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 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 23 /* All Rights Reserved */ 24 25 26 /* 27 * Copyright 1993-2003 Sun Microsystems, Inc. All rights reserved. 28 * Use is subject to license terms. 29 */ 30 31 32 #pragma ident "%Z%%M% %I% %E% SMI" /* SVr4.0 1.7 */ 33 34 /* 35 * t_rcv.c and t_rcvv.c are very similar and contain common code. 36 * Any changes to either of them should be reviewed to see whether they 37 * are applicable to the other file. 38 */ 39 #include "mt.h" 40 #include <stdlib.h> 41 #include <rpc/trace.h> 42 #include <errno.h> 43 #include <unistd.h> 44 #include <stropts.h> 45 #include <sys/stream.h> 46 #define _SUN_TPI_VERSION 2 47 #include <sys/tihdr.h> 48 #include <sys/timod.h> 49 #include <xti.h> 50 #include <syslog.h> 51 #include <assert.h> 52 #include "tx.h" 53 54 int 55 _tx_rcv(int fd, char *buf, unsigned nbytes, int *flags, int api_semantics) 56 { 57 struct strbuf ctlbuf, databuf; 58 int retval, flg = 0; 59 int msglen; 60 union T_primitives *pptr; 61 struct _ti_user *tiptr; 62 int sv_errno; 63 int didalloc; 64 65 trace3(TR_t_rcv, 0, fd, nbytes); 66 if ((tiptr = _t_checkfd(fd, 0, api_semantics)) == NULL) { 67 sv_errno = errno; 68 trace3(TR_t_rcv, 1, fd, nbytes); 69 errno = sv_errno; 70 return (-1); 71 } 72 sig_mutex_lock(&tiptr->ti_lock); 73 74 if (tiptr->ti_servtype == T_CLTS) { 75 t_errno = TNOTSUPPORT; 76 sig_mutex_unlock(&tiptr->ti_lock); 77 trace3(TR_t_rcv, 1, fd, nbytes); 78 return (-1); 79 } 80 81 if (_T_IS_XTI(api_semantics)) { 82 /* 83 * User level state verification only done for XTI 84 * because doing for TLI may break existing applications 85 */ 86 if (! (tiptr->ti_state == T_DATAXFER || 87 tiptr->ti_state == T_OUTREL)) { 88 t_errno = TOUTSTATE; 89 sig_mutex_unlock(&tiptr->ti_lock); 90 trace3(TR_t_rcv, 1, fd, nbytes); 91 return (-1); 92 } 93 } 94 95 /* 96 * Check in lookbuf for stuff 97 */ 98 if (tiptr->ti_lookcnt > 0) { 99 /* 100 * Implied preference rules give priority to 101 * T_DISCON_IND over T_ORDREL_IND. Also certain errors like 102 * data received after T_ORDREL_IND or a duplicate T_ORDREL_IND 103 * after a T_ORDRELING have priority over TLOOK. 104 * This manifests in following code behavior. 105 * 106 * (1) If something in lookbuf then check 107 * the stream head also. This may result 108 * in retuning a TLOOK error but only if there are 109 * - message at stream head but look buffer 110 * has a T_DISCON_IND event. 111 * - no messages are on the stream head 112 * 113 * (2) If there are messages on the stream head and 114 * all of them are T_ORDREL_IND(i.e. no message in 115 * look buffer is T_DISCON_IND), there 116 * could be data on stream head to be picked up and 117 * we work on the stream head and not return TLOOK. 118 * We remove the event on the stream head and queue it. 119 * 120 */ 121 do { 122 retval = _ioctl(fd, I_NREAD, &msglen); 123 } while (retval < 0 && errno == EINTR); 124 125 if (retval < 0) { 126 sv_errno = errno; 127 128 t_errno = TSYSERR; 129 sig_mutex_unlock(&tiptr->ti_lock); 130 trace3(TR_t_rcv, 1, fd, nbytes); 131 errno = sv_errno; 132 return (-1); 133 } 134 135 if (retval > 0) { 136 /* 137 * If any T_DISCON_IND event in look buffer 138 * list then return TLOOK. Else continue 139 * processing as what could be on the stream 140 * head might be a possible T_DISCON_IND (which 141 * would have priority over the T_ORDREL_INDs 142 * on the look buffer.) 143 */ 144 struct _ti_lookbufs *tlbs; 145 146 tlbs = &tiptr->ti_lookbufs; 147 do { 148 if (*((t_scalar_t *)tlbs->tl_lookcbuf) 149 == T_DISCON_IND) { 150 t_errno = TLOOK; 151 sig_mutex_unlock(&tiptr->ti_lock); 152 trace3(TR_t_rcv, 1, fd, nbytes); 153 return (-1); 154 } 155 } while ((tlbs = tlbs->tl_next) != NULL); 156 157 } else { /* retval == 0 */ 158 /* 159 * Nothing on stream head so whatever in 160 * look buffer has nothing that might override 161 * it. 162 */ 163 t_errno = TLOOK; 164 sig_mutex_unlock(&tiptr->ti_lock); 165 trace3(TR_t_rcv, 1, fd, nbytes); 166 return (-1); 167 } 168 } 169 170 /* 171 * Acquire ctlbuf for use in sending/receiving control part 172 * of the message. 173 */ 174 if (_t_acquire_ctlbuf(tiptr, &ctlbuf, &didalloc) < 0) { 175 sv_errno = errno; 176 sig_mutex_unlock(&tiptr->ti_lock); 177 trace3(TR_t_rcv, 1, fd, nbytes); 178 errno = sv_errno; 179 return (-1); 180 } 181 182 databuf.maxlen = nbytes; 183 databuf.len = 0; 184 databuf.buf = buf; 185 186 *flags = 0; 187 188 /* 189 * This is a call that may block indefinitely so we drop the 190 * lock and allow signals in MT case here and reacquire it. 191 * Error case should roll back state changes done above 192 * (happens to be no state change here) 193 */ 194 sig_mutex_unlock(&tiptr->ti_lock); 195 if ((retval = getmsg(fd, &ctlbuf, &databuf, &flg)) < 0) { 196 if (errno == EAGAIN) 197 t_errno = TNODATA; 198 else 199 t_errno = TSYSERR; 200 sv_errno = errno; 201 sig_mutex_lock(&tiptr->ti_lock); 202 errno = sv_errno; 203 goto err_out; 204 } 205 sig_mutex_lock(&tiptr->ti_lock); 206 207 assert((retval & MORECTL) == 0); /* MORECTL should not be on */ 208 209 if (databuf.len == -1) databuf.len = 0; 210 211 if (ctlbuf.len > 0) { 212 if (ctlbuf.len < (int)sizeof (t_scalar_t)) { 213 t_errno = TSYSERR; 214 errno = EPROTO; 215 goto err_out; 216 } 217 218 pptr = (union T_primitives *)ctlbuf.buf; 219 220 switch (pptr->type) { 221 222 case T_EXDATA_IND: 223 *flags |= T_EXPEDITED; 224 if (retval > 0) 225 tiptr->ti_flags |= EXPEDITED; 226 /* FALLTHROUGH */ 227 case T_DATA_IND: 228 /* 229 * Uses the fact T_DATA_IND and T_EXDATA_IND 230 * are same in size 231 */ 232 if ((ctlbuf.len < (int)sizeof (struct T_data_ind)) || 233 (tiptr->ti_lookcnt > 0)) { 234 /* 235 * ti_lookcnt > 0 implies data 236 * received after T_DISCON_IND or 237 * T_ORDREL_IND hence error 238 */ 239 t_errno = TSYSERR; 240 errno = EPROTO; 241 goto err_out; 242 } 243 244 if ((pptr->data_ind.MORE_flag) || retval) 245 *flags |= T_MORE; 246 if ((pptr->data_ind.MORE_flag) && retval) 247 tiptr->ti_flags |= MORE; 248 /* 249 * No real state change on T_RCV event (noop) 250 * 251 * We invoke the macro only for error logging 252 * part of its capabilities when in a bad state. 253 */ 254 _T_TX_NEXTSTATE(T_RCV, tiptr, 255 "t_rcv: invalid state event T_RCV"); 256 if (didalloc) 257 free(ctlbuf.buf); 258 else 259 tiptr->ti_ctlbuf = ctlbuf.buf; 260 sig_mutex_unlock(&tiptr->ti_lock); 261 trace3(TR_t_rcv, 1, fd, nbytes); 262 return (databuf.len); 263 264 case T_ORDREL_IND: 265 if (tiptr->ti_lookcnt > 0) { 266 /* 267 * ti_lookcnt > 0 implies T_ORDREL_IND 268 * received after T_DISCON_IND or 269 * another T_ORDREL_IND hence error. 270 */ 271 t_errno = TSYSERR; 272 errno = EPROTO; 273 goto err_out; 274 } 275 /* FALLTHROUGH */ 276 case T_DISCON_IND: 277 /* 278 * Post event (T_ORDREL_IND/T_DISCON_IND) to 279 * the lookbuffer list. 280 */ 281 282 if (_t_register_lookevent(tiptr, databuf.buf, 283 databuf.len, 284 ctlbuf.buf, ctlbuf.len) < 0) { 285 t_errno = TSYSERR; 286 errno = ENOMEM; 287 goto err_out; 288 } 289 /* 290 * We know that T_DISCON_IND is stored in 291 * last look buffer. If there is more data 292 * that follows, we try to append it to 293 * the same look buffer 294 */ 295 if (retval & MOREDATA) { 296 ctlbuf.maxlen = 0; /* XXX why ? */ 297 ctlbuf.len = 0; 298 299 /* 300 * XXX Will break (-ve maxlen) for 301 * transport provider with unbounded 302 * T_DISCON_IND data part (-1). 303 */ 304 databuf.maxlen = 305 tiptr->ti_rcvsize - databuf.len; 306 307 databuf.len = 0; 308 databuf.buf = 309 tiptr->ti_lookbufs.tl_lookdbuf + 310 tiptr->ti_lookbufs.tl_lookdlen; 311 *flags = 0; 312 313 /* 314 * Since MOREDATA was set, we assume 315 * that this getmsg will not block 316 * indefinitely 317 */ 318 do { 319 retval = getmsg(fd, &ctlbuf, 320 &databuf, &flg); 321 } while (retval < 0 && errno == EINTR); 322 323 if (retval < 0) { 324 t_errno = TSYSERR; 325 goto err_out; 326 } 327 if (databuf.len == -1) databuf.len = 0; 328 if (retval > 0) { 329 /* MORECTL should not be on */ 330 assert((retval & MORECTL) == 0); 331 /* 332 * XXX - Why ? 333 * No support for unbounded data 334 * on T_DISCON_IND ? 335 */ 336 t_errno = TSYSERR; 337 errno = EPROTO; 338 goto err_out; 339 } 340 tiptr->ti_lookbufs.tl_lookdlen += 341 databuf.len; 342 } 343 344 t_errno = TLOOK; 345 goto err_out; 346 347 default: 348 break; 349 } 350 351 t_errno = TSYSERR; 352 errno = EPROTO; 353 goto err_out; 354 355 } else { /* else for "if (ctlbuf.len > 0)" */ 356 if (!retval && (tiptr->ti_flags & MORE)) { 357 *flags |= T_MORE; 358 tiptr->ti_flags &= ~MORE; 359 } 360 if (retval & MOREDATA) 361 *flags |= T_MORE; 362 363 /* 364 * If inside an ETSDU, set expedited flag and turn 365 * of internal version when reach end of "ETIDU". 366 */ 367 if (tiptr->ti_flags & EXPEDITED) { 368 *flags |= T_EXPEDITED; 369 if (!retval) 370 tiptr->ti_flags &= ~EXPEDITED; 371 } 372 373 /* 374 * No real state change on T_RCV events (It is a NOOP) 375 * 376 * We invoke the macro only for error logging 377 * part of its capabilities when in a bad state. 378 */ 379 _T_TX_NEXTSTATE(T_RCV, tiptr, 380 "t_rcv: state invalid T_RCV event"); 381 if (didalloc) 382 free(ctlbuf.buf); 383 else 384 tiptr->ti_ctlbuf = ctlbuf.buf; 385 sig_mutex_unlock(&tiptr->ti_lock); 386 trace3(TR_t_rcv, 1, fd, nbytes); 387 return (databuf.len); 388 } 389 /* NOTREACHED */ 390 391 err_out: 392 sv_errno = errno; 393 if (didalloc) 394 free(ctlbuf.buf); 395 else 396 tiptr->ti_ctlbuf = ctlbuf.buf; 397 sig_mutex_unlock(&tiptr->ti_lock); 398 399 trace3(TR_t_rcv, 1, fd, nbytes); 400 errno = sv_errno; 401 return (-1); 402 } 403