xref: /linux/net/ipv4/sysctl_net_ipv4.c (revision 40d3057ac036f2501c1930728a6179be4fca577b)
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 <net/snmp.h>
16 #include <net/icmp.h>
17 #include <net/ip.h>
18 #include <net/route.h>
19 #include <net/tcp.h>
20 #include <net/udp.h>
21 #include <net/cipso_ipv4.h>
22 #include <net/inet_frag.h>
23 
24 static int zero;
25 static int tcp_retr1_max = 255;
26 static int ip_local_port_range_min[] = { 1, 1 };
27 static int ip_local_port_range_max[] = { 65535, 65535 };
28 
29 extern seqlock_t sysctl_port_range_lock;
30 extern int sysctl_local_port_range[2];
31 
32 /* Update system visible IP port range */
33 static void set_local_port_range(int range[2])
34 {
35 	write_seqlock(&sysctl_port_range_lock);
36 	sysctl_local_port_range[0] = range[0];
37 	sysctl_local_port_range[1] = range[1];
38 	write_sequnlock(&sysctl_port_range_lock);
39 }
40 
41 /* Validate changes from /proc interface. */
42 static int ipv4_local_port_range(ctl_table *table, int write, struct file *filp,
43 				 void __user *buffer,
44 				 size_t *lenp, loff_t *ppos)
45 {
46 	int ret;
47 	int range[2] = { sysctl_local_port_range[0],
48 			 sysctl_local_port_range[1] };
49 	ctl_table tmp = {
50 		.data = &range,
51 		.maxlen = sizeof(range),
52 		.mode = table->mode,
53 		.extra1 = &ip_local_port_range_min,
54 		.extra2 = &ip_local_port_range_max,
55 	};
56 
57 	ret = proc_dointvec_minmax(&tmp, write, filp, buffer, lenp, ppos);
58 
59 	if (write && ret == 0) {
60 		if (range[1] < range[0])
61 			ret = -EINVAL;
62 		else
63 			set_local_port_range(range);
64 	}
65 
66 	return ret;
67 }
68 
69 /* Validate changes from sysctl interface. */
70 static int ipv4_sysctl_local_port_range(ctl_table *table, int __user *name,
71 					 int nlen, void __user *oldval,
72 					 size_t __user *oldlenp,
73 					void __user *newval, size_t newlen)
74 {
75 	int ret;
76 	int range[2] = { sysctl_local_port_range[0],
77 			 sysctl_local_port_range[1] };
78 	ctl_table tmp = {
79 		.data = &range,
80 		.maxlen = sizeof(range),
81 		.mode = table->mode,
82 		.extra1 = &ip_local_port_range_min,
83 		.extra2 = &ip_local_port_range_max,
84 	};
85 
86 	ret = sysctl_intvec(&tmp, name, nlen, oldval, oldlenp, newval, newlen);
87 	if (ret == 0 && newval && newlen) {
88 		if (range[1] < range[0])
89 			ret = -EINVAL;
90 		else
91 			set_local_port_range(range);
92 	}
93 	return ret;
94 }
95 
96 
97 static int proc_tcp_congestion_control(ctl_table *ctl, int write, struct file * filp,
98 				       void __user *buffer, size_t *lenp, loff_t *ppos)
99 {
100 	char val[TCP_CA_NAME_MAX];
101 	ctl_table tbl = {
102 		.data = val,
103 		.maxlen = TCP_CA_NAME_MAX,
104 	};
105 	int ret;
106 
107 	tcp_get_default_congestion_control(val);
108 
109 	ret = proc_dostring(&tbl, write, filp, buffer, lenp, ppos);
110 	if (write && ret == 0)
111 		ret = tcp_set_default_congestion_control(val);
112 	return ret;
113 }
114 
115 static int sysctl_tcp_congestion_control(ctl_table *table, int __user *name,
116 					 int nlen, void __user *oldval,
117 					 size_t __user *oldlenp,
118 					 void __user *newval, size_t newlen)
119 {
120 	char val[TCP_CA_NAME_MAX];
121 	ctl_table tbl = {
122 		.data = val,
123 		.maxlen = TCP_CA_NAME_MAX,
124 	};
125 	int ret;
126 
127 	tcp_get_default_congestion_control(val);
128 	ret = sysctl_string(&tbl, name, nlen, oldval, oldlenp, newval, newlen);
129 	if (ret == 1 && newval && newlen)
130 		ret = tcp_set_default_congestion_control(val);
131 	return ret;
132 }
133 
134 static int proc_tcp_available_congestion_control(ctl_table *ctl,
135 						 int write, struct file * filp,
136 						 void __user *buffer, size_t *lenp,
137 						 loff_t *ppos)
138 {
139 	ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX, };
140 	int ret;
141 
142 	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
143 	if (!tbl.data)
144 		return -ENOMEM;
145 	tcp_get_available_congestion_control(tbl.data, TCP_CA_BUF_MAX);
146 	ret = proc_dostring(&tbl, write, filp, buffer, lenp, ppos);
147 	kfree(tbl.data);
148 	return ret;
149 }
150 
151 static int proc_allowed_congestion_control(ctl_table *ctl,
152 					   int write, struct file * filp,
153 					   void __user *buffer, size_t *lenp,
154 					   loff_t *ppos)
155 {
156 	ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX };
157 	int ret;
158 
159 	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
160 	if (!tbl.data)
161 		return -ENOMEM;
162 
163 	tcp_get_allowed_congestion_control(tbl.data, tbl.maxlen);
164 	ret = proc_dostring(&tbl, write, filp, buffer, lenp, ppos);
165 	if (write && ret == 0)
166 		ret = tcp_set_allowed_congestion_control(tbl.data);
167 	kfree(tbl.data);
168 	return ret;
169 }
170 
171 static int strategy_allowed_congestion_control(ctl_table *table, int __user *name,
172 					       int nlen, void __user *oldval,
173 					       size_t __user *oldlenp,
174 					       void __user *newval,
175 					       size_t newlen)
176 {
177 	ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX };
178 	int ret;
179 
180 	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
181 	if (!tbl.data)
182 		return -ENOMEM;
183 
184 	tcp_get_available_congestion_control(tbl.data, tbl.maxlen);
185 	ret = sysctl_string(&tbl, name, nlen, oldval, oldlenp, newval, newlen);
186 	if (ret == 1 && newval && newlen)
187 		ret = tcp_set_allowed_congestion_control(tbl.data);
188 	kfree(tbl.data);
189 
190 	return ret;
191 
192 }
193 
194 static struct ctl_table ipv4_table[] = {
195 	{
196 		.ctl_name	= NET_IPV4_TCP_TIMESTAMPS,
197 		.procname	= "tcp_timestamps",
198 		.data		= &sysctl_tcp_timestamps,
199 		.maxlen		= sizeof(int),
200 		.mode		= 0644,
201 		.proc_handler	= &proc_dointvec
202 	},
203 	{
204 		.ctl_name	= NET_IPV4_TCP_WINDOW_SCALING,
205 		.procname	= "tcp_window_scaling",
206 		.data		= &sysctl_tcp_window_scaling,
207 		.maxlen		= sizeof(int),
208 		.mode		= 0644,
209 		.proc_handler	= &proc_dointvec
210 	},
211 	{
212 		.ctl_name	= NET_IPV4_TCP_SACK,
213 		.procname	= "tcp_sack",
214 		.data		= &sysctl_tcp_sack,
215 		.maxlen		= sizeof(int),
216 		.mode		= 0644,
217 		.proc_handler	= &proc_dointvec
218 	},
219 	{
220 		.ctl_name	= NET_IPV4_TCP_RETRANS_COLLAPSE,
221 		.procname	= "tcp_retrans_collapse",
222 		.data		= &sysctl_tcp_retrans_collapse,
223 		.maxlen		= sizeof(int),
224 		.mode		= 0644,
225 		.proc_handler	= &proc_dointvec
226 	},
227 	{
228 		.ctl_name	= NET_IPV4_DEFAULT_TTL,
229 		.procname	= "ip_default_ttl",
230 		.data		= &sysctl_ip_default_ttl,
231 		.maxlen		= sizeof(int),
232 		.mode		= 0644,
233 		.proc_handler	= &ipv4_doint_and_flush,
234 		.strategy	= &ipv4_doint_and_flush_strategy,
235 		.extra2		= &init_net,
236 	},
237 	{
238 		.ctl_name	= NET_IPV4_NO_PMTU_DISC,
239 		.procname	= "ip_no_pmtu_disc",
240 		.data		= &ipv4_config.no_pmtu_disc,
241 		.maxlen		= sizeof(int),
242 		.mode		= 0644,
243 		.proc_handler	= &proc_dointvec
244 	},
245 	{
246 		.ctl_name	= NET_IPV4_NONLOCAL_BIND,
247 		.procname	= "ip_nonlocal_bind",
248 		.data		= &sysctl_ip_nonlocal_bind,
249 		.maxlen		= sizeof(int),
250 		.mode		= 0644,
251 		.proc_handler	= &proc_dointvec
252 	},
253 	{
254 		.ctl_name	= NET_IPV4_TCP_SYN_RETRIES,
255 		.procname	= "tcp_syn_retries",
256 		.data		= &sysctl_tcp_syn_retries,
257 		.maxlen		= sizeof(int),
258 		.mode		= 0644,
259 		.proc_handler	= &proc_dointvec
260 	},
261 	{
262 		.ctl_name	= NET_TCP_SYNACK_RETRIES,
263 		.procname	= "tcp_synack_retries",
264 		.data		= &sysctl_tcp_synack_retries,
265 		.maxlen		= sizeof(int),
266 		.mode		= 0644,
267 		.proc_handler	= &proc_dointvec
268 	},
269 	{
270 		.ctl_name	= NET_TCP_MAX_ORPHANS,
271 		.procname	= "tcp_max_orphans",
272 		.data		= &sysctl_tcp_max_orphans,
273 		.maxlen		= sizeof(int),
274 		.mode		= 0644,
275 		.proc_handler	= &proc_dointvec
276 	},
277 	{
278 		.ctl_name	= NET_TCP_MAX_TW_BUCKETS,
279 		.procname	= "tcp_max_tw_buckets",
280 		.data		= &tcp_death_row.sysctl_max_tw_buckets,
281 		.maxlen		= sizeof(int),
282 		.mode		= 0644,
283 		.proc_handler	= &proc_dointvec
284 	},
285 	{
286 		.ctl_name	= NET_IPV4_DYNADDR,
287 		.procname	= "ip_dynaddr",
288 		.data		= &sysctl_ip_dynaddr,
289 		.maxlen		= sizeof(int),
290 		.mode		= 0644,
291 		.proc_handler	= &proc_dointvec
292 	},
293 	{
294 		.ctl_name	= NET_IPV4_TCP_KEEPALIVE_TIME,
295 		.procname	= "tcp_keepalive_time",
296 		.data		= &sysctl_tcp_keepalive_time,
297 		.maxlen		= sizeof(int),
298 		.mode		= 0644,
299 		.proc_handler	= &proc_dointvec_jiffies,
300 		.strategy	= &sysctl_jiffies
301 	},
302 	{
303 		.ctl_name	= NET_IPV4_TCP_KEEPALIVE_PROBES,
304 		.procname	= "tcp_keepalive_probes",
305 		.data		= &sysctl_tcp_keepalive_probes,
306 		.maxlen		= sizeof(int),
307 		.mode		= 0644,
308 		.proc_handler	= &proc_dointvec
309 	},
310 	{
311 		.ctl_name	= NET_IPV4_TCP_KEEPALIVE_INTVL,
312 		.procname	= "tcp_keepalive_intvl",
313 		.data		= &sysctl_tcp_keepalive_intvl,
314 		.maxlen		= sizeof(int),
315 		.mode		= 0644,
316 		.proc_handler	= &proc_dointvec_jiffies,
317 		.strategy	= &sysctl_jiffies
318 	},
319 	{
320 		.ctl_name	= NET_IPV4_TCP_RETRIES1,
321 		.procname	= "tcp_retries1",
322 		.data		= &sysctl_tcp_retries1,
323 		.maxlen		= sizeof(int),
324 		.mode		= 0644,
325 		.proc_handler	= &proc_dointvec_minmax,
326 		.strategy	= &sysctl_intvec,
327 		.extra2		= &tcp_retr1_max
328 	},
329 	{
330 		.ctl_name	= NET_IPV4_TCP_RETRIES2,
331 		.procname	= "tcp_retries2",
332 		.data		= &sysctl_tcp_retries2,
333 		.maxlen		= sizeof(int),
334 		.mode		= 0644,
335 		.proc_handler	= &proc_dointvec
336 	},
337 	{
338 		.ctl_name	= NET_IPV4_TCP_FIN_TIMEOUT,
339 		.procname	= "tcp_fin_timeout",
340 		.data		= &sysctl_tcp_fin_timeout,
341 		.maxlen		= sizeof(int),
342 		.mode		= 0644,
343 		.proc_handler	= &proc_dointvec_jiffies,
344 		.strategy	= &sysctl_jiffies
345 	},
346 #ifdef CONFIG_SYN_COOKIES
347 	{
348 		.ctl_name	= NET_TCP_SYNCOOKIES,
349 		.procname	= "tcp_syncookies",
350 		.data		= &sysctl_tcp_syncookies,
351 		.maxlen		= sizeof(int),
352 		.mode		= 0644,
353 		.proc_handler	= &proc_dointvec
354 	},
355 #endif
356 	{
357 		.ctl_name	= NET_TCP_TW_RECYCLE,
358 		.procname	= "tcp_tw_recycle",
359 		.data		= &tcp_death_row.sysctl_tw_recycle,
360 		.maxlen		= sizeof(int),
361 		.mode		= 0644,
362 		.proc_handler	= &proc_dointvec
363 	},
364 	{
365 		.ctl_name	= NET_TCP_ABORT_ON_OVERFLOW,
366 		.procname	= "tcp_abort_on_overflow",
367 		.data		= &sysctl_tcp_abort_on_overflow,
368 		.maxlen		= sizeof(int),
369 		.mode		= 0644,
370 		.proc_handler	= &proc_dointvec
371 	},
372 	{
373 		.ctl_name	= NET_TCP_STDURG,
374 		.procname	= "tcp_stdurg",
375 		.data		= &sysctl_tcp_stdurg,
376 		.maxlen		= sizeof(int),
377 		.mode		= 0644,
378 		.proc_handler	= &proc_dointvec
379 	},
380 	{
381 		.ctl_name	= NET_TCP_RFC1337,
382 		.procname	= "tcp_rfc1337",
383 		.data		= &sysctl_tcp_rfc1337,
384 		.maxlen		= sizeof(int),
385 		.mode		= 0644,
386 		.proc_handler	= &proc_dointvec
387 	},
388 	{
389 		.ctl_name	= NET_TCP_MAX_SYN_BACKLOG,
390 		.procname	= "tcp_max_syn_backlog",
391 		.data		= &sysctl_max_syn_backlog,
392 		.maxlen		= sizeof(int),
393 		.mode		= 0644,
394 		.proc_handler	= &proc_dointvec
395 	},
396 	{
397 		.ctl_name	= NET_IPV4_LOCAL_PORT_RANGE,
398 		.procname	= "ip_local_port_range",
399 		.data		= &sysctl_local_port_range,
400 		.maxlen		= sizeof(sysctl_local_port_range),
401 		.mode		= 0644,
402 		.proc_handler	= &ipv4_local_port_range,
403 		.strategy	= &ipv4_sysctl_local_port_range,
404 	},
405 #ifdef CONFIG_IP_MULTICAST
406 	{
407 		.ctl_name	= NET_IPV4_IGMP_MAX_MEMBERSHIPS,
408 		.procname	= "igmp_max_memberships",
409 		.data		= &sysctl_igmp_max_memberships,
410 		.maxlen		= sizeof(int),
411 		.mode		= 0644,
412 		.proc_handler	= &proc_dointvec
413 	},
414 
415 #endif
416 	{
417 		.ctl_name	= NET_IPV4_IGMP_MAX_MSF,
418 		.procname	= "igmp_max_msf",
419 		.data		= &sysctl_igmp_max_msf,
420 		.maxlen		= sizeof(int),
421 		.mode		= 0644,
422 		.proc_handler	= &proc_dointvec
423 	},
424 	{
425 		.ctl_name	= NET_IPV4_INET_PEER_THRESHOLD,
426 		.procname	= "inet_peer_threshold",
427 		.data		= &inet_peer_threshold,
428 		.maxlen		= sizeof(int),
429 		.mode		= 0644,
430 		.proc_handler	= &proc_dointvec
431 	},
432 	{
433 		.ctl_name	= NET_IPV4_INET_PEER_MINTTL,
434 		.procname	= "inet_peer_minttl",
435 		.data		= &inet_peer_minttl,
436 		.maxlen		= sizeof(int),
437 		.mode		= 0644,
438 		.proc_handler	= &proc_dointvec_jiffies,
439 		.strategy	= &sysctl_jiffies
440 	},
441 	{
442 		.ctl_name	= NET_IPV4_INET_PEER_MAXTTL,
443 		.procname	= "inet_peer_maxttl",
444 		.data		= &inet_peer_maxttl,
445 		.maxlen		= sizeof(int),
446 		.mode		= 0644,
447 		.proc_handler	= &proc_dointvec_jiffies,
448 		.strategy	= &sysctl_jiffies
449 	},
450 	{
451 		.ctl_name	= NET_IPV4_INET_PEER_GC_MINTIME,
452 		.procname	= "inet_peer_gc_mintime",
453 		.data		= &inet_peer_gc_mintime,
454 		.maxlen		= sizeof(int),
455 		.mode		= 0644,
456 		.proc_handler	= &proc_dointvec_jiffies,
457 		.strategy	= &sysctl_jiffies
458 	},
459 	{
460 		.ctl_name	= NET_IPV4_INET_PEER_GC_MAXTIME,
461 		.procname	= "inet_peer_gc_maxtime",
462 		.data		= &inet_peer_gc_maxtime,
463 		.maxlen		= sizeof(int),
464 		.mode		= 0644,
465 		.proc_handler	= &proc_dointvec_jiffies,
466 		.strategy	= &sysctl_jiffies
467 	},
468 	{
469 		.ctl_name	= NET_TCP_ORPHAN_RETRIES,
470 		.procname	= "tcp_orphan_retries",
471 		.data		= &sysctl_tcp_orphan_retries,
472 		.maxlen		= sizeof(int),
473 		.mode		= 0644,
474 		.proc_handler	= &proc_dointvec
475 	},
476 	{
477 		.ctl_name	= NET_TCP_FACK,
478 		.procname	= "tcp_fack",
479 		.data		= &sysctl_tcp_fack,
480 		.maxlen		= sizeof(int),
481 		.mode		= 0644,
482 		.proc_handler	= &proc_dointvec
483 	},
484 	{
485 		.ctl_name	= NET_TCP_REORDERING,
486 		.procname	= "tcp_reordering",
487 		.data		= &sysctl_tcp_reordering,
488 		.maxlen		= sizeof(int),
489 		.mode		= 0644,
490 		.proc_handler	= &proc_dointvec
491 	},
492 	{
493 		.ctl_name	= NET_TCP_ECN,
494 		.procname	= "tcp_ecn",
495 		.data		= &sysctl_tcp_ecn,
496 		.maxlen		= sizeof(int),
497 		.mode		= 0644,
498 		.proc_handler	= &proc_dointvec
499 	},
500 	{
501 		.ctl_name	= NET_TCP_DSACK,
502 		.procname	= "tcp_dsack",
503 		.data		= &sysctl_tcp_dsack,
504 		.maxlen		= sizeof(int),
505 		.mode		= 0644,
506 		.proc_handler	= &proc_dointvec
507 	},
508 	{
509 		.ctl_name	= NET_TCP_MEM,
510 		.procname	= "tcp_mem",
511 		.data		= &sysctl_tcp_mem,
512 		.maxlen		= sizeof(sysctl_tcp_mem),
513 		.mode		= 0644,
514 		.proc_handler	= &proc_dointvec
515 	},
516 	{
517 		.ctl_name	= NET_TCP_WMEM,
518 		.procname	= "tcp_wmem",
519 		.data		= &sysctl_tcp_wmem,
520 		.maxlen		= sizeof(sysctl_tcp_wmem),
521 		.mode		= 0644,
522 		.proc_handler	= &proc_dointvec
523 	},
524 	{
525 		.ctl_name	= NET_TCP_RMEM,
526 		.procname	= "tcp_rmem",
527 		.data		= &sysctl_tcp_rmem,
528 		.maxlen		= sizeof(sysctl_tcp_rmem),
529 		.mode		= 0644,
530 		.proc_handler	= &proc_dointvec
531 	},
532 	{
533 		.ctl_name	= NET_TCP_APP_WIN,
534 		.procname	= "tcp_app_win",
535 		.data		= &sysctl_tcp_app_win,
536 		.maxlen		= sizeof(int),
537 		.mode		= 0644,
538 		.proc_handler	= &proc_dointvec
539 	},
540 	{
541 		.ctl_name	= NET_TCP_ADV_WIN_SCALE,
542 		.procname	= "tcp_adv_win_scale",
543 		.data		= &sysctl_tcp_adv_win_scale,
544 		.maxlen		= sizeof(int),
545 		.mode		= 0644,
546 		.proc_handler	= &proc_dointvec
547 	},
548 	{
549 		.ctl_name	= NET_TCP_TW_REUSE,
550 		.procname	= "tcp_tw_reuse",
551 		.data		= &sysctl_tcp_tw_reuse,
552 		.maxlen		= sizeof(int),
553 		.mode		= 0644,
554 		.proc_handler	= &proc_dointvec
555 	},
556 	{
557 		.ctl_name	= NET_TCP_FRTO,
558 		.procname	= "tcp_frto",
559 		.data		= &sysctl_tcp_frto,
560 		.maxlen		= sizeof(int),
561 		.mode		= 0644,
562 		.proc_handler	= &proc_dointvec
563 	},
564 	{
565 		.ctl_name	= NET_TCP_FRTO_RESPONSE,
566 		.procname	= "tcp_frto_response",
567 		.data		= &sysctl_tcp_frto_response,
568 		.maxlen		= sizeof(int),
569 		.mode		= 0644,
570 		.proc_handler	= &proc_dointvec
571 	},
572 	{
573 		.ctl_name	= NET_TCP_LOW_LATENCY,
574 		.procname	= "tcp_low_latency",
575 		.data		= &sysctl_tcp_low_latency,
576 		.maxlen		= sizeof(int),
577 		.mode		= 0644,
578 		.proc_handler	= &proc_dointvec
579 	},
580 	{
581 		.ctl_name	= NET_TCP_NO_METRICS_SAVE,
582 		.procname	= "tcp_no_metrics_save",
583 		.data		= &sysctl_tcp_nometrics_save,
584 		.maxlen		= sizeof(int),
585 		.mode		= 0644,
586 		.proc_handler	= &proc_dointvec,
587 	},
588 	{
589 		.ctl_name	= NET_TCP_MODERATE_RCVBUF,
590 		.procname	= "tcp_moderate_rcvbuf",
591 		.data		= &sysctl_tcp_moderate_rcvbuf,
592 		.maxlen		= sizeof(int),
593 		.mode		= 0644,
594 		.proc_handler	= &proc_dointvec,
595 	},
596 	{
597 		.ctl_name	= NET_TCP_TSO_WIN_DIVISOR,
598 		.procname	= "tcp_tso_win_divisor",
599 		.data		= &sysctl_tcp_tso_win_divisor,
600 		.maxlen		= sizeof(int),
601 		.mode		= 0644,
602 		.proc_handler	= &proc_dointvec,
603 	},
604 	{
605 		.ctl_name	= NET_TCP_CONG_CONTROL,
606 		.procname	= "tcp_congestion_control",
607 		.mode		= 0644,
608 		.maxlen		= TCP_CA_NAME_MAX,
609 		.proc_handler	= &proc_tcp_congestion_control,
610 		.strategy	= &sysctl_tcp_congestion_control,
611 	},
612 	{
613 		.ctl_name	= NET_TCP_ABC,
614 		.procname	= "tcp_abc",
615 		.data		= &sysctl_tcp_abc,
616 		.maxlen		= sizeof(int),
617 		.mode		= 0644,
618 		.proc_handler	= &proc_dointvec,
619 	},
620 	{
621 		.ctl_name	= NET_TCP_MTU_PROBING,
622 		.procname	= "tcp_mtu_probing",
623 		.data		= &sysctl_tcp_mtu_probing,
624 		.maxlen		= sizeof(int),
625 		.mode		= 0644,
626 		.proc_handler	= &proc_dointvec,
627 	},
628 	{
629 		.ctl_name	= NET_TCP_BASE_MSS,
630 		.procname	= "tcp_base_mss",
631 		.data		= &sysctl_tcp_base_mss,
632 		.maxlen		= sizeof(int),
633 		.mode		= 0644,
634 		.proc_handler	= &proc_dointvec,
635 	},
636 	{
637 		.ctl_name	= NET_IPV4_TCP_WORKAROUND_SIGNED_WINDOWS,
638 		.procname	= "tcp_workaround_signed_windows",
639 		.data		= &sysctl_tcp_workaround_signed_windows,
640 		.maxlen		= sizeof(int),
641 		.mode		= 0644,
642 		.proc_handler	= &proc_dointvec
643 	},
644 #ifdef CONFIG_NET_DMA
645 	{
646 		.ctl_name	= NET_TCP_DMA_COPYBREAK,
647 		.procname	= "tcp_dma_copybreak",
648 		.data		= &sysctl_tcp_dma_copybreak,
649 		.maxlen		= sizeof(int),
650 		.mode		= 0644,
651 		.proc_handler	= &proc_dointvec
652 	},
653 #endif
654 	{
655 		.ctl_name	= NET_TCP_SLOW_START_AFTER_IDLE,
656 		.procname	= "tcp_slow_start_after_idle",
657 		.data		= &sysctl_tcp_slow_start_after_idle,
658 		.maxlen		= sizeof(int),
659 		.mode		= 0644,
660 		.proc_handler	= &proc_dointvec
661 	},
662 #ifdef CONFIG_NETLABEL
663 	{
664 		.ctl_name	= NET_CIPSOV4_CACHE_ENABLE,
665 		.procname	= "cipso_cache_enable",
666 		.data		= &cipso_v4_cache_enabled,
667 		.maxlen		= sizeof(int),
668 		.mode		= 0644,
669 		.proc_handler	= &proc_dointvec,
670 	},
671 	{
672 		.ctl_name	= NET_CIPSOV4_CACHE_BUCKET_SIZE,
673 		.procname	= "cipso_cache_bucket_size",
674 		.data		= &cipso_v4_cache_bucketsize,
675 		.maxlen		= sizeof(int),
676 		.mode		= 0644,
677 		.proc_handler	= &proc_dointvec,
678 	},
679 	{
680 		.ctl_name	= NET_CIPSOV4_RBM_OPTFMT,
681 		.procname	= "cipso_rbm_optfmt",
682 		.data		= &cipso_v4_rbm_optfmt,
683 		.maxlen		= sizeof(int),
684 		.mode		= 0644,
685 		.proc_handler	= &proc_dointvec,
686 	},
687 	{
688 		.ctl_name	= NET_CIPSOV4_RBM_STRICTVALID,
689 		.procname	= "cipso_rbm_strictvalid",
690 		.data		= &cipso_v4_rbm_strictvalid,
691 		.maxlen		= sizeof(int),
692 		.mode		= 0644,
693 		.proc_handler	= &proc_dointvec,
694 	},
695 #endif /* CONFIG_NETLABEL */
696 	{
697 		.procname	= "tcp_available_congestion_control",
698 		.maxlen		= TCP_CA_BUF_MAX,
699 		.mode		= 0444,
700 		.proc_handler   = &proc_tcp_available_congestion_control,
701 	},
702 	{
703 		.ctl_name	= NET_TCP_ALLOWED_CONG_CONTROL,
704 		.procname	= "tcp_allowed_congestion_control",
705 		.maxlen		= TCP_CA_BUF_MAX,
706 		.mode		= 0644,
707 		.proc_handler   = &proc_allowed_congestion_control,
708 		.strategy	= &strategy_allowed_congestion_control,
709 	},
710 	{
711 		.ctl_name	= NET_TCP_MAX_SSTHRESH,
712 		.procname	= "tcp_max_ssthresh",
713 		.data		= &sysctl_tcp_max_ssthresh,
714 		.maxlen		= sizeof(int),
715 		.mode		= 0644,
716 		.proc_handler	= &proc_dointvec,
717 	},
718 	{
719 		.ctl_name	= CTL_UNNUMBERED,
720 		.procname	= "udp_mem",
721 		.data		= &sysctl_udp_mem,
722 		.maxlen		= sizeof(sysctl_udp_mem),
723 		.mode		= 0644,
724 		.proc_handler	= &proc_dointvec_minmax,
725 		.strategy	= &sysctl_intvec,
726 		.extra1		= &zero
727 	},
728 	{
729 		.ctl_name	= CTL_UNNUMBERED,
730 		.procname	= "udp_rmem_min",
731 		.data		= &sysctl_udp_rmem_min,
732 		.maxlen		= sizeof(sysctl_udp_rmem_min),
733 		.mode		= 0644,
734 		.proc_handler	= &proc_dointvec_minmax,
735 		.strategy	= &sysctl_intvec,
736 		.extra1		= &zero
737 	},
738 	{
739 		.ctl_name	= CTL_UNNUMBERED,
740 		.procname	= "udp_wmem_min",
741 		.data		= &sysctl_udp_wmem_min,
742 		.maxlen		= sizeof(sysctl_udp_wmem_min),
743 		.mode		= 0644,
744 		.proc_handler	= &proc_dointvec_minmax,
745 		.strategy	= &sysctl_intvec,
746 		.extra1		= &zero
747 	},
748 	{ .ctl_name = 0 }
749 };
750 
751 static struct ctl_table ipv4_net_table[] = {
752 	{
753 		.ctl_name	= NET_IPV4_ICMP_ECHO_IGNORE_ALL,
754 		.procname	= "icmp_echo_ignore_all",
755 		.data		= &init_net.ipv4.sysctl_icmp_echo_ignore_all,
756 		.maxlen		= sizeof(int),
757 		.mode		= 0644,
758 		.proc_handler	= &proc_dointvec
759 	},
760 	{
761 		.ctl_name	= NET_IPV4_ICMP_ECHO_IGNORE_BROADCASTS,
762 		.procname	= "icmp_echo_ignore_broadcasts",
763 		.data		= &init_net.ipv4.sysctl_icmp_echo_ignore_broadcasts,
764 		.maxlen		= sizeof(int),
765 		.mode		= 0644,
766 		.proc_handler	= &proc_dointvec
767 	},
768 	{
769 		.ctl_name	= NET_IPV4_ICMP_IGNORE_BOGUS_ERROR_RESPONSES,
770 		.procname	= "icmp_ignore_bogus_error_responses",
771 		.data		= &init_net.ipv4.sysctl_icmp_ignore_bogus_error_responses,
772 		.maxlen		= sizeof(int),
773 		.mode		= 0644,
774 		.proc_handler	= &proc_dointvec
775 	},
776 	{
777 		.ctl_name	= NET_IPV4_ICMP_ERRORS_USE_INBOUND_IFADDR,
778 		.procname	= "icmp_errors_use_inbound_ifaddr",
779 		.data		= &init_net.ipv4.sysctl_icmp_errors_use_inbound_ifaddr,
780 		.maxlen		= sizeof(int),
781 		.mode		= 0644,
782 		.proc_handler	= &proc_dointvec
783 	},
784 	{
785 		.ctl_name	= NET_IPV4_ICMP_RATELIMIT,
786 		.procname	= "icmp_ratelimit",
787 		.data		= &init_net.ipv4.sysctl_icmp_ratelimit,
788 		.maxlen		= sizeof(int),
789 		.mode		= 0644,
790 		.proc_handler	= &proc_dointvec_ms_jiffies,
791 		.strategy	= &sysctl_ms_jiffies
792 	},
793 	{
794 		.ctl_name	= NET_IPV4_ICMP_RATEMASK,
795 		.procname	= "icmp_ratemask",
796 		.data		= &init_net.ipv4.sysctl_icmp_ratemask,
797 		.maxlen		= sizeof(int),
798 		.mode		= 0644,
799 		.proc_handler	= &proc_dointvec
800 	},
801 	{ }
802 };
803 
804 struct ctl_path net_ipv4_ctl_path[] = {
805 	{ .procname = "net", .ctl_name = CTL_NET, },
806 	{ .procname = "ipv4", .ctl_name = NET_IPV4, },
807 	{ },
808 };
809 EXPORT_SYMBOL_GPL(net_ipv4_ctl_path);
810 
811 static __net_init int ipv4_sysctl_init_net(struct net *net)
812 {
813 	struct ctl_table *table;
814 
815 	table = ipv4_net_table;
816 	if (net != &init_net) {
817 		table = kmemdup(table, sizeof(ipv4_net_table), GFP_KERNEL);
818 		if (table == NULL)
819 			goto err_alloc;
820 
821 		table[0].data =
822 			&net->ipv4.sysctl_icmp_echo_ignore_all;
823 		table[1].data =
824 			&net->ipv4.sysctl_icmp_echo_ignore_broadcasts;
825 		table[2].data =
826 			&net->ipv4.sysctl_icmp_ignore_bogus_error_responses;
827 		table[3].data =
828 			&net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr;
829 		table[4].data =
830 			&net->ipv4.sysctl_icmp_ratelimit;
831 		table[5].data =
832 			&net->ipv4.sysctl_icmp_ratemask;
833 	}
834 
835 	net->ipv4.ipv4_hdr = register_net_sysctl_table(net,
836 			net_ipv4_ctl_path, table);
837 	if (net->ipv4.ipv4_hdr == NULL)
838 		goto err_reg;
839 
840 	return 0;
841 
842 err_reg:
843 	if (net != &init_net)
844 		kfree(table);
845 err_alloc:
846 	return -ENOMEM;
847 }
848 
849 static __net_exit void ipv4_sysctl_exit_net(struct net *net)
850 {
851 	struct ctl_table *table;
852 
853 	table = net->ipv4.ipv4_hdr->ctl_table_arg;
854 	unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
855 	kfree(table);
856 }
857 
858 static __net_initdata struct pernet_operations ipv4_sysctl_ops = {
859 	.init = ipv4_sysctl_init_net,
860 	.exit = ipv4_sysctl_exit_net,
861 };
862 
863 static __init int sysctl_ipv4_init(void)
864 {
865 	struct ctl_table_header *hdr;
866 
867 	hdr = register_sysctl_paths(net_ipv4_ctl_path, ipv4_table);
868 	if (hdr == NULL)
869 		return -ENOMEM;
870 
871 	if (register_pernet_subsys(&ipv4_sysctl_ops)) {
872 		unregister_sysctl_table(hdr);
873 		return -ENOMEM;
874 	}
875 
876 	return 0;
877 }
878 
879 __initcall(sysctl_ipv4_init);
880