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 struct tcp_options_received *opt_rx); 90 91 void mptcp_write_options(__be32 *ptr, struct mptcp_out_options *opts); 92 93 /* move the skb extension owership, with the assumption that 'to' is 94 * newly allocated 95 */ 96 static inline void mptcp_skb_ext_move(struct sk_buff *to, 97 struct sk_buff *from) 98 { 99 if (!skb_ext_exist(from, SKB_EXT_MPTCP)) 100 return; 101 102 if (WARN_ON_ONCE(to->active_extensions)) 103 skb_ext_put(to); 104 105 to->active_extensions = from->active_extensions; 106 to->extensions = from->extensions; 107 from->active_extensions = 0; 108 } 109 110 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 111 const struct mptcp_ext *from_ext) 112 { 113 /* MPTCP always clears the ext when adding it to the skb, so 114 * holes do not bother us here 115 */ 116 return !from_ext || 117 (to_ext && from_ext && 118 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 119 } 120 121 /* check if skbs can be collapsed. 122 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 123 * mapping, or if the extension of @to is the same as @from. 124 * Collapsing is not possible if @to lacks an extension, but @from carries one. 125 */ 126 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 127 const struct sk_buff *from) 128 { 129 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 130 skb_ext_find(from, SKB_EXT_MPTCP)); 131 } 132 133 void mptcp_seq_show(struct seq_file *seq); 134 int mptcp_subflow_init_cookie_req(struct request_sock *req, 135 const struct sock *sk_listener, 136 struct sk_buff *skb); 137 #else 138 139 static inline void mptcp_init(void) 140 { 141 } 142 143 static inline bool sk_is_mptcp(const struct sock *sk) 144 { 145 return false; 146 } 147 148 static inline bool rsk_is_mptcp(const struct request_sock *req) 149 { 150 return false; 151 } 152 153 static inline bool rsk_drop_req(const struct request_sock *req) 154 { 155 return false; 156 } 157 158 static inline void mptcp_parse_option(const struct sk_buff *skb, 159 const unsigned char *ptr, int opsize, 160 struct tcp_options_received *opt_rx) 161 { 162 } 163 164 static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 165 unsigned int *size, 166 struct mptcp_out_options *opts) 167 { 168 return false; 169 } 170 171 static inline bool mptcp_synack_options(const struct request_sock *req, 172 unsigned int *size, 173 struct mptcp_out_options *opts) 174 { 175 return false; 176 } 177 178 static inline bool mptcp_established_options(struct sock *sk, 179 struct sk_buff *skb, 180 unsigned int *size, 181 unsigned int remaining, 182 struct mptcp_out_options *opts) 183 { 184 return false; 185 } 186 187 static inline void mptcp_incoming_options(struct sock *sk, 188 struct sk_buff *skb, 189 struct tcp_options_received *opt_rx) 190 { 191 } 192 193 static inline void mptcp_skb_ext_move(struct sk_buff *to, 194 const struct sk_buff *from) 195 { 196 } 197 198 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 199 const struct sk_buff *from) 200 { 201 return true; 202 } 203 204 static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { } 205 static inline void mptcp_seq_show(struct seq_file *seq) { } 206 207 static inline int mptcp_subflow_init_cookie_req(struct request_sock *req, 208 const struct sock *sk_listener, 209 struct sk_buff *skb) 210 { 211 return 0; /* TCP fallback */ 212 } 213 #endif /* CONFIG_MPTCP */ 214 215 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 216 int mptcpv6_init(void); 217 void mptcpv6_handle_mapped(struct sock *sk, bool mapped); 218 #elif IS_ENABLED(CONFIG_IPV6) 219 static inline int mptcpv6_init(void) { return 0; } 220 static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } 221 #endif 222 223 #endif /* __NET_MPTCP_H */ 224