1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Multipath TCP
4 *
5 * Copyright (c) 2017 - 2019, Intel Corporation.
6 */
7
8 #ifndef __NET_MPTCP_H
9 #define __NET_MPTCP_H
10
11 #include <linux/skbuff.h>
12 #include <linux/tcp.h>
13 #include <linux/types.h>
14
15 struct mptcp_info;
16 struct mptcp_sock;
17 struct seq_file;
18
19 /* MPTCP sk_buff extension data */
20 struct mptcp_ext {
21 union {
22 u64 data_ack;
23 u32 data_ack32;
24 };
25 u64 data_seq;
26 u32 subflow_seq;
27 u16 data_len;
28 __sum16 csum;
29 u8 use_map:1,
30 dsn64:1,
31 data_fin:1,
32 use_ack:1,
33 ack64:1,
34 mpc_map:1,
35 frozen:1,
36 reset_transient:1;
37 u8 reset_reason:4,
38 csum_reqd:1,
39 infinite_map:1;
40 };
41
42 #define MPTCPOPT_HMAC_LEN 20
43 #define MPTCP_RM_IDS_MAX 8
44
45 struct mptcp_rm_list {
46 u8 ids[MPTCP_RM_IDS_MAX];
47 u8 nr;
48 };
49
50 struct mptcp_addr_info {
51 u8 id;
52 sa_family_t family;
53 __be16 port;
54 union {
55 struct in_addr addr;
56 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
57 struct in6_addr addr6;
58 #endif
59 };
60 };
61
62 struct mptcp_out_options {
63 #if IS_ENABLED(CONFIG_MPTCP)
64 u16 suboptions;
65 struct mptcp_rm_list rm_list;
66 u8 join_id;
67 u8 backup;
68 u8 reset_reason:4,
69 reset_transient:1,
70 csum_reqd:1,
71 allow_join_id0:1;
72 union {
73 struct {
74 u64 sndr_key;
75 u64 rcvr_key;
76 u64 data_seq;
77 u32 subflow_seq;
78 u16 data_len;
79 __sum16 csum;
80 };
81 struct {
82 struct mptcp_addr_info addr;
83 u64 ahmac;
84 };
85 struct {
86 struct mptcp_ext ext_copy;
87 u64 fail_seq;
88 };
89 struct {
90 u32 nonce;
91 u32 token;
92 u64 thmac;
93 u8 hmac[MPTCPOPT_HMAC_LEN];
94 };
95 };
96 #endif
97 };
98
99 #define MPTCP_SCHED_NAME_MAX 16
100 #define MPTCP_SCHED_MAX 128
101 #define MPTCP_SCHED_BUF_MAX (MPTCP_SCHED_NAME_MAX * MPTCP_SCHED_MAX)
102
103 #define MPTCP_SUBFLOWS_MAX 8
104
105 struct mptcp_sched_data {
106 bool reinject;
107 u8 subflows;
108 struct mptcp_subflow_context *contexts[MPTCP_SUBFLOWS_MAX];
109 };
110
111 struct mptcp_sched_ops {
112 int (*get_subflow)(struct mptcp_sock *msk,
113 struct mptcp_sched_data *data);
114
115 char name[MPTCP_SCHED_NAME_MAX];
116 struct module *owner;
117 struct list_head list;
118
119 void (*init)(struct mptcp_sock *msk);
120 void (*release)(struct mptcp_sock *msk);
121 } ____cacheline_aligned_in_smp;
122
123 #ifdef CONFIG_MPTCP
124 void mptcp_init(void);
125
126 static inline bool sk_is_mptcp(const struct sock *sk)
127 {
128 return tcp_sk(sk)->is_mptcp;
129 }
130
131 static inline bool rsk_is_mptcp(const struct request_sock *req)
132 {
133 return tcp_rsk(req)->is_mptcp;
134 }
135
136 static inline bool rsk_drop_req(const struct request_sock *req)
137 {
138 return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req;
139 }
140
141 void mptcp_space(const struct sock *ssk, int *space, int *full_space);
142 bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
143 unsigned int *size, struct mptcp_out_options *opts);
144 bool mptcp_synack_options(const struct request_sock *req, unsigned int *size,
145 struct mptcp_out_options *opts);
146 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
147 unsigned int *size, unsigned int remaining,
148 struct mptcp_out_options *opts);
149 bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb);
150
151 void mptcp_write_options(struct tcphdr *th, __be32 *ptr, struct tcp_sock *tp,
152 struct mptcp_out_options *opts);
153
154 void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info);
155
156 /* move the skb extension owership, with the assumption that 'to' is
157 * newly allocated
158 */
159 static inline void mptcp_skb_ext_move(struct sk_buff *to,
160 struct sk_buff *from)
161 {
162 if (!skb_ext_exist(from, SKB_EXT_MPTCP))
163 return;
164
165 if (WARN_ON_ONCE(to->active_extensions))
166 skb_ext_put(to);
167
168 to->active_extensions = from->active_extensions;
169 to->extensions = from->extensions;
170 from->active_extensions = 0;
171 }
172
173 static inline void mptcp_skb_ext_copy(struct sk_buff *to,
174 struct sk_buff *from)
175 {
176 struct mptcp_ext *from_ext;
177
178 from_ext = skb_ext_find(from, SKB_EXT_MPTCP);
179 if (!from_ext)
180 return;
181
182 from_ext->frozen = 1;
183 skb_ext_copy(to, from);
184 }
185
186 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext,
187 const struct mptcp_ext *from_ext)
188 {
189 /* MPTCP always clears the ext when adding it to the skb, so
190 * holes do not bother us here
191 */
192 return !from_ext ||
193 (to_ext && from_ext &&
194 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext)));
195 }
196
197 /* check if skbs can be collapsed.
198 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data
199 * mapping, or if the extension of @to is the same as @from.
200 * Collapsing is not possible if @to lacks an extension, but @from carries one.
201 */
202 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
203 const struct sk_buff *from)
204 {
205 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP),
206 skb_ext_find(from, SKB_EXT_MPTCP));
207 }
208
209 void mptcp_seq_show(struct seq_file *seq);
210 int mptcp_subflow_init_cookie_req(struct request_sock *req,
211 const struct sock *sk_listener,
212 struct sk_buff *skb);
213 struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops,
214 struct sock *sk_listener,
215 bool attach_listener);
216
217 __be32 mptcp_get_reset_option(const struct sk_buff *skb);
218
219 static inline __be32 mptcp_reset_option(const struct sk_buff *skb)
220 {
221 if (skb_ext_exist(skb, SKB_EXT_MPTCP))
222 return mptcp_get_reset_option(skb);
223
224 return htonl(0u);
225 }
226 #else
227
228 static inline void mptcp_init(void)
229 {
230 }
231
232 static inline bool sk_is_mptcp(const struct sock *sk)
233 {
234 return false;
235 }
236
237 static inline bool rsk_is_mptcp(const struct request_sock *req)
238 {
239 return false;
240 }
241
242 static inline bool rsk_drop_req(const struct request_sock *req)
243 {
244 return false;
245 }
246
247 static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
248 unsigned int *size,
249 struct mptcp_out_options *opts)
250 {
251 return false;
252 }
253
254 static inline bool mptcp_synack_options(const struct request_sock *req,
255 unsigned int *size,
256 struct mptcp_out_options *opts)
257 {
258 return false;
259 }
260
261 static inline bool mptcp_established_options(struct sock *sk,
262 struct sk_buff *skb,
263 unsigned int *size,
264 unsigned int remaining,
265 struct mptcp_out_options *opts)
266 {
267 return false;
268 }
269
270 static inline bool mptcp_incoming_options(struct sock *sk,
271 struct sk_buff *skb)
272 {
273 return true;
274 }
275
276 static inline void mptcp_skb_ext_move(struct sk_buff *to,
277 const struct sk_buff *from)
278 {
279 }
280
281 static inline void mptcp_skb_ext_copy(struct sk_buff *to,
282 struct sk_buff *from)
283 {
284 }
285
286 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
287 const struct sk_buff *from)
288 {
289 return true;
290 }
291
292 static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { }
293 static inline void mptcp_seq_show(struct seq_file *seq) { }
294
295 static inline int mptcp_subflow_init_cookie_req(struct request_sock *req,
296 const struct sock *sk_listener,
297 struct sk_buff *skb)
298 {
299 return 0; /* TCP fallback */
300 }
301
302 static inline struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops,
303 struct sock *sk_listener,
304 bool attach_listener)
305 {
306 return NULL;
307 }
308
309 static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); }
310 #endif /* CONFIG_MPTCP */
311
312 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
313 int mptcpv6_init(void);
314 void mptcpv6_handle_mapped(struct sock *sk, bool mapped);
315 #elif IS_ENABLED(CONFIG_IPV6)
316 static inline int mptcpv6_init(void) { return 0; }
317 static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { }
318 #endif
319
320 #if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL)
321 struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk);
322 #else
323 static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) { return NULL; }
324 #endif
325
326 #if !IS_ENABLED(CONFIG_MPTCP)
327 struct mptcp_sock { };
328 #endif
329
330 #endif /* __NET_MPTCP_H */
331
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