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 #ifdef CONFIG_MPTCP
100 void mptcp_init(void);
101
sk_is_mptcp(const struct sock * sk)102 static inline bool sk_is_mptcp(const struct sock *sk)
103 {
104 return tcp_sk(sk)->is_mptcp;
105 }
106
rsk_is_mptcp(const struct request_sock * req)107 static inline bool rsk_is_mptcp(const struct request_sock *req)
108 {
109 return tcp_rsk(req)->is_mptcp;
110 }
111
rsk_drop_req(const struct request_sock * req)112 static inline bool rsk_drop_req(const struct request_sock *req)
113 {
114 return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req;
115 }
116
117 void mptcp_space(const struct sock *ssk, int *space, int *full_space);
118 bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
119 unsigned int *size, struct mptcp_out_options *opts);
120 bool mptcp_synack_options(const struct request_sock *req, unsigned int *size,
121 struct mptcp_out_options *opts);
122 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
123 unsigned int *size, unsigned int remaining,
124 struct mptcp_out_options *opts);
125 bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb);
126
127 void mptcp_write_options(struct tcphdr *th, __be32 *ptr, struct tcp_sock *tp,
128 struct mptcp_out_options *opts);
129
130 void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info);
131
132 /* move the skb extension owership, with the assumption that 'to' is
133 * newly allocated
134 */
mptcp_skb_ext_move(struct sk_buff * to,struct sk_buff * from)135 static inline void mptcp_skb_ext_move(struct sk_buff *to,
136 struct sk_buff *from)
137 {
138 if (!skb_ext_exist(from, SKB_EXT_MPTCP))
139 return;
140
141 if (WARN_ON_ONCE(to->active_extensions))
142 skb_ext_put(to);
143
144 to->active_extensions = from->active_extensions;
145 to->extensions = from->extensions;
146 from->active_extensions = 0;
147 }
148
mptcp_skb_ext_copy(struct sk_buff * to,struct sk_buff * from)149 static inline void mptcp_skb_ext_copy(struct sk_buff *to,
150 struct sk_buff *from)
151 {
152 struct mptcp_ext *from_ext;
153
154 from_ext = skb_ext_find(from, SKB_EXT_MPTCP);
155 if (!from_ext)
156 return;
157
158 from_ext->frozen = 1;
159 skb_ext_copy(to, from);
160 }
161
mptcp_ext_matches(const struct mptcp_ext * to_ext,const struct mptcp_ext * from_ext)162 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext,
163 const struct mptcp_ext *from_ext)
164 {
165 /* MPTCP always clears the ext when adding it to the skb, so
166 * holes do not bother us here
167 */
168 return !from_ext ||
169 (to_ext && from_ext &&
170 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext)));
171 }
172
173 /* check if skbs can be collapsed.
174 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data
175 * mapping, or if the extension of @to is the same as @from.
176 * Collapsing is not possible if @to lacks an extension, but @from carries one.
177 */
mptcp_skb_can_collapse(const struct sk_buff * to,const struct sk_buff * from)178 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
179 const struct sk_buff *from)
180 {
181 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP),
182 skb_ext_find(from, SKB_EXT_MPTCP));
183 }
184
185 void mptcp_seq_show(struct seq_file *seq);
186 int mptcp_subflow_init_cookie_req(struct request_sock *req,
187 const struct sock *sk_listener,
188 struct sk_buff *skb);
189 struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops,
190 struct sock *sk_listener,
191 bool attach_listener);
192
193 __be32 mptcp_get_reset_option(const struct sk_buff *skb);
194
mptcp_reset_option(const struct sk_buff * skb)195 static inline __be32 mptcp_reset_option(const struct sk_buff *skb)
196 {
197 if (skb_ext_exist(skb, SKB_EXT_MPTCP))
198 return mptcp_get_reset_option(skb);
199
200 return htonl(0u);
201 }
202 #else
203
mptcp_init(void)204 static inline void mptcp_init(void)
205 {
206 }
207
sk_is_mptcp(const struct sock * sk)208 static inline bool sk_is_mptcp(const struct sock *sk)
209 {
210 return false;
211 }
212
rsk_is_mptcp(const struct request_sock * req)213 static inline bool rsk_is_mptcp(const struct request_sock *req)
214 {
215 return false;
216 }
217
rsk_drop_req(const struct request_sock * req)218 static inline bool rsk_drop_req(const struct request_sock *req)
219 {
220 return false;
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 #if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL)
297 struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk);
298 #else
bpf_mptcp_sock_from_subflow(struct sock * sk)299 static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) { return NULL; }
300 #endif
301
302 #if !IS_ENABLED(CONFIG_MPTCP)
303 struct mptcp_sock { };
304 #endif
305
306 #endif /* __NET_MPTCP_H */
307