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 15struct seq_file; 16 17/* MPTCP sk_buff extension data */ 18struct mptcp_ext { 19 union { 20 u64 data_ack; 21 u32 data_ack32; 22 }; 23 u64 data_seq; 24 u32 subflow_seq; 25 u16 data_len; 26 u8 use_map:1, 27 dsn64:1, 28 data_fin:1, 29 use_ack:1, 30 ack64:1, 31 mpc_map:1, 32 __unused:2; 33 /* one byte hole */ 34}; 35 36struct mptcp_out_options { 37#if IS_ENABLED(CONFIG_MPTCP) 38 u16 suboptions; 39 u64 sndr_key; 40 u64 rcvr_key; 41 union { 42 struct in_addr addr; 43#if IS_ENABLED(CONFIG_MPTCP_IPV6) 44 struct in6_addr addr6; 45#endif 46 }; 47 u8 addr_id; 48 u64 ahmac; 49 u8 rm_id; 50 u8 join_id; 51 u8 backup; 52 u32 nonce; 53 u64 thmac; 54 u32 token; 55 u8 hmac[20]; 56 struct mptcp_ext ext_copy; 57#endif 58}; 59 60#ifdef CONFIG_MPTCP 61void mptcp_init(void); 62 63static inline bool sk_is_mptcp(const struct sock *sk) 64{ 65 return tcp_sk(sk)->is_mptcp; 66} 67 68static inline bool rsk_is_mptcp(const struct request_sock *req) 69{ 70 return tcp_rsk(req)->is_mptcp; 71} 72 73static inline bool rsk_drop_req(const struct request_sock *req) 74{ 75 return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req; 76} 77 78void mptcp_space(const struct sock *ssk, int *space, int *full_space); 79bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 80 unsigned int *size, struct mptcp_out_options *opts); 81bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, 82 struct mptcp_out_options *opts); 83bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, 84 unsigned int *size, unsigned int remaining, 85 struct mptcp_out_options *opts); 86void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb); 87 88void mptcp_write_options(__be32 *ptr, struct mptcp_out_options *opts); 89 90/* move the skb extension owership, with the assumption that 'to' is 91 * newly allocated 92 */ 93static inline void mptcp_skb_ext_move(struct sk_buff *to, 94 struct sk_buff *from) 95{ 96 if (!skb_ext_exist(from, SKB_EXT_MPTCP)) 97 return; 98 99 if (WARN_ON_ONCE(to->active_extensions)) 100 skb_ext_put(to); 101 102 to->active_extensions = from->active_extensions; 103 to->extensions = from->extensions; 104 from->active_extensions = 0; 105} 106 107static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 108 const struct mptcp_ext *from_ext) 109{ 110 /* MPTCP always clears the ext when adding it to the skb, so 111 * holes do not bother us here 112 */ 113 return !from_ext || 114 (to_ext && from_ext && 115 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 116} 117 118/* check if skbs can be collapsed. 119 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 120 * mapping, or if the extension of @to is the same as @from. 121 * Collapsing is not possible if @to lacks an extension, but @from carries one. 122 */ 123static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 124 const struct sk_buff *from) 125{ 126 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 127 skb_ext_find(from, SKB_EXT_MPTCP)); 128} 129 130void mptcp_seq_show(struct seq_file *seq); 131int mptcp_subflow_init_cookie_req(struct request_sock *req, 132 const struct sock *sk_listener, 133 struct sk_buff *skb); 134struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops, 135 struct sock *sk_listener, 136 bool attach_listener); 137#else 138 139static inline void mptcp_init(void) 140{ 141} 142 143static inline bool sk_is_mptcp(const struct sock *sk) 144{ 145 return false; 146} 147 148static inline bool rsk_is_mptcp(const struct request_sock *req) 149{ 150 return false; 151} 152 153static inline bool rsk_drop_req(const struct request_sock *req) 154{ 155 return false; 156} 157 158static inline void mptcp_parse_option(const struct sk_buff *skb, 159 const unsigned char *ptr, int opsize, 160 struct tcp_options_received *opt_rx) 161{ 162} 163 164static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 165 unsigned int *size, 166 struct mptcp_out_options *opts) 167{ 168 return false; 169} 170 171static inline bool mptcp_synack_options(const struct request_sock *req, 172 unsigned int *size, 173 struct mptcp_out_options *opts) 174{ 175 return false; 176} 177 178static inline bool mptcp_established_options(struct sock *sk, 179 struct sk_buff *skb, 180 unsigned int *size, 181 unsigned int remaining, 182 struct mptcp_out_options *opts) 183{ 184 return false; 185} 186 187static inline void mptcp_incoming_options(struct sock *sk, 188 struct sk_buff *skb) 189{ 190} 191 192static inline void mptcp_skb_ext_move(struct sk_buff *to, 193 const struct sk_buff *from) 194{ 195} 196 197static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 198 const struct sk_buff *from) 199{ 200 return true; 201} 202 203static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { } 204static inline void mptcp_seq_show(struct seq_file *seq) { } 205 206static inline int mptcp_subflow_init_cookie_req(struct request_sock *req, 207 const struct sock *sk_listener, 208 struct sk_buff *skb) 209{ 210 return 0; /* TCP fallback */ 211} 212 213static inline struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops, 214 struct sock *sk_listener, 215 bool attach_listener) 216{ 217 return NULL; 218} 219#endif /* CONFIG_MPTCP */ 220 221#if IS_ENABLED(CONFIG_MPTCP_IPV6) 222int mptcpv6_init(void); 223void mptcpv6_handle_mapped(struct sock *sk, bool mapped); 224#elif IS_ENABLED(CONFIG_IPV6) 225static inline int mptcpv6_init(void) { return 0; } 226static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } 227#endif 228 229#endif /* __NET_MPTCP_H */ 230