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v6.2
  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
 20#include <net/ip.h>
 21#include <net/sock.h>
 22#include <net/net_ratelimit.h>
 23#include <net/busy_poll.h>
 24#include <net/pkt_sched.h>
 
 
 25
 26#include "dev.h"
 27
 28static int int_3600 = 3600;
 29static int min_sndbuf = SOCK_MIN_SNDBUF;
 30static int min_rcvbuf = SOCK_MIN_RCVBUF;
 31static int max_skb_frags = MAX_SKB_FRAGS;
 
 32
 33static int net_msg_warn;	/* Unused, but still a sysctl */
 34
 35int sysctl_fb_tunnels_only_for_init_net __read_mostly = 0;
 36EXPORT_SYMBOL(sysctl_fb_tunnels_only_for_init_net);
 37
 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
 44 */
 45int sysctl_devconf_inherit_init_net __read_mostly;
 46EXPORT_SYMBOL(sysctl_devconf_inherit_init_net);
 47
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 48#ifdef CONFIG_RPS
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 49static int rps_sock_flow_sysctl(struct ctl_table *table, int write,
 50				void *buffer, size_t *lenp, loff_t *ppos)
 51{
 52	unsigned int orig_size, size;
 53	int ret, i;
 54	struct ctl_table tmp = {
 55		.data = &size,
 56		.maxlen = sizeof(size),
 57		.mode = table->mode
 58	};
 59	struct rps_sock_flow_table *orig_sock_table, *sock_table;
 60	static DEFINE_MUTEX(sock_flow_mutex);
 61
 62	mutex_lock(&sock_flow_mutex);
 63
 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;
 67
 68	ret = proc_dointvec(&tmp, write, buffer, lenp, ppos);
 69
 70	if (write) {
 71		if (size) {
 72			if (size > 1<<29) {
 73				/* Enforce limit to prevent overflow */
 74				mutex_unlock(&sock_flow_mutex);
 75				return -EINVAL;
 76			}
 77			size = roundup_pow_of_two(size);
 78			if (size != orig_size) {
 79				sock_table =
 80				    vmalloc(RPS_SOCK_FLOW_TABLE_SIZE(size));
 81				if (!sock_table) {
 82					mutex_unlock(&sock_flow_mutex);
 83					return -ENOMEM;
 84				}
 85				rps_cpu_mask = roundup_pow_of_two(nr_cpu_ids) - 1;
 
 86				sock_table->mask = size - 1;
 87			} else
 88				sock_table = orig_sock_table;
 89
 90			for (i = 0; i < size; i++)
 91				sock_table->ents[i] = RPS_NO_CPU;
 92		} else
 93			sock_table = NULL;
 94
 95		if (sock_table != orig_sock_table) {
 96			rcu_assign_pointer(rps_sock_flow_table, sock_table);
 
 97			if (sock_table) {
 98				static_branch_inc(&rps_needed);
 99				static_branch_inc(&rfs_needed);
100			}
101			if (orig_sock_table) {
102				static_branch_dec(&rps_needed);
103				static_branch_dec(&rfs_needed);
104				kvfree_rcu(orig_sock_table);
105			}
106		}
107	}
108
109	mutex_unlock(&sock_flow_mutex);
110
111	return ret;
112}
113#endif /* CONFIG_RPS */
114
115#ifdef CONFIG_NET_FLOW_LIMIT
116static DEFINE_MUTEX(flow_limit_update_mutex);
117
118static int flow_limit_cpu_sysctl(struct ctl_table *table, int write,
119				 void *buffer, size_t *lenp, loff_t *ppos)
120{
121	struct sd_flow_limit *cur;
122	struct softnet_data *sd;
123	cpumask_var_t mask;
124	int i, len, ret = 0;
125
126	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
127		return -ENOMEM;
128
129	if (write) {
130		ret = cpumask_parse(buffer, mask);
131		if (ret)
132			goto done;
133
134		mutex_lock(&flow_limit_update_mutex);
135		len = sizeof(*cur) + netdev_flow_limit_table_len;
136		for_each_possible_cpu(i) {
137			sd = &per_cpu(softnet_data, i);
138			cur = rcu_dereference_protected(sd->flow_limit,
139				     lockdep_is_held(&flow_limit_update_mutex));
140			if (cur && !cpumask_test_cpu(i, mask)) {
141				RCU_INIT_POINTER(sd->flow_limit, NULL);
142				kfree_rcu(cur);
143			} else if (!cur && cpumask_test_cpu(i, mask)) {
144				cur = kzalloc_node(len, GFP_KERNEL,
145						   cpu_to_node(i));
146				if (!cur) {
147					/* not unwinding previous changes */
148					ret = -ENOMEM;
149					goto write_unlock;
150				}
151				cur->num_buckets = netdev_flow_limit_table_len;
152				rcu_assign_pointer(sd->flow_limit, cur);
153			}
154		}
155write_unlock:
156		mutex_unlock(&flow_limit_update_mutex);
157	} else {
158		char kbuf[128];
159
160		if (*ppos || !*lenp) {
161			*lenp = 0;
162			goto done;
163		}
164
165		cpumask_clear(mask);
166		rcu_read_lock();
167		for_each_possible_cpu(i) {
168			sd = &per_cpu(softnet_data, i);
169			if (rcu_dereference(sd->flow_limit))
170				cpumask_set_cpu(i, mask);
171		}
172		rcu_read_unlock();
173
174		len = min(sizeof(kbuf) - 1, *lenp);
175		len = scnprintf(kbuf, len, "%*pb", cpumask_pr_args(mask));
176		if (!len) {
177			*lenp = 0;
178			goto done;
179		}
180		if (len < *lenp)
181			kbuf[len++] = '\n';
182		memcpy(buffer, kbuf, len);
183		*lenp = len;
184		*ppos += len;
185	}
186
187done:
188	free_cpumask_var(mask);
189	return ret;
190}
191
192static int flow_limit_table_len_sysctl(struct ctl_table *table, int write,
193				       void *buffer, size_t *lenp, loff_t *ppos)
194{
195	unsigned int old, *ptr;
196	int ret;
197
198	mutex_lock(&flow_limit_update_mutex);
199
200	ptr = table->data;
201	old = *ptr;
202	ret = proc_dointvec(table, write, buffer, lenp, ppos);
203	if (!ret && write && !is_power_of_2(*ptr)) {
204		*ptr = old;
205		ret = -EINVAL;
206	}
207
208	mutex_unlock(&flow_limit_update_mutex);
209	return ret;
210}
211#endif /* CONFIG_NET_FLOW_LIMIT */
212
213#ifdef CONFIG_NET_SCHED
214static int set_default_qdisc(struct ctl_table *table, int write,
215			     void *buffer, size_t *lenp, loff_t *ppos)
216{
217	char id[IFNAMSIZ];
218	struct ctl_table tbl = {
219		.data = id,
220		.maxlen = IFNAMSIZ,
221	};
222	int ret;
223
224	qdisc_get_default(id, IFNAMSIZ);
225
226	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
227	if (write && ret == 0)
228		ret = qdisc_set_default(id);
229	return ret;
230}
231#endif
232
233static int proc_do_dev_weight(struct ctl_table *table, int write,
234			   void *buffer, size_t *lenp, loff_t *ppos)
235{
236	static DEFINE_MUTEX(dev_weight_mutex);
237	int ret, weight;
238
239	mutex_lock(&dev_weight_mutex);
240	ret = proc_dointvec(table, write, buffer, lenp, ppos);
241	if (!ret && write) {
242		weight = READ_ONCE(weight_p);
243		WRITE_ONCE(dev_rx_weight, weight * dev_weight_rx_bias);
244		WRITE_ONCE(dev_tx_weight, weight * dev_weight_tx_bias);
245	}
246	mutex_unlock(&dev_weight_mutex);
247
248	return ret;
249}
250
251static int proc_do_rss_key(struct ctl_table *table, int write,
252			   void *buffer, size_t *lenp, loff_t *ppos)
253{
254	struct ctl_table fake_table;
255	char buf[NETDEV_RSS_KEY_LEN * 3];
256
257	snprintf(buf, sizeof(buf), "%*phC", NETDEV_RSS_KEY_LEN, netdev_rss_key);
258	fake_table.data = buf;
259	fake_table.maxlen = sizeof(buf);
260	return proc_dostring(&fake_table, write, buffer, lenp, ppos);
261}
262
263#ifdef CONFIG_BPF_JIT
264static int proc_dointvec_minmax_bpf_enable(struct ctl_table *table, int write,
265					   void *buffer, size_t *lenp,
266					   loff_t *ppos)
267{
268	int ret, jit_enable = *(int *)table->data;
269	int min = *(int *)table->extra1;
270	int max = *(int *)table->extra2;
271	struct ctl_table tmp = *table;
272
273	if (write && !capable(CAP_SYS_ADMIN))
274		return -EPERM;
275
276	tmp.data = &jit_enable;
277	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
278	if (write && !ret) {
279		if (jit_enable < 2 ||
280		    (jit_enable == 2 && bpf_dump_raw_ok(current_cred()))) {
281			*(int *)table->data = jit_enable;
282			if (jit_enable == 2)
283				pr_warn("bpf_jit_enable = 2 was set! NEVER use this in production, only for JIT debugging!\n");
284		} else {
285			ret = -EPERM;
286		}
287	}
288
289	if (write && ret && min == max)
290		pr_info_once("CONFIG_BPF_JIT_ALWAYS_ON is enabled, bpf_jit_enable is permanently set to 1.\n");
291
292	return ret;
293}
294
295# ifdef CONFIG_HAVE_EBPF_JIT
296static int
297proc_dointvec_minmax_bpf_restricted(struct ctl_table *table, int write,
298				    void *buffer, size_t *lenp, loff_t *ppos)
299{
300	if (!capable(CAP_SYS_ADMIN))
301		return -EPERM;
302
303	return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
304}
305# endif /* CONFIG_HAVE_EBPF_JIT */
306
307static int
308proc_dolongvec_minmax_bpf_restricted(struct ctl_table *table, int write,
309				     void *buffer, size_t *lenp, loff_t *ppos)
310{
311	if (!capable(CAP_SYS_ADMIN))
312		return -EPERM;
313
314	return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
315}
316#endif
317
318static struct ctl_table net_core_table[] = {
319	{
320		.procname	= "wmem_max",
321		.data		= &sysctl_wmem_max,
322		.maxlen		= sizeof(int),
323		.mode		= 0644,
324		.proc_handler	= proc_dointvec_minmax,
325		.extra1		= &min_sndbuf,
326	},
327	{
328		.procname	= "rmem_max",
329		.data		= &sysctl_rmem_max,
330		.maxlen		= sizeof(int),
331		.mode		= 0644,
332		.proc_handler	= proc_dointvec_minmax,
333		.extra1		= &min_rcvbuf,
334	},
335	{
336		.procname	= "wmem_default",
337		.data		= &sysctl_wmem_default,
338		.maxlen		= sizeof(int),
339		.mode		= 0644,
340		.proc_handler	= proc_dointvec_minmax,
341		.extra1		= &min_sndbuf,
342	},
343	{
344		.procname	= "rmem_default",
345		.data		= &sysctl_rmem_default,
346		.maxlen		= sizeof(int),
347		.mode		= 0644,
348		.proc_handler	= proc_dointvec_minmax,
349		.extra1		= &min_rcvbuf,
350	},
351	{
 
 
 
 
 
 
 
 
352		.procname	= "dev_weight",
353		.data		= &weight_p,
354		.maxlen		= sizeof(int),
355		.mode		= 0644,
356		.proc_handler	= proc_do_dev_weight,
357	},
358	{
359		.procname	= "dev_weight_rx_bias",
360		.data		= &dev_weight_rx_bias,
361		.maxlen		= sizeof(int),
362		.mode		= 0644,
363		.proc_handler	= proc_do_dev_weight,
364	},
365	{
366		.procname	= "dev_weight_tx_bias",
367		.data		= &dev_weight_tx_bias,
368		.maxlen		= sizeof(int),
369		.mode		= 0644,
370		.proc_handler	= proc_do_dev_weight,
371	},
372	{
373		.procname	= "netdev_max_backlog",
374		.data		= &netdev_max_backlog,
375		.maxlen		= sizeof(int),
376		.mode		= 0644,
377		.proc_handler	= proc_dointvec
378	},
379	{
380		.procname	= "netdev_rss_key",
381		.data		= &netdev_rss_key,
382		.maxlen		= sizeof(int),
383		.mode		= 0444,
384		.proc_handler	= proc_do_rss_key,
385	},
386#ifdef CONFIG_BPF_JIT
387	{
388		.procname	= "bpf_jit_enable",
389		.data		= &bpf_jit_enable,
390		.maxlen		= sizeof(int),
391		.mode		= 0644,
392		.proc_handler	= proc_dointvec_minmax_bpf_enable,
393# ifdef CONFIG_BPF_JIT_ALWAYS_ON
394		.extra1		= SYSCTL_ONE,
395		.extra2		= SYSCTL_ONE,
396# else
397		.extra1		= SYSCTL_ZERO,
398		.extra2		= SYSCTL_TWO,
399# endif
400	},
401# ifdef CONFIG_HAVE_EBPF_JIT
402	{
403		.procname	= "bpf_jit_harden",
404		.data		= &bpf_jit_harden,
405		.maxlen		= sizeof(int),
406		.mode		= 0600,
407		.proc_handler	= proc_dointvec_minmax_bpf_restricted,
408		.extra1		= SYSCTL_ZERO,
409		.extra2		= SYSCTL_TWO,
410	},
411	{
412		.procname	= "bpf_jit_kallsyms",
413		.data		= &bpf_jit_kallsyms,
414		.maxlen		= sizeof(int),
415		.mode		= 0600,
416		.proc_handler	= proc_dointvec_minmax_bpf_restricted,
417		.extra1		= SYSCTL_ZERO,
418		.extra2		= SYSCTL_ONE,
419	},
420# endif
421	{
422		.procname	= "bpf_jit_limit",
423		.data		= &bpf_jit_limit,
424		.maxlen		= sizeof(long),
425		.mode		= 0600,
426		.proc_handler	= proc_dolongvec_minmax_bpf_restricted,
427		.extra1		= SYSCTL_LONG_ONE,
428		.extra2		= &bpf_jit_limit_max,
429	},
430#endif
431	{
432		.procname	= "netdev_tstamp_prequeue",
433		.data		= &netdev_tstamp_prequeue,
434		.maxlen		= sizeof(int),
435		.mode		= 0644,
436		.proc_handler	= proc_dointvec
437	},
438	{
439		.procname	= "message_cost",
440		.data		= &net_ratelimit_state.interval,
441		.maxlen		= sizeof(int),
442		.mode		= 0644,
443		.proc_handler	= proc_dointvec_jiffies,
444	},
445	{
446		.procname	= "message_burst",
447		.data		= &net_ratelimit_state.burst,
448		.maxlen		= sizeof(int),
449		.mode		= 0644,
450		.proc_handler	= proc_dointvec,
451	},
452	{
453		.procname	= "optmem_max",
454		.data		= &sysctl_optmem_max,
455		.maxlen		= sizeof(int),
456		.mode		= 0644,
457		.proc_handler	= proc_dointvec
458	},
459	{
460		.procname	= "tstamp_allow_data",
461		.data		= &sysctl_tstamp_allow_data,
462		.maxlen		= sizeof(int),
463		.mode		= 0644,
464		.proc_handler	= proc_dointvec_minmax,
465		.extra1		= SYSCTL_ZERO,
466		.extra2		= SYSCTL_ONE
467	},
468#ifdef CONFIG_RPS
469	{
470		.procname	= "rps_sock_flow_entries",
471		.maxlen		= sizeof(int),
472		.mode		= 0644,
473		.proc_handler	= rps_sock_flow_sysctl
474	},
475#endif
476#ifdef CONFIG_NET_FLOW_LIMIT
477	{
478		.procname	= "flow_limit_cpu_bitmap",
479		.mode		= 0644,
480		.proc_handler	= flow_limit_cpu_sysctl
481	},
482	{
483		.procname	= "flow_limit_table_len",
484		.data		= &netdev_flow_limit_table_len,
485		.maxlen		= sizeof(int),
486		.mode		= 0644,
487		.proc_handler	= flow_limit_table_len_sysctl
488	},
489#endif /* CONFIG_NET_FLOW_LIMIT */
490#ifdef CONFIG_NET_RX_BUSY_POLL
491	{
492		.procname	= "busy_poll",
493		.data		= &sysctl_net_busy_poll,
494		.maxlen		= sizeof(unsigned int),
495		.mode		= 0644,
496		.proc_handler	= proc_dointvec_minmax,
497		.extra1		= SYSCTL_ZERO,
498	},
499	{
500		.procname	= "busy_read",
501		.data		= &sysctl_net_busy_read,
502		.maxlen		= sizeof(unsigned int),
503		.mode		= 0644,
504		.proc_handler	= proc_dointvec_minmax,
505		.extra1		= SYSCTL_ZERO,
506	},
507#endif
508#ifdef CONFIG_NET_SCHED
509	{
510		.procname	= "default_qdisc",
511		.mode		= 0644,
512		.maxlen		= IFNAMSIZ,
513		.proc_handler	= set_default_qdisc
514	},
515#endif
516	{
517		.procname	= "netdev_budget",
518		.data		= &netdev_budget,
519		.maxlen		= sizeof(int),
520		.mode		= 0644,
521		.proc_handler	= proc_dointvec
522	},
523	{
524		.procname	= "warnings",
525		.data		= &net_msg_warn,
526		.maxlen		= sizeof(int),
527		.mode		= 0644,
528		.proc_handler	= proc_dointvec
529	},
530	{
531		.procname	= "max_skb_frags",
532		.data		= &sysctl_max_skb_frags,
533		.maxlen		= sizeof(int),
534		.mode		= 0644,
535		.proc_handler	= proc_dointvec_minmax,
536		.extra1		= SYSCTL_ONE,
537		.extra2		= &max_skb_frags,
538	},
539	{
540		.procname	= "netdev_budget_usecs",
541		.data		= &netdev_budget_usecs,
542		.maxlen		= sizeof(unsigned int),
543		.mode		= 0644,
544		.proc_handler	= proc_dointvec_minmax,
545		.extra1		= SYSCTL_ZERO,
546	},
547	{
548		.procname	= "fb_tunnels_only_for_init_net",
549		.data		= &sysctl_fb_tunnels_only_for_init_net,
550		.maxlen		= sizeof(int),
551		.mode		= 0644,
552		.proc_handler	= proc_dointvec_minmax,
553		.extra1		= SYSCTL_ZERO,
554		.extra2		= SYSCTL_TWO,
555	},
556	{
557		.procname	= "devconf_inherit_init_net",
558		.data		= &sysctl_devconf_inherit_init_net,
559		.maxlen		= sizeof(int),
560		.mode		= 0644,
561		.proc_handler	= proc_dointvec_minmax,
562		.extra1		= SYSCTL_ZERO,
563		.extra2		= SYSCTL_THREE,
564	},
565	{
566		.procname	= "high_order_alloc_disable",
567		.data		= &net_high_order_alloc_disable_key.key,
568		.maxlen         = sizeof(net_high_order_alloc_disable_key),
569		.mode		= 0644,
570		.proc_handler	= proc_do_static_key,
571	},
572	{
573		.procname	= "gro_normal_batch",
574		.data		= &gro_normal_batch,
575		.maxlen		= sizeof(unsigned int),
576		.mode		= 0644,
577		.proc_handler	= proc_dointvec_minmax,
578		.extra1		= SYSCTL_ONE,
579	},
580	{
581		.procname	= "netdev_unregister_timeout_secs",
582		.data		= &netdev_unregister_timeout_secs,
583		.maxlen		= sizeof(unsigned int),
584		.mode		= 0644,
585		.proc_handler	= proc_dointvec_minmax,
586		.extra1		= SYSCTL_ONE,
587		.extra2		= &int_3600,
588	},
589	{
590		.procname	= "skb_defer_max",
591		.data		= &sysctl_skb_defer_max,
592		.maxlen		= sizeof(unsigned int),
593		.mode		= 0644,
594		.proc_handler	= proc_dointvec_minmax,
595		.extra1		= SYSCTL_ZERO,
596	},
597	{ }
598};
599
600static struct ctl_table netns_core_table[] = {
 
 
 
 
 
 
 
 
601	{
602		.procname	= "somaxconn",
603		.data		= &init_net.core.sysctl_somaxconn,
604		.maxlen		= sizeof(int),
605		.mode		= 0644,
606		.extra1		= SYSCTL_ZERO,
607		.proc_handler	= proc_dointvec_minmax
608	},
609	{
 
 
 
 
 
 
 
 
610		.procname	= "txrehash",
611		.data		= &init_net.core.sysctl_txrehash,
612		.maxlen		= sizeof(u8),
613		.mode		= 0644,
614		.extra1		= SYSCTL_ZERO,
615		.extra2		= SYSCTL_ONE,
616		.proc_handler	= proc_dou8vec_minmax,
617	},
618	{ }
619};
620
621static int __init fb_tunnels_only_for_init_net_sysctl_setup(char *str)
622{
623	/* fallback tunnels for initns only */
624	if (!strncmp(str, "initns", 6))
625		sysctl_fb_tunnels_only_for_init_net = 1;
626	/* no fallback tunnels anywhere */
627	else if (!strncmp(str, "none", 4))
628		sysctl_fb_tunnels_only_for_init_net = 2;
629
630	return 1;
631}
632__setup("fb_tunnels=", fb_tunnels_only_for_init_net_sysctl_setup);
633
634static __net_init int sysctl_core_net_init(struct net *net)
635{
636	struct ctl_table *tbl, *tmp;
637
638	tbl = netns_core_table;
639	if (!net_eq(net, &init_net)) {
640		tbl = kmemdup(tbl, sizeof(netns_core_table), GFP_KERNEL);
641		if (tbl == NULL)
642			goto err_dup;
643
644		for (tmp = tbl; tmp->procname; tmp++)
645			tmp->data += (char *)net - (char *)&init_net;
646
647		/* Don't export any sysctls to unprivileged users */
648		if (net->user_ns != &init_user_ns) {
649			tbl[0].procname = NULL;
650		}
651	}
652
653	net->core.sysctl_hdr = register_net_sysctl(net, "net/core", tbl);
 
654	if (net->core.sysctl_hdr == NULL)
655		goto err_reg;
656
657	return 0;
658
659err_reg:
660	if (tbl != netns_core_table)
661		kfree(tbl);
662err_dup:
663	return -ENOMEM;
664}
665
666static __net_exit void sysctl_core_net_exit(struct net *net)
667{
668	struct ctl_table *tbl;
669
670	tbl = net->core.sysctl_hdr->ctl_table_arg;
671	unregister_net_sysctl_table(net->core.sysctl_hdr);
672	BUG_ON(tbl == netns_core_table);
 
 
 
673	kfree(tbl);
674}
675
676static __net_initdata struct pernet_operations sysctl_core_ops = {
677	.init = sysctl_core_net_init,
678	.exit = sysctl_core_net_exit,
679};
680
681static __init int sysctl_core_init(void)
682{
683	register_net_sysctl(&init_net, "net/core", net_core_table);
684	return register_pernet_subsys(&sysctl_core_ops);
685}
686
687fs_initcall(sysctl_core_init);
v6.9.4
  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#include <net/hotdata.h>
 27#include <net/rps.h>
 28
 29#include "dev.h"
 30
 31static int int_3600 = 3600;
 32static int min_sndbuf = SOCK_MIN_SNDBUF;
 33static int min_rcvbuf = SOCK_MIN_RCVBUF;
 34static int max_skb_frags = MAX_SKB_FRAGS;
 35static int min_mem_pcpu_rsv = SK_MEMORY_PCPU_RESERVE;
 36
 37static int net_msg_warn;	/* Unused, but still a sysctl */
 38
 39int sysctl_fb_tunnels_only_for_init_net __read_mostly = 0;
 40EXPORT_SYMBOL(sysctl_fb_tunnels_only_for_init_net);
 41
 42/* 0 - Keep current behavior:
 43 *     IPv4: inherit all current settings from init_net
 44 *     IPv6: reset all settings to default
 45 * 1 - Both inherit all current settings from init_net
 46 * 2 - Both reset all settings to default
 47 * 3 - Both inherit all settings from current netns
 48 */
 49int sysctl_devconf_inherit_init_net __read_mostly;
 50EXPORT_SYMBOL(sysctl_devconf_inherit_init_net);
 51
 52#if IS_ENABLED(CONFIG_NET_FLOW_LIMIT) || IS_ENABLED(CONFIG_RPS)
 53static void dump_cpumask(void *buffer, size_t *lenp, loff_t *ppos,
 54			 struct cpumask *mask)
 55{
 56	char kbuf[128];
 57	int len;
 58
 59	if (*ppos || !*lenp) {
 60		*lenp = 0;
 61		return;
 62	}
 63
 64	len = min(sizeof(kbuf) - 1, *lenp);
 65	len = scnprintf(kbuf, len, "%*pb", cpumask_pr_args(mask));
 66	if (!len) {
 67		*lenp = 0;
 68		return;
 69	}
 70
 71	if (len < *lenp)
 72		kbuf[len++] = '\n';
 73	memcpy(buffer, kbuf, len);
 74	*lenp = len;
 75	*ppos += len;
 76}
 77#endif
 78
 79#ifdef CONFIG_RPS
 80
 81static struct cpumask *rps_default_mask_cow_alloc(struct net *net)
 82{
 83	struct cpumask *rps_default_mask;
 84
 85	if (net->core.rps_default_mask)
 86		return net->core.rps_default_mask;
 87
 88	rps_default_mask = kzalloc(cpumask_size(), GFP_KERNEL);
 89	if (!rps_default_mask)
 90		return NULL;
 91
 92	/* pairs with READ_ONCE in rx_queue_default_mask() */
 93	WRITE_ONCE(net->core.rps_default_mask, rps_default_mask);
 94	return rps_default_mask;
 95}
 96
 97static int rps_default_mask_sysctl(struct ctl_table *table, int write,
 98				   void *buffer, size_t *lenp, loff_t *ppos)
 99{
100	struct net *net = (struct net *)table->data;
101	int err = 0;
102
103	rtnl_lock();
104	if (write) {
105		struct cpumask *rps_default_mask = rps_default_mask_cow_alloc(net);
106
107		err = -ENOMEM;
108		if (!rps_default_mask)
109			goto done;
110
111		err = cpumask_parse(buffer, rps_default_mask);
112		if (err)
113			goto done;
114
115		err = rps_cpumask_housekeeping(rps_default_mask);
116		if (err)
117			goto done;
118	} else {
119		dump_cpumask(buffer, lenp, ppos,
120			     net->core.rps_default_mask ? : cpu_none_mask);
121	}
122
123done:
124	rtnl_unlock();
125	return err;
126}
127
128static int rps_sock_flow_sysctl(struct ctl_table *table, int write,
129				void *buffer, size_t *lenp, loff_t *ppos)
130{
131	unsigned int orig_size, size;
132	int ret, i;
133	struct ctl_table tmp = {
134		.data = &size,
135		.maxlen = sizeof(size),
136		.mode = table->mode
137	};
138	struct rps_sock_flow_table *orig_sock_table, *sock_table;
139	static DEFINE_MUTEX(sock_flow_mutex);
140
141	mutex_lock(&sock_flow_mutex);
142
143	orig_sock_table = rcu_dereference_protected(
144					net_hotdata.rps_sock_flow_table,
145					lockdep_is_held(&sock_flow_mutex));
146	size = orig_size = orig_sock_table ? orig_sock_table->mask + 1 : 0;
147
148	ret = proc_dointvec(&tmp, write, buffer, lenp, ppos);
149
150	if (write) {
151		if (size) {
152			if (size > 1<<29) {
153				/* Enforce limit to prevent overflow */
154				mutex_unlock(&sock_flow_mutex);
155				return -EINVAL;
156			}
157			size = roundup_pow_of_two(size);
158			if (size != orig_size) {
159				sock_table =
160				    vmalloc(RPS_SOCK_FLOW_TABLE_SIZE(size));
161				if (!sock_table) {
162					mutex_unlock(&sock_flow_mutex);
163					return -ENOMEM;
164				}
165				net_hotdata.rps_cpu_mask =
166					roundup_pow_of_two(nr_cpu_ids) - 1;
167				sock_table->mask = size - 1;
168			} else
169				sock_table = orig_sock_table;
170
171			for (i = 0; i < size; i++)
172				sock_table->ents[i] = RPS_NO_CPU;
173		} else
174			sock_table = NULL;
175
176		if (sock_table != orig_sock_table) {
177			rcu_assign_pointer(net_hotdata.rps_sock_flow_table,
178					   sock_table);
179			if (sock_table) {
180				static_branch_inc(&rps_needed);
181				static_branch_inc(&rfs_needed);
182			}
183			if (orig_sock_table) {
184				static_branch_dec(&rps_needed);
185				static_branch_dec(&rfs_needed);
186				kvfree_rcu_mightsleep(orig_sock_table);
187			}
188		}
189	}
190
191	mutex_unlock(&sock_flow_mutex);
192
193	return ret;
194}
195#endif /* CONFIG_RPS */
196
197#ifdef CONFIG_NET_FLOW_LIMIT
198static DEFINE_MUTEX(flow_limit_update_mutex);
199
200static int flow_limit_cpu_sysctl(struct ctl_table *table, int write,
201				 void *buffer, size_t *lenp, loff_t *ppos)
202{
203	struct sd_flow_limit *cur;
204	struct softnet_data *sd;
205	cpumask_var_t mask;
206	int i, len, ret = 0;
207
208	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
209		return -ENOMEM;
210
211	if (write) {
212		ret = cpumask_parse(buffer, mask);
213		if (ret)
214			goto done;
215
216		mutex_lock(&flow_limit_update_mutex);
217		len = sizeof(*cur) + netdev_flow_limit_table_len;
218		for_each_possible_cpu(i) {
219			sd = &per_cpu(softnet_data, i);
220			cur = rcu_dereference_protected(sd->flow_limit,
221				     lockdep_is_held(&flow_limit_update_mutex));
222			if (cur && !cpumask_test_cpu(i, mask)) {
223				RCU_INIT_POINTER(sd->flow_limit, NULL);
224				kfree_rcu_mightsleep(cur);
225			} else if (!cur && cpumask_test_cpu(i, mask)) {
226				cur = kzalloc_node(len, GFP_KERNEL,
227						   cpu_to_node(i));
228				if (!cur) {
229					/* not unwinding previous changes */
230					ret = -ENOMEM;
231					goto write_unlock;
232				}
233				cur->num_buckets = netdev_flow_limit_table_len;
234				rcu_assign_pointer(sd->flow_limit, cur);
235			}
236		}
237write_unlock:
238		mutex_unlock(&flow_limit_update_mutex);
239	} else {
 
 
 
 
 
 
 
240		cpumask_clear(mask);
241		rcu_read_lock();
242		for_each_possible_cpu(i) {
243			sd = &per_cpu(softnet_data, i);
244			if (rcu_dereference(sd->flow_limit))
245				cpumask_set_cpu(i, mask);
246		}
247		rcu_read_unlock();
248
249		dump_cpumask(buffer, lenp, ppos, mask);
 
 
 
 
 
 
 
 
 
 
250	}
251
252done:
253	free_cpumask_var(mask);
254	return ret;
255}
256
257static int flow_limit_table_len_sysctl(struct ctl_table *table, int write,
258				       void *buffer, size_t *lenp, loff_t *ppos)
259{
260	unsigned int old, *ptr;
261	int ret;
262
263	mutex_lock(&flow_limit_update_mutex);
264
265	ptr = table->data;
266	old = *ptr;
267	ret = proc_dointvec(table, write, buffer, lenp, ppos);
268	if (!ret && write && !is_power_of_2(*ptr)) {
269		*ptr = old;
270		ret = -EINVAL;
271	}
272
273	mutex_unlock(&flow_limit_update_mutex);
274	return ret;
275}
276#endif /* CONFIG_NET_FLOW_LIMIT */
277
278#ifdef CONFIG_NET_SCHED
279static int set_default_qdisc(struct ctl_table *table, int write,
280			     void *buffer, size_t *lenp, loff_t *ppos)
281{
282	char id[IFNAMSIZ];
283	struct ctl_table tbl = {
284		.data = id,
285		.maxlen = IFNAMSIZ,
286	};
287	int ret;
288
289	qdisc_get_default(id, IFNAMSIZ);
290
291	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
292	if (write && ret == 0)
293		ret = qdisc_set_default(id);
294	return ret;
295}
296#endif
297
298static int proc_do_dev_weight(struct ctl_table *table, int write,
299			   void *buffer, size_t *lenp, loff_t *ppos)
300{
301	static DEFINE_MUTEX(dev_weight_mutex);
302	int ret, weight;
303
304	mutex_lock(&dev_weight_mutex);
305	ret = proc_dointvec(table, write, buffer, lenp, ppos);
306	if (!ret && write) {
307		weight = READ_ONCE(weight_p);
308		WRITE_ONCE(net_hotdata.dev_rx_weight, weight * dev_weight_rx_bias);
309		WRITE_ONCE(net_hotdata.dev_tx_weight, weight * dev_weight_tx_bias);
310	}
311	mutex_unlock(&dev_weight_mutex);
312
313	return ret;
314}
315
316static int proc_do_rss_key(struct ctl_table *table, int write,
317			   void *buffer, size_t *lenp, loff_t *ppos)
318{
319	struct ctl_table fake_table;
320	char buf[NETDEV_RSS_KEY_LEN * 3];
321
322	snprintf(buf, sizeof(buf), "%*phC", NETDEV_RSS_KEY_LEN, netdev_rss_key);
323	fake_table.data = buf;
324	fake_table.maxlen = sizeof(buf);
325	return proc_dostring(&fake_table, write, buffer, lenp, ppos);
326}
327
328#ifdef CONFIG_BPF_JIT
329static int proc_dointvec_minmax_bpf_enable(struct ctl_table *table, int write,
330					   void *buffer, size_t *lenp,
331					   loff_t *ppos)
332{
333	int ret, jit_enable = *(int *)table->data;
334	int min = *(int *)table->extra1;
335	int max = *(int *)table->extra2;
336	struct ctl_table tmp = *table;
337
338	if (write && !capable(CAP_SYS_ADMIN))
339		return -EPERM;
340
341	tmp.data = &jit_enable;
342	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
343	if (write && !ret) {
344		if (jit_enable < 2 ||
345		    (jit_enable == 2 && bpf_dump_raw_ok(current_cred()))) {
346			*(int *)table->data = jit_enable;
347			if (jit_enable == 2)
348				pr_warn("bpf_jit_enable = 2 was set! NEVER use this in production, only for JIT debugging!\n");
349		} else {
350			ret = -EPERM;
351		}
352	}
353
354	if (write && ret && min == max)
355		pr_info_once("CONFIG_BPF_JIT_ALWAYS_ON is enabled, bpf_jit_enable is permanently set to 1.\n");
356
357	return ret;
358}
359
360# ifdef CONFIG_HAVE_EBPF_JIT
361static int
362proc_dointvec_minmax_bpf_restricted(struct ctl_table *table, int write,
363				    void *buffer, size_t *lenp, loff_t *ppos)
364{
365	if (!capable(CAP_SYS_ADMIN))
366		return -EPERM;
367
368	return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
369}
370# endif /* CONFIG_HAVE_EBPF_JIT */
371
372static int
373proc_dolongvec_minmax_bpf_restricted(struct ctl_table *table, int write,
374				     void *buffer, size_t *lenp, loff_t *ppos)
375{
376	if (!capable(CAP_SYS_ADMIN))
377		return -EPERM;
378
379	return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
380}
381#endif
382
383static struct ctl_table net_core_table[] = {
384	{
385		.procname	= "wmem_max",
386		.data		= &sysctl_wmem_max,
387		.maxlen		= sizeof(int),
388		.mode		= 0644,
389		.proc_handler	= proc_dointvec_minmax,
390		.extra1		= &min_sndbuf,
391	},
392	{
393		.procname	= "rmem_max",
394		.data		= &sysctl_rmem_max,
395		.maxlen		= sizeof(int),
396		.mode		= 0644,
397		.proc_handler	= proc_dointvec_minmax,
398		.extra1		= &min_rcvbuf,
399	},
400	{
401		.procname	= "wmem_default",
402		.data		= &sysctl_wmem_default,
403		.maxlen		= sizeof(int),
404		.mode		= 0644,
405		.proc_handler	= proc_dointvec_minmax,
406		.extra1		= &min_sndbuf,
407	},
408	{
409		.procname	= "rmem_default",
410		.data		= &sysctl_rmem_default,
411		.maxlen		= sizeof(int),
412		.mode		= 0644,
413		.proc_handler	= proc_dointvec_minmax,
414		.extra1		= &min_rcvbuf,
415	},
416	{
417		.procname	= "mem_pcpu_rsv",
418		.data		= &sysctl_mem_pcpu_rsv,
419		.maxlen		= sizeof(int),
420		.mode		= 0644,
421		.proc_handler	= proc_dointvec_minmax,
422		.extra1		= &min_mem_pcpu_rsv,
423	},
424	{
425		.procname	= "dev_weight",
426		.data		= &weight_p,
427		.maxlen		= sizeof(int),
428		.mode		= 0644,
429		.proc_handler	= proc_do_dev_weight,
430	},
431	{
432		.procname	= "dev_weight_rx_bias",
433		.data		= &dev_weight_rx_bias,
434		.maxlen		= sizeof(int),
435		.mode		= 0644,
436		.proc_handler	= proc_do_dev_weight,
437	},
438	{
439		.procname	= "dev_weight_tx_bias",
440		.data		= &dev_weight_tx_bias,
441		.maxlen		= sizeof(int),
442		.mode		= 0644,
443		.proc_handler	= proc_do_dev_weight,
444	},
445	{
446		.procname	= "netdev_max_backlog",
447		.data		= &net_hotdata.max_backlog,
448		.maxlen		= sizeof(int),
449		.mode		= 0644,
450		.proc_handler	= proc_dointvec
451	},
452	{
453		.procname	= "netdev_rss_key",
454		.data		= &netdev_rss_key,
455		.maxlen		= sizeof(int),
456		.mode		= 0444,
457		.proc_handler	= proc_do_rss_key,
458	},
459#ifdef CONFIG_BPF_JIT
460	{
461		.procname	= "bpf_jit_enable",
462		.data		= &bpf_jit_enable,
463		.maxlen		= sizeof(int),
464		.mode		= 0644,
465		.proc_handler	= proc_dointvec_minmax_bpf_enable,
466# ifdef CONFIG_BPF_JIT_ALWAYS_ON
467		.extra1		= SYSCTL_ONE,
468		.extra2		= SYSCTL_ONE,
469# else
470		.extra1		= SYSCTL_ZERO,
471		.extra2		= SYSCTL_TWO,
472# endif
473	},
474# ifdef CONFIG_HAVE_EBPF_JIT
475	{
476		.procname	= "bpf_jit_harden",
477		.data		= &bpf_jit_harden,
478		.maxlen		= sizeof(int),
479		.mode		= 0600,
480		.proc_handler	= proc_dointvec_minmax_bpf_restricted,
481		.extra1		= SYSCTL_ZERO,
482		.extra2		= SYSCTL_TWO,
483	},
484	{
485		.procname	= "bpf_jit_kallsyms",
486		.data		= &bpf_jit_kallsyms,
487		.maxlen		= sizeof(int),
488		.mode		= 0600,
489		.proc_handler	= proc_dointvec_minmax_bpf_restricted,
490		.extra1		= SYSCTL_ZERO,
491		.extra2		= SYSCTL_ONE,
492	},
493# endif
494	{
495		.procname	= "bpf_jit_limit",
496		.data		= &bpf_jit_limit,
497		.maxlen		= sizeof(long),
498		.mode		= 0600,
499		.proc_handler	= proc_dolongvec_minmax_bpf_restricted,
500		.extra1		= SYSCTL_LONG_ONE,
501		.extra2		= &bpf_jit_limit_max,
502	},
503#endif
504	{
505		.procname	= "netdev_tstamp_prequeue",
506		.data		= &net_hotdata.tstamp_prequeue,
507		.maxlen		= sizeof(int),
508		.mode		= 0644,
509		.proc_handler	= proc_dointvec
510	},
511	{
512		.procname	= "message_cost",
513		.data		= &net_ratelimit_state.interval,
514		.maxlen		= sizeof(int),
515		.mode		= 0644,
516		.proc_handler	= proc_dointvec_jiffies,
517	},
518	{
519		.procname	= "message_burst",
520		.data		= &net_ratelimit_state.burst,
521		.maxlen		= sizeof(int),
522		.mode		= 0644,
523		.proc_handler	= proc_dointvec,
524	},
525	{
 
 
 
 
 
 
 
526		.procname	= "tstamp_allow_data",
527		.data		= &sysctl_tstamp_allow_data,
528		.maxlen		= sizeof(int),
529		.mode		= 0644,
530		.proc_handler	= proc_dointvec_minmax,
531		.extra1		= SYSCTL_ZERO,
532		.extra2		= SYSCTL_ONE
533	},
534#ifdef CONFIG_RPS
535	{
536		.procname	= "rps_sock_flow_entries",
537		.maxlen		= sizeof(int),
538		.mode		= 0644,
539		.proc_handler	= rps_sock_flow_sysctl
540	},
541#endif
542#ifdef CONFIG_NET_FLOW_LIMIT
543	{
544		.procname	= "flow_limit_cpu_bitmap",
545		.mode		= 0644,
546		.proc_handler	= flow_limit_cpu_sysctl
547	},
548	{
549		.procname	= "flow_limit_table_len",
550		.data		= &netdev_flow_limit_table_len,
551		.maxlen		= sizeof(int),
552		.mode		= 0644,
553		.proc_handler	= flow_limit_table_len_sysctl
554	},
555#endif /* CONFIG_NET_FLOW_LIMIT */
556#ifdef CONFIG_NET_RX_BUSY_POLL
557	{
558		.procname	= "busy_poll",
559		.data		= &sysctl_net_busy_poll,
560		.maxlen		= sizeof(unsigned int),
561		.mode		= 0644,
562		.proc_handler	= proc_dointvec_minmax,
563		.extra1		= SYSCTL_ZERO,
564	},
565	{
566		.procname	= "busy_read",
567		.data		= &sysctl_net_busy_read,
568		.maxlen		= sizeof(unsigned int),
569		.mode		= 0644,
570		.proc_handler	= proc_dointvec_minmax,
571		.extra1		= SYSCTL_ZERO,
572	},
573#endif
574#ifdef CONFIG_NET_SCHED
575	{
576		.procname	= "default_qdisc",
577		.mode		= 0644,
578		.maxlen		= IFNAMSIZ,
579		.proc_handler	= set_default_qdisc
580	},
581#endif
582	{
583		.procname	= "netdev_budget",
584		.data		= &net_hotdata.netdev_budget,
585		.maxlen		= sizeof(int),
586		.mode		= 0644,
587		.proc_handler	= proc_dointvec
588	},
589	{
590		.procname	= "warnings",
591		.data		= &net_msg_warn,
592		.maxlen		= sizeof(int),
593		.mode		= 0644,
594		.proc_handler	= proc_dointvec
595	},
596	{
597		.procname	= "max_skb_frags",
598		.data		= &sysctl_max_skb_frags,
599		.maxlen		= sizeof(int),
600		.mode		= 0644,
601		.proc_handler	= proc_dointvec_minmax,
602		.extra1		= SYSCTL_ONE,
603		.extra2		= &max_skb_frags,
604	},
605	{
606		.procname	= "netdev_budget_usecs",
607		.data		= &net_hotdata.netdev_budget_usecs,
608		.maxlen		= sizeof(unsigned int),
609		.mode		= 0644,
610		.proc_handler	= proc_dointvec_minmax,
611		.extra1		= SYSCTL_ZERO,
612	},
613	{
614		.procname	= "fb_tunnels_only_for_init_net",
615		.data		= &sysctl_fb_tunnels_only_for_init_net,
616		.maxlen		= sizeof(int),
617		.mode		= 0644,
618		.proc_handler	= proc_dointvec_minmax,
619		.extra1		= SYSCTL_ZERO,
620		.extra2		= SYSCTL_TWO,
621	},
622	{
623		.procname	= "devconf_inherit_init_net",
624		.data		= &sysctl_devconf_inherit_init_net,
625		.maxlen		= sizeof(int),
626		.mode		= 0644,
627		.proc_handler	= proc_dointvec_minmax,
628		.extra1		= SYSCTL_ZERO,
629		.extra2		= SYSCTL_THREE,
630	},
631	{
632		.procname	= "high_order_alloc_disable",
633		.data		= &net_high_order_alloc_disable_key.key,
634		.maxlen         = sizeof(net_high_order_alloc_disable_key),
635		.mode		= 0644,
636		.proc_handler	= proc_do_static_key,
637	},
638	{
639		.procname	= "gro_normal_batch",
640		.data		= &net_hotdata.gro_normal_batch,
641		.maxlen		= sizeof(unsigned int),
642		.mode		= 0644,
643		.proc_handler	= proc_dointvec_minmax,
644		.extra1		= SYSCTL_ONE,
645	},
646	{
647		.procname	= "netdev_unregister_timeout_secs",
648		.data		= &netdev_unregister_timeout_secs,
649		.maxlen		= sizeof(unsigned int),
650		.mode		= 0644,
651		.proc_handler	= proc_dointvec_minmax,
652		.extra1		= SYSCTL_ONE,
653		.extra2		= &int_3600,
654	},
655	{
656		.procname	= "skb_defer_max",
657		.data		= &sysctl_skb_defer_max,
658		.maxlen		= sizeof(unsigned int),
659		.mode		= 0644,
660		.proc_handler	= proc_dointvec_minmax,
661		.extra1		= SYSCTL_ZERO,
662	},
663	{ }
664};
665
666static struct ctl_table netns_core_table[] = {
667#if IS_ENABLED(CONFIG_RPS)
668	{
669		.procname	= "rps_default_mask",
670		.data		= &init_net,
671		.mode		= 0644,
672		.proc_handler	= rps_default_mask_sysctl
673	},
674#endif
675	{
676		.procname	= "somaxconn",
677		.data		= &init_net.core.sysctl_somaxconn,
678		.maxlen		= sizeof(int),
679		.mode		= 0644,
680		.extra1		= SYSCTL_ZERO,
681		.proc_handler	= proc_dointvec_minmax
682	},
683	{
684		.procname	= "optmem_max",
685		.data		= &init_net.core.sysctl_optmem_max,
686		.maxlen		= sizeof(int),
687		.mode		= 0644,
688		.extra1		= SYSCTL_ZERO,
689		.proc_handler	= proc_dointvec_minmax
690	},
691	{
692		.procname	= "txrehash",
693		.data		= &init_net.core.sysctl_txrehash,
694		.maxlen		= sizeof(u8),
695		.mode		= 0644,
696		.extra1		= SYSCTL_ZERO,
697		.extra2		= SYSCTL_ONE,
698		.proc_handler	= proc_dou8vec_minmax,
699	},
700	{ }
701};
702
703static int __init fb_tunnels_only_for_init_net_sysctl_setup(char *str)
704{
705	/* fallback tunnels for initns only */
706	if (!strncmp(str, "initns", 6))
707		sysctl_fb_tunnels_only_for_init_net = 1;
708	/* no fallback tunnels anywhere */
709	else if (!strncmp(str, "none", 4))
710		sysctl_fb_tunnels_only_for_init_net = 2;
711
712	return 1;
713}
714__setup("fb_tunnels=", fb_tunnels_only_for_init_net_sysctl_setup);
715
716static __net_init int sysctl_core_net_init(struct net *net)
717{
718	struct ctl_table *tbl, *tmp;
719
720	tbl = netns_core_table;
721	if (!net_eq(net, &init_net)) {
722		tbl = kmemdup(tbl, sizeof(netns_core_table), GFP_KERNEL);
723		if (tbl == NULL)
724			goto err_dup;
725
726		for (tmp = tbl; tmp->procname; tmp++)
727			tmp->data += (char *)net - (char *)&init_net;
 
 
 
 
 
728	}
729
730	net->core.sysctl_hdr = register_net_sysctl_sz(net, "net/core", tbl,
731						      ARRAY_SIZE(netns_core_table));
732	if (net->core.sysctl_hdr == NULL)
733		goto err_reg;
734
735	return 0;
736
737err_reg:
738	if (tbl != netns_core_table)
739		kfree(tbl);
740err_dup:
741	return -ENOMEM;
742}
743
744static __net_exit void sysctl_core_net_exit(struct net *net)
745{
746	struct ctl_table *tbl;
747
748	tbl = net->core.sysctl_hdr->ctl_table_arg;
749	unregister_net_sysctl_table(net->core.sysctl_hdr);
750	BUG_ON(tbl == netns_core_table);
751#if IS_ENABLED(CONFIG_RPS)
752	kfree(net->core.rps_default_mask);
753#endif
754	kfree(tbl);
755}
756
757static __net_initdata struct pernet_operations sysctl_core_ops = {
758	.init = sysctl_core_net_init,
759	.exit = sysctl_core_net_exit,
760};
761
762static __init int sysctl_core_init(void)
763{
764	register_net_sysctl(&init_net, "net/core", net_core_table);
765	return register_pernet_subsys(&sysctl_core_ops);
766}
767
768fs_initcall(sysctl_core_init);