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 18 static int mptcp_pernet_id; 19 20 #ifdef CONFIG_SYSCTL 21 static int mptcp_pm_type_max = __MPTCP_PM_TYPE_MAX; 22 #endif 23 24 struct mptcp_pernet { 25 #ifdef CONFIG_SYSCTL 26 struct ctl_table_header *ctl_table_hdr; 27 #endif 28 29 unsigned int add_addr_timeout; 30 unsigned int close_timeout; 31 unsigned int stale_loss_cnt; 32 u8 mptcp_enabled; 33 u8 checksum_enabled; 34 u8 allow_join_initial_addr_port; 35 u8 pm_type; 36 char scheduler[MPTCP_SCHED_NAME_MAX]; 37 }; 38 39 static struct mptcp_pernet *mptcp_get_pernet(const struct net *net) 40 { 41 return net_generic(net, mptcp_pernet_id); 42 } 43 44 int mptcp_is_enabled(const struct net *net) 45 { 46 return mptcp_get_pernet(net)->mptcp_enabled; 47 } 48 49 unsigned int mptcp_get_add_addr_timeout(const struct net *net) 50 { 51 return mptcp_get_pernet(net)->add_addr_timeout; 52 } 53 54 int mptcp_is_checksum_enabled(const struct net *net) 55 { 56 return mptcp_get_pernet(net)->checksum_enabled; 57 } 58 59 int mptcp_allow_join_id0(const struct net *net) 60 { 61 return mptcp_get_pernet(net)->allow_join_initial_addr_port; 62 } 63 64 unsigned int mptcp_stale_loss_cnt(const struct net *net) 65 { 66 return mptcp_get_pernet(net)->stale_loss_cnt; 67 } 68 69 unsigned int mptcp_close_timeout(const struct sock *sk) 70 { 71 if (sock_flag(sk, SOCK_DEAD)) 72 return TCP_TIMEWAIT_LEN; 73 return mptcp_get_pernet(sock_net(sk))->close_timeout; 74 } 75 76 int mptcp_get_pm_type(const struct net *net) 77 { 78 return mptcp_get_pernet(net)->pm_type; 79 } 80 81 const char *mptcp_get_scheduler(const struct net *net) 82 { 83 return mptcp_get_pernet(net)->scheduler; 84 } 85 86 static void mptcp_pernet_set_defaults(struct mptcp_pernet *pernet) 87 { 88 pernet->mptcp_enabled = 1; 89 pernet->add_addr_timeout = TCP_RTO_MAX; 90 pernet->close_timeout = TCP_TIMEWAIT_LEN; 91 pernet->checksum_enabled = 0; 92 pernet->allow_join_initial_addr_port = 1; 93 pernet->stale_loss_cnt = 4; 94 pernet->pm_type = MPTCP_PM_TYPE_KERNEL; 95 strscpy(pernet->scheduler, "default", sizeof(pernet->scheduler)); 96 } 97 98 #ifdef CONFIG_SYSCTL 99 static int mptcp_set_scheduler(const struct net *net, const char *name) 100 { 101 struct mptcp_pernet *pernet = mptcp_get_pernet(net); 102 struct mptcp_sched_ops *sched; 103 int ret = 0; 104 105 rcu_read_lock(); 106 sched = mptcp_sched_find(name); 107 if (sched) 108 strscpy(pernet->scheduler, name, MPTCP_SCHED_NAME_MAX); 109 else 110 ret = -ENOENT; 111 rcu_read_unlock(); 112 113 return ret; 114 } 115 116 static int proc_scheduler(const struct ctl_table *ctl, int write, 117 void *buffer, size_t *lenp, loff_t *ppos) 118 { 119 const struct net *net = current->nsproxy->net_ns; 120 char val[MPTCP_SCHED_NAME_MAX]; 121 struct ctl_table tbl = { 122 .data = val, 123 .maxlen = MPTCP_SCHED_NAME_MAX, 124 }; 125 int ret; 126 127 strscpy(val, mptcp_get_scheduler(net), MPTCP_SCHED_NAME_MAX); 128 129 ret = proc_dostring(&tbl, write, buffer, lenp, ppos); 130 if (write && ret == 0) 131 ret = mptcp_set_scheduler(net, val); 132 133 return ret; 134 } 135 136 static int proc_available_schedulers(const struct ctl_table *ctl, 137 int write, void *buffer, 138 size_t *lenp, loff_t *ppos) 139 { 140 struct ctl_table tbl = { .maxlen = MPTCP_SCHED_BUF_MAX, }; 141 int ret; 142 143 tbl.data = kmalloc(tbl.maxlen, GFP_USER); 144 if (!tbl.data) 145 return -ENOMEM; 146 147 mptcp_get_available_schedulers(tbl.data, MPTCP_SCHED_BUF_MAX); 148 ret = proc_dostring(&tbl, write, buffer, lenp, ppos); 149 kfree(tbl.data); 150 151 return ret; 152 } 153 154 static struct ctl_table mptcp_sysctl_table[] = { 155 { 156 .procname = "enabled", 157 .maxlen = sizeof(u8), 158 .mode = 0644, 159 /* users with CAP_NET_ADMIN or root (not and) can change this 160 * value, same as other sysctl or the 'net' tree. 161 */ 162 .proc_handler = proc_dou8vec_minmax, 163 .extra1 = SYSCTL_ZERO, 164 .extra2 = SYSCTL_ONE 165 }, 166 { 167 .procname = "add_addr_timeout", 168 .maxlen = sizeof(unsigned int), 169 .mode = 0644, 170 .proc_handler = proc_dointvec_jiffies, 171 }, 172 { 173 .procname = "checksum_enabled", 174 .maxlen = sizeof(u8), 175 .mode = 0644, 176 .proc_handler = proc_dou8vec_minmax, 177 .extra1 = SYSCTL_ZERO, 178 .extra2 = SYSCTL_ONE 179 }, 180 { 181 .procname = "allow_join_initial_addr_port", 182 .maxlen = sizeof(u8), 183 .mode = 0644, 184 .proc_handler = proc_dou8vec_minmax, 185 .extra1 = SYSCTL_ZERO, 186 .extra2 = SYSCTL_ONE 187 }, 188 { 189 .procname = "stale_loss_cnt", 190 .maxlen = sizeof(unsigned int), 191 .mode = 0644, 192 .proc_handler = proc_douintvec_minmax, 193 }, 194 { 195 .procname = "pm_type", 196 .maxlen = sizeof(u8), 197 .mode = 0644, 198 .proc_handler = proc_dou8vec_minmax, 199 .extra1 = SYSCTL_ZERO, 200 .extra2 = &mptcp_pm_type_max 201 }, 202 { 203 .procname = "scheduler", 204 .maxlen = MPTCP_SCHED_NAME_MAX, 205 .mode = 0644, 206 .proc_handler = proc_scheduler, 207 }, 208 { 209 .procname = "available_schedulers", 210 .maxlen = MPTCP_SCHED_BUF_MAX, 211 .mode = 0644, 212 .proc_handler = proc_available_schedulers, 213 }, 214 { 215 .procname = "close_timeout", 216 .maxlen = sizeof(unsigned int), 217 .mode = 0644, 218 .proc_handler = proc_dointvec_jiffies, 219 }, 220 }; 221 222 static int mptcp_pernet_new_table(struct net *net, struct mptcp_pernet *pernet) 223 { 224 struct ctl_table_header *hdr; 225 struct ctl_table *table; 226 227 table = mptcp_sysctl_table; 228 if (!net_eq(net, &init_net)) { 229 table = kmemdup(table, sizeof(mptcp_sysctl_table), GFP_KERNEL); 230 if (!table) 231 goto err_alloc; 232 } 233 234 table[0].data = &pernet->mptcp_enabled; 235 table[1].data = &pernet->add_addr_timeout; 236 table[2].data = &pernet->checksum_enabled; 237 table[3].data = &pernet->allow_join_initial_addr_port; 238 table[4].data = &pernet->stale_loss_cnt; 239 table[5].data = &pernet->pm_type; 240 table[6].data = &pernet->scheduler; 241 /* table[7] is for available_schedulers which is read-only info */ 242 table[8].data = &pernet->close_timeout; 243 244 hdr = register_net_sysctl_sz(net, MPTCP_SYSCTL_PATH, table, 245 ARRAY_SIZE(mptcp_sysctl_table)); 246 if (!hdr) 247 goto err_reg; 248 249 pernet->ctl_table_hdr = hdr; 250 251 return 0; 252 253 err_reg: 254 if (!net_eq(net, &init_net)) 255 kfree(table); 256 err_alloc: 257 return -ENOMEM; 258 } 259 260 static void mptcp_pernet_del_table(struct mptcp_pernet *pernet) 261 { 262 const struct ctl_table *table = pernet->ctl_table_hdr->ctl_table_arg; 263 264 unregister_net_sysctl_table(pernet->ctl_table_hdr); 265 266 kfree(table); 267 } 268 269 #else 270 271 static int mptcp_pernet_new_table(struct net *net, struct mptcp_pernet *pernet) 272 { 273 return 0; 274 } 275 276 static void mptcp_pernet_del_table(struct mptcp_pernet *pernet) {} 277 278 #endif /* CONFIG_SYSCTL */ 279 280 static int __net_init mptcp_net_init(struct net *net) 281 { 282 struct mptcp_pernet *pernet = mptcp_get_pernet(net); 283 284 mptcp_pernet_set_defaults(pernet); 285 286 return mptcp_pernet_new_table(net, pernet); 287 } 288 289 /* Note: the callback will only be called per extra netns */ 290 static void __net_exit mptcp_net_exit(struct net *net) 291 { 292 struct mptcp_pernet *pernet = mptcp_get_pernet(net); 293 294 mptcp_pernet_del_table(pernet); 295 } 296 297 static struct pernet_operations mptcp_pernet_ops = { 298 .init = mptcp_net_init, 299 .exit = mptcp_net_exit, 300 .id = &mptcp_pernet_id, 301 .size = sizeof(struct mptcp_pernet), 302 }; 303 304 void __init mptcp_init(void) 305 { 306 mptcp_join_cookie_init(); 307 mptcp_proto_init(); 308 309 if (register_pernet_subsys(&mptcp_pernet_ops) < 0) 310 panic("Failed to register MPTCP pernet subsystem.\n"); 311 } 312 313 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 314 int __init mptcpv6_init(void) 315 { 316 int err; 317 318 err = mptcp_proto_v6_init(); 319 320 return err; 321 } 322 #endif 323