1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 23 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 24 /* All Rights Reserved */ 25 26 /* 27 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 28 * Use is subject to license terms. 29 */ 30 31 #pragma ident "%Z%%M% %I% %E% SMI" /* SVr4.0 1.7 */ 32 33 /* 34 * t_rcv.c and t_rcvv.c are very similar and contain common code. 35 * Any changes to either of them should be reviewed to see whether they 36 * are applicable to the other file. 37 */ 38 #include "mt.h" 39 #include <stdlib.h> 40 #include <errno.h> 41 #include <unistd.h> 42 #include <stropts.h> 43 #include <sys/stream.h> 44 #define _SUN_TPI_VERSION 2 45 #include <sys/tihdr.h> 46 #include <sys/timod.h> 47 #include <xti.h> 48 #include <syslog.h> 49 #include <assert.h> 50 #include "tx.h" 51 52 int 53 _tx_rcv(int fd, char *buf, unsigned nbytes, int *flags, int api_semantics) 54 { 55 struct strbuf ctlbuf, databuf; 56 int retval, flg = 0; 57 int msglen; 58 union T_primitives *pptr; 59 struct _ti_user *tiptr; 60 int sv_errno; 61 int didalloc; 62 63 if ((tiptr = _t_checkfd(fd, 0, api_semantics)) == NULL) 64 return (-1); 65 sig_mutex_lock(&tiptr->ti_lock); 66 67 if (tiptr->ti_servtype == T_CLTS) { 68 t_errno = TNOTSUPPORT; 69 sig_mutex_unlock(&tiptr->ti_lock); 70 return (-1); 71 } 72 73 if (_T_IS_XTI(api_semantics)) { 74 /* 75 * User level state verification only done for XTI 76 * because doing for TLI may break existing applications 77 */ 78 if (!(tiptr->ti_state == T_DATAXFER || 79 tiptr->ti_state == T_OUTREL)) { 80 t_errno = TOUTSTATE; 81 sig_mutex_unlock(&tiptr->ti_lock); 82 return (-1); 83 } 84 } 85 86 /* 87 * Check in lookbuf for stuff 88 */ 89 if (tiptr->ti_lookcnt > 0) { 90 /* 91 * Implied preference rules give priority to 92 * T_DISCON_IND over T_ORDREL_IND. Also certain errors like 93 * data received after T_ORDREL_IND or a duplicate T_ORDREL_IND 94 * after a T_ORDRELING have priority over TLOOK. 95 * This manifests in following code behavior. 96 * 97 * (1) If something in lookbuf then check 98 * the stream head also. This may result 99 * in retuning a TLOOK error but only if there are 100 * - message at stream head but look buffer 101 * has a T_DISCON_IND event. 102 * - no messages are on the stream head 103 * 104 * (2) If there are messages on the stream head and 105 * all of them are T_ORDREL_IND(i.e. no message in 106 * look buffer is T_DISCON_IND), there 107 * could be data on stream head to be picked up and 108 * we work on the stream head and not return TLOOK. 109 * We remove the event on the stream head and queue it. 110 * 111 */ 112 do { 113 retval = ioctl(fd, I_NREAD, &msglen); 114 } while (retval < 0 && errno == EINTR); 115 116 if (retval < 0) { 117 sv_errno = errno; 118 119 t_errno = TSYSERR; 120 sig_mutex_unlock(&tiptr->ti_lock); 121 errno = sv_errno; 122 return (-1); 123 } 124 125 if (retval > 0) { 126 /* 127 * If any T_DISCON_IND event in look buffer 128 * list then return TLOOK. Else continue 129 * processing as what could be on the stream 130 * head might be a possible T_DISCON_IND (which 131 * would have priority over the T_ORDREL_INDs 132 * on the look buffer.) 133 */ 134 struct _ti_lookbufs *tlbs; 135 136 tlbs = &tiptr->ti_lookbufs; 137 do { 138 /* LINTED pointer cast */ 139 if (*((t_scalar_t *)tlbs->tl_lookcbuf) 140 == T_DISCON_IND) { 141 t_errno = TLOOK; 142 sig_mutex_unlock(&tiptr->ti_lock); 143 return (-1); 144 } 145 } while ((tlbs = tlbs->tl_next) != NULL); 146 147 } else { /* retval == 0 */ 148 /* 149 * Nothing on stream head so whatever in 150 * look buffer has nothing that might override 151 * it. 152 */ 153 t_errno = TLOOK; 154 sig_mutex_unlock(&tiptr->ti_lock); 155 return (-1); 156 } 157 } 158 159 /* 160 * Acquire ctlbuf for use in sending/receiving control part 161 * of the message. 162 */ 163 if (_t_acquire_ctlbuf(tiptr, &ctlbuf, &didalloc) < 0) { 164 sv_errno = errno; 165 sig_mutex_unlock(&tiptr->ti_lock); 166 errno = sv_errno; 167 return (-1); 168 } 169 170 databuf.maxlen = nbytes; 171 databuf.len = 0; 172 databuf.buf = buf; 173 174 *flags = 0; 175 176 /* 177 * This is a call that may block indefinitely so we drop the 178 * lock and allow signals in MT case here and reacquire it. 179 * Error case should roll back state changes done above 180 * (happens to be no state change here) 181 */ 182 sig_mutex_unlock(&tiptr->ti_lock); 183 if ((retval = getmsg(fd, &ctlbuf, &databuf, &flg)) < 0) { 184 if (errno == EAGAIN) 185 t_errno = TNODATA; 186 else 187 t_errno = TSYSERR; 188 sv_errno = errno; 189 sig_mutex_lock(&tiptr->ti_lock); 190 errno = sv_errno; 191 goto err_out; 192 } 193 sig_mutex_lock(&tiptr->ti_lock); 194 195 assert((retval & MORECTL) == 0); /* MORECTL should not be on */ 196 197 if (databuf.len == -1) databuf.len = 0; 198 199 if (ctlbuf.len > 0) { 200 if (ctlbuf.len < (int)sizeof (t_scalar_t)) { 201 t_errno = TSYSERR; 202 errno = EPROTO; 203 goto err_out; 204 } 205 206 /* LINTED pointer cast */ 207 pptr = (union T_primitives *)ctlbuf.buf; 208 209 switch (pptr->type) { 210 211 case T_EXDATA_IND: 212 *flags |= T_EXPEDITED; 213 if (retval > 0) 214 tiptr->ti_flags |= EXPEDITED; 215 /* FALLTHROUGH */ 216 case T_DATA_IND: 217 /* 218 * Uses the fact T_DATA_IND and T_EXDATA_IND 219 * are same in size 220 */ 221 if ((ctlbuf.len < (int)sizeof (struct T_data_ind)) || 222 (tiptr->ti_lookcnt > 0)) { 223 /* 224 * ti_lookcnt > 0 implies data 225 * received after T_DISCON_IND or 226 * T_ORDREL_IND hence error 227 */ 228 t_errno = TSYSERR; 229 errno = EPROTO; 230 goto err_out; 231 } 232 233 if ((pptr->data_ind.MORE_flag) || retval) 234 *flags |= T_MORE; 235 if ((pptr->data_ind.MORE_flag) && retval) 236 tiptr->ti_flags |= MORE; 237 /* 238 * No real state change on T_RCV event (noop) 239 * 240 * We invoke the macro only for error logging 241 * part of its capabilities when in a bad state. 242 */ 243 _T_TX_NEXTSTATE(T_RCV, tiptr, 244 "t_rcv: invalid state event T_RCV"); 245 if (didalloc) 246 free(ctlbuf.buf); 247 else 248 tiptr->ti_ctlbuf = ctlbuf.buf; 249 sig_mutex_unlock(&tiptr->ti_lock); 250 return (databuf.len); 251 252 case T_ORDREL_IND: 253 if (tiptr->ti_lookcnt > 0) { 254 /* 255 * ti_lookcnt > 0 implies T_ORDREL_IND 256 * received after T_DISCON_IND or 257 * another T_ORDREL_IND hence error. 258 */ 259 t_errno = TSYSERR; 260 errno = EPROTO; 261 goto err_out; 262 } 263 /* FALLTHROUGH */ 264 case T_DISCON_IND: 265 /* 266 * Post event (T_ORDREL_IND/T_DISCON_IND) to 267 * the lookbuffer list. 268 */ 269 270 if (_t_register_lookevent(tiptr, databuf.buf, 271 databuf.len, 272 ctlbuf.buf, ctlbuf.len) < 0) { 273 t_errno = TSYSERR; 274 errno = ENOMEM; 275 goto err_out; 276 } 277 /* 278 * We know that T_DISCON_IND is stored in 279 * last look buffer. If there is more data 280 * that follows, we try to append it to 281 * the same look buffer 282 */ 283 if (retval & MOREDATA) { 284 ctlbuf.maxlen = 0; /* XXX why ? */ 285 ctlbuf.len = 0; 286 287 /* 288 * XXX Will break (-ve maxlen) for 289 * transport provider with unbounded 290 * T_DISCON_IND data part (-1). 291 */ 292 databuf.maxlen = 293 tiptr->ti_rcvsize - databuf.len; 294 295 databuf.len = 0; 296 databuf.buf = 297 tiptr->ti_lookbufs.tl_lookdbuf + 298 tiptr->ti_lookbufs.tl_lookdlen; 299 *flags = 0; 300 301 /* 302 * Since MOREDATA was set, we assume 303 * that this getmsg will not block 304 * indefinitely 305 */ 306 do { 307 retval = getmsg(fd, &ctlbuf, 308 &databuf, &flg); 309 } while (retval < 0 && errno == EINTR); 310 311 if (retval < 0) { 312 t_errno = TSYSERR; 313 goto err_out; 314 } 315 if (databuf.len == -1) databuf.len = 0; 316 if (retval > 0) { 317 /* MORECTL should not be on */ 318 assert((retval & MORECTL) == 0); 319 /* 320 * XXX - Why ? 321 * No support for unbounded data 322 * on T_DISCON_IND ? 323 */ 324 t_errno = TSYSERR; 325 errno = EPROTO; 326 goto err_out; 327 } 328 tiptr->ti_lookbufs.tl_lookdlen += 329 databuf.len; 330 } 331 332 t_errno = TLOOK; 333 goto err_out; 334 335 default: 336 break; 337 } 338 339 t_errno = TSYSERR; 340 errno = EPROTO; 341 goto err_out; 342 343 } else { /* else for "if (ctlbuf.len > 0)" */ 344 if (!retval && (tiptr->ti_flags & MORE)) { 345 *flags |= T_MORE; 346 tiptr->ti_flags &= ~MORE; 347 } 348 if (retval & MOREDATA) 349 *flags |= T_MORE; 350 351 /* 352 * If inside an ETSDU, set expedited flag and turn 353 * of internal version when reach end of "ETIDU". 354 */ 355 if (tiptr->ti_flags & EXPEDITED) { 356 *flags |= T_EXPEDITED; 357 if (!retval) 358 tiptr->ti_flags &= ~EXPEDITED; 359 } 360 361 /* 362 * No real state change on T_RCV events (It is a NOOP) 363 * 364 * We invoke the macro only for error logging 365 * part of its capabilities when in a bad state. 366 */ 367 _T_TX_NEXTSTATE(T_RCV, tiptr, 368 "t_rcv: state invalid T_RCV event"); 369 if (didalloc) 370 free(ctlbuf.buf); 371 else 372 tiptr->ti_ctlbuf = ctlbuf.buf; 373 sig_mutex_unlock(&tiptr->ti_lock); 374 return (databuf.len); 375 } 376 /* NOTREACHED */ 377 378 err_out: 379 sv_errno = errno; 380 if (didalloc) 381 free(ctlbuf.buf); 382 else 383 tiptr->ti_ctlbuf = ctlbuf.buf; 384 sig_mutex_unlock(&tiptr->ti_lock); 385 386 errno = sv_errno; 387 return (-1); 388 } 389