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 23 static struct mptcp_pernet *mptcp_get_pernet(struct net *net) 24 { 25 return net_generic(net, mptcp_pernet_id); 26 } 27 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 46 static void mptcp_pernet_set_defaults(struct mptcp_pernet *pernet) 47 { 48 pernet->mptcp_enabled = 1; 49 } 50 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 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 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 */ 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 }; 112 113 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) 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