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