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