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 | extern struct request_sock_ops mptcp_subflow_request_sock_ops; |
101 | |
102 | void mptcp_init(void); |
103 | |
104 | static inline bool sk_is_mptcp(const struct sock *sk) |
105 | { |
106 | return tcp_sk(sk)->is_mptcp; |
107 | } |
108 | |
109 | static inline bool rsk_is_mptcp(const struct request_sock *req) |
110 | { |
111 | return tcp_rsk(req)->is_mptcp; |
112 | } |
113 | |
114 | static inline bool rsk_drop_req(const struct request_sock *req) |
115 | { |
116 | return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req; |
117 | } |
118 | |
119 | void mptcp_space(const struct sock *ssk, int *space, int *full_space); |
120 | bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, |
121 | unsigned int *size, struct mptcp_out_options *opts); |
122 | bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, |
123 | struct mptcp_out_options *opts); |
124 | bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, |
125 | unsigned int *size, unsigned int remaining, |
126 | struct mptcp_out_options *opts); |
127 | bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb); |
128 | |
129 | void mptcp_write_options(struct tcphdr *th, __be32 *ptr, struct tcp_sock *tp, |
130 | struct mptcp_out_options *opts); |
131 | |
132 | void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info); |
133 | |
134 | /* move the skb extension owership, with the assumption that 'to' is |
135 | * newly allocated |
136 | */ |
137 | static inline void mptcp_skb_ext_move(struct sk_buff *to, |
138 | struct sk_buff *from) |
139 | { |
140 | if (!skb_ext_exist(from, SKB_EXT_MPTCP)) |
141 | return; |
142 | |
143 | if (WARN_ON_ONCE(to->active_extensions)) |
144 | skb_ext_put(to); |
145 | |
146 | to->active_extensions = from->active_extensions; |
147 | to->extensions = from->extensions; |
148 | from->active_extensions = 0; |
149 | } |
150 | |
151 | static inline void mptcp_skb_ext_copy(struct sk_buff *to, |
152 | struct sk_buff *from) |
153 | { |
154 | struct mptcp_ext *from_ext; |
155 | |
156 | from_ext = skb_ext_find(from, SKB_EXT_MPTCP); |
157 | if (!from_ext) |
158 | return; |
159 | |
160 | from_ext->frozen = 1; |
161 | skb_ext_copy(to, from); |
162 | } |
163 | |
164 | static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, |
165 | const struct mptcp_ext *from_ext) |
166 | { |
167 | /* MPTCP always clears the ext when adding it to the skb, so |
168 | * holes do not bother us here |
169 | */ |
170 | return !from_ext || |
171 | (to_ext && from_ext && |
172 | !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); |
173 | } |
174 | |
175 | /* check if skbs can be collapsed. |
176 | * MPTCP collapse is allowed if neither @to or @from carry an mptcp data |
177 | * mapping, or if the extension of @to is the same as @from. |
178 | * Collapsing is not possible if @to lacks an extension, but @from carries one. |
179 | */ |
180 | static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, |
181 | const struct sk_buff *from) |
182 | { |
183 | return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), |
184 | skb_ext_find(from, SKB_EXT_MPTCP)); |
185 | } |
186 | |
187 | void mptcp_seq_show(struct seq_file *seq); |
188 | int mptcp_subflow_init_cookie_req(struct request_sock *req, |
189 | const struct sock *sk_listener, |
190 | struct sk_buff *skb); |
191 | |
192 | __be32 mptcp_get_reset_option(const struct sk_buff *skb); |
193 | |
194 | static inline __be32 mptcp_reset_option(const struct sk_buff *skb) |
195 | { |
196 | if (skb_ext_exist(skb, SKB_EXT_MPTCP)) |
197 | return mptcp_get_reset_option(skb); |
198 | |
199 | return htonl(0u); |
200 | } |
201 | #else |
202 | |
203 | static inline void mptcp_init(void) |
204 | { |
205 | } |
206 | |
207 | static inline bool sk_is_mptcp(const struct sock *sk) |
208 | { |
209 | return false; |
210 | } |
211 | |
212 | static inline bool rsk_is_mptcp(const struct request_sock *req) |
213 | { |
214 | return false; |
215 | } |
216 | |
217 | static inline bool rsk_drop_req(const struct request_sock *req) |
218 | { |
219 | return false; |
220 | } |
221 | |
222 | static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, |
223 | unsigned int *size, |
224 | struct mptcp_out_options *opts) |
225 | { |
226 | return false; |
227 | } |
228 | |
229 | static inline bool mptcp_synack_options(const struct request_sock *req, |
230 | unsigned int *size, |
231 | struct mptcp_out_options *opts) |
232 | { |
233 | return false; |
234 | } |
235 | |
236 | static inline bool mptcp_established_options(struct sock *sk, |
237 | struct sk_buff *skb, |
238 | unsigned int *size, |
239 | unsigned int remaining, |
240 | struct mptcp_out_options *opts) |
241 | { |
242 | return false; |
243 | } |
244 | |
245 | static inline bool mptcp_incoming_options(struct sock *sk, |
246 | struct sk_buff *skb) |
247 | { |
248 | return true; |
249 | } |
250 | |
251 | static inline void mptcp_skb_ext_move(struct sk_buff *to, |
252 | const struct sk_buff *from) |
253 | { |
254 | } |
255 | |
256 | static inline void mptcp_skb_ext_copy(struct sk_buff *to, |
257 | struct sk_buff *from) |
258 | { |
259 | } |
260 | |
261 | static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, |
262 | const struct sk_buff *from) |
263 | { |
264 | return true; |
265 | } |
266 | |
267 | static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { } |
268 | static inline void mptcp_seq_show(struct seq_file *seq) { } |
269 | |
270 | static inline int mptcp_subflow_init_cookie_req(struct request_sock *req, |
271 | const struct sock *sk_listener, |
272 | struct sk_buff *skb) |
273 | { |
274 | return 0; /* TCP fallback */ |
275 | } |
276 | |
277 | static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); } |
278 | #endif /* CONFIG_MPTCP */ |
279 | |
280 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) |
281 | int mptcpv6_init(void); |
282 | void mptcpv6_handle_mapped(struct sock *sk, bool mapped); |
283 | #elif IS_ENABLED(CONFIG_IPV6) |
284 | static inline int mptcpv6_init(void) { return 0; } |
285 | static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } |
286 | #endif |
287 | |
288 | #if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL) |
289 | struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk); |
290 | #else |
291 | static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) { return NULL; } |
292 | #endif |
293 | |
294 | #if !IS_ENABLED(CONFIG_MPTCP) |
295 | struct mptcp_sock { }; |
296 | #endif |
297 | |
298 | #endif /* __NET_MPTCP_H */ |
299 | |