xref: /openbmc/linux/net/ipv4/sysctl_net_ipv4.c (revision addee42a)
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 	struct net *net = container_of(ctl->data, struct net,
205 				       ipv4.tcp_congestion_control);
206 	char val[TCP_CA_NAME_MAX];
207 	struct ctl_table tbl = {
208 		.data = val,
209 		.maxlen = TCP_CA_NAME_MAX,
210 	};
211 	int ret;
212 
213 	tcp_get_default_congestion_control(net, val);
214 
215 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
216 	if (write && ret == 0)
217 		ret = tcp_set_default_congestion_control(net, val);
218 	return ret;
219 }
220 
221 static int proc_tcp_available_congestion_control(struct ctl_table *ctl,
222 						 int write,
223 						 void __user *buffer, size_t *lenp,
224 						 loff_t *ppos)
225 {
226 	struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX, };
227 	int ret;
228 
229 	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
230 	if (!tbl.data)
231 		return -ENOMEM;
232 	tcp_get_available_congestion_control(tbl.data, TCP_CA_BUF_MAX);
233 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
234 	kfree(tbl.data);
235 	return ret;
236 }
237 
238 static int proc_allowed_congestion_control(struct ctl_table *ctl,
239 					   int write,
240 					   void __user *buffer, size_t *lenp,
241 					   loff_t *ppos)
242 {
243 	struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX };
244 	int ret;
245 
246 	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
247 	if (!tbl.data)
248 		return -ENOMEM;
249 
250 	tcp_get_allowed_congestion_control(tbl.data, tbl.maxlen);
251 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
252 	if (write && ret == 0)
253 		ret = tcp_set_allowed_congestion_control(tbl.data);
254 	kfree(tbl.data);
255 	return ret;
256 }
257 
258 static int proc_tcp_fastopen_key(struct ctl_table *table, int write,
259 				 void __user *buffer, size_t *lenp,
260 				 loff_t *ppos)
261 {
262 	struct net *net = container_of(table->data, struct net,
263 	    ipv4.sysctl_tcp_fastopen);
264 	struct ctl_table tbl = { .maxlen = (TCP_FASTOPEN_KEY_LENGTH * 2 + 10) };
265 	struct tcp_fastopen_context *ctxt;
266 	int ret;
267 	u32  user_key[4]; /* 16 bytes, matching TCP_FASTOPEN_KEY_LENGTH */
268 
269 	tbl.data = kmalloc(tbl.maxlen, GFP_KERNEL);
270 	if (!tbl.data)
271 		return -ENOMEM;
272 
273 	rcu_read_lock();
274 	ctxt = rcu_dereference(net->ipv4.tcp_fastopen_ctx);
275 	if (ctxt)
276 		memcpy(user_key, ctxt->key, TCP_FASTOPEN_KEY_LENGTH);
277 	else
278 		memset(user_key, 0, sizeof(user_key));
279 	rcu_read_unlock();
280 
281 	snprintf(tbl.data, tbl.maxlen, "%08x-%08x-%08x-%08x",
282 		user_key[0], user_key[1], user_key[2], user_key[3]);
283 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
284 
285 	if (write && ret == 0) {
286 		if (sscanf(tbl.data, "%x-%x-%x-%x", user_key, user_key + 1,
287 			   user_key + 2, user_key + 3) != 4) {
288 			ret = -EINVAL;
289 			goto bad_key;
290 		}
291 		tcp_fastopen_reset_cipher(net, NULL, user_key,
292 					  TCP_FASTOPEN_KEY_LENGTH);
293 	}
294 
295 bad_key:
296 	pr_debug("proc FO key set 0x%x-%x-%x-%x <- 0x%s: %u\n",
297 	       user_key[0], user_key[1], user_key[2], user_key[3],
298 	       (char *)tbl.data, ret);
299 	kfree(tbl.data);
300 	return ret;
301 }
302 
303 static void proc_configure_early_demux(int enabled, int protocol)
304 {
305 	struct net_protocol *ipprot;
306 #if IS_ENABLED(CONFIG_IPV6)
307 	struct inet6_protocol *ip6prot;
308 #endif
309 
310 	rcu_read_lock();
311 
312 	ipprot = rcu_dereference(inet_protos[protocol]);
313 	if (ipprot)
314 		ipprot->early_demux = enabled ? ipprot->early_demux_handler :
315 						NULL;
316 
317 #if IS_ENABLED(CONFIG_IPV6)
318 	ip6prot = rcu_dereference(inet6_protos[protocol]);
319 	if (ip6prot)
320 		ip6prot->early_demux = enabled ? ip6prot->early_demux_handler :
321 						 NULL;
322 #endif
323 	rcu_read_unlock();
324 }
325 
326 static int proc_tcp_early_demux(struct ctl_table *table, int write,
327 				void __user *buffer, size_t *lenp, loff_t *ppos)
328 {
329 	int ret = 0;
330 
331 	ret = proc_dointvec(table, write, buffer, lenp, ppos);
332 
333 	if (write && !ret) {
334 		int enabled = init_net.ipv4.sysctl_tcp_early_demux;
335 
336 		proc_configure_early_demux(enabled, IPPROTO_TCP);
337 	}
338 
339 	return ret;
340 }
341 
342 static int proc_udp_early_demux(struct ctl_table *table, int write,
343 				void __user *buffer, size_t *lenp, loff_t *ppos)
344 {
345 	int ret = 0;
346 
347 	ret = proc_dointvec(table, write, buffer, lenp, ppos);
348 
349 	if (write && !ret) {
350 		int enabled = init_net.ipv4.sysctl_udp_early_demux;
351 
352 		proc_configure_early_demux(enabled, IPPROTO_UDP);
353 	}
354 
355 	return ret;
356 }
357 
358 static int proc_tfo_blackhole_detect_timeout(struct ctl_table *table,
359 					     int write,
360 					     void __user *buffer,
361 					     size_t *lenp, loff_t *ppos)
362 {
363 	struct net *net = container_of(table->data, struct net,
364 	    ipv4.sysctl_tcp_fastopen_blackhole_timeout);
365 	int ret;
366 
367 	ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
368 	if (write && ret == 0)
369 		atomic_set(&net->ipv4.tfo_active_disable_times, 0);
370 
371 	return ret;
372 }
373 
374 static int proc_tcp_available_ulp(struct ctl_table *ctl,
375 				  int write,
376 				  void __user *buffer, size_t *lenp,
377 				  loff_t *ppos)
378 {
379 	struct ctl_table tbl = { .maxlen = TCP_ULP_BUF_MAX, };
380 	int ret;
381 
382 	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
383 	if (!tbl.data)
384 		return -ENOMEM;
385 	tcp_get_available_ulp(tbl.data, TCP_ULP_BUF_MAX);
386 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
387 	kfree(tbl.data);
388 
389 	return ret;
390 }
391 
392 #ifdef CONFIG_IP_ROUTE_MULTIPATH
393 static int proc_fib_multipath_hash_policy(struct ctl_table *table, int write,
394 					  void __user *buffer, size_t *lenp,
395 					  loff_t *ppos)
396 {
397 	struct net *net = container_of(table->data, struct net,
398 	    ipv4.sysctl_fib_multipath_hash_policy);
399 	int ret;
400 
401 	ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
402 	if (write && ret == 0)
403 		call_netevent_notifiers(NETEVENT_IPV4_MPATH_HASH_UPDATE, net);
404 
405 	return ret;
406 }
407 #endif
408 
409 static struct ctl_table ipv4_table[] = {
410 	{
411 		.procname	= "tcp_max_orphans",
412 		.data		= &sysctl_tcp_max_orphans,
413 		.maxlen		= sizeof(int),
414 		.mode		= 0644,
415 		.proc_handler	= proc_dointvec
416 	},
417 	{
418 		.procname	= "inet_peer_threshold",
419 		.data		= &inet_peer_threshold,
420 		.maxlen		= sizeof(int),
421 		.mode		= 0644,
422 		.proc_handler	= proc_dointvec
423 	},
424 	{
425 		.procname	= "inet_peer_minttl",
426 		.data		= &inet_peer_minttl,
427 		.maxlen		= sizeof(int),
428 		.mode		= 0644,
429 		.proc_handler	= proc_dointvec_jiffies,
430 	},
431 	{
432 		.procname	= "inet_peer_maxttl",
433 		.data		= &inet_peer_maxttl,
434 		.maxlen		= sizeof(int),
435 		.mode		= 0644,
436 		.proc_handler	= proc_dointvec_jiffies,
437 	},
438 	{
439 		.procname	= "tcp_mem",
440 		.maxlen		= sizeof(sysctl_tcp_mem),
441 		.data		= &sysctl_tcp_mem,
442 		.mode		= 0644,
443 		.proc_handler	= proc_doulongvec_minmax,
444 	},
445 	{
446 		.procname	= "tcp_low_latency",
447 		.data		= &sysctl_tcp_low_latency,
448 		.maxlen		= sizeof(int),
449 		.mode		= 0644,
450 		.proc_handler	= proc_dointvec
451 	},
452 #ifdef CONFIG_NETLABEL
453 	{
454 		.procname	= "cipso_cache_enable",
455 		.data		= &cipso_v4_cache_enabled,
456 		.maxlen		= sizeof(int),
457 		.mode		= 0644,
458 		.proc_handler	= proc_dointvec,
459 	},
460 	{
461 		.procname	= "cipso_cache_bucket_size",
462 		.data		= &cipso_v4_cache_bucketsize,
463 		.maxlen		= sizeof(int),
464 		.mode		= 0644,
465 		.proc_handler	= proc_dointvec,
466 	},
467 	{
468 		.procname	= "cipso_rbm_optfmt",
469 		.data		= &cipso_v4_rbm_optfmt,
470 		.maxlen		= sizeof(int),
471 		.mode		= 0644,
472 		.proc_handler	= proc_dointvec,
473 	},
474 	{
475 		.procname	= "cipso_rbm_strictvalid",
476 		.data		= &cipso_v4_rbm_strictvalid,
477 		.maxlen		= sizeof(int),
478 		.mode		= 0644,
479 		.proc_handler	= proc_dointvec,
480 	},
481 #endif /* CONFIG_NETLABEL */
482 	{
483 		.procname	= "tcp_available_congestion_control",
484 		.maxlen		= TCP_CA_BUF_MAX,
485 		.mode		= 0444,
486 		.proc_handler   = proc_tcp_available_congestion_control,
487 	},
488 	{
489 		.procname	= "tcp_allowed_congestion_control",
490 		.maxlen		= TCP_CA_BUF_MAX,
491 		.mode		= 0644,
492 		.proc_handler   = proc_allowed_congestion_control,
493 	},
494 	{
495 		.procname	= "tcp_available_ulp",
496 		.maxlen		= TCP_ULP_BUF_MAX,
497 		.mode		= 0444,
498 		.proc_handler   = proc_tcp_available_ulp,
499 	},
500 	{
501 		.procname	= "icmp_msgs_per_sec",
502 		.data		= &sysctl_icmp_msgs_per_sec,
503 		.maxlen		= sizeof(int),
504 		.mode		= 0644,
505 		.proc_handler	= proc_dointvec_minmax,
506 		.extra1		= &zero,
507 	},
508 	{
509 		.procname	= "icmp_msgs_burst",
510 		.data		= &sysctl_icmp_msgs_burst,
511 		.maxlen		= sizeof(int),
512 		.mode		= 0644,
513 		.proc_handler	= proc_dointvec_minmax,
514 		.extra1		= &zero,
515 	},
516 	{
517 		.procname	= "udp_mem",
518 		.data		= &sysctl_udp_mem,
519 		.maxlen		= sizeof(sysctl_udp_mem),
520 		.mode		= 0644,
521 		.proc_handler	= proc_doulongvec_minmax,
522 	},
523 	{ }
524 };
525 
526 static struct ctl_table ipv4_net_table[] = {
527 	{
528 		.procname	= "icmp_echo_ignore_all",
529 		.data		= &init_net.ipv4.sysctl_icmp_echo_ignore_all,
530 		.maxlen		= sizeof(int),
531 		.mode		= 0644,
532 		.proc_handler	= proc_dointvec
533 	},
534 	{
535 		.procname	= "icmp_echo_ignore_broadcasts",
536 		.data		= &init_net.ipv4.sysctl_icmp_echo_ignore_broadcasts,
537 		.maxlen		= sizeof(int),
538 		.mode		= 0644,
539 		.proc_handler	= proc_dointvec
540 	},
541 	{
542 		.procname	= "icmp_ignore_bogus_error_responses",
543 		.data		= &init_net.ipv4.sysctl_icmp_ignore_bogus_error_responses,
544 		.maxlen		= sizeof(int),
545 		.mode		= 0644,
546 		.proc_handler	= proc_dointvec
547 	},
548 	{
549 		.procname	= "icmp_errors_use_inbound_ifaddr",
550 		.data		= &init_net.ipv4.sysctl_icmp_errors_use_inbound_ifaddr,
551 		.maxlen		= sizeof(int),
552 		.mode		= 0644,
553 		.proc_handler	= proc_dointvec
554 	},
555 	{
556 		.procname	= "icmp_ratelimit",
557 		.data		= &init_net.ipv4.sysctl_icmp_ratelimit,
558 		.maxlen		= sizeof(int),
559 		.mode		= 0644,
560 		.proc_handler	= proc_dointvec_ms_jiffies,
561 	},
562 	{
563 		.procname	= "icmp_ratemask",
564 		.data		= &init_net.ipv4.sysctl_icmp_ratemask,
565 		.maxlen		= sizeof(int),
566 		.mode		= 0644,
567 		.proc_handler	= proc_dointvec
568 	},
569 	{
570 		.procname	= "ping_group_range",
571 		.data		= &init_net.ipv4.ping_group_range.range,
572 		.maxlen		= sizeof(gid_t)*2,
573 		.mode		= 0644,
574 		.proc_handler	= ipv4_ping_group_range,
575 	},
576 	{
577 		.procname	= "tcp_ecn",
578 		.data		= &init_net.ipv4.sysctl_tcp_ecn,
579 		.maxlen		= sizeof(int),
580 		.mode		= 0644,
581 		.proc_handler	= proc_dointvec
582 	},
583 	{
584 		.procname	= "tcp_ecn_fallback",
585 		.data		= &init_net.ipv4.sysctl_tcp_ecn_fallback,
586 		.maxlen		= sizeof(int),
587 		.mode		= 0644,
588 		.proc_handler	= proc_dointvec
589 	},
590 	{
591 		.procname	= "ip_dynaddr",
592 		.data		= &init_net.ipv4.sysctl_ip_dynaddr,
593 		.maxlen		= sizeof(int),
594 		.mode		= 0644,
595 		.proc_handler	= proc_dointvec
596 	},
597 	{
598 		.procname	= "ip_early_demux",
599 		.data		= &init_net.ipv4.sysctl_ip_early_demux,
600 		.maxlen		= sizeof(int),
601 		.mode		= 0644,
602 		.proc_handler	= proc_dointvec
603 	},
604 	{
605 		.procname       = "udp_early_demux",
606 		.data           = &init_net.ipv4.sysctl_udp_early_demux,
607 		.maxlen         = sizeof(int),
608 		.mode           = 0644,
609 		.proc_handler   = proc_udp_early_demux
610 	},
611 	{
612 		.procname       = "tcp_early_demux",
613 		.data           = &init_net.ipv4.sysctl_tcp_early_demux,
614 		.maxlen         = sizeof(int),
615 		.mode           = 0644,
616 		.proc_handler   = proc_tcp_early_demux
617 	},
618 	{
619 		.procname	= "ip_default_ttl",
620 		.data		= &init_net.ipv4.sysctl_ip_default_ttl,
621 		.maxlen		= sizeof(int),
622 		.mode		= 0644,
623 		.proc_handler	= proc_dointvec_minmax,
624 		.extra1		= &ip_ttl_min,
625 		.extra2		= &ip_ttl_max,
626 	},
627 	{
628 		.procname	= "ip_local_port_range",
629 		.maxlen		= sizeof(init_net.ipv4.ip_local_ports.range),
630 		.data		= &init_net.ipv4.ip_local_ports.range,
631 		.mode		= 0644,
632 		.proc_handler	= ipv4_local_port_range,
633 	},
634 	{
635 		.procname	= "ip_local_reserved_ports",
636 		.data		= &init_net.ipv4.sysctl_local_reserved_ports,
637 		.maxlen		= 65536,
638 		.mode		= 0644,
639 		.proc_handler	= proc_do_large_bitmap,
640 	},
641 	{
642 		.procname	= "ip_no_pmtu_disc",
643 		.data		= &init_net.ipv4.sysctl_ip_no_pmtu_disc,
644 		.maxlen		= sizeof(int),
645 		.mode		= 0644,
646 		.proc_handler	= proc_dointvec
647 	},
648 	{
649 		.procname	= "ip_forward_use_pmtu",
650 		.data		= &init_net.ipv4.sysctl_ip_fwd_use_pmtu,
651 		.maxlen		= sizeof(int),
652 		.mode		= 0644,
653 		.proc_handler	= proc_dointvec,
654 	},
655 	{
656 		.procname	= "ip_nonlocal_bind",
657 		.data		= &init_net.ipv4.sysctl_ip_nonlocal_bind,
658 		.maxlen		= sizeof(int),
659 		.mode		= 0644,
660 		.proc_handler	= proc_dointvec
661 	},
662 	{
663 		.procname	= "fwmark_reflect",
664 		.data		= &init_net.ipv4.sysctl_fwmark_reflect,
665 		.maxlen		= sizeof(int),
666 		.mode		= 0644,
667 		.proc_handler	= proc_dointvec,
668 	},
669 	{
670 		.procname	= "tcp_fwmark_accept",
671 		.data		= &init_net.ipv4.sysctl_tcp_fwmark_accept,
672 		.maxlen		= sizeof(int),
673 		.mode		= 0644,
674 		.proc_handler	= proc_dointvec,
675 	},
676 #ifdef CONFIG_NET_L3_MASTER_DEV
677 	{
678 		.procname	= "tcp_l3mdev_accept",
679 		.data		= &init_net.ipv4.sysctl_tcp_l3mdev_accept,
680 		.maxlen		= sizeof(int),
681 		.mode		= 0644,
682 		.proc_handler	= proc_dointvec_minmax,
683 		.extra1		= &zero,
684 		.extra2		= &one,
685 	},
686 #endif
687 	{
688 		.procname	= "tcp_mtu_probing",
689 		.data		= &init_net.ipv4.sysctl_tcp_mtu_probing,
690 		.maxlen		= sizeof(int),
691 		.mode		= 0644,
692 		.proc_handler	= proc_dointvec,
693 	},
694 	{
695 		.procname	= "tcp_base_mss",
696 		.data		= &init_net.ipv4.sysctl_tcp_base_mss,
697 		.maxlen		= sizeof(int),
698 		.mode		= 0644,
699 		.proc_handler	= proc_dointvec,
700 	},
701 	{
702 		.procname	= "tcp_probe_threshold",
703 		.data		= &init_net.ipv4.sysctl_tcp_probe_threshold,
704 		.maxlen		= sizeof(int),
705 		.mode		= 0644,
706 		.proc_handler	= proc_dointvec,
707 	},
708 	{
709 		.procname	= "tcp_probe_interval",
710 		.data		= &init_net.ipv4.sysctl_tcp_probe_interval,
711 		.maxlen		= sizeof(int),
712 		.mode		= 0644,
713 		.proc_handler	= proc_dointvec,
714 	},
715 	{
716 		.procname	= "igmp_link_local_mcast_reports",
717 		.data		= &init_net.ipv4.sysctl_igmp_llm_reports,
718 		.maxlen		= sizeof(int),
719 		.mode		= 0644,
720 		.proc_handler	= proc_dointvec
721 	},
722 	{
723 		.procname	= "igmp_max_memberships",
724 		.data		= &init_net.ipv4.sysctl_igmp_max_memberships,
725 		.maxlen		= sizeof(int),
726 		.mode		= 0644,
727 		.proc_handler	= proc_dointvec
728 	},
729 	{
730 		.procname	= "igmp_max_msf",
731 		.data		= &init_net.ipv4.sysctl_igmp_max_msf,
732 		.maxlen		= sizeof(int),
733 		.mode		= 0644,
734 		.proc_handler	= proc_dointvec
735 	},
736 #ifdef CONFIG_IP_MULTICAST
737 	{
738 		.procname	= "igmp_qrv",
739 		.data		= &init_net.ipv4.sysctl_igmp_qrv,
740 		.maxlen		= sizeof(int),
741 		.mode		= 0644,
742 		.proc_handler	= proc_dointvec_minmax,
743 		.extra1		= &one
744 	},
745 #endif
746 	{
747 		.procname	= "tcp_congestion_control",
748 		.data		= &init_net.ipv4.tcp_congestion_control,
749 		.mode		= 0644,
750 		.maxlen		= TCP_CA_NAME_MAX,
751 		.proc_handler	= proc_tcp_congestion_control,
752 	},
753 	{
754 		.procname	= "tcp_keepalive_time",
755 		.data		= &init_net.ipv4.sysctl_tcp_keepalive_time,
756 		.maxlen		= sizeof(int),
757 		.mode		= 0644,
758 		.proc_handler	= proc_dointvec_jiffies,
759 	},
760 	{
761 		.procname	= "tcp_keepalive_probes",
762 		.data		= &init_net.ipv4.sysctl_tcp_keepalive_probes,
763 		.maxlen		= sizeof(int),
764 		.mode		= 0644,
765 		.proc_handler	= proc_dointvec
766 	},
767 	{
768 		.procname	= "tcp_keepalive_intvl",
769 		.data		= &init_net.ipv4.sysctl_tcp_keepalive_intvl,
770 		.maxlen		= sizeof(int),
771 		.mode		= 0644,
772 		.proc_handler	= proc_dointvec_jiffies,
773 	},
774 	{
775 		.procname	= "tcp_syn_retries",
776 		.data		= &init_net.ipv4.sysctl_tcp_syn_retries,
777 		.maxlen		= sizeof(int),
778 		.mode		= 0644,
779 		.proc_handler	= proc_dointvec_minmax,
780 		.extra1		= &tcp_syn_retries_min,
781 		.extra2		= &tcp_syn_retries_max
782 	},
783 	{
784 		.procname	= "tcp_synack_retries",
785 		.data		= &init_net.ipv4.sysctl_tcp_synack_retries,
786 		.maxlen		= sizeof(int),
787 		.mode		= 0644,
788 		.proc_handler	= proc_dointvec
789 	},
790 #ifdef CONFIG_SYN_COOKIES
791 	{
792 		.procname	= "tcp_syncookies",
793 		.data		= &init_net.ipv4.sysctl_tcp_syncookies,
794 		.maxlen		= sizeof(int),
795 		.mode		= 0644,
796 		.proc_handler	= proc_dointvec
797 	},
798 #endif
799 	{
800 		.procname	= "tcp_reordering",
801 		.data		= &init_net.ipv4.sysctl_tcp_reordering,
802 		.maxlen		= sizeof(int),
803 		.mode		= 0644,
804 		.proc_handler	= proc_dointvec
805 	},
806 	{
807 		.procname	= "tcp_retries1",
808 		.data		= &init_net.ipv4.sysctl_tcp_retries1,
809 		.maxlen		= sizeof(int),
810 		.mode		= 0644,
811 		.proc_handler	= proc_dointvec_minmax,
812 		.extra2		= &tcp_retr1_max
813 	},
814 	{
815 		.procname	= "tcp_retries2",
816 		.data		= &init_net.ipv4.sysctl_tcp_retries2,
817 		.maxlen		= sizeof(int),
818 		.mode		= 0644,
819 		.proc_handler	= proc_dointvec
820 	},
821 	{
822 		.procname	= "tcp_orphan_retries",
823 		.data		= &init_net.ipv4.sysctl_tcp_orphan_retries,
824 		.maxlen		= sizeof(int),
825 		.mode		= 0644,
826 		.proc_handler	= proc_dointvec
827 	},
828 	{
829 		.procname	= "tcp_fin_timeout",
830 		.data		= &init_net.ipv4.sysctl_tcp_fin_timeout,
831 		.maxlen		= sizeof(int),
832 		.mode		= 0644,
833 		.proc_handler	= proc_dointvec_jiffies,
834 	},
835 	{
836 		.procname	= "tcp_notsent_lowat",
837 		.data		= &init_net.ipv4.sysctl_tcp_notsent_lowat,
838 		.maxlen		= sizeof(unsigned int),
839 		.mode		= 0644,
840 		.proc_handler	= proc_douintvec,
841 	},
842 	{
843 		.procname	= "tcp_tw_reuse",
844 		.data		= &init_net.ipv4.sysctl_tcp_tw_reuse,
845 		.maxlen		= sizeof(int),
846 		.mode		= 0644,
847 		.proc_handler	= proc_dointvec
848 	},
849 	{
850 		.procname	= "tcp_max_tw_buckets",
851 		.data		= &init_net.ipv4.tcp_death_row.sysctl_max_tw_buckets,
852 		.maxlen		= sizeof(int),
853 		.mode		= 0644,
854 		.proc_handler	= proc_dointvec
855 	},
856 	{
857 		.procname	= "tcp_max_syn_backlog",
858 		.data		= &init_net.ipv4.sysctl_max_syn_backlog,
859 		.maxlen		= sizeof(int),
860 		.mode		= 0644,
861 		.proc_handler	= proc_dointvec
862 	},
863 	{
864 		.procname	= "tcp_fastopen",
865 		.data		= &init_net.ipv4.sysctl_tcp_fastopen,
866 		.maxlen		= sizeof(int),
867 		.mode		= 0644,
868 		.proc_handler	= proc_dointvec,
869 	},
870 	{
871 		.procname	= "tcp_fastopen_key",
872 		.mode		= 0600,
873 		.data		= &init_net.ipv4.sysctl_tcp_fastopen,
874 		.maxlen		= ((TCP_FASTOPEN_KEY_LENGTH * 2) + 10),
875 		.proc_handler	= proc_tcp_fastopen_key,
876 	},
877 	{
878 		.procname	= "tcp_fastopen_blackhole_timeout_sec",
879 		.data		= &init_net.ipv4.sysctl_tcp_fastopen_blackhole_timeout,
880 		.maxlen		= sizeof(int),
881 		.mode		= 0644,
882 		.proc_handler	= proc_tfo_blackhole_detect_timeout,
883 		.extra1		= &zero,
884 	},
885 #ifdef CONFIG_IP_ROUTE_MULTIPATH
886 	{
887 		.procname	= "fib_multipath_use_neigh",
888 		.data		= &init_net.ipv4.sysctl_fib_multipath_use_neigh,
889 		.maxlen		= sizeof(int),
890 		.mode		= 0644,
891 		.proc_handler	= proc_dointvec_minmax,
892 		.extra1		= &zero,
893 		.extra2		= &one,
894 	},
895 	{
896 		.procname	= "fib_multipath_hash_policy",
897 		.data		= &init_net.ipv4.sysctl_fib_multipath_hash_policy,
898 		.maxlen		= sizeof(int),
899 		.mode		= 0644,
900 		.proc_handler	= proc_fib_multipath_hash_policy,
901 		.extra1		= &zero,
902 		.extra2		= &one,
903 	},
904 #endif
905 	{
906 		.procname	= "ip_unprivileged_port_start",
907 		.maxlen		= sizeof(int),
908 		.data		= &init_net.ipv4.sysctl_ip_prot_sock,
909 		.mode		= 0644,
910 		.proc_handler	= ipv4_privileged_ports,
911 	},
912 #ifdef CONFIG_NET_L3_MASTER_DEV
913 	{
914 		.procname	= "udp_l3mdev_accept",
915 		.data		= &init_net.ipv4.sysctl_udp_l3mdev_accept,
916 		.maxlen		= sizeof(int),
917 		.mode		= 0644,
918 		.proc_handler	= proc_dointvec_minmax,
919 		.extra1		= &zero,
920 		.extra2		= &one,
921 	},
922 #endif
923 	{
924 		.procname	= "tcp_sack",
925 		.data		= &init_net.ipv4.sysctl_tcp_sack,
926 		.maxlen		= sizeof(int),
927 		.mode		= 0644,
928 		.proc_handler	= proc_dointvec
929 	},
930 	{
931 		.procname	= "tcp_window_scaling",
932 		.data		= &init_net.ipv4.sysctl_tcp_window_scaling,
933 		.maxlen		= sizeof(int),
934 		.mode		= 0644,
935 		.proc_handler	= proc_dointvec
936 	},
937 	{
938 		.procname	= "tcp_timestamps",
939 		.data		= &init_net.ipv4.sysctl_tcp_timestamps,
940 		.maxlen		= sizeof(int),
941 		.mode		= 0644,
942 		.proc_handler	= proc_dointvec
943 	},
944 	{
945 		.procname	= "tcp_early_retrans",
946 		.data		= &init_net.ipv4.sysctl_tcp_early_retrans,
947 		.maxlen		= sizeof(int),
948 		.mode		= 0644,
949 		.proc_handler	= proc_dointvec_minmax,
950 		.extra1		= &zero,
951 		.extra2		= &four,
952 	},
953 	{
954 		.procname	= "tcp_recovery",
955 		.data		= &init_net.ipv4.sysctl_tcp_recovery,
956 		.maxlen		= sizeof(int),
957 		.mode		= 0644,
958 		.proc_handler	= proc_dointvec,
959 	},
960 	{
961 		.procname       = "tcp_thin_linear_timeouts",
962 		.data           = &init_net.ipv4.sysctl_tcp_thin_linear_timeouts,
963 		.maxlen         = sizeof(int),
964 		.mode           = 0644,
965 		.proc_handler   = proc_dointvec
966 	},
967 	{
968 		.procname	= "tcp_slow_start_after_idle",
969 		.data		= &init_net.ipv4.sysctl_tcp_slow_start_after_idle,
970 		.maxlen		= sizeof(int),
971 		.mode		= 0644,
972 		.proc_handler	= proc_dointvec
973 	},
974 	{
975 		.procname	= "tcp_retrans_collapse",
976 		.data		= &init_net.ipv4.sysctl_tcp_retrans_collapse,
977 		.maxlen		= sizeof(int),
978 		.mode		= 0644,
979 		.proc_handler	= proc_dointvec
980 	},
981 	{
982 		.procname	= "tcp_stdurg",
983 		.data		= &init_net.ipv4.sysctl_tcp_stdurg,
984 		.maxlen		= sizeof(int),
985 		.mode		= 0644,
986 		.proc_handler	= proc_dointvec
987 	},
988 	{
989 		.procname	= "tcp_rfc1337",
990 		.data		= &init_net.ipv4.sysctl_tcp_rfc1337,
991 		.maxlen		= sizeof(int),
992 		.mode		= 0644,
993 		.proc_handler	= proc_dointvec
994 	},
995 	{
996 		.procname	= "tcp_abort_on_overflow",
997 		.data		= &init_net.ipv4.sysctl_tcp_abort_on_overflow,
998 		.maxlen		= sizeof(int),
999 		.mode		= 0644,
1000 		.proc_handler	= proc_dointvec
1001 	},
1002 	{
1003 		.procname	= "tcp_fack",
1004 		.data		= &init_net.ipv4.sysctl_tcp_fack,
1005 		.maxlen		= sizeof(int),
1006 		.mode		= 0644,
1007 		.proc_handler	= proc_dointvec
1008 	},
1009 	{
1010 		.procname	= "tcp_max_reordering",
1011 		.data		= &init_net.ipv4.sysctl_tcp_max_reordering,
1012 		.maxlen		= sizeof(int),
1013 		.mode		= 0644,
1014 		.proc_handler	= proc_dointvec
1015 	},
1016 	{
1017 		.procname	= "tcp_dsack",
1018 		.data		= &init_net.ipv4.sysctl_tcp_dsack,
1019 		.maxlen		= sizeof(int),
1020 		.mode		= 0644,
1021 		.proc_handler	= proc_dointvec
1022 	},
1023 	{
1024 		.procname	= "tcp_app_win",
1025 		.data		= &init_net.ipv4.sysctl_tcp_app_win,
1026 		.maxlen		= sizeof(int),
1027 		.mode		= 0644,
1028 		.proc_handler	= proc_dointvec
1029 	},
1030 	{
1031 		.procname	= "tcp_adv_win_scale",
1032 		.data		= &init_net.ipv4.sysctl_tcp_adv_win_scale,
1033 		.maxlen		= sizeof(int),
1034 		.mode		= 0644,
1035 		.proc_handler	= proc_dointvec_minmax,
1036 		.extra1		= &tcp_adv_win_scale_min,
1037 		.extra2		= &tcp_adv_win_scale_max,
1038 	},
1039 	{
1040 		.procname	= "tcp_frto",
1041 		.data		= &init_net.ipv4.sysctl_tcp_frto,
1042 		.maxlen		= sizeof(int),
1043 		.mode		= 0644,
1044 		.proc_handler	= proc_dointvec
1045 	},
1046 	{
1047 		.procname	= "tcp_no_metrics_save",
1048 		.data		= &init_net.ipv4.sysctl_tcp_nometrics_save,
1049 		.maxlen		= sizeof(int),
1050 		.mode		= 0644,
1051 		.proc_handler	= proc_dointvec,
1052 	},
1053 	{
1054 		.procname	= "tcp_moderate_rcvbuf",
1055 		.data		= &init_net.ipv4.sysctl_tcp_moderate_rcvbuf,
1056 		.maxlen		= sizeof(int),
1057 		.mode		= 0644,
1058 		.proc_handler	= proc_dointvec,
1059 	},
1060 	{
1061 		.procname	= "tcp_tso_win_divisor",
1062 		.data		= &init_net.ipv4.sysctl_tcp_tso_win_divisor,
1063 		.maxlen		= sizeof(int),
1064 		.mode		= 0644,
1065 		.proc_handler	= proc_dointvec,
1066 	},
1067 	{
1068 		.procname	= "tcp_workaround_signed_windows",
1069 		.data		= &init_net.ipv4.sysctl_tcp_workaround_signed_windows,
1070 		.maxlen		= sizeof(int),
1071 		.mode		= 0644,
1072 		.proc_handler	= proc_dointvec
1073 	},
1074 	{
1075 		.procname	= "tcp_limit_output_bytes",
1076 		.data		= &init_net.ipv4.sysctl_tcp_limit_output_bytes,
1077 		.maxlen		= sizeof(int),
1078 		.mode		= 0644,
1079 		.proc_handler	= proc_dointvec
1080 	},
1081 	{
1082 		.procname	= "tcp_challenge_ack_limit",
1083 		.data		= &init_net.ipv4.sysctl_tcp_challenge_ack_limit,
1084 		.maxlen		= sizeof(int),
1085 		.mode		= 0644,
1086 		.proc_handler	= proc_dointvec
1087 	},
1088 	{
1089 		.procname	= "tcp_min_tso_segs",
1090 		.data		= &init_net.ipv4.sysctl_tcp_min_tso_segs,
1091 		.maxlen		= sizeof(int),
1092 		.mode		= 0644,
1093 		.proc_handler	= proc_dointvec_minmax,
1094 		.extra1		= &one,
1095 		.extra2		= &gso_max_segs,
1096 	},
1097 	{
1098 		.procname	= "tcp_min_rtt_wlen",
1099 		.data		= &init_net.ipv4.sysctl_tcp_min_rtt_wlen,
1100 		.maxlen		= sizeof(int),
1101 		.mode		= 0644,
1102 		.proc_handler	= proc_dointvec
1103 	},
1104 	{
1105 		.procname	= "tcp_autocorking",
1106 		.data		= &init_net.ipv4.sysctl_tcp_autocorking,
1107 		.maxlen		= sizeof(int),
1108 		.mode		= 0644,
1109 		.proc_handler	= proc_dointvec_minmax,
1110 		.extra1		= &zero,
1111 		.extra2		= &one,
1112 	},
1113 	{
1114 		.procname	= "tcp_invalid_ratelimit",
1115 		.data		= &init_net.ipv4.sysctl_tcp_invalid_ratelimit,
1116 		.maxlen		= sizeof(int),
1117 		.mode		= 0644,
1118 		.proc_handler	= proc_dointvec_ms_jiffies,
1119 	},
1120 	{
1121 		.procname	= "tcp_pacing_ss_ratio",
1122 		.data		= &init_net.ipv4.sysctl_tcp_pacing_ss_ratio,
1123 		.maxlen		= sizeof(int),
1124 		.mode		= 0644,
1125 		.proc_handler	= proc_dointvec_minmax,
1126 		.extra1		= &zero,
1127 		.extra2		= &thousand,
1128 	},
1129 	{
1130 		.procname	= "tcp_pacing_ca_ratio",
1131 		.data		= &init_net.ipv4.sysctl_tcp_pacing_ca_ratio,
1132 		.maxlen		= sizeof(int),
1133 		.mode		= 0644,
1134 		.proc_handler	= proc_dointvec_minmax,
1135 		.extra1		= &zero,
1136 		.extra2		= &thousand,
1137 	},
1138 	{
1139 		.procname	= "tcp_wmem",
1140 		.data		= &init_net.ipv4.sysctl_tcp_wmem,
1141 		.maxlen		= sizeof(init_net.ipv4.sysctl_tcp_wmem),
1142 		.mode		= 0644,
1143 		.proc_handler	= proc_dointvec_minmax,
1144 		.extra1		= &one,
1145 	},
1146 	{
1147 		.procname	= "tcp_rmem",
1148 		.data		= &init_net.ipv4.sysctl_tcp_rmem,
1149 		.maxlen		= sizeof(init_net.ipv4.sysctl_tcp_rmem),
1150 		.mode		= 0644,
1151 		.proc_handler	= proc_dointvec_minmax,
1152 		.extra1		= &one,
1153 	},
1154 	{
1155 		.procname	= "udp_rmem_min",
1156 		.data		= &init_net.ipv4.sysctl_udp_rmem_min,
1157 		.maxlen		= sizeof(init_net.ipv4.sysctl_udp_rmem_min),
1158 		.mode		= 0644,
1159 		.proc_handler	= proc_dointvec_minmax,
1160 		.extra1		= &one
1161 	},
1162 	{
1163 		.procname	= "udp_wmem_min",
1164 		.data		= &init_net.ipv4.sysctl_udp_wmem_min,
1165 		.maxlen		= sizeof(init_net.ipv4.sysctl_udp_wmem_min),
1166 		.mode		= 0644,
1167 		.proc_handler	= proc_dointvec_minmax,
1168 		.extra1		= &one
1169 	},
1170 	{ }
1171 };
1172 
1173 static __net_init int ipv4_sysctl_init_net(struct net *net)
1174 {
1175 	struct ctl_table *table;
1176 
1177 	table = ipv4_net_table;
1178 	if (!net_eq(net, &init_net)) {
1179 		int i;
1180 
1181 		table = kmemdup(table, sizeof(ipv4_net_table), GFP_KERNEL);
1182 		if (!table)
1183 			goto err_alloc;
1184 
1185 		/* Update the variables to point into the current struct net */
1186 		for (i = 0; i < ARRAY_SIZE(ipv4_net_table) - 1; i++)
1187 			table[i].data += (void *)net - (void *)&init_net;
1188 	}
1189 
1190 	net->ipv4.ipv4_hdr = register_net_sysctl(net, "net/ipv4", table);
1191 	if (!net->ipv4.ipv4_hdr)
1192 		goto err_reg;
1193 
1194 	net->ipv4.sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
1195 	if (!net->ipv4.sysctl_local_reserved_ports)
1196 		goto err_ports;
1197 
1198 	return 0;
1199 
1200 err_ports:
1201 	unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
1202 err_reg:
1203 	if (!net_eq(net, &init_net))
1204 		kfree(table);
1205 err_alloc:
1206 	return -ENOMEM;
1207 }
1208 
1209 static __net_exit void ipv4_sysctl_exit_net(struct net *net)
1210 {
1211 	struct ctl_table *table;
1212 
1213 	kfree(net->ipv4.sysctl_local_reserved_ports);
1214 	table = net->ipv4.ipv4_hdr->ctl_table_arg;
1215 	unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
1216 	kfree(table);
1217 }
1218 
1219 static __net_initdata struct pernet_operations ipv4_sysctl_ops = {
1220 	.init = ipv4_sysctl_init_net,
1221 	.exit = ipv4_sysctl_exit_net,
1222 };
1223 
1224 static __init int sysctl_ipv4_init(void)
1225 {
1226 	struct ctl_table_header *hdr;
1227 
1228 	hdr = register_net_sysctl(&init_net, "net/ipv4", ipv4_table);
1229 	if (!hdr)
1230 		return -ENOMEM;
1231 
1232 	if (register_pernet_subsys(&ipv4_sysctl_ops)) {
1233 		unregister_net_sysctl_table(hdr);
1234 		return -ENOMEM;
1235 	}
1236 
1237 	return 0;
1238 }
1239 
1240 __initcall(sysctl_ipv4_init);
1241