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 u64 sndr_key; 62 u64 rcvr_key; 63 u64 ahmac; 64 struct mptcp_addr_info addr; 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 u32 nonce; 72 u64 thmac; 73 u32 token; 74 u8 hmac[20]; 75 struct mptcp_ext ext_copy; 76 #endif 77 }; 78 79 #ifdef CONFIG_MPTCP 80 extern struct request_sock_ops mptcp_subflow_request_sock_ops; 81 82 void mptcp_init(void); 83 84 static inline bool sk_is_mptcp(const struct sock *sk) 85 { 86 return tcp_sk(sk)->is_mptcp; 87 } 88 89 static inline bool rsk_is_mptcp(const struct request_sock *req) 90 { 91 return tcp_rsk(req)->is_mptcp; 92 } 93 94 static inline bool rsk_drop_req(const struct request_sock *req) 95 { 96 return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req; 97 } 98 99 void mptcp_space(const struct sock *ssk, int *space, int *full_space); 100 bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 101 unsigned int *size, struct mptcp_out_options *opts); 102 bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, 103 struct mptcp_out_options *opts); 104 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, 105 unsigned int *size, unsigned int remaining, 106 struct mptcp_out_options *opts); 107 void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb); 108 109 void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp, 110 struct mptcp_out_options *opts); 111 112 /* move the skb extension owership, with the assumption that 'to' is 113 * newly allocated 114 */ 115 static inline void mptcp_skb_ext_move(struct sk_buff *to, 116 struct sk_buff *from) 117 { 118 if (!skb_ext_exist(from, SKB_EXT_MPTCP)) 119 return; 120 121 if (WARN_ON_ONCE(to->active_extensions)) 122 skb_ext_put(to); 123 124 to->active_extensions = from->active_extensions; 125 to->extensions = from->extensions; 126 from->active_extensions = 0; 127 } 128 129 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 130 struct sk_buff *from) 131 { 132 struct mptcp_ext *from_ext; 133 134 from_ext = skb_ext_find(from, SKB_EXT_MPTCP); 135 if (!from_ext) 136 return; 137 138 from_ext->frozen = 1; 139 skb_ext_copy(to, from); 140 } 141 142 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 143 const struct mptcp_ext *from_ext) 144 { 145 /* MPTCP always clears the ext when adding it to the skb, so 146 * holes do not bother us here 147 */ 148 return !from_ext || 149 (to_ext && from_ext && 150 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 151 } 152 153 /* check if skbs can be collapsed. 154 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 155 * mapping, or if the extension of @to is the same as @from. 156 * Collapsing is not possible if @to lacks an extension, but @from carries one. 157 */ 158 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 159 const struct sk_buff *from) 160 { 161 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 162 skb_ext_find(from, SKB_EXT_MPTCP)); 163 } 164 165 void mptcp_seq_show(struct seq_file *seq); 166 int mptcp_subflow_init_cookie_req(struct request_sock *req, 167 const struct sock *sk_listener, 168 struct sk_buff *skb); 169 170 __be32 mptcp_get_reset_option(const struct sk_buff *skb); 171 172 static inline __be32 mptcp_reset_option(const struct sk_buff *skb) 173 { 174 if (skb_ext_exist(skb, SKB_EXT_MPTCP)) 175 return mptcp_get_reset_option(skb); 176 177 return htonl(0u); 178 } 179 #else 180 181 static inline void mptcp_init(void) 182 { 183 } 184 185 static inline bool sk_is_mptcp(const struct sock *sk) 186 { 187 return false; 188 } 189 190 static inline bool rsk_is_mptcp(const struct request_sock *req) 191 { 192 return false; 193 } 194 195 static inline bool rsk_drop_req(const struct request_sock *req) 196 { 197 return false; 198 } 199 200 static inline void mptcp_parse_option(const struct sk_buff *skb, 201 const unsigned char *ptr, int opsize, 202 struct tcp_options_received *opt_rx) 203 { 204 } 205 206 static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 207 unsigned int *size, 208 struct mptcp_out_options *opts) 209 { 210 return false; 211 } 212 213 static inline bool mptcp_synack_options(const struct request_sock *req, 214 unsigned int *size, 215 struct mptcp_out_options *opts) 216 { 217 return false; 218 } 219 220 static inline bool mptcp_established_options(struct sock *sk, 221 struct sk_buff *skb, 222 unsigned int *size, 223 unsigned int remaining, 224 struct mptcp_out_options *opts) 225 { 226 return false; 227 } 228 229 static inline void mptcp_incoming_options(struct sock *sk, 230 struct sk_buff *skb) 231 { 232 } 233 234 static inline void mptcp_skb_ext_move(struct sk_buff *to, 235 const struct sk_buff *from) 236 { 237 } 238 239 static inline void mptcp_skb_ext_copy(struct sk_buff *to, 240 struct sk_buff *from) 241 { 242 } 243 244 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 245 const struct sk_buff *from) 246 { 247 return true; 248 } 249 250 static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { } 251 static inline void mptcp_seq_show(struct seq_file *seq) { } 252 253 static inline int mptcp_subflow_init_cookie_req(struct request_sock *req, 254 const struct sock *sk_listener, 255 struct sk_buff *skb) 256 { 257 return 0; /* TCP fallback */ 258 } 259 260 static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); } 261 #endif /* CONFIG_MPTCP */ 262 263 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 264 int mptcpv6_init(void); 265 void mptcpv6_handle_mapped(struct sock *sk, bool mapped); 266 #elif IS_ENABLED(CONFIG_IPV6) 267 static inline int mptcpv6_init(void) { return 0; } 268 static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } 269 #endif 270 271 #endif /* __NET_MPTCP_H */ 272