include/net/mptcp.h

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