1 // SPDX-License-Identifier: GPL-2.0 2 /* -*- linux-c -*- 3 * sysctl_net_core.c: sysctl interface to net core subsystem. 4 * 5 * Begun April 1, 1996, Mike Shaver. 6 * Added /proc/sys/net/core directory entry (empty =) ). [MS] 7 */ 8 9 #include <linux/filter.h> 10 #include <linux/mm.h> 11 #include <linux/sysctl.h> 12 #include <linux/module.h> 13 #include <linux/socket.h> 14 #include <linux/netdevice.h> 15 #include <linux/ratelimit.h> 16 #include <linux/vmalloc.h> 17 #include <linux/init.h> 18 #include <linux/slab.h> 19 #include <linux/sched/isolation.h> 20 21 #include <net/ip.h> 22 #include <net/sock.h> 23 #include <net/net_ratelimit.h> 24 #include <net/busy_poll.h> 25 #include <net/pkt_sched.h> 26 27 #include "dev.h" 28 29 static int int_3600 = 3600; 30 static int min_sndbuf = SOCK_MIN_SNDBUF; 31 static int min_rcvbuf = SOCK_MIN_RCVBUF; 32 static int max_skb_frags = MAX_SKB_FRAGS; 33 34 static int net_msg_warn; /* Unused, but still a sysctl */ 35 36 int sysctl_fb_tunnels_only_for_init_net __read_mostly = 0; 37 EXPORT_SYMBOL(sysctl_fb_tunnels_only_for_init_net); 38 39 /* 0 - Keep current behavior: 40 * IPv4: inherit all current settings from init_net 41 * IPv6: reset all settings to default 42 * 1 - Both inherit all current settings from init_net 43 * 2 - Both reset all settings to default 44 * 3 - Both inherit all settings from current netns 45 */ 46 int sysctl_devconf_inherit_init_net __read_mostly; 47 EXPORT_SYMBOL(sysctl_devconf_inherit_init_net); 48 49 #if IS_ENABLED(CONFIG_NET_FLOW_LIMIT) || IS_ENABLED(CONFIG_RPS) 50 static void dump_cpumask(void *buffer, size_t *lenp, loff_t *ppos, 51 struct cpumask *mask) 52 { 53 char kbuf[128]; 54 int len; 55 56 if (*ppos || !*lenp) { 57 *lenp = 0; 58 return; 59 } 60 61 len = min(sizeof(kbuf) - 1, *lenp); 62 len = scnprintf(kbuf, len, "%*pb", cpumask_pr_args(mask)); 63 if (!len) { 64 *lenp = 0; 65 return; 66 } 67 68 if (len < *lenp) 69 kbuf[len++] = '\n'; 70 memcpy(buffer, kbuf, len); 71 *lenp = len; 72 *ppos += len; 73 } 74 #endif 75 76 #ifdef CONFIG_RPS 77 78 static struct cpumask *rps_default_mask_cow_alloc(struct net *net) 79 { 80 struct cpumask *rps_default_mask; 81 82 if (net->core.rps_default_mask) 83 return net->core.rps_default_mask; 84 85 rps_default_mask = kzalloc(cpumask_size(), GFP_KERNEL); 86 if (!rps_default_mask) 87 return NULL; 88 89 /* pairs with READ_ONCE in rx_queue_default_mask() */ 90 WRITE_ONCE(net->core.rps_default_mask, rps_default_mask); 91 return rps_default_mask; 92 } 93 94 static int rps_default_mask_sysctl(struct ctl_table *table, int write, 95 void *buffer, size_t *lenp, loff_t *ppos) 96 { 97 struct net *net = (struct net *)table->data; 98 int err = 0; 99 100 rtnl_lock(); 101 if (write) { 102 struct cpumask *rps_default_mask = rps_default_mask_cow_alloc(net); 103 104 err = -ENOMEM; 105 if (!rps_default_mask) 106 goto done; 107 108 err = cpumask_parse(buffer, rps_default_mask); 109 if (err) 110 goto done; 111 112 err = rps_cpumask_housekeeping(rps_default_mask); 113 if (err) 114 goto done; 115 } else { 116 dump_cpumask(buffer, lenp, ppos, 117 net->core.rps_default_mask ? : cpu_none_mask); 118 } 119 120 done: 121 rtnl_unlock(); 122 return err; 123 } 124 125 static int rps_sock_flow_sysctl(struct ctl_table *table, int write, 126 void *buffer, size_t *lenp, loff_t *ppos) 127 { 128 unsigned int orig_size, size; 129 int ret, i; 130 struct ctl_table tmp = { 131 .data = &size, 132 .maxlen = sizeof(size), 133 .mode = table->mode 134 }; 135 struct rps_sock_flow_table *orig_sock_table, *sock_table; 136 static DEFINE_MUTEX(sock_flow_mutex); 137 138 mutex_lock(&sock_flow_mutex); 139 140 orig_sock_table = rcu_dereference_protected(rps_sock_flow_table, 141 lockdep_is_held(&sock_flow_mutex)); 142 size = orig_size = orig_sock_table ? orig_sock_table->mask + 1 : 0; 143 144 ret = proc_dointvec(&tmp, write, buffer, lenp, ppos); 145 146 if (write) { 147 if (size) { 148 if (size > 1<<29) { 149 /* Enforce limit to prevent overflow */ 150 mutex_unlock(&sock_flow_mutex); 151 return -EINVAL; 152 } 153 size = roundup_pow_of_two(size); 154 if (size != orig_size) { 155 sock_table = 156 vmalloc(RPS_SOCK_FLOW_TABLE_SIZE(size)); 157 if (!sock_table) { 158 mutex_unlock(&sock_flow_mutex); 159 return -ENOMEM; 160 } 161 rps_cpu_mask = roundup_pow_of_two(nr_cpu_ids) - 1; 162 sock_table->mask = size - 1; 163 } else 164 sock_table = orig_sock_table; 165 166 for (i = 0; i < size; i++) 167 sock_table->ents[i] = RPS_NO_CPU; 168 } else 169 sock_table = NULL; 170 171 if (sock_table != orig_sock_table) { 172 rcu_assign_pointer(rps_sock_flow_table, sock_table); 173 if (sock_table) { 174 static_branch_inc(&rps_needed); 175 static_branch_inc(&rfs_needed); 176 } 177 if (orig_sock_table) { 178 static_branch_dec(&rps_needed); 179 static_branch_dec(&rfs_needed); 180 kvfree_rcu_mightsleep(orig_sock_table); 181 } 182 } 183 } 184 185 mutex_unlock(&sock_flow_mutex); 186 187 return ret; 188 } 189 #endif /* CONFIG_RPS */ 190 191 #ifdef CONFIG_NET_FLOW_LIMIT 192 static DEFINE_MUTEX(flow_limit_update_mutex); 193 194 static int flow_limit_cpu_sysctl(struct ctl_table *table, int write, 195 void *buffer, size_t *lenp, loff_t *ppos) 196 { 197 struct sd_flow_limit *cur; 198 struct softnet_data *sd; 199 cpumask_var_t mask; 200 int i, len, ret = 0; 201 202 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) 203 return -ENOMEM; 204 205 if (write) { 206 ret = cpumask_parse(buffer, mask); 207 if (ret) 208 goto done; 209 210 mutex_lock(&flow_limit_update_mutex); 211 len = sizeof(*cur) + netdev_flow_limit_table_len; 212 for_each_possible_cpu(i) { 213 sd = &per_cpu(softnet_data, i); 214 cur = rcu_dereference_protected(sd->flow_limit, 215 lockdep_is_held(&flow_limit_update_mutex)); 216 if (cur && !cpumask_test_cpu(i, mask)) { 217 RCU_INIT_POINTER(sd->flow_limit, NULL); 218 kfree_rcu_mightsleep(cur); 219 } else if (!cur && cpumask_test_cpu(i, mask)) { 220 cur = kzalloc_node(len, GFP_KERNEL, 221 cpu_to_node(i)); 222 if (!cur) { 223 /* not unwinding previous changes */ 224 ret = -ENOMEM; 225 goto write_unlock; 226 } 227 cur->num_buckets = netdev_flow_limit_table_len; 228 rcu_assign_pointer(sd->flow_limit, cur); 229 } 230 } 231 write_unlock: 232 mutex_unlock(&flow_limit_update_mutex); 233 } else { 234 cpumask_clear(mask); 235 rcu_read_lock(); 236 for_each_possible_cpu(i) { 237 sd = &per_cpu(softnet_data, i); 238 if (rcu_dereference(sd->flow_limit)) 239 cpumask_set_cpu(i, mask); 240 } 241 rcu_read_unlock(); 242 243 dump_cpumask(buffer, lenp, ppos, mask); 244 } 245 246 done: 247 free_cpumask_var(mask); 248 return ret; 249 } 250 251 static int flow_limit_table_len_sysctl(struct ctl_table *table, int write, 252 void *buffer, size_t *lenp, loff_t *ppos) 253 { 254 unsigned int old, *ptr; 255 int ret; 256 257 mutex_lock(&flow_limit_update_mutex); 258 259 ptr = table->data; 260 old = *ptr; 261 ret = proc_dointvec(table, write, buffer, lenp, ppos); 262 if (!ret && write && !is_power_of_2(*ptr)) { 263 *ptr = old; 264 ret = -EINVAL; 265 } 266 267 mutex_unlock(&flow_limit_update_mutex); 268 return ret; 269 } 270 #endif /* CONFIG_NET_FLOW_LIMIT */ 271 272 #ifdef CONFIG_NET_SCHED 273 static int set_default_qdisc(struct ctl_table *table, int write, 274 void *buffer, size_t *lenp, loff_t *ppos) 275 { 276 char id[IFNAMSIZ]; 277 struct ctl_table tbl = { 278 .data = id, 279 .maxlen = IFNAMSIZ, 280 }; 281 int ret; 282 283 qdisc_get_default(id, IFNAMSIZ); 284 285 ret = proc_dostring(&tbl, write, buffer, lenp, ppos); 286 if (write && ret == 0) 287 ret = qdisc_set_default(id); 288 return ret; 289 } 290 #endif 291 292 static int proc_do_dev_weight(struct ctl_table *table, int write, 293 void *buffer, size_t *lenp, loff_t *ppos) 294 { 295 static DEFINE_MUTEX(dev_weight_mutex); 296 int ret, weight; 297 298 mutex_lock(&dev_weight_mutex); 299 ret = proc_dointvec(table, write, buffer, lenp, ppos); 300 if (!ret && write) { 301 weight = READ_ONCE(weight_p); 302 WRITE_ONCE(dev_rx_weight, weight * dev_weight_rx_bias); 303 WRITE_ONCE(dev_tx_weight, weight * dev_weight_tx_bias); 304 } 305 mutex_unlock(&dev_weight_mutex); 306 307 return ret; 308 } 309 310 static int proc_do_rss_key(struct ctl_table *table, int write, 311 void *buffer, size_t *lenp, loff_t *ppos) 312 { 313 struct ctl_table fake_table; 314 char buf[NETDEV_RSS_KEY_LEN * 3]; 315 316 snprintf(buf, sizeof(buf), "%*phC", NETDEV_RSS_KEY_LEN, netdev_rss_key); 317 fake_table.data = buf; 318 fake_table.maxlen = sizeof(buf); 319 return proc_dostring(&fake_table, write, buffer, lenp, ppos); 320 } 321 322 #ifdef CONFIG_BPF_JIT 323 static int proc_dointvec_minmax_bpf_enable(struct ctl_table *table, int write, 324 void *buffer, size_t *lenp, 325 loff_t *ppos) 326 { 327 int ret, jit_enable = *(int *)table->data; 328 int min = *(int *)table->extra1; 329 int max = *(int *)table->extra2; 330 struct ctl_table tmp = *table; 331 332 if (write && !capable(CAP_SYS_ADMIN)) 333 return -EPERM; 334 335 tmp.data = &jit_enable; 336 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 337 if (write && !ret) { 338 if (jit_enable < 2 || 339 (jit_enable == 2 && bpf_dump_raw_ok(current_cred()))) { 340 *(int *)table->data = jit_enable; 341 if (jit_enable == 2) 342 pr_warn("bpf_jit_enable = 2 was set! NEVER use this in production, only for JIT debugging!\n"); 343 } else { 344 ret = -EPERM; 345 } 346 } 347 348 if (write && ret && min == max) 349 pr_info_once("CONFIG_BPF_JIT_ALWAYS_ON is enabled, bpf_jit_enable is permanently set to 1.\n"); 350 351 return ret; 352 } 353 354 # ifdef CONFIG_HAVE_EBPF_JIT 355 static int 356 proc_dointvec_minmax_bpf_restricted(struct ctl_table *table, int write, 357 void *buffer, size_t *lenp, loff_t *ppos) 358 { 359 if (!capable(CAP_SYS_ADMIN)) 360 return -EPERM; 361 362 return proc_dointvec_minmax(table, write, buffer, lenp, ppos); 363 } 364 # endif /* CONFIG_HAVE_EBPF_JIT */ 365 366 static int 367 proc_dolongvec_minmax_bpf_restricted(struct ctl_table *table, int write, 368 void *buffer, size_t *lenp, loff_t *ppos) 369 { 370 if (!capable(CAP_SYS_ADMIN)) 371 return -EPERM; 372 373 return proc_doulongvec_minmax(table, write, buffer, lenp, ppos); 374 } 375 #endif 376 377 static struct ctl_table net_core_table[] = { 378 { 379 .procname = "wmem_max", 380 .data = &sysctl_wmem_max, 381 .maxlen = sizeof(int), 382 .mode = 0644, 383 .proc_handler = proc_dointvec_minmax, 384 .extra1 = &min_sndbuf, 385 }, 386 { 387 .procname = "rmem_max", 388 .data = &sysctl_rmem_max, 389 .maxlen = sizeof(int), 390 .mode = 0644, 391 .proc_handler = proc_dointvec_minmax, 392 .extra1 = &min_rcvbuf, 393 }, 394 { 395 .procname = "wmem_default", 396 .data = &sysctl_wmem_default, 397 .maxlen = sizeof(int), 398 .mode = 0644, 399 .proc_handler = proc_dointvec_minmax, 400 .extra1 = &min_sndbuf, 401 }, 402 { 403 .procname = "rmem_default", 404 .data = &sysctl_rmem_default, 405 .maxlen = sizeof(int), 406 .mode = 0644, 407 .proc_handler = proc_dointvec_minmax, 408 .extra1 = &min_rcvbuf, 409 }, 410 { 411 .procname = "dev_weight", 412 .data = &weight_p, 413 .maxlen = sizeof(int), 414 .mode = 0644, 415 .proc_handler = proc_do_dev_weight, 416 }, 417 { 418 .procname = "dev_weight_rx_bias", 419 .data = &dev_weight_rx_bias, 420 .maxlen = sizeof(int), 421 .mode = 0644, 422 .proc_handler = proc_do_dev_weight, 423 }, 424 { 425 .procname = "dev_weight_tx_bias", 426 .data = &dev_weight_tx_bias, 427 .maxlen = sizeof(int), 428 .mode = 0644, 429 .proc_handler = proc_do_dev_weight, 430 }, 431 { 432 .procname = "netdev_max_backlog", 433 .data = &netdev_max_backlog, 434 .maxlen = sizeof(int), 435 .mode = 0644, 436 .proc_handler = proc_dointvec 437 }, 438 { 439 .procname = "netdev_rss_key", 440 .data = &netdev_rss_key, 441 .maxlen = sizeof(int), 442 .mode = 0444, 443 .proc_handler = proc_do_rss_key, 444 }, 445 #ifdef CONFIG_BPF_JIT 446 { 447 .procname = "bpf_jit_enable", 448 .data = &bpf_jit_enable, 449 .maxlen = sizeof(int), 450 .mode = 0644, 451 .proc_handler = proc_dointvec_minmax_bpf_enable, 452 # ifdef CONFIG_BPF_JIT_ALWAYS_ON 453 .extra1 = SYSCTL_ONE, 454 .extra2 = SYSCTL_ONE, 455 # else 456 .extra1 = SYSCTL_ZERO, 457 .extra2 = SYSCTL_TWO, 458 # endif 459 }, 460 # ifdef CONFIG_HAVE_EBPF_JIT 461 { 462 .procname = "bpf_jit_harden", 463 .data = &bpf_jit_harden, 464 .maxlen = sizeof(int), 465 .mode = 0600, 466 .proc_handler = proc_dointvec_minmax_bpf_restricted, 467 .extra1 = SYSCTL_ZERO, 468 .extra2 = SYSCTL_TWO, 469 }, 470 { 471 .procname = "bpf_jit_kallsyms", 472 .data = &bpf_jit_kallsyms, 473 .maxlen = sizeof(int), 474 .mode = 0600, 475 .proc_handler = proc_dointvec_minmax_bpf_restricted, 476 .extra1 = SYSCTL_ZERO, 477 .extra2 = SYSCTL_ONE, 478 }, 479 # endif 480 { 481 .procname = "bpf_jit_limit", 482 .data = &bpf_jit_limit, 483 .maxlen = sizeof(long), 484 .mode = 0600, 485 .proc_handler = proc_dolongvec_minmax_bpf_restricted, 486 .extra1 = SYSCTL_LONG_ONE, 487 .extra2 = &bpf_jit_limit_max, 488 }, 489 #endif 490 { 491 .procname = "netdev_tstamp_prequeue", 492 .data = &netdev_tstamp_prequeue, 493 .maxlen = sizeof(int), 494 .mode = 0644, 495 .proc_handler = proc_dointvec 496 }, 497 { 498 .procname = "message_cost", 499 .data = &net_ratelimit_state.interval, 500 .maxlen = sizeof(int), 501 .mode = 0644, 502 .proc_handler = proc_dointvec_jiffies, 503 }, 504 { 505 .procname = "message_burst", 506 .data = &net_ratelimit_state.burst, 507 .maxlen = sizeof(int), 508 .mode = 0644, 509 .proc_handler = proc_dointvec, 510 }, 511 { 512 .procname = "optmem_max", 513 .data = &sysctl_optmem_max, 514 .maxlen = sizeof(int), 515 .mode = 0644, 516 .proc_handler = proc_dointvec 517 }, 518 { 519 .procname = "tstamp_allow_data", 520 .data = &sysctl_tstamp_allow_data, 521 .maxlen = sizeof(int), 522 .mode = 0644, 523 .proc_handler = proc_dointvec_minmax, 524 .extra1 = SYSCTL_ZERO, 525 .extra2 = SYSCTL_ONE 526 }, 527 #ifdef CONFIG_RPS 528 { 529 .procname = "rps_sock_flow_entries", 530 .maxlen = sizeof(int), 531 .mode = 0644, 532 .proc_handler = rps_sock_flow_sysctl 533 }, 534 #endif 535 #ifdef CONFIG_NET_FLOW_LIMIT 536 { 537 .procname = "flow_limit_cpu_bitmap", 538 .mode = 0644, 539 .proc_handler = flow_limit_cpu_sysctl 540 }, 541 { 542 .procname = "flow_limit_table_len", 543 .data = &netdev_flow_limit_table_len, 544 .maxlen = sizeof(int), 545 .mode = 0644, 546 .proc_handler = flow_limit_table_len_sysctl 547 }, 548 #endif /* CONFIG_NET_FLOW_LIMIT */ 549 #ifdef CONFIG_NET_RX_BUSY_POLL 550 { 551 .procname = "busy_poll", 552 .data = &sysctl_net_busy_poll, 553 .maxlen = sizeof(unsigned int), 554 .mode = 0644, 555 .proc_handler = proc_dointvec_minmax, 556 .extra1 = SYSCTL_ZERO, 557 }, 558 { 559 .procname = "busy_read", 560 .data = &sysctl_net_busy_read, 561 .maxlen = sizeof(unsigned int), 562 .mode = 0644, 563 .proc_handler = proc_dointvec_minmax, 564 .extra1 = SYSCTL_ZERO, 565 }, 566 #endif 567 #ifdef CONFIG_NET_SCHED 568 { 569 .procname = "default_qdisc", 570 .mode = 0644, 571 .maxlen = IFNAMSIZ, 572 .proc_handler = set_default_qdisc 573 }, 574 #endif 575 { 576 .procname = "netdev_budget", 577 .data = &netdev_budget, 578 .maxlen = sizeof(int), 579 .mode = 0644, 580 .proc_handler = proc_dointvec 581 }, 582 { 583 .procname = "warnings", 584 .data = &net_msg_warn, 585 .maxlen = sizeof(int), 586 .mode = 0644, 587 .proc_handler = proc_dointvec 588 }, 589 { 590 .procname = "max_skb_frags", 591 .data = &sysctl_max_skb_frags, 592 .maxlen = sizeof(int), 593 .mode = 0644, 594 .proc_handler = proc_dointvec_minmax, 595 .extra1 = SYSCTL_ONE, 596 .extra2 = &max_skb_frags, 597 }, 598 { 599 .procname = "netdev_budget_usecs", 600 .data = &netdev_budget_usecs, 601 .maxlen = sizeof(unsigned int), 602 .mode = 0644, 603 .proc_handler = proc_dointvec_minmax, 604 .extra1 = SYSCTL_ZERO, 605 }, 606 { 607 .procname = "fb_tunnels_only_for_init_net", 608 .data = &sysctl_fb_tunnels_only_for_init_net, 609 .maxlen = sizeof(int), 610 .mode = 0644, 611 .proc_handler = proc_dointvec_minmax, 612 .extra1 = SYSCTL_ZERO, 613 .extra2 = SYSCTL_TWO, 614 }, 615 { 616 .procname = "devconf_inherit_init_net", 617 .data = &sysctl_devconf_inherit_init_net, 618 .maxlen = sizeof(int), 619 .mode = 0644, 620 .proc_handler = proc_dointvec_minmax, 621 .extra1 = SYSCTL_ZERO, 622 .extra2 = SYSCTL_THREE, 623 }, 624 { 625 .procname = "high_order_alloc_disable", 626 .data = &net_high_order_alloc_disable_key.key, 627 .maxlen = sizeof(net_high_order_alloc_disable_key), 628 .mode = 0644, 629 .proc_handler = proc_do_static_key, 630 }, 631 { 632 .procname = "gro_normal_batch", 633 .data = &gro_normal_batch, 634 .maxlen = sizeof(unsigned int), 635 .mode = 0644, 636 .proc_handler = proc_dointvec_minmax, 637 .extra1 = SYSCTL_ONE, 638 }, 639 { 640 .procname = "netdev_unregister_timeout_secs", 641 .data = &netdev_unregister_timeout_secs, 642 .maxlen = sizeof(unsigned int), 643 .mode = 0644, 644 .proc_handler = proc_dointvec_minmax, 645 .extra1 = SYSCTL_ONE, 646 .extra2 = &int_3600, 647 }, 648 { 649 .procname = "skb_defer_max", 650 .data = &sysctl_skb_defer_max, 651 .maxlen = sizeof(unsigned int), 652 .mode = 0644, 653 .proc_handler = proc_dointvec_minmax, 654 .extra1 = SYSCTL_ZERO, 655 }, 656 { } 657 }; 658 659 static struct ctl_table netns_core_table[] = { 660 #if IS_ENABLED(CONFIG_RPS) 661 { 662 .procname = "rps_default_mask", 663 .data = &init_net, 664 .mode = 0644, 665 .proc_handler = rps_default_mask_sysctl 666 }, 667 #endif 668 { 669 .procname = "somaxconn", 670 .data = &init_net.core.sysctl_somaxconn, 671 .maxlen = sizeof(int), 672 .mode = 0644, 673 .extra1 = SYSCTL_ZERO, 674 .proc_handler = proc_dointvec_minmax 675 }, 676 { 677 .procname = "txrehash", 678 .data = &init_net.core.sysctl_txrehash, 679 .maxlen = sizeof(u8), 680 .mode = 0644, 681 .extra1 = SYSCTL_ZERO, 682 .extra2 = SYSCTL_ONE, 683 .proc_handler = proc_dou8vec_minmax, 684 }, 685 { } 686 }; 687 688 static int __init fb_tunnels_only_for_init_net_sysctl_setup(char *str) 689 { 690 /* fallback tunnels for initns only */ 691 if (!strncmp(str, "initns", 6)) 692 sysctl_fb_tunnels_only_for_init_net = 1; 693 /* no fallback tunnels anywhere */ 694 else if (!strncmp(str, "none", 4)) 695 sysctl_fb_tunnels_only_for_init_net = 2; 696 697 return 1; 698 } 699 __setup("fb_tunnels=", fb_tunnels_only_for_init_net_sysctl_setup); 700 701 static __net_init int sysctl_core_net_init(struct net *net) 702 { 703 struct ctl_table *tbl, *tmp; 704 705 tbl = netns_core_table; 706 if (!net_eq(net, &init_net)) { 707 tbl = kmemdup(tbl, sizeof(netns_core_table), GFP_KERNEL); 708 if (tbl == NULL) 709 goto err_dup; 710 711 for (tmp = tbl; tmp->procname; tmp++) 712 tmp->data += (char *)net - (char *)&init_net; 713 } 714 715 net->core.sysctl_hdr = register_net_sysctl_sz(net, "net/core", tbl, 716 ARRAY_SIZE(netns_core_table)); 717 if (net->core.sysctl_hdr == NULL) 718 goto err_reg; 719 720 return 0; 721 722 err_reg: 723 if (tbl != netns_core_table) 724 kfree(tbl); 725 err_dup: 726 return -ENOMEM; 727 } 728 729 static __net_exit void sysctl_core_net_exit(struct net *net) 730 { 731 struct ctl_table *tbl; 732 733 tbl = net->core.sysctl_hdr->ctl_table_arg; 734 unregister_net_sysctl_table(net->core.sysctl_hdr); 735 BUG_ON(tbl == netns_core_table); 736 #if IS_ENABLED(CONFIG_RPS) 737 kfree(net->core.rps_default_mask); 738 #endif 739 kfree(tbl); 740 } 741 742 static __net_initdata struct pernet_operations sysctl_core_ops = { 743 .init = sysctl_core_net_init, 744 .exit = sysctl_core_net_exit, 745 }; 746 747 static __init int sysctl_core_init(void) 748 { 749 register_net_sysctl(&init_net, "net/core", net_core_table); 750 return register_pernet_subsys(&sysctl_core_ops); 751 } 752 753 fs_initcall(sysctl_core_init); 754