1/*
2 * net/tipc/subscr.c: TIPC network topology service
3 *
4 * Copyright (c) 2000-2017, Ericsson AB
5 * Copyright (c) 2005-2007, 2010-2013, Wind River Systems
6 * Copyright (c) 2020-2021, Red Hat Inc
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 3. Neither the names of the copyright holders nor the names of its
18 *    contributors may be used to endorse or promote products derived from
19 *    this software without specific prior written permission.
20 *
21 * Alternatively, this software may be distributed under the terms of the
22 * GNU General Public License ("GPL") version 2 as published by the Free
23 * Software Foundation.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
26 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
29 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
36 */
37
38#include "core.h"
39#include "name_table.h"
40#include "subscr.h"
41
42static void tipc_sub_send_event(struct tipc_subscription *sub,
43				struct publication *p,
44				u32 event)
45{
46	struct tipc_subscr *s = &sub->evt.s;
47	struct tipc_event *evt = &sub->evt;
48
49	if (sub->inactive)
50		return;
51	tipc_evt_write(evt, event, event);
52	if (p) {
53		tipc_evt_write(evt, found_lower, p->sr.lower);
54		tipc_evt_write(evt, found_upper, p->sr.upper);
55		tipc_evt_write(evt, port.ref, p->sk.ref);
56		tipc_evt_write(evt, port.node, p->sk.node);
57	} else {
58		tipc_evt_write(evt, found_lower, s->seq.lower);
59		tipc_evt_write(evt, found_upper, s->seq.upper);
60		tipc_evt_write(evt, port.ref, 0);
61		tipc_evt_write(evt, port.node, 0);
62	}
63	tipc_topsrv_queue_evt(sub->net, sub->conid, event, evt);
64}
65
66/**
67 * tipc_sub_check_overlap - test for subscription overlap with the given values
68 * @subscribed: the service range subscribed for
69 * @found: the service range we are checking for match
70 *
71 * Returns true if there is overlap, otherwise false.
72 */
73static bool tipc_sub_check_overlap(struct tipc_service_range *subscribed,
74				   struct tipc_service_range *found)
75{
76	u32 found_lower = found->lower;
77	u32 found_upper = found->upper;
78
79	if (found_lower < subscribed->lower)
80		found_lower = subscribed->lower;
81	if (found_upper > subscribed->upper)
82		found_upper = subscribed->upper;
83	return found_lower <= found_upper;
84}
85
86void tipc_sub_report_overlap(struct tipc_subscription *sub,
87			     struct publication *p,
88			     u32 event, bool must)
89{
90	struct tipc_service_range *sr = &sub->s.seq;
91	u32 filter = sub->s.filter;
92
93	if (!tipc_sub_check_overlap(sr, &p->sr))
94		return;
95	if (!must && !(filter & TIPC_SUB_PORTS))
96		return;
97	if (filter & TIPC_SUB_CLUSTER_SCOPE && p->scope == TIPC_NODE_SCOPE)
98		return;
99	if (filter & TIPC_SUB_NODE_SCOPE && p->scope != TIPC_NODE_SCOPE)
100		return;
101	spin_lock(&sub->lock);
102	tipc_sub_send_event(sub, p, event);
103	spin_unlock(&sub->lock);
104}
105
106static void tipc_sub_timeout(struct timer_list *t)
107{
108	struct tipc_subscription *sub = from_timer(sub, t, timer);
109
110	spin_lock(&sub->lock);
111	tipc_sub_send_event(sub, NULL, TIPC_SUBSCR_TIMEOUT);
112	sub->inactive = true;
113	spin_unlock(&sub->lock);
114}
115
116static void tipc_sub_kref_release(struct kref *kref)
117{
118	kfree(container_of(kref, struct tipc_subscription, kref));
119}
120
121void tipc_sub_put(struct tipc_subscription *subscription)
122{
123	kref_put(&subscription->kref, tipc_sub_kref_release);
124}
125
126void tipc_sub_get(struct tipc_subscription *subscription)
127{
128	kref_get(&subscription->kref);
129}
130
131struct tipc_subscription *tipc_sub_subscribe(struct net *net,
132					     struct tipc_subscr *s,
133					     int conid)
134{
135	u32 lower = tipc_sub_read(s, seq.lower);
136	u32 upper = tipc_sub_read(s, seq.upper);
137	u32 filter = tipc_sub_read(s, filter);
138	struct tipc_subscription *sub;
139	u32 timeout;
140
141	if ((filter & TIPC_SUB_PORTS && filter & TIPC_SUB_SERVICE) ||
142	    lower > upper) {
143		pr_warn("Subscription rejected, illegal request\n");
144		return NULL;
145	}
146	sub = kmalloc(sizeof(*sub), GFP_ATOMIC);
147	if (!sub) {
148		pr_warn("Subscription rejected, no memory\n");
149		return NULL;
150	}
151	INIT_LIST_HEAD(&sub->service_list);
152	INIT_LIST_HEAD(&sub->sub_list);
153	sub->net = net;
154	sub->conid = conid;
155	sub->inactive = false;
156	memcpy(&sub->evt.s, s, sizeof(*s));
157	sub->s.seq.type = tipc_sub_read(s, seq.type);
158	sub->s.seq.lower = lower;
159	sub->s.seq.upper = upper;
160	sub->s.filter = filter;
161	sub->s.timeout = tipc_sub_read(s, timeout);
162	memcpy(sub->s.usr_handle, s->usr_handle, 8);
163	spin_lock_init(&sub->lock);
164	kref_init(&sub->kref);
165	if (!tipc_nametbl_subscribe(sub)) {
166		kfree(sub);
167		return NULL;
168	}
169	timer_setup(&sub->timer, tipc_sub_timeout, 0);
170	timeout = tipc_sub_read(&sub->evt.s, timeout);
171	if (timeout != TIPC_WAIT_FOREVER)
172		mod_timer(&sub->timer, jiffies + msecs_to_jiffies(timeout));
173	return sub;
174}
175
176void tipc_sub_unsubscribe(struct tipc_subscription *sub)
177{
178	tipc_nametbl_unsubscribe(sub);
179	if (sub->evt.s.timeout != TIPC_WAIT_FOREVER)
180		del_timer_sync(&sub->timer);
181	list_del(&sub->sub_list);
182	tipc_sub_put(sub);
183}
184