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 __unused:3; 27 /* one byte hole */ 28 }; 29 30 struct mptcp_out_options { 31 #if IS_ENABLED(CONFIG_MPTCP) 32 u16 suboptions; 33 u64 sndr_key; 34 u64 rcvr_key; 35 struct mptcp_ext ext_copy; 36 #endif 37 }; 38 39 #ifdef CONFIG_MPTCP 40 41 void mptcp_init(void); 42 43 static inline bool sk_is_mptcp(const struct sock *sk) 44 { 45 return tcp_sk(sk)->is_mptcp; 46 } 47 48 static inline bool rsk_is_mptcp(const struct request_sock *req) 49 { 50 return tcp_rsk(req)->is_mptcp; 51 } 52 53 void mptcp_parse_option(const unsigned char *ptr, int opsize, 54 struct tcp_options_received *opt_rx); 55 bool mptcp_syn_options(struct sock *sk, unsigned int *size, 56 struct mptcp_out_options *opts); 57 void mptcp_rcv_synsent(struct sock *sk); 58 bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, 59 struct mptcp_out_options *opts); 60 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, 61 unsigned int *size, unsigned int remaining, 62 struct mptcp_out_options *opts); 63 64 void mptcp_write_options(__be32 *ptr, struct mptcp_out_options *opts); 65 66 /* move the skb extension owership, with the assumption that 'to' is 67 * newly allocated 68 */ 69 static inline void mptcp_skb_ext_move(struct sk_buff *to, 70 struct sk_buff *from) 71 { 72 if (!skb_ext_exist(from, SKB_EXT_MPTCP)) 73 return; 74 75 if (WARN_ON_ONCE(to->active_extensions)) 76 skb_ext_put(to); 77 78 to->active_extensions = from->active_extensions; 79 to->extensions = from->extensions; 80 from->active_extensions = 0; 81 } 82 83 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 84 const struct mptcp_ext *from_ext) 85 { 86 /* MPTCP always clears the ext when adding it to the skb, so 87 * holes do not bother us here 88 */ 89 return !from_ext || 90 (to_ext && from_ext && 91 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 92 } 93 94 /* check if skbs can be collapsed. 95 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 96 * mapping, or if the extension of @to is the same as @from. 97 * Collapsing is not possible if @to lacks an extension, but @from carries one. 98 */ 99 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 100 const struct sk_buff *from) 101 { 102 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 103 skb_ext_find(from, SKB_EXT_MPTCP)); 104 } 105 106 #else 107 108 static inline void mptcp_init(void) 109 { 110 } 111 112 static inline bool sk_is_mptcp(const struct sock *sk) 113 { 114 return false; 115 } 116 117 static inline bool rsk_is_mptcp(const struct request_sock *req) 118 { 119 return false; 120 } 121 122 static inline void mptcp_parse_option(const unsigned char *ptr, int opsize, 123 struct tcp_options_received *opt_rx) 124 { 125 } 126 127 static inline bool mptcp_syn_options(struct sock *sk, unsigned int *size, 128 struct mptcp_out_options *opts) 129 { 130 return false; 131 } 132 133 static inline void mptcp_rcv_synsent(struct sock *sk) 134 { 135 } 136 137 static inline bool mptcp_synack_options(const struct request_sock *req, 138 unsigned int *size, 139 struct mptcp_out_options *opts) 140 { 141 return false; 142 } 143 144 static inline bool mptcp_established_options(struct sock *sk, 145 struct sk_buff *skb, 146 unsigned int *size, 147 unsigned int remaining, 148 struct mptcp_out_options *opts) 149 { 150 return false; 151 } 152 153 static inline void mptcp_skb_ext_move(struct sk_buff *to, 154 const struct sk_buff *from) 155 { 156 } 157 158 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 159 const struct sk_buff *from) 160 { 161 return true; 162 } 163 164 #endif /* CONFIG_MPTCP */ 165 166 void mptcp_handle_ipv6_mapped(struct sock *sk, bool mapped); 167 168 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 169 int mptcpv6_init(void); 170 #elif IS_ENABLED(CONFIG_IPV6) 171 static inline int mptcpv6_init(void) 172 { 173 return 0; 174 } 175 #endif 176 177 #endif /* __NET_MPTCP_H */ 178