The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/netinet/tcp.h

Version: -  FREEBSD  -  FREEBSD-13-STABLE  -  FREEBSD-13-0  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  l41  -  OPENBSD  -  linux-2.6  -  MK84  -  PLAN9  -  xnu-8792 
SearchContext: -  none  -  3  -  10 

    1 /*-
    2  * SPDX-License-Identifier: BSD-3-Clause
    3  *
    4  * Copyright (c) 1982, 1986, 1993
    5  *      The Regents of the University of California.  All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  * 3. Neither the name of the University nor the names of its contributors
   16  *    may be used to endorse or promote products derived from this software
   17  *    without specific prior written permission.
   18  *
   19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   29  * SUCH DAMAGE.
   30  *
   31  *      @(#)tcp.h       8.1 (Berkeley) 6/10/93
   32  * $FreeBSD: releng/12.0/sys/netinet/tcp.h 334804 2018-06-07 18:18:13Z rrs $
   33  */
   34 
   35 #ifndef _NETINET_TCP_H_
   36 #define _NETINET_TCP_H_
   37 
   38 #include <sys/cdefs.h>
   39 #include <sys/types.h>
   40 
   41 #if __BSD_VISIBLE
   42 
   43 typedef u_int32_t tcp_seq;
   44 
   45 #define tcp6_seq        tcp_seq /* for KAME src sync over BSD*'s */
   46 #define tcp6hdr         tcphdr  /* for KAME src sync over BSD*'s */
   47 
   48 /*
   49  * TCP header.
   50  * Per RFC 793, September, 1981.
   51  */
   52 struct tcphdr {
   53         u_short th_sport;               /* source port */
   54         u_short th_dport;               /* destination port */
   55         tcp_seq th_seq;                 /* sequence number */
   56         tcp_seq th_ack;                 /* acknowledgement number */
   57 #if BYTE_ORDER == LITTLE_ENDIAN
   58         u_char  th_x2:4,                /* (unused) */
   59                 th_off:4;               /* data offset */
   60 #endif
   61 #if BYTE_ORDER == BIG_ENDIAN
   62         u_char  th_off:4,               /* data offset */
   63                 th_x2:4;                /* (unused) */
   64 #endif
   65         u_char  th_flags;
   66 #define TH_FIN  0x01
   67 #define TH_SYN  0x02
   68 #define TH_RST  0x04
   69 #define TH_PUSH 0x08
   70 #define TH_ACK  0x10
   71 #define TH_URG  0x20
   72 #define TH_ECE  0x40
   73 #define TH_CWR  0x80
   74 #define TH_FLAGS        (TH_FIN|TH_SYN|TH_RST|TH_PUSH|TH_ACK|TH_URG|TH_ECE|TH_CWR)
   75 #define PRINT_TH_FLAGS  "\2\1FIN\2SYN\3RST\4PUSH\5ACK\6URG\7ECE\10CWR"
   76 
   77         u_short th_win;                 /* window */
   78         u_short th_sum;                 /* checksum */
   79         u_short th_urp;                 /* urgent pointer */
   80 };
   81 
   82 #define TCPOPT_EOL              0
   83 #define    TCPOLEN_EOL                  1
   84 #define TCPOPT_PAD              0               /* padding after EOL */
   85 #define    TCPOLEN_PAD                  1
   86 #define TCPOPT_NOP              1
   87 #define    TCPOLEN_NOP                  1
   88 #define TCPOPT_MAXSEG           2
   89 #define    TCPOLEN_MAXSEG               4
   90 #define TCPOPT_WINDOW           3
   91 #define    TCPOLEN_WINDOW               3
   92 #define TCPOPT_SACK_PERMITTED   4
   93 #define    TCPOLEN_SACK_PERMITTED       2
   94 #define TCPOPT_SACK             5
   95 #define    TCPOLEN_SACKHDR              2
   96 #define    TCPOLEN_SACK                 8       /* 2*sizeof(tcp_seq) */
   97 #define TCPOPT_TIMESTAMP        8
   98 #define    TCPOLEN_TIMESTAMP            10
   99 #define    TCPOLEN_TSTAMP_APPA          (TCPOLEN_TIMESTAMP+2) /* appendix A */
  100 #define TCPOPT_SIGNATURE        19              /* Keyed MD5: RFC 2385 */
  101 #define    TCPOLEN_SIGNATURE            18
  102 #define TCPOPT_FAST_OPEN        34
  103 #define    TCPOLEN_FAST_OPEN_EMPTY      2
  104 
  105 /* Miscellaneous constants */
  106 #define MAX_SACK_BLKS   6       /* Max # SACK blocks stored at receiver side */
  107 #define TCP_MAX_SACK    4       /* MAX # SACKs sent in any segment */
  108 
  109 
  110 /*
  111  * The default maximum segment size (MSS) to be used for new TCP connections
  112  * when path MTU discovery is not enabled.
  113  *
  114  * RFC879 derives the default MSS from the largest datagram size hosts are
  115  * minimally required to handle directly or through IP reassembly minus the
  116  * size of the IP and TCP header.  With IPv6 the minimum MTU is specified
  117  * in RFC2460.
  118  *
  119  * For IPv4 the MSS is 576 - sizeof(struct tcpiphdr)
  120  * For IPv6 the MSS is IPV6_MMTU - sizeof(struct ip6_hdr) - sizeof(struct tcphdr)
  121  *
  122  * We use explicit numerical definition here to avoid header pollution.
  123  */
  124 #define TCP_MSS         536
  125 #define TCP6_MSS        1220
  126 
  127 /*
  128  * Limit the lowest MSS we accept for path MTU discovery and the TCP SYN MSS
  129  * option.  Allowing low values of MSS can consume significant resources and
  130  * be used to mount a resource exhaustion attack.
  131  * Connections requesting lower MSS values will be rounded up to this value
  132  * and the IP_DF flag will be cleared to allow fragmentation along the path.
  133  *
  134  * See tcp_subr.c tcp_minmss SYSCTL declaration for more comments.  Setting
  135  * it to "" disables the minmss check.
  136  *
  137  * The default value is fine for TCP across the Internet's smallest official
  138  * link MTU (256 bytes for AX.25 packet radio).  However, a connection is very
  139  * unlikely to come across such low MTU interfaces these days (anno domini 2003).
  140  */
  141 #define TCP_MINMSS 216
  142 
  143 #define TCP_MAXWIN      65535   /* largest value for (unscaled) window */
  144 #define TTCP_CLIENT_SND_WND     4096    /* dflt send window for T/TCP client */
  145 
  146 #define TCP_MAX_WINSHIFT        14      /* maximum window shift */
  147 
  148 #define TCP_MAXBURST            4       /* maximum segments in a burst */
  149 
  150 #define TCP_MAXHLEN     (0xf<<2)        /* max length of header in bytes */
  151 #define TCP_MAXOLEN     (TCP_MAXHLEN - sizeof(struct tcphdr))
  152                                         /* max space left for options */
  153 
  154 #define TCP_FASTOPEN_MIN_COOKIE_LEN     4       /* Per RFC7413 */
  155 #define TCP_FASTOPEN_MAX_COOKIE_LEN     16      /* Per RFC7413 */
  156 #define TCP_FASTOPEN_PSK_LEN            16      /* Same as TCP_FASTOPEN_KEY_LEN */
  157 #endif /* __BSD_VISIBLE */
  158 
  159 /*
  160  * User-settable options (used with setsockopt).  These are discrete
  161  * values and are not masked together.  Some values appear to be
  162  * bitmasks for historical reasons.
  163  */
  164 #define TCP_NODELAY     1       /* don't delay send to coalesce packets */
  165 #if __BSD_VISIBLE
  166 #define TCP_MAXSEG      2       /* set maximum segment size */
  167 #define TCP_NOPUSH      4       /* don't push last block of write */
  168 #define TCP_NOOPT       8       /* don't use TCP options */
  169 #define TCP_MD5SIG      16      /* use MD5 digests (RFC2385) */
  170 #define TCP_INFO        32      /* retrieve tcp_info structure */
  171 #define TCP_LOG         34      /* configure event logging for connection */
  172 #define TCP_LOGBUF      35      /* retrieve event log for connection */
  173 #define TCP_LOGID       36      /* configure log ID to correlate connections */
  174 #define TCP_LOGDUMP     37      /* dump connection log events to device */
  175 #define TCP_LOGDUMPID   38      /* dump events from connections with same ID to
  176                                    device */
  177 #define TCP_CONGESTION  64      /* get/set congestion control algorithm */
  178 #define TCP_CCALGOOPT   65      /* get/set cc algorithm specific options */
  179 #define TCP_DELACK      72      /* socket option for delayed ack */
  180 #define TCP_KEEPINIT    128     /* N, time to establish connection */
  181 #define TCP_KEEPIDLE    256     /* L,N,X start keeplives after this period */
  182 #define TCP_KEEPINTVL   512     /* L,N interval between keepalives */
  183 #define TCP_KEEPCNT     1024    /* L,N number of keepalives before close */
  184 #define TCP_FASTOPEN    1025    /* enable TFO / was created via TFO */
  185 #define TCP_PCAP_OUT    2048    /* number of output packets to keep */
  186 #define TCP_PCAP_IN     4096    /* number of input packets to keep */
  187 #define TCP_FUNCTION_BLK 8192   /* Set the tcp function pointers to the specified stack */
  188 /* Options for Rack and BBR */
  189 #define TCP_RACK_PROP         1051 /* RACK proportional rate reduction (bool) */
  190 #define TCP_RACK_TLP_REDUCE   1052 /* RACK TLP cwnd reduction (bool) */
  191 #define TCP_RACK_PACE_REDUCE  1053 /* RACK Pacing reduction factor (divisor) */
  192 #define TCP_RACK_PACE_MAX_SEG 1054 /* Max segments in a pace */
  193 #define TCP_RACK_PACE_ALWAYS  1055 /* Use the always pace method */
  194 #define TCP_RACK_PROP_RATE    1056 /* The proportional reduction rate */
  195 #define TCP_RACK_PRR_SENDALOT 1057 /* Allow PRR to send more than one seg */
  196 #define TCP_RACK_MIN_TO       1058 /* Minimum time between rack t-o's in ms */
  197 #define TCP_RACK_EARLY_RECOV  1059 /* Should recovery happen early (bool) */
  198 #define TCP_RACK_EARLY_SEG    1060 /* If early recovery max segments */
  199 #define TCP_RACK_REORD_THRESH 1061 /* RACK reorder threshold (shift amount) */
  200 #define TCP_RACK_REORD_FADE   1062 /* Does reordering fade after ms time */
  201 #define TCP_RACK_TLP_THRESH   1063 /* RACK TLP theshold i.e. srtt+(srtt/N) */
  202 #define TCP_RACK_PKT_DELAY    1064 /* RACK added ms i.e. rack-rtt + reord + N */
  203 #define TCP_RACK_TLP_INC_VAR  1065 /* Does TLP include rtt variance in t-o */
  204 #define TCP_RACK_SESS_CWV     1066 /* Enable RFC7611 cwnd validation on sess */
  205 #define TCP_BBR_IWINTSO       1067 /* Initial TSO window for BBRs first sends */
  206 #define TCP_BBR_RECFORCE      1068 /* Enter recovery force out a segment disregard pacer */
  207 #define TCP_BBR_STARTUP_PG    1069 /* Startup pacing gain */
  208 #define TCP_BBR_DRAIN_PG      1070 /* Drain pacing gain */
  209 #define TCP_BBR_RWND_IS_APP   1071 /* Rwnd limited is considered app limited */
  210 #define TCP_BBR_PROBE_RTT_INT 1072 /* How long in useconds between probe-rtt */
  211 #define TCP_BBR_ONE_RETRAN    1073 /* Is only one segment allowed out during retran */
  212 #define TCP_BBR_STARTUP_LOSS_EXIT 1074  /* Do we exit a loss during startup if not 20% incr */
  213 #define TCP_BBR_USE_LOWGAIN   1075 /* lower the gain in PROBE_BW enable */
  214 #define TCP_BBR_LOWGAIN_THRESH 1076 /* How many cycles do we stay in lowgain */
  215 #define TCP_BBR_LOWGAIN_HALF  1077 /* Do we halfstep lowgain down */
  216 #define TCP_BBR_LOWGAIN_FD    1078 /* Do we force a drain when lowgain in place */
  217 #define TCP_BBR_USEDEL_RATE   1079 /* Enable use of delivery rate for loss recovery */
  218 #define TCP_BBR_MIN_RTO       1080 /* Min RTO in milliseconds */
  219 #define TCP_BBR_MAX_RTO       1081 /* Max RTO in milliseconds */
  220 #define TCP_BBR_REC_OVER_HPTS 1082 /* Recovery override htps settings 0/1/3 */
  221 #define TCP_BBR_UNLIMITED     1083 /* Does BBR, in non-recovery not use cwnd */
  222 #define TCP_BBR_DRAIN_INC_EXTRA 1084 /* Does the 3/4 drain target include the extra gain */
  223 #define TCP_BBR_STARTUP_EXIT_EPOCH 1085 /* what epoch gets us out of startup */
  224 #define TCP_BBR_PACE_PER_SEC   1086
  225 #define TCP_BBR_PACE_DEL_TAR   1087
  226 #define TCP_BBR_PACE_SEG_MAX   1088
  227 #define TCP_BBR_PACE_SEG_MIN   1089
  228 #define TCP_BBR_PACE_CROSS     1090
  229 #define TCP_RACK_IDLE_REDUCE_HIGH 1092  /* Reduce the highest cwnd seen to IW on idle */
  230 #define TCP_RACK_IDLE_REDUCE_HIGH 1092  /* Reduce the highest cwnd seen to IW on idle */
  231 #define TCP_RACK_MIN_PACE      1093     /* Do we enforce rack min pace time */
  232 #define TCP_RACK_MIN_PACE_SEG  1094     /* If so what is the seg threshould */
  233 #define TCP_RACK_TLP_USE       1095
  234 #define TCP_BBR_ACK_COMP_ALG   1096     /* Not used */
  235 #define TCP_BBR_EXTRA_GAIN     1097
  236 #define TCP_BBR_RACK_RTT_USE   1098     /* what RTT should we use 0, 1, or 2? */
  237 #define TCP_BBR_RETRAN_WTSO    1099
  238 #define TCP_DATA_AFTER_CLOSE   1100
  239 #define TCP_BBR_PROBE_RTT_GAIN 1101
  240 #define TCP_BBR_PROBE_RTT_LEN  1102
  241 
  242 
  243 /* Start of reserved space for third-party user-settable options. */
  244 #define TCP_VENDOR      SO_VENDOR
  245 
  246 #define TCP_CA_NAME_MAX 16      /* max congestion control name length */
  247 
  248 #define TCPI_OPT_TIMESTAMPS     0x01
  249 #define TCPI_OPT_SACK           0x02
  250 #define TCPI_OPT_WSCALE         0x04
  251 #define TCPI_OPT_ECN            0x08
  252 #define TCPI_OPT_TOE            0x10
  253 
  254 /* Maximum length of log ID. */
  255 #define TCP_LOG_ID_LEN  64
  256 
  257 /*
  258  * The TCP_INFO socket option comes from the Linux 2.6 TCP API, and permits
  259  * the caller to query certain information about the state of a TCP
  260  * connection.  We provide an overlapping set of fields with the Linux
  261  * implementation, but since this is a fixed size structure, room has been
  262  * left for growth.  In order to maximize potential future compatibility with
  263  * the Linux API, the same variable names and order have been adopted, and
  264  * padding left to make room for omitted fields in case they are added later.
  265  *
  266  * XXX: This is currently an unstable ABI/API, in that it is expected to
  267  * change.
  268  */
  269 struct tcp_info {
  270         u_int8_t        tcpi_state;             /* TCP FSM state. */
  271         u_int8_t        __tcpi_ca_state;
  272         u_int8_t        __tcpi_retransmits;
  273         u_int8_t        __tcpi_probes;
  274         u_int8_t        __tcpi_backoff;
  275         u_int8_t        tcpi_options;           /* Options enabled on conn. */
  276         u_int8_t        tcpi_snd_wscale:4,      /* RFC1323 send shift value. */
  277                         tcpi_rcv_wscale:4;      /* RFC1323 recv shift value. */
  278 
  279         u_int32_t       tcpi_rto;               /* Retransmission timeout (usec). */
  280         u_int32_t       __tcpi_ato;
  281         u_int32_t       tcpi_snd_mss;           /* Max segment size for send. */
  282         u_int32_t       tcpi_rcv_mss;           /* Max segment size for receive. */
  283 
  284         u_int32_t       __tcpi_unacked;
  285         u_int32_t       __tcpi_sacked;
  286         u_int32_t       __tcpi_lost;
  287         u_int32_t       __tcpi_retrans;
  288         u_int32_t       __tcpi_fackets;
  289 
  290         /* Times; measurements in usecs. */
  291         u_int32_t       __tcpi_last_data_sent;
  292         u_int32_t       __tcpi_last_ack_sent;   /* Also unimpl. on Linux? */
  293         u_int32_t       tcpi_last_data_recv;    /* Time since last recv data. */
  294         u_int32_t       __tcpi_last_ack_recv;
  295 
  296         /* Metrics; variable units. */
  297         u_int32_t       __tcpi_pmtu;
  298         u_int32_t       __tcpi_rcv_ssthresh;
  299         u_int32_t       tcpi_rtt;               /* Smoothed RTT in usecs. */
  300         u_int32_t       tcpi_rttvar;            /* RTT variance in usecs. */
  301         u_int32_t       tcpi_snd_ssthresh;      /* Slow start threshold. */
  302         u_int32_t       tcpi_snd_cwnd;          /* Send congestion window. */
  303         u_int32_t       __tcpi_advmss;
  304         u_int32_t       __tcpi_reordering;
  305 
  306         u_int32_t       __tcpi_rcv_rtt;
  307         u_int32_t       tcpi_rcv_space;         /* Advertised recv window. */
  308 
  309         /* FreeBSD extensions to tcp_info. */
  310         u_int32_t       tcpi_snd_wnd;           /* Advertised send window. */
  311         u_int32_t       tcpi_snd_bwnd;          /* No longer used. */
  312         u_int32_t       tcpi_snd_nxt;           /* Next egress seqno */
  313         u_int32_t       tcpi_rcv_nxt;           /* Next ingress seqno */
  314         u_int32_t       tcpi_toe_tid;           /* HWTID for TOE endpoints */
  315         u_int32_t       tcpi_snd_rexmitpack;    /* Retransmitted packets */
  316         u_int32_t       tcpi_rcv_ooopack;       /* Out-of-order packets */
  317         u_int32_t       tcpi_snd_zerowin;       /* Zero-sized windows sent */
  318         
  319         /* Padding to grow without breaking ABI. */
  320         u_int32_t       __tcpi_pad[26];         /* Padding. */
  321 };
  322 
  323 /*
  324  * If this structure is provided when setting the TCP_FASTOPEN socket
  325  * option, and the enable member is non-zero, a subsequent connect will use
  326  * pre-shared key (PSK) mode using the provided key.
  327  */
  328 struct tcp_fastopen {
  329         int enable;
  330         uint8_t psk[TCP_FASTOPEN_PSK_LEN];
  331 };
  332 #endif
  333 #define TCP_FUNCTION_NAME_LEN_MAX 32
  334 
  335 struct tcp_function_set {
  336         char function_set_name[TCP_FUNCTION_NAME_LEN_MAX];
  337         uint32_t pcbcnt;
  338 };
  339 
  340 #endif /* !_NETINET_TCP_H_ */

Cache object: 88c1f75f7c4580f6156cba154c567f28


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.