xref: /openbmc/linux/net/ipv4/sysctl_net_ipv4.c (revision 2eb3ed33e55d003d721d4d1a5e72fe323c12b4c0)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * sysctl_net_ipv4.c: sysctl interface to net IPV4 subsystem.
4  *
5  * Begun April 1, 1996, Mike Shaver.
6  * Added /proc/sys/net/ipv4 directory entry (empty =) ). [MS]
7  */
8 
9 #include <linux/mm.h>
10 #include <linux/module.h>
11 #include <linux/sysctl.h>
12 #include <linux/igmp.h>
13 #include <linux/inetdevice.h>
14 #include <linux/seqlock.h>
15 #include <linux/init.h>
16 #include <linux/slab.h>
17 #include <linux/nsproxy.h>
18 #include <linux/swap.h>
19 #include <net/snmp.h>
20 #include <net/icmp.h>
21 #include <net/ip.h>
22 #include <net/route.h>
23 #include <net/tcp.h>
24 #include <net/udp.h>
25 #include <net/cipso_ipv4.h>
26 #include <net/inet_frag.h>
27 #include <net/ping.h>
28 #include <net/protocol.h>
29 #include <net/netevent.h>
30 
31 static int zero;
32 static int one = 1;
33 static int four = 4;
34 static int thousand = 1000;
35 static int gso_max_segs = GSO_MAX_SEGS;
36 static int tcp_retr1_max = 255;
37 static int ip_local_port_range_min[] = { 1, 1 };
38 static int ip_local_port_range_max[] = { 65535, 65535 };
39 static int tcp_adv_win_scale_min = -31;
40 static int tcp_adv_win_scale_max = 31;
41 static int ip_privileged_port_min;
42 static int ip_privileged_port_max = 65535;
43 static int ip_ttl_min = 1;
44 static int ip_ttl_max = 255;
45 static int tcp_syn_retries_min = 1;
46 static int tcp_syn_retries_max = MAX_TCP_SYNCNT;
47 static int ip_ping_group_range_min[] = { 0, 0 };
48 static int ip_ping_group_range_max[] = { GID_T_MAX, GID_T_MAX };
49 
50 /* obsolete */
51 static int sysctl_tcp_low_latency __read_mostly;
52 
53 /* Update system visible IP port range */
54 static void set_local_port_range(struct net *net, int range[2])
55 {
56 	bool same_parity = !((range[0] ^ range[1]) & 1);
57 
58 	write_seqlock_bh(&net->ipv4.ip_local_ports.lock);
59 	if (same_parity && !net->ipv4.ip_local_ports.warned) {
60 		net->ipv4.ip_local_ports.warned = true;
61 		pr_err_ratelimited("ip_local_port_range: prefer different parity for start/end values.\n");
62 	}
63 	net->ipv4.ip_local_ports.range[0] = range[0];
64 	net->ipv4.ip_local_ports.range[1] = range[1];
65 	write_sequnlock_bh(&net->ipv4.ip_local_ports.lock);
66 }
67 
68 /* Validate changes from /proc interface. */
69 static int ipv4_local_port_range(struct ctl_table *table, int write,
70 				 void __user *buffer,
71 				 size_t *lenp, loff_t *ppos)
72 {
73 	struct net *net =
74 		container_of(table->data, struct net, ipv4.ip_local_ports.range);
75 	int ret;
76 	int range[2];
77 	struct ctl_table tmp = {
78 		.data = &range,
79 		.maxlen = sizeof(range),
80 		.mode = table->mode,
81 		.extra1 = &ip_local_port_range_min,
82 		.extra2 = &ip_local_port_range_max,
83 	};
84 
85 	inet_get_local_port_range(net, &range[0], &range[1]);
86 
87 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
88 
89 	if (write && ret == 0) {
90 		/* Ensure that the upper limit is not smaller than the lower,
91 		 * and that the lower does not encroach upon the privileged
92 		 * port limit.
93 		 */
94 		if ((range[1] < range[0]) ||
95 		    (range[0] < net->ipv4.sysctl_ip_prot_sock))
96 			ret = -EINVAL;
97 		else
98 			set_local_port_range(net, range);
99 	}
100 
101 	return ret;
102 }
103 
104 /* Validate changes from /proc interface. */
105 static int ipv4_privileged_ports(struct ctl_table *table, int write,
106 				void __user *buffer, size_t *lenp, loff_t *ppos)
107 {
108 	struct net *net = container_of(table->data, struct net,
109 	    ipv4.sysctl_ip_prot_sock);
110 	int ret;
111 	int pports;
112 	int range[2];
113 	struct ctl_table tmp = {
114 		.data = &pports,
115 		.maxlen = sizeof(pports),
116 		.mode = table->mode,
117 		.extra1 = &ip_privileged_port_min,
118 		.extra2 = &ip_privileged_port_max,
119 	};
120 
121 	pports = net->ipv4.sysctl_ip_prot_sock;
122 
123 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
124 
125 	if (write && ret == 0) {
126 		inet_get_local_port_range(net, &range[0], &range[1]);
127 		/* Ensure that the local port range doesn't overlap with the
128 		 * privileged port range.
129 		 */
130 		if (range[0] < pports)
131 			ret = -EINVAL;
132 		else
133 			net->ipv4.sysctl_ip_prot_sock = pports;
134 	}
135 
136 	return ret;
137 }
138 
139 static void inet_get_ping_group_range_table(struct ctl_table *table, kgid_t *low, kgid_t *high)
140 {
141 	kgid_t *data = table->data;
142 	struct net *net =
143 		container_of(table->data, struct net, ipv4.ping_group_range.range);
144 	unsigned int seq;
145 	do {
146 		seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
147 
148 		*low = data[0];
149 		*high = data[1];
150 	} while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
151 }
152 
153 /* Update system visible IP port range */
154 static void set_ping_group_range(struct ctl_table *table, kgid_t low, kgid_t high)
155 {
156 	kgid_t *data = table->data;
157 	struct net *net =
158 		container_of(table->data, struct net, ipv4.ping_group_range.range);
159 	write_seqlock(&net->ipv4.ping_group_range.lock);
160 	data[0] = low;
161 	data[1] = high;
162 	write_sequnlock(&net->ipv4.ping_group_range.lock);
163 }
164 
165 /* Validate changes from /proc interface. */
166 static int ipv4_ping_group_range(struct ctl_table *table, int write,
167 				 void __user *buffer,
168 				 size_t *lenp, loff_t *ppos)
169 {
170 	struct user_namespace *user_ns = current_user_ns();
171 	int ret;
172 	gid_t urange[2];
173 	kgid_t low, high;
174 	struct ctl_table tmp = {
175 		.data = &urange,
176 		.maxlen = sizeof(urange),
177 		.mode = table->mode,
178 		.extra1 = &ip_ping_group_range_min,
179 		.extra2 = &ip_ping_group_range_max,
180 	};
181 
182 	inet_get_ping_group_range_table(table, &low, &high);
183 	urange[0] = from_kgid_munged(user_ns, low);
184 	urange[1] = from_kgid_munged(user_ns, high);
185 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
186 
187 	if (write && ret == 0) {
188 		low = make_kgid(user_ns, urange[0]);
189 		high = make_kgid(user_ns, urange[1]);
190 		if (!gid_valid(low) || !gid_valid(high) ||
191 		    (urange[1] < urange[0]) || gid_lt(high, low)) {
192 			low = make_kgid(&init_user_ns, 1);
193 			high = make_kgid(&init_user_ns, 0);
194 		}
195 		set_ping_group_range(table, low, high);
196 	}
197 
198 	return ret;
199 }
200 
201 static int proc_tcp_congestion_control(struct ctl_table *ctl, int write,
202 				       void __user *buffer, size_t *lenp, loff_t *ppos)
203 {
204 	char val[TCP_CA_NAME_MAX];
205 	struct ctl_table tbl = {
206 		.data = val,
207 		.maxlen = TCP_CA_NAME_MAX,
208 	};
209 	int ret;
210 
211 	tcp_get_default_congestion_control(val);
212 
213 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
214 	if (write && ret == 0)
215 		ret = tcp_set_default_congestion_control(val);
216 	return ret;
217 }
218 
219 static int proc_tcp_available_congestion_control(struct ctl_table *ctl,
220 						 int write,
221 						 void __user *buffer, size_t *lenp,
222 						 loff_t *ppos)
223 {
224 	struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX, };
225 	int ret;
226 
227 	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
228 	if (!tbl.data)
229 		return -ENOMEM;
230 	tcp_get_available_congestion_control(tbl.data, TCP_CA_BUF_MAX);
231 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
232 	kfree(tbl.data);
233 	return ret;
234 }
235 
236 static int proc_allowed_congestion_control(struct ctl_table *ctl,
237 					   int write,
238 					   void __user *buffer, size_t *lenp,
239 					   loff_t *ppos)
240 {
241 	struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX };
242 	int ret;
243 
244 	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
245 	if (!tbl.data)
246 		return -ENOMEM;
247 
248 	tcp_get_allowed_congestion_control(tbl.data, tbl.maxlen);
249 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
250 	if (write && ret == 0)
251 		ret = tcp_set_allowed_congestion_control(tbl.data);
252 	kfree(tbl.data);
253 	return ret;
254 }
255 
256 static int proc_tcp_fastopen_key(struct ctl_table *table, int write,
257 				 void __user *buffer, size_t *lenp,
258 				 loff_t *ppos)
259 {
260 	struct net *net = container_of(table->data, struct net,
261 	    ipv4.sysctl_tcp_fastopen);
262 	struct ctl_table tbl = { .maxlen = (TCP_FASTOPEN_KEY_LENGTH * 2 + 10) };
263 	struct tcp_fastopen_context *ctxt;
264 	int ret;
265 	u32  user_key[4]; /* 16 bytes, matching TCP_FASTOPEN_KEY_LENGTH */
266 
267 	tbl.data = kmalloc(tbl.maxlen, GFP_KERNEL);
268 	if (!tbl.data)
269 		return -ENOMEM;
270 
271 	rcu_read_lock();
272 	ctxt = rcu_dereference(net->ipv4.tcp_fastopen_ctx);
273 	if (ctxt)
274 		memcpy(user_key, ctxt->key, TCP_FASTOPEN_KEY_LENGTH);
275 	else
276 		memset(user_key, 0, sizeof(user_key));
277 	rcu_read_unlock();
278 
279 	snprintf(tbl.data, tbl.maxlen, "%08x-%08x-%08x-%08x",
280 		user_key[0], user_key[1], user_key[2], user_key[3]);
281 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
282 
283 	if (write && ret == 0) {
284 		if (sscanf(tbl.data, "%x-%x-%x-%x", user_key, user_key + 1,
285 			   user_key + 2, user_key + 3) != 4) {
286 			ret = -EINVAL;
287 			goto bad_key;
288 		}
289 		tcp_fastopen_reset_cipher(net, NULL, user_key,
290 					  TCP_FASTOPEN_KEY_LENGTH);
291 	}
292 
293 bad_key:
294 	pr_debug("proc FO key set 0x%x-%x-%x-%x <- 0x%s: %u\n",
295 	       user_key[0], user_key[1], user_key[2], user_key[3],
296 	       (char *)tbl.data, ret);
297 	kfree(tbl.data);
298 	return ret;
299 }
300 
301 static void proc_configure_early_demux(int enabled, int protocol)
302 {
303 	struct net_protocol *ipprot;
304 #if IS_ENABLED(CONFIG_IPV6)
305 	struct inet6_protocol *ip6prot;
306 #endif
307 
308 	rcu_read_lock();
309 
310 	ipprot = rcu_dereference(inet_protos[protocol]);
311 	if (ipprot)
312 		ipprot->early_demux = enabled ? ipprot->early_demux_handler :
313 						NULL;
314 
315 #if IS_ENABLED(CONFIG_IPV6)
316 	ip6prot = rcu_dereference(inet6_protos[protocol]);
317 	if (ip6prot)
318 		ip6prot->early_demux = enabled ? ip6prot->early_demux_handler :
319 						 NULL;
320 #endif
321 	rcu_read_unlock();
322 }
323 
324 static int proc_tcp_early_demux(struct ctl_table *table, int write,
325 				void __user *buffer, size_t *lenp, loff_t *ppos)
326 {
327 	int ret = 0;
328 
329 	ret = proc_dointvec(table, write, buffer, lenp, ppos);
330 
331 	if (write && !ret) {
332 		int enabled = init_net.ipv4.sysctl_tcp_early_demux;
333 
334 		proc_configure_early_demux(enabled, IPPROTO_TCP);
335 	}
336 
337 	return ret;
338 }
339 
340 static int proc_udp_early_demux(struct ctl_table *table, int write,
341 				void __user *buffer, size_t *lenp, loff_t *ppos)
342 {
343 	int ret = 0;
344 
345 	ret = proc_dointvec(table, write, buffer, lenp, ppos);
346 
347 	if (write && !ret) {
348 		int enabled = init_net.ipv4.sysctl_udp_early_demux;
349 
350 		proc_configure_early_demux(enabled, IPPROTO_UDP);
351 	}
352 
353 	return ret;
354 }
355 
356 static int proc_tfo_blackhole_detect_timeout(struct ctl_table *table,
357 					     int write,
358 					     void __user *buffer,
359 					     size_t *lenp, loff_t *ppos)
360 {
361 	struct net *net = container_of(table->data, struct net,
362 	    ipv4.sysctl_tcp_fastopen_blackhole_timeout);
363 	int ret;
364 
365 	ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
366 	if (write && ret == 0)
367 		atomic_set(&net->ipv4.tfo_active_disable_times, 0);
368 
369 	return ret;
370 }
371 
372 static int proc_tcp_available_ulp(struct ctl_table *ctl,
373 				  int write,
374 				  void __user *buffer, size_t *lenp,
375 				  loff_t *ppos)
376 {
377 	struct ctl_table tbl = { .maxlen = TCP_ULP_BUF_MAX, };
378 	int ret;
379 
380 	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
381 	if (!tbl.data)
382 		return -ENOMEM;
383 	tcp_get_available_ulp(tbl.data, TCP_ULP_BUF_MAX);
384 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
385 	kfree(tbl.data);
386 
387 	return ret;
388 }
389 
390 #ifdef CONFIG_IP_ROUTE_MULTIPATH
391 static int proc_fib_multipath_hash_policy(struct ctl_table *table, int write,
392 					  void __user *buffer, size_t *lenp,
393 					  loff_t *ppos)
394 {
395 	struct net *net = container_of(table->data, struct net,
396 	    ipv4.sysctl_fib_multipath_hash_policy);
397 	int ret;
398 
399 	ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
400 	if (write && ret == 0)
401 		call_netevent_notifiers(NETEVENT_MULTIPATH_HASH_UPDATE, net);
402 
403 	return ret;
404 }
405 #endif
406 
407 static struct ctl_table ipv4_table[] = {
408 	{
409 		.procname	= "tcp_max_orphans",
410 		.data		= &sysctl_tcp_max_orphans,
411 		.maxlen		= sizeof(int),
412 		.mode		= 0644,
413 		.proc_handler	= proc_dointvec
414 	},
415 	{
416 		.procname	= "inet_peer_threshold",
417 		.data		= &inet_peer_threshold,
418 		.maxlen		= sizeof(int),
419 		.mode		= 0644,
420 		.proc_handler	= proc_dointvec
421 	},
422 	{
423 		.procname	= "inet_peer_minttl",
424 		.data		= &inet_peer_minttl,
425 		.maxlen		= sizeof(int),
426 		.mode		= 0644,
427 		.proc_handler	= proc_dointvec_jiffies,
428 	},
429 	{
430 		.procname	= "inet_peer_maxttl",
431 		.data		= &inet_peer_maxttl,
432 		.maxlen		= sizeof(int),
433 		.mode		= 0644,
434 		.proc_handler	= proc_dointvec_jiffies,
435 	},
436 	{
437 		.procname	= "tcp_mem",
438 		.maxlen		= sizeof(sysctl_tcp_mem),
439 		.data		= &sysctl_tcp_mem,
440 		.mode		= 0644,
441 		.proc_handler	= proc_doulongvec_minmax,
442 	},
443 	{
444 		.procname	= "tcp_wmem",
445 		.data		= &sysctl_tcp_wmem,
446 		.maxlen		= sizeof(sysctl_tcp_wmem),
447 		.mode		= 0644,
448 		.proc_handler	= proc_dointvec_minmax,
449 		.extra1		= &one,
450 	},
451 	{
452 		.procname	= "tcp_rmem",
453 		.data		= &sysctl_tcp_rmem,
454 		.maxlen		= sizeof(sysctl_tcp_rmem),
455 		.mode		= 0644,
456 		.proc_handler	= proc_dointvec_minmax,
457 		.extra1		= &one,
458 	},
459 	{
460 		.procname	= "tcp_low_latency",
461 		.data		= &sysctl_tcp_low_latency,
462 		.maxlen		= sizeof(int),
463 		.mode		= 0644,
464 		.proc_handler	= proc_dointvec
465 	},
466 	{
467 		.procname	= "tcp_congestion_control",
468 		.mode		= 0644,
469 		.maxlen		= TCP_CA_NAME_MAX,
470 		.proc_handler	= proc_tcp_congestion_control,
471 	},
472 #ifdef CONFIG_NETLABEL
473 	{
474 		.procname	= "cipso_cache_enable",
475 		.data		= &cipso_v4_cache_enabled,
476 		.maxlen		= sizeof(int),
477 		.mode		= 0644,
478 		.proc_handler	= proc_dointvec,
479 	},
480 	{
481 		.procname	= "cipso_cache_bucket_size",
482 		.data		= &cipso_v4_cache_bucketsize,
483 		.maxlen		= sizeof(int),
484 		.mode		= 0644,
485 		.proc_handler	= proc_dointvec,
486 	},
487 	{
488 		.procname	= "cipso_rbm_optfmt",
489 		.data		= &cipso_v4_rbm_optfmt,
490 		.maxlen		= sizeof(int),
491 		.mode		= 0644,
492 		.proc_handler	= proc_dointvec,
493 	},
494 	{
495 		.procname	= "cipso_rbm_strictvalid",
496 		.data		= &cipso_v4_rbm_strictvalid,
497 		.maxlen		= sizeof(int),
498 		.mode		= 0644,
499 		.proc_handler	= proc_dointvec,
500 	},
501 #endif /* CONFIG_NETLABEL */
502 	{
503 		.procname	= "tcp_available_congestion_control",
504 		.maxlen		= TCP_CA_BUF_MAX,
505 		.mode		= 0444,
506 		.proc_handler   = proc_tcp_available_congestion_control,
507 	},
508 	{
509 		.procname	= "tcp_allowed_congestion_control",
510 		.maxlen		= TCP_CA_BUF_MAX,
511 		.mode		= 0644,
512 		.proc_handler   = proc_allowed_congestion_control,
513 	},
514 	{
515 		.procname	= "tcp_available_ulp",
516 		.maxlen		= TCP_ULP_BUF_MAX,
517 		.mode		= 0444,
518 		.proc_handler   = proc_tcp_available_ulp,
519 	},
520 	{
521 		.procname	= "icmp_msgs_per_sec",
522 		.data		= &sysctl_icmp_msgs_per_sec,
523 		.maxlen		= sizeof(int),
524 		.mode		= 0644,
525 		.proc_handler	= proc_dointvec_minmax,
526 		.extra1		= &zero,
527 	},
528 	{
529 		.procname	= "icmp_msgs_burst",
530 		.data		= &sysctl_icmp_msgs_burst,
531 		.maxlen		= sizeof(int),
532 		.mode		= 0644,
533 		.proc_handler	= proc_dointvec_minmax,
534 		.extra1		= &zero,
535 	},
536 	{
537 		.procname	= "udp_mem",
538 		.data		= &sysctl_udp_mem,
539 		.maxlen		= sizeof(sysctl_udp_mem),
540 		.mode		= 0644,
541 		.proc_handler	= proc_doulongvec_minmax,
542 	},
543 	{
544 		.procname	= "udp_rmem_min",
545 		.data		= &sysctl_udp_rmem_min,
546 		.maxlen		= sizeof(sysctl_udp_rmem_min),
547 		.mode		= 0644,
548 		.proc_handler	= proc_dointvec_minmax,
549 		.extra1		= &one
550 	},
551 	{
552 		.procname	= "udp_wmem_min",
553 		.data		= &sysctl_udp_wmem_min,
554 		.maxlen		= sizeof(sysctl_udp_wmem_min),
555 		.mode		= 0644,
556 		.proc_handler	= proc_dointvec_minmax,
557 		.extra1		= &one
558 	},
559 	{ }
560 };
561 
562 static struct ctl_table ipv4_net_table[] = {
563 	{
564 		.procname	= "icmp_echo_ignore_all",
565 		.data		= &init_net.ipv4.sysctl_icmp_echo_ignore_all,
566 		.maxlen		= sizeof(int),
567 		.mode		= 0644,
568 		.proc_handler	= proc_dointvec
569 	},
570 	{
571 		.procname	= "icmp_echo_ignore_broadcasts",
572 		.data		= &init_net.ipv4.sysctl_icmp_echo_ignore_broadcasts,
573 		.maxlen		= sizeof(int),
574 		.mode		= 0644,
575 		.proc_handler	= proc_dointvec
576 	},
577 	{
578 		.procname	= "icmp_ignore_bogus_error_responses",
579 		.data		= &init_net.ipv4.sysctl_icmp_ignore_bogus_error_responses,
580 		.maxlen		= sizeof(int),
581 		.mode		= 0644,
582 		.proc_handler	= proc_dointvec
583 	},
584 	{
585 		.procname	= "icmp_errors_use_inbound_ifaddr",
586 		.data		= &init_net.ipv4.sysctl_icmp_errors_use_inbound_ifaddr,
587 		.maxlen		= sizeof(int),
588 		.mode		= 0644,
589 		.proc_handler	= proc_dointvec
590 	},
591 	{
592 		.procname	= "icmp_ratelimit",
593 		.data		= &init_net.ipv4.sysctl_icmp_ratelimit,
594 		.maxlen		= sizeof(int),
595 		.mode		= 0644,
596 		.proc_handler	= proc_dointvec_ms_jiffies,
597 	},
598 	{
599 		.procname	= "icmp_ratemask",
600 		.data		= &init_net.ipv4.sysctl_icmp_ratemask,
601 		.maxlen		= sizeof(int),
602 		.mode		= 0644,
603 		.proc_handler	= proc_dointvec
604 	},
605 	{
606 		.procname	= "ping_group_range",
607 		.data		= &init_net.ipv4.ping_group_range.range,
608 		.maxlen		= sizeof(gid_t)*2,
609 		.mode		= 0644,
610 		.proc_handler	= ipv4_ping_group_range,
611 	},
612 	{
613 		.procname	= "tcp_ecn",
614 		.data		= &init_net.ipv4.sysctl_tcp_ecn,
615 		.maxlen		= sizeof(int),
616 		.mode		= 0644,
617 		.proc_handler	= proc_dointvec
618 	},
619 	{
620 		.procname	= "tcp_ecn_fallback",
621 		.data		= &init_net.ipv4.sysctl_tcp_ecn_fallback,
622 		.maxlen		= sizeof(int),
623 		.mode		= 0644,
624 		.proc_handler	= proc_dointvec
625 	},
626 	{
627 		.procname	= "ip_dynaddr",
628 		.data		= &init_net.ipv4.sysctl_ip_dynaddr,
629 		.maxlen		= sizeof(int),
630 		.mode		= 0644,
631 		.proc_handler	= proc_dointvec
632 	},
633 	{
634 		.procname	= "ip_early_demux",
635 		.data		= &init_net.ipv4.sysctl_ip_early_demux,
636 		.maxlen		= sizeof(int),
637 		.mode		= 0644,
638 		.proc_handler	= proc_dointvec
639 	},
640 	{
641 		.procname       = "udp_early_demux",
642 		.data           = &init_net.ipv4.sysctl_udp_early_demux,
643 		.maxlen         = sizeof(int),
644 		.mode           = 0644,
645 		.proc_handler   = proc_udp_early_demux
646 	},
647 	{
648 		.procname       = "tcp_early_demux",
649 		.data           = &init_net.ipv4.sysctl_tcp_early_demux,
650 		.maxlen         = sizeof(int),
651 		.mode           = 0644,
652 		.proc_handler   = proc_tcp_early_demux
653 	},
654 	{
655 		.procname	= "ip_default_ttl",
656 		.data		= &init_net.ipv4.sysctl_ip_default_ttl,
657 		.maxlen		= sizeof(int),
658 		.mode		= 0644,
659 		.proc_handler	= proc_dointvec_minmax,
660 		.extra1		= &ip_ttl_min,
661 		.extra2		= &ip_ttl_max,
662 	},
663 	{
664 		.procname	= "ip_local_port_range",
665 		.maxlen		= sizeof(init_net.ipv4.ip_local_ports.range),
666 		.data		= &init_net.ipv4.ip_local_ports.range,
667 		.mode		= 0644,
668 		.proc_handler	= ipv4_local_port_range,
669 	},
670 	{
671 		.procname	= "ip_local_reserved_ports",
672 		.data		= &init_net.ipv4.sysctl_local_reserved_ports,
673 		.maxlen		= 65536,
674 		.mode		= 0644,
675 		.proc_handler	= proc_do_large_bitmap,
676 	},
677 	{
678 		.procname	= "ip_no_pmtu_disc",
679 		.data		= &init_net.ipv4.sysctl_ip_no_pmtu_disc,
680 		.maxlen		= sizeof(int),
681 		.mode		= 0644,
682 		.proc_handler	= proc_dointvec
683 	},
684 	{
685 		.procname	= "ip_forward_use_pmtu",
686 		.data		= &init_net.ipv4.sysctl_ip_fwd_use_pmtu,
687 		.maxlen		= sizeof(int),
688 		.mode		= 0644,
689 		.proc_handler	= proc_dointvec,
690 	},
691 	{
692 		.procname	= "ip_nonlocal_bind",
693 		.data		= &init_net.ipv4.sysctl_ip_nonlocal_bind,
694 		.maxlen		= sizeof(int),
695 		.mode		= 0644,
696 		.proc_handler	= proc_dointvec
697 	},
698 	{
699 		.procname	= "fwmark_reflect",
700 		.data		= &init_net.ipv4.sysctl_fwmark_reflect,
701 		.maxlen		= sizeof(int),
702 		.mode		= 0644,
703 		.proc_handler	= proc_dointvec,
704 	},
705 	{
706 		.procname	= "tcp_fwmark_accept",
707 		.data		= &init_net.ipv4.sysctl_tcp_fwmark_accept,
708 		.maxlen		= sizeof(int),
709 		.mode		= 0644,
710 		.proc_handler	= proc_dointvec,
711 	},
712 #ifdef CONFIG_NET_L3_MASTER_DEV
713 	{
714 		.procname	= "tcp_l3mdev_accept",
715 		.data		= &init_net.ipv4.sysctl_tcp_l3mdev_accept,
716 		.maxlen		= sizeof(int),
717 		.mode		= 0644,
718 		.proc_handler	= proc_dointvec_minmax,
719 		.extra1		= &zero,
720 		.extra2		= &one,
721 	},
722 #endif
723 	{
724 		.procname	= "tcp_mtu_probing",
725 		.data		= &init_net.ipv4.sysctl_tcp_mtu_probing,
726 		.maxlen		= sizeof(int),
727 		.mode		= 0644,
728 		.proc_handler	= proc_dointvec,
729 	},
730 	{
731 		.procname	= "tcp_base_mss",
732 		.data		= &init_net.ipv4.sysctl_tcp_base_mss,
733 		.maxlen		= sizeof(int),
734 		.mode		= 0644,
735 		.proc_handler	= proc_dointvec,
736 	},
737 	{
738 		.procname	= "tcp_probe_threshold",
739 		.data		= &init_net.ipv4.sysctl_tcp_probe_threshold,
740 		.maxlen		= sizeof(int),
741 		.mode		= 0644,
742 		.proc_handler	= proc_dointvec,
743 	},
744 	{
745 		.procname	= "tcp_probe_interval",
746 		.data		= &init_net.ipv4.sysctl_tcp_probe_interval,
747 		.maxlen		= sizeof(int),
748 		.mode		= 0644,
749 		.proc_handler	= proc_dointvec,
750 	},
751 	{
752 		.procname	= "igmp_link_local_mcast_reports",
753 		.data		= &init_net.ipv4.sysctl_igmp_llm_reports,
754 		.maxlen		= sizeof(int),
755 		.mode		= 0644,
756 		.proc_handler	= proc_dointvec
757 	},
758 	{
759 		.procname	= "igmp_max_memberships",
760 		.data		= &init_net.ipv4.sysctl_igmp_max_memberships,
761 		.maxlen		= sizeof(int),
762 		.mode		= 0644,
763 		.proc_handler	= proc_dointvec
764 	},
765 	{
766 		.procname	= "igmp_max_msf",
767 		.data		= &init_net.ipv4.sysctl_igmp_max_msf,
768 		.maxlen		= sizeof(int),
769 		.mode		= 0644,
770 		.proc_handler	= proc_dointvec
771 	},
772 #ifdef CONFIG_IP_MULTICAST
773 	{
774 		.procname	= "igmp_qrv",
775 		.data		= &init_net.ipv4.sysctl_igmp_qrv,
776 		.maxlen		= sizeof(int),
777 		.mode		= 0644,
778 		.proc_handler	= proc_dointvec_minmax,
779 		.extra1		= &one
780 	},
781 #endif
782 	{
783 		.procname	= "tcp_keepalive_time",
784 		.data		= &init_net.ipv4.sysctl_tcp_keepalive_time,
785 		.maxlen		= sizeof(int),
786 		.mode		= 0644,
787 		.proc_handler	= proc_dointvec_jiffies,
788 	},
789 	{
790 		.procname	= "tcp_keepalive_probes",
791 		.data		= &init_net.ipv4.sysctl_tcp_keepalive_probes,
792 		.maxlen		= sizeof(int),
793 		.mode		= 0644,
794 		.proc_handler	= proc_dointvec
795 	},
796 	{
797 		.procname	= "tcp_keepalive_intvl",
798 		.data		= &init_net.ipv4.sysctl_tcp_keepalive_intvl,
799 		.maxlen		= sizeof(int),
800 		.mode		= 0644,
801 		.proc_handler	= proc_dointvec_jiffies,
802 	},
803 	{
804 		.procname	= "tcp_syn_retries",
805 		.data		= &init_net.ipv4.sysctl_tcp_syn_retries,
806 		.maxlen		= sizeof(int),
807 		.mode		= 0644,
808 		.proc_handler	= proc_dointvec_minmax,
809 		.extra1		= &tcp_syn_retries_min,
810 		.extra2		= &tcp_syn_retries_max
811 	},
812 	{
813 		.procname	= "tcp_synack_retries",
814 		.data		= &init_net.ipv4.sysctl_tcp_synack_retries,
815 		.maxlen		= sizeof(int),
816 		.mode		= 0644,
817 		.proc_handler	= proc_dointvec
818 	},
819 #ifdef CONFIG_SYN_COOKIES
820 	{
821 		.procname	= "tcp_syncookies",
822 		.data		= &init_net.ipv4.sysctl_tcp_syncookies,
823 		.maxlen		= sizeof(int),
824 		.mode		= 0644,
825 		.proc_handler	= proc_dointvec
826 	},
827 #endif
828 	{
829 		.procname	= "tcp_reordering",
830 		.data		= &init_net.ipv4.sysctl_tcp_reordering,
831 		.maxlen		= sizeof(int),
832 		.mode		= 0644,
833 		.proc_handler	= proc_dointvec
834 	},
835 	{
836 		.procname	= "tcp_retries1",
837 		.data		= &init_net.ipv4.sysctl_tcp_retries1,
838 		.maxlen		= sizeof(int),
839 		.mode		= 0644,
840 		.proc_handler	= proc_dointvec_minmax,
841 		.extra2		= &tcp_retr1_max
842 	},
843 	{
844 		.procname	= "tcp_retries2",
845 		.data		= &init_net.ipv4.sysctl_tcp_retries2,
846 		.maxlen		= sizeof(int),
847 		.mode		= 0644,
848 		.proc_handler	= proc_dointvec
849 	},
850 	{
851 		.procname	= "tcp_orphan_retries",
852 		.data		= &init_net.ipv4.sysctl_tcp_orphan_retries,
853 		.maxlen		= sizeof(int),
854 		.mode		= 0644,
855 		.proc_handler	= proc_dointvec
856 	},
857 	{
858 		.procname	= "tcp_fin_timeout",
859 		.data		= &init_net.ipv4.sysctl_tcp_fin_timeout,
860 		.maxlen		= sizeof(int),
861 		.mode		= 0644,
862 		.proc_handler	= proc_dointvec_jiffies,
863 	},
864 	{
865 		.procname	= "tcp_notsent_lowat",
866 		.data		= &init_net.ipv4.sysctl_tcp_notsent_lowat,
867 		.maxlen		= sizeof(unsigned int),
868 		.mode		= 0644,
869 		.proc_handler	= proc_douintvec,
870 	},
871 	{
872 		.procname	= "tcp_tw_reuse",
873 		.data		= &init_net.ipv4.sysctl_tcp_tw_reuse,
874 		.maxlen		= sizeof(int),
875 		.mode		= 0644,
876 		.proc_handler	= proc_dointvec
877 	},
878 	{
879 		.procname	= "tcp_max_tw_buckets",
880 		.data		= &init_net.ipv4.tcp_death_row.sysctl_max_tw_buckets,
881 		.maxlen		= sizeof(int),
882 		.mode		= 0644,
883 		.proc_handler	= proc_dointvec
884 	},
885 	{
886 		.procname	= "tcp_max_syn_backlog",
887 		.data		= &init_net.ipv4.sysctl_max_syn_backlog,
888 		.maxlen		= sizeof(int),
889 		.mode		= 0644,
890 		.proc_handler	= proc_dointvec
891 	},
892 	{
893 		.procname	= "tcp_fastopen",
894 		.data		= &init_net.ipv4.sysctl_tcp_fastopen,
895 		.maxlen		= sizeof(int),
896 		.mode		= 0644,
897 		.proc_handler	= proc_dointvec,
898 	},
899 	{
900 		.procname	= "tcp_fastopen_key",
901 		.mode		= 0600,
902 		.data		= &init_net.ipv4.sysctl_tcp_fastopen,
903 		.maxlen		= ((TCP_FASTOPEN_KEY_LENGTH * 2) + 10),
904 		.proc_handler	= proc_tcp_fastopen_key,
905 	},
906 	{
907 		.procname	= "tcp_fastopen_blackhole_timeout_sec",
908 		.data		= &init_net.ipv4.sysctl_tcp_fastopen_blackhole_timeout,
909 		.maxlen		= sizeof(int),
910 		.mode		= 0644,
911 		.proc_handler	= proc_tfo_blackhole_detect_timeout,
912 		.extra1		= &zero,
913 	},
914 #ifdef CONFIG_IP_ROUTE_MULTIPATH
915 	{
916 		.procname	= "fib_multipath_use_neigh",
917 		.data		= &init_net.ipv4.sysctl_fib_multipath_use_neigh,
918 		.maxlen		= sizeof(int),
919 		.mode		= 0644,
920 		.proc_handler	= proc_dointvec_minmax,
921 		.extra1		= &zero,
922 		.extra2		= &one,
923 	},
924 	{
925 		.procname	= "fib_multipath_hash_policy",
926 		.data		= &init_net.ipv4.sysctl_fib_multipath_hash_policy,
927 		.maxlen		= sizeof(int),
928 		.mode		= 0644,
929 		.proc_handler	= proc_fib_multipath_hash_policy,
930 		.extra1		= &zero,
931 		.extra2		= &one,
932 	},
933 #endif
934 	{
935 		.procname	= "ip_unprivileged_port_start",
936 		.maxlen		= sizeof(int),
937 		.data		= &init_net.ipv4.sysctl_ip_prot_sock,
938 		.mode		= 0644,
939 		.proc_handler	= ipv4_privileged_ports,
940 	},
941 #ifdef CONFIG_NET_L3_MASTER_DEV
942 	{
943 		.procname	= "udp_l3mdev_accept",
944 		.data		= &init_net.ipv4.sysctl_udp_l3mdev_accept,
945 		.maxlen		= sizeof(int),
946 		.mode		= 0644,
947 		.proc_handler	= proc_dointvec_minmax,
948 		.extra1		= &zero,
949 		.extra2		= &one,
950 	},
951 #endif
952 	{
953 		.procname	= "tcp_sack",
954 		.data		= &init_net.ipv4.sysctl_tcp_sack,
955 		.maxlen		= sizeof(int),
956 		.mode		= 0644,
957 		.proc_handler	= proc_dointvec
958 	},
959 	{
960 		.procname	= "tcp_window_scaling",
961 		.data		= &init_net.ipv4.sysctl_tcp_window_scaling,
962 		.maxlen		= sizeof(int),
963 		.mode		= 0644,
964 		.proc_handler	= proc_dointvec
965 	},
966 	{
967 		.procname	= "tcp_timestamps",
968 		.data		= &init_net.ipv4.sysctl_tcp_timestamps,
969 		.maxlen		= sizeof(int),
970 		.mode		= 0644,
971 		.proc_handler	= proc_dointvec
972 	},
973 	{
974 		.procname	= "tcp_early_retrans",
975 		.data		= &init_net.ipv4.sysctl_tcp_early_retrans,
976 		.maxlen		= sizeof(int),
977 		.mode		= 0644,
978 		.proc_handler	= proc_dointvec_minmax,
979 		.extra1		= &zero,
980 		.extra2		= &four,
981 	},
982 	{
983 		.procname	= "tcp_recovery",
984 		.data		= &init_net.ipv4.sysctl_tcp_recovery,
985 		.maxlen		= sizeof(int),
986 		.mode		= 0644,
987 		.proc_handler	= proc_dointvec,
988 	},
989 	{
990 		.procname       = "tcp_thin_linear_timeouts",
991 		.data           = &init_net.ipv4.sysctl_tcp_thin_linear_timeouts,
992 		.maxlen         = sizeof(int),
993 		.mode           = 0644,
994 		.proc_handler   = proc_dointvec
995 	},
996 	{
997 		.procname	= "tcp_slow_start_after_idle",
998 		.data		= &init_net.ipv4.sysctl_tcp_slow_start_after_idle,
999 		.maxlen		= sizeof(int),
1000 		.mode		= 0644,
1001 		.proc_handler	= proc_dointvec
1002 	},
1003 	{
1004 		.procname	= "tcp_retrans_collapse",
1005 		.data		= &init_net.ipv4.sysctl_tcp_retrans_collapse,
1006 		.maxlen		= sizeof(int),
1007 		.mode		= 0644,
1008 		.proc_handler	= proc_dointvec
1009 	},
1010 	{
1011 		.procname	= "tcp_stdurg",
1012 		.data		= &init_net.ipv4.sysctl_tcp_stdurg,
1013 		.maxlen		= sizeof(int),
1014 		.mode		= 0644,
1015 		.proc_handler	= proc_dointvec
1016 	},
1017 	{
1018 		.procname	= "tcp_rfc1337",
1019 		.data		= &init_net.ipv4.sysctl_tcp_rfc1337,
1020 		.maxlen		= sizeof(int),
1021 		.mode		= 0644,
1022 		.proc_handler	= proc_dointvec
1023 	},
1024 	{
1025 		.procname	= "tcp_abort_on_overflow",
1026 		.data		= &init_net.ipv4.sysctl_tcp_abort_on_overflow,
1027 		.maxlen		= sizeof(int),
1028 		.mode		= 0644,
1029 		.proc_handler	= proc_dointvec
1030 	},
1031 	{
1032 		.procname	= "tcp_fack",
1033 		.data		= &init_net.ipv4.sysctl_tcp_fack,
1034 		.maxlen		= sizeof(int),
1035 		.mode		= 0644,
1036 		.proc_handler	= proc_dointvec
1037 	},
1038 	{
1039 		.procname	= "tcp_max_reordering",
1040 		.data		= &init_net.ipv4.sysctl_tcp_max_reordering,
1041 		.maxlen		= sizeof(int),
1042 		.mode		= 0644,
1043 		.proc_handler	= proc_dointvec
1044 	},
1045 	{
1046 		.procname	= "tcp_dsack",
1047 		.data		= &init_net.ipv4.sysctl_tcp_dsack,
1048 		.maxlen		= sizeof(int),
1049 		.mode		= 0644,
1050 		.proc_handler	= proc_dointvec
1051 	},
1052 	{
1053 		.procname	= "tcp_app_win",
1054 		.data		= &init_net.ipv4.sysctl_tcp_app_win,
1055 		.maxlen		= sizeof(int),
1056 		.mode		= 0644,
1057 		.proc_handler	= proc_dointvec
1058 	},
1059 	{
1060 		.procname	= "tcp_adv_win_scale",
1061 		.data		= &init_net.ipv4.sysctl_tcp_adv_win_scale,
1062 		.maxlen		= sizeof(int),
1063 		.mode		= 0644,
1064 		.proc_handler	= proc_dointvec_minmax,
1065 		.extra1		= &tcp_adv_win_scale_min,
1066 		.extra2		= &tcp_adv_win_scale_max,
1067 	},
1068 	{
1069 		.procname	= "tcp_frto",
1070 		.data		= &init_net.ipv4.sysctl_tcp_frto,
1071 		.maxlen		= sizeof(int),
1072 		.mode		= 0644,
1073 		.proc_handler	= proc_dointvec
1074 	},
1075 	{
1076 		.procname	= "tcp_no_metrics_save",
1077 		.data		= &init_net.ipv4.sysctl_tcp_nometrics_save,
1078 		.maxlen		= sizeof(int),
1079 		.mode		= 0644,
1080 		.proc_handler	= proc_dointvec,
1081 	},
1082 	{
1083 		.procname	= "tcp_moderate_rcvbuf",
1084 		.data		= &init_net.ipv4.sysctl_tcp_moderate_rcvbuf,
1085 		.maxlen		= sizeof(int),
1086 		.mode		= 0644,
1087 		.proc_handler	= proc_dointvec,
1088 	},
1089 	{
1090 		.procname	= "tcp_tso_win_divisor",
1091 		.data		= &init_net.ipv4.sysctl_tcp_tso_win_divisor,
1092 		.maxlen		= sizeof(int),
1093 		.mode		= 0644,
1094 		.proc_handler	= proc_dointvec,
1095 	},
1096 	{
1097 		.procname	= "tcp_workaround_signed_windows",
1098 		.data		= &init_net.ipv4.sysctl_tcp_workaround_signed_windows,
1099 		.maxlen		= sizeof(int),
1100 		.mode		= 0644,
1101 		.proc_handler	= proc_dointvec
1102 	},
1103 	{
1104 		.procname	= "tcp_limit_output_bytes",
1105 		.data		= &init_net.ipv4.sysctl_tcp_limit_output_bytes,
1106 		.maxlen		= sizeof(int),
1107 		.mode		= 0644,
1108 		.proc_handler	= proc_dointvec
1109 	},
1110 	{
1111 		.procname	= "tcp_challenge_ack_limit",
1112 		.data		= &init_net.ipv4.sysctl_tcp_challenge_ack_limit,
1113 		.maxlen		= sizeof(int),
1114 		.mode		= 0644,
1115 		.proc_handler	= proc_dointvec
1116 	},
1117 	{
1118 		.procname	= "tcp_min_tso_segs",
1119 		.data		= &init_net.ipv4.sysctl_tcp_min_tso_segs,
1120 		.maxlen		= sizeof(int),
1121 		.mode		= 0644,
1122 		.proc_handler	= proc_dointvec_minmax,
1123 		.extra1		= &one,
1124 		.extra2		= &gso_max_segs,
1125 	},
1126 	{
1127 		.procname	= "tcp_min_rtt_wlen",
1128 		.data		= &init_net.ipv4.sysctl_tcp_min_rtt_wlen,
1129 		.maxlen		= sizeof(int),
1130 		.mode		= 0644,
1131 		.proc_handler	= proc_dointvec
1132 	},
1133 	{
1134 		.procname	= "tcp_autocorking",
1135 		.data		= &init_net.ipv4.sysctl_tcp_autocorking,
1136 		.maxlen		= sizeof(int),
1137 		.mode		= 0644,
1138 		.proc_handler	= proc_dointvec_minmax,
1139 		.extra1		= &zero,
1140 		.extra2		= &one,
1141 	},
1142 	{
1143 		.procname	= "tcp_invalid_ratelimit",
1144 		.data		= &init_net.ipv4.sysctl_tcp_invalid_ratelimit,
1145 		.maxlen		= sizeof(int),
1146 		.mode		= 0644,
1147 		.proc_handler	= proc_dointvec_ms_jiffies,
1148 	},
1149 	{
1150 		.procname	= "tcp_pacing_ss_ratio",
1151 		.data		= &init_net.ipv4.sysctl_tcp_pacing_ss_ratio,
1152 		.maxlen		= sizeof(int),
1153 		.mode		= 0644,
1154 		.proc_handler	= proc_dointvec_minmax,
1155 		.extra1		= &zero,
1156 		.extra2		= &thousand,
1157 	},
1158 	{
1159 		.procname	= "tcp_pacing_ca_ratio",
1160 		.data		= &init_net.ipv4.sysctl_tcp_pacing_ca_ratio,
1161 		.maxlen		= sizeof(int),
1162 		.mode		= 0644,
1163 		.proc_handler	= proc_dointvec_minmax,
1164 		.extra1		= &zero,
1165 		.extra2		= &thousand,
1166 	},
1167 	{ }
1168 };
1169 
1170 static __net_init int ipv4_sysctl_init_net(struct net *net)
1171 {
1172 	struct ctl_table *table;
1173 
1174 	table = ipv4_net_table;
1175 	if (!net_eq(net, &init_net)) {
1176 		int i;
1177 
1178 		table = kmemdup(table, sizeof(ipv4_net_table), GFP_KERNEL);
1179 		if (!table)
1180 			goto err_alloc;
1181 
1182 		/* Update the variables to point into the current struct net */
1183 		for (i = 0; i < ARRAY_SIZE(ipv4_net_table) - 1; i++)
1184 			table[i].data += (void *)net - (void *)&init_net;
1185 	}
1186 
1187 	net->ipv4.ipv4_hdr = register_net_sysctl(net, "net/ipv4", table);
1188 	if (!net->ipv4.ipv4_hdr)
1189 		goto err_reg;
1190 
1191 	net->ipv4.sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
1192 	if (!net->ipv4.sysctl_local_reserved_ports)
1193 		goto err_ports;
1194 
1195 	return 0;
1196 
1197 err_ports:
1198 	unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
1199 err_reg:
1200 	if (!net_eq(net, &init_net))
1201 		kfree(table);
1202 err_alloc:
1203 	return -ENOMEM;
1204 }
1205 
1206 static __net_exit void ipv4_sysctl_exit_net(struct net *net)
1207 {
1208 	struct ctl_table *table;
1209 
1210 	kfree(net->ipv4.sysctl_local_reserved_ports);
1211 	table = net->ipv4.ipv4_hdr->ctl_table_arg;
1212 	unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
1213 	kfree(table);
1214 }
1215 
1216 static __net_initdata struct pernet_operations ipv4_sysctl_ops = {
1217 	.init = ipv4_sysctl_init_net,
1218 	.exit = ipv4_sysctl_exit_net,
1219 };
1220 
1221 static __init int sysctl_ipv4_init(void)
1222 {
1223 	struct ctl_table_header *hdr;
1224 
1225 	hdr = register_net_sysctl(&init_net, "net/ipv4", ipv4_table);
1226 	if (!hdr)
1227 		return -ENOMEM;
1228 
1229 	if (register_pernet_subsys(&ipv4_sysctl_ops)) {
1230 		unregister_net_sysctl_table(hdr);
1231 		return -ENOMEM;
1232 	}
1233 
1234 	return 0;
1235 }
1236 
1237 __initcall(sysctl_ipv4_init);
1238