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 /* MPTCP sk_buff extension data */ 16 struct mptcp_ext { 17 u64 data_ack; 18 u64 data_seq; 19 u32 subflow_seq; 20 u16 data_len; 21 u8 use_map:1, 22 dsn64:1, 23 data_fin:1, 24 use_ack:1, 25 ack64:1, 26 mpc_map:1, 27 __unused:2; 28 /* one byte hole */ 29 }; 30 31 struct mptcp_out_options { 32 #if IS_ENABLED(CONFIG_MPTCP) 33 u16 suboptions; 34 u64 sndr_key; 35 u64 rcvr_key; 36 struct mptcp_ext ext_copy; 37 #endif 38 }; 39 40 #ifdef CONFIG_MPTCP 41 42 void mptcp_init(void); 43 44 static inline bool sk_is_mptcp(const struct sock *sk) 45 { 46 return tcp_sk(sk)->is_mptcp; 47 } 48 49 static inline bool rsk_is_mptcp(const struct request_sock *req) 50 { 51 return tcp_rsk(req)->is_mptcp; 52 } 53 54 void mptcp_parse_option(const struct sk_buff *skb, const unsigned char *ptr, 55 int opsize, struct tcp_options_received *opt_rx); 56 bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 57 unsigned int *size, struct mptcp_out_options *opts); 58 void mptcp_rcv_synsent(struct sock *sk); 59 bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, 60 struct mptcp_out_options *opts); 61 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, 62 unsigned int *size, unsigned int remaining, 63 struct mptcp_out_options *opts); 64 void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb, 65 struct tcp_options_received *opt_rx); 66 67 void mptcp_write_options(__be32 *ptr, struct mptcp_out_options *opts); 68 69 /* move the skb extension owership, with the assumption that 'to' is 70 * newly allocated 71 */ 72 static inline void mptcp_skb_ext_move(struct sk_buff *to, 73 struct sk_buff *from) 74 { 75 if (!skb_ext_exist(from, SKB_EXT_MPTCP)) 76 return; 77 78 if (WARN_ON_ONCE(to->active_extensions)) 79 skb_ext_put(to); 80 81 to->active_extensions = from->active_extensions; 82 to->extensions = from->extensions; 83 from->active_extensions = 0; 84 } 85 86 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 87 const struct mptcp_ext *from_ext) 88 { 89 /* MPTCP always clears the ext when adding it to the skb, so 90 * holes do not bother us here 91 */ 92 return !from_ext || 93 (to_ext && from_ext && 94 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 95 } 96 97 /* check if skbs can be collapsed. 98 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 99 * mapping, or if the extension of @to is the same as @from. 100 * Collapsing is not possible if @to lacks an extension, but @from carries one. 101 */ 102 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 103 const struct sk_buff *from) 104 { 105 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 106 skb_ext_find(from, SKB_EXT_MPTCP)); 107 } 108 109 #else 110 111 static inline void mptcp_init(void) 112 { 113 } 114 115 static inline bool sk_is_mptcp(const struct sock *sk) 116 { 117 return false; 118 } 119 120 static inline bool rsk_is_mptcp(const struct request_sock *req) 121 { 122 return false; 123 } 124 125 static inline void mptcp_parse_option(const struct sk_buff *skb, 126 const unsigned char *ptr, int opsize, 127 struct tcp_options_received *opt_rx) 128 { 129 } 130 131 static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 132 unsigned int *size, 133 struct mptcp_out_options *opts) 134 { 135 return false; 136 } 137 138 static inline void mptcp_rcv_synsent(struct sock *sk) 139 { 140 } 141 142 static inline bool mptcp_synack_options(const struct request_sock *req, 143 unsigned int *size, 144 struct mptcp_out_options *opts) 145 { 146 return false; 147 } 148 149 static inline bool mptcp_established_options(struct sock *sk, 150 struct sk_buff *skb, 151 unsigned int *size, 152 unsigned int remaining, 153 struct mptcp_out_options *opts) 154 { 155 return false; 156 } 157 158 static inline void mptcp_incoming_options(struct sock *sk, 159 struct sk_buff *skb, 160 struct tcp_options_received *opt_rx) 161 { 162 } 163 164 static inline void mptcp_skb_ext_move(struct sk_buff *to, 165 const struct sk_buff *from) 166 { 167 } 168 169 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 170 const struct sk_buff *from) 171 { 172 return true; 173 } 174 175 #endif /* CONFIG_MPTCP */ 176 177 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 178 int mptcpv6_init(void); 179 void mptcpv6_handle_mapped(struct sock *sk, bool mapped); 180 #elif IS_ENABLED(CONFIG_IPV6) 181 static inline int mptcpv6_init(void) { return 0; } 182 static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } 183 #endif 184 185 #endif /* __NET_MPTCP_H */ 186