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 
tipc_sub_send_event(struct tipc_subscription * sub,struct publication * p,u32 event)42 static 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  */
tipc_sub_check_overlap(struct tipc_service_range * subscribed,struct tipc_service_range * found)73 static 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 
tipc_sub_report_overlap(struct tipc_subscription * sub,struct publication * p,u32 event,bool must)86 void 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 
tipc_sub_timeout(struct timer_list * t)106 static 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 
tipc_sub_kref_release(struct kref * kref)116 static void tipc_sub_kref_release(struct kref *kref)
117 {
118 	kfree(container_of(kref, struct tipc_subscription, kref));
119 }
120 
tipc_sub_put(struct tipc_subscription * subscription)121 void tipc_sub_put(struct tipc_subscription *subscription)
122 {
123 	kref_put(&subscription->kref, tipc_sub_kref_release);
124 }
125 
tipc_sub_get(struct tipc_subscription * subscription)126 void tipc_sub_get(struct tipc_subscription *subscription)
127 {
128 	kref_get(&subscription->kref);
129 }
130 
tipc_sub_subscribe(struct net * net,struct tipc_subscr * s,int conid)131 struct 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 
tipc_sub_unsubscribe(struct tipc_subscription * sub)176 void 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