summaryrefslogtreecommitdiffstats
path: root/net/tipc/subscr.c
blob: f6ad0005218ce88d82fd9868d28848d84da9ef1f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
/*
 * 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, 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,
				u32 found_lower, u32 found_upper,
				u32 event, u32 port, u32 node)
{
	struct tipc_event *evt = &sub->evt;

	if (sub->inactive)
		return;
	tipc_evt_write(evt, event, event);
	tipc_evt_write(evt, found_lower, found_lower);
	tipc_evt_write(evt, found_upper, found_upper);
	tipc_evt_write(evt, port.ref, port);
	tipc_evt_write(evt, port.node, node);
	tipc_topsrv_queue_evt(sub->net, sub->conid, event, evt);
}

/**
 * tipc_sub_check_overlap - test for subscription overlap with the given values
 * @seq: tipc_name_seq to check
 * @found_lower: lower value to test
 * @found_upper: upper value to test
 *
 * Return: 1 if there is overlap, otherwise 0.
 */
int tipc_sub_check_overlap(struct tipc_service_range *seq, u32 found_lower,
			   u32 found_upper)
{
	if (found_lower < seq->lower)
		found_lower = seq->lower;
	if (found_upper > seq->upper)
		found_upper = seq->upper;
	if (found_lower > found_upper)
		return 0;
	return 1;
}

void tipc_sub_report_overlap(struct tipc_subscription *sub,
			     u32 found_lower, u32 found_upper,
			     u32 event, u32 port, u32 node,
			     u32 scope, int must)
{
	struct tipc_subscr *s = &sub->evt.s;
	u32 filter = tipc_sub_read(s, filter);
	struct tipc_service_range seq;

	seq.type = tipc_sub_read(s, seq.type);
	seq.lower = tipc_sub_read(s, seq.lower);
	seq.upper = tipc_sub_read(s, seq.upper);

	if (!tipc_sub_check_overlap(&seq, found_lower, found_upper))
		return;

	if (!must && !(filter & TIPC_SUB_PORTS))
		return;
	if (filter & TIPC_SUB_CLUSTER_SCOPE && scope == TIPC_NODE_SCOPE)
		return;
	if (filter & TIPC_SUB_NODE_SCOPE && scope != TIPC_NODE_SCOPE)
		return;
	spin_lock(&sub->lock);
	tipc_sub_send_event(sub, found_lower, found_upper,
			    event, port, node);
	spin_unlock(&sub->lock);
}

static void tipc_sub_timeout(struct timer_list *t)
{
	struct tipc_subscription *sub = from_timer(sub, t, timer);
	struct tipc_subscr *s = &sub->evt.s;

	spin_lock(&sub->lock);
	tipc_sub_send_event(sub, s->seq.lower, s->seq.upper,
			    TIPC_SUBSCR_TIMEOUT, 0, 0);
	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 filter = tipc_sub_read(s, filter);
	struct tipc_subscription *sub;
	u32 timeout;

	if ((filter & TIPC_SUB_PORTS && filter & TIPC_SUB_SERVICE) ||
	    (tipc_sub_read(s, seq.lower) > tipc_sub_read(s, seq.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));
	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);
}