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_SUBFLOWS_MAX 8 101 102 struct mptcp_sched_data { 103 bool reinject; 104 u8 subflows; 105 struct mptcp_subflow_context *contexts[MPTCP_SUBFLOWS_MAX]; 106 }; 107 108 struct mptcp_sched_ops { 109 int (*get_subflow)(struct mptcp_sock *msk, 110 struct mptcp_sched_data *data); 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 #ifdef CONFIG_MPTCP 121 void mptcp_init(void); 122 123 static inline bool sk_is_mptcp(const struct sock *sk) 124 { 125 return tcp_sk(sk)->is_mptcp; 126 } 127 128 static inline bool rsk_is_mptcp(const struct request_sock *req) 129 { 130 return tcp_rsk(req)->is_mptcp; 131 } 132 133 static inline bool rsk_drop_req(const struct request_sock *req) 134 { 135 return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req; 136 } 137 138 void mptcp_space(const struct sock *ssk, int *space, int *full_space); 139 bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 140 unsigned int *size, struct mptcp_out_options *opts); 141 bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, 142 struct mptcp_out_options *opts); 143 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, 144 unsigned int *size, unsigned int remaining, 145 struct mptcp_out_options *opts); 146 bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb); 147 148 void mptcp_write_options(struct tcphdr *th, __be32 *ptr, struct tcp_sock *tp, 149 struct mptcp_out_options *opts); 150 151 void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info); 152 153 /* move the skb extension owership, with the assumption that 'to' is 154 * newly allocated 155 */ 156 static inline void mptcp_skb_ext_move(struct sk_buff *to, 157 struct sk_buff *from) 158 { 159 if (!skb_ext_exist(from, SKB_EXT_MPTCP)) 160 return; 161 162 if (WARN_ON_ONCE(to->active_extensions)) 163 skb_ext_put(to); 164 165 to->active_extensions = from->active_extensions; 166 to->extensions = from->extensions; 167 from->active_extensions = 0; 168 } 169 170 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 171 struct sk_buff *from) 172 { 173 struct mptcp_ext *from_ext; 174 175 from_ext = skb_ext_find(from, SKB_EXT_MPTCP); 176 if (!from_ext) 177 return; 178 179 from_ext->frozen = 1; 180 skb_ext_copy(to, from); 181 } 182 183 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 184 const struct mptcp_ext *from_ext) 185 { 186 /* MPTCP always clears the ext when adding it to the skb, so 187 * holes do not bother us here 188 */ 189 return !from_ext || 190 (to_ext && from_ext && 191 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 192 } 193 194 /* check if skbs can be collapsed. 195 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 196 * mapping, or if the extension of @to is the same as @from. 197 * Collapsing is not possible if @to lacks an extension, but @from carries one. 198 */ 199 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 200 const struct sk_buff *from) 201 { 202 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 203 skb_ext_find(from, SKB_EXT_MPTCP)); 204 } 205 206 void mptcp_seq_show(struct seq_file *seq); 207 int mptcp_subflow_init_cookie_req(struct request_sock *req, 208 const struct sock *sk_listener, 209 struct sk_buff *skb); 210 struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops, 211 struct sock *sk_listener, 212 bool attach_listener); 213 214 __be32 mptcp_get_reset_option(const struct sk_buff *skb); 215 216 static inline __be32 mptcp_reset_option(const struct sk_buff *skb) 217 { 218 if (skb_ext_exist(skb, SKB_EXT_MPTCP)) 219 return mptcp_get_reset_option(skb); 220 221 return htonl(0u); 222 } 223 #else 224 225 static inline void mptcp_init(void) 226 { 227 } 228 229 static inline bool sk_is_mptcp(const struct sock *sk) 230 { 231 return false; 232 } 233 234 static inline bool rsk_is_mptcp(const struct request_sock *req) 235 { 236 return false; 237 } 238 239 static inline bool rsk_drop_req(const struct request_sock *req) 240 { 241 return false; 242 } 243 244 static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 245 unsigned int *size, 246 struct mptcp_out_options *opts) 247 { 248 return false; 249 } 250 251 static inline bool mptcp_synack_options(const struct request_sock *req, 252 unsigned int *size, 253 struct mptcp_out_options *opts) 254 { 255 return false; 256 } 257 258 static inline bool mptcp_established_options(struct sock *sk, 259 struct sk_buff *skb, 260 unsigned int *size, 261 unsigned int remaining, 262 struct mptcp_out_options *opts) 263 { 264 return false; 265 } 266 267 static inline bool mptcp_incoming_options(struct sock *sk, 268 struct sk_buff *skb) 269 { 270 return true; 271 } 272 273 static inline void mptcp_skb_ext_move(struct sk_buff *to, 274 const struct sk_buff *from) 275 { 276 } 277 278 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 279 struct sk_buff *from) 280 { 281 } 282 283 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 284 const struct sk_buff *from) 285 { 286 return true; 287 } 288 289 static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { } 290 static inline void mptcp_seq_show(struct seq_file *seq) { } 291 292 static inline int mptcp_subflow_init_cookie_req(struct request_sock *req, 293 const struct sock *sk_listener, 294 struct sk_buff *skb) 295 { 296 return 0; /* TCP fallback */ 297 } 298 299 static inline struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops, 300 struct sock *sk_listener, 301 bool attach_listener) 302 { 303 return NULL; 304 } 305 306 static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); } 307 #endif /* CONFIG_MPTCP */ 308 309 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 310 int mptcpv6_init(void); 311 void mptcpv6_handle_mapped(struct sock *sk, bool mapped); 312 #elif IS_ENABLED(CONFIG_IPV6) 313 static inline int mptcpv6_init(void) { return 0; } 314 static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } 315 #endif 316 317 #if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL) 318 struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk); 319 #else 320 static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) { return NULL; } 321 #endif 322 323 #if !IS_ENABLED(CONFIG_MPTCP) 324 struct mptcp_sock { }; 325 #endif 326 327 #endif /* __NET_MPTCP_H */ 328