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 #ifdef CONFIG_MPTCP 100 extern struct request_sock_ops mptcp_subflow_request_sock_ops; 101 102 void mptcp_init(void); 103 104 static inline bool sk_is_mptcp(const struct sock *sk) 105 { 106 return tcp_sk(sk)->is_mptcp; 107 } 108 109 static inline bool rsk_is_mptcp(const struct request_sock *req) 110 { 111 return tcp_rsk(req)->is_mptcp; 112 } 113 114 static inline bool rsk_drop_req(const struct request_sock *req) 115 { 116 return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req; 117 } 118 119 void mptcp_space(const struct sock *ssk, int *space, int *full_space); 120 bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 121 unsigned int *size, struct mptcp_out_options *opts); 122 bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, 123 struct mptcp_out_options *opts); 124 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, 125 unsigned int *size, unsigned int remaining, 126 struct mptcp_out_options *opts); 127 bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb); 128 129 void mptcp_write_options(struct tcphdr *th, __be32 *ptr, struct tcp_sock *tp, 130 struct mptcp_out_options *opts); 131 132 void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info); 133 134 /* move the skb extension owership, with the assumption that 'to' is 135 * newly allocated 136 */ 137 static inline void mptcp_skb_ext_move(struct sk_buff *to, 138 struct sk_buff *from) 139 { 140 if (!skb_ext_exist(from, SKB_EXT_MPTCP)) 141 return; 142 143 if (WARN_ON_ONCE(to->active_extensions)) 144 skb_ext_put(to); 145 146 to->active_extensions = from->active_extensions; 147 to->extensions = from->extensions; 148 from->active_extensions = 0; 149 } 150 151 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 152 struct sk_buff *from) 153 { 154 struct mptcp_ext *from_ext; 155 156 from_ext = skb_ext_find(from, SKB_EXT_MPTCP); 157 if (!from_ext) 158 return; 159 160 from_ext->frozen = 1; 161 skb_ext_copy(to, from); 162 } 163 164 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 165 const struct mptcp_ext *from_ext) 166 { 167 /* MPTCP always clears the ext when adding it to the skb, so 168 * holes do not bother us here 169 */ 170 return !from_ext || 171 (to_ext && from_ext && 172 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 173 } 174 175 /* check if skbs can be collapsed. 176 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 177 * mapping, or if the extension of @to is the same as @from. 178 * Collapsing is not possible if @to lacks an extension, but @from carries one. 179 */ 180 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 181 const struct sk_buff *from) 182 { 183 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 184 skb_ext_find(from, SKB_EXT_MPTCP)); 185 } 186 187 void mptcp_seq_show(struct seq_file *seq); 188 int mptcp_subflow_init_cookie_req(struct request_sock *req, 189 const struct sock *sk_listener, 190 struct sk_buff *skb); 191 192 __be32 mptcp_get_reset_option(const struct sk_buff *skb); 193 194 static inline __be32 mptcp_reset_option(const struct sk_buff *skb) 195 { 196 if (skb_ext_exist(skb, SKB_EXT_MPTCP)) 197 return mptcp_get_reset_option(skb); 198 199 return htonl(0u); 200 } 201 #else 202 203 static inline void mptcp_init(void) 204 { 205 } 206 207 static inline bool sk_is_mptcp(const struct sock *sk) 208 { 209 return false; 210 } 211 212 static inline bool rsk_is_mptcp(const struct request_sock *req) 213 { 214 return false; 215 } 216 217 static inline bool rsk_drop_req(const struct request_sock *req) 218 { 219 return false; 220 } 221 222 static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 223 unsigned int *size, 224 struct mptcp_out_options *opts) 225 { 226 return false; 227 } 228 229 static inline bool mptcp_synack_options(const struct request_sock *req, 230 unsigned int *size, 231 struct mptcp_out_options *opts) 232 { 233 return false; 234 } 235 236 static inline bool mptcp_established_options(struct sock *sk, 237 struct sk_buff *skb, 238 unsigned int *size, 239 unsigned int remaining, 240 struct mptcp_out_options *opts) 241 { 242 return false; 243 } 244 245 static inline bool mptcp_incoming_options(struct sock *sk, 246 struct sk_buff *skb) 247 { 248 return true; 249 } 250 251 static inline void mptcp_skb_ext_move(struct sk_buff *to, 252 const struct sk_buff *from) 253 { 254 } 255 256 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 257 struct sk_buff *from) 258 { 259 } 260 261 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 262 const struct sk_buff *from) 263 { 264 return true; 265 } 266 267 static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { } 268 static inline void mptcp_seq_show(struct seq_file *seq) { } 269 270 static inline int mptcp_subflow_init_cookie_req(struct request_sock *req, 271 const struct sock *sk_listener, 272 struct sk_buff *skb) 273 { 274 return 0; /* TCP fallback */ 275 } 276 277 static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); } 278 #endif /* CONFIG_MPTCP */ 279 280 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 281 int mptcpv6_init(void); 282 void mptcpv6_handle_mapped(struct sock *sk, bool mapped); 283 #elif IS_ENABLED(CONFIG_IPV6) 284 static inline int mptcpv6_init(void) { return 0; } 285 static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } 286 #endif 287 288 #if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL) 289 struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk); 290 #else 291 static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) { return NULL; } 292 #endif 293 294 #if !IS_ENABLED(CONFIG_MPTCP) 295 struct mptcp_sock { }; 296 #endif 297 298 #endif /* __NET_MPTCP_H */ 299