2 * Copyright(c) 2007 - 2008 Intel Corporation. All rights reserved.
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.
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
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.
17 * Maintained at www.Open-FCoE.org
23 * This block discovers all FC-4 remote ports, including FCP initiators. It
24 * also handles RSCN events and re-discovery if necessary.
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
35 #include <linux/timer.h>
36 #include <linux/slab.h>
37 #include <linux/err.h>
38 #include <asm/unaligned.h>
40 #include <scsi/fc/fc_gs.h>
42 #include <scsi/libfc.h>
46 #define FC_DISC_RETRY_LIMIT 3 /* max retries */
47 #define FC_DISC_RETRY_DELAY 500UL /* (msecs) delay */
49 static void fc_disc_gpn_ft_req(struct fc_disc *);
50 static void fc_disc_gpn_ft_resp(struct fc_seq *, struct fc_frame *, void *);
51 static void fc_disc_done(struct fc_disc *, enum fc_disc_event);
52 static void fc_disc_timeout(struct work_struct *);
53 static int fc_disc_single(struct fc_lport *, struct fc_disc_port *);
54 static void fc_disc_restart(struct fc_disc *);
57 * fc_disc_stop_rports() - Delete all the remote ports associated with the lport
58 * @disc: The discovery job to stop remote ports on
60 * Locking Note: This function expects that the lport mutex is locked before
63 void fc_disc_stop_rports(struct fc_disc *disc)
65 struct fc_lport *lport;
66 struct fc_rport_priv *rdata;
68 lport = fc_disc_lport(disc);
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);
77 * fc_disc_recv_rscn_req() - Handle Registered State Change Notification (RSCN)
78 * @disc: The discovery object to which the RSCN applies
81 * Locking Note: This function expects that the disc_mutex is locked
82 * before it is called.
84 static void fc_disc_recv_rscn_req(struct fc_disc *disc, struct fc_frame *fp)
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;
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;
97 lport = fc_disc_lport(disc);
99 FC_DISC_DBG(disc, "Received an RSCN event\n");
101 /* make sure the frame contains an RSCN message */
102 rp = fc_frame_payload_get(fp, sizeof(*rp));
105 /* make sure the page length is as expected (4 bytes) */
106 if (rp->rscn_page_len != sizeof(*pp))
108 /* get the RSCN payload length */
109 len = ntohs(rp->rscn_plen);
110 if (len < sizeof(*rp))
112 /* make sure the frame contains the expected payload */
113 rp = fc_frame_payload_get(fp, len);
116 /* payload must be a multiple of the RSCN page size */
118 if (len % sizeof(*pp))
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;
127 * if we get an address format other than port
128 * (area, domain, fabric), then do a full discovery
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);
140 dp->port_id = ntoh24(pp->rscn_fid);
141 list_add_tail(&dp->peers, &disc_ports);
143 case ELS_ADDR_FMT_AREA:
144 case ELS_ADDR_FMT_DOM:
145 case ELS_ADDR_FMT_FAB:
147 FC_DISC_DBG(disc, "Address format is (%d)\n", fmt);
152 lport->tt.seq_els_rsp_send(fp, ELS_LS_ACC, NULL);
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.
160 list_for_each_entry_safe(dp, next, &disc_ports, peers) {
161 list_del(&dp->peers);
163 redisc = fc_disc_single(lport, dp);
167 FC_DISC_DBG(disc, "RSCN received: rediscovering\n");
168 fc_disc_restart(disc);
170 FC_DISC_DBG(disc, "RSCN received: not rediscovering. "
171 "redisc %d state %d in_prog %d\n",
172 redisc, lport->state, disc->pending);
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);
185 * fc_disc_recv_req() - Handle incoming requests
186 * @lport: The local port receiving the request
187 * @fp: The request frame
189 * Locking Note: This function is called from the EM and will lock
190 * the disc_mutex before calling the handler for the
193 static void fc_disc_recv_req(struct fc_lport *lport, struct fc_frame *fp)
196 struct fc_disc *disc = &lport->disc;
198 op = fc_frame_payload_op(fp);
201 mutex_lock(&disc->disc_mutex);
202 fc_disc_recv_rscn_req(disc, fp);
203 mutex_unlock(&disc->disc_mutex);
206 FC_DISC_DBG(disc, "Received an unsupported request, "
207 "the opcode is (%x)\n", op);
214 * fc_disc_restart() - Restart discovery
215 * @disc: The discovery object to be restarted
217 * Locking Note: This function expects that the disc mutex
220 static void fc_disc_restart(struct fc_disc *disc)
222 if (!disc->disc_callback)
225 FC_DISC_DBG(disc, "Restarting discovery\n");
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.
236 disc->disc_id = (disc->disc_id + 2) | 1;
237 disc->retry_count = 0;
238 fc_disc_gpn_ft_req(disc);
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
246 static void fc_disc_start(void (*disc_callback)(struct fc_lport *,
248 struct fc_lport *lport)
250 struct fc_disc *disc = &lport->disc;
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.
257 mutex_lock(&disc->disc_mutex);
258 disc->disc_callback = disc_callback;
259 fc_disc_restart(disc);
260 mutex_unlock(&disc->disc_mutex);
264 * fc_disc_done() - Discovery has been completed
265 * @disc: The discovery context
266 * @event: The discovery completion status
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
272 static void fc_disc_done(struct fc_disc *disc, enum fc_disc_event event)
274 struct fc_lport *lport = fc_disc_lport(disc);
275 struct fc_rport_priv *rdata;
277 FC_DISC_DBG(disc, "Discovery complete\n");
280 if (disc->requested) {
281 fc_disc_restart(disc);
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.
291 list_for_each_entry_rcu(rdata, &disc->rports, peers) {
294 if (rdata->disc_id == disc->disc_id)
295 lport->tt.rport_login(rdata);
297 lport->tt.rport_logoff(rdata);
300 mutex_unlock(&disc->disc_mutex);
301 disc->disc_callback(lport, event);
302 mutex_lock(&disc->disc_mutex);
306 * fc_disc_error() - Handle error on dNS request
307 * @disc: The discovery context
308 * @fp: The error code encoded as a frame pointer
310 static void fc_disc_error(struct fc_disc *disc, struct fc_frame *fp)
312 struct fc_lport *lport = fc_disc_lport(disc);
313 unsigned long delay = 0;
315 FC_DISC_DBG(disc, "Error %ld, retries %d/%d\n",
316 PTR_ERR(fp), disc->retry_count,
317 FC_DISC_RETRY_LIMIT);
319 if (!fp || PTR_ERR(fp) == -FC_EX_TIMEOUT) {
321 * Memory allocation failure, or the exchange timed out,
324 if (disc->retry_count < FC_DISC_RETRY_LIMIT) {
325 /* go ahead and retry */
327 delay = msecs_to_jiffies(FC_DISC_RETRY_DELAY);
329 delay = msecs_to_jiffies(lport->e_d_tov);
331 /* timeout faster first time */
332 if (!disc->retry_count)
336 schedule_delayed_work(&disc->disc_work, delay);
338 fc_disc_done(disc, DISC_EV_FAILED);
343 * fc_disc_gpn_ft_req() - Send Get Port Names by FC-4 type (GPN_FT) request
344 * @lport: The discovery context
346 * Locking Note: This function expects that the disc_mutex is locked
347 * before it is called.
349 static void fc_disc_gpn_ft_req(struct fc_disc *disc)
352 struct fc_lport *lport = fc_disc_lport(disc);
354 WARN_ON(!fc_lport_test_ready(lport));
361 fp = fc_frame_alloc(lport,
362 sizeof(struct fc_ct_hdr) +
363 sizeof(struct fc_ns_gid_ft));
367 if (lport->tt.elsct_send(lport, 0, fp,
370 disc, 3 * lport->r_a_tov))
373 fc_disc_error(disc, NULL);
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
382 * Goes through the list of IDs and names resulting from a request.
384 static int fc_disc_gpn_ft_parse(struct fc_disc *disc, void *buf, size_t len)
386 struct fc_lport *lport;
387 struct fc_gpn_ft_resp *np;
392 struct fc_rport_identifiers ids;
393 struct fc_rport_priv *rdata;
395 lport = fc_disc_lport(disc);
399 * Handle partial name record left over from previous call.
403 np = (struct fc_gpn_ft_resp *)bp;
404 tlen = disc->buf_len;
407 WARN_ON(tlen >= sizeof(*np));
408 plen = sizeof(*np) - tlen;
410 WARN_ON(plen >= sizeof(*np));
413 np = &disc->partial_buf;
414 memcpy((char *)np + tlen, bp, plen);
417 * Set bp so that the loop below will advance it to the
418 * first valid full name element.
423 disc->buf_len = (unsigned char) plen;
424 if (plen == sizeof(*np))
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".
435 while (plen >= sizeof(*np)) {
436 ids.port_id = ntoh24(np->fp_fid);
437 ids.port_name = ntohll(np->fp_wwpn);
439 if (ids.port_id != lport->port_id &&
440 ids.port_name != lport->wwpn) {
441 rdata = lport->tt.rport_create(lport, ids.port_id);
443 rdata->ids.port_name = ids.port_name;
444 rdata->disc_id = disc->disc_id;
446 printk(KERN_WARNING "libfc: Failed to allocate "
447 "memory for the newly discovered port "
448 "(%6.6x)\n", ids.port_id);
453 if (np->fp_flags & FC_NS_FID_LAST) {
454 fc_disc_done(disc, DISC_EV_SUCCESS);
460 np = (struct fc_gpn_ft_resp *)bp;
465 * Save any partial record at the end of the buffer for next time.
467 if (error == 0 && len > 0 && len < sizeof(*np)) {
468 if (np != &disc->partial_buf) {
469 FC_DISC_DBG(disc, "Partial buffer remains "
471 memcpy(&disc->partial_buf, np, len);
473 disc->buf_len = (unsigned char) len;
479 * fc_disc_timeout() - Handler for discovery timeouts
480 * @work: Structure holding discovery context that needs to retry discovery
482 static void fc_disc_timeout(struct work_struct *work)
484 struct fc_disc *disc = container_of(work,
487 mutex_lock(&disc->disc_mutex);
488 fc_disc_gpn_ft_req(disc);
489 mutex_unlock(&disc->disc_mutex);
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
498 * Locking Note: This function is called without disc mutex held, and
499 * should do all its processing with the mutex held
501 static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp,
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;
512 mutex_lock(&disc->disc_mutex);
513 FC_DISC_DBG(disc, "Received a GPN_FT response\n");
516 fc_disc_error(disc, fp);
517 mutex_unlock(&disc->disc_mutex);
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));
528 FC_DISC_DBG(disc, "GPN_FT response too short, len %d\n",
530 event = DISC_EV_FAILED;
531 } else if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
533 /* Accepted, parse the response. */
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,
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;
545 FC_DISC_DBG(disc, "GPN_FT unexpected response code "
546 "%x\n", ntohs(cp->ct_cmd));
547 event = DISC_EV_FAILED;
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);
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;
558 fc_disc_error(disc, fp);
559 else if (event != DISC_EV_NONE)
560 fc_disc_done(disc, event);
562 mutex_unlock(&disc->disc_mutex);
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
571 * Locking Note: This function is called without disc mutex held.
573 static void fc_disc_gpn_id_resp(struct fc_seq *sp, struct fc_frame *fp,
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;
584 lport = rdata->local_port;
587 mutex_lock(&disc->disc_mutex);
588 if (PTR_ERR(fp) == -FC_EX_CLOSED)
593 cp = fc_frame_payload_get(fp, sizeof(*cp));
596 if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
597 if (fr_len(fp) < sizeof(struct fc_frame_header) +
598 sizeof(*cp) + sizeof(*pn))
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);
610 new_rdata = lport->tt.rport_create(lport,
613 new_rdata->disc_id = disc->disc_id;
614 lport->tt.rport_login(new_rdata);
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);
625 FC_DISC_DBG(disc, "GPN_ID unexpected response code %x\n",
628 fc_disc_restart(disc);
631 mutex_unlock(&disc->disc_mutex);
632 kref_put(&rdata->kref, lport->tt.rport_destroy);
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
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.
644 static int fc_disc_gpn_id_req(struct fc_lport *lport,
645 struct fc_rport_priv *rdata)
649 fp = fc_frame_alloc(lport, sizeof(struct fc_ct_hdr) +
650 sizeof(struct fc_ns_fid));
653 if (!lport->tt.elsct_send(lport, rdata->ids.port_id, fp, FC_NS_GPN_ID,
654 fc_disc_gpn_id_resp, rdata,
657 kref_get(&rdata->kref);
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
666 * Locking Note: This function expects that the disc_mutex is locked
667 * before it is called.
669 static int fc_disc_single(struct fc_lport *lport, struct fc_disc_port *dp)
671 struct fc_rport_priv *rdata;
673 rdata = lport->tt.rport_create(lport, dp->port_id);
677 return fc_disc_gpn_id_req(lport, rdata);
681 * fc_disc_stop() - Stop discovery for a given lport
682 * @lport: The local port that discovery should stop on
684 void fc_disc_stop(struct fc_lport *lport)
686 struct fc_disc *disc = &lport->disc;
689 cancel_delayed_work_sync(&disc->disc_work);
690 fc_disc_stop_rports(disc);
694 * fc_disc_stop_final() - Stop discovery for a given lport
695 * @lport: The lport that discovery should stop on
697 * This function will block until discovery has been
698 * completely stopped and all rports have been deleted.
700 void fc_disc_stop_final(struct fc_lport *lport)
703 lport->tt.rport_flush_queue();
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
710 int fc_disc_init(struct fc_lport *lport)
712 struct fc_disc *disc;
714 if (!lport->tt.disc_start)
715 lport->tt.disc_start = fc_disc_start;
717 if (!lport->tt.disc_stop)
718 lport->tt.disc_stop = fc_disc_stop;
720 if (!lport->tt.disc_stop_final)
721 lport->tt.disc_stop_final = fc_disc_stop_final;
723 if (!lport->tt.disc_recv_req)
724 lport->tt.disc_recv_req = fc_disc_recv_req;
727 INIT_DELAYED_WORK(&disc->disc_work, fc_disc_timeout);
728 mutex_init(&disc->disc_mutex);
729 INIT_LIST_HEAD(&disc->rports);
735 EXPORT_SYMBOL(fc_disc_init);