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