LXR linux/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
  41static 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 */
  63int 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
  75void 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
 103static 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
 115static void tipc_sub_kref_release(struct kref *kref)
 116{
 117        kfree(container_of(kref, struct tipc_subscription, kref));
 118}
 119
 120void tipc_sub_put(struct tipc_subscription *subscription)
 121{
 122        kref_put(&subscription->kref, tipc_sub_kref_release);
 123}
 124
 125void tipc_sub_get(struct tipc_subscription *subscription)
 126{
 127        kref_get(&subscription->kref);
 128}
 129
 130struct 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
 167void 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}
 175