xref: /linux/net/ipv4/sysctl_net_ipv4.c (revision 57885276cc16a2e2b76282c808a4e84cbecb3aae)
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/sysctl.h>
10 #include <linux/seqlock.h>
11 #include <linux/init.h>
12 #include <linux/slab.h>
13 #include <net/icmp.h>
14 #include <net/ip.h>
15 #include <net/ip_fib.h>
16 #include <net/tcp.h>
17 #include <net/udp.h>
18 #include <net/cipso_ipv4.h>
19 #include <net/ping.h>
20 #include <net/protocol.h>
21 #include <net/netevent.h>
22 
23 static int tcp_retr1_max = 255;
24 static int ip_local_port_range_min[] = { 1, 1 };
25 static int ip_local_port_range_max[] = { 65535, 65535 };
26 static int tcp_adv_win_scale_min = -31;
27 static int tcp_adv_win_scale_max = 31;
28 static int tcp_app_win_max = 31;
29 static int tcp_min_snd_mss_min = TCP_MIN_SND_MSS;
30 static int tcp_min_snd_mss_max = 65535;
31 static int tcp_rto_max_max = TCP_RTO_MAX_SEC * MSEC_PER_SEC;
32 static int ip_privileged_port_min;
33 static int ip_privileged_port_max = 65535;
34 static int ip_ttl_min = 1;
35 static int ip_ttl_max = 255;
36 static int tcp_syn_retries_min = 1;
37 static int tcp_syn_retries_max = MAX_TCP_SYNCNT;
38 static int tcp_syn_linear_timeouts_max = MAX_TCP_SYNCNT;
39 static unsigned long ip_ping_group_range_min[] = { 0, 0 };
40 static unsigned long ip_ping_group_range_max[] = { GID_T_MAX, GID_T_MAX };
41 static u32 u32_max_div_HZ = UINT_MAX / HZ;
42 static int one_day_secs = 24 * 3600;
43 static u32 fib_multipath_hash_fields_all_mask __maybe_unused =
44 	FIB_MULTIPATH_HASH_FIELD_ALL_MASK;
45 static unsigned int tcp_child_ehash_entries_max = 16 * 1024 * 1024;
46 static unsigned int udp_child_hash_entries_max = UDP_HTABLE_SIZE_MAX;
47 static int tcp_plb_max_rounds = 31;
48 static int tcp_plb_max_cong_thresh = 256;
49 static unsigned int tcp_tw_reuse_delay_max = TCP_PAWS_MSL * MSEC_PER_SEC;
50 static int tcp_ecn_mode_max = 5;
51 static u32 icmp_errors_extension_mask_all =
52 	GENMASK_U8(ICMP_ERR_EXT_COUNT - 1, 0);
53 
54 /* obsolete */
55 static int sysctl_tcp_low_latency __read_mostly;
56 
57 /* Update system visible IP port range */
58 static void set_local_port_range(struct net *net, unsigned int low, unsigned int high)
59 {
60 	bool same_parity = !((low ^ high) & 1);
61 
62 	if (same_parity && !net->ipv4.ip_local_ports.warned) {
63 		net->ipv4.ip_local_ports.warned = true;
64 		pr_err_ratelimited("ip_local_port_range: prefer different parity for start/end values.\n");
65 	}
66 	WRITE_ONCE(net->ipv4.ip_local_ports.range, high << 16 | low);
67 }
68 
69 /* Validate changes from /proc interface. */
70 static int ipv4_local_port_range(const struct ctl_table *table, int write,
71 				 void *buffer, size_t *lenp, loff_t *ppos)
72 {
73 	struct net *net = table->data;
74 	int ret;
75 	int range[2];
76 	struct ctl_table tmp = {
77 		.data = &range,
78 		.maxlen = sizeof(range),
79 		.mode = table->mode,
80 		.extra1 = &ip_local_port_range_min,
81 		.extra2 = &ip_local_port_range_max,
82 	};
83 
84 	inet_get_local_port_range(net, &range[0], &range[1]);
85 
86 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
87 
88 	if (write && ret == 0) {
89 		/* Ensure that the upper limit is not smaller than the lower,
90 		 * and that the lower does not encroach upon the privileged
91 		 * port limit.
92 		 */
93 		if ((range[1] < range[0]) ||
94 		    (range[0] < READ_ONCE(net->ipv4.sysctl_ip_prot_sock)))
95 			ret = -EINVAL;
96 		else
97 			set_local_port_range(net, range[0], range[1]);
98 	}
99 
100 	return ret;
101 }
102 
103 /* Validate changes from /proc interface. */
104 static int ipv4_privileged_ports(const struct ctl_table *table, int write,
105 				void *buffer, size_t *lenp, loff_t *ppos)
106 {
107 	struct net *net = container_of(table->data, struct net,
108 	    ipv4.sysctl_ip_prot_sock);
109 	int ret;
110 	int pports;
111 	int range[2];
112 	struct ctl_table tmp = {
113 		.data = &pports,
114 		.maxlen = sizeof(pports),
115 		.mode = table->mode,
116 		.extra1 = &ip_privileged_port_min,
117 		.extra2 = &ip_privileged_port_max,
118 	};
119 
120 	pports = READ_ONCE(net->ipv4.sysctl_ip_prot_sock);
121 
122 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
123 
124 	if (write && ret == 0) {
125 		inet_get_local_port_range(net, &range[0], &range[1]);
126 		/* Ensure that the local port range doesn't overlap with the
127 		 * privileged port range.
128 		 */
129 		if (range[0] < pports)
130 			ret = -EINVAL;
131 		else
132 			WRITE_ONCE(net->ipv4.sysctl_ip_prot_sock, pports);
133 	}
134 
135 	return ret;
136 }
137 
138 static void inet_get_ping_group_range_table(const struct ctl_table *table,
139 					    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(const struct ctl_table *table,
155 				 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(const struct ctl_table *table, int write,
168 				 void *buffer, size_t *lenp, loff_t *ppos)
169 {
170 	struct user_namespace *user_ns = current_user_ns();
171 	int ret;
172 	unsigned long 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_doulongvec_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 			return -EINVAL;
192 		if (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 ipv4_fwd_update_priority(const struct ctl_table *table, int write,
203 				    void *buffer, size_t *lenp, loff_t *ppos)
204 {
205 	struct net *net;
206 	int ret;
207 
208 	net = container_of(table->data, struct net,
209 			   ipv4.sysctl_ip_fwd_update_priority);
210 	ret = proc_dou8vec_minmax(table, write, buffer, lenp, ppos);
211 	if (write && ret == 0)
212 		call_netevent_notifiers(NETEVENT_IPV4_FWD_UPDATE_PRIORITY_UPDATE,
213 					net);
214 
215 	return ret;
216 }
217 
218 static int proc_tcp_congestion_control(const struct ctl_table *ctl, int write,
219 				       void *buffer, size_t *lenp, loff_t *ppos)
220 {
221 	struct net *net = container_of(ctl->data, struct net,
222 				       ipv4.tcp_congestion_control);
223 	char val[TCP_CA_NAME_MAX];
224 	struct ctl_table tbl = {
225 		.data = val,
226 		.maxlen = TCP_CA_NAME_MAX,
227 	};
228 	int ret;
229 
230 	tcp_get_default_congestion_control(net, val);
231 
232 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
233 	if (write && ret == 0)
234 		ret = tcp_set_default_congestion_control(net, val);
235 	return ret;
236 }
237 
238 static int proc_tcp_available_congestion_control(const struct ctl_table *ctl,
239 						 int write, void *buffer,
240 						 size_t *lenp, loff_t *ppos)
241 {
242 	struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX, };
243 	int ret;
244 
245 	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
246 	if (!tbl.data)
247 		return -ENOMEM;
248 	tcp_get_available_congestion_control(tbl.data, TCP_CA_BUF_MAX);
249 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
250 	kfree(tbl.data);
251 	return ret;
252 }
253 
254 static int proc_allowed_congestion_control(const struct ctl_table *ctl,
255 					   int write, void *buffer,
256 					   size_t *lenp, loff_t *ppos)
257 {
258 	struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX };
259 	int ret;
260 
261 	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
262 	if (!tbl.data)
263 		return -ENOMEM;
264 
265 	tcp_get_allowed_congestion_control(tbl.data, tbl.maxlen);
266 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
267 	if (write && ret == 0)
268 		ret = tcp_set_allowed_congestion_control(tbl.data);
269 	kfree(tbl.data);
270 	return ret;
271 }
272 
273 static int sscanf_key(char *buf, __le32 *key)
274 {
275 	u32 user_key[4];
276 	int i, ret = 0;
277 
278 	if (sscanf(buf, "%x-%x-%x-%x", user_key, user_key + 1,
279 		   user_key + 2, user_key + 3) != 4) {
280 		ret = -EINVAL;
281 	} else {
282 		for (i = 0; i < ARRAY_SIZE(user_key); i++)
283 			key[i] = cpu_to_le32(user_key[i]);
284 	}
285 	pr_debug("proc TFO key set 0x%x-%x-%x-%x <- 0x%s: %u\n",
286 		 user_key[0], user_key[1], user_key[2], user_key[3], buf, ret);
287 
288 	return ret;
289 }
290 
291 static int proc_tcp_fastopen_key(const struct ctl_table *table, int write,
292 				 void *buffer, size_t *lenp, loff_t *ppos)
293 {
294 	struct net *net = container_of(table->data, struct net,
295 	    ipv4.sysctl_tcp_fastopen);
296 	/* maxlen to print the list of keys in hex (*2), with dashes
297 	 * separating doublewords and a comma in between keys.
298 	 */
299 	struct ctl_table tbl = { .maxlen = ((TCP_FASTOPEN_KEY_LENGTH *
300 					    2 * TCP_FASTOPEN_KEY_MAX) +
301 					    (TCP_FASTOPEN_KEY_MAX * 5)) };
302 	u32 user_key[TCP_FASTOPEN_KEY_BUF_LENGTH / sizeof(u32)];
303 	__le32 key[TCP_FASTOPEN_KEY_BUF_LENGTH / sizeof(__le32)];
304 	char *backup_data;
305 	int ret, i = 0, off = 0, n_keys;
306 
307 	tbl.data = kmalloc(tbl.maxlen, GFP_KERNEL);
308 	if (!tbl.data)
309 		return -ENOMEM;
310 
311 	n_keys = tcp_fastopen_get_cipher(net, NULL, (u64 *)key);
312 	if (!n_keys) {
313 		memset(&key[0], 0, TCP_FASTOPEN_KEY_LENGTH);
314 		n_keys = 1;
315 	}
316 
317 	for (i = 0; i < n_keys * 4; i++)
318 		user_key[i] = le32_to_cpu(key[i]);
319 
320 	for (i = 0; i < n_keys; i++) {
321 		off += snprintf(tbl.data + off, tbl.maxlen - off,
322 				"%08x-%08x-%08x-%08x",
323 				user_key[i * 4],
324 				user_key[i * 4 + 1],
325 				user_key[i * 4 + 2],
326 				user_key[i * 4 + 3]);
327 
328 		if (WARN_ON_ONCE(off >= tbl.maxlen - 1))
329 			break;
330 
331 		if (i + 1 < n_keys)
332 			off += snprintf(tbl.data + off, tbl.maxlen - off, ",");
333 	}
334 
335 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
336 
337 	if (write && ret == 0) {
338 		backup_data = strchr(tbl.data, ',');
339 		if (backup_data) {
340 			*backup_data = '\0';
341 			backup_data++;
342 		}
343 		if (sscanf_key(tbl.data, key)) {
344 			ret = -EINVAL;
345 			goto bad_key;
346 		}
347 		if (backup_data) {
348 			if (sscanf_key(backup_data, key + 4)) {
349 				ret = -EINVAL;
350 				goto bad_key;
351 			}
352 		}
353 		tcp_fastopen_reset_cipher(net, NULL, key,
354 					  backup_data ? key + 4 : NULL);
355 	}
356 
357 bad_key:
358 	kfree(tbl.data);
359 	return ret;
360 }
361 
362 static int proc_tfo_blackhole_detect_timeout(const struct ctl_table *table,
363 					     int write, void *buffer,
364 					     size_t *lenp, loff_t *ppos)
365 {
366 	struct net *net = container_of(table->data, struct net,
367 	    ipv4.sysctl_tcp_fastopen_blackhole_timeout);
368 	int ret;
369 
370 	ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
371 	if (write && ret == 0)
372 		atomic_set(&net->ipv4.tfo_active_disable_times, 0);
373 
374 	return ret;
375 }
376 
377 static int proc_tcp_available_ulp(const struct ctl_table *ctl,
378 				  int write, void *buffer, size_t *lenp,
379 				  loff_t *ppos)
380 {
381 	struct ctl_table tbl = { .maxlen = TCP_ULP_BUF_MAX, };
382 	int ret;
383 
384 	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
385 	if (!tbl.data)
386 		return -ENOMEM;
387 	tcp_get_available_ulp(tbl.data, TCP_ULP_BUF_MAX);
388 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
389 	kfree(tbl.data);
390 
391 	return ret;
392 }
393 
394 static int proc_tcp_ehash_entries(const struct ctl_table *table, int write,
395 				  void *buffer, size_t *lenp, loff_t *ppos)
396 {
397 	struct net *net = container_of(table->data, struct net,
398 				       ipv4.sysctl_tcp_child_ehash_entries);
399 	struct inet_hashinfo *hinfo = net->ipv4.tcp_death_row.hashinfo;
400 	int tcp_ehash_entries;
401 	struct ctl_table tbl;
402 
403 	tcp_ehash_entries = hinfo->ehash_mask + 1;
404 
405 	/* A negative number indicates that the child netns
406 	 * shares the global ehash.
407 	 */
408 	if (!net_eq(net, &init_net) && !hinfo->pernet)
409 		tcp_ehash_entries *= -1;
410 
411 	memset(&tbl, 0, sizeof(tbl));
412 	tbl.data = &tcp_ehash_entries;
413 	tbl.maxlen = sizeof(int);
414 
415 	return proc_dointvec(&tbl, write, buffer, lenp, ppos);
416 }
417 
418 static int proc_udp_hash_entries(const struct ctl_table *table, int write,
419 				 void *buffer, size_t *lenp, loff_t *ppos)
420 {
421 	struct net *net = container_of(table->data, struct net,
422 				       ipv4.sysctl_udp_child_hash_entries);
423 	int udp_hash_entries;
424 	struct ctl_table tbl;
425 
426 	udp_hash_entries = net->ipv4.udp_table->mask + 1;
427 
428 	/* A negative number indicates that the child netns
429 	 * shares the global udp_table.
430 	 */
431 	if (!net_eq(net, &init_net) && net->ipv4.udp_table == &udp_table)
432 		udp_hash_entries *= -1;
433 
434 	memset(&tbl, 0, sizeof(tbl));
435 	tbl.data = &udp_hash_entries;
436 	tbl.maxlen = sizeof(int);
437 
438 	return proc_dointvec(&tbl, write, buffer, lenp, ppos);
439 }
440 
441 #ifdef CONFIG_IP_ROUTE_MULTIPATH
442 static int proc_fib_multipath_hash_policy(const struct ctl_table *table, int write,
443 					  void *buffer, size_t *lenp,
444 					  loff_t *ppos)
445 {
446 	struct net *net = container_of(table->data, struct net,
447 	    ipv4.sysctl_fib_multipath_hash_policy);
448 	int ret;
449 
450 	ret = proc_dou8vec_minmax(table, write, buffer, lenp, ppos);
451 	if (write && ret == 0)
452 		call_netevent_notifiers(NETEVENT_IPV4_MPATH_HASH_UPDATE, net);
453 
454 	return ret;
455 }
456 
457 static int proc_fib_multipath_hash_fields(const struct ctl_table *table, int write,
458 					  void *buffer, size_t *lenp,
459 					  loff_t *ppos)
460 {
461 	struct net *net;
462 	int ret;
463 
464 	net = container_of(table->data, struct net,
465 			   ipv4.sysctl_fib_multipath_hash_fields);
466 	ret = proc_douintvec_minmax(table, write, buffer, lenp, ppos);
467 	if (write && ret == 0)
468 		call_netevent_notifiers(NETEVENT_IPV4_MPATH_HASH_UPDATE, net);
469 
470 	return ret;
471 }
472 
473 static u32 proc_fib_multipath_hash_rand_seed __ro_after_init;
474 
475 static void proc_fib_multipath_hash_init_rand_seed(void)
476 {
477 	get_random_bytes(&proc_fib_multipath_hash_rand_seed,
478 			 sizeof(proc_fib_multipath_hash_rand_seed));
479 }
480 
481 static void proc_fib_multipath_hash_set_seed(struct net *net, u32 user_seed)
482 {
483 	struct sysctl_fib_multipath_hash_seed new = {
484 		.user_seed = user_seed,
485 		.mp_seed = (user_seed ? user_seed :
486 			    proc_fib_multipath_hash_rand_seed),
487 	};
488 
489 	WRITE_ONCE(net->ipv4.sysctl_fib_multipath_hash_seed.user_seed, new.user_seed);
490 	WRITE_ONCE(net->ipv4.sysctl_fib_multipath_hash_seed.mp_seed, new.mp_seed);
491 }
492 
493 static int proc_fib_multipath_hash_seed(const struct ctl_table *table, int write,
494 					void *buffer, size_t *lenp,
495 					loff_t *ppos)
496 {
497 	struct sysctl_fib_multipath_hash_seed *mphs;
498 	struct net *net = table->data;
499 	struct ctl_table tmp;
500 	u32 user_seed;
501 	int ret;
502 
503 	mphs = &net->ipv4.sysctl_fib_multipath_hash_seed;
504 	user_seed = READ_ONCE(mphs->user_seed);
505 
506 	tmp = *table;
507 	tmp.data = &user_seed;
508 
509 	ret = proc_douintvec_minmax(&tmp, write, buffer, lenp, ppos);
510 
511 	if (write && ret == 0) {
512 		proc_fib_multipath_hash_set_seed(net, user_seed);
513 		call_netevent_notifiers(NETEVENT_IPV4_MPATH_HASH_UPDATE, net);
514 	}
515 
516 	return ret;
517 }
518 #else
519 
520 static void proc_fib_multipath_hash_init_rand_seed(void)
521 {
522 }
523 
524 static void proc_fib_multipath_hash_set_seed(struct net *net, u32 user_seed)
525 {
526 }
527 
528 #endif
529 
530 static struct ctl_table ipv4_table[] = {
531 	{
532 		.procname	= "tcp_max_orphans",
533 		.data		= &sysctl_tcp_max_orphans,
534 		.maxlen		= sizeof(int),
535 		.mode		= 0644,
536 		.proc_handler	= proc_dointvec
537 	},
538 	{
539 		.procname	= "inet_peer_threshold",
540 		.data		= &inet_peer_threshold,
541 		.maxlen		= sizeof(int),
542 		.mode		= 0644,
543 		.proc_handler	= proc_dointvec
544 	},
545 	{
546 		.procname	= "inet_peer_minttl",
547 		.data		= &inet_peer_minttl,
548 		.maxlen		= sizeof(int),
549 		.mode		= 0644,
550 		.proc_handler	= proc_dointvec_jiffies,
551 	},
552 	{
553 		.procname	= "inet_peer_maxttl",
554 		.data		= &inet_peer_maxttl,
555 		.maxlen		= sizeof(int),
556 		.mode		= 0644,
557 		.proc_handler	= proc_dointvec_jiffies,
558 	},
559 	{
560 		.procname	= "tcp_mem",
561 		.maxlen		= sizeof(sysctl_tcp_mem),
562 		.data		= &sysctl_tcp_mem,
563 		.mode		= 0644,
564 		.proc_handler	= proc_doulongvec_minmax,
565 	},
566 	{
567 		.procname	= "tcp_low_latency",
568 		.data		= &sysctl_tcp_low_latency,
569 		.maxlen		= sizeof(int),
570 		.mode		= 0644,
571 		.proc_handler	= proc_dointvec
572 	},
573 #ifdef CONFIG_NETLABEL
574 	{
575 		.procname	= "cipso_cache_enable",
576 		.data		= &cipso_v4_cache_enabled,
577 		.maxlen		= sizeof(int),
578 		.mode		= 0644,
579 		.proc_handler	= proc_dointvec,
580 	},
581 	{
582 		.procname	= "cipso_cache_bucket_size",
583 		.data		= &cipso_v4_cache_bucketsize,
584 		.maxlen		= sizeof(int),
585 		.mode		= 0644,
586 		.proc_handler	= proc_dointvec,
587 	},
588 	{
589 		.procname	= "cipso_rbm_optfmt",
590 		.data		= &cipso_v4_rbm_optfmt,
591 		.maxlen		= sizeof(int),
592 		.mode		= 0644,
593 		.proc_handler	= proc_dointvec,
594 	},
595 	{
596 		.procname	= "cipso_rbm_strictvalid",
597 		.data		= &cipso_v4_rbm_strictvalid,
598 		.maxlen		= sizeof(int),
599 		.mode		= 0644,
600 		.proc_handler	= proc_dointvec,
601 	},
602 #endif /* CONFIG_NETLABEL */
603 	{
604 		.procname	= "tcp_available_ulp",
605 		.maxlen		= TCP_ULP_BUF_MAX,
606 		.mode		= 0444,
607 		.proc_handler   = proc_tcp_available_ulp,
608 	},
609 	{
610 		.procname	= "udp_mem",
611 		.data		= &sysctl_udp_mem,
612 		.maxlen		= sizeof(sysctl_udp_mem),
613 		.mode		= 0644,
614 		.proc_handler	= proc_doulongvec_minmax,
615 	},
616 	{
617 		.procname	= "fib_sync_mem",
618 		.data		= &sysctl_fib_sync_mem,
619 		.maxlen		= sizeof(sysctl_fib_sync_mem),
620 		.mode		= 0644,
621 		.proc_handler	= proc_douintvec_minmax,
622 		.extra1		= &sysctl_fib_sync_mem_min,
623 		.extra2		= &sysctl_fib_sync_mem_max,
624 	},
625 };
626 
627 static struct ctl_table ipv4_net_table[] = {
628 	{
629 		.procname	= "tcp_max_tw_buckets",
630 		.data		= &init_net.ipv4.tcp_death_row.sysctl_max_tw_buckets,
631 		.maxlen		= sizeof(int),
632 		.mode		= 0644,
633 		.proc_handler	= proc_dointvec
634 	},
635 	{
636 		.procname	= "icmp_echo_ignore_all",
637 		.data		= &init_net.ipv4.sysctl_icmp_echo_ignore_all,
638 		.maxlen		= sizeof(u8),
639 		.mode		= 0644,
640 		.proc_handler	= proc_dou8vec_minmax,
641 		.extra1		= SYSCTL_ZERO,
642 		.extra2		= SYSCTL_ONE
643 	},
644 	{
645 		.procname	= "icmp_echo_enable_probe",
646 		.data		= &init_net.ipv4.sysctl_icmp_echo_enable_probe,
647 		.maxlen		= sizeof(u8),
648 		.mode		= 0644,
649 		.proc_handler	= proc_dou8vec_minmax,
650 		.extra1		= SYSCTL_ZERO,
651 		.extra2		= SYSCTL_ONE
652 	},
653 	{
654 		.procname	= "icmp_echo_ignore_broadcasts",
655 		.data		= &init_net.ipv4.sysctl_icmp_echo_ignore_broadcasts,
656 		.maxlen		= sizeof(u8),
657 		.mode		= 0644,
658 		.proc_handler	= proc_dou8vec_minmax,
659 		.extra1		= SYSCTL_ZERO,
660 		.extra2		= SYSCTL_ONE
661 	},
662 	{
663 		.procname	= "icmp_ignore_bogus_error_responses",
664 		.data		= &init_net.ipv4.sysctl_icmp_ignore_bogus_error_responses,
665 		.maxlen		= sizeof(u8),
666 		.mode		= 0644,
667 		.proc_handler	= proc_dou8vec_minmax,
668 		.extra1		= SYSCTL_ZERO,
669 		.extra2		= SYSCTL_ONE
670 	},
671 	{
672 		.procname	= "icmp_errors_use_inbound_ifaddr",
673 		.data		= &init_net.ipv4.sysctl_icmp_errors_use_inbound_ifaddr,
674 		.maxlen		= sizeof(u8),
675 		.mode		= 0644,
676 		.proc_handler	= proc_dou8vec_minmax,
677 		.extra1		= SYSCTL_ZERO,
678 		.extra2		= SYSCTL_ONE
679 	},
680 	{
681 		.procname	= "icmp_errors_extension_mask",
682 		.data		= &init_net.ipv4.sysctl_icmp_errors_extension_mask,
683 		.maxlen		= sizeof(u8),
684 		.mode		= 0644,
685 		.proc_handler	= proc_dou8vec_minmax,
686 		.extra1		= SYSCTL_ZERO,
687 		.extra2		= &icmp_errors_extension_mask_all,
688 	},
689 	{
690 		.procname	= "icmp_ratelimit",
691 		.data		= &init_net.ipv4.sysctl_icmp_ratelimit,
692 		.maxlen		= sizeof(int),
693 		.mode		= 0644,
694 		.proc_handler	= proc_dointvec_ms_jiffies,
695 	},
696 	{
697 		.procname	= "icmp_ratemask",
698 		.data		= &init_net.ipv4.sysctl_icmp_ratemask,
699 		.maxlen		= sizeof(int),
700 		.mode		= 0644,
701 		.proc_handler	= proc_dointvec
702 	},
703 	{
704 		.procname	= "icmp_msgs_per_sec",
705 		.data		= &init_net.ipv4.sysctl_icmp_msgs_per_sec,
706 		.maxlen		= sizeof(int),
707 		.mode		= 0644,
708 		.proc_handler	= proc_dointvec_minmax,
709 		.extra1		= SYSCTL_ZERO,
710 	},
711 	{
712 		.procname	= "icmp_msgs_burst",
713 		.data		= &init_net.ipv4.sysctl_icmp_msgs_burst,
714 		.maxlen		= sizeof(int),
715 		.mode		= 0644,
716 		.proc_handler	= proc_dointvec_minmax,
717 		.extra1		= SYSCTL_ZERO,
718 	},
719 	{
720 		.procname	= "ping_group_range",
721 		.data		= &init_net.ipv4.ping_group_range.range,
722 		.maxlen		= sizeof(gid_t)*2,
723 		.mode		= 0644,
724 		.proc_handler	= ipv4_ping_group_range,
725 	},
726 #ifdef CONFIG_NET_L3_MASTER_DEV
727 	{
728 		.procname	= "raw_l3mdev_accept",
729 		.data		= &init_net.ipv4.sysctl_raw_l3mdev_accept,
730 		.maxlen		= sizeof(u8),
731 		.mode		= 0644,
732 		.proc_handler	= proc_dou8vec_minmax,
733 		.extra1		= SYSCTL_ZERO,
734 		.extra2		= SYSCTL_ONE,
735 	},
736 #endif
737 	{
738 		.procname	= "tcp_ecn",
739 		.data		= &init_net.ipv4.sysctl_tcp_ecn,
740 		.maxlen		= sizeof(u8),
741 		.mode		= 0644,
742 		.proc_handler	= proc_dou8vec_minmax,
743 		.extra1		= SYSCTL_ZERO,
744 		.extra2		= &tcp_ecn_mode_max,
745 	},
746 	{
747 		.procname	= "tcp_ecn_option",
748 		.data		= &init_net.ipv4.sysctl_tcp_ecn_option,
749 		.maxlen		= sizeof(u8),
750 		.mode		= 0644,
751 		.proc_handler	= proc_dou8vec_minmax,
752 		.extra1		= SYSCTL_ZERO,
753 		.extra2		= SYSCTL_THREE,
754 	},
755 	{
756 		.procname	= "tcp_ecn_option_beacon",
757 		.data		= &init_net.ipv4.sysctl_tcp_ecn_option_beacon,
758 		.maxlen		= sizeof(u8),
759 		.mode		= 0644,
760 		.proc_handler	= proc_dou8vec_minmax,
761 		.extra1		= SYSCTL_ZERO,
762 		.extra2		= SYSCTL_THREE,
763 	},
764 	{
765 		.procname	= "tcp_ecn_fallback",
766 		.data		= &init_net.ipv4.sysctl_tcp_ecn_fallback,
767 		.maxlen		= sizeof(u8),
768 		.mode		= 0644,
769 		.proc_handler	= proc_dou8vec_minmax,
770 		.extra1		= SYSCTL_ZERO,
771 		.extra2		= SYSCTL_ONE,
772 	},
773 	{
774 		.procname	= "ip_dynaddr",
775 		.data		= &init_net.ipv4.sysctl_ip_dynaddr,
776 		.maxlen		= sizeof(u8),
777 		.mode		= 0644,
778 		.proc_handler	= proc_dou8vec_minmax,
779 	},
780 	{
781 		.procname	= "ip_early_demux",
782 		.data		= &init_net.ipv4.sysctl_ip_early_demux,
783 		.maxlen		= sizeof(u8),
784 		.mode		= 0644,
785 		.proc_handler	= proc_dou8vec_minmax,
786 	},
787 	{
788 		.procname       = "udp_early_demux",
789 		.data           = &init_net.ipv4.sysctl_udp_early_demux,
790 		.maxlen         = sizeof(u8),
791 		.mode           = 0644,
792 		.proc_handler   = proc_dou8vec_minmax,
793 	},
794 	{
795 		.procname       = "tcp_early_demux",
796 		.data           = &init_net.ipv4.sysctl_tcp_early_demux,
797 		.maxlen         = sizeof(u8),
798 		.mode           = 0644,
799 		.proc_handler   = proc_dou8vec_minmax,
800 	},
801 	{
802 		.procname       = "nexthop_compat_mode",
803 		.data           = &init_net.ipv4.sysctl_nexthop_compat_mode,
804 		.maxlen         = sizeof(u8),
805 		.mode           = 0644,
806 		.proc_handler   = proc_dou8vec_minmax,
807 		.extra1		= SYSCTL_ZERO,
808 		.extra2		= SYSCTL_ONE,
809 	},
810 	{
811 		.procname	= "ip_default_ttl",
812 		.data		= &init_net.ipv4.sysctl_ip_default_ttl,
813 		.maxlen		= sizeof(u8),
814 		.mode		= 0644,
815 		.proc_handler	= proc_dou8vec_minmax,
816 		.extra1		= &ip_ttl_min,
817 		.extra2		= &ip_ttl_max,
818 	},
819 	{
820 		.procname	= "ip_local_port_range",
821 		.maxlen		= 0,
822 		.data		= &init_net,
823 		.mode		= 0644,
824 		.proc_handler	= ipv4_local_port_range,
825 	},
826 	{
827 		.procname	= "ip_local_reserved_ports",
828 		.data		= &init_net.ipv4.sysctl_local_reserved_ports,
829 		.maxlen		= 65536,
830 		.mode		= 0644,
831 		.proc_handler	= proc_do_large_bitmap,
832 	},
833 	{
834 		.procname	= "ip_no_pmtu_disc",
835 		.data		= &init_net.ipv4.sysctl_ip_no_pmtu_disc,
836 		.maxlen		= sizeof(u8),
837 		.mode		= 0644,
838 		.proc_handler	= proc_dou8vec_minmax,
839 	},
840 	{
841 		.procname	= "ip_forward_use_pmtu",
842 		.data		= &init_net.ipv4.sysctl_ip_fwd_use_pmtu,
843 		.maxlen		= sizeof(u8),
844 		.mode		= 0644,
845 		.proc_handler	= proc_dou8vec_minmax,
846 	},
847 	{
848 		.procname	= "ip_forward_update_priority",
849 		.data		= &init_net.ipv4.sysctl_ip_fwd_update_priority,
850 		.maxlen		= sizeof(u8),
851 		.mode		= 0644,
852 		.proc_handler   = ipv4_fwd_update_priority,
853 		.extra1		= SYSCTL_ZERO,
854 		.extra2		= SYSCTL_ONE,
855 	},
856 	{
857 		.procname	= "ip_nonlocal_bind",
858 		.data		= &init_net.ipv4.sysctl_ip_nonlocal_bind,
859 		.maxlen		= sizeof(u8),
860 		.mode		= 0644,
861 		.proc_handler	= proc_dou8vec_minmax,
862 	},
863 	{
864 		.procname	= "ip_autobind_reuse",
865 		.data		= &init_net.ipv4.sysctl_ip_autobind_reuse,
866 		.maxlen		= sizeof(u8),
867 		.mode		= 0644,
868 		.proc_handler	= proc_dou8vec_minmax,
869 		.extra1         = SYSCTL_ZERO,
870 		.extra2         = SYSCTL_ONE,
871 	},
872 	{
873 		.procname	= "fwmark_reflect",
874 		.data		= &init_net.ipv4.sysctl_fwmark_reflect,
875 		.maxlen		= sizeof(u8),
876 		.mode		= 0644,
877 		.proc_handler	= proc_dou8vec_minmax,
878 	},
879 	{
880 		.procname	= "tcp_fwmark_accept",
881 		.data		= &init_net.ipv4.sysctl_tcp_fwmark_accept,
882 		.maxlen		= sizeof(u8),
883 		.mode		= 0644,
884 		.proc_handler	= proc_dou8vec_minmax,
885 	},
886 #ifdef CONFIG_NET_L3_MASTER_DEV
887 	{
888 		.procname	= "tcp_l3mdev_accept",
889 		.data		= &init_net.ipv4.sysctl_tcp_l3mdev_accept,
890 		.maxlen		= sizeof(u8),
891 		.mode		= 0644,
892 		.proc_handler	= proc_dou8vec_minmax,
893 		.extra1		= SYSCTL_ZERO,
894 		.extra2		= SYSCTL_ONE,
895 	},
896 #endif
897 	{
898 		.procname	= "tcp_mtu_probing",
899 		.data		= &init_net.ipv4.sysctl_tcp_mtu_probing,
900 		.maxlen		= sizeof(u8),
901 		.mode		= 0644,
902 		.proc_handler	= proc_dou8vec_minmax,
903 	},
904 	{
905 		.procname	= "tcp_base_mss",
906 		.data		= &init_net.ipv4.sysctl_tcp_base_mss,
907 		.maxlen		= sizeof(int),
908 		.mode		= 0644,
909 		.proc_handler	= proc_dointvec,
910 	},
911 	{
912 		.procname	= "tcp_min_snd_mss",
913 		.data		= &init_net.ipv4.sysctl_tcp_min_snd_mss,
914 		.maxlen		= sizeof(int),
915 		.mode		= 0644,
916 		.proc_handler	= proc_dointvec_minmax,
917 		.extra1		= &tcp_min_snd_mss_min,
918 		.extra2		= &tcp_min_snd_mss_max,
919 	},
920 	{
921 		.procname	= "tcp_mtu_probe_floor",
922 		.data		= &init_net.ipv4.sysctl_tcp_mtu_probe_floor,
923 		.maxlen		= sizeof(int),
924 		.mode		= 0644,
925 		.proc_handler	= proc_dointvec_minmax,
926 		.extra1		= &tcp_min_snd_mss_min,
927 		.extra2		= &tcp_min_snd_mss_max,
928 	},
929 	{
930 		.procname	= "tcp_probe_threshold",
931 		.data		= &init_net.ipv4.sysctl_tcp_probe_threshold,
932 		.maxlen		= sizeof(int),
933 		.mode		= 0644,
934 		.proc_handler	= proc_dointvec,
935 	},
936 	{
937 		.procname	= "tcp_probe_interval",
938 		.data		= &init_net.ipv4.sysctl_tcp_probe_interval,
939 		.maxlen		= sizeof(u32),
940 		.mode		= 0644,
941 		.proc_handler	= proc_douintvec_minmax,
942 		.extra2		= &u32_max_div_HZ,
943 	},
944 	{
945 		.procname	= "igmp_link_local_mcast_reports",
946 		.data		= &init_net.ipv4.sysctl_igmp_llm_reports,
947 		.maxlen		= sizeof(u8),
948 		.mode		= 0644,
949 		.proc_handler	= proc_dou8vec_minmax,
950 	},
951 	{
952 		.procname	= "igmp_max_memberships",
953 		.data		= &init_net.ipv4.sysctl_igmp_max_memberships,
954 		.maxlen		= sizeof(int),
955 		.mode		= 0644,
956 		.proc_handler	= proc_dointvec
957 	},
958 	{
959 		.procname	= "igmp_max_msf",
960 		.data		= &init_net.ipv4.sysctl_igmp_max_msf,
961 		.maxlen		= sizeof(int),
962 		.mode		= 0644,
963 		.proc_handler	= proc_dointvec
964 	},
965 #ifdef CONFIG_IP_MULTICAST
966 	{
967 		.procname	= "igmp_qrv",
968 		.data		= &init_net.ipv4.sysctl_igmp_qrv,
969 		.maxlen		= sizeof(int),
970 		.mode		= 0644,
971 		.proc_handler	= proc_dointvec_minmax,
972 		.extra1		= SYSCTL_ONE
973 	},
974 #endif
975 	{
976 		.procname	= "tcp_congestion_control",
977 		.data		= &init_net.ipv4.tcp_congestion_control,
978 		.mode		= 0644,
979 		.maxlen		= TCP_CA_NAME_MAX,
980 		.proc_handler	= proc_tcp_congestion_control,
981 	},
982 	{
983 		.procname	= "tcp_available_congestion_control",
984 		.maxlen		= TCP_CA_BUF_MAX,
985 		.mode		= 0444,
986 		.proc_handler   = proc_tcp_available_congestion_control,
987 	},
988 	{
989 		.procname	= "tcp_allowed_congestion_control",
990 		.maxlen		= TCP_CA_BUF_MAX,
991 		.mode		= 0644,
992 		.proc_handler   = proc_allowed_congestion_control,
993 	},
994 	{
995 		.procname	= "tcp_keepalive_time",
996 		.data		= &init_net.ipv4.sysctl_tcp_keepalive_time,
997 		.maxlen		= sizeof(int),
998 		.mode		= 0644,
999 		.proc_handler	= proc_dointvec_jiffies,
1000 	},
1001 	{
1002 		.procname	= "tcp_keepalive_probes",
1003 		.data		= &init_net.ipv4.sysctl_tcp_keepalive_probes,
1004 		.maxlen		= sizeof(u8),
1005 		.mode		= 0644,
1006 		.proc_handler	= proc_dou8vec_minmax,
1007 	},
1008 	{
1009 		.procname	= "tcp_keepalive_intvl",
1010 		.data		= &init_net.ipv4.sysctl_tcp_keepalive_intvl,
1011 		.maxlen		= sizeof(int),
1012 		.mode		= 0644,
1013 		.proc_handler	= proc_dointvec_jiffies,
1014 	},
1015 	{
1016 		.procname	= "tcp_syn_retries",
1017 		.data		= &init_net.ipv4.sysctl_tcp_syn_retries,
1018 		.maxlen		= sizeof(u8),
1019 		.mode		= 0644,
1020 		.proc_handler	= proc_dou8vec_minmax,
1021 		.extra1		= &tcp_syn_retries_min,
1022 		.extra2		= &tcp_syn_retries_max
1023 	},
1024 	{
1025 		.procname	= "tcp_synack_retries",
1026 		.data		= &init_net.ipv4.sysctl_tcp_synack_retries,
1027 		.maxlen		= sizeof(u8),
1028 		.mode		= 0644,
1029 		.proc_handler	= proc_dou8vec_minmax,
1030 	},
1031 #ifdef CONFIG_SYN_COOKIES
1032 	{
1033 		.procname	= "tcp_syncookies",
1034 		.data		= &init_net.ipv4.sysctl_tcp_syncookies,
1035 		.maxlen		= sizeof(u8),
1036 		.mode		= 0644,
1037 		.proc_handler	= proc_dou8vec_minmax,
1038 	},
1039 #endif
1040 	{
1041 		.procname	= "tcp_migrate_req",
1042 		.data		= &init_net.ipv4.sysctl_tcp_migrate_req,
1043 		.maxlen		= sizeof(u8),
1044 		.mode		= 0644,
1045 		.proc_handler	= proc_dou8vec_minmax,
1046 		.extra1		= SYSCTL_ZERO,
1047 		.extra2		= SYSCTL_ONE
1048 	},
1049 	{
1050 		.procname	= "tcp_reordering",
1051 		.data		= &init_net.ipv4.sysctl_tcp_reordering,
1052 		.maxlen		= sizeof(int),
1053 		.mode		= 0644,
1054 		.proc_handler	= proc_dointvec
1055 	},
1056 	{
1057 		.procname	= "tcp_retries1",
1058 		.data		= &init_net.ipv4.sysctl_tcp_retries1,
1059 		.maxlen		= sizeof(u8),
1060 		.mode		= 0644,
1061 		.proc_handler	= proc_dou8vec_minmax,
1062 		.extra2		= &tcp_retr1_max
1063 	},
1064 	{
1065 		.procname	= "tcp_retries2",
1066 		.data		= &init_net.ipv4.sysctl_tcp_retries2,
1067 		.maxlen		= sizeof(u8),
1068 		.mode		= 0644,
1069 		.proc_handler	= proc_dou8vec_minmax,
1070 	},
1071 	{
1072 		.procname	= "tcp_orphan_retries",
1073 		.data		= &init_net.ipv4.sysctl_tcp_orphan_retries,
1074 		.maxlen		= sizeof(u8),
1075 		.mode		= 0644,
1076 		.proc_handler	= proc_dou8vec_minmax,
1077 	},
1078 	{
1079 		.procname	= "tcp_fin_timeout",
1080 		.data		= &init_net.ipv4.sysctl_tcp_fin_timeout,
1081 		.maxlen		= sizeof(int),
1082 		.mode		= 0644,
1083 		.proc_handler	= proc_dointvec_jiffies,
1084 	},
1085 	{
1086 		.procname	= "tcp_notsent_lowat",
1087 		.data		= &init_net.ipv4.sysctl_tcp_notsent_lowat,
1088 		.maxlen		= sizeof(unsigned int),
1089 		.mode		= 0644,
1090 		.proc_handler	= proc_douintvec,
1091 	},
1092 	{
1093 		.procname	= "tcp_tw_reuse",
1094 		.data		= &init_net.ipv4.sysctl_tcp_tw_reuse,
1095 		.maxlen		= sizeof(u8),
1096 		.mode		= 0644,
1097 		.proc_handler	= proc_dou8vec_minmax,
1098 		.extra1		= SYSCTL_ZERO,
1099 		.extra2		= SYSCTL_TWO,
1100 	},
1101 	{
1102 		.procname	= "tcp_tw_reuse_delay",
1103 		.data		= &init_net.ipv4.sysctl_tcp_tw_reuse_delay,
1104 		.maxlen		= sizeof(unsigned int),
1105 		.mode		= 0644,
1106 		.proc_handler	= proc_douintvec_minmax,
1107 		.extra1		= SYSCTL_ONE,
1108 		.extra2		= &tcp_tw_reuse_delay_max,
1109 	},
1110 	{
1111 		.procname	= "tcp_max_syn_backlog",
1112 		.data		= &init_net.ipv4.sysctl_max_syn_backlog,
1113 		.maxlen		= sizeof(int),
1114 		.mode		= 0644,
1115 		.proc_handler	= proc_dointvec
1116 	},
1117 	{
1118 		.procname	= "tcp_fastopen",
1119 		.data		= &init_net.ipv4.sysctl_tcp_fastopen,
1120 		.maxlen		= sizeof(int),
1121 		.mode		= 0644,
1122 		.proc_handler	= proc_dointvec,
1123 	},
1124 	{
1125 		.procname	= "tcp_fastopen_key",
1126 		.mode		= 0600,
1127 		.data		= &init_net.ipv4.sysctl_tcp_fastopen,
1128 		/* maxlen to print the list of keys in hex (*2), with dashes
1129 		 * separating doublewords and a comma in between keys.
1130 		 */
1131 		.maxlen		= ((TCP_FASTOPEN_KEY_LENGTH *
1132 				   2 * TCP_FASTOPEN_KEY_MAX) +
1133 				   (TCP_FASTOPEN_KEY_MAX * 5)),
1134 		.proc_handler	= proc_tcp_fastopen_key,
1135 	},
1136 	{
1137 		.procname	= "tcp_fastopen_blackhole_timeout_sec",
1138 		.data		= &init_net.ipv4.sysctl_tcp_fastopen_blackhole_timeout,
1139 		.maxlen		= sizeof(int),
1140 		.mode		= 0644,
1141 		.proc_handler	= proc_tfo_blackhole_detect_timeout,
1142 		.extra1		= SYSCTL_ZERO,
1143 	},
1144 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1145 	{
1146 		.procname	= "fib_multipath_use_neigh",
1147 		.data		= &init_net.ipv4.sysctl_fib_multipath_use_neigh,
1148 		.maxlen		= sizeof(u8),
1149 		.mode		= 0644,
1150 		.proc_handler	= proc_dou8vec_minmax,
1151 		.extra1		= SYSCTL_ZERO,
1152 		.extra2		= SYSCTL_ONE,
1153 	},
1154 	{
1155 		.procname	= "fib_multipath_hash_policy",
1156 		.data		= &init_net.ipv4.sysctl_fib_multipath_hash_policy,
1157 		.maxlen		= sizeof(u8),
1158 		.mode		= 0644,
1159 		.proc_handler	= proc_fib_multipath_hash_policy,
1160 		.extra1		= SYSCTL_ZERO,
1161 		.extra2		= SYSCTL_THREE,
1162 	},
1163 	{
1164 		.procname	= "fib_multipath_hash_fields",
1165 		.data		= &init_net.ipv4.sysctl_fib_multipath_hash_fields,
1166 		.maxlen		= sizeof(u32),
1167 		.mode		= 0644,
1168 		.proc_handler	= proc_fib_multipath_hash_fields,
1169 		.extra1		= SYSCTL_ONE,
1170 		.extra2		= &fib_multipath_hash_fields_all_mask,
1171 	},
1172 	{
1173 		.procname	= "fib_multipath_hash_seed",
1174 		.data		= &init_net,
1175 		.maxlen		= sizeof(u32),
1176 		.mode		= 0644,
1177 		.proc_handler	= proc_fib_multipath_hash_seed,
1178 	},
1179 #endif
1180 	{
1181 		.procname	= "ip_unprivileged_port_start",
1182 		.maxlen		= sizeof(int),
1183 		.data		= &init_net.ipv4.sysctl_ip_prot_sock,
1184 		.mode		= 0644,
1185 		.proc_handler	= ipv4_privileged_ports,
1186 	},
1187 #ifdef CONFIG_NET_L3_MASTER_DEV
1188 	{
1189 		.procname	= "udp_l3mdev_accept",
1190 		.data		= &init_net.ipv4.sysctl_udp_l3mdev_accept,
1191 		.maxlen		= sizeof(u8),
1192 		.mode		= 0644,
1193 		.proc_handler	= proc_dou8vec_minmax,
1194 		.extra1		= SYSCTL_ZERO,
1195 		.extra2		= SYSCTL_ONE,
1196 	},
1197 #endif
1198 	{
1199 		.procname	= "tcp_sack",
1200 		.data		= &init_net.ipv4.sysctl_tcp_sack,
1201 		.maxlen		= sizeof(u8),
1202 		.mode		= 0644,
1203 		.proc_handler	= proc_dou8vec_minmax,
1204 	},
1205 	{
1206 		.procname	= "tcp_window_scaling",
1207 		.data		= &init_net.ipv4.sysctl_tcp_window_scaling,
1208 		.maxlen		= sizeof(u8),
1209 		.mode		= 0644,
1210 		.proc_handler	= proc_dou8vec_minmax,
1211 	},
1212 	{
1213 		.procname	= "tcp_timestamps",
1214 		.data		= &init_net.ipv4.sysctl_tcp_timestamps,
1215 		.maxlen		= sizeof(u8),
1216 		.mode		= 0644,
1217 		.proc_handler	= proc_dou8vec_minmax,
1218 	},
1219 	{
1220 		.procname	= "tcp_early_retrans",
1221 		.data		= &init_net.ipv4.sysctl_tcp_early_retrans,
1222 		.maxlen		= sizeof(u8),
1223 		.mode		= 0644,
1224 		.proc_handler	= proc_dou8vec_minmax,
1225 		.extra1		= SYSCTL_ZERO,
1226 		.extra2		= SYSCTL_FOUR,
1227 	},
1228 	{
1229 		.procname	= "tcp_recovery",
1230 		.data		= &init_net.ipv4.sysctl_tcp_recovery,
1231 		.maxlen		= sizeof(u8),
1232 		.mode		= 0644,
1233 		.proc_handler	= proc_dou8vec_minmax,
1234 	},
1235 	{
1236 		.procname       = "tcp_thin_linear_timeouts",
1237 		.data           = &init_net.ipv4.sysctl_tcp_thin_linear_timeouts,
1238 		.maxlen         = sizeof(u8),
1239 		.mode           = 0644,
1240 		.proc_handler   = proc_dou8vec_minmax,
1241 	},
1242 	{
1243 		.procname	= "tcp_slow_start_after_idle",
1244 		.data		= &init_net.ipv4.sysctl_tcp_slow_start_after_idle,
1245 		.maxlen		= sizeof(u8),
1246 		.mode		= 0644,
1247 		.proc_handler	= proc_dou8vec_minmax,
1248 	},
1249 	{
1250 		.procname	= "tcp_retrans_collapse",
1251 		.data		= &init_net.ipv4.sysctl_tcp_retrans_collapse,
1252 		.maxlen		= sizeof(u8),
1253 		.mode		= 0644,
1254 		.proc_handler	= proc_dou8vec_minmax,
1255 	},
1256 	{
1257 		.procname	= "tcp_stdurg",
1258 		.data		= &init_net.ipv4.sysctl_tcp_stdurg,
1259 		.maxlen		= sizeof(u8),
1260 		.mode		= 0644,
1261 		.proc_handler	= proc_dou8vec_minmax,
1262 	},
1263 	{
1264 		.procname	= "tcp_rfc1337",
1265 		.data		= &init_net.ipv4.sysctl_tcp_rfc1337,
1266 		.maxlen		= sizeof(u8),
1267 		.mode		= 0644,
1268 		.proc_handler	= proc_dou8vec_minmax,
1269 	},
1270 	{
1271 		.procname	= "tcp_abort_on_overflow",
1272 		.data		= &init_net.ipv4.sysctl_tcp_abort_on_overflow,
1273 		.maxlen		= sizeof(u8),
1274 		.mode		= 0644,
1275 		.proc_handler	= proc_dou8vec_minmax,
1276 	},
1277 	{
1278 		.procname	= "tcp_fack",
1279 		.data		= &init_net.ipv4.sysctl_tcp_fack,
1280 		.maxlen		= sizeof(u8),
1281 		.mode		= 0644,
1282 		.proc_handler	= proc_dou8vec_minmax,
1283 	},
1284 	{
1285 		.procname	= "tcp_max_reordering",
1286 		.data		= &init_net.ipv4.sysctl_tcp_max_reordering,
1287 		.maxlen		= sizeof(int),
1288 		.mode		= 0644,
1289 		.proc_handler	= proc_dointvec
1290 	},
1291 	{
1292 		.procname	= "tcp_dsack",
1293 		.data		= &init_net.ipv4.sysctl_tcp_dsack,
1294 		.maxlen		= sizeof(u8),
1295 		.mode		= 0644,
1296 		.proc_handler	= proc_dou8vec_minmax,
1297 	},
1298 	{
1299 		.procname	= "tcp_app_win",
1300 		.data		= &init_net.ipv4.sysctl_tcp_app_win,
1301 		.maxlen		= sizeof(u8),
1302 		.mode		= 0644,
1303 		.proc_handler	= proc_dou8vec_minmax,
1304 		.extra1		= SYSCTL_ZERO,
1305 		.extra2		= &tcp_app_win_max,
1306 	},
1307 	{
1308 		.procname	= "tcp_adv_win_scale",
1309 		.data		= &init_net.ipv4.sysctl_tcp_adv_win_scale,
1310 		.maxlen		= sizeof(int),
1311 		.mode		= 0644,
1312 		.proc_handler	= proc_dointvec_minmax,
1313 		.extra1		= &tcp_adv_win_scale_min,
1314 		.extra2		= &tcp_adv_win_scale_max,
1315 	},
1316 	{
1317 		.procname	= "tcp_frto",
1318 		.data		= &init_net.ipv4.sysctl_tcp_frto,
1319 		.maxlen		= sizeof(u8),
1320 		.mode		= 0644,
1321 		.proc_handler	= proc_dou8vec_minmax,
1322 	},
1323 	{
1324 		.procname	= "tcp_no_metrics_save",
1325 		.data		= &init_net.ipv4.sysctl_tcp_nometrics_save,
1326 		.maxlen		= sizeof(u8),
1327 		.mode		= 0644,
1328 		.proc_handler	= proc_dou8vec_minmax,
1329 	},
1330 	{
1331 		.procname	= "tcp_no_ssthresh_metrics_save",
1332 		.data		= &init_net.ipv4.sysctl_tcp_no_ssthresh_metrics_save,
1333 		.maxlen		= sizeof(u8),
1334 		.mode		= 0644,
1335 		.proc_handler	= proc_dou8vec_minmax,
1336 		.extra1		= SYSCTL_ZERO,
1337 		.extra2		= SYSCTL_ONE,
1338 	},
1339 	{
1340 		.procname	= "tcp_moderate_rcvbuf",
1341 		.data		= &init_net.ipv4.sysctl_tcp_moderate_rcvbuf,
1342 		.maxlen		= sizeof(u8),
1343 		.mode		= 0644,
1344 		.proc_handler	= proc_dou8vec_minmax,
1345 	},
1346 	{
1347 		.procname	= "tcp_rcvbuf_low_rtt",
1348 		.data		= &init_net.ipv4.sysctl_tcp_rcvbuf_low_rtt,
1349 		.maxlen		= sizeof(int),
1350 		.mode		= 0644,
1351 		.proc_handler	= proc_dointvec_minmax,
1352 		.extra1		= SYSCTL_ZERO,
1353 		.extra2		= SYSCTL_INT_MAX,
1354 	},
1355 	{
1356 		.procname	= "tcp_tso_win_divisor",
1357 		.data		= &init_net.ipv4.sysctl_tcp_tso_win_divisor,
1358 		.maxlen		= sizeof(u8),
1359 		.mode		= 0644,
1360 		.proc_handler	= proc_dou8vec_minmax,
1361 	},
1362 	{
1363 		.procname	= "tcp_workaround_signed_windows",
1364 		.data		= &init_net.ipv4.sysctl_tcp_workaround_signed_windows,
1365 		.maxlen		= sizeof(u8),
1366 		.mode		= 0644,
1367 		.proc_handler	= proc_dou8vec_minmax,
1368 	},
1369 	{
1370 		.procname	= "tcp_limit_output_bytes",
1371 		.data		= &init_net.ipv4.sysctl_tcp_limit_output_bytes,
1372 		.maxlen		= sizeof(int),
1373 		.mode		= 0644,
1374 		.proc_handler	= proc_dointvec
1375 	},
1376 	{
1377 		.procname	= "tcp_challenge_ack_limit",
1378 		.data		= &init_net.ipv4.sysctl_tcp_challenge_ack_limit,
1379 		.maxlen		= sizeof(int),
1380 		.mode		= 0644,
1381 		.proc_handler	= proc_dointvec
1382 	},
1383 	{
1384 		.procname	= "tcp_min_tso_segs",
1385 		.data		= &init_net.ipv4.sysctl_tcp_min_tso_segs,
1386 		.maxlen		= sizeof(u8),
1387 		.mode		= 0644,
1388 		.proc_handler	= proc_dou8vec_minmax,
1389 		.extra1		= SYSCTL_ONE,
1390 	},
1391 	{
1392 		.procname	= "tcp_tso_rtt_log",
1393 		.data		= &init_net.ipv4.sysctl_tcp_tso_rtt_log,
1394 		.maxlen		= sizeof(u8),
1395 		.mode		= 0644,
1396 		.proc_handler	= proc_dou8vec_minmax,
1397 	},
1398 	{
1399 		.procname	= "tcp_min_rtt_wlen",
1400 		.data		= &init_net.ipv4.sysctl_tcp_min_rtt_wlen,
1401 		.maxlen		= sizeof(int),
1402 		.mode		= 0644,
1403 		.proc_handler	= proc_dointvec_minmax,
1404 		.extra1		= SYSCTL_ZERO,
1405 		.extra2		= &one_day_secs
1406 	},
1407 	{
1408 		.procname	= "tcp_autocorking",
1409 		.data		= &init_net.ipv4.sysctl_tcp_autocorking,
1410 		.maxlen		= sizeof(u8),
1411 		.mode		= 0644,
1412 		.proc_handler	= proc_dou8vec_minmax,
1413 		.extra1		= SYSCTL_ZERO,
1414 		.extra2		= SYSCTL_ONE,
1415 	},
1416 	{
1417 		.procname	= "tcp_invalid_ratelimit",
1418 		.data		= &init_net.ipv4.sysctl_tcp_invalid_ratelimit,
1419 		.maxlen		= sizeof(int),
1420 		.mode		= 0644,
1421 		.proc_handler	= proc_dointvec_ms_jiffies,
1422 	},
1423 	{
1424 		.procname	= "tcp_pacing_ss_ratio",
1425 		.data		= &init_net.ipv4.sysctl_tcp_pacing_ss_ratio,
1426 		.maxlen		= sizeof(int),
1427 		.mode		= 0644,
1428 		.proc_handler	= proc_dointvec_minmax,
1429 		.extra1		= SYSCTL_ZERO,
1430 		.extra2		= SYSCTL_ONE_THOUSAND,
1431 	},
1432 	{
1433 		.procname	= "tcp_pacing_ca_ratio",
1434 		.data		= &init_net.ipv4.sysctl_tcp_pacing_ca_ratio,
1435 		.maxlen		= sizeof(int),
1436 		.mode		= 0644,
1437 		.proc_handler	= proc_dointvec_minmax,
1438 		.extra1		= SYSCTL_ZERO,
1439 		.extra2		= SYSCTL_ONE_THOUSAND,
1440 	},
1441 	{
1442 		.procname	= "tcp_wmem",
1443 		.data		= &init_net.ipv4.sysctl_tcp_wmem,
1444 		.maxlen		= sizeof(init_net.ipv4.sysctl_tcp_wmem),
1445 		.mode		= 0644,
1446 		.proc_handler	= proc_dointvec_minmax,
1447 		.extra1		= SYSCTL_ONE,
1448 	},
1449 	{
1450 		.procname	= "tcp_rmem",
1451 		.data		= &init_net.ipv4.sysctl_tcp_rmem,
1452 		.maxlen		= sizeof(init_net.ipv4.sysctl_tcp_rmem),
1453 		.mode		= 0644,
1454 		.proc_handler	= proc_dointvec_minmax,
1455 		.extra1		= SYSCTL_ONE,
1456 	},
1457 	{
1458 		.procname	= "tcp_comp_sack_delay_ns",
1459 		.data		= &init_net.ipv4.sysctl_tcp_comp_sack_delay_ns,
1460 		.maxlen		= sizeof(unsigned long),
1461 		.mode		= 0644,
1462 		.proc_handler	= proc_doulongvec_minmax,
1463 	},
1464 	{
1465 		.procname	= "tcp_comp_sack_rtt_percent",
1466 		.data		= &init_net.ipv4.sysctl_tcp_comp_sack_rtt_percent,
1467 		.maxlen		= sizeof(int),
1468 		.mode		= 0644,
1469 		.proc_handler	= proc_dointvec_minmax,
1470 		.extra1		= SYSCTL_ONE,
1471 		.extra2		= SYSCTL_ONE_THOUSAND,
1472 	},
1473 	{
1474 		.procname	= "tcp_comp_sack_slack_ns",
1475 		.data		= &init_net.ipv4.sysctl_tcp_comp_sack_slack_ns,
1476 		.maxlen		= sizeof(unsigned long),
1477 		.mode		= 0644,
1478 		.proc_handler	= proc_doulongvec_minmax,
1479 	},
1480 	{
1481 		.procname	= "tcp_comp_sack_nr",
1482 		.data		= &init_net.ipv4.sysctl_tcp_comp_sack_nr,
1483 		.maxlen		= sizeof(u8),
1484 		.mode		= 0644,
1485 		.proc_handler	= proc_dou8vec_minmax,
1486 		.extra1		= SYSCTL_ZERO,
1487 	},
1488 	{
1489 		.procname	= "tcp_backlog_ack_defer",
1490 		.data		= &init_net.ipv4.sysctl_tcp_backlog_ack_defer,
1491 		.maxlen		= sizeof(u8),
1492 		.mode		= 0644,
1493 		.proc_handler	= proc_dou8vec_minmax,
1494 		.extra1		= SYSCTL_ZERO,
1495 		.extra2		= SYSCTL_ONE,
1496 	},
1497 	{
1498 		.procname       = "tcp_reflect_tos",
1499 		.data           = &init_net.ipv4.sysctl_tcp_reflect_tos,
1500 		.maxlen         = sizeof(u8),
1501 		.mode           = 0644,
1502 		.proc_handler   = proc_dou8vec_minmax,
1503 		.extra1         = SYSCTL_ZERO,
1504 		.extra2         = SYSCTL_ONE,
1505 	},
1506 	{
1507 		.procname	= "tcp_ehash_entries",
1508 		.data		= &init_net.ipv4.sysctl_tcp_child_ehash_entries,
1509 		.mode		= 0444,
1510 		.proc_handler	= proc_tcp_ehash_entries,
1511 	},
1512 	{
1513 		.procname	= "tcp_child_ehash_entries",
1514 		.data		= &init_net.ipv4.sysctl_tcp_child_ehash_entries,
1515 		.maxlen		= sizeof(unsigned int),
1516 		.mode		= 0644,
1517 		.proc_handler	= proc_douintvec_minmax,
1518 		.extra1		= SYSCTL_ZERO,
1519 		.extra2		= &tcp_child_ehash_entries_max,
1520 	},
1521 	{
1522 		.procname	= "udp_hash_entries",
1523 		.data		= &init_net.ipv4.sysctl_udp_child_hash_entries,
1524 		.mode		= 0444,
1525 		.proc_handler	= proc_udp_hash_entries,
1526 	},
1527 	{
1528 		.procname	= "udp_child_hash_entries",
1529 		.data		= &init_net.ipv4.sysctl_udp_child_hash_entries,
1530 		.maxlen		= sizeof(unsigned int),
1531 		.mode		= 0644,
1532 		.proc_handler	= proc_douintvec_minmax,
1533 		.extra1		= SYSCTL_ZERO,
1534 		.extra2		= &udp_child_hash_entries_max,
1535 	},
1536 	{
1537 		.procname	= "udp_rmem_min",
1538 		.data		= &init_net.ipv4.sysctl_udp_rmem_min,
1539 		.maxlen		= sizeof(init_net.ipv4.sysctl_udp_rmem_min),
1540 		.mode		= 0644,
1541 		.proc_handler	= proc_dointvec_minmax,
1542 		.extra1		= SYSCTL_ONE
1543 	},
1544 	{
1545 		.procname	= "udp_wmem_min",
1546 		.data		= &init_net.ipv4.sysctl_udp_wmem_min,
1547 		.maxlen		= sizeof(init_net.ipv4.sysctl_udp_wmem_min),
1548 		.mode		= 0644,
1549 		.proc_handler	= proc_dointvec_minmax,
1550 		.extra1		= SYSCTL_ONE
1551 	},
1552 	{
1553 		.procname	= "fib_notify_on_flag_change",
1554 		.data		= &init_net.ipv4.sysctl_fib_notify_on_flag_change,
1555 		.maxlen		= sizeof(u8),
1556 		.mode		= 0644,
1557 		.proc_handler	= proc_dou8vec_minmax,
1558 		.extra1		= SYSCTL_ZERO,
1559 		.extra2		= SYSCTL_TWO,
1560 	},
1561 	{
1562 		.procname       = "tcp_plb_enabled",
1563 		.data           = &init_net.ipv4.sysctl_tcp_plb_enabled,
1564 		.maxlen         = sizeof(u8),
1565 		.mode           = 0644,
1566 		.proc_handler   = proc_dou8vec_minmax,
1567 		.extra1         = SYSCTL_ZERO,
1568 		.extra2         = SYSCTL_ONE,
1569 	},
1570 	{
1571 		.procname       = "tcp_plb_idle_rehash_rounds",
1572 		.data           = &init_net.ipv4.sysctl_tcp_plb_idle_rehash_rounds,
1573 		.maxlen         = sizeof(u8),
1574 		.mode           = 0644,
1575 		.proc_handler   = proc_dou8vec_minmax,
1576 		.extra2		= &tcp_plb_max_rounds,
1577 	},
1578 	{
1579 		.procname       = "tcp_plb_rehash_rounds",
1580 		.data           = &init_net.ipv4.sysctl_tcp_plb_rehash_rounds,
1581 		.maxlen         = sizeof(u8),
1582 		.mode           = 0644,
1583 		.proc_handler   = proc_dou8vec_minmax,
1584 		.extra2         = &tcp_plb_max_rounds,
1585 	},
1586 	{
1587 		.procname       = "tcp_plb_suspend_rto_sec",
1588 		.data           = &init_net.ipv4.sysctl_tcp_plb_suspend_rto_sec,
1589 		.maxlen         = sizeof(u8),
1590 		.mode           = 0644,
1591 		.proc_handler   = proc_dou8vec_minmax,
1592 	},
1593 	{
1594 		.procname       = "tcp_plb_cong_thresh",
1595 		.data           = &init_net.ipv4.sysctl_tcp_plb_cong_thresh,
1596 		.maxlen         = sizeof(int),
1597 		.mode           = 0644,
1598 		.proc_handler   = proc_dointvec_minmax,
1599 		.extra1         = SYSCTL_ZERO,
1600 		.extra2         = &tcp_plb_max_cong_thresh,
1601 	},
1602 	{
1603 		.procname	= "tcp_syn_linear_timeouts",
1604 		.data		= &init_net.ipv4.sysctl_tcp_syn_linear_timeouts,
1605 		.maxlen		= sizeof(u8),
1606 		.mode		= 0644,
1607 		.proc_handler	= proc_dou8vec_minmax,
1608 		.extra1		= SYSCTL_ZERO,
1609 		.extra2		= &tcp_syn_linear_timeouts_max,
1610 	},
1611 	{
1612 		.procname	= "tcp_shrink_window",
1613 		.data		= &init_net.ipv4.sysctl_tcp_shrink_window,
1614 		.maxlen		= sizeof(u8),
1615 		.mode		= 0644,
1616 		.proc_handler	= proc_dou8vec_minmax,
1617 		.extra1		= SYSCTL_ZERO,
1618 		.extra2		= SYSCTL_ONE,
1619 	},
1620 	{
1621 		.procname	= "tcp_pingpong_thresh",
1622 		.data		= &init_net.ipv4.sysctl_tcp_pingpong_thresh,
1623 		.maxlen		= sizeof(u8),
1624 		.mode		= 0644,
1625 		.proc_handler	= proc_dou8vec_minmax,
1626 		.extra1		= SYSCTL_ONE,
1627 	},
1628 	{
1629 		.procname	= "tcp_rto_min_us",
1630 		.data		= &init_net.ipv4.sysctl_tcp_rto_min_us,
1631 		.maxlen		= sizeof(int),
1632 		.mode		= 0644,
1633 		.proc_handler	= proc_dointvec_minmax,
1634 		.extra1		= SYSCTL_ONE,
1635 	},
1636 	{
1637 		.procname	= "tcp_rto_max_ms",
1638 		.data		= &init_net.ipv4.sysctl_tcp_rto_max_ms,
1639 		.maxlen		= sizeof(int),
1640 		.mode		= 0644,
1641 		.proc_handler	= proc_dointvec_minmax,
1642 		.extra1		= SYSCTL_ONE_THOUSAND,
1643 		.extra2		= &tcp_rto_max_max,
1644 	},
1645 };
1646 
1647 static __net_init int ipv4_sysctl_init_net(struct net *net)
1648 {
1649 	size_t table_size = ARRAY_SIZE(ipv4_net_table);
1650 	struct ctl_table *table;
1651 
1652 	table = ipv4_net_table;
1653 	if (!net_eq(net, &init_net)) {
1654 		int i;
1655 
1656 		table = kmemdup(table, sizeof(ipv4_net_table), GFP_KERNEL);
1657 		if (!table)
1658 			goto err_alloc;
1659 
1660 		for (i = 0; i < table_size; i++) {
1661 			if (table[i].data) {
1662 				/* Update the variables to point into
1663 				 * the current struct net
1664 				 */
1665 				table[i].data += (void *)net - (void *)&init_net;
1666 			} else {
1667 				/* Entries without data pointer are global;
1668 				 * Make them read-only in non-init_net ns
1669 				 */
1670 				table[i].mode &= ~0222;
1671 			}
1672 		}
1673 	}
1674 
1675 	net->ipv4.ipv4_hdr = register_net_sysctl_sz(net, "net/ipv4", table,
1676 						    table_size);
1677 	if (!net->ipv4.ipv4_hdr)
1678 		goto err_reg;
1679 
1680 	net->ipv4.sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
1681 	if (!net->ipv4.sysctl_local_reserved_ports)
1682 		goto err_ports;
1683 
1684 	proc_fib_multipath_hash_set_seed(net, 0);
1685 
1686 	return 0;
1687 
1688 err_ports:
1689 	unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
1690 err_reg:
1691 	if (!net_eq(net, &init_net))
1692 		kfree(table);
1693 err_alloc:
1694 	return -ENOMEM;
1695 }
1696 
1697 static __net_exit void ipv4_sysctl_exit_net(struct net *net)
1698 {
1699 	const struct ctl_table *table;
1700 
1701 	kfree(net->ipv4.sysctl_local_reserved_ports);
1702 	table = net->ipv4.ipv4_hdr->ctl_table_arg;
1703 	unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
1704 	kfree(table);
1705 }
1706 
1707 static __net_initdata struct pernet_operations ipv4_sysctl_ops = {
1708 	.init = ipv4_sysctl_init_net,
1709 	.exit = ipv4_sysctl_exit_net,
1710 };
1711 
1712 static __init int sysctl_ipv4_init(void)
1713 {
1714 	struct ctl_table_header *hdr;
1715 
1716 	hdr = register_net_sysctl(&init_net, "net/ipv4", ipv4_table);
1717 	if (!hdr)
1718 		return -ENOMEM;
1719 
1720 	proc_fib_multipath_hash_init_rand_seed();
1721 
1722 	if (register_pernet_subsys(&ipv4_sysctl_ops)) {
1723 		unregister_net_sysctl_table(hdr);
1724 		return -ENOMEM;
1725 	}
1726 
1727 	return 0;
1728 }
1729 
1730 __initcall(sysctl_ipv4_init);
1731