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