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 mptcp_pm_addr_entry; 18 struct seq_file; 19 20 /* MPTCP sk_buff extension data */ 21 struct mptcp_ext { 22 union { 23 u64 data_ack; 24 u32 data_ack32; 25 }; 26 u64 data_seq; 27 u32 subflow_seq; 28 u16 data_len; 29 __sum16 csum; 30 u8 use_map:1, 31 dsn64:1, 32 data_fin:1, 33 use_ack:1, 34 ack64:1, 35 mpc_map:1, 36 frozen:1, 37 reset_transient:1; 38 u8 reset_reason:4, 39 csum_reqd:1, 40 infinite_map:1; 41 }; 42 43 #define MPTCPOPT_HMAC_LEN 20 44 #define MPTCP_RM_IDS_MAX 8 45 46 struct mptcp_rm_list { 47 u8 ids[MPTCP_RM_IDS_MAX]; 48 u8 nr; 49 }; 50 51 struct mptcp_addr_info { 52 u8 id; 53 sa_family_t family; 54 __be16 port; 55 union { 56 struct in_addr addr; 57 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 58 struct in6_addr addr6; 59 #endif 60 }; 61 }; 62 63 struct mptcp_out_options { 64 #if IS_ENABLED(CONFIG_MPTCP) 65 u16 suboptions; 66 struct mptcp_rm_list rm_list; 67 u8 join_id; 68 u8 backup; 69 u8 reset_reason:4, 70 reset_transient:1, 71 csum_reqd:1, 72 allow_join_id0:1; 73 union { 74 struct { 75 u64 sndr_key; 76 u64 rcvr_key; 77 u64 data_seq; 78 u32 subflow_seq; 79 u16 data_len; 80 __sum16 csum; 81 }; 82 struct { 83 struct mptcp_addr_info addr; 84 u64 ahmac; 85 }; 86 struct { 87 struct mptcp_ext ext_copy; 88 u64 fail_seq; 89 }; 90 struct { 91 u32 nonce; 92 u32 token; 93 u64 thmac; 94 u8 hmac[MPTCPOPT_HMAC_LEN]; 95 }; 96 }; 97 #endif 98 }; 99 100 #define MPTCP_SCHED_NAME_MAX 16 101 #define MPTCP_SCHED_MAX 128 102 #define MPTCP_SCHED_BUF_MAX (MPTCP_SCHED_NAME_MAX * MPTCP_SCHED_MAX) 103 104 #define MPTCP_SUBFLOWS_MAX 8 105 106 struct mptcp_sched_data { 107 u8 subflows; 108 struct mptcp_subflow_context *contexts[MPTCP_SUBFLOWS_MAX]; 109 }; 110 111 struct mptcp_sched_ops { 112 int (*get_send)(struct mptcp_sock *msk, 113 struct mptcp_sched_data *data); 114 int (*get_retrans)(struct mptcp_sock *msk, 115 struct mptcp_sched_data *data); 116 117 char name[MPTCP_SCHED_NAME_MAX]; 118 struct module *owner; 119 struct list_head list; 120 121 void (*init)(struct mptcp_sock *msk); 122 void (*release)(struct mptcp_sock *msk); 123 } ____cacheline_aligned_in_smp; 124 125 #define MPTCP_PM_NAME_MAX 16 126 #define MPTCP_PM_MAX 128 127 #define MPTCP_PM_BUF_MAX (MPTCP_PM_NAME_MAX * MPTCP_PM_MAX) 128 129 struct mptcp_pm_ops { 130 char name[MPTCP_PM_NAME_MAX]; 131 struct module *owner; 132 struct list_head list; 133 134 void (*init)(struct mptcp_sock *msk); 135 void (*release)(struct mptcp_sock *msk); 136 } ____cacheline_aligned_in_smp; 137 138 #ifdef CONFIG_MPTCP 139 void mptcp_init(void); 140 141 static inline bool sk_is_mptcp(const struct sock *sk) 142 { 143 return tcp_sk(sk)->is_mptcp; 144 } 145 146 static inline bool rsk_is_mptcp(const struct request_sock *req) 147 { 148 return tcp_rsk(req)->is_mptcp; 149 } 150 151 static inline bool rsk_drop_req(const struct request_sock *req) 152 { 153 return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req; 154 } 155 156 void mptcp_space(const struct sock *ssk, int *space, int *full_space); 157 bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 158 unsigned int *size, struct mptcp_out_options *opts); 159 bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, 160 struct mptcp_out_options *opts); 161 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, 162 unsigned int *size, unsigned int remaining, 163 struct mptcp_out_options *opts); 164 bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb); 165 166 void mptcp_write_options(struct tcphdr *th, __be32 *ptr, struct tcp_sock *tp, 167 struct mptcp_out_options *opts); 168 169 void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info); 170 171 /* move the skb extension owership, with the assumption that 'to' is 172 * newly allocated 173 */ 174 static inline void mptcp_skb_ext_move(struct sk_buff *to, 175 struct sk_buff *from) 176 { 177 if (!skb_ext_exist(from, SKB_EXT_MPTCP)) 178 return; 179 180 if (WARN_ON_ONCE(to->active_extensions)) 181 skb_ext_put(to); 182 183 to->active_extensions = from->active_extensions; 184 to->extensions = from->extensions; 185 from->active_extensions = 0; 186 } 187 188 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 189 struct sk_buff *from) 190 { 191 struct mptcp_ext *from_ext; 192 193 from_ext = skb_ext_find(from, SKB_EXT_MPTCP); 194 if (!from_ext) 195 return; 196 197 from_ext->frozen = 1; 198 skb_ext_copy(to, from); 199 } 200 201 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 202 const struct mptcp_ext *from_ext) 203 { 204 /* MPTCP always clears the ext when adding it to the skb, so 205 * holes do not bother us here 206 */ 207 return !from_ext || 208 (to_ext && from_ext && 209 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 210 } 211 212 /* check if skbs can be collapsed. 213 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 214 * mapping, or if the extension of @to is the same as @from. 215 * Collapsing is not possible if @to lacks an extension, but @from carries one. 216 */ 217 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 218 const struct sk_buff *from) 219 { 220 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 221 skb_ext_find(from, SKB_EXT_MPTCP)); 222 } 223 224 void mptcp_seq_show(struct seq_file *seq); 225 int mptcp_subflow_init_cookie_req(struct request_sock *req, 226 const struct sock *sk_listener, 227 struct sk_buff *skb); 228 struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops, 229 struct sock *sk_listener, 230 bool attach_listener); 231 232 __be32 mptcp_get_reset_option(const struct sk_buff *skb); 233 234 static inline __be32 mptcp_reset_option(const struct sk_buff *skb) 235 { 236 if (skb_ext_exist(skb, SKB_EXT_MPTCP)) 237 return mptcp_get_reset_option(skb); 238 239 return htonl(0u); 240 } 241 242 void mptcp_active_detect_blackhole(struct sock *sk, bool expired); 243 #else 244 245 static inline void mptcp_init(void) 246 { 247 } 248 249 static inline bool sk_is_mptcp(const struct sock *sk) 250 { 251 return false; 252 } 253 254 static inline bool rsk_is_mptcp(const struct request_sock *req) 255 { 256 return false; 257 } 258 259 static inline bool rsk_drop_req(const struct request_sock *req) 260 { 261 return false; 262 } 263 264 static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 265 unsigned int *size, 266 struct mptcp_out_options *opts) 267 { 268 return false; 269 } 270 271 static inline bool mptcp_synack_options(const struct request_sock *req, 272 unsigned int *size, 273 struct mptcp_out_options *opts) 274 { 275 return false; 276 } 277 278 static inline bool mptcp_established_options(struct sock *sk, 279 struct sk_buff *skb, 280 unsigned int *size, 281 unsigned int remaining, 282 struct mptcp_out_options *opts) 283 { 284 return false; 285 } 286 287 static inline bool mptcp_incoming_options(struct sock *sk, 288 struct sk_buff *skb) 289 { 290 return true; 291 } 292 293 static inline void mptcp_skb_ext_move(struct sk_buff *to, 294 const struct sk_buff *from) 295 { 296 } 297 298 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 299 struct sk_buff *from) 300 { 301 } 302 303 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 304 const struct sk_buff *from) 305 { 306 return true; 307 } 308 309 static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { } 310 static inline void mptcp_seq_show(struct seq_file *seq) { } 311 312 static inline int mptcp_subflow_init_cookie_req(struct request_sock *req, 313 const struct sock *sk_listener, 314 struct sk_buff *skb) 315 { 316 return 0; /* TCP fallback */ 317 } 318 319 static inline struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops, 320 struct sock *sk_listener, 321 bool attach_listener) 322 { 323 return NULL; 324 } 325 326 static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); } 327 328 static inline void mptcp_active_detect_blackhole(struct sock *sk, bool expired) { } 329 #endif /* CONFIG_MPTCP */ 330 331 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 332 int mptcpv6_init(void); 333 void mptcpv6_handle_mapped(struct sock *sk, bool mapped); 334 #elif IS_ENABLED(CONFIG_IPV6) 335 static inline int mptcpv6_init(void) { return 0; } 336 static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } 337 #endif 338 339 #if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL) 340 struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk); 341 #else 342 static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) { return NULL; } 343 #endif 344 345 #if !IS_ENABLED(CONFIG_MPTCP) 346 struct mptcp_sock { }; 347 #endif 348 349 #endif /* __NET_MPTCP_H */ 350