1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright(c) 2007 - 2008 Intel Corporation. All rights reserved.
4  *
5  * Maintained at www.Open-FCoE.org
6  */
7 
8 /*
9  * Target Discovery
10  *
11  * This block discovers all FC-4 remote ports, including FCP initiators. It
12  * also handles RSCN events and re-discovery if necessary.
13  */
14 
15 /*
16  * DISC LOCKING
17  *
18  * The disc mutex is can be locked when acquiring rport locks, but may not
19  * be held when acquiring the lport lock. Refer to fc_lport.c for more
20  * details.
21  */
22 
23 #include <linux/timer.h>
24 #include <linux/slab.h>
25 #include <linux/err.h>
26 #include <linux/export.h>
27 #include <linux/rculist.h>
28 
29 #include <asm/unaligned.h>
30 
31 #include <scsi/fc/fc_gs.h>
32 
33 #include <scsi/libfc.h>
34 
35 #include "fc_libfc.h"
36 
37 #define FC_DISC_RETRY_LIMIT	3	/* max retries */
38 #define FC_DISC_RETRY_DELAY	500UL	/* (msecs) delay */
39 
40 static void fc_disc_gpn_ft_req(struct fc_disc *);
41 static void fc_disc_gpn_ft_resp(struct fc_seq *, struct fc_frame *, void *);
42 static void fc_disc_done(struct fc_disc *, enum fc_disc_event);
43 static void fc_disc_timeout(struct work_struct *);
44 static int fc_disc_single(struct fc_lport *, struct fc_disc_port *);
45 static void fc_disc_restart(struct fc_disc *);
46 
47 /**
48  * fc_disc_stop_rports() - Delete all the remote ports associated with the lport
49  * @disc: The discovery job to stop remote ports on
50  */
fc_disc_stop_rports(struct fc_disc * disc)51 static void fc_disc_stop_rports(struct fc_disc *disc)
52 {
53 	struct fc_rport_priv *rdata;
54 
55 	lockdep_assert_held(&disc->disc_mutex);
56 
57 	list_for_each_entry(rdata, &disc->rports, peers) {
58 		if (kref_get_unless_zero(&rdata->kref)) {
59 			fc_rport_logoff(rdata);
60 			kref_put(&rdata->kref, fc_rport_destroy);
61 		}
62 	}
63 }
64 
65 /**
66  * fc_disc_recv_rscn_req() - Handle Registered State Change Notification (RSCN)
67  * @disc:  The discovery object to which the RSCN applies
68  * @fp:	   The RSCN frame
69  */
fc_disc_recv_rscn_req(struct fc_disc * disc,struct fc_frame * fp)70 static void fc_disc_recv_rscn_req(struct fc_disc *disc, struct fc_frame *fp)
71 {
72 	struct fc_lport *lport;
73 	struct fc_els_rscn *rp;
74 	struct fc_els_rscn_page *pp;
75 	struct fc_seq_els_data rjt_data;
76 	unsigned int len;
77 	int redisc = 0;
78 	enum fc_els_rscn_ev_qual ev_qual;
79 	enum fc_els_rscn_addr_fmt fmt;
80 	LIST_HEAD(disc_ports);
81 	struct fc_disc_port *dp, *next;
82 
83 	lockdep_assert_held(&disc->disc_mutex);
84 
85 	lport = fc_disc_lport(disc);
86 
87 	FC_DISC_DBG(disc, "Received an RSCN event\n");
88 
89 	/* make sure the frame contains an RSCN message */
90 	rp = fc_frame_payload_get(fp, sizeof(*rp));
91 	if (!rp)
92 		goto reject;
93 	/* make sure the page length is as expected (4 bytes) */
94 	if (rp->rscn_page_len != sizeof(*pp))
95 		goto reject;
96 	/* get the RSCN payload length */
97 	len = ntohs(rp->rscn_plen);
98 	if (len < sizeof(*rp))
99 		goto reject;
100 	/* make sure the frame contains the expected payload */
101 	rp = fc_frame_payload_get(fp, len);
102 	if (!rp)
103 		goto reject;
104 	/* payload must be a multiple of the RSCN page size */
105 	len -= sizeof(*rp);
106 	if (len % sizeof(*pp))
107 		goto reject;
108 
109 	for (pp = (void *)(rp + 1); len > 0; len -= sizeof(*pp), pp++) {
110 		ev_qual = pp->rscn_page_flags >> ELS_RSCN_EV_QUAL_BIT;
111 		ev_qual &= ELS_RSCN_EV_QUAL_MASK;
112 		fmt = pp->rscn_page_flags >> ELS_RSCN_ADDR_FMT_BIT;
113 		fmt &= ELS_RSCN_ADDR_FMT_MASK;
114 		/*
115 		 * if we get an address format other than port
116 		 * (area, domain, fabric), then do a full discovery
117 		 */
118 		switch (fmt) {
119 		case ELS_ADDR_FMT_PORT:
120 			FC_DISC_DBG(disc, "Port address format for port "
121 				    "(%6.6x)\n", ntoh24(pp->rscn_fid));
122 			dp = kzalloc(sizeof(*dp), GFP_KERNEL);
123 			if (!dp) {
124 				redisc = 1;
125 				break;
126 			}
127 			dp->lp = lport;
128 			dp->port_id = ntoh24(pp->rscn_fid);
129 			list_add_tail(&dp->peers, &disc_ports);
130 			break;
131 		case ELS_ADDR_FMT_AREA:
132 		case ELS_ADDR_FMT_DOM:
133 		case ELS_ADDR_FMT_FAB:
134 		default:
135 			FC_DISC_DBG(disc, "Address format is (%d)\n", fmt);
136 			redisc = 1;
137 			break;
138 		}
139 	}
140 	fc_seq_els_rsp_send(fp, ELS_LS_ACC, NULL);
141 
142 	/*
143 	 * If not doing a complete rediscovery, do GPN_ID on
144 	 * the individual ports mentioned in the list.
145 	 * If any of these get an error, do a full rediscovery.
146 	 * In any case, go through the list and free the entries.
147 	 */
148 	list_for_each_entry_safe(dp, next, &disc_ports, peers) {
149 		list_del(&dp->peers);
150 		if (!redisc)
151 			redisc = fc_disc_single(lport, dp);
152 		kfree(dp);
153 	}
154 	if (redisc) {
155 		FC_DISC_DBG(disc, "RSCN received: rediscovering\n");
156 		fc_disc_restart(disc);
157 	} else {
158 		FC_DISC_DBG(disc, "RSCN received: not rediscovering. "
159 			    "redisc %d state %d in_prog %d\n",
160 			    redisc, lport->state, disc->pending);
161 	}
162 	fc_frame_free(fp);
163 	return;
164 reject:
165 	FC_DISC_DBG(disc, "Received a bad RSCN frame\n");
166 	rjt_data.reason = ELS_RJT_LOGIC;
167 	rjt_data.explan = ELS_EXPL_NONE;
168 	fc_seq_els_rsp_send(fp, ELS_LS_RJT, &rjt_data);
169 	fc_frame_free(fp);
170 }
171 
172 /**
173  * fc_disc_recv_req() - Handle incoming requests
174  * @lport: The local port receiving the request
175  * @fp:	   The request frame
176  *
177  * Locking Note: This function is called from the EM and will lock
178  *		 the disc_mutex before calling the handler for the
179  *		 request.
180  */
fc_disc_recv_req(struct fc_lport * lport,struct fc_frame * fp)181 static void fc_disc_recv_req(struct fc_lport *lport, struct fc_frame *fp)
182 {
183 	u8 op;
184 	struct fc_disc *disc = &lport->disc;
185 
186 	op = fc_frame_payload_op(fp);
187 	switch (op) {
188 	case ELS_RSCN:
189 		mutex_lock(&disc->disc_mutex);
190 		fc_disc_recv_rscn_req(disc, fp);
191 		mutex_unlock(&disc->disc_mutex);
192 		break;
193 	default:
194 		FC_DISC_DBG(disc, "Received an unsupported request, "
195 			    "the opcode is (%x)\n", op);
196 		fc_frame_free(fp);
197 		break;
198 	}
199 }
200 
201 /**
202  * fc_disc_restart() - Restart discovery
203  * @disc: The discovery object to be restarted
204  */
fc_disc_restart(struct fc_disc * disc)205 static void fc_disc_restart(struct fc_disc *disc)
206 {
207 	lockdep_assert_held(&disc->disc_mutex);
208 
209 	if (!disc->disc_callback)
210 		return;
211 
212 	FC_DISC_DBG(disc, "Restarting discovery\n");
213 
214 	disc->requested = 1;
215 	if (disc->pending)
216 		return;
217 
218 	/*
219 	 * Advance disc_id.  This is an arbitrary non-zero number that will
220 	 * match the value in the fc_rport_priv after discovery for all
221 	 * freshly-discovered remote ports.  Avoid wrapping to zero.
222 	 */
223 	disc->disc_id = (disc->disc_id + 2) | 1;
224 	disc->retry_count = 0;
225 	fc_disc_gpn_ft_req(disc);
226 }
227 
228 /**
229  * fc_disc_start() - Start discovery on a local port
230  * @lport:	   The local port to have discovery started on
231  * @disc_callback: Callback function to be called when discovery is complete
232  */
fc_disc_start(void (* disc_callback)(struct fc_lport *,enum fc_disc_event),struct fc_lport * lport)233 static void fc_disc_start(void (*disc_callback)(struct fc_lport *,
234 						enum fc_disc_event),
235 			  struct fc_lport *lport)
236 {
237 	struct fc_disc *disc = &lport->disc;
238 
239 	/*
240 	 * At this point we may have a new disc job or an existing
241 	 * one. Either way, let's lock when we make changes to it
242 	 * and send the GPN_FT request.
243 	 */
244 	mutex_lock(&disc->disc_mutex);
245 	disc->disc_callback = disc_callback;
246 	fc_disc_restart(disc);
247 	mutex_unlock(&disc->disc_mutex);
248 }
249 
250 /**
251  * fc_disc_done() - Discovery has been completed
252  * @disc:  The discovery context
253  * @event: The discovery completion status
254  */
fc_disc_done(struct fc_disc * disc,enum fc_disc_event event)255 static void fc_disc_done(struct fc_disc *disc, enum fc_disc_event event)
256 {
257 	struct fc_lport *lport = fc_disc_lport(disc);
258 	struct fc_rport_priv *rdata;
259 
260 	lockdep_assert_held(&disc->disc_mutex);
261 	FC_DISC_DBG(disc, "Discovery complete\n");
262 
263 	disc->pending = 0;
264 	if (disc->requested) {
265 		fc_disc_restart(disc);
266 		return;
267 	}
268 
269 	/*
270 	 * Go through all remote ports.	 If they were found in the latest
271 	 * discovery, reverify or log them in.	Otherwise, log them out.
272 	 * Skip ports which were never discovered.  These are the dNS port
273 	 * and ports which were created by PLOGI.
274 	 *
275 	 * We don't need to use the _rcu variant here as the rport list
276 	 * is protected by the disc mutex which is already held on entry.
277 	 */
278 	list_for_each_entry(rdata, &disc->rports, peers) {
279 		if (!kref_get_unless_zero(&rdata->kref))
280 			continue;
281 		if (rdata->disc_id) {
282 			if (rdata->disc_id == disc->disc_id)
283 				fc_rport_login(rdata);
284 			else
285 				fc_rport_logoff(rdata);
286 		}
287 		kref_put(&rdata->kref, fc_rport_destroy);
288 	}
289 	mutex_unlock(&disc->disc_mutex);
290 	disc->disc_callback(lport, event);
291 	mutex_lock(&disc->disc_mutex);
292 }
293 
294 /**
295  * fc_disc_error() - Handle error on dNS request
296  * @disc: The discovery context
297  * @fp:	  The error code encoded as a frame pointer
298  */
fc_disc_error(struct fc_disc * disc,struct fc_frame * fp)299 static void fc_disc_error(struct fc_disc *disc, struct fc_frame *fp)
300 {
301 	struct fc_lport *lport = fc_disc_lport(disc);
302 	unsigned long delay = 0;
303 
304 	FC_DISC_DBG(disc, "Error %d, retries %d/%d\n",
305 		    PTR_ERR_OR_ZERO(fp), disc->retry_count,
306 		    FC_DISC_RETRY_LIMIT);
307 
308 	if (!fp || PTR_ERR(fp) == -FC_EX_TIMEOUT) {
309 		/*
310 		 * Memory allocation failure, or the exchange timed out,
311 		 * retry after delay.
312 		 */
313 		if (disc->retry_count < FC_DISC_RETRY_LIMIT) {
314 			/* go ahead and retry */
315 			if (!fp)
316 				delay = msecs_to_jiffies(FC_DISC_RETRY_DELAY);
317 			else {
318 				delay = msecs_to_jiffies(lport->e_d_tov);
319 
320 				/* timeout faster first time */
321 				if (!disc->retry_count)
322 					delay /= 4;
323 			}
324 			disc->retry_count++;
325 			schedule_delayed_work(&disc->disc_work, delay);
326 		} else
327 			fc_disc_done(disc, DISC_EV_FAILED);
328 	} else if (PTR_ERR(fp) == -FC_EX_CLOSED) {
329 		/*
330 		 * if discovery fails due to lport reset, clear
331 		 * pending flag so that subsequent discovery can
332 		 * continue
333 		 */
334 		disc->pending = 0;
335 	}
336 }
337 
338 /**
339  * fc_disc_gpn_ft_req() - Send Get Port Names by FC-4 type (GPN_FT) request
340  * @disc: The discovery context
341  */
fc_disc_gpn_ft_req(struct fc_disc * disc)342 static void fc_disc_gpn_ft_req(struct fc_disc *disc)
343 {
344 	struct fc_frame *fp;
345 	struct fc_lport *lport = fc_disc_lport(disc);
346 
347 	lockdep_assert_held(&disc->disc_mutex);
348 
349 	WARN_ON(!fc_lport_test_ready(lport));
350 
351 	disc->pending = 1;
352 	disc->requested = 0;
353 
354 	disc->buf_len = 0;
355 	disc->seq_count = 0;
356 	fp = fc_frame_alloc(lport,
357 			    sizeof(struct fc_ct_hdr) +
358 			    sizeof(struct fc_ns_gid_ft));
359 	if (!fp)
360 		goto err;
361 
362 	if (lport->tt.elsct_send(lport, 0, fp,
363 				 FC_NS_GPN_FT,
364 				 fc_disc_gpn_ft_resp,
365 				 disc, 3 * lport->r_a_tov))
366 		return;
367 err:
368 	fc_disc_error(disc, NULL);
369 }
370 
371 /**
372  * fc_disc_gpn_ft_parse() - Parse the body of the dNS GPN_FT response.
373  * @disc:  The discovery context
374  * @buf:   The GPN_FT response buffer
375  * @len:   The size of response buffer
376  *
377  * Goes through the list of IDs and names resulting from a request.
378  */
fc_disc_gpn_ft_parse(struct fc_disc * disc,void * buf,size_t len)379 static int fc_disc_gpn_ft_parse(struct fc_disc *disc, void *buf, size_t len)
380 {
381 	struct fc_lport *lport;
382 	struct fc_gpn_ft_resp *np;
383 	char *bp;
384 	size_t plen;
385 	size_t tlen;
386 	int error = 0;
387 	struct fc_rport_identifiers ids;
388 	struct fc_rport_priv *rdata;
389 
390 	lport = fc_disc_lport(disc);
391 	disc->seq_count++;
392 
393 	/*
394 	 * Handle partial name record left over from previous call.
395 	 */
396 	bp = buf;
397 	plen = len;
398 	np = (struct fc_gpn_ft_resp *)bp;
399 	tlen = disc->buf_len;
400 	disc->buf_len = 0;
401 	if (tlen) {
402 		WARN_ON(tlen >= sizeof(*np));
403 		plen = sizeof(*np) - tlen;
404 		WARN_ON(plen <= 0);
405 		WARN_ON(plen >= sizeof(*np));
406 		if (plen > len)
407 			plen = len;
408 		np = &disc->partial_buf;
409 		memcpy((char *)np + tlen, bp, plen);
410 
411 		/*
412 		 * Set bp so that the loop below will advance it to the
413 		 * first valid full name element.
414 		 */
415 		bp -= tlen;
416 		len += tlen;
417 		plen += tlen;
418 		disc->buf_len = (unsigned char) plen;
419 		if (plen == sizeof(*np))
420 			disc->buf_len = 0;
421 	}
422 
423 	/*
424 	 * Handle full name records, including the one filled from above.
425 	 * Normally, np == bp and plen == len, but from the partial case above,
426 	 * bp, len describe the overall buffer, and np, plen describe the
427 	 * partial buffer, which if would usually be full now.
428 	 * After the first time through the loop, things return to "normal".
429 	 */
430 	while (plen >= sizeof(*np)) {
431 		ids.port_id = ntoh24(np->fp_fid);
432 		ids.port_name = ntohll(np->fp_wwpn);
433 
434 		if (ids.port_id != lport->port_id &&
435 		    ids.port_name != lport->wwpn) {
436 			rdata = fc_rport_create(lport, ids.port_id);
437 			if (rdata) {
438 				rdata->ids.port_name = ids.port_name;
439 				rdata->disc_id = disc->disc_id;
440 			} else {
441 				printk(KERN_WARNING "libfc: Failed to allocate "
442 				       "memory for the newly discovered port "
443 				       "(%6.6x)\n", ids.port_id);
444 				error = -ENOMEM;
445 			}
446 		}
447 
448 		if (np->fp_flags & FC_NS_FID_LAST) {
449 			fc_disc_done(disc, DISC_EV_SUCCESS);
450 			len = 0;
451 			break;
452 		}
453 		len -= sizeof(*np);
454 		bp += sizeof(*np);
455 		np = (struct fc_gpn_ft_resp *)bp;
456 		plen = len;
457 	}
458 
459 	/*
460 	 * Save any partial record at the end of the buffer for next time.
461 	 */
462 	if (error == 0 && len > 0 && len < sizeof(*np)) {
463 		if (np != &disc->partial_buf) {
464 			FC_DISC_DBG(disc, "Partial buffer remains "
465 				    "for discovery\n");
466 			memcpy(&disc->partial_buf, np, len);
467 		}
468 		disc->buf_len = (unsigned char) len;
469 	}
470 	return error;
471 }
472 
473 /**
474  * fc_disc_timeout() - Handler for discovery timeouts
475  * @work: Structure holding discovery context that needs to retry discovery
476  */
fc_disc_timeout(struct work_struct * work)477 static void fc_disc_timeout(struct work_struct *work)
478 {
479 	struct fc_disc *disc = container_of(work,
480 					    struct fc_disc,
481 					    disc_work.work);
482 	mutex_lock(&disc->disc_mutex);
483 	fc_disc_gpn_ft_req(disc);
484 	mutex_unlock(&disc->disc_mutex);
485 }
486 
487 /**
488  * fc_disc_gpn_ft_resp() - Handle a response frame from Get Port Names (GPN_FT)
489  * @sp:	    The sequence that the GPN_FT response was received on
490  * @fp:	    The GPN_FT response frame
491  * @disc_arg: The discovery context
492  *
493  * Locking Note: This function is called without disc mutex held, and
494  *		 should do all its processing with the mutex held
495  */
fc_disc_gpn_ft_resp(struct fc_seq * sp,struct fc_frame * fp,void * disc_arg)496 static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp,
497 				void *disc_arg)
498 {
499 	struct fc_disc *disc = disc_arg;
500 	struct fc_ct_hdr *cp;
501 	struct fc_frame_header *fh;
502 	enum fc_disc_event event = DISC_EV_NONE;
503 	unsigned int seq_cnt;
504 	unsigned int len;
505 	int error = 0;
506 
507 	mutex_lock(&disc->disc_mutex);
508 	FC_DISC_DBG(disc, "Received a GPN_FT response\n");
509 
510 	if (IS_ERR(fp)) {
511 		fc_disc_error(disc, fp);
512 		mutex_unlock(&disc->disc_mutex);
513 		return;
514 	}
515 
516 	WARN_ON(!fc_frame_is_linear(fp));	/* buffer must be contiguous */
517 	fh = fc_frame_header_get(fp);
518 	len = fr_len(fp) - sizeof(*fh);
519 	seq_cnt = ntohs(fh->fh_seq_cnt);
520 	if (fr_sof(fp) == FC_SOF_I3 && seq_cnt == 0 && disc->seq_count == 0) {
521 		cp = fc_frame_payload_get(fp, sizeof(*cp));
522 		if (!cp) {
523 			FC_DISC_DBG(disc, "GPN_FT response too short, len %d\n",
524 				    fr_len(fp));
525 			event = DISC_EV_FAILED;
526 		} else if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
527 
528 			/* Accepted, parse the response. */
529 			len -= sizeof(*cp);
530 			error = fc_disc_gpn_ft_parse(disc, cp + 1, len);
531 		} else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
532 			FC_DISC_DBG(disc, "GPN_FT rejected reason %x exp %x "
533 				    "(check zoning)\n", cp->ct_reason,
534 				    cp->ct_explan);
535 			event = DISC_EV_FAILED;
536 			if (cp->ct_reason == FC_FS_RJT_UNABL &&
537 			    cp->ct_explan == FC_FS_EXP_FTNR)
538 				event = DISC_EV_SUCCESS;
539 		} else {
540 			FC_DISC_DBG(disc, "GPN_FT unexpected response code "
541 				    "%x\n", ntohs(cp->ct_cmd));
542 			event = DISC_EV_FAILED;
543 		}
544 	} else if (fr_sof(fp) == FC_SOF_N3 && seq_cnt == disc->seq_count) {
545 		error = fc_disc_gpn_ft_parse(disc, fh + 1, len);
546 	} else {
547 		FC_DISC_DBG(disc, "GPN_FT unexpected frame - out of sequence? "
548 			    "seq_cnt %x expected %x sof %x eof %x\n",
549 			    seq_cnt, disc->seq_count, fr_sof(fp), fr_eof(fp));
550 		event = DISC_EV_FAILED;
551 	}
552 	if (error)
553 		fc_disc_error(disc, ERR_PTR(error));
554 	else if (event != DISC_EV_NONE)
555 		fc_disc_done(disc, event);
556 	fc_frame_free(fp);
557 	mutex_unlock(&disc->disc_mutex);
558 }
559 
560 /**
561  * fc_disc_gpn_id_resp() - Handle a response frame from Get Port Names (GPN_ID)
562  * @sp:	       The sequence the GPN_ID is on
563  * @fp:	       The response frame
564  * @rdata_arg: The remote port that sent the GPN_ID response
565  *
566  * Locking Note: This function is called without disc mutex held.
567  */
fc_disc_gpn_id_resp(struct fc_seq * sp,struct fc_frame * fp,void * rdata_arg)568 static void fc_disc_gpn_id_resp(struct fc_seq *sp, struct fc_frame *fp,
569 				void *rdata_arg)
570 {
571 	struct fc_rport_priv *rdata = rdata_arg;
572 	struct fc_rport_priv *new_rdata;
573 	struct fc_lport *lport;
574 	struct fc_disc *disc;
575 	struct fc_ct_hdr *cp;
576 	struct fc_ns_gid_pn *pn;
577 	u64 port_name;
578 
579 	lport = rdata->local_port;
580 	disc = &lport->disc;
581 
582 	if (PTR_ERR(fp) == -FC_EX_CLOSED)
583 		goto out;
584 	if (IS_ERR(fp)) {
585 		mutex_lock(&disc->disc_mutex);
586 		fc_disc_restart(disc);
587 		mutex_unlock(&disc->disc_mutex);
588 		goto out;
589 	}
590 
591 	cp = fc_frame_payload_get(fp, sizeof(*cp));
592 	if (!cp)
593 		goto redisc;
594 	if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
595 		if (fr_len(fp) < sizeof(struct fc_frame_header) +
596 		    sizeof(*cp) + sizeof(*pn))
597 			goto redisc;
598 		pn = (struct fc_ns_gid_pn *)(cp + 1);
599 		port_name = get_unaligned_be64(&pn->fn_wwpn);
600 		mutex_lock(&rdata->rp_mutex);
601 		if (rdata->ids.port_name == -1)
602 			rdata->ids.port_name = port_name;
603 		else if (rdata->ids.port_name != port_name) {
604 			FC_DISC_DBG(disc, "GPN_ID accepted.  WWPN changed. "
605 				    "Port-id %6.6x wwpn %16.16llx\n",
606 				    rdata->ids.port_id, port_name);
607 			mutex_unlock(&rdata->rp_mutex);
608 			fc_rport_logoff(rdata);
609 			mutex_lock(&lport->disc.disc_mutex);
610 			new_rdata = fc_rport_create(lport, rdata->ids.port_id);
611 			mutex_unlock(&lport->disc.disc_mutex);
612 			if (new_rdata) {
613 				new_rdata->disc_id = disc->disc_id;
614 				fc_rport_login(new_rdata);
615 			}
616 			goto free_fp;
617 		}
618 		rdata->disc_id = disc->disc_id;
619 		mutex_unlock(&rdata->rp_mutex);
620 		fc_rport_login(rdata);
621 	} else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
622 		FC_DISC_DBG(disc, "GPN_ID rejected reason %x exp %x\n",
623 			    cp->ct_reason, cp->ct_explan);
624 		fc_rport_logoff(rdata);
625 	} else {
626 		FC_DISC_DBG(disc, "GPN_ID unexpected response code %x\n",
627 			    ntohs(cp->ct_cmd));
628 redisc:
629 		mutex_lock(&disc->disc_mutex);
630 		fc_disc_restart(disc);
631 		mutex_unlock(&disc->disc_mutex);
632 	}
633 free_fp:
634 	fc_frame_free(fp);
635 out:
636 	kref_put(&rdata->kref, fc_rport_destroy);
637 }
638 
639 /**
640  * fc_disc_gpn_id_req() - Send Get Port Names by ID (GPN_ID) request
641  * @lport: The local port to initiate discovery on
642  * @rdata: remote port private data
643  *
644  * On failure, an error code is returned.
645  */
fc_disc_gpn_id_req(struct fc_lport * lport,struct fc_rport_priv * rdata)646 static int fc_disc_gpn_id_req(struct fc_lport *lport,
647 			      struct fc_rport_priv *rdata)
648 {
649 	struct fc_frame *fp;
650 
651 	lockdep_assert_held(&lport->disc.disc_mutex);
652 	fp = fc_frame_alloc(lport, sizeof(struct fc_ct_hdr) +
653 			    sizeof(struct fc_ns_fid));
654 	if (!fp)
655 		return -ENOMEM;
656 	if (!lport->tt.elsct_send(lport, rdata->ids.port_id, fp, FC_NS_GPN_ID,
657 				  fc_disc_gpn_id_resp, rdata,
658 				  3 * lport->r_a_tov))
659 		return -ENOMEM;
660 	kref_get(&rdata->kref);
661 	return 0;
662 }
663 
664 /**
665  * fc_disc_single() - Discover the directory information for a single target
666  * @lport: The local port the remote port is associated with
667  * @dp:	   The port to rediscover
668  */
fc_disc_single(struct fc_lport * lport,struct fc_disc_port * dp)669 static int fc_disc_single(struct fc_lport *lport, struct fc_disc_port *dp)
670 {
671 	struct fc_rport_priv *rdata;
672 
673 	lockdep_assert_held(&lport->disc.disc_mutex);
674 
675 	rdata = fc_rport_create(lport, dp->port_id);
676 	if (!rdata)
677 		return -ENOMEM;
678 	rdata->disc_id = 0;
679 	return fc_disc_gpn_id_req(lport, rdata);
680 }
681 
682 /**
683  * fc_disc_stop() - Stop discovery for a given lport
684  * @lport: The local port that discovery should stop on
685  */
fc_disc_stop(struct fc_lport * lport)686 static void fc_disc_stop(struct fc_lport *lport)
687 {
688 	struct fc_disc *disc = &lport->disc;
689 
690 	if (disc->pending)
691 		cancel_delayed_work_sync(&disc->disc_work);
692 	mutex_lock(&disc->disc_mutex);
693 	fc_disc_stop_rports(disc);
694 	mutex_unlock(&disc->disc_mutex);
695 }
696 
697 /**
698  * fc_disc_stop_final() - Stop discovery for a given lport
699  * @lport: The lport that discovery should stop on
700  *
701  * This function will block until discovery has been
702  * completely stopped and all rports have been deleted.
703  */
fc_disc_stop_final(struct fc_lport * lport)704 static void fc_disc_stop_final(struct fc_lport *lport)
705 {
706 	fc_disc_stop(lport);
707 	fc_rport_flush_queue();
708 }
709 
710 /**
711  * fc_disc_config() - Configure the discovery layer for a local port
712  * @lport: The local port that needs the discovery layer to be configured
713  * @priv: Private data structre for users of the discovery layer
714  */
fc_disc_config(struct fc_lport * lport,void * priv)715 void fc_disc_config(struct fc_lport *lport, void *priv)
716 {
717 	struct fc_disc *disc;
718 
719 	if (!lport->tt.disc_start)
720 		lport->tt.disc_start = fc_disc_start;
721 
722 	if (!lport->tt.disc_stop)
723 		lport->tt.disc_stop = fc_disc_stop;
724 
725 	if (!lport->tt.disc_stop_final)
726 		lport->tt.disc_stop_final = fc_disc_stop_final;
727 
728 	if (!lport->tt.disc_recv_req)
729 		lport->tt.disc_recv_req = fc_disc_recv_req;
730 
731 	disc = &lport->disc;
732 
733 	disc->priv = priv;
734 }
735 EXPORT_SYMBOL(fc_disc_config);
736 
737 /**
738  * fc_disc_init() - Initialize the discovery layer for a local port
739  * @lport: The local port that needs the discovery layer to be initialized
740  */
fc_disc_init(struct fc_lport * lport)741 void fc_disc_init(struct fc_lport *lport)
742 {
743 	struct fc_disc *disc = &lport->disc;
744 
745 	INIT_DELAYED_WORK(&disc->disc_work, fc_disc_timeout);
746 	mutex_init(&disc->disc_mutex);
747 	INIT_LIST_HEAD(&disc->rports);
748 }
749 EXPORT_SYMBOL(fc_disc_init);
750