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