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 void mptcp_parse_option(const struct sk_buff *skb, const unsigned char *ptr,
  72                         int opsize, struct tcp_options_received *opt_rx);
  73 bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
  74                        unsigned int *size, struct mptcp_out_options *opts);
  75 void mptcp_rcv_synsent(struct sock *sk);
  76 bool mptcp_synack_options(const struct request_sock *req, unsigned int *size,
  77                           struct mptcp_out_options *opts);
  78 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
  79                                unsigned int *size, unsigned int remaining,
  80                                struct mptcp_out_options *opts);
  81 void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb,
  82                             struct tcp_options_received *opt_rx);
  83
  84 void mptcp_write_options(__be32 *ptr, struct mptcp_out_options *opts);
  85
  86 /* move the skb extension owership, with the assumption that 'to' is
  87  * newly allocated
  88  */
  89 static inline void mptcp_skb_ext_move(struct sk_buff *to,
  90                                       struct sk_buff *from)
  91 {
  92         if (!skb_ext_exist(from, SKB_EXT_MPTCP))
  93                 return;
  94
  95         if (WARN_ON_ONCE(to->active_extensions))
  96                 skb_ext_put(to);
  97
  98         to->active_extensions = from->active_extensions;
  99         to->extensions = from->extensions;
 100         from->active_extensions = 0;
 101 }
 102
 103 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext,
 104                                      const struct mptcp_ext *from_ext)
 105 {
 106         /* MPTCP always clears the ext when adding it to the skb, so
 107          * holes do not bother us here
 108          */
 109         return !from_ext ||
 110                (to_ext && from_ext &&
 111                 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext)));
 112 }
 113
 114 /* check if skbs can be collapsed.
 115  * MPTCP collapse is allowed if neither @to or @from carry an mptcp data
 116  * mapping, or if the extension of @to is the same as @from.
 117  * Collapsing is not possible if @to lacks an extension, but @from carries one.
 118  */
 119 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
 120                                           const struct sk_buff *from)
 121 {
 122         return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP),
 123                                  skb_ext_find(from, SKB_EXT_MPTCP));
 124 }
 125
 126 bool mptcp_sk_is_subflow(const struct sock *sk);
 127
 128 void mptcp_seq_show(struct seq_file *seq);
 129 #else
 130
 131 static inline void mptcp_init(void)
 132 {
 133 }
 134
 135 static inline bool sk_is_mptcp(const struct sock *sk)
 136 {
 137         return false;
 138 }
 139
 140 static inline bool rsk_is_mptcp(const struct request_sock *req)
 141 {
 142         return false;
 143 }
 144
 145 static inline void mptcp_parse_option(const struct sk_buff *skb,
 146                                       const unsigned char *ptr, int opsize,
 147                                       struct tcp_options_received *opt_rx)
 148 {
 149 }
 150
 151 static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
 152                                      unsigned int *size,
 153                                      struct mptcp_out_options *opts)
 154 {
 155         return false;
 156 }
 157
 158 static inline void mptcp_rcv_synsent(struct sock *sk)
 159 {
 160 }
 161
 162 static inline bool mptcp_synack_options(const struct request_sock *req,
 163                                         unsigned int *size,
 164                                         struct mptcp_out_options *opts)
 165 {
 166         return false;
 167 }
 168
 169 static inline bool mptcp_established_options(struct sock *sk,
 170                                              struct sk_buff *skb,
 171                                              unsigned int *size,
 172                                              unsigned int remaining,
 173                                              struct mptcp_out_options *opts)
 174 {
 175         return false;
 176 }
 177
 178 static inline void mptcp_incoming_options(struct sock *sk,
 179                                           struct sk_buff *skb,
 180                                           struct tcp_options_received *opt_rx)
 181 {
 182 }
 183
 184 static inline void mptcp_skb_ext_move(struct sk_buff *to,
 185                                       const struct sk_buff *from)
 186 {
 187 }
 188
 189 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
 190                                           const struct sk_buff *from)
 191 {
 192         return true;
 193 }
 194
 195 static inline bool mptcp_sk_is_subflow(const struct sock *sk)
 196 {
 197         return false;
 198 }
 199
 200 static inline void mptcp_seq_show(struct seq_file *seq) { }
 201 #endif /* CONFIG_MPTCP */
 202
 203 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 204 int mptcpv6_init(void);
 205 void mptcpv6_handle_mapped(struct sock *sk, bool mapped);
 206 #elif IS_ENABLED(CONFIG_IPV6)
 207 static inline int mptcpv6_init(void) { return 0; }
 208 static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { }
 209 #endif
 210
 211 #endif /* __NET_MPTCP_H */