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