1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * MLO link handling 4 * 5 * Copyright (C) 2022-2025 Intel Corporation 6 */ 7 #include <linux/slab.h> 8 #include <linux/kernel.h> 9 #include <net/mac80211.h> 10 #include "ieee80211_i.h" 11 #include "driver-ops.h" 12 #include "key.h" 13 #include "debugfs_netdev.h" 14 15 static void ieee80211_update_apvlan_links(struct ieee80211_sub_if_data *sdata) 16 { 17 struct ieee80211_sub_if_data *vlan; 18 struct ieee80211_link_data *link; 19 u16 ap_bss_links = sdata->vif.valid_links; 20 u16 new_links, vlan_links; 21 unsigned long add; 22 23 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) { 24 int link_id; 25 26 /* No support for 4addr with MLO yet */ 27 if (vlan->wdev.use_4addr) 28 return; 29 30 vlan_links = vlan->vif.valid_links; 31 32 new_links = ap_bss_links; 33 34 add = new_links & ~vlan_links; 35 if (!add) 36 continue; 37 38 ieee80211_vif_set_links(vlan, add, 0); 39 40 for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) { 41 link = sdata_dereference(vlan->link[link_id], vlan); 42 ieee80211_link_vlan_copy_chanctx(link); 43 } 44 } 45 } 46 47 void ieee80211_apvlan_link_setup(struct ieee80211_sub_if_data *sdata) 48 { 49 struct ieee80211_sub_if_data *ap_bss = container_of(sdata->bss, 50 struct ieee80211_sub_if_data, u.ap); 51 u16 new_links = ap_bss->vif.valid_links; 52 unsigned long add; 53 int link_id; 54 55 if (!ap_bss->vif.valid_links) 56 return; 57 58 add = new_links; 59 for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) { 60 sdata->wdev.valid_links |= BIT(link_id); 61 ether_addr_copy(sdata->wdev.links[link_id].addr, 62 ap_bss->wdev.links[link_id].addr); 63 } 64 65 ieee80211_vif_set_links(sdata, new_links, 0); 66 } 67 68 void ieee80211_apvlan_link_clear(struct ieee80211_sub_if_data *sdata) 69 { 70 if (!sdata->wdev.valid_links) 71 return; 72 73 sdata->wdev.valid_links = 0; 74 ieee80211_vif_clear_links(sdata); 75 } 76 77 void ieee80211_link_setup(struct ieee80211_link_data *link) 78 { 79 if (link->sdata->vif.type == NL80211_IFTYPE_STATION) 80 ieee80211_mgd_setup_link(link); 81 } 82 83 void ieee80211_link_init(struct ieee80211_sub_if_data *sdata, 84 int link_id, 85 struct ieee80211_link_data *link, 86 struct ieee80211_bss_conf *link_conf) 87 { 88 bool deflink = link_id < 0; 89 90 if (link_id < 0) 91 link_id = 0; 92 93 if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) { 94 struct ieee80211_sub_if_data *ap_bss; 95 struct ieee80211_bss_conf *ap_bss_conf; 96 97 ap_bss = container_of(sdata->bss, 98 struct ieee80211_sub_if_data, u.ap); 99 ap_bss_conf = sdata_dereference(ap_bss->vif.link_conf[link_id], 100 ap_bss); 101 memcpy(link_conf, ap_bss_conf, sizeof(*link_conf)); 102 } 103 104 link->sdata = sdata; 105 link->link_id = link_id; 106 link->conf = link_conf; 107 link_conf->link_id = link_id; 108 link_conf->vif = &sdata->vif; 109 link->ap_power_level = IEEE80211_UNSET_POWER_LEVEL; 110 link->user_power_level = sdata->local->user_power_level; 111 link_conf->txpower = INT_MIN; 112 113 wiphy_work_init(&link->csa.finalize_work, 114 ieee80211_csa_finalize_work); 115 wiphy_work_init(&link->color_change_finalize_work, 116 ieee80211_color_change_finalize_work); 117 wiphy_delayed_work_init(&link->color_collision_detect_work, 118 ieee80211_color_collision_detection_work); 119 wiphy_delayed_work_init(&link->dfs_cac_timer_work, 120 ieee80211_dfs_cac_timer_work); 121 122 if (!deflink) { 123 switch (sdata->vif.type) { 124 case NL80211_IFTYPE_AP: 125 case NL80211_IFTYPE_AP_VLAN: 126 ether_addr_copy(link_conf->addr, 127 sdata->wdev.links[link_id].addr); 128 link_conf->bssid = link_conf->addr; 129 WARN_ON(!(sdata->wdev.valid_links & BIT(link_id))); 130 break; 131 case NL80211_IFTYPE_STATION: 132 /* station sets the bssid in ieee80211_mgd_setup_link */ 133 break; 134 default: 135 WARN_ON(1); 136 } 137 138 ieee80211_link_debugfs_add(link); 139 } 140 141 rcu_assign_pointer(sdata->vif.link_conf[link_id], link_conf); 142 rcu_assign_pointer(sdata->link[link_id], link); 143 } 144 145 void ieee80211_link_stop(struct ieee80211_link_data *link) 146 { 147 if (link->sdata->vif.type == NL80211_IFTYPE_STATION) 148 ieee80211_mgd_stop_link(link); 149 150 wiphy_delayed_work_cancel(link->sdata->local->hw.wiphy, 151 &link->color_collision_detect_work); 152 wiphy_work_cancel(link->sdata->local->hw.wiphy, 153 &link->color_change_finalize_work); 154 wiphy_work_cancel(link->sdata->local->hw.wiphy, 155 &link->csa.finalize_work); 156 157 if (link->sdata->wdev.links[link->link_id].cac_started) { 158 wiphy_delayed_work_cancel(link->sdata->local->hw.wiphy, 159 &link->dfs_cac_timer_work); 160 cfg80211_cac_event(link->sdata->dev, 161 &link->conf->chanreq.oper, 162 NL80211_RADAR_CAC_ABORTED, 163 GFP_KERNEL, link->link_id); 164 } 165 166 ieee80211_link_release_channel(link); 167 } 168 169 struct link_container { 170 struct ieee80211_link_data data; 171 struct ieee80211_bss_conf conf; 172 }; 173 174 static void ieee80211_tear_down_links(struct ieee80211_sub_if_data *sdata, 175 struct link_container **links, u16 mask) 176 { 177 struct ieee80211_link_data *link; 178 LIST_HEAD(keys); 179 unsigned int link_id; 180 181 for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++) { 182 if (!(mask & BIT(link_id))) 183 continue; 184 link = &links[link_id]->data; 185 if (link_id == 0 && !link) 186 link = &sdata->deflink; 187 if (WARN_ON(!link)) 188 continue; 189 ieee80211_remove_link_keys(link, &keys); 190 ieee80211_link_debugfs_remove(link); 191 ieee80211_link_stop(link); 192 } 193 194 synchronize_rcu(); 195 196 ieee80211_free_key_list(sdata->local, &keys); 197 } 198 199 static void ieee80211_free_links(struct ieee80211_sub_if_data *sdata, 200 struct link_container **links) 201 { 202 unsigned int link_id; 203 204 for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++) 205 kfree(links[link_id]); 206 } 207 208 static int ieee80211_check_dup_link_addrs(struct ieee80211_sub_if_data *sdata) 209 { 210 unsigned int i, j; 211 212 for (i = 0; i < IEEE80211_MLD_MAX_NUM_LINKS; i++) { 213 struct ieee80211_link_data *link1; 214 215 link1 = sdata_dereference(sdata->link[i], sdata); 216 if (!link1) 217 continue; 218 for (j = i + 1; j < IEEE80211_MLD_MAX_NUM_LINKS; j++) { 219 struct ieee80211_link_data *link2; 220 221 link2 = sdata_dereference(sdata->link[j], sdata); 222 if (!link2) 223 continue; 224 225 if (ether_addr_equal(link1->conf->addr, 226 link2->conf->addr)) 227 return -EALREADY; 228 } 229 } 230 231 return 0; 232 } 233 234 static void ieee80211_set_vif_links_bitmaps(struct ieee80211_sub_if_data *sdata, 235 u16 valid_links, u16 dormant_links) 236 { 237 sdata->vif.valid_links = valid_links; 238 sdata->vif.dormant_links = dormant_links; 239 240 if (!valid_links || 241 WARN((~valid_links & dormant_links) || 242 !(valid_links & ~dormant_links), 243 "Invalid links: valid=0x%x, dormant=0x%x", 244 valid_links, dormant_links)) { 245 sdata->vif.active_links = 0; 246 sdata->vif.dormant_links = 0; 247 return; 248 } 249 250 switch (sdata->vif.type) { 251 case NL80211_IFTYPE_AP: 252 case NL80211_IFTYPE_AP_VLAN: 253 /* in an AP all links are always active */ 254 sdata->vif.active_links = valid_links; 255 256 /* AP links are not expected to be disabled */ 257 WARN_ON(dormant_links); 258 break; 259 case NL80211_IFTYPE_STATION: 260 if (sdata->vif.active_links) 261 break; 262 sdata->vif.active_links = valid_links & ~dormant_links; 263 WARN_ON(hweight16(sdata->vif.active_links) > 1); 264 break; 265 default: 266 WARN_ON(1); 267 } 268 } 269 270 static int ieee80211_vif_update_links(struct ieee80211_sub_if_data *sdata, 271 struct link_container **to_free, 272 u16 new_links, u16 dormant_links) 273 { 274 u16 old_links = sdata->vif.valid_links; 275 u16 old_active = sdata->vif.active_links; 276 unsigned long add = new_links & ~old_links; 277 unsigned long rem = old_links & ~new_links; 278 unsigned int link_id; 279 int ret; 280 struct link_container *links[IEEE80211_MLD_MAX_NUM_LINKS] = {}, *link; 281 struct ieee80211_bss_conf *old[IEEE80211_MLD_MAX_NUM_LINKS]; 282 struct ieee80211_link_data *old_data[IEEE80211_MLD_MAX_NUM_LINKS]; 283 bool use_deflink = old_links == 0; /* set for error case */ 284 285 lockdep_assert_wiphy(sdata->local->hw.wiphy); 286 287 memset(to_free, 0, sizeof(links)); 288 289 if (old_links == new_links && dormant_links == sdata->vif.dormant_links) 290 return 0; 291 292 /* if there were no old links, need to clear the pointers to deflink */ 293 if (!old_links) 294 rem |= BIT(0); 295 296 /* allocate new link structures first */ 297 for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) { 298 link = kzalloc(sizeof(*link), GFP_KERNEL); 299 if (!link) { 300 ret = -ENOMEM; 301 goto free; 302 } 303 links[link_id] = link; 304 } 305 306 /* keep track of the old pointers for the driver */ 307 BUILD_BUG_ON(sizeof(old) != sizeof(sdata->vif.link_conf)); 308 memcpy(old, sdata->vif.link_conf, sizeof(old)); 309 /* and for us in error cases */ 310 BUILD_BUG_ON(sizeof(old_data) != sizeof(sdata->link)); 311 memcpy(old_data, sdata->link, sizeof(old_data)); 312 313 /* grab old links to free later */ 314 for_each_set_bit(link_id, &rem, IEEE80211_MLD_MAX_NUM_LINKS) { 315 if (rcu_access_pointer(sdata->link[link_id]) != &sdata->deflink) { 316 /* 317 * we must have allocated the data through this path so 318 * we know we can free both at the same time 319 */ 320 to_free[link_id] = container_of(rcu_access_pointer(sdata->link[link_id]), 321 typeof(*links[link_id]), 322 data); 323 } 324 325 RCU_INIT_POINTER(sdata->link[link_id], NULL); 326 RCU_INIT_POINTER(sdata->vif.link_conf[link_id], NULL); 327 } 328 329 if (!old_links) 330 ieee80211_debugfs_recreate_netdev(sdata, true); 331 332 /* link them into data structures */ 333 for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) { 334 WARN_ON(!use_deflink && 335 rcu_access_pointer(sdata->link[link_id]) == &sdata->deflink); 336 337 link = links[link_id]; 338 ieee80211_link_init(sdata, link_id, &link->data, &link->conf); 339 ieee80211_link_setup(&link->data); 340 } 341 342 if (new_links == 0) 343 ieee80211_link_init(sdata, -1, &sdata->deflink, 344 &sdata->vif.bss_conf); 345 346 ret = ieee80211_check_dup_link_addrs(sdata); 347 if (!ret) { 348 /* for keys we will not be able to undo this */ 349 ieee80211_tear_down_links(sdata, to_free, rem); 350 351 ieee80211_set_vif_links_bitmaps(sdata, new_links, dormant_links); 352 353 /* tell the driver */ 354 if (sdata->vif.type != NL80211_IFTYPE_AP_VLAN) 355 ret = drv_change_vif_links(sdata->local, sdata, 356 old_links & old_active, 357 new_links & sdata->vif.active_links, 358 old); 359 if (!new_links) 360 ieee80211_debugfs_recreate_netdev(sdata, false); 361 362 if (sdata->vif.type == NL80211_IFTYPE_AP) 363 ieee80211_update_apvlan_links(sdata); 364 } 365 366 /* 367 * Ignore errors if we are only removing links as removal should 368 * always succeed 369 */ 370 if (!new_links) 371 ret = 0; 372 373 if (ret) { 374 /* restore config */ 375 memcpy(sdata->link, old_data, sizeof(old_data)); 376 memcpy(sdata->vif.link_conf, old, sizeof(old)); 377 ieee80211_set_vif_links_bitmaps(sdata, old_links, dormant_links); 378 /* and free (only) the newly allocated links */ 379 memset(to_free, 0, sizeof(links)); 380 goto free; 381 } 382 383 /* use deflink/bss_conf again if and only if there are no more links */ 384 use_deflink = new_links == 0; 385 386 goto deinit; 387 free: 388 /* if we failed during allocation, only free all */ 389 for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++) { 390 kfree(links[link_id]); 391 links[link_id] = NULL; 392 } 393 deinit: 394 if (use_deflink) 395 ieee80211_link_init(sdata, -1, &sdata->deflink, 396 &sdata->vif.bss_conf); 397 return ret; 398 } 399 400 int ieee80211_vif_set_links(struct ieee80211_sub_if_data *sdata, 401 u16 new_links, u16 dormant_links) 402 { 403 struct link_container *links[IEEE80211_MLD_MAX_NUM_LINKS]; 404 int ret; 405 406 ret = ieee80211_vif_update_links(sdata, links, new_links, 407 dormant_links); 408 ieee80211_free_links(sdata, links); 409 410 return ret; 411 } 412 413 static int _ieee80211_set_active_links(struct ieee80211_sub_if_data *sdata, 414 u16 active_links) 415 { 416 struct ieee80211_bss_conf *link_confs[IEEE80211_MLD_MAX_NUM_LINKS]; 417 struct ieee80211_local *local = sdata->local; 418 u16 old_active = sdata->vif.active_links; 419 unsigned long rem = old_active & ~active_links; 420 unsigned long add = active_links & ~old_active; 421 struct sta_info *sta; 422 unsigned int link_id; 423 int ret, i; 424 425 if (!ieee80211_sdata_running(sdata)) 426 return -ENETDOWN; 427 428 if (sdata->vif.type != NL80211_IFTYPE_STATION) 429 return -EINVAL; 430 431 if (active_links & ~ieee80211_vif_usable_links(&sdata->vif)) 432 return -EINVAL; 433 434 /* nothing to do */ 435 if (old_active == active_links) 436 return 0; 437 438 for (i = 0; i < IEEE80211_MLD_MAX_NUM_LINKS; i++) 439 link_confs[i] = sdata_dereference(sdata->vif.link_conf[i], 440 sdata); 441 442 if (add) { 443 sdata->vif.active_links |= active_links; 444 ret = drv_change_vif_links(local, sdata, 445 old_active, 446 sdata->vif.active_links, 447 link_confs); 448 if (ret) { 449 sdata->vif.active_links = old_active; 450 return ret; 451 } 452 } 453 454 for_each_set_bit(link_id, &rem, IEEE80211_MLD_MAX_NUM_LINKS) { 455 struct ieee80211_link_data *link; 456 457 link = sdata_dereference(sdata->link[link_id], sdata); 458 459 ieee80211_teardown_tdls_peers(link); 460 461 __ieee80211_link_release_channel(link, true); 462 463 /* 464 * If CSA is (still) active while the link is deactivated, 465 * just schedule the channel switch work for the time we 466 * had previously calculated, and we'll take the process 467 * from there. 468 */ 469 if (link->conf->csa_active) 470 wiphy_hrtimer_work_queue(local->hw.wiphy, 471 &link->u.mgd.csa.switch_work, 472 link->u.mgd.csa.time - 473 ktime_get_boottime()); 474 } 475 476 for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) { 477 struct ieee80211_link_data *link; 478 479 link = sdata_dereference(sdata->link[link_id], sdata); 480 481 /* 482 * This call really should not fail. Unfortunately, it appears 483 * that this may happen occasionally with some drivers. Should 484 * it happen, we are stuck in a bad place as going backwards is 485 * not really feasible. 486 * 487 * So lets just tell link_use_channel that it must not fail to 488 * assign the channel context (from mac80211's perspective) and 489 * assume the driver is going to trigger a recovery flow if it 490 * had a failure. 491 * That really is not great nor guaranteed to work. But at least 492 * the internal mac80211 state remains consistent and there is 493 * a chance that we can recover. 494 */ 495 ret = _ieee80211_link_use_channel(link, 496 &link->conf->chanreq, 497 IEEE80211_CHANCTX_SHARED, 498 true); 499 WARN_ON_ONCE(ret); 500 501 /* 502 * inform about the link info changed parameters after all 503 * stations are also added 504 */ 505 } 506 507 list_for_each_entry(sta, &local->sta_list, list) { 508 if (sdata != sta->sdata) 509 continue; 510 511 /* this is very temporary, but do it anyway */ 512 __ieee80211_sta_recalc_aggregates(sta, 513 old_active | active_links); 514 515 ret = drv_change_sta_links(local, sdata, &sta->sta, 516 old_active, 517 old_active | active_links); 518 WARN_ON_ONCE(ret); 519 } 520 521 ret = ieee80211_key_switch_links(sdata, rem, add); 522 WARN_ON_ONCE(ret); 523 524 list_for_each_entry(sta, &local->sta_list, list) { 525 if (sdata != sta->sdata) 526 continue; 527 528 __ieee80211_sta_recalc_aggregates(sta, active_links); 529 530 ret = drv_change_sta_links(local, sdata, &sta->sta, 531 old_active | active_links, 532 active_links); 533 WARN_ON_ONCE(ret); 534 535 /* 536 * Do it again, just in case - the driver might very 537 * well have called ieee80211_sta_recalc_aggregates() 538 * from there when filling in the new links, which 539 * would set it wrong since the vif's active links are 540 * not switched yet... 541 */ 542 __ieee80211_sta_recalc_aggregates(sta, active_links); 543 } 544 545 for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) { 546 struct ieee80211_link_data *link; 547 548 link = sdata_dereference(sdata->link[link_id], sdata); 549 550 ieee80211_mgd_set_link_qos_params(link); 551 ieee80211_link_info_change_notify(sdata, link, 552 BSS_CHANGED_ERP_CTS_PROT | 553 BSS_CHANGED_ERP_PREAMBLE | 554 BSS_CHANGED_ERP_SLOT | 555 BSS_CHANGED_HT | 556 BSS_CHANGED_BASIC_RATES | 557 BSS_CHANGED_BSSID | 558 BSS_CHANGED_CQM | 559 BSS_CHANGED_QOS | 560 BSS_CHANGED_TXPOWER | 561 BSS_CHANGED_BANDWIDTH | 562 BSS_CHANGED_TWT | 563 BSS_CHANGED_HE_OBSS_PD | 564 BSS_CHANGED_HE_BSS_COLOR); 565 } 566 567 old_active = sdata->vif.active_links; 568 sdata->vif.active_links = active_links; 569 570 if (rem) { 571 ret = drv_change_vif_links(local, sdata, old_active, 572 active_links, link_confs); 573 WARN_ON_ONCE(ret); 574 } 575 576 return 0; 577 } 578 579 int ieee80211_set_active_links(struct ieee80211_vif *vif, u16 active_links) 580 { 581 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 582 struct ieee80211_local *local = sdata->local; 583 u16 old_active; 584 int ret; 585 586 lockdep_assert_wiphy(local->hw.wiphy); 587 588 if (WARN_ON(!active_links)) 589 return -EINVAL; 590 591 old_active = sdata->vif.active_links; 592 if (old_active == active_links) 593 return 0; 594 595 if (!drv_can_activate_links(local, sdata, active_links)) 596 return -EINVAL; 597 598 if (old_active & active_links) { 599 /* 600 * if there's at least one link that stays active across 601 * the change then switch to it (to those) first, and 602 * then enable the additional links 603 */ 604 ret = _ieee80211_set_active_links(sdata, 605 old_active & active_links); 606 if (!ret) 607 ret = _ieee80211_set_active_links(sdata, active_links); 608 } else { 609 /* otherwise switch directly */ 610 ret = _ieee80211_set_active_links(sdata, active_links); 611 } 612 613 return ret; 614 } 615 EXPORT_SYMBOL_GPL(ieee80211_set_active_links); 616 617 void ieee80211_set_active_links_async(struct ieee80211_vif *vif, 618 u16 active_links) 619 { 620 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 621 622 if (WARN_ON(!active_links)) 623 return; 624 625 if (!ieee80211_sdata_running(sdata)) 626 return; 627 628 if (sdata->vif.type != NL80211_IFTYPE_STATION) 629 return; 630 631 if (active_links & ~ieee80211_vif_usable_links(&sdata->vif)) 632 return; 633 634 /* nothing to do */ 635 if (sdata->vif.active_links == active_links) 636 return; 637 638 sdata->desired_active_links = active_links; 639 wiphy_work_queue(sdata->local->hw.wiphy, &sdata->activate_links_work); 640 } 641 EXPORT_SYMBOL_GPL(ieee80211_set_active_links_async); 642