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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/list.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
40static void fc_disc_gpn_ft_req(struct fc_disc *);
41static void fc_disc_gpn_ft_resp(struct fc_seq *, struct fc_frame *, void *);
42static void fc_disc_done(struct fc_disc *, enum fc_disc_event);
43static void fc_disc_timeout(struct work_struct *);
44static int fc_disc_single(struct fc_lport *, struct fc_disc_port *);
45static 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 */
51static 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 */
70static 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_addr_fmt fmt;
79 LIST_HEAD(disc_ports);
80 struct fc_disc_port *dp, *next;
81
82 lockdep_assert_held(&disc->disc_mutex);
83
84 lport = fc_disc_lport(disc);
85
86 FC_DISC_DBG(disc, "Received an RSCN event\n");
87
88 /* make sure the frame contains an RSCN message */
89 rp = fc_frame_payload_get(fp, sizeof(*rp));
90 if (!rp)
91 goto reject;
92 /* make sure the page length is as expected (4 bytes) */
93 if (rp->rscn_page_len != sizeof(*pp))
94 goto reject;
95 /* get the RSCN payload length */
96 len = ntohs(rp->rscn_plen);
97 if (len < sizeof(*rp))
98 goto reject;
99 /* make sure the frame contains the expected payload */
100 rp = fc_frame_payload_get(fp, len);
101 if (!rp)
102 goto reject;
103 /* payload must be a multiple of the RSCN page size */
104 len -= sizeof(*rp);
105 if (len % sizeof(*pp))
106 goto reject;
107
108 for (pp = (void *)(rp + 1); len > 0; len -= sizeof(*pp), pp++) {
109 fmt = pp->rscn_page_flags >> ELS_RSCN_ADDR_FMT_BIT;
110 fmt &= ELS_RSCN_ADDR_FMT_MASK;
111 /*
112 * if we get an address format other than port
113 * (area, domain, fabric), then do a full discovery
114 */
115 switch (fmt) {
116 case ELS_ADDR_FMT_PORT:
117 FC_DISC_DBG(disc, "Port address format for port "
118 "(%6.6x)\n", ntoh24(pp->rscn_fid));
119 dp = kzalloc(sizeof(*dp), GFP_KERNEL);
120 if (!dp) {
121 redisc = 1;
122 break;
123 }
124 dp->lp = lport;
125 dp->port_id = ntoh24(pp->rscn_fid);
126 list_add_tail(&dp->peers, &disc_ports);
127 break;
128 case ELS_ADDR_FMT_AREA:
129 case ELS_ADDR_FMT_DOM:
130 case ELS_ADDR_FMT_FAB:
131 default:
132 FC_DISC_DBG(disc, "Address format is (%d)\n", fmt);
133 redisc = 1;
134 break;
135 }
136 }
137 fc_seq_els_rsp_send(fp, ELS_LS_ACC, NULL);
138
139 /*
140 * If not doing a complete rediscovery, do GPN_ID on
141 * the individual ports mentioned in the list.
142 * If any of these get an error, do a full rediscovery.
143 * In any case, go through the list and free the entries.
144 */
145 list_for_each_entry_safe(dp, next, &disc_ports, peers) {
146 list_del(&dp->peers);
147 if (!redisc)
148 redisc = fc_disc_single(lport, dp);
149 kfree(dp);
150 }
151 if (redisc) {
152 FC_DISC_DBG(disc, "RSCN received: rediscovering\n");
153 fc_disc_restart(disc);
154 } else {
155 FC_DISC_DBG(disc, "RSCN received: not rediscovering. "
156 "redisc %d state %d in_prog %d\n",
157 redisc, lport->state, disc->pending);
158 }
159 fc_frame_free(fp);
160 return;
161reject:
162 FC_DISC_DBG(disc, "Received a bad RSCN frame\n");
163 rjt_data.reason = ELS_RJT_LOGIC;
164 rjt_data.explan = ELS_EXPL_NONE;
165 fc_seq_els_rsp_send(fp, ELS_LS_RJT, &rjt_data);
166 fc_frame_free(fp);
167}
168
169/**
170 * fc_disc_recv_req() - Handle incoming requests
171 * @lport: The local port receiving the request
172 * @fp: The request frame
173 *
174 * Locking Note: This function is called from the EM and will lock
175 * the disc_mutex before calling the handler for the
176 * request.
177 */
178static void fc_disc_recv_req(struct fc_lport *lport, struct fc_frame *fp)
179{
180 u8 op;
181 struct fc_disc *disc = &lport->disc;
182
183 op = fc_frame_payload_op(fp);
184 switch (op) {
185 case ELS_RSCN:
186 mutex_lock(&disc->disc_mutex);
187 fc_disc_recv_rscn_req(disc, fp);
188 mutex_unlock(&disc->disc_mutex);
189 break;
190 default:
191 FC_DISC_DBG(disc, "Received an unsupported request, "
192 "the opcode is (%x)\n", op);
193 fc_frame_free(fp);
194 break;
195 }
196}
197
198/**
199 * fc_disc_restart() - Restart discovery
200 * @disc: The discovery object to be restarted
201 */
202static void fc_disc_restart(struct fc_disc *disc)
203{
204 lockdep_assert_held(&disc->disc_mutex);
205
206 if (!disc->disc_callback)
207 return;
208
209 FC_DISC_DBG(disc, "Restarting discovery\n");
210
211 disc->requested = 1;
212 if (disc->pending)
213 return;
214
215 /*
216 * Advance disc_id. This is an arbitrary non-zero number that will
217 * match the value in the fc_rport_priv after discovery for all
218 * freshly-discovered remote ports. Avoid wrapping to zero.
219 */
220 disc->disc_id = (disc->disc_id + 2) | 1;
221 disc->retry_count = 0;
222 fc_disc_gpn_ft_req(disc);
223}
224
225/**
226 * fc_disc_start() - Start discovery on a local port
227 * @lport: The local port to have discovery started on
228 * @disc_callback: Callback function to be called when discovery is complete
229 */
230static void fc_disc_start(void (*disc_callback)(struct fc_lport *,
231 enum fc_disc_event),
232 struct fc_lport *lport)
233{
234 struct fc_disc *disc = &lport->disc;
235
236 /*
237 * At this point we may have a new disc job or an existing
238 * one. Either way, let's lock when we make changes to it
239 * and send the GPN_FT request.
240 */
241 mutex_lock(&disc->disc_mutex);
242 disc->disc_callback = disc_callback;
243 fc_disc_restart(disc);
244 mutex_unlock(&disc->disc_mutex);
245}
246
247/**
248 * fc_disc_done() - Discovery has been completed
249 * @disc: The discovery context
250 * @event: The discovery completion status
251 */
252static void fc_disc_done(struct fc_disc *disc, enum fc_disc_event event)
253{
254 struct fc_lport *lport = fc_disc_lport(disc);
255 struct fc_rport_priv *rdata;
256
257 lockdep_assert_held(&disc->disc_mutex);
258 FC_DISC_DBG(disc, "Discovery complete\n");
259
260 disc->pending = 0;
261 if (disc->requested) {
262 fc_disc_restart(disc);
263 return;
264 }
265
266 /*
267 * Go through all remote ports. If they were found in the latest
268 * discovery, reverify or log them in. Otherwise, log them out.
269 * Skip ports which were never discovered. These are the dNS port
270 * and ports which were created by PLOGI.
271 *
272 * We don't need to use the _rcu variant here as the rport list
273 * is protected by the disc mutex which is already held on entry.
274 */
275 list_for_each_entry(rdata, &disc->rports, peers) {
276 if (!kref_get_unless_zero(&rdata->kref))
277 continue;
278 if (rdata->disc_id) {
279 if (rdata->disc_id == disc->disc_id)
280 fc_rport_login(rdata);
281 else
282 fc_rport_logoff(rdata);
283 }
284 kref_put(&rdata->kref, fc_rport_destroy);
285 }
286 mutex_unlock(&disc->disc_mutex);
287 disc->disc_callback(lport, event);
288 mutex_lock(&disc->disc_mutex);
289}
290
291/**
292 * fc_disc_error() - Handle error on dNS request
293 * @disc: The discovery context
294 * @fp: The error code encoded as a frame pointer
295 */
296static void fc_disc_error(struct fc_disc *disc, struct fc_frame *fp)
297{
298 struct fc_lport *lport = fc_disc_lport(disc);
299 unsigned long delay = 0;
300
301 FC_DISC_DBG(disc, "Error %d, retries %d/%d\n",
302 PTR_ERR_OR_ZERO(fp), disc->retry_count,
303 FC_DISC_RETRY_LIMIT);
304
305 if (!fp || PTR_ERR(fp) == -FC_EX_TIMEOUT) {
306 /*
307 * Memory allocation failure, or the exchange timed out,
308 * retry after delay.
309 */
310 if (disc->retry_count < FC_DISC_RETRY_LIMIT) {
311 /* go ahead and retry */
312 if (!fp)
313 delay = msecs_to_jiffies(FC_DISC_RETRY_DELAY);
314 else {
315 delay = msecs_to_jiffies(lport->e_d_tov);
316
317 /* timeout faster first time */
318 if (!disc->retry_count)
319 delay /= 4;
320 }
321 disc->retry_count++;
322 schedule_delayed_work(&disc->disc_work, delay);
323 } else
324 fc_disc_done(disc, DISC_EV_FAILED);
325 } else if (PTR_ERR(fp) == -FC_EX_CLOSED) {
326 /*
327 * if discovery fails due to lport reset, clear
328 * pending flag so that subsequent discovery can
329 * continue
330 */
331 disc->pending = 0;
332 }
333}
334
335/**
336 * fc_disc_gpn_ft_req() - Send Get Port Names by FC-4 type (GPN_FT) request
337 * @disc: The discovery context
338 */
339static void fc_disc_gpn_ft_req(struct fc_disc *disc)
340{
341 struct fc_frame *fp;
342 struct fc_lport *lport = fc_disc_lport(disc);
343
344 lockdep_assert_held(&disc->disc_mutex);
345
346 WARN_ON(!fc_lport_test_ready(lport));
347
348 disc->pending = 1;
349 disc->requested = 0;
350
351 disc->buf_len = 0;
352 disc->seq_count = 0;
353 fp = fc_frame_alloc(lport,
354 sizeof(struct fc_ct_hdr) +
355 sizeof(struct fc_ns_gid_ft));
356 if (!fp)
357 goto err;
358
359 if (lport->tt.elsct_send(lport, 0, fp,
360 FC_NS_GPN_FT,
361 fc_disc_gpn_ft_resp,
362 disc, 3 * lport->r_a_tov))
363 return;
364err:
365 fc_disc_error(disc, NULL);
366}
367
368/**
369 * fc_disc_gpn_ft_parse() - Parse the body of the dNS GPN_FT response.
370 * @disc: The discovery context
371 * @buf: The GPN_FT response buffer
372 * @len: The size of response buffer
373 *
374 * Goes through the list of IDs and names resulting from a request.
375 */
376static int fc_disc_gpn_ft_parse(struct fc_disc *disc, void *buf, size_t len)
377{
378 struct fc_lport *lport;
379 struct fc_gpn_ft_resp *np;
380 char *bp;
381 size_t plen;
382 size_t tlen;
383 int error = 0;
384 struct fc_rport_identifiers ids;
385 struct fc_rport_priv *rdata;
386
387 lport = fc_disc_lport(disc);
388 disc->seq_count++;
389
390 /*
391 * Handle partial name record left over from previous call.
392 */
393 bp = buf;
394 plen = len;
395 np = (struct fc_gpn_ft_resp *)bp;
396 tlen = disc->buf_len;
397 disc->buf_len = 0;
398 if (tlen) {
399 WARN_ON(tlen >= sizeof(*np));
400 plen = sizeof(*np) - tlen;
401 WARN_ON(plen <= 0);
402 WARN_ON(plen >= sizeof(*np));
403 if (plen > len)
404 plen = len;
405 np = &disc->partial_buf;
406 memcpy((char *)np + tlen, bp, plen);
407
408 /*
409 * Set bp so that the loop below will advance it to the
410 * first valid full name element.
411 */
412 bp -= tlen;
413 len += tlen;
414 plen += tlen;
415 disc->buf_len = (unsigned char) plen;
416 if (plen == sizeof(*np))
417 disc->buf_len = 0;
418 }
419
420 /*
421 * Handle full name records, including the one filled from above.
422 * Normally, np == bp and plen == len, but from the partial case above,
423 * bp, len describe the overall buffer, and np, plen describe the
424 * partial buffer, which if would usually be full now.
425 * After the first time through the loop, things return to "normal".
426 */
427 while (plen >= sizeof(*np)) {
428 ids.port_id = ntoh24(np->fp_fid);
429 ids.port_name = ntohll(np->fp_wwpn);
430
431 if (ids.port_id != lport->port_id &&
432 ids.port_name != lport->wwpn) {
433 rdata = fc_rport_create(lport, ids.port_id);
434 if (rdata) {
435 rdata->ids.port_name = ids.port_name;
436 rdata->disc_id = disc->disc_id;
437 } else {
438 printk(KERN_WARNING "libfc: Failed to allocate "
439 "memory for the newly discovered port "
440 "(%6.6x)\n", ids.port_id);
441 error = -ENOMEM;
442 }
443 }
444
445 if (np->fp_flags & FC_NS_FID_LAST) {
446 fc_disc_done(disc, DISC_EV_SUCCESS);
447 len = 0;
448 break;
449 }
450 len -= sizeof(*np);
451 bp += sizeof(*np);
452 np = (struct fc_gpn_ft_resp *)bp;
453 plen = len;
454 }
455
456 /*
457 * Save any partial record at the end of the buffer for next time.
458 */
459 if (error == 0 && len > 0 && len < sizeof(*np)) {
460 if (np != &disc->partial_buf) {
461 FC_DISC_DBG(disc, "Partial buffer remains "
462 "for discovery\n");
463 memcpy(&disc->partial_buf, np, len);
464 }
465 disc->buf_len = (unsigned char) len;
466 }
467 return error;
468}
469
470/**
471 * fc_disc_timeout() - Handler for discovery timeouts
472 * @work: Structure holding discovery context that needs to retry discovery
473 */
474static void fc_disc_timeout(struct work_struct *work)
475{
476 struct fc_disc *disc = container_of(work,
477 struct fc_disc,
478 disc_work.work);
479 mutex_lock(&disc->disc_mutex);
480 fc_disc_gpn_ft_req(disc);
481 mutex_unlock(&disc->disc_mutex);
482}
483
484/**
485 * fc_disc_gpn_ft_resp() - Handle a response frame from Get Port Names (GPN_FT)
486 * @sp: The sequence that the GPN_FT response was received on
487 * @fp: The GPN_FT response frame
488 * @disc_arg: The discovery context
489 *
490 * Locking Note: This function is called without disc mutex held, and
491 * should do all its processing with the mutex held
492 */
493static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp,
494 void *disc_arg)
495{
496 struct fc_disc *disc = disc_arg;
497 struct fc_ct_hdr *cp;
498 struct fc_frame_header *fh;
499 enum fc_disc_event event = DISC_EV_NONE;
500 unsigned int seq_cnt;
501 unsigned int len;
502 int error = 0;
503
504 mutex_lock(&disc->disc_mutex);
505 FC_DISC_DBG(disc, "Received a GPN_FT response\n");
506
507 if (IS_ERR(fp)) {
508 fc_disc_error(disc, fp);
509 mutex_unlock(&disc->disc_mutex);
510 return;
511 }
512
513 WARN_ON(!fc_frame_is_linear(fp)); /* buffer must be contiguous */
514 fh = fc_frame_header_get(fp);
515 len = fr_len(fp) - sizeof(*fh);
516 seq_cnt = ntohs(fh->fh_seq_cnt);
517 if (fr_sof(fp) == FC_SOF_I3 && seq_cnt == 0 && disc->seq_count == 0) {
518 cp = fc_frame_payload_get(fp, sizeof(*cp));
519 if (!cp) {
520 FC_DISC_DBG(disc, "GPN_FT response too short, len %d\n",
521 fr_len(fp));
522 event = DISC_EV_FAILED;
523 } else if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
524
525 /* Accepted, parse the response. */
526 len -= sizeof(*cp);
527 error = fc_disc_gpn_ft_parse(disc, cp + 1, len);
528 } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
529 FC_DISC_DBG(disc, "GPN_FT rejected reason %x exp %x "
530 "(check zoning)\n", cp->ct_reason,
531 cp->ct_explan);
532 event = DISC_EV_FAILED;
533 if (cp->ct_reason == FC_FS_RJT_UNABL &&
534 cp->ct_explan == FC_FS_EXP_FTNR)
535 event = DISC_EV_SUCCESS;
536 } else {
537 FC_DISC_DBG(disc, "GPN_FT unexpected response code "
538 "%x\n", ntohs(cp->ct_cmd));
539 event = DISC_EV_FAILED;
540 }
541 } else if (fr_sof(fp) == FC_SOF_N3 && seq_cnt == disc->seq_count) {
542 error = fc_disc_gpn_ft_parse(disc, fh + 1, len);
543 } else {
544 FC_DISC_DBG(disc, "GPN_FT unexpected frame - out of sequence? "
545 "seq_cnt %x expected %x sof %x eof %x\n",
546 seq_cnt, disc->seq_count, fr_sof(fp), fr_eof(fp));
547 event = DISC_EV_FAILED;
548 }
549 if (error)
550 fc_disc_error(disc, ERR_PTR(error));
551 else if (event != DISC_EV_NONE)
552 fc_disc_done(disc, event);
553 fc_frame_free(fp);
554 mutex_unlock(&disc->disc_mutex);
555}
556
557/**
558 * fc_disc_gpn_id_resp() - Handle a response frame from Get Port Names (GPN_ID)
559 * @sp: The sequence the GPN_ID is on
560 * @fp: The response frame
561 * @rdata_arg: The remote port that sent the GPN_ID response
562 *
563 * Locking Note: This function is called without disc mutex held.
564 */
565static void fc_disc_gpn_id_resp(struct fc_seq *sp, struct fc_frame *fp,
566 void *rdata_arg)
567{
568 struct fc_rport_priv *rdata = rdata_arg;
569 struct fc_rport_priv *new_rdata;
570 struct fc_lport *lport;
571 struct fc_disc *disc;
572 struct fc_ct_hdr *cp;
573 struct fc_ns_gid_pn *pn;
574 u64 port_name;
575
576 lport = rdata->local_port;
577 disc = &lport->disc;
578
579 if (PTR_ERR(fp) == -FC_EX_CLOSED)
580 goto out;
581 if (IS_ERR(fp)) {
582 mutex_lock(&disc->disc_mutex);
583 fc_disc_restart(disc);
584 mutex_unlock(&disc->disc_mutex);
585 goto out;
586 }
587
588 cp = fc_frame_payload_get(fp, sizeof(*cp));
589 if (!cp)
590 goto redisc;
591 if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
592 if (fr_len(fp) < sizeof(struct fc_frame_header) +
593 sizeof(*cp) + sizeof(*pn))
594 goto redisc;
595 pn = (struct fc_ns_gid_pn *)(cp + 1);
596 port_name = get_unaligned_be64(&pn->fn_wwpn);
597 mutex_lock(&rdata->rp_mutex);
598 if (rdata->ids.port_name == -1)
599 rdata->ids.port_name = port_name;
600 else if (rdata->ids.port_name != port_name) {
601 FC_DISC_DBG(disc, "GPN_ID accepted. WWPN changed. "
602 "Port-id %6.6x wwpn %16.16llx\n",
603 rdata->ids.port_id, port_name);
604 mutex_unlock(&rdata->rp_mutex);
605 fc_rport_logoff(rdata);
606 mutex_lock(&lport->disc.disc_mutex);
607 new_rdata = fc_rport_create(lport, rdata->ids.port_id);
608 mutex_unlock(&lport->disc.disc_mutex);
609 if (new_rdata) {
610 new_rdata->disc_id = disc->disc_id;
611 fc_rport_login(new_rdata);
612 }
613 goto free_fp;
614 }
615 rdata->disc_id = disc->disc_id;
616 mutex_unlock(&rdata->rp_mutex);
617 fc_rport_login(rdata);
618 } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
619 FC_DISC_DBG(disc, "GPN_ID rejected reason %x exp %x\n",
620 cp->ct_reason, cp->ct_explan);
621 fc_rport_logoff(rdata);
622 } else {
623 FC_DISC_DBG(disc, "GPN_ID unexpected response code %x\n",
624 ntohs(cp->ct_cmd));
625redisc:
626 mutex_lock(&disc->disc_mutex);
627 fc_disc_restart(disc);
628 mutex_unlock(&disc->disc_mutex);
629 }
630free_fp:
631 fc_frame_free(fp);
632out:
633 kref_put(&rdata->kref, fc_rport_destroy);
634}
635
636/**
637 * fc_disc_gpn_id_req() - Send Get Port Names by ID (GPN_ID) request
638 * @lport: The local port to initiate discovery on
639 * @rdata: remote port private data
640 *
641 * On failure, an error code is returned.
642 */
643static int fc_disc_gpn_id_req(struct fc_lport *lport,
644 struct fc_rport_priv *rdata)
645{
646 struct fc_frame *fp;
647
648 lockdep_assert_held(&lport->disc.disc_mutex);
649 fp = fc_frame_alloc(lport, sizeof(struct fc_ct_hdr) +
650 sizeof(struct fc_ns_fid));
651 if (!fp)
652 return -ENOMEM;
653 if (!lport->tt.elsct_send(lport, rdata->ids.port_id, fp, FC_NS_GPN_ID,
654 fc_disc_gpn_id_resp, rdata,
655 3 * lport->r_a_tov))
656 return -ENOMEM;
657 kref_get(&rdata->kref);
658 return 0;
659}
660
661/**
662 * fc_disc_single() - Discover the directory information for a single target
663 * @lport: The local port the remote port is associated with
664 * @dp: The port to rediscover
665 */
666static int fc_disc_single(struct fc_lport *lport, struct fc_disc_port *dp)
667{
668 struct fc_rport_priv *rdata;
669
670 lockdep_assert_held(&lport->disc.disc_mutex);
671
672 rdata = fc_rport_create(lport, dp->port_id);
673 if (!rdata)
674 return -ENOMEM;
675 rdata->disc_id = 0;
676 return fc_disc_gpn_id_req(lport, rdata);
677}
678
679/**
680 * fc_disc_stop() - Stop discovery for a given lport
681 * @lport: The local port that discovery should stop on
682 */
683static void fc_disc_stop(struct fc_lport *lport)
684{
685 struct fc_disc *disc = &lport->disc;
686
687 if (disc->pending)
688 cancel_delayed_work_sync(&disc->disc_work);
689 mutex_lock(&disc->disc_mutex);
690 fc_disc_stop_rports(disc);
691 mutex_unlock(&disc->disc_mutex);
692}
693
694/**
695 * fc_disc_stop_final() - Stop discovery for a given lport
696 * @lport: The lport that discovery should stop on
697 *
698 * This function will block until discovery has been
699 * completely stopped and all rports have been deleted.
700 */
701static void fc_disc_stop_final(struct fc_lport *lport)
702{
703 fc_disc_stop(lport);
704 fc_rport_flush_queue();
705}
706
707/**
708 * fc_disc_config() - Configure the discovery layer for a local port
709 * @lport: The local port that needs the discovery layer to be configured
710 * @priv: Private data structre for users of the discovery layer
711 */
712void fc_disc_config(struct fc_lport *lport, void *priv)
713{
714 struct fc_disc *disc;
715
716 if (!lport->tt.disc_start)
717 lport->tt.disc_start = fc_disc_start;
718
719 if (!lport->tt.disc_stop)
720 lport->tt.disc_stop = fc_disc_stop;
721
722 if (!lport->tt.disc_stop_final)
723 lport->tt.disc_stop_final = fc_disc_stop_final;
724
725 if (!lport->tt.disc_recv_req)
726 lport->tt.disc_recv_req = fc_disc_recv_req;
727
728 disc = &lport->disc;
729
730 disc->priv = priv;
731}
732EXPORT_SYMBOL(fc_disc_config);
733
734/**
735 * fc_disc_init() - Initialize the discovery layer for a local port
736 * @lport: The local port that needs the discovery layer to be initialized
737 */
738void fc_disc_init(struct fc_lport *lport)
739{
740 struct fc_disc *disc = &lport->disc;
741
742 INIT_DELAYED_WORK(&disc->disc_work, fc_disc_timeout);
743 mutex_init(&disc->disc_mutex);
744 INIT_LIST_HEAD(&disc->rports);
745}
746EXPORT_SYMBOL(fc_disc_init);
1/*
2 * Copyright(c) 2007 - 2008 Intel Corporation. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
16 *
17 * Maintained at www.Open-FCoE.org
18 */
19
20/*
21 * Target Discovery
22 *
23 * This block discovers all FC-4 remote ports, including FCP initiators. It
24 * also handles RSCN events and re-discovery if necessary.
25 */
26
27/*
28 * DISC LOCKING
29 *
30 * The disc mutex is can be locked when acquiring rport locks, but may not
31 * be held when acquiring the lport lock. Refer to fc_lport.c for more
32 * details.
33 */
34
35#include <linux/timer.h>
36#include <linux/slab.h>
37#include <linux/err.h>
38#include <asm/unaligned.h>
39
40#include <scsi/fc/fc_gs.h>
41
42#include <scsi/libfc.h>
43
44#include "fc_libfc.h"
45
46#define FC_DISC_RETRY_LIMIT 3 /* max retries */
47#define FC_DISC_RETRY_DELAY 500UL /* (msecs) delay */
48
49static void fc_disc_gpn_ft_req(struct fc_disc *);
50static void fc_disc_gpn_ft_resp(struct fc_seq *, struct fc_frame *, void *);
51static void fc_disc_done(struct fc_disc *, enum fc_disc_event);
52static void fc_disc_timeout(struct work_struct *);
53static int fc_disc_single(struct fc_lport *, struct fc_disc_port *);
54static void fc_disc_restart(struct fc_disc *);
55
56/**
57 * fc_disc_stop_rports() - Delete all the remote ports associated with the lport
58 * @disc: The discovery job to stop remote ports on
59 *
60 * Locking Note: This function expects that the lport mutex is locked before
61 * calling it.
62 */
63void fc_disc_stop_rports(struct fc_disc *disc)
64{
65 struct fc_lport *lport;
66 struct fc_rport_priv *rdata;
67
68 lport = fc_disc_lport(disc);
69
70 mutex_lock(&disc->disc_mutex);
71 list_for_each_entry_rcu(rdata, &disc->rports, peers)
72 lport->tt.rport_logoff(rdata);
73 mutex_unlock(&disc->disc_mutex);
74}
75
76/**
77 * fc_disc_recv_rscn_req() - Handle Registered State Change Notification (RSCN)
78 * @disc: The discovery object to which the RSCN applies
79 * @fp: The RSCN frame
80 *
81 * Locking Note: This function expects that the disc_mutex is locked
82 * before it is called.
83 */
84static void fc_disc_recv_rscn_req(struct fc_disc *disc, struct fc_frame *fp)
85{
86 struct fc_lport *lport;
87 struct fc_els_rscn *rp;
88 struct fc_els_rscn_page *pp;
89 struct fc_seq_els_data rjt_data;
90 unsigned int len;
91 int redisc = 0;
92 enum fc_els_rscn_ev_qual ev_qual;
93 enum fc_els_rscn_addr_fmt fmt;
94 LIST_HEAD(disc_ports);
95 struct fc_disc_port *dp, *next;
96
97 lport = fc_disc_lport(disc);
98
99 FC_DISC_DBG(disc, "Received an RSCN event\n");
100
101 /* make sure the frame contains an RSCN message */
102 rp = fc_frame_payload_get(fp, sizeof(*rp));
103 if (!rp)
104 goto reject;
105 /* make sure the page length is as expected (4 bytes) */
106 if (rp->rscn_page_len != sizeof(*pp))
107 goto reject;
108 /* get the RSCN payload length */
109 len = ntohs(rp->rscn_plen);
110 if (len < sizeof(*rp))
111 goto reject;
112 /* make sure the frame contains the expected payload */
113 rp = fc_frame_payload_get(fp, len);
114 if (!rp)
115 goto reject;
116 /* payload must be a multiple of the RSCN page size */
117 len -= sizeof(*rp);
118 if (len % sizeof(*pp))
119 goto reject;
120
121 for (pp = (void *)(rp + 1); len > 0; len -= sizeof(*pp), pp++) {
122 ev_qual = pp->rscn_page_flags >> ELS_RSCN_EV_QUAL_BIT;
123 ev_qual &= ELS_RSCN_EV_QUAL_MASK;
124 fmt = pp->rscn_page_flags >> ELS_RSCN_ADDR_FMT_BIT;
125 fmt &= ELS_RSCN_ADDR_FMT_MASK;
126 /*
127 * if we get an address format other than port
128 * (area, domain, fabric), then do a full discovery
129 */
130 switch (fmt) {
131 case ELS_ADDR_FMT_PORT:
132 FC_DISC_DBG(disc, "Port address format for port "
133 "(%6.6x)\n", ntoh24(pp->rscn_fid));
134 dp = kzalloc(sizeof(*dp), GFP_KERNEL);
135 if (!dp) {
136 redisc = 1;
137 break;
138 }
139 dp->lp = lport;
140 dp->port_id = ntoh24(pp->rscn_fid);
141 list_add_tail(&dp->peers, &disc_ports);
142 break;
143 case ELS_ADDR_FMT_AREA:
144 case ELS_ADDR_FMT_DOM:
145 case ELS_ADDR_FMT_FAB:
146 default:
147 FC_DISC_DBG(disc, "Address format is (%d)\n", fmt);
148 redisc = 1;
149 break;
150 }
151 }
152 lport->tt.seq_els_rsp_send(fp, ELS_LS_ACC, NULL);
153
154 /*
155 * If not doing a complete rediscovery, do GPN_ID on
156 * the individual ports mentioned in the list.
157 * If any of these get an error, do a full rediscovery.
158 * In any case, go through the list and free the entries.
159 */
160 list_for_each_entry_safe(dp, next, &disc_ports, peers) {
161 list_del(&dp->peers);
162 if (!redisc)
163 redisc = fc_disc_single(lport, dp);
164 kfree(dp);
165 }
166 if (redisc) {
167 FC_DISC_DBG(disc, "RSCN received: rediscovering\n");
168 fc_disc_restart(disc);
169 } else {
170 FC_DISC_DBG(disc, "RSCN received: not rediscovering. "
171 "redisc %d state %d in_prog %d\n",
172 redisc, lport->state, disc->pending);
173 }
174 fc_frame_free(fp);
175 return;
176reject:
177 FC_DISC_DBG(disc, "Received a bad RSCN frame\n");
178 rjt_data.reason = ELS_RJT_LOGIC;
179 rjt_data.explan = ELS_EXPL_NONE;
180 lport->tt.seq_els_rsp_send(fp, ELS_LS_RJT, &rjt_data);
181 fc_frame_free(fp);
182}
183
184/**
185 * fc_disc_recv_req() - Handle incoming requests
186 * @lport: The local port receiving the request
187 * @fp: The request frame
188 *
189 * Locking Note: This function is called from the EM and will lock
190 * the disc_mutex before calling the handler for the
191 * request.
192 */
193static void fc_disc_recv_req(struct fc_lport *lport, struct fc_frame *fp)
194{
195 u8 op;
196 struct fc_disc *disc = &lport->disc;
197
198 op = fc_frame_payload_op(fp);
199 switch (op) {
200 case ELS_RSCN:
201 mutex_lock(&disc->disc_mutex);
202 fc_disc_recv_rscn_req(disc, fp);
203 mutex_unlock(&disc->disc_mutex);
204 break;
205 default:
206 FC_DISC_DBG(disc, "Received an unsupported request, "
207 "the opcode is (%x)\n", op);
208 fc_frame_free(fp);
209 break;
210 }
211}
212
213/**
214 * fc_disc_restart() - Restart discovery
215 * @disc: The discovery object to be restarted
216 *
217 * Locking Note: This function expects that the disc mutex
218 * is already locked.
219 */
220static void fc_disc_restart(struct fc_disc *disc)
221{
222 if (!disc->disc_callback)
223 return;
224
225 FC_DISC_DBG(disc, "Restarting discovery\n");
226
227 disc->requested = 1;
228 if (disc->pending)
229 return;
230
231 /*
232 * Advance disc_id. This is an arbitrary non-zero number that will
233 * match the value in the fc_rport_priv after discovery for all
234 * freshly-discovered remote ports. Avoid wrapping to zero.
235 */
236 disc->disc_id = (disc->disc_id + 2) | 1;
237 disc->retry_count = 0;
238 fc_disc_gpn_ft_req(disc);
239}
240
241/**
242 * fc_disc_start() - Start discovery on a local port
243 * @lport: The local port to have discovery started on
244 * @disc_callback: Callback function to be called when discovery is complete
245 */
246static void fc_disc_start(void (*disc_callback)(struct fc_lport *,
247 enum fc_disc_event),
248 struct fc_lport *lport)
249{
250 struct fc_disc *disc = &lport->disc;
251
252 /*
253 * At this point we may have a new disc job or an existing
254 * one. Either way, let's lock when we make changes to it
255 * and send the GPN_FT request.
256 */
257 mutex_lock(&disc->disc_mutex);
258 disc->disc_callback = disc_callback;
259 fc_disc_restart(disc);
260 mutex_unlock(&disc->disc_mutex);
261}
262
263/**
264 * fc_disc_done() - Discovery has been completed
265 * @disc: The discovery context
266 * @event: The discovery completion status
267 *
268 * Locking Note: This function expects that the disc mutex is locked before
269 * it is called. The discovery callback is then made with the lock released,
270 * and the lock is re-taken before returning from this function
271 */
272static void fc_disc_done(struct fc_disc *disc, enum fc_disc_event event)
273{
274 struct fc_lport *lport = fc_disc_lport(disc);
275 struct fc_rport_priv *rdata;
276
277 FC_DISC_DBG(disc, "Discovery complete\n");
278
279 disc->pending = 0;
280 if (disc->requested) {
281 fc_disc_restart(disc);
282 return;
283 }
284
285 /*
286 * Go through all remote ports. If they were found in the latest
287 * discovery, reverify or log them in. Otherwise, log them out.
288 * Skip ports which were never discovered. These are the dNS port
289 * and ports which were created by PLOGI.
290 */
291 list_for_each_entry_rcu(rdata, &disc->rports, peers) {
292 if (!rdata->disc_id)
293 continue;
294 if (rdata->disc_id == disc->disc_id)
295 lport->tt.rport_login(rdata);
296 else
297 lport->tt.rport_logoff(rdata);
298 }
299
300 mutex_unlock(&disc->disc_mutex);
301 disc->disc_callback(lport, event);
302 mutex_lock(&disc->disc_mutex);
303}
304
305/**
306 * fc_disc_error() - Handle error on dNS request
307 * @disc: The discovery context
308 * @fp: The error code encoded as a frame pointer
309 */
310static void fc_disc_error(struct fc_disc *disc, struct fc_frame *fp)
311{
312 struct fc_lport *lport = fc_disc_lport(disc);
313 unsigned long delay = 0;
314
315 FC_DISC_DBG(disc, "Error %ld, retries %d/%d\n",
316 PTR_ERR(fp), disc->retry_count,
317 FC_DISC_RETRY_LIMIT);
318
319 if (!fp || PTR_ERR(fp) == -FC_EX_TIMEOUT) {
320 /*
321 * Memory allocation failure, or the exchange timed out,
322 * retry after delay.
323 */
324 if (disc->retry_count < FC_DISC_RETRY_LIMIT) {
325 /* go ahead and retry */
326 if (!fp)
327 delay = msecs_to_jiffies(FC_DISC_RETRY_DELAY);
328 else {
329 delay = msecs_to_jiffies(lport->e_d_tov);
330
331 /* timeout faster first time */
332 if (!disc->retry_count)
333 delay /= 4;
334 }
335 disc->retry_count++;
336 schedule_delayed_work(&disc->disc_work, delay);
337 } else
338 fc_disc_done(disc, DISC_EV_FAILED);
339 }
340}
341
342/**
343 * fc_disc_gpn_ft_req() - Send Get Port Names by FC-4 type (GPN_FT) request
344 * @lport: The discovery context
345 *
346 * Locking Note: This function expects that the disc_mutex is locked
347 * before it is called.
348 */
349static void fc_disc_gpn_ft_req(struct fc_disc *disc)
350{
351 struct fc_frame *fp;
352 struct fc_lport *lport = fc_disc_lport(disc);
353
354 WARN_ON(!fc_lport_test_ready(lport));
355
356 disc->pending = 1;
357 disc->requested = 0;
358
359 disc->buf_len = 0;
360 disc->seq_count = 0;
361 fp = fc_frame_alloc(lport,
362 sizeof(struct fc_ct_hdr) +
363 sizeof(struct fc_ns_gid_ft));
364 if (!fp)
365 goto err;
366
367 if (lport->tt.elsct_send(lport, 0, fp,
368 FC_NS_GPN_FT,
369 fc_disc_gpn_ft_resp,
370 disc, 3 * lport->r_a_tov))
371 return;
372err:
373 fc_disc_error(disc, NULL);
374}
375
376/**
377 * fc_disc_gpn_ft_parse() - Parse the body of the dNS GPN_FT response.
378 * @lport: The local port the GPN_FT was received on
379 * @buf: The GPN_FT response buffer
380 * @len: The size of response buffer
381 *
382 * Goes through the list of IDs and names resulting from a request.
383 */
384static int fc_disc_gpn_ft_parse(struct fc_disc *disc, void *buf, size_t len)
385{
386 struct fc_lport *lport;
387 struct fc_gpn_ft_resp *np;
388 char *bp;
389 size_t plen;
390 size_t tlen;
391 int error = 0;
392 struct fc_rport_identifiers ids;
393 struct fc_rport_priv *rdata;
394
395 lport = fc_disc_lport(disc);
396 disc->seq_count++;
397
398 /*
399 * Handle partial name record left over from previous call.
400 */
401 bp = buf;
402 plen = len;
403 np = (struct fc_gpn_ft_resp *)bp;
404 tlen = disc->buf_len;
405 disc->buf_len = 0;
406 if (tlen) {
407 WARN_ON(tlen >= sizeof(*np));
408 plen = sizeof(*np) - tlen;
409 WARN_ON(plen <= 0);
410 WARN_ON(plen >= sizeof(*np));
411 if (plen > len)
412 plen = len;
413 np = &disc->partial_buf;
414 memcpy((char *)np + tlen, bp, plen);
415
416 /*
417 * Set bp so that the loop below will advance it to the
418 * first valid full name element.
419 */
420 bp -= tlen;
421 len += tlen;
422 plen += tlen;
423 disc->buf_len = (unsigned char) plen;
424 if (plen == sizeof(*np))
425 disc->buf_len = 0;
426 }
427
428 /*
429 * Handle full name records, including the one filled from above.
430 * Normally, np == bp and plen == len, but from the partial case above,
431 * bp, len describe the overall buffer, and np, plen describe the
432 * partial buffer, which if would usually be full now.
433 * After the first time through the loop, things return to "normal".
434 */
435 while (plen >= sizeof(*np)) {
436 ids.port_id = ntoh24(np->fp_fid);
437 ids.port_name = ntohll(np->fp_wwpn);
438
439 if (ids.port_id != lport->port_id &&
440 ids.port_name != lport->wwpn) {
441 rdata = lport->tt.rport_create(lport, ids.port_id);
442 if (rdata) {
443 rdata->ids.port_name = ids.port_name;
444 rdata->disc_id = disc->disc_id;
445 } else {
446 printk(KERN_WARNING "libfc: Failed to allocate "
447 "memory for the newly discovered port "
448 "(%6.6x)\n", ids.port_id);
449 error = -ENOMEM;
450 }
451 }
452
453 if (np->fp_flags & FC_NS_FID_LAST) {
454 fc_disc_done(disc, DISC_EV_SUCCESS);
455 len = 0;
456 break;
457 }
458 len -= sizeof(*np);
459 bp += sizeof(*np);
460 np = (struct fc_gpn_ft_resp *)bp;
461 plen = len;
462 }
463
464 /*
465 * Save any partial record at the end of the buffer for next time.
466 */
467 if (error == 0 && len > 0 && len < sizeof(*np)) {
468 if (np != &disc->partial_buf) {
469 FC_DISC_DBG(disc, "Partial buffer remains "
470 "for discovery\n");
471 memcpy(&disc->partial_buf, np, len);
472 }
473 disc->buf_len = (unsigned char) len;
474 }
475 return error;
476}
477
478/**
479 * fc_disc_timeout() - Handler for discovery timeouts
480 * @work: Structure holding discovery context that needs to retry discovery
481 */
482static void fc_disc_timeout(struct work_struct *work)
483{
484 struct fc_disc *disc = container_of(work,
485 struct fc_disc,
486 disc_work.work);
487 mutex_lock(&disc->disc_mutex);
488 fc_disc_gpn_ft_req(disc);
489 mutex_unlock(&disc->disc_mutex);
490}
491
492/**
493 * fc_disc_gpn_ft_resp() - Handle a response frame from Get Port Names (GPN_FT)
494 * @sp: The sequence that the GPN_FT response was received on
495 * @fp: The GPN_FT response frame
496 * @lp_arg: The discovery context
497 *
498 * Locking Note: This function is called without disc mutex held, and
499 * should do all its processing with the mutex held
500 */
501static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp,
502 void *disc_arg)
503{
504 struct fc_disc *disc = disc_arg;
505 struct fc_ct_hdr *cp;
506 struct fc_frame_header *fh;
507 enum fc_disc_event event = DISC_EV_NONE;
508 unsigned int seq_cnt;
509 unsigned int len;
510 int error = 0;
511
512 mutex_lock(&disc->disc_mutex);
513 FC_DISC_DBG(disc, "Received a GPN_FT response\n");
514
515 if (IS_ERR(fp)) {
516 fc_disc_error(disc, fp);
517 mutex_unlock(&disc->disc_mutex);
518 return;
519 }
520
521 WARN_ON(!fc_frame_is_linear(fp)); /* buffer must be contiguous */
522 fh = fc_frame_header_get(fp);
523 len = fr_len(fp) - sizeof(*fh);
524 seq_cnt = ntohs(fh->fh_seq_cnt);
525 if (fr_sof(fp) == FC_SOF_I3 && seq_cnt == 0 && disc->seq_count == 0) {
526 cp = fc_frame_payload_get(fp, sizeof(*cp));
527 if (!cp) {
528 FC_DISC_DBG(disc, "GPN_FT response too short, len %d\n",
529 fr_len(fp));
530 event = DISC_EV_FAILED;
531 } else if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
532
533 /* Accepted, parse the response. */
534 len -= sizeof(*cp);
535 error = fc_disc_gpn_ft_parse(disc, cp + 1, len);
536 } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
537 FC_DISC_DBG(disc, "GPN_FT rejected reason %x exp %x "
538 "(check zoning)\n", cp->ct_reason,
539 cp->ct_explan);
540 event = DISC_EV_FAILED;
541 if (cp->ct_reason == FC_FS_RJT_UNABL &&
542 cp->ct_explan == FC_FS_EXP_FTNR)
543 event = DISC_EV_SUCCESS;
544 } else {
545 FC_DISC_DBG(disc, "GPN_FT unexpected response code "
546 "%x\n", ntohs(cp->ct_cmd));
547 event = DISC_EV_FAILED;
548 }
549 } else if (fr_sof(fp) == FC_SOF_N3 && seq_cnt == disc->seq_count) {
550 error = fc_disc_gpn_ft_parse(disc, fh + 1, len);
551 } else {
552 FC_DISC_DBG(disc, "GPN_FT unexpected frame - out of sequence? "
553 "seq_cnt %x expected %x sof %x eof %x\n",
554 seq_cnt, disc->seq_count, fr_sof(fp), fr_eof(fp));
555 event = DISC_EV_FAILED;
556 }
557 if (error)
558 fc_disc_error(disc, fp);
559 else if (event != DISC_EV_NONE)
560 fc_disc_done(disc, event);
561 fc_frame_free(fp);
562 mutex_unlock(&disc->disc_mutex);
563}
564
565/**
566 * fc_disc_gpn_id_resp() - Handle a response frame from Get Port Names (GPN_ID)
567 * @sp: The sequence the GPN_ID is on
568 * @fp: The response frame
569 * @rdata_arg: The remote port that sent the GPN_ID response
570 *
571 * Locking Note: This function is called without disc mutex held.
572 */
573static void fc_disc_gpn_id_resp(struct fc_seq *sp, struct fc_frame *fp,
574 void *rdata_arg)
575{
576 struct fc_rport_priv *rdata = rdata_arg;
577 struct fc_rport_priv *new_rdata;
578 struct fc_lport *lport;
579 struct fc_disc *disc;
580 struct fc_ct_hdr *cp;
581 struct fc_ns_gid_pn *pn;
582 u64 port_name;
583
584 lport = rdata->local_port;
585 disc = &lport->disc;
586
587 mutex_lock(&disc->disc_mutex);
588 if (PTR_ERR(fp) == -FC_EX_CLOSED)
589 goto out;
590 if (IS_ERR(fp))
591 goto redisc;
592
593 cp = fc_frame_payload_get(fp, sizeof(*cp));
594 if (!cp)
595 goto redisc;
596 if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
597 if (fr_len(fp) < sizeof(struct fc_frame_header) +
598 sizeof(*cp) + sizeof(*pn))
599 goto redisc;
600 pn = (struct fc_ns_gid_pn *)(cp + 1);
601 port_name = get_unaligned_be64(&pn->fn_wwpn);
602 if (rdata->ids.port_name == -1)
603 rdata->ids.port_name = port_name;
604 else if (rdata->ids.port_name != port_name) {
605 FC_DISC_DBG(disc, "GPN_ID accepted. WWPN changed. "
606 "Port-id %6.6x wwpn %16.16llx\n",
607 rdata->ids.port_id, port_name);
608 lport->tt.rport_logoff(rdata);
609
610 new_rdata = lport->tt.rport_create(lport,
611 rdata->ids.port_id);
612 if (new_rdata) {
613 new_rdata->disc_id = disc->disc_id;
614 lport->tt.rport_login(new_rdata);
615 }
616 goto out;
617 }
618 rdata->disc_id = disc->disc_id;
619 lport->tt.rport_login(rdata);
620 } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
621 FC_DISC_DBG(disc, "GPN_ID rejected reason %x exp %x\n",
622 cp->ct_reason, cp->ct_explan);
623 lport->tt.rport_logoff(rdata);
624 } else {
625 FC_DISC_DBG(disc, "GPN_ID unexpected response code %x\n",
626 ntohs(cp->ct_cmd));
627redisc:
628 fc_disc_restart(disc);
629 }
630out:
631 mutex_unlock(&disc->disc_mutex);
632 kref_put(&rdata->kref, lport->tt.rport_destroy);
633}
634
635/**
636 * fc_disc_gpn_id_req() - Send Get Port Names by ID (GPN_ID) request
637 * @lport: The local port to initiate discovery on
638 * @rdata: remote port private data
639 *
640 * Locking Note: This function expects that the disc_mutex is locked
641 * before it is called.
642 * On failure, an error code is returned.
643 */
644static int fc_disc_gpn_id_req(struct fc_lport *lport,
645 struct fc_rport_priv *rdata)
646{
647 struct fc_frame *fp;
648
649 fp = fc_frame_alloc(lport, sizeof(struct fc_ct_hdr) +
650 sizeof(struct fc_ns_fid));
651 if (!fp)
652 return -ENOMEM;
653 if (!lport->tt.elsct_send(lport, rdata->ids.port_id, fp, FC_NS_GPN_ID,
654 fc_disc_gpn_id_resp, rdata,
655 3 * lport->r_a_tov))
656 return -ENOMEM;
657 kref_get(&rdata->kref);
658 return 0;
659}
660
661/**
662 * fc_disc_single() - Discover the directory information for a single target
663 * @lport: The local port the remote port is associated with
664 * @dp: The port to rediscover
665 *
666 * Locking Note: This function expects that the disc_mutex is locked
667 * before it is called.
668 */
669static int fc_disc_single(struct fc_lport *lport, struct fc_disc_port *dp)
670{
671 struct fc_rport_priv *rdata;
672
673 rdata = lport->tt.rport_create(lport, dp->port_id);
674 if (!rdata)
675 return -ENOMEM;
676 rdata->disc_id = 0;
677 return fc_disc_gpn_id_req(lport, rdata);
678}
679
680/**
681 * fc_disc_stop() - Stop discovery for a given lport
682 * @lport: The local port that discovery should stop on
683 */
684void fc_disc_stop(struct fc_lport *lport)
685{
686 struct fc_disc *disc = &lport->disc;
687
688 if (disc->pending)
689 cancel_delayed_work_sync(&disc->disc_work);
690 fc_disc_stop_rports(disc);
691}
692
693/**
694 * fc_disc_stop_final() - Stop discovery for a given lport
695 * @lport: The lport that discovery should stop on
696 *
697 * This function will block until discovery has been
698 * completely stopped and all rports have been deleted.
699 */
700void fc_disc_stop_final(struct fc_lport *lport)
701{
702 fc_disc_stop(lport);
703 lport->tt.rport_flush_queue();
704}
705
706/**
707 * fc_disc_init() - Initialize the discovery layer for a local port
708 * @lport: The local port that needs the discovery layer to be initialized
709 */
710int fc_disc_init(struct fc_lport *lport)
711{
712 struct fc_disc *disc;
713
714 if (!lport->tt.disc_start)
715 lport->tt.disc_start = fc_disc_start;
716
717 if (!lport->tt.disc_stop)
718 lport->tt.disc_stop = fc_disc_stop;
719
720 if (!lport->tt.disc_stop_final)
721 lport->tt.disc_stop_final = fc_disc_stop_final;
722
723 if (!lport->tt.disc_recv_req)
724 lport->tt.disc_recv_req = fc_disc_recv_req;
725
726 disc = &lport->disc;
727 INIT_DELAYED_WORK(&disc->disc_work, fc_disc_timeout);
728 mutex_init(&disc->disc_mutex);
729 INIT_LIST_HEAD(&disc->rports);
730
731 disc->priv = lport;
732
733 return 0;
734}
735EXPORT_SYMBOL(fc_disc_init);