xref: /linux/net/sctp/sysctl.c (revision 07fdad3a93756b872da7b53647715c48d0f4a2d0)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* SCTP kernel implementation
3  * (C) Copyright IBM Corp. 2002, 2004
4  * Copyright (c) 2002 Intel Corp.
5  *
6  * This file is part of the SCTP kernel implementation
7  *
8  * Sysctl related interfaces for SCTP.
9  *
10  * Please send any bug reports or fixes you make to the
11  * email address(es):
12  *    lksctp developers <linux-sctp@vger.kernel.org>
13  *
14  * Written or modified by:
15  *    Mingqin Liu           <liuming@us.ibm.com>
16  *    Jon Grimm             <jgrimm@us.ibm.com>
17  *    Ardelle Fan           <ardelle.fan@intel.com>
18  *    Ryan Layer            <rmlayer@us.ibm.com>
19  *    Sridhar Samudrala     <sri@us.ibm.com>
20  */
21 
22 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23 
24 #include <net/sctp/structs.h>
25 #include <net/sctp/sctp.h>
26 #include <linux/sysctl.h>
27 
28 static int timer_max = 86400000; /* ms in one day */
29 static int sack_timer_min = 1;
30 static int sack_timer_max = 500;
31 static int addr_scope_max = SCTP_SCOPE_POLICY_MAX;
32 static int rwnd_scale_max = 16;
33 static int rto_alpha_min = 0;
34 static int rto_beta_min = 0;
35 static int rto_alpha_max = 1000;
36 static int rto_beta_max = 1000;
37 static int pf_expose_max = SCTP_PF_EXPOSE_MAX;
38 static int ps_retrans_max = SCTP_PS_RETRANS_MAX;
39 static int udp_port_max = 65535;
40 
41 static unsigned long max_autoclose_min = 0;
42 static unsigned long max_autoclose_max =
43 	(MAX_SCHEDULE_TIMEOUT / HZ > UINT_MAX)
44 	? UINT_MAX : MAX_SCHEDULE_TIMEOUT / HZ;
45 
46 static int proc_sctp_do_hmac_alg(const struct ctl_table *ctl, int write,
47 				 void *buffer, size_t *lenp, loff_t *ppos);
48 static int proc_sctp_do_rto_min(const struct ctl_table *ctl, int write,
49 				void *buffer, size_t *lenp, loff_t *ppos);
50 static int proc_sctp_do_rto_max(const struct ctl_table *ctl, int write, void *buffer,
51 				size_t *lenp, loff_t *ppos);
52 static int proc_sctp_do_udp_port(const struct ctl_table *ctl, int write, void *buffer,
53 				 size_t *lenp, loff_t *ppos);
54 static int proc_sctp_do_alpha_beta(const struct ctl_table *ctl, int write,
55 				   void *buffer, size_t *lenp, loff_t *ppos);
56 static int proc_sctp_do_auth(const struct ctl_table *ctl, int write,
57 			     void *buffer, size_t *lenp, loff_t *ppos);
58 static int proc_sctp_do_probe_interval(const struct ctl_table *ctl, int write,
59 				       void *buffer, size_t *lenp, loff_t *ppos);
60 
61 static struct ctl_table sctp_table[] = {
62 	{
63 		.procname	= "sctp_mem",
64 		.data		= &sysctl_sctp_mem,
65 		.maxlen		= sizeof(sysctl_sctp_mem),
66 		.mode		= 0644,
67 		.proc_handler	= proc_doulongvec_minmax
68 	},
69 	{
70 		.procname	= "sctp_rmem",
71 		.data		= &sysctl_sctp_rmem,
72 		.maxlen		= sizeof(sysctl_sctp_rmem),
73 		.mode		= 0644,
74 		.proc_handler	= proc_dointvec,
75 	},
76 	{
77 		.procname	= "sctp_wmem",
78 		.data		= &sysctl_sctp_wmem,
79 		.maxlen		= sizeof(sysctl_sctp_wmem),
80 		.mode		= 0644,
81 		.proc_handler	= proc_dointvec,
82 	},
83 };
84 
85 /* The following index defines are used in sctp_sysctl_net_register().
86  * If you add new items to the sctp_net_table, please ensure that
87  * the index values of these defines hold the same meaning indicated by
88  * their macro names when they appear in sctp_net_table.
89  */
90 #define SCTP_RTO_MIN_IDX       0
91 #define SCTP_RTO_MAX_IDX       1
92 #define SCTP_PF_RETRANS_IDX    2
93 #define SCTP_PS_RETRANS_IDX    3
94 
95 static struct ctl_table sctp_net_table[] = {
96 	[SCTP_RTO_MIN_IDX] = {
97 		.procname	= "rto_min",
98 		.data		= &init_net.sctp.rto_min,
99 		.maxlen		= sizeof(unsigned int),
100 		.mode		= 0644,
101 		.proc_handler	= proc_sctp_do_rto_min,
102 		.extra1         = SYSCTL_ONE,
103 		.extra2         = &init_net.sctp.rto_max
104 	},
105 	[SCTP_RTO_MAX_IDX] =  {
106 		.procname	= "rto_max",
107 		.data		= &init_net.sctp.rto_max,
108 		.maxlen		= sizeof(unsigned int),
109 		.mode		= 0644,
110 		.proc_handler	= proc_sctp_do_rto_max,
111 		.extra1         = &init_net.sctp.rto_min,
112 		.extra2         = &timer_max
113 	},
114 	[SCTP_PF_RETRANS_IDX] = {
115 		.procname	= "pf_retrans",
116 		.data		= &init_net.sctp.pf_retrans,
117 		.maxlen		= sizeof(int),
118 		.mode		= 0644,
119 		.proc_handler	= proc_dointvec_minmax,
120 		.extra1		= SYSCTL_ZERO,
121 		.extra2		= &init_net.sctp.ps_retrans,
122 	},
123 	[SCTP_PS_RETRANS_IDX] = {
124 		.procname	= "ps_retrans",
125 		.data		= &init_net.sctp.ps_retrans,
126 		.maxlen		= sizeof(int),
127 		.mode		= 0644,
128 		.proc_handler	= proc_dointvec_minmax,
129 		.extra1		= &init_net.sctp.pf_retrans,
130 		.extra2		= &ps_retrans_max,
131 	},
132 	{
133 		.procname	= "rto_initial",
134 		.data		= &init_net.sctp.rto_initial,
135 		.maxlen		= sizeof(unsigned int),
136 		.mode		= 0644,
137 		.proc_handler	= proc_dointvec_minmax,
138 		.extra1         = SYSCTL_ONE,
139 		.extra2         = &timer_max
140 	},
141 	{
142 		.procname	= "rto_alpha_exp_divisor",
143 		.data		= &init_net.sctp.rto_alpha,
144 		.maxlen		= sizeof(int),
145 		.mode		= 0644,
146 		.proc_handler	= proc_sctp_do_alpha_beta,
147 		.extra1		= &rto_alpha_min,
148 		.extra2		= &rto_alpha_max,
149 	},
150 	{
151 		.procname	= "rto_beta_exp_divisor",
152 		.data		= &init_net.sctp.rto_beta,
153 		.maxlen		= sizeof(int),
154 		.mode		= 0644,
155 		.proc_handler	= proc_sctp_do_alpha_beta,
156 		.extra1		= &rto_beta_min,
157 		.extra2		= &rto_beta_max,
158 	},
159 	{
160 		.procname	= "max_burst",
161 		.data		= &init_net.sctp.max_burst,
162 		.maxlen		= sizeof(int),
163 		.mode		= 0644,
164 		.proc_handler	= proc_dointvec_minmax,
165 		.extra1		= SYSCTL_ZERO,
166 		.extra2		= SYSCTL_INT_MAX,
167 	},
168 	{
169 		.procname	= "cookie_preserve_enable",
170 		.data		= &init_net.sctp.cookie_preserve_enable,
171 		.maxlen		= sizeof(int),
172 		.mode		= 0644,
173 		.proc_handler	= proc_dointvec,
174 	},
175 	{
176 		.procname	= "cookie_hmac_alg",
177 		.data		= &init_net.sctp.cookie_auth_enable,
178 		.maxlen		= 8,
179 		.mode		= 0644,
180 		.proc_handler	= proc_sctp_do_hmac_alg,
181 	},
182 	{
183 		.procname	= "valid_cookie_life",
184 		.data		= &init_net.sctp.valid_cookie_life,
185 		.maxlen		= sizeof(unsigned int),
186 		.mode		= 0644,
187 		.proc_handler	= proc_dointvec_minmax,
188 		.extra1         = SYSCTL_ONE,
189 		.extra2         = &timer_max
190 	},
191 	{
192 		.procname	= "sack_timeout",
193 		.data		= &init_net.sctp.sack_timeout,
194 		.maxlen		= sizeof(int),
195 		.mode		= 0644,
196 		.proc_handler	= proc_dointvec_minmax,
197 		.extra1         = &sack_timer_min,
198 		.extra2         = &sack_timer_max,
199 	},
200 	{
201 		.procname	= "hb_interval",
202 		.data		= &init_net.sctp.hb_interval,
203 		.maxlen		= sizeof(unsigned int),
204 		.mode		= 0644,
205 		.proc_handler	= proc_dointvec_minmax,
206 		.extra1         = SYSCTL_ONE,
207 		.extra2         = &timer_max
208 	},
209 	{
210 		.procname	= "association_max_retrans",
211 		.data		= &init_net.sctp.max_retrans_association,
212 		.maxlen		= sizeof(int),
213 		.mode		= 0644,
214 		.proc_handler	= proc_dointvec_minmax,
215 		.extra1		= SYSCTL_ONE,
216 		.extra2		= SYSCTL_INT_MAX,
217 	},
218 	{
219 		.procname	= "path_max_retrans",
220 		.data		= &init_net.sctp.max_retrans_path,
221 		.maxlen		= sizeof(int),
222 		.mode		= 0644,
223 		.proc_handler	= proc_dointvec_minmax,
224 		.extra1		= SYSCTL_ONE,
225 		.extra2		= SYSCTL_INT_MAX,
226 	},
227 	{
228 		.procname	= "max_init_retransmits",
229 		.data		= &init_net.sctp.max_retrans_init,
230 		.maxlen		= sizeof(int),
231 		.mode		= 0644,
232 		.proc_handler	= proc_dointvec_minmax,
233 		.extra1		= SYSCTL_ONE,
234 		.extra2		= SYSCTL_INT_MAX,
235 	},
236 	{
237 		.procname	= "sndbuf_policy",
238 		.data		= &init_net.sctp.sndbuf_policy,
239 		.maxlen		= sizeof(int),
240 		.mode		= 0644,
241 		.proc_handler	= proc_dointvec,
242 	},
243 	{
244 		.procname	= "rcvbuf_policy",
245 		.data		= &init_net.sctp.rcvbuf_policy,
246 		.maxlen		= sizeof(int),
247 		.mode		= 0644,
248 		.proc_handler	= proc_dointvec,
249 	},
250 	{
251 		.procname	= "default_auto_asconf",
252 		.data		= &init_net.sctp.default_auto_asconf,
253 		.maxlen		= sizeof(int),
254 		.mode		= 0644,
255 		.proc_handler	= proc_dointvec,
256 	},
257 	{
258 		.procname	= "addip_enable",
259 		.data		= &init_net.sctp.addip_enable,
260 		.maxlen		= sizeof(int),
261 		.mode		= 0644,
262 		.proc_handler	= proc_dointvec,
263 	},
264 	{
265 		.procname	= "addip_noauth_enable",
266 		.data		= &init_net.sctp.addip_noauth,
267 		.maxlen		= sizeof(int),
268 		.mode		= 0644,
269 		.proc_handler	= proc_dointvec,
270 	},
271 	{
272 		.procname	= "prsctp_enable",
273 		.data		= &init_net.sctp.prsctp_enable,
274 		.maxlen		= sizeof(int),
275 		.mode		= 0644,
276 		.proc_handler	= proc_dointvec,
277 	},
278 	{
279 		.procname	= "reconf_enable",
280 		.data		= &init_net.sctp.reconf_enable,
281 		.maxlen		= sizeof(int),
282 		.mode		= 0644,
283 		.proc_handler	= proc_dointvec,
284 	},
285 	{
286 		.procname	= "auth_enable",
287 		.data		= &init_net.sctp.auth_enable,
288 		.maxlen		= sizeof(int),
289 		.mode		= 0644,
290 		.proc_handler	= proc_sctp_do_auth,
291 	},
292 	{
293 		.procname	= "intl_enable",
294 		.data		= &init_net.sctp.intl_enable,
295 		.maxlen		= sizeof(int),
296 		.mode		= 0644,
297 		.proc_handler	= proc_dointvec,
298 	},
299 	{
300 		.procname	= "ecn_enable",
301 		.data		= &init_net.sctp.ecn_enable,
302 		.maxlen		= sizeof(int),
303 		.mode		= 0644,
304 		.proc_handler	= proc_dointvec,
305 	},
306 	{
307 		.procname	= "plpmtud_probe_interval",
308 		.data		= &init_net.sctp.probe_interval,
309 		.maxlen		= sizeof(int),
310 		.mode		= 0644,
311 		.proc_handler	= proc_sctp_do_probe_interval,
312 	},
313 	{
314 		.procname	= "udp_port",
315 		.data		= &init_net.sctp.udp_port,
316 		.maxlen		= sizeof(int),
317 		.mode		= 0644,
318 		.proc_handler	= proc_sctp_do_udp_port,
319 		.extra1		= SYSCTL_ZERO,
320 		.extra2		= &udp_port_max,
321 	},
322 	{
323 		.procname	= "encap_port",
324 		.data		= &init_net.sctp.encap_port,
325 		.maxlen		= sizeof(int),
326 		.mode		= 0644,
327 		.proc_handler	= proc_dointvec_minmax,
328 		.extra1		= SYSCTL_ZERO,
329 		.extra2		= &udp_port_max,
330 	},
331 	{
332 		.procname	= "addr_scope_policy",
333 		.data		= &init_net.sctp.scope_policy,
334 		.maxlen		= sizeof(int),
335 		.mode		= 0644,
336 		.proc_handler	= proc_dointvec_minmax,
337 		.extra1		= SYSCTL_ZERO,
338 		.extra2		= &addr_scope_max,
339 	},
340 	{
341 		.procname	= "rwnd_update_shift",
342 		.data		= &init_net.sctp.rwnd_upd_shift,
343 		.maxlen		= sizeof(int),
344 		.mode		= 0644,
345 		.proc_handler	= &proc_dointvec_minmax,
346 		.extra1		= SYSCTL_ONE,
347 		.extra2		= &rwnd_scale_max,
348 	},
349 	{
350 		.procname	= "max_autoclose",
351 		.data		= &init_net.sctp.max_autoclose,
352 		.maxlen		= sizeof(unsigned long),
353 		.mode		= 0644,
354 		.proc_handler	= &proc_doulongvec_minmax,
355 		.extra1		= &max_autoclose_min,
356 		.extra2		= &max_autoclose_max,
357 	},
358 #ifdef CONFIG_NET_L3_MASTER_DEV
359 	{
360 		.procname	= "l3mdev_accept",
361 		.data		= &init_net.sctp.l3mdev_accept,
362 		.maxlen		= sizeof(int),
363 		.mode		= 0644,
364 		.proc_handler	= proc_dointvec_minmax,
365 		.extra1		= SYSCTL_ZERO,
366 		.extra2		= SYSCTL_ONE,
367 	},
368 #endif
369 	{
370 		.procname	= "pf_enable",
371 		.data		= &init_net.sctp.pf_enable,
372 		.maxlen		= sizeof(int),
373 		.mode		= 0644,
374 		.proc_handler	= proc_dointvec,
375 	},
376 	{
377 		.procname	= "pf_expose",
378 		.data		= &init_net.sctp.pf_expose,
379 		.maxlen		= sizeof(int),
380 		.mode		= 0644,
381 		.proc_handler	= proc_dointvec_minmax,
382 		.extra1		= SYSCTL_ZERO,
383 		.extra2		= &pf_expose_max,
384 	},
385 };
386 
387 static int proc_sctp_do_hmac_alg(const struct ctl_table *ctl, int write,
388 				 void *buffer, size_t *lenp, loff_t *ppos)
389 {
390 	struct net *net = container_of(ctl->data, struct net,
391 				       sctp.cookie_auth_enable);
392 	struct ctl_table tbl;
393 	char tmp[8] = {0};
394 	int ret;
395 
396 	memset(&tbl, 0, sizeof(struct ctl_table));
397 
398 	if (write) {
399 		tbl.data = tmp;
400 		tbl.maxlen = sizeof(tmp) - 1;
401 		ret = proc_dostring(&tbl, 1, buffer, lenp, ppos);
402 		if (ret)
403 			return ret;
404 		if (!strcmp(tmp, "sha256")) {
405 			net->sctp.cookie_auth_enable = 1;
406 			return 0;
407 		}
408 		if (!strcmp(tmp, "none")) {
409 			net->sctp.cookie_auth_enable = 0;
410 			return 0;
411 		}
412 		return -EINVAL;
413 	}
414 	if (net->sctp.cookie_auth_enable)
415 		tbl.data = (char *)"sha256";
416 	else
417 		tbl.data = (char *)"none";
418 	tbl.maxlen = strlen(tbl.data);
419 	return proc_dostring(&tbl, 0, buffer, lenp, ppos);
420 }
421 
422 static int proc_sctp_do_rto_min(const struct ctl_table *ctl, int write,
423 				void *buffer, size_t *lenp, loff_t *ppos)
424 {
425 	struct net *net = container_of(ctl->data, struct net, sctp.rto_min);
426 	unsigned int min = *(unsigned int *) ctl->extra1;
427 	unsigned int max = *(unsigned int *) ctl->extra2;
428 	struct ctl_table tbl;
429 	int ret, new_value;
430 
431 	memset(&tbl, 0, sizeof(struct ctl_table));
432 	tbl.maxlen = sizeof(unsigned int);
433 
434 	if (write)
435 		tbl.data = &new_value;
436 	else
437 		tbl.data = &net->sctp.rto_min;
438 
439 	ret = proc_dointvec(&tbl, write, buffer, lenp, ppos);
440 	if (write && ret == 0) {
441 		if (new_value > max || new_value < min)
442 			return -EINVAL;
443 
444 		net->sctp.rto_min = new_value;
445 	}
446 
447 	return ret;
448 }
449 
450 static int proc_sctp_do_rto_max(const struct ctl_table *ctl, int write,
451 				void *buffer, size_t *lenp, loff_t *ppos)
452 {
453 	struct net *net = container_of(ctl->data, struct net, sctp.rto_max);
454 	unsigned int min = *(unsigned int *) ctl->extra1;
455 	unsigned int max = *(unsigned int *) ctl->extra2;
456 	struct ctl_table tbl;
457 	int ret, new_value;
458 
459 	memset(&tbl, 0, sizeof(struct ctl_table));
460 	tbl.maxlen = sizeof(unsigned int);
461 
462 	if (write)
463 		tbl.data = &new_value;
464 	else
465 		tbl.data = &net->sctp.rto_max;
466 
467 	ret = proc_dointvec(&tbl, write, buffer, lenp, ppos);
468 	if (write && ret == 0) {
469 		if (new_value > max || new_value < min)
470 			return -EINVAL;
471 
472 		net->sctp.rto_max = new_value;
473 	}
474 
475 	return ret;
476 }
477 
478 static int proc_sctp_do_alpha_beta(const struct ctl_table *ctl, int write,
479 				   void *buffer, size_t *lenp, loff_t *ppos)
480 {
481 	if (write)
482 		pr_warn_once("Changing rto_alpha or rto_beta may lead to "
483 			     "suboptimal rtt/srtt estimations!\n");
484 
485 	return proc_dointvec_minmax(ctl, write, buffer, lenp, ppos);
486 }
487 
488 static int proc_sctp_do_auth(const struct ctl_table *ctl, int write,
489 			     void *buffer, size_t *lenp, loff_t *ppos)
490 {
491 	struct net *net = container_of(ctl->data, struct net, sctp.auth_enable);
492 	struct ctl_table tbl;
493 	int new_value, ret;
494 
495 	memset(&tbl, 0, sizeof(struct ctl_table));
496 	tbl.maxlen = sizeof(unsigned int);
497 
498 	if (write)
499 		tbl.data = &new_value;
500 	else
501 		tbl.data = &net->sctp.auth_enable;
502 
503 	ret = proc_dointvec(&tbl, write, buffer, lenp, ppos);
504 	if (write && ret == 0) {
505 		struct sock *sk = net->sctp.ctl_sock;
506 
507 		net->sctp.auth_enable = new_value;
508 		/* Update the value in the control socket */
509 		lock_sock(sk);
510 		sctp_sk(sk)->ep->auth_enable = new_value;
511 		release_sock(sk);
512 	}
513 
514 	return ret;
515 }
516 
517 static DEFINE_MUTEX(sctp_sysctl_mutex);
518 
519 static int proc_sctp_do_udp_port(const struct ctl_table *ctl, int write,
520 				 void *buffer, size_t *lenp, loff_t *ppos)
521 {
522 	struct net *net = container_of(ctl->data, struct net, sctp.udp_port);
523 	unsigned int min = *(unsigned int *)ctl->extra1;
524 	unsigned int max = *(unsigned int *)ctl->extra2;
525 	struct ctl_table tbl;
526 	int ret, new_value;
527 
528 	memset(&tbl, 0, sizeof(struct ctl_table));
529 	tbl.maxlen = sizeof(unsigned int);
530 
531 	if (write)
532 		tbl.data = &new_value;
533 	else
534 		tbl.data = &net->sctp.udp_port;
535 
536 	ret = proc_dointvec(&tbl, write, buffer, lenp, ppos);
537 	if (write && ret == 0) {
538 		struct sock *sk = net->sctp.ctl_sock;
539 
540 		if (new_value > max || new_value < min)
541 			return -EINVAL;
542 
543 		mutex_lock(&sctp_sysctl_mutex);
544 		net->sctp.udp_port = new_value;
545 		sctp_udp_sock_stop(net);
546 		if (new_value) {
547 			ret = sctp_udp_sock_start(net);
548 			if (ret)
549 				net->sctp.udp_port = 0;
550 		}
551 
552 		/* Update the value in the control socket */
553 		lock_sock(sk);
554 		sctp_sk(sk)->udp_port = htons(net->sctp.udp_port);
555 		release_sock(sk);
556 		mutex_unlock(&sctp_sysctl_mutex);
557 	}
558 
559 	return ret;
560 }
561 
562 static int proc_sctp_do_probe_interval(const struct ctl_table *ctl, int write,
563 				       void *buffer, size_t *lenp, loff_t *ppos)
564 {
565 	struct net *net = container_of(ctl->data, struct net,
566 				       sctp.probe_interval);
567 	struct ctl_table tbl;
568 	int ret, new_value;
569 
570 	memset(&tbl, 0, sizeof(struct ctl_table));
571 	tbl.maxlen = sizeof(unsigned int);
572 
573 	if (write)
574 		tbl.data = &new_value;
575 	else
576 		tbl.data = &net->sctp.probe_interval;
577 
578 	ret = proc_dointvec(&tbl, write, buffer, lenp, ppos);
579 	if (write && ret == 0) {
580 		if (new_value && new_value < SCTP_PROBE_TIMER_MIN)
581 			return -EINVAL;
582 
583 		net->sctp.probe_interval = new_value;
584 	}
585 
586 	return ret;
587 }
588 
589 int sctp_sysctl_net_register(struct net *net)
590 {
591 	size_t table_size = ARRAY_SIZE(sctp_net_table);
592 	struct ctl_table *table;
593 	int i;
594 
595 	table = kmemdup(sctp_net_table, sizeof(sctp_net_table), GFP_KERNEL);
596 	if (!table)
597 		return -ENOMEM;
598 
599 	for (i = 0; i < table_size; i++)
600 		table[i].data += (char *)(&net->sctp) - (char *)&init_net.sctp;
601 
602 	table[SCTP_RTO_MIN_IDX].extra2 = &net->sctp.rto_max;
603 	table[SCTP_RTO_MAX_IDX].extra1 = &net->sctp.rto_min;
604 	table[SCTP_PF_RETRANS_IDX].extra2 = &net->sctp.ps_retrans;
605 	table[SCTP_PS_RETRANS_IDX].extra1 = &net->sctp.pf_retrans;
606 
607 	net->sctp.sysctl_header = register_net_sysctl_sz(net, "net/sctp",
608 							 table, table_size);
609 	if (net->sctp.sysctl_header == NULL) {
610 		kfree(table);
611 		return -ENOMEM;
612 	}
613 	return 0;
614 }
615 
616 void sctp_sysctl_net_unregister(struct net *net)
617 {
618 	const struct ctl_table *table;
619 
620 	table = net->sctp.sysctl_header->ctl_table_arg;
621 	unregister_net_sysctl_table(net->sctp.sysctl_header);
622 	kfree(table);
623 }
624 
625 static struct ctl_table_header *sctp_sysctl_header;
626 
627 /* Sysctl registration.  */
628 void sctp_sysctl_register(void)
629 {
630 	sctp_sysctl_header = register_net_sysctl(&init_net, "net/sctp", sctp_table);
631 }
632 
633 /* Sysctl deregistration.  */
634 void sctp_sysctl_unregister(void)
635 {
636 	unregister_net_sysctl_table(sctp_sysctl_header);
637 }
638