xref: /aosp_15_r20/external/iproute2/include/netinet/tcp.h (revision de1e4e894b0c224df933550f0afdecc354b238c4)

/*
 * Copyright (c) 1982, 1986, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)tcp.h	8.1 (Berkeley) 6/10/93
 */

#ifndef _NETINET_TCP_H
#define _NETINET_TCP_H	1

#include <features.h>

/*
 * User-settable options (used with setsockopt).
 */
#define	TCP_NODELAY	 1	/* Don't delay send to coalesce packets  */
#define	TCP_MAXSEG	 2	/* Set maximum segment size  */
#define TCP_CORK	 3	/* Control sending of partial frames  */
#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	/* Bock/reenable quick ACKs.  */
#define TCP_CONGESTION	 13	/* Congestion control algorithm.  */

#ifdef __USE_MISC
# include <sys/types.h>

# ifdef __FAVOR_BSD
typedef	u_int32_t tcp_seq;
/*
 * TCP header.
 * Per RFC 793, September, 1981.
 */
struct tcphdr
  {
    u_int16_t th_sport;		/* source port */
    u_int16_t th_dport;		/* destination port */
    tcp_seq th_seq;		/* sequence number */
    tcp_seq th_ack;		/* acknowledgement number */
#  if __BYTE_ORDER == __LITTLE_ENDIAN
    u_int8_t th_x2:4;		/* (unused) */
    u_int8_t th_off:4;		/* data offset */
#  endif
#  if __BYTE_ORDER == __BIG_ENDIAN
    u_int8_t th_off:4;		/* data offset */
    u_int8_t th_x2:4;		/* (unused) */
#  endif
    u_int8_t th_flags;
#  define TH_FIN	0x01
#  define TH_SYN	0x02
#  define TH_RST	0x04
#  define TH_PUSH	0x08
#  define TH_ACK	0x10
#  define TH_URG	0x20
    u_int16_t th_win;		/* window */
    u_int16_t th_sum;		/* checksum */
    u_int16_t th_urp;		/* urgent pointer */
};

# else /* !__FAVOR_BSD */
struct tcphdr
  {
    u_int16_t source;
    u_int16_t dest;
    u_int32_t seq;
    u_int32_t ack_seq;
#  if __BYTE_ORDER == __LITTLE_ENDIAN
    u_int16_t res1:4;
    u_int16_t doff:4;
    u_int16_t fin:1;
    u_int16_t syn:1;
    u_int16_t rst:1;
    u_int16_t psh:1;
    u_int16_t ack:1;
    u_int16_t urg:1;
    u_int16_t res2:2;
#  elif __BYTE_ORDER == __BIG_ENDIAN
    u_int16_t doff:4;
    u_int16_t res1:4;
    u_int16_t res2:2;
    u_int16_t urg:1;
    u_int16_t ack:1;
    u_int16_t psh:1;
    u_int16_t rst:1;
    u_int16_t syn:1;
    u_int16_t fin:1;
#  else
#   error "Adjust your <bits/endian.h> defines"
#  endif
    u_int16_t window;
    u_int16_t check;
    u_int16_t urg_ptr;
};
# endif /* __FAVOR_BSD */

enum
{
  TCP_ESTABLISHED = 1,
  TCP_SYN_SENT,
  TCP_SYN_RECV,
  TCP_FIN_WAIT1,
  TCP_FIN_WAIT2,
  TCP_TIME_WAIT,
  TCP_CLOSE,
  TCP_CLOSE_WAIT,
  TCP_LAST_ACK,
  TCP_LISTEN,
  TCP_CLOSING   /* now a valid state */
};

# define TCPOPT_EOL		0
# define TCPOPT_NOP		1
# define TCPOPT_MAXSEG		2
# define TCPOLEN_MAXSEG		4
# define TCPOPT_WINDOW		3
# define TCPOLEN_WINDOW		3
# define TCPOPT_SACK_PERMITTED	4		/* Experimental */
# define TCPOLEN_SACK_PERMITTED	2
# define TCPOPT_SACK		5		/* Experimental */
# define TCPOPT_TIMESTAMP	8
# define TCPOLEN_TIMESTAMP	10
# define TCPOLEN_TSTAMP_APPA	(TCPOLEN_TIMESTAMP+2) /* appendix A */

# define TCPOPT_TSTAMP_HDR	\
    (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)

/*
 * Default maximum segment size for TCP.
 * With an IP MSS of 576, this is 536,
 * but 512 is probably more convenient.
 * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)).
 */
# define TCP_MSS	512

# define TCP_MAXWIN	65535	/* largest value for (unscaled) window */

# define TCP_MAX_WINSHIFT	14	/* maximum window shift */

# define SOL_TCP		6	/* TCP level */


# define TCPI_OPT_TIMESTAMPS	1
# define TCPI_OPT_SACK		2
# define TCPI_OPT_WSCALE	4
# define TCPI_OPT_ECN		8
# define TCPI_OPT_ECN_SEEN	16

/* Values for tcpi_state.  */
enum tcp_ca_state
{
  TCP_CA_Open = 0,
  TCP_CA_Disorder = 1,
  TCP_CA_CWR = 2,
  TCP_CA_Recovery = 3,
  TCP_CA_Loss = 4
};

struct tcp_info
{
  u_int8_t	tcpi_state;
  u_int8_t	tcpi_ca_state;
  u_int8_t	tcpi_retransmits;
  u_int8_t	tcpi_probes;
  u_int8_t	tcpi_backoff;
  u_int8_t	tcpi_options;
  u_int8_t	tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4;

  u_int32_t	tcpi_rto;
  u_int32_t	tcpi_ato;
  u_int32_t	tcpi_snd_mss;
  u_int32_t	tcpi_rcv_mss;

  u_int32_t	tcpi_unacked;
  u_int32_t	tcpi_sacked;
  u_int32_t	tcpi_lost;
  u_int32_t	tcpi_retrans;
  u_int32_t	tcpi_fackets;

  /* Times. */
  u_int32_t	tcpi_last_data_sent;
  u_int32_t	tcpi_last_ack_sent;	/* Not remembered, sorry.  */
  u_int32_t	tcpi_last_data_recv;
  u_int32_t	tcpi_last_ack_recv;

  /* Metrics. */
  u_int32_t	tcpi_pmtu;
  u_int32_t	tcpi_rcv_ssthresh;
  u_int32_t	tcpi_rtt;
  u_int32_t	tcpi_rttvar;
  u_int32_t	tcpi_snd_ssthresh;
  u_int32_t	tcpi_snd_cwnd;
  u_int32_t	tcpi_advmss;
  u_int32_t	tcpi_reordering;
  u_int32_t	tcpi_rcv_rtt;
  u_int32_t	tcpi_rcv_space;
  u_int32_t	tcpi_total_retrans;

};

#endif /* Misc.  */

#endif /* netinet/tcp.h */