xref: /openbmc/linux/net/mptcp/ctrl.c (revision cf21eb6a)
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 
38 static struct mptcp_pernet *mptcp_get_pernet(const struct net *net)
39 {
40 	return net_generic(net, mptcp_pernet_id);
41 }
42 
43 int mptcp_is_enabled(const struct net *net)
44 {
45 	return mptcp_get_pernet(net)->mptcp_enabled;
46 }
47 
48 unsigned int mptcp_get_add_addr_timeout(const struct net *net)
49 {
50 	return mptcp_get_pernet(net)->add_addr_timeout;
51 }
52 
53 int mptcp_is_checksum_enabled(const struct net *net)
54 {
55 	return mptcp_get_pernet(net)->checksum_enabled;
56 }
57 
58 int mptcp_allow_join_id0(const struct net *net)
59 {
60 	return mptcp_get_pernet(net)->allow_join_initial_addr_port;
61 }
62 
63 unsigned int mptcp_stale_loss_cnt(const struct net *net)
64 {
65 	return mptcp_get_pernet(net)->stale_loss_cnt;
66 }
67 
68 int mptcp_get_pm_type(const struct net *net)
69 {
70 	return mptcp_get_pernet(net)->pm_type;
71 }
72 
73 const char *mptcp_get_scheduler(const struct net *net)
74 {
75 	return mptcp_get_pernet(net)->scheduler;
76 }
77 
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
90 static struct ctl_table mptcp_sysctl_table[] = {
91 	{
92 		.procname = "enabled",
93 		.maxlen = sizeof(u8),
94 		.mode = 0644,
95 		/* users with CAP_NET_ADMIN or root (not and) can change this
96 		 * value, same as other sysctl or the 'net' tree.
97 		 */
98 		.proc_handler = proc_dou8vec_minmax,
99 		.extra1       = SYSCTL_ZERO,
100 		.extra2       = SYSCTL_ONE
101 	},
102 	{
103 		.procname = "add_addr_timeout",
104 		.maxlen = sizeof(unsigned int),
105 		.mode = 0644,
106 		.proc_handler = proc_dointvec_jiffies,
107 	},
108 	{
109 		.procname = "checksum_enabled",
110 		.maxlen = sizeof(u8),
111 		.mode = 0644,
112 		.proc_handler = proc_dou8vec_minmax,
113 		.extra1       = SYSCTL_ZERO,
114 		.extra2       = SYSCTL_ONE
115 	},
116 	{
117 		.procname = "allow_join_initial_addr_port",
118 		.maxlen = sizeof(u8),
119 		.mode = 0644,
120 		.proc_handler = proc_dou8vec_minmax,
121 		.extra1       = SYSCTL_ZERO,
122 		.extra2       = SYSCTL_ONE
123 	},
124 	{
125 		.procname = "stale_loss_cnt",
126 		.maxlen = sizeof(unsigned int),
127 		.mode = 0644,
128 		.proc_handler = proc_douintvec_minmax,
129 	},
130 	{
131 		.procname = "pm_type",
132 		.maxlen = sizeof(u8),
133 		.mode = 0644,
134 		.proc_handler = proc_dou8vec_minmax,
135 		.extra1       = SYSCTL_ZERO,
136 		.extra2       = &mptcp_pm_type_max
137 	},
138 	{
139 		.procname = "scheduler",
140 		.maxlen	= MPTCP_SCHED_NAME_MAX,
141 		.mode = 0644,
142 		.proc_handler = proc_dostring,
143 	},
144 	{}
145 };
146 
147 static int mptcp_pernet_new_table(struct net *net, struct mptcp_pernet *pernet)
148 {
149 	struct ctl_table_header *hdr;
150 	struct ctl_table *table;
151 
152 	table = mptcp_sysctl_table;
153 	if (!net_eq(net, &init_net)) {
154 		table = kmemdup(table, sizeof(mptcp_sysctl_table), GFP_KERNEL);
155 		if (!table)
156 			goto err_alloc;
157 	}
158 
159 	table[0].data = &pernet->mptcp_enabled;
160 	table[1].data = &pernet->add_addr_timeout;
161 	table[2].data = &pernet->checksum_enabled;
162 	table[3].data = &pernet->allow_join_initial_addr_port;
163 	table[4].data = &pernet->stale_loss_cnt;
164 	table[5].data = &pernet->pm_type;
165 	table[6].data = &pernet->scheduler;
166 
167 	hdr = register_net_sysctl_sz(net, MPTCP_SYSCTL_PATH, table,
168 				     ARRAY_SIZE(mptcp_sysctl_table));
169 	if (!hdr)
170 		goto err_reg;
171 
172 	pernet->ctl_table_hdr = hdr;
173 
174 	return 0;
175 
176 err_reg:
177 	if (!net_eq(net, &init_net))
178 		kfree(table);
179 err_alloc:
180 	return -ENOMEM;
181 }
182 
183 static void mptcp_pernet_del_table(struct mptcp_pernet *pernet)
184 {
185 	struct ctl_table *table = pernet->ctl_table_hdr->ctl_table_arg;
186 
187 	unregister_net_sysctl_table(pernet->ctl_table_hdr);
188 
189 	kfree(table);
190 }
191 
192 #else
193 
194 static int mptcp_pernet_new_table(struct net *net, struct mptcp_pernet *pernet)
195 {
196 	return 0;
197 }
198 
199 static void mptcp_pernet_del_table(struct mptcp_pernet *pernet) {}
200 
201 #endif /* CONFIG_SYSCTL */
202 
203 static int __net_init mptcp_net_init(struct net *net)
204 {
205 	struct mptcp_pernet *pernet = mptcp_get_pernet(net);
206 
207 	mptcp_pernet_set_defaults(pernet);
208 
209 	return mptcp_pernet_new_table(net, pernet);
210 }
211 
212 /* Note: the callback will only be called per extra netns */
213 static void __net_exit mptcp_net_exit(struct net *net)
214 {
215 	struct mptcp_pernet *pernet = mptcp_get_pernet(net);
216 
217 	mptcp_pernet_del_table(pernet);
218 }
219 
220 static struct pernet_operations mptcp_pernet_ops = {
221 	.init = mptcp_net_init,
222 	.exit = mptcp_net_exit,
223 	.id = &mptcp_pernet_id,
224 	.size = sizeof(struct mptcp_pernet),
225 };
226 
227 void __init mptcp_init(void)
228 {
229 	mptcp_join_cookie_init();
230 	mptcp_proto_init();
231 
232 	if (register_pernet_subsys(&mptcp_pernet_ops) < 0)
233 		panic("Failed to register MPTCP pernet subsystem.\n");
234 }
235 
236 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
237 int __init mptcpv6_init(void)
238 {
239 	int err;
240 
241 	err = mptcp_proto_v6_init();
242 
243 	return err;
244 }
245 #endif
246