root/usr/src/uts/common/rpc/clnt_cots.c
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2016 by Delphix. All rights reserved.
 * Copyright 2019 Joyent, Inc.
 * Copyright 2020 Tintri by DDN. All rights reserved.
 */

/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T
 *              All Rights Reserved
 */

/*
 * Portions of this source code were derived from Berkeley 4.3 BSD
 * under license from the Regents of the University of California.
 */


/*
 * Implements a kernel based, client side RPC over Connection Oriented
 * Transports (COTS).
 */

/*
 * Much of this file has been re-written to let NFS work better over slow
 * transports. A description follows.
 *
 * One of the annoying things about kRPC/COTS is that it will temporarily
 * create more than one connection between a client and server. This
 * happens because when a connection is made, the end-points entry in the
 * linked list of connections (headed by cm_hd), is removed so that other
 * threads don't mess with it. Went ahead and bit the bullet by keeping
 * the endpoint on the connection list and introducing state bits,
 * condition variables etc. to the connection entry data structure (struct
 * cm_xprt).
 *
 * Here is a summary of the changes to cm-xprt:
 *
 *      x_ctime is the timestamp of when the endpoint was last
 *      connected or disconnected. If an end-point is ever disconnected
 *      or re-connected, then any outstanding RPC request is presumed
 *      lost, telling clnt_cots_kcallit that it needs to re-send the
 *      request, not just wait for the original request's reply to
 *      arrive.
 *
 *      x_thread flag which tells us if a thread is doing a connection attempt.
 *
 *      x_waitdis flag which tells us we are waiting a disconnect ACK.
 *
 *      x_needdis flag which tells us we need to send a T_DISCONN_REQ
 *      to kill the connection.
 *
 *      x_needrel flag which tells us we need to send a T_ORDREL_REQ to
 *      gracefully close the connection.
 *
 *      #defined bitmasks for the all the b_* bits so that more
 *      efficient (and at times less clumsy) masks can be used to
 *      manipulated state in cases where multiple bits have to
 *      set/cleared/checked in the same critical section.
 *
 *      x_conn_cv and x_dis-_cv are new condition variables to let
 *      threads knows when the connection attempt is done, and to let
 *      the connecting thread know when the disconnect handshake is
 *      done.
 *
 * Added the CONN_HOLD() macro so that all reference holds have the same
 * look and feel.
 *
 * In the private (cku_private) portion of the client handle,
 *
 *      cku_flags replaces the cku_sent a boolean. cku_flags keeps
 *      track of whether a request as been sent, and whether the
 *      client's handles call record is on the dispatch list (so that
 *      the reply can be matched by XID to the right client handle).
 *      The idea of CKU_ONQUEUE is that we can exit clnt_cots_kcallit()
 *      and still have the response find the right client handle so
 *      that the retry of CLNT_CALL() gets the result. Testing, found
 *      situations where if the timeout was increased, performance
 *      degraded. This was due to us hitting a window where the thread
 *      was back in rfscall() (probably printing server not responding)
 *      while the response came back but no place to put it.
 *
 *      cku_ctime is just a cache of x_ctime. If they match,
 *      clnt_cots_kcallit() won't to send a retry (unless the maximum
 *      receive count limit as been reached). If the don't match, then
 *      we assume the request has been lost, and a retry of the request
 *      is needed.
 *
 *      cku_recv_attempts counts the number of receive count attempts
 *      after one try is sent on the wire.
 *
 * Added the clnt_delay() routine so that interruptible and
 * noninterruptible delays are possible.
 *
 * CLNT_MIN_TIMEOUT has been bumped to 10 seconds from 3. This is used to
 * control how long the client delays before returned after getting
 * ECONNREFUSED. At 3 seconds, 8 client threads per mount really does bash
 * a server that may be booting and not yet started nfsd.
 *
 * CLNT_MAXRECV_WITHOUT_RETRY is a new macro (value of 3) (with a tunable)
 * Why don't we just wait forever (receive an infinite # of times)?
 * Because the server may have rebooted. More insidious is that some
 * servers (ours) will drop NFS/TCP requests in some cases. This is bad,
 * but it is a reality.
 *
 * The case of a server doing orderly release really messes up the
 * client's recovery, especially if the server's TCP implementation is
 * buggy.  It was found was that the kRPC/COTS client was breaking some
 * TPI rules, such as not waiting for the acknowledgement of a
 * T_DISCON_REQ (hence the added case statements T_ERROR_ACK, T_OK_ACK and
 * T_DISCON_REQ in clnt_dispatch_notifyall()).
 *
 * One of things that we've seen is that a kRPC TCP endpoint goes into
 * TIMEWAIT and a thus a reconnect takes a long time to satisfy because
 * that the TIMEWAIT state takes a while to finish.  If a server sends a
 * T_ORDREL_IND, there is little point in an RPC client doing a
 * T_ORDREL_REQ, because the RPC request isn't going to make it (the
 * server is saying that it won't accept any more data). So kRPC was
 * changed to send a T_DISCON_REQ when we get a T_ORDREL_IND. So now the
 * connection skips the TIMEWAIT state and goes straight to a bound state
 * that kRPC can quickly switch to connected.
 *
 * Code that issues TPI request must use waitforack() to wait for the
 * corresponding ack (assuming there is one) in any future modifications.
 * This works around problems that may be introduced by breaking TPI rules
 * (by submitting new calls before earlier requests have been acked) in the
 * case of a signal or other early return.  waitforack() depends on
 * clnt_dispatch_notifyconn() to issue the wakeup when the ack
 * arrives, so adding new TPI calls may require corresponding changes
 * to clnt_dispatch_notifyconn(). Presently, the timeout period is based on
 * CLNT_MIN_TIMEOUT which is 10 seconds. If you modify this value, be sure
 * not to set it too low or TPI ACKS will be lost.
 */

#include <sys/param.h>
#include <sys/types.h>
#include <sys/user.h>
#include <sys/systm.h>
#include <sys/sysmacros.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <sys/file.h>
#include <sys/stream.h>
#include <sys/strsubr.h>
#include <sys/stropts.h>
#include <sys/strsun.h>
#include <sys/timod.h>
#include <sys/tiuser.h>
#include <sys/tihdr.h>
#include <sys/t_kuser.h>
#include <sys/fcntl.h>
#include <sys/errno.h>
#include <sys/kmem.h>
#include <sys/debug.h>
#include <sys/systm.h>
#include <sys/kstat.h>
#include <sys/t_lock.h>
#include <sys/ddi.h>
#include <sys/cmn_err.h>
#include <sys/time.h>
#include <sys/isa_defs.h>
#include <sys/callb.h>
#include <sys/sunddi.h>
#include <sys/atomic.h>
#include <sys/sdt.h>

#include <netinet/in.h>
#include <netinet/tcp.h>

#include <rpc/types.h>
#include <rpc/xdr.h>
#include <rpc/auth.h>
#include <rpc/clnt.h>
#include <rpc/rpc_msg.h>

#define COTS_DEFAULT_ALLOCSIZE  2048

#define WIRE_HDR_SIZE   20      /* serialized call header, sans proc number */
#define MSG_OFFSET      128     /* offset of call into the mblk */

const char *kinet_ntop6(uchar_t *, char *, size_t);

static int      clnt_cots_ksettimers(CLIENT *, struct rpc_timers *,
    struct rpc_timers *, int, void(*)(int, int, caddr_t), caddr_t, uint32_t);
static enum clnt_stat   clnt_cots_kcallit(CLIENT *, rpcproc_t, xdrproc_t,
    caddr_t, xdrproc_t, caddr_t, struct timeval);
static void     clnt_cots_kabort(CLIENT *);
static void     clnt_cots_kerror(CLIENT *, struct rpc_err *);
static bool_t   clnt_cots_kfreeres(CLIENT *, xdrproc_t, caddr_t);
static void     clnt_cots_kdestroy(CLIENT *);
static bool_t   clnt_cots_kcontrol(CLIENT *, int, char *);


/* List of transports managed by the connection manager. */
struct cm_xprt {
        TIUSER          *x_tiptr;       /* transport handle */
        queue_t         *x_wq;          /* send queue */
        clock_t         x_time;         /* last time we handed this xprt out */
        clock_t         x_ctime;        /* time we went to CONNECTED */
        int             x_tidu_size;    /* TIDU size of this transport */
        union {
            struct {
                unsigned int
#ifdef  _BIT_FIELDS_HTOL
                b_closing:      1,      /* we've sent a ord rel on this conn */
                b_dead:         1,      /* transport is closed or disconn */
                b_doomed:       1,      /* too many conns, let this go idle */
                b_connected:    1,      /* this connection is connected */

                b_ordrel:       1,      /* do an orderly release? */
                b_thread:       1,      /* thread doing connect */
                b_waitdis:      1,      /* waiting for disconnect ACK */
                b_needdis:      1,      /* need T_DISCON_REQ */

                b_needrel:      1,      /* need T_ORDREL_REQ */
                b_early_disc:   1,      /* got a T_ORDREL_IND or T_DISCON_IND */
                                        /* disconnect during connect */

                b_pad:          22;

#endif

#ifdef  _BIT_FIELDS_LTOH
                b_pad:          22,

                b_early_disc:   1,      /* got a T_ORDREL_IND or T_DISCON_IND */
                                        /* disconnect during connect */
                b_needrel:      1,      /* need T_ORDREL_REQ */

                b_needdis:      1,      /* need T_DISCON_REQ */
                b_waitdis:      1,      /* waiting for disconnect ACK */
                b_thread:       1,      /* thread doing connect */
                b_ordrel:       1,      /* do an orderly release? */

                b_connected:    1,      /* this connection is connected */
                b_doomed:       1,      /* too many conns, let this go idle */
                b_dead:         1,      /* transport is closed or disconn */
                b_closing:      1;      /* we've sent a ord rel on this conn */
#endif
            } bit;          unsigned int word;

#define x_closing       x_state.bit.b_closing
#define x_dead          x_state.bit.b_dead
#define x_doomed        x_state.bit.b_doomed
#define x_connected     x_state.bit.b_connected

#define x_ordrel        x_state.bit.b_ordrel
#define x_thread        x_state.bit.b_thread
#define x_waitdis       x_state.bit.b_waitdis
#define x_needdis       x_state.bit.b_needdis

#define x_needrel       x_state.bit.b_needrel
#define x_early_disc    x_state.bit.b_early_disc

#define x_state_flags   x_state.word

#define X_CLOSING       0x80000000
#define X_DEAD          0x40000000
#define X_DOOMED        0x20000000
#define X_CONNECTED     0x10000000

#define X_ORDREL        0x08000000
#define X_THREAD        0x04000000
#define X_WAITDIS       0x02000000
#define X_NEEDDIS       0x01000000

#define X_NEEDREL       0x00800000
#define X_EARLYDISC     0x00400000

#define X_BADSTATES     (X_CLOSING | X_DEAD | X_DOOMED)

        }               x_state;
        int             x_ref;          /* number of users of this xprt */
        int             x_family;       /* address family of transport */
        dev_t           x_rdev;         /* device number of transport */
        struct cm_xprt  *x_next;

        struct netbuf   x_server;       /* destination address */
        struct netbuf   x_src;          /* src address (for retries) */
        kmutex_t        x_lock;         /* lock on this entry */
        kcondvar_t      x_cv;           /* to signal when can be closed */
        kcondvar_t      x_conn_cv;      /* to signal when connection attempt */
                                        /* is complete */
        kstat_t         *x_ksp;

        kcondvar_t      x_dis_cv;       /* to signal when disconnect attempt */
                                        /* is complete */
        zoneid_t        x_zoneid;       /* zone this xprt belongs to */
};

typedef struct cm_kstat_xprt {
        kstat_named_t   x_wq;
        kstat_named_t   x_server;
        kstat_named_t   x_family;
        kstat_named_t   x_rdev;
        kstat_named_t   x_time;
        kstat_named_t   x_state;
        kstat_named_t   x_ref;
        kstat_named_t   x_port;
} cm_kstat_xprt_t;

static cm_kstat_xprt_t cm_kstat_template = {
        { "write_queue", KSTAT_DATA_UINT32 },
        { "server",     KSTAT_DATA_STRING },
        { "addr_family", KSTAT_DATA_UINT32 },
        { "device",     KSTAT_DATA_UINT32 },
        { "time_stamp", KSTAT_DATA_UINT32 },
        { "status",     KSTAT_DATA_UINT32 },
        { "ref_count",  KSTAT_DATA_INT32 },
        { "port",       KSTAT_DATA_UINT32 },
};

/*
 * The inverse of this is connmgr_release().
 */
#define CONN_HOLD(Cm_entry)     {\
        mutex_enter(&(Cm_entry)->x_lock);       \
        (Cm_entry)->x_ref++;    \
        mutex_exit(&(Cm_entry)->x_lock);        \
}


/*
 * Private data per rpc handle.  This structure is allocated by
 * clnt_cots_kcreate, and freed by clnt_cots_kdestroy.
 */
typedef struct cku_private_s {
        CLIENT                  cku_client;     /* client handle */
        calllist_t              cku_call;       /* for dispatching calls */
        struct rpc_err          cku_err;        /* error status */

        struct netbuf           cku_srcaddr;    /* source or bind address */
                                                /* for retries */
        int                     cku_addrfmly;  /* for binding port */
        struct netbuf           cku_addr;       /* remote address */
        dev_t                   cku_device;     /* device to use */
        uint_t                  cku_flags;
#define CKU_ONQUEUE             0x1
#define CKU_SENT                0x2

        bool_t                  cku_progress;   /* for CLSET_PROGRESS */
        uint32_t                cku_xid;        /* current XID */
        clock_t                 cku_ctime;      /* time stamp of when */
                                                /* connection was created */
        uint_t                  cku_recv_attempts;
        XDR                     cku_outxdr;     /* xdr routine for output */
        XDR                     cku_inxdr;      /* xdr routine for input */
        char                    cku_rpchdr[WIRE_HDR_SIZE + 4];
                                                /* pre-serialized rpc header */

        uint_t                  cku_outbuflen;  /* default output mblk length */
        struct cred             *cku_cred;      /* credentials */
        bool_t                  cku_nodelayonerr;
                                                /* for CLSET_NODELAYONERR */
        int                     cku_useresvport; /* Use reserved port */
        int                     cku_bindsrc;    /* bind to src address */
        struct rpc_cots_client  *cku_stats;     /* stats for zone */
} cku_private_t;

static struct cm_xprt *connmgr_wrapconnect(struct cm_xprt *,
        const struct timeval *, struct netbuf *, int, struct netbuf *,
        struct rpc_err *, bool_t, bool_t, cred_t *);

static bool_t   connmgr_connect(struct cm_xprt *, queue_t *, struct netbuf *,
                                int, calllist_t *, int *, bool_t reconnect,
                                const struct timeval *, bool_t, cred_t *);

static void     *connmgr_opt_getoff(mblk_t *mp, t_uscalar_t offset,
                                t_uscalar_t length, uint_t align_size);
static bool_t   connmgr_setbufsz(calllist_t *e, queue_t *wq, cred_t *cr);
static bool_t   connmgr_getopt_int(queue_t *wq, int level, int name, int *val,
                                calllist_t *e, cred_t *cr);
static bool_t   connmgr_setopt_int(queue_t *wq, int level, int name, int val,
                                calllist_t *e, cred_t *cr);
static bool_t   connmgr_setopt(queue_t *, int, int, calllist_t *, cred_t *cr);
static void     connmgr_sndrel(struct cm_xprt *);
static void     connmgr_snddis(struct cm_xprt *);
static void     connmgr_close(struct cm_xprt *);
static void     connmgr_release(struct cm_xprt *);
static struct cm_xprt *connmgr_wrapget(struct netbuf *, const struct timeval *,
        cku_private_t *, bool_t);

static struct cm_xprt *connmgr_get(struct netbuf *, const struct timeval *,
        struct netbuf *, int, struct netbuf *, struct rpc_err *, dev_t,
        bool_t, int, cred_t *, bool_t);

static void connmgr_cancelconn(struct cm_xprt *);
static enum clnt_stat connmgr_cwait(struct cm_xprt *, const struct timeval *,
        bool_t);
static void connmgr_dis_and_wait(struct cm_xprt *);

static int      clnt_dispatch_send(queue_t *, mblk_t *, calllist_t *, uint_t,
                                        uint_t);

static int clnt_delay(clock_t, bool_t);

static int waitforack(calllist_t *, t_scalar_t, const struct timeval *, bool_t);

/*
 * Operations vector for TCP/IP based RPC
 */
static struct clnt_ops tcp_ops = {
        clnt_cots_kcallit,      /* do rpc call */
        clnt_cots_kabort,       /* abort call */
        clnt_cots_kerror,       /* return error status */
        clnt_cots_kfreeres,     /* free results */
        clnt_cots_kdestroy,     /* destroy rpc handle */
        clnt_cots_kcontrol,     /* the ioctl() of rpc */
        clnt_cots_ksettimers,   /* set retry timers */
};

static int rpc_kstat_instance = 0;  /* keeps the current instance */
                                /* number for the next kstat_create */

static struct cm_xprt *cm_hd = NULL;
static kmutex_t connmgr_lock;   /* for connection mngr's list of transports */

extern kmutex_t clnt_max_msg_lock;

static calllist_t *clnt_pending = NULL;
extern kmutex_t clnt_pending_lock;

static int clnt_cots_hash_size = DEFAULT_HASH_SIZE;

static call_table_t *cots_call_ht;

static const struct rpc_cots_client {
        kstat_named_t   rccalls;
        kstat_named_t   rcbadcalls;
        kstat_named_t   rcbadxids;
        kstat_named_t   rctimeouts;
        kstat_named_t   rcnewcreds;
        kstat_named_t   rcbadverfs;
        kstat_named_t   rctimers;
        kstat_named_t   rccantconn;
        kstat_named_t   rcnomem;
        kstat_named_t   rcintrs;
} cots_rcstat_tmpl = {
        { "calls",      KSTAT_DATA_UINT64 },
        { "badcalls",   KSTAT_DATA_UINT64 },
        { "badxids",    KSTAT_DATA_UINT64 },
        { "timeouts",   KSTAT_DATA_UINT64 },
        { "newcreds",   KSTAT_DATA_UINT64 },
        { "badverfs",   KSTAT_DATA_UINT64 },
        { "timers",     KSTAT_DATA_UINT64 },
        { "cantconn",   KSTAT_DATA_UINT64 },
        { "nomem",      KSTAT_DATA_UINT64 },
        { "interrupts", KSTAT_DATA_UINT64 }
};

#define COTSRCSTAT_INCR(p, x)   \
        atomic_inc_64(&(p)->x.value.ui64)

#define CLNT_MAX_CONNS  1       /* concurrent connections between clnt/srvr */
int clnt_max_conns = CLNT_MAX_CONNS;

#define CLNT_MIN_TIMEOUT        10      /* seconds to wait after we get a */
                                        /* connection reset */
#define CLNT_MIN_CONNTIMEOUT    5       /* seconds to wait for a connection */


int clnt_cots_min_tout = CLNT_MIN_TIMEOUT;
int clnt_cots_min_conntout = CLNT_MIN_CONNTIMEOUT;

/*
 * Limit the number of times we will attempt to receive a reply without
 * re-sending a response.
 */
#define CLNT_MAXRECV_WITHOUT_RETRY      3
uint_t clnt_cots_maxrecv        = CLNT_MAXRECV_WITHOUT_RETRY;

uint_t *clnt_max_msg_sizep;
void (*clnt_stop_idle)(queue_t *wq);

#define ptoh(p)         (&((p)->cku_client))
#define htop(h)         ((cku_private_t *)((h)->cl_private))

/*
 * Times to retry
 */
#define REFRESHES       2       /* authentication refreshes */

/*
 * The following is used to determine the global default behavior for
 * COTS when binding to a local port.
 *
 * If the value is set to 1 the default will be to select a reserved
 * (aka privileged) port, if the value is zero the default will be to
 * use non-reserved ports.  Users of kRPC may override this by using
 * CLNT_CONTROL() and CLSET_BINDRESVPORT.
 */
int clnt_cots_do_bindresvport = 1;

static zone_key_t zone_cots_key;

/*
 * Defaults TCP send and receive buffer size for RPC connections.
 * These values can be tuned by /etc/system.
 */
int rpc_send_bufsz = 1024*1024;
int rpc_recv_bufsz = 1024*1024;
/*
 * To use system-wide default for TCP send and receive buffer size,
 * use /etc/system to set rpc_default_tcp_bufsz to 1:
 *
 * set rpcmod:rpc_default_tcp_bufsz=1
 */
int rpc_default_tcp_bufsz = 0;

/*
 * We need to do this after all kernel threads in the zone have exited.
 */
/* ARGSUSED */
static void
clnt_zone_destroy(zoneid_t zoneid, void *unused)
{
        struct cm_xprt **cmp;
        struct cm_xprt *cm_entry;
        struct cm_xprt *freelist = NULL;

        mutex_enter(&connmgr_lock);
        cmp = &cm_hd;
        while ((cm_entry = *cmp) != NULL) {
                if (cm_entry->x_zoneid == zoneid) {
                        *cmp = cm_entry->x_next;
                        cm_entry->x_next = freelist;
                        freelist = cm_entry;
                } else {
                        cmp = &cm_entry->x_next;
                }
        }
        mutex_exit(&connmgr_lock);
        while ((cm_entry = freelist) != NULL) {
                freelist = cm_entry->x_next;
                connmgr_close(cm_entry);
        }
}

int
clnt_cots_kcreate(dev_t dev, struct netbuf *addr, int family, rpcprog_t prog,
    rpcvers_t vers, uint_t max_msgsize, cred_t *cred, CLIENT **ncl)
{
        CLIENT *h;
        cku_private_t *p;
        struct rpc_msg call_msg;
        struct rpcstat *rpcstat;

        RPCLOG(8, "clnt_cots_kcreate: prog %u\n", prog);

        rpcstat = zone_getspecific(rpcstat_zone_key, rpc_zone());
        ASSERT(rpcstat != NULL);

        /* Allocate and intialize the client handle. */
        p = kmem_zalloc(sizeof (*p), KM_SLEEP);

        h = ptoh(p);

        h->cl_private = (caddr_t)p;
        h->cl_auth = authkern_create();
        h->cl_ops = &tcp_ops;

        cv_init(&p->cku_call.call_cv, NULL, CV_DEFAULT, NULL);
        mutex_init(&p->cku_call.call_lock, NULL, MUTEX_DEFAULT, NULL);

        /*
         * If the current sanity check size in rpcmod is smaller
         * than the size needed, then increase the sanity check.
         */
        if (max_msgsize != 0 && clnt_max_msg_sizep != NULL &&
            max_msgsize > *clnt_max_msg_sizep) {
                mutex_enter(&clnt_max_msg_lock);
                if (max_msgsize > *clnt_max_msg_sizep)
                        *clnt_max_msg_sizep = max_msgsize;
                mutex_exit(&clnt_max_msg_lock);
        }

        p->cku_outbuflen = COTS_DEFAULT_ALLOCSIZE;

        /* Preserialize the call message header */

        call_msg.rm_xid = 0;
        call_msg.rm_direction = CALL;
        call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
        call_msg.rm_call.cb_prog = prog;
        call_msg.rm_call.cb_vers = vers;

        xdrmem_create(&p->cku_outxdr, p->cku_rpchdr, WIRE_HDR_SIZE, XDR_ENCODE);

        if (!xdr_callhdr(&p->cku_outxdr, &call_msg)) {
                XDR_DESTROY(&p->cku_outxdr);
                RPCLOG0(1, "clnt_cots_kcreate - Fatal header serialization "
                    "error\n");
                auth_destroy(h->cl_auth);
                kmem_free(p, sizeof (cku_private_t));
                RPCLOG0(1, "clnt_cots_kcreate: create failed error EINVAL\n");
                return (EINVAL);                /* XXX */
        }
        XDR_DESTROY(&p->cku_outxdr);

        /*
         * The zalloc initialized the fields below.
         * p->cku_xid = 0;
         * p->cku_flags = 0;
         * p->cku_srcaddr.buf = NULL;
         * p->cku_srcaddr.len = 0;
         * p->cku_srcaddr.maxlen = 0;
         */

        p->cku_cred = cred;
        p->cku_device = dev;
        p->cku_addrfmly = family;
        p->cku_addr.buf = kmem_zalloc(addr->maxlen, KM_SLEEP);
        p->cku_addr.maxlen = addr->maxlen;
        p->cku_addr.len = addr->len;
        bcopy(addr->buf, p->cku_addr.buf, addr->len);
        p->cku_stats = rpcstat->rpc_cots_client;
        p->cku_useresvport = -1; /* value has not been set */
        p->cku_bindsrc = 0;

        *ncl = h;
        return (0);
}

/*ARGSUSED*/
static void
clnt_cots_kabort(CLIENT *h)
{
}

/*
 * Return error info on this handle.
 */
static void
clnt_cots_kerror(CLIENT *h, struct rpc_err *err)
{
        /* LINTED pointer alignment */
        cku_private_t *p = htop(h);

        *err = p->cku_err;
}

/*ARGSUSED*/
static bool_t
clnt_cots_kfreeres(CLIENT *h, xdrproc_t xdr_res, caddr_t res_ptr)
{
        xdr_free(xdr_res, res_ptr);

        return (TRUE);
}

static bool_t
clnt_cots_kcontrol(CLIENT *h, int cmd, char *arg)
{
        cku_private_t *p = htop(h);

        switch (cmd) {
        case CLSET_PROGRESS:
                p->cku_progress = TRUE;
                return (TRUE);

        case CLSET_XID:
                if (arg == NULL)
                        return (FALSE);

                p->cku_xid = *((uint32_t *)arg);
                return (TRUE);

        case CLGET_XID:
                if (arg == NULL)
                        return (FALSE);

                *((uint32_t *)arg) = p->cku_xid;
                return (TRUE);

        case CLSET_NODELAYONERR:
                if (arg == NULL)
                        return (FALSE);

                if (*((bool_t *)arg) == TRUE) {
                        p->cku_nodelayonerr = TRUE;
                        return (TRUE);
                }
                if (*((bool_t *)arg) == FALSE) {
                        p->cku_nodelayonerr = FALSE;
                        return (TRUE);
                }
                return (FALSE);

        case CLGET_NODELAYONERR:
                if (arg == NULL)
                        return (FALSE);

                *((bool_t *)arg) = p->cku_nodelayonerr;
                return (TRUE);

        case CLSET_BINDRESVPORT:
                if (arg == NULL)
                        return (FALSE);

                if (*(int *)arg != 1 && *(int *)arg != 0)
                        return (FALSE);

                p->cku_useresvport = *(int *)arg;

                return (TRUE);

        case CLGET_BINDRESVPORT:
                if (arg == NULL)
                        return (FALSE);

                *(int *)arg = p->cku_useresvport;

                return (TRUE);

        case CLSET_BINDSRCADDR:
                if (arg == NULL)
                        return (FALSE);

                struct netbuf *addr = (struct netbuf *)arg;
                clnt_dup_netbuf(addr, &p->cku_srcaddr);
                p->cku_bindsrc = 1;

                return (TRUE);


        default:
                return (FALSE);
        }
}

/*
 * Destroy rpc handle.  Frees the space used for output buffer,
 * private data, and handle structure.
 */
static void
clnt_cots_kdestroy(CLIENT *h)
{
        /* LINTED pointer alignment */
        cku_private_t *p = htop(h);
        calllist_t *call = &p->cku_call;

        RPCLOG(8, "clnt_cots_kdestroy h: %p\n", (void *)h);
        RPCLOG(8, "clnt_cots_kdestroy h: xid=0x%x\n", p->cku_xid);

        if (p->cku_flags & CKU_ONQUEUE) {
                RPCLOG(64, "clnt_cots_kdestroy h: removing call for xid 0x%x "
                    "from dispatch list\n", p->cku_xid);
                call_table_remove(call);
        }

        if (call->call_reply)
                freemsg(call->call_reply);
        cv_destroy(&call->call_cv);
        mutex_destroy(&call->call_lock);

        kmem_free(p->cku_srcaddr.buf, p->cku_srcaddr.maxlen);
        kmem_free(p->cku_addr.buf, p->cku_addr.maxlen);
        kmem_free(p, sizeof (*p));
}

static int clnt_cots_pulls;
#define RM_HDR_SIZE     4       /* record mark header size */

/*
 * Call remote procedure.
 */
static enum clnt_stat
clnt_cots_kcallit(CLIENT *h, rpcproc_t procnum, xdrproc_t xdr_args,
    caddr_t argsp, xdrproc_t xdr_results, caddr_t resultsp, struct timeval wait)
{
        /* LINTED pointer alignment */
        cku_private_t *p = htop(h);
        calllist_t *call = &p->cku_call;
        XDR *xdrs;
        struct rpc_msg reply_msg;
        mblk_t *mp;
#ifdef  RPCDEBUG
        clock_t time_sent;
#endif
        struct netbuf *retryaddr;
        struct cm_xprt *cm_entry = NULL;
        queue_t *wq;
        int len, waitsecs, max_waitsecs;
        int mpsize;
        int refreshes = REFRESHES;
        int interrupted;
        int tidu_size;
        enum clnt_stat status;
        struct timeval cwait;
        bool_t delay_first = FALSE;
        bool_t srcbind_only = FALSE;
        clock_t ticks, now;

        RPCLOG(2, "clnt_cots_kcallit, procnum %u\n", procnum);
        COTSRCSTAT_INCR(p->cku_stats, rccalls);

        RPCLOG(2, "clnt_cots_kcallit: wait.tv_sec: %ld\n", wait.tv_sec);
        RPCLOG(2, "clnt_cots_kcallit: wait.tv_usec: %ld\n", wait.tv_usec);
        /*
         * Bug ID 1240234:
         * Look out for zero length timeouts. We don't want to
         * wait zero seconds for a connection to be established.
         */
        if (wait.tv_sec < clnt_cots_min_conntout) {
                cwait.tv_sec = clnt_cots_min_conntout;
                cwait.tv_usec = 0;
                RPCLOG(8, "clnt_cots_kcallit: wait.tv_sec (%ld) too low,",
                    wait.tv_sec);
                RPCLOG(8, " setting to: %d\n", clnt_cots_min_conntout);
        } else {
                cwait = wait;
        }

call_again:
        if (cm_entry) {
                connmgr_release(cm_entry);
                cm_entry = NULL;
        }

        mp = NULL;

        /*
         * If the call is not a retry, allocate a new xid and cache it
         * for future retries.
         * Bug ID 1246045:
         * Treat call as a retry for purposes of binding the source
         * port only if we actually attempted to send anything on
         * the previous call.
         */
        if (p->cku_xid == 0) {
                p->cku_xid = alloc_xid();
                call->call_zoneid = rpc_zoneid();

                /*
                 * We need to ASSERT here that our xid != 0 because this
                 * determines whether or not our call record gets placed on
                 * the hash table or the linked list.  By design, we mandate
                 * that RPC calls over cots must have xid's != 0, so we can
                 * ensure proper management of the hash table.
                 */
                ASSERT(p->cku_xid != 0);

                if (p->cku_bindsrc) {
                        retryaddr = &p->cku_srcaddr;
                        srcbind_only = TRUE;
                } else {
                        retryaddr = NULL;
                }
                p->cku_flags &= ~CKU_SENT;

                if (p->cku_flags & CKU_ONQUEUE) {
                        RPCLOG(8, "clnt_cots_kcallit: new call, dequeuing old"
                            " one (%p)\n", (void *)call);
                        call_table_remove(call);
                        p->cku_flags &= ~CKU_ONQUEUE;
                        RPCLOG(64, "clnt_cots_kcallit: removing call from "
                            "dispatch list because xid was zero (now 0x%x)\n",
                            p->cku_xid);
                }

                if (call->call_reply != NULL) {
                        freemsg(call->call_reply);
                        call->call_reply = NULL;
                }
        } else if (p->cku_srcaddr.buf == NULL || p->cku_srcaddr.len == 0) {
                retryaddr = NULL;

        } else if (p->cku_flags & CKU_SENT) {
                retryaddr = &p->cku_srcaddr;
                srcbind_only = FALSE;

        } else {
                /*
                 * Bug ID 1246045: Nothing was sent, so set retryaddr to
                 * NULL and let connmgr_get() bind to any source port it
                 * can get.
                 */
                if (p->cku_bindsrc) {
                        retryaddr = &p->cku_srcaddr;
                        srcbind_only = TRUE;
                } else {
                        retryaddr = NULL;
                }
        }

        RPCLOG(64, "clnt_cots_kcallit: xid = 0x%x", p->cku_xid);
        RPCLOG(64, " flags = 0x%x\n", p->cku_flags);

        p->cku_err.re_status = RPC_TIMEDOUT;
        p->cku_err.re_errno = p->cku_err.re_terrno = 0;

        cm_entry = connmgr_wrapget(retryaddr, &cwait, p, srcbind_only);

        if (cm_entry == NULL) {
                RPCLOG(1, "clnt_cots_kcallit: can't connect status %s\n",
                    clnt_sperrno(p->cku_err.re_status));

                /*
                 * The reasons why we fail to create a connection are
                 * varied. In most cases we don't want the caller to
                 * immediately retry. This could have one or more
                 * bad effects. This includes flooding the net with
                 * connect requests to ports with no listener; a hard
                 * kernel loop due to all the "reserved" TCP ports being
                 * in use.
                 */
                delay_first = TRUE;

                /*
                 * Even if we end up returning EINTR, we still count a
                 * a "can't connect", because the connection manager
                 * might have been committed to waiting for or timing out on
                 * a connection.
                 */
                COTSRCSTAT_INCR(p->cku_stats, rccantconn);
                switch (p->cku_err.re_status) {
                case RPC_INTR:
                        p->cku_err.re_errno = EINTR;

                        /*
                         * No need to delay because a UNIX signal(2)
                         * interrupted us. The caller likely won't
                         * retry the CLNT_CALL() and even if it does,
                         * we assume the caller knows what it is doing.
                         */
                        delay_first = FALSE;
                        break;

                case RPC_TIMEDOUT:
                        p->cku_err.re_errno = ETIMEDOUT;

                        /*
                         * No need to delay because timed out already
                         * on the connection request and assume that the
                         * transport time out is longer than our minimum
                         * timeout, or least not too much smaller.
                         */
                        delay_first = FALSE;
                        break;

                case RPC_SYSTEMERROR:
                case RPC_TLIERROR:
                        /*
                         * We want to delay here because a transient
                         * system error has a better chance of going away
                         * if we delay a bit. If it's not transient, then
                         * we don't want end up in a hard kernel loop
                         * due to retries.
                         */
                        ASSERT(p->cku_err.re_errno != 0);
                        break;


                case RPC_CANTCONNECT:
                        /*
                         * RPC_CANTCONNECT is set on T_ERROR_ACK which
                         * implies some error down in the TCP layer or
                         * below. If cku_nodelayonerror is set then we
                         * assume the caller knows not to try too hard.
                         */
                        RPCLOG0(8, "clnt_cots_kcallit: connection failed,");
                        RPCLOG0(8, " re_status=RPC_CANTCONNECT,");
                        RPCLOG(8, " re_errno=%d,", p->cku_err.re_errno);
                        RPCLOG(8, " cku_nodelayonerr=%d", p->cku_nodelayonerr);
                        if (p->cku_nodelayonerr == TRUE)
                                delay_first = FALSE;

                        p->cku_err.re_errno = EIO;

                        break;

                case RPC_XPRTFAILED:
                        /*
                         * We want to delay here because we likely
                         * got a refused connection.
                         */
                        if (p->cku_err.re_errno == 0)
                                p->cku_err.re_errno = EIO;

                        RPCLOG(1, "clnt_cots_kcallit: transport failed: %d\n",
                            p->cku_err.re_errno);

                        break;

                default:
                        /*
                         * We delay here because it is better to err
                         * on the side of caution. If we got here then
                         * status could have been RPC_SUCCESS, but we
                         * know that we did not get a connection, so
                         * force the rpc status to RPC_CANTCONNECT.
                         */
                        p->cku_err.re_status = RPC_CANTCONNECT;
                        p->cku_err.re_errno = EIO;
                        break;
                }
                if (delay_first == TRUE)
                        ticks = clnt_cots_min_tout * drv_usectohz(1000000);
                goto cots_done;
        }

        /*
         * If we've never sent any request on this connection (send count
         * is zero, or the connection has been reset), cache the
         * the connection's create time and send a request (possibly a retry)
         */
        if ((p->cku_flags & CKU_SENT) == 0 ||
            p->cku_ctime != cm_entry->x_ctime) {
                p->cku_ctime = cm_entry->x_ctime;

        } else if ((p->cku_flags & CKU_SENT) && (p->cku_flags & CKU_ONQUEUE) &&
            (call->call_reply != NULL ||
            p->cku_recv_attempts < clnt_cots_maxrecv)) {

                /*
                 * If we've sent a request and our call is on the dispatch
                 * queue and we haven't made too many receive attempts, then
                 * don't re-send, just receive.
                 */
                p->cku_recv_attempts++;
                goto read_again;
        }

        /*
         * Now we create the RPC request in a STREAMS message.  We have to do
         * this after the call to connmgr_get so that we have the correct
         * TIDU size for the transport.
         */
        tidu_size = cm_entry->x_tidu_size;
        len = MSG_OFFSET + MAX(tidu_size, RM_HDR_SIZE + WIRE_HDR_SIZE);

        while ((mp = allocb(len, BPRI_MED)) == NULL) {
                if (strwaitbuf(len, BPRI_MED)) {
                        p->cku_err.re_status = RPC_SYSTEMERROR;
                        p->cku_err.re_errno = ENOSR;
                        COTSRCSTAT_INCR(p->cku_stats, rcnomem);
                        goto cots_done;
                }
        }
        xdrs = &p->cku_outxdr;
        xdrmblk_init(xdrs, mp, XDR_ENCODE, tidu_size);
        mpsize = MBLKSIZE(mp);
        ASSERT(mpsize >= len);
        ASSERT(mp->b_rptr == mp->b_datap->db_base);

        /*
         * If the size of mblk is not appreciably larger than what we
         * asked, then resize the mblk to exactly len bytes. The reason for
         * this: suppose len is 1600 bytes, the tidu is 1460 bytes
         * (from TCP over ethernet), and the arguments to the RPC require
         * 2800 bytes. Ideally we want the protocol to render two
         * ~1400 byte segments over the wire. However if allocb() gives us a 2k
         * mblk, and we allocate a second mblk for the remainder, the protocol
         * module may generate 3 segments over the wire:
         * 1460 bytes for the first, 448 (2048 - 1600) for the second, and
         * 892 for the third. If we "waste" 448 bytes in the first mblk,
         * the XDR encoding will generate two ~1400 byte mblks, and the
         * protocol module is more likely to produce properly sized segments.
         */
        if ((mpsize >> 1) <= len)
                mp->b_rptr += (mpsize - len);

        /*
         * Adjust b_rptr to reserve space for the non-data protocol headers
         * any downstream modules might like to add, and for the
         * record marking header.
         */
        mp->b_rptr += (MSG_OFFSET + RM_HDR_SIZE);

        if (h->cl_auth->ah_cred.oa_flavor != RPCSEC_GSS) {
                /* Copy in the preserialized RPC header information. */
                bcopy(p->cku_rpchdr, mp->b_rptr, WIRE_HDR_SIZE);

                /* Use XDR_SETPOS() to set the b_wptr to past the RPC header. */
                XDR_SETPOS(xdrs, (uint_t)(mp->b_rptr - mp->b_datap->db_base +
                    WIRE_HDR_SIZE));

                ASSERT((mp->b_wptr - mp->b_rptr) == WIRE_HDR_SIZE);

                /* Serialize the procedure number and the arguments. */
                if ((!XDR_PUTINT32(xdrs, (int32_t *)&procnum)) ||
                    (!AUTH_MARSHALL(h->cl_auth, xdrs, p->cku_cred)) ||
                    (!(*xdr_args)(xdrs, argsp))) {
                        XDR_DESTROY(xdrs);
                        p->cku_err.re_status = RPC_CANTENCODEARGS;
                        p->cku_err.re_errno = EIO;
                        goto cots_done;
                }

                (*(uint32_t *)(mp->b_rptr)) = p->cku_xid;
        } else {
                uint32_t *uproc = (uint32_t *)&p->cku_rpchdr[WIRE_HDR_SIZE];
                IXDR_PUT_U_INT32(uproc, procnum);

                (*(uint32_t *)(&p->cku_rpchdr[0])) = p->cku_xid;

                /* Use XDR_SETPOS() to set the b_wptr. */
                XDR_SETPOS(xdrs, (uint_t)(mp->b_rptr - mp->b_datap->db_base));

                /* Serialize the procedure number and the arguments. */
                if (!AUTH_WRAP(h->cl_auth, p->cku_rpchdr, WIRE_HDR_SIZE+4,
                    xdrs, xdr_args, argsp)) {
                        XDR_DESTROY(xdrs);
                        p->cku_err.re_status = RPC_CANTENCODEARGS;
                        p->cku_err.re_errno = EIO;
                        goto cots_done;
                }
        }

        XDR_DESTROY(xdrs);

        RPCLOG(2, "clnt_cots_kcallit: connected, sending call, tidu_size %d\n",
            tidu_size);

        wq = cm_entry->x_wq;
        waitsecs = 0;

dispatch_again:
        status = clnt_dispatch_send(wq, mp, call, p->cku_xid,
            (p->cku_flags & CKU_ONQUEUE));

        if ((status == RPC_CANTSEND) && (call->call_reason == ENOBUFS)) {
                /*
                 * QFULL condition, allow some time for queue to drain
                 * and try again. Give up after waiting for all timeout
                 * specified for the call, or zone is going away.
                 */
                max_waitsecs = wait.tv_sec ? wait.tv_sec : clnt_cots_min_tout;
                if ((waitsecs++ < max_waitsecs) &&
                    !(zone_status_get(curproc->p_zone) >=
                    ZONE_IS_SHUTTING_DOWN)) {

                        /* wait 1 sec for queue to drain */
                        if (clnt_delay(drv_usectohz(1000000),
                            h->cl_nosignal) == EINTR) {
                                p->cku_err.re_errno = EINTR;
                                p->cku_err.re_status = RPC_INTR;

                                goto cots_done;
                        }

                        /* and try again */
                        goto dispatch_again;
                }
                p->cku_err.re_status = status;
                p->cku_err.re_errno = call->call_reason;
                DTRACE_PROBE(krpc__e__clntcots__kcallit__cantsend);

                goto cots_done;
        }

        if (waitsecs) {
                /* adjust timeout to account for time wait to send */
                wait.tv_sec -= waitsecs;
                if (wait.tv_sec < 0) {
                        /* pick up reply on next retry */
                        wait.tv_sec = 0;
                }
                DTRACE_PROBE2(clnt_cots__sendwait, CLIENT *, h,
                    int, waitsecs);
        }

        RPCLOG(64, "clnt_cots_kcallit: sent call for xid 0x%x\n",
            (uint_t)p->cku_xid);
        p->cku_flags = (CKU_ONQUEUE|CKU_SENT);
        p->cku_recv_attempts = 1;

#ifdef  RPCDEBUG
        time_sent = ddi_get_lbolt();
#endif

        /*
         * Wait for a reply or a timeout.  If there is no error or timeout,
         * (both indicated by call_status), call->call_reply will contain
         * the RPC reply message.
         */
read_again:
        mutex_enter(&call->call_lock);
        interrupted = 0;
        if (call->call_status == RPC_TIMEDOUT) {
                /*
                 * Indicate that the lwp is not to be stopped while waiting
                 * for this network traffic.  This is to avoid deadlock while
                 * debugging a process via /proc and also to avoid recursive
                 * mutex_enter()s due to NFS page faults while stopping
                 * (NFS holds locks when it calls here).
                 */
                clock_t cv_wait_ret;
                clock_t timout;
                clock_t oldlbolt;

                klwp_t *lwp = ttolwp(curthread);

                if (lwp != NULL)
                        lwp->lwp_nostop++;

                oldlbolt = ddi_get_lbolt();
                timout = wait.tv_sec * drv_usectohz(1000000) +
                    drv_usectohz(wait.tv_usec) + oldlbolt;
                /*
                 * Iterate until the call_status is changed to something
                 * other that RPC_TIMEDOUT, or if cv_timedwait_sig() returns
                 * something <=0 zero. The latter means that we timed
                 * out.
                 */
                if (h->cl_nosignal)
                        while ((cv_wait_ret = cv_timedwait(&call->call_cv,
                            &call->call_lock, timout)) > 0 &&
                            call->call_status == RPC_TIMEDOUT)
                                ;
                else
                        while ((cv_wait_ret = cv_timedwait_sig(
                            &call->call_cv,
                            &call->call_lock, timout)) > 0 &&
                            call->call_status == RPC_TIMEDOUT)
                                ;

                switch (cv_wait_ret) {
                case 0:
                        /*
                         * If we got out of the above loop with
                         * cv_timedwait_sig() returning 0, then we were
                         * interrupted regardless what call_status is.
                         */
                        interrupted = 1;
                        break;
                case -1:
                        /* cv_timedwait_sig() timed out */
                        break;
                default:

                        /*
                         * We were cv_signaled(). If we didn't
                         * get a successful call_status and returned
                         * before time expired, delay up to clnt_cots_min_tout
                         * seconds so that the caller doesn't immediately
                         * try to call us again and thus force the
                         * same condition that got us here (such
                         * as a RPC_XPRTFAILED due to the server not
                         * listening on the end-point.
                         */
                        if (call->call_status != RPC_SUCCESS) {
                                clock_t curlbolt;
                                clock_t diff;

                                curlbolt = ddi_get_lbolt();
                                ticks = clnt_cots_min_tout *
                                    drv_usectohz(1000000);
                                diff = curlbolt - oldlbolt;
                                if (diff < ticks) {
                                        delay_first = TRUE;
                                        if (diff > 0)
                                                ticks -= diff;
                                }
                        }
                        break;
                }

                if (lwp != NULL)
                        lwp->lwp_nostop--;
        }
        /*
         * Get the reply message, if any.  This will be freed at the end
         * whether or not an error occurred.
         */
        mp = call->call_reply;
        call->call_reply = NULL;

        /*
         * call_err is the error info when the call is on dispatch queue.
         * cku_err is the error info returned to the caller.
         * Sync cku_err with call_err for local message processing.
         */

        status = call->call_status;
        p->cku_err = call->call_err;
        mutex_exit(&call->call_lock);

        if (status != RPC_SUCCESS) {
                switch (status) {
                case RPC_TIMEDOUT:
                        now = ddi_get_lbolt();
                        if (interrupted) {
                                COTSRCSTAT_INCR(p->cku_stats, rcintrs);
                                p->cku_err.re_status = RPC_INTR;
                                p->cku_err.re_errno = EINTR;
                                RPCLOG(1, "clnt_cots_kcallit: xid 0x%x",
                                    p->cku_xid);
                                RPCLOG(1, "signal interrupted at %ld", now);
                                RPCLOG(1, ", was sent at %ld\n", time_sent);
                        } else {
                                COTSRCSTAT_INCR(p->cku_stats, rctimeouts);
                                p->cku_err.re_errno = ETIMEDOUT;
                                RPCLOG(1, "clnt_cots_kcallit: timed out at %ld",
                                    now);
                                RPCLOG(1, ", was sent at %ld\n", time_sent);
                        }
                        break;

                case RPC_XPRTFAILED:
                        if (p->cku_err.re_errno == 0)
                                p->cku_err.re_errno = EIO;

                        RPCLOG(1, "clnt_cots_kcallit: transport failed: %d\n",
                            p->cku_err.re_errno);
                        break;

                case RPC_SYSTEMERROR:
                        ASSERT(p->cku_err.re_errno);
                        RPCLOG(1, "clnt_cots_kcallit: system error: %d\n",
                            p->cku_err.re_errno);
                        break;

                default:
                        p->cku_err.re_status = RPC_SYSTEMERROR;
                        p->cku_err.re_errno = EIO;
                        RPCLOG(1, "clnt_cots_kcallit: error: %s\n",
                            clnt_sperrno(status));
                        break;
                }
                if (p->cku_err.re_status != RPC_TIMEDOUT) {

                        if (p->cku_flags & CKU_ONQUEUE) {
                                call_table_remove(call);
                                p->cku_flags &= ~CKU_ONQUEUE;
                        }

                        RPCLOG(64, "clnt_cots_kcallit: non TIMEOUT so xid 0x%x "
                            "taken off dispatch list\n", p->cku_xid);
                        if (call->call_reply) {
                                freemsg(call->call_reply);
                                call->call_reply = NULL;
                        }
                } else if (wait.tv_sec != 0) {
                        /*
                         * We've sent the request over TCP and so we have
                         * every reason to believe it will get
                         * delivered. In which case returning a timeout is not
                         * appropriate.
                         */
                        if (p->cku_progress == TRUE &&
                            p->cku_recv_attempts < clnt_cots_maxrecv) {
                                p->cku_err.re_status = RPC_INPROGRESS;
                        }
                }
                goto cots_done;
        }

        xdrs = &p->cku_inxdr;
        xdrmblk_init(xdrs, mp, XDR_DECODE, 0);

        reply_msg.rm_direction = REPLY;
        reply_msg.rm_reply.rp_stat = MSG_ACCEPTED;
        reply_msg.acpted_rply.ar_stat = SUCCESS;

        reply_msg.acpted_rply.ar_verf = _null_auth;
        /*
         *  xdr_results will be done in AUTH_UNWRAP.
         */
        reply_msg.acpted_rply.ar_results.where = NULL;
        reply_msg.acpted_rply.ar_results.proc = xdr_void;

        if (xdr_replymsg(xdrs, &reply_msg)) {
                enum clnt_stat re_status;

                _seterr_reply(&reply_msg, &p->cku_err);

                re_status = p->cku_err.re_status;
                if (re_status == RPC_SUCCESS) {
                        /*
                         * Reply is good, check auth.
                         */
                        if (!AUTH_VALIDATE(h->cl_auth,
                            &reply_msg.acpted_rply.ar_verf)) {
                                COTSRCSTAT_INCR(p->cku_stats, rcbadverfs);
                                RPCLOG0(1, "clnt_cots_kcallit: validation "
                                    "failure\n");
                                freemsg(mp);
                                (void) xdr_rpc_free_verifier(xdrs, &reply_msg);
                                XDR_DESTROY(xdrs);
                                mutex_enter(&call->call_lock);
                                if (call->call_reply == NULL)
                                        call->call_status = RPC_TIMEDOUT;
                                mutex_exit(&call->call_lock);
                                goto read_again;
                        } else if (!AUTH_UNWRAP(h->cl_auth, xdrs,
                            xdr_results, resultsp)) {
                                RPCLOG0(1, "clnt_cots_kcallit: validation "
                                    "failure (unwrap)\n");
                                p->cku_err.re_status = RPC_CANTDECODERES;
                                p->cku_err.re_errno = EIO;
                        }
                } else {
                        /* set errno in case we can't recover */
                        if (re_status != RPC_VERSMISMATCH &&
                            re_status != RPC_AUTHERROR &&
                            re_status != RPC_PROGVERSMISMATCH)
                                p->cku_err.re_errno = EIO;

                        if (re_status == RPC_AUTHERROR) {
                                /*
                                 * Maybe our credential need to be refreshed
                                 */
                                if (cm_entry) {
                                        /*
                                         * There is the potential that the
                                         * cm_entry has/will be marked dead,
                                         * so drop the connection altogether,
                                         * force REFRESH to establish new
                                         * connection.
                                         */
                                        connmgr_cancelconn(cm_entry);
                                        cm_entry = NULL;
                                }

                                (void) xdr_rpc_free_verifier(xdrs,
                                    &reply_msg);
                                XDR_DESTROY(xdrs);

                                if (p->cku_flags & CKU_ONQUEUE) {
                                        call_table_remove(call);
                                        p->cku_flags &= ~CKU_ONQUEUE;
                                }
                                RPCLOG(64,
                                    "clnt_cots_kcallit: AUTH_ERROR, xid"
                                    " 0x%x removed off dispatch list\n",
                                    p->cku_xid);
                                if (call->call_reply) {
                                        freemsg(call->call_reply);
                                        call->call_reply = NULL;
                                }

                                if ((refreshes > 0) &&
                                    AUTH_REFRESH(h->cl_auth, &reply_msg,
                                    p->cku_cred)) {
                                        refreshes--;
                                        freemsg(mp);
                                        mp = NULL;

                                        COTSRCSTAT_INCR(p->cku_stats,
                                            rcbadcalls);
                                        COTSRCSTAT_INCR(p->cku_stats,
                                            rcnewcreds);
                                        goto call_again;
                                }

                                /*
                                 * We have used the client handle to
                                 * do an AUTH_REFRESH and the RPC status may
                                 * be set to RPC_SUCCESS; Let's make sure to
                                 * set it to RPC_AUTHERROR.
                                 */
                                p->cku_err.re_status = RPC_AUTHERROR;

                                /*
                                 * Map recoverable and unrecoverable
                                 * authentication errors to appropriate errno
                                 */
                                switch (p->cku_err.re_why) {
                                case AUTH_TOOWEAK:
                                        /*
                                         * This could be a failure where the
                                         * server requires use of a reserved
                                         * port,  check and optionally set the
                                         * client handle useresvport trying
                                         * one more time. Next go round we
                                         * fall out with the tooweak error.
                                         */
                                        if (p->cku_useresvport != 1) {
                                                p->cku_useresvport = 1;
                                                p->cku_xid = 0;
                                                freemsg(mp);
                                                mp = NULL;
                                                goto call_again;
                                        }
                                        /* FALLTHRU */
                                case AUTH_BADCRED:
                                case AUTH_BADVERF:
                                case AUTH_INVALIDRESP:
                                case AUTH_FAILED:
                                case RPCSEC_GSS_NOCRED:
                                case RPCSEC_GSS_FAILED:
                                                p->cku_err.re_errno = EACCES;
                                                break;
                                case AUTH_REJECTEDCRED:
                                case AUTH_REJECTEDVERF:
                                default:        p->cku_err.re_errno = EIO;
                                                break;
                                }
                                RPCLOG(1, "clnt_cots_kcallit : authentication"
                                    " failed with RPC_AUTHERROR of type %d\n",
                                    (int)p->cku_err.re_why);
                                goto cots_done;
                        }
                }
        } else {
                /* reply didn't decode properly. */
                p->cku_err.re_status = RPC_CANTDECODERES;
                p->cku_err.re_errno = EIO;
                RPCLOG0(1, "clnt_cots_kcallit: decode failure\n");
        }

        (void) xdr_rpc_free_verifier(xdrs, &reply_msg);
        XDR_DESTROY(xdrs);

        if (p->cku_flags & CKU_ONQUEUE) {
                call_table_remove(call);
                p->cku_flags &= ~CKU_ONQUEUE;
        }

        RPCLOG(64, "clnt_cots_kcallit: xid 0x%x taken off dispatch list",
            p->cku_xid);
        RPCLOG(64, " status is %s\n", clnt_sperrno(p->cku_err.re_status));
cots_done:
        if (cm_entry)
                connmgr_release(cm_entry);

        if (mp != NULL)
                freemsg(mp);
        if ((p->cku_flags & CKU_ONQUEUE) == 0 && call->call_reply) {
                freemsg(call->call_reply);
                call->call_reply = NULL;
        }
        if (p->cku_err.re_status != RPC_SUCCESS) {
                RPCLOG0(1, "clnt_cots_kcallit: tail-end failure\n");
                COTSRCSTAT_INCR(p->cku_stats, rcbadcalls);
        }

        /*
         * No point in delaying if the zone is going away.
         */
        if (delay_first == TRUE &&
            !(zone_status_get(curproc->p_zone) >= ZONE_IS_SHUTTING_DOWN)) {
                if (clnt_delay(ticks, h->cl_nosignal) == EINTR) {
                        p->cku_err.re_errno = EINTR;
                        p->cku_err.re_status = RPC_INTR;
                }
        }
        return (p->cku_err.re_status);
}

/*
 * Kinit routine for cots.  This sets up the correct operations in
 * the client handle, as the handle may have previously been a clts
 * handle, and clears the xid field so there is no way a new call
 * could be mistaken for a retry.  It also sets in the handle the
 * information that is passed at create/kinit time but needed at
 * call time, as cots creates the transport at call time - device,
 * address of the server, protocol family.
 */
void
clnt_cots_kinit(CLIENT *h, dev_t dev, int family, struct netbuf *addr,
    int max_msgsize, cred_t *cred)
{
        /* LINTED pointer alignment */
        cku_private_t *p = htop(h);
        calllist_t *call = &p->cku_call;

        h->cl_ops = &tcp_ops;
        if (p->cku_flags & CKU_ONQUEUE) {
                call_table_remove(call);
                p->cku_flags &= ~CKU_ONQUEUE;
                RPCLOG(64, "clnt_cots_kinit: removing call for xid 0x%x from"
                    " dispatch list\n", p->cku_xid);
        }

        if (call->call_reply != NULL) {
                freemsg(call->call_reply);
                call->call_reply = NULL;
        }

        call->call_bucket = NULL;
        call->call_hash = 0;

        /*
         * We don't clear cku_flags here, because clnt_cots_kcallit()
         * takes care of handling the cku_flags reset.
         */
        p->cku_xid = 0;
        p->cku_device = dev;
        p->cku_addrfmly = family;
        p->cku_cred = cred;

        if (p->cku_addr.maxlen < addr->maxlen) {
                if (p->cku_addr.maxlen != 0 && p->cku_addr.buf != NULL)
                        kmem_free(p->cku_addr.buf, p->cku_addr.maxlen);

                p->cku_addr.buf = kmem_zalloc(addr->maxlen, KM_SLEEP);
                p->cku_addr.maxlen = addr->maxlen;
        }

        p->cku_addr.len = addr->len;
        bcopy(addr->buf, p->cku_addr.buf, addr->len);

        /*
         * If the current sanity check size in rpcmod is smaller
         * than the size needed, then increase the sanity check.
         */
        if (max_msgsize != 0 && clnt_max_msg_sizep != NULL &&
            max_msgsize > *clnt_max_msg_sizep) {
                mutex_enter(&clnt_max_msg_lock);
                if (max_msgsize > *clnt_max_msg_sizep)
                        *clnt_max_msg_sizep = max_msgsize;
                mutex_exit(&clnt_max_msg_lock);
        }
}

/*
 * ksettimers is a no-op for cots, with the exception of setting the xid.
 */
/* ARGSUSED */
static int
clnt_cots_ksettimers(CLIENT *h, struct rpc_timers *t, struct rpc_timers *all,
    int minimum, void (*feedback)(int, int, caddr_t), caddr_t arg, uint32_t xid)
{
        /* LINTED pointer alignment */
        cku_private_t *p = htop(h);

        if (xid)
                p->cku_xid = xid;
        COTSRCSTAT_INCR(p->cku_stats, rctimers);
        return (0);
}

extern void rpc_poptimod(struct vnode *);
extern int kstr_push(struct vnode *, char *);

int
conn_kstat_update(kstat_t *ksp, int rw)
{
        struct cm_xprt *cm_entry;
        struct cm_kstat_xprt *cm_ksp_data;
        uchar_t *b;
        char *fbuf;

        if (rw == KSTAT_WRITE)
                return (EACCES);
        if (ksp == NULL || ksp->ks_private == NULL)
                return (EIO);
        cm_entry  = (struct cm_xprt *)ksp->ks_private;
        cm_ksp_data = (struct cm_kstat_xprt *)ksp->ks_data;

        cm_ksp_data->x_wq.value.ui32 = (uint32_t)(uintptr_t)cm_entry->x_wq;
        cm_ksp_data->x_family.value.ui32 = cm_entry->x_family;
        cm_ksp_data->x_rdev.value.ui32 = (uint32_t)cm_entry->x_rdev;
        cm_ksp_data->x_time.value.ui32 = cm_entry->x_time;
        cm_ksp_data->x_ref.value.ui32 = cm_entry->x_ref;
        cm_ksp_data->x_state.value.ui32 = cm_entry->x_state_flags;

        if (cm_entry->x_server.buf) {
                fbuf = cm_ksp_data->x_server.value.str.addr.ptr;
                if (cm_entry->x_family == AF_INET &&
                    cm_entry->x_server.len ==
                    sizeof (struct sockaddr_in)) {
                        struct sockaddr_in  *sa;
                        sa = (struct sockaddr_in *)
                                cm_entry->x_server.buf;
                        b = (uchar_t *)&sa->sin_addr;
                        (void) sprintf(fbuf,
                            "%d.%d.%d.%d", b[0] & 0xFF, b[1] & 0xFF,
                            b[2] & 0xFF, b[3] & 0xFF);
                        cm_ksp_data->x_port.value.ui32 = ntohs(sa->sin_port);
                } else if (cm_entry->x_family == AF_INET6 &&
                                cm_entry->x_server.len >=
                                sizeof (struct sockaddr_in6)) {
                        /* extract server IP address & port */
                        struct sockaddr_in6 *sin6;
                        sin6 = (struct sockaddr_in6 *)cm_entry->x_server.buf;
                        (void) kinet_ntop6((uchar_t *)&sin6->sin6_addr, fbuf,
                                INET6_ADDRSTRLEN);
                        cm_ksp_data->x_port.value.ui32 = ntohs(sin6->sin6_port);
                } else {
                        struct sockaddr_in  *sa;

                        sa = (struct sockaddr_in *)cm_entry->x_server.buf;
                        b = (uchar_t *)&sa->sin_addr;
                        (void) sprintf(fbuf,
                            "%d.%d.%d.%d", b[0] & 0xFF, b[1] & 0xFF,
                            b[2] & 0xFF, b[3] & 0xFF);
                }
                KSTAT_NAMED_STR_BUFLEN(&cm_ksp_data->x_server) =
                    strlen(fbuf) + 1;
        }

        return (0);
}


/*
 * We want a version of delay which is interruptible by a UNIX signal
 * Return EINTR if an interrupt occured.
 */
static int
clnt_delay(clock_t ticks, bool_t nosignal)
{
        if (nosignal == TRUE) {
                delay(ticks);
                return (0);
        }
        return (delay_sig(ticks));
}

/*
 * Wait for a connection until a timeout, or until we are
 * signalled that there has been a connection state change.
 */
static enum clnt_stat
connmgr_cwait(struct cm_xprt *cm_entry, const struct timeval *waitp,
    bool_t nosignal)
{
        bool_t interrupted;
        clock_t timout, cv_stat;
        enum clnt_stat clstat;
        unsigned int old_state;

        ASSERT(MUTEX_HELD(&connmgr_lock));
        /*
         * We wait for the transport connection to be made, or an
         * indication that it could not be made.
         */
        clstat = RPC_TIMEDOUT;
        interrupted = FALSE;

        old_state = cm_entry->x_state_flags;
        /*
         * Now loop until cv_timedwait{_sig} returns because of
         * a signal(0) or timeout(-1) or cv_signal(>0). But it may be
         * cv_signalled for various other reasons too. So loop
         * until there is a state change on the connection.
         */

        timout = waitp->tv_sec * drv_usectohz(1000000) +
            drv_usectohz(waitp->tv_usec) + ddi_get_lbolt();

        if (nosignal) {
                while ((cv_stat = cv_timedwait(&cm_entry->x_conn_cv,
                    &connmgr_lock, timout)) > 0 &&
                    cm_entry->x_state_flags == old_state)
                        ;
        } else {
                while ((cv_stat = cv_timedwait_sig(&cm_entry->x_conn_cv,
                    &connmgr_lock, timout)) > 0 &&
                    cm_entry->x_state_flags == old_state)
                        ;

                if (cv_stat == 0) /* got intr signal? */
                        interrupted = TRUE;
        }

        if ((cm_entry->x_state_flags & (X_BADSTATES|X_CONNECTED)) ==
            X_CONNECTED) {
                clstat = RPC_SUCCESS;
        } else {
                if (interrupted == TRUE)
                        clstat = RPC_INTR;
                RPCLOG(1, "connmgr_cwait: can't connect, error: %s\n",
                    clnt_sperrno(clstat));
        }

        return (clstat);
}

/*
 * Primary interface for how RPC grabs a connection.
 */
static struct cm_xprt *
connmgr_wrapget(
        struct netbuf *retryaddr,
        const struct timeval *waitp,
        cku_private_t *p,
        bool_t srcbind_only)
{
        struct cm_xprt *cm_entry;

        cm_entry = connmgr_get(retryaddr, waitp, &p->cku_addr, p->cku_addrfmly,
            &p->cku_srcaddr, &p->cku_err, p->cku_device,
            p->cku_client.cl_nosignal, p->cku_useresvport, p->cku_cred,
            srcbind_only);

        if (cm_entry == NULL) {
                /*
                 * Re-map the call status to RPC_INTR if the err code is
                 * EINTR. This can happen if calls status is RPC_TLIERROR.
                 * However, don't re-map if signalling has been turned off.
                 * XXX Really need to create a separate thread whenever
                 * there isn't an existing connection.
                 */
                if (p->cku_err.re_errno == EINTR) {
                        if (p->cku_client.cl_nosignal == TRUE)
                                p->cku_err.re_errno = EIO;
                        else
                                p->cku_err.re_status = RPC_INTR;
                }
        }

        return (cm_entry);
}

/*
 * Obtains a transport to the server specified in addr.  If a suitable transport
 * does not already exist in the list of cached transports, a new connection
 * is created, connected, and added to the list. The connection is for sending
 * only - the reply message may come back on another transport connection.
 *
 * To implement round-robin load balancing with multiple client connections,
 * the last entry on the list is always selected. Once the entry is selected
 * it's re-inserted to the head of the list.
 */
static struct cm_xprt *
connmgr_get(
        struct netbuf   *retryaddr,
        const struct timeval    *waitp, /* changed to a ptr to converse stack */
        struct netbuf   *destaddr,
        int             addrfmly,
        struct netbuf   *srcaddr,
        struct rpc_err  *rpcerr,
        dev_t           device,
        bool_t          nosignal,
        int             useresvport,
        cred_t          *cr,
        bool_t          do_srcbind)
{
        struct cm_xprt *cm_entry;
        struct cm_xprt *lru_entry;
        struct cm_xprt **cmp, **prev;
        queue_t *wq;
        TIUSER *tiptr;
        int i;
        int retval;
        int tidu_size;
        bool_t  connected;
        zoneid_t zoneid = rpc_zoneid();

        /*
         * If the call is not a retry, look for a transport entry that
         * goes to the server of interest.
         */
        mutex_enter(&connmgr_lock);

        if (retryaddr == NULL || (do_srcbind && retryaddr != NULL)) {
use_new_conn:
                i = 0;
                cm_entry = lru_entry = NULL;

                prev = cmp = &cm_hd;
                while ((cm_entry = *cmp) != NULL) {
                        ASSERT(cm_entry != cm_entry->x_next);
                        /*
                         * Garbage collect conections that are marked
                         * for needs disconnect.
                         */
                        if (cm_entry->x_needdis) {
                                CONN_HOLD(cm_entry);
                                connmgr_dis_and_wait(cm_entry);
                                connmgr_release(cm_entry);
                                /*
                                 * connmgr_lock could have been
                                 * dropped for the disconnect
                                 * processing so start over.
                                 */
                                goto use_new_conn;
                        }

                        /*
                         * Garbage collect the dead connections that have
                         * no threads working on them.
                         */
                        if ((cm_entry->x_state_flags & (X_DEAD|X_THREAD)) ==
                            X_DEAD) {
                                mutex_enter(&cm_entry->x_lock);
                                if (cm_entry->x_ref != 0) {
                                        /*
                                         * Currently in use.
                                         * Cleanup later.
                                         */
                                        cmp = &cm_entry->x_next;
                                        mutex_exit(&cm_entry->x_lock);
                                        continue;
                                }
                                mutex_exit(&cm_entry->x_lock);
                                *cmp = cm_entry->x_next;
                                mutex_exit(&connmgr_lock);
                                connmgr_close(cm_entry);
                                mutex_enter(&connmgr_lock);
                                goto use_new_conn;
                        }


                        /*
                         * Playing safe, there is a goto below,
                         * which sets retryaddr to NULL,
                         * Invalidating the if check above.
                         */
                        if (retryaddr == NULL) {
                                do_srcbind = FALSE;
                        }
                        if ((cm_entry->x_state_flags & X_BADSTATES) == 0 &&
                            cm_entry->x_zoneid == zoneid &&
                            cm_entry->x_rdev == device &&
                            destaddr->len == cm_entry->x_server.len &&
                            bcmp(destaddr->buf, cm_entry->x_server.buf,
                            destaddr->len) == 0) {

                                if (do_srcbind) {
                                        if (cm_entry->x_src.buf == NULL ||
                                            clnt_cmp_netaddr(retryaddr,
                                            &cm_entry->x_src) != 0) {
                                                cmp = &cm_entry->x_next;
                                                continue;
                                        }
                                }
                                /*
                                 * If the matching entry isn't connected,
                                 * attempt to reconnect it.
                                 */
                                if (cm_entry->x_connected == FALSE) {
                                        /*
                                         * We don't go through trying
                                         * to find the least recently
                                         * used connected because
                                         * connmgr_reconnect() briefly
                                         * dropped the connmgr_lock,
                                         * allowing a window for our
                                         * accounting to be messed up.
                                         * In any case, a re-connected
                                         * connection is as good as
                                         * a LRU connection.
                                         */
                                        return (connmgr_wrapconnect(cm_entry,
                                            waitp, destaddr, addrfmly, srcaddr,
                                            rpcerr, TRUE, nosignal, cr));
                                }
                                i++;

                                /* keep track of the last entry */
                                lru_entry = cm_entry;
                                prev = cmp;
                        }
                        cmp = &cm_entry->x_next;
                }

                if (i > clnt_max_conns) {
                        RPCLOG(8, "connmgr_get: too many conns, dooming entry"
                            " %p\n", (void *)lru_entry->x_tiptr);
                        lru_entry->x_doomed = TRUE;
                        goto use_new_conn;
                }

                /*
                 * If we are at the maximum number of connections to
                 * the server, hand back the least recently used one.
                 */
                if (i == clnt_max_conns) {
                        /*
                         * Copy into the handle the source address of
                         * the connection, which we will use in case of
                         * a later retry.
                         */
                        if (srcaddr->len != lru_entry->x_src.len) {
                                kmem_free(srcaddr->buf, srcaddr->maxlen);
                                ASSERT(lru_entry->x_src.len != 0);
                                srcaddr->buf = kmem_alloc(
                                    lru_entry->x_src.len, KM_SLEEP);
                                srcaddr->maxlen = srcaddr->len =
                                    lru_entry->x_src.len;
                        }
                        bcopy(lru_entry->x_src.buf, srcaddr->buf, srcaddr->len);
                        RPCLOG(2, "connmgr_get: call going out on %p\n",
                            (void *)lru_entry);
                        lru_entry->x_time = ddi_get_lbolt();
                        CONN_HOLD(lru_entry);

                        if ((i > 1) && (prev != &cm_hd)) {
                                /*
                                 * remove and re-insert entry at head of list.
                                 */
                                *prev = lru_entry->x_next;
                                lru_entry->x_next = cm_hd;
                                cm_hd = lru_entry;
                        }

                        mutex_exit(&connmgr_lock);
                        return (lru_entry);
                }

        } else {
                /*
                 * This is the retry case (retryaddr != NULL).  Retries must
                 * be sent on the same source port as the original call.
                 */

                /*
                 * Walk the list looking for a connection with a source address
                 * that matches the retry address.
                 */
start_retry_loop:
                cmp = &cm_hd;
                while ((cm_entry = *cmp) != NULL) {
                        ASSERT(cm_entry != cm_entry->x_next);

                        /*
                         * determine if this connection matches the passed
                         * in retry address.  If it does not match, advance
                         * to the next element on the list.
                         */
                        if (zoneid != cm_entry->x_zoneid ||
                            device != cm_entry->x_rdev ||
                            retryaddr->len != cm_entry->x_src.len ||
                            bcmp(retryaddr->buf, cm_entry->x_src.buf,
                            retryaddr->len) != 0) {
                                cmp = &cm_entry->x_next;
                                continue;
                        }
                        /*
                         * Garbage collect conections that are marked
                         * for needs disconnect.
                         */
                        if (cm_entry->x_needdis) {
                                CONN_HOLD(cm_entry);
                                connmgr_dis_and_wait(cm_entry);
                                connmgr_release(cm_entry);
                                /*
                                 * connmgr_lock could have been
                                 * dropped for the disconnect
                                 * processing so start over.
                                 */
                                goto start_retry_loop;
                        }
                        /*
                         * Garbage collect the dead connections that have
                         * no threads working on them.
                         */
                        if ((cm_entry->x_state_flags & (X_DEAD|X_THREAD)) ==
                            X_DEAD) {
                                mutex_enter(&cm_entry->x_lock);
                                if (cm_entry->x_ref != 0) {
                                        /*
                                         * Currently in use.
                                         * Cleanup later.
                                         */
                                        cmp = &cm_entry->x_next;
                                        mutex_exit(&cm_entry->x_lock);
                                        continue;
                                }
                                mutex_exit(&cm_entry->x_lock);
                                *cmp = cm_entry->x_next;
                                mutex_exit(&connmgr_lock);
                                connmgr_close(cm_entry);
                                mutex_enter(&connmgr_lock);
                                goto start_retry_loop;
                        }

                        /*
                         * Sanity check: if the connection with our source
                         * port is going to some other server, something went
                         * wrong, as we never delete connections (i.e. release
                         * ports) unless they have been idle.  In this case,
                         * it is probably better to send the call out using
                         * a new source address than to fail it altogether,
                         * since that port may never be released.
                         */
                        if (destaddr->len != cm_entry->x_server.len ||
                            bcmp(destaddr->buf, cm_entry->x_server.buf,
                            destaddr->len) != 0) {
                                RPCLOG(1, "connmgr_get: tiptr %p"
                                    " is going to a different server"
                                    " with the port that belongs"
                                    " to us!\n", (void *)cm_entry->x_tiptr);
                                retryaddr = NULL;
                                goto use_new_conn;
                        }

                        /*
                         * If the connection of interest is not connected and we
                         * can't reconnect it, then the server is probably
                         * still down.  Return NULL to the caller and let it
                         * retry later if it wants to.  We have a delay so the
                         * machine doesn't go into a tight retry loop.  If the
                         * entry was already connected, or the reconnected was
                         * successful, return this entry.
                         */
                        if (cm_entry->x_connected == FALSE) {
                                return (connmgr_wrapconnect(cm_entry,
                                    waitp, destaddr, addrfmly, NULL,
                                    rpcerr, TRUE, nosignal, cr));
                        } else {
                                CONN_HOLD(cm_entry);

                                cm_entry->x_time = ddi_get_lbolt();
                                mutex_exit(&connmgr_lock);
                                RPCLOG(2, "connmgr_get: found old "
                                    "transport %p for retry\n",
                                    (void *)cm_entry);
                                return (cm_entry);
                        }
                }

                /*
                 * We cannot find an entry in the list for this retry.
                 * Either the entry has been removed temporarily to be
                 * reconnected by another thread, or the original call
                 * got a port but never got connected,
                 * and hence the transport never got put in the
                 * list.  Fall through to the "create new connection" code -
                 * the former case will fail there trying to rebind the port,
                 * and the later case (and any other pathological cases) will
                 * rebind and reconnect and not hang the client machine.
                 */
                RPCLOG0(8, "connmgr_get: no entry in list for retry\n");
        }
        /*
         * Set up a transport entry in the connection manager's list.
         */
        cm_entry = (struct cm_xprt *)
            kmem_zalloc(sizeof (struct cm_xprt), KM_SLEEP);

        cm_entry->x_server.buf = kmem_alloc(destaddr->len, KM_SLEEP);
        bcopy(destaddr->buf, cm_entry->x_server.buf, destaddr->len);
        cm_entry->x_server.len = cm_entry->x_server.maxlen = destaddr->len;

        cm_entry->x_state_flags = X_THREAD;
        cm_entry->x_ref = 1;
        cm_entry->x_family = addrfmly;
        cm_entry->x_rdev = device;
        cm_entry->x_zoneid = zoneid;
        mutex_init(&cm_entry->x_lock, NULL, MUTEX_DEFAULT, NULL);
        cv_init(&cm_entry->x_cv, NULL, CV_DEFAULT, NULL);
        cv_init(&cm_entry->x_conn_cv, NULL, CV_DEFAULT, NULL);
        cv_init(&cm_entry->x_dis_cv, NULL, CV_DEFAULT, NULL);

        /*
         * Note that we add this partially initialized entry to the
         * connection list. This is so that we don't have connections to
         * the same server.
         *
         * Note that x_src is not initialized at this point. This is because
         * retryaddr might be NULL in which case x_src is whatever
         * t_kbind/bindresvport gives us. If another thread wants a
         * connection to the same server, seemingly we have an issue, but we
         * don't. If the other thread comes in with retryaddr == NULL, then it
         * will never look at x_src, and it will end up waiting in
         * connmgr_cwait() for the first thread to finish the connection
         * attempt. If the other thread comes in with retryaddr != NULL, then
         * that means there was a request sent on a connection, in which case
         * the the connection should already exist. Thus the first thread
         * never gets here ... it finds the connection it its server in the
         * connection list.
         *
         * But even if theory is wrong, in the retryaddr != NULL case, the 2nd
         * thread will skip us because x_src.len == 0.
         */
        cm_entry->x_next = cm_hd;
        cm_hd = cm_entry;
        mutex_exit(&connmgr_lock);

        /*
         * Either we didn't find an entry to the server of interest, or we
         * don't have the maximum number of connections to that server -
         * create a new connection.
         */
        RPCLOG0(8, "connmgr_get: creating new connection\n");
        rpcerr->re_status = RPC_TLIERROR;

        i = t_kopen(NULL, device, FREAD|FWRITE|FNDELAY, &tiptr, zone_kcred());
        if (i) {
                RPCLOG(1, "connmgr_get: can't open cots device, error %d\n", i);
                rpcerr->re_errno = i;
                connmgr_cancelconn(cm_entry);
                return (NULL);
        }
        rpc_poptimod(tiptr->fp->f_vnode);

        if (i = strioctl(tiptr->fp->f_vnode, I_PUSH, (intptr_t)"rpcmod", 0,
            K_TO_K, kcred, &retval)) {
                RPCLOG(1, "connmgr_get: can't push cots module, %d\n", i);
                (void) t_kclose(tiptr, 1);
                rpcerr->re_errno = i;
                connmgr_cancelconn(cm_entry);
                return (NULL);
        }

        if (i = strioctl(tiptr->fp->f_vnode, RPC_CLIENT, 0, 0, K_TO_K,
            kcred, &retval)) {
                RPCLOG(1, "connmgr_get: can't set client status with cots "
                    "module, %d\n", i);
                (void) t_kclose(tiptr, 1);
                rpcerr->re_errno = i;
                connmgr_cancelconn(cm_entry);
                return (NULL);
        }

        mutex_enter(&connmgr_lock);

        wq = tiptr->fp->f_vnode->v_stream->sd_wrq->q_next;
        cm_entry->x_wq = wq;

        mutex_exit(&connmgr_lock);

        if (i = strioctl(tiptr->fp->f_vnode, I_PUSH, (intptr_t)"timod", 0,
            K_TO_K, kcred, &retval)) {
                RPCLOG(1, "connmgr_get: can't push timod, %d\n", i);
                (void) t_kclose(tiptr, 1);
                rpcerr->re_errno = i;
                connmgr_cancelconn(cm_entry);
                return (NULL);
        }

        /*
         * If the caller has not specified reserved port usage then
         * take the system default.
         */
        if (useresvport == -1)
                useresvport = clnt_cots_do_bindresvport;

        if ((useresvport || retryaddr != NULL) &&
            (addrfmly == AF_INET || addrfmly == AF_INET6)) {
                bool_t alloc_src = FALSE;

                if (srcaddr->len != destaddr->len) {
                        kmem_free(srcaddr->buf, srcaddr->maxlen);
                        srcaddr->buf = kmem_zalloc(destaddr->len, KM_SLEEP);
                        srcaddr->maxlen = destaddr->len;
                        srcaddr->len = destaddr->len;
                        alloc_src = TRUE;
                }

                if ((i = bindresvport(tiptr, retryaddr, srcaddr, TRUE)) != 0) {
                        (void) t_kclose(tiptr, 1);
                        RPCLOG(1, "connmgr_get: couldn't bind, retryaddr: "
                            "%p\n", (void *)retryaddr);

                        /*
                         * 1225408: If we allocated a source address, then it
                         * is either garbage or all zeroes. In that case
                         * we need to clear srcaddr.
                         */
                        if (alloc_src == TRUE) {
                                kmem_free(srcaddr->buf, srcaddr->maxlen);
                                srcaddr->maxlen = srcaddr->len = 0;
                                srcaddr->buf = NULL;
                        }
                        rpcerr->re_errno = i;
                        connmgr_cancelconn(cm_entry);
                        return (NULL);
                }
        } else {
                if ((i = t_kbind(tiptr, NULL, NULL)) != 0) {
                        RPCLOG(1, "clnt_cots_kcreate: t_kbind: %d\n", i);
                        (void) t_kclose(tiptr, 1);
                        rpcerr->re_errno = i;
                        connmgr_cancelconn(cm_entry);
                        return (NULL);
                }
        }

        {
                /*
                 * Keep the kernel stack lean. Don't move this call
                 * declaration to the top of this function because a
                 * call is declared in connmgr_wrapconnect()
                 */
                calllist_t call;

                bzero(&call, sizeof (call));
                cv_init(&call.call_cv, NULL, CV_DEFAULT, NULL);

                /*
                 * This is a bound end-point so don't close it's stream.
                 */
                connected = connmgr_connect(cm_entry, wq, destaddr, addrfmly,
                    &call, &tidu_size, FALSE, waitp, nosignal, cr);
                *rpcerr = call.call_err;
                cv_destroy(&call.call_cv);

        }

        mutex_enter(&connmgr_lock);

        /*
         * Set up a transport entry in the connection manager's list.
         */
        if (srcaddr->len > 0) {
                cm_entry->x_src.buf = kmem_alloc(srcaddr->len, KM_SLEEP);
                bcopy(srcaddr->buf, cm_entry->x_src.buf, srcaddr->len);
                cm_entry->x_src.len = cm_entry->x_src.maxlen = srcaddr->len;
        } /* Else kmem_zalloc() of cm_entry already sets its x_src to NULL. */

        cm_entry->x_tiptr = tiptr;
        cm_entry->x_time = ddi_get_lbolt();

        if (tiptr->tp_info.servtype == T_COTS_ORD)
                cm_entry->x_ordrel = TRUE;
        else
                cm_entry->x_ordrel = FALSE;

        cm_entry->x_tidu_size = tidu_size;

        if (cm_entry->x_early_disc) {
                /*
                 * We need to check if a disconnect request has come
                 * while we are connected, if so, then we need to
                 * set rpcerr->re_status appropriately before returning
                 * NULL to caller.
                 */
                if (rpcerr->re_status == RPC_SUCCESS)
                        rpcerr->re_status = RPC_XPRTFAILED;
                cm_entry->x_connected = FALSE;
        } else
                cm_entry->x_connected = connected;

        /*
         * There could be a discrepancy here such that
         * x_early_disc is TRUE yet connected is TRUE as well
         * and the connection is actually connected. In that case
         * lets be conservative and declare the connection as not
         * connected.
         */
        cm_entry->x_early_disc = FALSE;
        cm_entry->x_needdis = (cm_entry->x_connected == FALSE);
        cm_entry->x_ctime = ddi_get_lbolt();

        /*
         * Notify any threads waiting that the connection attempt is done.
         */
        cm_entry->x_thread = FALSE;
        cv_broadcast(&cm_entry->x_conn_cv);

        if (cm_entry->x_connected == FALSE) {
                mutex_exit(&connmgr_lock);
                connmgr_release(cm_entry);
                return (NULL);
        }

        mutex_exit(&connmgr_lock);

        return (cm_entry);
}

/*
 * Keep the cm_xprt entry on the connecton list when making a connection. This
 * is to prevent multiple connections to a slow server from appearing.
 * We use the bit field x_thread to tell if a thread is doing a connection
 * which keeps other interested threads from messing with connection.
 * Those other threads just wait if x_thread is set.
 *
 * If x_thread is not set, then we do the actual work of connecting via
 * connmgr_connect().
 *
 * mutex convention: called with connmgr_lock held, returns with it released.
 */
static struct cm_xprt *
connmgr_wrapconnect(
        struct cm_xprt  *cm_entry,
        const struct timeval    *waitp,
        struct netbuf   *destaddr,
        int             addrfmly,
        struct netbuf   *srcaddr,
        struct rpc_err  *rpcerr,
        bool_t          reconnect,
        bool_t          nosignal,
        cred_t          *cr)
{
        ASSERT(MUTEX_HELD(&connmgr_lock));
        /*
         * Hold this entry as we are about to drop connmgr_lock.
         */
        CONN_HOLD(cm_entry);

        /*
         * If there is a thread already making a connection for us, then
         * wait for it to complete the connection.
         */
        if (cm_entry->x_thread == TRUE) {
                rpcerr->re_status = connmgr_cwait(cm_entry, waitp, nosignal);

                if (rpcerr->re_status != RPC_SUCCESS) {
                        mutex_exit(&connmgr_lock);
                        connmgr_release(cm_entry);
                        return (NULL);
                }
        } else {
                bool_t connected;
                calllist_t call;

                cm_entry->x_thread = TRUE;

                while (cm_entry->x_needrel == TRUE) {
                        cm_entry->x_needrel = FALSE;

                        connmgr_sndrel(cm_entry);
                        delay(drv_usectohz(1000000));

                        mutex_enter(&connmgr_lock);
                }

                /*
                 * If we need to send a T_DISCON_REQ, send one.
                 */
                connmgr_dis_and_wait(cm_entry);
                cm_entry->x_dead = FALSE;

                mutex_exit(&connmgr_lock);

                bzero(&call, sizeof (call));
                cv_init(&call.call_cv, NULL, CV_DEFAULT, NULL);

                connected = connmgr_connect(cm_entry, cm_entry->x_wq,
                    destaddr, addrfmly, &call, &cm_entry->x_tidu_size,
                    reconnect, waitp, nosignal, cr);

                *rpcerr = call.call_err;
                cv_destroy(&call.call_cv);

                mutex_enter(&connmgr_lock);


                if (cm_entry->x_early_disc) {
                        /*
                         * We need to check if a disconnect request has come
                         * while we are connected, if so, then we need to
                         * set rpcerr->re_status appropriately before returning
                         * NULL to caller.
                         */
                        if (rpcerr->re_status == RPC_SUCCESS)
                                rpcerr->re_status = RPC_XPRTFAILED;
                        cm_entry->x_connected = FALSE;
                } else
                        cm_entry->x_connected = connected;

                /*
                 * There could be a discrepancy here such that
                 * x_early_disc is TRUE yet connected is TRUE as well
                 * and the connection is actually connected. In that case
                 * lets be conservative and declare the connection as not
                 * connected.
                 */

                cm_entry->x_early_disc = FALSE;
                cm_entry->x_needdis = (cm_entry->x_connected == FALSE);


                /*
                 * connmgr_connect() may have given up before the connection
                 * actually timed out. So ensure that before the next
                 * connection attempt we do a disconnect.
                 */
                cm_entry->x_ctime = ddi_get_lbolt();
                cm_entry->x_thread = FALSE;

                cv_broadcast(&cm_entry->x_conn_cv);

                if (cm_entry->x_connected == FALSE) {
                        mutex_exit(&connmgr_lock);
                        connmgr_release(cm_entry);
                        return (NULL);
                }
        }

        if (srcaddr != NULL) {
                /*
                 * Copy into the handle the
                 * source address of the
                 * connection, which we will use
                 * in case of a later retry.
                 */
                if (srcaddr->len != cm_entry->x_src.len) {
                        kmem_free(srcaddr->buf, srcaddr->maxlen);
                        ASSERT(cm_entry->x_src.len != 0);
                        srcaddr->buf = kmem_alloc(cm_entry->x_src.len,
                            KM_SLEEP);
                        srcaddr->maxlen = srcaddr->len = cm_entry->x_src.len;
                }
                bcopy(cm_entry->x_src.buf, srcaddr->buf, srcaddr->len);
        }
        cm_entry->x_time = ddi_get_lbolt();
        mutex_exit(&connmgr_lock);
        return (cm_entry);
}

/*
 * If we need to send a T_DISCON_REQ, send one.
 */
static void
connmgr_dis_and_wait(struct cm_xprt *cm_entry)
{
        ASSERT(MUTEX_HELD(&connmgr_lock));
        for (;;) {
                while (cm_entry->x_needdis == TRUE) {
                        RPCLOG(8, "connmgr_dis_and_wait: need "
                            "T_DISCON_REQ for connection 0x%p\n",
                            (void *)cm_entry);
                        cm_entry->x_needdis = FALSE;
                        cm_entry->x_waitdis = TRUE;

                        connmgr_snddis(cm_entry);

                        mutex_enter(&connmgr_lock);
                }

                if (cm_entry->x_waitdis == TRUE) {
                        clock_t timout;

                        RPCLOG(8, "connmgr_dis_and_wait waiting for "
                            "T_DISCON_REQ's ACK for connection %p\n",
                            (void *)cm_entry);

                        timout = clnt_cots_min_conntout * drv_usectohz(1000000);

                        /*
                         * The TPI spec says that the T_DISCON_REQ
                         * will get acknowledged, but in practice
                         * the ACK may never get sent. So don't
                         * block forever.
                         */
                        (void) cv_reltimedwait(&cm_entry->x_dis_cv,
                            &connmgr_lock, timout, TR_CLOCK_TICK);
                }
                /*
                 * If we got the ACK, break. If we didn't,
                 * then send another T_DISCON_REQ.
                 */
                if (cm_entry->x_waitdis == FALSE) {
                        cm_entry->x_dead = TRUE;
                        break;
                } else {
                        RPCLOG(8, "connmgr_dis_and_wait: did"
                            "not get T_DISCON_REQ's ACK for "
                            "connection  %p\n", (void *)cm_entry);
                        cm_entry->x_needdis = TRUE;
                }
        }
}

static void
connmgr_cancelconn(struct cm_xprt *cm_entry)
{
        /*
         * Mark the connection table entry as dead; the next thread that
         * goes through connmgr_release() will notice this and deal with it.
         */
        mutex_enter(&connmgr_lock);
        cm_entry->x_dead = TRUE;

        /*
         * Notify any threads waiting for the connection that it isn't
         * going to happen.
         */
        cm_entry->x_thread = FALSE;
        cv_broadcast(&cm_entry->x_conn_cv);
        mutex_exit(&connmgr_lock);

        connmgr_release(cm_entry);
}

static void
connmgr_close(struct cm_xprt *cm_entry)
{
        mutex_enter(&cm_entry->x_lock);
        while (cm_entry->x_ref != 0) {
                /*
                 * Must be a noninterruptible wait.
                 */
                cv_wait(&cm_entry->x_cv, &cm_entry->x_lock);
        }

        if (cm_entry->x_tiptr != NULL)
                (void) t_kclose(cm_entry->x_tiptr, 1);

        mutex_exit(&cm_entry->x_lock);
        if (cm_entry->x_ksp != NULL) {
                mutex_enter(cm_entry->x_ksp->ks_lock);
                cm_entry->x_ksp->ks_private = NULL;
                mutex_exit(cm_entry->x_ksp->ks_lock);

                /*
                 * Must free the buffer we allocated for the
                 * server address in the update function
                 */
                if (((struct cm_kstat_xprt *)(cm_entry->x_ksp->ks_data))->
                    x_server.value.str.addr.ptr != NULL)
                        kmem_free(((struct cm_kstat_xprt *)(cm_entry->x_ksp->
                            ks_data))->x_server.value.str.addr.ptr,
                            INET6_ADDRSTRLEN);
                kmem_free(cm_entry->x_ksp->ks_data,
                    cm_entry->x_ksp->ks_data_size);
                kstat_delete(cm_entry->x_ksp);
        }

        mutex_destroy(&cm_entry->x_lock);
        cv_destroy(&cm_entry->x_cv);
        cv_destroy(&cm_entry->x_conn_cv);
        cv_destroy(&cm_entry->x_dis_cv);

        kmem_free(cm_entry->x_server.buf, cm_entry->x_server.maxlen);
        kmem_free(cm_entry->x_src.buf, cm_entry->x_src.maxlen);
        kmem_free(cm_entry, sizeof (struct cm_xprt));
}

/*
 * Called by KRPC after sending the call message to release the connection
 * it was using.
 */
static void
connmgr_release(struct cm_xprt *cm_entry)
{
        mutex_enter(&cm_entry->x_lock);
        cm_entry->x_ref--;
        if (cm_entry->x_ref == 0)
                cv_signal(&cm_entry->x_cv);
        mutex_exit(&cm_entry->x_lock);
}

/*
 * Set TCP receive and xmit buffer size for RPC connections.
 */
static bool_t
connmgr_setbufsz(calllist_t *e, queue_t *wq, cred_t *cr)
{
        int ok = FALSE;
        int val;

        if (rpc_default_tcp_bufsz)
                return (FALSE);

        /*
         * Only set new buffer size if it's larger than the system
         * default buffer size. If smaller buffer size is needed
         * then use /etc/system to set rpc_default_tcp_bufsz to 1.
         */
        ok = connmgr_getopt_int(wq, SOL_SOCKET, SO_RCVBUF, &val, e, cr);
        if ((ok == TRUE) && (val < rpc_send_bufsz)) {
                ok = connmgr_setopt_int(wq, SOL_SOCKET, SO_RCVBUF,
                    rpc_send_bufsz, e, cr);
                DTRACE_PROBE2(krpc__i__connmgr_rcvbufsz,
                    int, ok, calllist_t *, e);
        }

        ok = connmgr_getopt_int(wq, SOL_SOCKET, SO_SNDBUF, &val, e, cr);
        if ((ok == TRUE) && (val < rpc_recv_bufsz)) {
                ok = connmgr_setopt_int(wq, SOL_SOCKET, SO_SNDBUF,
                    rpc_recv_bufsz, e, cr);
                DTRACE_PROBE2(krpc__i__connmgr_sndbufsz,
                    int, ok, calllist_t *, e);
        }
        return (TRUE);
}

/*
 * Given an open stream, connect to the remote.  Returns true if connected,
 * false otherwise.
 */
static bool_t
connmgr_connect(
        struct cm_xprt          *cm_entry,
        queue_t                 *wq,
        struct netbuf           *addr,
        int                     addrfmly,
        calllist_t              *e,
        int                     *tidu_ptr,
        bool_t                  reconnect,
        const struct timeval    *waitp,
        bool_t                  nosignal,
        cred_t                  *cr)
{
        mblk_t *mp;
        struct T_conn_req *tcr;
        struct T_info_ack *tinfo;
        int interrupted, error;
        int tidu_size, kstat_instance;

        /* if it's a reconnect, flush any lingering data messages */
        if (reconnect)
                (void) putctl1(wq, M_FLUSH, FLUSHRW);

        /*
         * Note: if the receiver uses SCM_UCRED/getpeerucred the pid will
         * appear as -1.
         */
        mp = allocb_cred(sizeof (*tcr) + addr->len, cr, NOPID);
        if (mp == NULL) {
                /*
                 * This is unfortunate, but we need to look up the stats for
                 * this zone to increment the "memory allocation failed"
                 * counter.  curproc->p_zone is safe since we're initiating a
                 * connection and not in some strange streams context.
                 */
                struct rpcstat *rpcstat;

                rpcstat = zone_getspecific(rpcstat_zone_key, rpc_zone());
                ASSERT(rpcstat != NULL);

                RPCLOG0(1, "connmgr_connect: cannot alloc mp for "
                    "sending conn request\n");
                COTSRCSTAT_INCR(rpcstat->rpc_cots_client, rcnomem);
                e->call_status = RPC_SYSTEMERROR;
                e->call_reason = ENOSR;
                return (FALSE);
        }

        /* Set TCP buffer size for RPC connections if needed */
        if (addrfmly == AF_INET || addrfmly == AF_INET6)
                (void) connmgr_setbufsz(e, wq, cr);

        mp->b_datap->db_type = M_PROTO;
        tcr = (struct T_conn_req *)mp->b_rptr;
        bzero(tcr, sizeof (*tcr));
        tcr->PRIM_type = T_CONN_REQ;
        tcr->DEST_length = addr->len;
        tcr->DEST_offset = sizeof (struct T_conn_req);
        mp->b_wptr = mp->b_rptr + sizeof (*tcr);

        bcopy(addr->buf, mp->b_wptr, tcr->DEST_length);
        mp->b_wptr += tcr->DEST_length;

        RPCLOG(8, "connmgr_connect: sending conn request on queue "
            "%p", (void *)wq);
        RPCLOG(8, " call %p\n", (void *)wq);
        /*
         * We use the entry in the handle that is normally used for
         * waiting for RPC replies to wait for the connection accept.
         */
        if (clnt_dispatch_send(wq, mp, e, 0, 0) != RPC_SUCCESS) {
                DTRACE_PROBE(krpc__e__connmgr__connect__cantsend);
                freemsg(mp);
                return (FALSE);
        }

        mutex_enter(&clnt_pending_lock);

        /*
         * We wait for the transport connection to be made, or an
         * indication that it could not be made.
         */
        interrupted = 0;

        /*
         * waitforack should have been called with T_OK_ACK, but the
         * present implementation needs to be passed T_INFO_ACK to
         * work correctly.
         */
        error = waitforack(e, T_INFO_ACK, waitp, nosignal);
        if (error == EINTR)
                interrupted = 1;
        if (zone_status_get(curproc->p_zone) >= ZONE_IS_EMPTY) {
                /*
                 * No time to lose; we essentially have been signaled to
                 * quit.
                 */
                interrupted = 1;
        }
#ifdef RPCDEBUG
        if (error == ETIME)
                RPCLOG0(8, "connmgr_connect: giving up "
                    "on connection attempt; "
                    "clnt_dispatch notifyconn "
                    "diagnostic 'no one waiting for "
                    "connection' should not be "
                    "unexpected\n");
#endif
        if (e->call_prev)
                e->call_prev->call_next = e->call_next;
        else
                clnt_pending = e->call_next;
        if (e->call_next)
                e->call_next->call_prev = e->call_prev;
        mutex_exit(&clnt_pending_lock);

        if (e->call_status != RPC_SUCCESS || error != 0) {
                if (interrupted)
                        e->call_status = RPC_INTR;
                else if (error == ETIME)
                        e->call_status = RPC_TIMEDOUT;
                else if (error == EPROTO) {
                        e->call_status = RPC_SYSTEMERROR;
                        e->call_reason = EPROTO;
                }

                RPCLOG(8, "connmgr_connect: can't connect, status: "
                    "%s\n", clnt_sperrno(e->call_status));

                if (e->call_reply) {
                        freemsg(e->call_reply);
                        e->call_reply = NULL;
                }

                return (FALSE);
        }
        /*
         * The result of the "connection accept" is a T_info_ack
         * in the call_reply field.
         */
        ASSERT(e->call_reply != NULL);
        mp = e->call_reply;
        e->call_reply = NULL;
        tinfo = (struct T_info_ack *)mp->b_rptr;

        tidu_size = tinfo->TIDU_size;
        tidu_size -= (tidu_size % BYTES_PER_XDR_UNIT);
        if (tidu_size > COTS_DEFAULT_ALLOCSIZE || (tidu_size <= 0))
                tidu_size = COTS_DEFAULT_ALLOCSIZE;
        *tidu_ptr = tidu_size;

        freemsg(mp);

        /*
         * Set up the pertinent options.  NODELAY is so the transport doesn't
         * buffer up RPC messages on either end.  This may not be valid for
         * all transports.  Failure to set this option is not cause to
         * bail out so we return success anyway.  Note that lack of NODELAY
         * or some other way to flush the message on both ends will cause
         * lots of retries and terrible performance.
         */
        if (addrfmly == AF_INET || addrfmly == AF_INET6) {
                (void) connmgr_setopt(wq, IPPROTO_TCP, TCP_NODELAY, e, cr);
                if (e->call_status == RPC_XPRTFAILED)
                        return (FALSE);
        }

        /*
         * Since we have a connection, we now need to figure out if
         * we need to create a kstat. If x_ksp is not NULL then we
         * are reusing a connection and so we do not need to create
         * another kstat -- lets just return.
         */
        if (cm_entry->x_ksp != NULL)
                return (TRUE);

        /*
         * We need to increment rpc_kstat_instance atomically to prevent
         * two kstats being created with the same instance.
         */
        kstat_instance = atomic_inc_32_nv((uint32_t *)&rpc_kstat_instance);

        if ((cm_entry->x_ksp = kstat_create_zone("unix", kstat_instance,
            "rpc_cots_connections", "rpc", KSTAT_TYPE_NAMED,
            (uint_t)(sizeof (cm_kstat_xprt_t) / sizeof (kstat_named_t)),
            KSTAT_FLAG_VIRTUAL, cm_entry->x_zoneid)) == NULL) {
                return (TRUE);
        }

        cm_entry->x_ksp->ks_lock = &connmgr_lock;
        cm_entry->x_ksp->ks_private = cm_entry;
        cm_entry->x_ksp->ks_data_size = ((INET6_ADDRSTRLEN * sizeof (char))
            + sizeof (cm_kstat_template));
        cm_entry->x_ksp->ks_data = kmem_alloc(cm_entry->x_ksp->ks_data_size,
            KM_SLEEP);
        bcopy(&cm_kstat_template, cm_entry->x_ksp->ks_data,
            cm_entry->x_ksp->ks_data_size);
        ((struct cm_kstat_xprt *)(cm_entry->x_ksp->ks_data))->
            x_server.value.str.addr.ptr =
            kmem_alloc(INET6_ADDRSTRLEN, KM_SLEEP);

        cm_entry->x_ksp->ks_update = conn_kstat_update;
        kstat_install(cm_entry->x_ksp);
        return (TRUE);
}

/*
 * Verify that the specified offset falls within the mblk and
 * that the resulting pointer is aligned.
 * Returns NULL if not.
 *
 * code from fs/sockfs/socksubr.c
 */
static void *
connmgr_opt_getoff(mblk_t *mp, t_uscalar_t offset,
    t_uscalar_t length, uint_t align_size)
{
        uintptr_t ptr1, ptr2;

        ASSERT(mp && mp->b_wptr >= mp->b_rptr);
        ptr1 = (uintptr_t)mp->b_rptr + offset;
        ptr2 = (uintptr_t)ptr1 + length;
        if (ptr1 < (uintptr_t)mp->b_rptr || ptr2 > (uintptr_t)mp->b_wptr) {
                return (NULL);
        }
        if ((ptr1 & (align_size - 1)) != 0) {
                return (NULL);
        }
        return ((void *)ptr1);
}

static bool_t
connmgr_getopt_int(queue_t *wq, int level, int name, int *val,
    calllist_t *e, cred_t *cr)
{
        mblk_t *mp;
        struct opthdr *opt, *opt_res;
        struct T_optmgmt_req *tor;
        struct T_optmgmt_ack *opt_ack;
        struct timeval waitp;
        int error;

        mp = allocb_cred(sizeof (struct T_optmgmt_req) +
            sizeof (struct opthdr) + sizeof (int), cr, NOPID);
        if (mp == NULL)
                return (FALSE);

        mp->b_datap->db_type = M_PROTO;
        tor = (struct T_optmgmt_req *)(mp->b_rptr);
        tor->PRIM_type = T_SVR4_OPTMGMT_REQ;
        tor->MGMT_flags = T_CURRENT;
        tor->OPT_length = sizeof (struct opthdr) + sizeof (int);
        tor->OPT_offset = sizeof (struct T_optmgmt_req);

        opt = (struct opthdr *)(mp->b_rptr + sizeof (struct T_optmgmt_req));
        opt->level = level;
        opt->name = name;
        opt->len = sizeof (int);
        mp->b_wptr += sizeof (struct T_optmgmt_req) + sizeof (struct opthdr) +
            sizeof (int);

        /*
         * We will use this connection regardless
         * of whether or not the option is readable.
         */
        if (clnt_dispatch_send(wq, mp, e, 0, 0) != RPC_SUCCESS) {
                DTRACE_PROBE(krpc__e__connmgr__getopt__cantsend);
                freemsg(mp);
                return (FALSE);
        }

        mutex_enter(&clnt_pending_lock);

        waitp.tv_sec = clnt_cots_min_conntout;
        waitp.tv_usec = 0;
        error = waitforack(e, T_OPTMGMT_ACK, &waitp, 1);

        if (e->call_prev)
                e->call_prev->call_next = e->call_next;
        else
                clnt_pending = e->call_next;
        if (e->call_next)
                e->call_next->call_prev = e->call_prev;
        mutex_exit(&clnt_pending_lock);

        /* get reply message */
        mp = e->call_reply;
        e->call_reply = NULL;

        if ((!mp) || (e->call_status != RPC_SUCCESS) || (error != 0)) {

                DTRACE_PROBE4(krpc__e__connmgr_getopt, int, name,
                    int, e->call_status, int, error, mblk_t *, mp);

                if (mp)
                        freemsg(mp);
                return (FALSE);
        }

        opt_ack = (struct T_optmgmt_ack *)mp->b_rptr;
        opt_res = (struct opthdr *)connmgr_opt_getoff(mp, opt_ack->OPT_offset,
            opt_ack->OPT_length, __TPI_ALIGN_SIZE);

        if (!opt_res) {
                DTRACE_PROBE4(krpc__e__connmgr_optres, mblk_t *, mp, int, name,
                    int, opt_ack->OPT_offset, int, opt_ack->OPT_length);
                freemsg(mp);
                return (FALSE);
        }
        *val = *(int *)&opt_res[1];

        DTRACE_PROBE2(connmgr_getopt__ok, int, name, int, *val);

        freemsg(mp);
        return (TRUE);
}

/*
 * Called by connmgr_connect to set an option on the new stream.
 */
static bool_t
connmgr_setopt_int(queue_t *wq, int level, int name, int val,
    calllist_t *e, cred_t *cr)
{
        mblk_t *mp;
        struct opthdr *opt;
        struct T_optmgmt_req *tor;
        struct timeval waitp;
        int error;

        mp = allocb_cred(sizeof (struct T_optmgmt_req) +
            sizeof (struct opthdr) + sizeof (int), cr, NOPID);
        if (mp == NULL) {
                RPCLOG0(1, "connmgr_setopt: cannot alloc mp for option "
                    "request\n");
                return (FALSE);
        }

        mp->b_datap->db_type = M_PROTO;
        tor = (struct T_optmgmt_req *)(mp->b_rptr);
        tor->PRIM_type = T_SVR4_OPTMGMT_REQ;
        tor->MGMT_flags = T_NEGOTIATE;
        tor->OPT_length = sizeof (struct opthdr) + sizeof (int);
        tor->OPT_offset = sizeof (struct T_optmgmt_req);

        opt = (struct opthdr *)(mp->b_rptr + sizeof (struct T_optmgmt_req));
        opt->level = level;
        opt->name = name;
        opt->len = sizeof (int);
        *(int *)((char *)opt + sizeof (*opt)) = val;
        mp->b_wptr += sizeof (struct T_optmgmt_req) + sizeof (struct opthdr) +
            sizeof (int);

        /*
         * We will use this connection regardless
         * of whether or not the option is settable.
         */
        if (clnt_dispatch_send(wq, mp, e, 0, 0) != RPC_SUCCESS) {
                DTRACE_PROBE(krpc__e__connmgr__setopt__cantsend);
                freemsg(mp);
                return (FALSE);
        }

        mutex_enter(&clnt_pending_lock);

        waitp.tv_sec = clnt_cots_min_conntout;
        waitp.tv_usec = 0;
        error = waitforack(e, T_OPTMGMT_ACK, &waitp, 1);

        if (e->call_prev)
                e->call_prev->call_next = e->call_next;
        else
                clnt_pending = e->call_next;
        if (e->call_next)
                e->call_next->call_prev = e->call_prev;
        mutex_exit(&clnt_pending_lock);

        if (e->call_reply != NULL) {
                freemsg(e->call_reply);
                e->call_reply = NULL;
        }

        if (e->call_status != RPC_SUCCESS || error != 0) {
                RPCLOG(1, "connmgr_setopt: can't set option: %d\n", name);
                return (FALSE);
        }
        RPCLOG(8, "connmgr_setopt: successfully set option: %d\n", name);
        return (TRUE);
}

static bool_t
connmgr_setopt(queue_t *wq, int level, int name, calllist_t *e, cred_t *cr)
{
        return (connmgr_setopt_int(wq, level, name, 1, e, cr));
}

#ifdef  DEBUG

/*
 * This is a knob to let us force code coverage in allocation failure
 * case.
 */
static int      connmgr_failsnd;
#define CONN_SND_ALLOC(Size, Pri)       \
        ((connmgr_failsnd-- > 0) ? NULL : allocb(Size, Pri))

#else

#define CONN_SND_ALLOC(Size, Pri)       allocb(Size, Pri)

#endif

/*
 * Sends an orderly release on the specified queue.
 * Entered with connmgr_lock. Exited without connmgr_lock
 */
static void
connmgr_sndrel(struct cm_xprt *cm_entry)
{
        struct T_ordrel_req *torr;
        mblk_t *mp;
        queue_t *q = cm_entry->x_wq;
        ASSERT(MUTEX_HELD(&connmgr_lock));
        mp = CONN_SND_ALLOC(sizeof (struct T_ordrel_req), BPRI_LO);
        if (mp == NULL) {
                cm_entry->x_needrel = TRUE;
                mutex_exit(&connmgr_lock);
                RPCLOG(1, "connmgr_sndrel: cannot alloc mp for sending ordrel "
                    "to queue %p\n", (void *)q);
                return;
        }
        mutex_exit(&connmgr_lock);

        mp->b_datap->db_type = M_PROTO;
        torr = (struct T_ordrel_req *)(mp->b_rptr);
        torr->PRIM_type = T_ORDREL_REQ;
        mp->b_wptr = mp->b_rptr + sizeof (struct T_ordrel_req);

        RPCLOG(8, "connmgr_sndrel: sending ordrel to queue %p\n", (void *)q);
        put(q, mp);
}

/*
 * Sends an disconnect on the specified queue.
 * Entered with connmgr_lock. Exited without connmgr_lock
 */
static void
connmgr_snddis(struct cm_xprt *cm_entry)
{
        struct T_discon_req *tdis;
        mblk_t *mp;
        queue_t *q = cm_entry->x_wq;

        ASSERT(MUTEX_HELD(&connmgr_lock));
        mp = CONN_SND_ALLOC(sizeof (*tdis), BPRI_LO);
        if (mp == NULL) {
                cm_entry->x_needdis = TRUE;
                mutex_exit(&connmgr_lock);
                RPCLOG(1, "connmgr_snddis: cannot alloc mp for sending discon "
                    "to queue %p\n", (void *)q);
                return;
        }
        mutex_exit(&connmgr_lock);

        mp->b_datap->db_type = M_PROTO;
        tdis = (struct T_discon_req *)mp->b_rptr;
        tdis->PRIM_type = T_DISCON_REQ;
        mp->b_wptr = mp->b_rptr + sizeof (*tdis);

        RPCLOG(8, "connmgr_snddis: sending discon to queue %p\n", (void *)q);
        put(q, mp);
}

/*
 * We end up here if there is a connection disconnect.
 * The cm_entry is taken off the list.
 */
void
connmgr_destroy(queue_t *wq)
{
        struct cm_xprt *cm_entry, *cm_prev;

        mutex_enter(&connmgr_lock);
        cm_entry = cm_hd;
        cm_prev = NULL;

        while (cm_entry) {
                if (cm_entry->x_wq == wq) {
                        if (cm_prev)
                                cm_prev->x_next = cm_entry->x_next;
                        else
                                cm_hd = cm_entry->x_next;
                        cm_entry->x_next = NULL;
                        break;
                }
                cm_prev = cm_entry;
                cm_entry = cm_entry->x_next;
        }
        mutex_exit(&connmgr_lock);

        if (cm_entry)
                connmgr_close(cm_entry);
}

/*
 * Sets up the entry for receiving replies, and calls rpcmod's write put proc
 * (through put) to send the call.
 */
static int
clnt_dispatch_send(queue_t *q, mblk_t *mp, calllist_t *e, uint_t xid,
    uint_t queue_flag)
{
        ASSERT(e != NULL);

        e->call_status = RPC_TIMEDOUT;  /* optimistic, eh? */
        e->call_reason = 0;
        e->call_wq = q;
        e->call_xid = xid;
        e->call_notified = FALSE;

        if (!canput(q)) {
                e->call_status = RPC_CANTSEND;
                e->call_reason = ENOBUFS;
                return (RPC_CANTSEND);
        }

        /*
         * If queue_flag is set then the calllist_t is already on the hash
         * queue.  In this case just send the message and return.
         */
        if (queue_flag) {
                put(q, mp);
                return (RPC_SUCCESS);

        }

        /*
         * Set up calls for RPC requests (with XID != 0) on the hash
         * queue for fast lookups and place other calls (i.e.
         * connection management) on the linked list.
         */
        if (xid != 0) {
                RPCLOG(64, "clnt_dispatch_send: putting xid 0x%x on "
                    "dispatch list\n", xid);
                e->call_hash = call_hash(xid, clnt_cots_hash_size);
                e->call_bucket = &cots_call_ht[e->call_hash];
                call_table_enter(e);
        } else {
                mutex_enter(&clnt_pending_lock);
                if (clnt_pending)
                        clnt_pending->call_prev = e;
                e->call_next = clnt_pending;
                e->call_prev = NULL;
                clnt_pending = e;
                mutex_exit(&clnt_pending_lock);
        }

        put(q, mp);
        return (RPC_SUCCESS);
}

/*
 * Called by rpcmod to notify a client with a clnt_pending call that its reply
 * has arrived.  If we can't find a client waiting for this reply, we log
 * the error and return.
 */
bool_t
clnt_dispatch_notify(mblk_t *mp, zoneid_t zoneid)
{
        calllist_t *e = NULL;
        call_table_t *chtp;
        uint32_t xid;
        uint_t hash;

        if ((IS_P2ALIGNED(mp->b_rptr, sizeof (uint32_t))) &&
            (mp->b_wptr - mp->b_rptr) >= sizeof (xid))
                xid = *((uint32_t *)mp->b_rptr);
        else {
                int i = 0;
                unsigned char *p = (unsigned char *)&xid;
                unsigned char *rptr;
                mblk_t *tmp = mp;

                /*
                 * Copy the xid, byte-by-byte into xid.
                 */
                while (tmp) {
                        rptr = tmp->b_rptr;
                        while (rptr < tmp->b_wptr) {
                                *p++ = *rptr++;
                                if (++i >= sizeof (xid))
                                        goto done_xid_copy;
                        }
                        tmp = tmp->b_cont;
                }

                /*
                 * If we got here, we ran out of mblk space before the
                 * xid could be copied.
                 */
                ASSERT(tmp == NULL && i < sizeof (xid));

                RPCLOG0(1,
                    "clnt_dispatch_notify: message less than size of xid\n");
                return (FALSE);

        }
done_xid_copy:

        hash = call_hash(xid, clnt_cots_hash_size);
        chtp = &cots_call_ht[hash];
        /* call_table_find returns with the hash bucket locked */
        call_table_find(chtp, xid, e);

        if (e != NULL) {
                /*
                 * Found thread waiting for this reply
                 */
                mutex_enter(&e->call_lock);

                /*
                 * verify that the reply is coming in on
                 * the same zone that it was sent from.
                 */
                if (e->call_zoneid != zoneid) {
                        mutex_exit(&e->call_lock);
                        mutex_exit(&chtp->ct_lock);
                        RPCLOG0(1, "clnt_dispatch_notify: incorrect zoneid\n");
                        return (FALSE);
                }

                if (e->call_reply)
                        /*
                         * This can happen under the following scenario:
                         * clnt_cots_kcallit() times out on the response,
                         * rfscall() repeats the CLNT_CALL() with
                         * the same xid, clnt_cots_kcallit() sends the retry,
                         * thereby putting the clnt handle on the pending list,
                         * the first response arrives, signalling the thread
                         * in clnt_cots_kcallit(). Before that thread is
                         * dispatched, the second response arrives as well,
                         * and clnt_dispatch_notify still finds the handle on
                         * the pending list, with call_reply set. So free the
                         * old reply now.
                         *
                         * It is also possible for a response intended for
                         * an RPC call with a different xid to reside here.
                         * This can happen if the thread that owned this
                         * client handle prior to the current owner bailed
                         * out and left its call record on the dispatch
                         * queue.  A window exists where the response can
                         * arrive before the current owner dispatches its
                         * RPC call.
                         *
                         * In any case, this is the very last point where we
                         * can safely check the call_reply field before
                         * placing the new response there.
                         */
                        freemsg(e->call_reply);
                e->call_reply = mp;
                e->call_status = RPC_SUCCESS;
                e->call_notified = TRUE;
                cv_signal(&e->call_cv);
                mutex_exit(&e->call_lock);
                mutex_exit(&chtp->ct_lock);
                return (TRUE);
        } else {
                zone_t *zone;
                struct rpcstat *rpcstat;

                mutex_exit(&chtp->ct_lock);
                RPCLOG(65, "clnt_dispatch_notify: no caller for reply 0x%x\n",
                    xid);
                /*
                 * This is unfortunate, but we need to lookup the zone so we
                 * can increment its "rcbadxids" counter.
                 */
                zone = zone_find_by_id(zoneid);
                if (zone == NULL) {
                        /*
                         * The zone went away...
                         */
                        return (FALSE);
                }
                rpcstat = zone_getspecific(rpcstat_zone_key, zone);
                if (zone_status_get(zone) >= ZONE_IS_SHUTTING_DOWN) {
                        /*
                         * Not interested
                         */
                        zone_rele(zone);
                        return (FALSE);
                }
                COTSRCSTAT_INCR(rpcstat->rpc_cots_client, rcbadxids);
                zone_rele(zone);
        }
        return (FALSE);
}

/*
 * Called by rpcmod when a non-data indication arrives.  The ones in which we
 * are interested are connection indications and options acks.  We dispatch
 * based on the queue the indication came in on.  If we are not interested in
 * what came in, we return false to rpcmod, who will then pass it upstream.
 */
bool_t
clnt_dispatch_notifyconn(queue_t *q, mblk_t *mp)
{
        calllist_t *e;
        int type;

        ASSERT((q->q_flag & QREADR) == 0);

        type = ((union T_primitives *)mp->b_rptr)->type;
        RPCLOG(8, "clnt_dispatch_notifyconn: prim type: [%s]\n",
            rpc_tpiprim2name(type));
        mutex_enter(&clnt_pending_lock);
        for (e = clnt_pending; /* NO CONDITION */; e = e->call_next) {
                if (e == NULL) {
                        mutex_exit(&clnt_pending_lock);
                        RPCLOG(1, "clnt_dispatch_notifyconn: no one waiting "
                            "for connection on queue 0x%p\n", (void *)q);
                        return (FALSE);
                }
                if (e->call_wq == q)
                        break;
        }

        switch (type) {
        case T_CONN_CON:
                /*
                 * The transport is now connected, send a T_INFO_REQ to get
                 * the tidu size.
                 */
                mutex_exit(&clnt_pending_lock);
                ASSERT(mp->b_datap->db_lim - mp->b_datap->db_base >=
                    sizeof (struct T_info_req));
                mp->b_rptr = mp->b_datap->db_base;
                ((union T_primitives *)mp->b_rptr)->type = T_INFO_REQ;
                mp->b_wptr = mp->b_rptr + sizeof (struct T_info_req);
                mp->b_datap->db_type = M_PCPROTO;
                put(q, mp);
                return (TRUE);
        case T_INFO_ACK:
        case T_OPTMGMT_ACK:
                e->call_status = RPC_SUCCESS;
                e->call_reply = mp;
                e->call_notified = TRUE;
                cv_signal(&e->call_cv);
                break;
        case T_ERROR_ACK:
                e->call_status = RPC_CANTCONNECT;
                e->call_reply = mp;
                e->call_notified = TRUE;
                cv_signal(&e->call_cv);
                break;
        case T_OK_ACK:
                /*
                 * Great, but we are really waiting for a T_CONN_CON
                 */
                freemsg(mp);
                break;
        default:
                mutex_exit(&clnt_pending_lock);
                RPCLOG(1, "clnt_dispatch_notifyconn: bad type %d\n", type);
                return (FALSE);
        }

        mutex_exit(&clnt_pending_lock);
        return (TRUE);
}

/*
 * Called by rpcmod when the transport is (or should be) going away.  Informs
 * all callers waiting for replies and marks the entry in the connection
 * manager's list as unconnected, and either closing (close handshake in
 * progress) or dead.
 */
void
clnt_dispatch_notifyall(queue_t *q, int32_t msg_type, int32_t reason)
{
        calllist_t *e;
        call_table_t *ctp;
        struct cm_xprt *cm_entry;
        int have_connmgr_lock;
        int i;

        ASSERT((q->q_flag & QREADR) == 0);

        RPCLOG(1, "clnt_dispatch_notifyall on queue %p", (void *)q);
        RPCLOG(1, " received a notifcation prim type [%s]",
            rpc_tpiprim2name(msg_type));
        RPCLOG(1, " and reason %d\n", reason);

        /*
         * Find the transport entry in the connection manager's list, close
         * the transport and delete the entry.  In the case where rpcmod's
         * idle timer goes off, it sends us a T_ORDREL_REQ, indicating we
         * should gracefully close the connection.
         */
        have_connmgr_lock = 1;
        mutex_enter(&connmgr_lock);
        for (cm_entry = cm_hd; cm_entry; cm_entry = cm_entry->x_next) {
                ASSERT(cm_entry != cm_entry->x_next);
                if (cm_entry->x_wq == q) {
                        ASSERT(MUTEX_HELD(&connmgr_lock));
                        ASSERT(have_connmgr_lock == 1);
                        switch (msg_type) {
                        case T_ORDREL_REQ:

                                if (cm_entry->x_dead) {
                                        RPCLOG(1, "idle timeout on dead "
                                            "connection: %p\n",
                                            (void *)cm_entry);
                                        if (clnt_stop_idle != NULL)
                                                (*clnt_stop_idle)(q);
                                        break;
                                }

                                /*
                                 * Only mark the connection as dead if it is
                                 * connected and idle.
                                 * An unconnected connection has probably
                                 * gone idle because the server is down,
                                 * and when it comes back up there will be
                                 * retries that need to use that connection.
                                 */
                                if (cm_entry->x_connected ||
                                    cm_entry->x_doomed) {
                                        if (cm_entry->x_ordrel) {
                                                if (cm_entry->x_closing ==
                                                    TRUE) {
                                                        /*
                                                         * The connection is
                                                         * obviously wedged due
                                                         * to a bug or problem
                                                         * with the transport.
                                                         * Mark it as dead.
                                                         * Otherwise we can
                                                         * leak connections.
                                                         */
                                                        cm_entry->x_dead = TRUE;
                                                        mutex_exit(
                                                            &connmgr_lock);
                                                        have_connmgr_lock = 0;
                                                        if (clnt_stop_idle !=
                                                            NULL)
                                                        (*clnt_stop_idle)(q);
                                                        break;
                                                }
                                                cm_entry->x_closing = TRUE;
                                                connmgr_sndrel(cm_entry);
                                                have_connmgr_lock = 0;
                                        } else {
                                                cm_entry->x_dead = TRUE;
                                                mutex_exit(&connmgr_lock);
                                                have_connmgr_lock = 0;
                                                if (clnt_stop_idle != NULL)
                                                        (*clnt_stop_idle)(q);
                                        }
                                } else {
                                        /*
                                         * We don't mark the connection
                                         * as dead, but we turn off the
                                         * idle timer.
                                         */
                                        mutex_exit(&connmgr_lock);
                                        have_connmgr_lock = 0;
                                        if (clnt_stop_idle != NULL)
                                                (*clnt_stop_idle)(q);
                                        RPCLOG(1, "clnt_dispatch_notifyall:"
                                            " ignoring timeout from rpcmod"
                                            " (q %p) because we are not "
                                            " connected\n", (void *)q);
                                }
                                break;
                        case T_ORDREL_IND:
                                /*
                                 * If this entry is marked closing, then we are
                                 * completing a close handshake, and the
                                 * connection is dead.  Otherwise, the server is
                                 * trying to close. Since the server will not
                                 * be sending any more RPC replies, we abort
                                 * the connection, including flushing
                                 * any RPC requests that are in-transit.
                                 * In either case, mark the entry as dead so
                                 * that it can be closed by the connection
                                 * manager's garbage collector.
                                 */
                                cm_entry->x_dead = TRUE;
                                if (cm_entry->x_closing) {
                                        mutex_exit(&connmgr_lock);
                                        have_connmgr_lock = 0;
                                        if (clnt_stop_idle != NULL)
                                                (*clnt_stop_idle)(q);
                                } else {
                                        /*
                                         * if we're getting a disconnect
                                         * before we've finished our
                                         * connect attempt, mark it for
                                         * later processing
                                         */
                                        if (cm_entry->x_thread)
                                                cm_entry->x_early_disc = TRUE;
                                        else
                                                cm_entry->x_connected = FALSE;
                                        cm_entry->x_waitdis = TRUE;
                                        connmgr_snddis(cm_entry);
                                        have_connmgr_lock = 0;
                                }
                                break;

                        case T_ERROR_ACK:
                        case T_OK_ACK:
                                cm_entry->x_waitdis = FALSE;
                                cv_signal(&cm_entry->x_dis_cv);
                                mutex_exit(&connmgr_lock);
                                return;

                        case T_DISCON_REQ:
                                if (cm_entry->x_thread)
                                        cm_entry->x_early_disc = TRUE;
                                else
                                        cm_entry->x_connected = FALSE;
                                cm_entry->x_waitdis = TRUE;

                                connmgr_snddis(cm_entry);
                                have_connmgr_lock = 0;
                                break;

                        case T_DISCON_IND:
                        default:
                                /*
                                 * if we're getting a disconnect before
                                 * we've finished our connect attempt,
                                 * mark it for later processing
                                 */
                                if (cm_entry->x_closing) {
                                        cm_entry->x_dead = TRUE;
                                        mutex_exit(&connmgr_lock);
                                        have_connmgr_lock = 0;
                                        if (clnt_stop_idle != NULL)
                                                (*clnt_stop_idle)(q);
                                } else {
                                        if (cm_entry->x_thread) {
                                                cm_entry->x_early_disc = TRUE;
                                        } else {
                                                cm_entry->x_dead = TRUE;
                                                cm_entry->x_connected = FALSE;
                                        }
                                }
                                break;
                        }
                        break;
                }
        }

        if (have_connmgr_lock)
                mutex_exit(&connmgr_lock);

        if (msg_type == T_ERROR_ACK || msg_type == T_OK_ACK) {
                RPCLOG(1, "clnt_dispatch_notifyall: (wq %p) could not find "
                    "connmgr entry for discon ack\n", (void *)q);
                return;
        }

        /*
         * Then kick all the clnt_pending calls out of their wait.  There
         * should be no clnt_pending calls in the case of rpcmod's idle
         * timer firing.
         */
        for (i = 0; i < clnt_cots_hash_size; i++) {
                ctp = &cots_call_ht[i];
                mutex_enter(&ctp->ct_lock);
                for (e = ctp->ct_call_next;
                    e != (calllist_t *)ctp;
                    e = e->call_next) {
                        if (e->call_wq == q && e->call_notified == FALSE) {
                                RPCLOG(1,
                                    "clnt_dispatch_notifyall for queue %p ",
                                    (void *)q);
                                RPCLOG(1, "aborting clnt_pending call %p\n",
                                    (void *)e);

                                if (msg_type == T_DISCON_IND)
                                        e->call_reason = reason;
                                e->call_notified = TRUE;
                                e->call_status = RPC_XPRTFAILED;
                                cv_signal(&e->call_cv);
                        }
                }
                mutex_exit(&ctp->ct_lock);
        }

        mutex_enter(&clnt_pending_lock);
        for (e = clnt_pending; e; e = e->call_next) {
                /*
                 * Only signal those RPC handles that haven't been
                 * signalled yet. Otherwise we can get a bogus call_reason.
                 * This can happen if thread A is making a call over a
                 * connection. If the server is killed, it will cause
                 * reset, and reason will default to EIO as a result of
                 * a T_ORDREL_IND. Thread B then attempts to recreate
                 * the connection but gets a T_DISCON_IND. If we set the
                 * call_reason code for all threads, then if thread A
                 * hasn't been dispatched yet, it will get the wrong
                 * reason. The bogus call_reason can make it harder to
                 * discriminate between calls that fail because the
                 * connection attempt failed versus those where the call
                 * may have been executed on the server.
                 */
                if (e->call_wq == q && e->call_notified == FALSE) {
                        RPCLOG(1, "clnt_dispatch_notifyall for queue %p ",
                            (void *)q);
                        RPCLOG(1, " aborting clnt_pending call %p\n",
                            (void *)e);

                        if (msg_type == T_DISCON_IND)
                                e->call_reason = reason;
                        e->call_notified = TRUE;
                        /*
                         * Let the caller timeout, else it will retry
                         * immediately.
                         */
                        e->call_status = RPC_XPRTFAILED;

                        /*
                         * We used to just signal those threads
                         * waiting for a connection, (call_xid = 0).
                         * That meant that threads waiting for a response
                         * waited till their timeout expired. This
                         * could be a long time if they've specified a
                         * maximum timeout. (2^31 - 1). So we
                         * Signal all threads now.
                         */
                        cv_signal(&e->call_cv);
                }
        }
        mutex_exit(&clnt_pending_lock);
}


/*ARGSUSED*/
/*
 * after resuming a system that's been suspended for longer than the
 * NFS server's idle timeout (svc_idle_timeout for Solaris 2), rfscall()
 * generates "NFS server X not responding" and "NFS server X ok" messages;
 * here we reset inet connections to cause a re-connect and avoid those
 * NFS messages.  see 4045054
 */
boolean_t
connmgr_cpr_reset(void *arg, int code)
{
        struct cm_xprt *cxp;

        if (code == CB_CODE_CPR_CHKPT)
                return (B_TRUE);

        if (mutex_tryenter(&connmgr_lock) == 0)
                return (B_FALSE);
        for (cxp = cm_hd; cxp; cxp = cxp->x_next) {
                if ((cxp->x_family == AF_INET || cxp->x_family == AF_INET6) &&
                    cxp->x_connected == TRUE) {
                        if (cxp->x_thread)
                                cxp->x_early_disc = TRUE;
                        else
                                cxp->x_connected = FALSE;
                        cxp->x_needdis = TRUE;
                }
        }
        mutex_exit(&connmgr_lock);
        return (B_TRUE);
}

void
clnt_cots_stats_init(zoneid_t zoneid, struct rpc_cots_client **statsp)
{

        *statsp = (struct rpc_cots_client *)rpcstat_zone_init_common(zoneid,
            "unix", "rpc_cots_client", (const kstat_named_t *)&cots_rcstat_tmpl,
            sizeof (cots_rcstat_tmpl));
}

void
clnt_cots_stats_fini(zoneid_t zoneid, struct rpc_cots_client **statsp)
{
        rpcstat_zone_fini_common(zoneid, "unix", "rpc_cots_client");
        kmem_free(*statsp, sizeof (cots_rcstat_tmpl));
}

void
clnt_cots_init(void)
{
        mutex_init(&connmgr_lock, NULL, MUTEX_DEFAULT, NULL);
        mutex_init(&clnt_pending_lock, NULL, MUTEX_DEFAULT, NULL);

        if (clnt_cots_hash_size < DEFAULT_MIN_HASH_SIZE)
                clnt_cots_hash_size = DEFAULT_MIN_HASH_SIZE;

        cots_call_ht = call_table_init(clnt_cots_hash_size);
        zone_key_create(&zone_cots_key, NULL, NULL, clnt_zone_destroy);
}

void
clnt_cots_fini(void)
{
        (void) zone_key_delete(zone_cots_key);
}

/*
 * Wait for TPI ack, returns success only if expected ack is received
 * within timeout period.
 */

static int
waitforack(calllist_t *e, t_scalar_t ack_prim, const struct timeval *waitp,
    bool_t nosignal)
{
        union T_primitives *tpr;
        clock_t timout;
        int cv_stat = 1;

        ASSERT(MUTEX_HELD(&clnt_pending_lock));
        while (e->call_reply == NULL) {
                if (waitp != NULL) {
                        timout = waitp->tv_sec * drv_usectohz(MICROSEC) +
                            drv_usectohz(waitp->tv_usec);
                        if (nosignal)
                                cv_stat = cv_reltimedwait(&e->call_cv,
                                    &clnt_pending_lock, timout, TR_CLOCK_TICK);
                        else
                                cv_stat = cv_reltimedwait_sig(&e->call_cv,
                                    &clnt_pending_lock, timout, TR_CLOCK_TICK);
                } else {
                        if (nosignal)
                                cv_wait(&e->call_cv, &clnt_pending_lock);
                        else
                                cv_stat = cv_wait_sig(&e->call_cv,
                                    &clnt_pending_lock);
                }
                if (cv_stat == -1)
                        return (ETIME);
                if (cv_stat == 0)
                        return (EINTR);
                /*
                 * if we received an error from the server and we know a reply
                 * is not going to be sent, do not wait for the full timeout,
                 * return now.
                 */
                if (e->call_status == RPC_XPRTFAILED)
                        return (e->call_reason);
        }
        tpr = (union T_primitives *)e->call_reply->b_rptr;
        if (tpr->type == ack_prim)
                return (0); /* Success */

        if (tpr->type == T_ERROR_ACK) {
                if (tpr->error_ack.TLI_error == TSYSERR)
                        return (tpr->error_ack.UNIX_error);
                else
                        return (t_tlitosyserr(tpr->error_ack.TLI_error));
        }

        return (EPROTO); /* unknown or unexpected primitive */
}