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;
 19struct mptcp_pernet {
 20#ifdef CONFIG_SYSCTL
 21	struct ctl_table_header *ctl_table_hdr;
 22#endif
 23
 24	u8 mptcp_enabled;
 25	unsigned int add_addr_timeout;
 26	u8 checksum_enabled;
 27	u8 allow_join_initial_addr_port;
 28};
 29
 30static struct mptcp_pernet *mptcp_get_pernet(struct net *net)
 31{
 32	return net_generic(net, mptcp_pernet_id);
 33}
 34
 35int mptcp_is_enabled(struct net *net)
 36{
 37	return mptcp_get_pernet(net)->mptcp_enabled;
 38}
 39
 40unsigned int mptcp_get_add_addr_timeout(struct net *net)
 41{
 42	return mptcp_get_pernet(net)->add_addr_timeout;
 43}
 44
 45int mptcp_is_checksum_enabled(struct net *net)
 46{
 47	return mptcp_get_pernet(net)->checksum_enabled;
 48}
 49
 50int mptcp_allow_join_id0(struct net *net)
 51{
 52	return mptcp_get_pernet(net)->allow_join_initial_addr_port;
 53}
 54
 55static void mptcp_pernet_set_defaults(struct mptcp_pernet *pernet)
 56{
 57	pernet->mptcp_enabled = 1;
 58	pernet->add_addr_timeout = TCP_RTO_MAX;
 59	pernet->checksum_enabled = 0;
 60	pernet->allow_join_initial_addr_port = 1;
 61}
 62
 63#ifdef CONFIG_SYSCTL
 64static struct ctl_table mptcp_sysctl_table[] = {
 65	{
 66		.procname = "enabled",
 67		.maxlen = sizeof(u8),
 68		.mode = 0644,
 69		/* users with CAP_NET_ADMIN or root (not and) can change this
 70		 * value, same as other sysctl or the 'net' tree.
 71		 */
 72		.proc_handler = proc_dou8vec_minmax,
 73		.extra1       = SYSCTL_ZERO,
 74		.extra2       = SYSCTL_ONE
 75	},
 76	{
 77		.procname = "add_addr_timeout",
 78		.maxlen = sizeof(unsigned int),
 79		.mode = 0644,
 80		.proc_handler = proc_dointvec_jiffies,
 81	},
 82	{
 83		.procname = "checksum_enabled",
 84		.maxlen = sizeof(u8),
 85		.mode = 0644,
 86		.proc_handler = proc_dou8vec_minmax,
 87		.extra1       = SYSCTL_ZERO,
 88		.extra2       = SYSCTL_ONE
 89	},
 90	{
 91		.procname = "allow_join_initial_addr_port",
 92		.maxlen = sizeof(u8),
 93		.mode = 0644,
 94		.proc_handler = proc_dou8vec_minmax,
 95		.extra1       = SYSCTL_ZERO,
 96		.extra2       = SYSCTL_ONE
 97	},
 98	{}
 99};
100
101static int mptcp_pernet_new_table(struct net *net, struct mptcp_pernet *pernet)
102{
103	struct ctl_table_header *hdr;
104	struct ctl_table *table;
105
106	table = mptcp_sysctl_table;
107	if (!net_eq(net, &init_net)) {
108		table = kmemdup(table, sizeof(mptcp_sysctl_table), GFP_KERNEL);
109		if (!table)
110			goto err_alloc;
111	}
112
113	table[0].data = &pernet->mptcp_enabled;
114	table[1].data = &pernet->add_addr_timeout;
115	table[2].data = &pernet->checksum_enabled;
116	table[3].data = &pernet->allow_join_initial_addr_port;
117
118	hdr = register_net_sysctl(net, MPTCP_SYSCTL_PATH, table);
119	if (!hdr)
120		goto err_reg;
121
122	pernet->ctl_table_hdr = hdr;
123
124	return 0;
125
126err_reg:
127	if (!net_eq(net, &init_net))
128		kfree(table);
129err_alloc:
130	return -ENOMEM;
131}
132
133static void mptcp_pernet_del_table(struct mptcp_pernet *pernet)
134{
135	struct ctl_table *table = pernet->ctl_table_hdr->ctl_table_arg;
136
137	unregister_net_sysctl_table(pernet->ctl_table_hdr);
138
139	kfree(table);
140}
141
142#else
143
144static int mptcp_pernet_new_table(struct net *net, struct mptcp_pernet *pernet)
145{
146	return 0;
147}
148
149static void mptcp_pernet_del_table(struct mptcp_pernet *pernet) {}
150
151#endif /* CONFIG_SYSCTL */
152
153static int __net_init mptcp_net_init(struct net *net)
154{
155	struct mptcp_pernet *pernet = mptcp_get_pernet(net);
156
157	mptcp_pernet_set_defaults(pernet);
158
159	return mptcp_pernet_new_table(net, pernet);
160}
161
162/* Note: the callback will only be called per extra netns */
163static void __net_exit mptcp_net_exit(struct net *net)
164{
165	struct mptcp_pernet *pernet = mptcp_get_pernet(net);
166
167	mptcp_pernet_del_table(pernet);
168}
169
170static struct pernet_operations mptcp_pernet_ops = {
171	.init = mptcp_net_init,
172	.exit = mptcp_net_exit,
173	.id = &mptcp_pernet_id,
174	.size = sizeof(struct mptcp_pernet),
175};
176
177void __init mptcp_init(void)
178{
179	mptcp_join_cookie_init();
180	mptcp_proto_init();
181
182	if (register_pernet_subsys(&mptcp_pernet_ops) < 0)
183		panic("Failed to register MPTCP pernet subsystem.\n");
184}
185
186#if IS_ENABLED(CONFIG_MPTCP_IPV6)
187int __init mptcpv6_init(void)
188{
189	int err;
190
191	err = mptcp_proto_v6_init();
192
193	return err;
194}
195#endif