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 seq_file; 16 17 /* MPTCP sk_buff extension data */ 18 struct mptcp_ext { 19 union { 20 u64 data_ack; 21 u32 data_ack32; 22 }; 23 u64 data_seq; 24 u32 subflow_seq; 25 u16 data_len; 26 __sum16 csum; 27 u8 use_map:1, 28 dsn64:1, 29 data_fin:1, 30 use_ack:1, 31 ack64:1, 32 mpc_map:1, 33 frozen:1, 34 reset_transient:1; 35 u8 reset_reason:4, 36 csum_reqd:1; 37 }; 38 39 #define MPTCP_RM_IDS_MAX 8 40 41 struct mptcp_rm_list { 42 u8 ids[MPTCP_RM_IDS_MAX]; 43 u8 nr; 44 }; 45 46 struct mptcp_addr_info { 47 u8 id; 48 sa_family_t family; 49 __be16 port; 50 union { 51 struct in_addr addr; 52 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 53 struct in6_addr addr6; 54 #endif 55 }; 56 }; 57 58 struct mptcp_out_options { 59 #if IS_ENABLED(CONFIG_MPTCP) 60 u16 suboptions; 61 struct mptcp_rm_list rm_list; 62 u8 join_id; 63 u8 backup; 64 u8 reset_reason:4, 65 reset_transient:1, 66 csum_reqd:1, 67 allow_join_id0:1; 68 union { 69 struct { 70 u64 sndr_key; 71 u64 rcvr_key; 72 }; 73 struct { 74 struct mptcp_addr_info addr; 75 u64 ahmac; 76 }; 77 struct { 78 struct mptcp_ext ext_copy; 79 u64 fail_seq; 80 }; 81 struct { 82 u32 nonce; 83 u32 token; 84 u64 thmac; 85 u8 hmac[20]; 86 }; 87 }; 88 #endif 89 }; 90 91 #ifdef CONFIG_MPTCP 92 extern struct request_sock_ops mptcp_subflow_request_sock_ops; 93 94 void mptcp_init(void); 95 96 static inline bool sk_is_mptcp(const struct sock *sk) 97 { 98 return tcp_sk(sk)->is_mptcp; 99 } 100 101 static inline bool rsk_is_mptcp(const struct request_sock *req) 102 { 103 return tcp_rsk(req)->is_mptcp; 104 } 105 106 static inline bool rsk_drop_req(const struct request_sock *req) 107 { 108 return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req; 109 } 110 111 void mptcp_space(const struct sock *ssk, int *space, int *full_space); 112 bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 113 unsigned int *size, struct mptcp_out_options *opts); 114 bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, 115 struct mptcp_out_options *opts); 116 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, 117 unsigned int *size, unsigned int remaining, 118 struct mptcp_out_options *opts); 119 bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb); 120 121 void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp, 122 struct mptcp_out_options *opts); 123 124 /* move the skb extension owership, with the assumption that 'to' is 125 * newly allocated 126 */ 127 static inline void mptcp_skb_ext_move(struct sk_buff *to, 128 struct sk_buff *from) 129 { 130 if (!skb_ext_exist(from, SKB_EXT_MPTCP)) 131 return; 132 133 if (WARN_ON_ONCE(to->active_extensions)) 134 skb_ext_put(to); 135 136 to->active_extensions = from->active_extensions; 137 to->extensions = from->extensions; 138 from->active_extensions = 0; 139 } 140 141 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 142 struct sk_buff *from) 143 { 144 struct mptcp_ext *from_ext; 145 146 from_ext = skb_ext_find(from, SKB_EXT_MPTCP); 147 if (!from_ext) 148 return; 149 150 from_ext->frozen = 1; 151 skb_ext_copy(to, from); 152 } 153 154 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 155 const struct mptcp_ext *from_ext) 156 { 157 /* MPTCP always clears the ext when adding it to the skb, so 158 * holes do not bother us here 159 */ 160 return !from_ext || 161 (to_ext && from_ext && 162 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 163 } 164 165 /* check if skbs can be collapsed. 166 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 167 * mapping, or if the extension of @to is the same as @from. 168 * Collapsing is not possible if @to lacks an extension, but @from carries one. 169 */ 170 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 171 const struct sk_buff *from) 172 { 173 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 174 skb_ext_find(from, SKB_EXT_MPTCP)); 175 } 176 177 void mptcp_seq_show(struct seq_file *seq); 178 int mptcp_subflow_init_cookie_req(struct request_sock *req, 179 const struct sock *sk_listener, 180 struct sk_buff *skb); 181 182 __be32 mptcp_get_reset_option(const struct sk_buff *skb); 183 184 static inline __be32 mptcp_reset_option(const struct sk_buff *skb) 185 { 186 if (skb_ext_exist(skb, SKB_EXT_MPTCP)) 187 return mptcp_get_reset_option(skb); 188 189 return htonl(0u); 190 } 191 #else 192 193 static inline void mptcp_init(void) 194 { 195 } 196 197 static inline bool sk_is_mptcp(const struct sock *sk) 198 { 199 return false; 200 } 201 202 static inline bool rsk_is_mptcp(const struct request_sock *req) 203 { 204 return false; 205 } 206 207 static inline bool rsk_drop_req(const struct request_sock *req) 208 { 209 return false; 210 } 211 212 static inline void mptcp_parse_option(const struct sk_buff *skb, 213 const unsigned char *ptr, int opsize, 214 struct tcp_options_received *opt_rx) 215 { 216 } 217 218 static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 219 unsigned int *size, 220 struct mptcp_out_options *opts) 221 { 222 return false; 223 } 224 225 static inline bool mptcp_synack_options(const struct request_sock *req, 226 unsigned int *size, 227 struct mptcp_out_options *opts) 228 { 229 return false; 230 } 231 232 static inline bool mptcp_established_options(struct sock *sk, 233 struct sk_buff *skb, 234 unsigned int *size, 235 unsigned int remaining, 236 struct mptcp_out_options *opts) 237 { 238 return false; 239 } 240 241 static inline bool mptcp_incoming_options(struct sock *sk, 242 struct sk_buff *skb) 243 { 244 return true; 245 } 246 247 static inline void mptcp_skb_ext_move(struct sk_buff *to, 248 const struct sk_buff *from) 249 { 250 } 251 252 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 253 struct sk_buff *from) 254 { 255 } 256 257 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 258 const struct sk_buff *from) 259 { 260 return true; 261 } 262 263 static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { } 264 static inline void mptcp_seq_show(struct seq_file *seq) { } 265 266 static inline int mptcp_subflow_init_cookie_req(struct request_sock *req, 267 const struct sock *sk_listener, 268 struct sk_buff *skb) 269 { 270 return 0; /* TCP fallback */ 271 } 272 273 static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); } 274 #endif /* CONFIG_MPTCP */ 275 276 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 277 int mptcpv6_init(void); 278 void mptcpv6_handle_mapped(struct sock *sk, bool mapped); 279 #elif IS_ENABLED(CONFIG_IPV6) 280 static inline int mptcpv6_init(void) { return 0; } 281 static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } 282 #endif 283 284 #endif /* __NET_MPTCP_H */ 285