5 files changed, 259 insertions, 36 deletions

diff --git a/drivers/scsi/libfc/fc_libfc.c b/drivers/scsi/libfc/fc_libfc.c
index 6a48c28e4420..ae3abef6523e 100644
--- a/drivers/scsi/libfc/fc_libfc.c
+++ b/drivers/scsi/libfc/fc_libfc.c
@@ -35,6 +35,23 @@ unsigned int fc_debug_logging;
 module_param_named(debug_logging, fc_debug_logging, int, S_IRUGO|S_IWUSR);
 MODULE_PARM_DESC(debug_logging, "a bit mask of logging levels");
 
+DEFINE_MUTEX(fc_prov_mutex);
+
+/*
+ * Providers which primarily send requests and PRLIs.
+ */
+struct fc4_prov *fc_active_prov[FC_FC4_PROV_SIZE] = {
+	[0] = &fc_rport_t0_prov,
+	[FC_TYPE_FCP] = &fc_rport_fcp_init,
+};
+
+/*
+ * Providers which receive requests.
+ */
+struct fc4_prov *fc_passive_prov[FC_FC4_PROV_SIZE] = {
+	[FC_TYPE_ELS] = &fc_lport_els_prov,
+};
+
 /**
  * libfc_init() - Initialize libfc.ko
  */
@@ -210,3 +227,46 @@ void fc_fill_reply_hdr(struct fc_frame *fp, const struct fc_frame *in_fp,
 	fc_fill_hdr(fp, in_fp, r_ctl, FC_FCTL_RESP, 0, parm_offset);
 }
 EXPORT_SYMBOL(fc_fill_reply_hdr);
+
+/**
+ * fc_fc4_register_provider() - register FC-4 upper-level provider.
+ * @type: FC-4 type, such as FC_TYPE_FCP
+ * @prov: structure describing provider including ops vector.
+ *
+ * Returns 0 on success, negative error otherwise.
+ */
+int fc_fc4_register_provider(enum fc_fh_type type, struct fc4_prov *prov)
+{
+	struct fc4_prov **prov_entry;
+	int ret = 0;
+
+	if (type >= FC_FC4_PROV_SIZE)
+		return -EINVAL;
+	mutex_lock(&fc_prov_mutex);
+	prov_entry = (prov->recv ? fc_passive_prov : fc_active_prov) + type;
+	if (*prov_entry)
+		ret = -EBUSY;
+	else
+		*prov_entry = prov;
+	mutex_unlock(&fc_prov_mutex);
+	return ret;
+}
+EXPORT_SYMBOL(fc_fc4_register_provider);
+
+/**
+ * fc_fc4_deregister_provider() - deregister FC-4 upper-level provider.
+ * @type: FC-4 type, such as FC_TYPE_FCP
+ * @prov: structure describing provider including ops vector.
+ */
+void fc_fc4_deregister_provider(enum fc_fh_type type, struct fc4_prov *prov)
+{
+	BUG_ON(type >= FC_FC4_PROV_SIZE);
+	mutex_lock(&fc_prov_mutex);
+	if (prov->recv)
+		rcu_assign_pointer(fc_passive_prov[type], NULL);
+	else
+		rcu_assign_pointer(fc_active_prov[type], NULL);
+	mutex_unlock(&fc_prov_mutex);
+	synchronize_rcu();
+}
+EXPORT_SYMBOL(fc_fc4_deregister_provider);
diff --git a/drivers/scsi/libfc/fc_libfc.h b/drivers/scsi/libfc/fc_libfc.h
index eea0c3541b71..205de285e456 100644
--- a/drivers/scsi/libfc/fc_libfc.h
+++ b/drivers/scsi/libfc/fc_libfc.h
@@ -94,6 +94,17 @@ extern unsigned int fc_debug_logging;
 				(lport)->host->host_no,	##args))
 
 /*
+ * FC-4 Providers.
+ */
+extern struct fc4_prov *fc_active_prov[];	/* providers without recv */
+extern struct fc4_prov *fc_passive_prov[];	/* providers with recv */
+extern struct mutex fc_prov_mutex;		/* lock over table changes */
+
+extern struct fc4_prov fc_rport_t0_prov;	/* type 0 provider */
+extern struct fc4_prov fc_lport_els_prov;	/* ELS provider */
+extern struct fc4_prov fc_rport_fcp_init;	/* FCP initiator provider */
+
+/*
  * Set up direct-data placement for this I/O request
  */
 void fc_fcp_ddp_setup(struct fc_fcp_pkt *fsp, u16 xid);
diff --git a/drivers/scsi/libfc/fc_lport.c b/drivers/scsi/libfc/fc_lport.c
index c5a10f94f845..e2cd087e71b2 100644
--- a/drivers/scsi/libfc/fc_lport.c
+++ b/drivers/scsi/libfc/fc_lport.c
@@ -849,7 +849,7 @@ out:
 }
 
 /**
- * fc_lport_recv_req() - The generic lport request handler
+ * fc_lport_recv_els_req() - The generic lport ELS request handler
  * @lport: The local port that received the request
  * @fp:	   The request frame
  *
@@ -859,9 +859,9 @@ out:
  * Locking Note: This function should not be called with the lport
  *		 lock held becuase it will grab the lock.
  */
-static void fc_lport_recv_req(struct fc_lport *lport, struct fc_frame *fp)
+static void fc_lport_recv_els_req(struct fc_lport *lport,
+				  struct fc_frame *fp)
 {
-	struct fc_frame_header *fh = fc_frame_header_get(fp);
 	void (*recv)(struct fc_lport *, struct fc_frame *);
 
 	mutex_lock(&lport->lp_mutex);
@@ -873,8 +873,7 @@ static void fc_lport_recv_req(struct fc_lport *lport, struct fc_frame *fp)
 	 */
 	if (!lport->link_up)
 		fc_frame_free(fp);
-	else if (fh->fh_type == FC_TYPE_ELS &&
-		 fh->fh_r_ctl == FC_RCTL_ELS_REQ) {
+	else {
 		/*
 		 * Check opcode.
 		 */
@@ -903,14 +902,62 @@ static void fc_lport_recv_req(struct fc_lport *lport, struct fc_frame *fp)
 		}
 
 		recv(lport, fp);
-	} else {
-		FC_LPORT_DBG(lport, "dropping invalid frame (eof %x)\n",
-			     fr_eof(fp));
-		fc_frame_free(fp);
 	}
 	mutex_unlock(&lport->lp_mutex);
 }
 
+static int fc_lport_els_prli(struct fc_rport_priv *rdata, u32 spp_len,
+			     const struct fc_els_spp *spp_in,
+			     struct fc_els_spp *spp_out)
+{
+	return FC_SPP_RESP_INVL;
+}
+
+struct fc4_prov fc_lport_els_prov = {
+	.prli = fc_lport_els_prli,
+	.recv = fc_lport_recv_els_req,
+};
+
+/**
+ * fc_lport_recv_req() - The generic lport request handler
+ * @lport: The lport that received the request
+ * @fp: The frame the request is in
+ *
+ * Locking Note: This function should not be called with the lport
+ *		 lock held becuase it may grab the lock.
+ */
+static void fc_lport_recv_req(struct fc_lport *lport,
+			      struct fc_frame *fp)
+{
+	struct fc_frame_header *fh = fc_frame_header_get(fp);
+	struct fc_seq *sp = fr_seq(fp);
+	struct fc4_prov *prov;
+
+	/*
+	 * Use RCU read lock and module_lock to be sure module doesn't
+	 * deregister and get unloaded while we're calling it.
+	 * try_module_get() is inlined and accepts a NULL parameter.
+	 * Only ELSes and FCP target ops should come through here.
+	 * The locking is unfortunate, and a better scheme is being sought.
+	 */
+
+	rcu_read_lock();
+	if (fh->fh_type >= FC_FC4_PROV_SIZE)
+		goto drop;
+	prov = rcu_dereference(fc_passive_prov[fh->fh_type]);
+	if (!prov || !try_module_get(prov->module))
+		goto drop;
+	rcu_read_unlock();
+	prov->recv(lport, fp);
+	module_put(prov->module);
+	return;
+drop:
+	rcu_read_unlock();
+	FC_LPORT_DBG(lport, "dropping unexpected frame type %x\n", fh->fh_type);
+	fc_frame_free(fp);
+	lport->tt.exch_done(sp);
+}
+
 /**
  * fc_lport_reset() - Reset a local port
  * @lport: The local port which should be reset
diff --git a/drivers/scsi/libfc/fc_rport.c b/drivers/scsi/libfc/fc_rport.c
index 309e3e713ea1..a92954c1f42f 100644
--- a/drivers/scsi/libfc/fc_rport.c
+++ b/drivers/scsi/libfc/fc_rport.c
@@ -257,6 +257,8 @@ static void fc_rport_work(struct work_struct *work)
 	struct fc_rport_operations *rport_ops;
 	struct fc_rport_identifiers ids;
 	struct fc_rport *rport;
+	struct fc4_prov *prov;
+	u8 type;
 
 	mutex_lock(&rdata->rp_mutex);
 	event = rdata->event;
@@ -306,6 +308,15 @@ static void fc_rport_work(struct work_struct *work)
 	case RPORT_EV_FAILED:
 	case RPORT_EV_LOGO:
 	case RPORT_EV_STOP:
+		if (rdata->prli_count) {
+			mutex_lock(&fc_prov_mutex);
+			for (type = 1; type < FC_FC4_PROV_SIZE; type++) {
+				prov = fc_passive_prov[type];
+				if (prov && prov->prlo)
+					prov->prlo(rdata);
+			}
+			mutex_unlock(&fc_prov_mutex);
+		}
 		port_id = rdata->ids.port_id;
 		mutex_unlock(&rdata->rp_mutex);
 
@@ -1643,9 +1654,9 @@ static void fc_rport_recv_prli_req(struct fc_rport_priv *rdata,
 	unsigned int len;
 	unsigned int plen;
 	enum fc_els_spp_resp resp;
+	enum fc_els_spp_resp passive;
 	struct fc_seq_els_data rjt_data;
-	u32 fcp_parm;
-	u32 roles = FC_RPORT_ROLE_UNKNOWN;
+	struct fc4_prov *prov;
 
 	FC_RPORT_DBG(rdata, "Received PRLI request while in state %s\n",
 		     fc_rport_state(rdata));
@@ -1679,46 +1690,41 @@ static void fc_rport_recv_prli_req(struct fc_rport_priv *rdata,
 	pp->prli.prli_len = htons(len);
 	len -= sizeof(struct fc_els_prli);
 
-	/* reinitialize remote port roles */
-	rdata->ids.roles = FC_RPORT_ROLE_UNKNOWN;
-
 	/*
 	 * Go through all the service parameter pages and build
 	 * response.  If plen indicates longer SPP than standard,
 	 * use that.  The entire response has been pre-cleared above.
 	 */
 	spp = &pp->spp;
+	mutex_lock(&fc_prov_mutex);
 	while (len >= plen) {
 		spp->spp_type = rspp->spp_type;
 		spp->spp_type_ext = rspp->spp_type_ext;
-		spp->spp_flags = rspp->spp_flags & FC_SPP_EST_IMG_PAIR;
-		resp = FC_SPP_RESP_ACK;
-
-		switch (rspp->spp_type) {
-		case 0:	/* common to all FC-4 types */
-			break;
-		case FC_TYPE_FCP:
-			fcp_parm = ntohl(rspp->spp_params);
-			if (fcp_parm & FCP_SPPF_RETRY)
-				rdata->flags |= FC_RP_FLAGS_RETRY;
-			rdata->supported_classes = FC_COS_CLASS3;
-			if (fcp_parm & FCP_SPPF_INIT_FCN)
-				roles |= FC_RPORT_ROLE_FCP_INITIATOR;
-			if (fcp_parm & FCP_SPPF_TARG_FCN)
-				roles |= FC_RPORT_ROLE_FCP_TARGET;
-			rdata->ids.roles = roles;
-
-			spp->spp_params = htonl(lport->service_params);
-			break;
-		default:
-			resp = FC_SPP_RESP_INVL;
-			break;
+		resp = 0;
+
+		if (rspp->spp_type < FC_FC4_PROV_SIZE) {
+			prov = fc_active_prov[rspp->spp_type];
+			if (prov)
+				resp = prov->prli(rdata, plen, rspp, spp);
+			prov = fc_passive_prov[rspp->spp_type];
+			if (prov) {
+				passive = prov->prli(rdata, plen, rspp, spp);
+				if (!resp || passive == FC_SPP_RESP_ACK)
+					resp = passive;
+			}
+		}
+		if (!resp) {
+			if (spp->spp_flags & FC_SPP_EST_IMG_PAIR)
+				resp |= FC_SPP_RESP_CONF;
+			else
+				resp |= FC_SPP_RESP_INVL;
 		}
 		spp->spp_flags |= resp;
 		len -= plen;
 		rspp = (struct fc_els_spp *)((char *)rspp + plen);
 		spp = (struct fc_els_spp *)((char *)spp + plen);
 	}
+	mutex_unlock(&fc_prov_mutex);
 
 	/*
 	 * Send LS_ACC.	 If this fails, the originator should retry.
@@ -1888,6 +1894,79 @@ int fc_rport_init(struct fc_lport *lport)
 EXPORT_SYMBOL(fc_rport_init);
 
 /**
+ * fc_rport_fcp_prli() - Handle incoming PRLI for the FCP initiator.
+ * @rdata: remote port private
+ * @spp_len: service parameter page length
+ * @rspp: received service parameter page
+ * @spp: response service parameter page
+ *
+ * Returns the value for the response code to be placed in spp_flags;
+ * Returns 0 if not an initiator.
+ */
+static int fc_rport_fcp_prli(struct fc_rport_priv *rdata, u32 spp_len,
+			     const struct fc_els_spp *rspp,
+			     struct fc_els_spp *spp)
+{
+	struct fc_lport *lport = rdata->local_port;
+	u32 fcp_parm;
+
+	fcp_parm = ntohl(rspp->spp_params);
+	rdata->ids.roles = FC_RPORT_ROLE_UNKNOWN;
+	if (fcp_parm & FCP_SPPF_INIT_FCN)
+		rdata->ids.roles |= FC_RPORT_ROLE_FCP_INITIATOR;
+	if (fcp_parm & FCP_SPPF_TARG_FCN)
+		rdata->ids.roles |= FC_RPORT_ROLE_FCP_TARGET;
+	if (fcp_parm & FCP_SPPF_RETRY)
+		rdata->flags |= FC_RP_FLAGS_RETRY;
+	rdata->supported_classes = FC_COS_CLASS3;
+
+	if (!(lport->service_params & FC_RPORT_ROLE_FCP_INITIATOR))
+		return 0;
+
+	spp->spp_flags |= rspp->spp_flags & FC_SPP_EST_IMG_PAIR;
+
+	/*
+	 * OR in our service parameters with other providers (target), if any.
+	 */
+	fcp_parm = ntohl(spp->spp_params);
+	spp->spp_params = htonl(fcp_parm | lport->service_params);
+	return FC_SPP_RESP_ACK;
+}
+
+/*
+ * FC-4 provider ops for FCP initiator.
+ */
+struct fc4_prov fc_rport_fcp_init = {
+	.prli = fc_rport_fcp_prli,
+};
+
+/**
+ * fc_rport_t0_prli() - Handle incoming PRLI parameters for type 0
+ * @rdata: remote port private
+ * @spp_len: service parameter page length
+ * @rspp: received service parameter page
+ * @spp: response service parameter page
+ */
+static int fc_rport_t0_prli(struct fc_rport_priv *rdata, u32 spp_len,
+			    const struct fc_els_spp *rspp,
+			    struct fc_els_spp *spp)
+{
+	if (rspp->spp_flags & FC_SPP_EST_IMG_PAIR)
+		return FC_SPP_RESP_INVL;
+	return FC_SPP_RESP_ACK;
+}
+
+/*
+ * FC-4 provider ops for type 0 service parameters.
+ *
+ * This handles the special case of type 0 which is always successful
+ * but doesn't do anything otherwise.
+ */
+struct fc4_prov fc_rport_t0_prov = {
+	.prli = fc_rport_t0_prli,
+};
+
+/**
  * fc_setup_rport() - Initialize the rport_event_queue
  */
 int fc_setup_rport(void)
diff --git a/include/scsi/libfc.h b/include/scsi/libfc.h
index f53c8e31d5fb..3ae2a760b4f3 100644
--- a/include/scsi/libfc.h
+++ b/include/scsi/libfc.h
@@ -35,6 +35,8 @@
 
 #include <scsi/fc_frame.h>
 
+#define	FC_FC4_PROV_SIZE	(FC_TYPE_FCP + 1)	/* size of tables */
+
 /*
  * libfc error codes
  */
@@ -179,6 +181,7 @@ struct fc_rport_libfc_priv {
  * @rp_mutex:       The mutex that protects the remote port
  * @retry_work:     Handle for retries
  * @event_callback: Callback when READY, FAILED or LOGO states complete
+ * @prli_count:     Count of open PRLI sessions in providers
  * @rcu:	    Structure used for freeing in an RCU-safe manner
  */
 struct fc_rport_priv {
@@ -202,6 +205,7 @@ struct fc_rport_priv {
 	struct list_head            peers;
 	struct work_struct          event_work;
 	u32			    supported_classes;
+	u16                         prli_count;
 	struct rcu_head		    rcu;
 };
 
@@ -848,6 +852,28 @@ struct fc_lport {
 	struct delayed_work	       retry_work;
 };
 
+/**
+ * struct fc4_prov - FC-4 provider registration
+ * @prli:               Handler for incoming PRLI
+ * @prlo:               Handler for session reset
+ * @recv:		Handler for incoming request
+ * @module:		Pointer to module.  May be NULL.
+ */
+struct fc4_prov {
+	int (*prli)(struct fc_rport_priv *, u32 spp_len,
+		    const struct fc_els_spp *spp_in,
+		    struct fc_els_spp *spp_out);
+	void (*prlo)(struct fc_rport_priv *);
+	void (*recv)(struct fc_lport *, struct fc_frame *);
+	struct module *module;
+};
+
+/*
+ * Register FC-4 provider with libfc.
+ */
+int fc_fc4_register_provider(enum fc_fh_type type, struct fc4_prov *);
+void fc_fc4_deregister_provider(enum fc_fh_type type, struct fc4_prov *);
+
 /*
  * FC_LPORT HELPER FUNCTIONS
  *****************************/