/*
 * 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) 1996, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2012 by Delphix. All rights reserved.
 * Copyright 2014 Nexenta Systems, Inc.  All rights reserved.
 * Copyright 2014 Gary Mills
 */


/*
 * nfs_tbind.c, common part for nfsd and lockd.
 */

#include <tiuser.h>
#include <fcntl.h>
#include <netconfig.h>
#include <stropts.h>
#include <errno.h>
#include <syslog.h>
#include <rpc/rpc.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <signal.h>
#include <netdir.h>
#include <unistd.h>
#include <string.h>
#include <netinet/tcp.h>
#include <malloc.h>
#include <stdlib.h>
#include "nfs_tbind.h"
#include <nfs/nfs.h>
#include <nfs/nfs_acl.h>
#include <nfs/nfssys.h>
#include <nfs/nfs4.h>
#include <zone.h>
#include <sys/socket.h>
#include <tsol/label.h>

/*
 * Determine valid semantics for most applications.
 */
#define OK_TPI_TYPE(_nconf) \
        (_nconf->nc_semantics == NC_TPI_CLTS || \
        _nconf->nc_semantics == NC_TPI_COTS || \
        _nconf->nc_semantics == NC_TPI_COTS_ORD)

#define BE32_TO_U32(a) \
        ((((ulong_t)((uchar_t *)a)[0] & 0xFF) << (ulong_t)24) | \
        (((ulong_t)((uchar_t *)a)[1] & 0xFF) << (ulong_t)16) | \
        (((ulong_t)((uchar_t *)a)[2] & 0xFF) << (ulong_t)8)  | \
        ((ulong_t)((uchar_t *)a)[3] & 0xFF))

/*
 * Number of elements to add to the poll array on each allocation.
 */
#define POLL_ARRAY_INC_SIZE     64

/*
 * Number of file descriptors by which the process soft limit may be
 * increased on each call to nofile_increase(0).
 */
#define NOFILE_INC_SIZE 64

/*
 * Default TCP send and receive buffer size of NFS server.
 */
#define NFSD_TCP_BUFSZ  (1024*1024)

struct conn_ind {
        struct conn_ind *conn_next;
        struct conn_ind *conn_prev;
        struct t_call   *conn_call;
};

struct conn_entry {
        bool_t                  closing;
        struct netconfig        nc;
};

/*
 * this file contains transport routines common to nfsd and lockd
 */
static  int     nofile_increase(int);
static  int     reuseaddr(int);
static  int     recvucred(int);
static  int     anonmlp(int);
static  void    add_to_poll_list(int, struct netconfig *);
static  char    *serv_name_to_port_name(char *);
static  int     bind_to_proto(char *, char *, struct netbuf **,
                                struct netconfig **);
static  int     bind_to_provider(char *, char *, struct netbuf **,
                                        struct netconfig **);
static  void    conn_close_oldest(void);
static  boolean_t conn_get(int, struct netconfig *, struct conn_ind **);
static  void    cots_listen_event(int, int);
static  int     discon_get(int, struct netconfig *, struct conn_ind **);
static  int     do_poll_clts_action(int, int);
static  int     do_poll_cots_action(int, int);
static  void    remove_from_poll_list(int);
static  int     set_addrmask(int, struct netconfig *, struct netbuf *);
static  int     is_listen_fd_index(int);

static  struct pollfd *poll_array;
static  struct conn_entry *conn_polled;
static  int     num_conns;              /* Current number of connections */
int             (*Mysvc4)(int, struct netbuf *, struct netconfig *, int,
                struct netbuf *);
static int      setopt(int fd, int level, int name, int value);
static int      get_opt(int fd, int level, int name);
static void     nfslib_set_sockbuf(int fd);

/*
 * Called to create and prepare a transport descriptor for in-kernel
 * RPC service.
 * Returns -1 on failure and a valid descriptor on success.
 */
int
nfslib_transport_open(struct netconfig *nconf)
{
        int fd;
        struct strioctl strioc;

        if ((nconf == (struct netconfig *)NULL) ||
            (nconf->nc_device == (char *)NULL)) {
                syslog(LOG_ERR, "no netconfig device");
                return (-1);
        }

        /*
         * Open the transport device.
         */
        fd = t_open(nconf->nc_device, O_RDWR, (struct t_info *)NULL);
        if (fd == -1) {
                if (t_errno == TSYSERR && errno == EMFILE &&
                    (nofile_increase(0) == 0)) {
                        /* Try again with a higher NOFILE limit. */
                        fd = t_open(nconf->nc_device, O_RDWR,
                            (struct t_info *)NULL);
                }
                if (fd == -1) {
                        syslog(LOG_ERR, "t_open %s failed:  t_errno %d, %m",
                            nconf->nc_device, t_errno);
                        return (-1);
                }
        }

        /*
         * Pop timod because the RPC module must be as close as possible
         * to the transport.
         */
        if (ioctl(fd, I_POP, 0) < 0) {
                syslog(LOG_ERR, "I_POP of timod failed: %m");
                (void) t_close(fd);
                return (-1);
        }

        /*
         * Common code for CLTS and COTS transports
         */
        if (ioctl(fd, I_PUSH, "rpcmod") < 0) {
                syslog(LOG_ERR, "I_PUSH of rpcmod failed: %m");
                (void) t_close(fd);
                return (-1);
        }

        strioc.ic_cmd = RPC_SERVER;
        strioc.ic_dp = (char *)0;
        strioc.ic_len = 0;
        strioc.ic_timout = -1;

        /* Tell rpcmod to act like a server stream. */
        if (ioctl(fd, I_STR, &strioc) < 0) {
                syslog(LOG_ERR, "rpcmod set-up ioctl failed: %m");
                (void) t_close(fd);
                return (-1);
        }

        /*
         * Re-push timod so that we will still be doing TLI
         * operations on the descriptor.
         */
        if (ioctl(fd, I_PUSH, "timod") < 0) {
                syslog(LOG_ERR, "I_PUSH of timod failed: %m");
                (void) t_close(fd);
                return (-1);
        }

        /*
         * Enable options of returning the ip's for udp.
         */
        if (strcmp(nconf->nc_netid, "udp6") == 0)
                __rpc_tli_set_options(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, 1);
        else if (strcmp(nconf->nc_netid, "udp") == 0)
                __rpc_tli_set_options(fd, IPPROTO_IP, IP_RECVDSTADDR, 1);

        return (fd);
}

static int
nofile_increase(int limit)
{
        struct rlimit rl;

        if (getrlimit(RLIMIT_NOFILE, &rl) == -1) {
                syslog(LOG_ERR, "getrlimit of NOFILE failed: %m");
                return (-1);
        }

        if (limit > 0)
                rl.rlim_cur = limit;
        else
                rl.rlim_cur += NOFILE_INC_SIZE;

        if (rl.rlim_cur > rl.rlim_max &&
            rl.rlim_max != RLIM_INFINITY)
                rl.rlim_max = rl.rlim_cur;

        if (setrlimit(RLIMIT_NOFILE, &rl) == -1) {
                syslog(LOG_ERR, "setrlimit of NOFILE to %d failed: %m",
                    rl.rlim_cur);
                return (-1);
        }

        return (0);
}

static void
nfslib_set_sockbuf(int fd)
{
        int curval, val;

        val = NFSD_TCP_BUFSZ;

        curval = get_opt(fd, SOL_SOCKET, SO_SNDBUF);
        syslog(LOG_DEBUG, "Current SO_SNDBUF value is %d", curval);
        if ((curval != -1) && (curval < val)) {
                syslog(LOG_DEBUG, "Set SO_SNDBUF  option to %d", val);
                if (setopt(fd, SOL_SOCKET, SO_SNDBUF, val) < 0) {
                        syslog(LOG_ERR,
                            "couldn't set SO_SNDBUF to %d - t_errno = %d",
                            val, t_errno);
                        syslog(LOG_ERR,
                            "Check and increase system-wide tcp_max_buf");
                }
        }

        curval = get_opt(fd, SOL_SOCKET, SO_RCVBUF);
        syslog(LOG_DEBUG, "Current SO_RCVBUF value is %d", curval);
        if ((curval != -1) && (curval < val)) {
                syslog(LOG_DEBUG, "Set SO_RCVBUF  option to %d", val);
                if (setopt(fd, SOL_SOCKET, SO_RCVBUF, val) < 0) {
                        syslog(LOG_ERR,
                            "couldn't set SO_RCVBUF to %d - t_errno = %d",
                            val, t_errno);
                        syslog(LOG_ERR,
                            "Check and increase system-wide tcp_max_buf");
                }
        }
}

int
nfslib_bindit(struct netconfig *nconf, struct netbuf **addr,
        struct nd_hostserv *hs, int backlog)
{
        int fd;
        struct t_bind  *ntb;
        struct t_bind tb;
        struct nd_addrlist *addrlist;
        struct t_optmgmt req, resp;
        struct opthdr *opt;
        char reqbuf[128];
        bool_t use_any = FALSE;
        bool_t gzone = TRUE;

        if ((fd = nfslib_transport_open(nconf)) == -1) {
                syslog(LOG_ERR, "cannot establish transport service over %s",
                    nconf->nc_device);
                return (-1);
        }

        addrlist = (struct nd_addrlist *)NULL;

        /* nfs4_callback service does not used a fieed port number */

        if (strcmp(hs->h_serv, "nfs4_callback") == 0) {
                tb.addr.maxlen = 0;
                tb.addr.len = 0;
                tb.addr.buf = 0;
                use_any = TRUE;
                gzone = (getzoneid() == GLOBAL_ZONEID);
        } else if (netdir_getbyname(nconf, hs, &addrlist) != 0) {

                syslog(LOG_ERR,
                "Cannot get address for transport %s host %s service %s",
                    nconf->nc_netid, hs->h_host, hs->h_serv);
                (void) t_close(fd);
                return (-1);
        }

        if (strcmp(nconf->nc_proto, "tcp") == 0) {
                /*
                 * If we're running over TCP, then set the
                 * SO_REUSEADDR option so that we can bind
                 * to our preferred address even if previously
                 * left connections exist in FIN_WAIT states.
                 * This is somewhat bogus, but otherwise you have
                 * to wait 2 minutes to restart after killing it.
                 */
                if (reuseaddr(fd) == -1) {
                        syslog(LOG_WARNING,
                        "couldn't set SO_REUSEADDR option on transport");
                }
        } else if (strcmp(nconf->nc_proto, "udp") == 0) {
                /*
                 * In order to run MLP on UDP, we need to handle creds.
                 */
                if (recvucred(fd) == -1) {
                        syslog(LOG_WARNING,
                            "couldn't set SO_RECVUCRED option on transport");
                }
        }

        /*
         * Make non global zone nfs4_callback port MLP
         */
        if (use_any && is_system_labeled() && !gzone) {
                if (anonmlp(fd) == -1) {
                        /*
                         * failing to set this option means nfs4_callback
                         * could fail silently later. So fail it with
                         * with an error message now.
                         */
                        syslog(LOG_ERR,
                            "couldn't set SO_ANON_MLP option on transport");
                        (void) t_close(fd);
                        return (-1);
                }
        }

        if (nconf->nc_semantics == NC_TPI_CLTS)
                tb.qlen = 0;
        else
                tb.qlen = backlog;

        /* LINTED pointer alignment */
        ntb = (struct t_bind *)t_alloc(fd, T_BIND, T_ALL);
        if (ntb == (struct t_bind *)NULL) {
                syslog(LOG_ERR, "t_alloc failed:  t_errno %d, %m", t_errno);
                (void) t_close(fd);
                netdir_free((void *)addrlist, ND_ADDRLIST);
                return (-1);
        }

        /*
         * XXX - what about the space tb->addr.buf points to? This should
         * be either a memcpy() to/from the buf fields, or t_alloc(fd,T_BIND,)
         * should't be called with T_ALL.
         */
        if (addrlist)
                tb.addr = *(addrlist->n_addrs);         /* structure copy */

        if (t_bind(fd, &tb, ntb) == -1) {
                syslog(LOG_ERR, "t_bind failed:  t_errno %d, %m", t_errno);
                (void) t_free((char *)ntb, T_BIND);
                netdir_free((void *)addrlist, ND_ADDRLIST);
                (void) t_close(fd);
                return (-1);
        }

        /* make sure we bound to the right address */
        if (use_any == FALSE &&
            (tb.addr.len != ntb->addr.len ||
            memcmp(tb.addr.buf, ntb->addr.buf, tb.addr.len) != 0)) {
                syslog(LOG_ERR, "t_bind to wrong address");
                (void) t_free((char *)ntb, T_BIND);
                netdir_free((void *)addrlist, ND_ADDRLIST);
                (void) t_close(fd);
                return (-1);
        }

        /*
         * Call nfs4svc_setport so that the kernel can be
         * informed what port number the daemon is listing
         * for incoming connection requests.
         */

        if ((nconf->nc_semantics == NC_TPI_COTS ||
            nconf->nc_semantics == NC_TPI_COTS_ORD) && Mysvc4 != NULL)
                (*Mysvc4)(fd, NULL, nconf, NFS4_SETPORT, &ntb->addr);

        *addr = &ntb->addr;
        netdir_free((void *)addrlist, ND_ADDRLIST);

        if (strcmp(nconf->nc_proto, "tcp") == 0) {
                /*
                 * Disable the Nagle algorithm on TCP connections.
                 * Connections accepted from this listener will
                 * inherit the listener options.
                 */

                /* LINTED pointer alignment */
                opt = (struct opthdr *)reqbuf;
                opt->level = IPPROTO_TCP;
                opt->name = TCP_NODELAY;
                opt->len = sizeof (int);

                /* LINTED pointer alignment */
                *(int *)((char *)opt + sizeof (*opt)) = 1;

                req.flags = T_NEGOTIATE;
                req.opt.len = sizeof (*opt) + opt->len;
                req.opt.buf = (char *)opt;
                resp.flags = 0;
                resp.opt.buf = reqbuf;
                resp.opt.maxlen = sizeof (reqbuf);

                if (t_optmgmt(fd, &req, &resp) < 0 ||
                    resp.flags != T_SUCCESS) {
                        syslog(LOG_ERR,
        "couldn't set NODELAY option for proto %s: t_errno = %d, %m",
                            nconf->nc_proto, t_errno);
                }

                nfslib_set_sockbuf(fd);
        }

        return (fd);
}

static int
get_opt(int fd, int level, int name)
{
        struct t_optmgmt req, res;
        struct {
                struct opthdr opt;
                int value;
        } reqbuf;

        reqbuf.opt.level = level;
        reqbuf.opt.name = name;
        reqbuf.opt.len = sizeof (int);
        reqbuf.value = 0;

        req.flags = T_CURRENT;
        req.opt.len = sizeof (reqbuf);
        req.opt.buf = (char *)&reqbuf;

        res.flags = 0;
        res.opt.buf = (char *)&reqbuf;
        res.opt.maxlen = sizeof (reqbuf);

        if (t_optmgmt(fd, &req, &res) < 0 || res.flags != T_SUCCESS) {
                t_error("t_optmgmt");
                return (-1);
        }
        return (reqbuf.value);
}

static int
setopt(int fd, int level, int name, int value)
{
        struct t_optmgmt req, resp;
        struct {
                struct opthdr opt;
                int value;
        } reqbuf;

        reqbuf.opt.level = level;
        reqbuf.opt.name = name;
        reqbuf.opt.len = sizeof (int);

        reqbuf.value = value;

        req.flags = T_NEGOTIATE;
        req.opt.len = sizeof (reqbuf);
        req.opt.buf = (char *)&reqbuf;

        resp.flags = 0;
        resp.opt.buf = (char *)&reqbuf;
        resp.opt.maxlen = sizeof (reqbuf);

        if (t_optmgmt(fd, &req, &resp) < 0 || resp.flags != T_SUCCESS) {
                t_error("t_optmgmt");
                return (-1);
        }
        return (0);
}

static int
reuseaddr(int fd)
{
        return (setopt(fd, SOL_SOCKET, SO_REUSEADDR, 1));
}

static int
recvucred(int fd)
{
        return (setopt(fd, SOL_SOCKET, SO_RECVUCRED, 1));
}

static int
anonmlp(int fd)
{
        return (setopt(fd, SOL_SOCKET, SO_ANON_MLP, 1));
}

void
nfslib_log_tli_error(char *tli_name, int fd, struct netconfig *nconf)
{
        int error;

        /*
         * Save the error code across syslog(), just in case syslog()
         * gets its own error and, therefore, overwrites errno.
         */
        error = errno;
        if (t_errno == TSYSERR) {
                syslog(LOG_ERR, "%s(file descriptor %d/transport %s) %m",
                    tli_name, fd, nconf->nc_proto);
        } else {
                syslog(LOG_ERR,
                    "%s(file descriptor %d/transport %s) TLI error %d",
                    tli_name, fd, nconf->nc_proto, t_errno);
        }
        errno = error;
}

/*
 * Called to set up service over a particular transport.
 */
void
do_one(char *provider, NETSELDECL(proto), struct protob *protobp0,
        int (*svc)(int, struct netbuf, struct netconfig *))
{
        register int sock;
        struct protob *protobp;
        struct netbuf *retaddr;
        struct netconfig *retnconf;
        struct netbuf addrmask;
        int vers;
        int err;
        int l;

        if (provider)
                sock = bind_to_provider(provider, protobp0->serv, &retaddr,
                    &retnconf);
        else
                sock = bind_to_proto(proto, protobp0->serv, &retaddr,
                    &retnconf);

        if (sock == -1) {
                (void) syslog(LOG_ERR,
        "Cannot establish %s service over %s: transport setup problem.",
                    protobp0->serv, provider ? provider : proto);
                return;
        }

        if (set_addrmask(sock, retnconf, &addrmask) < 0) {
                (void) syslog(LOG_ERR,
                    "Cannot set address mask for %s", retnconf->nc_netid);
                return;
        }

        /*
         * Register all versions of the programs in the protocol block list.
         */
        l = strlen(NC_UDP);
        for (protobp = protobp0; protobp; protobp = protobp->next) {
                for (vers = protobp->versmin; vers <= protobp->versmax;
                    vers++) {
                        if ((protobp->program == NFS_PROGRAM ||
                            protobp->program == NFS_ACL_PROGRAM) &&
                            vers == NFS_V4 &&
                            strncasecmp(retnconf->nc_proto, NC_UDP, l) == 0)
                                continue;

                        (void) rpcb_unset(protobp->program, vers, retnconf);
                        (void) rpcb_set(protobp->program, vers, retnconf,
                            retaddr);
                }
        }

        /*
         * Register services with CLTS semantics right now.
         * Note: services with COTS/COTS_ORD semantics will be
         * registered later from cots_listen_event function.
         */
        if (retnconf->nc_semantics == NC_TPI_CLTS) {
                /* Don't drop core if supporting module(s) aren't loaded. */
                (void) signal(SIGSYS, SIG_IGN);

                /*
                 * svc() doesn't block, it returns success or failure.
                 */

                if (svc == NULL && Mysvc4 != NULL)
                        err = (*Mysvc4)(sock, &addrmask, retnconf,
                            NFS4_SETPORT|NFS4_KRPC_START, retaddr);
                else
                        err = (*svc)(sock, addrmask, retnconf);

                if (err < 0) {
                        (void) syslog(LOG_ERR,
                            "Cannot establish %s service over <file desc."
                            " %d, protocol %s> : %m. Exiting",
                            protobp0->serv, sock, retnconf->nc_proto);
                        exit(1);
                }
        }
        free(addrmask.buf);

        /*
         * We successfully set up the server over this transport.
         * Add this descriptor to the one being polled on.
         */
        add_to_poll_list(sock, retnconf);
}

/*
 * Set up the NFS service over all the available transports.
 * Returns -1 for failure, 0 for success.
 */
int
do_all(struct protob *protobp,
        int (*svc)(int, struct netbuf, struct netconfig *))
{
        struct netconfig *nconf;
        NCONF_HANDLE *nc;
        int l;

        if ((nc = setnetconfig()) == (NCONF_HANDLE *)NULL) {
                syslog(LOG_ERR, "setnetconfig failed: %m");
                return (-1);
        }
        l = strlen(NC_UDP);
        while (nconf = getnetconfig(nc)) {
                if ((nconf->nc_flag & NC_VISIBLE) &&
                    strcmp(nconf->nc_protofmly, NC_LOOPBACK) != 0 &&
                    OK_TPI_TYPE(nconf) &&
                    (protobp->program != NFS4_CALLBACK ||
                    strncasecmp(nconf->nc_proto, NC_UDP, l) != 0))
                        do_one(nconf->nc_device, nconf->nc_proto,
                            protobp, svc);
        }
        (void) endnetconfig(nc);
        return (0);
}

/*
 * poll on the open transport descriptors for events and errors.
 */
void
poll_for_action(void)
{
        int nfds;
        int i;

        /*
         * Keep polling until all transports have been closed. When this
         * happens, we return.
         */
        while ((int)num_fds > 0) {
                nfds = poll(poll_array, num_fds, INFTIM);
                switch (nfds) {
                case 0:
                        continue;

                case -1:
                        /*
                         * Some errors from poll could be
                         * due to temporary conditions, and we try to
                         * be robust in the face of them. Other
                         * errors (should never happen in theory)
                         * are fatal (eg. EINVAL, EFAULT).
                         */
                        switch (errno) {
                        case EINTR:
                                continue;

                        case EAGAIN:
                        case ENOMEM:
                                (void) sleep(10);
                                continue;

                        default:
                                (void) syslog(LOG_ERR,
                                    "poll failed: %m. Exiting");
                                exit(1);
                        }
                default:
                        break;
                }

                /*
                 * Go through the poll list looking for events.
                 */
                for (i = 0; i < num_fds && nfds > 0; i++) {
                        if (poll_array[i].revents) {
                                nfds--;
                                /*
                                 * We have a message, so try to read it.
                                 * Record the error return in errno,
                                 * so that syslog(LOG_ERR, "...%m")
                                 * dumps the corresponding error string.
                                 */
                                if (conn_polled[i].nc.nc_semantics ==
                                    NC_TPI_CLTS) {
                                        errno = do_poll_clts_action(
                                            poll_array[i].fd, i);
                                } else {
                                        errno = do_poll_cots_action(
                                            poll_array[i].fd, i);
                                }

                                if (errno == 0)
                                        continue;
                                /*
                                 * Most returned error codes mean that there is
                                 * fatal condition which we can only deal with
                                 * by closing the transport.
                                 */
                                if (errno != EAGAIN && errno != ENOMEM) {
                                        (void) syslog(LOG_ERR,
                "Error (%m) reading descriptor %d/transport %s. Closing it.",
                                            poll_array[i].fd,
                                            conn_polled[i].nc.nc_proto);
                                        (void) t_close(poll_array[i].fd);
                                        remove_from_poll_list(poll_array[i].fd);

                                } else if (errno == ENOMEM)
                                        (void) sleep(5);
                        }
                }
        }

        (void) syslog(LOG_ERR,
            "All transports have been closed with errors. Exiting.");
}

/*
 * Allocate poll/transport array entries for this descriptor.
 */
static void
add_to_poll_list(int fd, struct netconfig *nconf)
{
        static int poll_array_size = 0;

        /*
         * If the arrays are full, allocate new ones.
         */
        if (num_fds == poll_array_size) {
                struct pollfd *tpa;
                struct conn_entry *tnp;

                if (poll_array_size != 0) {
                        tpa = poll_array;
                        tnp = conn_polled;
                } else
                        tpa = (struct pollfd *)0;

                poll_array_size += POLL_ARRAY_INC_SIZE;
                /*
                 * Allocate new arrays.
                 */
                poll_array = (struct pollfd *)
                    malloc(poll_array_size * sizeof (struct pollfd) + 256);
                conn_polled = (struct conn_entry *)
                    malloc(poll_array_size * sizeof (struct conn_entry) + 256);
                if (poll_array == (struct pollfd *)NULL ||
                    conn_polled == (struct conn_entry *)NULL) {
                        syslog(LOG_ERR, "malloc failed for poll array");
                        exit(1);
                }

                /*
                 * Copy the data of the old ones into new arrays, and
                 * free the old ones.
                 */
                if (tpa) {
                        (void) memcpy((void *)poll_array, (void *)tpa,
                            num_fds * sizeof (struct pollfd));
                        (void) memcpy((void *)conn_polled, (void *)tnp,
                            num_fds * sizeof (struct conn_entry));
                        free((void *)tpa);
                        free((void *)tnp);
                }
        }

        /*
         * Set the descriptor and event list. All possible events are
         * polled for.
         */
        poll_array[num_fds].fd = fd;
        poll_array[num_fds].events = POLLIN|POLLRDNORM|POLLRDBAND|POLLPRI;

        /*
         * Copy the transport data over too.
         */
        conn_polled[num_fds].nc = *nconf;
        conn_polled[num_fds].closing = 0;

        /*
         * Set the descriptor to non-blocking. Avoids a race
         * between data arriving on the stream and then having it
         * flushed before we can read it.
         */
        if (fcntl(fd, F_SETFL, O_NONBLOCK) == -1) {
                (void) syslog(LOG_ERR,
        "fcntl(file desc. %d/transport %s, F_SETFL, O_NONBLOCK): %m. Exiting",
                    num_fds, nconf->nc_proto);
                exit(1);
        }

        /*
         * Count this descriptor.
         */
        ++num_fds;
}

static void
remove_from_poll_list(int fd)
{
        int i;
        int num_to_copy;

        for (i = 0; i < num_fds; i++) {
                if (poll_array[i].fd == fd) {
                        --num_fds;
                        num_to_copy = num_fds - i;
                        (void) memcpy((void *)&poll_array[i],
                            (void *)&poll_array[i+1],
                            num_to_copy * sizeof (struct pollfd));
                        (void) memset((void *)&poll_array[num_fds], 0,
                            sizeof (struct pollfd));
                        (void) memcpy((void *)&conn_polled[i],
                            (void *)&conn_polled[i+1],
                            num_to_copy * sizeof (struct conn_entry));
                        (void) memset((void *)&conn_polled[num_fds], 0,
                            sizeof (struct conn_entry));
                        return;
                }
        }
        syslog(LOG_ERR, "attempt to remove nonexistent fd from poll list");

}

/*
 * Called to read and interpret the event on a connectionless descriptor.
 * Returns 0 if successful, or a UNIX error code if failure.
 */
static int
do_poll_clts_action(int fd, int conn_index)
{
        int error;
        int ret;
        int flags;
        struct netconfig *nconf = &conn_polled[conn_index].nc;
        static struct t_unitdata *unitdata = NULL;
        static struct t_uderr *uderr = NULL;
        static int oldfd = -1;
        struct nd_hostservlist *host = NULL;
        struct strbuf ctl[1], data[1];
        /*
         * We just need to have some space to consume the
         * message in the event we can't use the TLI interface to do the
         * job.
         *
         * We flush the message using getmsg(). For the control part
         * we allocate enough for any TPI header plus 32 bytes for address
         * and options. For the data part, there is nothing magic about
         * the size of the array, but 256 bytes is probably better than
         * 1 byte, and we don't expect any data portion anyway.
         *
         * If the array sizes are too small, we handle this because getmsg()
         * (called to consume the message) will return MOREDATA|MORECTL.
         * Thus we just call getmsg() until it's read the message.
         */
        char ctlbuf[sizeof (union T_primitives) + 32];
        char databuf[256];

        /*
         * If this is the same descriptor as the last time
         * do_poll_clts_action was called, we can save some
         * de-allocation and allocation.
         */
        if (oldfd != fd) {
                oldfd = fd;

                if (unitdata) {
                        (void) t_free((char *)unitdata, T_UNITDATA);
                        unitdata = NULL;
                }
                if (uderr) {
                        (void) t_free((char *)uderr, T_UDERROR);
                        uderr = NULL;
                }
        }

        /*
         * Allocate a unitdata structure for receiving the event.
         */
        if (unitdata == NULL) {
                /* LINTED pointer alignment */
                unitdata = (struct t_unitdata *)t_alloc(fd, T_UNITDATA, T_ALL);
                if (unitdata == NULL) {
                        if (t_errno == TSYSERR) {
                                /*
                                 * Save the error code across
                                 * syslog(), just in case
                                 * syslog() gets its own error
                                 * and therefore overwrites errno.
                                 */
                                error = errno;
                                (void) syslog(LOG_ERR,
        "t_alloc(file descriptor %d/transport %s, T_UNITDATA) failed: %m",
                                    fd, nconf->nc_proto);
                                return (error);
                        }
                        (void) syslog(LOG_ERR,
"t_alloc(file descriptor %d/transport %s, T_UNITDATA) failed TLI error %d",
                            fd, nconf->nc_proto, t_errno);
                        goto flush_it;
                }
        }

try_again:
        flags = 0;

        /*
         * The idea is we wait for T_UNITDATA_IND's. Of course,
         * we don't get any, because rpcmod filters them out.
         * However, we need to call t_rcvudata() to let TLI
         * tell us we have a T_UDERROR_IND.
         *
         * algorithm is:
         *      t_rcvudata(), expecting TLOOK.
         *      t_look(), expecting T_UDERR.
         *      t_rcvuderr(), expecting success (0).
         *      expand destination address into ASCII,
         *      and dump it.
         */

        ret = t_rcvudata(fd, unitdata, &flags);
        if (ret == 0 || t_errno == TBUFOVFLW) {
                (void) syslog(LOG_WARNING,
"t_rcvudata(file descriptor %d/transport %s) got unexpected data, %d bytes",
                    fd, nconf->nc_proto, unitdata->udata.len);

                /*
                 * Even though we don't expect any data, in case we do,
                 * keep reading until there is no more.
                 */
                if (flags & T_MORE)
                        goto try_again;

                return (0);
        }

        switch (t_errno) {
        case TNODATA:
                return (0);
        case TSYSERR:
                /*
                 * System errors are returned to caller.
                 * Save the error code across
                 * syslog(), just in case
                 * syslog() gets its own error
                 * and therefore overwrites errno.
                 */
                error = errno;
                (void) syslog(LOG_ERR,
                    "t_rcvudata(file descriptor %d/transport %s) %m",
                    fd, nconf->nc_proto);
                return (error);
        case TLOOK:
                break;
        default:
                (void) syslog(LOG_ERR,
                "t_rcvudata(file descriptor %d/transport %s) TLI error %d",
                    fd, nconf->nc_proto, t_errno);
                goto flush_it;
        }

        ret = t_look(fd);
        switch (ret) {
        case 0:
                return (0);
        case -1:
                /*
                 * System errors are returned to caller.
                 */
                if (t_errno == TSYSERR) {
                        /*
                         * Save the error code across
                         * syslog(), just in case
                         * syslog() gets its own error
                         * and therefore overwrites errno.
                         */
                        error = errno;
                        (void) syslog(LOG_ERR,
                            "t_look(file descriptor %d/transport %s) %m",
                            fd, nconf->nc_proto);
                        return (error);
                }
                (void) syslog(LOG_ERR,
                    "t_look(file descriptor %d/transport %s) TLI error %d",
                    fd, nconf->nc_proto, t_errno);
                goto flush_it;
        case T_UDERR:
                break;
        default:
                (void) syslog(LOG_WARNING,
        "t_look(file descriptor %d/transport %s) returned %d not T_UDERR (%d)",
                    fd, nconf->nc_proto, ret, T_UDERR);
        }

        if (uderr == NULL) {
                /* LINTED pointer alignment */
                uderr = (struct t_uderr *)t_alloc(fd, T_UDERROR, T_ALL);
                if (uderr == NULL) {
                        if (t_errno == TSYSERR) {
                                /*
                                 * Save the error code across
                                 * syslog(), just in case
                                 * syslog() gets its own error
                                 * and therefore overwrites errno.
                                 */
                                error = errno;
                                (void) syslog(LOG_ERR,
        "t_alloc(file descriptor %d/transport %s, T_UDERROR) failed: %m",
                                    fd, nconf->nc_proto);
                                return (error);
                        }
                        (void) syslog(LOG_ERR,
"t_alloc(file descriptor %d/transport %s, T_UDERROR) failed TLI error: %d",
                            fd, nconf->nc_proto, t_errno);
                        goto flush_it;
                }
        }

        ret = t_rcvuderr(fd, uderr);
        if (ret == 0) {

                /*
                 * Save the datagram error in errno, so that the
                 * %m argument to syslog picks up the error string.
                 */
                errno = uderr->error;

                /*
                 * Log the datagram error, then log the host that
                 * probably triggerred. Cannot log both in the
                 * same transaction because of packet size limitations
                 * in /dev/log.
                 */
                (void) syslog((errno == ECONNREFUSED) ? LOG_DEBUG : LOG_WARNING,
"NFS response over <file descriptor %d/transport %s> generated error: %m",
                    fd, nconf->nc_proto);

                /*
                 * Try to map the client's address back to a
                 * name.
                 */
                ret = netdir_getbyaddr(nconf, &host, &uderr->addr);
                if (ret != -1 && host && host->h_cnt > 0 &&
                    host->h_hostservs) {
                (void) syslog((errno == ECONNREFUSED) ? LOG_DEBUG : LOG_WARNING,
"Bad NFS response was sent to client with host name: %s; service port: %s",
                    host->h_hostservs->h_host,
                    host->h_hostservs->h_serv);
                } else {
                        int i, j;
                        char *buf;
                        char *hex = "0123456789abcdef";

                        /*
                         * Mapping failed, print the whole thing
                         * in ASCII hex.
                         */
                        buf = (char *)malloc(uderr->addr.len * 2 + 1);
                        for (i = 0, j = 0; i < uderr->addr.len; i++, j += 2) {
                                buf[j] = hex[((uderr->addr.buf[i]) >> 4) & 0xf];
                                buf[j+1] = hex[uderr->addr.buf[i] & 0xf];
                        }
                        buf[j] = '\0';
                (void) syslog((errno == ECONNREFUSED) ? LOG_DEBUG : LOG_WARNING,
        "Bad NFS response was sent to client with transport address: 0x%s",
                    buf);
                        free((void *)buf);
                }

                if (ret == 0 && host != NULL)
                        netdir_free((void *)host, ND_HOSTSERVLIST);
                return (0);
        }

        switch (t_errno) {
        case TNOUDERR:
                goto flush_it;
        case TSYSERR:
                /*
                 * System errors are returned to caller.
                 * Save the error code across
                 * syslog(), just in case
                 * syslog() gets its own error
                 * and therefore overwrites errno.
                 */
                error = errno;
                (void) syslog(LOG_ERR,
                    "t_rcvuderr(file descriptor %d/transport %s) %m",
                    fd, nconf->nc_proto);
                return (error);
        default:
                (void) syslog(LOG_ERR,
                "t_rcvuderr(file descriptor %d/transport %s) TLI error %d",
                    fd, nconf->nc_proto, t_errno);
                goto flush_it;
        }

flush_it:
        /*
         * If we get here, then we could not cope with whatever message
         * we attempted to read, so flush it. If we did read a message,
         * and one isn't present, that is all right, because fd is in
         * nonblocking mode.
         */
        (void) syslog(LOG_ERR,
        "Flushing one input message from <file descriptor %d/transport %s>",
            fd, nconf->nc_proto);

        /*
         * Read and discard the message. Do this this until there is
         * no more control/data in the message or until we get an error.
         */
        do {
                ctl->maxlen = sizeof (ctlbuf);
                ctl->buf = ctlbuf;
                data->maxlen = sizeof (databuf);
                data->buf = databuf;
                flags = 0;
                ret = getmsg(fd, ctl, data, &flags);
                if (ret == -1)
                        return (errno);
        } while (ret != 0);

        return (0);
}

static void
conn_close_oldest(void)
{
        int fd;
        int i1;

        /*
         * Find the oldest connection that is not already in the
         * process of shutting down.
         */
        for (i1 = end_listen_fds; /* no conditional expression */; i1++) {
                if (i1 >= num_fds)
                        return;
                if (conn_polled[i1].closing == 0)
                        break;
        }
#ifdef DEBUG
        printf("too many connections (%d), releasing oldest (%d)\n",
            num_conns, poll_array[i1].fd);
#else
        syslog(LOG_WARNING, "too many connections (%d), releasing oldest (%d)",
            num_conns, poll_array[i1].fd);
#endif
        fd = poll_array[i1].fd;
        if (conn_polled[i1].nc.nc_semantics == NC_TPI_COTS) {
                /*
                 * For politeness, send a T_DISCON_REQ to the transport
                 * provider.  We close the stream anyway.
                 */
                (void) t_snddis(fd, (struct t_call *)0);
                num_conns--;
                remove_from_poll_list(fd);
                (void) t_close(fd);
        } else {
                /*
                 * For orderly release, we do not close the stream
                 * until the T_ORDREL_IND arrives to complete
                 * the handshake.
                 */
                if (t_sndrel(fd) == 0)
                        conn_polled[i1].closing = 1;
        }
}

static boolean_t
conn_get(int fd, struct netconfig *nconf, struct conn_ind **connp)
{
        struct conn_ind *conn;
        struct conn_ind *next_conn;

        conn = (struct conn_ind *)malloc(sizeof (*conn));
        if (conn == NULL) {
                syslog(LOG_ERR, "malloc for listen indication failed");
                return (FALSE);
        }

        /* LINTED pointer alignment */
        conn->conn_call = (struct t_call *)t_alloc(fd, T_CALL, T_ALL);
        if (conn->conn_call == NULL) {
                free((char *)conn);
                nfslib_log_tli_error("t_alloc", fd, nconf);
                return (FALSE);
        }

        if (t_listen(fd, conn->conn_call) == -1) {
                nfslib_log_tli_error("t_listen", fd, nconf);
                (void) t_free((char *)conn->conn_call, T_CALL);
                free((char *)conn);
                return (FALSE);
        }

        if (conn->conn_call->udata.len > 0) {
                syslog(LOG_WARNING,
        "rejecting inbound connection(%s) with %d bytes of connect data",
                    nconf->nc_proto, conn->conn_call->udata.len);

                conn->conn_call->udata.len = 0;
                (void) t_snddis(fd, conn->conn_call);
                (void) t_free((char *)conn->conn_call, T_CALL);
                free((char *)conn);
                return (FALSE);
        }

        if ((next_conn = *connp) != NULL) {
                next_conn->conn_prev->conn_next = conn;
                conn->conn_next = next_conn;
                conn->conn_prev = next_conn->conn_prev;
                next_conn->conn_prev = conn;
        } else {
                conn->conn_next = conn;
                conn->conn_prev = conn;
                *connp = conn;
        }
        return (TRUE);
}

static int
discon_get(int fd, struct netconfig *nconf, struct conn_ind **connp)
{
        struct conn_ind *conn;
        struct t_discon discon;

        discon.udata.buf = (char *)0;
        discon.udata.maxlen = 0;
        if (t_rcvdis(fd, &discon) == -1) {
                nfslib_log_tli_error("t_rcvdis", fd, nconf);
                return (-1);
        }

        conn = *connp;
        if (conn == NULL)
                return (0);

        do {
                if (conn->conn_call->sequence == discon.sequence) {
                        if (conn->conn_next == conn)
                                *connp = (struct conn_ind *)0;
                        else {
                                if (conn == *connp) {
                                        *connp = conn->conn_next;
                                }
                                conn->conn_next->conn_prev = conn->conn_prev;
                                conn->conn_prev->conn_next = conn->conn_next;
                        }
                        free((char *)conn);
                        break;
                }
                conn = conn->conn_next;
        } while (conn != *connp);

        return (0);
}

static void
cots_listen_event(int fd, int conn_index)
{
        struct t_call *call;
        struct conn_ind *conn;
        struct conn_ind *conn_head;
        int event;
        struct netconfig *nconf = &conn_polled[conn_index].nc;
        int new_fd;
        struct netbuf addrmask;
        int ret = 0;
        char *clnt;
        char *clnt_uaddr = NULL;
        struct nd_hostservlist *clnt_serv = NULL;

        conn_head = NULL;
        (void) conn_get(fd, nconf, &conn_head);

        while ((conn = conn_head) != NULL) {
                conn_head = conn->conn_next;
                if (conn_head == conn)
                        conn_head = NULL;
                else {
                        conn_head->conn_prev = conn->conn_prev;
                        conn->conn_prev->conn_next = conn_head;
                }
                call = conn->conn_call;
                free(conn);

                /*
                 * If we have already accepted the maximum number of
                 * connections allowed on the command line, then drop
                 * the oldest connection (for any protocol) before
                 * accepting the new connection.  Unless explicitly
                 * set on the command line, max_conns_allowed is -1.
                 */
                if (max_conns_allowed != -1 && num_conns >= max_conns_allowed)
                        conn_close_oldest();

                /*
                 * Create a new transport endpoint for the same proto as
                 * the listener.
                 */
                new_fd = nfslib_transport_open(nconf);
                if (new_fd == -1) {
                        call->udata.len = 0;
                        (void) t_snddis(fd, call);
                        (void) t_free((char *)call, T_CALL);
                        syslog(LOG_ERR, "Cannot establish transport over %s",
                            nconf->nc_device);
                        continue;
                }

                /* Bind to a generic address/port for the accepting stream. */
                if (t_bind(new_fd, NULL, NULL) == -1) {
                        nfslib_log_tli_error("t_bind", new_fd, nconf);
                        call->udata.len = 0;
                        (void) t_snddis(fd, call);
                        (void) t_free((char *)call, T_CALL);
                        (void) t_close(new_fd);
                        continue;
                }

                while (t_accept(fd, new_fd, call) == -1) {
                        if (t_errno != TLOOK) {
#ifdef DEBUG
                                nfslib_log_tli_error("t_accept", fd, nconf);
#endif
                                call->udata.len = 0;
                                (void) t_snddis(fd, call);
                                (void) t_free((char *)call, T_CALL);
                                (void) t_close(new_fd);
                                goto do_next_conn;
                        }
                        while (event = t_look(fd)) {
                                switch (event) {
                                case T_LISTEN:
#ifdef DEBUG
                                        printf(
"cots_listen_event(%s): T_LISTEN during accept processing\n", nconf->nc_proto);
#endif
                                        (void) conn_get(fd, nconf, &conn_head);
                                        continue;
                                case T_DISCONNECT:
#ifdef DEBUG
                                        printf(
        "cots_listen_event(%s): T_DISCONNECT during accept processing\n",
                                            nconf->nc_proto);
#endif
                                        (void) discon_get(fd, nconf,
                                            &conn_head);
                                        continue;
                                default:
                                        syslog(LOG_ERR,
                        "unexpected event 0x%x during accept processing (%s)",
                                            event, nconf->nc_proto);
                                        call->udata.len = 0;
                                        (void) t_snddis(fd, call);
                                        (void) t_free((char *)call, T_CALL);
                                        (void) t_close(new_fd);
                                        goto do_next_conn;
                                }
                        }
                }

                if (set_addrmask(new_fd, nconf, &addrmask) < 0) {
                        (void) syslog(LOG_ERR,
                            "Cannot set address mask for %s",
                            nconf->nc_netid);
                        (void) t_snddis(new_fd, NULL);
                        (void) t_free((char *)call, T_CALL);
                        (void) t_close(new_fd);
                        continue;
                }

                /* Tell kRPC about the new stream. */
                if (Mysvc4 != NULL)
                        ret = (*Mysvc4)(new_fd, &addrmask, nconf,
                            NFS4_KRPC_START, &call->addr);
                else
                        ret = (*Mysvc)(new_fd, addrmask, nconf);

                if (ret < 0) {
                        if (errno != ENOTCONN) {
                                syslog(LOG_ERR,
                                    "unable to register new connection: %m");
                        } else {
                                /*
                                 * This is the only error that could be
                                 * caused by the client, so who was it?
                                 */
                                if (netdir_getbyaddr(nconf, &clnt_serv,
                                    &(call->addr)) == ND_OK &&
                                    clnt_serv->h_cnt > 0)
                                        clnt = clnt_serv->h_hostservs->h_host;
                                else
                                        clnt = clnt_uaddr = taddr2uaddr(nconf,
                                            &(call->addr));
                                /*
                                 * If we don't know who the client was,
                                 * remain silent.
                                 */
                                if (clnt)
                                        syslog(LOG_ERR,
"unable to register new connection: client %s has dropped connection", clnt);
                                if (clnt_serv) {
                                        netdir_free(clnt_serv, ND_HOSTSERVLIST);
                                        clnt_serv = NULL;
                                }
                                if (clnt_uaddr) {
                                        free(clnt_uaddr);
                                        clnt_uaddr = NULL;
                                }
                        }
                        free(addrmask.buf);
                        (void) t_snddis(new_fd, NULL);
                        (void) t_free((char *)call, T_CALL);
                        (void) t_close(new_fd);
                        goto do_next_conn;
                }

                free(addrmask.buf);
                (void) t_free((char *)call, T_CALL);

                /*
                 * Poll on the new descriptor so that we get disconnect
                 * and orderly release indications.
                 */
                num_conns++;
                add_to_poll_list(new_fd, nconf);

                /* Reset nconf in case it has been moved. */
                nconf = &conn_polled[conn_index].nc;
do_next_conn:;
        }
}

static int
do_poll_cots_action(int fd, int conn_index)
{
        char buf[256];
        int event;
        int i1;
        int flags;
        struct conn_entry *connent = &conn_polled[conn_index];
        struct netconfig *nconf = &(connent->nc);
        const char *errorstr;

        while (event = t_look(fd)) {
                switch (event) {
                case T_LISTEN:
#ifdef DEBUG
printf("do_poll_cots_action(%s,%d): T_LISTEN event\n", nconf->nc_proto, fd);
#endif
                        cots_listen_event(fd, conn_index);
                        break;

                case T_DATA:
#ifdef DEBUG
printf("do_poll_cots_action(%d,%s): T_DATA event\n", fd, nconf->nc_proto);
#endif
                        /*
                         * Receive a private notification from CONS rpcmod.
                         */
                        i1 = t_rcv(fd, buf, sizeof (buf), &flags);
                        if (i1 == -1) {
                                syslog(LOG_ERR, "t_rcv failed");
                                break;
                        }
                        if (i1 < sizeof (int))
                                break;
                        i1 = BE32_TO_U32(buf);
                        if (i1 == 1 || i1 == 2) {
                                /*
                                 * This connection has been idle for too long,
                                 * so release it as politely as we can.  If we
                                 * have already initiated an orderly release
                                 * and we get notified that the stream is
                                 * still idle, pull the plug.  This prevents
                                 * hung connections from continuing to consume
                                 * resources.
                                 */
#ifdef DEBUG
printf("do_poll_cots_action(%s,%d): ", nconf->nc_proto, fd);
printf("initiating orderly release of idle connection\n");
#endif
                                if (nconf->nc_semantics == NC_TPI_COTS ||
                                    connent->closing != 0) {
                                        (void) t_snddis(fd, (struct t_call *)0);
                                        goto fdclose;
                                }
                                /*
                                 * For NC_TPI_COTS_ORD, the stream is closed
                                 * and removed from the poll list when the
                                 * T_ORDREL is received from the provider.  We
                                 * don't wait for it here because it may take
                                 * a while for the transport to shut down.
                                 */
                                if (t_sndrel(fd) == -1) {
                                        syslog(LOG_ERR,
                                        "unable to send orderly release %m");
                                }
                                connent->closing = 1;
                        } else
                                syslog(LOG_ERR,
                                "unexpected event from CONS rpcmod %d", i1);
                        break;

                case T_ORDREL:
#ifdef DEBUG
printf("do_poll_cots_action(%s,%d): T_ORDREL event\n", nconf->nc_proto, fd);
#endif
                        /* Perform an orderly release. */
                        if (t_rcvrel(fd) == 0) {
                                /* T_ORDREL on listen fd's should be ignored */
                                if (!is_listen_fd_index(conn_index)) {
                                        (void) t_sndrel(fd);
                                        goto fdclose;
                                }
                                break;

                        } else if (t_errno == TLOOK) {
                                break;
                        } else {
                                nfslib_log_tli_error("t_rcvrel", fd, nconf);

                                /*
                                 * check to make sure we do not close
                                 * listen fd
                                 */
                                if (is_listen_fd_index(conn_index))
                                        break;
                                else
                                        goto fdclose;
                        }

                case T_DISCONNECT:
#ifdef DEBUG
printf("do_poll_cots_action(%s,%d): T_DISCONNECT event\n", nconf->nc_proto, fd);
#endif
                        if (t_rcvdis(fd, (struct t_discon *)NULL) == -1)
                                nfslib_log_tli_error("t_rcvdis", fd, nconf);

                        /*
                         * T_DISCONNECT on listen fd's should be ignored.
                         */
                        if (is_listen_fd_index(conn_index))
                                break;
                        else
                                goto fdclose;

                default:
                        if (t_errno == TSYSERR) {
                                if ((errorstr = strerror(errno)) == NULL) {
                                        (void) sprintf(buf,
                                            "Unknown error num %d", errno);
                                        errorstr = (const char *) buf;
                                }
                        } else if (event == -1)
                                errorstr = t_strerror(t_errno);
                        else
                                errorstr = "";
                        syslog(LOG_ERR,
                            "unexpected TLI event (0x%x) on "
                            "connection-oriented transport(%s,%d):%s",
                            event, nconf->nc_proto, fd, errorstr);
fdclose:
                        num_conns--;
                        remove_from_poll_list(fd);
                        (void) t_close(fd);
                        return (0);
                }
        }

        return (0);
}

static char *
serv_name_to_port_name(char *name)
{
        /*
         * Map service names (used primarily in logging) to
         * RPC port names (used by netdir_*() routines).
         */
        if (strcmp(name, "NFS") == 0) {
                return ("nfs");
        } else if (strcmp(name, "NLM") == 0) {
                return ("lockd");
        } else if (strcmp(name, "NFS4_CALLBACK") == 0) {
                return ("nfs4_callback");
        }

        return ("unrecognized");
}

static int
bind_to_provider(char *provider, char *serv, struct netbuf **addr,
                struct netconfig **retnconf)
{
        struct netconfig *nconf;
        NCONF_HANDLE *nc;
        struct nd_hostserv hs;

        hs.h_host = HOST_SELF;
        hs.h_serv = serv_name_to_port_name(serv);

        if ((nc = setnetconfig()) == (NCONF_HANDLE *)NULL) {
                syslog(LOG_ERR, "setnetconfig failed: %m");
                return (-1);
        }
        while (nconf = getnetconfig(nc)) {
                if (OK_TPI_TYPE(nconf) &&
                    strcmp(nconf->nc_device, provider) == 0) {
                        *retnconf = nconf;
                        return (nfslib_bindit(nconf, addr, &hs,
                            listen_backlog));
                }
        }
        (void) endnetconfig(nc);

        syslog(LOG_ERR, "couldn't find netconfig entry for provider %s",
            provider);
        return (-1);
}

static int
bind_to_proto(NETSELDECL(proto), char *serv, struct netbuf **addr,
                struct netconfig **retnconf)
{
        struct netconfig *nconf;
        NCONF_HANDLE *nc = NULL;
        struct nd_hostserv hs;

        hs.h_host = HOST_SELF;
        hs.h_serv = serv_name_to_port_name(serv);

        if ((nc = setnetconfig()) == (NCONF_HANDLE *)NULL) {
                syslog(LOG_ERR, "setnetconfig failed: %m");
                return (-1);
        }
        while (nconf = getnetconfig(nc)) {
                if (OK_TPI_TYPE(nconf) && NETSELEQ(nconf->nc_proto, proto)) {
                        *retnconf = nconf;
                        return (nfslib_bindit(nconf, addr, &hs,
                            listen_backlog));
                }
        }
        (void) endnetconfig(nc);

        syslog(LOG_ERR, "couldn't find netconfig entry for protocol %s",
            proto);
        return (-1);
}

#include <netinet/in.h>

/*
 * Create an address mask appropriate for the transport.
 * The mask is used to obtain the host-specific part of
 * a network address when comparing addresses.
 * For an internet address the host-specific part is just
 * the 32 bit IP address and this part of the mask is set
 * to all-ones. The port number part of the mask is zeroes.
 */
static int
set_addrmask(int fd,
        struct netconfig *nconf,
        struct netbuf *mask)
{
        struct t_info info;

        /*
         * Find the size of the address we need to mask.
         */
        if (t_getinfo(fd, &info) < 0) {
                t_error("t_getinfo");
                return (-1);
        }
        mask->len = mask->maxlen = info.addr;
        if (info.addr <= 0) {
                /*
                 * loopback devices have infinite addr size
                 * (it is identified by -1 in addr field of t_info structure),
                 * so don't build the netmask for them. It's a special case
                 * that should be handled properly.
                 */
                if ((info.addr == -1) &&
                    (0 == strcmp(nconf->nc_protofmly, NC_LOOPBACK))) {
                        memset(mask, 0, sizeof (*mask));
                        return (0);
                }

                syslog(LOG_ERR, "set_addrmask: address size: %ld", info.addr);
                return (-1);
        }

        mask->buf = (char *)malloc(mask->len);
        if (mask->buf == NULL) {
                syslog(LOG_ERR, "set_addrmask: no memory");
                return (-1);
        }
        (void) memset(mask->buf, 0, mask->len); /* reset all mask bits */

        if (strcmp(nconf->nc_protofmly, NC_INET) == 0) {
                /*
                 * Set the mask so that the port is ignored.
                 */
                /* LINTED pointer alignment */
                ((struct sockaddr_in *)mask->buf)->sin_addr.s_addr =
                    (ulong_t)~0;
                /* LINTED pointer alignment */
                ((struct sockaddr_in *)mask->buf)->sin_family =
                    (ushort_t)~0;
        } else if (strcmp(nconf->nc_protofmly, NC_INET6) == 0) {
                /* LINTED pointer alignment */
                (void) memset(&((struct sockaddr_in6 *)mask->buf)->sin6_addr,
                    (uchar_t)~0, sizeof (struct in6_addr));
                /* LINTED pointer alignment */
                ((struct sockaddr_in6 *)mask->buf)->sin6_family =
                    (ushort_t)~0;
        } else {

                /*
                 * Set all mask bits.
                 */
                (void) memset(mask->buf, 0xFF, mask->len);
        }
        return (0);
}

/*
 * For listen fd's index is always less than end_listen_fds.
 * end_listen_fds is defined externally in the daemon that uses this library.
 * It's value is equal to the number of open file descriptors after the
 * last listen end point was opened but before any connection was accepted.
 */
static int
is_listen_fd_index(int index)
{
        return (index < end_listen_fds);
}