net/tipc/subscr.c

0001 /*
0002  * net/tipc/subscr.c: TIPC network topology service
0003  *
0004  * Copyright (c) 2000-2017, Ericsson AB
0005  * Copyright (c) 2005-2007, 2010-2013, Wind River Systems
0006  * Copyright (c) 2020-2021, Red Hat Inc
0007  * All rights reserved.
0008  *
0009  * Redistribution and use in source and binary forms, with or without
0010  * modification, are permitted provided that the following conditions are met:
0011  *
0012  * 1. Redistributions of source code must retain the above copyright
0013  *    notice, this list of conditions and the following disclaimer.
0014  * 2. Redistributions in binary form must reproduce the above copyright
0015  *    notice, this list of conditions and the following disclaimer in the
0016  *    documentation and/or other materials provided with the distribution.
0017  * 3. Neither the names of the copyright holders nor the names of its
0018  *    contributors may be used to endorse or promote products derived from
0019  *    this software without specific prior written permission.
0020  *
0021  * Alternatively, this software may be distributed under the terms of the
0022  * GNU General Public License ("GPL") version 2 as published by the Free
0023  * Software Foundation.
0024  *
0025  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0026  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0027  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0028  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0029  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0030  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0031  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0032  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0033  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0034  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0035  * POSSIBILITY OF SUCH DAMAGE.
0036  */
0037
0038 #include "core.h"
0039 #include "name_table.h"
0040 #include "subscr.h"
0041
0042 static void tipc_sub_send_event(struct tipc_subscription *sub,
0043                 struct publication *p,
0044                 u32 event)
0045 {
0046     struct tipc_subscr *s = &sub->evt.s;
0047     struct tipc_event *evt = &sub->evt;
0048
0049     if (sub->inactive)
0050         return;
0051     tipc_evt_write(evt, event, event);
0052     if (p) {
0053         tipc_evt_write(evt, found_lower, p->sr.lower);
0054         tipc_evt_write(evt, found_upper, p->sr.upper);
0055         tipc_evt_write(evt, port.ref, p->sk.ref);
0056         tipc_evt_write(evt, port.node, p->sk.node);
0057     } else {
0058         tipc_evt_write(evt, found_lower, s->seq.lower);
0059         tipc_evt_write(evt, found_upper, s->seq.upper);
0060         tipc_evt_write(evt, port.ref, 0);
0061         tipc_evt_write(evt, port.node, 0);
0062     }
0063     tipc_topsrv_queue_evt(sub->net, sub->conid, event, evt);
0064 }
0065
0066 /**
0067  * tipc_sub_check_overlap - test for subscription overlap with the given values
0068  * @subscribed: the service range subscribed for
0069  * @found: the service range we are checking for match
0070  *
0071  * Returns true if there is overlap, otherwise false.
0072  */
0073 static bool tipc_sub_check_overlap(struct tipc_service_range *subscribed,
0074                    struct tipc_service_range *found)
0075 {
0076     u32 found_lower = found->lower;
0077     u32 found_upper = found->upper;
0078
0079     if (found_lower < subscribed->lower)
0080         found_lower = subscribed->lower;
0081     if (found_upper > subscribed->upper)
0082         found_upper = subscribed->upper;
0083     return found_lower <= found_upper;
0084 }
0085
0086 void tipc_sub_report_overlap(struct tipc_subscription *sub,
0087                  struct publication *p,
0088                  u32 event, bool must)
0089 {
0090     struct tipc_service_range *sr = &sub->s.seq;
0091     u32 filter = sub->s.filter;
0092
0093     if (!tipc_sub_check_overlap(sr, &p->sr))
0094         return;
0095     if (!must && !(filter & TIPC_SUB_PORTS))
0096         return;
0097     if (filter & TIPC_SUB_CLUSTER_SCOPE && p->scope == TIPC_NODE_SCOPE)
0098         return;
0099     if (filter & TIPC_SUB_NODE_SCOPE && p->scope != TIPC_NODE_SCOPE)
0100         return;
0101     spin_lock(&sub->lock);
0102     tipc_sub_send_event(sub, p, event);
0103     spin_unlock(&sub->lock);
0104 }
0105
0106 static void tipc_sub_timeout(struct timer_list *t)
0107 {
0108     struct tipc_subscription *sub = from_timer(sub, t, timer);
0109
0110     spin_lock(&sub->lock);
0111     tipc_sub_send_event(sub, NULL, TIPC_SUBSCR_TIMEOUT);
0112     sub->inactive = true;
0113     spin_unlock(&sub->lock);
0114 }
0115
0116 static void tipc_sub_kref_release(struct kref *kref)
0117 {
0118     kfree(container_of(kref, struct tipc_subscription, kref));
0119 }
0120
0121 void tipc_sub_put(struct tipc_subscription *subscription)
0122 {
0123     kref_put(&subscription->kref, tipc_sub_kref_release);
0124 }
0125
0126 void tipc_sub_get(struct tipc_subscription *subscription)
0127 {
0128     kref_get(&subscription->kref);
0129 }
0130
0131 struct tipc_subscription *tipc_sub_subscribe(struct net *net,
0132                          struct tipc_subscr *s,
0133                          int conid)
0134 {
0135     u32 lower = tipc_sub_read(s, seq.lower);
0136     u32 upper = tipc_sub_read(s, seq.upper);
0137     u32 filter = tipc_sub_read(s, filter);
0138     struct tipc_subscription *sub;
0139     u32 timeout;
0140
0141     if ((filter & TIPC_SUB_PORTS && filter & TIPC_SUB_SERVICE) ||
0142         lower > upper) {
0143         pr_warn("Subscription rejected, illegal request\n");
0144         return NULL;
0145     }
0146     sub = kmalloc(sizeof(*sub), GFP_ATOMIC);
0147     if (!sub) {
0148         pr_warn("Subscription rejected, no memory\n");
0149         return NULL;
0150     }
0151     INIT_LIST_HEAD(&sub->service_list);
0152     INIT_LIST_HEAD(&sub->sub_list);
0153     sub->net = net;
0154     sub->conid = conid;
0155     sub->inactive = false;
0156     memcpy(&sub->evt.s, s, sizeof(*s));
0157     sub->s.seq.type = tipc_sub_read(s, seq.type);
0158     sub->s.seq.lower = lower;
0159     sub->s.seq.upper = upper;
0160     sub->s.filter = filter;
0161     sub->s.timeout = tipc_sub_read(s, timeout);
0162     memcpy(sub->s.usr_handle, s->usr_handle, 8);
0163     spin_lock_init(&sub->lock);
0164     kref_init(&sub->kref);
0165     if (!tipc_nametbl_subscribe(sub)) {
0166         kfree(sub);
0167         return NULL;
0168     }
0169     timer_setup(&sub->timer, tipc_sub_timeout, 0);
0170     timeout = tipc_sub_read(&sub->evt.s, timeout);
0171     if (timeout != TIPC_WAIT_FOREVER)
0172         mod_timer(&sub->timer, jiffies + msecs_to_jiffies(timeout));
0173     return sub;
0174 }
0175
0176 void tipc_sub_unsubscribe(struct tipc_subscription *sub)
0177 {
0178     tipc_nametbl_unsubscribe(sub);
0179     if (sub->evt.s.timeout != TIPC_WAIT_FOREVER)
0180         del_timer_sync(&sub->timer);
0181     list_del(&sub->sub_list);
0182     tipc_sub_put(sub);
0183 }