summaryrefslogtreecommitdiffstats
path: root/include/net/mptcp.h
blob: 0bc4ab03f48786a11ee6be2b7aac60c0d8d176cb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Multipath TCP
 *
 * Copyright (c) 2017 - 2019, Intel Corporation.
 */

#ifndef __NET_MPTCP_H
#define __NET_MPTCP_H

#include <linux/skbuff.h>
#include <linux/tcp.h>
#include <linux/types.h>

struct mptcp_info;
struct mptcp_sock;
struct seq_file;

/* MPTCP sk_buff extension data */
struct mptcp_ext {
	union {
		u64	data_ack;
		u32	data_ack32;
	};
	u64		data_seq;
	u32		subflow_seq;
	u16		data_len;
	__sum16		csum;
	u8		use_map:1,
			dsn64:1,
			data_fin:1,
			use_ack:1,
			ack64:1,
			mpc_map:1,
			frozen:1,
			reset_transient:1;
	u8		reset_reason:4,
			csum_reqd:1,
			infinite_map:1;
};

#define MPTCPOPT_HMAC_LEN	20
#define MPTCP_RM_IDS_MAX	8

struct mptcp_rm_list {
	u8 ids[MPTCP_RM_IDS_MAX];
	u8 nr;
};

struct mptcp_addr_info {
	u8			id;
	sa_family_t		family;
	__be16			port;
	union {
		struct in_addr	addr;
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
		struct in6_addr	addr6;
#endif
	};
};

struct mptcp_out_options {
#if IS_ENABLED(CONFIG_MPTCP)
	u16 suboptions;
	struct mptcp_rm_list rm_list;
	u8 join_id;
	u8 backup;
	u8 reset_reason:4,
	   reset_transient:1,
	   csum_reqd:1,
	   allow_join_id0:1;
	union {
		struct {
			u64 sndr_key;
			u64 rcvr_key;
			u64 data_seq;
			u32 subflow_seq;
			u16 data_len;
			__sum16 csum;
		};
		struct {
			struct mptcp_addr_info addr;
			u64 ahmac;
		};
		struct {
			struct mptcp_ext ext_copy;
			u64 fail_seq;
		};
		struct {
			u32 nonce;
			u32 token;
			u64 thmac;
			u8 hmac[MPTCPOPT_HMAC_LEN];
		};
	};
#endif
};

#define MPTCP_SCHED_NAME_MAX	16
#define MPTCP_SCHED_MAX		128
#define MPTCP_SCHED_BUF_MAX	(MPTCP_SCHED_NAME_MAX * MPTCP_SCHED_MAX)

#define MPTCP_SUBFLOWS_MAX	8

struct mptcp_sched_data {
	bool	reinject;
	u8	subflows;
	struct mptcp_subflow_context *contexts[MPTCP_SUBFLOWS_MAX];
};

struct mptcp_sched_ops {
	int (*get_subflow)(struct mptcp_sock *msk,
			   struct mptcp_sched_data *data);

	char			name[MPTCP_SCHED_NAME_MAX];
	struct module		*owner;
	struct list_head	list;

	void (*init)(struct mptcp_sock *msk);
	void (*release)(struct mptcp_sock *msk);
} ____cacheline_aligned_in_smp;

#ifdef CONFIG_MPTCP
void mptcp_init(void);

static inline bool sk_is_mptcp(const struct sock *sk)
{
	return tcp_sk(sk)->is_mptcp;
}

static inline bool rsk_is_mptcp(const struct request_sock *req)
{
	return tcp_rsk(req)->is_mptcp;
}

static inline bool rsk_drop_req(const struct request_sock *req)
{
	return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req;
}

void mptcp_space(const struct sock *ssk, int *space, int *full_space);
bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
		       unsigned int *size, struct mptcp_out_options *opts);
bool mptcp_synack_options(const struct request_sock *req, unsigned int *size,
			  struct mptcp_out_options *opts);
bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
			       unsigned int *size, unsigned int remaining,
			       struct mptcp_out_options *opts);
bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb);

void mptcp_write_options(struct tcphdr *th, __be32 *ptr, struct tcp_sock *tp,
			 struct mptcp_out_options *opts);

void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info);

/* move the skb extension owership, with the assumption that 'to' is
 * newly allocated
 */
static inline void mptcp_skb_ext_move(struct sk_buff *to,
				      struct sk_buff *from)
{
	if (!skb_ext_exist(from, SKB_EXT_MPTCP))
		return;

	if (WARN_ON_ONCE(to->active_extensions))
		skb_ext_put(to);

	to->active_extensions = from->active_extensions;
	to->extensions = from->extensions;
	from->active_extensions = 0;
}

static inline void mptcp_skb_ext_copy(struct sk_buff *to,
				      struct sk_buff *from)
{
	struct mptcp_ext *from_ext;

	from_ext = skb_ext_find(from, SKB_EXT_MPTCP);
	if (!from_ext)
		return;

	from_ext->frozen = 1;
	skb_ext_copy(to, from);
}

static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext,
				     const struct mptcp_ext *from_ext)
{
	/* MPTCP always clears the ext when adding it to the skb, so
	 * holes do not bother us here
	 */
	return !from_ext ||
	       (to_ext && from_ext &&
	        !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext)));
}

/* check if skbs can be collapsed.
 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data
 * mapping, or if the extension of @to is the same as @from.
 * Collapsing is not possible if @to lacks an extension, but @from carries one.
 */
static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
					  const struct sk_buff *from)
{
	return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP),
				 skb_ext_find(from, SKB_EXT_MPTCP));
}

void mptcp_seq_show(struct seq_file *seq);
int mptcp_subflow_init_cookie_req(struct request_sock *req,
				  const struct sock *sk_listener,
				  struct sk_buff *skb);
struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops,
					       struct sock *sk_listener,
					       bool attach_listener);

__be32 mptcp_get_reset_option(const struct sk_buff *skb);

static inline __be32 mptcp_reset_option(const struct sk_buff *skb)
{
	if (skb_ext_exist(skb, SKB_EXT_MPTCP))
		return mptcp_get_reset_option(skb);

	return htonl(0u);
}
#else

static inline void mptcp_init(void)
{
}

static inline bool sk_is_mptcp(const struct sock *sk)
{
	return false;
}

static inline bool rsk_is_mptcp(const struct request_sock *req)
{
	return false;
}

static inline bool rsk_drop_req(const struct request_sock *req)
{
	return false;
}

static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
				     unsigned int *size,
				     struct mptcp_out_options *opts)
{
	return false;
}

static inline bool mptcp_synack_options(const struct request_sock *req,
					unsigned int *size,
					struct mptcp_out_options *opts)
{
	return false;
}

static inline bool mptcp_established_options(struct sock *sk,
					     struct sk_buff *skb,
					     unsigned int *size,
					     unsigned int remaining,
					     struct mptcp_out_options *opts)
{
	return false;
}

static inline bool mptcp_incoming_options(struct sock *sk,
					  struct sk_buff *skb)
{
	return true;
}

static inline void mptcp_skb_ext_move(struct sk_buff *to,
				      const struct sk_buff *from)
{
}

static inline void mptcp_skb_ext_copy(struct sk_buff *to,
				      struct sk_buff *from)
{
}

static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
					  const struct sk_buff *from)
{
	return true;
}

static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { }
static inline void mptcp_seq_show(struct seq_file *seq) { }

static inline int mptcp_subflow_init_cookie_req(struct request_sock *req,
						const struct sock *sk_listener,
						struct sk_buff *skb)
{
	return 0; /* TCP fallback */
}

static inline struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops,
							     struct sock *sk_listener,
							     bool attach_listener)
{
	return NULL;
}

static inline __be32 mptcp_reset_option(const struct sk_buff *skb)  { return htonl(0u); }
#endif /* CONFIG_MPTCP */

#if IS_ENABLED(CONFIG_MPTCP_IPV6)
int mptcpv6_init(void);
void mptcpv6_handle_mapped(struct sock *sk, bool mapped);
#elif IS_ENABLED(CONFIG_IPV6)
static inline int mptcpv6_init(void) { return 0; }
static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { }
#endif

#if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL)
struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk);
#else
static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) { return NULL; }
#endif

#if !IS_ENABLED(CONFIG_MPTCP)
struct mptcp_sock { };
#endif

#endif /* __NET_MPTCP_H */