Loading...
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// 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
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_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;
164reject:
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 */
181static 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 */
205static 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 */
233static 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 */
255static 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 */
299static 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 %ld, retries %d/%d\n",
305 PTR_ERR(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 */
342static 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;
367err:
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 */
379static 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 */
477static 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 */
496static 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 */
568static 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));
628redisc:
629 mutex_lock(&disc->disc_mutex);
630 fc_disc_restart(disc);
631 mutex_unlock(&disc->disc_mutex);
632 }
633free_fp:
634 fc_frame_free(fp);
635out:
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 */
646static 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 */
669static 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 */
686static 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 */
704static 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 */
715void 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}
735EXPORT_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 */
741void 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}
749EXPORT_SYMBOL(fc_disc_init);