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, 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 void mptcp_skb_ext_copy(struct sk_buff *to, 111 struct sk_buff *from) 112 { 113 struct mptcp_ext *from_ext; 114 115 from_ext = skb_ext_find(from, SKB_EXT_MPTCP); 116 if (!from_ext) 117 return; 118 119 from_ext->frozen = 1; 120 skb_ext_copy(to, from); 121 } 122 123 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 124 const struct mptcp_ext *from_ext) 125 { 126 /* MPTCP always clears the ext when adding it to the skb, so 127 * holes do not bother us here 128 */ 129 return !from_ext || 130 (to_ext && from_ext && 131 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 132 } 133 134 /* check if skbs can be collapsed. 135 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 136 * mapping, or if the extension of @to is the same as @from. 137 * Collapsing is not possible if @to lacks an extension, but @from carries one. 138 */ 139 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 140 const struct sk_buff *from) 141 { 142 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 143 skb_ext_find(from, SKB_EXT_MPTCP)); 144 } 145 146 void mptcp_seq_show(struct seq_file *seq); 147 int mptcp_subflow_init_cookie_req(struct request_sock *req, 148 const struct sock *sk_listener, 149 struct sk_buff *skb); 150 #else 151 152 static inline void mptcp_init(void) 153 { 154 } 155 156 static inline bool sk_is_mptcp(const struct sock *sk) 157 { 158 return false; 159 } 160 161 static inline bool rsk_is_mptcp(const struct request_sock *req) 162 { 163 return false; 164 } 165 166 static inline bool rsk_drop_req(const struct request_sock *req) 167 { 168 return false; 169 } 170 171 static inline void mptcp_parse_option(const struct sk_buff *skb, 172 const unsigned char *ptr, int opsize, 173 struct tcp_options_received *opt_rx) 174 { 175 } 176 177 static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 178 unsigned int *size, 179 struct mptcp_out_options *opts) 180 { 181 return false; 182 } 183 184 static inline bool mptcp_synack_options(const struct request_sock *req, 185 unsigned int *size, 186 struct mptcp_out_options *opts) 187 { 188 return false; 189 } 190 191 static inline bool mptcp_established_options(struct sock *sk, 192 struct sk_buff *skb, 193 unsigned int *size, 194 unsigned int remaining, 195 struct mptcp_out_options *opts) 196 { 197 return false; 198 } 199 200 static inline void mptcp_incoming_options(struct sock *sk, 201 struct sk_buff *skb) 202 { 203 } 204 205 static inline void mptcp_skb_ext_move(struct sk_buff *to, 206 const struct sk_buff *from) 207 { 208 } 209 210 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 211 struct sk_buff *from) 212 { 213 } 214 215 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 216 const struct sk_buff *from) 217 { 218 return true; 219 } 220 221 static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { } 222 static inline void mptcp_seq_show(struct seq_file *seq) { } 223 224 static inline int mptcp_subflow_init_cookie_req(struct request_sock *req, 225 const struct sock *sk_listener, 226 struct sk_buff *skb) 227 { 228 return 0; /* TCP fallback */ 229 } 230 #endif /* CONFIG_MPTCP */ 231 232 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 233 int mptcpv6_init(void); 234 void mptcpv6_handle_mapped(struct sock *sk, bool mapped); 235 #elif IS_ENABLED(CONFIG_IPV6) 236 static inline int mptcpv6_init(void) { return 0; } 237 static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } 238 #endif 239 240 #endif /* __NET_MPTCP_H */ 241