ipmi_msghandler.c

linux-2.6.15.6

/*
 * ipmi_msghandler.c
 *
 * Incoming and outgoing message routing for an IPMI interface.
 *
 * Author: MontaVista Software, Inc.
 *         Corey Minyard <[e-mail]>
 *         [e-mail]
 *
 * Copyright 2002 MontaVista Software Inc.
 *
 *  This program is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU General Public License as published by the
 *  Free Software Foundation; either version 2 of the License, or (at your
 *  option) any later version.
 *
 *
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 *  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 *  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 *  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 *  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 *  TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 *  USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <asm/system.h>
#include <linux/sched.h>
#include <linux/poll.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/ipmi.h>
#include <linux/ipmi_smi.h>
#include <linux/notifier.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/rcupdate.h>

#define PFX "IPMI message handler: "

#define IPMI_DRIVER_VERSION "38.0"

static struct ipmi_recv_msg *ipmi_alloc_recv_msg(void);
static int ipmi_init_msghandler(void);

static int initialized = 0;

#ifdef CONFIG_PROC_FS
struct proc_dir_entry *proc_ipmi_root = NULL;
#endif /* CONFIG_PROC_FS */

#define MAX_EVENTS_IN_QUEUE	25

/* Don't let a message sit in a queue forever, always time it with at lest
   the max message timer.  This is in milliseconds. */
#define MAX_MSG_TIMEOUT		60000


/*
 * The main "user" data structure.
 */
struct ipmi_user
{
	struct list_head link;

	/* Set to "0" when the user is destroyed. */
	int valid;

	struct kref refcount;

	/* The upper layer that handles receive messages. */
	struct ipmi_user_hndl *handler;
	void             *handler_data;

	/* The interface this user is bound to. */
	ipmi_smi_t intf;

	/* Does this interface receive IPMI events? */
	int gets_events;
};

struct cmd_rcvr
{
	struct list_head link;

	ipmi_user_t   user;
	unsigned char netfn;
	unsigned char cmd;

	/*
	 * This is used to form a linked lised during mass deletion.
	 * Since this is in an RCU list, we cannot use the link above
	 * or change any data until the RCU period completes.  So we
	 * use this next variable during mass deletion so we can have
	 * a list and don't have to wait and restart the search on
	 * every individual deletion of a command. */
	struct cmd_rcvr *next;
};

struct seq_table
{
	unsigned int         inuse : 1;
	unsigned int         broadcast : 1;

	unsigned long        timeout;
	unsigned long        orig_timeout;
	unsigned int         retries_left;

	/* To verify on an incoming send message response that this is
           the message that the response is for, we keep a sequence id
           and increment it every time we send a message. */
	long                 seqid;

	/* This is held so we can properly respond to the message on a
           timeout, and it is used to hold the temporary data for
           retransmission, too. */
	struct ipmi_recv_msg *recv_msg;
};

/* Store the information in a msgid (long) to allow us to find a
   sequence table entry from the msgid. */
#define STORE_SEQ_IN_MSGID(seq, seqid) (((seq&0xff)<<26) | (seqid&0x3ffffff))

#define GET_SEQ_FROM_MSGID(msgid, seq, seqid) \
	do {								\
		seq = ((msgid >> 26) & 0x3f);				\
		seqid = (msgid & 0x3fffff);				\
        } while (0)

#define NEXT_SEQID(seqid) (((seqid) + 1) & 0x3fffff)

struct ipmi_channel
{
	unsigned char medium;
	unsigned char protocol;

	/* My slave address.  This is initialized to IPMI_BMC_SLAVE_ADDR,
	   but may be changed by the user. */
	unsigned char address;

	/* My LUN.  This should generally stay the SMS LUN, but just in
	   case... */
	unsigned char lun;
};

#ifdef CONFIG_PROC_FS
struct ipmi_proc_entry
{
	char                   *name;
	struct ipmi_proc_entry *next;
};
#endif

#define IPMI_IPMB_NUM_SEQ	64
#define IPMI_MAX_CHANNELS       16
struct ipmi_smi
{
	/* What interface number are we? */
	int intf_num;

	struct kref refcount;

	/* The list of upper layers that are using me.  seq_lock
	 * protects this. */
	struct list_head users;

	/* Used for wake ups at startup. */
	wait_queue_head_t waitq;

	/* The IPMI version of the BMC on the other end. */
	unsigned char       version_major;
	unsigned char       version_minor;

	/* This is the lower-layer's sender routine. */
	struct ipmi_smi_handlers *handlers;
	void                     *send_info;

#ifdef CONFIG_PROC_FS
	/* A list of proc entries for this interface.  This does not
	   need a lock, only one thread creates it and only one thread
	   destroys it. */
	spinlock_t             proc_entry_lock;
	struct ipmi_proc_entry *proc_entries;
#endif

	/* A table of sequence numbers for this interface.  We use the
           sequence numbers for IPMB messages that go out of the
           interface to match them up with their responses.  A routine
           is called periodically to time the items in this list. */
	spinlock_t       seq_lock;
	struct seq_table seq_table[IPMI_IPMB_NUM_SEQ];
	int curr_seq;

	/* Messages that were delayed for some reason (out of memory,
           for instance), will go in here to be processed later in a
           periodic timer interrupt. */
	spinlock_t       waiting_msgs_lock;
	struct list_head waiting_msgs;

	/* The list of command receivers that are registered for commands
	   on this interface. */
	struct semaphore cmd_rcvrs_lock;
	struct list_head cmd_rcvrs;

	/* Events that were queues because no one was there to receive
           them. */
	spinlock_t       events_lock; /* For dealing with event stuff. */
	struct list_head waiting_events;
	unsigned int     waiting_events_count; /* How many events in queue? */

	/* The event receiver for my BMC, only really used at panic
	   shutdown as a place to store this. */
	unsigned char event_receiver;
	unsigned char event_receiver_lun;
	unsigned char local_sel_device;
	unsigned char local_event_generator;

	/* A cheap hack, if this is non-null and a message to an
	   interface comes in with a NULL user, call this routine with
	   it.  Note that the message will still be freed by the
	   caller.  This only works on the system interface. */
	void (*null_user_handler)(ipmi_smi_t intf, struct ipmi_recv_msg *msg);

	/* When we are scanning the channels for an SMI, this will
	   tell which channel we are scanning. */
	int curr_channel;

	/* Channel information */
	struct ipmi_channel channels[IPMI_MAX_CHANNELS];

	/* Proc FS stuff. */
	struct proc_dir_entry *proc_dir;
	char                  proc_dir_name[10];

	spinlock_t   counter_lock; /* For making counters atomic. */

	/* Commands we got that were invalid. */
	unsigned int sent_invalid_commands;

	/* Commands we sent to the MC. */
	unsigned int sent_local_commands;
	/* Responses from the MC that were delivered to a user. */
	unsigned int handled_local_responses;
	/* Responses from the MC that were not delivered to a user. */
	unsigned int unhandled_local_responses;

	/* Commands we sent out to the IPMB bus. */
	unsigned int sent_ipmb_commands;
	/* Commands sent on the IPMB that had errors on the SEND CMD */
	unsigned int sent_ipmb_command_errs;
	/* Each retransmit increments this count. */
	unsigned int retransmitted_ipmb_commands;
	/* When a message times out (runs out of retransmits) this is
           incremented. */
	unsigned int timed_out_ipmb_commands;

	/* This is like above, but for broadcasts.  Broadcasts are
           *not* included in the above count (they are expected to
           time out). */
	unsigned int timed_out_ipmb_broadcasts;

	/* Responses I have sent to the IPMB bus. */
	unsigned int sent_ipmb_responses;

	/* The response was delivered to the user. */
	unsigned int handled_ipmb_responses;
	/* The response had invalid data in it. */
	unsigned int invalid_ipmb_responses;
	/* The response didn't have anyone waiting for it. */
	unsigned int unhandled_ipmb_responses;

	/* Commands we sent out to the IPMB bus. */
	unsigned int sent_lan_commands;
	/* Commands sent on the IPMB that had errors on the SEND CMD */
	unsigned int sent_lan_command_errs;
	/* Each retransmit increments this count. */
	unsigned int retransmitted_lan_commands;
	/* When a message times out (runs out of retransmits) this is
           incremented. */
	unsigned int timed_out_lan_commands;

	/* Responses I have sent to the IPMB bus. */
	unsigned int sent_lan_responses;

	/* The response was delivered to the user. */
	unsigned int handled_lan_responses;
	/* The response had invalid data in it. */
	unsigned int invalid_lan_responses;
	/* The response didn't have anyone waiting for it. */
	unsigned int unhandled_lan_responses;

	/* The command was delivered to the user. */
	unsigned int handled_commands;
	/* The command had invalid data in it. */
	unsigned int invalid_commands;
	/* The command didn't have anyone waiting for it. */
	unsigned int unhandled_commands;

	/* Invalid data in an event. */
	unsigned int invalid_events;
	/* Events that were received with the proper format. */
	unsigned int events;
};

/* Used to mark an interface entry that cannot be used but is not a
 * free entry, either, primarily used at creation and deletion time so
 * a slot doesn't get reused too quickly. */
#define IPMI_INVALID_INTERFACE_ENTRY ((ipmi_smi_t) ((long) 1))
#define IPMI_INVALID_INTERFACE(i) (((i) == NULL) \
				   || (i == IPMI_INVALID_INTERFACE_ENTRY))

#define MAX_IPMI_INTERFACES 4
static ipmi_smi_t ipmi_interfaces[MAX_IPMI_INTERFACES];

/* Directly protects the ipmi_interfaces data structure. */
static DEFINE_SPINLOCK(interfaces_lock);

/* List of watchers that want to know when smi's are added and
   deleted. */
static struct list_head smi_watchers = LIST_HEAD_INIT(smi_watchers);
static DECLARE_RWSEM(smi_watchers_sem);


static void free_recv_msg_list(struct list_head *q)
{
	struct ipmi_recv_msg *msg, *msg2;

	list_for_each_entry_safe(msg, msg2, q, link) {
		list_del(&msg->link);
		ipmi_free_recv_msg(msg);
	}
}

static void clean_up_interface_data(ipmi_smi_t intf)
{
	int              i;
	struct cmd_rcvr  *rcvr, *rcvr2;
	struct list_head list;

	free_recv_msg_list(&intf->waiting_msgs);
	free_recv_msg_list(&intf->waiting_events);

	/* Wholesale remove all the entries from the list in the
	 * interface and wait for RCU to know that none are in use. */
	down(&intf->cmd_rcvrs_lock);
	list_add_rcu(&list, &intf->cmd_rcvrs);
	list_del_rcu(&intf->cmd_rcvrs);
	up(&intf->cmd_rcvrs_lock);
	synchronize_rcu();

	list_for_each_entry_safe(rcvr, rcvr2, &list, link)
		kfree(rcvr);

	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) {
		if ((intf->seq_table[i].inuse)
		    && (intf->seq_table[i].recv_msg))
		{
			ipmi_free_recv_msg(intf->seq_table[i].recv_msg);
		}
	}
}

static void intf_free(struct kref *ref)
{
	ipmi_smi_t intf = container_of(ref, struct ipmi_smi, refcount);

	clean_up_interface_data(intf);
	kfree(intf);
}

int ipmi_smi_watcher_register(struct ipmi_smi_watcher *watcher)
{
	int           i;
	unsigned long flags;

	down_write(&smi_watchers_sem);
	list_add(&(watcher->link), &smi_watchers);
	up_write(&smi_watchers_sem);
	spin_lock_irqsave(&interfaces_lock, flags);
	for (i = 0; i < MAX_IPMI_INTERFACES; i++) {
		ipmi_smi_t intf = ipmi_interfaces[i];
		if (IPMI_INVALID_INTERFACE(intf))
			continue;
		spin_unlock_irqrestore(&interfaces_lock, flags);
		watcher->new_smi(i);
		spin_lock_irqsave(&interfaces_lock, flags);
	}
	spin_unlock_irqrestore(&interfaces_lock, flags);
	return 0;
}

int ipmi_smi_watcher_unregister(struct ipmi_smi_watcher *watcher)
{
	down_write(&smi_watchers_sem);
	list_del(&(watcher->link));
	up_write(&smi_watchers_sem);
	return 0;
}

static void
call_smi_watchers(int i)
{
	struct ipmi_smi_watcher *w;

	down_read(&smi_watchers_sem);
	list_for_each_entry(w, &smi_watchers, link) {
		if (try_module_get(w->owner)) {
			w->new_smi(i);
			module_put(w->owner);
		}
	}
	up_read(&smi_watchers_sem);
}

static int
ipmi_addr_equal(struct ipmi_addr *addr1, struct ipmi_addr *addr2)
{
	if (addr1->addr_type != addr2->addr_type)
		return 0;

	if (addr1->channel != addr2->channel)
		return 0;

	if (addr1->addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE) {
		struct ipmi_system_interface_addr *smi_addr1
		    = (struct ipmi_system_interface_addr *) addr1;
		struct ipmi_system_interface_addr *smi_addr2
		    = (struct ipmi_system_interface_addr *) addr2;
		return (smi_addr1->lun == smi_addr2->lun);
	}

	if ((addr1->addr_type == IPMI_IPMB_ADDR_TYPE)
	    || (addr1->addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE))
	{
		struct ipmi_ipmb_addr *ipmb_addr1
		    = (struct ipmi_ipmb_addr *) addr1;
		struct ipmi_ipmb_addr *ipmb_addr2
		    = (struct ipmi_ipmb_addr *) addr2;

		return ((ipmb_addr1->slave_addr == ipmb_addr2->slave_addr)
			&& (ipmb_addr1->lun == ipmb_addr2->lun));
	}

	if (addr1->addr_type == IPMI_LAN_ADDR_TYPE) {
		struct ipmi_lan_addr *lan_addr1
			= (struct ipmi_lan_addr *) addr1;
		struct ipmi_lan_addr *lan_addr2
		    = (struct ipmi_lan_addr *) addr2;

		return ((lan_addr1->remote_SWID == lan_addr2->remote_SWID)
			&& (lan_addr1->local_SWID == lan_addr2->local_SWID)
			&& (lan_addr1->session_handle
			    == lan_addr2->session_handle)
			&& (lan_addr1->lun == lan_addr2->lun));
	}

	return 1;