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f870fa0b MM |
1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* Multipath TCP | |
3 | * | |
4 | * Copyright (c) 2017 - 2019, Intel Corporation. | |
5 | */ | |
6 | ||
7 | #ifndef __MPTCP_PROTOCOL_H | |
8 | #define __MPTCP_PROTOCOL_H | |
9 | ||
79c0949e PK |
10 | #include <linux/random.h> |
11 | #include <net/tcp.h> | |
12 | #include <net/inet_connection_sock.h> | |
13 | ||
cc7972ea | 14 | #define MPTCP_SUPPORTED_VERSION 1 |
eda7acdd PK |
15 | |
16 | /* MPTCP option bits */ | |
17 | #define OPTION_MPTCP_MPC_SYN BIT(0) | |
18 | #define OPTION_MPTCP_MPC_SYNACK BIT(1) | |
19 | #define OPTION_MPTCP_MPC_ACK BIT(2) | |
20 | ||
21 | /* MPTCP option subtypes */ | |
22 | #define MPTCPOPT_MP_CAPABLE 0 | |
23 | #define MPTCPOPT_MP_JOIN 1 | |
24 | #define MPTCPOPT_DSS 2 | |
25 | #define MPTCPOPT_ADD_ADDR 3 | |
26 | #define MPTCPOPT_RM_ADDR 4 | |
27 | #define MPTCPOPT_MP_PRIO 5 | |
28 | #define MPTCPOPT_MP_FAIL 6 | |
29 | #define MPTCPOPT_MP_FASTCLOSE 7 | |
30 | ||
31 | /* MPTCP suboption lengths */ | |
cc7972ea | 32 | #define TCPOLEN_MPTCP_MPC_SYN 4 |
eda7acdd PK |
33 | #define TCPOLEN_MPTCP_MPC_SYNACK 12 |
34 | #define TCPOLEN_MPTCP_MPC_ACK 20 | |
cc7972ea | 35 | #define TCPOLEN_MPTCP_MPC_ACK_DATA 22 |
6d0060f6 | 36 | #define TCPOLEN_MPTCP_DSS_BASE 4 |
648ef4b8 | 37 | #define TCPOLEN_MPTCP_DSS_ACK32 4 |
6d0060f6 | 38 | #define TCPOLEN_MPTCP_DSS_ACK64 8 |
648ef4b8 | 39 | #define TCPOLEN_MPTCP_DSS_MAP32 10 |
6d0060f6 MM |
40 | #define TCPOLEN_MPTCP_DSS_MAP64 14 |
41 | #define TCPOLEN_MPTCP_DSS_CHECKSUM 2 | |
eda7acdd PK |
42 | |
43 | /* MPTCP MP_CAPABLE flags */ | |
44 | #define MPTCP_VERSION_MASK (0x0F) | |
45 | #define MPTCP_CAP_CHECKSUM_REQD BIT(7) | |
46 | #define MPTCP_CAP_EXTENSIBILITY BIT(6) | |
65492c5a | 47 | #define MPTCP_CAP_HMAC_SHA256 BIT(0) |
eda7acdd PK |
48 | #define MPTCP_CAP_FLAG_MASK (0x3F) |
49 | ||
6d0060f6 MM |
50 | /* MPTCP DSS flags */ |
51 | #define MPTCP_DSS_DATA_FIN BIT(4) | |
52 | #define MPTCP_DSS_DSN64 BIT(3) | |
53 | #define MPTCP_DSS_HAS_MAP BIT(2) | |
54 | #define MPTCP_DSS_ACK64 BIT(1) | |
55 | #define MPTCP_DSS_HAS_ACK BIT(0) | |
648ef4b8 MM |
56 | #define MPTCP_DSS_FLAG_MASK (0x1F) |
57 | ||
58 | /* MPTCP socket flags */ | |
d99bfed5 FW |
59 | #define MPTCP_DATA_READY 0 |
60 | #define MPTCP_SEND_SPACE 1 | |
6d0060f6 | 61 | |
f870fa0b MM |
62 | /* MPTCP connection sock */ |
63 | struct mptcp_sock { | |
64 | /* inet_connection_sock must be the first member */ | |
65 | struct inet_connection_sock sk; | |
cec37a6e PK |
66 | u64 local_key; |
67 | u64 remote_key; | |
6d0060f6 MM |
68 | u64 write_seq; |
69 | u64 ack_seq; | |
79c0949e | 70 | u32 token; |
648ef4b8 | 71 | unsigned long flags; |
d22f4988 | 72 | bool can_ack; |
80992017 | 73 | struct work_struct work; |
cec37a6e | 74 | struct list_head conn_list; |
6d0060f6 | 75 | struct skb_ext *cached_ext; /* for the next sendmsg */ |
f870fa0b | 76 | struct socket *subflow; /* outgoing connect/listener/!mp_capable */ |
8ab183de | 77 | struct sock *first; |
f870fa0b MM |
78 | }; |
79 | ||
cec37a6e PK |
80 | #define mptcp_for_each_subflow(__msk, __subflow) \ |
81 | list_for_each_entry(__subflow, &((__msk)->conn_list), node) | |
82 | ||
f870fa0b MM |
83 | static inline struct mptcp_sock *mptcp_sk(const struct sock *sk) |
84 | { | |
85 | return (struct mptcp_sock *)sk; | |
86 | } | |
87 | ||
cec37a6e PK |
88 | struct mptcp_subflow_request_sock { |
89 | struct tcp_request_sock sk; | |
d22f4988 | 90 | u16 mp_capable : 1, |
cec37a6e | 91 | mp_join : 1, |
d22f4988 CP |
92 | backup : 1, |
93 | remote_key_valid : 1; | |
cec37a6e PK |
94 | u64 local_key; |
95 | u64 remote_key; | |
79c0949e PK |
96 | u64 idsn; |
97 | u32 token; | |
648ef4b8 | 98 | u32 ssn_offset; |
cec37a6e PK |
99 | }; |
100 | ||
101 | static inline struct mptcp_subflow_request_sock * | |
102 | mptcp_subflow_rsk(const struct request_sock *rsk) | |
103 | { | |
104 | return (struct mptcp_subflow_request_sock *)rsk; | |
105 | } | |
106 | ||
2303f994 PK |
107 | /* MPTCP subflow context */ |
108 | struct mptcp_subflow_context { | |
cec37a6e PK |
109 | struct list_head node;/* conn_list of subflows */ |
110 | u64 local_key; | |
111 | u64 remote_key; | |
79c0949e | 112 | u64 idsn; |
648ef4b8 | 113 | u64 map_seq; |
cc7972ea | 114 | u32 snd_isn; |
79c0949e | 115 | u32 token; |
6d0060f6 | 116 | u32 rel_write_seq; |
648ef4b8 MM |
117 | u32 map_subflow_seq; |
118 | u32 ssn_offset; | |
119 | u32 map_data_len; | |
cec37a6e PK |
120 | u32 request_mptcp : 1, /* send MP_CAPABLE */ |
121 | mp_capable : 1, /* remote is MPTCP capable */ | |
122 | fourth_ack : 1, /* send initial DSS */ | |
648ef4b8 MM |
123 | conn_finished : 1, |
124 | map_valid : 1, | |
d22f4988 | 125 | mpc_map : 1, |
648ef4b8 | 126 | data_avail : 1, |
d22f4988 | 127 | rx_eof : 1, |
76c42a29 | 128 | data_fin_tx_enable : 1, |
d22f4988 | 129 | can_ack : 1; /* only after processing the remote a key */ |
76c42a29 | 130 | u64 data_fin_tx_seq; |
648ef4b8 | 131 | |
2303f994 PK |
132 | struct sock *tcp_sock; /* tcp sk backpointer */ |
133 | struct sock *conn; /* parent mptcp_sock */ | |
cec37a6e | 134 | const struct inet_connection_sock_af_ops *icsk_af_ops; |
648ef4b8 MM |
135 | void (*tcp_data_ready)(struct sock *sk); |
136 | void (*tcp_state_change)(struct sock *sk); | |
137 | void (*tcp_write_space)(struct sock *sk); | |
138 | ||
2303f994 PK |
139 | struct rcu_head rcu; |
140 | }; | |
141 | ||
142 | static inline struct mptcp_subflow_context * | |
143 | mptcp_subflow_ctx(const struct sock *sk) | |
144 | { | |
145 | struct inet_connection_sock *icsk = inet_csk(sk); | |
146 | ||
147 | /* Use RCU on icsk_ulp_data only for sock diag code */ | |
148 | return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data; | |
149 | } | |
150 | ||
151 | static inline struct sock * | |
152 | mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow) | |
153 | { | |
154 | return subflow->tcp_sock; | |
155 | } | |
156 | ||
648ef4b8 MM |
157 | static inline u64 |
158 | mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow) | |
159 | { | |
160 | return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq - | |
161 | subflow->ssn_offset - | |
162 | subflow->map_subflow_seq; | |
163 | } | |
164 | ||
165 | static inline u64 | |
166 | mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow) | |
167 | { | |
168 | return subflow->map_seq + mptcp_subflow_get_map_offset(subflow); | |
169 | } | |
170 | ||
171 | int mptcp_is_enabled(struct net *net); | |
172 | bool mptcp_subflow_data_available(struct sock *sk); | |
2303f994 PK |
173 | void mptcp_subflow_init(void); |
174 | int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock); | |
175 | ||
648ef4b8 MM |
176 | static inline void mptcp_subflow_tcp_fallback(struct sock *sk, |
177 | struct mptcp_subflow_context *ctx) | |
178 | { | |
179 | sk->sk_data_ready = ctx->tcp_data_ready; | |
180 | sk->sk_state_change = ctx->tcp_state_change; | |
181 | sk->sk_write_space = ctx->tcp_write_space; | |
182 | ||
183 | inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops; | |
184 | } | |
185 | ||
cec37a6e PK |
186 | extern const struct inet_connection_sock_af_ops ipv4_specific; |
187 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
188 | extern const struct inet_connection_sock_af_ops ipv6_specific; | |
189 | #endif | |
190 | ||
648ef4b8 | 191 | void mptcp_proto_init(void); |
784325e9 MB |
192 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) |
193 | int mptcp_proto_v6_init(void); | |
194 | #endif | |
648ef4b8 | 195 | |
cec37a6e PK |
196 | void mptcp_get_options(const struct sk_buff *skb, |
197 | struct tcp_options_received *opt_rx); | |
198 | ||
199 | void mptcp_finish_connect(struct sock *sk); | |
2e52213c | 200 | void mptcp_data_ready(struct sock *sk, struct sock *ssk); |
cec37a6e | 201 | |
79c0949e PK |
202 | int mptcp_token_new_request(struct request_sock *req); |
203 | void mptcp_token_destroy_request(u32 token); | |
204 | int mptcp_token_new_connect(struct sock *sk); | |
205 | int mptcp_token_new_accept(u32 token); | |
206 | void mptcp_token_update_accept(struct sock *sk, struct sock *conn); | |
207 | void mptcp_token_destroy(u32 token); | |
208 | ||
209 | void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn); | |
210 | static inline void mptcp_crypto_key_gen_sha(u64 *key, u32 *token, u64 *idsn) | |
211 | { | |
212 | /* we might consider a faster version that computes the key as a | |
213 | * hash of some information available in the MPTCP socket. Use | |
214 | * random data at the moment, as it's probably the safest option | |
215 | * in case multiple sockets are opened in different namespaces at | |
216 | * the same time. | |
217 | */ | |
218 | get_random_bytes(key, sizeof(u64)); | |
219 | mptcp_crypto_key_sha(*key, token, idsn); | |
220 | } | |
221 | ||
222 | void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u32 nonce1, u32 nonce2, | |
65492c5a | 223 | void *hash_out); |
79c0949e | 224 | |
6d0060f6 MM |
225 | static inline struct mptcp_ext *mptcp_get_ext(struct sk_buff *skb) |
226 | { | |
227 | return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP); | |
228 | } | |
229 | ||
648ef4b8 MM |
230 | static inline bool before64(__u64 seq1, __u64 seq2) |
231 | { | |
232 | return (__s64)(seq1 - seq2) < 0; | |
233 | } | |
234 | ||
235 | #define after64(seq2, seq1) before64(seq1, seq2) | |
236 | ||
f870fa0b | 237 | #endif /* __MPTCP_PROTOCOL_H */ |