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