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 24 static struct mptcp_pernet *mptcp_get_pernet(struct net *net) 25 { 26 return net_generic(net, mptcp_pernet_id); 27 } 28 29 int mptcp_is_enabled(struct net *net) 30 { 31 return mptcp_get_pernet(net)->mptcp_enabled; 32 } 33 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 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 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 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 } 102 103 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 */ 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 }; 126 127 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) 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