/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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) 1984, 1986, 1987, 1988, 1989 AT&T */
/*        All Rights Reserved   */

/*
 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include "mt.h"
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <stropts.h>
#include <sys/stream.h>
#define _SUN_TPI_VERSION 2
#include <sys/tihdr.h>
#include <sys/timod.h>
#include <xti.h>
#include <signal.h>
#include <syslog.h>
#include <assert.h>
#include "tx.h"

int
_tx_accept(
        int fd,
        int resfd,
        const struct t_call *call,
        int api_semantics
)
{
        struct T_conn_res *cres;
        struct strfdinsert strfdinsert;
        int size, retval, sv_errno;
        struct _ti_user *tiptr;
        struct _ti_user *restiptr;
        sigset_t mask;
        struct strbuf ctlbuf;
        int didalloc;
        t_scalar_t conn_res_prim;

        if ((tiptr = _t_checkfd(fd, 0, api_semantics)) == NULL)
                return (-1);
        if ((restiptr = _t_checkfd(resfd, 0, api_semantics)) == NULL)
                return (-1);

        /*
         * We need to block signals to perform the I_FDINSERT operation
         * (sending T_CONN_RES downstream) which is non-idempotent.
         * Note that sig_mutex_lock() only defers signals, it does not
         * block them, so interruptible syscalls could still get EINTR.
         */
        (void) thr_sigsetmask(SIG_SETMASK, &fillset, &mask);
        sig_mutex_lock(&tiptr->ti_lock);

        if (tiptr->ti_servtype == T_CLTS) {
                t_errno = TNOTSUPPORT;
                sig_mutex_unlock(&tiptr->ti_lock);
                (void) thr_sigsetmask(SIG_SETMASK, &mask, NULL);
                return (-1);
        }

        if (_T_IS_XTI(api_semantics)) {
                /*
                 * User level state verification only done for XTI
                 * because doing for TLI may break existing applications
                 *
                 * For fd == resfd, state should be T_INCON
                 * For fd != resfd,
                 *          fd state should be T_INCON
                 *          resfd state should be T_IDLE (bound endpoint) or
                 *          it can be T_UNBND. The T_UNBND case is not (yet?)
                 *          allowed in the published XTI spec but fixed by the
                 *          corrigenda.
                 */
                if ((fd == resfd && tiptr->ti_state != T_INCON) ||
                    (fd != resfd &&
                        ((tiptr->ti_state != T_INCON) ||
                    !(restiptr->ti_state == T_IDLE ||
                        restiptr->ti_state == T_UNBND)))) {
                        t_errno = TOUTSTATE;
                        sig_mutex_unlock(&tiptr->ti_lock);
                        (void) thr_sigsetmask(SIG_SETMASK, &mask, NULL);
                        return (-1);
                }

                /*
                 * XTI says:
                 * If fd != resfd, and a resfd bound to a protocol address is
                 * passed, then it better not have a qlen > 0.
                 * That is, an endpoint bound as if it will be a listener
                 * cannot be used as an acceptor.
                 */
                if (fd != resfd && restiptr->ti_state == T_IDLE &&
                    restiptr->ti_qlen > 0) {
                        t_errno = TRESQLEN;
                        sig_mutex_unlock(&tiptr->ti_lock);
                        (void) thr_sigsetmask(SIG_SETMASK, &mask, NULL);
                        return (-1);
                }

                if (fd == resfd && tiptr->ti_ocnt > 1) {
                        t_errno = TINDOUT;
                        sig_mutex_unlock(&tiptr->ti_lock);
                        (void) thr_sigsetmask(SIG_SETMASK, &mask, NULL);
                        return (-1);
                }

                /*
                 * Note: TRESADDR error is specified by XTI. It happens
                 * when resfd is bound and fd and resfd are not BOUND to
                 * the same protocol address. TCP obviously does allow
                 * two endpoints to bind to the same address. Why is the
                 * need for this error considering there is an address switch
                 * that can be done for the endpoint at accept time ? Go
                 * figure and ask the XTI folks.
                 * We interpret this to be a transport specific error condition
                 * to be be coveyed by the transport provider in T_ERROR_ACK
                 * to T_CONN_RES on transports that allow two endpoints to
                 * be bound to the same address and have trouble with the
                 * idea of accepting connections on a resfd that has a qlen > 0
                 */
        }

        if (fd != resfd) {
                if ((retval = ioctl(resfd, I_NREAD, &size)) < 0) {
                        sv_errno = errno;

                        t_errno = TSYSERR;
                        sig_mutex_unlock(&tiptr->ti_lock);
                        (void) thr_sigsetmask(SIG_SETMASK, &mask, NULL);
                        errno = sv_errno;
                        return (-1);
                }
                if (retval > 0) {
                        t_errno = TBADF;
                        sig_mutex_unlock(&tiptr->ti_lock);
                        (void) thr_sigsetmask(SIG_SETMASK, &mask, NULL);
                        return (-1);
                }
        }

        /*
         * Acquire ctlbuf for use in sending/receiving control part
         * of the message.
         */
        if (_t_acquire_ctlbuf(tiptr, &ctlbuf, &didalloc) < 0) {
                sv_errno = errno;
                sig_mutex_unlock(&tiptr->ti_lock);
                (void) thr_sigsetmask(SIG_SETMASK, &mask, NULL);
                errno = sv_errno;
                return (-1);
        }

        /*
         * In Unix98 t_accept() need not return [TLOOK] if connect/disconnect
         * indications are present. TLI and Unix95 need to return error.
         */
        if (_T_API_VER_LT(api_semantics, TX_XTI_XNS5_API)) {
                if (_t_is_event(fd, tiptr) < 0)
                        goto err_out;
        }

        /* LINTED pointer cast */
        cres = (struct T_conn_res *)ctlbuf.buf;
        cres->OPT_length = call->opt.len;
        cres->OPT_offset = 0;
        cres->SEQ_number = call->sequence;
        if ((restiptr->ti_flags & V_ACCEPTOR_ID) != 0) {
                cres->ACCEPTOR_id = restiptr->acceptor_id;
                cres->PRIM_type = conn_res_prim = T_CONN_RES;
        } else {
                /* I_FDINSERT should use O_T_CONN_RES. */
                cres->ACCEPTOR_id = 0;
                cres->PRIM_type = conn_res_prim = O_T_CONN_RES;
        }

        size = (int)sizeof (struct T_conn_res);

        if (call->opt.len) {
                if (_t_aligned_copy(&ctlbuf, call->opt.len, size,
                    call->opt.buf, &cres->OPT_offset) < 0) {
                        /*
                         * Aligned copy will overflow buffer allocated based
                         * transport maximum options length.
                         * return error.
                         */
                        t_errno = TBADOPT;
                        goto err_out;
                }
                size = cres->OPT_offset + cres->OPT_length;
        }

        if (call->udata.len) {
                if ((tiptr->ti_cdatasize == T_INVALID /* -2 */) ||
                    ((tiptr->ti_cdatasize != T_INFINITE /* -1 */) &&
                        (call->udata.len > (uint32_t)tiptr->ti_cdatasize))) {
                        /*
                         * user data not valid with connect or it
                         * exceeds the limits specified by the transport
                         * provider
                         */
                        t_errno = TBADDATA;
                        goto err_out;
                }
        }


        ctlbuf.len = size;

        /*
         * Assumes signals are blocked so putmsg() will not block
         * indefinitely
         */
        if ((restiptr->ti_flags & V_ACCEPTOR_ID) != 0) {
                /*
                 * Assumes signals are blocked so putmsg() will not block
                 * indefinitely
                 */
                if (putmsg(fd, &ctlbuf,
                    (struct strbuf *)(call->udata.len? &call->udata: NULL), 0) <
                    0) {
                        if (errno == EAGAIN)
                                t_errno = TFLOW;
                        else
                                t_errno = TSYSERR;
                        goto err_out;
                }
        } else {
                strfdinsert.ctlbuf.maxlen = ctlbuf.maxlen;
                strfdinsert.ctlbuf.len = ctlbuf.len;
                strfdinsert.ctlbuf.buf = ctlbuf.buf;

                strfdinsert.databuf.maxlen = call->udata.maxlen;
                strfdinsert.databuf.len =
                    (call->udata.len? call->udata.len: -1);
                strfdinsert.databuf.buf = call->udata.buf;
                strfdinsert.fildes = resfd;
                strfdinsert.offset = (int)sizeof (t_scalar_t);
                strfdinsert.flags = 0;          /* could be EXPEDITED also */

                if (ioctl(fd, I_FDINSERT, &strfdinsert) < 0) {
                        if (errno == EAGAIN)
                                t_errno = TFLOW;
                        else
                                t_errno = TSYSERR;
                        goto err_out;
                }
        }

        if (_t_is_ok(fd, tiptr, conn_res_prim) < 0) {
                /*
                 * At the TPI level, the error returned in a T_ERROR_ACK
                 * received in response to a T_CONN_RES for a listener and
                 * acceptor endpoints not being the same kind of endpoints
                 * has changed to a new t_errno code introduced with
                 * XTI (TPROVMISMATCH). We need to adjust TLI error code
                 * to be same as before.
                 */
                if (_T_IS_TLI(api_semantics) && t_errno == TPROVMISMATCH) {
                        /* TLI only */
                        t_errno = TBADF;
                }
                goto err_out;
        }

        if (tiptr->ti_ocnt == 1) {
                if (fd == resfd) {
                        _T_TX_NEXTSTATE(T_ACCEPT1, tiptr,
                                "t_accept: invalid state event T_ACCEPT1");
                } else {
                        _T_TX_NEXTSTATE(T_ACCEPT2, tiptr,
                                "t_accept: invalid state event T_ACCEPT2");
                        /*
                         * XXX Here we lock the resfd lock also. This
                         * is an instance of holding two locks without
                         * any enforcement of a locking hiararchy.
                         * There is potential for deadlock in incorrect
                         * or buggy programs here but this is the safer
                         * choice in this case. Correct programs will not
                         * deadlock.
                         */
                        sig_mutex_lock(&restiptr->ti_lock);
                        _T_TX_NEXTSTATE(T_PASSCON, restiptr,
                                "t_accept: invalid state event T_PASSCON");
                        sig_mutex_unlock(&restiptr->ti_lock);
                }
        } else {
                _T_TX_NEXTSTATE(T_ACCEPT3, tiptr,
                                "t_accept: invalid state event T_ACCEPT3");
                if (fd != resfd)
                        sig_mutex_lock(&restiptr->ti_lock);
                _T_TX_NEXTSTATE(T_PASSCON, restiptr,
                                "t_accept: invalid state event T_PASSCON");
                if (fd != resfd)
                        sig_mutex_unlock(&restiptr->ti_lock);
        }

        tiptr->ti_ocnt--;
        tiptr->ti_flags &= ~TX_TQFULL_NOTIFIED;

        /*
         * Update attributes which may have been negotiated during
         * connection establishment for protocols where we suspect
         * such negotiation is likely (e.g. OSI). We do not do it for
         * all endpoints for performance reasons. Also, this code is
         * deliberately done after user level state changes so even
         * the (unlikely) failure case reflects a connected endpoint.
         */
        if (restiptr->ti_tsdusize != 0) {
                if (_t_do_postconn_sync(resfd, restiptr) < 0)
                        goto err_out;
        }

        if (didalloc)
                free(ctlbuf.buf);
        else
                tiptr->ti_ctlbuf = ctlbuf.buf;
        sig_mutex_unlock(&tiptr->ti_lock);
        (void) thr_sigsetmask(SIG_SETMASK, &mask, NULL);
        return (0);
        /* NOTREACHED */
err_out:
        sv_errno = errno;
        if (didalloc)
                free(ctlbuf.buf);
        else
                tiptr->ti_ctlbuf = ctlbuf.buf;
        sig_mutex_unlock(&tiptr->ti_lock);
        (void) thr_sigsetmask(SIG_SETMASK, &mask, NULL);
        errno = sv_errno;
        return (-1);
}