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) 2020-2021, 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 }