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 mptcp_info; 16struct mptcp_sock; 17struct seq_file; 18 19/* MPTCP sk_buff extension data */ 20struct mptcp_ext { 21 union { 22 u64 data_ack; 23 u32 data_ack32; 24 }; 25 u64 data_seq; 26 u32 subflow_seq; 27 u16 data_len; 28 __sum16 csum; 29 u8 use_map:1, 30 dsn64:1, 31 data_fin:1, 32 use_ack:1, 33 ack64:1, 34 mpc_map:1, 35 frozen:1, 36 reset_transient:1; 37 u8 reset_reason:4, 38 csum_reqd:1, 39 infinite_map:1; 40}; 41 42#define MPTCPOPT_HMAC_LEN 20 43#define MPTCP_RM_IDS_MAX 8 44 45struct mptcp_rm_list { 46 u8 ids[MPTCP_RM_IDS_MAX]; 47 u8 nr; 48}; 49 50struct mptcp_addr_info { 51 u8 id; 52 sa_family_t family; 53 __be16 port; 54 union { 55 struct in_addr addr; 56#if IS_ENABLED(CONFIG_MPTCP_IPV6) 57 struct in6_addr addr6; 58#endif 59 }; 60}; 61 62struct mptcp_out_options { 63#if IS_ENABLED(CONFIG_MPTCP) 64 u16 suboptions; 65 struct mptcp_rm_list rm_list; 66 u8 join_id; 67 u8 backup; 68 u8 reset_reason:4, 69 reset_transient:1, 70 csum_reqd:1, 71 allow_join_id0:1; 72 union { 73 struct { 74 u64 sndr_key; 75 u64 rcvr_key; 76 u64 data_seq; 77 u32 subflow_seq; 78 u16 data_len; 79 __sum16 csum; 80 }; 81 struct { 82 struct mptcp_addr_info addr; 83 u64 ahmac; 84 }; 85 struct { 86 struct mptcp_ext ext_copy; 87 u64 fail_seq; 88 }; 89 struct { 90 u32 nonce; 91 u32 token; 92 u64 thmac; 93 u8 hmac[MPTCPOPT_HMAC_LEN]; 94 }; 95 }; 96#endif 97}; 98 99#define MPTCP_SCHED_NAME_MAX 16 100#define MPTCP_SUBFLOWS_MAX 8 101 102struct mptcp_sched_data { 103 bool reinject; 104 u8 subflows; 105 struct mptcp_subflow_context *contexts[MPTCP_SUBFLOWS_MAX]; 106}; 107 108struct mptcp_sched_ops { 109 int (*get_subflow)(struct mptcp_sock *msk, 110 struct mptcp_sched_data *data); 111 112 char name[MPTCP_SCHED_NAME_MAX]; 113 struct module *owner; 114 struct list_head list; 115 116 void (*init)(struct mptcp_sock *msk); 117 void (*release)(struct mptcp_sock *msk); 118} ____cacheline_aligned_in_smp; 119 120#ifdef CONFIG_MPTCP 121void mptcp_init(void); 122 123static inline bool sk_is_mptcp(const struct sock *sk) 124{ 125 return tcp_sk(sk)->is_mptcp; 126} 127 128static inline bool rsk_is_mptcp(const struct request_sock *req) 129{ 130 return tcp_rsk(req)->is_mptcp; 131} 132 133static inline bool rsk_drop_req(const struct request_sock *req) 134{ 135 return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req; 136} 137 138void mptcp_space(const struct sock *ssk, int *space, int *full_space); 139bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 140 unsigned int *size, struct mptcp_out_options *opts); 141bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, 142 struct mptcp_out_options *opts); 143bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, 144 unsigned int *size, unsigned int remaining, 145 struct mptcp_out_options *opts); 146bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb); 147 148void mptcp_write_options(struct tcphdr *th, __be32 *ptr, struct tcp_sock *tp, 149 struct mptcp_out_options *opts); 150 151void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info); 152 153/* move the skb extension owership, with the assumption that 'to' is 154 * newly allocated 155 */ 156static inline void mptcp_skb_ext_move(struct sk_buff *to, 157 struct sk_buff *from) 158{ 159 if (!skb_ext_exist(from, SKB_EXT_MPTCP)) 160 return; 161 162 if (WARN_ON_ONCE(to->active_extensions)) 163 skb_ext_put(to); 164 165 to->active_extensions = from->active_extensions; 166 to->extensions = from->extensions; 167 from->active_extensions = 0; 168} 169 170static inline void mptcp_skb_ext_copy(struct sk_buff *to, 171 struct sk_buff *from) 172{ 173 struct mptcp_ext *from_ext; 174 175 from_ext = skb_ext_find(from, SKB_EXT_MPTCP); 176 if (!from_ext) 177 return; 178 179 from_ext->frozen = 1; 180 skb_ext_copy(to, from); 181} 182 183static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 184 const struct mptcp_ext *from_ext) 185{ 186 /* MPTCP always clears the ext when adding it to the skb, so 187 * holes do not bother us here 188 */ 189 return !from_ext || 190 (to_ext && from_ext && 191 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 192} 193 194/* check if skbs can be collapsed. 195 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 196 * mapping, or if the extension of @to is the same as @from. 197 * Collapsing is not possible if @to lacks an extension, but @from carries one. 198 */ 199static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 200 const struct sk_buff *from) 201{ 202 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 203 skb_ext_find(from, SKB_EXT_MPTCP)); 204} 205 206void mptcp_seq_show(struct seq_file *seq); 207int mptcp_subflow_init_cookie_req(struct request_sock *req, 208 const struct sock *sk_listener, 209 struct sk_buff *skb); 210struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops, 211 struct sock *sk_listener, 212 bool attach_listener); 213 214__be32 mptcp_get_reset_option(const struct sk_buff *skb); 215 216static inline __be32 mptcp_reset_option(const struct sk_buff *skb) 217{ 218 if (skb_ext_exist(skb, SKB_EXT_MPTCP)) 219 return mptcp_get_reset_option(skb); 220 221 return htonl(0u); 222} 223#else 224 225static inline void mptcp_init(void) 226{ 227} 228 229static inline bool sk_is_mptcp(const struct sock *sk) 230{ 231 return false; 232} 233 234static inline bool rsk_is_mptcp(const struct request_sock *req) 235{ 236 return false; 237} 238 239static inline bool rsk_drop_req(const struct request_sock *req) 240{ 241 return false; 242} 243 244static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, 245 unsigned int *size, 246 struct mptcp_out_options *opts) 247{ 248 return false; 249} 250 251static inline bool mptcp_synack_options(const struct request_sock *req, 252 unsigned int *size, 253 struct mptcp_out_options *opts) 254{ 255 return false; 256} 257 258static inline bool mptcp_established_options(struct sock *sk, 259 struct sk_buff *skb, 260 unsigned int *size, 261 unsigned int remaining, 262 struct mptcp_out_options *opts) 263{ 264 return false; 265} 266 267static inline bool mptcp_incoming_options(struct sock *sk, 268 struct sk_buff *skb) 269{ 270 return true; 271} 272 273static inline void mptcp_skb_ext_move(struct sk_buff *to, 274 const struct sk_buff *from) 275{ 276} 277 278static inline void mptcp_skb_ext_copy(struct sk_buff *to, 279 struct sk_buff *from) 280{ 281} 282 283static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 284 const struct sk_buff *from) 285{ 286 return true; 287} 288 289static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { } 290static inline void mptcp_seq_show(struct seq_file *seq) { } 291 292static inline int mptcp_subflow_init_cookie_req(struct request_sock *req, 293 const struct sock *sk_listener, 294 struct sk_buff *skb) 295{ 296 return 0; /* TCP fallback */ 297} 298 299static inline struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops, 300 struct sock *sk_listener, 301 bool attach_listener) 302{ 303 return NULL; 304} 305 306static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); } 307#endif /* CONFIG_MPTCP */ 308 309#if IS_ENABLED(CONFIG_MPTCP_IPV6) 310int mptcpv6_init(void); 311void mptcpv6_handle_mapped(struct sock *sk, bool mapped); 312#elif IS_ENABLED(CONFIG_IPV6) 313static inline int mptcpv6_init(void) { return 0; } 314static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } 315#endif 316 317#if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL) 318struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk); 319#else 320static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) { return NULL; } 321#endif 322 323#if !IS_ENABLED(CONFIG_MPTCP) 324struct mptcp_sock { }; 325#endif 326 327#endif /* __NET_MPTCP_H */ 328