Initial import of modified Linux 2.6.28 tree

Original upstream URL:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git | branch linux-2.6.28.y

1 files changed, 617 insertions, 0 deletions

diff --git a/net/tipc/subscr.c b/net/tipc/subscr.c
new file mode 100644
index 0000000..0747d8a
--- /dev/null
+++ b/net/tipc/subscr.c
@@ -0,0 +1,617 @@
+/*
+ * net/tipc/subscr.c: TIPC network topology service
+ *
+ * Copyright (c) 2000-2006, Ericsson AB
+ * Copyright (c) 2005-2007, Wind River Systems
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT OWNER OR CONTRIBUTORS 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.
+ */
+
+#include "core.h"
+#include "dbg.h"
+#include "name_table.h"
+#include "port.h"
+#include "ref.h"
+#include "subscr.h"
+
+/**
+ * struct subscriber - TIPC network topology subscriber
+ * @port_ref: object reference to server port connecting to subscriber
+ * @lock: pointer to spinlock controlling access to subscriber's server port
+ * @subscriber_list: adjacent subscribers in top. server's list of subscribers
+ * @subscription_list: list of subscription objects for this subscriber
+ */
+
+struct subscriber {
+	u32 port_ref;
+	spinlock_t *lock;
+	struct list_head subscriber_list;
+	struct list_head subscription_list;
+};
+
+/**
+ * struct top_srv - TIPC network topology subscription service
+ * @user_ref: TIPC userid of subscription service
+ * @setup_port: reference to TIPC port that handles subscription requests
+ * @subscription_count: number of active subscriptions (not subscribers!)
+ * @subscriber_list: list of ports subscribing to service
+ * @lock: spinlock govering access to subscriber list
+ */
+
+struct top_srv {
+	u32 user_ref;
+	u32 setup_port;
+	atomic_t subscription_count;
+	struct list_head subscriber_list;
+	spinlock_t lock;
+};
+
+static struct top_srv topsrv = { 0 };
+
+/**
+ * htohl - convert value to endianness used by destination
+ * @in: value to convert
+ * @swap: non-zero if endianness must be reversed
+ *
+ * Returns converted value
+ */
+
+static u32 htohl(u32 in, int swap)
+{
+	return swap ? swab32(in) : in;
+}
+
+/**
+ * subscr_send_event - send a message containing a tipc_event to the subscriber
+ *
+ * Note: Must not hold subscriber's server port lock, since tipc_send() will
+ *       try to take the lock if the message is rejected and returned!
+ */
+
+static void subscr_send_event(struct subscription *sub,
+			      u32 found_lower,
+			      u32 found_upper,
+			      u32 event,
+			      u32 port_ref,
+			      u32 node)
+{
+	struct iovec msg_sect;
+
+	msg_sect.iov_base = (void *)&sub->evt;
+	msg_sect.iov_len = sizeof(struct tipc_event);
+
+	sub->evt.event = htohl(event, sub->swap);
+	sub->evt.found_lower = htohl(found_lower, sub->swap);
+	sub->evt.found_upper = htohl(found_upper, sub->swap);
+	sub->evt.port.ref = htohl(port_ref, sub->swap);
+	sub->evt.port.node = htohl(node, sub->swap);
+	tipc_send(sub->server_ref, 1, &msg_sect);
+}
+
+/**
+ * tipc_subscr_overlap - test for subscription overlap with the given values
+ *
+ * Returns 1 if there is overlap, otherwise 0.
+ */
+
+int tipc_subscr_overlap(struct subscription *sub,
+			u32 found_lower,
+			u32 found_upper)
+
+{
+	if (found_lower < sub->seq.lower)
+		found_lower = sub->seq.lower;
+	if (found_upper > sub->seq.upper)
+		found_upper = sub->seq.upper;
+	if (found_lower > found_upper)
+		return 0;
+	return 1;
+}
+
+/**
+ * tipc_subscr_report_overlap - issue event if there is subscription overlap
+ *
+ * Protected by nameseq.lock in name_table.c
+ */
+
+void tipc_subscr_report_overlap(struct subscription *sub,
+				u32 found_lower,
+				u32 found_upper,
+				u32 event,
+				u32 port_ref,
+				u32 node,
+				int must)
+{
+	if (!tipc_subscr_overlap(sub, found_lower, found_upper))
+		return;
+	if (!must && !(sub->filter & TIPC_SUB_PORTS))
+		return;
+
+	sub->event_cb(sub, found_lower, found_upper, event, port_ref, node);
+}
+
+/**
+ * subscr_timeout - subscription timeout has occurred
+ */
+
+static void subscr_timeout(struct subscription *sub)
+{
+	struct port *server_port;
+
+	/* Validate server port reference (in case subscriber is terminating) */
+
+	server_port = tipc_port_lock(sub->server_ref);
+	if (server_port == NULL)
+		return;
+
+	/* Validate timeout (in case subscription is being cancelled) */
+
+	if (sub->timeout == TIPC_WAIT_FOREVER) {
+		tipc_port_unlock(server_port);
+		return;
+	}
+
+	/* Unlink subscription from name table */
+
+	tipc_nametbl_unsubscribe(sub);
+
+	/* Unlink subscription from subscriber */
+
+	list_del(&sub->subscription_list);
+
+	/* Release subscriber's server port */
+
+	tipc_port_unlock(server_port);
+
+	/* Notify subscriber of timeout */
+
+	subscr_send_event(sub, sub->evt.s.seq.lower, sub->evt.s.seq.upper,
+			  TIPC_SUBSCR_TIMEOUT, 0, 0);
+
+	/* Now destroy subscription */
+
+	k_term_timer(&sub->timer);
+	kfree(sub);
+	atomic_dec(&topsrv.subscription_count);
+}
+
+/**
+ * subscr_del - delete a subscription within a subscription list
+ *
+ * Called with subscriber port locked.
+ */
+
+static void subscr_del(struct subscription *sub)
+{
+	tipc_nametbl_unsubscribe(sub);
+	list_del(&sub->subscription_list);
+	kfree(sub);
+	atomic_dec(&topsrv.subscription_count);
+}
+
+/**
+ * subscr_terminate - terminate communication with a subscriber
+ *
+ * Called with subscriber port locked.  Routine must temporarily release lock
+ * to enable subscription timeout routine(s) to finish without deadlocking;
+ * the lock is then reclaimed to allow caller to release it upon return.
+ * (This should work even in the unlikely event some other thread creates
+ * a new object reference in the interim that uses this lock; this routine will
+ * simply wait for it to be released, then claim it.)
+ */
+
+static void subscr_terminate(struct subscriber *subscriber)
+{
+	u32 port_ref;
+	struct subscription *sub;
+	struct subscription *sub_temp;
+
+	/* Invalidate subscriber reference */
+
+	port_ref = subscriber->port_ref;
+	subscriber->port_ref = 0;
+	spin_unlock_bh(subscriber->lock);
+
+	/* Sever connection to subscriber */
+
+	tipc_shutdown(port_ref);
+	tipc_deleteport(port_ref);
+
+	/* Destroy any existing subscriptions for subscriber */
+
+	list_for_each_entry_safe(sub, sub_temp, &subscriber->subscription_list,
+				 subscription_list) {
+		if (sub->timeout != TIPC_WAIT_FOREVER) {
+			k_cancel_timer(&sub->timer);
+			k_term_timer(&sub->timer);
+		}
+		dbg("Term: Removing sub %u,%u,%u from subscriber %x list\n",
+		    sub->seq.type, sub->seq.lower, sub->seq.upper, subscriber);
+		subscr_del(sub);
+	}
+
+	/* Remove subscriber from topology server's subscriber list */
+
+	spin_lock_bh(&topsrv.lock);
+	list_del(&subscriber->subscriber_list);
+	spin_unlock_bh(&topsrv.lock);
+
+	/* Reclaim subscriber lock */
+
+	spin_lock_bh(subscriber->lock);
+
+	/* Now destroy subscriber */
+
+	kfree(subscriber);
+}
+
+/**
+ * subscr_cancel - handle subscription cancellation request
+ *
+ * Called with subscriber port locked.  Routine must temporarily release lock
+ * to enable the subscription timeout routine to finish without deadlocking;
+ * the lock is then reclaimed to allow caller to release it upon return.
+ *
+ * Note that fields of 's' use subscriber's endianness!
+ */
+
+static void subscr_cancel(struct tipc_subscr *s,
+			  struct subscriber *subscriber)
+{
+	struct subscription *sub;
+	struct subscription *sub_temp;
+	int found = 0;
+
+	/* Find first matching subscription, exit if not found */
+
+	list_for_each_entry_safe(sub, sub_temp, &subscriber->subscription_list,
+				 subscription_list) {
+		if (!memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr))) {
+			found = 1;
+			break;
+		}
+	}
+	if (!found)
+		return;
+
+	/* Cancel subscription timer (if used), then delete subscription */
+
+	if (sub->timeout != TIPC_WAIT_FOREVER) {
+		sub->timeout = TIPC_WAIT_FOREVER;
+		spin_unlock_bh(subscriber->lock);
+		k_cancel_timer(&sub->timer);
+		k_term_timer(&sub->timer);
+		spin_lock_bh(subscriber->lock);
+	}
+	dbg("Cancel: removing sub %u,%u,%u from subscriber %x list\n",
+	    sub->seq.type, sub->seq.lower, sub->seq.upper, subscriber);
+	subscr_del(sub);
+}
+
+/**
+ * subscr_subscribe - create subscription for subscriber
+ *
+ * Called with subscriber port locked.
+ */
+
+static struct subscription *subscr_subscribe(struct tipc_subscr *s,
+					     struct subscriber *subscriber)
+{
+	struct subscription *sub;
+	int swap;
+
+	/* Determine subscriber's endianness */
+
+	swap = !(s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE));
+
+	/* Detect & process a subscription cancellation request */
+
+	if (s->filter & htohl(TIPC_SUB_CANCEL, swap)) {
+		s->filter &= ~htohl(TIPC_SUB_CANCEL, swap);
+		subscr_cancel(s, subscriber);
+		return NULL;
+	}
+
+	/* Refuse subscription if global limit exceeded */
+
+	if (atomic_read(&topsrv.subscription_count) >= tipc_max_subscriptions) {
+		warn("Subscription rejected, subscription limit reached (%u)\n",
+		     tipc_max_subscriptions);
+		subscr_terminate(subscriber);
+		return NULL;
+	}
+
+	/* Allocate subscription object */
+
+	sub = kmalloc(sizeof(*sub), GFP_ATOMIC);
+	if (!sub) {
+		warn("Subscription rejected, no memory\n");
+		subscr_terminate(subscriber);
+		return NULL;
+	}
+
+	/* Initialize subscription object */
+
+	sub->seq.type = htohl(s->seq.type, swap);
+	sub->seq.lower = htohl(s->seq.lower, swap);
+	sub->seq.upper = htohl(s->seq.upper, swap);
+	sub->timeout = htohl(s->timeout, swap);
+	sub->filter = htohl(s->filter, swap);
+	if ((!(sub->filter & TIPC_SUB_PORTS)
+	     == !(sub->filter & TIPC_SUB_SERVICE))
+	    || (sub->seq.lower > sub->seq.upper)) {
+		warn("Subscription rejected, illegal request\n");
+		kfree(sub);
+		subscr_terminate(subscriber);
+		return NULL;
+	}
+	sub->event_cb = subscr_send_event;
+	INIT_LIST_HEAD(&sub->nameseq_list);
+	list_add(&sub->subscription_list, &subscriber->subscription_list);
+	sub->server_ref = subscriber->port_ref;
+	sub->swap = swap;
+	memcpy(&sub->evt.s, s, sizeof(struct tipc_subscr));
+	atomic_inc(&topsrv.subscription_count);
+	if (sub->timeout != TIPC_WAIT_FOREVER) {
+		k_init_timer(&sub->timer,
+			     (Handler)subscr_timeout, (unsigned long)sub);
+		k_start_timer(&sub->timer, sub->timeout);
+	}
+
+	return sub;
+}
+
+/**
+ * subscr_conn_shutdown_event - handle termination request from subscriber
+ *
+ * Called with subscriber's server port unlocked.
+ */
+
+static void subscr_conn_shutdown_event(void *usr_handle,
+				       u32 port_ref,
+				       struct sk_buff **buf,
+				       unsigned char const *data,
+				       unsigned int size,
+				       int reason)
+{
+	struct subscriber *subscriber = usr_handle;
+	spinlock_t *subscriber_lock;
+
+	if (tipc_port_lock(port_ref) == NULL)
+		return;
+
+	subscriber_lock = subscriber->lock;
+	subscr_terminate(subscriber);
+	spin_unlock_bh(subscriber_lock);
+}
+
+/**
+ * subscr_conn_msg_event - handle new subscription request from subscriber
+ *
+ * Called with subscriber's server port unlocked.
+ */
+
+static void subscr_conn_msg_event(void *usr_handle,
+				  u32 port_ref,
+				  struct sk_buff **buf,
+				  const unchar *data,
+				  u32 size)
+{
+	struct subscriber *subscriber = usr_handle;
+	spinlock_t *subscriber_lock;
+	struct subscription *sub;
+
+	/*
+	 * Lock subscriber's server port (& make a local copy of lock pointer,
+	 * in case subscriber is deleted while processing subscription request)
+	 */
+
+	if (tipc_port_lock(port_ref) == NULL)
+		return;
+
+	subscriber_lock = subscriber->lock;
+
+	if (size != sizeof(struct tipc_subscr)) {
+		subscr_terminate(subscriber);
+		spin_unlock_bh(subscriber_lock);
+	} else {
+		sub = subscr_subscribe((struct tipc_subscr *)data, subscriber);
+		spin_unlock_bh(subscriber_lock);
+		if (sub != NULL) {
+
+			/*
+			 * We must release the server port lock before adding a
+			 * subscription to the name table since TIPC needs to be
+			 * able to (re)acquire the port lock if an event message
+			 * issued by the subscription process is rejected and
+			 * returned.  The subscription cannot be deleted while
+			 * it is being added to the name table because:
+			 * a) the single-threading of the native API port code
+			 *    ensures the subscription cannot be cancelled and
+			 *    the subscriber connection cannot be broken, and
+			 * b) the name table lock ensures the subscription
+			 *    timeout code cannot delete the subscription,
+			 * so the subscription object is still protected.
+			 */
+
+			tipc_nametbl_subscribe(sub);
+		}
+	}
+}
+
+/**
+ * subscr_named_msg_event - handle request to establish a new subscriber
+ */
+
+static void subscr_named_msg_event(void *usr_handle,
+				   u32 port_ref,
+				   struct sk_buff **buf,
+				   const unchar *data,
+				   u32 size,
+				   u32 importance,
+				   struct tipc_portid const *orig,
+				   struct tipc_name_seq const *dest)
+{
+	static struct iovec msg_sect = {NULL, 0};
+
+	struct subscriber *subscriber;
+	u32 server_port_ref;
+
+	/* Create subscriber object */
+
+	subscriber = kzalloc(sizeof(struct subscriber), GFP_ATOMIC);
+	if (subscriber == NULL) {
+		warn("Subscriber rejected, no memory\n");
+		return;
+	}
+	INIT_LIST_HEAD(&subscriber->subscription_list);
+	INIT_LIST_HEAD(&subscriber->subscriber_list);
+
+	/* Create server port & establish connection to subscriber */
+
+	tipc_createport(topsrv.user_ref,
+			subscriber,
+			importance,
+			NULL,
+			NULL,
+			subscr_conn_shutdown_event,
+			NULL,
+			NULL,
+			subscr_conn_msg_event,
+			NULL,
+			&subscriber->port_ref);
+	if (subscriber->port_ref == 0) {
+		warn("Subscriber rejected, unable to create port\n");
+		kfree(subscriber);
+		return;
+	}
+	tipc_connect2port(subscriber->port_ref, orig);
+
+	/* Lock server port (& save lock address for future use) */
+
+	subscriber->lock = tipc_port_lock(subscriber->port_ref)->publ.lock;
+
+	/* Add subscriber to topology server's subscriber list */
+
+	spin_lock_bh(&topsrv.lock);
+	list_add(&subscriber->subscriber_list, &topsrv.subscriber_list);
+	spin_unlock_bh(&topsrv.lock);
+
+	/* Unlock server port */
+
+	server_port_ref = subscriber->port_ref;
+	spin_unlock_bh(subscriber->lock);
+
+	/* Send an ACK- to complete connection handshaking */
+
+	tipc_send(server_port_ref, 1, &msg_sect);
+
+	/* Handle optional subscription request */
+
+	if (size != 0) {
+		subscr_conn_msg_event(subscriber, server_port_ref,
+				      buf, data, size);
+	}
+}
+
+int tipc_subscr_start(void)
+{
+	struct tipc_name_seq seq = {TIPC_TOP_SRV, TIPC_TOP_SRV, TIPC_TOP_SRV};
+	int res = -1;
+
+	memset(&topsrv, 0, sizeof (topsrv));
+	spin_lock_init(&topsrv.lock);
+	INIT_LIST_HEAD(&topsrv.subscriber_list);
+
+	spin_lock_bh(&topsrv.lock);
+	res = tipc_attach(&topsrv.user_ref, NULL, NULL);
+	if (res) {
+		spin_unlock_bh(&topsrv.lock);
+		return res;
+	}
+
+	res = tipc_createport(topsrv.user_ref,
+			      NULL,
+			      TIPC_CRITICAL_IMPORTANCE,
+			      NULL,
+			      NULL,
+			      NULL,
+			      NULL,
+			      subscr_named_msg_event,
+			      NULL,
+			      NULL,
+			      &topsrv.setup_port);
+	if (res)
+		goto failed;
+
+	res = tipc_nametbl_publish_rsv(topsrv.setup_port, TIPC_NODE_SCOPE, &seq);
+	if (res)
+		goto failed;
+
+	spin_unlock_bh(&topsrv.lock);
+	return 0;
+
+failed:
+	err("Failed to create subscription service\n");
+	tipc_detach(topsrv.user_ref);
+	topsrv.user_ref = 0;
+	spin_unlock_bh(&topsrv.lock);
+	return res;
+}
+
+void tipc_subscr_stop(void)
+{
+	struct subscriber *subscriber;
+	struct subscriber *subscriber_temp;
+	spinlock_t *subscriber_lock;
+
+	if (topsrv.user_ref) {
+		tipc_deleteport(topsrv.setup_port);
+		list_for_each_entry_safe(subscriber, subscriber_temp,
+					 &topsrv.subscriber_list,
+					 subscriber_list) {
+			subscriber_lock = subscriber->lock;
+			spin_lock_bh(subscriber_lock);
+			subscr_terminate(subscriber);
+			spin_unlock_bh(subscriber_lock);
+		}
+		tipc_detach(topsrv.user_ref);
+		topsrv.user_ref = 0;
+	}
+}
+
+
+int tipc_ispublished(struct tipc_name const *name)
+{
+	u32 domain = 0;
+
+	return(tipc_nametbl_translate(name->type, name->instance,&domain) != 0);
+}
+