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1 /*
2  * sysctl_net_ipv4.c: sysctl interface to net IPV4 subsystem.
3  *
4  * Begun April 1, 1996, Mike Shaver.
5  * Added /proc/sys/net/ipv4 directory entry (empty =) ). [MS]
6  */
7 
8 #include <linux/mm.h>
9 #include <linux/module.h>
10 #include <linux/sysctl.h>
11 #include <linux/igmp.h>
12 #include <linux/inetdevice.h>
13 #include <linux/seqlock.h>
14 #include <linux/init.h>
15 #include <linux/slab.h>
16 #include <linux/nsproxy.h>
17 #include <linux/swap.h>
18 #include <net/snmp.h>
19 #include <net/icmp.h>
20 #include <net/ip.h>
21 #include <net/route.h>
22 #include <net/tcp.h>
23 #include <net/udp.h>
24 #include <net/cipso_ipv4.h>
25 #include <net/inet_frag.h>
26 #include <net/ping.h>
27 #include <net/tcp_memcontrol.h>
28 
29 static int zero;
30 static int one = 1;
31 static int four = 4;
32 static int gso_max_segs = GSO_MAX_SEGS;
33 static int tcp_retr1_max = 255;
34 static int ip_local_port_range_min[] = { 1, 1 };
35 static int ip_local_port_range_max[] = { 65535, 65535 };
36 static int tcp_adv_win_scale_min = -31;
37 static int tcp_adv_win_scale_max = 31;
38 static int ip_ttl_min = 1;
39 static int ip_ttl_max = 255;
40 static int tcp_syn_retries_min = 1;
41 static int tcp_syn_retries_max = MAX_TCP_SYNCNT;
42 static int ip_ping_group_range_min[] = { 0, 0 };
43 static int ip_ping_group_range_max[] = { GID_T_MAX, GID_T_MAX };
44 
45 /* Update system visible IP port range */
set_local_port_range(struct net * net,int range[2])46 static void set_local_port_range(struct net *net, int range[2])
47 {
48 	write_seqlock_bh(&net->ipv4.ip_local_ports.lock);
49 	net->ipv4.ip_local_ports.range[0] = range[0];
50 	net->ipv4.ip_local_ports.range[1] = range[1];
51 	write_sequnlock_bh(&net->ipv4.ip_local_ports.lock);
52 }
53 
54 /* Validate changes from /proc interface. */
ipv4_local_port_range(struct ctl_table * table,int write,void __user * buffer,size_t * lenp,loff_t * ppos)55 static int ipv4_local_port_range(struct ctl_table *table, int write,
56 				 void __user *buffer,
57 				 size_t *lenp, loff_t *ppos)
58 {
59 	struct net *net =
60 		container_of(table->data, struct net, ipv4.ip_local_ports.range);
61 	int ret;
62 	int range[2];
63 	struct ctl_table tmp = {
64 		.data = &range,
65 		.maxlen = sizeof(range),
66 		.mode = table->mode,
67 		.extra1 = &ip_local_port_range_min,
68 		.extra2 = &ip_local_port_range_max,
69 	};
70 
71 	inet_get_local_port_range(net, &range[0], &range[1]);
72 
73 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
74 
75 	if (write && ret == 0) {
76 		if (range[1] < range[0])
77 			ret = -EINVAL;
78 		else
79 			set_local_port_range(net, range);
80 	}
81 
82 	return ret;
83 }
84 
85 
inet_get_ping_group_range_table(struct ctl_table * table,kgid_t * low,kgid_t * high)86 static void inet_get_ping_group_range_table(struct ctl_table *table, kgid_t *low, kgid_t *high)
87 {
88 	kgid_t *data = table->data;
89 	struct net *net =
90 		container_of(table->data, struct net, ipv4.ping_group_range.range);
91 	unsigned int seq;
92 	do {
93 		seq = read_seqbegin(&net->ipv4.ip_local_ports.lock);
94 
95 		*low = data[0];
96 		*high = data[1];
97 	} while (read_seqretry(&net->ipv4.ip_local_ports.lock, seq));
98 }
99 
100 /* Update system visible IP port range */
set_ping_group_range(struct ctl_table * table,kgid_t low,kgid_t high)101 static void set_ping_group_range(struct ctl_table *table, kgid_t low, kgid_t high)
102 {
103 	kgid_t *data = table->data;
104 	struct net *net =
105 		container_of(table->data, struct net, ipv4.ping_group_range.range);
106 	write_seqlock_bh(&net->ipv4.ip_local_ports.lock);
107 	data[0] = low;
108 	data[1] = high;
109 	write_sequnlock_bh(&net->ipv4.ip_local_ports.lock);
110 }
111 
112 /* Validate changes from /proc interface. */
ipv4_ping_group_range(struct ctl_table * table,int write,void __user * buffer,size_t * lenp,loff_t * ppos)113 static int ipv4_ping_group_range(struct ctl_table *table, int write,
114 				 void __user *buffer,
115 				 size_t *lenp, loff_t *ppos)
116 {
117 	struct user_namespace *user_ns = current_user_ns();
118 	int ret;
119 	gid_t urange[2];
120 	kgid_t low, high;
121 	struct ctl_table tmp = {
122 		.data = &urange,
123 		.maxlen = sizeof(urange),
124 		.mode = table->mode,
125 		.extra1 = &ip_ping_group_range_min,
126 		.extra2 = &ip_ping_group_range_max,
127 	};
128 
129 	inet_get_ping_group_range_table(table, &low, &high);
130 	urange[0] = from_kgid_munged(user_ns, low);
131 	urange[1] = from_kgid_munged(user_ns, high);
132 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
133 
134 	if (write && ret == 0) {
135 		low = make_kgid(user_ns, urange[0]);
136 		high = make_kgid(user_ns, urange[1]);
137 		if (!gid_valid(low) || !gid_valid(high) ||
138 		    (urange[1] < urange[0]) || gid_lt(high, low)) {
139 			low = make_kgid(&init_user_ns, 1);
140 			high = make_kgid(&init_user_ns, 0);
141 		}
142 		set_ping_group_range(table, low, high);
143 	}
144 
145 	return ret;
146 }
147 
148 /* Validate changes from /proc interface. */
proc_tcp_default_init_rwnd(struct ctl_table * ctl,int write,void __user * buffer,size_t * lenp,loff_t * ppos)149 static int proc_tcp_default_init_rwnd(struct ctl_table *ctl, int write,
150 				      void __user *buffer,
151 				      size_t *lenp, loff_t *ppos)
152 {
153 	int old_value = *(int *)ctl->data;
154 	int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
155 	int new_value = *(int *)ctl->data;
156 
157 	if (write && ret == 0 && (new_value < 3 || new_value > 100))
158 		*(int *)ctl->data = old_value;
159 
160 	return ret;
161 }
162 
proc_tcp_congestion_control(struct ctl_table * ctl,int write,void __user * buffer,size_t * lenp,loff_t * ppos)163 static int proc_tcp_congestion_control(struct ctl_table *ctl, int write,
164 				       void __user *buffer, size_t *lenp, loff_t *ppos)
165 {
166 	char val[TCP_CA_NAME_MAX];
167 	struct ctl_table tbl = {
168 		.data = val,
169 		.maxlen = TCP_CA_NAME_MAX,
170 	};
171 	int ret;
172 
173 	tcp_get_default_congestion_control(val);
174 
175 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
176 	if (write && ret == 0)
177 		ret = tcp_set_default_congestion_control(val);
178 	return ret;
179 }
180 
proc_tcp_available_congestion_control(struct ctl_table * ctl,int write,void __user * buffer,size_t * lenp,loff_t * ppos)181 static int proc_tcp_available_congestion_control(struct ctl_table *ctl,
182 						 int write,
183 						 void __user *buffer, size_t *lenp,
184 						 loff_t *ppos)
185 {
186 	struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX, };
187 	int ret;
188 
189 	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
190 	if (!tbl.data)
191 		return -ENOMEM;
192 	tcp_get_available_congestion_control(tbl.data, TCP_CA_BUF_MAX);
193 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
194 	kfree(tbl.data);
195 	return ret;
196 }
197 
proc_allowed_congestion_control(struct ctl_table * ctl,int write,void __user * buffer,size_t * lenp,loff_t * ppos)198 static int proc_allowed_congestion_control(struct ctl_table *ctl,
199 					   int write,
200 					   void __user *buffer, size_t *lenp,
201 					   loff_t *ppos)
202 {
203 	struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX };
204 	int ret;
205 
206 	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
207 	if (!tbl.data)
208 		return -ENOMEM;
209 
210 	tcp_get_allowed_congestion_control(tbl.data, tbl.maxlen);
211 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
212 	if (write && ret == 0)
213 		ret = tcp_set_allowed_congestion_control(tbl.data);
214 	kfree(tbl.data);
215 	return ret;
216 }
217 
proc_tcp_fastopen_key(struct ctl_table * ctl,int write,void __user * buffer,size_t * lenp,loff_t * ppos)218 static int proc_tcp_fastopen_key(struct ctl_table *ctl, int write,
219 				 void __user *buffer, size_t *lenp,
220 				 loff_t *ppos)
221 {
222 	struct ctl_table tbl = { .maxlen = (TCP_FASTOPEN_KEY_LENGTH * 2 + 10) };
223 	struct tcp_fastopen_context *ctxt;
224 	int ret;
225 	u32  user_key[4]; /* 16 bytes, matching TCP_FASTOPEN_KEY_LENGTH */
226 
227 	tbl.data = kmalloc(tbl.maxlen, GFP_KERNEL);
228 	if (!tbl.data)
229 		return -ENOMEM;
230 
231 	rcu_read_lock();
232 	ctxt = rcu_dereference(tcp_fastopen_ctx);
233 	if (ctxt)
234 		memcpy(user_key, ctxt->key, TCP_FASTOPEN_KEY_LENGTH);
235 	else
236 		memset(user_key, 0, sizeof(user_key));
237 	rcu_read_unlock();
238 
239 	snprintf(tbl.data, tbl.maxlen, "%08x-%08x-%08x-%08x",
240 		user_key[0], user_key[1], user_key[2], user_key[3]);
241 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
242 
243 	if (write && ret == 0) {
244 		if (sscanf(tbl.data, "%x-%x-%x-%x", user_key, user_key + 1,
245 			   user_key + 2, user_key + 3) != 4) {
246 			ret = -EINVAL;
247 			goto bad_key;
248 		}
249 		/* Generate a dummy secret but don't publish it. This
250 		 * is needed so we don't regenerate a new key on the
251 		 * first invocation of tcp_fastopen_cookie_gen
252 		 */
253 		tcp_fastopen_init_key_once(false);
254 		tcp_fastopen_reset_cipher(user_key, TCP_FASTOPEN_KEY_LENGTH);
255 	}
256 
257 bad_key:
258 	pr_debug("proc FO key set 0x%x-%x-%x-%x <- 0x%s: %u\n",
259 	       user_key[0], user_key[1], user_key[2], user_key[3],
260 	       (char *)tbl.data, ret);
261 	kfree(tbl.data);
262 	return ret;
263 }
264 
265 static struct ctl_table ipv4_table[] = {
266 	{
267 		.procname	= "tcp_timestamps",
268 		.data		= &sysctl_tcp_timestamps,
269 		.maxlen		= sizeof(int),
270 		.mode		= 0644,
271 		.proc_handler	= proc_dointvec
272 	},
273 	{
274 		.procname	= "tcp_window_scaling",
275 		.data		= &sysctl_tcp_window_scaling,
276 		.maxlen		= sizeof(int),
277 		.mode		= 0644,
278 		.proc_handler	= proc_dointvec
279 	},
280 	{
281 		.procname	= "tcp_sack",
282 		.data		= &sysctl_tcp_sack,
283 		.maxlen		= sizeof(int),
284 		.mode		= 0644,
285 		.proc_handler	= proc_dointvec
286 	},
287 	{
288 		.procname	= "tcp_retrans_collapse",
289 		.data		= &sysctl_tcp_retrans_collapse,
290 		.maxlen		= sizeof(int),
291 		.mode		= 0644,
292 		.proc_handler	= proc_dointvec
293 	},
294 	{
295 		.procname	= "ip_default_ttl",
296 		.data		= &sysctl_ip_default_ttl,
297 		.maxlen		= sizeof(int),
298 		.mode		= 0644,
299 		.proc_handler	= proc_dointvec_minmax,
300 		.extra1		= &ip_ttl_min,
301 		.extra2		= &ip_ttl_max,
302 	},
303 	{
304 		.procname	= "tcp_syn_retries",
305 		.data		= &sysctl_tcp_syn_retries,
306 		.maxlen		= sizeof(int),
307 		.mode		= 0644,
308 		.proc_handler	= proc_dointvec_minmax,
309 		.extra1		= &tcp_syn_retries_min,
310 		.extra2		= &tcp_syn_retries_max
311 	},
312 	{
313 		.procname	= "tcp_synack_retries",
314 		.data		= &sysctl_tcp_synack_retries,
315 		.maxlen		= sizeof(int),
316 		.mode		= 0644,
317 		.proc_handler	= proc_dointvec
318 	},
319 	{
320 		.procname	= "tcp_max_orphans",
321 		.data		= &sysctl_tcp_max_orphans,
322 		.maxlen		= sizeof(int),
323 		.mode		= 0644,
324 		.proc_handler	= proc_dointvec
325 	},
326 	{
327 		.procname	= "tcp_max_tw_buckets",
328 		.data		= &tcp_death_row.sysctl_max_tw_buckets,
329 		.maxlen		= sizeof(int),
330 		.mode		= 0644,
331 		.proc_handler	= proc_dointvec
332 	},
333 	{
334 		.procname	= "ip_early_demux",
335 		.data		= &sysctl_ip_early_demux,
336 		.maxlen		= sizeof(int),
337 		.mode		= 0644,
338 		.proc_handler	= proc_dointvec
339 	},
340 	{
341 		.procname	= "ip_dynaddr",
342 		.data		= &sysctl_ip_dynaddr,
343 		.maxlen		= sizeof(int),
344 		.mode		= 0644,
345 		.proc_handler	= proc_dointvec
346 	},
347 	{
348 		.procname	= "tcp_keepalive_time",
349 		.data		= &sysctl_tcp_keepalive_time,
350 		.maxlen		= sizeof(int),
351 		.mode		= 0644,
352 		.proc_handler	= proc_dointvec_jiffies,
353 	},
354 	{
355 		.procname	= "tcp_keepalive_probes",
356 		.data		= &sysctl_tcp_keepalive_probes,
357 		.maxlen		= sizeof(int),
358 		.mode		= 0644,
359 		.proc_handler	= proc_dointvec
360 	},
361 	{
362 		.procname	= "tcp_keepalive_intvl",
363 		.data		= &sysctl_tcp_keepalive_intvl,
364 		.maxlen		= sizeof(int),
365 		.mode		= 0644,
366 		.proc_handler	= proc_dointvec_jiffies,
367 	},
368 	{
369 		.procname	= "tcp_retries1",
370 		.data		= &sysctl_tcp_retries1,
371 		.maxlen		= sizeof(int),
372 		.mode		= 0644,
373 		.proc_handler	= proc_dointvec_minmax,
374 		.extra2		= &tcp_retr1_max
375 	},
376 	{
377 		.procname	= "tcp_retries2",
378 		.data		= &sysctl_tcp_retries2,
379 		.maxlen		= sizeof(int),
380 		.mode		= 0644,
381 		.proc_handler	= proc_dointvec
382 	},
383 	{
384 		.procname	= "tcp_fin_timeout",
385 		.data		= &sysctl_tcp_fin_timeout,
386 		.maxlen		= sizeof(int),
387 		.mode		= 0644,
388 		.proc_handler	= proc_dointvec_jiffies,
389 	},
390 #ifdef CONFIG_SYN_COOKIES
391 	{
392 		.procname	= "tcp_syncookies",
393 		.data		= &sysctl_tcp_syncookies,
394 		.maxlen		= sizeof(int),
395 		.mode		= 0644,
396 		.proc_handler	= proc_dointvec
397 	},
398 #endif
399 	{
400 		.procname	= "tcp_fastopen",
401 		.data		= &sysctl_tcp_fastopen,
402 		.maxlen		= sizeof(int),
403 		.mode		= 0644,
404 		.proc_handler	= proc_dointvec,
405 	},
406 	{
407 		.procname	= "tcp_fastopen_key",
408 		.mode		= 0600,
409 		.maxlen		= ((TCP_FASTOPEN_KEY_LENGTH * 2) + 10),
410 		.proc_handler	= proc_tcp_fastopen_key,
411 	},
412 	{
413 		.procname	= "tcp_tw_recycle",
414 		.data		= &tcp_death_row.sysctl_tw_recycle,
415 		.maxlen		= sizeof(int),
416 		.mode		= 0644,
417 		.proc_handler	= proc_dointvec
418 	},
419 	{
420 		.procname	= "tcp_abort_on_overflow",
421 		.data		= &sysctl_tcp_abort_on_overflow,
422 		.maxlen		= sizeof(int),
423 		.mode		= 0644,
424 		.proc_handler	= proc_dointvec
425 	},
426 	{
427 		.procname	= "tcp_stdurg",
428 		.data		= &sysctl_tcp_stdurg,
429 		.maxlen		= sizeof(int),
430 		.mode		= 0644,
431 		.proc_handler	= proc_dointvec
432 	},
433 	{
434 		.procname	= "tcp_rfc1337",
435 		.data		= &sysctl_tcp_rfc1337,
436 		.maxlen		= sizeof(int),
437 		.mode		= 0644,
438 		.proc_handler	= proc_dointvec
439 	},
440 	{
441 		.procname	= "tcp_max_syn_backlog",
442 		.data		= &sysctl_max_syn_backlog,
443 		.maxlen		= sizeof(int),
444 		.mode		= 0644,
445 		.proc_handler	= proc_dointvec
446 	},
447 	{
448 		.procname	= "igmp_max_memberships",
449 		.data		= &sysctl_igmp_max_memberships,
450 		.maxlen		= sizeof(int),
451 		.mode		= 0644,
452 		.proc_handler	= proc_dointvec
453 	},
454 	{
455 		.procname	= "igmp_max_msf",
456 		.data		= &sysctl_igmp_max_msf,
457 		.maxlen		= sizeof(int),
458 		.mode		= 0644,
459 		.proc_handler	= proc_dointvec
460 	},
461 #ifdef CONFIG_IP_MULTICAST
462 	{
463 		.procname	= "igmp_qrv",
464 		.data		= &sysctl_igmp_qrv,
465 		.maxlen		= sizeof(int),
466 		.mode		= 0644,
467 		.proc_handler	= proc_dointvec_minmax,
468 		.extra1		= &one
469 	},
470 #endif
471 	{
472 		.procname	= "inet_peer_threshold",
473 		.data		= &inet_peer_threshold,
474 		.maxlen		= sizeof(int),
475 		.mode		= 0644,
476 		.proc_handler	= proc_dointvec
477 	},
478 	{
479 		.procname	= "inet_peer_minttl",
480 		.data		= &inet_peer_minttl,
481 		.maxlen		= sizeof(int),
482 		.mode		= 0644,
483 		.proc_handler	= proc_dointvec_jiffies,
484 	},
485 	{
486 		.procname	= "inet_peer_maxttl",
487 		.data		= &inet_peer_maxttl,
488 		.maxlen		= sizeof(int),
489 		.mode		= 0644,
490 		.proc_handler	= proc_dointvec_jiffies,
491 	},
492 	{
493 		.procname	= "tcp_orphan_retries",
494 		.data		= &sysctl_tcp_orphan_retries,
495 		.maxlen		= sizeof(int),
496 		.mode		= 0644,
497 		.proc_handler	= proc_dointvec
498 	},
499 	{
500 		.procname	= "tcp_fack",
501 		.data		= &sysctl_tcp_fack,
502 		.maxlen		= sizeof(int),
503 		.mode		= 0644,
504 		.proc_handler	= proc_dointvec
505 	},
506 	{
507 		.procname	= "tcp_reordering",
508 		.data		= &sysctl_tcp_reordering,
509 		.maxlen		= sizeof(int),
510 		.mode		= 0644,
511 		.proc_handler	= proc_dointvec
512 	},
513 	{
514 		.procname	= "tcp_dsack",
515 		.data		= &sysctl_tcp_dsack,
516 		.maxlen		= sizeof(int),
517 		.mode		= 0644,
518 		.proc_handler	= proc_dointvec
519 	},
520 	{
521 		.procname	= "tcp_mem",
522 		.maxlen		= sizeof(sysctl_tcp_mem),
523 		.data		= &sysctl_tcp_mem,
524 		.mode		= 0644,
525 		.proc_handler	= proc_doulongvec_minmax,
526 	},
527 	{
528 		.procname	= "tcp_wmem",
529 		.data		= &sysctl_tcp_wmem,
530 		.maxlen		= sizeof(sysctl_tcp_wmem),
531 		.mode		= 0644,
532 		.proc_handler	= proc_dointvec_minmax,
533 		.extra1		= &one,
534 	},
535 	{
536 		.procname	= "tcp_notsent_lowat",
537 		.data		= &sysctl_tcp_notsent_lowat,
538 		.maxlen		= sizeof(sysctl_tcp_notsent_lowat),
539 		.mode		= 0644,
540 		.proc_handler	= proc_dointvec,
541 	},
542 	{
543 		.procname	= "tcp_rmem",
544 		.data		= &sysctl_tcp_rmem,
545 		.maxlen		= sizeof(sysctl_tcp_rmem),
546 		.mode		= 0644,
547 		.proc_handler	= proc_dointvec_minmax,
548 		.extra1		= &one,
549 	},
550 	{
551 		.procname	= "tcp_app_win",
552 		.data		= &sysctl_tcp_app_win,
553 		.maxlen		= sizeof(int),
554 		.mode		= 0644,
555 		.proc_handler	= proc_dointvec
556 	},
557 	{
558 		.procname	= "tcp_adv_win_scale",
559 		.data		= &sysctl_tcp_adv_win_scale,
560 		.maxlen		= sizeof(int),
561 		.mode		= 0644,
562 		.proc_handler	= proc_dointvec_minmax,
563 		.extra1		= &tcp_adv_win_scale_min,
564 		.extra2		= &tcp_adv_win_scale_max,
565 	},
566 	{
567 		.procname	= "tcp_tw_reuse",
568 		.data		= &sysctl_tcp_tw_reuse,
569 		.maxlen		= sizeof(int),
570 		.mode		= 0644,
571 		.proc_handler	= proc_dointvec
572 	},
573 	{
574 		.procname	= "tcp_frto",
575 		.data		= &sysctl_tcp_frto,
576 		.maxlen		= sizeof(int),
577 		.mode		= 0644,
578 		.proc_handler	= proc_dointvec
579 	},
580 	{
581 		.procname	= "tcp_low_latency",
582 		.data		= &sysctl_tcp_low_latency,
583 		.maxlen		= sizeof(int),
584 		.mode		= 0644,
585 		.proc_handler	= proc_dointvec
586 	},
587 	{
588 		.procname	= "tcp_no_metrics_save",
589 		.data		= &sysctl_tcp_nometrics_save,
590 		.maxlen		= sizeof(int),
591 		.mode		= 0644,
592 		.proc_handler	= proc_dointvec,
593 	},
594 	{
595 		.procname	= "tcp_moderate_rcvbuf",
596 		.data		= &sysctl_tcp_moderate_rcvbuf,
597 		.maxlen		= sizeof(int),
598 		.mode		= 0644,
599 		.proc_handler	= proc_dointvec,
600 	},
601 	{
602 		.procname	= "tcp_tso_win_divisor",
603 		.data		= &sysctl_tcp_tso_win_divisor,
604 		.maxlen		= sizeof(int),
605 		.mode		= 0644,
606 		.proc_handler	= proc_dointvec,
607 	},
608 	{
609 		.procname	= "tcp_congestion_control",
610 		.mode		= 0644,
611 		.maxlen		= TCP_CA_NAME_MAX,
612 		.proc_handler	= proc_tcp_congestion_control,
613 	},
614 	{
615 		.procname	= "tcp_mtu_probing",
616 		.data		= &sysctl_tcp_mtu_probing,
617 		.maxlen		= sizeof(int),
618 		.mode		= 0644,
619 		.proc_handler	= proc_dointvec,
620 	},
621 	{
622 		.procname	= "tcp_base_mss",
623 		.data		= &sysctl_tcp_base_mss,
624 		.maxlen		= sizeof(int),
625 		.mode		= 0644,
626 		.proc_handler	= proc_dointvec,
627 	},
628 	{
629 		.procname	= "tcp_workaround_signed_windows",
630 		.data		= &sysctl_tcp_workaround_signed_windows,
631 		.maxlen		= sizeof(int),
632 		.mode		= 0644,
633 		.proc_handler	= proc_dointvec
634 	},
635 	{
636 		.procname	= "tcp_limit_output_bytes",
637 		.data		= &sysctl_tcp_limit_output_bytes,
638 		.maxlen		= sizeof(int),
639 		.mode		= 0644,
640 		.proc_handler	= proc_dointvec
641 	},
642 	{
643 		.procname	= "tcp_challenge_ack_limit",
644 		.data		= &sysctl_tcp_challenge_ack_limit,
645 		.maxlen		= sizeof(int),
646 		.mode		= 0644,
647 		.proc_handler	= proc_dointvec
648 	},
649 	{
650 		.procname	= "tcp_slow_start_after_idle",
651 		.data		= &sysctl_tcp_slow_start_after_idle,
652 		.maxlen		= sizeof(int),
653 		.mode		= 0644,
654 		.proc_handler	= proc_dointvec
655 	},
656 #ifdef CONFIG_NETLABEL
657 	{
658 		.procname	= "cipso_cache_enable",
659 		.data		= &cipso_v4_cache_enabled,
660 		.maxlen		= sizeof(int),
661 		.mode		= 0644,
662 		.proc_handler	= proc_dointvec,
663 	},
664 	{
665 		.procname	= "cipso_cache_bucket_size",
666 		.data		= &cipso_v4_cache_bucketsize,
667 		.maxlen		= sizeof(int),
668 		.mode		= 0644,
669 		.proc_handler	= proc_dointvec,
670 	},
671 	{
672 		.procname	= "cipso_rbm_optfmt",
673 		.data		= &cipso_v4_rbm_optfmt,
674 		.maxlen		= sizeof(int),
675 		.mode		= 0644,
676 		.proc_handler	= proc_dointvec,
677 	},
678 	{
679 		.procname	= "cipso_rbm_strictvalid",
680 		.data		= &cipso_v4_rbm_strictvalid,
681 		.maxlen		= sizeof(int),
682 		.mode		= 0644,
683 		.proc_handler	= proc_dointvec,
684 	},
685 #endif /* CONFIG_NETLABEL */
686 	{
687 		.procname	= "tcp_available_congestion_control",
688 		.maxlen		= TCP_CA_BUF_MAX,
689 		.mode		= 0444,
690 		.proc_handler   = proc_tcp_available_congestion_control,
691 	},
692 	{
693 		.procname	= "tcp_allowed_congestion_control",
694 		.maxlen		= TCP_CA_BUF_MAX,
695 		.mode		= 0644,
696 		.proc_handler   = proc_allowed_congestion_control,
697 	},
698 	{
699 		.procname       = "tcp_thin_linear_timeouts",
700 		.data           = &sysctl_tcp_thin_linear_timeouts,
701 		.maxlen         = sizeof(int),
702 		.mode           = 0644,
703 		.proc_handler   = proc_dointvec
704 	},
705 	{
706 		.procname       = "tcp_thin_dupack",
707 		.data           = &sysctl_tcp_thin_dupack,
708 		.maxlen         = sizeof(int),
709 		.mode           = 0644,
710 		.proc_handler   = proc_dointvec
711 	},
712 	{
713 		.procname	= "tcp_early_retrans",
714 		.data		= &sysctl_tcp_early_retrans,
715 		.maxlen		= sizeof(int),
716 		.mode		= 0644,
717 		.proc_handler	= proc_dointvec_minmax,
718 		.extra1		= &zero,
719 		.extra2		= &four,
720 	},
721 	{
722 		.procname	= "tcp_min_tso_segs",
723 		.data		= &sysctl_tcp_min_tso_segs,
724 		.maxlen		= sizeof(int),
725 		.mode		= 0644,
726 		.proc_handler	= proc_dointvec_minmax,
727 		.extra1		= &zero,
728 		.extra2		= &gso_max_segs,
729 	},
730 	{
731 		.procname	= "tcp_autocorking",
732 		.data		= &sysctl_tcp_autocorking,
733 		.maxlen		= sizeof(int),
734 		.mode		= 0644,
735 		.proc_handler	= proc_dointvec_minmax,
736 		.extra1		= &zero,
737 		.extra2		= &one,
738 	},
739 	{
740 		.procname       = "tcp_default_init_rwnd",
741 		.data           = &sysctl_tcp_default_init_rwnd,
742 		.maxlen         = sizeof(int),
743 		.mode           = 0644,
744 		.proc_handler   = proc_tcp_default_init_rwnd
745 	},
746 	{
747 		.procname	= "icmp_msgs_per_sec",
748 		.data		= &sysctl_icmp_msgs_per_sec,
749 		.maxlen		= sizeof(int),
750 		.mode		= 0644,
751 		.proc_handler	= proc_dointvec_minmax,
752 		.extra1		= &zero,
753 	},
754 	{
755 		.procname	= "icmp_msgs_burst",
756 		.data		= &sysctl_icmp_msgs_burst,
757 		.maxlen		= sizeof(int),
758 		.mode		= 0644,
759 		.proc_handler	= proc_dointvec_minmax,
760 		.extra1		= &zero,
761 	},
762 	{
763 		.procname	= "udp_mem",
764 		.data		= &sysctl_udp_mem,
765 		.maxlen		= sizeof(sysctl_udp_mem),
766 		.mode		= 0644,
767 		.proc_handler	= proc_doulongvec_minmax,
768 	},
769 	{
770 		.procname	= "udp_rmem_min",
771 		.data		= &sysctl_udp_rmem_min,
772 		.maxlen		= sizeof(sysctl_udp_rmem_min),
773 		.mode		= 0644,
774 		.proc_handler	= proc_dointvec_minmax,
775 		.extra1		= &one
776 	},
777 	{
778 		.procname	= "udp_wmem_min",
779 		.data		= &sysctl_udp_wmem_min,
780 		.maxlen		= sizeof(sysctl_udp_wmem_min),
781 		.mode		= 0644,
782 		.proc_handler	= proc_dointvec_minmax,
783 		.extra1		= &one
784 	},
785 	{ }
786 };
787 
788 static struct ctl_table ipv4_net_table[] = {
789 	{
790 		.procname	= "icmp_echo_ignore_all",
791 		.data		= &init_net.ipv4.sysctl_icmp_echo_ignore_all,
792 		.maxlen		= sizeof(int),
793 		.mode		= 0644,
794 		.proc_handler	= proc_dointvec
795 	},
796 	{
797 		.procname	= "icmp_echo_ignore_broadcasts",
798 		.data		= &init_net.ipv4.sysctl_icmp_echo_ignore_broadcasts,
799 		.maxlen		= sizeof(int),
800 		.mode		= 0644,
801 		.proc_handler	= proc_dointvec
802 	},
803 	{
804 		.procname	= "icmp_ignore_bogus_error_responses",
805 		.data		= &init_net.ipv4.sysctl_icmp_ignore_bogus_error_responses,
806 		.maxlen		= sizeof(int),
807 		.mode		= 0644,
808 		.proc_handler	= proc_dointvec
809 	},
810 	{
811 		.procname	= "icmp_errors_use_inbound_ifaddr",
812 		.data		= &init_net.ipv4.sysctl_icmp_errors_use_inbound_ifaddr,
813 		.maxlen		= sizeof(int),
814 		.mode		= 0644,
815 		.proc_handler	= proc_dointvec
816 	},
817 	{
818 		.procname	= "icmp_ratelimit",
819 		.data		= &init_net.ipv4.sysctl_icmp_ratelimit,
820 		.maxlen		= sizeof(int),
821 		.mode		= 0644,
822 		.proc_handler	= proc_dointvec_ms_jiffies,
823 	},
824 	{
825 		.procname	= "icmp_ratemask",
826 		.data		= &init_net.ipv4.sysctl_icmp_ratemask,
827 		.maxlen		= sizeof(int),
828 		.mode		= 0644,
829 		.proc_handler	= proc_dointvec
830 	},
831 	{
832 		.procname	= "ping_group_range",
833 		.data		= &init_net.ipv4.ping_group_range.range,
834 		.maxlen		= sizeof(gid_t)*2,
835 		.mode		= 0644,
836 		.proc_handler	= ipv4_ping_group_range,
837 	},
838 	{
839 		.procname	= "tcp_ecn",
840 		.data		= &init_net.ipv4.sysctl_tcp_ecn,
841 		.maxlen		= sizeof(int),
842 		.mode		= 0644,
843 		.proc_handler	= proc_dointvec
844 	},
845 	{
846 		.procname	= "ip_local_port_range",
847 		.maxlen		= sizeof(init_net.ipv4.ip_local_ports.range),
848 		.data		= &init_net.ipv4.ip_local_ports.range,
849 		.mode		= 0644,
850 		.proc_handler	= ipv4_local_port_range,
851 	},
852 	{
853 		.procname	= "ip_local_reserved_ports",
854 		.data		= &init_net.ipv4.sysctl_local_reserved_ports,
855 		.maxlen		= 65536,
856 		.mode		= 0644,
857 		.proc_handler	= proc_do_large_bitmap,
858 	},
859 	{
860 		.procname	= "ip_no_pmtu_disc",
861 		.data		= &init_net.ipv4.sysctl_ip_no_pmtu_disc,
862 		.maxlen		= sizeof(int),
863 		.mode		= 0644,
864 		.proc_handler	= proc_dointvec
865 	},
866 	{
867 		.procname	= "ip_forward_use_pmtu",
868 		.data		= &init_net.ipv4.sysctl_ip_fwd_use_pmtu,
869 		.maxlen		= sizeof(int),
870 		.mode		= 0644,
871 		.proc_handler	= proc_dointvec,
872 	},
873 	{
874 		.procname	= "ip_nonlocal_bind",
875 		.data		= &init_net.ipv4.sysctl_ip_nonlocal_bind,
876 		.maxlen		= sizeof(int),
877 		.mode		= 0644,
878 		.proc_handler	= proc_dointvec
879 	},
880 	{
881 		.procname	= "fwmark_reflect",
882 		.data		= &init_net.ipv4.sysctl_fwmark_reflect,
883 		.maxlen		= sizeof(int),
884 		.mode		= 0644,
885 		.proc_handler	= proc_dointvec,
886 	},
887 	{
888 		.procname	= "tcp_fwmark_accept",
889 		.data		= &init_net.ipv4.sysctl_tcp_fwmark_accept,
890 		.maxlen		= sizeof(int),
891 		.mode		= 0644,
892 		.proc_handler	= proc_dointvec,
893 	},
894 	{ }
895 };
896 
ipv4_sysctl_init_net(struct net * net)897 static __net_init int ipv4_sysctl_init_net(struct net *net)
898 {
899 	struct ctl_table *table;
900 
901 	table = ipv4_net_table;
902 	if (!net_eq(net, &init_net)) {
903 		int i;
904 
905 		table = kmemdup(table, sizeof(ipv4_net_table), GFP_KERNEL);
906 		if (table == NULL)
907 			goto err_alloc;
908 
909 		/* Update the variables to point into the current struct net */
910 		for (i = 0; i < ARRAY_SIZE(ipv4_net_table) - 1; i++)
911 			table[i].data += (void *)net - (void *)&init_net;
912 	}
913 
914 	net->ipv4.ipv4_hdr = register_net_sysctl(net, "net/ipv4", table);
915 	if (net->ipv4.ipv4_hdr == NULL)
916 		goto err_reg;
917 
918 	net->ipv4.sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
919 	if (!net->ipv4.sysctl_local_reserved_ports)
920 		goto err_ports;
921 
922 	return 0;
923 
924 err_ports:
925 	unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
926 err_reg:
927 	if (!net_eq(net, &init_net))
928 		kfree(table);
929 err_alloc:
930 	return -ENOMEM;
931 }
932 
ipv4_sysctl_exit_net(struct net * net)933 static __net_exit void ipv4_sysctl_exit_net(struct net *net)
934 {
935 	struct ctl_table *table;
936 
937 	kfree(net->ipv4.sysctl_local_reserved_ports);
938 	table = net->ipv4.ipv4_hdr->ctl_table_arg;
939 	unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
940 	kfree(table);
941 }
942 
943 static __net_initdata struct pernet_operations ipv4_sysctl_ops = {
944 	.init = ipv4_sysctl_init_net,
945 	.exit = ipv4_sysctl_exit_net,
946 };
947 
sysctl_ipv4_init(void)948 static __init int sysctl_ipv4_init(void)
949 {
950 	struct ctl_table_header *hdr;
951 
952 	hdr = register_net_sysctl(&init_net, "net/ipv4", ipv4_table);
953 	if (hdr == NULL)
954 		return -ENOMEM;
955 
956 	if (register_pernet_subsys(&ipv4_sysctl_ops)) {
957 		unregister_net_sysctl_table(hdr);
958 		return -ENOMEM;
959 	}
960 
961 	return 0;
962 }
963 
964 __initcall(sysctl_ipv4_init);
965