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 u16 port; 50 u64 ahmac; 51 u8 rm_id; 52 u8 join_id; 53 u8 backup; 54 u32 nonce; 55 u64 thmac; 56 u32 token; 57 u8 hmac[20]; 58 struct mptcp_ext ext_copy; 59 #endif 60 }; 61 62 #ifdef CONFIG_MPTCP 63 extern struct request_sock_ops mptcp_subflow_request_sock_ops; 64 65 void mptcp_init(void); 66 67 static inline bool sk_is_mptcp(const struct sock *sk) 68 { 69 return tcp_sk(sk)->is_mptcp; 70 } 71 72 static inline bool rsk_is_mptcp(const struct request_sock *req) 73 { 74 return tcp_rsk(req)->is_mptcp; 75 } 76 77 static inline bool rsk_drop_req(const struct request_sock *req) 78 { 79 return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req; 80 } 81 82 void mptcp_space(const struct sock *ssk, int *space, int *full_space); 83 bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 84 unsigned int *size, struct mptcp_out_options *opts); 85 bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, 86 struct mptcp_out_options *opts); 87 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, 88 unsigned int *size, unsigned int remaining, 89 struct mptcp_out_options *opts); 90 void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb); 91 92 void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp, 93 struct mptcp_out_options *opts); 94 95 /* move the skb extension owership, with the assumption that 'to' is 96 * newly allocated 97 */ 98 static inline void mptcp_skb_ext_move(struct sk_buff *to, 99 struct sk_buff *from) 100 { 101 if (!skb_ext_exist(from, SKB_EXT_MPTCP)) 102 return; 103 104 if (WARN_ON_ONCE(to->active_extensions)) 105 skb_ext_put(to); 106 107 to->active_extensions = from->active_extensions; 108 to->extensions = from->extensions; 109 from->active_extensions = 0; 110 } 111 112 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 113 struct sk_buff *from) 114 { 115 struct mptcp_ext *from_ext; 116 117 from_ext = skb_ext_find(from, SKB_EXT_MPTCP); 118 if (!from_ext) 119 return; 120 121 from_ext->frozen = 1; 122 skb_ext_copy(to, from); 123 } 124 125 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 126 const struct mptcp_ext *from_ext) 127 { 128 /* MPTCP always clears the ext when adding it to the skb, so 129 * holes do not bother us here 130 */ 131 return !from_ext || 132 (to_ext && from_ext && 133 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 134 } 135 136 /* check if skbs can be collapsed. 137 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 138 * mapping, or if the extension of @to is the same as @from. 139 * Collapsing is not possible if @to lacks an extension, but @from carries one. 140 */ 141 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 142 const struct sk_buff *from) 143 { 144 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 145 skb_ext_find(from, SKB_EXT_MPTCP)); 146 } 147 148 void mptcp_seq_show(struct seq_file *seq); 149 int mptcp_subflow_init_cookie_req(struct request_sock *req, 150 const struct sock *sk_listener, 151 struct sk_buff *skb); 152 #else 153 154 static inline void mptcp_init(void) 155 { 156 } 157 158 static inline bool sk_is_mptcp(const struct sock *sk) 159 { 160 return false; 161 } 162 163 static inline bool rsk_is_mptcp(const struct request_sock *req) 164 { 165 return false; 166 } 167 168 static inline bool rsk_drop_req(const struct request_sock *req) 169 { 170 return false; 171 } 172 173 static inline void mptcp_parse_option(const struct sk_buff *skb, 174 const unsigned char *ptr, int opsize, 175 struct tcp_options_received *opt_rx) 176 { 177 } 178 179 static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 180 unsigned int *size, 181 struct mptcp_out_options *opts) 182 { 183 return false; 184 } 185 186 static inline bool mptcp_synack_options(const struct request_sock *req, 187 unsigned int *size, 188 struct mptcp_out_options *opts) 189 { 190 return false; 191 } 192 193 static inline bool mptcp_established_options(struct sock *sk, 194 struct sk_buff *skb, 195 unsigned int *size, 196 unsigned int remaining, 197 struct mptcp_out_options *opts) 198 { 199 return false; 200 } 201 202 static inline void mptcp_incoming_options(struct sock *sk, 203 struct sk_buff *skb) 204 { 205 } 206 207 static inline void mptcp_skb_ext_move(struct sk_buff *to, 208 const struct sk_buff *from) 209 { 210 } 211 212 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 213 struct sk_buff *from) 214 { 215 } 216 217 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 218 const struct sk_buff *from) 219 { 220 return true; 221 } 222 223 static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { } 224 static inline void mptcp_seq_show(struct seq_file *seq) { } 225 226 static inline int mptcp_subflow_init_cookie_req(struct request_sock *req, 227 const struct sock *sk_listener, 228 struct sk_buff *skb) 229 { 230 return 0; /* TCP fallback */ 231 } 232 #endif /* CONFIG_MPTCP */ 233 234 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 235 int mptcpv6_init(void); 236 void mptcpv6_handle_mapped(struct sock *sk, bool mapped); 237 #elif IS_ENABLED(CONFIG_IPV6) 238 static inline int mptcpv6_init(void) { return 0; } 239 static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } 240 #endif 241 242 #endif /* __NET_MPTCP_H */ 243