/* * 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. */ /* * t_rcv.c and t_rcvv.c are very similar and contain common code. * Any changes to either of them should be reviewed to see whether they * are applicable to the other file. */ #include "mt.h" #include #include #include #include #include #define _SUN_TPI_VERSION 2 #include #include #include #include #include #include "tx.h" int _tx_rcv(int fd, char *buf, unsigned nbytes, int *flags, int api_semantics) { struct strbuf ctlbuf, databuf; int retval, flg = 0; int msglen; union T_primitives *pptr; struct _ti_user *tiptr; int sv_errno; int didalloc; if ((tiptr = _t_checkfd(fd, 0, api_semantics)) == NULL) return (-1); sig_mutex_lock(&tiptr->ti_lock); if (tiptr->ti_servtype == T_CLTS) { t_errno = TNOTSUPPORT; sig_mutex_unlock(&tiptr->ti_lock); return (-1); } if (_T_IS_XTI(api_semantics)) { /* * User level state verification only done for XTI * because doing for TLI may break existing applications */ if (!(tiptr->ti_state == T_DATAXFER || tiptr->ti_state == T_OUTREL)) { t_errno = TOUTSTATE; sig_mutex_unlock(&tiptr->ti_lock); return (-1); } } /* * Check in lookbuf for stuff */ if (tiptr->ti_lookcnt > 0) { /* * Implied preference rules give priority to * T_DISCON_IND over T_ORDREL_IND. Also certain errors like * data received after T_ORDREL_IND or a duplicate T_ORDREL_IND * after a T_ORDRELING have priority over TLOOK. * This manifests in following code behavior. * * (1) If something in lookbuf then check * the stream head also. This may result * in retuning a TLOOK error but only if there are * - message at stream head but look buffer * has a T_DISCON_IND event. * - no messages are on the stream head * * (2) If there are messages on the stream head and * all of them are T_ORDREL_IND(i.e. no message in * look buffer is T_DISCON_IND), there * could be data on stream head to be picked up and * we work on the stream head and not return TLOOK. * We remove the event on the stream head and queue it. * */ do { retval = ioctl(fd, I_NREAD, &msglen); } while (retval < 0 && errno == EINTR); if (retval < 0) { sv_errno = errno; t_errno = TSYSERR; sig_mutex_unlock(&tiptr->ti_lock); errno = sv_errno; return (-1); } if (retval > 0) { /* * If any T_DISCON_IND event in look buffer * list then return TLOOK. Else continue * processing as what could be on the stream * head might be a possible T_DISCON_IND (which * would have priority over the T_ORDREL_INDs * on the look buffer.) */ struct _ti_lookbufs *tlbs; tlbs = &tiptr->ti_lookbufs; do { /* LINTED pointer cast */ if (*((t_scalar_t *)tlbs->tl_lookcbuf) == T_DISCON_IND) { t_errno = TLOOK; sig_mutex_unlock(&tiptr->ti_lock); return (-1); } } while ((tlbs = tlbs->tl_next) != NULL); } else { /* retval == 0 */ /* * Nothing on stream head so whatever in * look buffer has nothing that might override * it. */ t_errno = TLOOK; sig_mutex_unlock(&tiptr->ti_lock); 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); errno = sv_errno; return (-1); } databuf.maxlen = nbytes; databuf.len = 0; databuf.buf = buf; *flags = 0; /* * This is a call that may block indefinitely so we drop the * lock and allow signals in MT case here and reacquire it. * Error case should roll back state changes done above * (happens to be no state change here) */ sig_mutex_unlock(&tiptr->ti_lock); if ((retval = getmsg(fd, &ctlbuf, &databuf, &flg)) < 0) { if (errno == EAGAIN) t_errno = TNODATA; else t_errno = TSYSERR; sv_errno = errno; sig_mutex_lock(&tiptr->ti_lock); errno = sv_errno; goto err_out; } sig_mutex_lock(&tiptr->ti_lock); assert((retval & MORECTL) == 0); /* MORECTL should not be on */ if (databuf.len == -1) databuf.len = 0; if (ctlbuf.len > 0) { if (ctlbuf.len < (int)sizeof (t_scalar_t)) { t_errno = TSYSERR; errno = EPROTO; goto err_out; } /* LINTED pointer cast */ pptr = (union T_primitives *)ctlbuf.buf; switch (pptr->type) { case T_EXDATA_IND: *flags |= T_EXPEDITED; if (retval > 0) tiptr->ti_flags |= EXPEDITED; /* FALLTHROUGH */ case T_DATA_IND: /* * Uses the fact T_DATA_IND and T_EXDATA_IND * are same in size */ if ((ctlbuf.len < (int)sizeof (struct T_data_ind)) || (tiptr->ti_lookcnt > 0)) { /* * ti_lookcnt > 0 implies data * received after T_DISCON_IND or * T_ORDREL_IND hence error */ t_errno = TSYSERR; errno = EPROTO; goto err_out; } if ((pptr->data_ind.MORE_flag) || retval) *flags |= T_MORE; if ((pptr->data_ind.MORE_flag) && retval) tiptr->ti_flags |= MORE; /* * No real state change on T_RCV event (noop) * * We invoke the macro only for error logging * part of its capabilities when in a bad state. */ _T_TX_NEXTSTATE(T_RCV, tiptr, "t_rcv: invalid state event T_RCV"); if (didalloc) free(ctlbuf.buf); else tiptr->ti_ctlbuf = ctlbuf.buf; sig_mutex_unlock(&tiptr->ti_lock); return (databuf.len); case T_ORDREL_IND: if (tiptr->ti_lookcnt > 0) { /* * ti_lookcnt > 0 implies T_ORDREL_IND * received after T_DISCON_IND or * another T_ORDREL_IND hence error. */ t_errno = TSYSERR; errno = EPROTO; goto err_out; } /* FALLTHROUGH */ case T_DISCON_IND: /* * Post event (T_ORDREL_IND/T_DISCON_IND) to * the lookbuffer list. */ if (_t_register_lookevent(tiptr, databuf.buf, databuf.len, ctlbuf.buf, ctlbuf.len) < 0) { t_errno = TSYSERR; errno = ENOMEM; goto err_out; } /* * We know that T_DISCON_IND is stored in * last look buffer. If there is more data * that follows, we try to append it to * the same look buffer */ if (retval & MOREDATA) { ctlbuf.maxlen = 0; /* XXX why ? */ ctlbuf.len = 0; /* * XXX Will break (-ve maxlen) for * transport provider with unbounded * T_DISCON_IND data part (-1). */ databuf.maxlen = tiptr->ti_rcvsize - databuf.len; databuf.len = 0; databuf.buf = tiptr->ti_lookbufs.tl_lookdbuf + tiptr->ti_lookbufs.tl_lookdlen; *flags = 0; /* * Since MOREDATA was set, we assume * that this getmsg will not block * indefinitely */ do { retval = getmsg(fd, &ctlbuf, &databuf, &flg); } while (retval < 0 && errno == EINTR); if (retval < 0) { t_errno = TSYSERR; goto err_out; } if (databuf.len == -1) databuf.len = 0; if (retval > 0) { /* MORECTL should not be on */ assert((retval & MORECTL) == 0); /* * XXX - Why ? * No support for unbounded data * on T_DISCON_IND ? */ t_errno = TSYSERR; errno = EPROTO; goto err_out; } tiptr->ti_lookbufs.tl_lookdlen += databuf.len; } t_errno = TLOOK; goto err_out; default: break; } t_errno = TSYSERR; errno = EPROTO; goto err_out; } else { /* else for "if (ctlbuf.len > 0)" */ if (!retval && (tiptr->ti_flags & MORE)) { *flags |= T_MORE; tiptr->ti_flags &= ~MORE; } if (retval & MOREDATA) *flags |= T_MORE; /* * If inside an ETSDU, set expedited flag and turn * of internal version when reach end of "ETIDU". */ if (tiptr->ti_flags & EXPEDITED) { *flags |= T_EXPEDITED; if (!retval) tiptr->ti_flags &= ~EXPEDITED; } /* * No real state change on T_RCV events (It is a NOOP) * * We invoke the macro only for error logging * part of its capabilities when in a bad state. */ _T_TX_NEXTSTATE(T_RCV, tiptr, "t_rcv: state invalid T_RCV event"); if (didalloc) free(ctlbuf.buf); else tiptr->ti_ctlbuf = ctlbuf.buf; sig_mutex_unlock(&tiptr->ti_lock); return (databuf.len); } /* NOTREACHED */ err_out: sv_errno = errno; if (didalloc) free(ctlbuf.buf); else tiptr->ti_ctlbuf = ctlbuf.buf; sig_mutex_unlock(&tiptr->ti_lock); errno = sv_errno; return (-1); }