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 mptcp_info; 16 struct mptcp_sock; 17 struct seq_file; 18 19 /* MPTCP sk_buff extension data */ 20 struct mptcp_ext { 21 union { 22 u64 data_ack; 23 u32 data_ack32; 24 }; 25 u64 data_seq; 26 u32 subflow_seq; 27 u16 data_len; 28 __sum16 csum; 29 u8 use_map:1, 30 dsn64:1, 31 data_fin:1, 32 use_ack:1, 33 ack64:1, 34 mpc_map:1, 35 frozen:1, 36 reset_transient:1; 37 u8 reset_reason:4, 38 csum_reqd:1; 39 }; 40 41 #define MPTCP_RM_IDS_MAX 8 42 43 struct mptcp_rm_list { 44 u8 ids[MPTCP_RM_IDS_MAX]; 45 u8 nr; 46 }; 47 48 struct mptcp_addr_info { 49 u8 id; 50 sa_family_t family; 51 __be16 port; 52 union { 53 struct in_addr addr; 54 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 55 struct in6_addr addr6; 56 #endif 57 }; 58 }; 59 60 struct mptcp_out_options { 61 #if IS_ENABLED(CONFIG_MPTCP) 62 u16 suboptions; 63 struct mptcp_rm_list rm_list; 64 u8 join_id; 65 u8 backup; 66 u8 reset_reason:4, 67 reset_transient:1, 68 csum_reqd:1, 69 allow_join_id0:1; 70 union { 71 struct { 72 u64 sndr_key; 73 u64 rcvr_key; 74 u64 data_seq; 75 u32 subflow_seq; 76 u16 data_len; 77 __sum16 csum; 78 }; 79 struct { 80 struct mptcp_addr_info addr; 81 u64 ahmac; 82 }; 83 struct { 84 struct mptcp_ext ext_copy; 85 u64 fail_seq; 86 }; 87 struct { 88 u32 nonce; 89 u32 token; 90 u64 thmac; 91 u8 hmac[20]; 92 }; 93 }; 94 #endif 95 }; 96 97 #ifdef CONFIG_MPTCP 98 extern struct request_sock_ops mptcp_subflow_request_sock_ops; 99 100 void mptcp_init(void); 101 102 static inline bool sk_is_mptcp(const struct sock *sk) 103 { 104 return tcp_sk(sk)->is_mptcp; 105 } 106 107 static inline bool rsk_is_mptcp(const struct request_sock *req) 108 { 109 return tcp_rsk(req)->is_mptcp; 110 } 111 112 static inline bool rsk_drop_req(const struct request_sock *req) 113 { 114 return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req; 115 } 116 117 void mptcp_space(const struct sock *ssk, int *space, int *full_space); 118 bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 119 unsigned int *size, struct mptcp_out_options *opts); 120 bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, 121 struct mptcp_out_options *opts); 122 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, 123 unsigned int *size, unsigned int remaining, 124 struct mptcp_out_options *opts); 125 bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb); 126 127 void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp, 128 struct mptcp_out_options *opts); 129 130 void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info); 131 132 /* move the skb extension owership, with the assumption that 'to' is 133 * newly allocated 134 */ 135 static inline void mptcp_skb_ext_move(struct sk_buff *to, 136 struct sk_buff *from) 137 { 138 if (!skb_ext_exist(from, SKB_EXT_MPTCP)) 139 return; 140 141 if (WARN_ON_ONCE(to->active_extensions)) 142 skb_ext_put(to); 143 144 to->active_extensions = from->active_extensions; 145 to->extensions = from->extensions; 146 from->active_extensions = 0; 147 } 148 149 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 150 struct sk_buff *from) 151 { 152 struct mptcp_ext *from_ext; 153 154 from_ext = skb_ext_find(from, SKB_EXT_MPTCP); 155 if (!from_ext) 156 return; 157 158 from_ext->frozen = 1; 159 skb_ext_copy(to, from); 160 } 161 162 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 163 const struct mptcp_ext *from_ext) 164 { 165 /* MPTCP always clears the ext when adding it to the skb, so 166 * holes do not bother us here 167 */ 168 return !from_ext || 169 (to_ext && from_ext && 170 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 171 } 172 173 /* check if skbs can be collapsed. 174 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 175 * mapping, or if the extension of @to is the same as @from. 176 * Collapsing is not possible if @to lacks an extension, but @from carries one. 177 */ 178 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 179 const struct sk_buff *from) 180 { 181 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 182 skb_ext_find(from, SKB_EXT_MPTCP)); 183 } 184 185 void mptcp_seq_show(struct seq_file *seq); 186 int mptcp_subflow_init_cookie_req(struct request_sock *req, 187 const struct sock *sk_listener, 188 struct sk_buff *skb); 189 190 __be32 mptcp_get_reset_option(const struct sk_buff *skb); 191 192 static inline __be32 mptcp_reset_option(const struct sk_buff *skb) 193 { 194 if (skb_ext_exist(skb, SKB_EXT_MPTCP)) 195 return mptcp_get_reset_option(skb); 196 197 return htonl(0u); 198 } 199 #else 200 201 static inline void mptcp_init(void) 202 { 203 } 204 205 static inline bool sk_is_mptcp(const struct sock *sk) 206 { 207 return false; 208 } 209 210 static inline bool rsk_is_mptcp(const struct request_sock *req) 211 { 212 return false; 213 } 214 215 static inline bool rsk_drop_req(const struct request_sock *req) 216 { 217 return false; 218 } 219 220 static inline void mptcp_parse_option(const struct sk_buff *skb, 221 const unsigned char *ptr, int opsize, 222 struct tcp_options_received *opt_rx) 223 { 224 } 225 226 static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 227 unsigned int *size, 228 struct mptcp_out_options *opts) 229 { 230 return false; 231 } 232 233 static inline bool mptcp_synack_options(const struct request_sock *req, 234 unsigned int *size, 235 struct mptcp_out_options *opts) 236 { 237 return false; 238 } 239 240 static inline bool mptcp_established_options(struct sock *sk, 241 struct sk_buff *skb, 242 unsigned int *size, 243 unsigned int remaining, 244 struct mptcp_out_options *opts) 245 { 246 return false; 247 } 248 249 static inline bool mptcp_incoming_options(struct sock *sk, 250 struct sk_buff *skb) 251 { 252 return true; 253 } 254 255 static inline void mptcp_skb_ext_move(struct sk_buff *to, 256 const struct sk_buff *from) 257 { 258 } 259 260 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 261 struct sk_buff *from) 262 { 263 } 264 265 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 266 const struct sk_buff *from) 267 { 268 return true; 269 } 270 271 static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { } 272 static inline void mptcp_seq_show(struct seq_file *seq) { } 273 274 static inline int mptcp_subflow_init_cookie_req(struct request_sock *req, 275 const struct sock *sk_listener, 276 struct sk_buff *skb) 277 { 278 return 0; /* TCP fallback */ 279 } 280 281 static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); } 282 #endif /* CONFIG_MPTCP */ 283 284 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 285 int mptcpv6_init(void); 286 void mptcpv6_handle_mapped(struct sock *sk, bool mapped); 287 #elif IS_ENABLED(CONFIG_IPV6) 288 static inline int mptcpv6_init(void) { return 0; } 289 static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } 290 #endif 291 292 #endif /* __NET_MPTCP_H */ 293