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 * 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
  42static 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 */
  73static 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
  86void 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
 106static 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
 116static void tipc_sub_kref_release(struct kref *kref)
 117{
 118        kfree(container_of(kref, struct tipc_subscription, kref));
 119}
 120
 121void tipc_sub_put(struct tipc_subscription *subscription)
 122{
 123        kref_put(&subscription->kref, tipc_sub_kref_release);
 124}
 125
 126void tipc_sub_get(struct tipc_subscription *subscription)
 127{
 128        kref_get(&subscription->kref);
 129}
 130
 131struct 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
 176void 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