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 infinite_map:1; 40 }; 41 42 #define MPTCPOPT_HMAC_LEN 20 43 #define MPTCP_RM_IDS_MAX 8 44 45 struct mptcp_rm_list { 46 u8 ids[MPTCP_RM_IDS_MAX]; 47 u8 nr; 48 }; 49 50 struct mptcp_addr_info { 51 u8 id; 52 sa_family_t family; 53 __be16 port; 54 union { 55 struct in_addr addr; 56 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 57 struct in6_addr addr6; 58 #endif 59 }; 60 }; 61 62 struct mptcp_out_options { 63 #if IS_ENABLED(CONFIG_MPTCP) 64 u16 suboptions; 65 struct mptcp_rm_list rm_list; 66 u8 join_id; 67 u8 backup; 68 u8 reset_reason:4, 69 reset_transient:1, 70 csum_reqd:1, 71 allow_join_id0:1; 72 union { 73 struct { 74 u64 sndr_key; 75 u64 rcvr_key; 76 u64 data_seq; 77 u32 subflow_seq; 78 u16 data_len; 79 __sum16 csum; 80 }; 81 struct { 82 struct mptcp_addr_info addr; 83 u64 ahmac; 84 }; 85 struct { 86 struct mptcp_ext ext_copy; 87 u64 fail_seq; 88 }; 89 struct { 90 u32 nonce; 91 u32 token; 92 u64 thmac; 93 u8 hmac[MPTCPOPT_HMAC_LEN]; 94 }; 95 }; 96 #endif 97 }; 98 99 #ifdef CONFIG_MPTCP 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(struct tcphdr *th, __be32 *ptr, 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 struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops, 190 struct sock *sk_listener, 191 bool attach_listener); 192 193 __be32 mptcp_get_reset_option(const struct sk_buff *skb); 194 195 static inline __be32 mptcp_reset_option(const struct sk_buff *skb) 196 { 197 if (skb_ext_exist(skb, SKB_EXT_MPTCP)) 198 return mptcp_get_reset_option(skb); 199 200 return htonl(0u); 201 } 202 #else 203 204 static inline void mptcp_init(void) 205 { 206 } 207 208 static inline bool sk_is_mptcp(const struct sock *sk) 209 { 210 return false; 211 } 212 213 static inline bool rsk_is_mptcp(const struct request_sock *req) 214 { 215 return false; 216 } 217 218 static inline bool rsk_drop_req(const struct request_sock *req) 219 { 220 return false; 221 } 222 223 static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 224 unsigned int *size, 225 struct mptcp_out_options *opts) 226 { 227 return false; 228 } 229 230 static inline bool mptcp_synack_options(const struct request_sock *req, 231 unsigned int *size, 232 struct mptcp_out_options *opts) 233 { 234 return false; 235 } 236 237 static inline bool mptcp_established_options(struct sock *sk, 238 struct sk_buff *skb, 239 unsigned int *size, 240 unsigned int remaining, 241 struct mptcp_out_options *opts) 242 { 243 return false; 244 } 245 246 static inline bool mptcp_incoming_options(struct sock *sk, 247 struct sk_buff *skb) 248 { 249 return true; 250 } 251 252 static inline void mptcp_skb_ext_move(struct sk_buff *to, 253 const struct sk_buff *from) 254 { 255 } 256 257 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 258 struct sk_buff *from) 259 { 260 } 261 262 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 263 const struct sk_buff *from) 264 { 265 return true; 266 } 267 268 static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { } 269 static inline void mptcp_seq_show(struct seq_file *seq) { } 270 271 static inline int mptcp_subflow_init_cookie_req(struct request_sock *req, 272 const struct sock *sk_listener, 273 struct sk_buff *skb) 274 { 275 return 0; /* TCP fallback */ 276 } 277 278 static inline struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops, 279 struct sock *sk_listener, 280 bool attach_listener) 281 { 282 return NULL; 283 } 284 285 static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); } 286 #endif /* CONFIG_MPTCP */ 287 288 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 289 int mptcpv6_init(void); 290 void mptcpv6_handle_mapped(struct sock *sk, bool mapped); 291 #elif IS_ENABLED(CONFIG_IPV6) 292 static inline int mptcpv6_init(void) { return 0; } 293 static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } 294 #endif 295 296 #if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL) 297 struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk); 298 #else 299 static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) { return NULL; } 300 #endif 301 302 #if !IS_ENABLED(CONFIG_MPTCP) 303 struct mptcp_sock { }; 304 #endif 305 306 #endif /* __NET_MPTCP_H */ 307