1 // SPDX-License-Identifier: GPL-2.0
3 * sysctl_net_core.c: sysctl interface to net core subsystem.
5 * Begun April 1, 1996, Mike Shaver.
6 * Added /proc/sys/net/core directory entry (empty =) ). [MS]
9 #include <linux/filter.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>
22 #include <net/net_ratelimit.h>
23 #include <net/busy_poll.h>
24 #include <net/pkt_sched.h>
28 static int int_3600 = 3600;
29 static int min_sndbuf = SOCK_MIN_SNDBUF;
30 static int min_rcvbuf = SOCK_MIN_RCVBUF;
31 static int max_skb_frags = MAX_SKB_FRAGS;
32 static int min_mem_pcpu_rsv = SK_MEMORY_PCPU_RESERVE;
34 static int net_msg_warn; /* Unused, but still a sysctl */
36 int sysctl_fb_tunnels_only_for_init_net __read_mostly = 0;
37 EXPORT_SYMBOL(sysctl_fb_tunnels_only_for_init_net);
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
46 int sysctl_devconf_inherit_init_net __read_mostly;
47 EXPORT_SYMBOL(sysctl_devconf_inherit_init_net);
50 static int rps_sock_flow_sysctl(struct ctl_table *table, int write,
51 void *buffer, size_t *lenp, loff_t *ppos)
53 unsigned int orig_size, size;
55 struct ctl_table tmp = {
57 .maxlen = sizeof(size),
60 struct rps_sock_flow_table *orig_sock_table, *sock_table;
61 static DEFINE_MUTEX(sock_flow_mutex);
63 mutex_lock(&sock_flow_mutex);
65 orig_sock_table = rcu_dereference_protected(rps_sock_flow_table,
66 lockdep_is_held(&sock_flow_mutex));
67 size = orig_size = orig_sock_table ? orig_sock_table->mask + 1 : 0;
69 ret = proc_dointvec(&tmp, write, buffer, lenp, ppos);
74 /* Enforce limit to prevent overflow */
75 mutex_unlock(&sock_flow_mutex);
78 size = roundup_pow_of_two(size);
79 if (size != orig_size) {
81 vmalloc(RPS_SOCK_FLOW_TABLE_SIZE(size));
83 mutex_unlock(&sock_flow_mutex);
86 rps_cpu_mask = roundup_pow_of_two(nr_cpu_ids) - 1;
87 sock_table->mask = size - 1;
89 sock_table = orig_sock_table;
91 for (i = 0; i < size; i++)
92 sock_table->ents[i] = RPS_NO_CPU;
96 if (sock_table != orig_sock_table) {
97 rcu_assign_pointer(rps_sock_flow_table, sock_table);
99 static_branch_inc(&rps_needed);
100 static_branch_inc(&rfs_needed);
102 if (orig_sock_table) {
103 static_branch_dec(&rps_needed);
104 static_branch_dec(&rfs_needed);
105 kvfree_rcu(orig_sock_table);
110 mutex_unlock(&sock_flow_mutex);
114 #endif /* CONFIG_RPS */
116 #ifdef CONFIG_NET_FLOW_LIMIT
117 static DEFINE_MUTEX(flow_limit_update_mutex);
119 static int flow_limit_cpu_sysctl(struct ctl_table *table, int write,
120 void *buffer, size_t *lenp, loff_t *ppos)
122 struct sd_flow_limit *cur;
123 struct softnet_data *sd;
127 if (!alloc_cpumask_var(&mask, GFP_KERNEL))
131 ret = cpumask_parse(buffer, mask);
135 mutex_lock(&flow_limit_update_mutex);
136 len = sizeof(*cur) + netdev_flow_limit_table_len;
137 for_each_possible_cpu(i) {
138 sd = &per_cpu(softnet_data, i);
139 cur = rcu_dereference_protected(sd->flow_limit,
140 lockdep_is_held(&flow_limit_update_mutex));
141 if (cur && !cpumask_test_cpu(i, mask)) {
142 RCU_INIT_POINTER(sd->flow_limit, NULL);
144 } else if (!cur && cpumask_test_cpu(i, mask)) {
145 cur = kzalloc_node(len, GFP_KERNEL,
148 /* not unwinding previous changes */
152 cur->num_buckets = netdev_flow_limit_table_len;
153 rcu_assign_pointer(sd->flow_limit, cur);
157 mutex_unlock(&flow_limit_update_mutex);
161 if (*ppos || !*lenp) {
168 for_each_possible_cpu(i) {
169 sd = &per_cpu(softnet_data, i);
170 if (rcu_dereference(sd->flow_limit))
171 cpumask_set_cpu(i, mask);
175 len = min(sizeof(kbuf) - 1, *lenp);
176 len = scnprintf(kbuf, len, "%*pb", cpumask_pr_args(mask));
183 memcpy(buffer, kbuf, len);
189 free_cpumask_var(mask);
193 static int flow_limit_table_len_sysctl(struct ctl_table *table, int write,
194 void *buffer, size_t *lenp, loff_t *ppos)
196 unsigned int old, *ptr;
199 mutex_lock(&flow_limit_update_mutex);
203 ret = proc_dointvec(table, write, buffer, lenp, ppos);
204 if (!ret && write && !is_power_of_2(*ptr)) {
209 mutex_unlock(&flow_limit_update_mutex);
212 #endif /* CONFIG_NET_FLOW_LIMIT */
214 #ifdef CONFIG_NET_SCHED
215 static int set_default_qdisc(struct ctl_table *table, int write,
216 void *buffer, size_t *lenp, loff_t *ppos)
219 struct ctl_table tbl = {
225 qdisc_get_default(id, IFNAMSIZ);
227 ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
228 if (write && ret == 0)
229 ret = qdisc_set_default(id);
234 static int proc_do_dev_weight(struct ctl_table *table, int write,
235 void *buffer, size_t *lenp, loff_t *ppos)
237 static DEFINE_MUTEX(dev_weight_mutex);
240 mutex_lock(&dev_weight_mutex);
241 ret = proc_dointvec(table, write, buffer, lenp, ppos);
243 weight = READ_ONCE(weight_p);
244 WRITE_ONCE(dev_rx_weight, weight * dev_weight_rx_bias);
245 WRITE_ONCE(dev_tx_weight, weight * dev_weight_tx_bias);
247 mutex_unlock(&dev_weight_mutex);
252 static int proc_do_rss_key(struct ctl_table *table, int write,
253 void *buffer, size_t *lenp, loff_t *ppos)
255 struct ctl_table fake_table;
256 char buf[NETDEV_RSS_KEY_LEN * 3];
258 snprintf(buf, sizeof(buf), "%*phC", NETDEV_RSS_KEY_LEN, netdev_rss_key);
259 fake_table.data = buf;
260 fake_table.maxlen = sizeof(buf);
261 return proc_dostring(&fake_table, write, buffer, lenp, ppos);
264 #ifdef CONFIG_BPF_JIT
265 static int proc_dointvec_minmax_bpf_enable(struct ctl_table *table, int write,
266 void *buffer, size_t *lenp,
269 int ret, jit_enable = *(int *)table->data;
270 int min = *(int *)table->extra1;
271 int max = *(int *)table->extra2;
272 struct ctl_table tmp = *table;
274 if (write && !capable(CAP_SYS_ADMIN))
277 tmp.data = &jit_enable;
278 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
280 if (jit_enable < 2 ||
281 (jit_enable == 2 && bpf_dump_raw_ok(current_cred()))) {
282 *(int *)table->data = jit_enable;
284 pr_warn("bpf_jit_enable = 2 was set! NEVER use this in production, only for JIT debugging!\n");
290 if (write && ret && min == max)
291 pr_info_once("CONFIG_BPF_JIT_ALWAYS_ON is enabled, bpf_jit_enable is permanently set to 1.\n");
296 # ifdef CONFIG_HAVE_EBPF_JIT
298 proc_dointvec_minmax_bpf_restricted(struct ctl_table *table, int write,
299 void *buffer, size_t *lenp, loff_t *ppos)
301 if (!capable(CAP_SYS_ADMIN))
304 return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
306 # endif /* CONFIG_HAVE_EBPF_JIT */
309 proc_dolongvec_minmax_bpf_restricted(struct ctl_table *table, int write,
310 void *buffer, size_t *lenp, loff_t *ppos)
312 if (!capable(CAP_SYS_ADMIN))
315 return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
319 static struct ctl_table net_core_table[] = {
321 .procname = "wmem_max",
322 .data = &sysctl_wmem_max,
323 .maxlen = sizeof(int),
325 .proc_handler = proc_dointvec_minmax,
326 .extra1 = &min_sndbuf,
329 .procname = "rmem_max",
330 .data = &sysctl_rmem_max,
331 .maxlen = sizeof(int),
333 .proc_handler = proc_dointvec_minmax,
334 .extra1 = &min_rcvbuf,
337 .procname = "wmem_default",
338 .data = &sysctl_wmem_default,
339 .maxlen = sizeof(int),
341 .proc_handler = proc_dointvec_minmax,
342 .extra1 = &min_sndbuf,
345 .procname = "rmem_default",
346 .data = &sysctl_rmem_default,
347 .maxlen = sizeof(int),
349 .proc_handler = proc_dointvec_minmax,
350 .extra1 = &min_rcvbuf,
353 .procname = "mem_pcpu_rsv",
354 .data = &sysctl_mem_pcpu_rsv,
355 .maxlen = sizeof(int),
357 .proc_handler = proc_dointvec_minmax,
358 .extra1 = &min_mem_pcpu_rsv,
361 .procname = "dev_weight",
363 .maxlen = sizeof(int),
365 .proc_handler = proc_do_dev_weight,
368 .procname = "dev_weight_rx_bias",
369 .data = &dev_weight_rx_bias,
370 .maxlen = sizeof(int),
372 .proc_handler = proc_do_dev_weight,
375 .procname = "dev_weight_tx_bias",
376 .data = &dev_weight_tx_bias,
377 .maxlen = sizeof(int),
379 .proc_handler = proc_do_dev_weight,
382 .procname = "netdev_max_backlog",
383 .data = &netdev_max_backlog,
384 .maxlen = sizeof(int),
386 .proc_handler = proc_dointvec
389 .procname = "netdev_rss_key",
390 .data = &netdev_rss_key,
391 .maxlen = sizeof(int),
393 .proc_handler = proc_do_rss_key,
395 #ifdef CONFIG_BPF_JIT
397 .procname = "bpf_jit_enable",
398 .data = &bpf_jit_enable,
399 .maxlen = sizeof(int),
401 .proc_handler = proc_dointvec_minmax_bpf_enable,
402 # ifdef CONFIG_BPF_JIT_ALWAYS_ON
403 .extra1 = SYSCTL_ONE,
404 .extra2 = SYSCTL_ONE,
406 .extra1 = SYSCTL_ZERO,
407 .extra2 = SYSCTL_TWO,
410 # ifdef CONFIG_HAVE_EBPF_JIT
412 .procname = "bpf_jit_harden",
413 .data = &bpf_jit_harden,
414 .maxlen = sizeof(int),
416 .proc_handler = proc_dointvec_minmax_bpf_restricted,
417 .extra1 = SYSCTL_ZERO,
418 .extra2 = SYSCTL_TWO,
421 .procname = "bpf_jit_kallsyms",
422 .data = &bpf_jit_kallsyms,
423 .maxlen = sizeof(int),
425 .proc_handler = proc_dointvec_minmax_bpf_restricted,
426 .extra1 = SYSCTL_ZERO,
427 .extra2 = SYSCTL_ONE,
431 .procname = "bpf_jit_limit",
432 .data = &bpf_jit_limit,
433 .maxlen = sizeof(long),
435 .proc_handler = proc_dolongvec_minmax_bpf_restricted,
436 .extra1 = SYSCTL_LONG_ONE,
437 .extra2 = &bpf_jit_limit_max,
441 .procname = "netdev_tstamp_prequeue",
442 .data = &netdev_tstamp_prequeue,
443 .maxlen = sizeof(int),
445 .proc_handler = proc_dointvec
448 .procname = "message_cost",
449 .data = &net_ratelimit_state.interval,
450 .maxlen = sizeof(int),
452 .proc_handler = proc_dointvec_jiffies,
455 .procname = "message_burst",
456 .data = &net_ratelimit_state.burst,
457 .maxlen = sizeof(int),
459 .proc_handler = proc_dointvec,
462 .procname = "optmem_max",
463 .data = &sysctl_optmem_max,
464 .maxlen = sizeof(int),
466 .proc_handler = proc_dointvec
469 .procname = "tstamp_allow_data",
470 .data = &sysctl_tstamp_allow_data,
471 .maxlen = sizeof(int),
473 .proc_handler = proc_dointvec_minmax,
474 .extra1 = SYSCTL_ZERO,
479 .procname = "rps_sock_flow_entries",
480 .maxlen = sizeof(int),
482 .proc_handler = rps_sock_flow_sysctl
485 #ifdef CONFIG_NET_FLOW_LIMIT
487 .procname = "flow_limit_cpu_bitmap",
489 .proc_handler = flow_limit_cpu_sysctl
492 .procname = "flow_limit_table_len",
493 .data = &netdev_flow_limit_table_len,
494 .maxlen = sizeof(int),
496 .proc_handler = flow_limit_table_len_sysctl
498 #endif /* CONFIG_NET_FLOW_LIMIT */
499 #ifdef CONFIG_NET_RX_BUSY_POLL
501 .procname = "busy_poll",
502 .data = &sysctl_net_busy_poll,
503 .maxlen = sizeof(unsigned int),
505 .proc_handler = proc_dointvec_minmax,
506 .extra1 = SYSCTL_ZERO,
509 .procname = "busy_read",
510 .data = &sysctl_net_busy_read,
511 .maxlen = sizeof(unsigned int),
513 .proc_handler = proc_dointvec_minmax,
514 .extra1 = SYSCTL_ZERO,
517 #ifdef CONFIG_NET_SCHED
519 .procname = "default_qdisc",
522 .proc_handler = set_default_qdisc
526 .procname = "netdev_budget",
527 .data = &netdev_budget,
528 .maxlen = sizeof(int),
530 .proc_handler = proc_dointvec
533 .procname = "warnings",
534 .data = &net_msg_warn,
535 .maxlen = sizeof(int),
537 .proc_handler = proc_dointvec
540 .procname = "max_skb_frags",
541 .data = &sysctl_max_skb_frags,
542 .maxlen = sizeof(int),
544 .proc_handler = proc_dointvec_minmax,
545 .extra1 = SYSCTL_ONE,
546 .extra2 = &max_skb_frags,
549 .procname = "netdev_budget_usecs",
550 .data = &netdev_budget_usecs,
551 .maxlen = sizeof(unsigned int),
553 .proc_handler = proc_dointvec_minmax,
554 .extra1 = SYSCTL_ZERO,
557 .procname = "fb_tunnels_only_for_init_net",
558 .data = &sysctl_fb_tunnels_only_for_init_net,
559 .maxlen = sizeof(int),
561 .proc_handler = proc_dointvec_minmax,
562 .extra1 = SYSCTL_ZERO,
563 .extra2 = SYSCTL_TWO,
566 .procname = "devconf_inherit_init_net",
567 .data = &sysctl_devconf_inherit_init_net,
568 .maxlen = sizeof(int),
570 .proc_handler = proc_dointvec_minmax,
571 .extra1 = SYSCTL_ZERO,
572 .extra2 = SYSCTL_THREE,
575 .procname = "high_order_alloc_disable",
576 .data = &net_high_order_alloc_disable_key.key,
577 .maxlen = sizeof(net_high_order_alloc_disable_key),
579 .proc_handler = proc_do_static_key,
582 .procname = "gro_normal_batch",
583 .data = &gro_normal_batch,
584 .maxlen = sizeof(unsigned int),
586 .proc_handler = proc_dointvec_minmax,
587 .extra1 = SYSCTL_ONE,
590 .procname = "netdev_unregister_timeout_secs",
591 .data = &netdev_unregister_timeout_secs,
592 .maxlen = sizeof(unsigned int),
594 .proc_handler = proc_dointvec_minmax,
595 .extra1 = SYSCTL_ONE,
599 .procname = "skb_defer_max",
600 .data = &sysctl_skb_defer_max,
601 .maxlen = sizeof(unsigned int),
603 .proc_handler = proc_dointvec_minmax,
604 .extra1 = SYSCTL_ZERO,
609 static struct ctl_table netns_core_table[] = {
611 .procname = "somaxconn",
612 .data = &init_net.core.sysctl_somaxconn,
613 .maxlen = sizeof(int),
615 .extra1 = SYSCTL_ZERO,
616 .proc_handler = proc_dointvec_minmax
619 .procname = "txrehash",
620 .data = &init_net.core.sysctl_txrehash,
621 .maxlen = sizeof(u8),
623 .extra1 = SYSCTL_ZERO,
624 .extra2 = SYSCTL_ONE,
625 .proc_handler = proc_dou8vec_minmax,
630 static int __init fb_tunnels_only_for_init_net_sysctl_setup(char *str)
632 /* fallback tunnels for initns only */
633 if (!strncmp(str, "initns", 6))
634 sysctl_fb_tunnels_only_for_init_net = 1;
635 /* no fallback tunnels anywhere */
636 else if (!strncmp(str, "none", 4))
637 sysctl_fb_tunnels_only_for_init_net = 2;
641 __setup("fb_tunnels=", fb_tunnels_only_for_init_net_sysctl_setup);
643 static __net_init int sysctl_core_net_init(struct net *net)
645 struct ctl_table *tbl, *tmp;
647 tbl = netns_core_table;
648 if (!net_eq(net, &init_net)) {
649 tbl = kmemdup(tbl, sizeof(netns_core_table), GFP_KERNEL);
653 for (tmp = tbl; tmp->procname; tmp++)
654 tmp->data += (char *)net - (char *)&init_net;
656 /* Don't export any sysctls to unprivileged users */
657 if (net->user_ns != &init_user_ns) {
658 tbl[0].procname = NULL;
662 net->core.sysctl_hdr = register_net_sysctl(net, "net/core", tbl);
663 if (net->core.sysctl_hdr == NULL)
669 if (tbl != netns_core_table)
675 static __net_exit void sysctl_core_net_exit(struct net *net)
677 struct ctl_table *tbl;
679 tbl = net->core.sysctl_hdr->ctl_table_arg;
680 unregister_net_sysctl_table(net->core.sysctl_hdr);
681 BUG_ON(tbl == netns_core_table);
685 static __net_initdata struct pernet_operations sysctl_core_ops = {
686 .init = sysctl_core_net_init,
687 .exit = sysctl_core_net_exit,
690 static __init int sysctl_core_init(void)
692 register_net_sysctl(&init_net, "net/core", net_core_table);
693 return register_pernet_subsys(&sysctl_core_ops);
696 fs_initcall(sysctl_core_init);