1 // SPDX-License-Identifier: GPL-2.0
2 /* Multipath TCP
3 *
4 * Copyright (c) 2019, Tessares SA.
5 */
6
7 #include <linux/sysctl.h>
8
9 #include <net/net_namespace.h>
10 #include <net/netns/generic.h>
11
12 #include "protocol.h"
13
14 #define MPTCP_SYSCTL_PATH "net/mptcp"
15
16 static int mptcp_pernet_id;
17 struct mptcp_pernet {
18 struct ctl_table_header *ctl_table_hdr;
19
20 int mptcp_enabled;
21 unsigned int add_addr_timeout;
22 };
23
mptcp_get_pernet(struct net * net)24 static struct mptcp_pernet *mptcp_get_pernet(struct net *net)
25 {
26 return net_generic(net, mptcp_pernet_id);
27 }
28
mptcp_is_enabled(struct net * net)29 int mptcp_is_enabled(struct net *net)
30 {
31 return mptcp_get_pernet(net)->mptcp_enabled;
32 }
33
mptcp_get_add_addr_timeout(struct net * net)34 unsigned int mptcp_get_add_addr_timeout(struct net *net)
35 {
36 return mptcp_get_pernet(net)->add_addr_timeout;
37 }
38
39 static struct ctl_table mptcp_sysctl_table[] = {
40 {
41 .procname = "enabled",
42 .maxlen = sizeof(int),
43 .mode = 0644,
44 /* users with CAP_NET_ADMIN or root (not and) can change this
45 * value, same as other sysctl or the 'net' tree.
46 */
47 .proc_handler = proc_dointvec,
48 },
49 {
50 .procname = "add_addr_timeout",
51 .maxlen = sizeof(unsigned int),
52 .mode = 0644,
53 .proc_handler = proc_dointvec_jiffies,
54 },
55 {}
56 };
57
mptcp_pernet_set_defaults(struct mptcp_pernet * pernet)58 static void mptcp_pernet_set_defaults(struct mptcp_pernet *pernet)
59 {
60 pernet->mptcp_enabled = 1;
61 pernet->add_addr_timeout = TCP_RTO_MAX;
62 }
63
mptcp_pernet_new_table(struct net * net,struct mptcp_pernet * pernet)64 static int mptcp_pernet_new_table(struct net *net, struct mptcp_pernet *pernet)
65 {
66 struct ctl_table_header *hdr;
67 struct ctl_table *table;
68
69 table = mptcp_sysctl_table;
70 if (!net_eq(net, &init_net)) {
71 table = kmemdup(table, sizeof(mptcp_sysctl_table), GFP_KERNEL);
72 if (!table)
73 goto err_alloc;
74 }
75
76 table[0].data = &pernet->mptcp_enabled;
77 table[1].data = &pernet->add_addr_timeout;
78
79 hdr = register_net_sysctl(net, MPTCP_SYSCTL_PATH, table);
80 if (!hdr)
81 goto err_reg;
82
83 pernet->ctl_table_hdr = hdr;
84
85 return 0;
86
87 err_reg:
88 if (!net_eq(net, &init_net))
89 kfree(table);
90 err_alloc:
91 return -ENOMEM;
92 }
93
mptcp_pernet_del_table(struct mptcp_pernet * pernet)94 static void mptcp_pernet_del_table(struct mptcp_pernet *pernet)
95 {
96 struct ctl_table *table = pernet->ctl_table_hdr->ctl_table_arg;
97
98 unregister_net_sysctl_table(pernet->ctl_table_hdr);
99
100 kfree(table);
101 }
102
mptcp_net_init(struct net * net)103 static int __net_init mptcp_net_init(struct net *net)
104 {
105 struct mptcp_pernet *pernet = mptcp_get_pernet(net);
106
107 mptcp_pernet_set_defaults(pernet);
108
109 return mptcp_pernet_new_table(net, pernet);
110 }
111
112 /* Note: the callback will only be called per extra netns */
mptcp_net_exit(struct net * net)113 static void __net_exit mptcp_net_exit(struct net *net)
114 {
115 struct mptcp_pernet *pernet = mptcp_get_pernet(net);
116
117 mptcp_pernet_del_table(pernet);
118 }
119
120 static struct pernet_operations mptcp_pernet_ops = {
121 .init = mptcp_net_init,
122 .exit = mptcp_net_exit,
123 .id = &mptcp_pernet_id,
124 .size = sizeof(struct mptcp_pernet),
125 };
126
mptcp_init(void)127 void __init mptcp_init(void)
128 {
129 mptcp_join_cookie_init();
130 mptcp_proto_init();
131
132 if (register_pernet_subsys(&mptcp_pernet_ops) < 0)
133 panic("Failed to register MPTCP pernet subsystem.\n");
134 }
135
136 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
mptcpv6_init(void)137 int __init mptcpv6_init(void)
138 {
139 int err;
140
141 err = mptcp_proto_v6_init();
142
143 return err;
144 }
145 #endif
146