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 seq_file; 16 17 /* MPTCP sk_buff extension data */ 18 struct mptcp_ext { 19 union { 20 u64 data_ack; 21 u32 data_ack32; 22 }; 23 u64 data_seq; 24 u32 subflow_seq; 25 u16 data_len; 26 u8 use_map:1, 27 dsn64:1, 28 data_fin:1, 29 use_ack:1, 30 ack64:1, 31 mpc_map:1, 32 __unused:2; 33 /* one byte hole */ 34 }; 35 36 struct mptcp_out_options { 37 #if IS_ENABLED(CONFIG_MPTCP) 38 u16 suboptions; 39 u64 sndr_key; 40 u64 rcvr_key; 41 union { 42 struct in_addr addr; 43 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 44 struct in6_addr addr6; 45 #endif 46 }; 47 u8 addr_id; 48 u64 ahmac; 49 u8 rm_id; 50 u8 join_id; 51 u8 backup; 52 u32 nonce; 53 u64 thmac; 54 u32 token; 55 u8 hmac[20]; 56 struct mptcp_ext ext_copy; 57 #endif 58 }; 59 60 #ifdef CONFIG_MPTCP 61 extern struct request_sock_ops mptcp_subflow_request_sock_ops; 62 63 void mptcp_init(void); 64 65 static inline bool sk_is_mptcp(const struct sock *sk) 66 { 67 return tcp_sk(sk)->is_mptcp; 68 } 69 70 static inline bool rsk_is_mptcp(const struct request_sock *req) 71 { 72 return tcp_rsk(req)->is_mptcp; 73 } 74 75 static inline bool rsk_drop_req(const struct request_sock *req) 76 { 77 return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req; 78 } 79 80 void mptcp_space(const struct sock *ssk, int *space, int *full_space); 81 bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 82 unsigned int *size, struct mptcp_out_options *opts); 83 bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, 84 struct mptcp_out_options *opts); 85 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, 86 unsigned int *size, unsigned int remaining, 87 struct mptcp_out_options *opts); 88 void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb); 89 90 void mptcp_write_options(__be32 *ptr, struct mptcp_out_options *opts); 91 92 /* move the skb extension owership, with the assumption that 'to' is 93 * newly allocated 94 */ 95 static inline void mptcp_skb_ext_move(struct sk_buff *to, 96 struct sk_buff *from) 97 { 98 if (!skb_ext_exist(from, SKB_EXT_MPTCP)) 99 return; 100 101 if (WARN_ON_ONCE(to->active_extensions)) 102 skb_ext_put(to); 103 104 to->active_extensions = from->active_extensions; 105 to->extensions = from->extensions; 106 from->active_extensions = 0; 107 } 108 109 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 110 const struct mptcp_ext *from_ext) 111 { 112 /* MPTCP always clears the ext when adding it to the skb, so 113 * holes do not bother us here 114 */ 115 return !from_ext || 116 (to_ext && from_ext && 117 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 118 } 119 120 /* check if skbs can be collapsed. 121 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 122 * mapping, or if the extension of @to is the same as @from. 123 * Collapsing is not possible if @to lacks an extension, but @from carries one. 124 */ 125 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 126 const struct sk_buff *from) 127 { 128 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 129 skb_ext_find(from, SKB_EXT_MPTCP)); 130 } 131 132 void mptcp_seq_show(struct seq_file *seq); 133 int mptcp_subflow_init_cookie_req(struct request_sock *req, 134 const struct sock *sk_listener, 135 struct sk_buff *skb); 136 #else 137 138 static inline void mptcp_init(void) 139 { 140 } 141 142 static inline bool sk_is_mptcp(const struct sock *sk) 143 { 144 return false; 145 } 146 147 static inline bool rsk_is_mptcp(const struct request_sock *req) 148 { 149 return false; 150 } 151 152 static inline bool rsk_drop_req(const struct request_sock *req) 153 { 154 return false; 155 } 156 157 static inline void mptcp_parse_option(const struct sk_buff *skb, 158 const unsigned char *ptr, int opsize, 159 struct tcp_options_received *opt_rx) 160 { 161 } 162 163 static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 164 unsigned int *size, 165 struct mptcp_out_options *opts) 166 { 167 return false; 168 } 169 170 static inline bool mptcp_synack_options(const struct request_sock *req, 171 unsigned int *size, 172 struct mptcp_out_options *opts) 173 { 174 return false; 175 } 176 177 static inline bool mptcp_established_options(struct sock *sk, 178 struct sk_buff *skb, 179 unsigned int *size, 180 unsigned int remaining, 181 struct mptcp_out_options *opts) 182 { 183 return false; 184 } 185 186 static inline void mptcp_incoming_options(struct sock *sk, 187 struct sk_buff *skb) 188 { 189 } 190 191 static inline void mptcp_skb_ext_move(struct sk_buff *to, 192 const struct sk_buff *from) 193 { 194 } 195 196 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 197 const struct sk_buff *from) 198 { 199 return true; 200 } 201 202 static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { } 203 static inline void mptcp_seq_show(struct seq_file *seq) { } 204 205 static inline int mptcp_subflow_init_cookie_req(struct request_sock *req, 206 const struct sock *sk_listener, 207 struct sk_buff *skb) 208 { 209 return 0; /* TCP fallback */ 210 } 211 #endif /* CONFIG_MPTCP */ 212 213 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 214 int mptcpv6_init(void); 215 void mptcpv6_handle_mapped(struct sock *sk, bool mapped); 216 #elif IS_ENABLED(CONFIG_IPV6) 217 static inline int mptcpv6_init(void) { return 0; } 218 static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } 219 #endif 220 221 #endif /* __NET_MPTCP_H */ 222