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iscsi_rcv.c revision 1.24
      1 /*	$NetBSD: iscsi_rcv.c,v 1.24 2017/12/03 19:07:10 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2004,2005,2006,2011 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Wasabi Systems, Inc.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 #include "iscsi_globals.h"
     32 
     33 #include <sys/file.h>
     34 #include <sys/socket.h>
     35 #include <sys/socketvar.h>
     36 
     37 /*****************************************************************************/
     38 
     39 /*
     40  * my_soo_read:
     41  *    Replacement for soo_read with flag handling.
     42  *
     43  *    Parameter:
     44  *          conn     The connection
     45  *          u        The uio descriptor
     46  *          flags    Read flags
     47  *
     48  *    Returns:    0 on success, else 1
     49  */
     50 
     51 STATIC int
     52 my_soo_read(connection_t *conn, struct uio *u, int flags)
     53 {
     54 	struct socket *so = conn->c_sock->f_socket;
     55 	int ret;
     56 #ifdef ISCSI_DEBUG
     57 	size_t resid = u->uio_resid;
     58 #endif
     59 
     60 	DEBC(conn, 99, ("soo_read req: %zu\n", resid));
     61 
     62 	if (flags & MSG_WAITALL) {
     63 		flags &= ~MSG_WAITALL;
     64 		do {
     65 			int oresid = u->uio_resid;
     66 			ret = (*so->so_receive)(so, NULL, u, NULL, NULL, &flags);
     67 			if (!ret && u->uio_resid == oresid)
     68 				break;
     69 		} while (!ret && u->uio_resid > 0);
     70 	} else
     71 		ret = (*so->so_receive)(so, NULL, u, NULL, NULL, &flags);
     72 
     73 	if (ret || (flags != MSG_DONTWAIT && u->uio_resid)) {
     74 		DEBC(conn, 1, ("Read failed (ret: %d, req: %zu, out: %zu)\n",
     75 		               ret, resid, u->uio_resid));
     76 		handle_connection_error(conn, ISCSI_STATUS_SOCKET_ERROR,
     77 		                        RECOVER_CONNECTION);
     78 		return 1;
     79 	}
     80 	return 0;
     81 }
     82 
     83 
     84 /*
     85  * try_resynch_receive:
     86  *    Skip over everything in the socket's receive buffer, in the hope of
     87  *    ending up at the start of a new PDU.
     88  *
     89  *    Parameter:
     90  *          conn     The connection
     91  */
     92 
     93 STATIC void
     94 try_resynch_receive(connection_t *conn)
     95 {
     96 	uint8_t buffer[64];
     97 	struct uio uio;
     98 	struct iovec io_vec;
     99 	int rc;
    100 
    101 	uio.uio_rw = UIO_READ;
    102 	UIO_SETUP_SYSSPACE(&uio);
    103 
    104 	do {
    105 		io_vec.iov_base = buffer;
    106 		uio.uio_iov = &io_vec;
    107 		uio.uio_iovcnt = 1;
    108 		uio.uio_resid = io_vec.iov_len = sizeof(buffer);
    109 
    110 		rc = my_soo_read(conn, &uio, MSG_DONTWAIT);
    111 		DEBC(conn, 9, ("try_resynch_receive: rc = %d, resid = %zu\n",
    112 				rc, uio.uio_resid));
    113 	} while (!rc && !uio.uio_resid);
    114 }
    115 
    116 
    117 /*
    118  * ccb_from_itt
    119  *    Translate ITT into CCB pointer.
    120  *
    121  *    Parameter:
    122  *          conn     The connection
    123  *          itt      The Initiator Task Tag
    124  *
    125  *    Returns:
    126  *          Pointer to CCB, or NULL if ITT is not a valid CCB index.
    127  */
    128 
    129 STATIC ccb_t *
    130 ccb_from_itt(connection_t *conn, uint32_t itt)
    131 {
    132 	ccb_t *ccb;
    133 	int cidx;
    134 
    135 	if (itt == 0xffffffff)
    136 		return NULL;
    137 
    138 	cidx = itt & 0xff;
    139 	if (cidx >= CCBS_PER_SESSION)
    140 		return NULL;
    141 
    142 	ccb = &conn->c_session->s_ccb[cidx];
    143 
    144 	if (ccb->ccb_ITT != itt) {
    145 		DEBC(conn, 0,
    146 		     ("ccb_from_itt: received invalid CCB itt %08x != %08x\n",
    147 		      itt, ccb->ccb_ITT));
    148 		return NULL;
    149 	}
    150 
    151 	if (ccb->ccb_disp <= CCBDISP_BUSY) {
    152 		DEBC(conn, 0,
    153 		     ("ccb_from_itt: received CCB with invalid disp %d\n",
    154 		      ccb->ccb_disp));
    155 		return NULL;
    156 	}
    157 
    158 	return ccb;
    159 }
    160 
    161 
    162 /*
    163  * read_pdu_data:
    164  *    Initialize the uio structure for receiving everything after the
    165  *    header, including data (if present), and padding. Read the data.
    166  *
    167  *    Parameter:
    168  *          pdu      The PDU
    169  *          data     Pointer to data (may be NULL for auto-allocation)
    170  *          offset   The offset into the data pointer
    171  *
    172  *    Returns:     0 on success
    173  *                 1 if an error occurs during read
    174  *                -1 if the data digest was incorrect (PDU must be ignored)
    175  */
    176 
    177 STATIC int
    178 read_pdu_data(pdu_t *pdu, uint8_t *data, uint32_t offset)
    179 {
    180 	static uint8_t pad_bytes[4];
    181 	uint32_t len, digest;
    182 	struct uio *uio;
    183 	int i, pad;
    184 	connection_t *conn = pdu->pdu_connection;
    185 
    186 	DEB(15, ("read_pdu_data: data segment length = %d\n",
    187 		ntoh3(pdu->pdu_hdr.pduh_DataSegmentLength)));
    188 	if (!(len = ntoh3(pdu->pdu_hdr.pduh_DataSegmentLength))) {
    189 		return 0;
    190 	}
    191 	pad = len & 0x03;
    192 	if (pad) {
    193 		pad = 4 - pad;
    194 	}
    195 
    196 	KASSERT(data != NULL || offset == 0);
    197 
    198 	if (data == NULL) {
    199 		/*
    200 		 * NOTE: Always allocate 2 extra bytes when reading temp data,
    201 		 * since temp data is mostly used for received text, and we can
    202 		 * make sure there's a double zero at the end of the data to mark EOF.
    203 		 */
    204 		if ((data = (uint8_t *) malloc(len + 2, M_TEMP, M_WAITOK)) == NULL) {
    205 			DEBOUT(("ran out of mem on receive\n"));
    206 			handle_connection_error(pdu->pdu_connection,
    207 				ISCSI_STATUS_NO_RESOURCES, LOGOUT_SESSION);
    208 			return 1;
    209 		}
    210 		pdu->pdu_temp_data = data;
    211 		pdu->pdu_temp_data_len = len;
    212 	}
    213 
    214 	pdu->pdu_io_vec[0].iov_base = data + offset;
    215 	pdu->pdu_io_vec[0].iov_len = len;
    216 
    217 	uio = &pdu->pdu_uio;
    218 
    219 	uio->uio_iov = pdu->pdu_io_vec;
    220 	uio->uio_iovcnt = 1;
    221 	uio->uio_rw = UIO_READ;
    222 	uio->uio_resid = len;
    223 	UIO_SETUP_SYSSPACE(uio);
    224 
    225 	if (pad) {
    226 		uio->uio_iovcnt++;
    227 		uio->uio_iov[1].iov_base = pad_bytes;
    228 		uio->uio_iov[1].iov_len = pad;
    229 		uio->uio_resid += pad;
    230 	}
    231 
    232 	if (conn->c_DataDigest) {
    233 		i = uio->uio_iovcnt++;
    234 		pdu->pdu_io_vec[i].iov_base = &pdu->pdu_data_digest;
    235 		pdu->pdu_io_vec[i].iov_len = 4;
    236 		uio->uio_resid += 4;
    237 	}
    238 
    239 	/* get the data */
    240 	if (my_soo_read(conn, &pdu->pdu_uio, MSG_WAITALL) != 0) {
    241 		return 1;
    242 	}
    243 	if (conn->c_DataDigest) {
    244 		digest = gen_digest_2(data, len, pad_bytes, pad);
    245 
    246 		if (digest != pdu->pdu_data_digest) {
    247 			DEBOUT(("Data Digest Error: comp = %08x, rx = %08x\n",
    248 					digest, pdu->pdu_data_digest));
    249 			switch (pdu->pdu_hdr.pduh_Opcode & OPCODE_MASK) {
    250 			case TOP_SCSI_Response:
    251 			case TOP_Text_Response:
    252 				send_snack(pdu->pdu_connection, pdu, NULL, SNACK_STATUS_NAK);
    253 				break;
    254 
    255 			case TOP_SCSI_Data_in:
    256 				send_snack(pdu->pdu_connection, pdu, NULL, SNACK_DATA_NAK);
    257 				break;
    258 
    259 			default:
    260 				/* ignore all others */
    261 				break;
    262 			}
    263 			return -1;
    264 		}
    265 	}
    266 	return 0;
    267 }
    268 
    269 
    270 /*
    271  * collect_text_data
    272  *    Handle text continuation in login and text response PDUs
    273  *
    274  *    Parameter:
    275  *          pdu      The received PDU
    276  *          req_CCB  The CCB associated with the original request
    277  *
    278  *    Returns:    -1    if continue flag is set
    279  *                0     if text is complete
    280  *                +1    if an error occurred (out of resources)
    281  */
    282 STATIC int
    283 collect_text_data(pdu_t *pdu, ccb_t *req_ccb)
    284 {
    285 
    286 	if (req_ccb->ccb_text_data) {
    287 		int nlen;
    288 		uint8_t *newp;
    289 
    290 		nlen = req_ccb->ccb_text_len + pdu->pdu_temp_data_len;
    291 		/* Note: allocate extra 2 bytes for text terminator */
    292 		if ((newp = malloc(nlen + 2, M_TEMP, M_WAITOK)) == NULL) {
    293 			DEBOUT(("Collect Text Data: Out of Memory, ccb = %p\n", req_ccb));
    294 			req_ccb->ccb_status = ISCSI_STATUS_NO_RESOURCES;
    295 			/* XXX where is CCB freed? */
    296 			return 1;
    297 		}
    298 		memcpy(newp, req_ccb->ccb_text_data, req_ccb->ccb_text_len);
    299 		memcpy(&newp[req_ccb->ccb_text_len], pdu->pdu_temp_data, pdu->pdu_temp_data_len);
    300 
    301 		free(req_ccb->ccb_text_data, M_TEMP);
    302 		free(pdu->pdu_temp_data, M_TEMP);
    303 
    304 		req_ccb->ccb_text_data = NULL;
    305 		pdu->pdu_temp_data = newp;
    306 		pdu->pdu_temp_data_len = nlen;
    307 	}
    308 
    309 	if (pdu->pdu_hdr.pduh_Flags & FLAG_CONTINUE) {
    310 		req_ccb->ccb_text_data = pdu->pdu_temp_data;
    311 		req_ccb->ccb_text_len = pdu->pdu_temp_data_len;
    312 		pdu->pdu_temp_data = NULL;
    313 
    314 		acknowledge_text(req_ccb->ccb_connection, pdu, req_ccb);
    315 		return -1;
    316 	}
    317 	return 0;
    318 }
    319 
    320 
    321 /*
    322  * check_StatSN
    323  *    Check received vs. expected StatSN
    324  *
    325  *    Parameter:
    326  *          conn     The connection
    327  *          nw_sn    The received StatSN in network byte order
    328  *          ack      Acknowledge this SN if TRUE
    329  */
    330 
    331 STATIC int
    332 check_StatSN(connection_t *conn, uint32_t nw_sn, bool ack)
    333 {
    334 	int rc;
    335 	uint32_t sn = ntohl(nw_sn);
    336 
    337 	rc = add_sernum(&conn->c_StatSN_buf, sn);
    338 
    339 	if (ack)
    340 		ack_sernum(&conn->c_StatSN_buf, sn);
    341 
    342 	if (rc != 1) {
    343 		if (rc == 0) {
    344 			DEBOUT(("Duplicate PDU, ExpSN %d, Recvd: %d\n",
    345 				conn->c_StatSN_buf.ExpSN, sn));
    346 			return -1;
    347 		}
    348 
    349 		if (rc < 0) {
    350 			DEBOUT(("Excessive outstanding Status PDUs, ExpSN %d, Recvd: %d\n",
    351 					conn->c_StatSN_buf.ExpSN, sn));
    352 			handle_connection_error(conn, ISCSI_STATUS_PDUS_LOST,
    353 									RECOVER_CONNECTION);
    354 			return rc;
    355 		}
    356 
    357 		DEBOUT(("Missing Status PDUs: First %d, num: %d\n",
    358 				conn->c_StatSN_buf.ExpSN, rc - 1));
    359 		if (conn->c_state == ST_FULL_FEATURE &&
    360 			conn->c_session->s_ErrorRecoveryLevel) {
    361 			snack_missing(conn, NULL, SNACK_STATUS_NAK,
    362 						  conn->c_StatSN_buf.ExpSN, rc - 1);
    363 		} else {
    364 			DEBOUT(("StatSN killing connection (State = %d, "
    365 					"ErrorRecoveryLevel = %d)\n",
    366 					conn->c_state, conn->c_session->s_ErrorRecoveryLevel));
    367 			handle_connection_error(conn, ISCSI_STATUS_PDUS_LOST,
    368 									RECOVER_CONNECTION);
    369 			return -1;
    370 		}
    371 	}
    372 	return 0;
    373 }
    374 
    375 
    376 /*
    377  * check_CmdSN
    378  *    Check received vs. expected CmdSN
    379  *
    380  *    Parameter:
    381  *          conn     The connection
    382  *          nw_sn    The received ExpCmdSN in network byte order
    383  */
    384 
    385 STATIC void
    386 check_CmdSN(connection_t *conn, uint32_t nw_sn)
    387 {
    388 	uint32_t sn = ntohl(nw_sn);
    389 	ccb_t *ccb, *nxt;
    390 
    391 	TAILQ_FOREACH_SAFE(ccb, &conn->c_ccbs_waiting, ccb_chain, nxt) {
    392 		DEBC(conn, 10,
    393 			("CheckCmdSN - CmdSN=%d, ExpCmdSn=%d, waiting=%p, flags=%x\n",
    394 			ccb->ccb_CmdSN, sn, ccb->ccb_pdu_waiting, ccb->ccb_flags));
    395 		if (ccb->ccb_pdu_waiting != NULL &&
    396 			sn_a_lt_b(sn, ccb->ccb_CmdSN) &&
    397 			!(ccb->ccb_flags & CCBF_GOT_RSP)) {
    398 			DEBC(conn, 1, ("CheckCmdSN resending - CmdSN=%d, ExpCmdSn=%d\n",
    399 			               ccb->ccb_CmdSN, sn));
    400 
    401 			ccb->ccb_total_tries++;
    402 
    403 			if (++ccb->ccb_num_timeouts > MAX_CCB_TIMEOUTS ||
    404 				ccb->ccb_total_tries > MAX_CCB_TRIES) {
    405 				handle_connection_error(conn,
    406 					ISCSI_STATUS_TIMEOUT,
    407 					(ccb->ccb_total_tries <= MAX_CCB_TRIES)
    408 						? RECOVER_CONNECTION
    409 						: LOGOUT_CONNECTION);
    410 				break;
    411 			} else {
    412 				resend_pdu(ccb);
    413 			}
    414 		}
    415 
    416 		/*
    417 		 * The target can respond to a NOP-In before subsequent
    418 		 * commands are processed. So our CmdSN can exceed the
    419 		 * returned ExpCmdSN by the number of commands that are
    420 		 * in flight. Adjust the expected value accordingly.
    421 		 */
    422 		sn++;
    423 	}
    424 }
    425 
    426 
    427 /*
    428  * receive_login_pdu
    429  *    Handle receipt of a login response PDU.
    430  *
    431  *    Parameter:
    432  *          conn     The connection
    433  *          pdu      The PDU
    434  *          req_CCB  The CCB associated with the original request (if any)
    435  */
    436 
    437 STATIC int
    438 receive_login_pdu(connection_t *conn, pdu_t *pdu, ccb_t *req_ccb)
    439 {
    440 	int rc;
    441 
    442 	DEBC(conn, 9, ("Received Login Response PDU, op=%x, flags=%x, sn=%u\n",
    443 			pdu->pdu_hdr.pduh_Opcode, pdu->pdu_hdr.pduh_Flags,
    444 			ntohl(pdu->pdu_hdr.pduh_p.login_rsp.StatSN)));
    445 
    446 	if (req_ccb == NULL) {
    447 		/* Duplicate?? */
    448 		DEBOUT(("Received duplicate login response (no associated CCB)\n"));
    449 		return -1;
    450 	}
    451 
    452 	if (pdu->pdu_hdr.pduh_p.login_rsp.StatusClass) {
    453 		DEBC(conn, 1, ("Login problem - Class = %x, Detail = %x\n",
    454 				pdu->pdu_hdr.pduh_p.login_rsp.StatusClass,
    455 				pdu->pdu_hdr.pduh_p.login_rsp.StatusDetail));
    456 		wake_ccb(req_ccb, ISCSI_STATUS_LOGIN_FAILED);
    457 		return 0;
    458 	}
    459 
    460 	if (!conn->c_StatSN_buf.next_sn) {
    461 		conn->c_StatSN_buf.next_sn = conn->c_StatSN_buf.ExpSN =
    462 			ntohl(pdu->pdu_hdr.pduh_p.login_rsp.StatSN) + 1;
    463 	} else if (check_StatSN(conn, pdu->pdu_hdr.pduh_p.login_rsp.StatSN, TRUE))
    464 		return -1;
    465 
    466 	if (pdu->pdu_temp_data_len) {
    467 		if ((rc = collect_text_data(pdu, req_ccb)) != 0)
    468 			return max(rc, 0);
    469 	}
    470 
    471 	negotiate_login(conn, pdu, req_ccb);
    472 
    473 	/* negotiate_login will decide whether login is complete or not */
    474 	return 0;
    475 }
    476 
    477 
    478 /*
    479  * receive_text_response_pdu
    480  *    Handle receipt of a text response PDU.
    481  *
    482  *    Parameter:
    483  *          conn     The connection
    484  *          pdu      The PDU
    485  *          req_CCB  The CCB associated with the original request (if any)
    486  */
    487 
    488 STATIC int
    489 receive_text_response_pdu(connection_t *conn, pdu_t *pdu, ccb_t *req_ccb)
    490 {
    491 	int rc;
    492 
    493 	DEBC(conn, 9, ("Received Text Response PDU, op=%x, flags=%x\n",
    494 			pdu->pdu_hdr.pduh_Opcode, pdu->pdu_hdr.pduh_Flags));
    495 
    496 	if (check_StatSN(conn, pdu->pdu_hdr.pduh_p.text_rsp.StatSN, TRUE)) {
    497 		return -1;
    498 	}
    499 	if (req_ccb == NULL) {
    500 		DEBOUT(("Received unsolicited text response\n"));
    501 		handle_connection_error(conn, ISCSI_STATUS_TARGET_ERROR,
    502 							LOGOUT_CONNECTION);
    503 		return -1;
    504 	}
    505 
    506 	if (req_ccb->ccb_pdu_waiting != NULL) {
    507 		ccb_timeout_start(req_ccb, COMMAND_TIMEOUT);
    508 		req_ccb->ccb_num_timeouts = 0;
    509 	}
    510 
    511 	if ((rc = collect_text_data(pdu, req_ccb)) != 0) {
    512 		return max(0, rc);
    513 	}
    514 	negotiate_text(conn, pdu, req_ccb);
    515 
    516 	return 0;
    517 }
    518 
    519 
    520 /*
    521  * receive_logout_pdu
    522  *    Handle receipt of a logout response PDU.
    523  *
    524  *    Parameter:
    525  *          conn     The connection
    526  *          pdu      The PDU
    527  *          req_CCB  The CCB associated with the original request (if any)
    528  */
    529 
    530 STATIC int
    531 receive_logout_pdu(connection_t *conn, pdu_t *pdu, ccb_t *req_ccb)
    532 {
    533 	bool otherconn;
    534 	uint8_t response;
    535 	uint32_t status;
    536 
    537 	otherconn = (req_ccb != NULL) ? (req_ccb->ccb_flags & CCBF_OTHERCONN) != 0 : 1;
    538 	response = pdu->pdu_hdr.pduh_OpcodeSpecific [0];
    539 	DEBC(conn, 1,
    540 		("Received Logout PDU - CCB = %p, otherconn=%d, response=%d\n",
    541 		req_ccb, otherconn, response));
    542 
    543 	if (req_ccb == NULL)
    544 		return 0;
    545 
    546 	if (otherconn && check_StatSN(conn, pdu->pdu_hdr.pduh_p.logout_rsp.StatSN, TRUE))
    547 		return -1;
    548 
    549 	switch (response) {
    550 	case 0:
    551 		status = ISCSI_STATUS_SUCCESS;
    552 		break;
    553 	case 1:
    554 		status = ISCSI_STATUS_LOGOUT_CID_NOT_FOUND;
    555 		break;
    556 	case 2:
    557 		status = ISCSI_STATUS_LOGOUT_RECOVERY_NS;
    558 		break;
    559 	default:
    560 		status = ISCSI_STATUS_LOGOUT_ERROR;
    561 		break;
    562 	}
    563 
    564 	if (conn->c_session->s_ErrorRecoveryLevel >= 2 && response != 1) {
    565 		connection_t *refconn = (otherconn) ? req_ccb->ccb_par : conn;
    566 
    567 		refconn->c_Time2Wait = ntohs(pdu->pdu_hdr.pduh_p.logout_rsp.Time2Wait);
    568 		refconn->c_Time2Retain = ntohs(pdu->pdu_hdr.pduh_p.logout_rsp.Time2Retain);
    569 	}
    570 
    571 	wake_ccb(req_ccb, status);
    572 
    573 	if (!otherconn && conn->c_state == ST_LOGOUT_SENT) {
    574 		conn->c_terminating = ISCSI_STATUS_LOGOUT;
    575 		conn->c_state = ST_SETTLING;
    576 		conn->c_loggedout = (response) ? LOGOUT_FAILED : LOGOUT_SUCCESS;
    577 
    578 		connection_timeout_stop(conn);
    579 
    580 		/* let send thread take over next step of cleanup */
    581 		mutex_enter(&conn->c_lock);
    582 		cv_broadcast(&conn->c_conn_cv);
    583 		mutex_exit(&conn->c_lock);
    584 	}
    585 
    586 	return !otherconn;
    587 }
    588 
    589 
    590 /*
    591  * receive_data_in_pdu
    592  *    Handle receipt of a data in PDU.
    593  *
    594  *    Parameter:
    595  *          conn     The connection
    596  *          pdu      The PDU
    597  *          req_CCB  The CCB associated with the original request (if any)
    598  */
    599 
    600 STATIC int
    601 receive_data_in_pdu(connection_t *conn, pdu_t *pdu, ccb_t *req_ccb)
    602 {
    603 	uint32_t dsl, sn;
    604 	bool done;
    605 	int rc;
    606 
    607 	dsl = ntoh3(pdu->pdu_hdr.pduh_DataSegmentLength);
    608 
    609 	if (req_ccb == NULL || !req_ccb->ccb_data_in || !req_ccb->ccb_data_len) {
    610 		DEBOUT(("Received Data In, but req_ccb not waiting for it, ignored\n"));
    611 		return 0;
    612 	}
    613 	req_ccb->ccb_flags |= CCBF_GOT_RSP;
    614 
    615 	if (req_ccb->ccb_pdu_waiting != NULL) {
    616 		ccb_timeout_start(req_ccb, COMMAND_TIMEOUT);
    617 		req_ccb->ccb_num_timeouts = 0;
    618 	}
    619 
    620 	sn = ntohl(pdu->pdu_hdr.pduh_p.data_in.DataSN);
    621 
    622 	if ((rc = add_sernum(&req_ccb->ccb_DataSN_buf, sn)) != 1) {
    623 		if (!rc) {
    624 			return -1;
    625 		}
    626 		if (rc < 0) {
    627 			DEBOUT(("Excessive outstanding Data PDUs\n"));
    628 			handle_connection_error(req_ccb->ccb_connection,
    629 				ISCSI_STATUS_PDUS_LOST, LOGOUT_CONNECTION);
    630 			return -1;
    631 		}
    632 		DEBOUT(("Missing Data PDUs: First %d, num: %d\n",
    633 				req_ccb->ccb_DataSN_buf.ExpSN, rc - 1));
    634 
    635 		if (conn->c_state == ST_FULL_FEATURE &&
    636 			conn->c_session->s_ErrorRecoveryLevel) {
    637 			snack_missing(req_ccb->ccb_connection, req_ccb,
    638 				SNACK_DATA_NAK, req_ccb->ccb_DataSN_buf.ExpSN,
    639 				rc - 1);
    640 		} else {
    641 			DEBOUT(("Killing connection (State=%d, ErrorRecoveryLevel=%d)\n",
    642 					conn->c_state, conn->c_session->s_ErrorRecoveryLevel));
    643 			handle_connection_error(conn, ISCSI_STATUS_PDUS_LOST,
    644 						LOGOUT_CONNECTION);
    645 			return -1;
    646 		}
    647 	}
    648 
    649 	ack_sernum(&req_ccb->ccb_DataSN_buf, sn);
    650 
    651 	req_ccb->ccb_xfer_len += dsl;
    652 
    653 	if ((pdu->pdu_hdr.pduh_Flags & FLAG_ACK) && conn->c_session->s_ErrorRecoveryLevel)
    654 		send_snack(conn, pdu, req_ccb, SNACK_DATA_ACK);
    655 
    656 	done = sn_empty(&req_ccb->ccb_DataSN_buf);
    657 
    658 	if (pdu->pdu_hdr.pduh_Flags & FLAG_STATUS) {
    659 		DEBC(conn, 10, ("Rx Data In %d, done = %d\n",
    660 			req_ccb->ccb_CmdSN, done));
    661 
    662 		req_ccb->ccb_flags |= CCBF_COMPLETE;
    663 		/* successful transfer, reset recover count */
    664 		conn->c_recover = 0;
    665 
    666 		if (done)
    667 			wake_ccb(req_ccb, ISCSI_STATUS_SUCCESS);
    668 		if (check_StatSN(conn, pdu->pdu_hdr.pduh_p.data_in.StatSN, done))
    669 			return -1;
    670 
    671 	} else if (done && (req_ccb->ccb_flags & CCBF_COMPLETE)) {
    672 		wake_ccb(req_ccb, ISCSI_STATUS_SUCCESS);
    673 	}
    674 	/* else wait for command response */
    675 
    676 	return 0;
    677 }
    678 
    679 
    680 /*
    681  * receive_r2t_pdu
    682  *    Handle receipt of a R2T PDU.
    683  *
    684  *    Parameter:
    685  *          conn     The connection
    686  *          pdu      The PDU
    687  *          req_CCB  The CCB associated with the original request (if any)
    688  */
    689 
    690 STATIC int
    691 receive_r2t_pdu(connection_t *conn, pdu_t *pdu, ccb_t *req_ccb)
    692 {
    693 
    694 	DEBC(conn, 10, ("Received R2T PDU - CCB = %p\n", req_ccb));
    695 
    696 	if (req_ccb != NULL) {
    697 		if (req_ccb->ccb_pdu_waiting != NULL) {
    698 			ccb_timeout_start(req_ccb, COMMAND_TIMEOUT);
    699 			req_ccb->ccb_num_timeouts = 0;
    700 		}
    701 		send_data_out(conn, pdu, req_ccb, CCBDISP_NOWAIT, TRUE);
    702 	}
    703 
    704 	return 0;
    705 }
    706 
    707 
    708 /*
    709  * receive_command_response_pdu
    710  *    Handle receipt of a command response PDU.
    711  *
    712  *    Parameter:
    713  *          conn     The connection
    714  *          pdu      The PDU
    715  *          req_CCB  The CCB associated with the original request (if any)
    716  */
    717 
    718 STATIC int
    719 receive_command_response_pdu(connection_t *conn, pdu_t *pdu, ccb_t *req_ccb)
    720 {
    721 	int len, rc;
    722 	bool done;
    723 	uint32_t status;
    724 
    725 	/* Read any provided data */
    726 	if (pdu->pdu_temp_data_len && req_ccb != NULL && req_ccb->ccb_sense_len_req) {
    727 		len = min(req_ccb->ccb_sense_len_req,
    728 				  ntohs(*((uint16_t *) pdu->pdu_temp_data)));
    729 		memcpy(req_ccb->ccb_sense_ptr, ((uint16_t *) pdu->pdu_temp_data) + 1,
    730 					len);
    731 		req_ccb->ccb_sense_len_got = len;
    732 	}
    733 
    734 	if (req_ccb == NULL) {
    735 		/* Assume duplicate... */
    736 		DEBOUT(("Possibly duplicate command response (no associated CCB)\n"));
    737 		return -1;
    738 	}
    739 
    740 	if (req_ccb->ccb_pdu_waiting != NULL) {
    741 		ccb_timeout_start(req_ccb, COMMAND_TIMEOUT);
    742 		req_ccb->ccb_num_timeouts = 0;
    743 	}
    744 
    745 	req_ccb->ccb_flags |= CCBF_COMPLETE;
    746 	conn->c_recover = 0;	/* successful transfer, reset recover count */
    747 
    748 	if (pdu->pdu_hdr.pduh_OpcodeSpecific[0]) {	/* Response */
    749 		status = ISCSI_STATUS_TARGET_FAILURE;
    750 	} else {
    751 		switch (pdu->pdu_hdr.pduh_OpcodeSpecific[1]) {	/* Status */
    752 		case 0x00:
    753 			status = ISCSI_STATUS_SUCCESS;
    754 			break;
    755 
    756 		case 0x02:
    757 			status = ISCSI_STATUS_CHECK_CONDITION;
    758 			break;
    759 
    760 		case 0x08:
    761 			status = ISCSI_STATUS_TARGET_BUSY;
    762 			break;
    763 
    764 		default:
    765 			status = ISCSI_STATUS_TARGET_ERROR;
    766 			break;
    767 		}
    768 	}
    769 
    770 	if (pdu->pdu_hdr.pduh_Flags & (FLAG_OVERFLOW | FLAG_UNDERFLOW))
    771 		req_ccb->ccb_residual = ntohl(pdu->pdu_hdr.pduh_p.response.ResidualCount);
    772 
    773 	done = status || sn_empty(&req_ccb->ccb_DataSN_buf);
    774 
    775 	DEBC(conn, 10, ("Rx Response: CmdSN %d, rsp = %x, status = %x\n",
    776 			req_ccb->ccb_CmdSN,
    777 			pdu->pdu_hdr.pduh_OpcodeSpecific[0],
    778 			pdu->pdu_hdr.pduh_OpcodeSpecific[1]));
    779 
    780 	rc = check_StatSN(conn, pdu->pdu_hdr.pduh_p.response.StatSN, done);
    781 
    782 	if (done)
    783 		wake_ccb(req_ccb, status);
    784 
    785 	return rc;
    786 }
    787 
    788 
    789 /*
    790  * receive_asynch_pdu
    791  *    Handle receipt of an asynchronous message PDU.
    792  *
    793  *    Parameter:
    794  *          conn     The connection
    795  *          pdu      The PDU
    796  */
    797 
    798 STATIC int
    799 receive_asynch_pdu(connection_t *conn, pdu_t *pdu)
    800 {
    801 
    802 	DEBOUT(("Received Asynch PDU, Event %d\n", pdu->pdu_hdr.pduh_p.asynch.AsyncEvent));
    803 
    804 	switch (pdu->pdu_hdr.pduh_p.asynch.AsyncEvent) {
    805 	case 0:		   		/* SCSI Asynch event. Don't know what to do with it... */
    806 		break;
    807 
    808 	case 1:		   		/* Target requests logout. */
    809 		if (conn->c_session->s_active_connections > 1) {
    810 			kill_connection(conn, ISCSI_STATUS_TARGET_LOGOUT,
    811 						LOGOUT_CONNECTION, FALSE);
    812 		} else {
    813 			kill_session(conn->c_session, ISCSI_STATUS_TARGET_LOGOUT,
    814 						 LOGOUT_SESSION, FALSE);
    815 		}
    816 		break;
    817 
    818 	case 2:				/* Target is dropping connection */
    819 		conn = find_connection(conn->c_session,
    820 					ntohs(pdu->pdu_hdr.pduh_p.asynch.Parameter1));
    821 		if (conn != NULL) {
    822 			conn->c_Time2Wait = ntohs(pdu->pdu_hdr.pduh_p.asynch.Parameter2);
    823 			conn->c_Time2Retain = ntohs(pdu->pdu_hdr.pduh_p.asynch.Parameter3);
    824 			kill_connection(conn, ISCSI_STATUS_TARGET_DROP,
    825 					NO_LOGOUT, TRUE);
    826 		}
    827 		break;
    828 
    829 	case 3:				/* Target is dropping all connections of session */
    830 		conn->c_session->s_DefaultTime2Wait = ntohs(pdu->pdu_hdr.pduh_p.asynch.Parameter2);
    831 		conn->c_session->s_DefaultTime2Retain = ntohs(pdu->pdu_hdr.pduh_p.asynch.Parameter3);
    832 		kill_session(conn->c_session, ISCSI_STATUS_TARGET_DROP, NO_LOGOUT, TRUE);
    833 		break;
    834 
    835 	case 4:				/* Target requests parameter negotiation */
    836 		start_text_negotiation(conn);
    837 		break;
    838 
    839 	default:
    840 		/* ignore */
    841 		break;
    842 	}
    843 	return 0;
    844 }
    845 
    846 
    847 /*
    848  * receive_reject_pdu
    849  *    Handle receipt of a reject PDU.
    850  *
    851  *    Parameter:
    852  *          conn     The connection
    853  *          pdu      The PDU
    854  */
    855 
    856 STATIC int
    857 receive_reject_pdu(connection_t *conn, pdu_t *pdu)
    858 {
    859 	pdu_header_t *hpdu;
    860 	ccb_t *req_ccb;
    861 	uint32_t status;
    862 
    863 	DEBOUT(("Received Reject PDU, reason = %x, data_len = %d\n",
    864 			pdu->pdu_hdr.pduh_OpcodeSpecific[0], pdu->pdu_temp_data_len));
    865 
    866 	if (pdu->pdu_temp_data_len >= BHS_SIZE) {
    867 		hpdu = (pdu_header_t *) pdu->pdu_temp_data;
    868 		req_ccb = ccb_from_itt(conn, hpdu->pduh_InitiatorTaskTag);
    869 
    870 		DEBC(conn, 9, ("Reject PDU ITT (ccb)= %x (%p)\n",
    871 				hpdu->pduh_InitiatorTaskTag, req_ccb));
    872 		if (!req_ccb) {
    873 			return 0;
    874 		}
    875 		switch (pdu->pdu_hdr.pduh_OpcodeSpecific[0]) {
    876 		case REJECT_DIGEST_ERROR:
    877 			/* don't retransmit data out */
    878 			if ((hpdu->pduh_Opcode & OPCODE_MASK) == IOP_SCSI_Data_out)
    879 				return 0;
    880 			resend_pdu(req_ccb);
    881 			return 0;
    882 
    883 		case REJECT_IMMED_COMMAND:
    884 		case REJECT_LONG_OPERATION:
    885 			resend_pdu(req_ccb);
    886 			return 0;
    887 
    888 		case REJECT_SNACK:
    889 		case REJECT_PROTOCOL_ERROR:
    890 			status = ISCSI_STATUS_PROTOCOL_ERROR;
    891 			break;
    892 
    893 		case REJECT_CMD_NOT_SUPPORTED:
    894 			status = ISCSI_STATUS_CMD_NOT_SUPPORTED;
    895 			break;
    896 
    897 		case REJECT_INVALID_PDU_FIELD:
    898 			status = ISCSI_STATUS_PDU_ERROR;
    899 			break;
    900 
    901 		default:
    902 			status = ISCSI_STATUS_GENERAL_ERROR;
    903 			break;
    904 		}
    905 
    906 		wake_ccb(req_ccb, status);
    907 		handle_connection_error(conn, ISCSI_STATUS_PROTOCOL_ERROR,
    908 							LOGOUT_CONNECTION);
    909 	}
    910 	return 0;
    911 }
    912 
    913 
    914 /*
    915  * receive_task_management_pdu
    916  *    Handle receipt of a task management PDU.
    917  *
    918  *    Parameter:
    919  *          conn     The connection
    920  *          pdu      The PDU
    921  *          req_CCB  The CCB associated with the original request (if any)
    922  */
    923 
    924 STATIC int
    925 receive_task_management_pdu(connection_t *conn, pdu_t *pdu, ccb_t *req_ccb)
    926 {
    927 	uint32_t status;
    928 
    929 	DEBC(conn, 2, ("Received Task Management PDU, response %d, req_ccb %p\n",
    930 			pdu->pdu_hdr.pduh_OpcodeSpecific[0], req_ccb));
    931 
    932 	if (req_ccb != NULL) {
    933 		switch (pdu->pdu_hdr.pduh_OpcodeSpecific[0]) {	/* Response */
    934 		case 0:
    935 			status = ISCSI_STATUS_SUCCESS;
    936 			break;
    937 		case 1:
    938 			status = ISCSI_STATUS_TASK_NOT_FOUND;
    939 			break;
    940 		case 2:
    941 			status = ISCSI_STATUS_LUN_NOT_FOUND;
    942 			break;
    943 		case 3:
    944 			status = ISCSI_STATUS_TASK_ALLEGIANT;
    945 			break;
    946 		case 4:
    947 			status = ISCSI_STATUS_CANT_REASSIGN;
    948 			break;
    949 		case 5:
    950 			status = ISCSI_STATUS_FUNCTION_UNSUPPORTED;
    951 			break;
    952 		case 6:
    953 			status = ISCSI_STATUS_FUNCTION_NOT_AUTHORIZED;
    954 			break;
    955 		case 255:
    956 			status = ISCSI_STATUS_FUNCTION_REJECTED;
    957 			break;
    958 		default:
    959 			status = ISCSI_STATUS_UNKNOWN_REASON;
    960 			break;
    961 		}
    962 		wake_ccb(req_ccb, status);
    963 	}
    964 
    965 	check_StatSN(conn, pdu->pdu_hdr.pduh_p.task_rsp.StatSN, TRUE);
    966 
    967 	return 0;
    968 }
    969 
    970 
    971 /*
    972  * receive_nop_in_pdu
    973  *    Handle receipt of a Nop-In PDU.
    974  *
    975  *    Parameter:
    976  *          conn     The connection
    977  *          pdu      The PDU
    978  *          req_CCB  The CCB associated with the original request (if any)
    979  */
    980 
    981 STATIC int
    982 receive_nop_in_pdu(connection_t *conn, pdu_t *pdu, ccb_t *req_ccb)
    983 {
    984 	DEBC(conn, 10,
    985 		("Received NOP_In PDU, req_ccb=%p, ITT=%x, TTT=%x, StatSN=%u\n",
    986 		req_ccb, pdu->pdu_hdr.pduh_InitiatorTaskTag,
    987 		pdu->pdu_hdr.pduh_p.nop_in.TargetTransferTag,
    988 		ntohl(pdu->pdu_hdr.pduh_p.nop_in.StatSN)));
    989 
    990 	if (pdu->pdu_hdr.pduh_InitiatorTaskTag == 0xffffffff) {
    991 		/* this is a target ping - respond with a pong */
    992 		if (pdu->pdu_hdr.pduh_p.nop_in.TargetTransferTag != 0xffffffff)
    993 			send_nop_out(conn, pdu);
    994 
    995 		/*
    996 		   Any receive resets the connection timeout, but we got a ping, which
    997 		   means that it's likely the other side was waiting for something to
    998 		   happen on the connection. If we aren't idle, send a ping right
    999 		   away to synch counters (don't synch on this ping because other
   1000 		   PDUs may be on the way).
   1001 		 */
   1002 		if (TAILQ_FIRST(&conn->c_ccbs_waiting) != NULL)
   1003 			send_nop_out(conn, NULL);
   1004 	} else if (req_ccb != NULL) {
   1005 		/* this is a solicited ping, check CmdSN for lost commands */
   1006 		/* and advance StatSN */
   1007 		check_CmdSN(conn, pdu->pdu_hdr.pduh_p.nop_in.ExpCmdSN);
   1008 
   1009 		wake_ccb(req_ccb, ISCSI_STATUS_SUCCESS);
   1010 
   1011 		check_StatSN(conn, pdu->pdu_hdr.pduh_p.nop_in.StatSN, TRUE);
   1012 	} else {
   1013 		DEBC(conn, 0, ("Received unsolicted NOP_In, itt=%08x\n",
   1014 		               pdu->pdu_hdr.pduh_InitiatorTaskTag));
   1015 	}
   1016 
   1017 	return 0;
   1018 }
   1019 
   1020 
   1021 /*
   1022  * receive_pdu
   1023  *    Get parameters, call the appropriate handler for a received PDU.
   1024  *
   1025  *    Parameter:
   1026  *          conn     The connection
   1027  *          pdu      The PDU
   1028  *
   1029  *    Returns:    0 on success, nonzero if the connection is broken.
   1030  */
   1031 
   1032 STATIC int
   1033 receive_pdu(connection_t *conn, pdu_t *pdu)
   1034 {
   1035 	ccb_t *req_ccb;
   1036 	int rc;
   1037 	uint32_t MaxCmdSN, ExpCmdSN, digest;
   1038 	session_t *sess = conn->c_session;
   1039 
   1040 	if (conn->c_HeaderDigest) {
   1041 		digest = gen_digest(&pdu->pdu_hdr, BHS_SIZE);
   1042 		if (digest != pdu->pdu_hdr.pduh_HeaderDigest) {
   1043 			DEBOUT(("Header Digest Error: comp = %08x, rx = %08x\n",
   1044 					digest, pdu->pdu_hdr.pduh_HeaderDigest));
   1045 			/* try to skip to next PDU */
   1046 			try_resynch_receive(conn);
   1047 			free_pdu(pdu);
   1048 			return 0;
   1049 		}
   1050 	}
   1051 
   1052 	DEBC(conn, 10, ("Received PDU StatSN=%u, ExpCmdSN=%u MaxCmdSN=%u ExpDataSN=%u\n",
   1053 	     ntohl(pdu->pdu_hdr.pduh_p.response.StatSN),
   1054 	     ntohl(pdu->pdu_hdr.pduh_p.response.ExpCmdSN),
   1055 	     ntohl(pdu->pdu_hdr.pduh_p.response.MaxCmdSN),
   1056 	     ntohl(pdu->pdu_hdr.pduh_p.response.ExpDataSN)));
   1057 
   1058 	req_ccb = ccb_from_itt(conn, pdu->pdu_hdr.pduh_InitiatorTaskTag);
   1059 
   1060 	if (req_ccb != NULL && req_ccb->ccb_data_in && req_ccb->ccb_data_len &&
   1061 		(pdu->pdu_hdr.pduh_Opcode & OPCODE_MASK) == TOP_SCSI_Data_in) {
   1062 		uint32_t dsl, offset;
   1063 
   1064 		dsl = ntoh3(pdu->pdu_hdr.pduh_DataSegmentLength);
   1065 		offset = ntohl(pdu->pdu_hdr.pduh_p.data_in.BufferOffset);
   1066 
   1067 		if ((offset + dsl) > req_ccb->ccb_data_len) {
   1068 			DEBOUT(("Received more data than requested (len %d, offset %d)\n",
   1069 					dsl, offset));
   1070 			handle_connection_error(conn, ISCSI_STATUS_TARGET_ERROR, NO_LOGOUT);
   1071 			return 1;
   1072 		}
   1073 		DEBC(conn, 10,
   1074 			("Received Data in PDU - CCB = %p, Datalen = %d, Offset = %d\n",
   1075 			req_ccb, dsl, offset));
   1076 
   1077 		rc = read_pdu_data(pdu, req_ccb->ccb_data_ptr, offset);
   1078 	} else {
   1079 		rc = read_pdu_data(pdu, NULL, 0);
   1080 	}
   1081 	if (!rc && (conn->c_state <= ST_WINDING_DOWN ||
   1082 		(pdu->pdu_hdr.pduh_Opcode & OPCODE_MASK) == TOP_Logout_Response)) {
   1083 
   1084 		switch (pdu->pdu_hdr.pduh_Opcode & OPCODE_MASK) {
   1085 		case TOP_NOP_In:
   1086 			rc = receive_nop_in_pdu(conn, pdu, req_ccb);
   1087 			break;
   1088 
   1089 		case TOP_SCSI_Response:
   1090 			rc = receive_command_response_pdu(conn, pdu, req_ccb);
   1091 			break;
   1092 
   1093 		case TOP_SCSI_Task_Management:
   1094 			rc = receive_task_management_pdu(conn, pdu, req_ccb);
   1095 			break;
   1096 
   1097 		case TOP_Login_Response:
   1098 			rc = receive_login_pdu(conn, pdu, req_ccb);
   1099 			break;
   1100 
   1101 		case TOP_Text_Response:
   1102 			rc = receive_text_response_pdu(conn, pdu, req_ccb);
   1103 			break;
   1104 
   1105 		case TOP_SCSI_Data_in:
   1106 			rc = receive_data_in_pdu(conn, pdu, req_ccb);
   1107 			break;
   1108 
   1109 		case TOP_Logout_Response:
   1110 			rc = receive_logout_pdu(conn, pdu, req_ccb);
   1111 			break;
   1112 
   1113 		case TOP_R2T:
   1114 			rc = receive_r2t_pdu(conn, pdu, req_ccb);
   1115 			break;
   1116 
   1117 		case TOP_Asynchronous_Message:
   1118 			rc = receive_asynch_pdu(conn, pdu);
   1119 			break;
   1120 
   1121 		case TOP_Reject:
   1122 			rc = receive_reject_pdu(conn, pdu);
   1123 			break;
   1124 
   1125 		default:
   1126 			DEBOUT(("Received Invalid Opcode %x\n", pdu->pdu_hdr.pduh_Opcode));
   1127 			try_resynch_receive(conn);
   1128 			rc = -1;
   1129 			break;
   1130 		}
   1131 	}
   1132 
   1133 	free_pdu(pdu);
   1134 	if (rc)
   1135 		return rc;
   1136 
   1137 	/* MaxCmdSN and ExpCmdSN are in the same place in all received PDUs */
   1138 	ExpCmdSN = ntohl(pdu->pdu_hdr.pduh_p.nop_in.ExpCmdSN);
   1139 	MaxCmdSN = ntohl(pdu->pdu_hdr.pduh_p.nop_in.MaxCmdSN);
   1140 
   1141 	/* received a valid frame, reset timeout */
   1142 	if ((pdu->pdu_hdr.pduh_Opcode & OPCODE_MASK) == TOP_NOP_In &&
   1143 	    TAILQ_EMPTY(&conn->c_ccbs_waiting))
   1144 		connection_timeout_start(conn, conn->c_idle_timeout_val);
   1145 	else
   1146 		connection_timeout_start(conn, CONNECTION_TIMEOUT);
   1147 	conn->c_num_timeouts = 0;
   1148 
   1149 	/* Update session window */
   1150 	mutex_enter(&sess->s_lock);
   1151 	if (sn_a_le_b(ExpCmdSN - 1, MaxCmdSN)) {
   1152 		if (sn_a_lt_b(sess->s_ExpCmdSN, ExpCmdSN))
   1153 			sess->s_ExpCmdSN = ExpCmdSN;
   1154 		if (sn_a_lt_b(sess->s_MaxCmdSN, MaxCmdSN))
   1155 			sess->s_MaxCmdSN = MaxCmdSN;
   1156 	}
   1157 	mutex_exit(&sess->s_lock);
   1158 
   1159 	return 0;
   1160 }
   1161 
   1162 /*****************************************************************************/
   1163 
   1164 /*
   1165  * iscsi_receive_thread
   1166  *    Per connection thread handling receive data.
   1167  *
   1168  *    Parameter:
   1169  *          conn     The connection
   1170  */
   1171 
   1172 void
   1173 iscsi_rcv_thread(void *par)
   1174 {
   1175 	connection_t *conn = (connection_t *) par;
   1176 	pdu_t *pdu;
   1177 	size_t hlen;
   1178 
   1179 	do {
   1180 		while (!conn->c_terminating) {
   1181 			pdu = get_pdu(conn, TRUE);
   1182 			if (pdu == NULL) {
   1183 				KASSERT(conn->c_terminating);
   1184 				break;
   1185 			}
   1186 
   1187 			pdu->pdu_uio.uio_iov = pdu->pdu_io_vec;
   1188 			UIO_SETUP_SYSSPACE(&pdu->pdu_uio);
   1189 			pdu->pdu_uio.uio_iovcnt = 1;
   1190 			pdu->pdu_uio.uio_rw = UIO_READ;
   1191 
   1192 			pdu->pdu_io_vec[0].iov_base = &pdu->pdu_hdr;
   1193 			hlen = (conn->c_HeaderDigest) ? BHS_SIZE + 4 : BHS_SIZE;
   1194 			pdu->pdu_io_vec[0].iov_len = hlen;
   1195 			pdu->pdu_uio.uio_resid = hlen;
   1196 
   1197 			DEBC(conn, 99, ("Receive thread waiting for data\n"));
   1198 			if (my_soo_read(conn, &pdu->pdu_uio, MSG_WAITALL)) {
   1199 				free_pdu(pdu);
   1200 				break;
   1201 			}
   1202 			/* Check again for header digest */
   1203 			/* (it may have changed during the wait) */
   1204 			if (hlen == BHS_SIZE && conn->c_HeaderDigest) {
   1205 				pdu->pdu_uio.uio_iov = pdu->pdu_io_vec;
   1206 				pdu->pdu_uio.uio_iovcnt = 1;
   1207 				pdu->pdu_io_vec[0].iov_base = &pdu->pdu_hdr.pduh_HeaderDigest;
   1208 				pdu->pdu_io_vec[0].iov_len = 4;
   1209 				pdu->pdu_uio.uio_resid = 4;
   1210 				if (my_soo_read(conn, &pdu->pdu_uio, MSG_WAITALL)) {
   1211 					free_pdu(pdu);
   1212 					break;
   1213 				}
   1214 			}
   1215 
   1216 			if (receive_pdu(conn, pdu) > 0) {
   1217 				break;
   1218 			}
   1219 		}
   1220 		mutex_enter(&conn->c_lock);
   1221 		if (!conn->c_destroy) {
   1222 			cv_timedwait(&conn->c_idle_cv, &conn->c_lock, CONNECTION_IDLE_TIMEOUT);
   1223 		}
   1224 		mutex_exit(&conn->c_lock);
   1225 	} while (!conn->c_destroy);
   1226 
   1227 	conn->c_rcvproc = NULL;
   1228 	DEBC(conn, 5, ("Receive thread exits\n"));
   1229 	kthread_exit(0);
   1230 }
   1231