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 };
22
mptcp_get_pernet(struct net * net)23 static struct mptcp_pernet *mptcp_get_pernet(struct net *net)
24 {
25 return net_generic(net, mptcp_pernet_id);
26 }
27
mptcp_is_enabled(struct net * net)28 int mptcp_is_enabled(struct net *net)
29 {
30 return mptcp_get_pernet(net)->mptcp_enabled;
31 }
32
33 static struct ctl_table mptcp_sysctl_table[] = {
34 {
35 .procname = "enabled",
36 .maxlen = sizeof(int),
37 .mode = 0644,
38 /* users with CAP_NET_ADMIN or root (not and) can change this
39 * value, same as other sysctl or the 'net' tree.
40 */
41 .proc_handler = proc_dointvec,
42 },
43 {}
44 };
45
mptcp_pernet_set_defaults(struct mptcp_pernet * pernet)46 static void mptcp_pernet_set_defaults(struct mptcp_pernet *pernet)
47 {
48 pernet->mptcp_enabled = 1;
49 }
50
mptcp_pernet_new_table(struct net * net,struct mptcp_pernet * pernet)51 static int mptcp_pernet_new_table(struct net *net, struct mptcp_pernet *pernet)
52 {
53 struct ctl_table_header *hdr;
54 struct ctl_table *table;
55
56 table = mptcp_sysctl_table;
57 if (!net_eq(net, &init_net)) {
58 table = kmemdup(table, sizeof(mptcp_sysctl_table), GFP_KERNEL);
59 if (!table)
60 goto err_alloc;
61 }
62
63 table[0].data = &pernet->mptcp_enabled;
64
65 hdr = register_net_sysctl(net, MPTCP_SYSCTL_PATH, table);
66 if (!hdr)
67 goto err_reg;
68
69 pernet->ctl_table_hdr = hdr;
70
71 return 0;
72
73 err_reg:
74 if (!net_eq(net, &init_net))
75 kfree(table);
76 err_alloc:
77 return -ENOMEM;
78 }
79
mptcp_pernet_del_table(struct mptcp_pernet * pernet)80 static void mptcp_pernet_del_table(struct mptcp_pernet *pernet)
81 {
82 struct ctl_table *table = pernet->ctl_table_hdr->ctl_table_arg;
83
84 unregister_net_sysctl_table(pernet->ctl_table_hdr);
85
86 kfree(table);
87 }
88
mptcp_net_init(struct net * net)89 static int __net_init mptcp_net_init(struct net *net)
90 {
91 struct mptcp_pernet *pernet = mptcp_get_pernet(net);
92
93 mptcp_pernet_set_defaults(pernet);
94
95 return mptcp_pernet_new_table(net, pernet);
96 }
97
98 /* Note: the callback will only be called per extra netns */
mptcp_net_exit(struct net * net)99 static void __net_exit mptcp_net_exit(struct net *net)
100 {
101 struct mptcp_pernet *pernet = mptcp_get_pernet(net);
102
103 mptcp_pernet_del_table(pernet);
104 }
105
106 static struct pernet_operations mptcp_pernet_ops = {
107 .init = mptcp_net_init,
108 .exit = mptcp_net_exit,
109 .id = &mptcp_pernet_id,
110 .size = sizeof(struct mptcp_pernet),
111 };
112
mptcp_init(void)113 void __init mptcp_init(void)
114 {
115 mptcp_join_cookie_init();
116 mptcp_proto_init();
117
118 if (register_pernet_subsys(&mptcp_pernet_ops) < 0)
119 panic("Failed to register MPTCP pernet subsystem.\n");
120 }
121
122 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
mptcpv6_init(void)123 int __init mptcpv6_init(void)
124 {
125 int err;
126
127 err = mptcp_proto_v6_init();
128
129 return err;
130 }
131 #endif
132
