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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);
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 * @lport: 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 * @lport: The local port the GPN_FT was received on
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 * @lp_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 goto redisc;
586
587 cp = fc_frame_payload_get(fp, sizeof(*cp));
588 if (!cp)
589 goto redisc;
590 if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
591 if (fr_len(fp) < sizeof(struct fc_frame_header) +
592 sizeof(*cp) + sizeof(*pn))
593 goto redisc;
594 pn = (struct fc_ns_gid_pn *)(cp + 1);
595 port_name = get_unaligned_be64(&pn->fn_wwpn);
596 mutex_lock(&rdata->rp_mutex);
597 if (rdata->ids.port_name == -1)
598 rdata->ids.port_name = port_name;
599 else if (rdata->ids.port_name != port_name) {
600 FC_DISC_DBG(disc, "GPN_ID accepted. WWPN changed. "
601 "Port-id %6.6x wwpn %16.16llx\n",
602 rdata->ids.port_id, port_name);
603 mutex_unlock(&rdata->rp_mutex);
604 fc_rport_logoff(rdata);
605 mutex_lock(&lport->disc.disc_mutex);
606 new_rdata = fc_rport_create(lport, rdata->ids.port_id);
607 mutex_unlock(&lport->disc.disc_mutex);
608 if (new_rdata) {
609 new_rdata->disc_id = disc->disc_id;
610 fc_rport_login(new_rdata);
611 }
612 goto out;
613 }
614 rdata->disc_id = disc->disc_id;
615 mutex_unlock(&rdata->rp_mutex);
616 fc_rport_login(rdata);
617 } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
618 FC_DISC_DBG(disc, "GPN_ID rejected reason %x exp %x\n",
619 cp->ct_reason, cp->ct_explan);
620 fc_rport_logoff(rdata);
621 } else {
622 FC_DISC_DBG(disc, "GPN_ID unexpected response code %x\n",
623 ntohs(cp->ct_cmd));
624redisc:
625 mutex_lock(&disc->disc_mutex);
626 fc_disc_restart(disc);
627 mutex_unlock(&disc->disc_mutex);
628 }
629out:
630 kref_put(&rdata->kref, fc_rport_destroy);
631}
632
633/**
634 * fc_disc_gpn_id_req() - Send Get Port Names by ID (GPN_ID) request
635 * @lport: The local port to initiate discovery on
636 * @rdata: remote port private data
637 *
638 * On failure, an error code is returned.
639 */
640static int fc_disc_gpn_id_req(struct fc_lport *lport,
641 struct fc_rport_priv *rdata)
642{
643 struct fc_frame *fp;
644
645 lockdep_assert_held(&lport->disc.disc_mutex);
646 fp = fc_frame_alloc(lport, sizeof(struct fc_ct_hdr) +
647 sizeof(struct fc_ns_fid));
648 if (!fp)
649 return -ENOMEM;
650 if (!lport->tt.elsct_send(lport, rdata->ids.port_id, fp, FC_NS_GPN_ID,
651 fc_disc_gpn_id_resp, rdata,
652 3 * lport->r_a_tov))
653 return -ENOMEM;
654 kref_get(&rdata->kref);
655 return 0;
656}
657
658/**
659 * fc_disc_single() - Discover the directory information for a single target
660 * @lport: The local port the remote port is associated with
661 * @dp: The port to rediscover
662 */
663static int fc_disc_single(struct fc_lport *lport, struct fc_disc_port *dp)
664{
665 struct fc_rport_priv *rdata;
666
667 lockdep_assert_held(&lport->disc.disc_mutex);
668
669 rdata = fc_rport_create(lport, dp->port_id);
670 if (!rdata)
671 return -ENOMEM;
672 rdata->disc_id = 0;
673 return fc_disc_gpn_id_req(lport, rdata);
674}
675
676/**
677 * fc_disc_stop() - Stop discovery for a given lport
678 * @lport: The local port that discovery should stop on
679 */
680static void fc_disc_stop(struct fc_lport *lport)
681{
682 struct fc_disc *disc = &lport->disc;
683
684 if (disc->pending)
685 cancel_delayed_work_sync(&disc->disc_work);
686 mutex_lock(&disc->disc_mutex);
687 fc_disc_stop_rports(disc);
688 mutex_unlock(&disc->disc_mutex);
689}
690
691/**
692 * fc_disc_stop_final() - Stop discovery for a given lport
693 * @lport: The lport that discovery should stop on
694 *
695 * This function will block until discovery has been
696 * completely stopped and all rports have been deleted.
697 */
698static void fc_disc_stop_final(struct fc_lport *lport)
699{
700 fc_disc_stop(lport);
701 fc_rport_flush_queue();
702}
703
704/**
705 * fc_disc_config() - Configure the discovery layer for a local port
706 * @lport: The local port that needs the discovery layer to be configured
707 * @priv: Private data structre for users of the discovery layer
708 */
709void fc_disc_config(struct fc_lport *lport, void *priv)
710{
711 struct fc_disc *disc;
712
713 if (!lport->tt.disc_start)
714 lport->tt.disc_start = fc_disc_start;
715
716 if (!lport->tt.disc_stop)
717 lport->tt.disc_stop = fc_disc_stop;
718
719 if (!lport->tt.disc_stop_final)
720 lport->tt.disc_stop_final = fc_disc_stop_final;
721
722 if (!lport->tt.disc_recv_req)
723 lport->tt.disc_recv_req = fc_disc_recv_req;
724
725 disc = &lport->disc;
726
727 disc->priv = priv;
728}
729EXPORT_SYMBOL(fc_disc_config);
730
731/**
732 * fc_disc_init() - Initialize the discovery layer for a local port
733 * @lport: The local port that needs the discovery layer to be initialized
734 */
735void fc_disc_init(struct fc_lport *lport)
736{
737 struct fc_disc *disc = &lport->disc;
738
739 INIT_DELAYED_WORK(&disc->disc_work, fc_disc_timeout);
740 mutex_init(&disc->disc_mutex);
741 INIT_LIST_HEAD(&disc->rports);
742}
743EXPORT_SYMBOL(fc_disc_init);