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 }; 40 41 #define MPTCP_RM_IDS_MAX 8 42 43 struct mptcp_rm_list { 44 u8 ids[MPTCP_RM_IDS_MAX]; 45 u8 nr; 46 }; 47 48 struct mptcp_addr_info { 49 u8 id; 50 sa_family_t family; 51 __be16 port; 52 union { 53 struct in_addr addr; 54 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 55 struct in6_addr addr6; 56 #endif 57 }; 58 }; 59 60 struct mptcp_out_options { 61 #if IS_ENABLED(CONFIG_MPTCP) 62 u16 suboptions; 63 struct mptcp_rm_list rm_list; 64 u8 join_id; 65 u8 backup; 66 u8 reset_reason:4, 67 reset_transient:1, 68 csum_reqd:1, 69 allow_join_id0:1; 70 union { 71 struct { 72 u64 sndr_key; 73 u64 rcvr_key; 74 }; 75 struct { 76 struct mptcp_addr_info addr; 77 u64 ahmac; 78 }; 79 struct { 80 struct mptcp_ext ext_copy; 81 u64 fail_seq; 82 }; 83 struct { 84 u32 nonce; 85 u32 token; 86 u64 thmac; 87 u8 hmac[20]; 88 }; 89 }; 90 #endif 91 }; 92 93 #ifdef CONFIG_MPTCP 94 extern struct request_sock_ops mptcp_subflow_request_sock_ops; 95 96 void mptcp_init(void); 97 98 static inline bool sk_is_mptcp(const struct sock *sk) 99 { 100 return tcp_sk(sk)->is_mptcp; 101 } 102 103 static inline bool rsk_is_mptcp(const struct request_sock *req) 104 { 105 return tcp_rsk(req)->is_mptcp; 106 } 107 108 static inline bool rsk_drop_req(const struct request_sock *req) 109 { 110 return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req; 111 } 112 113 void mptcp_space(const struct sock *ssk, int *space, int *full_space); 114 bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 115 unsigned int *size, struct mptcp_out_options *opts); 116 bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, 117 struct mptcp_out_options *opts); 118 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, 119 unsigned int *size, unsigned int remaining, 120 struct mptcp_out_options *opts); 121 bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb); 122 123 void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp, 124 struct mptcp_out_options *opts); 125 126 void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info); 127 128 /* move the skb extension owership, with the assumption that 'to' is 129 * newly allocated 130 */ 131 static inline void mptcp_skb_ext_move(struct sk_buff *to, 132 struct sk_buff *from) 133 { 134 if (!skb_ext_exist(from, SKB_EXT_MPTCP)) 135 return; 136 137 if (WARN_ON_ONCE(to->active_extensions)) 138 skb_ext_put(to); 139 140 to->active_extensions = from->active_extensions; 141 to->extensions = from->extensions; 142 from->active_extensions = 0; 143 } 144 145 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 146 struct sk_buff *from) 147 { 148 struct mptcp_ext *from_ext; 149 150 from_ext = skb_ext_find(from, SKB_EXT_MPTCP); 151 if (!from_ext) 152 return; 153 154 from_ext->frozen = 1; 155 skb_ext_copy(to, from); 156 } 157 158 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 159 const struct mptcp_ext *from_ext) 160 { 161 /* MPTCP always clears the ext when adding it to the skb, so 162 * holes do not bother us here 163 */ 164 return !from_ext || 165 (to_ext && from_ext && 166 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 167 } 168 169 /* check if skbs can be collapsed. 170 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 171 * mapping, or if the extension of @to is the same as @from. 172 * Collapsing is not possible if @to lacks an extension, but @from carries one. 173 */ 174 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 175 const struct sk_buff *from) 176 { 177 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 178 skb_ext_find(from, SKB_EXT_MPTCP)); 179 } 180 181 void mptcp_seq_show(struct seq_file *seq); 182 int mptcp_subflow_init_cookie_req(struct request_sock *req, 183 const struct sock *sk_listener, 184 struct sk_buff *skb); 185 186 __be32 mptcp_get_reset_option(const struct sk_buff *skb); 187 188 static inline __be32 mptcp_reset_option(const struct sk_buff *skb) 189 { 190 if (skb_ext_exist(skb, SKB_EXT_MPTCP)) 191 return mptcp_get_reset_option(skb); 192 193 return htonl(0u); 194 } 195 #else 196 197 static inline void mptcp_init(void) 198 { 199 } 200 201 static inline bool sk_is_mptcp(const struct sock *sk) 202 { 203 return false; 204 } 205 206 static inline bool rsk_is_mptcp(const struct request_sock *req) 207 { 208 return false; 209 } 210 211 static inline bool rsk_drop_req(const struct request_sock *req) 212 { 213 return false; 214 } 215 216 static inline void mptcp_parse_option(const struct sk_buff *skb, 217 const unsigned char *ptr, int opsize, 218 struct tcp_options_received *opt_rx) 219 { 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 #endif /* __NET_MPTCP_H */ 289