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 void mptcp_parse_option(const struct sk_buff *skb, const unsigned char *ptr, 72 int opsize, struct tcp_options_received *opt_rx); 73 bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 74 unsigned int *size, struct mptcp_out_options *opts); 75 void mptcp_rcv_synsent(struct sock *sk); 76 bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, 77 struct mptcp_out_options *opts); 78 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, 79 unsigned int *size, unsigned int remaining, 80 struct mptcp_out_options *opts); 81 void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb, 82 struct tcp_options_received *opt_rx); 83 84 void mptcp_write_options(__be32 *ptr, struct mptcp_out_options *opts); 85 86 /* move the skb extension owership, with the assumption that 'to' is 87 * newly allocated 88 */ 89 static inline void mptcp_skb_ext_move(struct sk_buff *to, 90 struct sk_buff *from) 91 { 92 if (!skb_ext_exist(from, SKB_EXT_MPTCP)) 93 return; 94 95 if (WARN_ON_ONCE(to->active_extensions)) 96 skb_ext_put(to); 97 98 to->active_extensions = from->active_extensions; 99 to->extensions = from->extensions; 100 from->active_extensions = 0; 101 } 102 103 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 104 const struct mptcp_ext *from_ext) 105 { 106 /* MPTCP always clears the ext when adding it to the skb, so 107 * holes do not bother us here 108 */ 109 return !from_ext || 110 (to_ext && from_ext && 111 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 112 } 113 114 /* check if skbs can be collapsed. 115 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 116 * mapping, or if the extension of @to is the same as @from. 117 * Collapsing is not possible if @to lacks an extension, but @from carries one. 118 */ 119 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 120 const struct sk_buff *from) 121 { 122 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 123 skb_ext_find(from, SKB_EXT_MPTCP)); 124 } 125 126 bool mptcp_sk_is_subflow(const struct sock *sk); 127 128 void mptcp_seq_show(struct seq_file *seq); 129 #else 130 131 static inline void mptcp_init(void) 132 { 133 } 134 135 static inline bool sk_is_mptcp(const struct sock *sk) 136 { 137 return false; 138 } 139 140 static inline bool rsk_is_mptcp(const struct request_sock *req) 141 { 142 return false; 143 } 144 145 static inline void mptcp_parse_option(const struct sk_buff *skb, 146 const unsigned char *ptr, int opsize, 147 struct tcp_options_received *opt_rx) 148 { 149 } 150 151 static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 152 unsigned int *size, 153 struct mptcp_out_options *opts) 154 { 155 return false; 156 } 157 158 static inline void mptcp_rcv_synsent(struct sock *sk) 159 { 160 } 161 162 static inline bool mptcp_synack_options(const struct request_sock *req, 163 unsigned int *size, 164 struct mptcp_out_options *opts) 165 { 166 return false; 167 } 168 169 static inline bool mptcp_established_options(struct sock *sk, 170 struct sk_buff *skb, 171 unsigned int *size, 172 unsigned int remaining, 173 struct mptcp_out_options *opts) 174 { 175 return false; 176 } 177 178 static inline void mptcp_incoming_options(struct sock *sk, 179 struct sk_buff *skb, 180 struct tcp_options_received *opt_rx) 181 { 182 } 183 184 static inline void mptcp_skb_ext_move(struct sk_buff *to, 185 const struct sk_buff *from) 186 { 187 } 188 189 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 190 const struct sk_buff *from) 191 { 192 return true; 193 } 194 195 static inline bool mptcp_sk_is_subflow(const struct sock *sk) 196 { 197 return false; 198 } 199 200 static inline void mptcp_seq_show(struct seq_file *seq) { } 201 #endif /* CONFIG_MPTCP */ 202 203 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 204 int mptcpv6_init(void); 205 void mptcpv6_handle_mapped(struct sock *sk, bool mapped); 206 #elif IS_ENABLED(CONFIG_IPV6) 207 static inline int mptcpv6_init(void) { return 0; } 208 static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } 209 #endif 210 211 #endif /* __NET_MPTCP_H */ 212