xref: /netbsd-src/sys/dev/iscsi/iscsi_rcv.c (revision 8450a7c42673d65e3b1f6560d3b6ecd317a6cbe8)
1 /*	$NetBSD: iscsi_rcv.c,v 1.22 2016/06/15 04:33:52 mlelstv 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->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->session->ccb[cidx];
143 
144 	if (ccb->ITT != itt) {
145 		DEBC(conn, 0,
146 		     ("ccb_from_itt: received invalid CCB itt %08x != %08x\n",
147 		      itt, ccb->ITT));
148 		return NULL;
149 	}
150 
151 	if (ccb->disp <= CCBDISP_BUSY) {
152 		DEBC(conn, 0,
153 		     ("ccb_from_itt: received CCB with invalid disp %d\n",
154 		      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->connection;
185 
186 	DEB(15, ("read_pdu_data: data segment length = %d\n",
187 		ntoh3(pdu->pdu.DataSegmentLength)));
188 	if (!(len = ntoh3(pdu->pdu.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->connection,
207 				ISCSI_STATUS_NO_RESOURCES, LOGOUT_SESSION);
208 			return 1;
209 		}
210 		pdu->temp_data = data;
211 		pdu->temp_data_len = len;
212 	}
213 
214 	pdu->io_vec[0].iov_base = data + offset;
215 	pdu->io_vec[0].iov_len = len;
216 
217 	uio = &pdu->uio;
218 
219 	uio->uio_iov = 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->DataDigest) {
233 		i = uio->uio_iovcnt++;
234 		pdu->io_vec[i].iov_base = &pdu->data_digest;
235 		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->uio, MSG_WAITALL) != 0) {
241 		return 1;
242 	}
243 	if (conn->DataDigest) {
244 		digest = gen_digest_2(data, len, pad_bytes, pad);
245 
246 		if (digest != pdu->data_digest) {
247 			DEBOUT(("Data Digest Error: comp = %08x, rx = %08x\n",
248 					digest, pdu->data_digest));
249 			switch (pdu->pdu.Opcode & OPCODE_MASK) {
250 			case TOP_SCSI_Response:
251 			case TOP_Text_Response:
252 				send_snack(pdu->connection, pdu, NULL, SNACK_STATUS_NAK);
253 				break;
254 
255 			case TOP_SCSI_Data_in:
256 				send_snack(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->text_data) {
287 		int nlen;
288 		uint8_t *newp;
289 
290 		nlen = req_ccb->text_len + 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->status = ISCSI_STATUS_NO_RESOURCES;
295 			/* XXX where is CCB freed? */
296 			return 1;
297 		}
298 		memcpy(newp, req_ccb->text_data, req_ccb->text_len);
299 		memcpy(&newp[req_ccb->text_len], pdu->temp_data, pdu->temp_data_len);
300 
301 		free(req_ccb->text_data, M_TEMP);
302 		free(pdu->temp_data, M_TEMP);
303 
304 		req_ccb->text_data = NULL;
305 		pdu->temp_data = newp;
306 		pdu->temp_data_len = nlen;
307 	}
308 
309 	if (pdu->pdu.Flags & FLAG_CONTINUE) {
310 		req_ccb->text_data = pdu->temp_data;
311 		req_ccb->text_len = pdu->temp_data_len;
312 		pdu->temp_data = NULL;
313 
314 		acknowledge_text(req_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->StatSN_buf, sn);
338 
339 	if (ack)
340 		ack_sernum(&conn->StatSN_buf, sn);
341 
342 	if (rc != 1) {
343 		if (rc == 0) {
344 			DEBOUT(("Duplicate PDU, ExpSN %d, Recvd: %d\n",
345 				conn->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->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->StatSN_buf.ExpSN, rc - 1));
359 		if (conn->state == ST_FULL_FEATURE &&
360 			conn->session->ErrorRecoveryLevel) {
361 			snack_missing(conn, NULL, SNACK_STATUS_NAK,
362 						  conn->StatSN_buf.ExpSN, rc - 1);
363 		} else {
364 			DEBOUT(("StatSN killing connection (State = %d, "
365 					"ErrorRecoveryLevel = %d)\n",
366 					conn->state, conn->session->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->ccbs_waiting, chain, nxt) {
392 		DEBC(conn, 10,
393 			("CheckCmdSN - CmdSN=%d, ExpCmdSn=%d, waiting=%p, flags=%x\n",
394 			ccb->CmdSN, sn, ccb->pdu_waiting, ccb->flags));
395 		if (ccb->pdu_waiting != NULL &&
396 			sn_a_lt_b(sn, ccb->CmdSN) &&
397 			!(ccb->flags & CCBF_GOT_RSP)) {
398 			DEBC(conn, 1, ("CheckCmdSN resending - CmdSN=%d, ExpCmdSn=%d\n",
399 			               ccb->CmdSN, sn));
400 
401 			ccb->total_tries++;
402 
403 			if (++ccb->num_timeouts > MAX_CCB_TIMEOUTS ||
404 				ccb->total_tries > MAX_CCB_TRIES) {
405 				handle_connection_error(conn,
406 					ISCSI_STATUS_TIMEOUT,
407 					(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.Opcode, pdu->pdu.Flags,
444 			ntohl(pdu->pdu.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.p.login_rsp.StatusClass) {
453 		DEBC(conn, 1, ("Login problem - Class = %x, Detail = %x\n",
454 				pdu->pdu.p.login_rsp.StatusClass,
455 				pdu->pdu.p.login_rsp.StatusDetail));
456 		wake_ccb(req_ccb, ISCSI_STATUS_LOGIN_FAILED);
457 		return 0;
458 	}
459 
460 	if (!conn->StatSN_buf.next_sn) {
461 		conn->StatSN_buf.next_sn = conn->StatSN_buf.ExpSN =
462 			ntohl(pdu->pdu.p.login_rsp.StatSN) + 1;
463 	} else if (check_StatSN(conn, pdu->pdu.p.login_rsp.StatSN, TRUE))
464 		return -1;
465 
466 	if (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.Opcode, pdu->pdu.Flags));
495 
496 	if (check_StatSN(conn, pdu->pdu.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->pdu_waiting != NULL) {
507 		ccb_timeout_start(req_ccb, COMMAND_TIMEOUT);
508 		req_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->flags & CCBF_OTHERCONN) != 0 : 1;
538 	response = pdu->pdu.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.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->session->ErrorRecoveryLevel >= 2 && response != 1) {
565 		connection_t *refconn = (otherconn) ? req_ccb->par : conn;
566 
567 		refconn->Time2Wait = ntohs(pdu->pdu.p.logout_rsp.Time2Wait);
568 		refconn->Time2Retain = ntohs(pdu->pdu.p.logout_rsp.Time2Retain);
569 	}
570 
571 	wake_ccb(req_ccb, status);
572 
573 	if (!otherconn && conn->state == ST_LOGOUT_SENT) {
574 		conn->terminating = ISCSI_STATUS_LOGOUT;
575 		conn->state = ST_SETTLING;
576 		conn->loggedout = (response) ? LOGOUT_FAILED : LOGOUT_SUCCESS;
577 
578 		connection_timeout_stop(conn);
579 
580 		/* let send thread take over next step of cleanup */
581 		cv_broadcast(&conn->conn_cv);
582 	}
583 
584 	return !otherconn;
585 }
586 
587 
588 /*
589  * receive_data_in_pdu
590  *    Handle receipt of a data in PDU.
591  *
592  *    Parameter:
593  *          conn     The connection
594  *          pdu      The PDU
595  *          req_CCB  The CCB associated with the original request (if any)
596  */
597 
598 STATIC int
599 receive_data_in_pdu(connection_t *conn, pdu_t *pdu, ccb_t *req_ccb)
600 {
601 	uint32_t dsl, sn;
602 	bool done;
603 	int rc;
604 
605 	dsl = ntoh3(pdu->pdu.DataSegmentLength);
606 
607 	if (req_ccb == NULL || !req_ccb->data_in || !req_ccb->data_len) {
608 		DEBOUT(("Received Data In, but req_ccb not waiting for it, ignored\n"));
609 		return 0;
610 	}
611 	req_ccb->flags |= CCBF_GOT_RSP;
612 
613 	if (req_ccb->pdu_waiting != NULL) {
614 		ccb_timeout_start(req_ccb, COMMAND_TIMEOUT);
615 		req_ccb->num_timeouts = 0;
616 	}
617 
618 	sn = ntohl(pdu->pdu.p.data_in.DataSN);
619 
620 	if ((rc = add_sernum(&req_ccb->DataSN_buf, sn)) != 1) {
621 		if (!rc) {
622 			return -1;
623 		}
624 		if (rc < 0) {
625 			DEBOUT(("Excessive outstanding Data PDUs\n"));
626 			handle_connection_error(req_ccb->connection,
627 				ISCSI_STATUS_PDUS_LOST, LOGOUT_CONNECTION);
628 			return -1;
629 		}
630 		DEBOUT(("Missing Data PDUs: First %d, num: %d\n",
631 				req_ccb->DataSN_buf.ExpSN, rc - 1));
632 
633 		if (conn->state == ST_FULL_FEATURE &&
634 			conn->session->ErrorRecoveryLevel) {
635 			snack_missing(req_ccb->connection, req_ccb,
636 				SNACK_DATA_NAK, req_ccb->DataSN_buf.ExpSN,
637 				rc - 1);
638 		} else {
639 			DEBOUT(("Killing connection (State=%d, ErrorRecoveryLevel=%d)\n",
640 					conn->state, conn->session->ErrorRecoveryLevel));
641 			handle_connection_error(conn, ISCSI_STATUS_PDUS_LOST,
642 						LOGOUT_CONNECTION);
643 			return -1;
644 		}
645 	}
646 
647 	ack_sernum(&req_ccb->DataSN_buf, sn);
648 
649 	req_ccb->xfer_len += dsl;
650 
651 	if ((pdu->pdu.Flags & FLAG_ACK) && conn->session->ErrorRecoveryLevel)
652 		send_snack(conn, pdu, req_ccb, SNACK_DATA_ACK);
653 
654 	done = sn_empty(&req_ccb->DataSN_buf);
655 
656 	if (pdu->pdu.Flags & FLAG_STATUS) {
657 		DEBC(conn, 10, ("Rx Data In %d, done = %d\n",
658 			req_ccb->CmdSN, done));
659 
660 		req_ccb->flags |= CCBF_COMPLETE;
661 		/* successful transfer, reset recover count */
662 		conn->recover = 0;
663 
664 		if (done)
665 			wake_ccb(req_ccb, ISCSI_STATUS_SUCCESS);
666 		if (check_StatSN(conn, pdu->pdu.p.data_in.StatSN, done))
667 			return -1;
668 
669 	} else if (done && (req_ccb->flags & CCBF_COMPLETE)) {
670 		wake_ccb(req_ccb, ISCSI_STATUS_SUCCESS);
671 	}
672 	/* else wait for command response */
673 
674 	return 0;
675 }
676 
677 
678 /*
679  * receive_r2t_pdu
680  *    Handle receipt of a R2T PDU.
681  *
682  *    Parameter:
683  *          conn     The connection
684  *          pdu      The PDU
685  *          req_CCB  The CCB associated with the original request (if any)
686  */
687 
688 STATIC int
689 receive_r2t_pdu(connection_t *conn, pdu_t *pdu, ccb_t *req_ccb)
690 {
691 
692 	DEBC(conn, 10, ("Received R2T PDU - CCB = %p\n", req_ccb));
693 
694 	if (req_ccb != NULL) {
695 		if (req_ccb->pdu_waiting != NULL) {
696 			ccb_timeout_start(req_ccb, COMMAND_TIMEOUT);
697 			req_ccb->num_timeouts = 0;
698 		}
699 		send_data_out(conn, pdu, req_ccb, CCBDISP_NOWAIT, TRUE);
700 	}
701 
702 	return 0;
703 }
704 
705 
706 /*
707  * receive_command_response_pdu
708  *    Handle receipt of a command response PDU.
709  *
710  *    Parameter:
711  *          conn     The connection
712  *          pdu      The PDU
713  *          req_CCB  The CCB associated with the original request (if any)
714  */
715 
716 STATIC int
717 receive_command_response_pdu(connection_t *conn, pdu_t *pdu, ccb_t *req_ccb)
718 {
719 	int len, rc;
720 	bool done;
721 	uint32_t status;
722 
723 	/* Read any provided data */
724 	if (pdu->temp_data_len && req_ccb != NULL && req_ccb->sense_len_req) {
725 		len = min(req_ccb->sense_len_req,
726 				  ntohs(*((uint16_t *) pdu->temp_data)));
727 		memcpy(req_ccb->sense_ptr, ((uint16_t *) pdu->temp_data) + 1,
728 					len);
729 		req_ccb->sense_len_got = len;
730 	}
731 
732 	if (req_ccb == NULL) {
733 		/* Assume duplicate... */
734 		DEBOUT(("Possibly duplicate command response (no associated CCB)\n"));
735 		return -1;
736 	}
737 
738 	if (req_ccb->pdu_waiting != NULL) {
739 		ccb_timeout_start(req_ccb, COMMAND_TIMEOUT);
740 		req_ccb->num_timeouts = 0;
741 	}
742 
743 	req_ccb->flags |= CCBF_COMPLETE;
744 	conn->recover = 0;	/* successful transfer, reset recover count */
745 
746 	if (pdu->pdu.OpcodeSpecific[0]) {	/* Response */
747 		status = ISCSI_STATUS_TARGET_FAILURE;
748 	} else {
749 		switch (pdu->pdu.OpcodeSpecific[1]) {	/* Status */
750 		case 0x00:
751 			status = ISCSI_STATUS_SUCCESS;
752 			break;
753 
754 		case 0x02:
755 			status = ISCSI_STATUS_CHECK_CONDITION;
756 			break;
757 
758 		case 0x08:
759 			status = ISCSI_STATUS_TARGET_BUSY;
760 			break;
761 
762 		default:
763 			status = ISCSI_STATUS_TARGET_ERROR;
764 			break;
765 		}
766 	}
767 
768 	if (pdu->pdu.Flags & (FLAG_OVERFLOW | FLAG_UNDERFLOW))
769 		req_ccb->residual = ntohl(pdu->pdu.p.response.ResidualCount);
770 
771 	done = status || sn_empty(&req_ccb->DataSN_buf);
772 
773 	DEBC(conn, 10, ("Rx Response: CmdSN %d, rsp = %x, status = %x\n",
774 			req_ccb->CmdSN,
775 			pdu->pdu.OpcodeSpecific[0],
776 			pdu->pdu.OpcodeSpecific[1]));
777 
778 	rc = check_StatSN(conn, pdu->pdu.p.response.StatSN, done);
779 
780 	if (done)
781 		wake_ccb(req_ccb, status);
782 
783 	return rc;
784 }
785 
786 
787 /*
788  * receive_asynch_pdu
789  *    Handle receipt of an asynchronous message PDU.
790  *
791  *    Parameter:
792  *          conn     The connection
793  *          pdu      The PDU
794  */
795 
796 STATIC int
797 receive_asynch_pdu(connection_t *conn, pdu_t *pdu)
798 {
799 
800 	DEBOUT(("Received Asynch PDU, Event %d\n", pdu->pdu.p.asynch.AsyncEvent));
801 
802 	switch (pdu->pdu.p.asynch.AsyncEvent) {
803 	case 0:		   		/* SCSI Asynch event. Don't know what to do with it... */
804 		break;
805 
806 	case 1:		   		/* Target requests logout. */
807 		if (conn->session->active_connections > 1) {
808 			kill_connection(conn, ISCSI_STATUS_TARGET_LOGOUT,
809 						LOGOUT_CONNECTION, FALSE);
810 		} else {
811 			kill_session(conn->session, ISCSI_STATUS_TARGET_LOGOUT,
812 						 LOGOUT_SESSION, FALSE);
813 		}
814 		break;
815 
816 	case 2:				/* Target is dropping connection */
817 		conn = find_connection(conn->session,
818 					ntohs(pdu->pdu.p.asynch.Parameter1));
819 		if (conn != NULL) {
820 			conn->Time2Wait = ntohs(pdu->pdu.p.asynch.Parameter2);
821 			conn->Time2Retain = ntohs(pdu->pdu.p.asynch.Parameter3);
822 			kill_connection(conn, ISCSI_STATUS_TARGET_DROP,
823 					NO_LOGOUT, TRUE);
824 		}
825 		break;
826 
827 	case 3:				/* Target is dropping all connections of session */
828 		conn->session->DefaultTime2Wait = ntohs(pdu->pdu.p.asynch.Parameter2);
829 		conn->session->DefaultTime2Retain = ntohs(pdu->pdu.p.asynch.Parameter3);
830 		kill_session(conn->session, ISCSI_STATUS_TARGET_DROP, NO_LOGOUT, TRUE);
831 		break;
832 
833 	case 4:				/* Target requests parameter negotiation */
834 		start_text_negotiation(conn);
835 		break;
836 
837 	default:
838 		/* ignore */
839 		break;
840 	}
841 	return 0;
842 }
843 
844 
845 /*
846  * receive_reject_pdu
847  *    Handle receipt of a reject PDU.
848  *
849  *    Parameter:
850  *          conn     The connection
851  *          pdu      The PDU
852  */
853 
854 STATIC int
855 receive_reject_pdu(connection_t *conn, pdu_t *pdu)
856 {
857 	pdu_header_t *hpdu;
858 	ccb_t *req_ccb;
859 	uint32_t status;
860 
861 	DEBOUT(("Received Reject PDU, reason = %x, data_len = %d\n",
862 			pdu->pdu.OpcodeSpecific[0], pdu->temp_data_len));
863 
864 	if (pdu->temp_data_len >= BHS_SIZE) {
865 		hpdu = (pdu_header_t *) pdu->temp_data;
866 		req_ccb = ccb_from_itt(conn, hpdu->InitiatorTaskTag);
867 
868 		DEBC(conn, 9, ("Reject PDU ITT (ccb)= %x (%p)\n",
869 				hpdu->InitiatorTaskTag, req_ccb));
870 		if (!req_ccb) {
871 			return 0;
872 		}
873 		switch (pdu->pdu.OpcodeSpecific[0]) {
874 		case REJECT_DIGEST_ERROR:
875 			/* don't retransmit data out */
876 			if ((hpdu->Opcode & OPCODE_MASK) == IOP_SCSI_Data_out)
877 				return 0;
878 			resend_pdu(req_ccb);
879 			return 0;
880 
881 		case REJECT_IMMED_COMMAND:
882 		case REJECT_LONG_OPERATION:
883 			resend_pdu(req_ccb);
884 			return 0;
885 
886 		case REJECT_SNACK:
887 		case REJECT_PROTOCOL_ERROR:
888 			status = ISCSI_STATUS_PROTOCOL_ERROR;
889 			break;
890 
891 		case REJECT_CMD_NOT_SUPPORTED:
892 			status = ISCSI_STATUS_CMD_NOT_SUPPORTED;
893 			break;
894 
895 		case REJECT_INVALID_PDU_FIELD:
896 			status = ISCSI_STATUS_PDU_ERROR;
897 			break;
898 
899 		default:
900 			status = ISCSI_STATUS_GENERAL_ERROR;
901 			break;
902 		}
903 
904 		wake_ccb(req_ccb, status);
905 		handle_connection_error(conn, ISCSI_STATUS_PROTOCOL_ERROR,
906 							LOGOUT_CONNECTION);
907 	}
908 	return 0;
909 }
910 
911 
912 /*
913  * receive_task_management_pdu
914  *    Handle receipt of a task management PDU.
915  *
916  *    Parameter:
917  *          conn     The connection
918  *          pdu      The PDU
919  *          req_CCB  The CCB associated with the original request (if any)
920  */
921 
922 STATIC int
923 receive_task_management_pdu(connection_t *conn, pdu_t *pdu, ccb_t *req_ccb)
924 {
925 	uint32_t status;
926 
927 	DEBC(conn, 2, ("Received Task Management PDU, response %d, req_ccb %p\n",
928 			pdu->pdu.OpcodeSpecific[0], req_ccb));
929 
930 	if (req_ccb != NULL) {
931 		switch (pdu->pdu.OpcodeSpecific[0]) {	/* Response */
932 		case 0:
933 			status = ISCSI_STATUS_SUCCESS;
934 			break;
935 		case 1:
936 			status = ISCSI_STATUS_TASK_NOT_FOUND;
937 			break;
938 		case 2:
939 			status = ISCSI_STATUS_LUN_NOT_FOUND;
940 			break;
941 		case 3:
942 			status = ISCSI_STATUS_TASK_ALLEGIANT;
943 			break;
944 		case 4:
945 			status = ISCSI_STATUS_CANT_REASSIGN;
946 			break;
947 		case 5:
948 			status = ISCSI_STATUS_FUNCTION_UNSUPPORTED;
949 			break;
950 		case 6:
951 			status = ISCSI_STATUS_FUNCTION_NOT_AUTHORIZED;
952 			break;
953 		case 255:
954 			status = ISCSI_STATUS_FUNCTION_REJECTED;
955 			break;
956 		default:
957 			status = ISCSI_STATUS_UNKNOWN_REASON;
958 			break;
959 		}
960 		wake_ccb(req_ccb, status);
961 	}
962 
963 	check_StatSN(conn, pdu->pdu.p.task_rsp.StatSN, TRUE);
964 
965 	return 0;
966 }
967 
968 
969 /*
970  * receive_nop_in_pdu
971  *    Handle receipt of a Nop-In PDU.
972  *
973  *    Parameter:
974  *          conn     The connection
975  *          pdu      The PDU
976  *          req_CCB  The CCB associated with the original request (if any)
977  */
978 
979 STATIC int
980 receive_nop_in_pdu(connection_t *conn, pdu_t *pdu, ccb_t *req_ccb)
981 {
982 	DEBC(conn, 10,
983 		("Received NOP_In PDU, req_ccb=%p, ITT=%x, TTT=%x, StatSN=%u\n",
984 		req_ccb, pdu->pdu.InitiatorTaskTag,
985 		pdu->pdu.p.nop_in.TargetTransferTag,
986 		ntohl(pdu->pdu.p.nop_in.StatSN)));
987 
988 	if (pdu->pdu.InitiatorTaskTag == 0xffffffff) {
989 		/* this is a target ping - respond with a pong */
990 		if (pdu->pdu.p.nop_in.TargetTransferTag != 0xffffffff)
991 			send_nop_out(conn, pdu);
992 
993 		/*
994 		   Any receive resets the connection timeout, but we got a ping, which
995 		   means that it's likely the other side was waiting for something to
996 		   happen on the connection. If we aren't idle, send a ping right
997 		   away to synch counters (don't synch on this ping because other
998 		   PDUs may be on the way).
999 		 */
1000 		if (TAILQ_FIRST(&conn->ccbs_waiting) != NULL)
1001 			send_nop_out(conn, NULL);
1002 	} else if (req_ccb != NULL) {
1003 		/* this is a solicited ping, check CmdSN for lost commands */
1004 		/* and advance StatSN */
1005 		check_CmdSN(conn, pdu->pdu.p.nop_in.ExpCmdSN);
1006 
1007 		wake_ccb(req_ccb, ISCSI_STATUS_SUCCESS);
1008 
1009 		check_StatSN(conn, pdu->pdu.p.nop_in.StatSN, TRUE);
1010 	} else {
1011 		DEBC(conn, 0, ("Received unsolicted NOP_In, itt=%08x\n",
1012 		               pdu->pdu.InitiatorTaskTag));
1013 	}
1014 
1015 	return 0;
1016 }
1017 
1018 
1019 /*
1020  * receive_pdu
1021  *    Get parameters, call the appropriate handler for a received PDU.
1022  *
1023  *    Parameter:
1024  *          conn     The connection
1025  *          pdu      The PDU
1026  *
1027  *    Returns:    0 on success, nonzero if the connection is broken.
1028  */
1029 
1030 STATIC int
1031 receive_pdu(connection_t *conn, pdu_t *pdu)
1032 {
1033 	ccb_t *req_ccb;
1034 	int rc;
1035 	uint32_t MaxCmdSN, ExpCmdSN, digest;
1036 	session_t *sess = conn->session;
1037 
1038 	if (conn->HeaderDigest) {
1039 		digest = gen_digest(&pdu->pdu, BHS_SIZE);
1040 		if (digest != pdu->pdu.HeaderDigest) {
1041 			DEBOUT(("Header Digest Error: comp = %08x, rx = %08x\n",
1042 					digest, pdu->pdu.HeaderDigest));
1043 			/* try to skip to next PDU */
1044 			try_resynch_receive(conn);
1045 			free_pdu(pdu);
1046 			return 0;
1047 		}
1048 	}
1049 
1050 	DEBC(conn, 10, ("Received PDU StatSN=%u, ExpCmdSN=%u MaxCmdSN=%u ExpDataSN=%u\n",
1051 	     ntohl(pdu->pdu.p.response.StatSN),
1052 	     ntohl(pdu->pdu.p.response.ExpCmdSN),
1053 	     ntohl(pdu->pdu.p.response.MaxCmdSN),
1054 	     ntohl(pdu->pdu.p.response.ExpDataSN)));
1055 
1056 	req_ccb = ccb_from_itt(conn, pdu->pdu.InitiatorTaskTag);
1057 
1058 	if (req_ccb != NULL && req_ccb->data_in && req_ccb->data_len &&
1059 		(pdu->pdu.Opcode & OPCODE_MASK) == TOP_SCSI_Data_in) {
1060 		uint32_t dsl, offset;
1061 
1062 		dsl = ntoh3(pdu->pdu.DataSegmentLength);
1063 		offset = ntohl(pdu->pdu.p.data_in.BufferOffset);
1064 
1065 		if ((offset + dsl) > req_ccb->data_len) {
1066 			DEBOUT(("Received more data than requested (len %d, offset %d)\n",
1067 					dsl, offset));
1068 			handle_connection_error(conn, ISCSI_STATUS_TARGET_ERROR, NO_LOGOUT);
1069 			return 1;
1070 		}
1071 		DEBC(conn, 10,
1072 			("Received Data in PDU - CCB = %p, Datalen = %d, Offset = %d\n",
1073 			req_ccb, dsl, offset));
1074 
1075 		rc = read_pdu_data(pdu, req_ccb->data_ptr, offset);
1076 	} else {
1077 		rc = read_pdu_data(pdu, NULL, 0);
1078 	}
1079 	if (!rc && (conn->state <= ST_WINDING_DOWN ||
1080 		(pdu->pdu.Opcode & OPCODE_MASK) == TOP_Logout_Response)) {
1081 
1082 		switch (pdu->pdu.Opcode & OPCODE_MASK) {
1083 		case TOP_NOP_In:
1084 			rc = receive_nop_in_pdu(conn, pdu, req_ccb);
1085 			break;
1086 
1087 		case TOP_SCSI_Response:
1088 			rc = receive_command_response_pdu(conn, pdu, req_ccb);
1089 			break;
1090 
1091 		case TOP_SCSI_Task_Management:
1092 			rc = receive_task_management_pdu(conn, pdu, req_ccb);
1093 			break;
1094 
1095 		case TOP_Login_Response:
1096 			rc = receive_login_pdu(conn, pdu, req_ccb);
1097 			break;
1098 
1099 		case TOP_Text_Response:
1100 			rc = receive_text_response_pdu(conn, pdu, req_ccb);
1101 			break;
1102 
1103 		case TOP_SCSI_Data_in:
1104 			rc = receive_data_in_pdu(conn, pdu, req_ccb);
1105 			break;
1106 
1107 		case TOP_Logout_Response:
1108 			rc = receive_logout_pdu(conn, pdu, req_ccb);
1109 			break;
1110 
1111 		case TOP_R2T:
1112 			rc = receive_r2t_pdu(conn, pdu, req_ccb);
1113 			break;
1114 
1115 		case TOP_Asynchronous_Message:
1116 			rc = receive_asynch_pdu(conn, pdu);
1117 			break;
1118 
1119 		case TOP_Reject:
1120 			rc = receive_reject_pdu(conn, pdu);
1121 			break;
1122 
1123 		default:
1124 			DEBOUT(("Received Invalid Opcode %x\n", pdu->pdu.Opcode));
1125 			try_resynch_receive(conn);
1126 			rc = -1;
1127 			break;
1128 		}
1129 	}
1130 
1131 	free_pdu(pdu);
1132 	if (rc)
1133 		return rc;
1134 
1135 	/* MaxCmdSN and ExpCmdSN are in the same place in all received PDUs */
1136 	ExpCmdSN = ntohl(pdu->pdu.p.nop_in.ExpCmdSN);
1137 	MaxCmdSN = ntohl(pdu->pdu.p.nop_in.MaxCmdSN);
1138 
1139 	/* received a valid frame, reset timeout */
1140 	if ((pdu->pdu.Opcode & OPCODE_MASK) == TOP_NOP_In &&
1141 	    TAILQ_EMPTY(&conn->ccbs_waiting))
1142 		connection_timeout_start(conn, conn->idle_timeout_val);
1143 	else
1144 		connection_timeout_start(conn, CONNECTION_TIMEOUT);
1145 	conn->num_timeouts = 0;
1146 
1147 	/* Update session window */
1148 	mutex_enter(&sess->lock);
1149 	if (sn_a_le_b(ExpCmdSN - 1, MaxCmdSN)) {
1150 		if (sn_a_lt_b(sess->ExpCmdSN, ExpCmdSN))
1151 			sess->ExpCmdSN = ExpCmdSN;
1152 		if (sn_a_lt_b(sess->MaxCmdSN, MaxCmdSN))
1153 			sess->MaxCmdSN = MaxCmdSN;
1154 	}
1155 	mutex_exit(&sess->lock);
1156 
1157 	return 0;
1158 }
1159 
1160 /*****************************************************************************/
1161 
1162 /*
1163  * iscsi_receive_thread
1164  *    Per connection thread handling receive data.
1165  *
1166  *    Parameter:
1167  *          conn     The connection
1168  */
1169 
1170 void
1171 iscsi_rcv_thread(void *par)
1172 {
1173 	connection_t *conn = (connection_t *) par;
1174 	pdu_t *pdu;
1175 	size_t hlen;
1176 
1177 	do {
1178 		while (!conn->terminating) {
1179 			pdu = get_pdu(conn, TRUE);
1180 			if (pdu == NULL) {
1181 				KASSERT(conn->terminating);
1182 				break;
1183 			}
1184 
1185 			pdu->uio.uio_iov = pdu->io_vec;
1186 			UIO_SETUP_SYSSPACE(&pdu->uio);
1187 			pdu->uio.uio_iovcnt = 1;
1188 			pdu->uio.uio_rw = UIO_READ;
1189 
1190 			pdu->io_vec[0].iov_base = &pdu->pdu;
1191 			hlen = (conn->HeaderDigest) ? BHS_SIZE + 4 : BHS_SIZE;
1192 			pdu->io_vec[0].iov_len = hlen;
1193 			pdu->uio.uio_resid = hlen;
1194 
1195 			DEBC(conn, 99, ("Receive thread waiting for data\n"));
1196 			if (my_soo_read(conn, &pdu->uio, MSG_WAITALL)) {
1197 				free_pdu(pdu);
1198 				break;
1199 			}
1200 			/* Check again for header digest */
1201 			/* (it may have changed during the wait) */
1202 			if (hlen == BHS_SIZE && conn->HeaderDigest) {
1203 				pdu->uio.uio_iov = pdu->io_vec;
1204 				pdu->uio.uio_iovcnt = 1;
1205 				pdu->io_vec[0].iov_base = &pdu->pdu.HeaderDigest;
1206 				pdu->io_vec[0].iov_len = 4;
1207 				pdu->uio.uio_resid = 4;
1208 				if (my_soo_read(conn, &pdu->uio, MSG_WAITALL)) {
1209 					free_pdu(pdu);
1210 					break;
1211 				}
1212 			}
1213 
1214 			if (receive_pdu(conn, pdu) > 0) {
1215 				break;
1216 			}
1217 		}
1218 		mutex_enter(&conn->lock);
1219 		if (!conn->destroy) {
1220 			cv_timedwait(&conn->idle_cv, &conn->lock, CONNECTION_IDLE_TIMEOUT);
1221 		}
1222 		mutex_exit(&conn->lock);
1223 	} while (!conn->destroy);
1224 
1225 	conn->rcvproc = NULL;
1226 	DEBC(conn, 5, ("Receive thread exits\n"));
1227 	kthread_exit(0);
1228 }
1229