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