bsd/netinet/tcp.h

   1 /*
   2  * Copyright (c) 2000-2014 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*
  29  * Copyright (c) 1982, 1986, 1993
  30  *      The Regents of the University of California.  All rights reserved.
  31  *
  32  * Redistribution and use in source and binary forms, with or without
  33  * modification, are permitted provided that the following conditions
  34  * are met:
  35  * 1. Redistributions of source code must retain the above copyright
  36  *    notice, this list of conditions and the following disclaimer.
  37  * 2. Redistributions in binary form must reproduce the above copyright
  38  *    notice, this list of conditions and the following disclaimer in the
  39  *    documentation and/or other materials provided with the distribution.
  40  * 3. All advertising materials mentioning features or use of this software
  41  *    must display the following acknowledgement:
  42  *      This product includes software developed by the University of
  43  *      California, Berkeley and its contributors.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      @(#)tcp.h       8.1 (Berkeley) 6/10/93
  61  * $FreeBSD: src/sys/netinet/tcp.h,v 1.13.2.3 2001/03/01 22:08:42 jlemon Exp $
  62  */
  63
  64 #ifndef _NETINET_TCP_H_
  65 #define _NETINET_TCP_H_
  66 #include <sys/types.h>
  67 #include <sys/appleapiopts.h>
  68 #include <machine/endian.h>
  69
  70 #if !defined(_POSIX_C_SOURCE) || defined(_DARWIN_C_SOURCE)
  71 typedef __uint32_t tcp_seq;
  72 typedef __uint32_t tcp_cc;              /* connection count per rfc1644 */
  73
  74 #define tcp6_seq        tcp_seq /* for KAME src sync over BSD*'s */
  75 #define tcp6hdr         tcphdr  /* for KAME src sync over BSD*'s */
  76
  77 /*
  78  * TCP header.
  79  * Per RFC 793, September, 1981.
  80  */
  81 struct tcphdr {
  82         unsigned short  th_sport;       /* source port */
  83         unsigned short  th_dport;       /* destination port */
  84         tcp_seq th_seq;                 /* sequence number */
  85         tcp_seq th_ack;                 /* acknowledgement number */
  86 #if __DARWIN_BYTE_ORDER == __DARWIN_LITTLE_ENDIAN
  87         unsigned int    th_x2:4,        /* (unused) */
  88                         th_off:4;       /* data offset */
  89 #endif
  90 #if __DARWIN_BYTE_ORDER == __DARWIN_BIG_ENDIAN
  91         unsigned int    th_off:4,       /* data offset */
  92                         th_x2:4;        /* (unused) */
  93 #endif
  94         unsigned char   th_flags;
  95 #define TH_FIN  0x01
  96 #define TH_SYN  0x02
  97 #define TH_RST  0x04
  98 #define TH_PUSH 0x08
  99 #define TH_ACK  0x10
 100 #define TH_URG  0x20
 101 #define TH_ECE  0x40
 102 #define TH_CWR  0x80
 103 #define TH_FLAGS        (TH_FIN|TH_SYN|TH_RST|TH_ACK|TH_URG|TH_ECE|TH_CWR)
 104
 105         unsigned short  th_win;         /* window */
 106         unsigned short  th_sum;         /* checksum */
 107         unsigned short  th_urp;         /* urgent pointer */
 108 };
 109
 110 #define TCPOPT_EOL              0
 111 #define TCPOPT_NOP              1
 112 #define TCPOPT_MAXSEG           2
 113 #define TCPOLEN_MAXSEG          4
 114 #define TCPOPT_WINDOW           3
 115 #define TCPOLEN_WINDOW          3
 116 #define TCPOPT_SACK_PERMITTED   4               /* Experimental */
 117 #define TCPOLEN_SACK_PERMITTED  2
 118 #define TCPOPT_SACK             5               /* Experimental */
 119 #define TCPOLEN_SACK            8               /* len of sack block */
 120 #define TCPOPT_TIMESTAMP        8
 121 #define TCPOLEN_TIMESTAMP       10
 122 #define TCPOLEN_TSTAMP_APPA             (TCPOLEN_TIMESTAMP+2) /* appendix A */
 123 #define TCPOPT_TSTAMP_HDR               \
 124     (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)
 125
 126 #define MAX_TCPOPTLEN           40      /* Absolute maximum TCP options len */
 127
 128 #define TCPOPT_CC               11              /* CC options: RFC-1644 */
 129 #define TCPOPT_CCNEW            12
 130 #define TCPOPT_CCECHO           13
 131 #define    TCPOLEN_CC                   6
 132 #define    TCPOLEN_CC_APPA              (TCPOLEN_CC+2)
 133 #define    TCPOPT_CC_HDR(ccopt)         \
 134     (TCPOPT_NOP<<24|TCPOPT_NOP<<16|(ccopt)<<8|TCPOLEN_CC)
 135 #define TCPOPT_SIGNATURE                19      /* Keyed MD5: RFC 2385 */
 136 #define    TCPOLEN_SIGNATURE            18
 137 #if MPTCP
 138 #define TCPOPT_MULTIPATH                30
 139 #endif
 140
 141 #define TCPOPT_FASTOPEN                 34
 142 #define TCPOLEN_FASTOPEN_REQ            2
 143
 144 /* Option definitions */
 145 #define TCPOPT_SACK_PERMIT_HDR  \
 146 (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_SACK_PERMITTED<<8|TCPOLEN_SACK_PERMITTED)
 147 #define TCPOPT_SACK_HDR         (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_SACK<<8)
 148 /* Miscellaneous constants */
 149 #define MAX_SACK_BLKS   6       /* Max # SACK blocks stored at sender side */
 150
 151 /*
 152  * A SACK option that specifies n blocks will have a length of (8*n + 2)
 153  * bytes, so the 40 bytes available for TCP options can specify a
 154  * maximum of 4 blocks.
 155  */
 156
 157 #define TCP_MAX_SACK    4       /* MAX # SACKs sent in any segment */
 158
 159
 160 /*
 161  * Default maximum segment size for TCP.
 162  * With an IP MTU of 576, this is 536,
 163  * but 512 is probably more convenient.
 164  * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)).
 165  */
 166 #define TCP_MSS 512
 167
 168 /*
 169  * TCP_MINMSS is defined to be 216 which is fine for the smallest
 170  * link MTU (256 bytes, SLIP interface) in the Internet.
 171  * However it is very unlikely to come across such low MTU interfaces
 172  * these days (anno dato 2004).
 173  * Probably it can be set to 512 without ill effects. But we play safe.
 174  * See tcp_subr.c tcp_minmss SYSCTL declaration for more comments.
 175  * Setting this to "0" disables the minmss check.
 176  */
 177 #define TCP_MINMSS 216
 178
 179 /*
 180  * Default maximum segment size for TCP6.
 181  * With an IP6 MSS of 1280, this is 1220,
 182  * but 1024 is probably more convenient. (xxx kazu in doubt)
 183  * This should be defined as MIN(1024, IP6_MSS - sizeof (struct tcpip6hdr))
 184  */
 185 #define TCP6_MSS        1024
 186
 187 #define TCP_MAXWIN      65535   /* largest value for (unscaled) window */
 188 #define TTCP_CLIENT_SND_WND     4096    /* dflt send window for T/TCP client */
 189
 190 #define TCP_MAX_WINSHIFT        14      /* maximum window shift */
 191
 192 #define TCP_MAXHLEN     (0xf<<2)        /* max length of header in bytes */
 193 #define TCP_MAXOLEN     (TCP_MAXHLEN - sizeof(struct tcphdr))
 194                                         /* max space left for options */
 195 #endif /* (_POSIX_C_SOURCE && !_DARWIN_C_SOURCE) */
 196
 197 /*
 198  * User-settable options (used with setsockopt).
 199  */
 200 #define TCP_NODELAY             0x01    /* don't delay send to coalesce packets */
 201 #if !defined(_POSIX_C_SOURCE) || defined(_DARWIN_C_SOURCE)
 202 #define TCP_MAXSEG              0x02    /* set maximum segment size */
 203 #define TCP_NOPUSH              0x04    /* don't push last block of write */
 204 #define TCP_NOOPT               0x08    /* don't use TCP options */
 205 #define TCP_KEEPALIVE           0x10    /* idle time used when SO_KEEPALIVE is enabled */
 206 #define TCP_CONNECTIONTIMEOUT   0x20    /* connection timeout */
 207 #define PERSIST_TIMEOUT         0x40    /* time after which a connection in
 208                                          *  persist timeout will terminate.
 209                                          *  see draft-ananth-tcpm-persist-02.txt
 210                                          */
 211 #define TCP_RXT_CONNDROPTIME    0x80    /* time after which tcp retransmissions will be
 212                                          * stopped and the connection will be dropped
 213                                          */
 214 #define TCP_RXT_FINDROP         0x100   /* when this option is set, drop a connection
 215                                          * after retransmitting the FIN 3 times. It will
 216                                          * prevent holding too many mbufs in socket
 217                                          * buffer queues.
 218                                          */
 219 #define TCP_KEEPINTVL           0x101   /* interval between keepalives */
 220 #define TCP_KEEPCNT             0x102   /* number of keepalives before close */
 221 #define TCP_SENDMOREACKS        0x103   /* always ack every other packet */
 222 #define TCP_ENABLE_ECN          0x104   /* Enable ECN on a connection */
 223 #define TCP_FASTOPEN            0x105   /* Enable/Disable TCP Fastopen on this socket */
 224 #define TCP_CONNECTION_INFO     0x106   /* State of TCP connection */
 225
 226 #ifdef PRIVATE
 227 #define TCP_INFO                0x200   /* retrieve tcp_info structure */
 228 #define TCP_MEASURE_SND_BW      0x202   /* Measure sender's bandwidth for this connection */
 229 #endif /* PRIVATE */
 230
 231
 232 #define TCP_NOTSENT_LOWAT       0x201   /* Low water mark for TCP unsent data */
 233
 234 #ifdef PRIVATE
 235 #define TCP_MEASURE_BW_BURST    0x203   /* Burst size to use for bandwidth measurement */
 236 #define TCP_PEER_PID            0x204   /* Lookup pid of the process we're connected to */
 237 #define TCP_ADAPTIVE_READ_TIMEOUT       0x205   /* Read timeout used as a multiple of RTT */
 238 /*
 239  * Enable message delivery on a socket, this feature is currently unsupported and
 240  * is subjected to change in future.
 241  */
 242 #define TCP_ENABLE_MSGS                 0x206
 243 #define TCP_ADAPTIVE_WRITE_TIMEOUT      0x207   /* Write timeout used as a multiple of RTT */
 244 #define TCP_NOTIMEWAIT                  0x208   /* Avoid going into time-wait */
 245 #define TCP_DISABLE_BLACKHOLE_DETECTION 0x209   /* disable PMTU blackhole detection */
 246 #define TCP_ECN_MODE                    0x210   /* fine grain control for A/B testing */
 247
 248 #define ECN_MODE_DEFAULT        0x0     /* per interface or system wide default */
 249 #define ECN_MODE_ENABLE         0x1     /* force enable ECN on connection */
 250 #define ECN_MODE_DISABLE        0x2     /* force disable ECN on connection */
 251
 252 /*
 253  * The TCP_INFO socket option is a private API and is subject to change
 254  */
 255 #pragma pack(4)
 256
 257 #define TCPI_OPT_TIMESTAMPS     0x01
 258 #define TCPI_OPT_SACK           0x02
 259 #define TCPI_OPT_WSCALE         0x04
 260 #define TCPI_OPT_ECN            0x08
 261
 262 #define TCPI_FLAG_LOSSRECOVERY  0x01    /* Currently in loss recovery */
 263
 264 struct tcp_conn_status {
 265         unsigned int    probe_activated : 1;
 266         unsigned int    write_probe_failed : 1;
 267         unsigned int    read_probe_failed : 1;
 268         unsigned int    conn_probe_failed : 1;
 269 };
 270
 271 /*
 272  * Add new fields to this structure at the end only. This will preserve
 273  * binary compatibility.
 274  */
 275 struct tcp_info {
 276         u_int8_t        tcpi_state;                     /* TCP FSM state. */
 277         u_int8_t        tcpi_options;           /* Options enabled on conn. */
 278         u_int8_t        tcpi_snd_wscale;        /* RFC1323 send shift value. */
 279         u_int8_t        tcpi_rcv_wscale;        /* RFC1323 recv shift value. */
 280
 281         u_int32_t       tcpi_flags;                     /* extra flags (TCPI_FLAG_xxx) */
 282
 283         u_int32_t       tcpi_rto;                       /* Retransmission timeout in milliseconds */
 284         u_int32_t       tcpi_snd_mss;           /* Max segment size for send. */
 285         u_int32_t       tcpi_rcv_mss;           /* Max segment size for receive. */
 286
 287         u_int32_t       tcpi_rttcur;            /* Most recent value of RTT */
 288         u_int32_t       tcpi_srtt;                      /* Smoothed RTT */
 289         u_int32_t       tcpi_rttvar;            /* RTT variance */
 290         u_int32_t       tcpi_rttbest;           /* Best RTT we've seen */
 291
 292         u_int32_t       tcpi_snd_ssthresh;      /* Slow start threshold. */
 293         u_int32_t       tcpi_snd_cwnd;          /* Send congestion window. */
 294
 295         u_int32_t       tcpi_rcv_space;         /* Advertised recv window. */
 296
 297         u_int32_t       tcpi_snd_wnd;           /* Advertised send window. */
 298         u_int32_t       tcpi_snd_nxt;           /* Next egress seqno */
 299         u_int32_t       tcpi_rcv_nxt;           /* Next ingress seqno */
 300
 301         int32_t         tcpi_last_outif;        /* if_index of interface used to send last */
 302         u_int32_t       tcpi_snd_sbbytes;       /* bytes in snd buffer including data inflight */
 303
 304         u_int64_t       tcpi_txpackets __attribute__((aligned(8)));     /* total packets sent */
 305         u_int64_t       tcpi_txbytes __attribute__((aligned(8)));
 306                                                                         /* total bytes sent */
 307         u_int64_t       tcpi_txretransmitbytes __attribute__((aligned(8)));
 308                                                                         /* total bytes retransmitted */
 309         u_int64_t       tcpi_txunacked __attribute__((aligned(8)));
 310                                                                         /* current number of bytes not acknowledged */
 311         u_int64_t       tcpi_rxpackets __attribute__((aligned(8)));     /* total packets received */
 312         u_int64_t       tcpi_rxbytes __attribute__((aligned(8)));
 313                                                                         /* total bytes received */
 314         u_int64_t       tcpi_rxduplicatebytes __attribute__((aligned(8)));
 315                                                                         /* total duplicate bytes received */
 316         u_int64_t       tcpi_rxoutoforderbytes __attribute__((aligned(8)));
 317                                                                         /* total out of order bytes received */
 318         u_int64_t       tcpi_snd_bw __attribute__((aligned(8)));        /* measured send bandwidth in bits/sec */
 319         u_int8_t        tcpi_synrexmits;        /* Number of syn retransmits before connect */
 320         u_int8_t        tcpi_unused1;
 321         u_int16_t       tcpi_unused2;
 322         u_int64_t       tcpi_cell_rxpackets __attribute((aligned(8)));  /* packets received over cellular */
 323         u_int64_t       tcpi_cell_rxbytes __attribute((aligned(8)));    /* bytes received over cellular */
 324         u_int64_t       tcpi_cell_txpackets __attribute((aligned(8)));  /* packets transmitted over cellular */
 325         u_int64_t       tcpi_cell_txbytes __attribute((aligned(8)));    /* bytes transmitted over cellular */
 326         u_int64_t       tcpi_wifi_rxpackets __attribute((aligned(8)));  /* packets received over Wi-Fi */
 327         u_int64_t       tcpi_wifi_rxbytes __attribute((aligned(8)));    /* bytes received over Wi-Fi */
 328         u_int64_t       tcpi_wifi_txpackets __attribute((aligned(8)));  /* packets transmitted over Wi-Fi */
 329         u_int64_t       tcpi_wifi_txbytes __attribute((aligned(8)));    /* bytes transmitted over Wi-Fi */
 330         u_int64_t       tcpi_wired_rxpackets __attribute((aligned(8))); /* packets received over Wired */
 331         u_int64_t       tcpi_wired_rxbytes __attribute((aligned(8)));   /* bytes received over Wired */
 332         u_int64_t       tcpi_wired_txpackets __attribute((aligned(8))); /* packets transmitted over Wired */
 333         u_int64_t       tcpi_wired_txbytes __attribute((aligned(8)));   /* bytes transmitted over Wired */
 334         struct tcp_conn_status  tcpi_connstatus; /* status of connection probes */
 335
 336         u_int16_t       /* Client-side information */
 337                 tcpi_tfo_cookie_req:1, /* Cookie requested? */
 338                 tcpi_tfo_cookie_rcv:1, /* Cookie received? */
 339                 tcpi_tfo_syn_loss:1,   /* Fallback to reg. TCP after SYN-loss */
 340                 tcpi_tfo_syn_data_sent:1, /* SYN+data has been sent out */
 341                 tcpi_tfo_syn_data_acked:1, /* SYN+data has been fully acknowledged */
 342                 /* And the following are for server-side information (must be set on the listener socket) */
 343                 tcpi_tfo_syn_data_rcv:1, /* Server received SYN+data with a valid cookie */
 344                 tcpi_tfo_cookie_req_rcv:1, /* Server received cookie-request */
 345                 tcpi_tfo_cookie_sent:1, /* Server announced cookie */
 346                 tcpi_tfo_cookie_invalid:1; /* Server received an invalid cookie */
 347
 348         u_int16_t       tcpi_ecn_client_setup:1,        /* Attempted ECN setup from client side */
 349                         tcpi_ecn_server_setup:1,        /* Attempted ECN setup from server side */
 350                         tcpi_ecn_success:1,             /* peer negotiated ECN */
 351                         tcpi_ecn_lost_syn:1,            /* Lost SYN with ECN setup */
 352                         tcpi_ecn_lost_synack:1,         /* Lost SYN-ACK with ECN setup */
 353                         tcpi_local_peer:1,              /* Local to the host or the subnet */
 354                         tcpi_if_cell:1,                 /* Interface is cellular */
 355                         tcpi_if_wifi:1;                 /* Interface is WiFi */
 356
 357         u_int32_t       tcpi_ecn_recv_ce;       /* Packets received with CE */
 358         u_int32_t       tcpi_ecn_recv_cwr;      /* Packets received with CWR */
 359
 360         u_int32_t       tcpi_rcvoopack;         /* out-of-order packets received */
 361         u_int32_t       tcpi_pawsdrop;          /* segments dropped due to PAWS */
 362         u_int32_t       tcpi_sack_recovery_episode; /* SACK recovery episodes */
 363         u_int32_t       tcpi_reordered_pkts;    /* packets reorderd */
 364         u_int32_t       tcpi_dsack_sent;        /* Sent DSACK notification */
 365         u_int32_t       tcpi_dsack_recvd;       /* Received a valid DSACK option */
 366         u_int32_t       tcpi_flowhash;          /* Unique id for the connection */
 367 };
 368
 369 struct tcp_measure_bw_burst {
 370         u_int32_t       min_burst_size; /* Minimum number of packets to use */
 371         u_int32_t       max_burst_size; /* Maximum number of packets to use */
 372 };
 373
 374 /*
 375  * Note that IPv6 link local addresses should have the appropriate scope ID
 376  */
 377
 378 struct info_tuple {
 379         u_int8_t        itpl_proto;
 380         union {
 381                 struct sockaddr         _itpl_sa;
 382                 struct sockaddr_in      _itpl_sin;
 383                 struct sockaddr_in6     _itpl_sin6;
 384         } itpl_localaddr;
 385         union {
 386                 struct sockaddr         _itpl_sa;
 387                 struct sockaddr_in      _itpl_sin;
 388                 struct sockaddr_in6     _itpl_sin6;
 389         } itpl_remoteaddr;
 390 };
 391
 392 #define itpl_local_sa           itpl_localaddr._itpl_sa
 393 #define itpl_local_sin          itpl_localaddr._itpl_sin
 394 #define itpl_local_sin6         itpl_localaddr._itpl_sin6
 395 #define itpl_remote_sa          itpl_remoteaddr._itpl_sa
 396 #define itpl_remote_sin         itpl_remoteaddr._itpl_sin
 397 #define itpl_remote_sin6        itpl_remoteaddr._itpl_sin6
 398
 399 /*
 400  * TCP connection info auxiliary data (CIAUX_TCP)
 401  *
 402  * Do not add new fields to this structure, just add them to tcp_info
 403  * structure towards the end. This will preserve binary compatibility.
 404  */
 405 typedef struct conninfo_tcp {
 406         pid_t                   tcpci_peer_pid; /* loopback peer PID if > 0 */
 407         struct tcp_info         tcpci_tcp_info; /* TCP info */
 408 } conninfo_tcp_t;
 409
 410 #pragma pack()
 411
 412 #endif /* PRIVATE */
 413
 414 struct tcp_connection_info {
 415         u_int8_t        tcpi_state;     /* connection state */
 416         u_int8_t        tcpi_snd_wscale; /* Window scale for send window */
 417         u_int8_t        tcpi_rcv_wscale; /* Window scale for receive window */
 418         u_int8_t        __pad1;
 419         u_int32_t       tcpi_options;   /* TCP options supported */
 420 #define TCPCI_OPT_TIMESTAMPS    0x00000001 /* Timestamps enabled */
 421 #define TCPCI_OPT_SACK          0x00000002 /* SACK enabled */
 422 #define TCPCI_OPT_WSCALE        0x00000004 /* Window scaling enabled */
 423 #define TCPCI_OPT_ECN           0x00000008 /* ECN enabled */
 424         u_int32_t       tcpi_flags;     /* flags */
 425 #define TCPCI_FLAG_LOSSRECOVERY 0x00000001
 426 #define TCPCI_FLAG_REORDERING_DETECTED  0x00000002
 427         u_int32_t       tcpi_rto;       /* retransmit timeout in ms */
 428         u_int32_t       tcpi_maxseg;    /* maximum segment size supported */
 429         u_int32_t       tcpi_snd_ssthresh; /* slow start threshold in bytes */
 430         u_int32_t       tcpi_snd_cwnd;  /* send congestion window in bytes */
 431         u_int32_t       tcpi_snd_wnd;   /* send widnow in bytes */
 432         u_int32_t       tcpi_snd_sbbytes; /* bytes in send socket buffer, including in-flight data */
 433         u_int32_t       tcpi_rcv_wnd;   /* receive window in bytes*/
 434         u_int32_t       tcpi_rttcur;    /* most recent RTT in ms */
 435         u_int32_t       tcpi_srtt;      /* average RTT in ms */
 436         u_int32_t       tcpi_rttvar;    /* RTT variance */
 437         u_int32_t
 438                         /* Client-side information */
 439                         tcpi_tfo_cookie_req:1, /* Cookie requested? */
 440                         tcpi_tfo_cookie_rcv:1, /* Cookie received? */
 441                         tcpi_tfo_syn_loss:1,   /* Fallback to reg. TCP after SYN-loss */
 442                         tcpi_tfo_syn_data_sent:1, /* SYN+data has been sent out */
 443                         tcpi_tfo_syn_data_acked:1, /* SYN+data has been fully acknowledged */
 444                         /* And the following are for server-side information (must be set on the listener socket) */
 445                         tcpi_tfo_syn_data_rcv:1, /* Server received SYN+data with a valid cookie */
 446                         tcpi_tfo_cookie_req_rcv:1, /* Server received cookie-request */
 447                         tcpi_tfo_cookie_sent:1, /* Server announced cookie */
 448                         tcpi_tfo_cookie_invalid:1, /* Server received an invalid cookie */
 449                         __pad2:23;
 450         u_int64_t       tcpi_txpackets __attribute__((aligned(8)));
 451         u_int64_t       tcpi_txbytes __attribute__((aligned(8)));
 452         u_int64_t       tcpi_txretransmitbytes __attribute__((aligned(8)));
 453         u_int64_t       tcpi_rxpackets __attribute__((aligned(8)));
 454         u_int64_t       tcpi_rxbytes __attribute__((aligned(8)));
 455         u_int64_t       tcpi_rxoutoforderbytes __attribute__((aligned(8)));
 456 };
 457 #endif /* (_POSIX_C_SOURCE && !_DARWIN_C_SOURCE) */
 458
 459 #endif