[SCSI] fcoe, libfcoe: Add support for FIP. FCoE discovery and keep-alive.

FIP is the new standard way to discover Fibre-Channel Forwarders (FCFs)
by sending solicitations and listening for advertisements from FCFs.

It also provides for keep-alives and period advertisements so that both
parties know they have connectivity.  If the FCF loses connectivity to
the storage fabric, it can send a Link Reset to inform the E_node.

This version is also compatible with pre-FIP implementations, so no
configured selection between FIP mode and non-FIP mode is required.

We wait a couple seconds after sending the initial solicitation
and then send an old-style FLOGI.  If we receive any FIP frames,
we use FIP only mode.  If the old FLOGI receives a response,
we disable FIP mode.  After every reset or link up, this
determination is repeated.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 133 insertions, 1 deletions

diff --git a/include/scsi/libfcoe.h b/include/scsi/libfcoe.h
index d07ebe688403..666cc131732e 100644
--- a/include/scsi/libfcoe.h
+++ b/include/scsi/libfcoe.h
@@ -1,5 +1,6 @@
 /*
- * Copyright(c) 2007 - 2008 Intel Corporation. All rights reserved.
+ * Copyright (c) 2008-2009 Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2007-2008 Intel Corporation.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -20,11 +21,142 @@
 #ifndef _LIBFCOE_H
 #define _LIBFCOE_H
 
+#include <linux/etherdevice.h>
+#include <linux/if_ether.h>
 #include <linux/netdevice.h>
 #include <linux/skbuff.h>
+#include <linux/workqueue.h>
 #include <scsi/fc/fc_fcoe.h>
 #include <scsi/libfc.h>
 
+/*
+ * FIP tunable parameters.
+ */
+#define FCOE_CTLR_START_DELAY   2000    /* mS after first adv. to choose FCF */
+#define FCOE_CTRL_SOL_TOV       2000    /* min. solicitation interval (mS) */
+#define FCOE_CTLR_FCF_LIMIT     20      /* max. number of FCF entries */
+
+/**
+ * enum fip_state - internal state of FCoE controller.
+ * @FIP_ST_DISABLED:    controller has been disabled or not yet enabled.
+ * @FIP_ST_LINK_WAIT:   the physical link is down or unusable.
+ * @FIP_ST_AUTO:        determining whether to use FIP or non-FIP mode.
+ * @FIP_ST_NON_FIP:     non-FIP mode selected.
+ * @FIP_ST_ENABLED:     FIP mode selected.
+ */
+enum fip_state {
+        FIP_ST_DISABLED,
+        FIP_ST_LINK_WAIT,
+        FIP_ST_AUTO,
+        FIP_ST_NON_FIP,
+        FIP_ST_ENABLED,
+};
+
+/**
+ * struct fcoe_ctlr - FCoE Controller and FIP state.
+ * @state:      internal FIP state for network link and FIP or non-FIP mode.
+ * @lp:         &fc_lport: libfc local port.
+ * @sel_fcf:    currently selected FCF, or NULL.
+ * @fcfs:       list of discovered FCFs.
+ * @fcf_count:  number of discovered FCF entries.
+ * @sol_time:   time when a multicast solicitation was last sent.
+ * @sel_time:   time after which to select an FCF.
+ * @port_ka_time: time of next port keep-alive.
+ * @ctlr_ka_time: time of next controller keep-alive.
+ * @timer:      timer struct used for all delayed events.
+ * @link_work:  &work_struct for doing FCF selection.
+ * @recv_work:  &work_struct for receiving FIP frames.
+ * @fip_recv_list: list of received FIP frames.
+ * @user_mfs:   configured maximum FC frame size, including FC header.
+ * @flogi_oxid: exchange ID of most recent fabric login.
+ * @flogi_count: number of FLOGI attempts in AUTO mode.
+ * @link:       current link status for libfc.
+ * @last_link:  last link state reported to libfc.
+ * @map_dest:   use the FC_MAP mode for destination MAC addresses.
+ * @dest_addr:  MAC address of the selected FC forwarder.
+ * @ctl_src_addr: the native MAC address of our local port.
+ * @data_src_addr: the assigned MAC address for the local port after FLOGI.
+ * @send:       LLD-supplied function to handle sending of FIP Ethernet frames.
+ * @update_mac: LLD-supplied function to handle changes to MAC addresses.
+ * @lock:       lock protecting this structure.
+ *
+ * This structure is used by all FCoE drivers.  It contains information
+ * needed by all FCoE low-level drivers (LLDs) as well as internal state
+ * for FIP, and fields shared with the LLDS.
+ */
+struct fcoe_ctlr {
+        enum fip_state state;
+        struct fc_lport *lp;
+        struct fcoe_fcf *sel_fcf;
+        struct list_head fcfs;
+        u16 fcf_count;
+        unsigned long sol_time;
+        unsigned long sel_time;
+        unsigned long port_ka_time;
+        unsigned long ctlr_ka_time;
+        struct timer_list timer;
+        struct work_struct link_work;
+        struct work_struct recv_work;
+        struct sk_buff_head fip_recv_list;
+        u16 user_mfs;
+        u16 flogi_oxid;
+        u8 flogi_count;
+        u8 link;
+        u8 last_link;
+        u8 map_dest;
+        u8 dest_addr[ETH_ALEN];
+        u8 ctl_src_addr[ETH_ALEN];
+        u8 data_src_addr[ETH_ALEN];
+
+        void (*send)(struct fcoe_ctlr *, struct sk_buff *);
+        void (*update_mac)(struct fcoe_ctlr *, u8 *old, u8 *new);
+        spinlock_t lock;
+};
+
+/*
+ * struct fcoe_fcf - Fibre-Channel Forwarder.
+ * @list:       list linkage.
+ * @time:       system time (jiffies) when an advertisement was last received.
+ * @switch_name: WWN of switch from advertisement.
+ * @fabric_name: WWN of fabric from advertisement.
+ * @fc_map:     FC_MAP value from advertisement.
+ * @fcf_mac:    Ethernet address of the FCF.
+ * @vfid:       virtual fabric ID.
+ * @pri:        seletion priority, smaller values are better.
+ * @flags:      flags received from advertisement.
+ * @fka_period: keep-alive period, in jiffies.
+ *
+ * A Fibre-Channel Forwarder (FCF) is the entity on the Ethernet that
+ * passes FCoE frames on to an FC fabric.  This structure represents
+ * one FCF from which advertisements have been received.
+ *
+ * When looking up an FCF, @switch_name, @fabric_name, @fc_map, @vfid, and
+ * @fcf_mac together form the lookup key.
+ */
+struct fcoe_fcf {
+        struct list_head list;
+        unsigned long time;
+
+        u64 switch_name;
+        u64 fabric_name;
+        u32 fc_map;
+        u16 vfid;
+        u8 fcf_mac[ETH_ALEN];
+
+        u8 pri;
+        u16 flags;
+        u32 fka_period;
+};
+
+/* FIP API functions */
+void fcoe_ctlr_init(struct fcoe_ctlr *);
+void fcoe_ctlr_destroy(struct fcoe_ctlr *);
+void fcoe_ctlr_link_up(struct fcoe_ctlr *);
+int fcoe_ctlr_link_down(struct fcoe_ctlr *);
+int fcoe_ctlr_els_send(struct fcoe_ctlr *, struct sk_buff *);
+void fcoe_ctlr_recv(struct fcoe_ctlr *, struct sk_buff *);
+int fcoe_ctlr_recv_flogi(struct fcoe_ctlr *, struct fc_frame *fp, u8 *sa);
+
 /* libfcoe funcs */
 u64 fcoe_wwn_from_mac(unsigned char mac[], unsigned int, unsigned int);
 int fcoe_libfc_config(struct fc_lport *, struct libfc_function_template *);