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 u64 data_ack; 20 u64 data_seq; 21 u32 subflow_seq; 22 u16 data_len; 23 u8 use_map:1, 24 dsn64:1, 25 data_fin:1, 26 use_ack:1, 27 ack64:1, 28 mpc_map:1, 29 __unused:2; 30 /* one byte hole */ 31 }; 32 33 struct mptcp_out_options { 34 #if IS_ENABLED(CONFIG_MPTCP) 35 u16 suboptions; 36 u64 sndr_key; 37 u64 rcvr_key; 38 union { 39 struct in_addr addr; 40 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 41 struct in6_addr addr6; 42 #endif 43 }; 44 u8 addr_id; 45 u64 ahmac; 46 u8 rm_id; 47 u8 join_id; 48 u8 backup; 49 u32 nonce; 50 u64 thmac; 51 u32 token; 52 u8 hmac[20]; 53 struct mptcp_ext ext_copy; 54 #endif 55 }; 56 57 #ifdef CONFIG_MPTCP 58 59 void mptcp_init(void); 60 61 static inline bool sk_is_mptcp(const struct sock *sk) 62 { 63 return tcp_sk(sk)->is_mptcp; 64 } 65 66 static inline bool rsk_is_mptcp(const struct request_sock *req) 67 { 68 return tcp_rsk(req)->is_mptcp; 69 } 70 71 static inline bool rsk_drop_req(const struct request_sock *req) 72 { 73 return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req; 74 } 75 76 void mptcp_space(const struct sock *ssk, int *space, int *full_space); 77 bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 78 unsigned int *size, struct mptcp_out_options *opts); 79 bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, 80 struct mptcp_out_options *opts); 81 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, 82 unsigned int *size, unsigned int remaining, 83 struct mptcp_out_options *opts); 84 void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb, 85 struct tcp_options_received *opt_rx); 86 87 void mptcp_write_options(__be32 *ptr, struct mptcp_out_options *opts); 88 89 /* move the skb extension owership, with the assumption that 'to' is 90 * newly allocated 91 */ 92 static inline void mptcp_skb_ext_move(struct sk_buff *to, 93 struct sk_buff *from) 94 { 95 if (!skb_ext_exist(from, SKB_EXT_MPTCP)) 96 return; 97 98 if (WARN_ON_ONCE(to->active_extensions)) 99 skb_ext_put(to); 100 101 to->active_extensions = from->active_extensions; 102 to->extensions = from->extensions; 103 from->active_extensions = 0; 104 } 105 106 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 107 const struct mptcp_ext *from_ext) 108 { 109 /* MPTCP always clears the ext when adding it to the skb, so 110 * holes do not bother us here 111 */ 112 return !from_ext || 113 (to_ext && from_ext && 114 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 115 } 116 117 /* check if skbs can be collapsed. 118 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 119 * mapping, or if the extension of @to is the same as @from. 120 * Collapsing is not possible if @to lacks an extension, but @from carries one. 121 */ 122 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 123 const struct sk_buff *from) 124 { 125 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 126 skb_ext_find(from, SKB_EXT_MPTCP)); 127 } 128 129 void mptcp_seq_show(struct seq_file *seq); 130 #else 131 132 static inline void mptcp_init(void) 133 { 134 } 135 136 static inline bool sk_is_mptcp(const struct sock *sk) 137 { 138 return false; 139 } 140 141 static inline bool rsk_is_mptcp(const struct request_sock *req) 142 { 143 return false; 144 } 145 146 static inline bool rsk_drop_req(const struct request_sock *req) 147 { 148 return false; 149 } 150 151 static inline void mptcp_parse_option(const struct sk_buff *skb, 152 const unsigned char *ptr, int opsize, 153 struct tcp_options_received *opt_rx) 154 { 155 } 156 157 static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 158 unsigned int *size, 159 struct mptcp_out_options *opts) 160 { 161 return false; 162 } 163 164 static inline void mptcp_rcv_synsent(struct sock *sk) 165 { 166 } 167 168 static inline bool mptcp_synack_options(const struct request_sock *req, 169 unsigned int *size, 170 struct mptcp_out_options *opts) 171 { 172 return false; 173 } 174 175 static inline bool mptcp_established_options(struct sock *sk, 176 struct sk_buff *skb, 177 unsigned int *size, 178 unsigned int remaining, 179 struct mptcp_out_options *opts) 180 { 181 return false; 182 } 183 184 static inline void mptcp_incoming_options(struct sock *sk, 185 struct sk_buff *skb, 186 struct tcp_options_received *opt_rx) 187 { 188 } 189 190 static inline void mptcp_skb_ext_move(struct sk_buff *to, 191 const struct sk_buff *from) 192 { 193 } 194 195 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 196 const struct sk_buff *from) 197 { 198 return true; 199 } 200 201 static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { } 202 static inline void mptcp_seq_show(struct seq_file *seq) { } 203 #endif /* CONFIG_MPTCP */ 204 205 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 206 int mptcpv6_init(void); 207 void mptcpv6_handle_mapped(struct sock *sk, bool mapped); 208 #elif IS_ENABLED(CONFIG_IPV6) 209 static inline int mptcpv6_init(void) { return 0; } 210 static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } 211 #endif 212 213 #endif /* __NET_MPTCP_H */ 214