1 files changed, 365 insertions, 0 deletions
diff --git a/net/tipc/subscr.c b/net/tipc/subscr.c
new file mode 100644
index 000000000000..4f80f00cd8f9
--- /dev/null
+++ b/net/tipc/subscr.c
@@ -0,0 +1,365 @@
+/*
+ * net/tipc/subscr.c: TIPC network topology service
+ *
+ * Copyright (c) 2000-2006, Ericsson AB
+ * Copyright (c) 2005-2007, 2010-2013, 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 "name_table.h"
+#include "subscr.h"
+
+/**
+ * struct tipc_subscriber - TIPC network topology subscriber
+ * @kref: reference counter to tipc_subscription object
+ * @conid: connection identifier to server connecting to subscriber
+ * @lock: control access to subscriber
+ * @subscrp_list: list of subscription objects for this subscriber
+ */
+struct tipc_subscriber {
+	struct kref kref;
+	int conid;
+	spinlock_t lock;
+	struct list_head subscrp_list;
+};
+
+static void tipc_subscrp_delete(struct tipc_subscription *sub);
+static void tipc_subscrb_put(struct tipc_subscriber *subscriber);
+
+/**
+ * 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;
+}
+
+static void tipc_subscrp_send_event(struct tipc_subscription *sub,
+				    u32 found_lower, u32 found_upper,
+				    u32 event, u32 port_ref, u32 node)
+{
+	struct tipc_net *tn = net_generic(sub->net, tipc_net_id);
+	struct tipc_subscriber *subscriber = sub->subscriber;
+	struct kvec 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_conn_sendmsg(tn->topsrv, subscriber->conid, NULL,
+			  msg_sect.iov_base, msg_sect.iov_len);
+}
+
+/**
+ * tipc_subscrp_check_overlap - test for subscription overlap with the
+ * given values
+ *
+ * Returns 1 if there is overlap, otherwise 0.
+ */
+int tipc_subscrp_check_overlap(struct tipc_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;
+}
+
+void tipc_subscrp_report_overlap(struct tipc_subscription *sub, u32 found_lower,
+				 u32 found_upper, u32 event, u32 port_ref,
+				 u32 node, int must)
+{
+	if (!tipc_subscrp_check_overlap(sub, found_lower, found_upper))
+		return;
+	if (!must && !(sub->filter & TIPC_SUB_PORTS))
+		return;
+
+	tipc_subscrp_send_event(sub, found_lower, found_upper, event, port_ref,
+				node);
+}
+
+static void tipc_subscrp_timeout(unsigned long data)
+{
+	struct tipc_subscription *sub = (struct tipc_subscription *)data;
+	struct tipc_subscriber *subscriber = sub->subscriber;
+
+	/* Notify subscriber of timeout */
+	tipc_subscrp_send_event(sub, sub->evt.s.seq.lower, sub->evt.s.seq.upper,
+				TIPC_SUBSCR_TIMEOUT, 0, 0);
+
+	spin_lock_bh(&subscriber->lock);
+	tipc_subscrp_delete(sub);
+	spin_unlock_bh(&subscriber->lock);
+
+	tipc_subscrb_put(subscriber);
+}
+
+static void tipc_subscrb_kref_release(struct kref *kref)
+{
+	struct tipc_subscriber *subcriber = container_of(kref,
+					    struct tipc_subscriber, kref);
+
+	kfree(subcriber);
+}
+
+static void tipc_subscrb_put(struct tipc_subscriber *subscriber)
+{
+	kref_put(&subscriber->kref, tipc_subscrb_kref_release);
+}
+
+static void tipc_subscrb_get(struct tipc_subscriber *subscriber)
+{
+	kref_get(&subscriber->kref);
+}
+
+static struct tipc_subscriber *tipc_subscrb_create(int conid)
+{
+	struct tipc_subscriber *subscriber;
+
+	subscriber = kzalloc(sizeof(*subscriber), GFP_ATOMIC);
+	if (!subscriber) {
+		pr_warn("Subscriber rejected, no memory\n");
+		return NULL;
+	}
+	kref_init(&subscriber->kref);
+	INIT_LIST_HEAD(&subscriber->subscrp_list);
+	subscriber->conid = conid;
+	spin_lock_init(&subscriber->lock);
+
+	return subscriber;
+}
+
+static void tipc_subscrb_delete(struct tipc_subscriber *subscriber)
+{
+	struct tipc_subscription *sub, *temp;
+
+	spin_lock_bh(&subscriber->lock);
+	/* Destroy any existing subscriptions for subscriber */
+	list_for_each_entry_safe(sub, temp, &subscriber->subscrp_list,
+				 subscrp_list) {
+		if (del_timer(&sub->timer)) {
+			tipc_subscrp_delete(sub);
+			tipc_subscrb_put(subscriber);
+		}
+	}
+	spin_unlock_bh(&subscriber->lock);
+
+	tipc_subscrb_put(subscriber);
+}
+
+static void tipc_subscrp_delete(struct tipc_subscription *sub)
+{
+	struct tipc_net *tn = net_generic(sub->net, tipc_net_id);
+
+	tipc_nametbl_unsubscribe(sub);
+	list_del(&sub->subscrp_list);
+	kfree(sub);
+	atomic_dec(&tn->subscription_count);
+}
+
+static void tipc_subscrp_cancel(struct tipc_subscr *s,
+				struct tipc_subscriber *subscriber)
+{
+	struct tipc_subscription *sub, *temp;
+
+	spin_lock_bh(&subscriber->lock);
+	/* Find first matching subscription, exit if not found */
+	list_for_each_entry_safe(sub, temp, &subscriber->subscrp_list,
+				 subscrp_list) {
+		if (!memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr))) {
+			if (del_timer(&sub->timer)) {
+				tipc_subscrp_delete(sub);
+				tipc_subscrb_put(subscriber);
+			}
+			break;
+		}
+	}
+	spin_unlock_bh(&subscriber->lock);
+}
+
+static int tipc_subscrp_create(struct net *net, struct tipc_subscr *s,
+			       struct tipc_subscriber *subscriber,
+			       struct tipc_subscription **sub_p)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_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);
+		tipc_subscrp_cancel(s, subscriber);
+		return 0;
+	}
+
+	/* Refuse subscription if global limit exceeded */
+	if (atomic_read(&tn->subscription_count) >= TIPC_MAX_SUBSCRIPTIONS) {
+		pr_warn("Subscription rejected, limit reached (%u)\n",
+			TIPC_MAX_SUBSCRIPTIONS);
+		return -EINVAL;
+	}
+
+	/* Allocate subscription object */
+	sub = kmalloc(sizeof(*sub), GFP_ATOMIC);
+	if (!sub) {
+		pr_warn("Subscription rejected, no memory\n");
+		return -ENOMEM;
+	}
+
+	/* Initialize subscription object */
+	sub->net = net;
+	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 = msecs_to_jiffies(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)) {
+		pr_warn("Subscription rejected, illegal request\n");
+		kfree(sub);
+		return -EINVAL;
+	}
+	spin_lock_bh(&subscriber->lock);
+	list_add(&sub->subscrp_list, &subscriber->subscrp_list);
+	spin_unlock_bh(&subscriber->lock);
+	sub->subscriber = subscriber;
+	sub->swap = swap;
+	memcpy(&sub->evt.s, s, sizeof(*s));
+	atomic_inc(&tn->subscription_count);
+	setup_timer(&sub->timer, tipc_subscrp_timeout, (unsigned long)sub);
+	if (sub->timeout != TIPC_WAIT_FOREVER)
+		sub->timeout += jiffies;
+	if (!mod_timer(&sub->timer, sub->timeout))
+		tipc_subscrb_get(subscriber);
+	*sub_p = sub;
+	return 0;
+}
+
+/* Handle one termination request for the subscriber */
+static void tipc_subscrb_shutdown_cb(int conid, void *usr_data)
+{
+	tipc_subscrb_delete((struct tipc_subscriber *)usr_data);
+}
+
+/* Handle one request to create a new subscription for the subscriber */
+static void tipc_subscrb_rcv_cb(struct net *net, int conid,
+				struct sockaddr_tipc *addr, void *usr_data,
+				void *buf, size_t len)
+{
+	struct tipc_subscriber *subscrb = usr_data;
+	struct tipc_subscription *sub = NULL;
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+
+	if (tipc_subscrp_create(net, (struct tipc_subscr *)buf, subscrb, &sub))
+		return tipc_conn_terminate(tn->topsrv, subscrb->conid);
+
+	if (sub)
+		tipc_nametbl_subscribe(sub);
+}
+
+/* Handle one request to establish a new subscriber */
+static void *tipc_subscrb_connect_cb(int conid)
+{
+	return (void *)tipc_subscrb_create(conid);
+}
+
+static int tipc_topsrv_start(struct net *net)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	const char name[] = "topology_server";
+	struct tipc_server *topsrv;
+	struct sockaddr_tipc *saddr;
+
+	saddr = kzalloc(sizeof(*saddr), GFP_ATOMIC);
+	if (!saddr)
+		return -ENOMEM;
+	saddr->family			= AF_TIPC;
+	saddr->addrtype			= TIPC_ADDR_NAMESEQ;
+	saddr->addr.nameseq.type	= TIPC_TOP_SRV;
+	saddr->addr.nameseq.lower	= TIPC_TOP_SRV;
+	saddr->addr.nameseq.upper	= TIPC_TOP_SRV;
+	saddr->scope			= TIPC_NODE_SCOPE;
+
+	topsrv = kzalloc(sizeof(*topsrv), GFP_ATOMIC);
+	if (!topsrv) {
+		kfree(saddr);
+		return -ENOMEM;
+	}
+	topsrv->net			= net;
+	topsrv->saddr			= saddr;
+	topsrv->imp			= TIPC_CRITICAL_IMPORTANCE;
+	topsrv->type			= SOCK_SEQPACKET;
+	topsrv->max_rcvbuf_size		= sizeof(struct tipc_subscr);
+	topsrv->tipc_conn_recvmsg	= tipc_subscrb_rcv_cb;
+	topsrv->tipc_conn_new		= tipc_subscrb_connect_cb;
+	topsrv->tipc_conn_shutdown	= tipc_subscrb_shutdown_cb;
+
+	strscpy(topsrv->name, name, sizeof(topsrv->name));
+	tn->topsrv = topsrv;
+	atomic_set(&tn->subscription_count, 0);
+
+	return tipc_server_start(topsrv);
+}
+
+static void tipc_topsrv_stop(struct net *net)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_server *topsrv = tn->topsrv;
+
+	tipc_server_stop(topsrv);
+	kfree(topsrv->saddr);
+	kfree(topsrv);
+}
+
+int __net_init tipc_topsrv_init_net(struct net *net)
+{
+	return tipc_topsrv_start(net);
+}
+
+void __net_exit tipc_topsrv_exit_net(struct net *net)
+{
+	tipc_topsrv_stop(net);
+}