LL_STATE_INIT, IPV4LL_STATE_STOPPED)) {
 407                 log_ipv4ll(ll, "Changing MAC address on running IPv4LL "
 408                            "client, restarting");
 409                 ll = ipv4ll_stop(ll, IPV4LL_EVENT_STOP);
 410                 need_restart = true;
 411         }
 412
 413         if (!ll)
 414                 return 0;
 415
 416         memcpy(&ll->mac_addr, addr, ETH_ALEN);
 417
 418         if (need_restart)
 419                 sd_ipv4ll_start(ll);
 420
 421         return 0;
 422 }
 423
 424 int sd_ipv4ll_detach_event(sd_ipv4ll *ll) {
 425         assert_return(ll, -EINVAL);
 426
 427         ll->event = sd_event_unref(ll->event);
 428
 429         return 0;
 430 }
 431
 432 int sd_ipv4ll_attach_event(sd_ipv4ll *ll, sd_event *event, int priority) {
 433         int r;
 434
 435         assert_return(ll, -EINVAL);
 436         assert_return(!ll->event, -EBUSY);
 437
 438         if (event)
 439                 ll->event = sd_event_ref(event);
 440         else {
 441                 r = sd_event_default(&ll->event);
 442                 if (r < 0) {
 443                         ipv4ll_stop(ll, IPV4LL_EVENT_STOP);
 444                         return r;
 445                 }
 446         }
 447
 448         ll->event_priority = priority;
 449
 450         return 0;
 451 }
 452
 453 int sd_ipv4ll_set_callback(sd_ipv4ll *ll, sd_ipv4ll_cb_t cb, void *userdata) {
 454         assert_return(ll, -EINVAL);
 455
 456         ll->cb = cb;
 457         ll->userdata = userdata;
 458
 459         return 0;
 460 }
 461
 462 int sd_ipv4ll_get_address(sd_ipv4ll *ll, struct in_addr *address){
 463         assert_return(ll, -EINVAL);
 464         assert_return(address, -EINVAL);
 465
 466         if (ll->claimed_address == 0)
 467                 return -ENOENT;
 468
 469         address->s_addr = ll->claimed_address;
 470         return 0;
 471 }
 472
 473 int sd_ipv4ll_set_address_seed (sd_ipv4ll *ll, uint8_t seed[8]) {
 474         unsigned int entropy;
 475         int r;
 476
 477         assert_return(ll, -EINVAL);
 478         assert_return(seed, -EINVAL);
 479
 480         entropy = *seed;
 481
 482         free(ll->random_data);
 483         free(ll->random_data_state);
 484
 485         ll->random_data = new0(struct random_data, 1);
 486         ll->random_data_state = new0(char, 128);
 487
 488         if (!ll->random_data || !ll->random_data_state) {
 489                 r = -ENOMEM;
 490                 goto error;
 491         }
 492
 493         r = initstate_r((unsigned int)entropy, ll->random_data_state, 128, ll->random_data);
 494         if (r < 0)
 495                 goto error;
 496
 497 error:
 498         if (r < 0){
 499                 free(ll->random_data);
 500                 free(ll->random_data_state);
 501                 ll->random_data = NULL;
 502                 ll->random_data_state = NULL;
 503         }
 504         return r;
 505 }
 506
 507 bool sd_ipv4ll_is_running(sd_ipv4ll *ll) {
 508         assert_return(ll, false);
 509
 510         return !IN_SET(ll->state, IPV4LL_STATE_INIT, IPV4LL_STATE_STOPPED);
 511 }
 512
 513 #define HASH_KEY SD_ID128_MAKE(df,04,22,98,3f,ad,14,52,f9,87,2e,d1,9c,70,e2,f2)
 514
 515 int sd_ipv4ll_start (sd_ipv4ll *ll) {
 516         int r;
 517
 518         assert_return(ll, -EINVAL);
 519         assert_return(ll->event, -EINVAL);
 520         assert_return(ll->index > 0, -EINVAL);
 521         assert_return(IN_SET(ll->state, IPV4LL_STATE_INIT,
 522                              IPV4LL_STATE_STOPPED), -EBUSY);
 523
 524         ll->state = IPV4LL_STATE_INIT;
 525
 526         r = arp_network_bind_raw_socket(ll->index, &ll->link);
 527
 528         if (r < 0)
 529                 goto out;
 530
 531         ll->fd = r;
 532         ll->conflict = 0;
 533         ll->defend_window = 0;
 534         ll->claimed_address = 0;
 535
 536         if (!ll->random_data) {
 537                 uint8_t seed[8];
 538
 539                 /* Fallback to mac */
 540                 siphash24(seed, &ll->mac_addr.ether_addr_octet,
 541                           ETH_ALEN, HASH_KEY.bytes);
 542
 543                 r = sd_ipv4ll_set_address_seed(ll, seed);
 544                 if (r < 0)
 545                         goto out;
 546         }
 547
 548         if (ll->address == 0) {
 549                 r = ipv4ll_pick_address(ll, &ll->address);
 550                 if (r < 0)
 551                         goto out;
 552         }
 553
 554         ipv4ll_set_state (ll, IPV4LL_STATE_INIT, 1);
 555
 556         r = sd_event_add_io(ll->event, &ll->receive_message, ll->fd,
 557                             EPOLLIN, ipv4ll_receive_message, ll);
 558         if (r < 0)
 559                 goto out;
 560
 561         r = sd_event_source_set_priority(ll->receive_message, ll->event_priority);
 562         if (r < 0)
 563                 goto out;
 564
 565         r = sd_event_source_set_description(ll->receive_message, "ipv4ll-receive-message");
 566         if (r < 0)
 567                 goto out;
 568
 569         r = sd_event_add_time(ll->event,
 570                               &ll->timer,
 571                               clock_boottime_or_monotonic(),
 572                               now(clock_boottime_or_monotonic()), 0,
 573                               ipv4ll_timer, ll);
 574
 575         if (r < 0)
 576                 goto out;
 577
 578         r = sd_event_source_set_priority(ll->timer, ll->event_priority);
 579         if (r < 0)
 580                 goto out;
 581
 582         r = sd_event_source_set_description(ll->timer, "ipv4ll-timer");
 583 out:
 584         if (r < 0)
 585                 ipv4ll_stop(ll, IPV4LL_EVENT_STOP);
 586
 587         return 0;
 588 }
 589
 590 int sd_ipv4ll_stop(sd_ipv4ll *ll) {
 591         ipv4ll_stop(ll, IPV4LL_EVENT_STOP);
 592         if (ll)
 593                 ipv4ll_set_state(ll, IPV4LL_STATE_STOPPED, 1);
 594
 595         return 0;
 596 }
 597
 598 sd_ipv4ll *sd_ipv4ll_ref(sd_ipv4ll *ll) {
 599
 600         if (!ll)
 601                 return NULL;
 602
 603         assert(ll->n_ref >= 1);
 604         ll->n_ref++;
 605
 606         return ll;
 607 }
 608
 609 sd_ipv4ll *sd_ipv4ll_unref(sd_ipv4ll *ll) {
 610
 611         if (!ll)
 612                 return NULL;
 613
 614         assert(ll->n_ref >= 1);
 615         ll->n_ref--;
 616
 617         if (ll->n_ref > 0)
 618                 return ll;
 619
 620         ll->receive_message = sd_event_source_unref(ll->receive_message);
 621         ll->fd = safe_close(ll->fd);
 622
 623         ll->timer = sd_event_source_unref(ll->timer);
 624
 625         sd_ipv4ll_detach_event(ll);
 626
 627         free(ll->random_data);
 628         free(ll->random_data_state);
 629         free(ll);
 630
 631         return NULL;
 632 }
 633
 634 DEFINE_TRIVIAL_CLEANUP_FUNC(sd_ipv4ll*, sd_ipv4ll_unref);
 635 #define _cleanup_ipv4ll_free_ _cleanup_(sd_ipv4ll_unrefp)
 636
 637 int sd_ipv4ll_new(sd_ipv4ll **ret) {
 638         _cleanup_ipv4ll_free_ sd_ipv4ll *ll = NULL;
 639
 640         assert_return(ret, -EINVAL);
 641
 642         ll = new0(sd_ipv4ll, 1);
 643         if (!ll)
 644                 return -ENOMEM;
 645
 646         ll->n_ref = 1;
 647         ll->state = IPV4LL_STATE_INIT;
 648         ll->index = -1;
 649         ll->fd = -1;
 650
 651         *ret = ll;
 652         ll = NULL;
 653
 654         return 0;
 655 }