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>
18 #include <linux/kmemleak.h>
22 #include <net/net_ratelimit.h>
23 #include <net/busy_poll.h>
24 #include <net/pkt_sched.h>
28 static int min_sndbuf = SOCK_MIN_SNDBUF;
29 static int min_rcvbuf = SOCK_MIN_RCVBUF;
30 static int max_skb_frags = MAX_SKB_FRAGS;
32 static int net_msg_warn; /* Unused, but still a sysctl */
35 static int rps_sock_flow_sysctl(struct ctl_table *table, int write,
36 void __user *buffer, size_t *lenp, loff_t *ppos)
38 unsigned int orig_size, size;
40 struct ctl_table tmp = {
42 .maxlen = sizeof(size),
45 struct rps_sock_flow_table *orig_sock_table, *sock_table;
46 static DEFINE_MUTEX(sock_flow_mutex);
48 mutex_lock(&sock_flow_mutex);
50 orig_sock_table = rcu_dereference_protected(rps_sock_flow_table,
51 lockdep_is_held(&sock_flow_mutex));
52 size = orig_size = orig_sock_table ? orig_sock_table->mask + 1 : 0;
54 ret = proc_dointvec(&tmp, write, buffer, lenp, ppos);
59 /* Enforce limit to prevent overflow */
60 mutex_unlock(&sock_flow_mutex);
63 size = roundup_pow_of_two(size);
64 if (size != orig_size) {
66 vmalloc(RPS_SOCK_FLOW_TABLE_SIZE(size));
68 mutex_unlock(&sock_flow_mutex);
71 rps_cpu_mask = roundup_pow_of_two(nr_cpu_ids) - 1;
72 sock_table->mask = size - 1;
74 sock_table = orig_sock_table;
76 for (i = 0; i < size; i++)
77 sock_table->ents[i] = RPS_NO_CPU;
81 if (sock_table != orig_sock_table) {
82 rcu_assign_pointer(rps_sock_flow_table, sock_table);
84 static_key_slow_inc(&rps_needed);
85 static_key_slow_inc(&rfs_needed);
87 if (orig_sock_table) {
88 static_key_slow_dec(&rps_needed);
89 static_key_slow_dec(&rfs_needed);
91 vfree(orig_sock_table);
96 mutex_unlock(&sock_flow_mutex);
100 #endif /* CONFIG_RPS */
102 #ifdef CONFIG_NET_FLOW_LIMIT
103 static DEFINE_MUTEX(flow_limit_update_mutex);
105 static int flow_limit_cpu_sysctl(struct ctl_table *table, int write,
106 void __user *buffer, size_t *lenp,
109 struct sd_flow_limit *cur;
110 struct softnet_data *sd;
114 if (!alloc_cpumask_var(&mask, GFP_KERNEL))
118 ret = cpumask_parse_user(buffer, *lenp, mask);
122 mutex_lock(&flow_limit_update_mutex);
123 len = sizeof(*cur) + netdev_flow_limit_table_len;
124 for_each_possible_cpu(i) {
125 sd = &per_cpu(softnet_data, i);
126 cur = rcu_dereference_protected(sd->flow_limit,
127 lockdep_is_held(&flow_limit_update_mutex));
128 if (cur && !cpumask_test_cpu(i, mask)) {
129 RCU_INIT_POINTER(sd->flow_limit, NULL);
132 } else if (!cur && cpumask_test_cpu(i, mask)) {
133 cur = kzalloc_node(len, GFP_KERNEL,
136 /* not unwinding previous changes */
140 cur->num_buckets = netdev_flow_limit_table_len;
141 rcu_assign_pointer(sd->flow_limit, cur);
145 mutex_unlock(&flow_limit_update_mutex);
149 if (*ppos || !*lenp) {
156 for_each_possible_cpu(i) {
157 sd = &per_cpu(softnet_data, i);
158 if (rcu_dereference(sd->flow_limit))
159 cpumask_set_cpu(i, mask);
163 len = min(sizeof(kbuf) - 1, *lenp);
164 len = scnprintf(kbuf, len, "%*pb", cpumask_pr_args(mask));
171 if (copy_to_user(buffer, kbuf, len)) {
180 free_cpumask_var(mask);
184 static int flow_limit_table_len_sysctl(struct ctl_table *table, int write,
185 void __user *buffer, size_t *lenp,
188 unsigned int old, *ptr;
191 mutex_lock(&flow_limit_update_mutex);
195 ret = proc_dointvec(table, write, buffer, lenp, ppos);
196 if (!ret && write && !is_power_of_2(*ptr)) {
201 mutex_unlock(&flow_limit_update_mutex);
204 #endif /* CONFIG_NET_FLOW_LIMIT */
206 #ifdef CONFIG_NET_SCHED
207 static int set_default_qdisc(struct ctl_table *table, int write,
208 void __user *buffer, size_t *lenp, loff_t *ppos)
211 struct ctl_table tbl = {
217 qdisc_get_default(id, IFNAMSIZ);
219 ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
220 if (write && ret == 0)
221 ret = qdisc_set_default(id);
226 static int proc_do_dev_weight(struct ctl_table *table, int write,
227 void __user *buffer, size_t *lenp, loff_t *ppos)
231 ret = proc_dointvec(table, write, buffer, lenp, ppos);
235 dev_rx_weight = weight_p * dev_weight_rx_bias;
236 dev_tx_weight = weight_p * dev_weight_tx_bias;
241 static int proc_do_rss_key(struct ctl_table *table, int write,
242 void __user *buffer, size_t *lenp, loff_t *ppos)
244 struct ctl_table fake_table;
245 char buf[NETDEV_RSS_KEY_LEN * 3];
247 snprintf(buf, sizeof(buf), "%*phC", NETDEV_RSS_KEY_LEN, netdev_rss_key);
248 fake_table.data = buf;
249 fake_table.maxlen = sizeof(buf);
250 return proc_dostring(&fake_table, write, buffer, lenp, ppos);
253 static struct ctl_table net_core_table[] = {
256 .procname = "wmem_max",
257 .data = &sysctl_wmem_max,
258 .maxlen = sizeof(int),
260 .proc_handler = proc_dointvec_minmax,
261 .extra1 = &min_sndbuf,
264 .procname = "rmem_max",
265 .data = &sysctl_rmem_max,
266 .maxlen = sizeof(int),
268 .proc_handler = proc_dointvec_minmax,
269 .extra1 = &min_rcvbuf,
272 .procname = "wmem_default",
273 .data = &sysctl_wmem_default,
274 .maxlen = sizeof(int),
276 .proc_handler = proc_dointvec_minmax,
277 .extra1 = &min_sndbuf,
280 .procname = "rmem_default",
281 .data = &sysctl_rmem_default,
282 .maxlen = sizeof(int),
284 .proc_handler = proc_dointvec_minmax,
285 .extra1 = &min_rcvbuf,
288 .procname = "dev_weight",
290 .maxlen = sizeof(int),
292 .proc_handler = proc_do_dev_weight,
295 .procname = "dev_weight_rx_bias",
296 .data = &dev_weight_rx_bias,
297 .maxlen = sizeof(int),
299 .proc_handler = proc_do_dev_weight,
302 .procname = "dev_weight_tx_bias",
303 .data = &dev_weight_tx_bias,
304 .maxlen = sizeof(int),
306 .proc_handler = proc_do_dev_weight,
309 .procname = "netdev_max_backlog",
310 .data = &netdev_max_backlog,
311 .maxlen = sizeof(int),
313 .proc_handler = proc_dointvec
316 .procname = "netdev_rss_key",
317 .data = &netdev_rss_key,
318 .maxlen = sizeof(int),
320 .proc_handler = proc_do_rss_key,
322 #ifdef CONFIG_BPF_JIT
324 .procname = "bpf_jit_enable",
325 .data = &bpf_jit_enable,
326 .maxlen = sizeof(int),
328 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
329 .proc_handler = proc_dointvec
331 .proc_handler = proc_dointvec_minmax,
336 # ifdef CONFIG_HAVE_EBPF_JIT
338 .procname = "bpf_jit_harden",
339 .data = &bpf_jit_harden,
340 .maxlen = sizeof(int),
342 .proc_handler = proc_dointvec,
345 .procname = "bpf_jit_kallsyms",
346 .data = &bpf_jit_kallsyms,
347 .maxlen = sizeof(int),
349 .proc_handler = proc_dointvec,
354 .procname = "netdev_tstamp_prequeue",
355 .data = &netdev_tstamp_prequeue,
356 .maxlen = sizeof(int),
358 .proc_handler = proc_dointvec
361 .procname = "message_cost",
362 .data = &net_ratelimit_state.interval,
363 .maxlen = sizeof(int),
365 .proc_handler = proc_dointvec_jiffies,
368 .procname = "message_burst",
369 .data = &net_ratelimit_state.burst,
370 .maxlen = sizeof(int),
372 .proc_handler = proc_dointvec,
375 .procname = "optmem_max",
376 .data = &sysctl_optmem_max,
377 .maxlen = sizeof(int),
379 .proc_handler = proc_dointvec
382 .procname = "tstamp_allow_data",
383 .data = &sysctl_tstamp_allow_data,
384 .maxlen = sizeof(int),
386 .proc_handler = proc_dointvec_minmax,
392 .procname = "rps_sock_flow_entries",
393 .maxlen = sizeof(int),
395 .proc_handler = rps_sock_flow_sysctl
398 #ifdef CONFIG_NET_FLOW_LIMIT
400 .procname = "flow_limit_cpu_bitmap",
402 .proc_handler = flow_limit_cpu_sysctl
405 .procname = "flow_limit_table_len",
406 .data = &netdev_flow_limit_table_len,
407 .maxlen = sizeof(int),
409 .proc_handler = flow_limit_table_len_sysctl
411 #endif /* CONFIG_NET_FLOW_LIMIT */
412 #ifdef CONFIG_NET_RX_BUSY_POLL
414 .procname = "busy_poll",
415 .data = &sysctl_net_busy_poll,
416 .maxlen = sizeof(unsigned int),
418 .proc_handler = proc_dointvec_minmax,
422 .procname = "busy_read",
423 .data = &sysctl_net_busy_read,
424 .maxlen = sizeof(unsigned int),
426 .proc_handler = proc_dointvec_minmax,
430 #ifdef CONFIG_NET_SCHED
432 .procname = "default_qdisc",
435 .proc_handler = set_default_qdisc
438 #endif /* CONFIG_NET */
440 .procname = "netdev_budget",
441 .data = &netdev_budget,
442 .maxlen = sizeof(int),
444 .proc_handler = proc_dointvec
447 .procname = "warnings",
448 .data = &net_msg_warn,
449 .maxlen = sizeof(int),
451 .proc_handler = proc_dointvec
454 .procname = "max_skb_frags",
455 .data = &sysctl_max_skb_frags,
456 .maxlen = sizeof(int),
458 .proc_handler = proc_dointvec_minmax,
460 .extra2 = &max_skb_frags,
463 .procname = "netdev_budget_usecs",
464 .data = &netdev_budget_usecs,
465 .maxlen = sizeof(unsigned int),
467 .proc_handler = proc_dointvec_minmax,
473 static struct ctl_table netns_core_table[] = {
475 .procname = "somaxconn",
476 .data = &init_net.core.sysctl_somaxconn,
477 .maxlen = sizeof(int),
480 .proc_handler = proc_dointvec_minmax
485 static __net_init int sysctl_core_net_init(struct net *net)
487 struct ctl_table *tbl;
489 tbl = netns_core_table;
490 if (!net_eq(net, &init_net)) {
491 tbl = kmemdup(tbl, sizeof(netns_core_table), GFP_KERNEL);
495 tbl[0].data = &net->core.sysctl_somaxconn;
497 /* Don't export any sysctls to unprivileged users */
498 if (net->user_ns != &init_user_ns) {
499 tbl[0].procname = NULL;
503 net->core.sysctl_hdr = register_net_sysctl(net, "net/core", tbl);
504 if (net->core.sysctl_hdr == NULL)
510 if (tbl != netns_core_table)
516 static __net_exit void sysctl_core_net_exit(struct net *net)
518 struct ctl_table *tbl;
520 tbl = net->core.sysctl_hdr->ctl_table_arg;
521 unregister_net_sysctl_table(net->core.sysctl_hdr);
522 BUG_ON(tbl == netns_core_table);
526 static __net_initdata struct pernet_operations sysctl_core_ops = {
527 .init = sysctl_core_net_init,
528 .exit = sysctl_core_net_exit,
531 static __init int sysctl_core_init(void)
533 register_net_sysctl(&init_net, "net/core", net_core_table);
534 return register_pernet_subsys(&sysctl_core_ops);
537 fs_initcall(sysctl_core_init);