2 * sysctl_net_ipv4.c: sysctl interface to net IPV4 subsystem.
4 * Begun April 1, 1996, Mike Shaver.
5 * Added /proc/sys/net/ipv4 directory entry (empty =) ). [MS]
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>
20 #include <net/route.h>
23 #include <net/cipso_ipv4.h>
24 #include <net/inet_frag.h>
28 static int tcp_retr1_max = 255;
29 static int ip_local_port_range_min[] = { 1, 1 };
30 static int ip_local_port_range_max[] = { 65535, 65535 };
31 static int tcp_adv_win_scale_min = -31;
32 static int tcp_min_snd_mss_min = TCP_MIN_SND_MSS;
33 static int tcp_min_snd_mss_max = 65535;
34 static int tcp_adv_win_scale_max = 31;
35 static int ip_ttl_min = 1;
36 static int ip_ttl_max = 255;
37 static int tcp_syn_retries_min = 1;
38 static int tcp_syn_retries_max = MAX_TCP_SYNCNT;
39 static int ip_ping_group_range_min[] = { 0, 0 };
40 static int ip_ping_group_range_max[] = { GID_T_MAX, GID_T_MAX };
42 /* Update system visible IP port range */
43 static void set_local_port_range(int range[2])
45 write_seqlock(&sysctl_local_ports.lock);
46 sysctl_local_ports.range[0] = range[0];
47 sysctl_local_ports.range[1] = range[1];
48 write_sequnlock(&sysctl_local_ports.lock);
51 /* Validate changes from /proc interface. */
52 static int ipv4_local_port_range(ctl_table *table, int write,
54 size_t *lenp, loff_t *ppos)
60 .maxlen = sizeof(range),
62 .extra1 = &ip_local_port_range_min,
63 .extra2 = &ip_local_port_range_max,
66 inet_get_local_port_range(range, range + 1);
67 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
69 if (write && ret == 0) {
70 if (range[1] < range[0])
73 set_local_port_range(range);
80 void inet_get_ping_group_range_table(struct ctl_table *table, gid_t *low, gid_t *high)
82 gid_t *data = table->data;
85 seq = read_seqbegin(&sysctl_local_ports.lock);
89 } while (read_seqretry(&sysctl_local_ports.lock, seq));
92 /* Update system visible IP port range */
93 static void set_ping_group_range(struct ctl_table *table, int range[2])
95 gid_t *data = table->data;
96 write_seqlock(&sysctl_local_ports.lock);
99 write_sequnlock(&sysctl_local_ports.lock);
102 /* Validate changes from /proc interface. */
103 static int ipv4_ping_group_range(ctl_table *table, int write,
105 size_t *lenp, loff_t *ppos)
111 .maxlen = sizeof(range),
113 .extra1 = &ip_ping_group_range_min,
114 .extra2 = &ip_ping_group_range_max,
117 inet_get_ping_group_range_table(table, range, range + 1);
118 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
120 if (write && ret == 0)
121 set_ping_group_range(table, range);
126 static int proc_tcp_congestion_control(ctl_table *ctl, int write,
127 void __user *buffer, size_t *lenp, loff_t *ppos)
129 char val[TCP_CA_NAME_MAX];
132 .maxlen = TCP_CA_NAME_MAX,
136 tcp_get_default_congestion_control(val);
138 ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
139 if (write && ret == 0)
140 ret = tcp_set_default_congestion_control(val);
144 static int proc_tcp_available_congestion_control(ctl_table *ctl,
146 void __user *buffer, size_t *lenp,
149 ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX, };
152 tbl.data = kmalloc(tbl.maxlen, GFP_USER);
155 tcp_get_available_congestion_control(tbl.data, TCP_CA_BUF_MAX);
156 ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
161 static int proc_allowed_congestion_control(ctl_table *ctl,
163 void __user *buffer, size_t *lenp,
166 ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX };
169 tbl.data = kmalloc(tbl.maxlen, GFP_USER);
173 tcp_get_allowed_congestion_control(tbl.data, tbl.maxlen);
174 ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
175 if (write && ret == 0)
176 ret = tcp_set_allowed_congestion_control(tbl.data);
181 static struct ctl_table ipv4_table[] = {
183 .procname = "tcp_timestamps",
184 .data = &sysctl_tcp_timestamps,
185 .maxlen = sizeof(int),
187 .proc_handler = proc_dointvec
190 .procname = "tcp_window_scaling",
191 .data = &sysctl_tcp_window_scaling,
192 .maxlen = sizeof(int),
194 .proc_handler = proc_dointvec
197 .procname = "tcp_sack",
198 .data = &sysctl_tcp_sack,
199 .maxlen = sizeof(int),
201 .proc_handler = proc_dointvec
204 .procname = "tcp_retrans_collapse",
205 .data = &sysctl_tcp_retrans_collapse,
206 .maxlen = sizeof(int),
208 .proc_handler = proc_dointvec
211 .procname = "ip_default_ttl",
212 .data = &sysctl_ip_default_ttl,
213 .maxlen = sizeof(int),
215 .proc_handler = proc_dointvec_minmax,
216 .extra1 = &ip_ttl_min,
217 .extra2 = &ip_ttl_max,
220 .procname = "ip_no_pmtu_disc",
221 .data = &ipv4_config.no_pmtu_disc,
222 .maxlen = sizeof(int),
224 .proc_handler = proc_dointvec
227 .procname = "ip_nonlocal_bind",
228 .data = &sysctl_ip_nonlocal_bind,
229 .maxlen = sizeof(int),
231 .proc_handler = proc_dointvec
234 .procname = "tcp_syn_retries",
235 .data = &sysctl_tcp_syn_retries,
236 .maxlen = sizeof(int),
238 .proc_handler = proc_dointvec_minmax,
239 .extra1 = &tcp_syn_retries_min,
240 .extra2 = &tcp_syn_retries_max
243 .procname = "tcp_synack_retries",
244 .data = &sysctl_tcp_synack_retries,
245 .maxlen = sizeof(int),
247 .proc_handler = proc_dointvec
250 .procname = "tcp_max_orphans",
251 .data = &sysctl_tcp_max_orphans,
252 .maxlen = sizeof(int),
254 .proc_handler = proc_dointvec
257 .procname = "tcp_max_tw_buckets",
258 .data = &tcp_death_row.sysctl_max_tw_buckets,
259 .maxlen = sizeof(int),
261 .proc_handler = proc_dointvec
264 .procname = "ip_dynaddr",
265 .data = &sysctl_ip_dynaddr,
266 .maxlen = sizeof(int),
268 .proc_handler = proc_dointvec
271 .procname = "tcp_keepalive_time",
272 .data = &sysctl_tcp_keepalive_time,
273 .maxlen = sizeof(int),
275 .proc_handler = proc_dointvec_jiffies,
278 .procname = "tcp_keepalive_probes",
279 .data = &sysctl_tcp_keepalive_probes,
280 .maxlen = sizeof(int),
282 .proc_handler = proc_dointvec
285 .procname = "tcp_keepalive_intvl",
286 .data = &sysctl_tcp_keepalive_intvl,
287 .maxlen = sizeof(int),
289 .proc_handler = proc_dointvec_jiffies,
292 .procname = "tcp_retries1",
293 .data = &sysctl_tcp_retries1,
294 .maxlen = sizeof(int),
296 .proc_handler = proc_dointvec_minmax,
297 .extra2 = &tcp_retr1_max
300 .procname = "tcp_retries2",
301 .data = &sysctl_tcp_retries2,
302 .maxlen = sizeof(int),
304 .proc_handler = proc_dointvec
307 .procname = "tcp_fin_timeout",
308 .data = &sysctl_tcp_fin_timeout,
309 .maxlen = sizeof(int),
311 .proc_handler = proc_dointvec_jiffies,
313 #ifdef CONFIG_SYN_COOKIES
315 .procname = "tcp_syncookies",
316 .data = &sysctl_tcp_syncookies,
317 .maxlen = sizeof(int),
319 .proc_handler = proc_dointvec
323 .procname = "tcp_tw_recycle",
324 .data = &tcp_death_row.sysctl_tw_recycle,
325 .maxlen = sizeof(int),
327 .proc_handler = proc_dointvec
330 .procname = "tcp_abort_on_overflow",
331 .data = &sysctl_tcp_abort_on_overflow,
332 .maxlen = sizeof(int),
334 .proc_handler = proc_dointvec
337 .procname = "tcp_stdurg",
338 .data = &sysctl_tcp_stdurg,
339 .maxlen = sizeof(int),
341 .proc_handler = proc_dointvec
344 .procname = "tcp_rfc1337",
345 .data = &sysctl_tcp_rfc1337,
346 .maxlen = sizeof(int),
348 .proc_handler = proc_dointvec
351 .procname = "tcp_max_syn_backlog",
352 .data = &sysctl_max_syn_backlog,
353 .maxlen = sizeof(int),
355 .proc_handler = proc_dointvec
358 .procname = "ip_local_port_range",
359 .data = &sysctl_local_ports.range,
360 .maxlen = sizeof(sysctl_local_ports.range),
362 .proc_handler = ipv4_local_port_range,
365 .procname = "ip_local_reserved_ports",
366 .data = NULL, /* initialized in sysctl_ipv4_init */
369 .proc_handler = proc_do_large_bitmap,
372 .procname = "igmp_max_memberships",
373 .data = &sysctl_igmp_max_memberships,
374 .maxlen = sizeof(int),
376 .proc_handler = proc_dointvec
379 .procname = "igmp_max_msf",
380 .data = &sysctl_igmp_max_msf,
381 .maxlen = sizeof(int),
383 .proc_handler = proc_dointvec
386 .procname = "inet_peer_threshold",
387 .data = &inet_peer_threshold,
388 .maxlen = sizeof(int),
390 .proc_handler = proc_dointvec
393 .procname = "inet_peer_minttl",
394 .data = &inet_peer_minttl,
395 .maxlen = sizeof(int),
397 .proc_handler = proc_dointvec_jiffies,
400 .procname = "inet_peer_maxttl",
401 .data = &inet_peer_maxttl,
402 .maxlen = sizeof(int),
404 .proc_handler = proc_dointvec_jiffies,
407 .procname = "tcp_orphan_retries",
408 .data = &sysctl_tcp_orphan_retries,
409 .maxlen = sizeof(int),
411 .proc_handler = proc_dointvec
414 .procname = "tcp_fack",
415 .data = &sysctl_tcp_fack,
416 .maxlen = sizeof(int),
418 .proc_handler = proc_dointvec
421 .procname = "tcp_reordering",
422 .data = &sysctl_tcp_reordering,
423 .maxlen = sizeof(int),
425 .proc_handler = proc_dointvec
428 .procname = "tcp_ecn",
429 .data = &sysctl_tcp_ecn,
430 .maxlen = sizeof(int),
432 .proc_handler = proc_dointvec
435 .procname = "tcp_dsack",
436 .data = &sysctl_tcp_dsack,
437 .maxlen = sizeof(int),
439 .proc_handler = proc_dointvec
442 .procname = "tcp_mem",
443 .data = &sysctl_tcp_mem,
444 .maxlen = sizeof(sysctl_tcp_mem),
446 .proc_handler = proc_doulongvec_minmax
449 .procname = "tcp_wmem",
450 .data = &sysctl_tcp_wmem,
451 .maxlen = sizeof(sysctl_tcp_wmem),
453 .proc_handler = proc_dointvec_minmax,
457 .procname = "tcp_rmem",
458 .data = &sysctl_tcp_rmem,
459 .maxlen = sizeof(sysctl_tcp_rmem),
461 .proc_handler = proc_dointvec_minmax,
465 .procname = "tcp_app_win",
466 .data = &sysctl_tcp_app_win,
467 .maxlen = sizeof(int),
469 .proc_handler = proc_dointvec
472 .procname = "tcp_adv_win_scale",
473 .data = &sysctl_tcp_adv_win_scale,
474 .maxlen = sizeof(int),
476 .proc_handler = proc_dointvec_minmax,
477 .extra1 = &tcp_adv_win_scale_min,
478 .extra2 = &tcp_adv_win_scale_max,
481 .procname = "tcp_tw_reuse",
482 .data = &sysctl_tcp_tw_reuse,
483 .maxlen = sizeof(int),
485 .proc_handler = proc_dointvec
488 .procname = "tcp_frto",
489 .data = &sysctl_tcp_frto,
490 .maxlen = sizeof(int),
492 .proc_handler = proc_dointvec
495 .procname = "tcp_frto_response",
496 .data = &sysctl_tcp_frto_response,
497 .maxlen = sizeof(int),
499 .proc_handler = proc_dointvec
502 .procname = "tcp_low_latency",
503 .data = &sysctl_tcp_low_latency,
504 .maxlen = sizeof(int),
506 .proc_handler = proc_dointvec
509 .procname = "tcp_no_metrics_save",
510 .data = &sysctl_tcp_nometrics_save,
511 .maxlen = sizeof(int),
513 .proc_handler = proc_dointvec,
516 .procname = "tcp_moderate_rcvbuf",
517 .data = &sysctl_tcp_moderate_rcvbuf,
518 .maxlen = sizeof(int),
520 .proc_handler = proc_dointvec,
523 .procname = "tcp_tso_win_divisor",
524 .data = &sysctl_tcp_tso_win_divisor,
525 .maxlen = sizeof(int),
527 .proc_handler = proc_dointvec,
530 .procname = "tcp_congestion_control",
532 .maxlen = TCP_CA_NAME_MAX,
533 .proc_handler = proc_tcp_congestion_control,
536 .procname = "tcp_abc",
537 .data = &sysctl_tcp_abc,
538 .maxlen = sizeof(int),
540 .proc_handler = proc_dointvec,
543 .procname = "tcp_mtu_probing",
544 .data = &sysctl_tcp_mtu_probing,
545 .maxlen = sizeof(int),
547 .proc_handler = proc_dointvec,
550 .procname = "tcp_base_mss",
551 .data = &sysctl_tcp_base_mss,
552 .maxlen = sizeof(int),
554 .proc_handler = proc_dointvec,
557 .procname = "tcp_min_snd_mss",
558 .data = &sysctl_tcp_min_snd_mss,
559 .maxlen = sizeof(int),
561 .proc_handler = proc_dointvec_minmax,
562 .extra1 = &tcp_min_snd_mss_min,
563 .extra2 = &tcp_min_snd_mss_max,
566 .procname = "tcp_workaround_signed_windows",
567 .data = &sysctl_tcp_workaround_signed_windows,
568 .maxlen = sizeof(int),
570 .proc_handler = proc_dointvec
573 .procname = "tcp_challenge_ack_limit",
574 .data = &sysctl_tcp_challenge_ack_limit,
575 .maxlen = sizeof(int),
577 .proc_handler = proc_dointvec
579 #ifdef CONFIG_NET_DMA
581 .procname = "tcp_dma_copybreak",
582 .data = &sysctl_tcp_dma_copybreak,
583 .maxlen = sizeof(int),
585 .proc_handler = proc_dointvec
589 .procname = "tcp_slow_start_after_idle",
590 .data = &sysctl_tcp_slow_start_after_idle,
591 .maxlen = sizeof(int),
593 .proc_handler = proc_dointvec
595 #ifdef CONFIG_NETLABEL
597 .procname = "cipso_cache_enable",
598 .data = &cipso_v4_cache_enabled,
599 .maxlen = sizeof(int),
601 .proc_handler = proc_dointvec,
604 .procname = "cipso_cache_bucket_size",
605 .data = &cipso_v4_cache_bucketsize,
606 .maxlen = sizeof(int),
608 .proc_handler = proc_dointvec,
611 .procname = "cipso_rbm_optfmt",
612 .data = &cipso_v4_rbm_optfmt,
613 .maxlen = sizeof(int),
615 .proc_handler = proc_dointvec,
618 .procname = "cipso_rbm_strictvalid",
619 .data = &cipso_v4_rbm_strictvalid,
620 .maxlen = sizeof(int),
622 .proc_handler = proc_dointvec,
624 #endif /* CONFIG_NETLABEL */
626 .procname = "tcp_available_congestion_control",
627 .maxlen = TCP_CA_BUF_MAX,
629 .proc_handler = proc_tcp_available_congestion_control,
632 .procname = "tcp_allowed_congestion_control",
633 .maxlen = TCP_CA_BUF_MAX,
635 .proc_handler = proc_allowed_congestion_control,
638 .procname = "tcp_max_ssthresh",
639 .data = &sysctl_tcp_max_ssthresh,
640 .maxlen = sizeof(int),
642 .proc_handler = proc_dointvec,
645 .procname = "tcp_cookie_size",
646 .data = &sysctl_tcp_cookie_size,
647 .maxlen = sizeof(int),
649 .proc_handler = proc_dointvec
652 .procname = "tcp_thin_linear_timeouts",
653 .data = &sysctl_tcp_thin_linear_timeouts,
654 .maxlen = sizeof(int),
656 .proc_handler = proc_dointvec
659 .procname = "tcp_thin_dupack",
660 .data = &sysctl_tcp_thin_dupack,
661 .maxlen = sizeof(int),
663 .proc_handler = proc_dointvec
666 .procname = "udp_mem",
667 .data = &sysctl_udp_mem,
668 .maxlen = sizeof(sysctl_udp_mem),
670 .proc_handler = proc_doulongvec_minmax,
673 .procname = "udp_rmem_min",
674 .data = &sysctl_udp_rmem_min,
675 .maxlen = sizeof(sysctl_udp_rmem_min),
677 .proc_handler = proc_dointvec_minmax,
681 .procname = "udp_wmem_min",
682 .data = &sysctl_udp_wmem_min,
683 .maxlen = sizeof(sysctl_udp_wmem_min),
685 .proc_handler = proc_dointvec_minmax,
691 static struct ctl_table ipv4_net_table[] = {
693 .procname = "icmp_echo_ignore_all",
694 .data = &init_net.ipv4.sysctl_icmp_echo_ignore_all,
695 .maxlen = sizeof(int),
697 .proc_handler = proc_dointvec
700 .procname = "icmp_echo_ignore_broadcasts",
701 .data = &init_net.ipv4.sysctl_icmp_echo_ignore_broadcasts,
702 .maxlen = sizeof(int),
704 .proc_handler = proc_dointvec
707 .procname = "icmp_ignore_bogus_error_responses",
708 .data = &init_net.ipv4.sysctl_icmp_ignore_bogus_error_responses,
709 .maxlen = sizeof(int),
711 .proc_handler = proc_dointvec
714 .procname = "icmp_errors_use_inbound_ifaddr",
715 .data = &init_net.ipv4.sysctl_icmp_errors_use_inbound_ifaddr,
716 .maxlen = sizeof(int),
718 .proc_handler = proc_dointvec
721 .procname = "icmp_ratelimit",
722 .data = &init_net.ipv4.sysctl_icmp_ratelimit,
723 .maxlen = sizeof(int),
725 .proc_handler = proc_dointvec_ms_jiffies,
728 .procname = "icmp_ratemask",
729 .data = &init_net.ipv4.sysctl_icmp_ratemask,
730 .maxlen = sizeof(int),
732 .proc_handler = proc_dointvec
735 .procname = "rt_cache_rebuild_count",
736 .data = &init_net.ipv4.sysctl_rt_cache_rebuild_count,
737 .maxlen = sizeof(int),
739 .proc_handler = proc_dointvec
742 .procname = "ping_group_range",
743 .data = &init_net.ipv4.sysctl_ping_group_range,
744 .maxlen = sizeof(init_net.ipv4.sysctl_ping_group_range),
746 .proc_handler = ipv4_ping_group_range,
751 struct ctl_path net_ipv4_ctl_path[] = {
752 { .procname = "net", },
753 { .procname = "ipv4", },
756 EXPORT_SYMBOL_GPL(net_ipv4_ctl_path);
758 static __net_init int ipv4_sysctl_init_net(struct net *net)
760 struct ctl_table *table;
762 table = ipv4_net_table;
763 if (!net_eq(net, &init_net)) {
764 table = kmemdup(table, sizeof(ipv4_net_table), GFP_KERNEL);
769 &net->ipv4.sysctl_icmp_echo_ignore_all;
771 &net->ipv4.sysctl_icmp_echo_ignore_broadcasts;
773 &net->ipv4.sysctl_icmp_ignore_bogus_error_responses;
775 &net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr;
777 &net->ipv4.sysctl_icmp_ratelimit;
779 &net->ipv4.sysctl_icmp_ratemask;
781 &net->ipv4.sysctl_rt_cache_rebuild_count;
783 &net->ipv4.sysctl_ping_group_range;
788 * Sane defaults - nobody may create ping sockets.
789 * Boot scripts should set this to distro-specific group.
791 net->ipv4.sysctl_ping_group_range[0] = 1;
792 net->ipv4.sysctl_ping_group_range[1] = 0;
794 net->ipv4.sysctl_rt_cache_rebuild_count = 4;
796 net->ipv4.ipv4_hdr = register_net_sysctl_table(net,
797 net_ipv4_ctl_path, table);
798 if (net->ipv4.ipv4_hdr == NULL)
804 if (!net_eq(net, &init_net))
810 static __net_exit void ipv4_sysctl_exit_net(struct net *net)
812 struct ctl_table *table;
814 table = net->ipv4.ipv4_hdr->ctl_table_arg;
815 unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
819 static __net_initdata struct pernet_operations ipv4_sysctl_ops = {
820 .init = ipv4_sysctl_init_net,
821 .exit = ipv4_sysctl_exit_net,
824 static __init int sysctl_ipv4_init(void)
826 struct ctl_table_header *hdr;
829 for (i = ipv4_table; i->procname; i++) {
830 if (strcmp(i->procname, "ip_local_reserved_ports") == 0) {
831 i->data = sysctl_local_reserved_ports;
838 hdr = register_sysctl_paths(net_ipv4_ctl_path, ipv4_table);
842 if (register_pernet_subsys(&ipv4_sysctl_ops)) {
843 unregister_sysctl_table(hdr);
850 __initcall(sysctl_ipv4_init);