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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
15struct mptcp_info;
16struct mptcp_sock;
17struct seq_file;
18
19/* MPTCP sk_buff extension data */
20struct 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
45struct mptcp_rm_list {
46 u8 ids[MPTCP_RM_IDS_MAX];
47 u8 nr;
48};
49
50struct 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
62struct 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
105struct mptcp_sched_data {
106 bool reinject;
107 u8 subflows;
108 struct mptcp_subflow_context *contexts[MPTCP_SUBFLOWS_MAX];
109};
110
111struct 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
124void mptcp_init(void);
125
126static inline bool sk_is_mptcp(const struct sock *sk)
127{
128 return tcp_sk(sk)->is_mptcp;
129}
130
131static inline bool rsk_is_mptcp(const struct request_sock *req)
132{
133 return tcp_rsk(req)->is_mptcp;
134}
135
136static 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
141void mptcp_space(const struct sock *ssk, int *space, int *full_space);
142bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
143 unsigned int *size, struct mptcp_out_options *opts);
144bool mptcp_synack_options(const struct request_sock *req, unsigned int *size,
145 struct mptcp_out_options *opts);
146bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
147 unsigned int *size, unsigned int remaining,
148 struct mptcp_out_options *opts);
149bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb);
150
151void mptcp_write_options(struct tcphdr *th, __be32 *ptr, struct tcp_sock *tp,
152 struct mptcp_out_options *opts);
153
154void 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 */
159static 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
173static 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
186static 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 */
202static 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
209void mptcp_seq_show(struct seq_file *seq);
210int mptcp_subflow_init_cookie_req(struct request_sock *req,
211 const struct sock *sk_listener,
212 struct sk_buff *skb);
213struct 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
219static 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
227void mptcp_active_detect_blackhole(struct sock *sk, bool expired);
228#else
229
230static inline void mptcp_init(void)
231{
232}
233
234static inline bool sk_is_mptcp(const struct sock *sk)
235{
236 return false;
237}
238
239static inline bool rsk_is_mptcp(const struct request_sock *req)
240{
241 return false;
242}
243
244static inline bool rsk_drop_req(const struct request_sock *req)
245{
246 return false;
247}
248
249static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
250 unsigned int *size,
251 struct mptcp_out_options *opts)
252{
253 return false;
254}
255
256static inline bool mptcp_synack_options(const struct request_sock *req,
257 unsigned int *size,
258 struct mptcp_out_options *opts)
259{
260 return false;
261}
262
263static inline bool mptcp_established_options(struct sock *sk,
264 struct sk_buff *skb,
265 unsigned int *size,
266 unsigned int remaining,
267 struct mptcp_out_options *opts)
268{
269 return false;
270}
271
272static inline bool mptcp_incoming_options(struct sock *sk,
273 struct sk_buff *skb)
274{
275 return true;
276}
277
278static inline void mptcp_skb_ext_move(struct sk_buff *to,
279 const struct sk_buff *from)
280{
281}
282
283static inline void mptcp_skb_ext_copy(struct sk_buff *to,
284 struct sk_buff *from)
285{
286}
287
288static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
289 const struct sk_buff *from)
290{
291 return true;
292}
293
294static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { }
295static inline void mptcp_seq_show(struct seq_file *seq) { }
296
297static inline int mptcp_subflow_init_cookie_req(struct request_sock *req,
298 const struct sock *sk_listener,
299 struct sk_buff *skb)
300{
301 return 0; /* TCP fallback */
302}
303
304static inline struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops,
305 struct sock *sk_listener,
306 bool attach_listener)
307{
308 return NULL;
309}
310
311static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); }
312
313static inline void mptcp_active_detect_blackhole(struct sock *sk, bool expired) { }
314#endif /* CONFIG_MPTCP */
315
316#if IS_ENABLED(CONFIG_MPTCP_IPV6)
317int mptcpv6_init(void);
318void mptcpv6_handle_mapped(struct sock *sk, bool mapped);
319#elif IS_ENABLED(CONFIG_IPV6)
320static inline int mptcpv6_init(void) { return 0; }
321static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { }
322#endif
323
324#if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL)
325struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk);
326#else
327static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) { return NULL; }
328#endif
329
330#if !IS_ENABLED(CONFIG_MPTCP)
331struct mptcp_sock { };
332#endif
333
334#endif /* __NET_MPTCP_H */