1// SPDX-License-Identifier: GPL-2.0
  2/* Multipath TCP
  3 *
  4 * Copyright (c) 2019, Tessares SA.
  5 */
  6
  7#ifdef CONFIG_SYSCTL
  8#include <linux/sysctl.h>
  9#endif
 10
 11#include <net/net_namespace.h>
 12#include <net/netns/generic.h>
 13
 14#include "protocol.h"
 15
 16#define MPTCP_SYSCTL_PATH "net/mptcp"
 17
 18static int mptcp_pernet_id;
 19
 20#ifdef CONFIG_SYSCTL
 21static int mptcp_pm_type_max = __MPTCP_PM_TYPE_MAX;
 22#endif
 23
 24struct mptcp_pernet {
 25#ifdef CONFIG_SYSCTL
 26	struct ctl_table_header *ctl_table_hdr;
 27#endif
 28
 29	unsigned int add_addr_timeout;
 30	unsigned int close_timeout;
 31	unsigned int stale_loss_cnt;
 32	u8 mptcp_enabled;
 33	u8 checksum_enabled;
 34	u8 allow_join_initial_addr_port;
 35	u8 pm_type;
 36	char scheduler[MPTCP_SCHED_NAME_MAX];
 37};
 38
 39static struct mptcp_pernet *mptcp_get_pernet(const struct net *net)
 40{
 41	return net_generic(net, mptcp_pernet_id);
 42}
 43
 44int mptcp_is_enabled(const struct net *net)
 45{
 46	return mptcp_get_pernet(net)->mptcp_enabled;
 47}
 48
 49unsigned int mptcp_get_add_addr_timeout(const struct net *net)
 50{
 51	return mptcp_get_pernet(net)->add_addr_timeout;
 52}
 53
 54int mptcp_is_checksum_enabled(const struct net *net)
 55{
 56	return mptcp_get_pernet(net)->checksum_enabled;
 57}
 58
 59int mptcp_allow_join_id0(const struct net *net)
 60{
 61	return mptcp_get_pernet(net)->allow_join_initial_addr_port;
 62}
 63
 64unsigned int mptcp_stale_loss_cnt(const struct net *net)
 65{
 66	return mptcp_get_pernet(net)->stale_loss_cnt;
 67}
 68
 69unsigned int mptcp_close_timeout(const struct sock *sk)
 70{
 71	if (sock_flag(sk, SOCK_DEAD))
 72		return TCP_TIMEWAIT_LEN;
 73	return mptcp_get_pernet(sock_net(sk))->close_timeout;
 74}
 75
 76int mptcp_get_pm_type(const struct net *net)
 77{
 78	return mptcp_get_pernet(net)->pm_type;
 79}
 80
 81const char *mptcp_get_scheduler(const struct net *net)
 82{
 83	return mptcp_get_pernet(net)->scheduler;
 84}
 85
 86static void mptcp_pernet_set_defaults(struct mptcp_pernet *pernet)
 87{
 88	pernet->mptcp_enabled = 1;
 89	pernet->add_addr_timeout = TCP_RTO_MAX;
 90	pernet->close_timeout = TCP_TIMEWAIT_LEN;
 91	pernet->checksum_enabled = 0;
 92	pernet->allow_join_initial_addr_port = 1;
 93	pernet->stale_loss_cnt = 4;
 94	pernet->pm_type = MPTCP_PM_TYPE_KERNEL;
 95	strcpy(pernet->scheduler, "default");
 96}
 97
 98#ifdef CONFIG_SYSCTL
 99static int mptcp_set_scheduler(const struct net *net, const char *name)
100{
101	struct mptcp_pernet *pernet = mptcp_get_pernet(net);
102	struct mptcp_sched_ops *sched;
103	int ret = 0;
104
105	rcu_read_lock();
106	sched = mptcp_sched_find(name);
107	if (sched)
108		strscpy(pernet->scheduler, name, MPTCP_SCHED_NAME_MAX);
109	else
110		ret = -ENOENT;
111	rcu_read_unlock();
112
113	return ret;
114}
115
116static int proc_scheduler(struct ctl_table *ctl, int write,
117			  void *buffer, size_t *lenp, loff_t *ppos)
118{
119	const struct net *net = current->nsproxy->net_ns;
120	char val[MPTCP_SCHED_NAME_MAX];
121	struct ctl_table tbl = {
122		.data = val,
123		.maxlen = MPTCP_SCHED_NAME_MAX,
124	};
125	int ret;
126
127	strscpy(val, mptcp_get_scheduler(net), MPTCP_SCHED_NAME_MAX);
128
129	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
130	if (write && ret == 0)
131		ret = mptcp_set_scheduler(net, val);
132
133	return ret;
134}
135
136static struct ctl_table mptcp_sysctl_table[] = {
137	{
138		.procname = "enabled",
139		.maxlen = sizeof(u8),
140		.mode = 0644,
141		/* users with CAP_NET_ADMIN or root (not and) can change this
142		 * value, same as other sysctl or the 'net' tree.
143		 */
144		.proc_handler = proc_dou8vec_minmax,
145		.extra1       = SYSCTL_ZERO,
146		.extra2       = SYSCTL_ONE
147	},
148	{
149		.procname = "add_addr_timeout",
150		.maxlen = sizeof(unsigned int),
151		.mode = 0644,
152		.proc_handler = proc_dointvec_jiffies,
153	},
154	{
155		.procname = "checksum_enabled",
156		.maxlen = sizeof(u8),
157		.mode = 0644,
158		.proc_handler = proc_dou8vec_minmax,
159		.extra1       = SYSCTL_ZERO,
160		.extra2       = SYSCTL_ONE
161	},
162	{
163		.procname = "allow_join_initial_addr_port",
164		.maxlen = sizeof(u8),
165		.mode = 0644,
166		.proc_handler = proc_dou8vec_minmax,
167		.extra1       = SYSCTL_ZERO,
168		.extra2       = SYSCTL_ONE
169	},
170	{
171		.procname = "stale_loss_cnt",
172		.maxlen = sizeof(unsigned int),
173		.mode = 0644,
174		.proc_handler = proc_douintvec_minmax,
175	},
176	{
177		.procname = "pm_type",
178		.maxlen = sizeof(u8),
179		.mode = 0644,
180		.proc_handler = proc_dou8vec_minmax,
181		.extra1       = SYSCTL_ZERO,
182		.extra2       = &mptcp_pm_type_max
183	},
184	{
185		.procname = "scheduler",
186		.maxlen	= MPTCP_SCHED_NAME_MAX,
187		.mode = 0644,
188		.proc_handler = proc_scheduler,
189	},
190	{
191		.procname = "close_timeout",
192		.maxlen = sizeof(unsigned int),
193		.mode = 0644,
194		.proc_handler = proc_dointvec_jiffies,
195	},
196	{}
197};
198
199static int mptcp_pernet_new_table(struct net *net, struct mptcp_pernet *pernet)
200{
201	struct ctl_table_header *hdr;
202	struct ctl_table *table;
203
204	table = mptcp_sysctl_table;
205	if (!net_eq(net, &init_net)) {
206		table = kmemdup(table, sizeof(mptcp_sysctl_table), GFP_KERNEL);
207		if (!table)
208			goto err_alloc;
209	}
210
211	table[0].data = &pernet->mptcp_enabled;
212	table[1].data = &pernet->add_addr_timeout;
213	table[2].data = &pernet->checksum_enabled;
214	table[3].data = &pernet->allow_join_initial_addr_port;
215	table[4].data = &pernet->stale_loss_cnt;
216	table[5].data = &pernet->pm_type;
217	table[6].data = &pernet->scheduler;
218	table[7].data = &pernet->close_timeout;
219
220	hdr = register_net_sysctl_sz(net, MPTCP_SYSCTL_PATH, table,
221				     ARRAY_SIZE(mptcp_sysctl_table));
222	if (!hdr)
223		goto err_reg;
224
225	pernet->ctl_table_hdr = hdr;
226
227	return 0;
228
229err_reg:
230	if (!net_eq(net, &init_net))
231		kfree(table);
232err_alloc:
233	return -ENOMEM;
234}
235
236static void mptcp_pernet_del_table(struct mptcp_pernet *pernet)
237{
238	struct ctl_table *table = pernet->ctl_table_hdr->ctl_table_arg;
239
240	unregister_net_sysctl_table(pernet->ctl_table_hdr);
241
242	kfree(table);
243}
244
245#else
246
247static int mptcp_pernet_new_table(struct net *net, struct mptcp_pernet *pernet)
248{
249	return 0;
250}
251
252static void mptcp_pernet_del_table(struct mptcp_pernet *pernet) {}
253
254#endif /* CONFIG_SYSCTL */
255
256static int __net_init mptcp_net_init(struct net *net)
257{
258	struct mptcp_pernet *pernet = mptcp_get_pernet(net);
259
260	mptcp_pernet_set_defaults(pernet);
261
262	return mptcp_pernet_new_table(net, pernet);
263}
264
265/* Note: the callback will only be called per extra netns */
266static void __net_exit mptcp_net_exit(struct net *net)
267{
268	struct mptcp_pernet *pernet = mptcp_get_pernet(net);
269
270	mptcp_pernet_del_table(pernet);
271}
272
273static struct pernet_operations mptcp_pernet_ops = {
274	.init = mptcp_net_init,
275	.exit = mptcp_net_exit,
276	.id = &mptcp_pernet_id,
277	.size = sizeof(struct mptcp_pernet),
278};
279
280void __init mptcp_init(void)
281{
282	mptcp_join_cookie_init();
283	mptcp_proto_init();
284
285	if (register_pernet_subsys(&mptcp_pernet_ops) < 0)
286		panic("Failed to register MPTCP pernet subsystem.\n");
287}
288
289#if IS_ENABLED(CONFIG_MPTCP_IPV6)
290int __init mptcpv6_init(void)
291{
292	int err;
293
294	err = mptcp_proto_v6_init();
295
296	return err;
297}
298#endif