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                 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 = 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 = 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(&nexthop->id, sizeof(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                 if (ret)
 255                         *ret = nexthop;
 256                 return 0;
 257         }
 258
 259         return -ENOENT;
 260 }
 261
 262 static int nexthop_get_request_by_id(Manager *manager, uint32_t id, Request **ret) {
 263         Request *req;
 264
 265         assert(manager);
 266
 267         req = ordered_set_get(
 268                         manager->request_queue,
 269                         &(Request) {
 270                                 .type = REQUEST_TYPE_NEXTHOP,
 271                                 .userdata = (void*) &(const NextHop) { .id = id },
 272                                 .hash_func = (hash_func_t) nexthop_hash_func,
 273                                 .compare_func = (compare_func_t) nexthop_compare_func,
 274                         });
 275         if (!req)
 276                 return -ENOENT;
 277
 278         if (ret)
 279                 *ret = req;
 280         return 0;
 281 }
 282
 283 static int nexthop_get_request(Link *link, const NextHop *in, Request **ret) {
 284         Request *req;
 285         int ifindex;
 286
 287         assert(link);
 288         assert(link->manager);
 289         assert(in);
 290
 291         if (in->id > 0)
 292                 return nexthop_get_request_by_id(link->manager, in->id, ret);
 293
 294         /* If ManageForeignNextHops=no, nexthop with id == 0 should be already filtered by
 295          * nexthop_section_verify(). */
 296         assert(link->manager->manage_foreign_nexthops);
 297
 298         ifindex = nexthop_bound_to_link(in) ? link->ifindex : 0;
 299
 300         ORDERED_SET_FOREACH(req, link->manager->request_queue) {
 301                 if (req->type != REQUEST_TYPE_NEXTHOP)
 302                         continue;
 303
 304                 NextHop *nexthop = ASSERT_PTR(req->userdata);
 305                 if (nexthop->ifindex != ifindex)
 306                         continue;
 307                 if (nexthop_compare_full(nexthop, in) != 0)
 308                         continue;
 309
 310                 if (ret)
 311                         *ret = req;
 312                 return 0;
 313         }
 314
 315         return -ENOENT;
 316 }
 317
 318 static int nexthop_add_new(Manager *manager, uint32_t id, NextHop **ret) {
 319         _cleanup_(nexthop_freep) NextHop *nexthop = NULL;
 320         int r;
 321
 322         assert(manager);
 323         assert(id > 0);
 324
 325         r = nexthop_new(&nexthop);
 326         if (r < 0)
 327                 return r;
 328
 329         nexthop->id = id;
 330
 331         r = hashmap_ensure_put(&manager->nexthops_by_id, &nexthop_hash_ops, UINT32_TO_PTR(nexthop->id), nexthop);
 332         if (r < 0)
 333                 return r;
 334         if (r == 0)
 335                 return -EEXIST;
 336
 337         nexthop->manager = manager;
 338
 339         if (ret)
 340                 *ret = nexthop;
 341
 342         TAKE_PTR(nexthop);
 343         return 0;
 344 }
 345
 346 static int nexthop_acquire_id(Manager *manager, NextHop *nexthop) {
 347         _cleanup_set_free_ Set *ids = NULL;
 348         Network *network;
 349         int r;
 350
 351         assert(manager);
 352         assert(nexthop);
 353
 354         if (nexthop->id > 0)
 355                 return 0;
 356
 357         /* If ManageForeignNextHops=no, nexthop with id == 0 should be already filtered by
 358          * nexthop_section_verify(). */
 359         assert(manager->manage_foreign_nexthops);
 360
 361         /* Find the lowest unused ID. */
 362
 363         ORDERED_HASHMAP_FOREACH(network, manager->networks) {
 364                 NextHop *tmp;
 365
 366                 HASHMAP_FOREACH(tmp, network->nexthops_by_section) {
 367                         if (tmp->id == 0)
 368                                 continue;
 369
 370                         r = set_ensure_put(&ids, NULL, UINT32_TO_PTR(tmp->id));
 371                         if (r < 0)
 372                                 return r;
 373                 }
 374         }
 375
 376         for (uint32_t id = 1; id < UINT32_MAX; id++) {
 377                 if (nexthop_get_by_id(manager, id, NULL) >= 0)
 378                         continue;
 379                 if (nexthop_get_request_by_id(manager, id, NULL) >= 0)
 380                         continue;
 381                 if (set_contains(ids, UINT32_TO_PTR(id)))
 382                         continue;
 383
 384                 nexthop->id = id;
 385                 return 0;
 386         }
 387
 388         return -EBUSY;
 389 }
 390
 391 static void log_nexthop_debug(const NextHop *nexthop, const char *str, Manager *manager) {
 392         _cleanup_free_ char *state = NULL, *group = NULL, *flags = NULL;
 393         struct nexthop_grp *nhg;
 394         Link *link = NULL;
 395
 396         assert(nexthop);
 397         assert(str);
 398         assert(manager);
 399
 400         if (!DEBUG_LOGGING)
 401                 return;
 402
 403         (void) link_get_by_index(manager, nexthop->ifindex, &link);
 404         (void) network_config_state_to_string_alloc(nexthop->state, &state);
 405         (void) route_flags_to_string_alloc(nexthop->flags, &flags);
 406
 407         HASHMAP_FOREACH(nhg, nexthop->group)
 408                 (void) strextendf_with_separator(&group, ",", "%"PRIu32":%"PRIu32, nhg->id, nhg->weight+1u);
 409
 410         log_link_debug(link, "%s %s nexthop (%s): id: %"PRIu32", gw: %s, blackhole: %s, group: %s, flags: %s",
 411                        str, strna(network_config_source_to_string(nexthop->source)), strna(state),
 412                        nexthop->id,
 413                        IN_ADDR_TO_STRING(nexthop->family, &nexthop->gw),
 414                        yes_no(nexthop->blackhole), strna(group), strna(flags));
 415 }
 416
 417 static int nexthop_remove_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) {
 418         int r;
 419
 420         assert(m);
 421
 422         /* link may be NULL. */
 423
 424         if (link && IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
 425                 return 1;
 426
 427         r = sd_netlink_message_get_errno(m);
 428         if (r < 0 && r != -ENOENT)
 429                 log_link_message_warning_errno(link, m, r, "Could not drop nexthop, ignoring");
 430
 431         return 1;
 432 }
 433
 434 static int nexthop_remove(NextHop *nexthop) {
 435         _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
 436         Manager *manager;
 437         Link *link = NULL;
 438         Request *req;
 439         int r;
 440
 441         assert(nexthop);
 442         assert(nexthop->id > 0);
 443
 444         manager = ASSERT_PTR(nexthop->manager);
 445
 446         /* link may be NULL. */
 447         (void) link_get_by_index(manager, nexthop->ifindex, &link);
 448
 449         log_nexthop_debug(nexthop, "Removing", manager);
 450
 451         r = sd_rtnl_message_new_nexthop(manager->rtnl, &m, RTM_DELNEXTHOP, AF_UNSPEC, RTPROT_UNSPEC);
 452         if (r < 0)
 453                 return log_link_error_errno(link, r, "Could not create RTM_DELNEXTHOP message: %m");
 454
 455         r = sd_netlink_message_append_u32(m, NHA_ID, nexthop->id);
 456         if (r < 0)
 457                 return log_link_error_errno(link, r, "Could not append NHA_ID attribute: %m");
 458
 459         r = netlink_call_async(manager->rtnl, NULL, m, nexthop_remove_handler,
 460                                link ? link_netlink_destroy_callback : NULL, link);
 461         if (r < 0)
 462                 return log_link_error_errno(link, r, "Could not send rtnetlink message: %m");
 463
 464         link_ref(link); /* link may be NULL, link_ref() is OK with that */
 465
 466         nexthop_enter_removing(nexthop);
 467         if (nexthop_get_request_by_id(manager, nexthop->id, &req) >= 0)
 468                 nexthop_enter_removing(req->userdata);
 469
 470         return 0;
 471 }
 472
 473 static int nexthop_configure(NextHop *nexthop, Link *link, Request *req) {
 474         _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
 475         int r;
 476
 477         assert(nexthop);
 478         assert(nexthop->id > 0);
 479         assert(IN_SET(nexthop->family, AF_UNSPEC, AF_INET, AF_INET6));
 480         assert(link);
 481         assert(link->manager);
 482         assert(link->manager->rtnl);
 483         assert(link->ifindex > 0);
 484         assert(req);
 485
 486         log_nexthop_debug(nexthop, "Configuring", link->manager);
 487
 488         r = sd_rtnl_message_new_nexthop(link->manager->rtnl, &m, RTM_NEWNEXTHOP, nexthop->family, nexthop->protocol);
 489         if (r < 0)
 490                 return r;
 491
 492         r = sd_netlink_message_append_u32(m, NHA_ID, nexthop->id);
 493         if (r < 0)
 494                 return r;
 495
 496         if (!hashmap_isempty(nexthop->group)) {
 497                 _cleanup_free_ struct nexthop_grp *group = NULL;
 498                 struct nexthop_grp *p, *nhg;
 499
 500                 group = new(struct nexthop_grp, hashmap_size(nexthop->group));
 501                 if (!group)
 502                         return log_oom();
 503
 504                 p = group;
 505                 HASHMAP_FOREACH(nhg, nexthop->group)
 506                         *p++ = *nhg;
 507
 508                 r = sd_netlink_message_append_data(m, NHA_GROUP, group, sizeof(struct nexthop_grp) * hashmap_size(nexthop->group));
 509                 if (r < 0)
 510                         return r;
 511
 512         } else if (nexthop->blackhole) {
 513                 r = sd_netlink_message_append_flag(m, NHA_BLACKHOLE);
 514                 if (r < 0)
 515                         return r;
 516         } else {
 517                 assert(nexthop->ifindex == link->ifindex);
 518
 519                 r = sd_netlink_message_append_u32(m, NHA_OIF, nexthop->ifindex);
 520                 if (r < 0)
 521                         return r;
 522
 523                 if (in_addr_is_set(nexthop->family, &nexthop->gw)) {
 524                         r = netlink_message_append_in_addr_union(m, NHA_GATEWAY, nexthop->family, &nexthop->gw);
 525                         if (r < 0)
 526                                 return r;
 527
 528                         r = sd_rtnl_message_nexthop_set_flags(m, nexthop->flags & RTNH_F_ONLINK);
 529                         if (r < 0)
 530                                 return r;
 531                 }
 532         }
 533
 534         return request_call_netlink_async(link->manager->rtnl, m, req);
 535 }
 536
 537 static int static_nexthop_handler(sd_netlink *rtnl, sd_netlink_message *m, Request *req, Link *link, NextHop *nexthop) {
 538         int r;
 539
 540         assert(m);
 541         assert(link);
 542
 543         r = sd_netlink_message_get_errno(m);
 544         if (r < 0 && r != -EEXIST) {
 545                 log_link_message_warning_errno(link, m, r, "Could not set nexthop");
 546                 link_enter_failed(link);
 547                 return 1;
 548         }
 549
 550         if (link->static_nexthop_messages == 0) {
 551                 log_link_debug(link, "Nexthops set");
 552                 link->static_nexthops_configured = true;
 553                 link_check_ready(link);
 554         }
 555
 556         return 1;
 557 }
 558
 559 static bool nexthop_is_ready_to_configure(Link *link, const NextHop *nexthop) {
 560         struct nexthop_grp *nhg;
 561
 562         assert(link);
 563         assert(nexthop);
 564         assert(nexthop->id > 0);
 565
 566         if (!link_is_ready_to_configure(link, false))
 567                 return false;
 568
 569         if (nexthop_bound_to_link(nexthop)) {
 570                 assert(nexthop->ifindex == link->ifindex);
 571
 572                 /* TODO: fdb nexthop does not require IFF_UP. The conditions below needs to be updated
 573                  * when fdb nexthop support is added. See rtm_to_nh_config() in net/ipv4/nexthop.c of
 574                  * kernel. */
 575                 if (link->set_flags_messages > 0)
 576                         return false;
 577                 if (!FLAGS_SET(link->flags, IFF_UP))
 578                         return false;
 579         }
 580
 581         /* All group members must be configured first. */
 582         HASHMAP_FOREACH(nhg, nexthop->group) {
 583                 NextHop *g;
 584
 585                 if (nexthop_get_by_id(link->manager, nhg->id, &g) < 0)
 586                         return false;
 587
 588                 if (!nexthop_exists(g))
 589                         return false;
 590         }
 591
 592         return gateway_is_ready(link, FLAGS_SET(nexthop->flags, RTNH_F_ONLINK), nexthop->family, &nexthop->gw);
 593 }
 594
 595 static int nexthop_process_request(Request *req, Link *link, NextHop *nexthop) {
 596         NextHop *existing;
 597         int r;
 598
 599         assert(req);
 600         assert(link);
 601         assert(link->manager);
 602         assert(nexthop);
 603
 604         if (!nexthop_is_ready_to_configure(link, nexthop))
 605                 return 0;
 606
 607         r = nexthop_configure(nexthop, link, req);
 608         if (r < 0)
 609                 return log_link_warning_errno(link, r, "Failed to configure nexthop");
 610
 611         nexthop_enter_configuring(nexthop);
 612         if (nexthop_get_by_id(link->manager, nexthop->id, &existing) >= 0)
 613                 nexthop_enter_configuring(existing);
 614
 615         return 1;
 616 }
 617
 618 static int link_request_nexthop(Link *link, const NextHop *nexthop) {
 619         _cleanup_(nexthop_freep) NextHop *tmp = NULL;
 620         NextHop *existing = NULL;
 621         int r;
 622
 623         assert(link);
 624         assert(link->manager);
 625         assert(nexthop);
 626         assert(nexthop->source != NETWORK_CONFIG_SOURCE_FOREIGN);
 627
 628         if (nexthop_get_request(link, nexthop, NULL) >= 0)
 629                 return 0; /* already requested, skipping. */
 630
 631         r = nexthop_dup(nexthop, &tmp);
 632         if (r < 0)
 633                 return r;
 634
 635         if (nexthop_get(link, nexthop, &existing) < 0) {
 636                 r = nexthop_acquire_id(link->manager, tmp);
 637                 if (r < 0)
 638                         return r;
 639         } else {
 640                 /* Copy ID */
 641                 assert(tmp->id == 0 || tmp->id == existing->id);
 642                 tmp->id = existing->id;
 643
 644                 /* Copy state for logging below. */
 645                 tmp->state = existing->state;
 646         }
 647
 648         if (nexthop_bound_to_link(tmp))
 649                 tmp->ifindex = link->ifindex;
 650
 651         log_nexthop_debug(tmp, "Requesting", link->manager);
 652         r = link_queue_request_safe(link, REQUEST_TYPE_NEXTHOP,
 653                                     tmp,
 654                                     nexthop_free,
 655                                     nexthop_hash_func,
 656                                     nexthop_compare_func,
 657                                     nexthop_process_request,
 658                                     &link->static_nexthop_messages,
 659                                     static_nexthop_handler,
 660                                     NULL);
 661         if (r <= 0)
 662                 return r;
 663
 664         nexthop_enter_requesting(tmp);
 665         if (existing)
 666                 nexthop_enter_requesting(existing);
 667
 668         TAKE_PTR(tmp);
 669         return 1;
 670 }
 671
 672 int link_request_static_nexthops(Link *link, bool only_ipv4) {
 673         NextHop *nh;
 674         int r;
 675
 676         assert(link);
 677         assert(link->network);
 678
 679         link->static_nexthops_configured = false;
 680
 681         HASHMAP_FOREACH(nh, link->network->nexthops_by_section) {
 682                 if (only_ipv4 && nh->family != AF_INET)
 683                         continue;
 684
 685                 r = link_request_nexthop(link, nh);
 686                 if (r < 0)
 687                         return log_link_warning_errno(link, r, "Could not request nexthop: %m");
 688         }
 689
 690         if (link->static_nexthop_messages == 0) {
 691                 link->static_nexthops_configured = true;
 692                 link_check_ready(link);
 693         } else {
 694                 log_link_debug(link, "Requesting nexthops");
 695                 link_set_state(link, LINK_STATE_CONFIGURING);
 696         }
 697
 698         return 0;
 699 }
 700
 701 static bool nexthop_can_update(const NextHop *assigned_nexthop, const NextHop *requested_nexthop) {
 702         assert(assigned_nexthop);
 703         assert(assigned_nexthop->manager);
 704         assert(requested_nexthop);
 705         assert(requested_nexthop->network);
 706
 707         /* A group nexthop cannot be replaced with a non-group nexthop, and vice versa.
 708          * See replace_nexthop_grp() and replace_nexthop_single() in net/ipv4/nexthop.c of the kernel. */
 709         if (hashmap_isempty(assigned_nexthop->group) != hashmap_isempty(requested_nexthop->group))
 710                 return false;
 711
 712         /* There are several more conditions if we can replace a group nexthop, e.g. hash threshold and
 713          * resilience. But, currently we do not support to modify that. Let's add checks for them in the
 714          * future when we support to configure them.*/
 715
 716         /* When a nexthop is replaced with a blackhole nexthop, and a group nexthop has multiple nexthops
 717          * including this nexthop, then the kernel refuses to replace the existing nexthop.
 718          * So, here, for simplicity, let's unconditionally refuse to replace a non-blackhole nexthop with
 719          * a blackhole nexthop. See replace_nexthop() in net/ipv4/nexthop.c of the kernel. */
 720         if (!assigned_nexthop->blackhole && requested_nexthop->blackhole)
 721                 return false;
 722
 723         return true;
 724 }
 725
 726 static void link_mark_nexthops(Link *link, bool foreign) {
 727         NextHop *nexthop;
 728         Link *other;
 729
 730         assert(link);
 731         assert(link->manager);
 732
 733         /* First, mark all nexthops. */
 734         HASHMAP_FOREACH(nexthop, link->manager->nexthops_by_id) {
 735                 /* do not touch nexthop created by the kernel */
 736                 if (nexthop->protocol == RTPROT_KERNEL)
 737                         continue;
 738
 739                 /* When 'foreign' is true, mark only foreign nexthops, and vice versa. */
 740                 if (foreign != (nexthop->source == NETWORK_CONFIG_SOURCE_FOREIGN))
 741                         continue;
 742
 743                 /* Ignore nexthops not assigned yet or already removed. */
 744                 if (!nexthop_exists(nexthop))
 745                         continue;
 746
 747                 /* Ignore nexthops bound to other links. */
 748                 if (nexthop->ifindex > 0 && nexthop->ifindex != link->ifindex)
 749                         continue;
 750
 751                 nexthop_mark(nexthop);
 752         }
 753
 754         /* Then, unmark all nexthops requested by active links. */
 755         HASHMAP_FOREACH(other, link->manager->links_by_index) {
 756                 if (!foreign && other == link)
 757                         continue;
 758
 759                 if (!IN_SET(other->state, LINK_STATE_CONFIGURING, LINK_STATE_CONFIGURED))
 760                         continue;
 761
 762                 HASHMAP_FOREACH(nexthop, other->network->nexthops_by_section) {
 763                         NextHop *existing;
 764
 765                         if (nexthop_get(other, nexthop, &existing) < 0)
 766                                 continue;
 767
 768                         if (!nexthop_can_update(existing, nexthop))
 769                                 continue;
 770
 771                         /* Found matching static configuration. Keep the existing nexthop. */
 772                         nexthop_unmark(existing);
 773                 }
 774         }
 775 }
 776
 777 int link_drop_nexthops(Link *link, bool foreign) {
 778         NextHop *nexthop;
 779         int r = 0;
 780
 781         assert(link);
 782         assert(link->manager);
 783
 784         link_mark_nexthops(link, foreign);
 785
 786         HASHMAP_FOREACH(nexthop, link->manager->nexthops_by_id) {
 787                 if (!nexthop_is_marked(nexthop))
 788                         continue;
 789
 790                 RET_GATHER(r, nexthop_remove(nexthop));
 791         }
 792
 793         return r;
 794 }
 795
 796 void link_foreignize_nexthops(Link *link) {
 797         NextHop *nexthop;
 798
 799         assert(link);
 800         assert(link->manager);
 801
 802         link_mark_nexthops(link, /* foreign = */ false);
 803
 804         HASHMAP_FOREACH(nexthop, link->manager->nexthops_by_id) {
 805                 if (!nexthop_is_marked(nexthop))
 806                         continue;
 807
 808                 nexthop->source = NETWORK_CONFIG_SOURCE_FOREIGN;
 809         }
 810 }
 811
 812 static int nexthop_update_group(NextHop *nexthop, const struct nexthop_grp *group, size_t size) {
 813         _cleanup_hashmap_free_free_ Hashmap *h = NULL;
 814         size_t n_group;
 815         int r;
 816
 817         assert(nexthop);
 818         assert(group || size == 0);
 819
 820         if (size == 0 || size % sizeof(struct nexthop_grp) != 0)
 821                 return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
 822                                        "rtnl: received nexthop message with invalid nexthop group size, ignoring.");
 823
 824         if ((uintptr_t) group % alignof(struct nexthop_grp) != 0)
 825                 return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
 826                                        "rtnl: received nexthop message with invalid alignment, ignoring.");
 827
 828         n_group = size / sizeof(struct nexthop_grp);
 829         for (size_t i = 0; i < n_group; i++) {
 830                 _cleanup_free_ struct nexthop_grp *nhg = NULL;
 831
 832                 if (group[i].id == 0) {
 833                         log_debug("rtnl: received nexthop message with invalid ID in group, ignoring.");
 834                         continue;
 835                 }
 836
 837                 if (group[i].weight > 254) {
 838                         log_debug("rtnl: received nexthop message with invalid weight in group, ignoring.");
 839                         continue;
 840                 }
 841
 842                 nhg = newdup(struct nexthop_grp, group + i, 1);
 843                 if (!nhg)
 844                         return log_oom();
 845
 846                 r = hashmap_ensure_put(&h, NULL, UINT32_TO_PTR(nhg->id), nhg);
 847                 if (r == -ENOMEM)
 848                         return log_oom();
 849                 if (r < 0) {
 850                         log_debug_errno(r, "Failed to store nexthop group, ignoring: %m");
 851                         continue;
 852                 }
 853                 if (r > 0)
 854                         TAKE_PTR(nhg);
 855         }
 856
 857         hashmap_free_free(nexthop->group);
 858         nexthop->group = TAKE_PTR(h);
 859         return 0;
 860 }
 861
 862 int manager_rtnl_process_nexthop(sd_netlink *rtnl, sd_netlink_message *message, Manager *m) {
 863         _cleanup_free_ void *raw_group = NULL;
 864         size_t raw_group_size;
 865         uint16_t type;
 866         uint32_t id, ifindex;
 867         NextHop *nexthop = NULL;
 868         Request *req = NULL;
 869         bool is_new = false;
 870         int r;
 871
 872         assert(rtnl);
 873         assert(message);
 874         assert(m);
 875
 876         if (sd_netlink_message_is_error(message)) {
 877                 r = sd_netlink_message_get_errno(message);
 878                 if (r < 0)
 879                         log_message_warning_errno(message, r, "rtnl: failed to receive rule message, ignoring");
 880
 881                 return 0;
 882         }
 883
 884         r = sd_netlink_message_get_type(message, &type);
 885         if (r < 0) {
 886                 log_warning_errno(r, "rtnl: could not get message type, ignoring: %m");
 887                 return 0;
 888         } else if (!IN_SET(type, RTM_NEWNEXTHOP, RTM_DELNEXTHOP)) {
 889                 log_warning("rtnl: received unexpected message type %u when processing nexthop, ignoring.", type);
 890                 return 0;
 891         }
 892
 893         r = sd_netlink_message_read_u32(message, NHA_ID, &id);
 894         if (r == -ENODATA) {
 895                 log_warning_errno(r, "rtnl: received nexthop message without NHA_ID attribute, ignoring: %m");
 896                 return 0;
 897         } else if (r < 0) {
 898                 log_warning_errno(r, "rtnl: could not get NHA_ID attribute, ignoring: %m");
 899                 return 0;
 900         } else if (id == 0) {
 901                 log_warning("rtnl: received nexthop message with invalid nexthop ID, ignoring: %m");
 902                 return 0;
 903         }
 904
 905         (void) nexthop_get_by_id(m, id, &nexthop);
 906         (void) nexthop_get_request_by_id(m, id, &req);
 907
 908         if (type == RTM_DELNEXTHOP) {
 909                 if (nexthop) {
 910                         nexthop_enter_removed(nexthop);
 911                         log_nexthop_debug(nexthop, "Forgetting removed", m);
 912                         nexthop_free(nexthop);
 913                 } else
 914                         log_nexthop_debug(&(const NextHop) { .id = id }, "Kernel removed unknown", m);
 915
 916                 if (req)
 917                         nexthop_enter_removed(req->userdata);
 918
 919                 return 0;
 920         }
 921
 922         /* If we did not know the nexthop, then save it. */
 923         if (!nexthop) {
 924                 r = nexthop_add_new(m, id, &nexthop);
 925                 if (r < 0) {
 926                         log_warning_errno(r, "Failed to add received nexthop, ignoring: %m");
 927                         return 0;
 928                 }
 929
 930                 is_new = true;
 931         }
 932
 933         /* Also update information that cannot be obtained through netlink notification. */
 934         if (req && req->waiting_reply) {
 935                 NextHop *n = ASSERT_PTR(req->userdata);
 936
 937                 nexthop->source = n->source;
 938         }
 939
 940         r = sd_rtnl_message_get_family(message, &nexthop->family);
 941         if (r < 0)
 942                 log_debug_errno(r, "rtnl: could not get nexthop family, ignoring: %m");
 943
 944         r = sd_rtnl_message_nexthop_get_protocol(message, &nexthop->protocol);
 945         if (r < 0)
 946                 log_debug_errno(r, "rtnl: could not get nexthop protocol, ignoring: %m");
 947
 948         r = sd_rtnl_message_nexthop_get_flags(message, &nexthop->flags);
 949         if (r < 0)
 950                 log_debug_errno(r, "rtnl: could not get nexthop flags, ignoring: %m");
 951
 952         r = sd_netlink_message_read_data(message, NHA_GROUP, &raw_group_size, &raw_group);
 953         if (r == -ENODATA)
 954                 nexthop->group = hashmap_free_free(nexthop->group);
 955         else if (r < 0)
 956                 log_debug_errno(r, "rtnl: could not get NHA_GROUP attribute, ignoring: %m");
 957         else
 958                 (void) nexthop_update_group(nexthop, raw_group, raw_group_size);
 959
 960         if (nexthop->family != AF_UNSPEC) {
 961                 r = netlink_message_read_in_addr_union(message, NHA_GATEWAY, nexthop->family, &nexthop->gw);
 962                 if (r == -ENODATA)
 963                         nexthop->gw = IN_ADDR_NULL;
 964                 else if (r < 0)
 965                         log_debug_errno(r, "rtnl: could not get NHA_GATEWAY attribute, ignoring: %m");
 966         }
 967
 968         r = sd_netlink_message_has_flag(message, NHA_BLACKHOLE);
 969         if (r < 0)
 970                 log_debug_errno(r, "rtnl: could not get NHA_BLACKHOLE attribute, ignoring: %m");
 971         else
 972                 nexthop->blackhole = r;
 973
 974         r = sd_netlink_message_read_u32(message, NHA_OIF, &ifindex);
 975         if (r == -ENODATA)
 976                 nexthop->ifindex = 0;
 977         else if (r < 0)
 978                 log_debug_errno(r, "rtnl: could not get NHA_OIF attribute, ignoring: %m");
 979         else if (ifindex > INT32_MAX)
 980                 log_debug_errno(r, "rtnl: received invalid NHA_OIF attribute, ignoring: %m");
 981         else
 982                 nexthop->ifindex = (int) ifindex;
 983
 984         /* All blackhole or group nexthops are managed by Manager. Note that the linux kernel does not
 985          * set NHA_OID attribute when NHA_BLACKHOLE or NHA_GROUP is set. Just for safety. */
 986         if (!nexthop_bound_to_link(nexthop))
 987                 nexthop->ifindex = 0;
 988
 989         nexthop_enter_configured(nexthop);
 990         if (req)
 991                 nexthop_enter_configured(req->userdata);
 992
 993         log_nexthop_debug(nexthop, is_new ? "Remembering" : "Received remembered", m);
 994         return 1;
 995 }
 996
 997 static int nexthop_section_verify(NextHop *nh) {
 998         if (section_is_invalid(nh->section))
 999                 return -EINVAL;
1000
1001         if (!nh->network->manager->manage_foreign_nexthops && nh->id == 0)
1002                 return log_warning_errno(SYNTHETIC_ERRNO(EINVAL),
1003                                          "%s: [NextHop] section without specifying Id= is not supported "
1004                                          "if ManageForeignNextHops=no is set in networkd.conf. "
1005                                          "Ignoring [NextHop] section from line %u.",
1006                                          nh->section->filename, nh->section->line);
1007
1008         if (!hashmap_isempty(nh->group)) {
1009                 if (in_addr_is_set(nh->family, &nh->gw))
1010                         return log_warning_errno(SYNTHETIC_ERRNO(EINVAL),
1011                                                  "%s: nexthop group cannot have gateway address. "
1012                                                  "Ignoring [NextHop] section from line %u.",
1013                                                  nh->section->filename, nh->section->line);
1014
1015                 if (nh->family != AF_UNSPEC)
1016                         return log_warning_errno(SYNTHETIC_ERRNO(EINVAL),
1017                                                  "%s: nexthop group cannot have Family= setting. "
1018                                                  "Ignoring [NextHop] section from line %u.",
1019                                                  nh->section->filename, nh->section->line);
1020
1021                 if (nh->blackhole && in_addr_is_set(nh->family, &nh->gw))
1022                         return log_warning_errno(SYNTHETIC_ERRNO(EINVAL),
1023                                                  "%s: nexthop group cannot be a blackhole. "
1024                                                  "Ignoring [NextHop] section from line %u.",
1025                                                  nh->section->filename, nh->section->line);
1026         } else if (nh->family == AF_UNSPEC)
1027                 /* When neither Family=, Gateway=, nor Group= is specified, assume IPv4. */
1028                 nh->family = AF_INET;
1029
1030         if (nh->blackhole && in_addr_is_set(nh->family, &nh->gw))
1031                 return log_warning_errno(SYNTHETIC_ERRNO(EINVAL),
1032                                          "%s: blackhole nexthop cannot have gateway address. "
1033                                          "Ignoring [NextHop] section from line %u.",
1034                                          nh->section->filename, nh->section->line);
1035
1036         if (nh->onlink < 0 && in_addr_is_set(nh->family, &nh->gw) &&
1037             ordered_hashmap_isempty(nh->network->addresses_by_section)) {
1038                 /* If no address is configured, in most cases the gateway cannot be reachable.
1039                  * TODO: we may need to improve the condition above. */
1040                 log_warning("%s: Gateway= without static address configured. "
1041                             "Enabling OnLink= option.",
1042                             nh->section->filename);
1043                 nh->onlink = true;
1044         }
1045
1046         if (nh->onlink >= 0)
1047                 SET_FLAG(nh->flags, RTNH_F_ONLINK, nh->onlink);
1048
1049         return 0;
1050 }
1051
1052 void network_drop_invalid_nexthops(Network *network) {
1053         NextHop *nh;
1054
1055         assert(network);
1056
1057         HASHMAP_FOREACH(nh, network->nexthops_by_section)
1058                 if (nexthop_section_verify(nh) < 0)
1059                         nexthop_free(nh);
1060 }
1061
1062 int config_parse_nexthop_id(
1063                 const char *unit,
1064                 const char *filename,
1065                 unsigned line,
1066                 const char *section,
1067                 unsigned section_line,
1068                 const char *lvalue,
1069                 int ltype,
1070                 const char *rvalue,
1071                 void *data,
1072                 void *userdata) {
1073
1074         _cleanup_(nexthop_free_or_set_invalidp) NextHop *n = NULL;
1075         Network *network = userdata;
1076         uint32_t id;
1077         int r;
1078
1079         assert(filename);
1080         assert(section);
1081         assert(lvalue);
1082         assert(rvalue);
1083         assert(data);
1084
1085         r = nexthop_new_static(network, filename, section_line, &n);
1086         if (r < 0)
1087                 return log_oom();
1088
1089         if (isempty(rvalue)) {
1090                 n->id = 0;
1091                 TAKE_PTR(n);
1092                 return 0;
1093         }
1094
1095         r = safe_atou32(rvalue, &id);
1096         if (r < 0) {
1097                 log_syntax(unit, LOG_WARNING, filename, line, r,
1098                            "Could not parse nexthop id \"%s\", ignoring assignment: %m", rvalue);
1099                 return 0;
1100         }
1101         if (id == 0) {
1102                 log_syntax(unit, LOG_WARNING, filename, line, 0,
1103                            "Invalid nexthop id \"%s\", ignoring assignment: %m", rvalue);
1104                 return 0;
1105         }
1106
1107         n->id = id;
1108         TAKE_PTR(n);
1109         return 0;
1110 }
1111
1112 int config_parse_nexthop_gateway(
1113                 const char *unit,
1114                 const char *filename,
1115                 unsigned line,
1116                 const char *section,
1117                 unsigned section_line,
1118                 const char *lvalue,
1119                 int ltype,
1120                 const char *rvalue,
1121                 void *data,
1122                 void *userdata) {
1123
1124         _cleanup_(nexthop_free_or_set_invalidp) NextHop *n = NULL;
1125         Network *network = userdata;
1126         int r;
1127
1128         assert(filename);
1129         assert(section);
1130         assert(lvalue);
1131         assert(rvalue);
1132         assert(data);
1133
1134         r = nexthop_new_static(network, filename, section_line, &n);
1135         if (r < 0)
1136                 return log_oom();
1137
1138         if (isempty(rvalue)) {
1139                 n->family = AF_UNSPEC;
1140                 n->gw = IN_ADDR_NULL;
1141
1142                 TAKE_PTR(n);
1143                 return 0;
1144         }
1145
1146         r = in_addr_from_string_auto(rvalue, &n->family, &n->gw);
1147         if (r < 0) {
1148                 log_syntax(unit, LOG_WARNING, filename, line, r,
1149                            "Invalid %s='%s', ignoring assignment: %m", lvalue, rvalue);
1150                 return 0;
1151         }
1152
1153         TAKE_PTR(n);
1154         return 0;
1155 }
1156
1157 int config_parse_nexthop_family(
1158                 const char *unit,
1159                 const char *filename,
1160                 unsigned line,
1161                 const char *section,
1162                 unsigned section_line,
1163                 const char *lvalue,
1164                 int ltype,
1165                 const char *rvalue,
1166                 void *data,
1167                 void *userdata) {
1168
1169         _cleanup_(nexthop_free_or_set_invalidp) NextHop *n = NULL;
1170         Network *network = userdata;
1171         AddressFamily a;
1172         int r;
1173
1174         assert(filename);
1175         assert(section);
1176         assert(lvalue);
1177         assert(rvalue);
1178         assert(data);
1179
1180         r = nexthop_new_static(network, filename, section_line, &n);
1181         if (r < 0)
1182                 return log_oom();
1183
1184         if (isempty(rvalue) &&
1185             !in_addr_is_set(n->family, &n->gw)) {
1186                 /* Accept an empty string only when Gateway= is null or not specified. */
1187                 n->family = AF_UNSPEC;
1188                 TAKE_PTR(n);
1189                 return 0;
1190         }
1191
1192         a = nexthop_address_family_from_string(rvalue);
1193         if (a < 0) {
1194                 log_syntax(unit, LOG_WARNING, filename, line, 0,
1195                            "Invalid %s='%s', ignoring assignment: %m", lvalue, rvalue);
1196                 return 0;
1197         }
1198
1199         if (in_addr_is_set(n->family, &n->gw) &&
1200             ((a == ADDRESS_FAMILY_IPV4 && n->family == AF_INET6) ||
1201              (a == ADDRESS_FAMILY_IPV6 && n->family == AF_INET))) {
1202                 log_syntax(unit, LOG_WARNING, filename, line, 0,
1203                            "Specified family '%s' conflicts with the family of the previously specified Gateway=, "
1204                            "ignoring assignment.", rvalue);
1205                 return 0;
1206         }
1207
1208         switch (a) {
1209         case ADDRESS_FAMILY_IPV4:
1210                 n->family = AF_INET;
1211                 break;
1212         case ADDRESS_FAMILY_IPV6:
1213                 n->family = AF_INET6;
1214                 break;
1215         default:
1216                 assert_not_reached();
1217         }
1218
1219         TAKE_PTR(n);
1220         return 0;
1221 }
1222
1223 int config_parse_nexthop_onlink(
1224                 const char *unit,
1225                 const char *filename,
1226                 unsigned line,
1227                 const char *section,
1228                 unsigned section_line,
1229                 const char *lvalue,
1230                 int ltype,
1231                 const char *rvalue,
1232                 void *data,
1233                 void *userdata) {
1234
1235         _cleanup_(nexthop_free_or_set_invalidp) NextHop *n = NULL;
1236         Network *network = userdata;
1237         int r;
1238
1239         assert(filename);
1240         assert(section);
1241         assert(lvalue);
1242         assert(rvalue);
1243         assert(data);
1244
1245         r = nexthop_new_static(network, filename, section_line, &n);
1246         if (r < 0)
1247                 return log_oom();
1248
1249         r = parse_tristate(rvalue, &n->onlink);
1250         if (r < 0) {
1251                 log_syntax(unit, LOG_WARNING, filename, line, r,
1252                            "Failed to parse %s=, ignoring assignment: %s", lvalue, rvalue);
1253                 return 0;
1254         }
1255
1256         TAKE_PTR(n);
1257         return 0;
1258 }
1259
1260 int config_parse_nexthop_blackhole(
1261                 const char *unit,
1262                 const char *filename,
1263                 unsigned line,
1264                 const char *section,
1265                 unsigned section_line,
1266                 const char *lvalue,
1267                 int ltype,
1268                 const char *rvalue,
1269                 void *data,
1270                 void *userdata) {
1271
1272         _cleanup_(nexthop_free_or_set_invalidp) NextHop *n = NULL;
1273         Network *network = userdata;
1274         int r;
1275
1276         assert(filename);
1277         assert(section);
1278         assert(lvalue);
1279         assert(rvalue);
1280         assert(data);
1281
1282         r = nexthop_new_static(network, filename, section_line, &n);
1283         if (r < 0)
1284                 return log_oom();
1285
1286         r = parse_boolean(rvalue);
1287         if (r < 0) {
1288                 log_syntax(unit, LOG_WARNING, filename, line, r,
1289                            "Failed to parse %s=, ignoring assignment: %s", lvalue, rvalue);
1290                 return 0;
1291         }
1292
1293         n->blackhole = r;
1294
1295         TAKE_PTR(n);
1296         return 0;
1297 }
1298
1299 int config_parse_nexthop_group(
1300                 const char *unit,
1301                 const char *filename,
1302                 unsigned line,
1303                 const char *section,
1304                 unsigned section_line,
1305                 const char *lvalue,
1306                 int ltype,
1307                 const char *rvalue,
1308                 void *data,
1309                 void *userdata) {
1310
1311         _cleanup_(nexthop_free_or_set_invalidp) NextHop *n = NULL;
1312         Network *network = userdata;
1313         int r;
1314
1315         assert(filename);
1316         assert(section);
1317         assert(lvalue);
1318         assert(rvalue);
1319         assert(data);
1320
1321         r = nexthop_new_static(network, filename, section_line, &n);
1322         if (r < 0)
1323                 return log_oom();
1324
1325         if (isempty(rvalue)) {
1326                 n->group = hashmap_free_free(n->group);
1327                 TAKE_PTR(n);
1328                 return 0;
1329         }
1330
1331         for (const char *p = rvalue;;) {
1332                 _cleanup_free_ struct nexthop_grp *nhg = NULL;
1333                 _cleanup_free_ char *word = NULL;
1334                 uint32_t w;
1335                 char *sep;
1336
1337                 r = extract_first_word(&p, &word, NULL, 0);
1338                 if (r == -ENOMEM)
1339                         return log_oom();
1340                 if (r < 0) {
1341                         log_syntax(unit, LOG_WARNING, filename, line, r,
1342                                    "Invalid %s=, ignoring assignment: %s", lvalue, rvalue);
1343                         return 0;
1344                 }
1345                 if (r == 0)
1346                         break;
1347
1348                 nhg = new0(struct nexthop_grp, 1);
1349                 if (!nhg)
1350                         return log_oom();
1351
1352                 sep = strchr(word, ':');
1353                 if (sep) {
1354                         *sep++ = '\0';
1355                         r = safe_atou32(sep, &w);
1356                         if (r < 0) {
1357                                 log_syntax(unit, LOG_WARNING, filename, line, r,
1358                                            "Failed to parse weight for nexthop group, ignoring assignment: %s:%s",
1359                                            word, sep);
1360                                 continue;
1361                         }
1362                         if (w == 0 || w > 256) {
1363                                 log_syntax(unit, LOG_WARNING, filename, line, 0,
1364                                            "Invalid weight for nexthop group, ignoring assignment: %s:%s",
1365                                            word, sep);
1366                                 continue;
1367                         }
1368                         /* See comments in config_parse_multipath_route(). */
1369                         nhg->weight = w - 1;
1370                 }
1371
1372                 r = safe_atou32(word, &nhg->id);
1373                 if (r < 0) {
1374                         log_syntax(unit, LOG_WARNING, filename, line, r,
1375                                    "Failed to parse nexthop ID in %s=, ignoring assignment: %s%s%s",
1376                                    lvalue, word, sep ? ":" : "", strempty(sep));
1377                         continue;
1378                 }
1379                 if (nhg->id == 0) {
1380                         log_syntax(unit, LOG_WARNING, filename, line, 0,
1381                                    "Nexthop ID in %s= must be positive, ignoring assignment: %s%s%s",
1382                                    lvalue, word, sep ? ":" : "", strempty(sep));
1383                         continue;
1384                 }
1385
1386                 r = hashmap_ensure_put(&n->group, NULL, UINT32_TO_PTR(nhg->id), nhg);
1387                 if (r == -ENOMEM)
1388                         return log_oom();
1389                 if (r == -EEXIST) {
1390                         log_syntax(unit, LOG_WARNING, filename, line, r,
1391                                    "Nexthop ID %"PRIu32" is specified multiple times in %s=, ignoring assignment: %s%s%s",
1392                                    nhg->id, lvalue, word, sep ? ":" : "", strempty(sep));
1393                         continue;
1394                 }
1395                 assert(r > 0);
1396                 TAKE_PTR(nhg);
1397         }
1398
1399         TAKE_PTR(n);
1400         return 0;
1401 }