1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 1991, 2010, Oracle and/or its affiliates. All rights reserved.
  23  * Copyright (c) 2011, Joyent, Inc. All rights reserved.
  24  * Copyright (c) 2011 Nexenta Systems, Inc. All rights reserved.
  25  * Copyright (c) 2014, 2017 by Delphix. All rights reserved.
  26  */
  27 /* Copyright (c) 1990 Mentat Inc. */
  28 
  29 #ifndef _INET_TCP_H
  30 #define _INET_TCP_H
  31 
  32 #ifdef  __cplusplus
  33 extern "C" {
  34 #endif
  35 
  36 #include <sys/inttypes.h>
  37 #include <netinet/ip6.h>
  38 #include <netinet/tcp.h>
  39 #include <sys/socket.h>
  40 #include <sys/socket_proto.h>
  41 #include <sys/md5.h>
  42 #include <inet/common.h>
  43 #include <inet/ip.h>
  44 #include <inet/ip6.h>
  45 #include <inet/mi.h>
  46 #include <inet/mib2.h>
  47 #include <inet/tcp_stack.h>
  48 #include <inet/tcp_sack.h>
  49 #include <inet/cc.h>
  50 
  51 /* TCP states */
  52 #define TCPS_CLOSED             -6
  53 #define TCPS_IDLE               -5      /* idle (opened, but not bound) */
  54 #define TCPS_BOUND              -4      /* bound, ready to connect or accept */
  55 #define TCPS_LISTEN             -3      /* listening for connection */
  56 #define TCPS_SYN_SENT           -2      /* active, have sent syn */
  57 #define TCPS_SYN_RCVD           -1      /* have received syn (and sent ours) */
  58 /* states < TCPS_ESTABLISHED are those where connections not established */
  59 #define TCPS_ESTABLISHED        0       /* established */
  60 #define TCPS_CLOSE_WAIT         1       /* rcvd fin, waiting for close */
  61 /* states > TCPS_CLOSE_WAIT are those where user has closed */
  62 #define TCPS_FIN_WAIT_1         2       /* have closed and sent fin */
  63 #define TCPS_CLOSING            3       /* closed, xchd FIN, await FIN ACK */
  64 #define TCPS_LAST_ACK           4       /* had fin and close; await FIN ACK */
  65 /* states > TCPS_CLOSE_WAIT && < TCPS_FIN_WAIT_2 await ACK of FIN */
  66 #define TCPS_FIN_WAIT_2         5       /* have closed, fin is acked */
  67 #define TCPS_TIME_WAIT          6       /* in 2*msl quiet wait after close */
  68 
  69 /*
  70  * Internal flags used in conjunction with the packet header flags.
  71  * Used in tcp_input_data to keep track of what needs to be done.
  72  */
  73 #define TH_LIMIT_XMIT           0x0400  /* Limited xmit is needed */
  74 #define TH_XMIT_NEEDED          0x0800  /* Window opened - send queued data */
  75 #define TH_REXMIT_NEEDED        0x1000  /* Time expired for unacked data */
  76 #define TH_ACK_NEEDED           0x2000  /* Send an ack now. */
  77 #define TH_NEED_SACK_REXMIT     0x4000  /* Use SACK info to retransmission */
  78 #define TH_ACK_TIMER_NEEDED     0x8000  /* Start the delayed ACK timer */
  79 #define TH_ORDREL_NEEDED        0x10000 /* Generate an ordrel indication */
  80 #define TH_MARKNEXT_NEEDED      0x20000 /* Data should have MSGMARKNEXT */
  81 #define TH_SEND_URP_MARK        0x40000 /* Send up tcp_urp_mark_mp */
  82 
  83 /*
  84  * TCP sequence numbers are 32 bit integers operated
  85  * on with modular arithmetic.  These macros can be
  86  * used to compare such integers.
  87  */
  88 #define SEQ_LT(a, b)    ((int32_t)((a)-(b)) < 0)
  89 #define SEQ_LEQ(a, b)   ((int32_t)((a)-(b)) <= 0)
  90 #define SEQ_GT(a, b)    ((int32_t)((a)-(b)) > 0)
  91 #define SEQ_GEQ(a, b)   ((int32_t)((a)-(b)) >= 0)
  92 
  93 /* TCP Protocol header */
  94 typedef struct tcphdr_s {
  95         uint8_t         th_lport[2];    /* Source port */
  96         uint8_t         th_fport[2];    /* Destination port */
  97         uint8_t         th_seq[4];      /* Sequence number */
  98         uint8_t         th_ack[4];      /* Acknowledgement number */
  99         uint8_t         th_offset_and_rsrvd[1]; /* Offset to the packet data */
 100         uint8_t         th_flags[1];
 101         uint8_t         th_win[2];      /* Allocation number */
 102         uint8_t         th_sum[2];      /* TCP checksum */
 103         uint8_t         th_urp[2];      /* Urgent pointer */
 104 } tcph_t;
 105 
 106 #define TCP_HDR_LENGTH(tcph) \
 107         ((((tcph_t *)tcph)->th_offset_and_rsrvd[0] >>2) &(0xF << 2))
 108 #define TCP_MAX_COMBINED_HEADER_LENGTH  (60 + 60) /* Maxed out ip + tcp */
 109 #define TCP_MAX_IP_OPTIONS_LENGTH       (60 - IP_SIMPLE_HDR_LENGTH)
 110 #define TCP_MAX_HDR_LENGTH              60
 111 #define TCP_MAX_TCP_OPTIONS_LENGTH      (60 - sizeof (tcpha_t))
 112 #define TCP_MIN_HEADER_LENGTH           20
 113 #define TCP_MAXWIN                      65535
 114 #define TCP_PORT_LEN                    sizeof (in_port_t)
 115 #define TCP_MAX_WINSHIFT                14
 116 #define TCP_MAX_LARGEWIN                (TCP_MAXWIN << TCP_MAX_WINSHIFT)
 117 #define TCP_MAX_LSO_LENGTH      (IP_MAXPACKET - TCP_MAX_COMBINED_HEADER_LENGTH)
 118 
 119 #define TCPIP_HDR_LENGTH(mp, n)                                 \
 120         (n) = IPH_HDR_LENGTH((mp)->b_rptr),                  \
 121         (n) += TCP_HDR_LENGTH((tcpha_t *)&(mp)->b_rptr[(n)])
 122 
 123 /* TCP Protocol header (used if the header is known to be 32-bit aligned) */
 124 typedef struct tcphdra_s {
 125         in_port_t       tha_lport;      /* Source port */
 126         in_port_t       tha_fport;      /* Destination port */
 127         uint32_t        tha_seq;        /* Sequence number */
 128         uint32_t        tha_ack;        /* Acknowledgement number */
 129         uint8_t tha_offset_and_reserved; /* Offset to the packet data */
 130         uint8_t         tha_flags;
 131         uint16_t        tha_win;        /* Allocation number */
 132         uint16_t        tha_sum;        /* TCP checksum */
 133         uint16_t        tha_urp;        /* Urgent pointer */
 134 } tcpha_t;
 135 
 136 struct conn_s;
 137 struct tcp_listen_cnt_s;
 138 
 139 /*
 140  * Control structure for each open TCP stream,
 141  * defined only within the kernel or for a kmem user.
 142  * NOTE: tcp_reinit_values MUST have a line for each field in this structure!
 143  */
 144 #if (defined(_KERNEL) || defined(_KMEMUSER))
 145 
 146 typedef struct tcp_s {
 147         struct tcp_s    *tcp_time_wait_next;
 148                                 /* Pointer to next T/W block */
 149         struct tcp_s    *tcp_time_wait_prev;
 150                                 /* Pointer to previous T/W next */
 151         int64_t         tcp_time_wait_expire;
 152 
 153         struct conn_s   *tcp_connp;     /* back pointer to conn_t */
 154         tcp_stack_t     *tcp_tcps;      /* back pointer to tcp_stack_t */
 155 
 156         struct cc_algo  *tcp_cc_algo;   /* congestion control algorithm */
 157         struct cc_var   tcp_ccv;        /* congestion control specific vars */
 158 
 159         int32_t tcp_state;
 160         int32_t tcp_rcv_ws;             /* My window scale power */
 161         int32_t tcp_snd_ws;             /* Sender's window scale power */
 162         uint32_t tcp_ts_recent;         /* Timestamp of earliest unacked */
 163                                         /*  data segment */
 164         clock_t tcp_rto;                /* Round trip timeout */
 165         int64_t tcp_last_rcv_lbolt;
 166                                 /* lbolt on last packet, used for PAWS */
 167         uint32_t tcp_rto_initial;       /* Initial RTO */
 168         uint32_t tcp_rto_min;           /* Minimum RTO */
 169         uint32_t tcp_rto_max;           /* Maximum RTO */
 170 
 171         uint32_t tcp_snxt;              /* Senders next seq num */
 172         uint32_t tcp_swnd;              /* Senders window (relative to suna) */
 173         uint32_t tcp_mss;               /* Max segment size */
 174         uint32_t tcp_iss;               /* Initial send seq num */
 175         uint32_t tcp_rnxt;              /* Seq we expect to recv next */
 176         uint32_t tcp_rwnd;
 177 
 178         /* Fields arranged in approximate access order along main paths */
 179         mblk_t  *tcp_xmit_head;         /* Head of xmit/rexmit list */
 180         mblk_t  *tcp_xmit_last;         /* Last valid data seen by tcp_wput */
 181         mblk_t  *tcp_xmit_tail;         /* Last data sent */
 182         uint32_t tcp_unsent;            /* # of bytes in hand that are unsent */
 183         uint32_t tcp_xmit_tail_unsent;  /* # of unsent bytes in xmit_tail */
 184         uint32_t tcp_suna;              /* Sender unacknowledged */
 185         uint32_t tcp_rexmit_nxt;        /* Next rexmit seq num */
 186         uint32_t tcp_rexmit_max;        /* Max retran seq num */
 187         uint32_t tcp_cwnd;              /* Congestion window */
 188         int32_t tcp_cwnd_cnt;           /* cwnd cnt in congestion avoidance */
 189         uint32_t tcp_naglim;            /* Tunable nagle limit */
 190         uint32_t        tcp_valid_bits;
 191 #define TCP_ISS_VALID   0x1     /* Is the tcp_iss seq num active? */
 192 #define TCP_FSS_VALID   0x2     /* Is the tcp_fss seq num active? */
 193 #define TCP_URG_VALID   0x4     /* Is the tcp_urg seq num active? */
 194 #define TCP_OFO_FIN_VALID 0x8   /* Has TCP received an out of order FIN? */
 195 
 196         timeout_id_t    tcp_timer_tid;  /* Control block for timer service */
 197         uchar_t tcp_timer_backoff;      /* Backoff shift count. */
 198         int64_t tcp_last_recv_time;     /* Last time we receive a segment. */
 199         uint32_t tcp_init_cwnd;         /* Initial cwnd (start/restart) */
 200 
 201         /* Following manipulated by TCP under squeue protection */
 202         uint32_t
 203                 tcp_urp_last_valid : 1, /* Is tcp_urp_last valid? */
 204                 tcp_hard_binding : 1,   /* TCP_DETACHED_NONEAGER */
 205                 tcp_fin_acked : 1,      /* Has our FIN been acked? */
 206                 tcp_fin_rcvd : 1,       /* Have we seen a FIN? */
 207 
 208                 tcp_fin_sent : 1,       /* Have we sent our FIN yet? */
 209                 tcp_ordrel_done : 1,    /* Have we sent the ord_rel upstream? */
 210                 tcp_detached : 1,       /* If we're detached from a stream */
 211                 tcp_zero_win_probe: 1,  /* Zero win probing is in progress */
 212 
 213                 tcp_loopback: 1,        /* src and dst are the same machine */
 214                 tcp_localnet: 1,        /* src and dst are on the same subnet */
 215                 tcp_syn_defense: 1,     /* For defense against SYN attack */
 216 #define tcp_dontdrop    tcp_syn_defense
 217                 tcp_set_timer : 1,
 218 
 219                 tcp_active_open: 1,     /* This is a active open */
 220                 tcp_rexmit : 1,         /* TCP is retransmitting */
 221                 tcp_snd_sack_ok : 1,    /* Can use SACK for this connection */
 222                 tcp_hwcksum : 1,        /* The NIC is capable of hwcksum */
 223 
 224                 tcp_ip_forward_progress : 1,
 225                 tcp_ecn_ok : 1,         /* Can use ECN for this connection */
 226                 tcp_ecn_echo_on : 1,    /* Need to do ECN echo */
 227                 tcp_ecn_cwr_sent : 1,   /* ECN_CWR has been sent */
 228 
 229                 tcp_cwr : 1,            /* Cwnd has reduced recently */
 230 
 231                 tcp_pad_to_bit31 : 11;
 232 
 233         /* Following manipulated by TCP under squeue protection */
 234         uint32_t
 235                 tcp_snd_ts_ok  : 1,
 236                 tcp_snd_ws_ok  : 1,
 237                 tcp_reserved_port : 1,
 238                 tcp_in_free_list : 1,
 239 
 240                 tcp_snd_zcopy_on : 1,   /* xmit zero-copy enabled */
 241                 tcp_snd_zcopy_aware : 1, /* client is zero-copy aware */
 242                 tcp_xmit_zc_clean : 1,  /* the xmit list is free of zc-mblk */
 243                 tcp_wait_for_eagers : 1, /* Wait for eagers to disappear */
 244 
 245                 tcp_accept_error : 1,   /* Error during TLI accept */
 246                 tcp_send_discon_ind : 1, /* TLI accept err, send discon ind */
 247                 tcp_cork : 1,           /* tcp_cork option */
 248                 tcp_tconnind_started : 1, /* conn_ind message is being sent */
 249 
 250                 tcp_lso :1,             /* Lower layer is capable of LSO */
 251                 tcp_is_wnd_shrnk : 1,   /* Window has shrunk */
 252 
 253                 tcp_pad_to_bit_31 : 18;
 254 
 255         uint32_t        tcp_initial_pmtu; /* Initial outgoing Path MTU. */
 256 
 257         mblk_t  *tcp_reass_head;        /* Out of order reassembly list head */
 258         mblk_t  *tcp_reass_tail;        /* Out of order reassembly list tail */
 259 
 260         /* SACK related info */
 261         tcp_sack_info_t tcp_sack_info;
 262 
 263 #define tcp_pipe                tcp_sack_info.tcp_pipe
 264 #define tcp_fack                tcp_sack_info.tcp_fack
 265 #define tcp_sack_snxt           tcp_sack_info.tcp_sack_snxt
 266 #define tcp_max_sack_blk        tcp_sack_info.tcp_max_sack_blk
 267 #define tcp_num_sack_blk        tcp_sack_info.tcp_num_sack_blk
 268 #define tcp_sack_list           tcp_sack_info.tcp_sack_list
 269 #define tcp_num_notsack_blk     tcp_sack_info.tcp_num_notsack_blk
 270 #define tcp_cnt_notsack_list    tcp_sack_info.tcp_cnt_notsack_list
 271 #define tcp_notsack_list        tcp_sack_info.tcp_notsack_list
 272 
 273         mblk_t  *tcp_rcv_list;          /* Queued until push, urgent data, */
 274         mblk_t  *tcp_rcv_last_head;     /* optdata, or the count exceeds */
 275         mblk_t  *tcp_rcv_last_tail;     /* tcp_rcv_push_wait. */
 276         uint32_t tcp_rcv_cnt;           /* tcp_rcv_list is b_next chain. */
 277 
 278         uint32_t tcp_cwnd_ssthresh;     /* Congestion window */
 279         uint32_t tcp_cwnd_max;
 280         uint32_t tcp_csuna;             /* Clear (no rexmits in window) suna */
 281 
 282         hrtime_t tcp_rtt_sum;           /* Round trip sum */
 283         uint32_t tcp_rtt_cnt;           /* Round trip count (non_dup ACKs) */
 284         hrtime_t tcp_rtt_sa;            /* Round trip smoothed average */
 285         hrtime_t tcp_rtt_sd;            /* Round trip smoothed deviation */
 286         uint32_t tcp_rtt_update;        /* Round trip update(s) */
 287         clock_t tcp_ms_we_have_waited;  /* Total retrans time */
 288 
 289         uint32_t tcp_swl1;              /* These help us avoid using stale */
 290         uint32_t tcp_swl2;              /*  packets to update state */
 291 
 292         uint32_t tcp_rack;              /* Seq # we have acked */
 293         uint32_t tcp_rack_cnt;          /* # of segs we have deferred ack */
 294         uint32_t tcp_rack_cur_max;      /* # of segs we may defer ack for now */
 295         uint32_t tcp_rack_abs_max;      /* # of segs we may defer ack ever */
 296         timeout_id_t    tcp_ack_tid;    /* Delayed ACK timer ID */
 297         timeout_id_t    tcp_push_tid;   /* Push timer ID */
 298 
 299         uint32_t tcp_max_swnd;          /* Maximum swnd we have seen */
 300 
 301         struct tcp_s *tcp_listener;     /* Our listener */
 302 
 303         uint32_t tcp_irs;               /* Initial recv seq num */
 304         uint32_t tcp_fss;               /* Final/fin send seq num */
 305         uint32_t tcp_urg;               /* Urgent data seq num */
 306 
 307         clock_t tcp_first_timer_threshold;  /* When to prod IP */
 308         clock_t tcp_second_timer_threshold; /* When to give up completely */
 309         clock_t tcp_first_ctimer_threshold; /* 1st threshold while connecting */
 310         clock_t tcp_second_ctimer_threshold; /* 2nd ... while connecting */
 311 
 312         uint32_t tcp_urp_last;          /* Last urp for which signal sent */
 313         mblk_t  *tcp_urp_mp;            /* T_EXDATA_IND for urgent byte */
 314         mblk_t  *tcp_urp_mark_mp;       /* zero-length marked/unmarked msg */
 315 
 316         int tcp_conn_req_cnt_q0;        /* # of conn reqs in SYN_RCVD */
 317         int tcp_conn_req_cnt_q; /* # of conn reqs in ESTABLISHED */
 318         int tcp_conn_req_max;   /* # of ESTABLISHED conn reqs allowed */
 319         t_scalar_t tcp_conn_req_seqnum; /* Incrementing pending conn req ID */
 320 #define tcp_ip_addr_cache       tcp_reass_tail
 321                                         /* Cache ip addresses that */
 322                                         /* complete the 3-way handshake */
 323         kmutex_t  tcp_eager_lock;
 324         struct tcp_s *tcp_eager_next_q; /* next eager in ESTABLISHED state */
 325         struct tcp_s *tcp_eager_last_q; /* last eager in ESTABLISHED state */
 326         struct tcp_s *tcp_eager_next_q0; /* next eager in SYN_RCVD state */
 327         struct tcp_s *tcp_eager_prev_q0; /* prev eager in SYN_RCVD state */
 328                                         /* all eagers form a circular list */
 329         boolean_t tcp_conn_def_q0;      /* move from q0 to q deferred */
 330 
 331         union {
 332             mblk_t *tcp_eager_conn_ind; /* T_CONN_IND waiting for 3rd ack. */
 333             mblk_t *tcp_opts_conn_req; /* T_CONN_REQ w/ options processed */
 334         } tcp_conn;
 335         uint32_t tcp_syn_rcvd_timeout;  /* How many SYN_RCVD timeout in q0 */
 336 
 337         /*
 338          * TCP Keepalive Timer members.
 339          * All keepalive timer intervals are in milliseconds.
 340          */
 341         int32_t tcp_ka_last_intrvl;     /* Last probe interval */
 342         timeout_id_t tcp_ka_tid;        /* Keepalive timer ID */
 343         uint32_t tcp_ka_interval;       /* Keepalive interval */
 344 
 345         /*
 346          * TCP connection is terminated if we don't hear back from the peer
 347          * for tcp_ka_abort_thres milliseconds after the first keepalive probe.
 348          * tcp_ka_rinterval is the interval in milliseconds between successive
 349          * keepalive probes. tcp_ka_cnt is the number of keepalive probes to
 350          * be sent before terminating the connection, if we don't hear back from
 351          * peer.
 352          * tcp_ka_abort_thres = tcp_ka_rinterval * tcp_ka_cnt
 353          */
 354         uint32_t tcp_ka_rinterval;      /* keepalive retransmit interval */
 355         uint32_t tcp_ka_abort_thres;    /* Keepalive abort threshold */
 356         uint32_t tcp_ka_cnt;            /* count of keepalive probes */
 357 
 358         int32_t tcp_client_errno;       /* How the client screwed up */
 359 
 360         /*
 361          * The header template lives in conn_ht_iphc allocated by tcp_build_hdrs
 362          * We maintain three pointers into conn_ht_iphc.
 363          */
 364         ipha_t  *tcp_ipha;              /* IPv4 header in conn_ht_iphc */
 365         ip6_t   *tcp_ip6h;              /* IPv6 header in conn_ht_iphc */
 366         tcpha_t *tcp_tcpha;             /* TCP header in conn_ht_iphc */
 367 
 368         uint16_t tcp_last_sent_len;     /* Record length for nagle */
 369         uint16_t tcp_last_recv_len;     /* Used by DTrace */
 370         uint16_t tcp_dupack_cnt;        /* # of consequtive duplicate acks */
 371 
 372         kmutex_t        *tcp_acceptor_lockp;    /* Ptr to tf_lock */
 373 
 374         mblk_t          *tcp_ordrel_mp;         /* T_ordrel_ind mblk */
 375         t_uscalar_t     tcp_acceptor_id;        /* ACCEPTOR_id */
 376 
 377         int             tcp_ipsec_overhead;
 378 
 379         uint_t          tcp_recvifindex; /* Last received IPV6_RCVPKTINFO */
 380         uint_t          tcp_recvhops;   /* Last received IPV6_RECVHOPLIMIT */
 381         uint_t          tcp_recvtclass; /* Last received IPV6_RECVTCLASS */
 382         ip6_hbh_t       *tcp_hopopts;   /* Last received IPV6_RECVHOPOPTS */
 383         ip6_dest_t      *tcp_dstopts;   /* Last received IPV6_RECVDSTOPTS */
 384         ip6_dest_t      *tcp_rthdrdstopts; /* Last recv IPV6_RECVRTHDRDSTOPTS */
 385         ip6_rthdr_t     *tcp_rthdr;     /* Last received IPV6_RECVRTHDR */
 386         uint_t          tcp_hopoptslen;
 387         uint_t          tcp_dstoptslen;
 388         uint_t          tcp_rthdrdstoptslen;
 389         uint_t          tcp_rthdrlen;
 390 
 391         mblk_t          *tcp_timercache;
 392 
 393         kmutex_t        tcp_closelock;
 394         kcondvar_t      tcp_closecv;
 395         uint8_t         tcp_closed;
 396         uint8_t         tcp_closeflags;
 397         mblk_t          tcp_closemp;
 398         timeout_id_t    tcp_linger_tid; /* Linger timer ID */
 399 
 400         struct tcp_s *tcp_acceptor_hash; /* Acceptor hash chain */
 401         struct tcp_s **tcp_ptpahn; /* Pointer to previous accept hash next. */
 402         struct tcp_s *tcp_bind_hash; /* Bind hash chain */
 403         struct tcp_s *tcp_bind_hash_port; /* tcp_t's bound to the same lport */
 404         struct tcp_s **tcp_ptpbhn;
 405 
 406         uint_t          tcp_maxpsz_multiplier;
 407 
 408         uint32_t        tcp_lso_max; /* maximum LSO payload */
 409 
 410         uint32_t        tcp_ofo_fin_seq; /* Recv out of order FIN seq num */
 411         uint32_t        tcp_cwr_snd_max;
 412 
 413         struct tcp_s *tcp_saved_listener;       /* saved value of listener */
 414 
 415         uint32_t        tcp_in_ack_unsent;      /* ACK for unsent data cnt. */
 416 
 417         /*
 418          * All fusion-related fields are protected by squeue.
 419          */
 420         struct tcp_s *tcp_loopback_peer;        /* peer tcp for loopback */
 421         mblk_t  *tcp_fused_sigurg_mp;           /* M_PCSIG mblk for SIGURG */
 422 
 423         uint32_t
 424                 tcp_fused : 1,          /* loopback tcp in fusion mode */
 425                 tcp_unfusable : 1,      /* fusion not allowed on endpoint */
 426                 tcp_fused_sigurg : 1,   /* send SIGURG upon draining */
 427 
 428                 tcp_fuse_to_bit_31 : 29;
 429 
 430         kmutex_t tcp_non_sq_lock;
 431 
 432         /*
 433          * This variable is accessed without any lock protection
 434          * and therefore must not be declared as a bit field along
 435          * with the rest which require such condition.
 436          */
 437         boolean_t       tcp_issocket;   /* this is a socket tcp */
 438 
 439         /* protected by the tcp_non_sq_lock lock */
 440         uint32_t        tcp_squeue_bytes;
 441 
 442         /*
 443          * tcp_closemp_used is protected by listener's tcp_eager_lock
 444          * when used for eagers. When used for a tcp in TIME_WAIT state
 445          * or in tcp_close(), it is not protected by any lock as we
 446          * do not expect any other thread to use it concurrently.
 447          * We do allow re-use of tcp_closemp in tcp_time_wait_collector()
 448          * and tcp_close() but not concurrently.
 449          */
 450         boolean_t tcp_closemp_used;
 451 
 452         /*
 453          * previous and next eagers in the list of droppable eagers. See
 454          * the comments before MAKE_DROPPABLE(). These pointers are
 455          * protected by listener's tcp_eager_lock.
 456          */
 457         struct tcp_s    *tcp_eager_prev_drop_q0;
 458         struct tcp_s    *tcp_eager_next_drop_q0;
 459 
 460         /*
 461          * Have we flow controlled xmitter?
 462          * This variable can be modified outside the squeue and hence must
 463          * not be declared as a bit field along with the rest that are
 464          * modified only within the squeue.
 465          * protected by the tcp_non_sq_lock lock.
 466          */
 467         boolean_t       tcp_flow_stopped;
 468 
 469         /*
 470          * Sender's next sequence number at the time the window was shrunk.
 471          */
 472         uint32_t        tcp_snxt_shrunk;
 473 
 474         /*
 475          * Socket generation number which is bumped when a connection attempt
 476          * is initiated. Its main purpose is to ensure that the socket does not
 477          * miss the asynchronous connected/disconnected notification.
 478          */
 479         sock_connid_t   tcp_connid;
 480 
 481         /* mblk_t used to enter TCP's squeue from the service routine. */
 482         mblk_t          *tcp_rsrv_mp;
 483         /* Mutex for accessing tcp_rsrv_mp */
 484         kmutex_t        tcp_rsrv_mp_lock;
 485 
 486         /* For connection counting. */
 487         struct tcp_listen_cnt_s *tcp_listen_cnt;
 488 
 489         /* Segment reassembly timer. */
 490         timeout_id_t            tcp_reass_tid;
 491 
 492         /* FIN-WAIT-2 flush timeout */
 493         uint32_t                tcp_fin_wait_2_flush_interval;
 494 
 495         tcp_conn_stats_t        tcp_cs;
 496 
 497 #ifdef DEBUG
 498         pc_t                    tcmp_stk[15];
 499 #endif
 500 } tcp_t;
 501 
 502 #ifdef DEBUG
 503 #define TCP_DEBUG_GETPCSTACK(buffer, depth)     ((void) getpcstack(buffer, \
 504                                                     depth))
 505 #else
 506 #define TCP_DEBUG_GETPCSTACK(buffer, depth)
 507 #endif
 508 
 509 extern void     tcp_conn_reclaim(void *);
 510 extern void     tcp_free(tcp_t *tcp);
 511 extern void     tcp_ddi_g_init(void);
 512 extern void     tcp_ddi_g_destroy(void);
 513 extern conn_t   *tcp_get_conn(void *arg, tcp_stack_t *);
 514 extern mblk_t   *tcp_snmp_get(queue_t *, mblk_t *, boolean_t);
 515 extern int      tcp_snmp_set(queue_t *, int, int, uchar_t *, int len);
 516 
 517 /* Pad for the tf_t structure to avoid false cache line sharing. */
 518 #define TF_CACHEL_PAD   64
 519 
 520 /*
 521  * The TCP Fanout structure for bind and acceptor hashes.
 522  * The hash tables and their linkage (tcp_*_hash, tcp_ptp*hn) are
 523  * protected by the per-bucket tf_lock.  Each tcp_t
 524  * inserted in the list points back at this lock using tcp_*_lockp.
 525  *
 526  * The bind and acceptor hash queues are lists of tcp_t.
 527  */
 528 /* listener hash and acceptor hash queue head */
 529 typedef struct tf_s {
 530         tcp_t           *tf_tcp;
 531         kmutex_t        tf_lock;
 532         unsigned char   tf_pad[TF_CACHEL_PAD -
 533             (sizeof (tcp_t *) + sizeof (kmutex_t))];
 534 } tf_t;
 535 
 536 
 537 /* Also used in ipclassifier.c */
 538 extern struct kmem_cache  *tcp_sack_info_cache;
 539 
 540 #endif  /* (defined(_KERNEL) || defined(_KMEMUSER)) */
 541 
 542 /* Contract private interface between TCP and Clustering. */
 543 
 544 #define CL_TCPI_V1      1       /* cl_tcpi_version number */
 545 
 546 typedef struct cl_tcp_info_s {
 547         ushort_t        cl_tcpi_version;        /* cl_tcp_info_t's version no */
 548         ushort_t        cl_tcpi_ipversion;      /* IP version */
 549         int32_t         cl_tcpi_state;          /* TCP state */
 550         in_port_t       cl_tcpi_lport;          /* Local port */
 551         in_port_t       cl_tcpi_fport;          /* Remote port */
 552         in6_addr_t      cl_tcpi_laddr_v6;       /* Local IP address */
 553         in6_addr_t      cl_tcpi_faddr_v6;       /* Remote IP address */
 554 #ifdef _KERNEL
 555 /* Note: V4_PART_OF_V6 is meant to be used only for _KERNEL defined stuff */
 556 #define cl_tcpi_laddr   V4_PART_OF_V6(cl_tcpi_laddr_v6)
 557 #define cl_tcpi_faddr   V4_PART_OF_V6(cl_tcpi_faddr_v6)
 558 
 559 #endif  /* _KERNEL */
 560 } cl_tcp_info_t;
 561 
 562 /*
 563  * Hook functions to enable cluster networking
 564  * On non-clustered systems these vectors must always be NULL.
 565  */
 566 extern void     (*cl_inet_listen)(netstackid_t, uint8_t, sa_family_t,
 567                     uint8_t *, in_port_t, void *);
 568 extern void     (*cl_inet_unlisten)(netstackid_t, uint8_t, sa_family_t,
 569                     uint8_t *, in_port_t, void *);
 570 
 571 /*
 572  * Contracted Consolidation Private ioctl for aborting TCP connections.
 573  * In order to keep the offsets and size of the structure the same between
 574  * a 32-bit application and a 64-bit amd64 kernel, we use a #pragma
 575  * pack(4).
 576  */
 577 #define TCP_IOC_ABORT_CONN      (('T' << 8) + 91)
 578 
 579 #if _LONG_LONG_ALIGNMENT == 8 && _LONG_LONG_ALIGNMENT_32 == 4
 580 #pragma pack(4)
 581 #endif
 582 
 583 typedef struct tcp_ioc_abort_conn_s {
 584         struct sockaddr_storage ac_local;       /* local addr and port */
 585         struct sockaddr_storage ac_remote;      /* remote addr and port */
 586         int32_t ac_start;                       /* start state */
 587         int32_t ac_end;                         /* end state  */
 588         int32_t ac_zoneid;                      /* zoneid */
 589 } tcp_ioc_abort_conn_t;
 590 
 591 #if _LONG_LONG_ALIGNMENT == 8 && _LONG_LONG_ALIGNMENT_32 == 4
 592 #pragma pack()
 593 #endif
 594 
 595 #ifdef  __cplusplus
 596 }
 597 #endif
 598 
 599 #endif  /* _INET_TCP_H */