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 void mptcp_parse_option(const unsigned char *ptr, int opsize, 43 struct tcp_options_received *opt_rx); 44 void mptcp_write_options(__be32 *ptr, struct mptcp_out_options *opts); 45 46 /* move the skb extension owership, with the assumption that 'to' is 47 * newly allocated 48 */ 49 static inline void mptcp_skb_ext_move(struct sk_buff *to, 50 struct sk_buff *from) 51 { 52 if (!skb_ext_exist(from, SKB_EXT_MPTCP)) 53 return; 54 55 if (WARN_ON_ONCE(to->active_extensions)) 56 skb_ext_put(to); 57 58 to->active_extensions = from->active_extensions; 59 to->extensions = from->extensions; 60 from->active_extensions = 0; 61 } 62 63 static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, 64 const struct mptcp_ext *from_ext) 65 { 66 /* MPTCP always clears the ext when adding it to the skb, so 67 * holes do not bother us here 68 */ 69 return !from_ext || 70 (to_ext && from_ext && 71 !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); 72 } 73 74 /* check if skbs can be collapsed. 75 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data 76 * mapping, or if the extension of @to is the same as @from. 77 * Collapsing is not possible if @to lacks an extension, but @from carries one. 78 */ 79 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 80 const struct sk_buff *from) 81 { 82 return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), 83 skb_ext_find(from, SKB_EXT_MPTCP)); 84 } 85 86 #else 87 88 static inline void mptcp_init(void) 89 { 90 } 91 92 static inline void mptcp_parse_option(const unsigned char *ptr, int opsize, 93 struct tcp_options_received *opt_rx) 94 { 95 } 96 97 static inline void mptcp_skb_ext_move(struct sk_buff *to, 98 const struct sk_buff *from) 99 { 100 } 101 102 static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, 103 const struct sk_buff *from) 104 { 105 return true; 106 } 107 108 #endif /* CONFIG_MPTCP */ 109 110 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 111 int mptcpv6_init(void); 112 #elif IS_ENABLED(CONFIG_IPV6) 113 static inline int mptcpv6_init(void) 114 { 115 return 0; 116 } 117 #endif 118 119 #endif /* __NET_MPTCP_H */ 120