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 stale_loss_cnt;
 31	u8 mptcp_enabled;
 32	u8 checksum_enabled;
 33	u8 allow_join_initial_addr_port;
 34	u8 pm_type;
 35};
 36
 37static struct mptcp_pernet *mptcp_get_pernet(const struct net *net)
 38{
 39	return net_generic(net, mptcp_pernet_id);
 40}
 41
 42int mptcp_is_enabled(const struct net *net)
 43{
 44	return mptcp_get_pernet(net)->mptcp_enabled;
 45}
 46
 47unsigned int mptcp_get_add_addr_timeout(const struct net *net)
 48{
 49	return mptcp_get_pernet(net)->add_addr_timeout;
 50}
 51
 52int mptcp_is_checksum_enabled(const struct net *net)
 53{
 54	return mptcp_get_pernet(net)->checksum_enabled;
 55}
 56
 57int mptcp_allow_join_id0(const struct net *net)
 58{
 59	return mptcp_get_pernet(net)->allow_join_initial_addr_port;
 60}
 61
 62unsigned int mptcp_stale_loss_cnt(const struct net *net)
 63{
 64	return mptcp_get_pernet(net)->stale_loss_cnt;
 65}
 66
 67int mptcp_get_pm_type(const struct net *net)
 68{
 69	return mptcp_get_pernet(net)->pm_type;
 70}
 71
 72static void mptcp_pernet_set_defaults(struct mptcp_pernet *pernet)
 73{
 74	pernet->mptcp_enabled = 1;
 75	pernet->add_addr_timeout = TCP_RTO_MAX;
 76	pernet->checksum_enabled = 0;
 77	pernet->allow_join_initial_addr_port = 1;
 78	pernet->stale_loss_cnt = 4;
 79	pernet->pm_type = MPTCP_PM_TYPE_KERNEL;
 80}
 81
 82#ifdef CONFIG_SYSCTL
 83static struct ctl_table mptcp_sysctl_table[] = {
 84	{
 85		.procname = "enabled",
 86		.maxlen = sizeof(u8),
 87		.mode = 0644,
 88		/* users with CAP_NET_ADMIN or root (not and) can change this
 89		 * value, same as other sysctl or the 'net' tree.
 90		 */
 91		.proc_handler = proc_dou8vec_minmax,
 92		.extra1       = SYSCTL_ZERO,
 93		.extra2       = SYSCTL_ONE
 94	},
 95	{
 96		.procname = "add_addr_timeout",
 97		.maxlen = sizeof(unsigned int),
 98		.mode = 0644,
 99		.proc_handler = proc_dointvec_jiffies,
100	},
101	{
102		.procname = "checksum_enabled",
103		.maxlen = sizeof(u8),
104		.mode = 0644,
105		.proc_handler = proc_dou8vec_minmax,
106		.extra1       = SYSCTL_ZERO,
107		.extra2       = SYSCTL_ONE
108	},
109	{
110		.procname = "allow_join_initial_addr_port",
111		.maxlen = sizeof(u8),
112		.mode = 0644,
113		.proc_handler = proc_dou8vec_minmax,
114		.extra1       = SYSCTL_ZERO,
115		.extra2       = SYSCTL_ONE
116	},
117	{
118		.procname = "stale_loss_cnt",
119		.maxlen = sizeof(unsigned int),
120		.mode = 0644,
121		.proc_handler = proc_douintvec_minmax,
122	},
123	{
124		.procname = "pm_type",
125		.maxlen = sizeof(u8),
126		.mode = 0644,
127		.proc_handler = proc_dou8vec_minmax,
128		.extra1       = SYSCTL_ZERO,
129		.extra2       = &mptcp_pm_type_max
130	},
131	{}
132};
133
134static int mptcp_pernet_new_table(struct net *net, struct mptcp_pernet *pernet)
135{
136	struct ctl_table_header *hdr;
137	struct ctl_table *table;
138
139	table = mptcp_sysctl_table;
140	if (!net_eq(net, &init_net)) {
141		table = kmemdup(table, sizeof(mptcp_sysctl_table), GFP_KERNEL);
142		if (!table)
143			goto err_alloc;
144	}
145
146	table[0].data = &pernet->mptcp_enabled;
147	table[1].data = &pernet->add_addr_timeout;
148	table[2].data = &pernet->checksum_enabled;
149	table[3].data = &pernet->allow_join_initial_addr_port;
150	table[4].data = &pernet->stale_loss_cnt;
151	table[5].data = &pernet->pm_type;
152
153	hdr = register_net_sysctl(net, MPTCP_SYSCTL_PATH, table);
154	if (!hdr)
155		goto err_reg;
156
157	pernet->ctl_table_hdr = hdr;
158
159	return 0;
160
161err_reg:
162	if (!net_eq(net, &init_net))
163		kfree(table);
164err_alloc:
165	return -ENOMEM;
166}
167
168static void mptcp_pernet_del_table(struct mptcp_pernet *pernet)
169{
170	struct ctl_table *table = pernet->ctl_table_hdr->ctl_table_arg;
171
172	unregister_net_sysctl_table(pernet->ctl_table_hdr);
173
174	kfree(table);
175}
176
177#else
178
179static int mptcp_pernet_new_table(struct net *net, struct mptcp_pernet *pernet)
180{
181	return 0;
182}
183
184static void mptcp_pernet_del_table(struct mptcp_pernet *pernet) {}
185
186#endif /* CONFIG_SYSCTL */
187
188static int __net_init mptcp_net_init(struct net *net)
189{
190	struct mptcp_pernet *pernet = mptcp_get_pernet(net);
191
192	mptcp_pernet_set_defaults(pernet);
193
194	return mptcp_pernet_new_table(net, pernet);
195}
196
197/* Note: the callback will only be called per extra netns */
198static void __net_exit mptcp_net_exit(struct net *net)
199{
200	struct mptcp_pernet *pernet = mptcp_get_pernet(net);
201
202	mptcp_pernet_del_table(pernet);
203}
204
205static struct pernet_operations mptcp_pernet_ops = {
206	.init = mptcp_net_init,
207	.exit = mptcp_net_exit,
208	.id = &mptcp_pernet_id,
209	.size = sizeof(struct mptcp_pernet),
210};
211
212void __init mptcp_init(void)
213{
214	mptcp_join_cookie_init();
215	mptcp_proto_init();
216
217	if (register_pernet_subsys(&mptcp_pernet_ops) < 0)
218		panic("Failed to register MPTCP pernet subsystem.\n");
219}
220
221#if IS_ENABLED(CONFIG_MPTCP_IPV6)
222int __init mptcpv6_init(void)
223{
224	int err;
225
226	err = mptcp_proto_v6_init();
227
228	return err;
229}
230#endif