net/tipc/subscr.c

   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, 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                                 u32 found_lower, u32 found_upper,
  44                                 u32 event, u32 port, u32 node)
  45 {
  46         struct tipc_event *evt = &sub->evt;
  47
  48         if (sub->inactive)
  49                 return;
  50         tipc_evt_write(evt, event, event);
  51         tipc_evt_write(evt, found_lower, found_lower);
  52         tipc_evt_write(evt, found_upper, found_upper);
  53         tipc_evt_write(evt, port.ref, port);
  54         tipc_evt_write(evt, port.node, node);
  55         tipc_topsrv_queue_evt(sub->net, sub->conid, event, evt);
  56 }
  57
  58 /**
  59  * tipc_sub_check_overlap - test for subscription overlap with the given values
  60  * @seq: tipc_name_seq to check
  61  * @found_lower: lower value to test
  62  * @found_upper: upper value to test
  63  *
  64  * Return: 1 if there is overlap, otherwise 0.
  65  */
  66 int tipc_sub_check_overlap(struct tipc_service_range *seq, u32 found_lower,
  67                            u32 found_upper)
  68 {
  69         if (found_lower < seq->lower)
  70                 found_lower = seq->lower;
  71         if (found_upper > seq->upper)
  72                 found_upper = seq->upper;
  73         if (found_lower > found_upper)
  74                 return 0;
  75         return 1;
  76 }
  77
  78 void tipc_sub_report_overlap(struct tipc_subscription *sub,
  79                              u32 found_lower, u32 found_upper,
  80                              u32 event, u32 port, u32 node,
  81                              u32 scope, int must)
  82 {
  83         struct tipc_subscr *s = &sub->evt.s;
  84         u32 filter = tipc_sub_read(s, filter);
  85         struct tipc_service_range seq;
  86
  87         seq.type = tipc_sub_read(s, seq.type);
  88         seq.lower = tipc_sub_read(s, seq.lower);
  89         seq.upper = tipc_sub_read(s, seq.upper);
  90
  91         if (!tipc_sub_check_overlap(&seq, found_lower, found_upper))
  92                 return;
  93
  94         if (!must && !(filter & TIPC_SUB_PORTS))
  95                 return;
  96         if (filter & TIPC_SUB_CLUSTER_SCOPE && scope == TIPC_NODE_SCOPE)
  97                 return;
  98         if (filter & TIPC_SUB_NODE_SCOPE && scope != TIPC_NODE_SCOPE)
  99                 return;
 100         spin_lock(&sub->lock);
 101         tipc_sub_send_event(sub, found_lower, found_upper,
 102                             event, port, node);
 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         struct tipc_subscr *s = &sub->evt.s;
 110
 111         spin_lock(&sub->lock);
 112         tipc_sub_send_event(sub, s->seq.lower, s->seq.upper,
 113                             TIPC_SUBSCR_TIMEOUT, 0, 0);
 114         sub->inactive = true;
 115         spin_unlock(&sub->lock);
 116 }
 117
 118 static void tipc_sub_kref_release(struct kref *kref)
 119 {
 120         kfree(container_of(kref, struct tipc_subscription, kref));
 121 }
 122
 123 void tipc_sub_put(struct tipc_subscription *subscription)
 124 {
 125         kref_put(&subscription->kref, tipc_sub_kref_release);
 126 }
 127
 128 void tipc_sub_get(struct tipc_subscription *subscription)
 129 {
 130         kref_get(&subscription->kref);
 131 }
 132
 133 struct tipc_subscription *tipc_sub_subscribe(struct net *net,
 134                                              struct tipc_subscr *s,
 135                                              int conid)
 136 {
 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             (tipc_sub_read(s, seq.lower) > tipc_sub_read(s, seq.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         spin_lock_init(&sub->lock);
 158         kref_init(&sub->kref);
 159         if (!tipc_nametbl_subscribe(sub)) {
 160                 kfree(sub);
 161                 return NULL;
 162         }
 163         timer_setup(&sub->timer, tipc_sub_timeout, 0);
 164         timeout = tipc_sub_read(&sub->evt.s, timeout);
 165         if (timeout != TIPC_WAIT_FOREVER)
 166                 mod_timer(&sub->timer, jiffies + msecs_to_jiffies(timeout));
 167         return sub;
 168 }
 169
 170 void tipc_sub_unsubscribe(struct tipc_subscription *sub)
 171 {
 172         tipc_nametbl_unsubscribe(sub);
 173         if (sub->evt.s.timeout != TIPC_WAIT_FOREVER)
 174                 del_timer_sync(&sub->timer);
 175         list_del(&sub->sub_list);
 176         tipc_sub_put(sub);
 177 }