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