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