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
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 */
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
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
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
116 static void tipc_sub_kref_release(struct kref *kref)
117 {
118 kfree(container_of(kref, struct tipc_subscription, kref));
119 }
120
121 void tipc_sub_put(struct tipc_subscription *subscription)
122 {
123 kref_put(&subscription->kref, tipc_sub_kref_release);
124 }
125
126 void tipc_sub_get(struct tipc_subscription *subscription)
127 {
128 kref_get(&subscription->kref);
129 }
130
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
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
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