1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * net-sysfs.c - network device class and attributes 4 * 5 * Copyright (c) 2003 Stephen Hemminger <shemminger@osdl.org> 6 */ 7 8 #include <linux/capability.h> 9 #include <linux/kernel.h> 10 #include <linux/netdevice.h> 11 #include <linux/if_arp.h> 12 #include <linux/slab.h> 13 #include <linux/sched/signal.h> 14 #include <linux/sched/isolation.h> 15 #include <linux/nsproxy.h> 16 #include <net/sock.h> 17 #include <net/net_namespace.h> 18 #include <linux/rtnetlink.h> 19 #include <linux/vmalloc.h> 20 #include <linux/export.h> 21 #include <linux/jiffies.h> 22 #include <linux/pm_runtime.h> 23 #include <linux/of.h> 24 #include <linux/of_net.h> 25 #include <linux/cpu.h> 26 #include <net/netdev_lock.h> 27 #include <net/netdev_rx_queue.h> 28 #include <net/rps.h> 29 30 #include "dev.h" 31 #include "net-sysfs.h" 32 33 #ifdef CONFIG_SYSFS 34 static const char fmt_hex[] = "%#x\n"; 35 static const char fmt_dec[] = "%d\n"; 36 static const char fmt_uint[] = "%u\n"; 37 static const char fmt_ulong[] = "%lu\n"; 38 static const char fmt_u64[] = "%llu\n"; 39 40 /* Caller holds RTNL, netdev->lock or RCU */ 41 static inline int dev_isalive(const struct net_device *dev) 42 { 43 return READ_ONCE(dev->reg_state) <= NETREG_REGISTERED; 44 } 45 46 /* There is a possible ABBA deadlock between rtnl_lock and kernfs_node->active, 47 * when unregistering a net device and accessing associated sysfs files. The 48 * potential deadlock is as follow: 49 * 50 * CPU 0 CPU 1 51 * 52 * rtnl_lock vfs_read 53 * unregister_netdevice_many kernfs_seq_start 54 * device_del / kobject_put kernfs_get_active (kn->active++) 55 * kernfs_drain sysfs_kf_seq_show 56 * wait_event( rtnl_lock 57 * kn->active == KN_DEACTIVATED_BIAS) -> waits on CPU 0 to release 58 * -> waits on CPU 1 to decrease kn->active the rtnl lock. 59 * 60 * The historical fix was to use rtnl_trylock with restart_syscall to bail out 61 * of sysfs operations when the lock couldn't be taken. This fixed the above 62 * issue as it allowed CPU 1 to bail out of the ABBA situation. 63 * 64 * But it came with performances issues, as syscalls are being restarted in 65 * loops when there was contention on the rtnl lock, with huge slow downs in 66 * specific scenarios (e.g. lots of virtual interfaces created and userspace 67 * daemons querying their attributes). 68 * 69 * The idea below is to bail out of the active kernfs_node protection 70 * (kn->active) while trying to take the rtnl lock. 71 * 72 * This replaces rtnl_lock() and still has to be used with rtnl_unlock(). The 73 * net device is guaranteed to be alive if this returns successfully. 74 */ 75 static int sysfs_rtnl_lock(struct kobject *kobj, struct attribute *attr, 76 struct net_device *ndev) 77 { 78 struct kernfs_node *kn; 79 int ret = 0; 80 81 /* First, we hold a reference to the net device as the unregistration 82 * path might run in parallel. This will ensure the net device and the 83 * associated sysfs objects won't be freed while we try to take the rtnl 84 * lock. 85 */ 86 dev_hold(ndev); 87 /* sysfs_break_active_protection was introduced to allow self-removal of 88 * devices and their associated sysfs files by bailing out of the 89 * sysfs/kernfs protection. We do this here to allow the unregistration 90 * path to complete in parallel. The following takes a reference on the 91 * kobject and the kernfs_node being accessed. 92 * 93 * This works because we hold a reference onto the net device and the 94 * unregistration path will wait for us eventually in netdev_run_todo 95 * (outside an rtnl lock section). 96 */ 97 kn = sysfs_break_active_protection(kobj, attr); 98 /* We can now try to take the rtnl lock. This can't deadlock us as the 99 * unregistration path is able to drain sysfs files (kernfs_node) thanks 100 * to the above dance. 101 */ 102 if (rtnl_lock_interruptible()) { 103 ret = -ERESTARTSYS; 104 goto unbreak; 105 } 106 /* Check dismantle on the device hasn't started, otherwise deny the 107 * operation. 108 */ 109 if (!dev_isalive(ndev)) { 110 rtnl_unlock(); 111 ret = -ENODEV; 112 goto unbreak; 113 } 114 /* We are now sure the device dismantle hasn't started nor that it can 115 * start before we exit the locking section as we hold the rtnl lock. 116 * There's no need to keep unbreaking the sysfs protection nor to hold 117 * a net device reference from that point; that was only needed to take 118 * the rtnl lock. 119 */ 120 unbreak: 121 sysfs_unbreak_active_protection(kn); 122 dev_put(ndev); 123 124 return ret; 125 } 126 127 /* use same locking rules as GIF* ioctl's */ 128 static ssize_t netdev_show(const struct device *dev, 129 struct device_attribute *attr, char *buf, 130 ssize_t (*format)(const struct net_device *, char *)) 131 { 132 struct net_device *ndev = to_net_dev(dev); 133 ssize_t ret = -EINVAL; 134 135 rcu_read_lock(); 136 if (dev_isalive(ndev)) 137 ret = (*format)(ndev, buf); 138 rcu_read_unlock(); 139 140 return ret; 141 } 142 143 /* generate a show function for simple field */ 144 #define NETDEVICE_SHOW(field, format_string) \ 145 static ssize_t format_##field(const struct net_device *dev, char *buf) \ 146 { \ 147 return sysfs_emit(buf, format_string, READ_ONCE(dev->field)); \ 148 } \ 149 static ssize_t field##_show(struct device *dev, \ 150 struct device_attribute *attr, char *buf) \ 151 { \ 152 return netdev_show(dev, attr, buf, format_##field); \ 153 } \ 154 155 #define NETDEVICE_SHOW_RO(field, format_string) \ 156 NETDEVICE_SHOW(field, format_string); \ 157 static DEVICE_ATTR_RO(field) 158 159 #define NETDEVICE_SHOW_RW(field, format_string) \ 160 NETDEVICE_SHOW(field, format_string); \ 161 static DEVICE_ATTR_RW(field) 162 163 /* use same locking and permission rules as SIF* ioctl's */ 164 static ssize_t netdev_store(struct device *dev, struct device_attribute *attr, 165 const char *buf, size_t len, 166 int (*set)(struct net_device *, unsigned long)) 167 { 168 struct net_device *netdev = to_net_dev(dev); 169 struct net *net = dev_net(netdev); 170 unsigned long new; 171 int ret; 172 173 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 174 return -EPERM; 175 176 ret = kstrtoul(buf, 0, &new); 177 if (ret) 178 goto err; 179 180 ret = sysfs_rtnl_lock(&dev->kobj, &attr->attr, netdev); 181 if (ret) 182 goto err; 183 184 ret = (*set)(netdev, new); 185 if (ret == 0) 186 ret = len; 187 188 rtnl_unlock(); 189 err: 190 return ret; 191 } 192 193 /* Same as netdev_store() but takes netdev_lock() instead of rtnl_lock() */ 194 static ssize_t 195 netdev_lock_store(struct device *dev, struct device_attribute *attr, 196 const char *buf, size_t len, 197 int (*set)(struct net_device *, unsigned long)) 198 { 199 struct net_device *netdev = to_net_dev(dev); 200 struct net *net = dev_net(netdev); 201 unsigned long new; 202 int ret; 203 204 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 205 return -EPERM; 206 207 ret = kstrtoul(buf, 0, &new); 208 if (ret) 209 return ret; 210 211 netdev_lock(netdev); 212 213 if (dev_isalive(netdev)) { 214 ret = (*set)(netdev, new); 215 if (ret == 0) 216 ret = len; 217 } 218 netdev_unlock(netdev); 219 220 return ret; 221 } 222 223 NETDEVICE_SHOW_RO(dev_id, fmt_hex); 224 NETDEVICE_SHOW_RO(dev_port, fmt_dec); 225 NETDEVICE_SHOW_RO(addr_assign_type, fmt_dec); 226 NETDEVICE_SHOW_RO(addr_len, fmt_dec); 227 NETDEVICE_SHOW_RO(ifindex, fmt_dec); 228 NETDEVICE_SHOW_RO(type, fmt_dec); 229 NETDEVICE_SHOW_RO(link_mode, fmt_dec); 230 231 static ssize_t iflink_show(struct device *dev, struct device_attribute *attr, 232 char *buf) 233 { 234 struct net_device *ndev = to_net_dev(dev); 235 236 return sysfs_emit(buf, fmt_dec, dev_get_iflink(ndev)); 237 } 238 static DEVICE_ATTR_RO(iflink); 239 240 static ssize_t format_name_assign_type(const struct net_device *dev, char *buf) 241 { 242 return sysfs_emit(buf, fmt_dec, READ_ONCE(dev->name_assign_type)); 243 } 244 245 static ssize_t name_assign_type_show(struct device *dev, 246 struct device_attribute *attr, 247 char *buf) 248 { 249 struct net_device *ndev = to_net_dev(dev); 250 ssize_t ret = -EINVAL; 251 252 if (READ_ONCE(ndev->name_assign_type) != NET_NAME_UNKNOWN) 253 ret = netdev_show(dev, attr, buf, format_name_assign_type); 254 255 return ret; 256 } 257 static DEVICE_ATTR_RO(name_assign_type); 258 259 /* use same locking rules as GIFHWADDR ioctl's (dev_get_mac_address()) */ 260 static ssize_t address_show(struct device *dev, struct device_attribute *attr, 261 char *buf) 262 { 263 struct net_device *ndev = to_net_dev(dev); 264 ssize_t ret = -EINVAL; 265 266 down_read(&dev_addr_sem); 267 268 rcu_read_lock(); 269 if (dev_isalive(ndev)) 270 ret = sysfs_format_mac(buf, ndev->dev_addr, ndev->addr_len); 271 rcu_read_unlock(); 272 273 up_read(&dev_addr_sem); 274 return ret; 275 } 276 static DEVICE_ATTR_RO(address); 277 278 static ssize_t broadcast_show(struct device *dev, 279 struct device_attribute *attr, char *buf) 280 { 281 struct net_device *ndev = to_net_dev(dev); 282 int ret = -EINVAL; 283 284 rcu_read_lock(); 285 if (dev_isalive(ndev)) 286 ret = sysfs_format_mac(buf, ndev->broadcast, ndev->addr_len); 287 rcu_read_unlock(); 288 return ret; 289 } 290 static DEVICE_ATTR_RO(broadcast); 291 292 static int change_carrier(struct net_device *dev, unsigned long new_carrier) 293 { 294 if (!netif_running(dev)) 295 return -EINVAL; 296 return dev_change_carrier(dev, (bool)new_carrier); 297 } 298 299 static ssize_t carrier_store(struct device *dev, struct device_attribute *attr, 300 const char *buf, size_t len) 301 { 302 struct net_device *netdev = to_net_dev(dev); 303 304 /* The check is also done in change_carrier; this helps returning early 305 * without hitting the locking section in netdev_store. 306 */ 307 if (!netdev->netdev_ops->ndo_change_carrier) 308 return -EOPNOTSUPP; 309 310 return netdev_store(dev, attr, buf, len, change_carrier); 311 } 312 313 static ssize_t carrier_show(struct device *dev, 314 struct device_attribute *attr, char *buf) 315 { 316 struct net_device *netdev = to_net_dev(dev); 317 int ret; 318 319 ret = sysfs_rtnl_lock(&dev->kobj, &attr->attr, netdev); 320 if (ret) 321 return ret; 322 323 ret = -EINVAL; 324 if (netif_running(netdev)) { 325 /* Synchronize carrier state with link watch, 326 * see also rtnl_getlink(). 327 */ 328 linkwatch_sync_dev(netdev); 329 330 ret = sysfs_emit(buf, fmt_dec, !!netif_carrier_ok(netdev)); 331 } 332 333 rtnl_unlock(); 334 return ret; 335 } 336 static DEVICE_ATTR_RW(carrier); 337 338 static ssize_t speed_show(struct device *dev, 339 struct device_attribute *attr, char *buf) 340 { 341 struct net_device *netdev = to_net_dev(dev); 342 int ret = -EINVAL; 343 344 /* The check is also done in __ethtool_get_link_ksettings; this helps 345 * returning early without hitting the locking section below. 346 */ 347 if (!netdev->ethtool_ops->get_link_ksettings) 348 return ret; 349 350 ret = sysfs_rtnl_lock(&dev->kobj, &attr->attr, netdev); 351 if (ret) 352 return ret; 353 354 ret = -EINVAL; 355 if (netif_running(netdev)) { 356 struct ethtool_link_ksettings cmd; 357 358 if (!__ethtool_get_link_ksettings(netdev, &cmd)) 359 ret = sysfs_emit(buf, fmt_dec, cmd.base.speed); 360 } 361 rtnl_unlock(); 362 return ret; 363 } 364 static DEVICE_ATTR_RO(speed); 365 366 static ssize_t duplex_show(struct device *dev, 367 struct device_attribute *attr, char *buf) 368 { 369 struct net_device *netdev = to_net_dev(dev); 370 int ret = -EINVAL; 371 372 /* The check is also done in __ethtool_get_link_ksettings; this helps 373 * returning early without hitting the locking section below. 374 */ 375 if (!netdev->ethtool_ops->get_link_ksettings) 376 return ret; 377 378 ret = sysfs_rtnl_lock(&dev->kobj, &attr->attr, netdev); 379 if (ret) 380 return ret; 381 382 ret = -EINVAL; 383 if (netif_running(netdev)) { 384 struct ethtool_link_ksettings cmd; 385 386 if (!__ethtool_get_link_ksettings(netdev, &cmd)) { 387 const char *duplex; 388 389 switch (cmd.base.duplex) { 390 case DUPLEX_HALF: 391 duplex = "half"; 392 break; 393 case DUPLEX_FULL: 394 duplex = "full"; 395 break; 396 default: 397 duplex = "unknown"; 398 break; 399 } 400 ret = sysfs_emit(buf, "%s\n", duplex); 401 } 402 } 403 rtnl_unlock(); 404 return ret; 405 } 406 static DEVICE_ATTR_RO(duplex); 407 408 static ssize_t testing_show(struct device *dev, 409 struct device_attribute *attr, char *buf) 410 { 411 struct net_device *netdev = to_net_dev(dev); 412 413 if (netif_running(netdev)) 414 return sysfs_emit(buf, fmt_dec, !!netif_testing(netdev)); 415 416 return -EINVAL; 417 } 418 static DEVICE_ATTR_RO(testing); 419 420 static ssize_t dormant_show(struct device *dev, 421 struct device_attribute *attr, char *buf) 422 { 423 struct net_device *netdev = to_net_dev(dev); 424 425 if (netif_running(netdev)) 426 return sysfs_emit(buf, fmt_dec, !!netif_dormant(netdev)); 427 428 return -EINVAL; 429 } 430 static DEVICE_ATTR_RO(dormant); 431 432 static const char *const operstates[] = { 433 "unknown", 434 "notpresent", /* currently unused */ 435 "down", 436 "lowerlayerdown", 437 "testing", 438 "dormant", 439 "up" 440 }; 441 442 static ssize_t operstate_show(struct device *dev, 443 struct device_attribute *attr, char *buf) 444 { 445 const struct net_device *netdev = to_net_dev(dev); 446 unsigned char operstate; 447 448 operstate = READ_ONCE(netdev->operstate); 449 if (!netif_running(netdev)) 450 operstate = IF_OPER_DOWN; 451 452 if (operstate >= ARRAY_SIZE(operstates)) 453 return -EINVAL; /* should not happen */ 454 455 return sysfs_emit(buf, "%s\n", operstates[operstate]); 456 } 457 static DEVICE_ATTR_RO(operstate); 458 459 static ssize_t carrier_changes_show(struct device *dev, 460 struct device_attribute *attr, 461 char *buf) 462 { 463 struct net_device *netdev = to_net_dev(dev); 464 465 return sysfs_emit(buf, fmt_dec, 466 atomic_read(&netdev->carrier_up_count) + 467 atomic_read(&netdev->carrier_down_count)); 468 } 469 static DEVICE_ATTR_RO(carrier_changes); 470 471 static ssize_t carrier_up_count_show(struct device *dev, 472 struct device_attribute *attr, 473 char *buf) 474 { 475 struct net_device *netdev = to_net_dev(dev); 476 477 return sysfs_emit(buf, fmt_dec, atomic_read(&netdev->carrier_up_count)); 478 } 479 static DEVICE_ATTR_RO(carrier_up_count); 480 481 static ssize_t carrier_down_count_show(struct device *dev, 482 struct device_attribute *attr, 483 char *buf) 484 { 485 struct net_device *netdev = to_net_dev(dev); 486 487 return sysfs_emit(buf, fmt_dec, atomic_read(&netdev->carrier_down_count)); 488 } 489 static DEVICE_ATTR_RO(carrier_down_count); 490 491 /* read-write attributes */ 492 493 static int change_mtu(struct net_device *dev, unsigned long new_mtu) 494 { 495 return dev_set_mtu(dev, (int)new_mtu); 496 } 497 498 static ssize_t mtu_store(struct device *dev, struct device_attribute *attr, 499 const char *buf, size_t len) 500 { 501 return netdev_store(dev, attr, buf, len, change_mtu); 502 } 503 NETDEVICE_SHOW_RW(mtu, fmt_dec); 504 505 static int change_flags(struct net_device *dev, unsigned long new_flags) 506 { 507 return dev_change_flags(dev, (unsigned int)new_flags, NULL); 508 } 509 510 static ssize_t flags_store(struct device *dev, struct device_attribute *attr, 511 const char *buf, size_t len) 512 { 513 return netdev_store(dev, attr, buf, len, change_flags); 514 } 515 NETDEVICE_SHOW_RW(flags, fmt_hex); 516 517 static ssize_t tx_queue_len_store(struct device *dev, 518 struct device_attribute *attr, 519 const char *buf, size_t len) 520 { 521 if (!capable(CAP_NET_ADMIN)) 522 return -EPERM; 523 524 return netdev_store(dev, attr, buf, len, dev_change_tx_queue_len); 525 } 526 NETDEVICE_SHOW_RW(tx_queue_len, fmt_dec); 527 528 static int change_gro_flush_timeout(struct net_device *dev, unsigned long val) 529 { 530 netdev_set_gro_flush_timeout(dev, val); 531 return 0; 532 } 533 534 static ssize_t gro_flush_timeout_store(struct device *dev, 535 struct device_attribute *attr, 536 const char *buf, size_t len) 537 { 538 if (!capable(CAP_NET_ADMIN)) 539 return -EPERM; 540 541 return netdev_lock_store(dev, attr, buf, len, change_gro_flush_timeout); 542 } 543 NETDEVICE_SHOW_RW(gro_flush_timeout, fmt_ulong); 544 545 static int change_napi_defer_hard_irqs(struct net_device *dev, unsigned long val) 546 { 547 if (val > S32_MAX) 548 return -ERANGE; 549 550 netdev_set_defer_hard_irqs(dev, (u32)val); 551 return 0; 552 } 553 554 static ssize_t napi_defer_hard_irqs_store(struct device *dev, 555 struct device_attribute *attr, 556 const char *buf, size_t len) 557 { 558 if (!capable(CAP_NET_ADMIN)) 559 return -EPERM; 560 561 return netdev_lock_store(dev, attr, buf, len, 562 change_napi_defer_hard_irqs); 563 } 564 NETDEVICE_SHOW_RW(napi_defer_hard_irqs, fmt_uint); 565 566 static ssize_t ifalias_store(struct device *dev, struct device_attribute *attr, 567 const char *buf, size_t len) 568 { 569 struct net_device *netdev = to_net_dev(dev); 570 struct net *net = dev_net(netdev); 571 size_t count = len; 572 ssize_t ret; 573 574 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 575 return -EPERM; 576 577 /* ignore trailing newline */ 578 if (len > 0 && buf[len - 1] == '\n') 579 --count; 580 581 ret = sysfs_rtnl_lock(&dev->kobj, &attr->attr, netdev); 582 if (ret) 583 return ret; 584 585 ret = dev_set_alias(netdev, buf, count); 586 if (ret < 0) 587 goto err; 588 ret = len; 589 netdev_state_change(netdev); 590 err: 591 rtnl_unlock(); 592 593 return ret; 594 } 595 596 static ssize_t ifalias_show(struct device *dev, 597 struct device_attribute *attr, char *buf) 598 { 599 const struct net_device *netdev = to_net_dev(dev); 600 char tmp[IFALIASZ]; 601 ssize_t ret; 602 603 ret = dev_get_alias(netdev, tmp, sizeof(tmp)); 604 if (ret > 0) 605 ret = sysfs_emit(buf, "%s\n", tmp); 606 return ret; 607 } 608 static DEVICE_ATTR_RW(ifalias); 609 610 static int change_group(struct net_device *dev, unsigned long new_group) 611 { 612 dev_set_group(dev, (int)new_group); 613 return 0; 614 } 615 616 static ssize_t group_store(struct device *dev, struct device_attribute *attr, 617 const char *buf, size_t len) 618 { 619 return netdev_store(dev, attr, buf, len, change_group); 620 } 621 NETDEVICE_SHOW(group, fmt_dec); 622 static DEVICE_ATTR(netdev_group, 0644, group_show, group_store); 623 624 static int change_proto_down(struct net_device *dev, unsigned long proto_down) 625 { 626 return dev_change_proto_down(dev, (bool)proto_down); 627 } 628 629 static ssize_t proto_down_store(struct device *dev, 630 struct device_attribute *attr, 631 const char *buf, size_t len) 632 { 633 return netdev_store(dev, attr, buf, len, change_proto_down); 634 } 635 NETDEVICE_SHOW_RW(proto_down, fmt_dec); 636 637 static ssize_t phys_port_id_show(struct device *dev, 638 struct device_attribute *attr, char *buf) 639 { 640 struct net_device *netdev = to_net_dev(dev); 641 struct netdev_phys_item_id ppid; 642 ssize_t ret; 643 644 /* The check is also done in dev_get_phys_port_id; this helps returning 645 * early without hitting the locking section below. 646 */ 647 if (!netdev->netdev_ops->ndo_get_phys_port_id) 648 return -EOPNOTSUPP; 649 650 ret = sysfs_rtnl_lock(&dev->kobj, &attr->attr, netdev); 651 if (ret) 652 return ret; 653 654 ret = dev_get_phys_port_id(netdev, &ppid); 655 if (!ret) 656 ret = sysfs_emit(buf, "%*phN\n", ppid.id_len, ppid.id); 657 658 rtnl_unlock(); 659 660 return ret; 661 } 662 static DEVICE_ATTR_RO(phys_port_id); 663 664 static ssize_t phys_port_name_show(struct device *dev, 665 struct device_attribute *attr, char *buf) 666 { 667 struct net_device *netdev = to_net_dev(dev); 668 char name[IFNAMSIZ]; 669 ssize_t ret; 670 671 /* The checks are also done in dev_get_phys_port_name; this helps 672 * returning early without hitting the locking section below. 673 */ 674 if (!netdev->netdev_ops->ndo_get_phys_port_name && 675 !netdev->devlink_port) 676 return -EOPNOTSUPP; 677 678 ret = sysfs_rtnl_lock(&dev->kobj, &attr->attr, netdev); 679 if (ret) 680 return ret; 681 682 ret = dev_get_phys_port_name(netdev, name, sizeof(name)); 683 if (!ret) 684 ret = sysfs_emit(buf, "%s\n", name); 685 686 rtnl_unlock(); 687 688 return ret; 689 } 690 static DEVICE_ATTR_RO(phys_port_name); 691 692 static ssize_t phys_switch_id_show(struct device *dev, 693 struct device_attribute *attr, char *buf) 694 { 695 struct net_device *netdev = to_net_dev(dev); 696 struct netdev_phys_item_id ppid = { }; 697 ssize_t ret; 698 699 /* The checks are also done in dev_get_phys_port_name; this helps 700 * returning early without hitting the locking section below. This works 701 * because recurse is false when calling dev_get_port_parent_id. 702 */ 703 if (!netdev->netdev_ops->ndo_get_port_parent_id && 704 !netdev->devlink_port) 705 return -EOPNOTSUPP; 706 707 ret = sysfs_rtnl_lock(&dev->kobj, &attr->attr, netdev); 708 if (ret) 709 return ret; 710 711 ret = dev_get_port_parent_id(netdev, &ppid, false); 712 if (!ret) 713 ret = sysfs_emit(buf, "%*phN\n", ppid.id_len, ppid.id); 714 715 rtnl_unlock(); 716 717 return ret; 718 } 719 static DEVICE_ATTR_RO(phys_switch_id); 720 721 static ssize_t threaded_show(struct device *dev, 722 struct device_attribute *attr, char *buf) 723 { 724 struct net_device *netdev = to_net_dev(dev); 725 ssize_t ret = -EINVAL; 726 727 rcu_read_lock(); 728 729 if (dev_isalive(netdev)) 730 ret = sysfs_emit(buf, fmt_dec, READ_ONCE(netdev->threaded)); 731 732 rcu_read_unlock(); 733 734 return ret; 735 } 736 737 static int modify_napi_threaded(struct net_device *dev, unsigned long val) 738 { 739 int ret; 740 741 if (list_empty(&dev->napi_list)) 742 return -EOPNOTSUPP; 743 744 if (val != 0 && val != 1) 745 return -EOPNOTSUPP; 746 747 ret = dev_set_threaded(dev, val); 748 749 return ret; 750 } 751 752 static ssize_t threaded_store(struct device *dev, 753 struct device_attribute *attr, 754 const char *buf, size_t len) 755 { 756 return netdev_lock_store(dev, attr, buf, len, modify_napi_threaded); 757 } 758 static DEVICE_ATTR_RW(threaded); 759 760 static struct attribute *net_class_attrs[] __ro_after_init = { 761 &dev_attr_netdev_group.attr, 762 &dev_attr_type.attr, 763 &dev_attr_dev_id.attr, 764 &dev_attr_dev_port.attr, 765 &dev_attr_iflink.attr, 766 &dev_attr_ifindex.attr, 767 &dev_attr_name_assign_type.attr, 768 &dev_attr_addr_assign_type.attr, 769 &dev_attr_addr_len.attr, 770 &dev_attr_link_mode.attr, 771 &dev_attr_address.attr, 772 &dev_attr_broadcast.attr, 773 &dev_attr_speed.attr, 774 &dev_attr_duplex.attr, 775 &dev_attr_dormant.attr, 776 &dev_attr_testing.attr, 777 &dev_attr_operstate.attr, 778 &dev_attr_carrier_changes.attr, 779 &dev_attr_ifalias.attr, 780 &dev_attr_carrier.attr, 781 &dev_attr_mtu.attr, 782 &dev_attr_flags.attr, 783 &dev_attr_tx_queue_len.attr, 784 &dev_attr_gro_flush_timeout.attr, 785 &dev_attr_napi_defer_hard_irqs.attr, 786 &dev_attr_phys_port_id.attr, 787 &dev_attr_phys_port_name.attr, 788 &dev_attr_phys_switch_id.attr, 789 &dev_attr_proto_down.attr, 790 &dev_attr_carrier_up_count.attr, 791 &dev_attr_carrier_down_count.attr, 792 &dev_attr_threaded.attr, 793 NULL, 794 }; 795 ATTRIBUTE_GROUPS(net_class); 796 797 /* Show a given an attribute in the statistics group */ 798 static ssize_t netstat_show(const struct device *d, 799 struct device_attribute *attr, char *buf, 800 unsigned long offset) 801 { 802 struct net_device *dev = to_net_dev(d); 803 ssize_t ret = -EINVAL; 804 805 WARN_ON(offset > sizeof(struct rtnl_link_stats64) || 806 offset % sizeof(u64) != 0); 807 808 rcu_read_lock(); 809 if (dev_isalive(dev)) { 810 struct rtnl_link_stats64 temp; 811 const struct rtnl_link_stats64 *stats = dev_get_stats(dev, &temp); 812 813 ret = sysfs_emit(buf, fmt_u64, *(u64 *)(((u8 *)stats) + offset)); 814 } 815 rcu_read_unlock(); 816 return ret; 817 } 818 819 /* generate a read-only statistics attribute */ 820 #define NETSTAT_ENTRY(name) \ 821 static ssize_t name##_show(struct device *d, \ 822 struct device_attribute *attr, char *buf) \ 823 { \ 824 return netstat_show(d, attr, buf, \ 825 offsetof(struct rtnl_link_stats64, name)); \ 826 } \ 827 static DEVICE_ATTR_RO(name) 828 829 NETSTAT_ENTRY(rx_packets); 830 NETSTAT_ENTRY(tx_packets); 831 NETSTAT_ENTRY(rx_bytes); 832 NETSTAT_ENTRY(tx_bytes); 833 NETSTAT_ENTRY(rx_errors); 834 NETSTAT_ENTRY(tx_errors); 835 NETSTAT_ENTRY(rx_dropped); 836 NETSTAT_ENTRY(tx_dropped); 837 NETSTAT_ENTRY(multicast); 838 NETSTAT_ENTRY(collisions); 839 NETSTAT_ENTRY(rx_length_errors); 840 NETSTAT_ENTRY(rx_over_errors); 841 NETSTAT_ENTRY(rx_crc_errors); 842 NETSTAT_ENTRY(rx_frame_errors); 843 NETSTAT_ENTRY(rx_fifo_errors); 844 NETSTAT_ENTRY(rx_missed_errors); 845 NETSTAT_ENTRY(tx_aborted_errors); 846 NETSTAT_ENTRY(tx_carrier_errors); 847 NETSTAT_ENTRY(tx_fifo_errors); 848 NETSTAT_ENTRY(tx_heartbeat_errors); 849 NETSTAT_ENTRY(tx_window_errors); 850 NETSTAT_ENTRY(rx_compressed); 851 NETSTAT_ENTRY(tx_compressed); 852 NETSTAT_ENTRY(rx_nohandler); 853 854 static struct attribute *netstat_attrs[] __ro_after_init = { 855 &dev_attr_rx_packets.attr, 856 &dev_attr_tx_packets.attr, 857 &dev_attr_rx_bytes.attr, 858 &dev_attr_tx_bytes.attr, 859 &dev_attr_rx_errors.attr, 860 &dev_attr_tx_errors.attr, 861 &dev_attr_rx_dropped.attr, 862 &dev_attr_tx_dropped.attr, 863 &dev_attr_multicast.attr, 864 &dev_attr_collisions.attr, 865 &dev_attr_rx_length_errors.attr, 866 &dev_attr_rx_over_errors.attr, 867 &dev_attr_rx_crc_errors.attr, 868 &dev_attr_rx_frame_errors.attr, 869 &dev_attr_rx_fifo_errors.attr, 870 &dev_attr_rx_missed_errors.attr, 871 &dev_attr_tx_aborted_errors.attr, 872 &dev_attr_tx_carrier_errors.attr, 873 &dev_attr_tx_fifo_errors.attr, 874 &dev_attr_tx_heartbeat_errors.attr, 875 &dev_attr_tx_window_errors.attr, 876 &dev_attr_rx_compressed.attr, 877 &dev_attr_tx_compressed.attr, 878 &dev_attr_rx_nohandler.attr, 879 NULL 880 }; 881 882 static const struct attribute_group netstat_group = { 883 .name = "statistics", 884 .attrs = netstat_attrs, 885 }; 886 887 static struct attribute *wireless_attrs[] = { 888 NULL 889 }; 890 891 static const struct attribute_group wireless_group = { 892 .name = "wireless", 893 .attrs = wireless_attrs, 894 }; 895 896 static bool wireless_group_needed(struct net_device *ndev) 897 { 898 #if IS_ENABLED(CONFIG_CFG80211) 899 if (ndev->ieee80211_ptr) 900 return true; 901 #endif 902 #if IS_ENABLED(CONFIG_WIRELESS_EXT) 903 if (ndev->wireless_handlers) 904 return true; 905 #endif 906 return false; 907 } 908 909 #else /* CONFIG_SYSFS */ 910 #define net_class_groups NULL 911 #endif /* CONFIG_SYSFS */ 912 913 #ifdef CONFIG_SYSFS 914 #define to_rx_queue_attr(_attr) \ 915 container_of(_attr, struct rx_queue_attribute, attr) 916 917 #define to_rx_queue(obj) container_of(obj, struct netdev_rx_queue, kobj) 918 919 static ssize_t rx_queue_attr_show(struct kobject *kobj, struct attribute *attr, 920 char *buf) 921 { 922 const struct rx_queue_attribute *attribute = to_rx_queue_attr(attr); 923 struct netdev_rx_queue *queue = to_rx_queue(kobj); 924 925 if (!attribute->show) 926 return -EIO; 927 928 return attribute->show(queue, buf); 929 } 930 931 static ssize_t rx_queue_attr_store(struct kobject *kobj, struct attribute *attr, 932 const char *buf, size_t count) 933 { 934 const struct rx_queue_attribute *attribute = to_rx_queue_attr(attr); 935 struct netdev_rx_queue *queue = to_rx_queue(kobj); 936 937 if (!attribute->store) 938 return -EIO; 939 940 return attribute->store(queue, buf, count); 941 } 942 943 static const struct sysfs_ops rx_queue_sysfs_ops = { 944 .show = rx_queue_attr_show, 945 .store = rx_queue_attr_store, 946 }; 947 948 #ifdef CONFIG_RPS 949 static ssize_t show_rps_map(struct netdev_rx_queue *queue, char *buf) 950 { 951 struct rps_map *map; 952 cpumask_var_t mask; 953 int i, len; 954 955 if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) 956 return -ENOMEM; 957 958 rcu_read_lock(); 959 map = rcu_dereference(queue->rps_map); 960 if (map) 961 for (i = 0; i < map->len; i++) 962 cpumask_set_cpu(map->cpus[i], mask); 963 964 len = sysfs_emit(buf, "%*pb\n", cpumask_pr_args(mask)); 965 rcu_read_unlock(); 966 free_cpumask_var(mask); 967 968 return len < PAGE_SIZE ? len : -EINVAL; 969 } 970 971 static int netdev_rx_queue_set_rps_mask(struct netdev_rx_queue *queue, 972 cpumask_var_t mask) 973 { 974 static DEFINE_MUTEX(rps_map_mutex); 975 struct rps_map *old_map, *map; 976 int cpu, i; 977 978 map = kzalloc(max_t(unsigned int, 979 RPS_MAP_SIZE(cpumask_weight(mask)), L1_CACHE_BYTES), 980 GFP_KERNEL); 981 if (!map) 982 return -ENOMEM; 983 984 i = 0; 985 for_each_cpu_and(cpu, mask, cpu_online_mask) 986 map->cpus[i++] = cpu; 987 988 if (i) { 989 map->len = i; 990 } else { 991 kfree(map); 992 map = NULL; 993 } 994 995 mutex_lock(&rps_map_mutex); 996 old_map = rcu_dereference_protected(queue->rps_map, 997 mutex_is_locked(&rps_map_mutex)); 998 rcu_assign_pointer(queue->rps_map, map); 999 1000 if (map) 1001 static_branch_inc(&rps_needed); 1002 if (old_map) 1003 static_branch_dec(&rps_needed); 1004 1005 mutex_unlock(&rps_map_mutex); 1006 1007 if (old_map) 1008 kfree_rcu(old_map, rcu); 1009 return 0; 1010 } 1011 1012 int rps_cpumask_housekeeping(struct cpumask *mask) 1013 { 1014 if (!cpumask_empty(mask)) { 1015 cpumask_and(mask, mask, housekeeping_cpumask(HK_TYPE_DOMAIN)); 1016 cpumask_and(mask, mask, housekeeping_cpumask(HK_TYPE_WQ)); 1017 if (cpumask_empty(mask)) 1018 return -EINVAL; 1019 } 1020 return 0; 1021 } 1022 1023 static ssize_t store_rps_map(struct netdev_rx_queue *queue, 1024 const char *buf, size_t len) 1025 { 1026 cpumask_var_t mask; 1027 int err; 1028 1029 if (!capable(CAP_NET_ADMIN)) 1030 return -EPERM; 1031 1032 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) 1033 return -ENOMEM; 1034 1035 err = bitmap_parse(buf, len, cpumask_bits(mask), nr_cpumask_bits); 1036 if (err) 1037 goto out; 1038 1039 err = rps_cpumask_housekeeping(mask); 1040 if (err) 1041 goto out; 1042 1043 err = netdev_rx_queue_set_rps_mask(queue, mask); 1044 1045 out: 1046 free_cpumask_var(mask); 1047 return err ? : len; 1048 } 1049 1050 static ssize_t show_rps_dev_flow_table_cnt(struct netdev_rx_queue *queue, 1051 char *buf) 1052 { 1053 struct rps_dev_flow_table *flow_table; 1054 unsigned long val = 0; 1055 1056 rcu_read_lock(); 1057 flow_table = rcu_dereference(queue->rps_flow_table); 1058 if (flow_table) 1059 val = 1UL << flow_table->log; 1060 rcu_read_unlock(); 1061 1062 return sysfs_emit(buf, "%lu\n", val); 1063 } 1064 1065 static void rps_dev_flow_table_release(struct rcu_head *rcu) 1066 { 1067 struct rps_dev_flow_table *table = container_of(rcu, 1068 struct rps_dev_flow_table, rcu); 1069 vfree(table); 1070 } 1071 1072 static ssize_t store_rps_dev_flow_table_cnt(struct netdev_rx_queue *queue, 1073 const char *buf, size_t len) 1074 { 1075 unsigned long mask, count; 1076 struct rps_dev_flow_table *table, *old_table; 1077 static DEFINE_SPINLOCK(rps_dev_flow_lock); 1078 int rc; 1079 1080 if (!capable(CAP_NET_ADMIN)) 1081 return -EPERM; 1082 1083 rc = kstrtoul(buf, 0, &count); 1084 if (rc < 0) 1085 return rc; 1086 1087 if (count) { 1088 mask = count - 1; 1089 /* mask = roundup_pow_of_two(count) - 1; 1090 * without overflows... 1091 */ 1092 while ((mask | (mask >> 1)) != mask) 1093 mask |= (mask >> 1); 1094 /* On 64 bit arches, must check mask fits in table->mask (u32), 1095 * and on 32bit arches, must check 1096 * RPS_DEV_FLOW_TABLE_SIZE(mask + 1) doesn't overflow. 1097 */ 1098 #if BITS_PER_LONG > 32 1099 if (mask > (unsigned long)(u32)mask) 1100 return -EINVAL; 1101 #else 1102 if (mask > (ULONG_MAX - RPS_DEV_FLOW_TABLE_SIZE(1)) 1103 / sizeof(struct rps_dev_flow)) { 1104 /* Enforce a limit to prevent overflow */ 1105 return -EINVAL; 1106 } 1107 #endif 1108 table = vmalloc(RPS_DEV_FLOW_TABLE_SIZE(mask + 1)); 1109 if (!table) 1110 return -ENOMEM; 1111 1112 table->log = ilog2(mask) + 1; 1113 for (count = 0; count <= mask; count++) 1114 table->flows[count].cpu = RPS_NO_CPU; 1115 } else { 1116 table = NULL; 1117 } 1118 1119 spin_lock(&rps_dev_flow_lock); 1120 old_table = rcu_dereference_protected(queue->rps_flow_table, 1121 lockdep_is_held(&rps_dev_flow_lock)); 1122 rcu_assign_pointer(queue->rps_flow_table, table); 1123 spin_unlock(&rps_dev_flow_lock); 1124 1125 if (old_table) 1126 call_rcu(&old_table->rcu, rps_dev_flow_table_release); 1127 1128 return len; 1129 } 1130 1131 static struct rx_queue_attribute rps_cpus_attribute __ro_after_init 1132 = __ATTR(rps_cpus, 0644, show_rps_map, store_rps_map); 1133 1134 static struct rx_queue_attribute rps_dev_flow_table_cnt_attribute __ro_after_init 1135 = __ATTR(rps_flow_cnt, 0644, 1136 show_rps_dev_flow_table_cnt, store_rps_dev_flow_table_cnt); 1137 #endif /* CONFIG_RPS */ 1138 1139 static struct attribute *rx_queue_default_attrs[] __ro_after_init = { 1140 #ifdef CONFIG_RPS 1141 &rps_cpus_attribute.attr, 1142 &rps_dev_flow_table_cnt_attribute.attr, 1143 #endif 1144 NULL 1145 }; 1146 ATTRIBUTE_GROUPS(rx_queue_default); 1147 1148 static void rx_queue_release(struct kobject *kobj) 1149 { 1150 struct netdev_rx_queue *queue = to_rx_queue(kobj); 1151 #ifdef CONFIG_RPS 1152 struct rps_map *map; 1153 struct rps_dev_flow_table *flow_table; 1154 1155 map = rcu_dereference_protected(queue->rps_map, 1); 1156 if (map) { 1157 RCU_INIT_POINTER(queue->rps_map, NULL); 1158 kfree_rcu(map, rcu); 1159 } 1160 1161 flow_table = rcu_dereference_protected(queue->rps_flow_table, 1); 1162 if (flow_table) { 1163 RCU_INIT_POINTER(queue->rps_flow_table, NULL); 1164 call_rcu(&flow_table->rcu, rps_dev_flow_table_release); 1165 } 1166 #endif 1167 1168 memset(kobj, 0, sizeof(*kobj)); 1169 netdev_put(queue->dev, &queue->dev_tracker); 1170 } 1171 1172 static const void *rx_queue_namespace(const struct kobject *kobj) 1173 { 1174 struct netdev_rx_queue *queue = to_rx_queue(kobj); 1175 struct device *dev = &queue->dev->dev; 1176 const void *ns = NULL; 1177 1178 if (dev->class && dev->class->namespace) 1179 ns = dev->class->namespace(dev); 1180 1181 return ns; 1182 } 1183 1184 static void rx_queue_get_ownership(const struct kobject *kobj, 1185 kuid_t *uid, kgid_t *gid) 1186 { 1187 const struct net *net = rx_queue_namespace(kobj); 1188 1189 net_ns_get_ownership(net, uid, gid); 1190 } 1191 1192 static const struct kobj_type rx_queue_ktype = { 1193 .sysfs_ops = &rx_queue_sysfs_ops, 1194 .release = rx_queue_release, 1195 .namespace = rx_queue_namespace, 1196 .get_ownership = rx_queue_get_ownership, 1197 }; 1198 1199 static int rx_queue_default_mask(struct net_device *dev, 1200 struct netdev_rx_queue *queue) 1201 { 1202 #if IS_ENABLED(CONFIG_RPS) && IS_ENABLED(CONFIG_SYSCTL) 1203 struct cpumask *rps_default_mask = READ_ONCE(dev_net(dev)->core.rps_default_mask); 1204 1205 if (rps_default_mask && !cpumask_empty(rps_default_mask)) 1206 return netdev_rx_queue_set_rps_mask(queue, rps_default_mask); 1207 #endif 1208 return 0; 1209 } 1210 1211 static int rx_queue_add_kobject(struct net_device *dev, int index) 1212 { 1213 struct netdev_rx_queue *queue = dev->_rx + index; 1214 struct kobject *kobj = &queue->kobj; 1215 int error = 0; 1216 1217 /* Rx queues are cleared in rx_queue_release to allow later 1218 * re-registration. This is triggered when their kobj refcount is 1219 * dropped. 1220 * 1221 * If a queue is removed while both a read (or write) operation and a 1222 * the re-addition of the same queue are pending (waiting on rntl_lock) 1223 * it might happen that the re-addition will execute before the read, 1224 * making the initial removal to never happen (queue's kobj refcount 1225 * won't drop enough because of the pending read). In such rare case, 1226 * return to allow the removal operation to complete. 1227 */ 1228 if (unlikely(kobj->state_initialized)) { 1229 netdev_warn_once(dev, "Cannot re-add rx queues before their removal completed"); 1230 return -EAGAIN; 1231 } 1232 1233 /* Kobject_put later will trigger rx_queue_release call which 1234 * decreases dev refcount: Take that reference here 1235 */ 1236 netdev_hold(queue->dev, &queue->dev_tracker, GFP_KERNEL); 1237 1238 kobj->kset = dev->queues_kset; 1239 error = kobject_init_and_add(kobj, &rx_queue_ktype, NULL, 1240 "rx-%u", index); 1241 if (error) 1242 goto err; 1243 1244 queue->groups = rx_queue_default_groups; 1245 error = sysfs_create_groups(kobj, queue->groups); 1246 if (error) 1247 goto err; 1248 1249 if (dev->sysfs_rx_queue_group) { 1250 error = sysfs_create_group(kobj, dev->sysfs_rx_queue_group); 1251 if (error) 1252 goto err_default_groups; 1253 } 1254 1255 error = rx_queue_default_mask(dev, queue); 1256 if (error) 1257 goto err_default_groups; 1258 1259 kobject_uevent(kobj, KOBJ_ADD); 1260 1261 return error; 1262 1263 err_default_groups: 1264 sysfs_remove_groups(kobj, queue->groups); 1265 err: 1266 kobject_put(kobj); 1267 return error; 1268 } 1269 1270 static int rx_queue_change_owner(struct net_device *dev, int index, kuid_t kuid, 1271 kgid_t kgid) 1272 { 1273 struct netdev_rx_queue *queue = dev->_rx + index; 1274 struct kobject *kobj = &queue->kobj; 1275 int error; 1276 1277 error = sysfs_change_owner(kobj, kuid, kgid); 1278 if (error) 1279 return error; 1280 1281 if (dev->sysfs_rx_queue_group) 1282 error = sysfs_group_change_owner( 1283 kobj, dev->sysfs_rx_queue_group, kuid, kgid); 1284 1285 return error; 1286 } 1287 #endif /* CONFIG_SYSFS */ 1288 1289 int 1290 net_rx_queue_update_kobjects(struct net_device *dev, int old_num, int new_num) 1291 { 1292 #ifdef CONFIG_SYSFS 1293 int i; 1294 int error = 0; 1295 1296 #ifndef CONFIG_RPS 1297 if (!dev->sysfs_rx_queue_group) 1298 return 0; 1299 #endif 1300 for (i = old_num; i < new_num; i++) { 1301 error = rx_queue_add_kobject(dev, i); 1302 if (error) { 1303 new_num = old_num; 1304 break; 1305 } 1306 } 1307 1308 while (--i >= new_num) { 1309 struct netdev_rx_queue *queue = &dev->_rx[i]; 1310 struct kobject *kobj = &queue->kobj; 1311 1312 if (!refcount_read(&dev_net(dev)->ns.count)) 1313 kobj->uevent_suppress = 1; 1314 if (dev->sysfs_rx_queue_group) 1315 sysfs_remove_group(kobj, dev->sysfs_rx_queue_group); 1316 sysfs_remove_groups(kobj, queue->groups); 1317 kobject_put(kobj); 1318 } 1319 1320 return error; 1321 #else 1322 return 0; 1323 #endif 1324 } 1325 1326 static int net_rx_queue_change_owner(struct net_device *dev, int num, 1327 kuid_t kuid, kgid_t kgid) 1328 { 1329 #ifdef CONFIG_SYSFS 1330 int error = 0; 1331 int i; 1332 1333 #ifndef CONFIG_RPS 1334 if (!dev->sysfs_rx_queue_group) 1335 return 0; 1336 #endif 1337 for (i = 0; i < num; i++) { 1338 error = rx_queue_change_owner(dev, i, kuid, kgid); 1339 if (error) 1340 break; 1341 } 1342 1343 return error; 1344 #else 1345 return 0; 1346 #endif 1347 } 1348 1349 #ifdef CONFIG_SYSFS 1350 /* 1351 * netdev_queue sysfs structures and functions. 1352 */ 1353 struct netdev_queue_attribute { 1354 struct attribute attr; 1355 ssize_t (*show)(struct kobject *kobj, struct attribute *attr, 1356 struct netdev_queue *queue, char *buf); 1357 ssize_t (*store)(struct kobject *kobj, struct attribute *attr, 1358 struct netdev_queue *queue, const char *buf, 1359 size_t len); 1360 }; 1361 #define to_netdev_queue_attr(_attr) \ 1362 container_of(_attr, struct netdev_queue_attribute, attr) 1363 1364 #define to_netdev_queue(obj) container_of(obj, struct netdev_queue, kobj) 1365 1366 static ssize_t netdev_queue_attr_show(struct kobject *kobj, 1367 struct attribute *attr, char *buf) 1368 { 1369 const struct netdev_queue_attribute *attribute 1370 = to_netdev_queue_attr(attr); 1371 struct netdev_queue *queue = to_netdev_queue(kobj); 1372 1373 if (!attribute->show) 1374 return -EIO; 1375 1376 return attribute->show(kobj, attr, queue, buf); 1377 } 1378 1379 static ssize_t netdev_queue_attr_store(struct kobject *kobj, 1380 struct attribute *attr, 1381 const char *buf, size_t count) 1382 { 1383 const struct netdev_queue_attribute *attribute 1384 = to_netdev_queue_attr(attr); 1385 struct netdev_queue *queue = to_netdev_queue(kobj); 1386 1387 if (!attribute->store) 1388 return -EIO; 1389 1390 return attribute->store(kobj, attr, queue, buf, count); 1391 } 1392 1393 static const struct sysfs_ops netdev_queue_sysfs_ops = { 1394 .show = netdev_queue_attr_show, 1395 .store = netdev_queue_attr_store, 1396 }; 1397 1398 static ssize_t tx_timeout_show(struct kobject *kobj, struct attribute *attr, 1399 struct netdev_queue *queue, char *buf) 1400 { 1401 unsigned long trans_timeout = atomic_long_read(&queue->trans_timeout); 1402 1403 return sysfs_emit(buf, fmt_ulong, trans_timeout); 1404 } 1405 1406 static unsigned int get_netdev_queue_index(struct netdev_queue *queue) 1407 { 1408 struct net_device *dev = queue->dev; 1409 unsigned int i; 1410 1411 i = queue - dev->_tx; 1412 BUG_ON(i >= dev->num_tx_queues); 1413 1414 return i; 1415 } 1416 1417 static ssize_t traffic_class_show(struct kobject *kobj, struct attribute *attr, 1418 struct netdev_queue *queue, char *buf) 1419 { 1420 struct net_device *dev = queue->dev; 1421 int num_tc, tc, index, ret; 1422 1423 if (!netif_is_multiqueue(dev)) 1424 return -ENOENT; 1425 1426 ret = sysfs_rtnl_lock(kobj, attr, queue->dev); 1427 if (ret) 1428 return ret; 1429 1430 index = get_netdev_queue_index(queue); 1431 1432 /* If queue belongs to subordinate dev use its TC mapping */ 1433 dev = netdev_get_tx_queue(dev, index)->sb_dev ? : dev; 1434 1435 num_tc = dev->num_tc; 1436 tc = netdev_txq_to_tc(dev, index); 1437 1438 rtnl_unlock(); 1439 1440 if (tc < 0) 1441 return -EINVAL; 1442 1443 /* We can report the traffic class one of two ways: 1444 * Subordinate device traffic classes are reported with the traffic 1445 * class first, and then the subordinate class so for example TC0 on 1446 * subordinate device 2 will be reported as "0-2". If the queue 1447 * belongs to the root device it will be reported with just the 1448 * traffic class, so just "0" for TC 0 for example. 1449 */ 1450 return num_tc < 0 ? sysfs_emit(buf, "%d%d\n", tc, num_tc) : 1451 sysfs_emit(buf, "%d\n", tc); 1452 } 1453 1454 #ifdef CONFIG_XPS 1455 static ssize_t tx_maxrate_show(struct kobject *kobj, struct attribute *attr, 1456 struct netdev_queue *queue, char *buf) 1457 { 1458 return sysfs_emit(buf, "%lu\n", queue->tx_maxrate); 1459 } 1460 1461 static ssize_t tx_maxrate_store(struct kobject *kobj, struct attribute *attr, 1462 struct netdev_queue *queue, const char *buf, 1463 size_t len) 1464 { 1465 int err, index = get_netdev_queue_index(queue); 1466 struct net_device *dev = queue->dev; 1467 u32 rate = 0; 1468 1469 if (!capable(CAP_NET_ADMIN)) 1470 return -EPERM; 1471 1472 /* The check is also done later; this helps returning early without 1473 * hitting the locking section below. 1474 */ 1475 if (!dev->netdev_ops->ndo_set_tx_maxrate) 1476 return -EOPNOTSUPP; 1477 1478 err = kstrtou32(buf, 10, &rate); 1479 if (err < 0) 1480 return err; 1481 1482 err = sysfs_rtnl_lock(kobj, attr, dev); 1483 if (err) 1484 return err; 1485 1486 err = -EOPNOTSUPP; 1487 netdev_lock_ops(dev); 1488 if (dev->netdev_ops->ndo_set_tx_maxrate) 1489 err = dev->netdev_ops->ndo_set_tx_maxrate(dev, index, rate); 1490 netdev_unlock_ops(dev); 1491 1492 if (!err) { 1493 queue->tx_maxrate = rate; 1494 rtnl_unlock(); 1495 return len; 1496 } 1497 1498 rtnl_unlock(); 1499 return err; 1500 } 1501 1502 static struct netdev_queue_attribute queue_tx_maxrate __ro_after_init 1503 = __ATTR_RW(tx_maxrate); 1504 #endif 1505 1506 static struct netdev_queue_attribute queue_trans_timeout __ro_after_init 1507 = __ATTR_RO(tx_timeout); 1508 1509 static struct netdev_queue_attribute queue_traffic_class __ro_after_init 1510 = __ATTR_RO(traffic_class); 1511 1512 #ifdef CONFIG_BQL 1513 /* 1514 * Byte queue limits sysfs structures and functions. 1515 */ 1516 static ssize_t bql_show(char *buf, unsigned int value) 1517 { 1518 return sysfs_emit(buf, "%u\n", value); 1519 } 1520 1521 static ssize_t bql_set(const char *buf, const size_t count, 1522 unsigned int *pvalue) 1523 { 1524 unsigned int value; 1525 int err; 1526 1527 if (!strcmp(buf, "max") || !strcmp(buf, "max\n")) { 1528 value = DQL_MAX_LIMIT; 1529 } else { 1530 err = kstrtouint(buf, 10, &value); 1531 if (err < 0) 1532 return err; 1533 if (value > DQL_MAX_LIMIT) 1534 return -EINVAL; 1535 } 1536 1537 *pvalue = value; 1538 1539 return count; 1540 } 1541 1542 static ssize_t bql_show_hold_time(struct kobject *kobj, struct attribute *attr, 1543 struct netdev_queue *queue, char *buf) 1544 { 1545 struct dql *dql = &queue->dql; 1546 1547 return sysfs_emit(buf, "%u\n", jiffies_to_msecs(dql->slack_hold_time)); 1548 } 1549 1550 static ssize_t bql_set_hold_time(struct kobject *kobj, struct attribute *attr, 1551 struct netdev_queue *queue, const char *buf, 1552 size_t len) 1553 { 1554 struct dql *dql = &queue->dql; 1555 unsigned int value; 1556 int err; 1557 1558 err = kstrtouint(buf, 10, &value); 1559 if (err < 0) 1560 return err; 1561 1562 dql->slack_hold_time = msecs_to_jiffies(value); 1563 1564 return len; 1565 } 1566 1567 static struct netdev_queue_attribute bql_hold_time_attribute __ro_after_init 1568 = __ATTR(hold_time, 0644, 1569 bql_show_hold_time, bql_set_hold_time); 1570 1571 static ssize_t bql_show_stall_thrs(struct kobject *kobj, struct attribute *attr, 1572 struct netdev_queue *queue, char *buf) 1573 { 1574 struct dql *dql = &queue->dql; 1575 1576 return sysfs_emit(buf, "%u\n", jiffies_to_msecs(dql->stall_thrs)); 1577 } 1578 1579 static ssize_t bql_set_stall_thrs(struct kobject *kobj, struct attribute *attr, 1580 struct netdev_queue *queue, const char *buf, 1581 size_t len) 1582 { 1583 struct dql *dql = &queue->dql; 1584 unsigned int value; 1585 int err; 1586 1587 err = kstrtouint(buf, 10, &value); 1588 if (err < 0) 1589 return err; 1590 1591 value = msecs_to_jiffies(value); 1592 if (value && (value < 4 || value > 4 / 2 * BITS_PER_LONG)) 1593 return -ERANGE; 1594 1595 if (!dql->stall_thrs && value) 1596 dql->last_reap = jiffies; 1597 /* Force last_reap to be live */ 1598 smp_wmb(); 1599 dql->stall_thrs = value; 1600 1601 return len; 1602 } 1603 1604 static struct netdev_queue_attribute bql_stall_thrs_attribute __ro_after_init = 1605 __ATTR(stall_thrs, 0644, bql_show_stall_thrs, bql_set_stall_thrs); 1606 1607 static ssize_t bql_show_stall_max(struct kobject *kobj, struct attribute *attr, 1608 struct netdev_queue *queue, char *buf) 1609 { 1610 return sysfs_emit(buf, "%u\n", READ_ONCE(queue->dql.stall_max)); 1611 } 1612 1613 static ssize_t bql_set_stall_max(struct kobject *kobj, struct attribute *attr, 1614 struct netdev_queue *queue, const char *buf, 1615 size_t len) 1616 { 1617 WRITE_ONCE(queue->dql.stall_max, 0); 1618 return len; 1619 } 1620 1621 static struct netdev_queue_attribute bql_stall_max_attribute __ro_after_init = 1622 __ATTR(stall_max, 0644, bql_show_stall_max, bql_set_stall_max); 1623 1624 static ssize_t bql_show_stall_cnt(struct kobject *kobj, struct attribute *attr, 1625 struct netdev_queue *queue, char *buf) 1626 { 1627 struct dql *dql = &queue->dql; 1628 1629 return sysfs_emit(buf, "%lu\n", dql->stall_cnt); 1630 } 1631 1632 static struct netdev_queue_attribute bql_stall_cnt_attribute __ro_after_init = 1633 __ATTR(stall_cnt, 0444, bql_show_stall_cnt, NULL); 1634 1635 static ssize_t bql_show_inflight(struct kobject *kobj, struct attribute *attr, 1636 struct netdev_queue *queue, char *buf) 1637 { 1638 struct dql *dql = &queue->dql; 1639 1640 return sysfs_emit(buf, "%u\n", dql->num_queued - dql->num_completed); 1641 } 1642 1643 static struct netdev_queue_attribute bql_inflight_attribute __ro_after_init = 1644 __ATTR(inflight, 0444, bql_show_inflight, NULL); 1645 1646 #define BQL_ATTR(NAME, FIELD) \ 1647 static ssize_t bql_show_ ## NAME(struct kobject *kobj, \ 1648 struct attribute *attr, \ 1649 struct netdev_queue *queue, char *buf) \ 1650 { \ 1651 return bql_show(buf, queue->dql.FIELD); \ 1652 } \ 1653 \ 1654 static ssize_t bql_set_ ## NAME(struct kobject *kobj, \ 1655 struct attribute *attr, \ 1656 struct netdev_queue *queue, \ 1657 const char *buf, size_t len) \ 1658 { \ 1659 return bql_set(buf, len, &queue->dql.FIELD); \ 1660 } \ 1661 \ 1662 static struct netdev_queue_attribute bql_ ## NAME ## _attribute __ro_after_init \ 1663 = __ATTR(NAME, 0644, \ 1664 bql_show_ ## NAME, bql_set_ ## NAME) 1665 1666 BQL_ATTR(limit, limit); 1667 BQL_ATTR(limit_max, max_limit); 1668 BQL_ATTR(limit_min, min_limit); 1669 1670 static struct attribute *dql_attrs[] __ro_after_init = { 1671 &bql_limit_attribute.attr, 1672 &bql_limit_max_attribute.attr, 1673 &bql_limit_min_attribute.attr, 1674 &bql_hold_time_attribute.attr, 1675 &bql_inflight_attribute.attr, 1676 &bql_stall_thrs_attribute.attr, 1677 &bql_stall_cnt_attribute.attr, 1678 &bql_stall_max_attribute.attr, 1679 NULL 1680 }; 1681 1682 static const struct attribute_group dql_group = { 1683 .name = "byte_queue_limits", 1684 .attrs = dql_attrs, 1685 }; 1686 #else 1687 /* Fake declaration, all the code using it should be dead */ 1688 static const struct attribute_group dql_group = {}; 1689 #endif /* CONFIG_BQL */ 1690 1691 #ifdef CONFIG_XPS 1692 static ssize_t xps_queue_show(struct net_device *dev, unsigned int index, 1693 int tc, char *buf, enum xps_map_type type) 1694 { 1695 struct xps_dev_maps *dev_maps; 1696 unsigned long *mask; 1697 unsigned int nr_ids; 1698 int j, len; 1699 1700 rcu_read_lock(); 1701 dev_maps = rcu_dereference(dev->xps_maps[type]); 1702 1703 /* Default to nr_cpu_ids/dev->num_rx_queues and do not just return 0 1704 * when dev_maps hasn't been allocated yet, to be backward compatible. 1705 */ 1706 nr_ids = dev_maps ? dev_maps->nr_ids : 1707 (type == XPS_CPUS ? nr_cpu_ids : dev->num_rx_queues); 1708 1709 mask = bitmap_zalloc(nr_ids, GFP_NOWAIT); 1710 if (!mask) { 1711 rcu_read_unlock(); 1712 return -ENOMEM; 1713 } 1714 1715 if (!dev_maps || tc >= dev_maps->num_tc) 1716 goto out_no_maps; 1717 1718 for (j = 0; j < nr_ids; j++) { 1719 int i, tci = j * dev_maps->num_tc + tc; 1720 struct xps_map *map; 1721 1722 map = rcu_dereference(dev_maps->attr_map[tci]); 1723 if (!map) 1724 continue; 1725 1726 for (i = map->len; i--;) { 1727 if (map->queues[i] == index) { 1728 __set_bit(j, mask); 1729 break; 1730 } 1731 } 1732 } 1733 out_no_maps: 1734 rcu_read_unlock(); 1735 1736 len = bitmap_print_to_pagebuf(false, buf, mask, nr_ids); 1737 bitmap_free(mask); 1738 1739 return len < PAGE_SIZE ? len : -EINVAL; 1740 } 1741 1742 static ssize_t xps_cpus_show(struct kobject *kobj, struct attribute *attr, 1743 struct netdev_queue *queue, char *buf) 1744 { 1745 struct net_device *dev = queue->dev; 1746 unsigned int index; 1747 int len, tc, ret; 1748 1749 if (!netif_is_multiqueue(dev)) 1750 return -ENOENT; 1751 1752 index = get_netdev_queue_index(queue); 1753 1754 ret = sysfs_rtnl_lock(kobj, attr, queue->dev); 1755 if (ret) 1756 return ret; 1757 1758 /* If queue belongs to subordinate dev use its map */ 1759 dev = netdev_get_tx_queue(dev, index)->sb_dev ? : dev; 1760 1761 tc = netdev_txq_to_tc(dev, index); 1762 if (tc < 0) { 1763 rtnl_unlock(); 1764 return -EINVAL; 1765 } 1766 1767 /* Increase the net device refcnt to make sure it won't be freed while 1768 * xps_queue_show is running. 1769 */ 1770 dev_hold(dev); 1771 rtnl_unlock(); 1772 1773 len = xps_queue_show(dev, index, tc, buf, XPS_CPUS); 1774 1775 dev_put(dev); 1776 return len; 1777 } 1778 1779 static ssize_t xps_cpus_store(struct kobject *kobj, struct attribute *attr, 1780 struct netdev_queue *queue, const char *buf, 1781 size_t len) 1782 { 1783 struct net_device *dev = queue->dev; 1784 unsigned int index; 1785 cpumask_var_t mask; 1786 int err; 1787 1788 if (!netif_is_multiqueue(dev)) 1789 return -ENOENT; 1790 1791 if (!capable(CAP_NET_ADMIN)) 1792 return -EPERM; 1793 1794 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) 1795 return -ENOMEM; 1796 1797 index = get_netdev_queue_index(queue); 1798 1799 err = bitmap_parse(buf, len, cpumask_bits(mask), nr_cpumask_bits); 1800 if (err) { 1801 free_cpumask_var(mask); 1802 return err; 1803 } 1804 1805 err = sysfs_rtnl_lock(kobj, attr, dev); 1806 if (err) { 1807 free_cpumask_var(mask); 1808 return err; 1809 } 1810 1811 err = netif_set_xps_queue(dev, mask, index); 1812 rtnl_unlock(); 1813 1814 free_cpumask_var(mask); 1815 1816 return err ? : len; 1817 } 1818 1819 static struct netdev_queue_attribute xps_cpus_attribute __ro_after_init 1820 = __ATTR_RW(xps_cpus); 1821 1822 static ssize_t xps_rxqs_show(struct kobject *kobj, struct attribute *attr, 1823 struct netdev_queue *queue, char *buf) 1824 { 1825 struct net_device *dev = queue->dev; 1826 unsigned int index; 1827 int tc, ret; 1828 1829 index = get_netdev_queue_index(queue); 1830 1831 ret = sysfs_rtnl_lock(kobj, attr, dev); 1832 if (ret) 1833 return ret; 1834 1835 tc = netdev_txq_to_tc(dev, index); 1836 1837 /* Increase the net device refcnt to make sure it won't be freed while 1838 * xps_queue_show is running. 1839 */ 1840 dev_hold(dev); 1841 rtnl_unlock(); 1842 1843 ret = tc >= 0 ? xps_queue_show(dev, index, tc, buf, XPS_RXQS) : -EINVAL; 1844 dev_put(dev); 1845 return ret; 1846 } 1847 1848 static ssize_t xps_rxqs_store(struct kobject *kobj, struct attribute *attr, 1849 struct netdev_queue *queue, const char *buf, 1850 size_t len) 1851 { 1852 struct net_device *dev = queue->dev; 1853 struct net *net = dev_net(dev); 1854 unsigned long *mask; 1855 unsigned int index; 1856 int err; 1857 1858 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1859 return -EPERM; 1860 1861 mask = bitmap_zalloc(dev->num_rx_queues, GFP_KERNEL); 1862 if (!mask) 1863 return -ENOMEM; 1864 1865 index = get_netdev_queue_index(queue); 1866 1867 err = bitmap_parse(buf, len, mask, dev->num_rx_queues); 1868 if (err) { 1869 bitmap_free(mask); 1870 return err; 1871 } 1872 1873 err = sysfs_rtnl_lock(kobj, attr, dev); 1874 if (err) { 1875 bitmap_free(mask); 1876 return err; 1877 } 1878 1879 cpus_read_lock(); 1880 err = __netif_set_xps_queue(dev, mask, index, XPS_RXQS); 1881 cpus_read_unlock(); 1882 1883 rtnl_unlock(); 1884 1885 bitmap_free(mask); 1886 return err ? : len; 1887 } 1888 1889 static struct netdev_queue_attribute xps_rxqs_attribute __ro_after_init 1890 = __ATTR_RW(xps_rxqs); 1891 #endif /* CONFIG_XPS */ 1892 1893 static struct attribute *netdev_queue_default_attrs[] __ro_after_init = { 1894 &queue_trans_timeout.attr, 1895 &queue_traffic_class.attr, 1896 #ifdef CONFIG_XPS 1897 &xps_cpus_attribute.attr, 1898 &xps_rxqs_attribute.attr, 1899 &queue_tx_maxrate.attr, 1900 #endif 1901 NULL 1902 }; 1903 ATTRIBUTE_GROUPS(netdev_queue_default); 1904 1905 static void netdev_queue_release(struct kobject *kobj) 1906 { 1907 struct netdev_queue *queue = to_netdev_queue(kobj); 1908 1909 memset(kobj, 0, sizeof(*kobj)); 1910 netdev_put(queue->dev, &queue->dev_tracker); 1911 } 1912 1913 static const void *netdev_queue_namespace(const struct kobject *kobj) 1914 { 1915 struct netdev_queue *queue = to_netdev_queue(kobj); 1916 struct device *dev = &queue->dev->dev; 1917 const void *ns = NULL; 1918 1919 if (dev->class && dev->class->namespace) 1920 ns = dev->class->namespace(dev); 1921 1922 return ns; 1923 } 1924 1925 static void netdev_queue_get_ownership(const struct kobject *kobj, 1926 kuid_t *uid, kgid_t *gid) 1927 { 1928 const struct net *net = netdev_queue_namespace(kobj); 1929 1930 net_ns_get_ownership(net, uid, gid); 1931 } 1932 1933 static const struct kobj_type netdev_queue_ktype = { 1934 .sysfs_ops = &netdev_queue_sysfs_ops, 1935 .release = netdev_queue_release, 1936 .namespace = netdev_queue_namespace, 1937 .get_ownership = netdev_queue_get_ownership, 1938 }; 1939 1940 static bool netdev_uses_bql(const struct net_device *dev) 1941 { 1942 if (dev->lltx || (dev->priv_flags & IFF_NO_QUEUE)) 1943 return false; 1944 1945 return IS_ENABLED(CONFIG_BQL); 1946 } 1947 1948 static int netdev_queue_add_kobject(struct net_device *dev, int index) 1949 { 1950 struct netdev_queue *queue = dev->_tx + index; 1951 struct kobject *kobj = &queue->kobj; 1952 int error = 0; 1953 1954 /* Tx queues are cleared in netdev_queue_release to allow later 1955 * re-registration. This is triggered when their kobj refcount is 1956 * dropped. 1957 * 1958 * If a queue is removed while both a read (or write) operation and a 1959 * the re-addition of the same queue are pending (waiting on rntl_lock) 1960 * it might happen that the re-addition will execute before the read, 1961 * making the initial removal to never happen (queue's kobj refcount 1962 * won't drop enough because of the pending read). In such rare case, 1963 * return to allow the removal operation to complete. 1964 */ 1965 if (unlikely(kobj->state_initialized)) { 1966 netdev_warn_once(dev, "Cannot re-add tx queues before their removal completed"); 1967 return -EAGAIN; 1968 } 1969 1970 /* Kobject_put later will trigger netdev_queue_release call 1971 * which decreases dev refcount: Take that reference here 1972 */ 1973 netdev_hold(queue->dev, &queue->dev_tracker, GFP_KERNEL); 1974 1975 kobj->kset = dev->queues_kset; 1976 error = kobject_init_and_add(kobj, &netdev_queue_ktype, NULL, 1977 "tx-%u", index); 1978 if (error) 1979 goto err; 1980 1981 queue->groups = netdev_queue_default_groups; 1982 error = sysfs_create_groups(kobj, queue->groups); 1983 if (error) 1984 goto err; 1985 1986 if (netdev_uses_bql(dev)) { 1987 error = sysfs_create_group(kobj, &dql_group); 1988 if (error) 1989 goto err_default_groups; 1990 } 1991 1992 kobject_uevent(kobj, KOBJ_ADD); 1993 return 0; 1994 1995 err_default_groups: 1996 sysfs_remove_groups(kobj, queue->groups); 1997 err: 1998 kobject_put(kobj); 1999 return error; 2000 } 2001 2002 static int tx_queue_change_owner(struct net_device *ndev, int index, 2003 kuid_t kuid, kgid_t kgid) 2004 { 2005 struct netdev_queue *queue = ndev->_tx + index; 2006 struct kobject *kobj = &queue->kobj; 2007 int error; 2008 2009 error = sysfs_change_owner(kobj, kuid, kgid); 2010 if (error) 2011 return error; 2012 2013 if (netdev_uses_bql(ndev)) 2014 error = sysfs_group_change_owner(kobj, &dql_group, kuid, kgid); 2015 2016 return error; 2017 } 2018 #endif /* CONFIG_SYSFS */ 2019 2020 int 2021 netdev_queue_update_kobjects(struct net_device *dev, int old_num, int new_num) 2022 { 2023 #ifdef CONFIG_SYSFS 2024 int i; 2025 int error = 0; 2026 2027 /* Tx queue kobjects are allowed to be updated when a device is being 2028 * unregistered, but solely to remove queues from qdiscs. Any path 2029 * adding queues should be fixed. 2030 */ 2031 WARN(dev->reg_state == NETREG_UNREGISTERING && new_num > old_num, 2032 "New queues can't be registered after device unregistration."); 2033 2034 for (i = old_num; i < new_num; i++) { 2035 error = netdev_queue_add_kobject(dev, i); 2036 if (error) { 2037 new_num = old_num; 2038 break; 2039 } 2040 } 2041 2042 while (--i >= new_num) { 2043 struct netdev_queue *queue = dev->_tx + i; 2044 2045 if (!refcount_read(&dev_net(dev)->ns.count)) 2046 queue->kobj.uevent_suppress = 1; 2047 2048 if (netdev_uses_bql(dev)) 2049 sysfs_remove_group(&queue->kobj, &dql_group); 2050 2051 sysfs_remove_groups(&queue->kobj, queue->groups); 2052 kobject_put(&queue->kobj); 2053 } 2054 2055 return error; 2056 #else 2057 return 0; 2058 #endif /* CONFIG_SYSFS */ 2059 } 2060 2061 static int net_tx_queue_change_owner(struct net_device *dev, int num, 2062 kuid_t kuid, kgid_t kgid) 2063 { 2064 #ifdef CONFIG_SYSFS 2065 int error = 0; 2066 int i; 2067 2068 for (i = 0; i < num; i++) { 2069 error = tx_queue_change_owner(dev, i, kuid, kgid); 2070 if (error) 2071 break; 2072 } 2073 2074 return error; 2075 #else 2076 return 0; 2077 #endif /* CONFIG_SYSFS */ 2078 } 2079 2080 static int register_queue_kobjects(struct net_device *dev) 2081 { 2082 int error = 0, txq = 0, rxq = 0, real_rx = 0, real_tx = 0; 2083 2084 #ifdef CONFIG_SYSFS 2085 dev->queues_kset = kset_create_and_add("queues", 2086 NULL, &dev->dev.kobj); 2087 if (!dev->queues_kset) 2088 return -ENOMEM; 2089 real_rx = dev->real_num_rx_queues; 2090 #endif 2091 real_tx = dev->real_num_tx_queues; 2092 2093 error = net_rx_queue_update_kobjects(dev, 0, real_rx); 2094 if (error) 2095 goto error; 2096 rxq = real_rx; 2097 2098 error = netdev_queue_update_kobjects(dev, 0, real_tx); 2099 if (error) 2100 goto error; 2101 txq = real_tx; 2102 2103 return 0; 2104 2105 error: 2106 netdev_queue_update_kobjects(dev, txq, 0); 2107 net_rx_queue_update_kobjects(dev, rxq, 0); 2108 #ifdef CONFIG_SYSFS 2109 kset_unregister(dev->queues_kset); 2110 #endif 2111 return error; 2112 } 2113 2114 static int queue_change_owner(struct net_device *ndev, kuid_t kuid, kgid_t kgid) 2115 { 2116 int error = 0, real_rx = 0, real_tx = 0; 2117 2118 #ifdef CONFIG_SYSFS 2119 if (ndev->queues_kset) { 2120 error = sysfs_change_owner(&ndev->queues_kset->kobj, kuid, kgid); 2121 if (error) 2122 return error; 2123 } 2124 real_rx = ndev->real_num_rx_queues; 2125 #endif 2126 real_tx = ndev->real_num_tx_queues; 2127 2128 error = net_rx_queue_change_owner(ndev, real_rx, kuid, kgid); 2129 if (error) 2130 return error; 2131 2132 error = net_tx_queue_change_owner(ndev, real_tx, kuid, kgid); 2133 if (error) 2134 return error; 2135 2136 return 0; 2137 } 2138 2139 static void remove_queue_kobjects(struct net_device *dev) 2140 { 2141 int real_rx = 0, real_tx = 0; 2142 2143 #ifdef CONFIG_SYSFS 2144 real_rx = dev->real_num_rx_queues; 2145 #endif 2146 real_tx = dev->real_num_tx_queues; 2147 2148 net_rx_queue_update_kobjects(dev, real_rx, 0); 2149 netdev_queue_update_kobjects(dev, real_tx, 0); 2150 2151 netdev_lock_ops(dev); 2152 dev->real_num_rx_queues = 0; 2153 dev->real_num_tx_queues = 0; 2154 netdev_unlock_ops(dev); 2155 #ifdef CONFIG_SYSFS 2156 kset_unregister(dev->queues_kset); 2157 #endif 2158 } 2159 2160 static bool net_current_may_mount(void) 2161 { 2162 struct net *net = current->nsproxy->net_ns; 2163 2164 return ns_capable(net->user_ns, CAP_SYS_ADMIN); 2165 } 2166 2167 static void *net_grab_current_ns(void) 2168 { 2169 struct net *ns = current->nsproxy->net_ns; 2170 #ifdef CONFIG_NET_NS 2171 if (ns) 2172 refcount_inc(&ns->passive); 2173 #endif 2174 return ns; 2175 } 2176 2177 static const void *net_initial_ns(void) 2178 { 2179 return &init_net; 2180 } 2181 2182 static const void *net_netlink_ns(struct sock *sk) 2183 { 2184 return sock_net(sk); 2185 } 2186 2187 const struct kobj_ns_type_operations net_ns_type_operations = { 2188 .type = KOBJ_NS_TYPE_NET, 2189 .current_may_mount = net_current_may_mount, 2190 .grab_current_ns = net_grab_current_ns, 2191 .netlink_ns = net_netlink_ns, 2192 .initial_ns = net_initial_ns, 2193 .drop_ns = net_drop_ns, 2194 }; 2195 EXPORT_SYMBOL_GPL(net_ns_type_operations); 2196 2197 static int netdev_uevent(const struct device *d, struct kobj_uevent_env *env) 2198 { 2199 const struct net_device *dev = to_net_dev(d); 2200 int retval; 2201 2202 /* pass interface to uevent. */ 2203 retval = add_uevent_var(env, "INTERFACE=%s", dev->name); 2204 if (retval) 2205 goto exit; 2206 2207 /* pass ifindex to uevent. 2208 * ifindex is useful as it won't change (interface name may change) 2209 * and is what RtNetlink uses natively. 2210 */ 2211 retval = add_uevent_var(env, "IFINDEX=%d", dev->ifindex); 2212 2213 exit: 2214 return retval; 2215 } 2216 2217 /* 2218 * netdev_release -- destroy and free a dead device. 2219 * Called when last reference to device kobject is gone. 2220 */ 2221 static void netdev_release(struct device *d) 2222 { 2223 struct net_device *dev = to_net_dev(d); 2224 2225 BUG_ON(dev->reg_state != NETREG_RELEASED); 2226 2227 /* no need to wait for rcu grace period: 2228 * device is dead and about to be freed. 2229 */ 2230 kfree(rcu_access_pointer(dev->ifalias)); 2231 kvfree(dev); 2232 } 2233 2234 static const void *net_namespace(const struct device *d) 2235 { 2236 const struct net_device *dev = to_net_dev(d); 2237 2238 return dev_net(dev); 2239 } 2240 2241 static void net_get_ownership(const struct device *d, kuid_t *uid, kgid_t *gid) 2242 { 2243 const struct net_device *dev = to_net_dev(d); 2244 const struct net *net = dev_net(dev); 2245 2246 net_ns_get_ownership(net, uid, gid); 2247 } 2248 2249 static const struct class net_class = { 2250 .name = "net", 2251 .dev_release = netdev_release, 2252 .dev_groups = net_class_groups, 2253 .dev_uevent = netdev_uevent, 2254 .ns_type = &net_ns_type_operations, 2255 .namespace = net_namespace, 2256 .get_ownership = net_get_ownership, 2257 }; 2258 2259 #ifdef CONFIG_OF 2260 static int of_dev_node_match(struct device *dev, const void *data) 2261 { 2262 for (; dev; dev = dev->parent) { 2263 if (dev->of_node == data) 2264 return 1; 2265 } 2266 2267 return 0; 2268 } 2269 2270 /* 2271 * of_find_net_device_by_node - lookup the net device for the device node 2272 * @np: OF device node 2273 * 2274 * Looks up the net_device structure corresponding with the device node. 2275 * If successful, returns a pointer to the net_device with the embedded 2276 * struct device refcount incremented by one, or NULL on failure. The 2277 * refcount must be dropped when done with the net_device. 2278 */ 2279 struct net_device *of_find_net_device_by_node(struct device_node *np) 2280 { 2281 struct device *dev; 2282 2283 dev = class_find_device(&net_class, NULL, np, of_dev_node_match); 2284 if (!dev) 2285 return NULL; 2286 2287 return to_net_dev(dev); 2288 } 2289 EXPORT_SYMBOL(of_find_net_device_by_node); 2290 #endif 2291 2292 /* Delete sysfs entries but hold kobject reference until after all 2293 * netdev references are gone. 2294 */ 2295 void netdev_unregister_kobject(struct net_device *ndev) 2296 { 2297 struct device *dev = &ndev->dev; 2298 2299 if (!refcount_read(&dev_net(ndev)->ns.count)) 2300 dev_set_uevent_suppress(dev, 1); 2301 2302 kobject_get(&dev->kobj); 2303 2304 remove_queue_kobjects(ndev); 2305 2306 pm_runtime_set_memalloc_noio(dev, false); 2307 2308 device_del(dev); 2309 } 2310 2311 /* Create sysfs entries for network device. */ 2312 int netdev_register_kobject(struct net_device *ndev) 2313 { 2314 struct device *dev = &ndev->dev; 2315 const struct attribute_group **groups = ndev->sysfs_groups; 2316 int error = 0; 2317 2318 device_initialize(dev); 2319 dev->class = &net_class; 2320 dev->platform_data = ndev; 2321 dev->groups = groups; 2322 2323 dev_set_name(dev, "%s", ndev->name); 2324 2325 #ifdef CONFIG_SYSFS 2326 /* Allow for a device specific group */ 2327 if (*groups) 2328 groups++; 2329 2330 *groups++ = &netstat_group; 2331 2332 if (wireless_group_needed(ndev)) 2333 *groups++ = &wireless_group; 2334 #endif /* CONFIG_SYSFS */ 2335 2336 error = device_add(dev); 2337 if (error) 2338 return error; 2339 2340 error = register_queue_kobjects(ndev); 2341 if (error) { 2342 device_del(dev); 2343 return error; 2344 } 2345 2346 pm_runtime_set_memalloc_noio(dev, true); 2347 2348 return error; 2349 } 2350 2351 /* Change owner for sysfs entries when moving network devices across network 2352 * namespaces owned by different user namespaces. 2353 */ 2354 int netdev_change_owner(struct net_device *ndev, const struct net *net_old, 2355 const struct net *net_new) 2356 { 2357 kuid_t old_uid = GLOBAL_ROOT_UID, new_uid = GLOBAL_ROOT_UID; 2358 kgid_t old_gid = GLOBAL_ROOT_GID, new_gid = GLOBAL_ROOT_GID; 2359 struct device *dev = &ndev->dev; 2360 int error; 2361 2362 net_ns_get_ownership(net_old, &old_uid, &old_gid); 2363 net_ns_get_ownership(net_new, &new_uid, &new_gid); 2364 2365 /* The network namespace was changed but the owning user namespace is 2366 * identical so there's no need to change the owner of sysfs entries. 2367 */ 2368 if (uid_eq(old_uid, new_uid) && gid_eq(old_gid, new_gid)) 2369 return 0; 2370 2371 error = device_change_owner(dev, new_uid, new_gid); 2372 if (error) 2373 return error; 2374 2375 error = queue_change_owner(ndev, new_uid, new_gid); 2376 if (error) 2377 return error; 2378 2379 return 0; 2380 } 2381 2382 int netdev_class_create_file_ns(const struct class_attribute *class_attr, 2383 const void *ns) 2384 { 2385 return class_create_file_ns(&net_class, class_attr, ns); 2386 } 2387 EXPORT_SYMBOL(netdev_class_create_file_ns); 2388 2389 void netdev_class_remove_file_ns(const struct class_attribute *class_attr, 2390 const void *ns) 2391 { 2392 class_remove_file_ns(&net_class, class_attr, ns); 2393 } 2394 EXPORT_SYMBOL(netdev_class_remove_file_ns); 2395 2396 int __init netdev_kobject_init(void) 2397 { 2398 kobj_ns_type_register(&net_ns_type_operations); 2399 return class_register(&net_class); 2400 } 2401