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]
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>
21 #include <net/net_ratelimit.h>
22 #include <net/busy_poll.h>
23 #include <net/pkt_sched.h>
27 static int min_sndbuf = SOCK_MIN_SNDBUF;
28 static int min_rcvbuf = SOCK_MIN_RCVBUF;
29 static int max_skb_frags = MAX_SKB_FRAGS;
30 static long long_one __maybe_unused = 1;
31 static long long_max __maybe_unused = LONG_MAX;
33 static int net_msg_warn; /* Unused, but still a sysctl */
35 int sysctl_fb_tunnels_only_for_init_net __read_mostly = 0;
36 EXPORT_SYMBOL(sysctl_fb_tunnels_only_for_init_net);
38 /* 0 - Keep current behavior:
39 * IPv4: inherit all current settings from init_net
40 * IPv6: reset all settings to default
41 * 1 - Both inherit all current settings from init_net
42 * 2 - Both reset all settings to default
43 * 3 - Both inherit all settings from current netns
45 int sysctl_devconf_inherit_init_net __read_mostly;
46 EXPORT_SYMBOL(sysctl_devconf_inherit_init_net);
49 static int rps_sock_flow_sysctl(struct ctl_table *table, int write,
50 void *buffer, size_t *lenp, loff_t *ppos)
52 unsigned int orig_size, size;
54 struct ctl_table tmp = {
56 .maxlen = sizeof(size),
59 struct rps_sock_flow_table *orig_sock_table, *sock_table;
60 static DEFINE_MUTEX(sock_flow_mutex);
62 mutex_lock(&sock_flow_mutex);
64 orig_sock_table = rcu_dereference_protected(rps_sock_flow_table,
65 lockdep_is_held(&sock_flow_mutex));
66 size = orig_size = orig_sock_table ? orig_sock_table->mask + 1 : 0;
68 ret = proc_dointvec(&tmp, write, buffer, lenp, ppos);
73 /* Enforce limit to prevent overflow */
74 mutex_unlock(&sock_flow_mutex);
77 size = roundup_pow_of_two(size);
78 if (size != orig_size) {
80 vmalloc(RPS_SOCK_FLOW_TABLE_SIZE(size));
82 mutex_unlock(&sock_flow_mutex);
85 rps_cpu_mask = roundup_pow_of_two(nr_cpu_ids) - 1;
86 sock_table->mask = size - 1;
88 sock_table = orig_sock_table;
90 for (i = 0; i < size; i++)
91 sock_table->ents[i] = RPS_NO_CPU;
95 if (sock_table != orig_sock_table) {
96 rcu_assign_pointer(rps_sock_flow_table, sock_table);
98 static_branch_inc(&rps_needed);
99 static_branch_inc(&rfs_needed);
101 if (orig_sock_table) {
102 static_branch_dec(&rps_needed);
103 static_branch_dec(&rfs_needed);
105 vfree(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);
145 } else if (!cur && cpumask_test_cpu(i, mask)) {
146 cur = kzalloc_node(len, GFP_KERNEL,
149 /* not unwinding previous changes */
153 cur->num_buckets = netdev_flow_limit_table_len;
154 rcu_assign_pointer(sd->flow_limit, cur);
158 mutex_unlock(&flow_limit_update_mutex);
162 if (*ppos || !*lenp) {
169 for_each_possible_cpu(i) {
170 sd = &per_cpu(softnet_data, i);
171 if (rcu_dereference(sd->flow_limit))
172 cpumask_set_cpu(i, mask);
176 len = min(sizeof(kbuf) - 1, *lenp);
177 len = scnprintf(kbuf, len, "%*pb", cpumask_pr_args(mask));
184 memcpy(buffer, kbuf, len);
190 free_cpumask_var(mask);
194 static int flow_limit_table_len_sysctl(struct ctl_table *table, int write,
195 void *buffer, size_t *lenp, loff_t *ppos)
197 unsigned int old, *ptr;
200 mutex_lock(&flow_limit_update_mutex);
204 ret = proc_dointvec(table, write, buffer, lenp, ppos);
205 if (!ret && write && !is_power_of_2(*ptr)) {
210 mutex_unlock(&flow_limit_update_mutex);
213 #endif /* CONFIG_NET_FLOW_LIMIT */
215 #ifdef CONFIG_NET_SCHED
216 static int set_default_qdisc(struct ctl_table *table, int write,
217 void *buffer, size_t *lenp, loff_t *ppos)
220 struct ctl_table tbl = {
226 qdisc_get_default(id, IFNAMSIZ);
228 ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
229 if (write && ret == 0)
230 ret = qdisc_set_default(id);
235 static int proc_do_dev_weight(struct ctl_table *table, int write,
236 void *buffer, size_t *lenp, loff_t *ppos)
240 ret = proc_dointvec(table, write, buffer, lenp, ppos);
244 dev_rx_weight = weight_p * dev_weight_rx_bias;
245 dev_tx_weight = weight_p * dev_weight_tx_bias;
250 static int proc_do_rss_key(struct ctl_table *table, int write,
251 void *buffer, size_t *lenp, loff_t *ppos)
253 struct ctl_table fake_table;
254 char buf[NETDEV_RSS_KEY_LEN * 3];
256 snprintf(buf, sizeof(buf), "%*phC", NETDEV_RSS_KEY_LEN, netdev_rss_key);
257 fake_table.data = buf;
258 fake_table.maxlen = sizeof(buf);
259 return proc_dostring(&fake_table, write, buffer, lenp, ppos);
262 #ifdef CONFIG_BPF_JIT
263 static int proc_dointvec_minmax_bpf_enable(struct ctl_table *table, int write,
264 void *buffer, size_t *lenp,
267 int ret, jit_enable = *(int *)table->data;
268 struct ctl_table tmp = *table;
270 if (write && !capable(CAP_SYS_ADMIN))
273 tmp.data = &jit_enable;
274 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
276 if (jit_enable < 2 ||
277 (jit_enable == 2 && bpf_dump_raw_ok(current_cred()))) {
278 *(int *)table->data = jit_enable;
280 pr_warn("bpf_jit_enable = 2 was set! NEVER use this in production, only for JIT debugging!\n");
288 # ifdef CONFIG_HAVE_EBPF_JIT
290 proc_dointvec_minmax_bpf_restricted(struct ctl_table *table, int write,
291 void *buffer, size_t *lenp, loff_t *ppos)
293 if (!capable(CAP_SYS_ADMIN))
296 return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
298 # endif /* CONFIG_HAVE_EBPF_JIT */
301 proc_dolongvec_minmax_bpf_restricted(struct ctl_table *table, int write,
302 void *buffer, size_t *lenp, loff_t *ppos)
304 if (!capable(CAP_SYS_ADMIN))
307 return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
311 static struct ctl_table net_core_table[] = {
313 .procname = "wmem_max",
314 .data = &sysctl_wmem_max,
315 .maxlen = sizeof(int),
317 .proc_handler = proc_dointvec_minmax,
318 .extra1 = &min_sndbuf,
321 .procname = "rmem_max",
322 .data = &sysctl_rmem_max,
323 .maxlen = sizeof(int),
325 .proc_handler = proc_dointvec_minmax,
326 .extra1 = &min_rcvbuf,
329 .procname = "wmem_default",
330 .data = &sysctl_wmem_default,
331 .maxlen = sizeof(int),
333 .proc_handler = proc_dointvec_minmax,
334 .extra1 = &min_sndbuf,
337 .procname = "rmem_default",
338 .data = &sysctl_rmem_default,
339 .maxlen = sizeof(int),
341 .proc_handler = proc_dointvec_minmax,
342 .extra1 = &min_rcvbuf,
345 .procname = "dev_weight",
347 .maxlen = sizeof(int),
349 .proc_handler = proc_do_dev_weight,
352 .procname = "dev_weight_rx_bias",
353 .data = &dev_weight_rx_bias,
354 .maxlen = sizeof(int),
356 .proc_handler = proc_do_dev_weight,
359 .procname = "dev_weight_tx_bias",
360 .data = &dev_weight_tx_bias,
361 .maxlen = sizeof(int),
363 .proc_handler = proc_do_dev_weight,
366 .procname = "netdev_max_backlog",
367 .data = &netdev_max_backlog,
368 .maxlen = sizeof(int),
370 .proc_handler = proc_dointvec
373 .procname = "netdev_rss_key",
374 .data = &netdev_rss_key,
375 .maxlen = sizeof(int),
377 .proc_handler = proc_do_rss_key,
379 #ifdef CONFIG_BPF_JIT
381 .procname = "bpf_jit_enable",
382 .data = &bpf_jit_enable,
383 .maxlen = sizeof(int),
385 .proc_handler = proc_dointvec_minmax_bpf_enable,
386 # ifdef CONFIG_BPF_JIT_ALWAYS_ON
387 .extra1 = SYSCTL_ONE,
388 .extra2 = SYSCTL_ONE,
390 .extra1 = SYSCTL_ZERO,
394 # ifdef CONFIG_HAVE_EBPF_JIT
396 .procname = "bpf_jit_harden",
397 .data = &bpf_jit_harden,
398 .maxlen = sizeof(int),
400 .proc_handler = proc_dointvec_minmax_bpf_restricted,
401 .extra1 = SYSCTL_ZERO,
405 .procname = "bpf_jit_kallsyms",
406 .data = &bpf_jit_kallsyms,
407 .maxlen = sizeof(int),
409 .proc_handler = proc_dointvec_minmax_bpf_restricted,
410 .extra1 = SYSCTL_ZERO,
411 .extra2 = SYSCTL_ONE,
415 .procname = "bpf_jit_limit",
416 .data = &bpf_jit_limit,
417 .maxlen = sizeof(long),
419 .proc_handler = proc_dolongvec_minmax_bpf_restricted,
425 .procname = "netdev_tstamp_prequeue",
426 .data = &netdev_tstamp_prequeue,
427 .maxlen = sizeof(int),
429 .proc_handler = proc_dointvec
432 .procname = "message_cost",
433 .data = &net_ratelimit_state.interval,
434 .maxlen = sizeof(int),
436 .proc_handler = proc_dointvec_jiffies,
439 .procname = "message_burst",
440 .data = &net_ratelimit_state.burst,
441 .maxlen = sizeof(int),
443 .proc_handler = proc_dointvec,
446 .procname = "optmem_max",
447 .data = &sysctl_optmem_max,
448 .maxlen = sizeof(int),
450 .proc_handler = proc_dointvec
453 .procname = "tstamp_allow_data",
454 .data = &sysctl_tstamp_allow_data,
455 .maxlen = sizeof(int),
457 .proc_handler = proc_dointvec_minmax,
458 .extra1 = SYSCTL_ZERO,
463 .procname = "rps_sock_flow_entries",
464 .maxlen = sizeof(int),
466 .proc_handler = rps_sock_flow_sysctl
469 #ifdef CONFIG_NET_FLOW_LIMIT
471 .procname = "flow_limit_cpu_bitmap",
473 .proc_handler = flow_limit_cpu_sysctl
476 .procname = "flow_limit_table_len",
477 .data = &netdev_flow_limit_table_len,
478 .maxlen = sizeof(int),
480 .proc_handler = flow_limit_table_len_sysctl
482 #endif /* CONFIG_NET_FLOW_LIMIT */
483 #ifdef CONFIG_NET_RX_BUSY_POLL
485 .procname = "busy_poll",
486 .data = &sysctl_net_busy_poll,
487 .maxlen = sizeof(unsigned int),
489 .proc_handler = proc_dointvec_minmax,
490 .extra1 = SYSCTL_ZERO,
493 .procname = "busy_read",
494 .data = &sysctl_net_busy_read,
495 .maxlen = sizeof(unsigned int),
497 .proc_handler = proc_dointvec_minmax,
498 .extra1 = SYSCTL_ZERO,
501 #ifdef CONFIG_NET_SCHED
503 .procname = "default_qdisc",
506 .proc_handler = set_default_qdisc
510 .procname = "netdev_budget",
511 .data = &netdev_budget,
512 .maxlen = sizeof(int),
514 .proc_handler = proc_dointvec
517 .procname = "warnings",
518 .data = &net_msg_warn,
519 .maxlen = sizeof(int),
521 .proc_handler = proc_dointvec
524 .procname = "max_skb_frags",
525 .data = &sysctl_max_skb_frags,
526 .maxlen = sizeof(int),
528 .proc_handler = proc_dointvec_minmax,
529 .extra1 = SYSCTL_ONE,
530 .extra2 = &max_skb_frags,
533 .procname = "netdev_budget_usecs",
534 .data = &netdev_budget_usecs,
535 .maxlen = sizeof(unsigned int),
537 .proc_handler = proc_dointvec_minmax,
538 .extra1 = SYSCTL_ZERO,
541 .procname = "fb_tunnels_only_for_init_net",
542 .data = &sysctl_fb_tunnels_only_for_init_net,
543 .maxlen = sizeof(int),
545 .proc_handler = proc_dointvec_minmax,
546 .extra1 = SYSCTL_ZERO,
550 .procname = "devconf_inherit_init_net",
551 .data = &sysctl_devconf_inherit_init_net,
552 .maxlen = sizeof(int),
554 .proc_handler = proc_dointvec_minmax,
555 .extra1 = SYSCTL_ZERO,
559 .procname = "high_order_alloc_disable",
560 .data = &net_high_order_alloc_disable_key.key,
561 .maxlen = sizeof(net_high_order_alloc_disable_key),
563 .proc_handler = proc_do_static_key,
566 .procname = "gro_normal_batch",
567 .data = &gro_normal_batch,
568 .maxlen = sizeof(unsigned int),
570 .proc_handler = proc_dointvec_minmax,
571 .extra1 = SYSCTL_ONE,
576 static struct ctl_table netns_core_table[] = {
578 .procname = "somaxconn",
579 .data = &init_net.core.sysctl_somaxconn,
580 .maxlen = sizeof(int),
582 .extra1 = SYSCTL_ZERO,
583 .proc_handler = proc_dointvec_minmax
588 static int __init fb_tunnels_only_for_init_net_sysctl_setup(char *str)
590 /* fallback tunnels for initns only */
591 if (!strncmp(str, "initns", 6))
592 sysctl_fb_tunnels_only_for_init_net = 1;
593 /* no fallback tunnels anywhere */
594 else if (!strncmp(str, "none", 4))
595 sysctl_fb_tunnels_only_for_init_net = 2;
599 __setup("fb_tunnels=", fb_tunnels_only_for_init_net_sysctl_setup);
601 static __net_init int sysctl_core_net_init(struct net *net)
603 struct ctl_table *tbl;
605 tbl = netns_core_table;
606 if (!net_eq(net, &init_net)) {
607 tbl = kmemdup(tbl, sizeof(netns_core_table), GFP_KERNEL);
611 tbl[0].data = &net->core.sysctl_somaxconn;
613 /* Don't export any sysctls to unprivileged users */
614 if (net->user_ns != &init_user_ns) {
615 tbl[0].procname = NULL;
619 net->core.sysctl_hdr = register_net_sysctl(net, "net/core", tbl);
620 if (net->core.sysctl_hdr == NULL)
626 if (tbl != netns_core_table)
632 static __net_exit void sysctl_core_net_exit(struct net *net)
634 struct ctl_table *tbl;
636 tbl = net->core.sysctl_hdr->ctl_table_arg;
637 unregister_net_sysctl_table(net->core.sysctl_hdr);
638 BUG_ON(tbl == netns_core_table);
642 static __net_initdata struct pernet_operations sysctl_core_ops = {
643 .init = sysctl_core_net_init,
644 .exit = sysctl_core_net_exit,
647 static __init int sysctl_core_init(void)
649 register_net_sysctl(&init_net, "net/core", net_core_table);
650 return register_pernet_subsys(&sysctl_core_ops);
653 fs_initcall(sysctl_core_init);