/* * INET An implementation of the TCP/IP protocol suite for the LINUX * operating system. INET is implemented using the BSD Socket * interface as the means of communication with the user level. * * Definitions for the TCP protocol. * * Version: @(#)tcp.h 1.0.2 04/28/93 * * Author: Fred N. van Kempen, * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #ifndef _UAPI_LINUX_TCP_H #define _UAPI_LINUX_TCP_H #include #include #include struct tcphdr { __be16 source; __be16 dest; __be32 seq; __be32 ack_seq; #if defined(__LITTLE_ENDIAN_BITFIELD) __u16 res1:4, doff:4, fin:1, syn:1, rst:1, psh:1, ack:1, urg:1, ece:1, cwr:1; #elif defined(__BIG_ENDIAN_BITFIELD) __u16 doff:4, res1:4, cwr:1, ece:1, urg:1, ack:1, psh:1, rst:1, syn:1, fin:1; #else #error "Adjust your defines" #endif __be16 window; __sum16 check; __be16 urg_ptr; }; /* * The union cast uses a gcc extension to avoid aliasing problems * (union is compatible to any of its members) * This means this part of the code is -fstrict-aliasing safe now. */ union tcp_word_hdr { struct tcphdr hdr; __be32 words[5]; }; #define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3]) enum { TCP_FLAG_CWR = __constant_cpu_to_be32(0x00800000), TCP_FLAG_ECE = __constant_cpu_to_be32(0x00400000), TCP_FLAG_URG = __constant_cpu_to_be32(0x00200000), TCP_FLAG_ACK = __constant_cpu_to_be32(0x00100000), TCP_FLAG_PSH = __constant_cpu_to_be32(0x00080000), TCP_FLAG_RST = __constant_cpu_to_be32(0x00040000), TCP_FLAG_SYN = __constant_cpu_to_be32(0x00020000), TCP_FLAG_FIN = __constant_cpu_to_be32(0x00010000), TCP_RESERVED_BITS = __constant_cpu_to_be32(0x0F000000), TCP_DATA_OFFSET = __constant_cpu_to_be32(0xF0000000) }; /* * TCP general constants */ #define TCP_MSS_DEFAULT 536U /* IPv4 (RFC1122, RFC2581) */ #define TCP_MSS_DESIRED 1220U /* IPv6 (tunneled), EDNS0 (RFC3226) */ /* TCP socket options */ #define TCP_NODELAY 1 /* Turn off Nagle's algorithm. */ #define TCP_MAXSEG 2 /* Limit MSS */ #define TCP_CORK 3 /* Never send partially complete segments */ #define TCP_KEEPIDLE 4 /* Start keeplives after this period */ #define TCP_KEEPINTVL 5 /* Interval between keepalives */ #define TCP_KEEPCNT 6 /* Number of keepalives before death */ #define TCP_SYNCNT 7 /* Number of SYN retransmits */ #define TCP_LINGER2 8 /* Life time of orphaned FIN-WAIT-2 state */ #define TCP_DEFER_ACCEPT 9 /* Wake up listener only when data arrive */ #define TCP_WINDOW_CLAMP 10 /* Bound advertised window */ #define TCP_INFO 11 /* Information about this connection. */ #define TCP_QUICKACK 12 /* Block/reenable quick acks */ #define TCP_CONGESTION 13 /* Congestion control algorithm */ #define TCP_MD5SIG 14 /* TCP MD5 Signature (RFC2385) */ #define TCP_THIN_LINEAR_TIMEOUTS 16 /* Use linear timeouts for thin streams*/ #define TCP_THIN_DUPACK 17 /* Fast retrans. after 1 dupack */ #define TCP_USER_TIMEOUT 18 /* How long for loss retry before timeout */ #define TCP_REPAIR 19 /* TCP sock is under repair right now */ #define TCP_REPAIR_QUEUE 20 #define TCP_QUEUE_SEQ 21 #define TCP_REPAIR_OPTIONS 22 #define TCP_FASTOPEN 23 /* Enable FastOpen on listeners */ #define TCP_TIMESTAMP 24 #define TCP_NOTSENT_LOWAT 25 /* limit number of unsent bytes in write queue */ #define TCP_CC_INFO 26 /* Get Congestion Control (optional) info */ #define TCP_SAVE_SYN 27 /* Record SYN headers for new connections */ #define TCP_SAVED_SYN 28 /* Get SYN headers recorded for connection */ #define TCP_REPAIR_WINDOW 29 /* Get/set window parameters */ #define TCP_FASTOPEN_CONNECT 30 /* Attempt FastOpen with connect */ #define TCP_ULP 31 /* Attach a ULP to a TCP connection */ #define TCP_MD5SIG_EXT 32 /* TCP MD5 Signature with extensions */ #define TCP_FASTOPEN_KEY 33 /* Set the key for Fast Open (cookie) */ #define TCP_FASTOPEN_NO_COOKIE 34 /* Enable TFO without a TFO cookie */ struct tcp_repair_opt { __u32 opt_code; __u32 opt_val; }; struct tcp_repair_window { __u32 snd_wl1; __u32 snd_wnd; __u32 max_window; __u32 rcv_wnd; __u32 rcv_wup; }; enum { TCP_NO_QUEUE, TCP_RECV_QUEUE, TCP_SEND_QUEUE, TCP_QUEUES_NR, }; /* for TCP_INFO socket option */ #define TCPI_OPT_TIMESTAMPS 1 #define TCPI_OPT_SACK 2 #define TCPI_OPT_WSCALE 4 #define TCPI_OPT_ECN 8 /* ECN was negociated at TCP session init */ #define TCPI_OPT_ECN_SEEN 16 /* we received at least one packet with ECT */ #define TCPI_OPT_SYN_DATA 32 /* SYN-ACK acked data in SYN sent or rcvd */ enum tcp_ca_state { TCP_CA_Open = 0, #define TCPF_CA_Open (1<