// SPDX-License-Identifier: GPL-2.0-only /* * Copyright(c) 2007 - 2008 Intel Corporation. All rights reserved. * * Maintained at www.Open-FCoE.org */ /* * Target Discovery * * This block discovers all FC-4 remote ports, including FCP initiators. It * also handles RSCN events and re-discovery if necessary. */ /* * DISC LOCKING * * The disc mutex is can be locked when acquiring rport locks, but may not * be held when acquiring the lport lock. Refer to fc_lport.c for more * details. */ #include #include #include #include #include #include #include #include #include "fc_libfc.h" #define FC_DISC_RETRY_LIMIT 3 /* max retries */ #define FC_DISC_RETRY_DELAY 500UL /* (msecs) delay */ static void fc_disc_gpn_ft_req(struct fc_disc *); static void fc_disc_gpn_ft_resp(struct fc_seq *, struct fc_frame *, void *); static void fc_disc_done(struct fc_disc *, enum fc_disc_event); static void fc_disc_timeout(struct work_struct *); static int fc_disc_single(struct fc_lport *, struct fc_disc_port *); static void fc_disc_restart(struct fc_disc *); /** * fc_disc_stop_rports() - Delete all the remote ports associated with the lport * @disc: The discovery job to stop remote ports on */ static void fc_disc_stop_rports(struct fc_disc *disc) { struct fc_rport_priv *rdata; lockdep_assert_held(&disc->disc_mutex); list_for_each_entry(rdata, &disc->rports, peers) { if (kref_get_unless_zero(&rdata->kref)) { fc_rport_logoff(rdata); kref_put(&rdata->kref, fc_rport_destroy); } } } /** * fc_disc_recv_rscn_req() - Handle Registered State Change Notification (RSCN) * @disc: The discovery object to which the RSCN applies * @fp: The RSCN frame */ static void fc_disc_recv_rscn_req(struct fc_disc *disc, struct fc_frame *fp) { struct fc_lport *lport; struct fc_els_rscn *rp; struct fc_els_rscn_page *pp; struct fc_seq_els_data rjt_data; unsigned int len; int redisc = 0; enum fc_els_rscn_ev_qual ev_qual; enum fc_els_rscn_addr_fmt fmt; LIST_HEAD(disc_ports); struct fc_disc_port *dp, *next; lockdep_assert_held(&disc->disc_mutex); lport = fc_disc_lport(disc); FC_DISC_DBG(disc, "Received an RSCN event\n"); /* make sure the frame contains an RSCN message */ rp = fc_frame_payload_get(fp, sizeof(*rp)); if (!rp) goto reject; /* make sure the page length is as expected (4 bytes) */ if (rp->rscn_page_len != sizeof(*pp)) goto reject; /* get the RSCN payload length */ len = ntohs(rp->rscn_plen); if (len < sizeof(*rp)) goto reject; /* make sure the frame contains the expected payload */ rp = fc_frame_payload_get(fp, len); if (!rp) goto reject; /* payload must be a multiple of the RSCN page size */ len -= sizeof(*rp); if (len % sizeof(*pp)) goto reject; for (pp = (void *)(rp + 1); len > 0; len -= sizeof(*pp), pp++) { ev_qual = pp->rscn_page_flags >> ELS_RSCN_EV_QUAL_BIT; ev_qual &= ELS_RSCN_EV_QUAL_MASK; fmt = pp->rscn_page_flags >> ELS_RSCN_ADDR_FMT_BIT; fmt &= ELS_RSCN_ADDR_FMT_MASK; /* * if we get an address format other than port * (area, domain, fabric), then do a full discovery */ switch (fmt) { case ELS_ADDR_FMT_PORT: FC_DISC_DBG(disc, "Port address format for port " "(%6.6x)\n", ntoh24(pp->rscn_fid)); dp = kzalloc(sizeof(*dp), GFP_KERNEL); if (!dp) { redisc = 1; break; } dp->lp = lport; dp->port_id = ntoh24(pp->rscn_fid); list_add_tail(&dp->peers, &disc_ports); break; case ELS_ADDR_FMT_AREA: case ELS_ADDR_FMT_DOM: case ELS_ADDR_FMT_FAB: default: FC_DISC_DBG(disc, "Address format is (%d)\n", fmt); redisc = 1; break; } } fc_seq_els_rsp_send(fp, ELS_LS_ACC, NULL); /* * If not doing a complete rediscovery, do GPN_ID on * the individual ports mentioned in the list. * If any of these get an error, do a full rediscovery. * In any case, go through the list and free the entries. */ list_for_each_entry_safe(dp, next, &disc_ports, peers) { list_del(&dp->peers); if (!redisc) redisc = fc_disc_single(lport, dp); kfree(dp); } if (redisc) { FC_DISC_DBG(disc, "RSCN received: rediscovering\n"); fc_disc_restart(disc); } else { FC_DISC_DBG(disc, "RSCN received: not rediscovering. " "redisc %d state %d in_prog %d\n", redisc, lport->state, disc->pending); } fc_frame_free(fp); return; reject: FC_DISC_DBG(disc, "Received a bad RSCN frame\n"); rjt_data.reason = ELS_RJT_LOGIC; rjt_data.explan = ELS_EXPL_NONE; fc_seq_els_rsp_send(fp, ELS_LS_RJT, &rjt_data); fc_frame_free(fp); } /** * fc_disc_recv_req() - Handle incoming requests * @lport: The local port receiving the request * @fp: The request frame * * Locking Note: This function is called from the EM and will lock * the disc_mutex before calling the handler for the * request. */ static void fc_disc_recv_req(struct fc_lport *lport, struct fc_frame *fp) { u8 op; struct fc_disc *disc = &lport->disc; op = fc_frame_payload_op(fp); switch (op) { case ELS_RSCN: mutex_lock(&disc->disc_mutex); fc_disc_recv_rscn_req(disc, fp); mutex_unlock(&disc->disc_mutex); break; default: FC_DISC_DBG(disc, "Received an unsupported request, " "the opcode is (%x)\n", op); fc_frame_free(fp); break; } } /** * fc_disc_restart() - Restart discovery * @disc: The discovery object to be restarted */ static void fc_disc_restart(struct fc_disc *disc) { lockdep_assert_held(&disc->disc_mutex); if (!disc->disc_callback) return; FC_DISC_DBG(disc, "Restarting discovery\n"); disc->requested = 1; if (disc->pending) return; /* * Advance disc_id. This is an arbitrary non-zero number that will * match the value in the fc_rport_priv after discovery for all * freshly-discovered remote ports. Avoid wrapping to zero. */ disc->disc_id = (disc->disc_id + 2) | 1; disc->retry_count = 0; fc_disc_gpn_ft_req(disc); } /** * fc_disc_start() - Start discovery on a local port * @lport: The local port to have discovery started on * @disc_callback: Callback function to be called when discovery is complete */ static void fc_disc_start(void (*disc_callback)(struct fc_lport *, enum fc_disc_event), struct fc_lport *lport) { struct fc_disc *disc = &lport->disc; /* * At this point we may have a new disc job or an existing * one. Either way, let's lock when we make changes to it * and send the GPN_FT request. */ mutex_lock(&disc->disc_mutex); disc->disc_callback = disc_callback; fc_disc_restart(disc); mutex_unlock(&disc->disc_mutex); } /** * fc_disc_done() - Discovery has been completed * @disc: The discovery context * @event: The discovery completion status */ static void fc_disc_done(struct fc_disc *disc, enum fc_disc_event event) { struct fc_lport *lport = fc_disc_lport(disc); struct fc_rport_priv *rdata; lockdep_assert_held(&disc->disc_mutex); FC_DISC_DBG(disc, "Discovery complete\n"); disc->pending = 0; if (disc->requested) { fc_disc_restart(disc); return; } /* * Go through all remote ports. If they were found in the latest * discovery, reverify or log them in. Otherwise, log them out. * Skip ports which were never discovered. These are the dNS port * and ports which were created by PLOGI. * * We don't need to use the _rcu variant here as the rport list * is protected by the disc mutex which is already held on entry. */ list_for_each_entry(rdata, &disc->rports, peers) { if (!kref_get_unless_zero(&rdata->kref)) continue; if (rdata->disc_id) { if (rdata->disc_id == disc->disc_id) fc_rport_login(rdata); else fc_rport_logoff(rdata); } kref_put(&rdata->kref, fc_rport_destroy); } mutex_unlock(&disc->disc_mutex); disc->disc_callback(lport, event); mutex_lock(&disc->disc_mutex); } /** * fc_disc_error() - Handle error on dNS request * @disc: The discovery context * @fp: The error code encoded as a frame pointer */ static void fc_disc_error(struct fc_disc *disc, struct fc_frame *fp) { struct fc_lport *lport = fc_disc_lport(disc); unsigned long delay = 0; FC_DISC_DBG(disc, "Error %ld, retries %d/%d\n", PTR_ERR(fp), disc->retry_count, FC_DISC_RETRY_LIMIT); if (!fp || PTR_ERR(fp) == -FC_EX_TIMEOUT) { /* * Memory allocation failure, or the exchange timed out, * retry after delay. */ if (disc->retry_count < FC_DISC_RETRY_LIMIT) { /* go ahead and retry */ if (!fp) delay = msecs_to_jiffies(FC_DISC_RETRY_DELAY); else { delay = msecs_to_jiffies(lport->e_d_tov); /* timeout faster first time */ if (!disc->retry_count) delay /= 4; } disc->retry_count++; schedule_delayed_work(&disc->disc_work, delay); } else fc_disc_done(disc, DISC_EV_FAILED); } else if (PTR_ERR(fp) == -FC_EX_CLOSED) { /* * if discovery fails due to lport reset, clear * pending flag so that subsequent discovery can * continue */ disc->pending = 0; } } /** * fc_disc_gpn_ft_req() - Send Get Port Names by FC-4 type (GPN_FT) request * @disc: The discovery context */ static void fc_disc_gpn_ft_req(struct fc_disc *disc) { struct fc_frame *fp; struct fc_lport *lport = fc_disc_lport(disc); lockdep_assert_held(&disc->disc_mutex); WARN_ON(!fc_lport_test_ready(lport)); disc->pending = 1; disc->requested = 0; disc->buf_len = 0; disc->seq_count = 0; fp = fc_frame_alloc(lport, sizeof(struct fc_ct_hdr) + sizeof(struct fc_ns_gid_ft)); if (!fp) goto err; if (lport->tt.elsct_send(lport, 0, fp, FC_NS_GPN_FT, fc_disc_gpn_ft_resp, disc, 3 * lport->r_a_tov)) return; err: fc_disc_error(disc, NULL); } /** * fc_disc_gpn_ft_parse() - Parse the body of the dNS GPN_FT response. * @disc: The descovery context * @buf: The GPN_FT response buffer * @len: The size of response buffer * * Goes through the list of IDs and names resulting from a request. */ static int fc_disc_gpn_ft_parse(struct fc_disc *disc, void *buf, size_t len) { struct fc_lport *lport; struct fc_gpn_ft_resp *np; char *bp; size_t plen; size_t tlen; int error = 0; struct fc_rport_identifiers ids; struct fc_rport_priv *rdata; lport = fc_disc_lport(disc); disc->seq_count++; /* * Handle partial name record left over from previous call. */ bp = buf; plen = len; np = (struct fc_gpn_ft_resp *)bp; tlen = disc->buf_len; disc->buf_len = 0; if (tlen) { WARN_ON(tlen >= sizeof(*np)); plen = sizeof(*np) - tlen; WARN_ON(plen <= 0); WARN_ON(plen >= sizeof(*np)); if (plen > len) plen = len; np = &disc->partial_buf; memcpy((char *)np + tlen, bp, plen); /* * Set bp so that the loop below will advance it to the * first valid full name element. */ bp -= tlen; len += tlen; plen += tlen; disc->buf_len = (unsigned char) plen; if (plen == sizeof(*np)) disc->buf_len = 0; } /* * Handle full name records, including the one filled from above. * Normally, np == bp and plen == len, but from the partial case above, * bp, len describe the overall buffer, and np, plen describe the * partial buffer, which if would usually be full now. * After the first time through the loop, things return to "normal". */ while (plen >= sizeof(*np)) { ids.port_id = ntoh24(np->fp_fid); ids.port_name = ntohll(np->fp_wwpn); if (ids.port_id != lport->port_id && ids.port_name != lport->wwpn) { rdata = fc_rport_create(lport, ids.port_id); if (rdata) { rdata->ids.port_name = ids.port_name; rdata->disc_id = disc->disc_id; } else { printk(KERN_WARNING "libfc: Failed to allocate " "memory for the newly discovered port " "(%6.6x)\n", ids.port_id); error = -ENOMEM; } } if (np->fp_flags & FC_NS_FID_LAST) { fc_disc_done(disc, DISC_EV_SUCCESS); len = 0; break; } len -= sizeof(*np); bp += sizeof(*np); np = (struct fc_gpn_ft_resp *)bp; plen = len; } /* * Save any partial record at the end of the buffer for next time. */ if (error == 0 && len > 0 && len < sizeof(*np)) { if (np != &disc->partial_buf) { FC_DISC_DBG(disc, "Partial buffer remains " "for discovery\n"); memcpy(&disc->partial_buf, np, len); } disc->buf_len = (unsigned char) len; } return error; } /** * fc_disc_timeout() - Handler for discovery timeouts * @work: Structure holding discovery context that needs to retry discovery */ static void fc_disc_timeout(struct work_struct *work) { struct fc_disc *disc = container_of(work, struct fc_disc, disc_work.work); mutex_lock(&disc->disc_mutex); fc_disc_gpn_ft_req(disc); mutex_unlock(&disc->disc_mutex); } /** * fc_disc_gpn_ft_resp() - Handle a response frame from Get Port Names (GPN_FT) * @sp: The sequence that the GPN_FT response was received on * @fp: The GPN_FT response frame * @disc_arg: The discovery context * * Locking Note: This function is called without disc mutex held, and * should do all its processing with the mutex held */ static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp, void *disc_arg) { struct fc_disc *disc = disc_arg; struct fc_ct_hdr *cp; struct fc_frame_header *fh; enum fc_disc_event event = DISC_EV_NONE; unsigned int seq_cnt; unsigned int len; int error = 0; mutex_lock(&disc->disc_mutex); FC_DISC_DBG(disc, "Received a GPN_FT response\n"); if (IS_ERR(fp)) { fc_disc_error(disc, fp); mutex_unlock(&disc->disc_mutex); return; } WARN_ON(!fc_frame_is_linear(fp)); /* buffer must be contiguous */ fh = fc_frame_header_get(fp); len = fr_len(fp) - sizeof(*fh); seq_cnt = ntohs(fh->fh_seq_cnt); if (fr_sof(fp) == FC_SOF_I3 && seq_cnt == 0 && disc->seq_count == 0) { cp = fc_frame_payload_get(fp, sizeof(*cp)); if (!cp) { FC_DISC_DBG(disc, "GPN_FT response too short, len %d\n", fr_len(fp)); event = DISC_EV_FAILED; } else if (ntohs(cp->ct_cmd) == FC_FS_ACC) { /* Accepted, parse the response. */ len -= sizeof(*cp); error = fc_disc_gpn_ft_parse(disc, cp + 1, len); } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) { FC_DISC_DBG(disc, "GPN_FT rejected reason %x exp %x " "(check zoning)\n", cp->ct_reason, cp->ct_explan); event = DISC_EV_FAILED; if (cp->ct_reason == FC_FS_RJT_UNABL && cp->ct_explan == FC_FS_EXP_FTNR) event = DISC_EV_SUCCESS; } else { FC_DISC_DBG(disc, "GPN_FT unexpected response code " "%x\n", ntohs(cp->ct_cmd)); event = DISC_EV_FAILED; } } else if (fr_sof(fp) == FC_SOF_N3 && seq_cnt == disc->seq_count) { error = fc_disc_gpn_ft_parse(disc, fh + 1, len); } else { FC_DISC_DBG(disc, "GPN_FT unexpected frame - out of sequence? " "seq_cnt %x expected %x sof %x eof %x\n", seq_cnt, disc->seq_count, fr_sof(fp), fr_eof(fp)); event = DISC_EV_FAILED; } if (error) fc_disc_error(disc, ERR_PTR(error)); else if (event != DISC_EV_NONE) fc_disc_done(disc, event); fc_frame_free(fp); mutex_unlock(&disc->disc_mutex); } /** * fc_disc_gpn_id_resp() - Handle a response frame from Get Port Names (GPN_ID) * @sp: The sequence the GPN_ID is on * @fp: The response frame * @rdata_arg: The remote port that sent the GPN_ID response * * Locking Note: This function is called without disc mutex held. */ static void fc_disc_gpn_id_resp(struct fc_seq *sp, struct fc_frame *fp, void *rdata_arg) { struct fc_rport_priv *rdata = rdata_arg; struct fc_rport_priv *new_rdata; struct fc_lport *lport; struct fc_disc *disc; struct fc_ct_hdr *cp; struct fc_ns_gid_pn *pn; u64 port_name; lport = rdata->local_port; disc = &lport->disc; if (PTR_ERR(fp) == -FC_EX_CLOSED) goto out; if (IS_ERR(fp)) goto redisc; cp = fc_frame_payload_get(fp, sizeof(*cp)); if (!cp) goto redisc; if (ntohs(cp->ct_cmd) == FC_FS_ACC) { if (fr_len(fp) < sizeof(struct fc_frame_header) + sizeof(*cp) + sizeof(*pn)) goto redisc; pn = (struct fc_ns_gid_pn *)(cp + 1); port_name = get_unaligned_be64(&pn->fn_wwpn); mutex_lock(&rdata->rp_mutex); if (rdata->ids.port_name == -1) rdata->ids.port_name = port_name; else if (rdata->ids.port_name != port_name) { FC_DISC_DBG(disc, "GPN_ID accepted. WWPN changed. " "Port-id %6.6x wwpn %16.16llx\n", rdata->ids.port_id, port_name); mutex_unlock(&rdata->rp_mutex); fc_rport_logoff(rdata); mutex_lock(&lport->disc.disc_mutex); new_rdata = fc_rport_create(lport, rdata->ids.port_id); mutex_unlock(&lport->disc.disc_mutex); if (new_rdata) { new_rdata->disc_id = disc->disc_id; fc_rport_login(new_rdata); } goto out; } rdata->disc_id = disc->disc_id; mutex_unlock(&rdata->rp_mutex); fc_rport_login(rdata); } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) { FC_DISC_DBG(disc, "GPN_ID rejected reason %x exp %x\n", cp->ct_reason, cp->ct_explan); fc_rport_logoff(rdata); } else { FC_DISC_DBG(disc, "GPN_ID unexpected response code %x\n", ntohs(cp->ct_cmd)); redisc: mutex_lock(&disc->disc_mutex); fc_disc_restart(disc); mutex_unlock(&disc->disc_mutex); } out: kref_put(&rdata->kref, fc_rport_destroy); if (!IS_ERR(fp)) fc_frame_free(fp); } /** * fc_disc_gpn_id_req() - Send Get Port Names by ID (GPN_ID) request * @lport: The local port to initiate discovery on * @rdata: remote port private data * * On failure, an error code is returned. */ static int fc_disc_gpn_id_req(struct fc_lport *lport, struct fc_rport_priv *rdata) { struct fc_frame *fp; lockdep_assert_held(&lport->disc.disc_mutex); fp = fc_frame_alloc(lport, sizeof(struct fc_ct_hdr) + sizeof(struct fc_ns_fid)); if (!fp) return -ENOMEM; if (!lport->tt.elsct_send(lport, rdata->ids.port_id, fp, FC_NS_GPN_ID, fc_disc_gpn_id_resp, rdata, 3 * lport->r_a_tov)) return -ENOMEM; kref_get(&rdata->kref); return 0; } /** * fc_disc_single() - Discover the directory information for a single target * @lport: The local port the remote port is associated with * @dp: The port to rediscover */ static int fc_disc_single(struct fc_lport *lport, struct fc_disc_port *dp) { struct fc_rport_priv *rdata; lockdep_assert_held(&lport->disc.disc_mutex); rdata = fc_rport_create(lport, dp->port_id); if (!rdata) return -ENOMEM; rdata->disc_id = 0; return fc_disc_gpn_id_req(lport, rdata); } /** * fc_disc_stop() - Stop discovery for a given lport * @lport: The local port that discovery should stop on */ static void fc_disc_stop(struct fc_lport *lport) { struct fc_disc *disc = &lport->disc; if (disc->pending) cancel_delayed_work_sync(&disc->disc_work); mutex_lock(&disc->disc_mutex); fc_disc_stop_rports(disc); mutex_unlock(&disc->disc_mutex); } /** * fc_disc_stop_final() - Stop discovery for a given lport * @lport: The lport that discovery should stop on * * This function will block until discovery has been * completely stopped and all rports have been deleted. */ static void fc_disc_stop_final(struct fc_lport *lport) { fc_disc_stop(lport); fc_rport_flush_queue(); } /** * fc_disc_config() - Configure the discovery layer for a local port * @lport: The local port that needs the discovery layer to be configured * @priv: Private data structre for users of the discovery layer */ void fc_disc_config(struct fc_lport *lport, void *priv) { struct fc_disc *disc; if (!lport->tt.disc_start) lport->tt.disc_start = fc_disc_start; if (!lport->tt.disc_stop) lport->tt.disc_stop = fc_disc_stop; if (!lport->tt.disc_stop_final) lport->tt.disc_stop_final = fc_disc_stop_final; if (!lport->tt.disc_recv_req) lport->tt.disc_recv_req = fc_disc_recv_req; disc = &lport->disc; disc->priv = priv; } EXPORT_SYMBOL(fc_disc_config); /** * fc_disc_init() - Initialize the discovery layer for a local port * @lport: The local port that needs the discovery layer to be initialized */ void fc_disc_init(struct fc_lport *lport) { struct fc_disc *disc = &lport->disc; INIT_DELAYED_WORK(&disc->disc_work, fc_disc_timeout); mutex_init(&disc->disc_mutex); INIT_LIST_HEAD(&disc->rports); } EXPORT_SYMBOL(fc_disc_init);