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 MPTCP_RM_IDS_MAX 8 43 44 struct mptcp_rm_list { 45 u8 ids[MPTCP_RM_IDS_MAX]; 46 u8 nr; 47 }; 48 49 struct mptcp_addr_info { 50 u8 id; 51 sa_family_t family; 52 __be16 port; 53 union { 54 struct in_addr addr; 55 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 56 struct in6_addr addr6; 57 #endif 58 }; 59 }; 60 61 struct mptcp_out_options { 62 #if IS_ENABLED(CONFIG_MPTCP) 63 u16 suboptions; 64 struct mptcp_rm_list rm_list; 65 u8 join_id; 66 u8 backup; 67 u8 reset_reason:4, 68 reset_transient:1, 69 csum_reqd:1, 70 allow_join_id0:1; 71 union { 72 struct { 73 u64 sndr_key; 74 u64 rcvr_key; 75 u64 data_seq; 76 u32 subflow_seq; 77 u16 data_len; 78 __sum16 csum; 79 }; 80 struct { 81 struct mptcp_addr_info addr; 82 u64 ahmac; 83 }; 84 struct { 85 struct mptcp_ext ext_copy; 86 u64 fail_seq; 87 }; 88 struct { 89 u32 nonce; 90 u32 token; 91 u64 thmac; 92 u8 hmac[20]; 93 }; 94 }; 95 #endif 96 }; 97 98 #ifdef CONFIG_MPTCP 99 extern struct request_sock_ops mptcp_subflow_request_sock_ops; 100 101 void mptcp_init(void); 102 103 static inline bool sk_is_mptcp(const struct sock *sk) 104 { 105 return tcp_sk(sk)->is_mptcp; 106 } 107 108 static inline bool rsk_is_mptcp(const struct request_sock *req) 109 { 110 return tcp_rsk(req)->is_mptcp; 111 } 112 113 static inline bool rsk_drop_req(const struct request_sock *req) 114 { 115 return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req; 116 } 117 118 void mptcp_space(const struct sock *ssk, int *space, int *full_space); 119 bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 120 unsigned int *size, struct mptcp_out_options *opts); 121 bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, 122 struct mptcp_out_options *opts); 123 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, 124 unsigned int *size, unsigned int remaining, 125 struct mptcp_out_options *opts); 126 bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb); 127 128 void mptcp_write_options(struct tcphdr *th, __be32 *ptr, struct tcp_sock *tp, 129 struct mptcp_out_options *opts); 130 131 void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info); 132 133 /* move the skb extension owership, with the assumption that 'to' is 134 * newly allocated 135 */ 136 static inline void mptcp_skb_ext_move(struct sk_buff *to, 137 struct sk_buff *from) 138 { 139 if (!skb_ext_exist(from, SKB_EXT_MPTCP)) 140 return; 141 142 if (WARN_ON_ONCE(to->active_extensions)) 143 skb_ext_put(to); 144 145 to->active_extensions = from->active_extensions; 146 to->extensions = from->extensions; 147 from->active_extensions = 0; 148 } 149 150 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 151 struct sk_buff *from) 152 { 153 struct mptcp_ext *from_ext; 154 155 from_ext = skb_ext_find(from, SKB_EXT_MPTCP); 156 if (!from_ext) 157 return; 158 159 from_ext->frozen = 1; 160 skb_ext_copy(to, from); 161 } 162 163 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 164 const struct mptcp_ext *from_ext) 165 { 166 /* MPTCP always clears the ext when adding it to the skb, so 167 * holes do not bother us here 168 */ 169 return !from_ext || 170 (to_ext && from_ext && 171 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 172 } 173 174 /* check if skbs can be collapsed. 175 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 176 * mapping, or if the extension of @to is the same as @from. 177 * Collapsing is not possible if @to lacks an extension, but @from carries one. 178 */ 179 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 180 const struct sk_buff *from) 181 { 182 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 183 skb_ext_find(from, SKB_EXT_MPTCP)); 184 } 185 186 void mptcp_seq_show(struct seq_file *seq); 187 int mptcp_subflow_init_cookie_req(struct request_sock *req, 188 const struct sock *sk_listener, 189 struct sk_buff *skb); 190 191 __be32 mptcp_get_reset_option(const struct sk_buff *skb); 192 193 static inline __be32 mptcp_reset_option(const struct sk_buff *skb) 194 { 195 if (skb_ext_exist(skb, SKB_EXT_MPTCP)) 196 return mptcp_get_reset_option(skb); 197 198 return htonl(0u); 199 } 200 #else 201 202 static inline void mptcp_init(void) 203 { 204 } 205 206 static inline bool sk_is_mptcp(const struct sock *sk) 207 { 208 return false; 209 } 210 211 static inline bool rsk_is_mptcp(const struct request_sock *req) 212 { 213 return false; 214 } 215 216 static inline bool rsk_drop_req(const struct request_sock *req) 217 { 218 return false; 219 } 220 221 static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 222 unsigned int *size, 223 struct mptcp_out_options *opts) 224 { 225 return false; 226 } 227 228 static inline bool mptcp_synack_options(const struct request_sock *req, 229 unsigned int *size, 230 struct mptcp_out_options *opts) 231 { 232 return false; 233 } 234 235 static inline bool mptcp_established_options(struct sock *sk, 236 struct sk_buff *skb, 237 unsigned int *size, 238 unsigned int remaining, 239 struct mptcp_out_options *opts) 240 { 241 return false; 242 } 243 244 static inline bool mptcp_incoming_options(struct sock *sk, 245 struct sk_buff *skb) 246 { 247 return true; 248 } 249 250 static inline void mptcp_skb_ext_move(struct sk_buff *to, 251 const struct sk_buff *from) 252 { 253 } 254 255 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 256 struct sk_buff *from) 257 { 258 } 259 260 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 261 const struct sk_buff *from) 262 { 263 return true; 264 } 265 266 static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { } 267 static inline void mptcp_seq_show(struct seq_file *seq) { } 268 269 static inline int mptcp_subflow_init_cookie_req(struct request_sock *req, 270 const struct sock *sk_listener, 271 struct sk_buff *skb) 272 { 273 return 0; /* TCP fallback */ 274 } 275 276 static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); } 277 #endif /* CONFIG_MPTCP */ 278 279 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 280 int mptcpv6_init(void); 281 void mptcpv6_handle_mapped(struct sock *sk, bool mapped); 282 #elif IS_ENABLED(CONFIG_IPV6) 283 static inline int mptcpv6_init(void) { return 0; } 284 static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } 285 #endif 286 287 #if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL) 288 struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk); 289 #else 290 static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) { return NULL; } 291 #endif 292 293 #endif /* __NET_MPTCP_H */ 294