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 frozen:1, 33 __unused:1; 34 /* one byte hole */ 35 }; 36 37 struct mptcp_out_options { 38 #if IS_ENABLED(CONFIG_MPTCP) 39 u16 suboptions; 40 u64 sndr_key; 41 u64 rcvr_key; 42 union { 43 struct in_addr addr; 44 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 45 struct in6_addr addr6; 46 #endif 47 }; 48 u8 addr_id; 49 u64 ahmac; 50 u8 rm_id; 51 u8 join_id; 52 u8 backup; 53 u32 nonce; 54 u64 thmac; 55 u32 token; 56 u8 hmac[20]; 57 struct mptcp_ext ext_copy; 58 #endif 59 }; 60 61 #ifdef CONFIG_MPTCP 62 extern struct request_sock_ops mptcp_subflow_request_sock_ops; 63 64 void mptcp_init(void); 65 66 static inline bool sk_is_mptcp(const struct sock *sk) 67 { 68 return tcp_sk(sk)->is_mptcp; 69 } 70 71 static inline bool rsk_is_mptcp(const struct request_sock *req) 72 { 73 return tcp_rsk(req)->is_mptcp; 74 } 75 76 static inline bool rsk_drop_req(const struct request_sock *req) 77 { 78 return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req; 79 } 80 81 void mptcp_space(const struct sock *ssk, int *space, int *full_space); 82 bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 83 unsigned int *size, struct mptcp_out_options *opts); 84 bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, 85 struct mptcp_out_options *opts); 86 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, 87 unsigned int *size, unsigned int remaining, 88 struct mptcp_out_options *opts); 89 void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb); 90 91 void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp, 92 struct mptcp_out_options *opts); 93 94 /* move the skb extension owership, with the assumption that 'to' is 95 * newly allocated 96 */ 97 static inline void mptcp_skb_ext_move(struct sk_buff *to, 98 struct sk_buff *from) 99 { 100 if (!skb_ext_exist(from, SKB_EXT_MPTCP)) 101 return; 102 103 if (WARN_ON_ONCE(to->active_extensions)) 104 skb_ext_put(to); 105 106 to->active_extensions = from->active_extensions; 107 to->extensions = from->extensions; 108 from->active_extensions = 0; 109 } 110 111 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 112 struct sk_buff *from) 113 { 114 struct mptcp_ext *from_ext; 115 116 from_ext = skb_ext_find(from, SKB_EXT_MPTCP); 117 if (!from_ext) 118 return; 119 120 from_ext->frozen = 1; 121 skb_ext_copy(to, from); 122 } 123 124 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 125 const struct mptcp_ext *from_ext) 126 { 127 /* MPTCP always clears the ext when adding it to the skb, so 128 * holes do not bother us here 129 */ 130 return !from_ext || 131 (to_ext && from_ext && 132 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 133 } 134 135 /* check if skbs can be collapsed. 136 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 137 * mapping, or if the extension of @to is the same as @from. 138 * Collapsing is not possible if @to lacks an extension, but @from carries one. 139 */ 140 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 141 const struct sk_buff *from) 142 { 143 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 144 skb_ext_find(from, SKB_EXT_MPTCP)); 145 } 146 147 void mptcp_seq_show(struct seq_file *seq); 148 int mptcp_subflow_init_cookie_req(struct request_sock *req, 149 const struct sock *sk_listener, 150 struct sk_buff *skb); 151 #else 152 153 static inline void mptcp_init(void) 154 { 155 } 156 157 static inline bool sk_is_mptcp(const struct sock *sk) 158 { 159 return false; 160 } 161 162 static inline bool rsk_is_mptcp(const struct request_sock *req) 163 { 164 return false; 165 } 166 167 static inline bool rsk_drop_req(const struct request_sock *req) 168 { 169 return false; 170 } 171 172 static inline void mptcp_parse_option(const struct sk_buff *skb, 173 const unsigned char *ptr, int opsize, 174 struct tcp_options_received *opt_rx) 175 { 176 } 177 178 static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 179 unsigned int *size, 180 struct mptcp_out_options *opts) 181 { 182 return false; 183 } 184 185 static inline bool mptcp_synack_options(const struct request_sock *req, 186 unsigned int *size, 187 struct mptcp_out_options *opts) 188 { 189 return false; 190 } 191 192 static inline bool mptcp_established_options(struct sock *sk, 193 struct sk_buff *skb, 194 unsigned int *size, 195 unsigned int remaining, 196 struct mptcp_out_options *opts) 197 { 198 return false; 199 } 200 201 static inline void mptcp_incoming_options(struct sock *sk, 202 struct sk_buff *skb) 203 { 204 } 205 206 static inline void mptcp_skb_ext_move(struct sk_buff *to, 207 const struct sk_buff *from) 208 { 209 } 210 211 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 212 struct sk_buff *from) 213 { 214 } 215 216 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 217 const struct sk_buff *from) 218 { 219 return true; 220 } 221 222 static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { } 223 static inline void mptcp_seq_show(struct seq_file *seq) { } 224 225 static inline int mptcp_subflow_init_cookie_req(struct request_sock *req, 226 const struct sock *sk_listener, 227 struct sk_buff *skb) 228 { 229 return 0; /* TCP fallback */ 230 } 231 #endif /* CONFIG_MPTCP */ 232 233 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 234 int mptcpv6_init(void); 235 void mptcpv6_handle_mapped(struct sock *sk, bool mapped); 236 #elif IS_ENABLED(CONFIG_IPV6) 237 static inline int mptcpv6_init(void) { return 0; } 238 static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } 239 #endif 240 241 #endif /* __NET_MPTCP_H */ 242