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 bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 72 unsigned int *size, struct mptcp_out_options *opts); 73 bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, 74 struct mptcp_out_options *opts); 75 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, 76 unsigned int *size, unsigned int remaining, 77 struct mptcp_out_options *opts); 78 void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb, 79 struct tcp_options_received *opt_rx); 80 81 void mptcp_write_options(__be32 *ptr, struct mptcp_out_options *opts); 82 83 /* move the skb extension owership, with the assumption that 'to' is 84 * newly allocated 85 */ 86 static inline void mptcp_skb_ext_move(struct sk_buff *to, 87 struct sk_buff *from) 88 { 89 if (!skb_ext_exist(from, SKB_EXT_MPTCP)) 90 return; 91 92 if (WARN_ON_ONCE(to->active_extensions)) 93 skb_ext_put(to); 94 95 to->active_extensions = from->active_extensions; 96 to->extensions = from->extensions; 97 from->active_extensions = 0; 98 } 99 100 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 101 const struct mptcp_ext *from_ext) 102 { 103 /* MPTCP always clears the ext when adding it to the skb, so 104 * holes do not bother us here 105 */ 106 return !from_ext || 107 (to_ext && from_ext && 108 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 109 } 110 111 /* check if skbs can be collapsed. 112 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 113 * mapping, or if the extension of @to is the same as @from. 114 * Collapsing is not possible if @to lacks an extension, but @from carries one. 115 */ 116 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 117 const struct sk_buff *from) 118 { 119 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 120 skb_ext_find(from, SKB_EXT_MPTCP)); 121 } 122 123 bool mptcp_sk_is_subflow(const struct sock *sk); 124 125 void mptcp_seq_show(struct seq_file *seq); 126 #else 127 128 static inline void mptcp_init(void) 129 { 130 } 131 132 static inline bool sk_is_mptcp(const struct sock *sk) 133 { 134 return false; 135 } 136 137 static inline bool rsk_is_mptcp(const struct request_sock *req) 138 { 139 return false; 140 } 141 142 static inline void mptcp_parse_option(const struct sk_buff *skb, 143 const unsigned char *ptr, int opsize, 144 struct tcp_options_received *opt_rx) 145 { 146 } 147 148 static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 149 unsigned int *size, 150 struct mptcp_out_options *opts) 151 { 152 return false; 153 } 154 155 static inline void mptcp_rcv_synsent(struct sock *sk) 156 { 157 } 158 159 static inline bool mptcp_synack_options(const struct request_sock *req, 160 unsigned int *size, 161 struct mptcp_out_options *opts) 162 { 163 return false; 164 } 165 166 static inline bool mptcp_established_options(struct sock *sk, 167 struct sk_buff *skb, 168 unsigned int *size, 169 unsigned int remaining, 170 struct mptcp_out_options *opts) 171 { 172 return false; 173 } 174 175 static inline void mptcp_incoming_options(struct sock *sk, 176 struct sk_buff *skb, 177 struct tcp_options_received *opt_rx) 178 { 179 } 180 181 static inline void mptcp_skb_ext_move(struct sk_buff *to, 182 const struct sk_buff *from) 183 { 184 } 185 186 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 187 const struct sk_buff *from) 188 { 189 return true; 190 } 191 192 static inline bool mptcp_sk_is_subflow(const struct sock *sk) 193 { 194 return false; 195 } 196 197 static inline void mptcp_seq_show(struct seq_file *seq) { } 198 #endif /* CONFIG_MPTCP */ 199 200 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 201 int mptcpv6_init(void); 202 void mptcpv6_handle_mapped(struct sock *sk, bool mapped); 203 #elif IS_ENABLED(CONFIG_IPV6) 204 static inline int mptcpv6_init(void) { return 0; } 205 static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } 206 #endif 207 208 #endif /* __NET_MPTCP_H */ 209