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