xref: /dragonfly/sys/dev/disk/iscsi/initiator/isc_sm.c (revision 73e0051e)
1 /*-
2  * Copyright (c) 2005-2008 Daniel Braniss <danny@cs.huji.ac.il>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD: src/sys/dev/iscsi/initiator/isc_sm.c,v 1.3 2008/11/25 07:17:11 scottl Exp $
27  */
28 /*
29  | iSCSI - Session Manager
30  | $Id: isc_sm.c,v 1.30 2007/04/22 09:53:09 danny Exp danny $
31  */
32 
33 #include "opt_iscsi_initiator.h"
34 
35 #include <sys/param.h>
36 #include <sys/kernel.h>
37 #include <sys/conf.h>
38 #include <sys/systm.h>
39 #include <sys/malloc.h>
40 #include <sys/ctype.h>
41 #include <sys/errno.h>
42 #include <sys/sysctl.h>
43 #include <sys/file.h>
44 #include <sys/uio.h>
45 #include <sys/socketvar.h>
46 #include <sys/socket.h>
47 #include <sys/protosw.h>
48 #include <sys/proc.h>
49 #include <sys/ioccom.h>
50 #include <sys/queue.h>
51 #include <sys/kthread.h>
52 #include <sys/syslog.h>
53 #include <sys/mbuf.h>
54 #include <sys/bus.h>
55 #include <sys/eventhandler.h>
56 #include <sys/mutex.h>
57 #include <sys/mutex2.h>
58 
59 #include <bus/cam/cam.h>
60 #include <bus/cam/cam_ccb.h>
61 #include <bus/cam/cam_sim.h>
62 #include <bus/cam/cam_xpt_sim.h>
63 #include <bus/cam/cam_periph.h>
64 
65 #include <dev/disk/iscsi/initiator/iscsi.h>
66 #include <dev/disk/iscsi/initiator/iscsivar.h>
67 
68 static void
69 _async(isc_session_t *sp, pduq_t *pq)
70 {
71      debug_called(8);
72 
73      iscsi_async(sp, pq);
74 
75      pdu_free(sp->isc, pq);
76 }
77 
78 static void
79 _reject(isc_session_t *sp, pduq_t *pq)
80 {
81      pduq_t	*opq;
82      pdu_t	*pdu;
83      reject_t	*reject;
84      int	itt;
85 
86      debug_called(8);
87      pdu = mtod(pq->mp, pdu_t *);
88      itt = pdu->ipdu.bhs.itt;
89      reject = &pq->pdu.ipdu.reject;
90      sdebug(2, "itt=%x reason=0x%x", ntohl(itt), reject->reason);
91      opq = i_search_hld(sp, itt, 0);
92      if(opq != NULL)
93 	  iscsi_reject(sp, opq, pq);
94      else {
95 	  switch(pq->pdu.ipdu.bhs.opcode) {
96 	  case ISCSI_LOGOUT_CMD: // XXX: wasabi does this - can't figure out why
97 	       sdebug(2, "ISCSI_LOGOUT_CMD ...");
98 	       break;
99 	  default:
100 	       xdebug("%d] we lost something itt=%x",
101 		      sp->sid, ntohl(pq->pdu.ipdu.bhs.itt));
102 	  }
103      }
104      pdu_free(sp->isc, pq);
105 }
106 
107 static void
108 _r2t(isc_session_t *sp, pduq_t *pq)
109 {
110      pduq_t	*opq;
111 
112      debug_called(8);
113      opq = i_search_hld(sp, pq->pdu.ipdu.bhs.itt, 1);
114      if(opq != NULL) {
115 	  iscsi_r2t(sp, opq, pq);
116      }
117      else {
118 	  r2t_t		*r2t = &pq->pdu.ipdu.r2t;
119 
120 	  xdebug("%d] we lost something itt=%x r2tSN=%d bo=%x ddtl=%x",
121 		 sp->sid, ntohl(pq->pdu.ipdu.bhs.itt),
122 		 ntohl(r2t->r2tSN), ntohl(r2t->bo), ntohl(r2t->ddtl));
123      }
124      pdu_free(sp->isc, pq);
125 }
126 
127 static void
128 _scsi_rsp(isc_session_t *sp, pduq_t *pq)
129 {
130      pduq_t	*opq;
131 
132      debug_called(8);
133      opq = i_search_hld(sp, pq->pdu.ipdu.bhs.itt, 0);
134      debug(5, "itt=%x pq=%p opq=%p", ntohl(pq->pdu.ipdu.bhs.itt), pq, opq);
135      if(opq != NULL)
136 	  iscsi_done(sp, opq, pq);
137      else
138 	  xdebug("%d] we lost something itt=%x",
139 		 sp->sid, ntohl(pq->pdu.ipdu.bhs.itt));
140      pdu_free(sp->isc, pq);
141 }
142 
143 static void
144 _read_data(isc_session_t *sp, pduq_t *pq)
145 {
146      pduq_t		*opq;
147 
148      debug_called(8);
149      opq = i_search_hld(sp, pq->pdu.ipdu.bhs.itt, 1);
150      if(opq != NULL) {
151 	  if(scsi_decap(sp, opq, pq) != 1) {
152 	       i_remove_hld(sp, opq); // done
153 	       pdu_free(sp->isc, opq);
154 	  }
155      }
156      else
157 	  xdebug("%d] we lost something itt=%x",
158 		 sp->sid, ntohl(pq->pdu.ipdu.bhs.itt));
159      pdu_free(sp->isc, pq);
160 }
161 /*
162  | this is a kludge,
163  | the jury is not back with a veredict, user or kernel
164  */
165 static void
166 _nop_out(isc_session_t *sp)
167 {
168      pduq_t	*pq;
169      nop_out_t	*nop_out;
170 
171      debug_called(8);
172 
173      sdebug(4, "cws=%d", sp->cws);
174      if(sp->cws == 0) {
175 	  /*
176 	   | only send a nop if window is closed.
177 	   */
178 	  if((pq = pdu_alloc(sp->isc, M_NOWAIT)) == NULL)
179 	       // I guess we ran out of resources
180 	       return;
181 	  nop_out = &pq->pdu.ipdu.nop_out;
182 	  nop_out->opcode = ISCSI_NOP_OUT;
183 	  nop_out->itt = htonl(sp->sn.itt);
184 	  nop_out->ttt = -1;
185 	  nop_out->I = 1;
186 	  nop_out->F = 1;
187 	  if(isc_qout(sp, pq) != 0) {
188 	       sdebug(1, "failed");
189 	       pdu_free(sp->isc, pq);
190 	  }
191      }
192 }
193 
194 static void
195 _nop_in(isc_session_t *sp, pduq_t *pq)
196 {
197      pdu_t	*pp = &pq->pdu;
198      nop_in_t	*nop_in = &pp->ipdu.nop_in;
199      bhs_t	*bhs = &pp->ipdu.bhs;
200 
201      debug_called(8);
202 
203      sdebug(5, "itt=%x ttt=%x", htonl(nop_in->itt), htonl(nop_in->ttt));
204      if(nop_in->itt == -1) {
205 	  if(pp->ds_len != 0) {
206 	       /*
207 		| according to RFC 3720 this should be zero
208 		| what to do if not?
209 		*/
210 	       xdebug("%d] dslen not zero", sp->sid);
211 	  }
212 	  if(nop_in->ttt != -1) {
213 	       nop_out_t	*nop_out;
214 	       /*
215 		| target wants a nop_out
216 	        */
217 	       bhs->opcode = ISCSI_NOP_OUT;
218 	       bhs->I = 1;
219 	       bhs->F = 1;
220 	       /*
221 		| we are reusing the pdu, so bhs->ttt == nop_in->ttt;
222 		| and need to zero out 'Reserved'
223 		| small cludge here.
224 	        */
225 	       nop_out = &pp->ipdu.nop_out;
226 	       nop_out->sn.maxcmd = 0;
227 	       memset(nop_out->mbz, 0, sizeof(nop_out->mbz));
228 	       (void)isc_qout(sp, pq); //XXX: should check return?
229 	       return;
230 	  }
231 	  //else {
232 	       // just making noise?
233 	       // see 10.9.1: target does not want and answer.
234 	  //}
235 
236      } else
237      if(nop_in->ttt == -1) {
238 	  /*
239 	   | it is an answer to a nop_in from us
240 	   */
241 	  if(nop_in->itt != -1) {
242 #ifdef ISC_WAIT4PING
243 	       // XXX: MUTEX please
244 	       if(sp->flags & ISC_WAIT4PING) {
245 		    i_nqueue_rsp(sp, pq);
246 		    wakeup(&sp->rsp);
247 		    return;
248 	       }
249 #endif
250 	  }
251      }
252      /*
253       | drop it
254       */
255      pdu_free(sp->isc, pq);
256      return;
257 }
258 
259 int
260 i_prepPDU(isc_session_t *sp, pduq_t *pq)
261 {
262      size_t	len, n;
263      pdu_t	*pp = &pq->pdu;
264      bhs_t	*bhp = &pp->ipdu.bhs;
265 
266      len = sizeof(bhs_t);
267      if(pp->ahs_len) {
268 	  len += pp->ahs_len;
269 	  bhp->AHSLength =  pp->ahs_len / 4;
270      }
271      if(sp->hdrDigest)
272 	  len += 4;
273      if(pp->ds_len) {
274 	  n = pp->ds_len;
275 	  len += n;
276 #if BYTE_ORDER == LITTLE_ENDIAN
277 	  bhp->DSLength = ((n & 0x00ff0000) >> 16)
278 	       | (n & 0x0000ff00)
279 	       | ((n & 0x000000ff) << 16);
280 #else
281 	  bhp->DSLength = n;
282 #endif
283 	  if(len & 03) {
284 	       n = 4 - (len & 03);
285 	       len += n;
286 	  }
287 	  if(sp->dataDigest)
288 	       len += 4;
289      }
290 
291      pq->len = len;
292      len -= sizeof(bhs_t);
293      if(sp->opt.maxBurstLength && (len > sp->opt.maxBurstLength)) {
294 	  xdebug("%d] pdu len=%zd > %d",
295 		 sp->sid, len, sp->opt.maxBurstLength);
296 	  // XXX: when this happens it used to hang ...
297 	  return E2BIG;
298      }
299      return 0;
300 }
301 
302 int
303 isc_qout(isc_session_t *sp, pduq_t *pq)
304 {
305      int error = 0;
306 
307      debug_called(8);
308 
309      if(pq->len == 0 && (error = i_prepPDU(sp, pq)))
310 	  return error;
311 
312      if(pq->pdu.ipdu.bhs.I)
313 	  i_nqueue_isnd(sp, pq);
314      else
315      if(pq->pdu.ipdu.data_out.opcode == ISCSI_WRITE_DATA)
316 	  i_nqueue_wsnd(sp, pq);
317      else
318 	  i_nqueue_csnd(sp, pq);
319 
320      sdebug(5, "enqued: pq=%p", pq);
321 
322      iscsi_lock_ex(&sp->io_mtx);
323      sp->flags |= ISC_OQNOTEMPTY;
324      if(sp->flags & ISC_OWAITING)
325      wakeup(&sp->flags);
326      iscsi_unlock_ex(&sp->io_mtx);
327 
328      return error;
329 }
330 /*
331  | called when a fullPhase is restarted
332  */
333 static void
334 ism_restart(isc_session_t *sp)
335 {
336      int lastcmd;
337 
338      sdebug(2, "restart ...");
339      lastcmd = iscsi_requeue(sp);
340 #if 0
341      if(lastcmd != sp->sn.cmd) {
342 	  sdebug(1, "resetting CmdSN to=%d (from %d)", lastcmd, sp->sn.cmd);
343 	  sp->sn.cmd = lastcmd;
344      }
345 #endif
346      iscsi_lock_ex(&sp->io_mtx);
347      if(sp->flags & ISC_OWAITING) {
348 	  wakeup(&sp->flags);
349      }
350      iscsi_unlock_ex(&sp->io_mtx);
351 
352      sdebug(2, "restarted lastcmd=0x%x", lastcmd);
353 }
354 
355 int
356 ism_fullfeature(struct cdev *dev, int flag)
357 {
358      isc_session_t *sp = (isc_session_t *)dev->si_drv2;
359      int	error;
360 
361      sdebug(2, "flag=%d", flag);
362 
363      error = 0;
364      switch(flag) {
365      case 0: // stop
366 	  sp->flags &= ~ISC_FFPHASE;
367 	  break;
368      case 1: // start
369 	  error = ic_fullfeature(dev);
370 	  break;
371      case 2: // restart
372 	  ism_restart(sp);
373 	  break;
374      }
375      return error;
376 }
377 
378 void
379 ism_recv(isc_session_t *sp, pduq_t *pq)
380 {
381      bhs_t	*bhs;
382      int	statSN;
383 
384      debug_called(8);
385 
386      bhs = &pq->pdu.ipdu.bhs;
387      statSN = ntohl(bhs->OpcodeSpecificFields[1]);
388 #if 0
389      {
390 	  /*
391 	   | this code is only for debugging.
392 	   */
393 	  sn_t	*sn = &sp->sn;
394 	  if(sp->cws == 0) {
395 	       if((sp->flags & ISC_STALLED) == 0) {
396 		    sdebug(4, "window closed: max=0x%x exp=0x%x opcode=0x%x cmd=0x%x cws=%d.",
397 			   sn->maxCmd, sn->expCmd, bhs->opcode, sn->cmd, sp->cws);
398 		    sp->flags |= ISC_STALLED;
399 	       } else
400 	       if(sp->flags & ISC_STALLED) {
401 		    sdebug(4, "window opened: max=0x%x exp=0x%x opcode=0x%x cmd=0x%x cws=%d.",
402 			   sn->maxCmd, sn->expCmd, bhs->opcode, sn->cmd, sp->cws);
403 		    sp->flags &= ~ISC_STALLED;;
404 	       }
405 	  }
406      }
407 #endif
408 
409 #ifdef notyet
410      if(sp->sn.expCmd != sn->cmd) {
411 	  sdebug(1, "we lost something ... exp=0x%x cmd=0x%x",
412 		 sn->expCmd, sn->cmd);
413      }
414 #endif
415      sdebug(5, "opcode=0x%x itt=0x%x stat#0x%x maxcmd=0x%0x",
416 	    bhs->opcode, ntohl(bhs->itt), statSN, sp->sn.maxCmd);
417 
418      switch(bhs->opcode) {
419      case ISCSI_READ_DATA: {
420 	  data_in_t 	*cmd = &pq->pdu.ipdu.data_in;
421 
422 	  if(cmd->S == 0)
423 	       break;
424      }
425 
426      default:
427 	  if(statSN > (sp->sn.stat + 1)) {
428 	       sdebug(1, "we lost some rec=0x%x exp=0x%x",
429 		      statSN, sp->sn.stat);
430 	       // XXX: must do some error recovery here.
431 	  }
432 	  sp->sn.stat = statSN;
433      }
434 
435      switch(bhs->opcode) {
436      case ISCSI_LOGIN_RSP:
437      case ISCSI_TEXT_RSP:
438      case ISCSI_LOGOUT_RSP:
439 	  i_nqueue_rsp(sp, pq);
440 	  wakeup(&sp->rsp);
441 	  sdebug(3, "wakeup rsp");
442 	  break;
443 
444      case ISCSI_NOP_IN:		_nop_in(sp, pq);	break;
445      case ISCSI_SCSI_RSP:	_scsi_rsp(sp, pq);	break;
446      case ISCSI_READ_DATA:	_read_data(sp, pq);	break;
447      case ISCSI_R2T:		_r2t(sp, pq);		break;
448      case ISCSI_REJECT:		_reject(sp, pq);	break;
449      case ISCSI_ASYNC:		_async(sp, pq);		break;
450 
451      case ISCSI_TASK_RSP:
452      default:
453 	  sdebug(1, "opcode=0x%x itt=0x%x not implemented yet",
454 		 bhs->opcode, ntohl(bhs->itt));
455 	  break;
456      }
457 }
458 
459 /*
460  | go through the out queues looking for work
461  | if either nothing to do, or window is closed
462  | return.
463  */
464 static int
465 proc_out(isc_session_t *sp)
466 {
467      sn_t	*sn = &sp->sn;
468      pduq_t	*pq;
469      int	error, ndone;
470      int	which;
471 
472      debug_called(8);
473      error = ndone = 0;
474 
475      while(sp->flags & ISC_LINK_UP) {
476 	  pdu_t *pp;
477 	  bhs_t	*bhs;
478 	  /*
479 	   | check if there is outstanding work in:
480 	   | 1- the Immediate queue
481 	   | 2- the R2T queue
482 	   | 3- the cmd queue, only if the command window allows it.
483 	   */
484 	  which = BIT(0) | BIT(1);
485 	  if(SNA_GT(sn->cmd, sn->maxCmd) == 0) // if(sn->maxCmd - sn->smc + 1) > 0
486 	       which |= BIT(2);
487 
488 	  sdebug(4, "which=%d sn->maxCmd=%d sn->cmd=%d", which, sn->maxCmd, sn->cmd);
489 
490 	  if((pq = i_dqueue_snd(sp, which)) == NULL)
491 	       break;
492 	  sdebug(4, "pq=%p", pq);
493 
494 	  pp = &pq->pdu;
495 	  bhs = &pp->ipdu.bhs;
496 	  switch(bhs->opcode) {
497 	  case ISCSI_SCSI_CMD:
498 	       sn->itt++;
499 	       bhs->itt = htonl(sn->itt);
500 
501 	  case ISCSI_LOGIN_CMD:
502 	  case ISCSI_TEXT_CMD:
503 	  case ISCSI_LOGOUT_CMD:
504 	  case ISCSI_SNACK:
505 	  case ISCSI_NOP_OUT:
506 	  case ISCSI_TASK_CMD:
507 	       bhs->CmdSN = htonl(sn->cmd);
508 	       if(bhs->I == 0)
509 		    sn->cmd++;
510 
511 	  case ISCSI_WRITE_DATA:
512 	       bhs->ExpStSN = htonl(sn->stat);
513 	       break;
514 
515 	  default:
516 	       // XXX: can this happen?
517 	       xdebug("bad opcode=0x%x sn(cmd=0x%x expCmd=0x%x maxCmd=0x%x expStat=0x%x itt=0x%x)",
518 		      bhs->opcode,
519 		      sn->cmd, sn->expCmd, sn->maxCmd, sn->expStat, sn->itt);
520 	       // XXX: and now?
521 	  }
522 
523 	  sdebug(4, "opcode=0x%x sn(cmd=0x%x expCmd=0x%x maxCmd=0x%x expStat=0x%x itt=0x%x)",
524 		bhs->opcode,
525 		sn->cmd, sn->expCmd, sn->maxCmd, sn->expStat, sn->itt);
526 
527 	  if(pq->ccb)
528 	       i_nqueue_hld(sp, pq);
529 
530 	  if((error = isc_sendPDU(sp, pq)) == 0) {
531 	       ndone++;
532 	       if(pq->ccb == NULL)
533 		    pdu_free(sp->isc, pq);
534 	  }
535 	  else {
536 	       xdebug("error=%d ndone=%d opcode=0x%x ccb=%p itt=%x",
537 		      error, ndone, bhs->opcode, pq->ccb, ntohl(bhs->itt));
538 	       if(pq->ccb)
539 		    i_remove_hld(sp, pq);
540 	       switch(error) {
541 	       case EPIPE:
542 		    sp->flags &= ~ISC_LINK_UP;
543 
544 	       case EAGAIN:
545 		    xdebug("requed");
546 		    i_rqueue_pdu(sp, pq);
547 		    break;
548 
549 	       default:
550 	       if(pq->ccb) {
551 			 xdebug("back to cam");
552 			 pq->ccb->ccb_h.status |= CAM_REQUEUE_REQ; // some better error?
553 			 XPT_DONE(sp->isc, pq->ccb);
554 			 pdu_free(sp->isc, pq);
555 	       }
556 		    else
557 			 xdebug("we lost it!");
558 	       }
559 	  }
560      }
561      return error;
562 }
563 
564 /*
565  | survives link breakdowns.
566  */
567 static void
568 ism_proc(void *vp)
569 {
570      isc_session_t 	*sp = (isc_session_t *)vp;
571      int		error;
572 
573      debug_called(8);
574 
575      sdebug(3, "started sp->flags=%x", sp->flags);
576      do {
577 	  if((sp->flags & ISC_HOLD) == 0) {
578 	       error = proc_out(sp);
579 	       if(error) {
580 		    sdebug(3, "error=%d", error);
581 	       }
582 	  }
583 	  iscsi_lock_ex(&sp->io_mtx);
584 	  if((sp->flags & ISC_LINK_UP) == 0) {
585 	       wakeup(&sp->soc);
586 	  }
587 
588 	  if((sp->flags & (ISC_OQNOTEMPTY | ISC_SM_RUN)) == ISC_SM_RUN) {
589 	       sp->flags |= ISC_OWAITING;
590 	       if(issleep(&sp->flags, &sp->io_mtx, 0, "iscproc", hz*30) == EWOULDBLOCK) {
591 		    if(sp->flags & ISC_CON_RUNNING)
592 		    _nop_out(sp);
593 	       }
594 	       sp->flags &= ~ISC_OWAITING;
595 	  }
596 	  sp->flags &= ~ISC_OQNOTEMPTY;
597 	  iscsi_unlock_ex(&sp->io_mtx);
598      } while(sp->flags & ISC_SM_RUN);
599 
600      sp->flags &= ~ISC_SM_RUNNING;
601      sdebug(3, "dropped ISC_SM_RUNNING");
602 
603      wakeup(sp);
604 
605      debug(3, "terminated sp=%p sp->sid=%d", sp, sp->sid);
606 
607      kthread_exit();
608 }
609 
610 #if 0
611 static int
612 isc_dump_options(SYSCTL_HANDLER_ARGS)
613 {
614      int error;
615      isc_session_t *sp;
616      char	buf[1024], *bp;
617 
618      sp = (isc_session_t *)arg1;
619      bp = buf;
620      ksprintf(bp, "targetname='%s'", sp->opt.targetName);
621      bp += strlen(bp);
622      ksprintf(bp, " targetname='%s'", sp->opt.targetAddress);
623      error = SYSCTL_OUT(req, buf, strlen(buf));
624      return error;
625 }
626 #endif
627 
628 static int
629 isc_dump_stats(SYSCTL_HANDLER_ARGS)
630 {
631      isc_session_t	*sp;
632      struct isc_softc	*sc;
633      char	buf[1024], *bp;
634      int 	error, n;
635 
636      sp = (isc_session_t *)arg1;
637      sc = sp->isc;
638 
639      bp = buf;
640      n = sizeof(buf);
641      ksnprintf(bp, n, "recv=%d sent=%d", sp->stats.nrecv, sp->stats.nsent);
642      bp += strlen(bp);
643      n -= strlen(bp);
644      ksnprintf(bp, n, " flags=0x%08x pdus-alloc=%d pdus-max=%d",
645 		  sp->flags, sc->npdu_alloc, sc->npdu_max);
646      bp += strlen(bp);
647      n -= strlen(bp);
648      ksnprintf(bp, n, " cws=%d cmd=%x exp=%x max=%x stat=%x itt=%x",
649 		  sp->cws, sp->sn.cmd, sp->sn.expCmd, sp->sn.maxCmd, sp->sn.stat, sp->sn.itt);
650      error = SYSCTL_OUT(req, buf, strlen(buf));
651      return error;
652 }
653 
654 static int
655 isc_sysctl_targetName(SYSCTL_HANDLER_ARGS)
656 {
657      char	buf[128], **cp;
658      int 	error;
659 
660      cp = (char **)arg1;
661      ksnprintf(buf, sizeof(buf), "%s", *cp);
662      error = SYSCTL_OUT(req, buf, strlen(buf));
663      return error;
664 }
665 static int
666 isc_sysctl_targetAddress(SYSCTL_HANDLER_ARGS)
667 {
668      char	buf[128], **cp;
669      int 	error;
670 
671      cp = (char **)arg1;
672      ksnprintf(buf, sizeof(buf), "%s", *cp);
673      error = SYSCTL_OUT(req, buf, strlen(buf));
674      return error;
675 }
676 static void
677 isc_add_sysctls(isc_session_t *sp)
678 {
679      debug_called(8);
680      sdebug(6, "sid=%d %s", sp->sid, sp->dev->si_name);
681 
682      sysctl_ctx_init(&sp->clist);
683      sp->oid = SYSCTL_ADD_NODE(&sp->clist,
684 			       SYSCTL_CHILDREN(sp->isc->oid),
685 			       OID_AUTO,
686 			       sp->dev->si_name+5, // iscsi0
687 			       CTLFLAG_RD,
688 			       0,
689 			       "initiator");
690      SYSCTL_ADD_PROC(&sp->clist,
691 		     SYSCTL_CHILDREN(sp->oid),
692 		     OID_AUTO,
693 		     "targetname",
694 		     CTLFLAG_RD,
695 		     (void *)&sp->opt.targetName, 0,
696 		     isc_sysctl_targetName, "A", "target name");
697 
698      SYSCTL_ADD_PROC(&sp->clist,
699 		     SYSCTL_CHILDREN(sp->oid),
700 		     OID_AUTO,
701 		     "targeaddress",
702 		     CTLFLAG_RD,
703 		     (void *)&sp->opt.targetAddress, 0,
704 		     isc_sysctl_targetAddress, "A", "target address");
705 
706      SYSCTL_ADD_PROC(&sp->clist,
707 		     SYSCTL_CHILDREN(sp->oid),
708 		     OID_AUTO,
709 		     "stats",
710 		     CTLFLAG_RD,
711 		     (void *)sp, 0,
712 		     isc_dump_stats, "A", "statistics");
713 
714      SYSCTL_ADD_INT(&sp->clist,
715 		     SYSCTL_CHILDREN(sp->oid),
716 		     OID_AUTO,
717 		     "douio",
718 		     CTLFLAG_RW,
719 		     &sp->douio, 0, "enable uio on read");
720 }
721 
722 void
723 ism_stop(isc_session_t *sp)
724 {
725      struct isc_softc *sc = sp->isc;
726      cdev_t	dev;
727 
728      debug_called(8);
729      sdebug(2, "terminating");
730      /*
731       | first stop the receiver
732       */
733      isc_stop_receiver(sp);
734 
735      /*
736       | now stop the xmitter
737       */
738      sp->flags &= ~ISC_SM_RUN;
739      while(sp->flags & ISC_SM_RUNNING) {
740 	  sdebug(2, "waiting for ism to stop");
741 	  wakeup(&sp->flags);
742 	  tsleep(sp, 0, "-", hz);
743      }
744      sdebug(2, "ism stopped");
745      sp->flags &= ~ISC_FFPHASE;
746 
747      iscsi_cleanup(sp);
748 
749      (void)i_pdu_flush(sp);
750 
751      ic_lost_target(sp, sp->sid);
752 
753      lockmgr(&sc->lock, LK_EXCLUSIVE);
754      TAILQ_REMOVE(&sc->isc_sess, sp, sp_link);
755      sc->nsess--;
756      lockmgr(&sc->lock, LK_RELEASE);
757 
758      dev = sp->dev;
759      sp->dev = NULL;
760 
761      release_dev(dev);
762      destroy_dev(dev);
763 
764      mtx_uninit(&sp->rsp_mtx);
765      mtx_uninit(&sp->rsv_mtx);
766      mtx_uninit(&sp->hld_mtx);
767      mtx_uninit(&sp->snd_mtx);
768      mtx_uninit(&sp->io_mtx);
769 
770      i_freeopt(&sp->opt);
771      sc->sessions[sp->sid] = NULL;
772 
773      if(sysctl_ctx_free(&sp->clist))
774 	  xdebug("sysctl_ctx_free failed");
775 
776      kfree(sp, M_ISCSI);
777 }
778 
779 int
780 ism_start(isc_session_t *sp)
781 {
782      debug_called(8);
783     /*
784      | now is a good time to do some initialization
785      */
786      TAILQ_INIT(&sp->rsp);
787      TAILQ_INIT(&sp->rsv);
788      TAILQ_INIT(&sp->csnd);
789      TAILQ_INIT(&sp->isnd);
790      TAILQ_INIT(&sp->wsnd);
791      TAILQ_INIT(&sp->hld);
792 
793      mtx_init(&sp->rsv_mtx);
794      mtx_init(&sp->rsp_mtx);
795      mtx_init(&sp->snd_mtx);
796      mtx_init(&sp->hld_mtx);
797 
798      mtx_init(&sp->io_mtx);
799 
800      isc_add_sysctls(sp);
801 
802      sp->flags |= ISC_SM_RUN;
803      sp->flags |= ISC_SM_RUNNING;
804 
805      debug(4, "starting ism_proc: sp->sid=%d", sp->sid);
806      return kthread_create(ism_proc, sp, &sp->stp, "ism_%d", sp->sid);
807 }
808