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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/*
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 <linux/export.h>
39#include <linux/rculist.h>
40
41#include <asm/unaligned.h>
42
43#include <scsi/fc/fc_gs.h>
44
45#include <scsi/libfc.h>
46
47#include "fc_libfc.h"
48
49#define FC_DISC_RETRY_LIMIT 3 /* max retries */
50#define FC_DISC_RETRY_DELAY 500UL /* (msecs) delay */
51
52static void fc_disc_gpn_ft_req(struct fc_disc *);
53static void fc_disc_gpn_ft_resp(struct fc_seq *, struct fc_frame *, void *);
54static void fc_disc_done(struct fc_disc *, enum fc_disc_event);
55static void fc_disc_timeout(struct work_struct *);
56static int fc_disc_single(struct fc_lport *, struct fc_disc_port *);
57static void fc_disc_restart(struct fc_disc *);
58
59/**
60 * fc_disc_stop_rports() - Delete all the remote ports associated with the lport
61 * @disc: The discovery job to stop remote ports on
62 *
63 * Locking Note: This function expects that the lport mutex is locked before
64 * calling it.
65 */
66static void fc_disc_stop_rports(struct fc_disc *disc)
67{
68 struct fc_lport *lport;
69 struct fc_rport_priv *rdata;
70
71 lport = fc_disc_lport(disc);
72
73 rcu_read_lock();
74 list_for_each_entry_rcu(rdata, &disc->rports, peers) {
75 if (kref_get_unless_zero(&rdata->kref)) {
76 fc_rport_logoff(rdata);
77 kref_put(&rdata->kref, fc_rport_destroy);
78 }
79 }
80 rcu_read_unlock();
81}
82
83/**
84 * fc_disc_recv_rscn_req() - Handle Registered State Change Notification (RSCN)
85 * @disc: The discovery object to which the RSCN applies
86 * @fp: The RSCN frame
87 *
88 * Locking Note: This function expects that the disc_mutex is locked
89 * before it is called.
90 */
91static void fc_disc_recv_rscn_req(struct fc_disc *disc, struct fc_frame *fp)
92{
93 struct fc_lport *lport;
94 struct fc_els_rscn *rp;
95 struct fc_els_rscn_page *pp;
96 struct fc_seq_els_data rjt_data;
97 unsigned int len;
98 int redisc = 0;
99 enum fc_els_rscn_ev_qual ev_qual;
100 enum fc_els_rscn_addr_fmt fmt;
101 LIST_HEAD(disc_ports);
102 struct fc_disc_port *dp, *next;
103
104 lport = fc_disc_lport(disc);
105
106 FC_DISC_DBG(disc, "Received an RSCN event\n");
107
108 /* make sure the frame contains an RSCN message */
109 rp = fc_frame_payload_get(fp, sizeof(*rp));
110 if (!rp)
111 goto reject;
112 /* make sure the page length is as expected (4 bytes) */
113 if (rp->rscn_page_len != sizeof(*pp))
114 goto reject;
115 /* get the RSCN payload length */
116 len = ntohs(rp->rscn_plen);
117 if (len < sizeof(*rp))
118 goto reject;
119 /* make sure the frame contains the expected payload */
120 rp = fc_frame_payload_get(fp, len);
121 if (!rp)
122 goto reject;
123 /* payload must be a multiple of the RSCN page size */
124 len -= sizeof(*rp);
125 if (len % sizeof(*pp))
126 goto reject;
127
128 for (pp = (void *)(rp + 1); len > 0; len -= sizeof(*pp), pp++) {
129 ev_qual = pp->rscn_page_flags >> ELS_RSCN_EV_QUAL_BIT;
130 ev_qual &= ELS_RSCN_EV_QUAL_MASK;
131 fmt = pp->rscn_page_flags >> ELS_RSCN_ADDR_FMT_BIT;
132 fmt &= ELS_RSCN_ADDR_FMT_MASK;
133 /*
134 * if we get an address format other than port
135 * (area, domain, fabric), then do a full discovery
136 */
137 switch (fmt) {
138 case ELS_ADDR_FMT_PORT:
139 FC_DISC_DBG(disc, "Port address format for port "
140 "(%6.6x)\n", ntoh24(pp->rscn_fid));
141 dp = kzalloc(sizeof(*dp), GFP_KERNEL);
142 if (!dp) {
143 redisc = 1;
144 break;
145 }
146 dp->lp = lport;
147 dp->port_id = ntoh24(pp->rscn_fid);
148 list_add_tail(&dp->peers, &disc_ports);
149 break;
150 case ELS_ADDR_FMT_AREA:
151 case ELS_ADDR_FMT_DOM:
152 case ELS_ADDR_FMT_FAB:
153 default:
154 FC_DISC_DBG(disc, "Address format is (%d)\n", fmt);
155 redisc = 1;
156 break;
157 }
158 }
159 fc_seq_els_rsp_send(fp, ELS_LS_ACC, NULL);
160
161 /*
162 * If not doing a complete rediscovery, do GPN_ID on
163 * the individual ports mentioned in the list.
164 * If any of these get an error, do a full rediscovery.
165 * In any case, go through the list and free the entries.
166 */
167 list_for_each_entry_safe(dp, next, &disc_ports, peers) {
168 list_del(&dp->peers);
169 if (!redisc)
170 redisc = fc_disc_single(lport, dp);
171 kfree(dp);
172 }
173 if (redisc) {
174 FC_DISC_DBG(disc, "RSCN received: rediscovering\n");
175 fc_disc_restart(disc);
176 } else {
177 FC_DISC_DBG(disc, "RSCN received: not rediscovering. "
178 "redisc %d state %d in_prog %d\n",
179 redisc, lport->state, disc->pending);
180 }
181 fc_frame_free(fp);
182 return;
183reject:
184 FC_DISC_DBG(disc, "Received a bad RSCN frame\n");
185 rjt_data.reason = ELS_RJT_LOGIC;
186 rjt_data.explan = ELS_EXPL_NONE;
187 fc_seq_els_rsp_send(fp, ELS_LS_RJT, &rjt_data);
188 fc_frame_free(fp);
189}
190
191/**
192 * fc_disc_recv_req() - Handle incoming requests
193 * @lport: The local port receiving the request
194 * @fp: The request frame
195 *
196 * Locking Note: This function is called from the EM and will lock
197 * the disc_mutex before calling the handler for the
198 * request.
199 */
200static void fc_disc_recv_req(struct fc_lport *lport, struct fc_frame *fp)
201{
202 u8 op;
203 struct fc_disc *disc = &lport->disc;
204
205 op = fc_frame_payload_op(fp);
206 switch (op) {
207 case ELS_RSCN:
208 mutex_lock(&disc->disc_mutex);
209 fc_disc_recv_rscn_req(disc, fp);
210 mutex_unlock(&disc->disc_mutex);
211 break;
212 default:
213 FC_DISC_DBG(disc, "Received an unsupported request, "
214 "the opcode is (%x)\n", op);
215 fc_frame_free(fp);
216 break;
217 }
218}
219
220/**
221 * fc_disc_restart() - Restart discovery
222 * @disc: The discovery object to be restarted
223 *
224 * Locking Note: This function expects that the disc mutex
225 * is already locked.
226 */
227static void fc_disc_restart(struct fc_disc *disc)
228{
229 if (!disc->disc_callback)
230 return;
231
232 FC_DISC_DBG(disc, "Restarting discovery\n");
233
234 disc->requested = 1;
235 if (disc->pending)
236 return;
237
238 /*
239 * Advance disc_id. This is an arbitrary non-zero number that will
240 * match the value in the fc_rport_priv after discovery for all
241 * freshly-discovered remote ports. Avoid wrapping to zero.
242 */
243 disc->disc_id = (disc->disc_id + 2) | 1;
244 disc->retry_count = 0;
245 fc_disc_gpn_ft_req(disc);
246}
247
248/**
249 * fc_disc_start() - Start discovery on a local port
250 * @lport: The local port to have discovery started on
251 * @disc_callback: Callback function to be called when discovery is complete
252 */
253static void fc_disc_start(void (*disc_callback)(struct fc_lport *,
254 enum fc_disc_event),
255 struct fc_lport *lport)
256{
257 struct fc_disc *disc = &lport->disc;
258
259 /*
260 * At this point we may have a new disc job or an existing
261 * one. Either way, let's lock when we make changes to it
262 * and send the GPN_FT request.
263 */
264 mutex_lock(&disc->disc_mutex);
265 disc->disc_callback = disc_callback;
266 fc_disc_restart(disc);
267 mutex_unlock(&disc->disc_mutex);
268}
269
270/**
271 * fc_disc_done() - Discovery has been completed
272 * @disc: The discovery context
273 * @event: The discovery completion status
274 *
275 * Locking Note: This function expects that the disc mutex is locked before
276 * it is called. The discovery callback is then made with the lock released,
277 * and the lock is re-taken before returning from this function
278 */
279static void fc_disc_done(struct fc_disc *disc, enum fc_disc_event event)
280{
281 struct fc_lport *lport = fc_disc_lport(disc);
282 struct fc_rport_priv *rdata;
283
284 FC_DISC_DBG(disc, "Discovery complete\n");
285
286 disc->pending = 0;
287 if (disc->requested) {
288 fc_disc_restart(disc);
289 return;
290 }
291
292 /*
293 * Go through all remote ports. If they were found in the latest
294 * discovery, reverify or log them in. Otherwise, log them out.
295 * Skip ports which were never discovered. These are the dNS port
296 * and ports which were created by PLOGI.
297 */
298 rcu_read_lock();
299 list_for_each_entry_rcu(rdata, &disc->rports, peers) {
300 if (!kref_get_unless_zero(&rdata->kref))
301 continue;
302 if (rdata->disc_id) {
303 if (rdata->disc_id == disc->disc_id)
304 fc_rport_login(rdata);
305 else
306 fc_rport_logoff(rdata);
307 }
308 kref_put(&rdata->kref, fc_rport_destroy);
309 }
310 rcu_read_unlock();
311 mutex_unlock(&disc->disc_mutex);
312 disc->disc_callback(lport, event);
313 mutex_lock(&disc->disc_mutex);
314}
315
316/**
317 * fc_disc_error() - Handle error on dNS request
318 * @disc: The discovery context
319 * @fp: The error code encoded as a frame pointer
320 */
321static void fc_disc_error(struct fc_disc *disc, struct fc_frame *fp)
322{
323 struct fc_lport *lport = fc_disc_lport(disc);
324 unsigned long delay = 0;
325
326 FC_DISC_DBG(disc, "Error %ld, retries %d/%d\n",
327 PTR_ERR(fp), disc->retry_count,
328 FC_DISC_RETRY_LIMIT);
329
330 if (!fp || PTR_ERR(fp) == -FC_EX_TIMEOUT) {
331 /*
332 * Memory allocation failure, or the exchange timed out,
333 * retry after delay.
334 */
335 if (disc->retry_count < FC_DISC_RETRY_LIMIT) {
336 /* go ahead and retry */
337 if (!fp)
338 delay = msecs_to_jiffies(FC_DISC_RETRY_DELAY);
339 else {
340 delay = msecs_to_jiffies(lport->e_d_tov);
341
342 /* timeout faster first time */
343 if (!disc->retry_count)
344 delay /= 4;
345 }
346 disc->retry_count++;
347 schedule_delayed_work(&disc->disc_work, delay);
348 } else
349 fc_disc_done(disc, DISC_EV_FAILED);
350 } else if (PTR_ERR(fp) == -FC_EX_CLOSED) {
351 /*
352 * if discovery fails due to lport reset, clear
353 * pending flag so that subsequent discovery can
354 * continue
355 */
356 disc->pending = 0;
357 }
358}
359
360/**
361 * fc_disc_gpn_ft_req() - Send Get Port Names by FC-4 type (GPN_FT) request
362 * @lport: The discovery context
363 *
364 * Locking Note: This function expects that the disc_mutex is locked
365 * before it is called.
366 */
367static void fc_disc_gpn_ft_req(struct fc_disc *disc)
368{
369 struct fc_frame *fp;
370 struct fc_lport *lport = fc_disc_lport(disc);
371
372 WARN_ON(!fc_lport_test_ready(lport));
373
374 disc->pending = 1;
375 disc->requested = 0;
376
377 disc->buf_len = 0;
378 disc->seq_count = 0;
379 fp = fc_frame_alloc(lport,
380 sizeof(struct fc_ct_hdr) +
381 sizeof(struct fc_ns_gid_ft));
382 if (!fp)
383 goto err;
384
385 if (lport->tt.elsct_send(lport, 0, fp,
386 FC_NS_GPN_FT,
387 fc_disc_gpn_ft_resp,
388 disc, 3 * lport->r_a_tov))
389 return;
390err:
391 fc_disc_error(disc, NULL);
392}
393
394/**
395 * fc_disc_gpn_ft_parse() - Parse the body of the dNS GPN_FT response.
396 * @lport: The local port the GPN_FT was received on
397 * @buf: The GPN_FT response buffer
398 * @len: The size of response buffer
399 *
400 * Goes through the list of IDs and names resulting from a request.
401 */
402static int fc_disc_gpn_ft_parse(struct fc_disc *disc, void *buf, size_t len)
403{
404 struct fc_lport *lport;
405 struct fc_gpn_ft_resp *np;
406 char *bp;
407 size_t plen;
408 size_t tlen;
409 int error = 0;
410 struct fc_rport_identifiers ids;
411 struct fc_rport_priv *rdata;
412
413 lport = fc_disc_lport(disc);
414 disc->seq_count++;
415
416 /*
417 * Handle partial name record left over from previous call.
418 */
419 bp = buf;
420 plen = len;
421 np = (struct fc_gpn_ft_resp *)bp;
422 tlen = disc->buf_len;
423 disc->buf_len = 0;
424 if (tlen) {
425 WARN_ON(tlen >= sizeof(*np));
426 plen = sizeof(*np) - tlen;
427 WARN_ON(plen <= 0);
428 WARN_ON(plen >= sizeof(*np));
429 if (plen > len)
430 plen = len;
431 np = &disc->partial_buf;
432 memcpy((char *)np + tlen, bp, plen);
433
434 /*
435 * Set bp so that the loop below will advance it to the
436 * first valid full name element.
437 */
438 bp -= tlen;
439 len += tlen;
440 plen += tlen;
441 disc->buf_len = (unsigned char) plen;
442 if (plen == sizeof(*np))
443 disc->buf_len = 0;
444 }
445
446 /*
447 * Handle full name records, including the one filled from above.
448 * Normally, np == bp and plen == len, but from the partial case above,
449 * bp, len describe the overall buffer, and np, plen describe the
450 * partial buffer, which if would usually be full now.
451 * After the first time through the loop, things return to "normal".
452 */
453 while (plen >= sizeof(*np)) {
454 ids.port_id = ntoh24(np->fp_fid);
455 ids.port_name = ntohll(np->fp_wwpn);
456
457 if (ids.port_id != lport->port_id &&
458 ids.port_name != lport->wwpn) {
459 rdata = fc_rport_create(lport, ids.port_id);
460 if (rdata) {
461 rdata->ids.port_name = ids.port_name;
462 rdata->disc_id = disc->disc_id;
463 } else {
464 printk(KERN_WARNING "libfc: Failed to allocate "
465 "memory for the newly discovered port "
466 "(%6.6x)\n", ids.port_id);
467 error = -ENOMEM;
468 }
469 }
470
471 if (np->fp_flags & FC_NS_FID_LAST) {
472 fc_disc_done(disc, DISC_EV_SUCCESS);
473 len = 0;
474 break;
475 }
476 len -= sizeof(*np);
477 bp += sizeof(*np);
478 np = (struct fc_gpn_ft_resp *)bp;
479 plen = len;
480 }
481
482 /*
483 * Save any partial record at the end of the buffer for next time.
484 */
485 if (error == 0 && len > 0 && len < sizeof(*np)) {
486 if (np != &disc->partial_buf) {
487 FC_DISC_DBG(disc, "Partial buffer remains "
488 "for discovery\n");
489 memcpy(&disc->partial_buf, np, len);
490 }
491 disc->buf_len = (unsigned char) len;
492 }
493 return error;
494}
495
496/**
497 * fc_disc_timeout() - Handler for discovery timeouts
498 * @work: Structure holding discovery context that needs to retry discovery
499 */
500static void fc_disc_timeout(struct work_struct *work)
501{
502 struct fc_disc *disc = container_of(work,
503 struct fc_disc,
504 disc_work.work);
505 mutex_lock(&disc->disc_mutex);
506 fc_disc_gpn_ft_req(disc);
507 mutex_unlock(&disc->disc_mutex);
508}
509
510/**
511 * fc_disc_gpn_ft_resp() - Handle a response frame from Get Port Names (GPN_FT)
512 * @sp: The sequence that the GPN_FT response was received on
513 * @fp: The GPN_FT response frame
514 * @lp_arg: The discovery context
515 *
516 * Locking Note: This function is called without disc mutex held, and
517 * should do all its processing with the mutex held
518 */
519static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp,
520 void *disc_arg)
521{
522 struct fc_disc *disc = disc_arg;
523 struct fc_ct_hdr *cp;
524 struct fc_frame_header *fh;
525 enum fc_disc_event event = DISC_EV_NONE;
526 unsigned int seq_cnt;
527 unsigned int len;
528 int error = 0;
529
530 mutex_lock(&disc->disc_mutex);
531 FC_DISC_DBG(disc, "Received a GPN_FT response\n");
532
533 if (IS_ERR(fp)) {
534 fc_disc_error(disc, fp);
535 mutex_unlock(&disc->disc_mutex);
536 return;
537 }
538
539 WARN_ON(!fc_frame_is_linear(fp)); /* buffer must be contiguous */
540 fh = fc_frame_header_get(fp);
541 len = fr_len(fp) - sizeof(*fh);
542 seq_cnt = ntohs(fh->fh_seq_cnt);
543 if (fr_sof(fp) == FC_SOF_I3 && seq_cnt == 0 && disc->seq_count == 0) {
544 cp = fc_frame_payload_get(fp, sizeof(*cp));
545 if (!cp) {
546 FC_DISC_DBG(disc, "GPN_FT response too short, len %d\n",
547 fr_len(fp));
548 event = DISC_EV_FAILED;
549 } else if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
550
551 /* Accepted, parse the response. */
552 len -= sizeof(*cp);
553 error = fc_disc_gpn_ft_parse(disc, cp + 1, len);
554 } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
555 FC_DISC_DBG(disc, "GPN_FT rejected reason %x exp %x "
556 "(check zoning)\n", cp->ct_reason,
557 cp->ct_explan);
558 event = DISC_EV_FAILED;
559 if (cp->ct_reason == FC_FS_RJT_UNABL &&
560 cp->ct_explan == FC_FS_EXP_FTNR)
561 event = DISC_EV_SUCCESS;
562 } else {
563 FC_DISC_DBG(disc, "GPN_FT unexpected response code "
564 "%x\n", ntohs(cp->ct_cmd));
565 event = DISC_EV_FAILED;
566 }
567 } else if (fr_sof(fp) == FC_SOF_N3 && seq_cnt == disc->seq_count) {
568 error = fc_disc_gpn_ft_parse(disc, fh + 1, len);
569 } else {
570 FC_DISC_DBG(disc, "GPN_FT unexpected frame - out of sequence? "
571 "seq_cnt %x expected %x sof %x eof %x\n",
572 seq_cnt, disc->seq_count, fr_sof(fp), fr_eof(fp));
573 event = DISC_EV_FAILED;
574 }
575 if (error)
576 fc_disc_error(disc, ERR_PTR(error));
577 else if (event != DISC_EV_NONE)
578 fc_disc_done(disc, event);
579 fc_frame_free(fp);
580 mutex_unlock(&disc->disc_mutex);
581}
582
583/**
584 * fc_disc_gpn_id_resp() - Handle a response frame from Get Port Names (GPN_ID)
585 * @sp: The sequence the GPN_ID is on
586 * @fp: The response frame
587 * @rdata_arg: The remote port that sent the GPN_ID response
588 *
589 * Locking Note: This function is called without disc mutex held.
590 */
591static void fc_disc_gpn_id_resp(struct fc_seq *sp, struct fc_frame *fp,
592 void *rdata_arg)
593{
594 struct fc_rport_priv *rdata = rdata_arg;
595 struct fc_rport_priv *new_rdata;
596 struct fc_lport *lport;
597 struct fc_disc *disc;
598 struct fc_ct_hdr *cp;
599 struct fc_ns_gid_pn *pn;
600 u64 port_name;
601
602 lport = rdata->local_port;
603 disc = &lport->disc;
604
605 if (PTR_ERR(fp) == -FC_EX_CLOSED)
606 goto out;
607 if (IS_ERR(fp))
608 goto redisc;
609
610 cp = fc_frame_payload_get(fp, sizeof(*cp));
611 if (!cp)
612 goto redisc;
613 if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
614 if (fr_len(fp) < sizeof(struct fc_frame_header) +
615 sizeof(*cp) + sizeof(*pn))
616 goto redisc;
617 pn = (struct fc_ns_gid_pn *)(cp + 1);
618 port_name = get_unaligned_be64(&pn->fn_wwpn);
619 mutex_lock(&rdata->rp_mutex);
620 if (rdata->ids.port_name == -1)
621 rdata->ids.port_name = port_name;
622 else if (rdata->ids.port_name != port_name) {
623 FC_DISC_DBG(disc, "GPN_ID accepted. WWPN changed. "
624 "Port-id %6.6x wwpn %16.16llx\n",
625 rdata->ids.port_id, port_name);
626 mutex_unlock(&rdata->rp_mutex);
627 fc_rport_logoff(rdata);
628 mutex_lock(&lport->disc.disc_mutex);
629 new_rdata = fc_rport_create(lport, rdata->ids.port_id);
630 mutex_unlock(&lport->disc.disc_mutex);
631 if (new_rdata) {
632 new_rdata->disc_id = disc->disc_id;
633 fc_rport_login(new_rdata);
634 }
635 goto out;
636 }
637 rdata->disc_id = disc->disc_id;
638 mutex_unlock(&rdata->rp_mutex);
639 fc_rport_login(rdata);
640 } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
641 FC_DISC_DBG(disc, "GPN_ID rejected reason %x exp %x\n",
642 cp->ct_reason, cp->ct_explan);
643 fc_rport_logoff(rdata);
644 } else {
645 FC_DISC_DBG(disc, "GPN_ID unexpected response code %x\n",
646 ntohs(cp->ct_cmd));
647redisc:
648 mutex_lock(&disc->disc_mutex);
649 fc_disc_restart(disc);
650 mutex_unlock(&disc->disc_mutex);
651 }
652out:
653 kref_put(&rdata->kref, fc_rport_destroy);
654}
655
656/**
657 * fc_disc_gpn_id_req() - Send Get Port Names by ID (GPN_ID) request
658 * @lport: The local port to initiate discovery on
659 * @rdata: remote port private data
660 *
661 * Locking Note: This function expects that the disc_mutex is locked
662 * before it is called.
663 * On failure, an error code is returned.
664 */
665static int fc_disc_gpn_id_req(struct fc_lport *lport,
666 struct fc_rport_priv *rdata)
667{
668 struct fc_frame *fp;
669
670 fp = fc_frame_alloc(lport, sizeof(struct fc_ct_hdr) +
671 sizeof(struct fc_ns_fid));
672 if (!fp)
673 return -ENOMEM;
674 if (!lport->tt.elsct_send(lport, rdata->ids.port_id, fp, FC_NS_GPN_ID,
675 fc_disc_gpn_id_resp, rdata,
676 3 * lport->r_a_tov))
677 return -ENOMEM;
678 kref_get(&rdata->kref);
679 return 0;
680}
681
682/**
683 * fc_disc_single() - Discover the directory information for a single target
684 * @lport: The local port the remote port is associated with
685 * @dp: The port to rediscover
686 *
687 * Locking Note: This function expects that the disc_mutex is locked
688 * before it is called.
689 */
690static int fc_disc_single(struct fc_lport *lport, struct fc_disc_port *dp)
691{
692 struct fc_rport_priv *rdata;
693
694 rdata = fc_rport_create(lport, dp->port_id);
695 if (!rdata)
696 return -ENOMEM;
697 rdata->disc_id = 0;
698 return fc_disc_gpn_id_req(lport, rdata);
699}
700
701/**
702 * fc_disc_stop() - Stop discovery for a given lport
703 * @lport: The local port that discovery should stop on
704 */
705static void fc_disc_stop(struct fc_lport *lport)
706{
707 struct fc_disc *disc = &lport->disc;
708
709 if (disc->pending)
710 cancel_delayed_work_sync(&disc->disc_work);
711 fc_disc_stop_rports(disc);
712}
713
714/**
715 * fc_disc_stop_final() - Stop discovery for a given lport
716 * @lport: The lport that discovery should stop on
717 *
718 * This function will block until discovery has been
719 * completely stopped and all rports have been deleted.
720 */
721static void fc_disc_stop_final(struct fc_lport *lport)
722{
723 fc_disc_stop(lport);
724 fc_rport_flush_queue();
725}
726
727/**
728 * fc_disc_config() - Configure the discovery layer for a local port
729 * @lport: The local port that needs the discovery layer to be configured
730 * @priv: Private data structre for users of the discovery layer
731 */
732void fc_disc_config(struct fc_lport *lport, void *priv)
733{
734 struct fc_disc *disc;
735
736 if (!lport->tt.disc_start)
737 lport->tt.disc_start = fc_disc_start;
738
739 if (!lport->tt.disc_stop)
740 lport->tt.disc_stop = fc_disc_stop;
741
742 if (!lport->tt.disc_stop_final)
743 lport->tt.disc_stop_final = fc_disc_stop_final;
744
745 if (!lport->tt.disc_recv_req)
746 lport->tt.disc_recv_req = fc_disc_recv_req;
747
748 disc = &lport->disc;
749
750 disc->priv = priv;
751}
752EXPORT_SYMBOL(fc_disc_config);
753
754/**
755 * fc_disc_init() - Initialize the discovery layer for a local port
756 * @lport: The local port that needs the discovery layer to be initialized
757 */
758void fc_disc_init(struct fc_lport *lport)
759{
760 struct fc_disc *disc = &lport->disc;
761
762 INIT_DELAYED_WORK(&disc->disc_work, fc_disc_timeout);
763 mutex_init(&disc->disc_mutex);
764 INIT_LIST_HEAD(&disc->rports);
765}
766EXPORT_SYMBOL(fc_disc_init);