xref: /linux/net/ipv4/sysctl_net_ipv4.c (revision 1a9239bb4253f9076b5b4b2a1a4e8d7defd77a95)
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 
51 /* obsolete */
52 static int sysctl_tcp_low_latency __read_mostly;
53 
54 /* Update system visible IP port range */
set_local_port_range(struct net * net,unsigned int low,unsigned int high)55 static void set_local_port_range(struct net *net, unsigned int low, unsigned int high)
56 {
57 	bool same_parity = !((low ^ high) & 1);
58 
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 	WRITE_ONCE(net->ipv4.ip_local_ports.range, high << 16 | low);
64 }
65 
66 /* Validate changes from /proc interface. */
ipv4_local_port_range(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)67 static int ipv4_local_port_range(const struct ctl_table *table, int write,
68 				 void *buffer, size_t *lenp, loff_t *ppos)
69 {
70 	struct net *net = table->data;
71 	int ret;
72 	int range[2];
73 	struct ctl_table tmp = {
74 		.data = &range,
75 		.maxlen = sizeof(range),
76 		.mode = table->mode,
77 		.extra1 = &ip_local_port_range_min,
78 		.extra2 = &ip_local_port_range_max,
79 	};
80 
81 	inet_get_local_port_range(net, &range[0], &range[1]);
82 
83 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
84 
85 	if (write && ret == 0) {
86 		/* Ensure that the upper limit is not smaller than the lower,
87 		 * and that the lower does not encroach upon the privileged
88 		 * port limit.
89 		 */
90 		if ((range[1] < range[0]) ||
91 		    (range[0] < READ_ONCE(net->ipv4.sysctl_ip_prot_sock)))
92 			ret = -EINVAL;
93 		else
94 			set_local_port_range(net, range[0], range[1]);
95 	}
96 
97 	return ret;
98 }
99 
100 /* Validate changes from /proc interface. */
ipv4_privileged_ports(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)101 static int ipv4_privileged_ports(const struct ctl_table *table, int write,
102 				void *buffer, size_t *lenp, loff_t *ppos)
103 {
104 	struct net *net = container_of(table->data, struct net,
105 	    ipv4.sysctl_ip_prot_sock);
106 	int ret;
107 	int pports;
108 	int range[2];
109 	struct ctl_table tmp = {
110 		.data = &pports,
111 		.maxlen = sizeof(pports),
112 		.mode = table->mode,
113 		.extra1 = &ip_privileged_port_min,
114 		.extra2 = &ip_privileged_port_max,
115 	};
116 
117 	pports = READ_ONCE(net->ipv4.sysctl_ip_prot_sock);
118 
119 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
120 
121 	if (write && ret == 0) {
122 		inet_get_local_port_range(net, &range[0], &range[1]);
123 		/* Ensure that the local port range doesn't overlap with the
124 		 * privileged port range.
125 		 */
126 		if (range[0] < pports)
127 			ret = -EINVAL;
128 		else
129 			WRITE_ONCE(net->ipv4.sysctl_ip_prot_sock, pports);
130 	}
131 
132 	return ret;
133 }
134 
inet_get_ping_group_range_table(const struct ctl_table * table,kgid_t * low,kgid_t * high)135 static void inet_get_ping_group_range_table(const struct ctl_table *table,
136 					    kgid_t *low, kgid_t *high)
137 {
138 	kgid_t *data = table->data;
139 	struct net *net =
140 		container_of(table->data, struct net, ipv4.ping_group_range.range);
141 	unsigned int seq;
142 	do {
143 		seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
144 
145 		*low = data[0];
146 		*high = data[1];
147 	} while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
148 }
149 
150 /* Update system visible IP port range */
set_ping_group_range(const struct ctl_table * table,kgid_t low,kgid_t high)151 static void set_ping_group_range(const struct ctl_table *table,
152 				 kgid_t low, kgid_t high)
153 {
154 	kgid_t *data = table->data;
155 	struct net *net =
156 		container_of(table->data, struct net, ipv4.ping_group_range.range);
157 	write_seqlock(&net->ipv4.ping_group_range.lock);
158 	data[0] = low;
159 	data[1] = high;
160 	write_sequnlock(&net->ipv4.ping_group_range.lock);
161 }
162 
163 /* Validate changes from /proc interface. */
ipv4_ping_group_range(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)164 static int ipv4_ping_group_range(const struct ctl_table *table, int write,
165 				 void *buffer, size_t *lenp, loff_t *ppos)
166 {
167 	struct user_namespace *user_ns = current_user_ns();
168 	int ret;
169 	unsigned long urange[2];
170 	kgid_t low, high;
171 	struct ctl_table tmp = {
172 		.data = &urange,
173 		.maxlen = sizeof(urange),
174 		.mode = table->mode,
175 		.extra1 = &ip_ping_group_range_min,
176 		.extra2 = &ip_ping_group_range_max,
177 	};
178 
179 	inet_get_ping_group_range_table(table, &low, &high);
180 	urange[0] = from_kgid_munged(user_ns, low);
181 	urange[1] = from_kgid_munged(user_ns, high);
182 	ret = proc_doulongvec_minmax(&tmp, write, buffer, lenp, ppos);
183 
184 	if (write && ret == 0) {
185 		low = make_kgid(user_ns, urange[0]);
186 		high = make_kgid(user_ns, urange[1]);
187 		if (!gid_valid(low) || !gid_valid(high))
188 			return -EINVAL;
189 		if (urange[1] < urange[0] || gid_lt(high, low)) {
190 			low = make_kgid(&init_user_ns, 1);
191 			high = make_kgid(&init_user_ns, 0);
192 		}
193 		set_ping_group_range(table, low, high);
194 	}
195 
196 	return ret;
197 }
198 
ipv4_fwd_update_priority(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)199 static int ipv4_fwd_update_priority(const struct ctl_table *table, int write,
200 				    void *buffer, size_t *lenp, loff_t *ppos)
201 {
202 	struct net *net;
203 	int ret;
204 
205 	net = container_of(table->data, struct net,
206 			   ipv4.sysctl_ip_fwd_update_priority);
207 	ret = proc_dou8vec_minmax(table, write, buffer, lenp, ppos);
208 	if (write && ret == 0)
209 		call_netevent_notifiers(NETEVENT_IPV4_FWD_UPDATE_PRIORITY_UPDATE,
210 					net);
211 
212 	return ret;
213 }
214 
proc_tcp_congestion_control(const struct ctl_table * ctl,int write,void * buffer,size_t * lenp,loff_t * ppos)215 static int proc_tcp_congestion_control(const struct ctl_table *ctl, int write,
216 				       void *buffer, size_t *lenp, loff_t *ppos)
217 {
218 	struct net *net = container_of(ctl->data, struct net,
219 				       ipv4.tcp_congestion_control);
220 	char val[TCP_CA_NAME_MAX];
221 	struct ctl_table tbl = {
222 		.data = val,
223 		.maxlen = TCP_CA_NAME_MAX,
224 	};
225 	int ret;
226 
227 	tcp_get_default_congestion_control(net, val);
228 
229 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
230 	if (write && ret == 0)
231 		ret = tcp_set_default_congestion_control(net, val);
232 	return ret;
233 }
234 
proc_tcp_available_congestion_control(const struct ctl_table * ctl,int write,void * buffer,size_t * lenp,loff_t * ppos)235 static int proc_tcp_available_congestion_control(const struct ctl_table *ctl,
236 						 int write, void *buffer,
237 						 size_t *lenp, loff_t *ppos)
238 {
239 	struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX, };
240 	int ret;
241 
242 	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
243 	if (!tbl.data)
244 		return -ENOMEM;
245 	tcp_get_available_congestion_control(tbl.data, TCP_CA_BUF_MAX);
246 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
247 	kfree(tbl.data);
248 	return ret;
249 }
250 
proc_allowed_congestion_control(const struct ctl_table * ctl,int write,void * buffer,size_t * lenp,loff_t * ppos)251 static int proc_allowed_congestion_control(const struct ctl_table *ctl,
252 					   int write, void *buffer,
253 					   size_t *lenp, loff_t *ppos)
254 {
255 	struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX };
256 	int ret;
257 
258 	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
259 	if (!tbl.data)
260 		return -ENOMEM;
261 
262 	tcp_get_allowed_congestion_control(tbl.data, tbl.maxlen);
263 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
264 	if (write && ret == 0)
265 		ret = tcp_set_allowed_congestion_control(tbl.data);
266 	kfree(tbl.data);
267 	return ret;
268 }
269 
sscanf_key(char * buf,__le32 * key)270 static int sscanf_key(char *buf, __le32 *key)
271 {
272 	u32 user_key[4];
273 	int i, ret = 0;
274 
275 	if (sscanf(buf, "%x-%x-%x-%x", user_key, user_key + 1,
276 		   user_key + 2, user_key + 3) != 4) {
277 		ret = -EINVAL;
278 	} else {
279 		for (i = 0; i < ARRAY_SIZE(user_key); i++)
280 			key[i] = cpu_to_le32(user_key[i]);
281 	}
282 	pr_debug("proc TFO key set 0x%x-%x-%x-%x <- 0x%s: %u\n",
283 		 user_key[0], user_key[1], user_key[2], user_key[3], buf, ret);
284 
285 	return ret;
286 }
287 
proc_tcp_fastopen_key(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)288 static int proc_tcp_fastopen_key(const struct ctl_table *table, int write,
289 				 void *buffer, size_t *lenp, loff_t *ppos)
290 {
291 	struct net *net = container_of(table->data, struct net,
292 	    ipv4.sysctl_tcp_fastopen);
293 	/* maxlen to print the list of keys in hex (*2), with dashes
294 	 * separating doublewords and a comma in between keys.
295 	 */
296 	struct ctl_table tbl = { .maxlen = ((TCP_FASTOPEN_KEY_LENGTH *
297 					    2 * TCP_FASTOPEN_KEY_MAX) +
298 					    (TCP_FASTOPEN_KEY_MAX * 5)) };
299 	u32 user_key[TCP_FASTOPEN_KEY_BUF_LENGTH / sizeof(u32)];
300 	__le32 key[TCP_FASTOPEN_KEY_BUF_LENGTH / sizeof(__le32)];
301 	char *backup_data;
302 	int ret, i = 0, off = 0, n_keys;
303 
304 	tbl.data = kmalloc(tbl.maxlen, GFP_KERNEL);
305 	if (!tbl.data)
306 		return -ENOMEM;
307 
308 	n_keys = tcp_fastopen_get_cipher(net, NULL, (u64 *)key);
309 	if (!n_keys) {
310 		memset(&key[0], 0, TCP_FASTOPEN_KEY_LENGTH);
311 		n_keys = 1;
312 	}
313 
314 	for (i = 0; i < n_keys * 4; i++)
315 		user_key[i] = le32_to_cpu(key[i]);
316 
317 	for (i = 0; i < n_keys; i++) {
318 		off += snprintf(tbl.data + off, tbl.maxlen - off,
319 				"%08x-%08x-%08x-%08x",
320 				user_key[i * 4],
321 				user_key[i * 4 + 1],
322 				user_key[i * 4 + 2],
323 				user_key[i * 4 + 3]);
324 
325 		if (WARN_ON_ONCE(off >= tbl.maxlen - 1))
326 			break;
327 
328 		if (i + 1 < n_keys)
329 			off += snprintf(tbl.data + off, tbl.maxlen - off, ",");
330 	}
331 
332 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
333 
334 	if (write && ret == 0) {
335 		backup_data = strchr(tbl.data, ',');
336 		if (backup_data) {
337 			*backup_data = '\0';
338 			backup_data++;
339 		}
340 		if (sscanf_key(tbl.data, key)) {
341 			ret = -EINVAL;
342 			goto bad_key;
343 		}
344 		if (backup_data) {
345 			if (sscanf_key(backup_data, key + 4)) {
346 				ret = -EINVAL;
347 				goto bad_key;
348 			}
349 		}
350 		tcp_fastopen_reset_cipher(net, NULL, key,
351 					  backup_data ? key + 4 : NULL);
352 	}
353 
354 bad_key:
355 	kfree(tbl.data);
356 	return ret;
357 }
358 
proc_tfo_blackhole_detect_timeout(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)359 static int proc_tfo_blackhole_detect_timeout(const struct ctl_table *table,
360 					     int write, void *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 
proc_tcp_available_ulp(const struct ctl_table * ctl,int write,void * buffer,size_t * lenp,loff_t * ppos)374 static int proc_tcp_available_ulp(const struct ctl_table *ctl,
375 				  int write, void *buffer, size_t *lenp,
376 				  loff_t *ppos)
377 {
378 	struct ctl_table tbl = { .maxlen = TCP_ULP_BUF_MAX, };
379 	int ret;
380 
381 	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
382 	if (!tbl.data)
383 		return -ENOMEM;
384 	tcp_get_available_ulp(tbl.data, TCP_ULP_BUF_MAX);
385 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
386 	kfree(tbl.data);
387 
388 	return ret;
389 }
390 
proc_tcp_ehash_entries(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)391 static int proc_tcp_ehash_entries(const struct ctl_table *table, int write,
392 				  void *buffer, size_t *lenp, loff_t *ppos)
393 {
394 	struct net *net = container_of(table->data, struct net,
395 				       ipv4.sysctl_tcp_child_ehash_entries);
396 	struct inet_hashinfo *hinfo = net->ipv4.tcp_death_row.hashinfo;
397 	int tcp_ehash_entries;
398 	struct ctl_table tbl;
399 
400 	tcp_ehash_entries = hinfo->ehash_mask + 1;
401 
402 	/* A negative number indicates that the child netns
403 	 * shares the global ehash.
404 	 */
405 	if (!net_eq(net, &init_net) && !hinfo->pernet)
406 		tcp_ehash_entries *= -1;
407 
408 	memset(&tbl, 0, sizeof(tbl));
409 	tbl.data = &tcp_ehash_entries;
410 	tbl.maxlen = sizeof(int);
411 
412 	return proc_dointvec(&tbl, write, buffer, lenp, ppos);
413 }
414 
proc_udp_hash_entries(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)415 static int proc_udp_hash_entries(const struct ctl_table *table, int write,
416 				 void *buffer, size_t *lenp, loff_t *ppos)
417 {
418 	struct net *net = container_of(table->data, struct net,
419 				       ipv4.sysctl_udp_child_hash_entries);
420 	int udp_hash_entries;
421 	struct ctl_table tbl;
422 
423 	udp_hash_entries = net->ipv4.udp_table->mask + 1;
424 
425 	/* A negative number indicates that the child netns
426 	 * shares the global udp_table.
427 	 */
428 	if (!net_eq(net, &init_net) && net->ipv4.udp_table == &udp_table)
429 		udp_hash_entries *= -1;
430 
431 	memset(&tbl, 0, sizeof(tbl));
432 	tbl.data = &udp_hash_entries;
433 	tbl.maxlen = sizeof(int);
434 
435 	return proc_dointvec(&tbl, write, buffer, lenp, ppos);
436 }
437 
438 #ifdef CONFIG_IP_ROUTE_MULTIPATH
proc_fib_multipath_hash_policy(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)439 static int proc_fib_multipath_hash_policy(const struct ctl_table *table, int write,
440 					  void *buffer, size_t *lenp,
441 					  loff_t *ppos)
442 {
443 	struct net *net = container_of(table->data, struct net,
444 	    ipv4.sysctl_fib_multipath_hash_policy);
445 	int ret;
446 
447 	ret = proc_dou8vec_minmax(table, write, buffer, lenp, ppos);
448 	if (write && ret == 0)
449 		call_netevent_notifiers(NETEVENT_IPV4_MPATH_HASH_UPDATE, net);
450 
451 	return ret;
452 }
453 
proc_fib_multipath_hash_fields(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)454 static int proc_fib_multipath_hash_fields(const struct ctl_table *table, int write,
455 					  void *buffer, size_t *lenp,
456 					  loff_t *ppos)
457 {
458 	struct net *net;
459 	int ret;
460 
461 	net = container_of(table->data, struct net,
462 			   ipv4.sysctl_fib_multipath_hash_fields);
463 	ret = proc_douintvec_minmax(table, write, buffer, lenp, ppos);
464 	if (write && ret == 0)
465 		call_netevent_notifiers(NETEVENT_IPV4_MPATH_HASH_UPDATE, net);
466 
467 	return ret;
468 }
469 
470 static u32 proc_fib_multipath_hash_rand_seed __ro_after_init;
471 
proc_fib_multipath_hash_init_rand_seed(void)472 static void proc_fib_multipath_hash_init_rand_seed(void)
473 {
474 	get_random_bytes(&proc_fib_multipath_hash_rand_seed,
475 			 sizeof(proc_fib_multipath_hash_rand_seed));
476 }
477 
proc_fib_multipath_hash_set_seed(struct net * net,u32 user_seed)478 static void proc_fib_multipath_hash_set_seed(struct net *net, u32 user_seed)
479 {
480 	struct sysctl_fib_multipath_hash_seed new = {
481 		.user_seed = user_seed,
482 		.mp_seed = (user_seed ? user_seed :
483 			    proc_fib_multipath_hash_rand_seed),
484 	};
485 
486 	WRITE_ONCE(net->ipv4.sysctl_fib_multipath_hash_seed, new);
487 }
488 
proc_fib_multipath_hash_seed(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)489 static int proc_fib_multipath_hash_seed(const struct ctl_table *table, int write,
490 					void *buffer, size_t *lenp,
491 					loff_t *ppos)
492 {
493 	struct sysctl_fib_multipath_hash_seed *mphs;
494 	struct net *net = table->data;
495 	struct ctl_table tmp;
496 	u32 user_seed;
497 	int ret;
498 
499 	mphs = &net->ipv4.sysctl_fib_multipath_hash_seed;
500 	user_seed = mphs->user_seed;
501 
502 	tmp = *table;
503 	tmp.data = &user_seed;
504 
505 	ret = proc_douintvec_minmax(&tmp, write, buffer, lenp, ppos);
506 
507 	if (write && ret == 0) {
508 		proc_fib_multipath_hash_set_seed(net, user_seed);
509 		call_netevent_notifiers(NETEVENT_IPV4_MPATH_HASH_UPDATE, net);
510 	}
511 
512 	return ret;
513 }
514 #else
515 
proc_fib_multipath_hash_init_rand_seed(void)516 static void proc_fib_multipath_hash_init_rand_seed(void)
517 {
518 }
519 
proc_fib_multipath_hash_set_seed(struct net * net,u32 user_seed)520 static void proc_fib_multipath_hash_set_seed(struct net *net, u32 user_seed)
521 {
522 }
523 
524 #endif
525 
526 static struct ctl_table ipv4_table[] = {
527 	{
528 		.procname	= "tcp_max_orphans",
529 		.data		= &sysctl_tcp_max_orphans,
530 		.maxlen		= sizeof(int),
531 		.mode		= 0644,
532 		.proc_handler	= proc_dointvec
533 	},
534 	{
535 		.procname	= "inet_peer_threshold",
536 		.data		= &inet_peer_threshold,
537 		.maxlen		= sizeof(int),
538 		.mode		= 0644,
539 		.proc_handler	= proc_dointvec
540 	},
541 	{
542 		.procname	= "inet_peer_minttl",
543 		.data		= &inet_peer_minttl,
544 		.maxlen		= sizeof(int),
545 		.mode		= 0644,
546 		.proc_handler	= proc_dointvec_jiffies,
547 	},
548 	{
549 		.procname	= "inet_peer_maxttl",
550 		.data		= &inet_peer_maxttl,
551 		.maxlen		= sizeof(int),
552 		.mode		= 0644,
553 		.proc_handler	= proc_dointvec_jiffies,
554 	},
555 	{
556 		.procname	= "tcp_mem",
557 		.maxlen		= sizeof(sysctl_tcp_mem),
558 		.data		= &sysctl_tcp_mem,
559 		.mode		= 0644,
560 		.proc_handler	= proc_doulongvec_minmax,
561 	},
562 	{
563 		.procname	= "tcp_low_latency",
564 		.data		= &sysctl_tcp_low_latency,
565 		.maxlen		= sizeof(int),
566 		.mode		= 0644,
567 		.proc_handler	= proc_dointvec
568 	},
569 #ifdef CONFIG_NETLABEL
570 	{
571 		.procname	= "cipso_cache_enable",
572 		.data		= &cipso_v4_cache_enabled,
573 		.maxlen		= sizeof(int),
574 		.mode		= 0644,
575 		.proc_handler	= proc_dointvec,
576 	},
577 	{
578 		.procname	= "cipso_cache_bucket_size",
579 		.data		= &cipso_v4_cache_bucketsize,
580 		.maxlen		= sizeof(int),
581 		.mode		= 0644,
582 		.proc_handler	= proc_dointvec,
583 	},
584 	{
585 		.procname	= "cipso_rbm_optfmt",
586 		.data		= &cipso_v4_rbm_optfmt,
587 		.maxlen		= sizeof(int),
588 		.mode		= 0644,
589 		.proc_handler	= proc_dointvec,
590 	},
591 	{
592 		.procname	= "cipso_rbm_strictvalid",
593 		.data		= &cipso_v4_rbm_strictvalid,
594 		.maxlen		= sizeof(int),
595 		.mode		= 0644,
596 		.proc_handler	= proc_dointvec,
597 	},
598 #endif /* CONFIG_NETLABEL */
599 	{
600 		.procname	= "tcp_available_ulp",
601 		.maxlen		= TCP_ULP_BUF_MAX,
602 		.mode		= 0444,
603 		.proc_handler   = proc_tcp_available_ulp,
604 	},
605 	{
606 		.procname	= "udp_mem",
607 		.data		= &sysctl_udp_mem,
608 		.maxlen		= sizeof(sysctl_udp_mem),
609 		.mode		= 0644,
610 		.proc_handler	= proc_doulongvec_minmax,
611 	},
612 	{
613 		.procname	= "fib_sync_mem",
614 		.data		= &sysctl_fib_sync_mem,
615 		.maxlen		= sizeof(sysctl_fib_sync_mem),
616 		.mode		= 0644,
617 		.proc_handler	= proc_douintvec_minmax,
618 		.extra1		= &sysctl_fib_sync_mem_min,
619 		.extra2		= &sysctl_fib_sync_mem_max,
620 	},
621 };
622 
623 static struct ctl_table ipv4_net_table[] = {
624 	{
625 		.procname	= "tcp_max_tw_buckets",
626 		.data		= &init_net.ipv4.tcp_death_row.sysctl_max_tw_buckets,
627 		.maxlen		= sizeof(int),
628 		.mode		= 0644,
629 		.proc_handler	= proc_dointvec
630 	},
631 	{
632 		.procname	= "icmp_echo_ignore_all",
633 		.data		= &init_net.ipv4.sysctl_icmp_echo_ignore_all,
634 		.maxlen		= sizeof(u8),
635 		.mode		= 0644,
636 		.proc_handler	= proc_dou8vec_minmax,
637 		.extra1		= SYSCTL_ZERO,
638 		.extra2		= SYSCTL_ONE
639 	},
640 	{
641 		.procname	= "icmp_echo_enable_probe",
642 		.data		= &init_net.ipv4.sysctl_icmp_echo_enable_probe,
643 		.maxlen		= sizeof(u8),
644 		.mode		= 0644,
645 		.proc_handler	= proc_dou8vec_minmax,
646 		.extra1		= SYSCTL_ZERO,
647 		.extra2		= SYSCTL_ONE
648 	},
649 	{
650 		.procname	= "icmp_echo_ignore_broadcasts",
651 		.data		= &init_net.ipv4.sysctl_icmp_echo_ignore_broadcasts,
652 		.maxlen		= sizeof(u8),
653 		.mode		= 0644,
654 		.proc_handler	= proc_dou8vec_minmax,
655 		.extra1		= SYSCTL_ZERO,
656 		.extra2		= SYSCTL_ONE
657 	},
658 	{
659 		.procname	= "icmp_ignore_bogus_error_responses",
660 		.data		= &init_net.ipv4.sysctl_icmp_ignore_bogus_error_responses,
661 		.maxlen		= sizeof(u8),
662 		.mode		= 0644,
663 		.proc_handler	= proc_dou8vec_minmax,
664 		.extra1		= SYSCTL_ZERO,
665 		.extra2		= SYSCTL_ONE
666 	},
667 	{
668 		.procname	= "icmp_errors_use_inbound_ifaddr",
669 		.data		= &init_net.ipv4.sysctl_icmp_errors_use_inbound_ifaddr,
670 		.maxlen		= sizeof(u8),
671 		.mode		= 0644,
672 		.proc_handler	= proc_dou8vec_minmax,
673 		.extra1		= SYSCTL_ZERO,
674 		.extra2		= SYSCTL_ONE
675 	},
676 	{
677 		.procname	= "icmp_ratelimit",
678 		.data		= &init_net.ipv4.sysctl_icmp_ratelimit,
679 		.maxlen		= sizeof(int),
680 		.mode		= 0644,
681 		.proc_handler	= proc_dointvec_ms_jiffies,
682 	},
683 	{
684 		.procname	= "icmp_ratemask",
685 		.data		= &init_net.ipv4.sysctl_icmp_ratemask,
686 		.maxlen		= sizeof(int),
687 		.mode		= 0644,
688 		.proc_handler	= proc_dointvec
689 	},
690 	{
691 		.procname	= "icmp_msgs_per_sec",
692 		.data		= &init_net.ipv4.sysctl_icmp_msgs_per_sec,
693 		.maxlen		= sizeof(int),
694 		.mode		= 0644,
695 		.proc_handler	= proc_dointvec_minmax,
696 		.extra1		= SYSCTL_ZERO,
697 	},
698 	{
699 		.procname	= "icmp_msgs_burst",
700 		.data		= &init_net.ipv4.sysctl_icmp_msgs_burst,
701 		.maxlen		= sizeof(int),
702 		.mode		= 0644,
703 		.proc_handler	= proc_dointvec_minmax,
704 		.extra1		= SYSCTL_ZERO,
705 	},
706 	{
707 		.procname	= "ping_group_range",
708 		.data		= &init_net.ipv4.ping_group_range.range,
709 		.maxlen		= sizeof(gid_t)*2,
710 		.mode		= 0644,
711 		.proc_handler	= ipv4_ping_group_range,
712 	},
713 #ifdef CONFIG_NET_L3_MASTER_DEV
714 	{
715 		.procname	= "raw_l3mdev_accept",
716 		.data		= &init_net.ipv4.sysctl_raw_l3mdev_accept,
717 		.maxlen		= sizeof(u8),
718 		.mode		= 0644,
719 		.proc_handler	= proc_dou8vec_minmax,
720 		.extra1		= SYSCTL_ZERO,
721 		.extra2		= SYSCTL_ONE,
722 	},
723 #endif
724 	{
725 		.procname	= "tcp_ecn",
726 		.data		= &init_net.ipv4.sysctl_tcp_ecn,
727 		.maxlen		= sizeof(u8),
728 		.mode		= 0644,
729 		.proc_handler	= proc_dou8vec_minmax,
730 		.extra1		= SYSCTL_ZERO,
731 		.extra2		= SYSCTL_TWO,
732 	},
733 	{
734 		.procname	= "tcp_ecn_fallback",
735 		.data		= &init_net.ipv4.sysctl_tcp_ecn_fallback,
736 		.maxlen		= sizeof(u8),
737 		.mode		= 0644,
738 		.proc_handler	= proc_dou8vec_minmax,
739 		.extra1		= SYSCTL_ZERO,
740 		.extra2		= SYSCTL_ONE,
741 	},
742 	{
743 		.procname	= "ip_dynaddr",
744 		.data		= &init_net.ipv4.sysctl_ip_dynaddr,
745 		.maxlen		= sizeof(u8),
746 		.mode		= 0644,
747 		.proc_handler	= proc_dou8vec_minmax,
748 	},
749 	{
750 		.procname	= "ip_early_demux",
751 		.data		= &init_net.ipv4.sysctl_ip_early_demux,
752 		.maxlen		= sizeof(u8),
753 		.mode		= 0644,
754 		.proc_handler	= proc_dou8vec_minmax,
755 	},
756 	{
757 		.procname       = "udp_early_demux",
758 		.data           = &init_net.ipv4.sysctl_udp_early_demux,
759 		.maxlen         = sizeof(u8),
760 		.mode           = 0644,
761 		.proc_handler   = proc_dou8vec_minmax,
762 	},
763 	{
764 		.procname       = "tcp_early_demux",
765 		.data           = &init_net.ipv4.sysctl_tcp_early_demux,
766 		.maxlen         = sizeof(u8),
767 		.mode           = 0644,
768 		.proc_handler   = proc_dou8vec_minmax,
769 	},
770 	{
771 		.procname       = "nexthop_compat_mode",
772 		.data           = &init_net.ipv4.sysctl_nexthop_compat_mode,
773 		.maxlen         = sizeof(u8),
774 		.mode           = 0644,
775 		.proc_handler   = proc_dou8vec_minmax,
776 		.extra1		= SYSCTL_ZERO,
777 		.extra2		= SYSCTL_ONE,
778 	},
779 	{
780 		.procname	= "ip_default_ttl",
781 		.data		= &init_net.ipv4.sysctl_ip_default_ttl,
782 		.maxlen		= sizeof(u8),
783 		.mode		= 0644,
784 		.proc_handler	= proc_dou8vec_minmax,
785 		.extra1		= &ip_ttl_min,
786 		.extra2		= &ip_ttl_max,
787 	},
788 	{
789 		.procname	= "ip_local_port_range",
790 		.maxlen		= 0,
791 		.data		= &init_net,
792 		.mode		= 0644,
793 		.proc_handler	= ipv4_local_port_range,
794 	},
795 	{
796 		.procname	= "ip_local_reserved_ports",
797 		.data		= &init_net.ipv4.sysctl_local_reserved_ports,
798 		.maxlen		= 65536,
799 		.mode		= 0644,
800 		.proc_handler	= proc_do_large_bitmap,
801 	},
802 	{
803 		.procname	= "ip_no_pmtu_disc",
804 		.data		= &init_net.ipv4.sysctl_ip_no_pmtu_disc,
805 		.maxlen		= sizeof(u8),
806 		.mode		= 0644,
807 		.proc_handler	= proc_dou8vec_minmax,
808 	},
809 	{
810 		.procname	= "ip_forward_use_pmtu",
811 		.data		= &init_net.ipv4.sysctl_ip_fwd_use_pmtu,
812 		.maxlen		= sizeof(u8),
813 		.mode		= 0644,
814 		.proc_handler	= proc_dou8vec_minmax,
815 	},
816 	{
817 		.procname	= "ip_forward_update_priority",
818 		.data		= &init_net.ipv4.sysctl_ip_fwd_update_priority,
819 		.maxlen		= sizeof(u8),
820 		.mode		= 0644,
821 		.proc_handler   = ipv4_fwd_update_priority,
822 		.extra1		= SYSCTL_ZERO,
823 		.extra2		= SYSCTL_ONE,
824 	},
825 	{
826 		.procname	= "ip_nonlocal_bind",
827 		.data		= &init_net.ipv4.sysctl_ip_nonlocal_bind,
828 		.maxlen		= sizeof(u8),
829 		.mode		= 0644,
830 		.proc_handler	= proc_dou8vec_minmax,
831 	},
832 	{
833 		.procname	= "ip_autobind_reuse",
834 		.data		= &init_net.ipv4.sysctl_ip_autobind_reuse,
835 		.maxlen		= sizeof(u8),
836 		.mode		= 0644,
837 		.proc_handler	= proc_dou8vec_minmax,
838 		.extra1         = SYSCTL_ZERO,
839 		.extra2         = SYSCTL_ONE,
840 	},
841 	{
842 		.procname	= "fwmark_reflect",
843 		.data		= &init_net.ipv4.sysctl_fwmark_reflect,
844 		.maxlen		= sizeof(u8),
845 		.mode		= 0644,
846 		.proc_handler	= proc_dou8vec_minmax,
847 	},
848 	{
849 		.procname	= "tcp_fwmark_accept",
850 		.data		= &init_net.ipv4.sysctl_tcp_fwmark_accept,
851 		.maxlen		= sizeof(u8),
852 		.mode		= 0644,
853 		.proc_handler	= proc_dou8vec_minmax,
854 	},
855 #ifdef CONFIG_NET_L3_MASTER_DEV
856 	{
857 		.procname	= "tcp_l3mdev_accept",
858 		.data		= &init_net.ipv4.sysctl_tcp_l3mdev_accept,
859 		.maxlen		= sizeof(u8),
860 		.mode		= 0644,
861 		.proc_handler	= proc_dou8vec_minmax,
862 		.extra1		= SYSCTL_ZERO,
863 		.extra2		= SYSCTL_ONE,
864 	},
865 #endif
866 	{
867 		.procname	= "tcp_mtu_probing",
868 		.data		= &init_net.ipv4.sysctl_tcp_mtu_probing,
869 		.maxlen		= sizeof(u8),
870 		.mode		= 0644,
871 		.proc_handler	= proc_dou8vec_minmax,
872 	},
873 	{
874 		.procname	= "tcp_base_mss",
875 		.data		= &init_net.ipv4.sysctl_tcp_base_mss,
876 		.maxlen		= sizeof(int),
877 		.mode		= 0644,
878 		.proc_handler	= proc_dointvec,
879 	},
880 	{
881 		.procname	= "tcp_min_snd_mss",
882 		.data		= &init_net.ipv4.sysctl_tcp_min_snd_mss,
883 		.maxlen		= sizeof(int),
884 		.mode		= 0644,
885 		.proc_handler	= proc_dointvec_minmax,
886 		.extra1		= &tcp_min_snd_mss_min,
887 		.extra2		= &tcp_min_snd_mss_max,
888 	},
889 	{
890 		.procname	= "tcp_mtu_probe_floor",
891 		.data		= &init_net.ipv4.sysctl_tcp_mtu_probe_floor,
892 		.maxlen		= sizeof(int),
893 		.mode		= 0644,
894 		.proc_handler	= proc_dointvec_minmax,
895 		.extra1		= &tcp_min_snd_mss_min,
896 		.extra2		= &tcp_min_snd_mss_max,
897 	},
898 	{
899 		.procname	= "tcp_probe_threshold",
900 		.data		= &init_net.ipv4.sysctl_tcp_probe_threshold,
901 		.maxlen		= sizeof(int),
902 		.mode		= 0644,
903 		.proc_handler	= proc_dointvec,
904 	},
905 	{
906 		.procname	= "tcp_probe_interval",
907 		.data		= &init_net.ipv4.sysctl_tcp_probe_interval,
908 		.maxlen		= sizeof(u32),
909 		.mode		= 0644,
910 		.proc_handler	= proc_douintvec_minmax,
911 		.extra2		= &u32_max_div_HZ,
912 	},
913 	{
914 		.procname	= "igmp_link_local_mcast_reports",
915 		.data		= &init_net.ipv4.sysctl_igmp_llm_reports,
916 		.maxlen		= sizeof(u8),
917 		.mode		= 0644,
918 		.proc_handler	= proc_dou8vec_minmax,
919 	},
920 	{
921 		.procname	= "igmp_max_memberships",
922 		.data		= &init_net.ipv4.sysctl_igmp_max_memberships,
923 		.maxlen		= sizeof(int),
924 		.mode		= 0644,
925 		.proc_handler	= proc_dointvec
926 	},
927 	{
928 		.procname	= "igmp_max_msf",
929 		.data		= &init_net.ipv4.sysctl_igmp_max_msf,
930 		.maxlen		= sizeof(int),
931 		.mode		= 0644,
932 		.proc_handler	= proc_dointvec
933 	},
934 #ifdef CONFIG_IP_MULTICAST
935 	{
936 		.procname	= "igmp_qrv",
937 		.data		= &init_net.ipv4.sysctl_igmp_qrv,
938 		.maxlen		= sizeof(int),
939 		.mode		= 0644,
940 		.proc_handler	= proc_dointvec_minmax,
941 		.extra1		= SYSCTL_ONE
942 	},
943 #endif
944 	{
945 		.procname	= "tcp_congestion_control",
946 		.data		= &init_net.ipv4.tcp_congestion_control,
947 		.mode		= 0644,
948 		.maxlen		= TCP_CA_NAME_MAX,
949 		.proc_handler	= proc_tcp_congestion_control,
950 	},
951 	{
952 		.procname	= "tcp_available_congestion_control",
953 		.maxlen		= TCP_CA_BUF_MAX,
954 		.mode		= 0444,
955 		.proc_handler   = proc_tcp_available_congestion_control,
956 	},
957 	{
958 		.procname	= "tcp_allowed_congestion_control",
959 		.maxlen		= TCP_CA_BUF_MAX,
960 		.mode		= 0644,
961 		.proc_handler   = proc_allowed_congestion_control,
962 	},
963 	{
964 		.procname	= "tcp_keepalive_time",
965 		.data		= &init_net.ipv4.sysctl_tcp_keepalive_time,
966 		.maxlen		= sizeof(int),
967 		.mode		= 0644,
968 		.proc_handler	= proc_dointvec_jiffies,
969 	},
970 	{
971 		.procname	= "tcp_keepalive_probes",
972 		.data		= &init_net.ipv4.sysctl_tcp_keepalive_probes,
973 		.maxlen		= sizeof(u8),
974 		.mode		= 0644,
975 		.proc_handler	= proc_dou8vec_minmax,
976 	},
977 	{
978 		.procname	= "tcp_keepalive_intvl",
979 		.data		= &init_net.ipv4.sysctl_tcp_keepalive_intvl,
980 		.maxlen		= sizeof(int),
981 		.mode		= 0644,
982 		.proc_handler	= proc_dointvec_jiffies,
983 	},
984 	{
985 		.procname	= "tcp_syn_retries",
986 		.data		= &init_net.ipv4.sysctl_tcp_syn_retries,
987 		.maxlen		= sizeof(u8),
988 		.mode		= 0644,
989 		.proc_handler	= proc_dou8vec_minmax,
990 		.extra1		= &tcp_syn_retries_min,
991 		.extra2		= &tcp_syn_retries_max
992 	},
993 	{
994 		.procname	= "tcp_synack_retries",
995 		.data		= &init_net.ipv4.sysctl_tcp_synack_retries,
996 		.maxlen		= sizeof(u8),
997 		.mode		= 0644,
998 		.proc_handler	= proc_dou8vec_minmax,
999 	},
1000 #ifdef CONFIG_SYN_COOKIES
1001 	{
1002 		.procname	= "tcp_syncookies",
1003 		.data		= &init_net.ipv4.sysctl_tcp_syncookies,
1004 		.maxlen		= sizeof(u8),
1005 		.mode		= 0644,
1006 		.proc_handler	= proc_dou8vec_minmax,
1007 	},
1008 #endif
1009 	{
1010 		.procname	= "tcp_migrate_req",
1011 		.data		= &init_net.ipv4.sysctl_tcp_migrate_req,
1012 		.maxlen		= sizeof(u8),
1013 		.mode		= 0644,
1014 		.proc_handler	= proc_dou8vec_minmax,
1015 		.extra1		= SYSCTL_ZERO,
1016 		.extra2		= SYSCTL_ONE
1017 	},
1018 	{
1019 		.procname	= "tcp_reordering",
1020 		.data		= &init_net.ipv4.sysctl_tcp_reordering,
1021 		.maxlen		= sizeof(int),
1022 		.mode		= 0644,
1023 		.proc_handler	= proc_dointvec
1024 	},
1025 	{
1026 		.procname	= "tcp_retries1",
1027 		.data		= &init_net.ipv4.sysctl_tcp_retries1,
1028 		.maxlen		= sizeof(u8),
1029 		.mode		= 0644,
1030 		.proc_handler	= proc_dou8vec_minmax,
1031 		.extra2		= &tcp_retr1_max
1032 	},
1033 	{
1034 		.procname	= "tcp_retries2",
1035 		.data		= &init_net.ipv4.sysctl_tcp_retries2,
1036 		.maxlen		= sizeof(u8),
1037 		.mode		= 0644,
1038 		.proc_handler	= proc_dou8vec_minmax,
1039 	},
1040 	{
1041 		.procname	= "tcp_orphan_retries",
1042 		.data		= &init_net.ipv4.sysctl_tcp_orphan_retries,
1043 		.maxlen		= sizeof(u8),
1044 		.mode		= 0644,
1045 		.proc_handler	= proc_dou8vec_minmax,
1046 	},
1047 	{
1048 		.procname	= "tcp_fin_timeout",
1049 		.data		= &init_net.ipv4.sysctl_tcp_fin_timeout,
1050 		.maxlen		= sizeof(int),
1051 		.mode		= 0644,
1052 		.proc_handler	= proc_dointvec_jiffies,
1053 	},
1054 	{
1055 		.procname	= "tcp_notsent_lowat",
1056 		.data		= &init_net.ipv4.sysctl_tcp_notsent_lowat,
1057 		.maxlen		= sizeof(unsigned int),
1058 		.mode		= 0644,
1059 		.proc_handler	= proc_douintvec,
1060 	},
1061 	{
1062 		.procname	= "tcp_tw_reuse",
1063 		.data		= &init_net.ipv4.sysctl_tcp_tw_reuse,
1064 		.maxlen		= sizeof(u8),
1065 		.mode		= 0644,
1066 		.proc_handler	= proc_dou8vec_minmax,
1067 		.extra1		= SYSCTL_ZERO,
1068 		.extra2		= SYSCTL_TWO,
1069 	},
1070 	{
1071 		.procname	= "tcp_tw_reuse_delay",
1072 		.data		= &init_net.ipv4.sysctl_tcp_tw_reuse_delay,
1073 		.maxlen		= sizeof(unsigned int),
1074 		.mode		= 0644,
1075 		.proc_handler	= proc_douintvec_minmax,
1076 		.extra1		= SYSCTL_ONE,
1077 		.extra2		= &tcp_tw_reuse_delay_max,
1078 	},
1079 	{
1080 		.procname	= "tcp_max_syn_backlog",
1081 		.data		= &init_net.ipv4.sysctl_max_syn_backlog,
1082 		.maxlen		= sizeof(int),
1083 		.mode		= 0644,
1084 		.proc_handler	= proc_dointvec
1085 	},
1086 	{
1087 		.procname	= "tcp_fastopen",
1088 		.data		= &init_net.ipv4.sysctl_tcp_fastopen,
1089 		.maxlen		= sizeof(int),
1090 		.mode		= 0644,
1091 		.proc_handler	= proc_dointvec,
1092 	},
1093 	{
1094 		.procname	= "tcp_fastopen_key",
1095 		.mode		= 0600,
1096 		.data		= &init_net.ipv4.sysctl_tcp_fastopen,
1097 		/* maxlen to print the list of keys in hex (*2), with dashes
1098 		 * separating doublewords and a comma in between keys.
1099 		 */
1100 		.maxlen		= ((TCP_FASTOPEN_KEY_LENGTH *
1101 				   2 * TCP_FASTOPEN_KEY_MAX) +
1102 				   (TCP_FASTOPEN_KEY_MAX * 5)),
1103 		.proc_handler	= proc_tcp_fastopen_key,
1104 	},
1105 	{
1106 		.procname	= "tcp_fastopen_blackhole_timeout_sec",
1107 		.data		= &init_net.ipv4.sysctl_tcp_fastopen_blackhole_timeout,
1108 		.maxlen		= sizeof(int),
1109 		.mode		= 0644,
1110 		.proc_handler	= proc_tfo_blackhole_detect_timeout,
1111 		.extra1		= SYSCTL_ZERO,
1112 	},
1113 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1114 	{
1115 		.procname	= "fib_multipath_use_neigh",
1116 		.data		= &init_net.ipv4.sysctl_fib_multipath_use_neigh,
1117 		.maxlen		= sizeof(u8),
1118 		.mode		= 0644,
1119 		.proc_handler	= proc_dou8vec_minmax,
1120 		.extra1		= SYSCTL_ZERO,
1121 		.extra2		= SYSCTL_ONE,
1122 	},
1123 	{
1124 		.procname	= "fib_multipath_hash_policy",
1125 		.data		= &init_net.ipv4.sysctl_fib_multipath_hash_policy,
1126 		.maxlen		= sizeof(u8),
1127 		.mode		= 0644,
1128 		.proc_handler	= proc_fib_multipath_hash_policy,
1129 		.extra1		= SYSCTL_ZERO,
1130 		.extra2		= SYSCTL_THREE,
1131 	},
1132 	{
1133 		.procname	= "fib_multipath_hash_fields",
1134 		.data		= &init_net.ipv4.sysctl_fib_multipath_hash_fields,
1135 		.maxlen		= sizeof(u32),
1136 		.mode		= 0644,
1137 		.proc_handler	= proc_fib_multipath_hash_fields,
1138 		.extra1		= SYSCTL_ONE,
1139 		.extra2		= &fib_multipath_hash_fields_all_mask,
1140 	},
1141 	{
1142 		.procname	= "fib_multipath_hash_seed",
1143 		.data		= &init_net,
1144 		.maxlen		= sizeof(u32),
1145 		.mode		= 0644,
1146 		.proc_handler	= proc_fib_multipath_hash_seed,
1147 	},
1148 #endif
1149 	{
1150 		.procname	= "ip_unprivileged_port_start",
1151 		.maxlen		= sizeof(int),
1152 		.data		= &init_net.ipv4.sysctl_ip_prot_sock,
1153 		.mode		= 0644,
1154 		.proc_handler	= ipv4_privileged_ports,
1155 	},
1156 #ifdef CONFIG_NET_L3_MASTER_DEV
1157 	{
1158 		.procname	= "udp_l3mdev_accept",
1159 		.data		= &init_net.ipv4.sysctl_udp_l3mdev_accept,
1160 		.maxlen		= sizeof(u8),
1161 		.mode		= 0644,
1162 		.proc_handler	= proc_dou8vec_minmax,
1163 		.extra1		= SYSCTL_ZERO,
1164 		.extra2		= SYSCTL_ONE,
1165 	},
1166 #endif
1167 	{
1168 		.procname	= "tcp_sack",
1169 		.data		= &init_net.ipv4.sysctl_tcp_sack,
1170 		.maxlen		= sizeof(u8),
1171 		.mode		= 0644,
1172 		.proc_handler	= proc_dou8vec_minmax,
1173 	},
1174 	{
1175 		.procname	= "tcp_window_scaling",
1176 		.data		= &init_net.ipv4.sysctl_tcp_window_scaling,
1177 		.maxlen		= sizeof(u8),
1178 		.mode		= 0644,
1179 		.proc_handler	= proc_dou8vec_minmax,
1180 	},
1181 	{
1182 		.procname	= "tcp_timestamps",
1183 		.data		= &init_net.ipv4.sysctl_tcp_timestamps,
1184 		.maxlen		= sizeof(u8),
1185 		.mode		= 0644,
1186 		.proc_handler	= proc_dou8vec_minmax,
1187 	},
1188 	{
1189 		.procname	= "tcp_early_retrans",
1190 		.data		= &init_net.ipv4.sysctl_tcp_early_retrans,
1191 		.maxlen		= sizeof(u8),
1192 		.mode		= 0644,
1193 		.proc_handler	= proc_dou8vec_minmax,
1194 		.extra1		= SYSCTL_ZERO,
1195 		.extra2		= SYSCTL_FOUR,
1196 	},
1197 	{
1198 		.procname	= "tcp_recovery",
1199 		.data		= &init_net.ipv4.sysctl_tcp_recovery,
1200 		.maxlen		= sizeof(u8),
1201 		.mode		= 0644,
1202 		.proc_handler	= proc_dou8vec_minmax,
1203 	},
1204 	{
1205 		.procname       = "tcp_thin_linear_timeouts",
1206 		.data           = &init_net.ipv4.sysctl_tcp_thin_linear_timeouts,
1207 		.maxlen         = sizeof(u8),
1208 		.mode           = 0644,
1209 		.proc_handler   = proc_dou8vec_minmax,
1210 	},
1211 	{
1212 		.procname	= "tcp_slow_start_after_idle",
1213 		.data		= &init_net.ipv4.sysctl_tcp_slow_start_after_idle,
1214 		.maxlen		= sizeof(u8),
1215 		.mode		= 0644,
1216 		.proc_handler	= proc_dou8vec_minmax,
1217 	},
1218 	{
1219 		.procname	= "tcp_retrans_collapse",
1220 		.data		= &init_net.ipv4.sysctl_tcp_retrans_collapse,
1221 		.maxlen		= sizeof(u8),
1222 		.mode		= 0644,
1223 		.proc_handler	= proc_dou8vec_minmax,
1224 	},
1225 	{
1226 		.procname	= "tcp_stdurg",
1227 		.data		= &init_net.ipv4.sysctl_tcp_stdurg,
1228 		.maxlen		= sizeof(u8),
1229 		.mode		= 0644,
1230 		.proc_handler	= proc_dou8vec_minmax,
1231 	},
1232 	{
1233 		.procname	= "tcp_rfc1337",
1234 		.data		= &init_net.ipv4.sysctl_tcp_rfc1337,
1235 		.maxlen		= sizeof(u8),
1236 		.mode		= 0644,
1237 		.proc_handler	= proc_dou8vec_minmax,
1238 	},
1239 	{
1240 		.procname	= "tcp_abort_on_overflow",
1241 		.data		= &init_net.ipv4.sysctl_tcp_abort_on_overflow,
1242 		.maxlen		= sizeof(u8),
1243 		.mode		= 0644,
1244 		.proc_handler	= proc_dou8vec_minmax,
1245 	},
1246 	{
1247 		.procname	= "tcp_fack",
1248 		.data		= &init_net.ipv4.sysctl_tcp_fack,
1249 		.maxlen		= sizeof(u8),
1250 		.mode		= 0644,
1251 		.proc_handler	= proc_dou8vec_minmax,
1252 	},
1253 	{
1254 		.procname	= "tcp_max_reordering",
1255 		.data		= &init_net.ipv4.sysctl_tcp_max_reordering,
1256 		.maxlen		= sizeof(int),
1257 		.mode		= 0644,
1258 		.proc_handler	= proc_dointvec
1259 	},
1260 	{
1261 		.procname	= "tcp_dsack",
1262 		.data		= &init_net.ipv4.sysctl_tcp_dsack,
1263 		.maxlen		= sizeof(u8),
1264 		.mode		= 0644,
1265 		.proc_handler	= proc_dou8vec_minmax,
1266 	},
1267 	{
1268 		.procname	= "tcp_app_win",
1269 		.data		= &init_net.ipv4.sysctl_tcp_app_win,
1270 		.maxlen		= sizeof(u8),
1271 		.mode		= 0644,
1272 		.proc_handler	= proc_dou8vec_minmax,
1273 		.extra1		= SYSCTL_ZERO,
1274 		.extra2		= &tcp_app_win_max,
1275 	},
1276 	{
1277 		.procname	= "tcp_adv_win_scale",
1278 		.data		= &init_net.ipv4.sysctl_tcp_adv_win_scale,
1279 		.maxlen		= sizeof(int),
1280 		.mode		= 0644,
1281 		.proc_handler	= proc_dointvec_minmax,
1282 		.extra1		= &tcp_adv_win_scale_min,
1283 		.extra2		= &tcp_adv_win_scale_max,
1284 	},
1285 	{
1286 		.procname	= "tcp_frto",
1287 		.data		= &init_net.ipv4.sysctl_tcp_frto,
1288 		.maxlen		= sizeof(u8),
1289 		.mode		= 0644,
1290 		.proc_handler	= proc_dou8vec_minmax,
1291 	},
1292 	{
1293 		.procname	= "tcp_no_metrics_save",
1294 		.data		= &init_net.ipv4.sysctl_tcp_nometrics_save,
1295 		.maxlen		= sizeof(u8),
1296 		.mode		= 0644,
1297 		.proc_handler	= proc_dou8vec_minmax,
1298 	},
1299 	{
1300 		.procname	= "tcp_no_ssthresh_metrics_save",
1301 		.data		= &init_net.ipv4.sysctl_tcp_no_ssthresh_metrics_save,
1302 		.maxlen		= sizeof(u8),
1303 		.mode		= 0644,
1304 		.proc_handler	= proc_dou8vec_minmax,
1305 		.extra1		= SYSCTL_ZERO,
1306 		.extra2		= SYSCTL_ONE,
1307 	},
1308 	{
1309 		.procname	= "tcp_moderate_rcvbuf",
1310 		.data		= &init_net.ipv4.sysctl_tcp_moderate_rcvbuf,
1311 		.maxlen		= sizeof(u8),
1312 		.mode		= 0644,
1313 		.proc_handler	= proc_dou8vec_minmax,
1314 	},
1315 	{
1316 		.procname	= "tcp_tso_win_divisor",
1317 		.data		= &init_net.ipv4.sysctl_tcp_tso_win_divisor,
1318 		.maxlen		= sizeof(u8),
1319 		.mode		= 0644,
1320 		.proc_handler	= proc_dou8vec_minmax,
1321 	},
1322 	{
1323 		.procname	= "tcp_workaround_signed_windows",
1324 		.data		= &init_net.ipv4.sysctl_tcp_workaround_signed_windows,
1325 		.maxlen		= sizeof(u8),
1326 		.mode		= 0644,
1327 		.proc_handler	= proc_dou8vec_minmax,
1328 	},
1329 	{
1330 		.procname	= "tcp_limit_output_bytes",
1331 		.data		= &init_net.ipv4.sysctl_tcp_limit_output_bytes,
1332 		.maxlen		= sizeof(int),
1333 		.mode		= 0644,
1334 		.proc_handler	= proc_dointvec
1335 	},
1336 	{
1337 		.procname	= "tcp_challenge_ack_limit",
1338 		.data		= &init_net.ipv4.sysctl_tcp_challenge_ack_limit,
1339 		.maxlen		= sizeof(int),
1340 		.mode		= 0644,
1341 		.proc_handler	= proc_dointvec
1342 	},
1343 	{
1344 		.procname	= "tcp_min_tso_segs",
1345 		.data		= &init_net.ipv4.sysctl_tcp_min_tso_segs,
1346 		.maxlen		= sizeof(u8),
1347 		.mode		= 0644,
1348 		.proc_handler	= proc_dou8vec_minmax,
1349 		.extra1		= SYSCTL_ONE,
1350 	},
1351 	{
1352 		.procname	= "tcp_tso_rtt_log",
1353 		.data		= &init_net.ipv4.sysctl_tcp_tso_rtt_log,
1354 		.maxlen		= sizeof(u8),
1355 		.mode		= 0644,
1356 		.proc_handler	= proc_dou8vec_minmax,
1357 	},
1358 	{
1359 		.procname	= "tcp_min_rtt_wlen",
1360 		.data		= &init_net.ipv4.sysctl_tcp_min_rtt_wlen,
1361 		.maxlen		= sizeof(int),
1362 		.mode		= 0644,
1363 		.proc_handler	= proc_dointvec_minmax,
1364 		.extra1		= SYSCTL_ZERO,
1365 		.extra2		= &one_day_secs
1366 	},
1367 	{
1368 		.procname	= "tcp_autocorking",
1369 		.data		= &init_net.ipv4.sysctl_tcp_autocorking,
1370 		.maxlen		= sizeof(u8),
1371 		.mode		= 0644,
1372 		.proc_handler	= proc_dou8vec_minmax,
1373 		.extra1		= SYSCTL_ZERO,
1374 		.extra2		= SYSCTL_ONE,
1375 	},
1376 	{
1377 		.procname	= "tcp_invalid_ratelimit",
1378 		.data		= &init_net.ipv4.sysctl_tcp_invalid_ratelimit,
1379 		.maxlen		= sizeof(int),
1380 		.mode		= 0644,
1381 		.proc_handler	= proc_dointvec_ms_jiffies,
1382 	},
1383 	{
1384 		.procname	= "tcp_pacing_ss_ratio",
1385 		.data		= &init_net.ipv4.sysctl_tcp_pacing_ss_ratio,
1386 		.maxlen		= sizeof(int),
1387 		.mode		= 0644,
1388 		.proc_handler	= proc_dointvec_minmax,
1389 		.extra1		= SYSCTL_ZERO,
1390 		.extra2		= SYSCTL_ONE_THOUSAND,
1391 	},
1392 	{
1393 		.procname	= "tcp_pacing_ca_ratio",
1394 		.data		= &init_net.ipv4.sysctl_tcp_pacing_ca_ratio,
1395 		.maxlen		= sizeof(int),
1396 		.mode		= 0644,
1397 		.proc_handler	= proc_dointvec_minmax,
1398 		.extra1		= SYSCTL_ZERO,
1399 		.extra2		= SYSCTL_ONE_THOUSAND,
1400 	},
1401 	{
1402 		.procname	= "tcp_wmem",
1403 		.data		= &init_net.ipv4.sysctl_tcp_wmem,
1404 		.maxlen		= sizeof(init_net.ipv4.sysctl_tcp_wmem),
1405 		.mode		= 0644,
1406 		.proc_handler	= proc_dointvec_minmax,
1407 		.extra1		= SYSCTL_ONE,
1408 	},
1409 	{
1410 		.procname	= "tcp_rmem",
1411 		.data		= &init_net.ipv4.sysctl_tcp_rmem,
1412 		.maxlen		= sizeof(init_net.ipv4.sysctl_tcp_rmem),
1413 		.mode		= 0644,
1414 		.proc_handler	= proc_dointvec_minmax,
1415 		.extra1		= SYSCTL_ONE,
1416 	},
1417 	{
1418 		.procname	= "tcp_comp_sack_delay_ns",
1419 		.data		= &init_net.ipv4.sysctl_tcp_comp_sack_delay_ns,
1420 		.maxlen		= sizeof(unsigned long),
1421 		.mode		= 0644,
1422 		.proc_handler	= proc_doulongvec_minmax,
1423 	},
1424 	{
1425 		.procname	= "tcp_comp_sack_slack_ns",
1426 		.data		= &init_net.ipv4.sysctl_tcp_comp_sack_slack_ns,
1427 		.maxlen		= sizeof(unsigned long),
1428 		.mode		= 0644,
1429 		.proc_handler	= proc_doulongvec_minmax,
1430 	},
1431 	{
1432 		.procname	= "tcp_comp_sack_nr",
1433 		.data		= &init_net.ipv4.sysctl_tcp_comp_sack_nr,
1434 		.maxlen		= sizeof(u8),
1435 		.mode		= 0644,
1436 		.proc_handler	= proc_dou8vec_minmax,
1437 		.extra1		= SYSCTL_ZERO,
1438 	},
1439 	{
1440 		.procname	= "tcp_backlog_ack_defer",
1441 		.data		= &init_net.ipv4.sysctl_tcp_backlog_ack_defer,
1442 		.maxlen		= sizeof(u8),
1443 		.mode		= 0644,
1444 		.proc_handler	= proc_dou8vec_minmax,
1445 		.extra1		= SYSCTL_ZERO,
1446 		.extra2		= SYSCTL_ONE,
1447 	},
1448 	{
1449 		.procname       = "tcp_reflect_tos",
1450 		.data           = &init_net.ipv4.sysctl_tcp_reflect_tos,
1451 		.maxlen         = sizeof(u8),
1452 		.mode           = 0644,
1453 		.proc_handler   = proc_dou8vec_minmax,
1454 		.extra1         = SYSCTL_ZERO,
1455 		.extra2         = SYSCTL_ONE,
1456 	},
1457 	{
1458 		.procname	= "tcp_ehash_entries",
1459 		.data		= &init_net.ipv4.sysctl_tcp_child_ehash_entries,
1460 		.mode		= 0444,
1461 		.proc_handler	= proc_tcp_ehash_entries,
1462 	},
1463 	{
1464 		.procname	= "tcp_child_ehash_entries",
1465 		.data		= &init_net.ipv4.sysctl_tcp_child_ehash_entries,
1466 		.maxlen		= sizeof(unsigned int),
1467 		.mode		= 0644,
1468 		.proc_handler	= proc_douintvec_minmax,
1469 		.extra1		= SYSCTL_ZERO,
1470 		.extra2		= &tcp_child_ehash_entries_max,
1471 	},
1472 	{
1473 		.procname	= "udp_hash_entries",
1474 		.data		= &init_net.ipv4.sysctl_udp_child_hash_entries,
1475 		.mode		= 0444,
1476 		.proc_handler	= proc_udp_hash_entries,
1477 	},
1478 	{
1479 		.procname	= "udp_child_hash_entries",
1480 		.data		= &init_net.ipv4.sysctl_udp_child_hash_entries,
1481 		.maxlen		= sizeof(unsigned int),
1482 		.mode		= 0644,
1483 		.proc_handler	= proc_douintvec_minmax,
1484 		.extra1		= SYSCTL_ZERO,
1485 		.extra2		= &udp_child_hash_entries_max,
1486 	},
1487 	{
1488 		.procname	= "udp_rmem_min",
1489 		.data		= &init_net.ipv4.sysctl_udp_rmem_min,
1490 		.maxlen		= sizeof(init_net.ipv4.sysctl_udp_rmem_min),
1491 		.mode		= 0644,
1492 		.proc_handler	= proc_dointvec_minmax,
1493 		.extra1		= SYSCTL_ONE
1494 	},
1495 	{
1496 		.procname	= "udp_wmem_min",
1497 		.data		= &init_net.ipv4.sysctl_udp_wmem_min,
1498 		.maxlen		= sizeof(init_net.ipv4.sysctl_udp_wmem_min),
1499 		.mode		= 0644,
1500 		.proc_handler	= proc_dointvec_minmax,
1501 		.extra1		= SYSCTL_ONE
1502 	},
1503 	{
1504 		.procname	= "fib_notify_on_flag_change",
1505 		.data		= &init_net.ipv4.sysctl_fib_notify_on_flag_change,
1506 		.maxlen		= sizeof(u8),
1507 		.mode		= 0644,
1508 		.proc_handler	= proc_dou8vec_minmax,
1509 		.extra1		= SYSCTL_ZERO,
1510 		.extra2		= SYSCTL_TWO,
1511 	},
1512 	{
1513 		.procname       = "tcp_plb_enabled",
1514 		.data           = &init_net.ipv4.sysctl_tcp_plb_enabled,
1515 		.maxlen         = sizeof(u8),
1516 		.mode           = 0644,
1517 		.proc_handler   = proc_dou8vec_minmax,
1518 		.extra1         = SYSCTL_ZERO,
1519 		.extra2         = SYSCTL_ONE,
1520 	},
1521 	{
1522 		.procname       = "tcp_plb_idle_rehash_rounds",
1523 		.data           = &init_net.ipv4.sysctl_tcp_plb_idle_rehash_rounds,
1524 		.maxlen         = sizeof(u8),
1525 		.mode           = 0644,
1526 		.proc_handler   = proc_dou8vec_minmax,
1527 		.extra2		= &tcp_plb_max_rounds,
1528 	},
1529 	{
1530 		.procname       = "tcp_plb_rehash_rounds",
1531 		.data           = &init_net.ipv4.sysctl_tcp_plb_rehash_rounds,
1532 		.maxlen         = sizeof(u8),
1533 		.mode           = 0644,
1534 		.proc_handler   = proc_dou8vec_minmax,
1535 		.extra2         = &tcp_plb_max_rounds,
1536 	},
1537 	{
1538 		.procname       = "tcp_plb_suspend_rto_sec",
1539 		.data           = &init_net.ipv4.sysctl_tcp_plb_suspend_rto_sec,
1540 		.maxlen         = sizeof(u8),
1541 		.mode           = 0644,
1542 		.proc_handler   = proc_dou8vec_minmax,
1543 	},
1544 	{
1545 		.procname       = "tcp_plb_cong_thresh",
1546 		.data           = &init_net.ipv4.sysctl_tcp_plb_cong_thresh,
1547 		.maxlen         = sizeof(int),
1548 		.mode           = 0644,
1549 		.proc_handler   = proc_dointvec_minmax,
1550 		.extra1         = SYSCTL_ZERO,
1551 		.extra2         = &tcp_plb_max_cong_thresh,
1552 	},
1553 	{
1554 		.procname	= "tcp_syn_linear_timeouts",
1555 		.data		= &init_net.ipv4.sysctl_tcp_syn_linear_timeouts,
1556 		.maxlen		= sizeof(u8),
1557 		.mode		= 0644,
1558 		.proc_handler	= proc_dou8vec_minmax,
1559 		.extra1		= SYSCTL_ZERO,
1560 		.extra2		= &tcp_syn_linear_timeouts_max,
1561 	},
1562 	{
1563 		.procname	= "tcp_shrink_window",
1564 		.data		= &init_net.ipv4.sysctl_tcp_shrink_window,
1565 		.maxlen		= sizeof(u8),
1566 		.mode		= 0644,
1567 		.proc_handler	= proc_dou8vec_minmax,
1568 		.extra1		= SYSCTL_ZERO,
1569 		.extra2		= SYSCTL_ONE,
1570 	},
1571 	{
1572 		.procname	= "tcp_pingpong_thresh",
1573 		.data		= &init_net.ipv4.sysctl_tcp_pingpong_thresh,
1574 		.maxlen		= sizeof(u8),
1575 		.mode		= 0644,
1576 		.proc_handler	= proc_dou8vec_minmax,
1577 		.extra1		= SYSCTL_ONE,
1578 	},
1579 	{
1580 		.procname	= "tcp_rto_min_us",
1581 		.data		= &init_net.ipv4.sysctl_tcp_rto_min_us,
1582 		.maxlen		= sizeof(int),
1583 		.mode		= 0644,
1584 		.proc_handler	= proc_dointvec_minmax,
1585 		.extra1		= SYSCTL_ONE,
1586 	},
1587 	{
1588 		.procname	= "tcp_rto_max_ms",
1589 		.data		= &init_net.ipv4.sysctl_tcp_rto_max_ms,
1590 		.maxlen		= sizeof(int),
1591 		.mode		= 0644,
1592 		.proc_handler	= proc_dointvec_minmax,
1593 		.extra1		= SYSCTL_ONE_THOUSAND,
1594 		.extra2		= &tcp_rto_max_max,
1595 	},
1596 };
1597 
ipv4_sysctl_init_net(struct net * net)1598 static __net_init int ipv4_sysctl_init_net(struct net *net)
1599 {
1600 	size_t table_size = ARRAY_SIZE(ipv4_net_table);
1601 	struct ctl_table *table;
1602 
1603 	table = ipv4_net_table;
1604 	if (!net_eq(net, &init_net)) {
1605 		int i;
1606 
1607 		table = kmemdup(table, sizeof(ipv4_net_table), GFP_KERNEL);
1608 		if (!table)
1609 			goto err_alloc;
1610 
1611 		for (i = 0; i < table_size; i++) {
1612 			if (table[i].data) {
1613 				/* Update the variables to point into
1614 				 * the current struct net
1615 				 */
1616 				table[i].data += (void *)net - (void *)&init_net;
1617 			} else {
1618 				/* Entries without data pointer are global;
1619 				 * Make them read-only in non-init_net ns
1620 				 */
1621 				table[i].mode &= ~0222;
1622 			}
1623 		}
1624 	}
1625 
1626 	net->ipv4.ipv4_hdr = register_net_sysctl_sz(net, "net/ipv4", table,
1627 						    table_size);
1628 	if (!net->ipv4.ipv4_hdr)
1629 		goto err_reg;
1630 
1631 	net->ipv4.sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
1632 	if (!net->ipv4.sysctl_local_reserved_ports)
1633 		goto err_ports;
1634 
1635 	proc_fib_multipath_hash_set_seed(net, 0);
1636 
1637 	return 0;
1638 
1639 err_ports:
1640 	unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
1641 err_reg:
1642 	if (!net_eq(net, &init_net))
1643 		kfree(table);
1644 err_alloc:
1645 	return -ENOMEM;
1646 }
1647 
ipv4_sysctl_exit_net(struct net * net)1648 static __net_exit void ipv4_sysctl_exit_net(struct net *net)
1649 {
1650 	const struct ctl_table *table;
1651 
1652 	kfree(net->ipv4.sysctl_local_reserved_ports);
1653 	table = net->ipv4.ipv4_hdr->ctl_table_arg;
1654 	unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
1655 	kfree(table);
1656 }
1657 
1658 static __net_initdata struct pernet_operations ipv4_sysctl_ops = {
1659 	.init = ipv4_sysctl_init_net,
1660 	.exit = ipv4_sysctl_exit_net,
1661 };
1662 
sysctl_ipv4_init(void)1663 static __init int sysctl_ipv4_init(void)
1664 {
1665 	struct ctl_table_header *hdr;
1666 
1667 	hdr = register_net_sysctl(&init_net, "net/ipv4", ipv4_table);
1668 	if (!hdr)
1669 		return -ENOMEM;
1670 
1671 	proc_fib_multipath_hash_init_rand_seed();
1672 
1673 	if (register_pernet_subsys(&ipv4_sysctl_ops)) {
1674 		unregister_net_sysctl_table(hdr);
1675 		return -ENOMEM;
1676 	}
1677 
1678 	return 0;
1679 }
1680 
1681 __initcall(sysctl_ipv4_init);
1682