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 #define MPTCP_SCHED_NAME_MAX 16 100 #define MPTCP_SCHED_MAX 128 101 #define MPTCP_SCHED_BUF_MAX (MPTCP_SCHED_NAME_MAX * MPTCP_SCHED_MAX) 102 103 #define MPTCP_SUBFLOWS_MAX 8 104 105 struct mptcp_sched_data { 106 u8 subflows; 107 struct mptcp_subflow_context *contexts[MPTCP_SUBFLOWS_MAX]; 108 }; 109 110 struct mptcp_sched_ops { 111 int (*get_send)(struct mptcp_sock *msk, 112 struct mptcp_sched_data *data); 113 int (*get_retrans)(struct mptcp_sock *msk, 114 struct mptcp_sched_data *data); 115 116 char name[MPTCP_SCHED_NAME_MAX]; 117 struct module *owner; 118 struct list_head list; 119 120 void (*init)(struct mptcp_sock *msk); 121 void (*release)(struct mptcp_sock *msk); 122 } ____cacheline_aligned_in_smp; 123 124 #ifdef CONFIG_MPTCP 125 void mptcp_init(void); 126 127 static inline bool sk_is_mptcp(const struct sock *sk) 128 { 129 return tcp_sk(sk)->is_mptcp; 130 } 131 132 static inline bool rsk_is_mptcp(const struct request_sock *req) 133 { 134 return tcp_rsk(req)->is_mptcp; 135 } 136 137 static inline bool rsk_drop_req(const struct request_sock *req) 138 { 139 return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req; 140 } 141 142 void mptcp_space(const struct sock *ssk, int *space, int *full_space); 143 bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 144 unsigned int *size, struct mptcp_out_options *opts); 145 bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, 146 struct mptcp_out_options *opts); 147 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, 148 unsigned int *size, unsigned int remaining, 149 struct mptcp_out_options *opts); 150 bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb); 151 152 void mptcp_write_options(struct tcphdr *th, __be32 *ptr, struct tcp_sock *tp, 153 struct mptcp_out_options *opts); 154 155 void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info); 156 157 /* move the skb extension owership, with the assumption that 'to' is 158 * newly allocated 159 */ 160 static inline void mptcp_skb_ext_move(struct sk_buff *to, 161 struct sk_buff *from) 162 { 163 if (!skb_ext_exist(from, SKB_EXT_MPTCP)) 164 return; 165 166 if (WARN_ON_ONCE(to->active_extensions)) 167 skb_ext_put(to); 168 169 to->active_extensions = from->active_extensions; 170 to->extensions = from->extensions; 171 from->active_extensions = 0; 172 } 173 174 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 175 struct sk_buff *from) 176 { 177 struct mptcp_ext *from_ext; 178 179 from_ext = skb_ext_find(from, SKB_EXT_MPTCP); 180 if (!from_ext) 181 return; 182 183 from_ext->frozen = 1; 184 skb_ext_copy(to, from); 185 } 186 187 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 188 const struct mptcp_ext *from_ext) 189 { 190 /* MPTCP always clears the ext when adding it to the skb, so 191 * holes do not bother us here 192 */ 193 return !from_ext || 194 (to_ext && from_ext && 195 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 196 } 197 198 /* check if skbs can be collapsed. 199 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 200 * mapping, or if the extension of @to is the same as @from. 201 * Collapsing is not possible if @to lacks an extension, but @from carries one. 202 */ 203 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 204 const struct sk_buff *from) 205 { 206 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 207 skb_ext_find(from, SKB_EXT_MPTCP)); 208 } 209 210 void mptcp_seq_show(struct seq_file *seq); 211 int mptcp_subflow_init_cookie_req(struct request_sock *req, 212 const struct sock *sk_listener, 213 struct sk_buff *skb); 214 struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops, 215 struct sock *sk_listener, 216 bool attach_listener); 217 218 __be32 mptcp_get_reset_option(const struct sk_buff *skb); 219 220 static inline __be32 mptcp_reset_option(const struct sk_buff *skb) 221 { 222 if (skb_ext_exist(skb, SKB_EXT_MPTCP)) 223 return mptcp_get_reset_option(skb); 224 225 return htonl(0u); 226 } 227 228 void mptcp_active_detect_blackhole(struct sock *sk, bool expired); 229 #else 230 231 static inline void mptcp_init(void) 232 { 233 } 234 235 static inline bool sk_is_mptcp(const struct sock *sk) 236 { 237 return false; 238 } 239 240 static inline bool rsk_is_mptcp(const struct request_sock *req) 241 { 242 return false; 243 } 244 245 static inline bool rsk_drop_req(const struct request_sock *req) 246 { 247 return false; 248 } 249 250 static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 251 unsigned int *size, 252 struct mptcp_out_options *opts) 253 { 254 return false; 255 } 256 257 static inline bool mptcp_synack_options(const struct request_sock *req, 258 unsigned int *size, 259 struct mptcp_out_options *opts) 260 { 261 return false; 262 } 263 264 static inline bool mptcp_established_options(struct sock *sk, 265 struct sk_buff *skb, 266 unsigned int *size, 267 unsigned int remaining, 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