1 files changed, 183 insertions, 0 deletions
diff --git a/net/tipc/subscr.c b/net/tipc/subscr.c
new file mode 100644
index 000000000..05d49ad81
--- /dev/null
+++ b/net/tipc/subscr.c
@@ -0,0 +1,183 @@
+/*
+ * net/tipc/subscr.c: TIPC network topology service
+ *
+ * Copyright (c) 2000-2017, Ericsson AB
+ * Copyright (c) 2005-2007, 2010-2013, Wind River Systems
+ * Copyright (c) 2020-2021, Red Hat Inc
+ * 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 "name_table.h"
+#include "subscr.h"
+
+static void tipc_sub_send_event(struct tipc_subscription *sub,
+				struct publication *p,
+				u32 event)
+{
+	struct tipc_subscr *s = &sub->evt.s;
+	struct tipc_event *evt = &sub->evt;
+
+	if (sub->inactive)
+		return;
+	tipc_evt_write(evt, event, event);
+	if (p) {
+		tipc_evt_write(evt, found_lower, p->sr.lower);
+		tipc_evt_write(evt, found_upper, p->sr.upper);
+		tipc_evt_write(evt, port.ref, p->sk.ref);
+		tipc_evt_write(evt, port.node, p->sk.node);
+	} else {
+		tipc_evt_write(evt, found_lower, s->seq.lower);
+		tipc_evt_write(evt, found_upper, s->seq.upper);
+		tipc_evt_write(evt, port.ref, 0);
+		tipc_evt_write(evt, port.node, 0);
+	}
+	tipc_topsrv_queue_evt(sub->net, sub->conid, event, evt);
+}
+
+/**
+ * tipc_sub_check_overlap - test for subscription overlap with the given values
+ * @subscribed: the service range subscribed for
+ * @found: the service range we are checking for match
+ *
+ * Returns true if there is overlap, otherwise false.
+ */
+static bool tipc_sub_check_overlap(struct tipc_service_range *subscribed,
+				   struct tipc_service_range *found)
+{
+	u32 found_lower = found->lower;
+	u32 found_upper = found->upper;
+
+	if (found_lower < subscribed->lower)
+		found_lower = subscribed->lower;
+	if (found_upper > subscribed->upper)
+		found_upper = subscribed->upper;
+	return found_lower <= found_upper;
+}
+
+void tipc_sub_report_overlap(struct tipc_subscription *sub,
+			     struct publication *p,
+			     u32 event, bool must)
+{
+	struct tipc_service_range *sr = &sub->s.seq;
+	u32 filter = sub->s.filter;
+
+	if (!tipc_sub_check_overlap(sr, &p->sr))
+		return;
+	if (!must && !(filter & TIPC_SUB_PORTS))
+		return;
+	if (filter & TIPC_SUB_CLUSTER_SCOPE && p->scope == TIPC_NODE_SCOPE)
+		return;
+	if (filter & TIPC_SUB_NODE_SCOPE && p->scope != TIPC_NODE_SCOPE)
+		return;
+	spin_lock(&sub->lock);
+	tipc_sub_send_event(sub, p, event);
+	spin_unlock(&sub->lock);
+}
+
+static void tipc_sub_timeout(struct timer_list *t)
+{
+	struct tipc_subscription *sub = from_timer(sub, t, timer);
+
+	spin_lock(&sub->lock);
+	tipc_sub_send_event(sub, NULL, TIPC_SUBSCR_TIMEOUT);
+	sub->inactive = true;
+	spin_unlock(&sub->lock);
+}
+
+static void tipc_sub_kref_release(struct kref *kref)
+{
+	kfree(container_of(kref, struct tipc_subscription, kref));
+}
+
+void tipc_sub_put(struct tipc_subscription *subscription)
+{
+	kref_put(&subscription->kref, tipc_sub_kref_release);
+}
+
+void tipc_sub_get(struct tipc_subscription *subscription)
+{
+	kref_get(&subscription->kref);
+}
+
+struct tipc_subscription *tipc_sub_subscribe(struct net *net,
+					     struct tipc_subscr *s,
+					     int conid)
+{
+	u32 lower = tipc_sub_read(s, seq.lower);
+	u32 upper = tipc_sub_read(s, seq.upper);
+	u32 filter = tipc_sub_read(s, filter);
+	struct tipc_subscription *sub;
+	u32 timeout;
+
+	if ((filter & TIPC_SUB_PORTS && filter & TIPC_SUB_SERVICE) ||
+	    lower > upper) {
+		pr_warn("Subscription rejected, illegal request\n");
+		return NULL;
+	}
+	sub = kmalloc(sizeof(*sub), GFP_ATOMIC);
+	if (!sub) {
+		pr_warn("Subscription rejected, no memory\n");
+		return NULL;
+	}
+	INIT_LIST_HEAD(&sub->service_list);
+	INIT_LIST_HEAD(&sub->sub_list);
+	sub->net = net;
+	sub->conid = conid;
+	sub->inactive = false;
+	memcpy(&sub->evt.s, s, sizeof(*s));
+	sub->s.seq.type = tipc_sub_read(s, seq.type);
+	sub->s.seq.lower = lower;
+	sub->s.seq.upper = upper;
+	sub->s.filter = filter;
+	sub->s.timeout = tipc_sub_read(s, timeout);
+	memcpy(sub->s.usr_handle, s->usr_handle, 8);
+	spin_lock_init(&sub->lock);
+	kref_init(&sub->kref);
+	if (!tipc_nametbl_subscribe(sub)) {
+		kfree(sub);
+		return NULL;
+	}
+	timer_setup(&sub->timer, tipc_sub_timeout, 0);
+	timeout = tipc_sub_read(&sub->evt.s, timeout);
+	if (timeout != TIPC_WAIT_FOREVER)
+		mod_timer(&sub->timer, jiffies + msecs_to_jiffies(timeout));
+	return sub;
+}
+
+void tipc_sub_unsubscribe(struct tipc_subscription *sub)
+{
+	tipc_nametbl_unsubscribe(sub);
+	if (sub->evt.s.timeout != TIPC_WAIT_FOREVER)
+		del_timer_sync(&sub->timer);
+	list_del(&sub->sub_list);
+	tipc_sub_put(sub);
+}