1/*
2 * iSCSI lib functions
3 *
4 * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
5 * Copyright (C) 2004 - 2006 Mike Christie
6 * Copyright (C) 2004 - 2005 Dmitry Yusupov
7 * Copyright (C) 2004 - 2005 Alex Aizman
8 * maintained by open-iscsi@googlegroups.com
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23 */
24#include <linux/types.h>
25#include <linux/mutex.h>
26#include <linux/kfifo.h>
27#include <linux/delay.h>
28#include <asm/unaligned.h>
29#include <net/tcp.h>
30#include <scsi/scsi_cmnd.h>
31#include <scsi/scsi_device.h>
32#include <scsi/scsi_eh.h>
33#include <scsi/scsi_tcq.h>
34#include <scsi/scsi_host.h>
35#include <scsi/scsi.h>
36#include <scsi/iscsi_proto.h>
37#include <scsi/scsi_transport.h>
38#include <scsi/scsi_transport_iscsi.h>
39#include <scsi/libiscsi.h>
40
41struct iscsi_session *
42class_to_transport_session(struct iscsi_cls_session *cls_session)
43{
44	struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
45	return iscsi_hostdata(shost->hostdata);
46}
47EXPORT_SYMBOL_GPL(class_to_transport_session);
48
49#define INVALID_SN_DELTA	0xffff
50
51int
52iscsi_check_assign_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
53{
54	uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
55	uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);
56
57	if (max_cmdsn < exp_cmdsn -1 &&
58	    max_cmdsn > exp_cmdsn - INVALID_SN_DELTA)
59		return ISCSI_ERR_MAX_CMDSN;
60	if (max_cmdsn > session->max_cmdsn ||
61	    max_cmdsn < session->max_cmdsn - INVALID_SN_DELTA)
62		session->max_cmdsn = max_cmdsn;
63	if (exp_cmdsn > session->exp_cmdsn ||
64	    exp_cmdsn < session->exp_cmdsn - INVALID_SN_DELTA)
65		session->exp_cmdsn = exp_cmdsn;
66
67	return 0;
68}
69EXPORT_SYMBOL_GPL(iscsi_check_assign_cmdsn);
70
71void iscsi_prep_unsolicit_data_pdu(struct iscsi_cmd_task *ctask,
72				   struct iscsi_data *hdr)
73{
74	struct iscsi_conn *conn = ctask->conn;
75
76	memset(hdr, 0, sizeof(struct iscsi_data));
77	hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
78	hdr->datasn = cpu_to_be32(ctask->unsol_datasn);
79	ctask->unsol_datasn++;
80	hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
81	memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
82
83	hdr->itt = ctask->hdr->itt;
84	hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
85	hdr->offset = cpu_to_be32(ctask->unsol_offset);
86
87	if (ctask->unsol_count > conn->max_xmit_dlength) {
88		hton24(hdr->dlength, conn->max_xmit_dlength);
89		ctask->data_count = conn->max_xmit_dlength;
90		ctask->unsol_offset += ctask->data_count;
91		hdr->flags = 0;
92	} else {
93		hton24(hdr->dlength, ctask->unsol_count);
94		ctask->data_count = ctask->unsol_count;
95		hdr->flags = ISCSI_FLAG_CMD_FINAL;
96	}
97}
98EXPORT_SYMBOL_GPL(iscsi_prep_unsolicit_data_pdu);
99
100/**
101 * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
102 * @ctask: iscsi cmd task
103 *
104 * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
105 * fields like dlength or final based on how much data it sends
106 */
107static void iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask)
108{
109	struct iscsi_conn *conn = ctask->conn;
110	struct iscsi_session *session = conn->session;
111	struct iscsi_cmd *hdr = ctask->hdr;
112	struct scsi_cmnd *sc = ctask->sc;
113
114        hdr->opcode = ISCSI_OP_SCSI_CMD;
115        hdr->flags = ISCSI_ATTR_SIMPLE;
116        int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
117        hdr->itt = build_itt(ctask->itt, conn->id, session->age);
118        hdr->data_length = cpu_to_be32(sc->request_bufflen);
119        hdr->cmdsn = cpu_to_be32(session->cmdsn);
120        session->cmdsn++;
121        hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
122        memcpy(hdr->cdb, sc->cmnd, sc->cmd_len);
123        memset(&hdr->cdb[sc->cmd_len], 0, MAX_COMMAND_SIZE - sc->cmd_len);
124
125	ctask->data_count = 0;
126	if (sc->sc_data_direction == DMA_TO_DEVICE) {
127		hdr->flags |= ISCSI_FLAG_CMD_WRITE;
128		/*
129		 * Write counters:
130		 *
131		 *	imm_count	bytes to be sent right after
132		 *			SCSI PDU Header
133		 *
134		 *	unsol_count	bytes(as Data-Out) to be sent
135		 *			without	R2T ack right after
136		 *			immediate data
137		 *
138		 *	r2t_data_count	bytes to be sent via R2T ack's
139		 *
140		 *      pad_count       bytes to be sent as zero-padding
141		 */
142		ctask->imm_count = 0;
143		ctask->unsol_count = 0;
144		ctask->unsol_offset = 0;
145		ctask->unsol_datasn = 0;
146
147		if (session->imm_data_en) {
148			if (ctask->total_length >= session->first_burst)
149				ctask->imm_count = min(session->first_burst,
150							conn->max_xmit_dlength);
151			else
152				ctask->imm_count = min(ctask->total_length,
153							conn->max_xmit_dlength);
154			hton24(ctask->hdr->dlength, ctask->imm_count);
155		} else
156			zero_data(ctask->hdr->dlength);
157
158		if (!session->initial_r2t_en) {
159			ctask->unsol_count = min(session->first_burst,
160				ctask->total_length) - ctask->imm_count;
161			ctask->unsol_offset = ctask->imm_count;
162		}
163
164		if (!ctask->unsol_count)
165			/* No unsolicit Data-Out's */
166			ctask->hdr->flags |= ISCSI_FLAG_CMD_FINAL;
167	} else {
168		ctask->datasn = 0;
169		hdr->flags |= ISCSI_FLAG_CMD_FINAL;
170		zero_data(hdr->dlength);
171
172		if (sc->sc_data_direction == DMA_FROM_DEVICE)
173			hdr->flags |= ISCSI_FLAG_CMD_READ;
174	}
175
176	conn->scsicmd_pdus_cnt++;
177}
178EXPORT_SYMBOL_GPL(iscsi_prep_scsi_cmd_pdu);
179
180/**
181 * iscsi_complete_command - return command back to scsi-ml
182 * @ctask: iscsi cmd task
183 *
184 * Must be called with session lock.
185 * This function returns the scsi command to scsi-ml and returns
186 * the cmd task to the pool of available cmd tasks.
187 */
188static void iscsi_complete_command(struct iscsi_cmd_task *ctask)
189{
190	struct iscsi_session *session = ctask->conn->session;
191	struct scsi_cmnd *sc = ctask->sc;
192
193	ctask->state = ISCSI_TASK_COMPLETED;
194	ctask->sc = NULL;
195	/* SCSI eh reuses commands to verify us */
196	sc->SCp.ptr = NULL;
197	list_del_init(&ctask->running);
198	__kfifo_put(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
199	sc->scsi_done(sc);
200}
201
202static void __iscsi_get_ctask(struct iscsi_cmd_task *ctask)
203{
204	atomic_inc(&ctask->refcount);
205}
206
207static void iscsi_get_ctask(struct iscsi_cmd_task *ctask)
208{
209	spin_lock_bh(&ctask->conn->session->lock);
210	__iscsi_get_ctask(ctask);
211	spin_unlock_bh(&ctask->conn->session->lock);
212}
213
214static void __iscsi_put_ctask(struct iscsi_cmd_task *ctask)
215{
216	if (atomic_dec_and_test(&ctask->refcount))
217		iscsi_complete_command(ctask);
218}
219
220static void iscsi_put_ctask(struct iscsi_cmd_task *ctask)
221{
222	spin_lock_bh(&ctask->conn->session->lock);
223	__iscsi_put_ctask(ctask);
224	spin_unlock_bh(&ctask->conn->session->lock);
225}
226
227/**
228 * iscsi_cmd_rsp - SCSI Command Response processing
229 * @conn: iscsi connection
230 * @hdr: iscsi header
231 * @ctask: scsi command task
232 * @data: cmd data buffer
233 * @datalen: len of buffer
234 *
235 * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
236 * then completes the command and task.
237 **/
238static int iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
239			      struct iscsi_cmd_task *ctask, char *data,
240			      int datalen)
241{
242	int rc;
243	struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
244	struct iscsi_session *session = conn->session;
245	struct scsi_cmnd *sc = ctask->sc;
246
247	rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
248	if (rc) {
249		sc->result = DID_ERROR << 16;
250		goto out;
251	}
252
253	conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
254
255	sc->result = (DID_OK << 16) | rhdr->cmd_status;
256
257	if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
258		sc->result = DID_ERROR << 16;
259		goto out;
260	}
261
262	if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
263		uint16_t senselen;
264
265		if (datalen < 2) {
266invalid_datalen:
267			printk(KERN_ERR "iscsi: Got CHECK_CONDITION but "
268			       "invalid data buffer size of %d\n", datalen);
269			sc->result = DID_BAD_TARGET << 16;
270			goto out;
271		}
272
273		senselen = be16_to_cpu(get_unaligned((__be16 *) data));
274		if (datalen < senselen)
275			goto invalid_datalen;
276
277		memcpy(sc->sense_buffer, data + 2,
278		       min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
279		debug_scsi("copied %d bytes of sense\n",
280			   min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
281	}
282
283	if (sc->sc_data_direction == DMA_TO_DEVICE)
284		goto out;
285
286	if (rhdr->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
287		int res_count = be32_to_cpu(rhdr->residual_count);
288
289		if (res_count > 0 && res_count <= sc->request_bufflen)
290			sc->resid = res_count;
291		else
292			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
293	} else if (rhdr->flags & ISCSI_FLAG_CMD_BIDI_UNDERFLOW)
294		sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
295	else if (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW)
296		sc->resid = be32_to_cpu(rhdr->residual_count);
297
298out:
299	debug_scsi("done [sc %lx res %d itt 0x%x]\n",
300		   (long)sc, sc->result, ctask->itt);
301	conn->scsirsp_pdus_cnt++;
302
303	__iscsi_put_ctask(ctask);
304	return rc;
305}
306
307static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
308{
309	struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
310
311	conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
312	conn->tmfrsp_pdus_cnt++;
313
314	if (conn->tmabort_state != TMABORT_INITIAL)
315		return;
316
317	if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
318		conn->tmabort_state = TMABORT_SUCCESS;
319	else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
320		conn->tmabort_state = TMABORT_NOT_FOUND;
321	else
322		conn->tmabort_state = TMABORT_FAILED;
323	wake_up(&conn->ehwait);
324}
325
326static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
327			       char *data, int datalen)
328{
329	struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
330	struct iscsi_hdr rejected_pdu;
331	uint32_t itt;
332
333	conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
334
335	if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
336		if (ntoh24(reject->dlength) > datalen)
337			return ISCSI_ERR_PROTO;
338
339		if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
340			memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
341			itt = get_itt(rejected_pdu.itt);
342			printk(KERN_ERR "itt 0x%x had pdu (op 0x%x) rejected "
343				"due to DataDigest error.\n", itt,
344				rejected_pdu.opcode);
345		}
346	}
347	return 0;
348}
349
350/**
351 * __iscsi_complete_pdu - complete pdu
352 * @conn: iscsi conn
353 * @hdr: iscsi header
354 * @data: data buffer
355 * @datalen: len of data buffer
356 *
357 * Completes pdu processing by freeing any resources allocated at
358 * queuecommand or send generic. session lock must be held and verify
359 * itt must have been called.
360 */
361int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
362			 char *data, int datalen)
363{
364	struct iscsi_session *session = conn->session;
365	int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
366	struct iscsi_cmd_task *ctask;
367	struct iscsi_mgmt_task *mtask;
368	uint32_t itt;
369
370	if (hdr->itt != RESERVED_ITT)
371		itt = get_itt(hdr->itt);
372	else
373		itt = ~0U;
374
375	if (itt < session->cmds_max) {
376		ctask = session->cmds[itt];
377
378		debug_scsi("cmdrsp [op 0x%x cid %d itt 0x%x len %d]\n",
379			   opcode, conn->id, ctask->itt, datalen);
380
381		switch(opcode) {
382		case ISCSI_OP_SCSI_CMD_RSP:
383			BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
384			rc = iscsi_scsi_cmd_rsp(conn, hdr, ctask, data,
385						datalen);
386			break;
387		case ISCSI_OP_SCSI_DATA_IN:
388			BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
389			if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
390				conn->scsirsp_pdus_cnt++;
391				__iscsi_put_ctask(ctask);
392			}
393			break;
394		case ISCSI_OP_R2T:
395			/* LLD handles this for now */
396			break;
397		default:
398			rc = ISCSI_ERR_BAD_OPCODE;
399			break;
400		}
401	} else if (itt >= ISCSI_MGMT_ITT_OFFSET &&
402		   itt < ISCSI_MGMT_ITT_OFFSET + session->mgmtpool_max) {
403		mtask = session->mgmt_cmds[itt - ISCSI_MGMT_ITT_OFFSET];
404
405		debug_scsi("immrsp [op 0x%x cid %d itt 0x%x len %d]\n",
406			   opcode, conn->id, mtask->itt, datalen);
407
408		rc = iscsi_check_assign_cmdsn(session,
409					      (struct iscsi_nopin*)hdr);
410		if (rc)
411			goto done;
412
413		switch(opcode) {
414		case ISCSI_OP_LOGOUT_RSP:
415			if (datalen) {
416				rc = ISCSI_ERR_PROTO;
417				break;
418			}
419			conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
420			/* fall through */
421		case ISCSI_OP_LOGIN_RSP:
422		case ISCSI_OP_TEXT_RSP:
423			/*
424			 * login related PDU's exp_statsn is handled in
425			 * userspace
426			 */
427			if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
428				rc = ISCSI_ERR_CONN_FAILED;
429			list_del(&mtask->running);
430			if (conn->login_mtask != mtask)
431				__kfifo_put(session->mgmtpool.queue,
432					    (void*)&mtask, sizeof(void*));
433			break;
434		case ISCSI_OP_SCSI_TMFUNC_RSP:
435			if (datalen) {
436				rc = ISCSI_ERR_PROTO;
437				break;
438			}
439
440			iscsi_tmf_rsp(conn, hdr);
441			break;
442		case ISCSI_OP_NOOP_IN:
443			if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
444				rc = ISCSI_ERR_PROTO;
445				break;
446			}
447			conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
448
449			if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
450				rc = ISCSI_ERR_CONN_FAILED;
451			list_del(&mtask->running);
452			if (conn->login_mtask != mtask)
453				__kfifo_put(session->mgmtpool.queue,
454					    (void*)&mtask, sizeof(void*));
455			break;
456		default:
457			rc = ISCSI_ERR_BAD_OPCODE;
458			break;
459		}
460	} else if (itt == ~0U) {
461		rc = iscsi_check_assign_cmdsn(session,
462					     (struct iscsi_nopin*)hdr);
463		if (rc)
464			goto done;
465
466		switch(opcode) {
467		case ISCSI_OP_NOOP_IN:
468			if (datalen) {
469				rc = ISCSI_ERR_PROTO;
470				break;
471			}
472
473			if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
474				break;
475
476			if (iscsi_recv_pdu(conn->cls_conn, hdr, NULL, 0))
477				rc = ISCSI_ERR_CONN_FAILED;
478			break;
479		case ISCSI_OP_REJECT:
480			rc = iscsi_handle_reject(conn, hdr, data, datalen);
481			break;
482		case ISCSI_OP_ASYNC_EVENT:
483			conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
484			if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
485				rc = ISCSI_ERR_CONN_FAILED;
486			break;
487		default:
488			rc = ISCSI_ERR_BAD_OPCODE;
489			break;
490		}
491	} else
492		rc = ISCSI_ERR_BAD_ITT;
493
494done:
495	return rc;
496}
497EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
498
499int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
500		       char *data, int datalen)
501{
502	int rc;
503
504	spin_lock(&conn->session->lock);
505	rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
506	spin_unlock(&conn->session->lock);
507	return rc;
508}
509EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
510
511/* verify itt (itt encoding: age+cid+itt) */
512int iscsi_verify_itt(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
513		     uint32_t *ret_itt)
514{
515	struct iscsi_session *session = conn->session;
516	struct iscsi_cmd_task *ctask;
517	uint32_t itt;
518
519	if (hdr->itt != RESERVED_ITT) {
520		if (((__force u32)hdr->itt & ISCSI_AGE_MASK) !=
521		    (session->age << ISCSI_AGE_SHIFT)) {
522			printk(KERN_ERR "iscsi: received itt %x expected "
523				"session age (%x)\n", (__force u32)hdr->itt,
524				session->age & ISCSI_AGE_MASK);
525			return ISCSI_ERR_BAD_ITT;
526		}
527
528		if (((__force u32)hdr->itt & ISCSI_CID_MASK) !=
529		    (conn->id << ISCSI_CID_SHIFT)) {
530			printk(KERN_ERR "iscsi: received itt %x, expected "
531				"CID (%x)\n", (__force u32)hdr->itt, conn->id);
532			return ISCSI_ERR_BAD_ITT;
533		}
534		itt = get_itt(hdr->itt);
535	} else
536		itt = ~0U;
537
538	if (itt < session->cmds_max) {
539		ctask = session->cmds[itt];
540
541		if (!ctask->sc) {
542			printk(KERN_INFO "iscsi: dropping ctask with "
543			       "itt 0x%x\n", ctask->itt);
544			/* force drop */
545			return ISCSI_ERR_NO_SCSI_CMD;
546		}
547
548		if (ctask->sc->SCp.phase != session->age) {
549			printk(KERN_ERR "iscsi: ctask's session age %d, "
550				"expected %d\n", ctask->sc->SCp.phase,
551				session->age);
552			return ISCSI_ERR_SESSION_FAILED;
553		}
554	}
555
556	*ret_itt = itt;
557	return 0;
558}
559EXPORT_SYMBOL_GPL(iscsi_verify_itt);
560
561void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
562{
563	struct iscsi_session *session = conn->session;
564	unsigned long flags;
565
566	spin_lock_irqsave(&session->lock, flags);
567	if (session->state == ISCSI_STATE_FAILED) {
568		spin_unlock_irqrestore(&session->lock, flags);
569		return;
570	}
571
572	if (conn->stop_stage == 0)
573		session->state = ISCSI_STATE_FAILED;
574	spin_unlock_irqrestore(&session->lock, flags);
575	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
576	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
577	iscsi_conn_error(conn->cls_conn, err);
578}
579EXPORT_SYMBOL_GPL(iscsi_conn_failure);
580
581static int iscsi_xmit_mtask(struct iscsi_conn *conn)
582{
583	struct iscsi_hdr *hdr = conn->mtask->hdr;
584	int rc, was_logout = 0;
585
586	if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT) {
587		conn->session->state = ISCSI_STATE_IN_RECOVERY;
588		iscsi_block_session(session_to_cls(conn->session));
589		was_logout = 1;
590	}
591	rc = conn->session->tt->xmit_mgmt_task(conn, conn->mtask);
592	if (rc)
593		return rc;
594
595	/* done with this in-progress mtask */
596	conn->mtask = NULL;
597
598	if (was_logout) {
599		set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
600		return -ENODATA;
601	}
602	return 0;
603}
604
605/**
606 * iscsi_data_xmit - xmit any command into the scheduled connection
607 * @conn: iscsi connection
608 *
609 * Notes:
610 *	The function can return -EAGAIN in which case the caller must
611 *	re-schedule it again later or recover. '0' return code means
612 *	successful xmit.
613 **/
614static int iscsi_data_xmit(struct iscsi_conn *conn)
615{
616	struct iscsi_transport *tt;
617	int rc = 0;
618
619	if (unlikely(conn->suspend_tx)) {
620		debug_scsi("conn %d Tx suspended!\n", conn->id);
621		return -ENODATA;
622	}
623	tt = conn->session->tt;
624
625	/*
626	 * Transmit in the following order:
627	 *
628	 * 1) un-finished xmit (ctask or mtask)
629	 * 2) immediate control PDUs
630	 * 3) write data
631	 * 4) SCSI commands
632	 * 5) non-immediate control PDUs
633	 *
634	 * No need to lock around __kfifo_get as long as
635	 * there's one producer and one consumer.
636	 */
637
638	BUG_ON(conn->ctask && conn->mtask);
639
640	if (conn->ctask) {
641		iscsi_get_ctask(conn->ctask);
642		rc = tt->xmit_cmd_task(conn, conn->ctask);
643		iscsi_put_ctask(conn->ctask);
644		if (rc)
645			goto again;
646		/* done with this in-progress ctask */
647		conn->ctask = NULL;
648	}
649	if (conn->mtask) {
650		rc = iscsi_xmit_mtask(conn);
651	        if (rc)
652		        goto again;
653	}
654
655	/* process immediate first */
656        if (unlikely(__kfifo_len(conn->immqueue))) {
657	        while (__kfifo_get(conn->immqueue, (void*)&conn->mtask,
658			           sizeof(void*))) {
659			spin_lock_bh(&conn->session->lock);
660			list_add_tail(&conn->mtask->running,
661				      &conn->mgmt_run_list);
662			spin_unlock_bh(&conn->session->lock);
663			rc = iscsi_xmit_mtask(conn);
664		        if (rc)
665			        goto again;
666	        }
667	}
668
669	/* process command queue */
670	spin_lock_bh(&conn->session->lock);
671	while (!list_empty(&conn->xmitqueue)) {
672		/*
673		 * iscsi tcp may readd the task to the xmitqueue to send
674		 * write data
675		 */
676		conn->ctask = list_entry(conn->xmitqueue.next,
677					 struct iscsi_cmd_task, running);
678		conn->ctask->state = ISCSI_TASK_RUNNING;
679		list_move_tail(conn->xmitqueue.next, &conn->run_list);
680		__iscsi_get_ctask(conn->ctask);
681		spin_unlock_bh(&conn->session->lock);
682
683		rc = tt->xmit_cmd_task(conn, conn->ctask);
684
685		spin_lock_bh(&conn->session->lock);
686		__iscsi_put_ctask(conn->ctask);
687		if (rc) {
688			spin_unlock_bh(&conn->session->lock);
689			goto again;
690		}
691	}
692	spin_unlock_bh(&conn->session->lock);
693	/* done with this ctask */
694	conn->ctask = NULL;
695
696	/* process the rest control plane PDUs, if any */
697        if (unlikely(__kfifo_len(conn->mgmtqueue))) {
698	        while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask,
699			           sizeof(void*))) {
700			spin_lock_bh(&conn->session->lock);
701			list_add_tail(&conn->mtask->running,
702				      &conn->mgmt_run_list);
703			spin_unlock_bh(&conn->session->lock);
704			rc = iscsi_xmit_mtask(conn);
705		        if (rc)
706			        goto again;
707	        }
708	}
709
710	return -ENODATA;
711
712again:
713	if (unlikely(conn->suspend_tx))
714		return -ENODATA;
715
716	return rc;
717}
718
719static void iscsi_xmitworker(struct work_struct *work)
720{
721	struct iscsi_conn *conn =
722		container_of(work, struct iscsi_conn, xmitwork);
723	int rc;
724	/*
725	 * serialize Xmit worker on a per-connection basis.
726	 */
727	mutex_lock(&conn->xmitmutex);
728	do {
729		rc = iscsi_data_xmit(conn);
730	} while (rc >= 0 || rc == -EAGAIN);
731	mutex_unlock(&conn->xmitmutex);
732}
733
734enum {
735	FAILURE_BAD_HOST = 1,
736	FAILURE_SESSION_FAILED,
737	FAILURE_SESSION_FREED,
738	FAILURE_WINDOW_CLOSED,
739	FAILURE_OOM,
740	FAILURE_SESSION_TERMINATE,
741	FAILURE_SESSION_IN_RECOVERY,
742	FAILURE_SESSION_RECOVERY_TIMEOUT,
743};
744
745int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
746{
747	struct Scsi_Host *host;
748	int reason = 0;
749	struct iscsi_session *session;
750	struct iscsi_conn *conn;
751	struct iscsi_cmd_task *ctask = NULL;
752
753	sc->scsi_done = done;
754	sc->result = 0;
755	sc->SCp.ptr = NULL;
756
757	host = sc->device->host;
758	session = iscsi_hostdata(host->hostdata);
759
760	spin_lock(&session->lock);
761
762	/*
763	 * ISCSI_STATE_FAILED is a temp. state. The recovery
764	 * code will decide what is best to do with command queued
765	 * during this time
766	 */
767	if (session->state != ISCSI_STATE_LOGGED_IN &&
768	    session->state != ISCSI_STATE_FAILED) {
769		/*
770		 * to handle the race between when we set the recovery state
771		 * and block the session we requeue here (commands could
772		 * be entering our queuecommand while a block is starting
773		 * up because the block code is not locked)
774		 */
775		if (session->state == ISCSI_STATE_IN_RECOVERY) {
776			reason = FAILURE_SESSION_IN_RECOVERY;
777			goto reject;
778		}
779
780		if (session->state == ISCSI_STATE_RECOVERY_FAILED)
781			reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
782		else if (session->state == ISCSI_STATE_TERMINATE)
783			reason = FAILURE_SESSION_TERMINATE;
784		else
785			reason = FAILURE_SESSION_FREED;
786		goto fault;
787	}
788
789	/*
790	 * Check for iSCSI window and take care of CmdSN wrap-around
791	 */
792	if ((int)(session->max_cmdsn - session->cmdsn) < 0) {
793		reason = FAILURE_WINDOW_CLOSED;
794		goto reject;
795	}
796
797	conn = session->leadconn;
798	if (!conn) {
799		reason = FAILURE_SESSION_FREED;
800		goto fault;
801	}
802
803	if (!__kfifo_get(session->cmdpool.queue, (void*)&ctask,
804			 sizeof(void*))) {
805		reason = FAILURE_OOM;
806		goto reject;
807	}
808	sc->SCp.phase = session->age;
809	sc->SCp.ptr = (char *)ctask;
810
811	atomic_set(&ctask->refcount, 1);
812	ctask->state = ISCSI_TASK_PENDING;
813	ctask->mtask = NULL;
814	ctask->conn = conn;
815	ctask->sc = sc;
816	INIT_LIST_HEAD(&ctask->running);
817	ctask->total_length = sc->request_bufflen;
818	iscsi_prep_scsi_cmd_pdu(ctask);
819
820	session->tt->init_cmd_task(ctask);
821
822	list_add_tail(&ctask->running, &conn->xmitqueue);
823	debug_scsi(
824	       "ctask enq [%s cid %d sc %p cdb 0x%x itt 0x%x len %d cmdsn %d "
825		"win %d]\n",
826		sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
827		conn->id, sc, sc->cmnd[0], ctask->itt, sc->request_bufflen,
828		session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
829	spin_unlock(&session->lock);
830
831	scsi_queue_work(host, &conn->xmitwork);
832	return 0;
833
834reject:
835	spin_unlock(&session->lock);
836	debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
837	return SCSI_MLQUEUE_HOST_BUSY;
838
839fault:
840	spin_unlock(&session->lock);
841	printk(KERN_ERR "iscsi: cmd 0x%x is not queued (%d)\n",
842	       sc->cmnd[0], reason);
843	sc->result = (DID_NO_CONNECT << 16);
844	sc->resid = sc->request_bufflen;
845	sc->scsi_done(sc);
846	return 0;
847}
848EXPORT_SYMBOL_GPL(iscsi_queuecommand);
849
850int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
851{
852	if (depth > ISCSI_MAX_CMD_PER_LUN)
853		depth = ISCSI_MAX_CMD_PER_LUN;
854	scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
855	return sdev->queue_depth;
856}
857EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
858
859static int
860iscsi_conn_send_generic(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
861			char *data, uint32_t data_size)
862{
863	struct iscsi_session *session = conn->session;
864	struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
865	struct iscsi_mgmt_task *mtask;
866
867	spin_lock_bh(&session->lock);
868	if (session->state == ISCSI_STATE_TERMINATE) {
869		spin_unlock_bh(&session->lock);
870		return -EPERM;
871	}
872	if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
873	    hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
874		/*
875		 * Login and Text are sent serially, in
876		 * request-followed-by-response sequence.
877		 * Same mtask can be used. Same ITT must be used.
878		 * Note that login_mtask is preallocated at conn_create().
879		 */
880		mtask = conn->login_mtask;
881	else {
882		BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
883		BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
884
885		nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
886		if (!__kfifo_get(session->mgmtpool.queue,
887				 (void*)&mtask, sizeof(void*))) {
888			spin_unlock_bh(&session->lock);
889			return -ENOSPC;
890		}
891	}
892
893	/*
894	 * pre-format CmdSN for outgoing PDU.
895	 */
896	if (hdr->itt != RESERVED_ITT) {
897		hdr->itt = build_itt(mtask->itt, conn->id, session->age);
898		nop->cmdsn = cpu_to_be32(session->cmdsn);
899		if (conn->c_stage == ISCSI_CONN_STARTED &&
900		    !(hdr->opcode & ISCSI_OP_IMMEDIATE))
901			session->cmdsn++;
902	} else
903		/* do not advance CmdSN */
904		nop->cmdsn = cpu_to_be32(session->cmdsn);
905
906	if (data_size) {
907		memcpy(mtask->data, data, data_size);
908		mtask->data_count = data_size;
909	} else
910		mtask->data_count = 0;
911
912	INIT_LIST_HEAD(&mtask->running);
913	memcpy(mtask->hdr, hdr, sizeof(struct iscsi_hdr));
914	if (session->tt->init_mgmt_task)
915		session->tt->init_mgmt_task(conn, mtask, data, data_size);
916	spin_unlock_bh(&session->lock);
917
918	debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
919		   hdr->opcode, hdr->itt, data_size);
920
921	/*
922	 * since send_pdu() could be called at least from two contexts,
923	 * we need to serialize __kfifo_put, so we don't have to take
924	 * additional lock on fast data-path
925	 */
926        if (hdr->opcode & ISCSI_OP_IMMEDIATE)
927	        __kfifo_put(conn->immqueue, (void*)&mtask, sizeof(void*));
928	else
929	        __kfifo_put(conn->mgmtqueue, (void*)&mtask, sizeof(void*));
930
931	scsi_queue_work(session->host, &conn->xmitwork);
932	return 0;
933}
934
935int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
936			char *data, uint32_t data_size)
937{
938	struct iscsi_conn *conn = cls_conn->dd_data;
939	int rc;
940
941	mutex_lock(&conn->xmitmutex);
942	rc = iscsi_conn_send_generic(conn, hdr, data, data_size);
943	mutex_unlock(&conn->xmitmutex);
944
945	return rc;
946}
947EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
948
949void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
950{
951	struct iscsi_session *session = class_to_transport_session(cls_session);
952	struct iscsi_conn *conn = session->leadconn;
953
954	spin_lock_bh(&session->lock);
955	if (session->state != ISCSI_STATE_LOGGED_IN) {
956		session->state = ISCSI_STATE_RECOVERY_FAILED;
957		if (conn)
958			wake_up(&conn->ehwait);
959	}
960	spin_unlock_bh(&session->lock);
961}
962EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
963
964int iscsi_eh_host_reset(struct scsi_cmnd *sc)
965{
966	struct Scsi_Host *host = sc->device->host;
967	struct iscsi_session *session = iscsi_hostdata(host->hostdata);
968	struct iscsi_conn *conn = session->leadconn;
969	int fail_session = 0;
970
971	spin_lock_bh(&session->lock);
972	if (session->state == ISCSI_STATE_TERMINATE) {
973failed:
974		debug_scsi("failing host reset: session terminated "
975			   "[CID %d age %d]\n", conn->id, session->age);
976		spin_unlock_bh(&session->lock);
977		return FAILED;
978	}
979
980	if (sc->SCp.phase == session->age) {
981		debug_scsi("failing connection CID %d due to SCSI host reset\n",
982			   conn->id);
983		fail_session = 1;
984	}
985	spin_unlock_bh(&session->lock);
986
987	/*
988	 * we drop the lock here but the leadconn cannot be destoyed while
989	 * we are in the scsi eh
990	 */
991	if (fail_session)
992		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
993
994	debug_scsi("iscsi_eh_host_reset wait for relogin\n");
995	wait_event_interruptible(conn->ehwait,
996				 session->state == ISCSI_STATE_TERMINATE ||
997				 session->state == ISCSI_STATE_LOGGED_IN ||
998				 session->state == ISCSI_STATE_RECOVERY_FAILED);
999	if (signal_pending(current))
1000		flush_signals(current);
1001
1002	spin_lock_bh(&session->lock);
1003	if (session->state == ISCSI_STATE_LOGGED_IN)
1004		printk(KERN_INFO "iscsi: host reset succeeded\n");
1005	else
1006		goto failed;
1007	spin_unlock_bh(&session->lock);
1008
1009	return SUCCESS;
1010}
1011EXPORT_SYMBOL_GPL(iscsi_eh_host_reset);
1012
1013static void iscsi_tmabort_timedout(unsigned long data)
1014{
1015	struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)data;
1016	struct iscsi_conn *conn = ctask->conn;
1017	struct iscsi_session *session = conn->session;
1018
1019	spin_lock(&session->lock);
1020	if (conn->tmabort_state == TMABORT_INITIAL) {
1021		conn->tmabort_state = TMABORT_TIMEDOUT;
1022		debug_scsi("tmabort timedout [sc %p itt 0x%x]\n",
1023			ctask->sc, ctask->itt);
1024		/* unblock eh_abort() */
1025		wake_up(&conn->ehwait);
1026	}
1027	spin_unlock(&session->lock);
1028}
1029
1030/* must be called with the mutex lock */
1031static int iscsi_exec_abort_task(struct scsi_cmnd *sc,
1032				 struct iscsi_cmd_task *ctask)
1033{
1034	struct iscsi_conn *conn = ctask->conn;
1035	struct iscsi_session *session = conn->session;
1036	struct iscsi_tm *hdr = &conn->tmhdr;
1037	int rc;
1038
1039	/*
1040	 * ctask timed out but session is OK requests must be serialized.
1041	 */
1042	memset(hdr, 0, sizeof(struct iscsi_tm));
1043	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1044	hdr->flags = ISCSI_TM_FUNC_ABORT_TASK;
1045	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1046	memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1047	hdr->rtt = ctask->hdr->itt;
1048	hdr->refcmdsn = ctask->hdr->cmdsn;
1049
1050	rc = iscsi_conn_send_generic(conn, (struct iscsi_hdr *)hdr,
1051				     NULL, 0);
1052	if (rc) {
1053		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1054		debug_scsi("abort sent failure [itt 0x%x] %d\n", ctask->itt,
1055		           rc);
1056		return rc;
1057	}
1058
1059	debug_scsi("abort sent [itt 0x%x]\n", ctask->itt);
1060
1061	spin_lock_bh(&session->lock);
1062	ctask->mtask = (struct iscsi_mgmt_task *)
1063			session->mgmt_cmds[get_itt(hdr->itt) -
1064					ISCSI_MGMT_ITT_OFFSET];
1065
1066	if (conn->tmabort_state == TMABORT_INITIAL) {
1067		conn->tmfcmd_pdus_cnt++;
1068		conn->tmabort_timer.expires = 10*HZ + jiffies;
1069		conn->tmabort_timer.function = iscsi_tmabort_timedout;
1070		conn->tmabort_timer.data = (unsigned long)ctask;
1071		add_timer(&conn->tmabort_timer);
1072		debug_scsi("abort set timeout [itt 0x%x]\n", ctask->itt);
1073	}
1074	spin_unlock_bh(&session->lock);
1075	mutex_unlock(&conn->xmitmutex);
1076
1077	/*
1078	 * block eh thread until:
1079	 *
1080	 * 1) abort response
1081	 * 2) abort timeout
1082	 * 3) session is terminated or restarted or userspace has
1083	 * given up on recovery
1084	 */
1085	wait_event_interruptible(conn->ehwait,
1086				 sc->SCp.phase != session->age ||
1087				 session->state != ISCSI_STATE_LOGGED_IN ||
1088				 conn->tmabort_state != TMABORT_INITIAL);
1089	if (signal_pending(current))
1090		flush_signals(current);
1091	del_timer_sync(&conn->tmabort_timer);
1092
1093	mutex_lock(&conn->xmitmutex);
1094	return 0;
1095}
1096
1097/*
1098 * xmit mutex and session lock must be held
1099 */
1100static struct iscsi_mgmt_task *
1101iscsi_remove_mgmt_task(struct kfifo *fifo, uint32_t itt)
1102{
1103	int i, nr_tasks = __kfifo_len(fifo) / sizeof(void*);
1104	struct iscsi_mgmt_task *task;
1105
1106	debug_scsi("searching %d tasks\n", nr_tasks);
1107
1108	for (i = 0; i < nr_tasks; i++) {
1109		__kfifo_get(fifo, (void*)&task, sizeof(void*));
1110		debug_scsi("check task %u\n", task->itt);
1111
1112		if (task->itt == itt) {
1113			debug_scsi("matched task\n");
1114			return task;
1115		}
1116
1117		__kfifo_put(fifo, (void*)&task, sizeof(void*));
1118	}
1119	return NULL;
1120}
1121
1122static int iscsi_ctask_mtask_cleanup(struct iscsi_cmd_task *ctask)
1123{
1124	struct iscsi_conn *conn = ctask->conn;
1125	struct iscsi_session *session = conn->session;
1126
1127	if (!ctask->mtask)
1128		return -EINVAL;
1129
1130	if (!iscsi_remove_mgmt_task(conn->immqueue, ctask->mtask->itt))
1131		list_del(&ctask->mtask->running);
1132	__kfifo_put(session->mgmtpool.queue, (void*)&ctask->mtask,
1133		    sizeof(void*));
1134	ctask->mtask = NULL;
1135	return 0;
1136}
1137
1138/*
1139 * session lock and xmitmutex must be held
1140 */
1141static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1142			 int err)
1143{
1144	struct scsi_cmnd *sc;
1145
1146	sc = ctask->sc;
1147	if (!sc)
1148		return;
1149
1150	conn->session->tt->cleanup_cmd_task(conn, ctask);
1151	iscsi_ctask_mtask_cleanup(ctask);
1152
1153	sc->result = err;
1154	sc->resid = sc->request_bufflen;
1155	/* release ref from queuecommand */
1156	__iscsi_put_ctask(ctask);
1157}
1158
1159int iscsi_eh_abort(struct scsi_cmnd *sc)
1160{
1161	struct iscsi_cmd_task *ctask;
1162	struct iscsi_conn *conn;
1163	struct iscsi_session *session;
1164	int rc;
1165
1166	/*
1167	 * if session was ISCSI_STATE_IN_RECOVERY then we may not have
1168	 * got the command.
1169	 */
1170	if (!sc->SCp.ptr) {
1171		debug_scsi("sc never reached iscsi layer or it completed.\n");
1172		return SUCCESS;
1173	}
1174
1175	ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
1176	conn = ctask->conn;
1177	session = conn->session;
1178
1179	conn->eh_abort_cnt++;
1180	debug_scsi("aborting [sc %p itt 0x%x]\n", sc, ctask->itt);
1181
1182	mutex_lock(&conn->xmitmutex);
1183	spin_lock_bh(&session->lock);
1184
1185	/*
1186	 * If we are not logged in or we have started a new session
1187	 * then let the host reset code handle this
1188	 */
1189	if (session->state != ISCSI_STATE_LOGGED_IN ||
1190	    sc->SCp.phase != session->age)
1191		goto failed;
1192
1193	/* ctask completed before time out */
1194	if (!ctask->sc) {
1195		spin_unlock_bh(&session->lock);
1196		debug_scsi("sc completed while abort in progress\n");
1197		goto success_rel_mutex;
1198	}
1199
1200	/* what should we do here ? */
1201	if (conn->ctask == ctask) {
1202		printk(KERN_INFO "iscsi: sc %p itt 0x%x partially sent. "
1203		       "Failing abort\n", sc, ctask->itt);
1204		goto failed;
1205	}
1206
1207	if (ctask->state == ISCSI_TASK_PENDING)
1208		goto success_cleanup;
1209
1210	conn->tmabort_state = TMABORT_INITIAL;
1211
1212	spin_unlock_bh(&session->lock);
1213	rc = iscsi_exec_abort_task(sc, ctask);
1214	spin_lock_bh(&session->lock);
1215
1216	if (rc || sc->SCp.phase != session->age ||
1217	    session->state != ISCSI_STATE_LOGGED_IN)
1218		goto failed;
1219	iscsi_ctask_mtask_cleanup(ctask);
1220
1221	switch (conn->tmabort_state) {
1222	case TMABORT_SUCCESS:
1223		goto success_cleanup;
1224	case TMABORT_NOT_FOUND:
1225		if (!ctask->sc) {
1226			/* ctask completed before tmf abort response */
1227			spin_unlock_bh(&session->lock);
1228			debug_scsi("sc completed while abort in progress\n");
1229			goto success_rel_mutex;
1230		}
1231		/* fall through */
1232	default:
1233		/* timedout or failed */
1234		spin_unlock_bh(&session->lock);
1235		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1236		spin_lock_bh(&session->lock);
1237		goto failed;
1238	}
1239
1240success_cleanup:
1241	debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1242	spin_unlock_bh(&session->lock);
1243
1244	/*
1245	 * clean up task if aborted. we have the xmitmutex so grab
1246	 * the recv lock as a writer
1247	 */
1248	write_lock_bh(conn->recv_lock);
1249	spin_lock(&session->lock);
1250	fail_command(conn, ctask, DID_ABORT << 16);
1251	spin_unlock(&session->lock);
1252	write_unlock_bh(conn->recv_lock);
1253
1254success_rel_mutex:
1255	mutex_unlock(&conn->xmitmutex);
1256	return SUCCESS;
1257
1258failed:
1259	spin_unlock_bh(&session->lock);
1260	mutex_unlock(&conn->xmitmutex);
1261
1262	debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1263	return FAILED;
1264}
1265EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1266
1267int
1268iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size)
1269{
1270	int i;
1271
1272	*items = kmalloc(max * sizeof(void*), GFP_KERNEL);
1273	if (*items == NULL)
1274		return -ENOMEM;
1275
1276	q->max = max;
1277	q->pool = kmalloc(max * sizeof(void*), GFP_KERNEL);
1278	if (q->pool == NULL) {
1279		kfree(*items);
1280		return -ENOMEM;
1281	}
1282
1283	q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1284			      GFP_KERNEL, NULL);
1285	if (q->queue == ERR_PTR(-ENOMEM)) {
1286		kfree(q->pool);
1287		kfree(*items);
1288		return -ENOMEM;
1289	}
1290
1291	for (i = 0; i < max; i++) {
1292		q->pool[i] = kmalloc(item_size, GFP_KERNEL);
1293		if (q->pool[i] == NULL) {
1294			int j;
1295
1296			for (j = 0; j < i; j++)
1297				kfree(q->pool[j]);
1298
1299			kfifo_free(q->queue);
1300			kfree(q->pool);
1301			kfree(*items);
1302			return -ENOMEM;
1303		}
1304		memset(q->pool[i], 0, item_size);
1305		(*items)[i] = q->pool[i];
1306		__kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1307	}
1308	return 0;
1309}
1310EXPORT_SYMBOL_GPL(iscsi_pool_init);
1311
1312void iscsi_pool_free(struct iscsi_queue *q, void **items)
1313{
1314	int i;
1315
1316	for (i = 0; i < q->max; i++)
1317		kfree(items[i]);
1318	kfree(q->pool);
1319	kfree(items);
1320}
1321EXPORT_SYMBOL_GPL(iscsi_pool_free);
1322
1323/*
1324 * iSCSI Session's hostdata organization:
1325 *
1326 *    *------------------* <== hostdata_session(host->hostdata)
1327 *    | ptr to class sess|
1328 *    |------------------| <== iscsi_hostdata(host->hostdata)
1329 *    | iscsi_session    |
1330 *    *------------------*
1331 */
1332
1333#define hostdata_privsize(_sz)	(sizeof(unsigned long) + _sz + \
1334				 _sz % sizeof(unsigned long))
1335
1336#define hostdata_session(_hostdata) (iscsi_ptr(*(unsigned long *)_hostdata))
1337
1338/**
1339 * iscsi_session_setup - create iscsi cls session and host and session
1340 * @scsit: scsi transport template
1341 * @iscsit: iscsi transport template
1342 * @initial_cmdsn: initial CmdSN
1343 * @hostno: host no allocated
1344 *
1345 * This can be used by software iscsi_transports that allocate
1346 * a session per scsi host.
1347 **/
1348struct iscsi_cls_session *
1349iscsi_session_setup(struct iscsi_transport *iscsit,
1350		    struct scsi_transport_template *scsit,
1351		    int cmd_task_size, int mgmt_task_size,
1352		    uint32_t initial_cmdsn, uint32_t *hostno)
1353{
1354	struct Scsi_Host *shost;
1355	struct iscsi_session *session;
1356	struct iscsi_cls_session *cls_session;
1357	int cmd_i;
1358
1359	shost = scsi_host_alloc(iscsit->host_template,
1360				hostdata_privsize(sizeof(*session)));
1361	if (!shost)
1362		return NULL;
1363
1364	shost->max_id = 1;
1365	shost->max_channel = 0;
1366	shost->max_lun = iscsit->max_lun;
1367	shost->max_cmd_len = iscsit->max_cmd_len;
1368	shost->transportt = scsit;
1369	shost->transportt->create_work_queue = 1;
1370	*hostno = shost->host_no;
1371
1372	session = iscsi_hostdata(shost->hostdata);
1373	memset(session, 0, sizeof(struct iscsi_session));
1374	session->host = shost;
1375	session->state = ISCSI_STATE_FREE;
1376	session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX;
1377	session->cmds_max = ISCSI_XMIT_CMDS_MAX;
1378	session->cmdsn = initial_cmdsn;
1379	session->exp_cmdsn = initial_cmdsn + 1;
1380	session->max_cmdsn = initial_cmdsn + 1;
1381	session->max_r2t = 1;
1382	session->tt = iscsit;
1383
1384	/* initialize SCSI PDU commands pool */
1385	if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
1386			    (void***)&session->cmds,
1387			    cmd_task_size + sizeof(struct iscsi_cmd_task)))
1388		goto cmdpool_alloc_fail;
1389
1390	/* pre-format cmds pool with ITT */
1391	for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1392		struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
1393
1394		if (cmd_task_size)
1395			ctask->dd_data = &ctask[1];
1396		ctask->itt = cmd_i;
1397		INIT_LIST_HEAD(&ctask->running);
1398	}
1399
1400	spin_lock_init(&session->lock);
1401
1402	/* initialize immediate command pool */
1403	if (iscsi_pool_init(&session->mgmtpool, session->mgmtpool_max,
1404			   (void***)&session->mgmt_cmds,
1405			   mgmt_task_size + sizeof(struct iscsi_mgmt_task)))
1406		goto mgmtpool_alloc_fail;
1407
1408
1409	/* pre-format immediate cmds pool with ITT */
1410	for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
1411		struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
1412
1413		if (mgmt_task_size)
1414			mtask->dd_data = &mtask[1];
1415		mtask->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i;
1416		INIT_LIST_HEAD(&mtask->running);
1417	}
1418
1419	if (scsi_add_host(shost, NULL))
1420		goto add_host_fail;
1421
1422	if (!try_module_get(iscsit->owner))
1423		goto cls_session_fail;
1424
1425	cls_session = iscsi_create_session(shost, iscsit, 0);
1426	if (!cls_session)
1427		goto module_put;
1428	*(unsigned long*)shost->hostdata = (unsigned long)cls_session;
1429
1430	return cls_session;
1431
1432module_put:
1433	module_put(iscsit->owner);
1434cls_session_fail:
1435	scsi_remove_host(shost);
1436add_host_fail:
1437	iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1438mgmtpool_alloc_fail:
1439	iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1440cmdpool_alloc_fail:
1441	scsi_host_put(shost);
1442	return NULL;
1443}
1444EXPORT_SYMBOL_GPL(iscsi_session_setup);
1445
1446/**
1447 * iscsi_session_teardown - destroy session, host, and cls_session
1448 * shost: scsi host
1449 *
1450 * This can be used by software iscsi_transports that allocate
1451 * a session per scsi host.
1452 **/
1453void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
1454{
1455	struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1456	struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1457	struct module *owner = cls_session->transport->owner;
1458
1459	scsi_remove_host(shost);
1460
1461	iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1462	iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1463
1464	kfree(session->targetname);
1465
1466	iscsi_destroy_session(cls_session);
1467	scsi_host_put(shost);
1468	module_put(owner);
1469}
1470EXPORT_SYMBOL_GPL(iscsi_session_teardown);
1471
1472/**
1473 * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
1474 * @cls_session: iscsi_cls_session
1475 * @conn_idx: cid
1476 **/
1477struct iscsi_cls_conn *
1478iscsi_conn_setup(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1479{
1480	struct iscsi_session *session = class_to_transport_session(cls_session);
1481	struct iscsi_conn *conn;
1482	struct iscsi_cls_conn *cls_conn;
1483	char *data;
1484
1485	cls_conn = iscsi_create_conn(cls_session, conn_idx);
1486	if (!cls_conn)
1487		return NULL;
1488	conn = cls_conn->dd_data;
1489	memset(conn, 0, sizeof(*conn));
1490
1491	conn->session = session;
1492	conn->cls_conn = cls_conn;
1493	conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
1494	conn->id = conn_idx;
1495	conn->exp_statsn = 0;
1496	conn->tmabort_state = TMABORT_INITIAL;
1497	INIT_LIST_HEAD(&conn->run_list);
1498	INIT_LIST_HEAD(&conn->mgmt_run_list);
1499	INIT_LIST_HEAD(&conn->xmitqueue);
1500
1501	/* initialize general immediate & non-immediate PDU commands queue */
1502	conn->immqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
1503			                GFP_KERNEL, NULL);
1504	if (conn->immqueue == ERR_PTR(-ENOMEM))
1505		goto immqueue_alloc_fail;
1506
1507	conn->mgmtqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
1508			                GFP_KERNEL, NULL);
1509	if (conn->mgmtqueue == ERR_PTR(-ENOMEM))
1510		goto mgmtqueue_alloc_fail;
1511
1512	INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
1513
1514	/* allocate login_mtask used for the login/text sequences */
1515	spin_lock_bh(&session->lock);
1516	if (!__kfifo_get(session->mgmtpool.queue,
1517                         (void*)&conn->login_mtask,
1518			 sizeof(void*))) {
1519		spin_unlock_bh(&session->lock);
1520		goto login_mtask_alloc_fail;
1521	}
1522	spin_unlock_bh(&session->lock);
1523
1524	data = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN, GFP_KERNEL);
1525	if (!data)
1526		goto login_mtask_data_alloc_fail;
1527	conn->login_mtask->data = conn->data = data;
1528
1529	init_timer(&conn->tmabort_timer);
1530	mutex_init(&conn->xmitmutex);
1531	init_waitqueue_head(&conn->ehwait);
1532
1533	return cls_conn;
1534
1535login_mtask_data_alloc_fail:
1536	__kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1537		    sizeof(void*));
1538login_mtask_alloc_fail:
1539	kfifo_free(conn->mgmtqueue);
1540mgmtqueue_alloc_fail:
1541	kfifo_free(conn->immqueue);
1542immqueue_alloc_fail:
1543	iscsi_destroy_conn(cls_conn);
1544	return NULL;
1545}
1546EXPORT_SYMBOL_GPL(iscsi_conn_setup);
1547
1548/**
1549 * iscsi_conn_teardown - teardown iscsi connection
1550 * cls_conn: iscsi class connection
1551 *
1552 * TODO: we may need to make this into a two step process
1553 * like scsi-mls remove + put host
1554 */
1555void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
1556{
1557	struct iscsi_conn *conn = cls_conn->dd_data;
1558	struct iscsi_session *session = conn->session;
1559	unsigned long flags;
1560
1561	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1562	mutex_lock(&conn->xmitmutex);
1563
1564	spin_lock_bh(&session->lock);
1565	conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
1566	if (session->leadconn == conn) {
1567		/*
1568		 * leading connection? then give up on recovery.
1569		 */
1570		session->state = ISCSI_STATE_TERMINATE;
1571		wake_up(&conn->ehwait);
1572	}
1573	spin_unlock_bh(&session->lock);
1574
1575	mutex_unlock(&conn->xmitmutex);
1576
1577	/*
1578	 * Block until all in-progress commands for this connection
1579	 * time out or fail.
1580	 */
1581	for (;;) {
1582		spin_lock_irqsave(session->host->host_lock, flags);
1583		if (!session->host->host_busy) { /* OK for ERL == 0 */
1584			spin_unlock_irqrestore(session->host->host_lock, flags);
1585			break;
1586		}
1587		spin_unlock_irqrestore(session->host->host_lock, flags);
1588		msleep_interruptible(500);
1589		printk(KERN_INFO "iscsi: scsi conn_destroy(): host_busy %d "
1590		       "host_failed %d\n", session->host->host_busy,
1591		       session->host->host_failed);
1592		/*
1593		 * force eh_abort() to unblock
1594		 */
1595		wake_up(&conn->ehwait);
1596	}
1597
1598	/* flush queued up work because we free the connection below */
1599	scsi_flush_work(session->host);
1600
1601	spin_lock_bh(&session->lock);
1602	kfree(conn->data);
1603	kfree(conn->persistent_address);
1604	__kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1605		    sizeof(void*));
1606	if (session->leadconn == conn) {
1607		session->leadconn = NULL;
1608		/* no connections exits.. reset sequencing */
1609		session->cmdsn = session->max_cmdsn = session->exp_cmdsn = 1;
1610	}
1611	spin_unlock_bh(&session->lock);
1612
1613	kfifo_free(conn->immqueue);
1614	kfifo_free(conn->mgmtqueue);
1615
1616	iscsi_destroy_conn(cls_conn);
1617}
1618EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
1619
1620int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
1621{
1622	struct iscsi_conn *conn = cls_conn->dd_data;
1623	struct iscsi_session *session = conn->session;
1624
1625	if (!session) {
1626		printk(KERN_ERR "iscsi: can't start unbound connection\n");
1627		return -EPERM;
1628	}
1629
1630	if ((session->imm_data_en || !session->initial_r2t_en) &&
1631	     session->first_burst > session->max_burst) {
1632		printk("iscsi: invalid burst lengths: "
1633		       "first_burst %d max_burst %d\n",
1634		       session->first_burst, session->max_burst);
1635		return -EINVAL;
1636	}
1637
1638	spin_lock_bh(&session->lock);
1639	conn->c_stage = ISCSI_CONN_STARTED;
1640	session->state = ISCSI_STATE_LOGGED_IN;
1641
1642	switch(conn->stop_stage) {
1643	case STOP_CONN_RECOVER:
1644		/*
1645		 * unblock eh_abort() if it is blocked. re-try all
1646		 * commands after successful recovery
1647		 */
1648		conn->stop_stage = 0;
1649		conn->tmabort_state = TMABORT_INITIAL;
1650		session->age++;
1651		spin_unlock_bh(&session->lock);
1652
1653		iscsi_unblock_session(session_to_cls(session));
1654		wake_up(&conn->ehwait);
1655		return 0;
1656	case STOP_CONN_TERM:
1657		conn->stop_stage = 0;
1658		break;
1659	default:
1660		break;
1661	}
1662	spin_unlock_bh(&session->lock);
1663
1664	return 0;
1665}
1666EXPORT_SYMBOL_GPL(iscsi_conn_start);
1667
1668static void
1669flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
1670{
1671	struct iscsi_mgmt_task *mtask, *tmp;
1672
1673	/* handle pending */
1674	while (__kfifo_get(conn->immqueue, (void*)&mtask, sizeof(void*)) ||
1675	       __kfifo_get(conn->mgmtqueue, (void*)&mtask, sizeof(void*))) {
1676		if (mtask == conn->login_mtask)
1677			continue;
1678		debug_scsi("flushing pending mgmt task itt 0x%x\n", mtask->itt);
1679		__kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1680			    sizeof(void*));
1681	}
1682
1683	/* handle running */
1684	list_for_each_entry_safe(mtask, tmp, &conn->mgmt_run_list, running) {
1685		debug_scsi("flushing running mgmt task itt 0x%x\n", mtask->itt);
1686		list_del(&mtask->running);
1687
1688		if (mtask == conn->login_mtask)
1689			continue;
1690		__kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1691			   sizeof(void*));
1692	}
1693
1694	conn->mtask = NULL;
1695}
1696
1697/* Fail commands. Mutex and session lock held and recv side suspended */
1698static void fail_all_commands(struct iscsi_conn *conn)
1699{
1700	struct iscsi_cmd_task *ctask, *tmp;
1701
1702	/* flush pending */
1703	list_for_each_entry_safe(ctask, tmp, &conn->xmitqueue, running) {
1704		debug_scsi("failing pending sc %p itt 0x%x\n", ctask->sc,
1705			   ctask->itt);
1706		fail_command(conn, ctask, DID_BUS_BUSY << 16);
1707	}
1708
1709	/* fail all other running */
1710	list_for_each_entry_safe(ctask, tmp, &conn->run_list, running) {
1711		debug_scsi("failing in progress sc %p itt 0x%x\n",
1712			   ctask->sc, ctask->itt);
1713		fail_command(conn, ctask, DID_BUS_BUSY << 16);
1714	}
1715
1716	conn->ctask = NULL;
1717}
1718
1719static void iscsi_start_session_recovery(struct iscsi_session *session,
1720					 struct iscsi_conn *conn, int flag)
1721{
1722	int old_stop_stage;
1723
1724	spin_lock_bh(&session->lock);
1725	if (conn->stop_stage == STOP_CONN_TERM) {
1726		spin_unlock_bh(&session->lock);
1727		return;
1728	}
1729
1730	/*
1731	 * When this is called for the in_login state, we only want to clean
1732	 * up the login task and connection. We do not need to block and set
1733	 * the recovery state again
1734	 */
1735	if (flag == STOP_CONN_TERM)
1736		session->state = ISCSI_STATE_TERMINATE;
1737	else if (conn->stop_stage != STOP_CONN_RECOVER)
1738		session->state = ISCSI_STATE_IN_RECOVERY;
1739
1740	old_stop_stage = conn->stop_stage;
1741	conn->stop_stage = flag;
1742	conn->c_stage = ISCSI_CONN_STOPPED;
1743	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1744	spin_unlock_bh(&session->lock);
1745
1746	write_lock_bh(conn->recv_lock);
1747	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1748	write_unlock_bh(conn->recv_lock);
1749
1750	mutex_lock(&conn->xmitmutex);
1751	/*
1752	 * for connection level recovery we should not calculate
1753	 * header digest. conn->hdr_size used for optimization
1754	 * in hdr_extract() and will be re-negotiated at
1755	 * set_param() time.
1756	 */
1757	if (flag == STOP_CONN_RECOVER) {
1758		conn->hdrdgst_en = 0;
1759		conn->datadgst_en = 0;
1760		if (session->state == ISCSI_STATE_IN_RECOVERY &&
1761		    old_stop_stage != STOP_CONN_RECOVER) {
1762			debug_scsi("blocking session\n");
1763			iscsi_block_session(session_to_cls(session));
1764		}
1765	}
1766
1767	/*
1768	 * flush queues.
1769	 */
1770	spin_lock_bh(&session->lock);
1771	fail_all_commands(conn);
1772	flush_control_queues(session, conn);
1773	spin_unlock_bh(&session->lock);
1774
1775	mutex_unlock(&conn->xmitmutex);
1776}
1777
1778void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1779{
1780	struct iscsi_conn *conn = cls_conn->dd_data;
1781	struct iscsi_session *session = conn->session;
1782
1783	switch (flag) {
1784	case STOP_CONN_RECOVER:
1785	case STOP_CONN_TERM:
1786		iscsi_start_session_recovery(session, conn, flag);
1787		break;
1788	default:
1789		printk(KERN_ERR "iscsi: invalid stop flag %d\n", flag);
1790	}
1791}
1792EXPORT_SYMBOL_GPL(iscsi_conn_stop);
1793
1794int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
1795		    struct iscsi_cls_conn *cls_conn, int is_leading)
1796{
1797	struct iscsi_session *session = class_to_transport_session(cls_session);
1798	struct iscsi_conn *conn = cls_conn->dd_data;
1799
1800	spin_lock_bh(&session->lock);
1801	if (is_leading)
1802		session->leadconn = conn;
1803	spin_unlock_bh(&session->lock);
1804
1805	/*
1806	 * Unblock xmitworker(), Login Phase will pass through.
1807	 */
1808	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1809	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1810	return 0;
1811}
1812EXPORT_SYMBOL_GPL(iscsi_conn_bind);
1813
1814
1815int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
1816		    enum iscsi_param param, char *buf, int buflen)
1817{
1818	struct iscsi_conn *conn = cls_conn->dd_data;
1819	struct iscsi_session *session = conn->session;
1820	uint32_t value;
1821
1822	switch(param) {
1823	case ISCSI_PARAM_MAX_RECV_DLENGTH:
1824		sscanf(buf, "%d", &conn->max_recv_dlength);
1825		break;
1826	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
1827		sscanf(buf, "%d", &conn->max_xmit_dlength);
1828		break;
1829	case ISCSI_PARAM_HDRDGST_EN:
1830		sscanf(buf, "%d", &conn->hdrdgst_en);
1831		break;
1832	case ISCSI_PARAM_DATADGST_EN:
1833		sscanf(buf, "%d", &conn->datadgst_en);
1834		break;
1835	case ISCSI_PARAM_INITIAL_R2T_EN:
1836		sscanf(buf, "%d", &session->initial_r2t_en);
1837		break;
1838	case ISCSI_PARAM_MAX_R2T:
1839		sscanf(buf, "%d", &session->max_r2t);
1840		break;
1841	case ISCSI_PARAM_IMM_DATA_EN:
1842		sscanf(buf, "%d", &session->imm_data_en);
1843		break;
1844	case ISCSI_PARAM_FIRST_BURST:
1845		sscanf(buf, "%d", &session->first_burst);
1846		break;
1847	case ISCSI_PARAM_MAX_BURST:
1848		sscanf(buf, "%d", &session->max_burst);
1849		break;
1850	case ISCSI_PARAM_PDU_INORDER_EN:
1851		sscanf(buf, "%d", &session->pdu_inorder_en);
1852		break;
1853	case ISCSI_PARAM_DATASEQ_INORDER_EN:
1854		sscanf(buf, "%d", &session->dataseq_inorder_en);
1855		break;
1856	case ISCSI_PARAM_ERL:
1857		sscanf(buf, "%d", &session->erl);
1858		break;
1859	case ISCSI_PARAM_IFMARKER_EN:
1860		sscanf(buf, "%d", &value);
1861		BUG_ON(value);
1862		break;
1863	case ISCSI_PARAM_OFMARKER_EN:
1864		sscanf(buf, "%d", &value);
1865		BUG_ON(value);
1866		break;
1867	case ISCSI_PARAM_EXP_STATSN:
1868		sscanf(buf, "%u", &conn->exp_statsn);
1869		break;
1870	case ISCSI_PARAM_TARGET_NAME:
1871		/* this should not change between logins */
1872		if (session->targetname)
1873			break;
1874
1875		session->targetname = kstrdup(buf, GFP_KERNEL);
1876		if (!session->targetname)
1877			return -ENOMEM;
1878		break;
1879	case ISCSI_PARAM_TPGT:
1880		sscanf(buf, "%d", &session->tpgt);
1881		break;
1882	case ISCSI_PARAM_PERSISTENT_PORT:
1883		sscanf(buf, "%d", &conn->persistent_port);
1884		break;
1885	case ISCSI_PARAM_PERSISTENT_ADDRESS:
1886		/*
1887		 * this is the address returned in discovery so it should
1888		 * not change between logins.
1889		 */
1890		if (conn->persistent_address)
1891			break;
1892
1893		conn->persistent_address = kstrdup(buf, GFP_KERNEL);
1894		if (!conn->persistent_address)
1895			return -ENOMEM;
1896		break;
1897	default:
1898		return -ENOSYS;
1899	}
1900
1901	return 0;
1902}
1903EXPORT_SYMBOL_GPL(iscsi_set_param);
1904
1905int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
1906			    enum iscsi_param param, char *buf)
1907{
1908	struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1909	struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1910	int len;
1911
1912	switch(param) {
1913	case ISCSI_PARAM_INITIAL_R2T_EN:
1914		len = sprintf(buf, "%d\n", session->initial_r2t_en);
1915		break;
1916	case ISCSI_PARAM_MAX_R2T:
1917		len = sprintf(buf, "%hu\n", session->max_r2t);
1918		break;
1919	case ISCSI_PARAM_IMM_DATA_EN:
1920		len = sprintf(buf, "%d\n", session->imm_data_en);
1921		break;
1922	case ISCSI_PARAM_FIRST_BURST:
1923		len = sprintf(buf, "%u\n", session->first_burst);
1924		break;
1925	case ISCSI_PARAM_MAX_BURST:
1926		len = sprintf(buf, "%u\n", session->max_burst);
1927		break;
1928	case ISCSI_PARAM_PDU_INORDER_EN:
1929		len = sprintf(buf, "%d\n", session->pdu_inorder_en);
1930		break;
1931	case ISCSI_PARAM_DATASEQ_INORDER_EN:
1932		len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
1933		break;
1934	case ISCSI_PARAM_ERL:
1935		len = sprintf(buf, "%d\n", session->erl);
1936		break;
1937	case ISCSI_PARAM_TARGET_NAME:
1938		len = sprintf(buf, "%s\n", session->targetname);
1939		break;
1940	case ISCSI_PARAM_TPGT:
1941		len = sprintf(buf, "%d\n", session->tpgt);
1942		break;
1943	default:
1944		return -ENOSYS;
1945	}
1946
1947	return len;
1948}
1949EXPORT_SYMBOL_GPL(iscsi_session_get_param);
1950
1951int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
1952			 enum iscsi_param param, char *buf)
1953{
1954	struct iscsi_conn *conn = cls_conn->dd_data;
1955	int len;
1956
1957	switch(param) {
1958	case ISCSI_PARAM_MAX_RECV_DLENGTH:
1959		len = sprintf(buf, "%u\n", conn->max_recv_dlength);
1960		break;
1961	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
1962		len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
1963		break;
1964	case ISCSI_PARAM_HDRDGST_EN:
1965		len = sprintf(buf, "%d\n", conn->hdrdgst_en);
1966		break;
1967	case ISCSI_PARAM_DATADGST_EN:
1968		len = sprintf(buf, "%d\n", conn->datadgst_en);
1969		break;
1970	case ISCSI_PARAM_IFMARKER_EN:
1971		len = sprintf(buf, "%d\n", conn->ifmarker_en);
1972		break;
1973	case ISCSI_PARAM_OFMARKER_EN:
1974		len = sprintf(buf, "%d\n", conn->ofmarker_en);
1975		break;
1976	case ISCSI_PARAM_EXP_STATSN:
1977		len = sprintf(buf, "%u\n", conn->exp_statsn);
1978		break;
1979	case ISCSI_PARAM_PERSISTENT_PORT:
1980		len = sprintf(buf, "%d\n", conn->persistent_port);
1981		break;
1982	case ISCSI_PARAM_PERSISTENT_ADDRESS:
1983		len = sprintf(buf, "%s\n", conn->persistent_address);
1984		break;
1985	default:
1986		return -ENOSYS;
1987	}
1988
1989	return len;
1990}
1991EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
1992
1993MODULE_AUTHOR("Mike Christie");
1994MODULE_DESCRIPTION("iSCSI library functions");
1995MODULE_LICENSE("GPL");
1996