xref: /openbmc/linux/net/ipv4/sysctl_net_ipv4.c (revision d2ba09c1)
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 static int comp_sack_nr_max = 255;
50 
51 /* obsolete */
52 static int sysctl_tcp_low_latency __read_mostly;
53 
54 /* Update system visible IP port range */
55 static void set_local_port_range(struct net *net, int range[2])
56 {
57 	bool same_parity = !((range[0] ^ range[1]) & 1);
58 
59 	write_seqlock_bh(&net->ipv4.ip_local_ports.lock);
60 	if (same_parity && !net->ipv4.ip_local_ports.warned) {
61 		net->ipv4.ip_local_ports.warned = true;
62 		pr_err_ratelimited("ip_local_port_range: prefer different parity for start/end values.\n");
63 	}
64 	net->ipv4.ip_local_ports.range[0] = range[0];
65 	net->ipv4.ip_local_ports.range[1] = range[1];
66 	write_sequnlock_bh(&net->ipv4.ip_local_ports.lock);
67 }
68 
69 /* Validate changes from /proc interface. */
70 static int ipv4_local_port_range(struct ctl_table *table, int write,
71 				 void __user *buffer,
72 				 size_t *lenp, loff_t *ppos)
73 {
74 	struct net *net =
75 		container_of(table->data, struct net, ipv4.ip_local_ports.range);
76 	int ret;
77 	int range[2];
78 	struct ctl_table tmp = {
79 		.data = &range,
80 		.maxlen = sizeof(range),
81 		.mode = table->mode,
82 		.extra1 = &ip_local_port_range_min,
83 		.extra2 = &ip_local_port_range_max,
84 	};
85 
86 	inet_get_local_port_range(net, &range[0], &range[1]);
87 
88 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
89 
90 	if (write && ret == 0) {
91 		/* Ensure that the upper limit is not smaller than the lower,
92 		 * and that the lower does not encroach upon the privileged
93 		 * port limit.
94 		 */
95 		if ((range[1] < range[0]) ||
96 		    (range[0] < net->ipv4.sysctl_ip_prot_sock))
97 			ret = -EINVAL;
98 		else
99 			set_local_port_range(net, range);
100 	}
101 
102 	return ret;
103 }
104 
105 /* Validate changes from /proc interface. */
106 static int ipv4_privileged_ports(struct ctl_table *table, int write,
107 				void __user *buffer, size_t *lenp, loff_t *ppos)
108 {
109 	struct net *net = container_of(table->data, struct net,
110 	    ipv4.sysctl_ip_prot_sock);
111 	int ret;
112 	int pports;
113 	int range[2];
114 	struct ctl_table tmp = {
115 		.data = &pports,
116 		.maxlen = sizeof(pports),
117 		.mode = table->mode,
118 		.extra1 = &ip_privileged_port_min,
119 		.extra2 = &ip_privileged_port_max,
120 	};
121 
122 	pports = net->ipv4.sysctl_ip_prot_sock;
123 
124 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
125 
126 	if (write && ret == 0) {
127 		inet_get_local_port_range(net, &range[0], &range[1]);
128 		/* Ensure that the local port range doesn't overlap with the
129 		 * privileged port range.
130 		 */
131 		if (range[0] < pports)
132 			ret = -EINVAL;
133 		else
134 			net->ipv4.sysctl_ip_prot_sock = pports;
135 	}
136 
137 	return ret;
138 }
139 
140 static void inet_get_ping_group_range_table(struct ctl_table *table, kgid_t *low, kgid_t *high)
141 {
142 	kgid_t *data = table->data;
143 	struct net *net =
144 		container_of(table->data, struct net, ipv4.ping_group_range.range);
145 	unsigned int seq;
146 	do {
147 		seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
148 
149 		*low = data[0];
150 		*high = data[1];
151 	} while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
152 }
153 
154 /* Update system visible IP port range */
155 static void set_ping_group_range(struct ctl_table *table, kgid_t low, kgid_t high)
156 {
157 	kgid_t *data = table->data;
158 	struct net *net =
159 		container_of(table->data, struct net, ipv4.ping_group_range.range);
160 	write_seqlock(&net->ipv4.ping_group_range.lock);
161 	data[0] = low;
162 	data[1] = high;
163 	write_sequnlock(&net->ipv4.ping_group_range.lock);
164 }
165 
166 /* Validate changes from /proc interface. */
167 static int ipv4_ping_group_range(struct ctl_table *table, int write,
168 				 void __user *buffer,
169 				 size_t *lenp, loff_t *ppos)
170 {
171 	struct user_namespace *user_ns = current_user_ns();
172 	int ret;
173 	gid_t urange[2];
174 	kgid_t low, high;
175 	struct ctl_table tmp = {
176 		.data = &urange,
177 		.maxlen = sizeof(urange),
178 		.mode = table->mode,
179 		.extra1 = &ip_ping_group_range_min,
180 		.extra2 = &ip_ping_group_range_max,
181 	};
182 
183 	inet_get_ping_group_range_table(table, &low, &high);
184 	urange[0] = from_kgid_munged(user_ns, low);
185 	urange[1] = from_kgid_munged(user_ns, high);
186 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
187 
188 	if (write && ret == 0) {
189 		low = make_kgid(user_ns, urange[0]);
190 		high = make_kgid(user_ns, urange[1]);
191 		if (!gid_valid(low) || !gid_valid(high) ||
192 		    (urange[1] < urange[0]) || gid_lt(high, low)) {
193 			low = make_kgid(&init_user_ns, 1);
194 			high = make_kgid(&init_user_ns, 0);
195 		}
196 		set_ping_group_range(table, low, high);
197 	}
198 
199 	return ret;
200 }
201 
202 static int proc_tcp_congestion_control(struct ctl_table *ctl, int write,
203 				       void __user *buffer, size_t *lenp, loff_t *ppos)
204 {
205 	struct net *net = container_of(ctl->data, struct net,
206 				       ipv4.tcp_congestion_control);
207 	char val[TCP_CA_NAME_MAX];
208 	struct ctl_table tbl = {
209 		.data = val,
210 		.maxlen = TCP_CA_NAME_MAX,
211 	};
212 	int ret;
213 
214 	tcp_get_default_congestion_control(net, val);
215 
216 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
217 	if (write && ret == 0)
218 		ret = tcp_set_default_congestion_control(net, val);
219 	return ret;
220 }
221 
222 static int proc_tcp_available_congestion_control(struct ctl_table *ctl,
223 						 int write,
224 						 void __user *buffer, size_t *lenp,
225 						 loff_t *ppos)
226 {
227 	struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX, };
228 	int ret;
229 
230 	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
231 	if (!tbl.data)
232 		return -ENOMEM;
233 	tcp_get_available_congestion_control(tbl.data, TCP_CA_BUF_MAX);
234 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
235 	kfree(tbl.data);
236 	return ret;
237 }
238 
239 static int proc_allowed_congestion_control(struct ctl_table *ctl,
240 					   int write,
241 					   void __user *buffer, size_t *lenp,
242 					   loff_t *ppos)
243 {
244 	struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX };
245 	int ret;
246 
247 	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
248 	if (!tbl.data)
249 		return -ENOMEM;
250 
251 	tcp_get_allowed_congestion_control(tbl.data, tbl.maxlen);
252 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
253 	if (write && ret == 0)
254 		ret = tcp_set_allowed_congestion_control(tbl.data);
255 	kfree(tbl.data);
256 	return ret;
257 }
258 
259 static int proc_tcp_fastopen_key(struct ctl_table *table, int write,
260 				 void __user *buffer, size_t *lenp,
261 				 loff_t *ppos)
262 {
263 	struct net *net = container_of(table->data, struct net,
264 	    ipv4.sysctl_tcp_fastopen);
265 	struct ctl_table tbl = { .maxlen = (TCP_FASTOPEN_KEY_LENGTH * 2 + 10) };
266 	struct tcp_fastopen_context *ctxt;
267 	int ret;
268 	u32  user_key[4]; /* 16 bytes, matching TCP_FASTOPEN_KEY_LENGTH */
269 
270 	tbl.data = kmalloc(tbl.maxlen, GFP_KERNEL);
271 	if (!tbl.data)
272 		return -ENOMEM;
273 
274 	rcu_read_lock();
275 	ctxt = rcu_dereference(net->ipv4.tcp_fastopen_ctx);
276 	if (ctxt)
277 		memcpy(user_key, ctxt->key, TCP_FASTOPEN_KEY_LENGTH);
278 	else
279 		memset(user_key, 0, sizeof(user_key));
280 	rcu_read_unlock();
281 
282 	snprintf(tbl.data, tbl.maxlen, "%08x-%08x-%08x-%08x",
283 		user_key[0], user_key[1], user_key[2], user_key[3]);
284 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
285 
286 	if (write && ret == 0) {
287 		if (sscanf(tbl.data, "%x-%x-%x-%x", user_key, user_key + 1,
288 			   user_key + 2, user_key + 3) != 4) {
289 			ret = -EINVAL;
290 			goto bad_key;
291 		}
292 		tcp_fastopen_reset_cipher(net, NULL, user_key,
293 					  TCP_FASTOPEN_KEY_LENGTH);
294 	}
295 
296 bad_key:
297 	pr_debug("proc FO key set 0x%x-%x-%x-%x <- 0x%s: %u\n",
298 	       user_key[0], user_key[1], user_key[2], user_key[3],
299 	       (char *)tbl.data, ret);
300 	kfree(tbl.data);
301 	return ret;
302 }
303 
304 static void proc_configure_early_demux(int enabled, int protocol)
305 {
306 	struct net_protocol *ipprot;
307 #if IS_ENABLED(CONFIG_IPV6)
308 	struct inet6_protocol *ip6prot;
309 #endif
310 
311 	rcu_read_lock();
312 
313 	ipprot = rcu_dereference(inet_protos[protocol]);
314 	if (ipprot)
315 		ipprot->early_demux = enabled ? ipprot->early_demux_handler :
316 						NULL;
317 
318 #if IS_ENABLED(CONFIG_IPV6)
319 	ip6prot = rcu_dereference(inet6_protos[protocol]);
320 	if (ip6prot)
321 		ip6prot->early_demux = enabled ? ip6prot->early_demux_handler :
322 						 NULL;
323 #endif
324 	rcu_read_unlock();
325 }
326 
327 static int proc_tcp_early_demux(struct ctl_table *table, int write,
328 				void __user *buffer, size_t *lenp, loff_t *ppos)
329 {
330 	int ret = 0;
331 
332 	ret = proc_dointvec(table, write, buffer, lenp, ppos);
333 
334 	if (write && !ret) {
335 		int enabled = init_net.ipv4.sysctl_tcp_early_demux;
336 
337 		proc_configure_early_demux(enabled, IPPROTO_TCP);
338 	}
339 
340 	return ret;
341 }
342 
343 static int proc_udp_early_demux(struct ctl_table *table, int write,
344 				void __user *buffer, size_t *lenp, loff_t *ppos)
345 {
346 	int ret = 0;
347 
348 	ret = proc_dointvec(table, write, buffer, lenp, ppos);
349 
350 	if (write && !ret) {
351 		int enabled = init_net.ipv4.sysctl_udp_early_demux;
352 
353 		proc_configure_early_demux(enabled, IPPROTO_UDP);
354 	}
355 
356 	return ret;
357 }
358 
359 static int proc_tfo_blackhole_detect_timeout(struct ctl_table *table,
360 					     int write,
361 					     void __user *buffer,
362 					     size_t *lenp, loff_t *ppos)
363 {
364 	struct net *net = container_of(table->data, struct net,
365 	    ipv4.sysctl_tcp_fastopen_blackhole_timeout);
366 	int ret;
367 
368 	ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
369 	if (write && ret == 0)
370 		atomic_set(&net->ipv4.tfo_active_disable_times, 0);
371 
372 	return ret;
373 }
374 
375 static int proc_tcp_available_ulp(struct ctl_table *ctl,
376 				  int write,
377 				  void __user *buffer, size_t *lenp,
378 				  loff_t *ppos)
379 {
380 	struct ctl_table tbl = { .maxlen = TCP_ULP_BUF_MAX, };
381 	int ret;
382 
383 	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
384 	if (!tbl.data)
385 		return -ENOMEM;
386 	tcp_get_available_ulp(tbl.data, TCP_ULP_BUF_MAX);
387 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
388 	kfree(tbl.data);
389 
390 	return ret;
391 }
392 
393 #ifdef CONFIG_IP_ROUTE_MULTIPATH
394 static int proc_fib_multipath_hash_policy(struct ctl_table *table, int write,
395 					  void __user *buffer, size_t *lenp,
396 					  loff_t *ppos)
397 {
398 	struct net *net = container_of(table->data, struct net,
399 	    ipv4.sysctl_fib_multipath_hash_policy);
400 	int ret;
401 
402 	ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
403 	if (write && ret == 0)
404 		call_netevent_notifiers(NETEVENT_IPV4_MPATH_HASH_UPDATE, net);
405 
406 	return ret;
407 }
408 #endif
409 
410 static struct ctl_table ipv4_table[] = {
411 	{
412 		.procname	= "tcp_max_orphans",
413 		.data		= &sysctl_tcp_max_orphans,
414 		.maxlen		= sizeof(int),
415 		.mode		= 0644,
416 		.proc_handler	= proc_dointvec
417 	},
418 	{
419 		.procname	= "inet_peer_threshold",
420 		.data		= &inet_peer_threshold,
421 		.maxlen		= sizeof(int),
422 		.mode		= 0644,
423 		.proc_handler	= proc_dointvec
424 	},
425 	{
426 		.procname	= "inet_peer_minttl",
427 		.data		= &inet_peer_minttl,
428 		.maxlen		= sizeof(int),
429 		.mode		= 0644,
430 		.proc_handler	= proc_dointvec_jiffies,
431 	},
432 	{
433 		.procname	= "inet_peer_maxttl",
434 		.data		= &inet_peer_maxttl,
435 		.maxlen		= sizeof(int),
436 		.mode		= 0644,
437 		.proc_handler	= proc_dointvec_jiffies,
438 	},
439 	{
440 		.procname	= "tcp_mem",
441 		.maxlen		= sizeof(sysctl_tcp_mem),
442 		.data		= &sysctl_tcp_mem,
443 		.mode		= 0644,
444 		.proc_handler	= proc_doulongvec_minmax,
445 	},
446 	{
447 		.procname	= "tcp_low_latency",
448 		.data		= &sysctl_tcp_low_latency,
449 		.maxlen		= sizeof(int),
450 		.mode		= 0644,
451 		.proc_handler	= proc_dointvec
452 	},
453 #ifdef CONFIG_NETLABEL
454 	{
455 		.procname	= "cipso_cache_enable",
456 		.data		= &cipso_v4_cache_enabled,
457 		.maxlen		= sizeof(int),
458 		.mode		= 0644,
459 		.proc_handler	= proc_dointvec,
460 	},
461 	{
462 		.procname	= "cipso_cache_bucket_size",
463 		.data		= &cipso_v4_cache_bucketsize,
464 		.maxlen		= sizeof(int),
465 		.mode		= 0644,
466 		.proc_handler	= proc_dointvec,
467 	},
468 	{
469 		.procname	= "cipso_rbm_optfmt",
470 		.data		= &cipso_v4_rbm_optfmt,
471 		.maxlen		= sizeof(int),
472 		.mode		= 0644,
473 		.proc_handler	= proc_dointvec,
474 	},
475 	{
476 		.procname	= "cipso_rbm_strictvalid",
477 		.data		= &cipso_v4_rbm_strictvalid,
478 		.maxlen		= sizeof(int),
479 		.mode		= 0644,
480 		.proc_handler	= proc_dointvec,
481 	},
482 #endif /* CONFIG_NETLABEL */
483 	{
484 		.procname	= "tcp_available_congestion_control",
485 		.maxlen		= TCP_CA_BUF_MAX,
486 		.mode		= 0444,
487 		.proc_handler   = proc_tcp_available_congestion_control,
488 	},
489 	{
490 		.procname	= "tcp_allowed_congestion_control",
491 		.maxlen		= TCP_CA_BUF_MAX,
492 		.mode		= 0644,
493 		.proc_handler   = proc_allowed_congestion_control,
494 	},
495 	{
496 		.procname	= "tcp_available_ulp",
497 		.maxlen		= TCP_ULP_BUF_MAX,
498 		.mode		= 0444,
499 		.proc_handler   = proc_tcp_available_ulp,
500 	},
501 	{
502 		.procname	= "icmp_msgs_per_sec",
503 		.data		= &sysctl_icmp_msgs_per_sec,
504 		.maxlen		= sizeof(int),
505 		.mode		= 0644,
506 		.proc_handler	= proc_dointvec_minmax,
507 		.extra1		= &zero,
508 	},
509 	{
510 		.procname	= "icmp_msgs_burst",
511 		.data		= &sysctl_icmp_msgs_burst,
512 		.maxlen		= sizeof(int),
513 		.mode		= 0644,
514 		.proc_handler	= proc_dointvec_minmax,
515 		.extra1		= &zero,
516 	},
517 	{
518 		.procname	= "udp_mem",
519 		.data		= &sysctl_udp_mem,
520 		.maxlen		= sizeof(sysctl_udp_mem),
521 		.mode		= 0644,
522 		.proc_handler	= proc_doulongvec_minmax,
523 	},
524 	{ }
525 };
526 
527 static struct ctl_table ipv4_net_table[] = {
528 	{
529 		.procname	= "icmp_echo_ignore_all",
530 		.data		= &init_net.ipv4.sysctl_icmp_echo_ignore_all,
531 		.maxlen		= sizeof(int),
532 		.mode		= 0644,
533 		.proc_handler	= proc_dointvec
534 	},
535 	{
536 		.procname	= "icmp_echo_ignore_broadcasts",
537 		.data		= &init_net.ipv4.sysctl_icmp_echo_ignore_broadcasts,
538 		.maxlen		= sizeof(int),
539 		.mode		= 0644,
540 		.proc_handler	= proc_dointvec
541 	},
542 	{
543 		.procname	= "icmp_ignore_bogus_error_responses",
544 		.data		= &init_net.ipv4.sysctl_icmp_ignore_bogus_error_responses,
545 		.maxlen		= sizeof(int),
546 		.mode		= 0644,
547 		.proc_handler	= proc_dointvec
548 	},
549 	{
550 		.procname	= "icmp_errors_use_inbound_ifaddr",
551 		.data		= &init_net.ipv4.sysctl_icmp_errors_use_inbound_ifaddr,
552 		.maxlen		= sizeof(int),
553 		.mode		= 0644,
554 		.proc_handler	= proc_dointvec
555 	},
556 	{
557 		.procname	= "icmp_ratelimit",
558 		.data		= &init_net.ipv4.sysctl_icmp_ratelimit,
559 		.maxlen		= sizeof(int),
560 		.mode		= 0644,
561 		.proc_handler	= proc_dointvec_ms_jiffies,
562 	},
563 	{
564 		.procname	= "icmp_ratemask",
565 		.data		= &init_net.ipv4.sysctl_icmp_ratemask,
566 		.maxlen		= sizeof(int),
567 		.mode		= 0644,
568 		.proc_handler	= proc_dointvec
569 	},
570 	{
571 		.procname	= "ping_group_range",
572 		.data		= &init_net.ipv4.ping_group_range.range,
573 		.maxlen		= sizeof(gid_t)*2,
574 		.mode		= 0644,
575 		.proc_handler	= ipv4_ping_group_range,
576 	},
577 	{
578 		.procname	= "tcp_ecn",
579 		.data		= &init_net.ipv4.sysctl_tcp_ecn,
580 		.maxlen		= sizeof(int),
581 		.mode		= 0644,
582 		.proc_handler	= proc_dointvec
583 	},
584 	{
585 		.procname	= "tcp_ecn_fallback",
586 		.data		= &init_net.ipv4.sysctl_tcp_ecn_fallback,
587 		.maxlen		= sizeof(int),
588 		.mode		= 0644,
589 		.proc_handler	= proc_dointvec
590 	},
591 	{
592 		.procname	= "ip_dynaddr",
593 		.data		= &init_net.ipv4.sysctl_ip_dynaddr,
594 		.maxlen		= sizeof(int),
595 		.mode		= 0644,
596 		.proc_handler	= proc_dointvec
597 	},
598 	{
599 		.procname	= "ip_early_demux",
600 		.data		= &init_net.ipv4.sysctl_ip_early_demux,
601 		.maxlen		= sizeof(int),
602 		.mode		= 0644,
603 		.proc_handler	= proc_dointvec
604 	},
605 	{
606 		.procname       = "udp_early_demux",
607 		.data           = &init_net.ipv4.sysctl_udp_early_demux,
608 		.maxlen         = sizeof(int),
609 		.mode           = 0644,
610 		.proc_handler   = proc_udp_early_demux
611 	},
612 	{
613 		.procname       = "tcp_early_demux",
614 		.data           = &init_net.ipv4.sysctl_tcp_early_demux,
615 		.maxlen         = sizeof(int),
616 		.mode           = 0644,
617 		.proc_handler   = proc_tcp_early_demux
618 	},
619 	{
620 		.procname	= "ip_default_ttl",
621 		.data		= &init_net.ipv4.sysctl_ip_default_ttl,
622 		.maxlen		= sizeof(int),
623 		.mode		= 0644,
624 		.proc_handler	= proc_dointvec_minmax,
625 		.extra1		= &ip_ttl_min,
626 		.extra2		= &ip_ttl_max,
627 	},
628 	{
629 		.procname	= "ip_local_port_range",
630 		.maxlen		= sizeof(init_net.ipv4.ip_local_ports.range),
631 		.data		= &init_net.ipv4.ip_local_ports.range,
632 		.mode		= 0644,
633 		.proc_handler	= ipv4_local_port_range,
634 	},
635 	{
636 		.procname	= "ip_local_reserved_ports",
637 		.data		= &init_net.ipv4.sysctl_local_reserved_ports,
638 		.maxlen		= 65536,
639 		.mode		= 0644,
640 		.proc_handler	= proc_do_large_bitmap,
641 	},
642 	{
643 		.procname	= "ip_no_pmtu_disc",
644 		.data		= &init_net.ipv4.sysctl_ip_no_pmtu_disc,
645 		.maxlen		= sizeof(int),
646 		.mode		= 0644,
647 		.proc_handler	= proc_dointvec
648 	},
649 	{
650 		.procname	= "ip_forward_use_pmtu",
651 		.data		= &init_net.ipv4.sysctl_ip_fwd_use_pmtu,
652 		.maxlen		= sizeof(int),
653 		.mode		= 0644,
654 		.proc_handler	= proc_dointvec,
655 	},
656 	{
657 		.procname	= "ip_nonlocal_bind",
658 		.data		= &init_net.ipv4.sysctl_ip_nonlocal_bind,
659 		.maxlen		= sizeof(int),
660 		.mode		= 0644,
661 		.proc_handler	= proc_dointvec
662 	},
663 	{
664 		.procname	= "fwmark_reflect",
665 		.data		= &init_net.ipv4.sysctl_fwmark_reflect,
666 		.maxlen		= sizeof(int),
667 		.mode		= 0644,
668 		.proc_handler	= proc_dointvec,
669 	},
670 	{
671 		.procname	= "tcp_fwmark_accept",
672 		.data		= &init_net.ipv4.sysctl_tcp_fwmark_accept,
673 		.maxlen		= sizeof(int),
674 		.mode		= 0644,
675 		.proc_handler	= proc_dointvec,
676 	},
677 #ifdef CONFIG_NET_L3_MASTER_DEV
678 	{
679 		.procname	= "tcp_l3mdev_accept",
680 		.data		= &init_net.ipv4.sysctl_tcp_l3mdev_accept,
681 		.maxlen		= sizeof(int),
682 		.mode		= 0644,
683 		.proc_handler	= proc_dointvec_minmax,
684 		.extra1		= &zero,
685 		.extra2		= &one,
686 	},
687 #endif
688 	{
689 		.procname	= "tcp_mtu_probing",
690 		.data		= &init_net.ipv4.sysctl_tcp_mtu_probing,
691 		.maxlen		= sizeof(int),
692 		.mode		= 0644,
693 		.proc_handler	= proc_dointvec,
694 	},
695 	{
696 		.procname	= "tcp_base_mss",
697 		.data		= &init_net.ipv4.sysctl_tcp_base_mss,
698 		.maxlen		= sizeof(int),
699 		.mode		= 0644,
700 		.proc_handler	= proc_dointvec,
701 	},
702 	{
703 		.procname	= "tcp_probe_threshold",
704 		.data		= &init_net.ipv4.sysctl_tcp_probe_threshold,
705 		.maxlen		= sizeof(int),
706 		.mode		= 0644,
707 		.proc_handler	= proc_dointvec,
708 	},
709 	{
710 		.procname	= "tcp_probe_interval",
711 		.data		= &init_net.ipv4.sysctl_tcp_probe_interval,
712 		.maxlen		= sizeof(int),
713 		.mode		= 0644,
714 		.proc_handler	= proc_dointvec,
715 	},
716 	{
717 		.procname	= "igmp_link_local_mcast_reports",
718 		.data		= &init_net.ipv4.sysctl_igmp_llm_reports,
719 		.maxlen		= sizeof(int),
720 		.mode		= 0644,
721 		.proc_handler	= proc_dointvec
722 	},
723 	{
724 		.procname	= "igmp_max_memberships",
725 		.data		= &init_net.ipv4.sysctl_igmp_max_memberships,
726 		.maxlen		= sizeof(int),
727 		.mode		= 0644,
728 		.proc_handler	= proc_dointvec
729 	},
730 	{
731 		.procname	= "igmp_max_msf",
732 		.data		= &init_net.ipv4.sysctl_igmp_max_msf,
733 		.maxlen		= sizeof(int),
734 		.mode		= 0644,
735 		.proc_handler	= proc_dointvec
736 	},
737 #ifdef CONFIG_IP_MULTICAST
738 	{
739 		.procname	= "igmp_qrv",
740 		.data		= &init_net.ipv4.sysctl_igmp_qrv,
741 		.maxlen		= sizeof(int),
742 		.mode		= 0644,
743 		.proc_handler	= proc_dointvec_minmax,
744 		.extra1		= &one
745 	},
746 #endif
747 	{
748 		.procname	= "tcp_congestion_control",
749 		.data		= &init_net.ipv4.tcp_congestion_control,
750 		.mode		= 0644,
751 		.maxlen		= TCP_CA_NAME_MAX,
752 		.proc_handler	= proc_tcp_congestion_control,
753 	},
754 	{
755 		.procname	= "tcp_keepalive_time",
756 		.data		= &init_net.ipv4.sysctl_tcp_keepalive_time,
757 		.maxlen		= sizeof(int),
758 		.mode		= 0644,
759 		.proc_handler	= proc_dointvec_jiffies,
760 	},
761 	{
762 		.procname	= "tcp_keepalive_probes",
763 		.data		= &init_net.ipv4.sysctl_tcp_keepalive_probes,
764 		.maxlen		= sizeof(int),
765 		.mode		= 0644,
766 		.proc_handler	= proc_dointvec
767 	},
768 	{
769 		.procname	= "tcp_keepalive_intvl",
770 		.data		= &init_net.ipv4.sysctl_tcp_keepalive_intvl,
771 		.maxlen		= sizeof(int),
772 		.mode		= 0644,
773 		.proc_handler	= proc_dointvec_jiffies,
774 	},
775 	{
776 		.procname	= "tcp_syn_retries",
777 		.data		= &init_net.ipv4.sysctl_tcp_syn_retries,
778 		.maxlen		= sizeof(int),
779 		.mode		= 0644,
780 		.proc_handler	= proc_dointvec_minmax,
781 		.extra1		= &tcp_syn_retries_min,
782 		.extra2		= &tcp_syn_retries_max
783 	},
784 	{
785 		.procname	= "tcp_synack_retries",
786 		.data		= &init_net.ipv4.sysctl_tcp_synack_retries,
787 		.maxlen		= sizeof(int),
788 		.mode		= 0644,
789 		.proc_handler	= proc_dointvec
790 	},
791 #ifdef CONFIG_SYN_COOKIES
792 	{
793 		.procname	= "tcp_syncookies",
794 		.data		= &init_net.ipv4.sysctl_tcp_syncookies,
795 		.maxlen		= sizeof(int),
796 		.mode		= 0644,
797 		.proc_handler	= proc_dointvec
798 	},
799 #endif
800 	{
801 		.procname	= "tcp_reordering",
802 		.data		= &init_net.ipv4.sysctl_tcp_reordering,
803 		.maxlen		= sizeof(int),
804 		.mode		= 0644,
805 		.proc_handler	= proc_dointvec
806 	},
807 	{
808 		.procname	= "tcp_retries1",
809 		.data		= &init_net.ipv4.sysctl_tcp_retries1,
810 		.maxlen		= sizeof(int),
811 		.mode		= 0644,
812 		.proc_handler	= proc_dointvec_minmax,
813 		.extra2		= &tcp_retr1_max
814 	},
815 	{
816 		.procname	= "tcp_retries2",
817 		.data		= &init_net.ipv4.sysctl_tcp_retries2,
818 		.maxlen		= sizeof(int),
819 		.mode		= 0644,
820 		.proc_handler	= proc_dointvec
821 	},
822 	{
823 		.procname	= "tcp_orphan_retries",
824 		.data		= &init_net.ipv4.sysctl_tcp_orphan_retries,
825 		.maxlen		= sizeof(int),
826 		.mode		= 0644,
827 		.proc_handler	= proc_dointvec
828 	},
829 	{
830 		.procname	= "tcp_fin_timeout",
831 		.data		= &init_net.ipv4.sysctl_tcp_fin_timeout,
832 		.maxlen		= sizeof(int),
833 		.mode		= 0644,
834 		.proc_handler	= proc_dointvec_jiffies,
835 	},
836 	{
837 		.procname	= "tcp_notsent_lowat",
838 		.data		= &init_net.ipv4.sysctl_tcp_notsent_lowat,
839 		.maxlen		= sizeof(unsigned int),
840 		.mode		= 0644,
841 		.proc_handler	= proc_douintvec,
842 	},
843 	{
844 		.procname	= "tcp_tw_reuse",
845 		.data		= &init_net.ipv4.sysctl_tcp_tw_reuse,
846 		.maxlen		= sizeof(int),
847 		.mode		= 0644,
848 		.proc_handler	= proc_dointvec
849 	},
850 	{
851 		.procname	= "tcp_max_tw_buckets",
852 		.data		= &init_net.ipv4.tcp_death_row.sysctl_max_tw_buckets,
853 		.maxlen		= sizeof(int),
854 		.mode		= 0644,
855 		.proc_handler	= proc_dointvec
856 	},
857 	{
858 		.procname	= "tcp_max_syn_backlog",
859 		.data		= &init_net.ipv4.sysctl_max_syn_backlog,
860 		.maxlen		= sizeof(int),
861 		.mode		= 0644,
862 		.proc_handler	= proc_dointvec
863 	},
864 	{
865 		.procname	= "tcp_fastopen",
866 		.data		= &init_net.ipv4.sysctl_tcp_fastopen,
867 		.maxlen		= sizeof(int),
868 		.mode		= 0644,
869 		.proc_handler	= proc_dointvec,
870 	},
871 	{
872 		.procname	= "tcp_fastopen_key",
873 		.mode		= 0600,
874 		.data		= &init_net.ipv4.sysctl_tcp_fastopen,
875 		.maxlen		= ((TCP_FASTOPEN_KEY_LENGTH * 2) + 10),
876 		.proc_handler	= proc_tcp_fastopen_key,
877 	},
878 	{
879 		.procname	= "tcp_fastopen_blackhole_timeout_sec",
880 		.data		= &init_net.ipv4.sysctl_tcp_fastopen_blackhole_timeout,
881 		.maxlen		= sizeof(int),
882 		.mode		= 0644,
883 		.proc_handler	= proc_tfo_blackhole_detect_timeout,
884 		.extra1		= &zero,
885 	},
886 #ifdef CONFIG_IP_ROUTE_MULTIPATH
887 	{
888 		.procname	= "fib_multipath_use_neigh",
889 		.data		= &init_net.ipv4.sysctl_fib_multipath_use_neigh,
890 		.maxlen		= sizeof(int),
891 		.mode		= 0644,
892 		.proc_handler	= proc_dointvec_minmax,
893 		.extra1		= &zero,
894 		.extra2		= &one,
895 	},
896 	{
897 		.procname	= "fib_multipath_hash_policy",
898 		.data		= &init_net.ipv4.sysctl_fib_multipath_hash_policy,
899 		.maxlen		= sizeof(int),
900 		.mode		= 0644,
901 		.proc_handler	= proc_fib_multipath_hash_policy,
902 		.extra1		= &zero,
903 		.extra2		= &one,
904 	},
905 #endif
906 	{
907 		.procname	= "ip_unprivileged_port_start",
908 		.maxlen		= sizeof(int),
909 		.data		= &init_net.ipv4.sysctl_ip_prot_sock,
910 		.mode		= 0644,
911 		.proc_handler	= ipv4_privileged_ports,
912 	},
913 #ifdef CONFIG_NET_L3_MASTER_DEV
914 	{
915 		.procname	= "udp_l3mdev_accept",
916 		.data		= &init_net.ipv4.sysctl_udp_l3mdev_accept,
917 		.maxlen		= sizeof(int),
918 		.mode		= 0644,
919 		.proc_handler	= proc_dointvec_minmax,
920 		.extra1		= &zero,
921 		.extra2		= &one,
922 	},
923 #endif
924 	{
925 		.procname	= "tcp_sack",
926 		.data		= &init_net.ipv4.sysctl_tcp_sack,
927 		.maxlen		= sizeof(int),
928 		.mode		= 0644,
929 		.proc_handler	= proc_dointvec
930 	},
931 	{
932 		.procname	= "tcp_window_scaling",
933 		.data		= &init_net.ipv4.sysctl_tcp_window_scaling,
934 		.maxlen		= sizeof(int),
935 		.mode		= 0644,
936 		.proc_handler	= proc_dointvec
937 	},
938 	{
939 		.procname	= "tcp_timestamps",
940 		.data		= &init_net.ipv4.sysctl_tcp_timestamps,
941 		.maxlen		= sizeof(int),
942 		.mode		= 0644,
943 		.proc_handler	= proc_dointvec
944 	},
945 	{
946 		.procname	= "tcp_early_retrans",
947 		.data		= &init_net.ipv4.sysctl_tcp_early_retrans,
948 		.maxlen		= sizeof(int),
949 		.mode		= 0644,
950 		.proc_handler	= proc_dointvec_minmax,
951 		.extra1		= &zero,
952 		.extra2		= &four,
953 	},
954 	{
955 		.procname	= "tcp_recovery",
956 		.data		= &init_net.ipv4.sysctl_tcp_recovery,
957 		.maxlen		= sizeof(int),
958 		.mode		= 0644,
959 		.proc_handler	= proc_dointvec,
960 	},
961 	{
962 		.procname       = "tcp_thin_linear_timeouts",
963 		.data           = &init_net.ipv4.sysctl_tcp_thin_linear_timeouts,
964 		.maxlen         = sizeof(int),
965 		.mode           = 0644,
966 		.proc_handler   = proc_dointvec
967 	},
968 	{
969 		.procname	= "tcp_slow_start_after_idle",
970 		.data		= &init_net.ipv4.sysctl_tcp_slow_start_after_idle,
971 		.maxlen		= sizeof(int),
972 		.mode		= 0644,
973 		.proc_handler	= proc_dointvec
974 	},
975 	{
976 		.procname	= "tcp_retrans_collapse",
977 		.data		= &init_net.ipv4.sysctl_tcp_retrans_collapse,
978 		.maxlen		= sizeof(int),
979 		.mode		= 0644,
980 		.proc_handler	= proc_dointvec
981 	},
982 	{
983 		.procname	= "tcp_stdurg",
984 		.data		= &init_net.ipv4.sysctl_tcp_stdurg,
985 		.maxlen		= sizeof(int),
986 		.mode		= 0644,
987 		.proc_handler	= proc_dointvec
988 	},
989 	{
990 		.procname	= "tcp_rfc1337",
991 		.data		= &init_net.ipv4.sysctl_tcp_rfc1337,
992 		.maxlen		= sizeof(int),
993 		.mode		= 0644,
994 		.proc_handler	= proc_dointvec
995 	},
996 	{
997 		.procname	= "tcp_abort_on_overflow",
998 		.data		= &init_net.ipv4.sysctl_tcp_abort_on_overflow,
999 		.maxlen		= sizeof(int),
1000 		.mode		= 0644,
1001 		.proc_handler	= proc_dointvec
1002 	},
1003 	{
1004 		.procname	= "tcp_fack",
1005 		.data		= &init_net.ipv4.sysctl_tcp_fack,
1006 		.maxlen		= sizeof(int),
1007 		.mode		= 0644,
1008 		.proc_handler	= proc_dointvec
1009 	},
1010 	{
1011 		.procname	= "tcp_max_reordering",
1012 		.data		= &init_net.ipv4.sysctl_tcp_max_reordering,
1013 		.maxlen		= sizeof(int),
1014 		.mode		= 0644,
1015 		.proc_handler	= proc_dointvec
1016 	},
1017 	{
1018 		.procname	= "tcp_dsack",
1019 		.data		= &init_net.ipv4.sysctl_tcp_dsack,
1020 		.maxlen		= sizeof(int),
1021 		.mode		= 0644,
1022 		.proc_handler	= proc_dointvec
1023 	},
1024 	{
1025 		.procname	= "tcp_app_win",
1026 		.data		= &init_net.ipv4.sysctl_tcp_app_win,
1027 		.maxlen		= sizeof(int),
1028 		.mode		= 0644,
1029 		.proc_handler	= proc_dointvec
1030 	},
1031 	{
1032 		.procname	= "tcp_adv_win_scale",
1033 		.data		= &init_net.ipv4.sysctl_tcp_adv_win_scale,
1034 		.maxlen		= sizeof(int),
1035 		.mode		= 0644,
1036 		.proc_handler	= proc_dointvec_minmax,
1037 		.extra1		= &tcp_adv_win_scale_min,
1038 		.extra2		= &tcp_adv_win_scale_max,
1039 	},
1040 	{
1041 		.procname	= "tcp_frto",
1042 		.data		= &init_net.ipv4.sysctl_tcp_frto,
1043 		.maxlen		= sizeof(int),
1044 		.mode		= 0644,
1045 		.proc_handler	= proc_dointvec
1046 	},
1047 	{
1048 		.procname	= "tcp_no_metrics_save",
1049 		.data		= &init_net.ipv4.sysctl_tcp_nometrics_save,
1050 		.maxlen		= sizeof(int),
1051 		.mode		= 0644,
1052 		.proc_handler	= proc_dointvec,
1053 	},
1054 	{
1055 		.procname	= "tcp_moderate_rcvbuf",
1056 		.data		= &init_net.ipv4.sysctl_tcp_moderate_rcvbuf,
1057 		.maxlen		= sizeof(int),
1058 		.mode		= 0644,
1059 		.proc_handler	= proc_dointvec,
1060 	},
1061 	{
1062 		.procname	= "tcp_tso_win_divisor",
1063 		.data		= &init_net.ipv4.sysctl_tcp_tso_win_divisor,
1064 		.maxlen		= sizeof(int),
1065 		.mode		= 0644,
1066 		.proc_handler	= proc_dointvec,
1067 	},
1068 	{
1069 		.procname	= "tcp_workaround_signed_windows",
1070 		.data		= &init_net.ipv4.sysctl_tcp_workaround_signed_windows,
1071 		.maxlen		= sizeof(int),
1072 		.mode		= 0644,
1073 		.proc_handler	= proc_dointvec
1074 	},
1075 	{
1076 		.procname	= "tcp_limit_output_bytes",
1077 		.data		= &init_net.ipv4.sysctl_tcp_limit_output_bytes,
1078 		.maxlen		= sizeof(int),
1079 		.mode		= 0644,
1080 		.proc_handler	= proc_dointvec
1081 	},
1082 	{
1083 		.procname	= "tcp_challenge_ack_limit",
1084 		.data		= &init_net.ipv4.sysctl_tcp_challenge_ack_limit,
1085 		.maxlen		= sizeof(int),
1086 		.mode		= 0644,
1087 		.proc_handler	= proc_dointvec
1088 	},
1089 	{
1090 		.procname	= "tcp_min_tso_segs",
1091 		.data		= &init_net.ipv4.sysctl_tcp_min_tso_segs,
1092 		.maxlen		= sizeof(int),
1093 		.mode		= 0644,
1094 		.proc_handler	= proc_dointvec_minmax,
1095 		.extra1		= &one,
1096 		.extra2		= &gso_max_segs,
1097 	},
1098 	{
1099 		.procname	= "tcp_min_rtt_wlen",
1100 		.data		= &init_net.ipv4.sysctl_tcp_min_rtt_wlen,
1101 		.maxlen		= sizeof(int),
1102 		.mode		= 0644,
1103 		.proc_handler	= proc_dointvec
1104 	},
1105 	{
1106 		.procname	= "tcp_autocorking",
1107 		.data		= &init_net.ipv4.sysctl_tcp_autocorking,
1108 		.maxlen		= sizeof(int),
1109 		.mode		= 0644,
1110 		.proc_handler	= proc_dointvec_minmax,
1111 		.extra1		= &zero,
1112 		.extra2		= &one,
1113 	},
1114 	{
1115 		.procname	= "tcp_invalid_ratelimit",
1116 		.data		= &init_net.ipv4.sysctl_tcp_invalid_ratelimit,
1117 		.maxlen		= sizeof(int),
1118 		.mode		= 0644,
1119 		.proc_handler	= proc_dointvec_ms_jiffies,
1120 	},
1121 	{
1122 		.procname	= "tcp_pacing_ss_ratio",
1123 		.data		= &init_net.ipv4.sysctl_tcp_pacing_ss_ratio,
1124 		.maxlen		= sizeof(int),
1125 		.mode		= 0644,
1126 		.proc_handler	= proc_dointvec_minmax,
1127 		.extra1		= &zero,
1128 		.extra2		= &thousand,
1129 	},
1130 	{
1131 		.procname	= "tcp_pacing_ca_ratio",
1132 		.data		= &init_net.ipv4.sysctl_tcp_pacing_ca_ratio,
1133 		.maxlen		= sizeof(int),
1134 		.mode		= 0644,
1135 		.proc_handler	= proc_dointvec_minmax,
1136 		.extra1		= &zero,
1137 		.extra2		= &thousand,
1138 	},
1139 	{
1140 		.procname	= "tcp_wmem",
1141 		.data		= &init_net.ipv4.sysctl_tcp_wmem,
1142 		.maxlen		= sizeof(init_net.ipv4.sysctl_tcp_wmem),
1143 		.mode		= 0644,
1144 		.proc_handler	= proc_dointvec_minmax,
1145 		.extra1		= &one,
1146 	},
1147 	{
1148 		.procname	= "tcp_rmem",
1149 		.data		= &init_net.ipv4.sysctl_tcp_rmem,
1150 		.maxlen		= sizeof(init_net.ipv4.sysctl_tcp_rmem),
1151 		.mode		= 0644,
1152 		.proc_handler	= proc_dointvec_minmax,
1153 		.extra1		= &one,
1154 	},
1155 	{
1156 		.procname	= "tcp_comp_sack_delay_ns",
1157 		.data		= &init_net.ipv4.sysctl_tcp_comp_sack_delay_ns,
1158 		.maxlen		= sizeof(unsigned long),
1159 		.mode		= 0644,
1160 		.proc_handler	= proc_doulongvec_minmax,
1161 	},
1162 	{
1163 		.procname	= "tcp_comp_sack_nr",
1164 		.data		= &init_net.ipv4.sysctl_tcp_comp_sack_nr,
1165 		.maxlen		= sizeof(int),
1166 		.mode		= 0644,
1167 		.proc_handler	= proc_dointvec_minmax,
1168 		.extra1		= &zero,
1169 		.extra2		= &comp_sack_nr_max,
1170 	},
1171 	{
1172 		.procname	= "udp_rmem_min",
1173 		.data		= &init_net.ipv4.sysctl_udp_rmem_min,
1174 		.maxlen		= sizeof(init_net.ipv4.sysctl_udp_rmem_min),
1175 		.mode		= 0644,
1176 		.proc_handler	= proc_dointvec_minmax,
1177 		.extra1		= &one
1178 	},
1179 	{
1180 		.procname	= "udp_wmem_min",
1181 		.data		= &init_net.ipv4.sysctl_udp_wmem_min,
1182 		.maxlen		= sizeof(init_net.ipv4.sysctl_udp_wmem_min),
1183 		.mode		= 0644,
1184 		.proc_handler	= proc_dointvec_minmax,
1185 		.extra1		= &one
1186 	},
1187 	{ }
1188 };
1189 
1190 static __net_init int ipv4_sysctl_init_net(struct net *net)
1191 {
1192 	struct ctl_table *table;
1193 
1194 	table = ipv4_net_table;
1195 	if (!net_eq(net, &init_net)) {
1196 		int i;
1197 
1198 		table = kmemdup(table, sizeof(ipv4_net_table), GFP_KERNEL);
1199 		if (!table)
1200 			goto err_alloc;
1201 
1202 		/* Update the variables to point into the current struct net */
1203 		for (i = 0; i < ARRAY_SIZE(ipv4_net_table) - 1; i++)
1204 			table[i].data += (void *)net - (void *)&init_net;
1205 	}
1206 
1207 	net->ipv4.ipv4_hdr = register_net_sysctl(net, "net/ipv4", table);
1208 	if (!net->ipv4.ipv4_hdr)
1209 		goto err_reg;
1210 
1211 	net->ipv4.sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
1212 	if (!net->ipv4.sysctl_local_reserved_ports)
1213 		goto err_ports;
1214 
1215 	return 0;
1216 
1217 err_ports:
1218 	unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
1219 err_reg:
1220 	if (!net_eq(net, &init_net))
1221 		kfree(table);
1222 err_alloc:
1223 	return -ENOMEM;
1224 }
1225 
1226 static __net_exit void ipv4_sysctl_exit_net(struct net *net)
1227 {
1228 	struct ctl_table *table;
1229 
1230 	kfree(net->ipv4.sysctl_local_reserved_ports);
1231 	table = net->ipv4.ipv4_hdr->ctl_table_arg;
1232 	unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
1233 	kfree(table);
1234 }
1235 
1236 static __net_initdata struct pernet_operations ipv4_sysctl_ops = {
1237 	.init = ipv4_sysctl_init_net,
1238 	.exit = ipv4_sysctl_exit_net,
1239 };
1240 
1241 static __init int sysctl_ipv4_init(void)
1242 {
1243 	struct ctl_table_header *hdr;
1244 
1245 	hdr = register_net_sysctl(&init_net, "net/ipv4", ipv4_table);
1246 	if (!hdr)
1247 		return -ENOMEM;
1248 
1249 	if (register_pernet_subsys(&ipv4_sysctl_ops)) {
1250 		unregister_net_sysctl_table(hdr);
1251 		return -ENOMEM;
1252 	}
1253 
1254 	return 0;
1255 }
1256 
1257 __initcall(sysctl_ipv4_init);
1258