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 u64 data_seq; 23 u32 subflow_seq; 24 u16 data_len; 25 __sum16 csum; 26 27 struct_group(flags, 28 u8 use_map:1, 29 dsn64:1, 30 data_fin:1, 31 use_ack:1, 32 ack64:1, 33 mpc_map:1, 34 frozen:1, 35 reset_transient:1; 36 u8 reset_reason:4, 37 csum_reqd:1, 38 infinite_map:1; 39 ); /* end of flags group */ 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 drop_ts: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 struct mptcp_sched_ops { 105 int (*get_send)(struct mptcp_sock *msk); 106 int (*get_retrans)(struct mptcp_sock *msk); 107 108 char name[MPTCP_SCHED_NAME_MAX]; 109 struct module *owner; 110 struct list_head list; 111 112 void (*init)(struct mptcp_sock *msk); 113 void (*release)(struct mptcp_sock *msk); 114 } ____cacheline_aligned_in_smp; 115 116 #define MPTCP_PM_NAME_MAX 16 117 #define MPTCP_PM_MAX 128 118 #define MPTCP_PM_BUF_MAX (MPTCP_PM_NAME_MAX * MPTCP_PM_MAX) 119 120 struct mptcp_pm_ops { 121 char name[MPTCP_PM_NAME_MAX]; 122 struct module *owner; 123 struct list_head list; 124 125 void (*init)(struct mptcp_sock *msk); 126 void (*release)(struct mptcp_sock *msk); 127 } ____cacheline_aligned_in_smp; 128 129 #ifdef CONFIG_MPTCP 130 void mptcp_init(void); 131 132 static inline bool sk_is_mptcp(const struct sock *sk) 133 { 134 return tcp_sk(sk)->is_mptcp; 135 } 136 137 static inline bool rsk_is_mptcp(const struct request_sock *req) 138 { 139 return tcp_rsk(req)->is_mptcp; 140 } 141 142 static inline bool rsk_drop_req(const struct request_sock *req) 143 { 144 return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req; 145 } 146 147 void mptcp_space(const struct sock *ssk, int *space, int *full_space); 148 bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 149 unsigned int *size, struct mptcp_out_options *opts); 150 bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, 151 struct mptcp_out_options *opts); 152 int mptcp_established_options(struct sock *sk, struct sk_buff *skb, 153 unsigned int remaining, bool has_ts, 154 struct mptcp_out_options *opts); 155 bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb); 156 157 void mptcp_write_options(struct tcphdr *th, __be32 *ptr, struct tcp_sock *tp, 158 struct mptcp_out_options *opts); 159 160 void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info); 161 162 /* move the skb extension owership, with the assumption that 'to' is 163 * newly allocated 164 */ 165 static inline void mptcp_skb_ext_move(struct sk_buff *to, 166 struct sk_buff *from) 167 { 168 if (!skb_ext_exist(from, SKB_EXT_MPTCP)) 169 return; 170 171 if (WARN_ON_ONCE(to->active_extensions)) 172 skb_ext_put(to); 173 174 to->active_extensions = from->active_extensions; 175 to->extensions = from->extensions; 176 from->active_extensions = 0; 177 } 178 179 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 180 struct sk_buff *from) 181 { 182 struct mptcp_ext *from_ext; 183 184 from_ext = skb_ext_find(from, SKB_EXT_MPTCP); 185 if (!from_ext) 186 return; 187 188 from_ext->frozen = 1; 189 skb_ext_copy(to, from); 190 } 191 192 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 193 const struct mptcp_ext *from_ext) 194 { 195 /* MPTCP always clears the ext when adding it to the skb, so 196 * holes do not bother us here 197 */ 198 return !from_ext || 199 (to_ext && from_ext && 200 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 201 } 202 203 /* check if skbs can be collapsed. 204 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 205 * mapping, or if the extension of @to is the same as @from. 206 * Collapsing is not possible if @to lacks an extension, but @from carries one. 207 */ 208 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 209 const struct sk_buff *from) 210 { 211 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 212 skb_ext_find(from, SKB_EXT_MPTCP)); 213 } 214 215 void mptcp_seq_show(struct seq_file *seq); 216 int mptcp_subflow_init_cookie_req(struct request_sock *req, 217 const struct sock *sk_listener, 218 struct sk_buff *skb); 219 struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops, 220 struct sock *sk_listener, 221 bool attach_listener); 222 /* Caller must hold an RCU read-side lock. */ 223 void mptcp_subflow_reqsk_clone(struct request_sock *req, 224 struct request_sock *new_req); 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_incoming_options(struct sock *sk, 273 struct sk_buff *skb) 274 { 275 return true; 276 } 277 278 static inline void mptcp_skb_ext_move(struct sk_buff *to, 279 const struct sk_buff *from) 280 { 281 } 282 283 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 284 struct sk_buff *from) 285 { 286 } 287 288 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 289 const struct sk_buff *from) 290 { 291 return true; 292 } 293 294 static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { } 295 static inline void mptcp_seq_show(struct seq_file *seq) { } 296 297 static inline int mptcp_subflow_init_cookie_req(struct request_sock *req, 298 const struct sock *sk_listener, 299 struct sk_buff *skb) 300 { 301 return 0; /* TCP fallback */ 302 } 303 304 static inline struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops, 305 struct sock *sk_listener, 306 bool attach_listener) 307 { 308 return NULL; 309 } 310 311 /* Caller must hold an RCU read-side lock. */ 312 static inline void mptcp_subflow_reqsk_clone(struct request_sock *req, 313 struct request_sock *new_req) 314 { 315 } 316 317 static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); } 318 319 static inline void mptcp_active_detect_blackhole(struct sock *sk, bool expired) { } 320 #endif /* CONFIG_MPTCP */ 321 322 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 323 int mptcpv6_init(void); 324 void mptcpv6_handle_mapped(struct sock *sk, bool mapped); 325 #elif IS_ENABLED(CONFIG_IPV6) 326 static inline int mptcpv6_init(void) { return 0; } 327 static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } 328 #endif 329 330 #if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL) 331 struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk); 332 #else 333 static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) { return NULL; } 334 #endif 335 336 #if !IS_ENABLED(CONFIG_MPTCP) 337 struct mptcp_sock { }; 338 #endif 339 340 #endif /* __NET_MPTCP_H */ 341