src/network/networkd-nexthop.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later
   2  * Copyright © 2019 VMware, Inc.
   3  */
   4
   5 #include <net/if.h>
   6 #include <linux/nexthop.h>
   7
   8 #include "alloc-util.h"
   9 #include "netlink-util.h"
  10 #include "networkd-link.h"
  11 #include "networkd-manager.h"
  12 #include "networkd-network.h"
  13 #include "networkd-nexthop.h"
  14 #include "networkd-queue.h"
  15 #include "networkd-route-util.h"
  16 #include "parse-util.h"
  17 #include "set.h"
  18 #include "stdio-util.h"
  19 #include "string-util.h"
  20
  21 NextHop *nexthop_free(NextHop *nexthop) {
  22         if (!nexthop)
  23                 return NULL;
  24
  25         if (nexthop->network) {
  26                 assert(nexthop->section);
  27                 ordered_hashmap_remove(nexthop->network->nexthops_by_section, nexthop->section);
  28         }
  29
  30         config_section_free(nexthop->section);
  31
  32         if (nexthop->manager) {
  33                 assert(nexthop->id > 0);
  34                 hashmap_remove(nexthop->manager->nexthops_by_id, UINT32_TO_PTR(nexthop->id));
  35         }
  36
  37         hashmap_free_free(nexthop->group);
  38
  39         return mfree(nexthop);
  40 }
  41
  42 DEFINE_SECTION_CLEANUP_FUNCTIONS(NextHop, nexthop_free);
  43
  44 DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(
  45                 nexthop_hash_ops,
  46                 void,
  47                 trivial_hash_func,
  48                 trivial_compare_func,
  49                 NextHop,
  50                 nexthop_free);
  51
  52 static int nexthop_new(NextHop **ret) {
  53         _cleanup_(nexthop_freep) NextHop *nexthop = NULL;
  54
  55         nexthop = new(NextHop, 1);
  56         if (!nexthop)
  57                 return -ENOMEM;
  58
  59         *nexthop = (NextHop) {
  60                 .family = AF_UNSPEC,
  61                 .onlink = -1,
  62         };
  63
  64         *ret = TAKE_PTR(nexthop);
  65
  66         return 0;
  67 }
  68
  69 static int nexthop_new_static(Network *network, const char *filename, unsigned section_line, NextHop **ret) {
  70         _cleanup_(config_section_freep) ConfigSection *n = NULL;
  71         _cleanup_(nexthop_freep) NextHop *nexthop = NULL;
  72         int r;
  73
  74         assert(network);
  75         assert(ret);
  76         assert(filename);
  77         assert(section_line > 0);
  78
  79         r = config_section_new(filename, section_line, &n);
  80         if (r < 0)
  81                 return r;
  82
  83         nexthop = ordered_hashmap_get(network->nexthops_by_section, n);
  84         if (nexthop) {
  85                 *ret = TAKE_PTR(nexthop);
  86                 return 0;
  87         }
  88
  89         r = nexthop_new(&nexthop);
  90         if (r < 0)
  91                 return r;
  92
  93         nexthop->protocol = RTPROT_STATIC;
  94         nexthop->network = network;
  95         nexthop->section = TAKE_PTR(n);
  96         nexthop->source = NETWORK_CONFIG_SOURCE_STATIC;
  97
  98         r = ordered_hashmap_ensure_put(&network->nexthops_by_section, &config_section_hash_ops, nexthop->section, nexthop);
  99         if (r < 0)
 100                 return r;
 101
 102         *ret = TAKE_PTR(nexthop);
 103         return 0;
 104 }
 105
 106 static void nexthop_hash_func(const NextHop *nexthop, struct siphash *state) {
 107         assert(nexthop);
 108         assert(state);
 109
 110         siphash24_compress_typesafe(nexthop->id, state);
 111 }
 112
 113 static int nexthop_compare_func(const NextHop *a, const NextHop *b) {
 114         assert(a);
 115         assert(b);
 116
 117         return CMP(a->id, b->id);
 118 }
 119
 120 static int nexthop_compare_full(const NextHop *a, const NextHop *b) {
 121         int r;
 122
 123         assert(a);
 124         assert(b);
 125
 126         /* This compares detailed configs, except for ID and ifindex. */
 127
 128         r = CMP(a->protocol, b->protocol);
 129         if (r != 0)
 130                 return r;
 131
 132         r = CMP(a->flags, b->flags);
 133         if (r != 0)
 134                 return r;
 135
 136         r = CMP(hashmap_size(a->group), hashmap_size(b->group));
 137         if (r != 0)
 138                 return r;
 139
 140         if (!hashmap_isempty(a->group)) {
 141                 struct nexthop_grp *ga;
 142
 143                 HASHMAP_FOREACH(ga, a->group) {
 144                         struct nexthop_grp *gb;
 145
 146                         gb = hashmap_get(b->group, UINT32_TO_PTR(ga->id));
 147                         if (!gb)
 148                                 return CMP(ga, gb);
 149
 150                         r = CMP(ga->weight, gb->weight);
 151                         if (r != 0)
 152                                 return r;
 153                 }
 154         }
 155
 156         r = CMP(a->blackhole, b->blackhole);
 157         if (r != 0)
 158                 return r;
 159
 160         r = CMP(a->family, b->family);
 161         if (r != 0)
 162                 return r;
 163
 164         if (IN_SET(a->family, AF_INET, AF_INET6)) {
 165                 r = memcmp(&a->gw, &b->gw, FAMILY_ADDRESS_SIZE(a->family));
 166                 if (r != 0)
 167                         return r;
 168         }
 169
 170         return 0;
 171 }
 172
 173 static int nexthop_dup(const NextHop *src, NextHop **ret) {
 174         _cleanup_(nexthop_freep) NextHop *dest = NULL;
 175         struct nexthop_grp *nhg;
 176         int r;
 177
 178         assert(src);
 179         assert(ret);
 180
 181         dest = newdup(NextHop, src, 1);
 182         if (!dest)
 183                 return -ENOMEM;
 184
 185         /* unset all pointers */
 186         dest->manager = NULL;
 187         dest->network = NULL;
 188         dest->section = NULL;
 189         dest->group = NULL;
 190
 191         HASHMAP_FOREACH(nhg, src->group) {
 192                 _cleanup_free_ struct nexthop_grp *g = NULL;
 193
 194                 g = newdup(struct nexthop_grp, nhg, 1);
 195                 if (!g)
 196                         return -ENOMEM;
 197
 198                 r = hashmap_ensure_put(&dest->group, NULL, UINT32_TO_PTR(g->id), g);
 199                 if (r < 0)
 200                         return r;
 201                 if (r > 0)
 202                         TAKE_PTR(g);
 203         }
 204
 205         *ret = TAKE_PTR(dest);
 206         return 0;
 207 }
 208
 209 static bool nexthop_bound_to_link(const NextHop *nexthop) {
 210         assert(nexthop);
 211         return !nexthop->blackhole && hashmap_isempty(nexthop->group);
 212 }
 213
 214 int nexthop_get_by_id(Manager *manager, uint32_t id, NextHop **ret) {
 215         NextHop *nh;
 216
 217         assert(manager);
 218
 219         if (id == 0)
 220                 return -EINVAL;
 221
 222         nh = hashmap_get(manager->nexthops_by_id, UINT32_TO_PTR(id));
 223         if (!nh)
 224                 return -ENOENT;
 225
 226         if (ret)
 227                 *ret = nh;
 228         return 0;
 229 }
 230
 231 static int nexthop_get(Link *link, const NextHop *in, NextHop **ret) {
 232         NextHop *nexthop;
 233         int ifindex;
 234
 235         assert(link);
 236         assert(link->manager);
 237         assert(in);
 238
 239         if (in->id > 0)
 240                 return nexthop_get_by_id(link->manager, in->id, ret);
 241
 242         /* If ManageForeignNextHops=no, nexthop with id == 0 should be already filtered by
 243          * nexthop_section_verify(). */
 244         assert(link->manager->manage_foreign_nexthops);
 245
 246         ifindex = nexthop_bound_to_link(in) ? link->ifindex : 0;
 247
 248         HASHMAP_FOREACH(nexthop, link->manager->nexthops_by_id) {
 249                 if (nexthop->ifindex != ifindex)
 250                         continue;
 251                 if (nexthop_compare_full(nexthop, in) != 0)
 252                         continue;
 253
 254                 /* Even if the configuration matches, it may be configured with another [NextHop] section
 255                  * that has an explicit ID. If so, the assigned nexthop is not the one we are looking for. */
 256                 if (set_contains(link->manager->nexthop_ids, UINT32_TO_PTR(nexthop->id)))
 257                         continue;
 258
 259                 if (ret)
 260                         *ret = nexthop;
 261                 return 0;
 262         }
 263
 264         return -ENOENT;
 265 }
 266
 267 static int nexthop_get_request_by_id(Manager *manager, uint32_t id, Request **ret) {
 268         Request *req;
 269
 270         assert(manager);
 271
 272         if (id == 0)
 273                 return -EINVAL;
 274
 275         req = ordered_set_get(
 276                         manager->request_queue,
 277                         &(Request) {
 278                                 .type = REQUEST_TYPE_NEXTHOP,
 279                                 .userdata = (void*) &(const NextHop) { .id = id },
 280                                 .hash_func = (hash_func_t) nexthop_hash_func,
 281                                 .compare_func = (compare_func_t) nexthop_compare_func,
 282                         });
 283         if (!req)
 284                 return -ENOENT;
 285
 286         if (ret)
 287                 *ret = req;
 288         return 0;
 289 }
 290
 291 static int nexthop_get_request(Link *link, const NextHop *in, Request **ret) {
 292         Request *req;
 293         int ifindex;
 294
 295         assert(link);
 296         assert(link->manager);
 297         assert(in);
 298
 299         if (in->id > 0)
 300                 return nexthop_get_request_by_id(link->manager, in->id, ret);
 301
 302         /* If ManageForeignNextHops=no, nexthop with id == 0 should be already filtered by
 303          * nexthop_section_verify(). */
 304         assert(link->manager->manage_foreign_nexthops);
 305
 306         ifindex = nexthop_bound_to_link(in) ? link->ifindex : 0;
 307
 308         ORDERED_SET_FOREACH(req, link->manager->request_queue) {
 309                 if (req->type != REQUEST_TYPE_NEXTHOP)
 310                         continue;
 311
 312                 NextHop *nexthop = ASSERT_PTR(req->userdata);
 313                 if (nexthop->ifindex != ifindex)
 314                         continue;
 315                 if (nexthop_compare_full(nexthop, in) != 0)
 316                         continue;
 317
 318                 /* Even if the configuration matches, it may be requested by another [NextHop] section
 319                  * that has an explicit ID. If so, the request is not the one we are looking for. */
 320                 if (set_contains(link->manager->nexthop_ids, UINT32_TO_PTR(nexthop->id)))
 321                         continue;
 322
 323                 if (ret)
 324                         *ret = req;
 325                 return 0;
 326         }
 327
 328         return -ENOENT;
 329 }
 330
 331 static int nexthop_add_new(Manager *manager, uint32_t id, NextHop **ret) {
 332         _cleanup_(nexthop_freep) NextHop *nexthop = NULL;
 333         int r;
 334
 335         assert(manager);
 336         assert(id > 0);
 337
 338         r = nexthop_new(&nexthop);
 339         if (r < 0)
 340                 return r;
 341
 342         nexthop->id = id;
 343
 344         r = hashmap_ensure_put(&manager->nexthops_by_id, &nexthop_hash_ops, UINT32_TO_PTR(nexthop->id), nexthop);
 345         if (r < 0)
 346                 return r;
 347         if (r == 0)
 348                 return -EEXIST;
 349
 350         nexthop->manager = manager;
 351
 352         if (ret)
 353                 *ret = nexthop;
 354
 355         TAKE_PTR(nexthop);
 356         return 0;
 357 }
 358
 359 static int nexthop_acquire_id(Manager *manager, NextHop *nexthop) {
 360         assert(manager);
 361         assert(nexthop);
 362
 363         if (nexthop->id > 0)
 364                 return 0;
 365
 366         /* If ManageForeignNextHops=no, nexthop with id == 0 should be already filtered by
 367          * nexthop_section_verify(). */
 368         assert(manager->manage_foreign_nexthops);
 369
 370         /* Find the lowest unused ID. */
 371
 372         for (uint32_t id = 1; id < UINT32_MAX; id++) {
 373                 if (nexthop_get_by_id(manager, id, NULL) >= 0)
 374                         continue;
 375                 if (nexthop_get_request_by_id(manager, id, NULL) >= 0)
 376                         continue;
 377                 if (set_contains(manager->nexthop_ids, UINT32_TO_PTR(id)))
 378                         continue;
 379
 380                 nexthop->id = id;
 381                 return 0;
 382         }
 383
 384         return -EBUSY;
 385 }
 386
 387 static void log_nexthop_debug(const NextHop *nexthop, const char *str, Manager *manager) {
 388         _cleanup_free_ char *state = NULL, *group = NULL, *flags = NULL;
 389         struct nexthop_grp *nhg;
 390         Link *link = NULL;
 391
 392         assert(nexthop);
 393         assert(str);
 394         assert(manager);
 395
 396         if (!DEBUG_LOGGING)
 397                 return;
 398
 399         (void) link_get_by_index(manager, nexthop->ifindex, &link);
 400         (void) network_config_state_to_string_alloc(nexthop->state, &state);
 401         (void) route_flags_to_string_alloc(nexthop->flags, &flags);
 402
 403         HASHMAP_FOREACH(nhg, nexthop->group)
 404                 (void) strextendf_with_separator(&group, ",", "%"PRIu32":%"PRIu32, nhg->id, nhg->weight+1u);
 405
 406         log_link_debug(link, "%s %s nexthop (%s): id: %"PRIu32", gw: %s, blackhole: %s, group: %s, flags: %s",
 407                        str, strna(network_config_source_to_string(nexthop->source)), strna(state),
 408                        nexthop->id,
 409                        IN_ADDR_TO_STRING(nexthop->family, &nexthop->gw),
 410                        yes_no(nexthop->blackhole), strna(group), strna(flags));
 411 }
 412
 413 static int nexthop_remove_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) {
 414         int r;
 415
 416         assert(m);
 417
 418         /* link may be NULL. */
 419
 420         if (link && IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
 421                 return 1;
 422
 423         r = sd_netlink_message_get_errno(m);
 424         if (r < 0 && r != -ENOENT)
 425                 log_link_message_warning_errno(link, m, r, "Could not drop nexthop, ignoring");
 426
 427         return 1;
 428 }
 429
 430 int nexthop_remove(NextHop *nexthop, Manager *manager) {
 431         _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
 432         Link *link = NULL;
 433         int r;
 434
 435         assert(nexthop);
 436         assert(nexthop->id > 0);
 437         assert(manager);
 438
 439         /* link may be NULL. */
 440         (void) link_get_by_index(manager, nexthop->ifindex, &link);
 441
 442         log_nexthop_debug(nexthop, "Removing", manager);
 443
 444         r = sd_rtnl_message_new_nexthop(manager->rtnl, &m, RTM_DELNEXTHOP, AF_UNSPEC, RTPROT_UNSPEC);
 445         if (r < 0)
 446                 return log_link_error_errno(link, r, "Could not create RTM_DELNEXTHOP message: %m");
 447
 448         r = sd_netlink_message_append_u32(m, NHA_ID, nexthop->id);
 449         if (r < 0)
 450                 return log_link_error_errno(link, r, "Could not append NHA_ID attribute: %m");
 451
 452         r = netlink_call_async(manager->rtnl, NULL, m, nexthop_remove_handler,
 453                                link ? link_netlink_destroy_callback : NULL, link);
 454         if (r < 0)
 455                 return log_link_error_errno(link, r, "Could not send rtnetlink message: %m");
 456
 457         link_ref(link); /* link may be NULL, link_ref() is OK with that */
 458
 459         nexthop_enter_removing(nexthop);
 460         return 0;
 461 }
 462
 463 static int nexthop_configure(NextHop *nexthop, Link *link, Request *req) {
 464         _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
 465         int r;
 466
 467         assert(nexthop);
 468         assert(nexthop->id > 0);
 469         assert(IN_SET(nexthop->family, AF_UNSPEC, AF_INET, AF_INET6));
 470         assert(link);
 471         assert(link->manager);
 472         assert(link->manager->rtnl);
 473         assert(link->ifindex > 0);
 474         assert(req);
 475
 476         log_nexthop_debug(nexthop, "Configuring", link->manager);
 477
 478         r = sd_rtnl_message_new_nexthop(link->manager->rtnl, &m, RTM_NEWNEXTHOP, nexthop->family, nexthop->protocol);
 479         if (r < 0)
 480                 return r;
 481
 482         r = sd_netlink_message_append_u32(m, NHA_ID, nexthop->id);
 483         if (r < 0)
 484                 return r;
 485
 486         if (!hashmap_isempty(nexthop->group)) {
 487                 _cleanup_free_ struct nexthop_grp *group = NULL;
 488                 struct nexthop_grp *p, *nhg;
 489
 490                 group = new(struct nexthop_grp, hashmap_size(nexthop->group));
 491                 if (!group)
 492                         return log_oom();
 493
 494                 p = group;
 495                 HASHMAP_FOREACH(nhg, nexthop->group)
 496                         *p++ = *nhg;
 497
 498                 r = sd_netlink_message_append_data(m, NHA_GROUP, group, sizeof(struct nexthop_grp) * hashmap_size(nexthop->group));
 499                 if (r < 0)
 500                         return r;
 501
 502         } else if (nexthop->blackhole) {
 503                 r = sd_netlink_message_append_flag(m, NHA_BLACKHOLE);
 504                 if (r < 0)
 505                         return r;
 506         } else {
 507                 assert(nexthop->ifindex == link->ifindex);
 508
 509                 r = sd_netlink_message_append_u32(m, NHA_OIF, nexthop->ifindex);
 510                 if (r < 0)
 511                         return r;
 512
 513                 if (in_addr_is_set(nexthop->family, &nexthop->gw)) {
 514                         r = netlink_message_append_in_addr_union(m, NHA_GATEWAY, nexthop->family, &nexthop->gw);
 515                         if (r < 0)
 516                                 return r;
 517
 518                         r = sd_rtnl_message_nexthop_set_flags(m, nexthop->flags & RTNH_F_ONLINK);
 519                         if (r < 0)
 520                                 return r;
 521                 }
 522         }
 523
 524         return request_call_netlink_async(link->manager->rtnl, m, req);
 525 }
 526
 527 static int static_nexthop_handler(sd_netlink *rtnl, sd_netlink_message *m, Request *req, Link *link, NextHop *nexthop) {
 528         int r;
 529
 530         assert(m);
 531         assert(link);
 532
 533         r = sd_netlink_message_get_errno(m);
 534         if (r < 0 && r != -EEXIST) {
 535                 log_link_message_warning_errno(link, m, r, "Could not set nexthop");
 536                 link_enter_failed(link);
 537                 return 1;
 538         }
 539
 540         if (link->static_nexthop_messages == 0) {
 541                 log_link_debug(link, "Nexthops set");
 542                 link->static_nexthops_configured = true;
 543                 link_check_ready(link);
 544         }
 545
 546         return 1;
 547 }
 548
 549 int nexthop_is_ready(Manager *manager, uint32_t id, NextHop **ret) {
 550         NextHop *nexthop;
 551
 552         assert(manager);
 553
 554         if (id == 0)
 555                 return -EINVAL;
 556
 557         if (nexthop_get_request_by_id(manager, id, NULL) >= 0)
 558                 goto not_ready;
 559
 560         if (nexthop_get_by_id(manager, id, &nexthop) < 0)
 561                 goto not_ready;
 562
 563         if (!nexthop_exists(nexthop))
 564                 goto not_ready;
 565
 566         if (ret)
 567                 *ret = nexthop;
 568
 569         return true;
 570
 571 not_ready:
 572         if (ret)
 573                 *ret = NULL;
 574
 575         return false;
 576 }
 577
 578 static bool nexthop_is_ready_to_configure(Link *link, const NextHop *nexthop) {
 579         struct nexthop_grp *nhg;
 580         int r;
 581
 582         assert(link);
 583         assert(nexthop);
 584         assert(nexthop->id > 0);
 585
 586         if (!link_is_ready_to_configure(link, false))
 587                 return false;
 588
 589         if (nexthop_bound_to_link(nexthop)) {
 590                 assert(nexthop->ifindex == link->ifindex);
 591
 592                 /* TODO: fdb nexthop does not require IFF_UP. The conditions below needs to be updated
 593                  * when fdb nexthop support is added. See rtm_to_nh_config() in net/ipv4/nexthop.c of
 594                  * kernel. */
 595                 if (link->set_flags_messages > 0)
 596                         return false;
 597                 if (!FLAGS_SET(link->flags, IFF_UP))
 598                         return false;
 599         }
 600
 601         /* All group members must be configured first. */
 602         HASHMAP_FOREACH(nhg, nexthop->group) {
 603                 r = nexthop_is_ready(link->manager, nhg->id, NULL);
 604                 if (r <= 0)
 605                         return r;
 606         }
 607
 608         return gateway_is_ready(link, FLAGS_SET(nexthop->flags, RTNH_F_ONLINK), nexthop->family, &nexthop->gw);
 609 }
 610
 611 static int nexthop_process_request(Request *req, Link *link, NextHop *nexthop) {
 612         NextHop *existing;
 613         int r;
 614
 615         assert(req);
 616         assert(link);
 617         assert(link->manager);
 618         assert(nexthop);
 619
 620         if (!nexthop_is_ready_to_configure(link, nexthop))
 621                 return 0;
 622
 623         r = nexthop_configure(nexthop, link, req);
 624         if (r < 0)
 625                 return log_link_warning_errno(link, r, "Failed to configure nexthop");
 626
 627         nexthop_enter_configuring(nexthop);
 628         if (nexthop_get_by_id(link->manager, nexthop->id, &existing) >= 0)
 629                 nexthop_enter_configuring(existing);
 630
 631         return 1;
 632 }
 633
 634 static int link_request_nexthop(Link *link, const NextHop *nexthop) {
 635         _cleanup_(nexthop_freep) NextHop *tmp = NULL;
 636         NextHop *existing = NULL;
 637         int r;
 638
 639         assert(link);
 640         assert(link->manager);
 641         assert(nexthop);
 642         assert(nexthop->source != NETWORK_CONFIG_SOURCE_FOREIGN);
 643
 644         if (nexthop_get_request(link, nexthop, NULL) >= 0)
 645                 return 0; /* already requested, skipping. */
 646
 647         r = nexthop_dup(nexthop, &tmp);
 648         if (r < 0)
 649                 return r;
 650
 651         if (nexthop_get(link, nexthop, &existing) < 0) {
 652                 r = nexthop_acquire_id(link->manager, tmp);
 653                 if (r < 0)
 654                         return r;
 655         } else {
 656                 /* Copy ID */
 657                 assert(tmp->id == 0 || tmp->id == existing->id);
 658                 tmp->id = existing->id;
 659
 660                 /* Copy state for logging below. */
 661                 tmp->state = existing->state;
 662         }
 663
 664         if (nexthop_bound_to_link(tmp))
 665                 tmp->ifindex = link->ifindex;
 666
 667         log_nexthop_debug(tmp, "Requesting", link->manager);
 668         r = link_queue_request_safe(link, REQUEST_TYPE_NEXTHOP,
 669                                     tmp,
 670                                     nexthop_free,
 671                                     nexthop_hash_func,
 672                                     nexthop_compare_func,
 673                                     nexthop_process_request,
 674                                     &link->static_nexthop_messages,
 675                                     static_nexthop_handler,
 676                                     NULL);
 677         if (r <= 0)
 678                 return r;
 679
 680         nexthop_enter_requesting(tmp);
 681         if (existing)
 682                 nexthop_enter_requesting(existing);
 683
 684         TAKE_PTR(tmp);
 685         return 1;
 686 }
 687
 688 int link_request_static_nexthops(Link *link, bool only_ipv4) {
 689         NextHop *nh;
 690         int r;
 691
 692         assert(link);
 693         assert(link->network);
 694
 695         link->static_nexthops_configured = false;
 696
 697         ORDERED_HASHMAP_FOREACH(nh, link->network->nexthops_by_section) {
 698                 if (only_ipv4 && nh->family != AF_INET)
 699                         continue;
 700
 701                 r = link_request_nexthop(link, nh);
 702                 if (r < 0)
 703                         return log_link_warning_errno(link, r, "Could not request nexthop: %m");
 704         }
 705
 706         if (link->static_nexthop_messages == 0) {
 707                 link->static_nexthops_configured = true;
 708                 link_check_ready(link);
 709         } else {
 710                 log_link_debug(link, "Requesting nexthops");
 711                 link_set_state(link, LINK_STATE_CONFIGURING);
 712         }
 713
 714         return 0;
 715 }
 716
 717 static bool nexthop_can_update(const NextHop *assigned_nexthop, const NextHop *requested_nexthop) {
 718         assert(assigned_nexthop);
 719         assert(assigned_nexthop->manager);
 720         assert(requested_nexthop);
 721         assert(requested_nexthop->network);
 722
 723         /* A group nexthop cannot be replaced with a non-group nexthop, and vice versa.
 724          * See replace_nexthop_grp() and replace_nexthop_single() in net/ipv4/nexthop.c of the kernel. */
 725         if (hashmap_isempty(assigned_nexthop->group) != hashmap_isempty(requested_nexthop->group))
 726                 return false;
 727
 728         /* There are several more conditions if we can replace a group nexthop, e.g. hash threshold and
 729          * resilience. But, currently we do not support to modify that. Let's add checks for them in the
 730          * future when we support to configure them.*/
 731
 732         /* When a nexthop is replaced with a blackhole nexthop, and a group nexthop has multiple nexthops
 733          * including this nexthop, then the kernel refuses to replace the existing nexthop.
 734          * So, here, for simplicity, let's unconditionally refuse to replace a non-blackhole nexthop with
 735          * a blackhole nexthop. See replace_nexthop() in net/ipv4/nexthop.c of the kernel. */
 736         if (!assigned_nexthop->blackhole && requested_nexthop->blackhole)
 737                 return false;
 738
 739         return true;
 740 }
 741
 742 static void link_mark_nexthops(Link *link, bool foreign) {
 743         NextHop *nexthop;
 744         Link *other;
 745
 746         assert(link);
 747         assert(link->manager);
 748
 749         /* First, mark all nexthops. */
 750         HASHMAP_FOREACH(nexthop, link->manager->nexthops_by_id) {
 751                 /* do not touch nexthop created by the kernel */
 752                 if (nexthop->protocol == RTPROT_KERNEL)
 753                         continue;
 754
 755                 /* When 'foreign' is true, mark only foreign nexthops, and vice versa. */
 756                 if (foreign != (nexthop->source == NETWORK_CONFIG_SOURCE_FOREIGN))
 757                         continue;
 758
 759                 /* Ignore nexthops not assigned yet or already removed. */
 760                 if (!nexthop_exists(nexthop))
 761                         continue;
 762
 763                 /* Ignore nexthops bound to other links. */
 764                 if (nexthop->ifindex > 0 && nexthop->ifindex != link->ifindex)
 765                         continue;
 766
 767                 nexthop_mark(nexthop);
 768         }
 769
 770         /* Then, unmark all nexthops requested by active links. */
 771         HASHMAP_FOREACH(other, link->manager->links_by_index) {
 772                 if (!foreign && other == link)
 773                         continue;
 774
 775                 if (!IN_SET(other->state, LINK_STATE_CONFIGURING, LINK_STATE_CONFIGURED))
 776                         continue;
 777
 778                 ORDERED_HASHMAP_FOREACH(nexthop, other->network->nexthops_by_section) {
 779                         NextHop *existing;
 780
 781                         if (nexthop_get(other, nexthop, &existing) < 0)
 782                                 continue;
 783
 784                         if (!nexthop_can_update(existing, nexthop))
 785                                 continue;
 786
 787                         /* Found matching static configuration. Keep the existing nexthop. */
 788                         nexthop_unmark(existing);
 789                 }
 790         }
 791 }
 792
 793 int link_drop_nexthops(Link *link, bool foreign) {
 794         NextHop *nexthop;
 795         int r = 0;
 796
 797         assert(link);
 798         assert(link->manager);
 799
 800         link_mark_nexthops(link, foreign);
 801
 802         HASHMAP_FOREACH(nexthop, link->manager->nexthops_by_id) {
 803                 if (!nexthop_is_marked(nexthop))
 804                         continue;
 805
 806                 RET_GATHER(r, nexthop_remove(nexthop, link->manager));
 807         }
 808
 809         return r;
 810 }
 811
 812 void link_foreignize_nexthops(Link *link) {
 813         NextHop *nexthop;
 814
 815         assert(link);
 816         assert(link->manager);
 817
 818         link_mark_nexthops(link, /* foreign = */ false);
 819
 820         HASHMAP_FOREACH(nexthop, link->manager->nexthops_by_id) {
 821                 if (!nexthop_is_marked(nexthop))
 822                         continue;
 823
 824                 nexthop->source = NETWORK_CONFIG_SOURCE_FOREIGN;
 825         }
 826 }
 827
 828 static int nexthop_update_group(NextHop *nexthop, const struct nexthop_grp *group, size_t size) {
 829         _cleanup_hashmap_free_free_ Hashmap *h = NULL;
 830         size_t n_group;
 831         int r;
 832
 833         assert(nexthop);
 834         assert(group || size == 0);
 835
 836         if (size == 0 || size % sizeof(struct nexthop_grp) != 0)
 837                 return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
 838                                        "rtnl: received nexthop message with invalid nexthop group size, ignoring.");
 839
 840         if ((uintptr_t) group % alignof(struct nexthop_grp) != 0)
 841                 return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
 842                                        "rtnl: received nexthop message with invalid alignment, ignoring.");
 843
 844         n_group = size / sizeof(struct nexthop_grp);
 845         for (size_t i = 0; i < n_group; i++) {
 846                 _cleanup_free_ struct nexthop_grp *nhg = NULL;
 847
 848                 if (group[i].id == 0) {
 849                         log_debug("rtnl: received nexthop message with invalid ID in group, ignoring.");
 850                         continue;
 851                 }
 852
 853                 if (group[i].weight > 254) {
 854                         log_debug("rtnl: received nexthop message with invalid weight in group, ignoring.");
 855                         continue;
 856                 }
 857
 858                 nhg = newdup(struct nexthop_grp, group + i, 1);
 859                 if (!nhg)
 860                         return log_oom();
 861
 862                 r = hashmap_ensure_put(&h, NULL, UINT32_TO_PTR(nhg->id), nhg);
 863                 if (r == -ENOMEM)
 864                         return log_oom();
 865                 if (r < 0) {
 866                         log_debug_errno(r, "Failed to store nexthop group, ignoring: %m");
 867                         continue;
 868                 }
 869                 if (r > 0)
 870                         TAKE_PTR(nhg);
 871         }
 872
 873         hashmap_free_free(nexthop->group);
 874         nexthop->group = TAKE_PTR(h);
 875         return 0;
 876 }
 877
 878 int manager_rtnl_process_nexthop(sd_netlink *rtnl, sd_netlink_message *message, Manager *m) {
 879         _cleanup_free_ void *raw_group = NULL;
 880         size_t raw_group_size;
 881         uint16_t type;
 882         uint32_t id, ifindex;
 883         NextHop *nexthop = NULL;
 884         Request *req = NULL;
 885         bool is_new = false;
 886         int r;
 887
 888         assert(rtnl);
 889         assert(message);
 890         assert(m);
 891
 892         if (sd_netlink_message_is_error(message)) {
 893                 r = sd_netlink_message_get_errno(message);
 894                 if (r < 0)
 895                         log_message_warning_errno(message, r, "rtnl: failed to receive rule message, ignoring");
 896
 897                 return 0;
 898         }
 899
 900         r = sd_netlink_message_get_type(message, &type);
 901         if (r < 0) {
 902                 log_warning_errno(r, "rtnl: could not get message type, ignoring: %m");
 903                 return 0;
 904         } else if (!IN_SET(type, RTM_NEWNEXTHOP, RTM_DELNEXTHOP)) {
 905                 log_warning("rtnl: received unexpected message type %u when processing nexthop, ignoring.", type);
 906                 return 0;
 907         }
 908
 909         r = sd_netlink_message_read_u32(message, NHA_ID, &id);
 910         if (r == -ENODATA) {
 911                 log_warning_errno(r, "rtnl: received nexthop message without NHA_ID attribute, ignoring: %m");
 912                 return 0;
 913         } else if (r < 0) {
 914                 log_warning_errno(r, "rtnl: could not get NHA_ID attribute, ignoring: %m");
 915                 return 0;
 916         } else if (id == 0) {
 917                 log_warning("rtnl: received nexthop message with invalid nexthop ID, ignoring: %m");
 918                 return 0;
 919         }
 920
 921         (void) nexthop_get_by_id(m, id, &nexthop);
 922         (void) nexthop_get_request_by_id(m, id, &req);
 923
 924         if (type == RTM_DELNEXTHOP) {
 925                 if (nexthop) {
 926                         nexthop_enter_removed(nexthop);
 927                         log_nexthop_debug(nexthop, "Forgetting removed", m);
 928                         nexthop_free(nexthop);
 929                 } else
 930                         log_nexthop_debug(&(const NextHop) { .id = id }, "Kernel removed unknown", m);
 931
 932                 if (req)
 933                         nexthop_enter_removed(req->userdata);
 934
 935                 return 0;
 936         }
 937
 938         /* If we did not know the nexthop, then save it. */
 939         if (!nexthop) {
 940                 r = nexthop_add_new(m, id, &nexthop);
 941                 if (r < 0) {
 942                         log_warning_errno(r, "Failed to add received nexthop, ignoring: %m");
 943                         return 0;
 944                 }
 945
 946                 is_new = true;
 947         }
 948
 949         /* Also update information that cannot be obtained through netlink notification. */
 950         if (req && req->waiting_reply) {
 951                 NextHop *n = ASSERT_PTR(req->userdata);
 952
 953                 nexthop->source = n->source;
 954         }
 955
 956         r = sd_rtnl_message_get_family(message, &nexthop->family);
 957         if (r < 0)
 958                 log_debug_errno(r, "rtnl: could not get nexthop family, ignoring: %m");
 959
 960         r = sd_rtnl_message_nexthop_get_protocol(message, &nexthop->protocol);
 961         if (r < 0)
 962                 log_debug_errno(r, "rtnl: could not get nexthop protocol, ignoring: %m");
 963
 964         r = sd_rtnl_message_nexthop_get_flags(message, &nexthop->flags);
 965         if (r < 0)
 966                 log_debug_errno(r, "rtnl: could not get nexthop flags, ignoring: %m");
 967
 968         r = sd_netlink_message_read_data(message, NHA_GROUP, &raw_group_size, &raw_group);
 969         if (r == -ENODATA)
 970                 nexthop->group = hashmap_free_free(nexthop->group);
 971         else if (r < 0)
 972                 log_debug_errno(r, "rtnl: could not get NHA_GROUP attribute, ignoring: %m");
 973         else
 974                 (void) nexthop_update_group(nexthop, raw_group, raw_group_size);
 975
 976         if (nexthop->family != AF_UNSPEC) {
 977                 r = netlink_message_read_in_addr_union(message, NHA_GATEWAY, nexthop->family, &nexthop->gw);
 978                 if (r == -ENODATA)
 979                         nexthop->gw = IN_ADDR_NULL;
 980                 else if (r < 0)
 981                         log_debug_errno(r, "rtnl: could not get NHA_GATEWAY attribute, ignoring: %m");
 982         }
 983
 984         r = sd_netlink_message_has_flag(message, NHA_BLACKHOLE);
 985         if (r < 0)
 986                 log_debug_errno(r, "rtnl: could not get NHA_BLACKHOLE attribute, ignoring: %m");
 987         else
 988                 nexthop->blackhole = r;
 989
 990         r = sd_netlink_message_read_u32(message, NHA_OIF, &ifindex);
 991         if (r == -ENODATA)
 992                 nexthop->ifindex = 0;
 993         else if (r < 0)
 994                 log_debug_errno(r, "rtnl: could not get NHA_OIF attribute, ignoring: %m");
 995         else if (ifindex > INT32_MAX)
 996                 log_debug_errno(r, "rtnl: received invalid NHA_OIF attribute, ignoring: %m");
 997         else
 998                 nexthop->ifindex = (int) ifindex;
 999
1000         /* All blackhole or group nexthops are managed by Manager. Note that the linux kernel does not
1001          * set NHA_OID attribute when NHA_BLACKHOLE or NHA_GROUP is set. Just for safety. */
1002         if (!nexthop_bound_to_link(nexthop))
1003                 nexthop->ifindex = 0;
1004
1005         nexthop_enter_configured(nexthop);
1006         if (req)
1007                 nexthop_enter_configured(req->userdata);
1008
1009         log_nexthop_debug(nexthop, is_new ? "Remembering" : "Received remembered", m);
1010         return 1;
1011 }
1012
1013 static int nexthop_section_verify(NextHop *nh) {
1014         if (section_is_invalid(nh->section))
1015                 return -EINVAL;
1016
1017         if (!nh->network->manager->manage_foreign_nexthops && nh->id == 0)
1018                 return log_warning_errno(SYNTHETIC_ERRNO(EINVAL),
1019                                          "%s: [NextHop] section without specifying Id= is not supported "
1020                                          "if ManageForeignNextHops=no is set in networkd.conf. "
1021                                          "Ignoring [NextHop] section from line %u.",
1022                                          nh->section->filename, nh->section->line);
1023
1024         if (!hashmap_isempty(nh->group)) {
1025                 if (in_addr_is_set(nh->family, &nh->gw))
1026                         return log_warning_errno(SYNTHETIC_ERRNO(EINVAL),
1027                                                  "%s: nexthop group cannot have gateway address. "
1028                                                  "Ignoring [NextHop] section from line %u.",
1029                                                  nh->section->filename, nh->section->line);
1030
1031                 if (nh->family != AF_UNSPEC)
1032                         return log_warning_errno(SYNTHETIC_ERRNO(EINVAL),
1033                                                  "%s: nexthop group cannot have Family= setting. "
1034                                                  "Ignoring [NextHop] section from line %u.",
1035                                                  nh->section->filename, nh->section->line);
1036
1037                 if (nh->blackhole)
1038                         return log_warning_errno(SYNTHETIC_ERRNO(EINVAL),
1039                                                  "%s: nexthop group cannot be a blackhole. "
1040                                                  "Ignoring [NextHop] section from line %u.",
1041                                                  nh->section->filename, nh->section->line);
1042
1043                 if (nh->onlink > 0)
1044                         return log_warning_errno(SYNTHETIC_ERRNO(EINVAL),
1045                                                  "%s: nexthop group cannot have on-link flag. "
1046                                                  "Ignoring [NextHop] section from line %u.",
1047                                                  nh->section->filename, nh->section->line);
1048         } else if (nh->family == AF_UNSPEC)
1049                 /* When neither Family=, Gateway=, nor Group= is specified, assume IPv4. */
1050                 nh->family = AF_INET;
1051
1052         if (nh->blackhole) {
1053                 if (in_addr_is_set(nh->family, &nh->gw))
1054                         return log_warning_errno(SYNTHETIC_ERRNO(EINVAL),
1055                                                  "%s: blackhole nexthop cannot have gateway address. "
1056                                                  "Ignoring [NextHop] section from line %u.",
1057                                                  nh->section->filename, nh->section->line);
1058
1059                 if (nh->onlink > 0)
1060                         return log_warning_errno(SYNTHETIC_ERRNO(EINVAL),
1061                                                  "%s: blackhole nexthop cannot have on-link flag. "
1062                                                  "Ignoring [NextHop] section from line %u.",
1063                                                  nh->section->filename, nh->section->line);
1064         }
1065
1066         if (nh->onlink < 0 && in_addr_is_set(nh->family, &nh->gw) &&
1067             ordered_hashmap_isempty(nh->network->addresses_by_section)) {
1068                 /* If no address is configured, in most cases the gateway cannot be reachable.
1069                  * TODO: we may need to improve the condition above. */
1070                 log_warning("%s: Gateway= without static address configured. "
1071                             "Enabling OnLink= option.",
1072                             nh->section->filename);
1073                 nh->onlink = true;
1074         }
1075
1076         if (nh->onlink >= 0)
1077                 SET_FLAG(nh->flags, RTNH_F_ONLINK, nh->onlink);
1078
1079         return 0;
1080 }
1081
1082 int network_drop_invalid_nexthops(Network *network) {
1083         _cleanup_hashmap_free_ Hashmap *nexthops = NULL;
1084         NextHop *nh;
1085         int r;
1086
1087         assert(network);
1088
1089         ORDERED_HASHMAP_FOREACH(nh, network->nexthops_by_section) {
1090                 if (nexthop_section_verify(nh) < 0) {
1091                         nexthop_free(nh);
1092                         continue;
1093                 }
1094
1095                 if (nh->id == 0)
1096                         continue;
1097
1098                 /* Always use the setting specified later. So, remove the previously assigned setting. */
1099                 NextHop *dup = hashmap_remove(nexthops, UINT32_TO_PTR(nh->id));
1100                 if (dup) {
1101                         log_warning("%s: Duplicated nexthop settings for ID %"PRIu32" is specified at line %u and %u, "
1102                                     "dropping the nexthop setting specified at line %u.",
1103                                     dup->section->filename,
1104                                     nh->id, nh->section->line,
1105                                     dup->section->line, dup->section->line);
1106                         /* nexthop_free() will drop the nexthop from nexthops_by_section. */
1107                         nexthop_free(dup);
1108                 }
1109
1110                 r = hashmap_ensure_put(&nexthops, NULL, UINT32_TO_PTR(nh->id), nh);
1111                 if (r < 0)
1112                         return log_oom();
1113                 assert(r > 0);
1114         }
1115
1116         return 0;
1117 }
1118
1119 int manager_build_nexthop_ids(Manager *manager) {
1120         Network *network;
1121         int r;
1122
1123         assert(manager);
1124
1125         if (!manager->manage_foreign_nexthops)
1126                 return 0;
1127
1128         manager->nexthop_ids = set_free(manager->nexthop_ids);
1129
1130         ORDERED_HASHMAP_FOREACH(network, manager->networks) {
1131                 NextHop *nh;
1132
1133                 ORDERED_HASHMAP_FOREACH(nh, network->nexthops_by_section) {
1134                         if (nh->id == 0)
1135                                 continue;
1136
1137                         r = set_ensure_put(&manager->nexthop_ids, NULL, UINT32_TO_PTR(nh->id));
1138                         if (r < 0)
1139                                 return r;
1140                 }
1141         }
1142
1143         return 0;
1144 }
1145
1146 int config_parse_nexthop_id(
1147                 const char *unit,
1148                 const char *filename,
1149                 unsigned line,
1150                 const char *section,
1151                 unsigned section_line,
1152                 const char *lvalue,
1153                 int ltype,
1154                 const char *rvalue,
1155                 void *data,
1156                 void *userdata) {
1157
1158         _cleanup_(nexthop_free_or_set_invalidp) NextHop *n = NULL;
1159         Network *network = userdata;
1160         uint32_t id;
1161         int r;
1162
1163         assert(filename);
1164         assert(section);
1165         assert(lvalue);
1166         assert(rvalue);
1167         assert(data);
1168
1169         r = nexthop_new_static(network, filename, section_line, &n);
1170         if (r < 0)
1171                 return log_oom();
1172
1173         if (isempty(rvalue)) {
1174                 n->id = 0;
1175                 TAKE_PTR(n);
1176                 return 0;
1177         }
1178
1179         r = safe_atou32(rvalue, &id);
1180         if (r < 0) {
1181                 log_syntax(unit, LOG_WARNING, filename, line, r,
1182                            "Could not parse nexthop id \"%s\", ignoring assignment: %m", rvalue);
1183                 return 0;
1184         }
1185         if (id == 0) {
1186                 log_syntax(unit, LOG_WARNING, filename, line, 0,
1187                            "Invalid nexthop id \"%s\", ignoring assignment: %m", rvalue);
1188                 return 0;
1189         }
1190
1191         n->id = id;
1192         TAKE_PTR(n);
1193         return 0;
1194 }
1195
1196 int config_parse_nexthop_gateway(
1197                 const char *unit,
1198                 const char *filename,
1199                 unsigned line,
1200                 const char *section,
1201                 unsigned section_line,
1202                 const char *lvalue,
1203                 int ltype,
1204                 const char *rvalue,
1205                 void *data,
1206                 void *userdata) {
1207
1208         _cleanup_(nexthop_free_or_set_invalidp) NextHop *n = NULL;
1209         Network *network = userdata;
1210         int r;
1211
1212         assert(filename);
1213         assert(section);
1214         assert(lvalue);
1215         assert(rvalue);
1216         assert(data);
1217
1218         r = nexthop_new_static(network, filename, section_line, &n);
1219         if (r < 0)
1220                 return log_oom();
1221
1222         if (isempty(rvalue)) {
1223                 n->family = AF_UNSPEC;
1224                 n->gw = IN_ADDR_NULL;
1225
1226                 TAKE_PTR(n);
1227                 return 0;
1228         }
1229
1230         r = in_addr_from_string_auto(rvalue, &n->family, &n->gw);
1231         if (r < 0) {
1232                 log_syntax(unit, LOG_WARNING, filename, line, r,
1233                            "Invalid %s='%s', ignoring assignment: %m", lvalue, rvalue);
1234                 return 0;
1235         }
1236
1237         TAKE_PTR(n);
1238         return 0;
1239 }
1240
1241 int config_parse_nexthop_family(
1242                 const char *unit,
1243                 const char *filename,
1244                 unsigned line,
1245                 const char *section,
1246                 unsigned section_line,
1247                 const char *lvalue,
1248                 int ltype,
1249                 const char *rvalue,
1250                 void *data,
1251                 void *userdata) {
1252
1253         _cleanup_(nexthop_free_or_set_invalidp) NextHop *n = NULL;
1254         Network *network = userdata;
1255         AddressFamily a;
1256         int r;
1257
1258         assert(filename);
1259         assert(section);
1260         assert(lvalue);
1261         assert(rvalue);
1262         assert(data);
1263
1264         r = nexthop_new_static(network, filename, section_line, &n);
1265         if (r < 0)
1266                 return log_oom();
1267
1268         if (isempty(rvalue) &&
1269             !in_addr_is_set(n->family, &n->gw)) {
1270                 /* Accept an empty string only when Gateway= is null or not specified. */
1271                 n->family = AF_UNSPEC;
1272                 TAKE_PTR(n);
1273                 return 0;
1274         }
1275
1276         a = nexthop_address_family_from_string(rvalue);
1277         if (a < 0) {
1278                 log_syntax(unit, LOG_WARNING, filename, line, 0,
1279                            "Invalid %s='%s', ignoring assignment: %m", lvalue, rvalue);
1280                 return 0;
1281         }
1282
1283         if (in_addr_is_set(n->family, &n->gw) &&
1284             ((a == ADDRESS_FAMILY_IPV4 && n->family == AF_INET6) ||
1285              (a == ADDRESS_FAMILY_IPV6 && n->family == AF_INET))) {
1286                 log_syntax(unit, LOG_WARNING, filename, line, 0,
1287                            "Specified family '%s' conflicts with the family of the previously specified Gateway=, "
1288                            "ignoring assignment.", rvalue);
1289                 return 0;
1290         }
1291
1292         switch (a) {
1293         case ADDRESS_FAMILY_IPV4:
1294                 n->family = AF_INET;
1295                 break;
1296         case ADDRESS_FAMILY_IPV6:
1297                 n->family = AF_INET6;
1298                 break;
1299         default:
1300                 assert_not_reached();
1301         }
1302
1303         TAKE_PTR(n);
1304         return 0;
1305 }
1306
1307 int config_parse_nexthop_onlink(
1308                 const char *unit,
1309                 const char *filename,
1310                 unsigned line,
1311                 const char *section,
1312                 unsigned section_line,
1313                 const char *lvalue,
1314                 int ltype,
1315                 const char *rvalue,
1316                 void *data,
1317                 void *userdata) {
1318
1319         _cleanup_(nexthop_free_or_set_invalidp) NextHop *n = NULL;
1320         Network *network = userdata;
1321         int r;
1322
1323         assert(filename);
1324         assert(section);
1325         assert(lvalue);
1326         assert(rvalue);
1327         assert(data);
1328
1329         r = nexthop_new_static(network, filename, section_line, &n);
1330         if (r < 0)
1331                 return log_oom();
1332
1333         r = parse_tristate(rvalue, &n->onlink);
1334         if (r < 0) {
1335                 log_syntax(unit, LOG_WARNING, filename, line, r,
1336                            "Failed to parse %s=, ignoring assignment: %s", lvalue, rvalue);
1337                 return 0;
1338         }
1339
1340         TAKE_PTR(n);
1341         return 0;
1342 }
1343
1344 int config_parse_nexthop_blackhole(
1345                 const char *unit,
1346                 const char *filename,
1347                 unsigned line,
1348                 const char *section,
1349                 unsigned section_line,
1350                 const char *lvalue,
1351                 int ltype,
1352                 const char *rvalue,
1353                 void *data,
1354                 void *userdata) {
1355
1356         _cleanup_(nexthop_free_or_set_invalidp) NextHop *n = NULL;
1357         Network *network = userdata;
1358         int r;
1359
1360         assert(filename);
1361         assert(section);
1362         assert(lvalue);
1363         assert(rvalue);
1364         assert(data);
1365
1366         r = nexthop_new_static(network, filename, section_line, &n);
1367         if (r < 0)
1368                 return log_oom();
1369
1370         r = parse_boolean(rvalue);
1371         if (r < 0) {
1372                 log_syntax(unit, LOG_WARNING, filename, line, r,
1373                            "Failed to parse %s=, ignoring assignment: %s", lvalue, rvalue);
1374                 return 0;
1375         }
1376
1377         n->blackhole = r;
1378
1379         TAKE_PTR(n);
1380         return 0;
1381 }
1382
1383 int config_parse_nexthop_group(
1384                 const char *unit,
1385                 const char *filename,
1386                 unsigned line,
1387                 const char *section,
1388                 unsigned section_line,
1389                 const char *lvalue,
1390                 int ltype,
1391                 const char *rvalue,
1392                 void *data,
1393                 void *userdata) {
1394
1395         _cleanup_(nexthop_free_or_set_invalidp) NextHop *n = NULL;
1396         Network *network = userdata;
1397         int r;
1398
1399         assert(filename);
1400         assert(section);
1401         assert(lvalue);
1402         assert(rvalue);
1403         assert(data);
1404
1405         r = nexthop_new_static(network, filename, section_line, &n);
1406         if (r < 0)
1407                 return log_oom();
1408
1409         if (isempty(rvalue)) {
1410                 n->group = hashmap_free_free(n->group);
1411                 TAKE_PTR(n);
1412                 return 0;
1413         }
1414
1415         for (const char *p = rvalue;;) {
1416                 _cleanup_free_ struct nexthop_grp *nhg = NULL;
1417                 _cleanup_free_ char *word = NULL;
1418                 uint32_t w;
1419                 char *sep;
1420
1421                 r = extract_first_word(&p, &word, NULL, 0);
1422                 if (r == -ENOMEM)
1423                         return log_oom();
1424                 if (r < 0) {
1425                         log_syntax(unit, LOG_WARNING, filename, line, r,
1426                                    "Invalid %s=, ignoring assignment: %s", lvalue, rvalue);
1427                         return 0;
1428                 }
1429                 if (r == 0)
1430                         break;
1431
1432                 nhg = new0(struct nexthop_grp, 1);
1433                 if (!nhg)
1434                         return log_oom();
1435
1436                 sep = strchr(word, ':');
1437                 if (sep) {
1438                         *sep++ = '\0';
1439                         r = safe_atou32(sep, &w);
1440                         if (r < 0) {
1441                                 log_syntax(unit, LOG_WARNING, filename, line, r,
1442                                            "Failed to parse weight for nexthop group, ignoring assignment: %s:%s",
1443                                            word, sep);
1444                                 continue;
1445                         }
1446                         if (w == 0 || w > 256) {
1447                                 log_syntax(unit, LOG_WARNING, filename, line, 0,
1448                                            "Invalid weight for nexthop group, ignoring assignment: %s:%s",
1449                                            word, sep);
1450                                 continue;
1451                         }
1452                         /* See comments in config_parse_multipath_route(). */
1453                         nhg->weight = w - 1;
1454                 }
1455
1456                 r = safe_atou32(word, &nhg->id);
1457                 if (r < 0) {
1458                         log_syntax(unit, LOG_WARNING, filename, line, r,
1459                                    "Failed to parse nexthop ID in %s=, ignoring assignment: %s%s%s",
1460                                    lvalue, word, sep ? ":" : "", strempty(sep));
1461                         continue;
1462                 }
1463                 if (nhg->id == 0) {
1464                         log_syntax(unit, LOG_WARNING, filename, line, 0,
1465                                    "Nexthop ID in %s= must be positive, ignoring assignment: %s%s%s",
1466                                    lvalue, word, sep ? ":" : "", strempty(sep));
1467                         continue;
1468                 }
1469
1470                 r = hashmap_ensure_put(&n->group, NULL, UINT32_TO_PTR(nhg->id), nhg);
1471                 if (r == -ENOMEM)
1472                         return log_oom();
1473                 if (r == -EEXIST) {
1474                         log_syntax(unit, LOG_WARNING, filename, line, r,
1475                                    "Nexthop ID %"PRIu32" is specified multiple times in %s=, ignoring assignment: %s%s%s",
1476                                    nhg->id, lvalue, word, sep ? ":" : "", strempty(sep));
1477                         continue;
1478                 }
1479                 assert(r > 0);
1480                 TAKE_PTR(nhg);
1481         }
1482
1483         TAKE_PTR(n);
1484         return 0;
1485 }