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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /net/tipc/subscr.c
Initial import
Diffstat (limited to 'net/tipc/subscr.c')
-rw-r--r--net/tipc/subscr.c377
1 files changed, 377 insertions, 0 deletions
diff --git a/net/tipc/subscr.c b/net/tipc/subscr.c
new file mode 100644
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+++ b/net/tipc/subscr.c
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+/*
+ * net/tipc/subscr.c: TIPC network topology service
+ *
+ * Copyright (c) 2000-2006, Ericsson AB
+ * Copyright (c) 2005-2007, 2010-2013, Wind River Systems
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "core.h"
+#include "name_table.h"
+#include "subscr.h"
+
+/**
+ * struct tipc_subscriber - TIPC network topology subscriber
+ * @conid: connection identifier to server connecting to subscriber
+ * @lock: control access to subscriber
+ * @subscription_list: list of subscription objects for this subscriber
+ */
+struct tipc_subscriber {
+ int conid;
+ spinlock_t lock;
+ struct list_head subscription_list;
+};
+
+/**
+ * htohl - convert value to endianness used by destination
+ * @in: value to convert
+ * @swap: non-zero if endianness must be reversed
+ *
+ * Returns converted value
+ */
+static u32 htohl(u32 in, int swap)
+{
+ return swap ? swab32(in) : in;
+}
+
+static void subscr_send_event(struct tipc_subscription *sub, u32 found_lower,
+ u32 found_upper, u32 event, u32 port_ref,
+ u32 node)
+{
+ struct tipc_net *tn = net_generic(sub->net, tipc_net_id);
+ struct tipc_subscriber *subscriber = sub->subscriber;
+ struct kvec msg_sect;
+
+ msg_sect.iov_base = (void *)&sub->evt;
+ msg_sect.iov_len = sizeof(struct tipc_event);
+ sub->evt.event = htohl(event, sub->swap);
+ sub->evt.found_lower = htohl(found_lower, sub->swap);
+ sub->evt.found_upper = htohl(found_upper, sub->swap);
+ sub->evt.port.ref = htohl(port_ref, sub->swap);
+ sub->evt.port.node = htohl(node, sub->swap);
+ tipc_conn_sendmsg(tn->topsrv, subscriber->conid, NULL,
+ msg_sect.iov_base, msg_sect.iov_len);
+}
+
+/**
+ * tipc_subscr_overlap - test for subscription overlap with the given values
+ *
+ * Returns 1 if there is overlap, otherwise 0.
+ */
+int tipc_subscr_overlap(struct tipc_subscription *sub, u32 found_lower,
+ u32 found_upper)
+{
+ if (found_lower < sub->seq.lower)
+ found_lower = sub->seq.lower;
+ if (found_upper > sub->seq.upper)
+ found_upper = sub->seq.upper;
+ if (found_lower > found_upper)
+ return 0;
+ return 1;
+}
+
+/**
+ * tipc_subscr_report_overlap - issue event if there is subscription overlap
+ *
+ * Protected by nameseq.lock in name_table.c
+ */
+void tipc_subscr_report_overlap(struct tipc_subscription *sub, u32 found_lower,
+ u32 found_upper, u32 event, u32 port_ref,
+ u32 node, int must)
+{
+ if (!tipc_subscr_overlap(sub, found_lower, found_upper))
+ return;
+ if (!must && !(sub->filter & TIPC_SUB_PORTS))
+ return;
+
+ subscr_send_event(sub, found_lower, found_upper, event, port_ref, node);
+}
+
+static void subscr_timeout(unsigned long data)
+{
+ struct tipc_subscription *sub = (struct tipc_subscription *)data;
+ struct tipc_subscriber *subscriber = sub->subscriber;
+ struct tipc_net *tn = net_generic(sub->net, tipc_net_id);
+
+ /* The spin lock per subscriber is used to protect its members */
+ spin_lock_bh(&subscriber->lock);
+
+ /* Validate timeout (in case subscription is being cancelled) */
+ if (sub->timeout == TIPC_WAIT_FOREVER) {
+ spin_unlock_bh(&subscriber->lock);
+ return;
+ }
+
+ /* Unlink subscription from name table */
+ tipc_nametbl_unsubscribe(sub);
+
+ /* Unlink subscription from subscriber */
+ list_del(&sub->subscription_list);
+
+ spin_unlock_bh(&subscriber->lock);
+
+ /* Notify subscriber of timeout */
+ subscr_send_event(sub, sub->evt.s.seq.lower, sub->evt.s.seq.upper,
+ TIPC_SUBSCR_TIMEOUT, 0, 0);
+
+ /* Now destroy subscription */
+ kfree(sub);
+ atomic_dec(&tn->subscription_count);
+}
+
+/**
+ * subscr_del - delete a subscription within a subscription list
+ *
+ * Called with subscriber lock held.
+ */
+static void subscr_del(struct tipc_subscription *sub)
+{
+ struct tipc_net *tn = net_generic(sub->net, tipc_net_id);
+
+ tipc_nametbl_unsubscribe(sub);
+ list_del(&sub->subscription_list);
+ kfree(sub);
+ atomic_dec(&tn->subscription_count);
+}
+
+static void subscr_release(struct tipc_subscriber *subscriber)
+{
+ struct tipc_subscription *sub;
+ struct tipc_subscription *sub_temp;
+
+ spin_lock_bh(&subscriber->lock);
+
+ /* Destroy any existing subscriptions for subscriber */
+ list_for_each_entry_safe(sub, sub_temp, &subscriber->subscription_list,
+ subscription_list) {
+ if (sub->timeout != TIPC_WAIT_FOREVER) {
+ spin_unlock_bh(&subscriber->lock);
+ del_timer_sync(&sub->timer);
+ spin_lock_bh(&subscriber->lock);
+ }
+ subscr_del(sub);
+ }
+ spin_unlock_bh(&subscriber->lock);
+
+ /* Now destroy subscriber */
+ kfree(subscriber);
+}
+
+/**
+ * subscr_cancel - handle subscription cancellation request
+ *
+ * Called with subscriber lock held. Routine must temporarily release lock
+ * to enable the subscription timeout routine to finish without deadlocking;
+ * the lock is then reclaimed to allow caller to release it upon return.
+ *
+ * Note that fields of 's' use subscriber's endianness!
+ */
+static void subscr_cancel(struct tipc_subscr *s,
+ struct tipc_subscriber *subscriber)
+{
+ struct tipc_subscription *sub;
+ struct tipc_subscription *sub_temp;
+ int found = 0;
+
+ /* Find first matching subscription, exit if not found */
+ list_for_each_entry_safe(sub, sub_temp, &subscriber->subscription_list,
+ subscription_list) {
+ if (!memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr))) {
+ found = 1;
+ break;
+ }
+ }
+ if (!found)
+ return;
+
+ /* Cancel subscription timer (if used), then delete subscription */
+ if (sub->timeout != TIPC_WAIT_FOREVER) {
+ sub->timeout = TIPC_WAIT_FOREVER;
+ spin_unlock_bh(&subscriber->lock);
+ del_timer_sync(&sub->timer);
+ spin_lock_bh(&subscriber->lock);
+ }
+ subscr_del(sub);
+}
+
+/**
+ * subscr_subscribe - create subscription for subscriber
+ *
+ * Called with subscriber lock held.
+ */
+static int subscr_subscribe(struct net *net, struct tipc_subscr *s,
+ struct tipc_subscriber *subscriber,
+ struct tipc_subscription **sub_p)
+{
+ struct tipc_net *tn = net_generic(net, tipc_net_id);
+ struct tipc_subscription *sub;
+ int swap;
+
+ /* Determine subscriber's endianness */
+ swap = !(s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE));
+
+ /* Detect & process a subscription cancellation request */
+ if (s->filter & htohl(TIPC_SUB_CANCEL, swap)) {
+ s->filter &= ~htohl(TIPC_SUB_CANCEL, swap);
+ subscr_cancel(s, subscriber);
+ return 0;
+ }
+
+ /* Refuse subscription if global limit exceeded */
+ if (atomic_read(&tn->subscription_count) >= TIPC_MAX_SUBSCRIPTIONS) {
+ pr_warn("Subscription rejected, limit reached (%u)\n",
+ TIPC_MAX_SUBSCRIPTIONS);
+ return -EINVAL;
+ }
+
+ /* Allocate subscription object */
+ sub = kmalloc(sizeof(*sub), GFP_ATOMIC);
+ if (!sub) {
+ pr_warn("Subscription rejected, no memory\n");
+ return -ENOMEM;
+ }
+
+ /* Initialize subscription object */
+ sub->net = net;
+ sub->seq.type = htohl(s->seq.type, swap);
+ sub->seq.lower = htohl(s->seq.lower, swap);
+ sub->seq.upper = htohl(s->seq.upper, swap);
+ sub->timeout = msecs_to_jiffies(htohl(s->timeout, swap));
+ sub->filter = htohl(s->filter, swap);
+ if ((!(sub->filter & TIPC_SUB_PORTS) ==
+ !(sub->filter & TIPC_SUB_SERVICE)) ||
+ (sub->seq.lower > sub->seq.upper)) {
+ pr_warn("Subscription rejected, illegal request\n");
+ kfree(sub);
+ return -EINVAL;
+ }
+ list_add(&sub->subscription_list, &subscriber->subscription_list);
+ sub->subscriber = subscriber;
+ sub->swap = swap;
+ memcpy(&sub->evt.s, s, sizeof(struct tipc_subscr));
+ atomic_inc(&tn->subscription_count);
+ if (sub->timeout != TIPC_WAIT_FOREVER) {
+ setup_timer(&sub->timer, subscr_timeout, (unsigned long)sub);
+ mod_timer(&sub->timer, jiffies + sub->timeout);
+ }
+ *sub_p = sub;
+ return 0;
+}
+
+/* Handle one termination request for the subscriber */
+static void subscr_conn_shutdown_event(int conid, void *usr_data)
+{
+ subscr_release((struct tipc_subscriber *)usr_data);
+}
+
+/* Handle one request to create a new subscription for the subscriber */
+static void subscr_conn_msg_event(struct net *net, int conid,
+ struct sockaddr_tipc *addr, void *usr_data,
+ void *buf, size_t len)
+{
+ struct tipc_subscriber *subscriber = usr_data;
+ struct tipc_subscription *sub = NULL;
+ struct tipc_net *tn = net_generic(net, tipc_net_id);
+
+ spin_lock_bh(&subscriber->lock);
+ subscr_subscribe(net, (struct tipc_subscr *)buf, subscriber, &sub);
+ if (sub)
+ tipc_nametbl_subscribe(sub);
+ else
+ tipc_conn_terminate(tn->topsrv, subscriber->conid);
+ spin_unlock_bh(&subscriber->lock);
+}
+
+/* Handle one request to establish a new subscriber */
+static void *subscr_named_msg_event(int conid)
+{
+ struct tipc_subscriber *subscriber;
+
+ /* Create subscriber object */
+ subscriber = kzalloc(sizeof(struct tipc_subscriber), GFP_ATOMIC);
+ if (subscriber == NULL) {
+ pr_warn("Subscriber rejected, no memory\n");
+ return NULL;
+ }
+ INIT_LIST_HEAD(&subscriber->subscription_list);
+ subscriber->conid = conid;
+ spin_lock_init(&subscriber->lock);
+
+ return (void *)subscriber;
+}
+
+int tipc_subscr_start(struct net *net)
+{
+ struct tipc_net *tn = net_generic(net, tipc_net_id);
+ const char name[] = "topology_server";
+ struct tipc_server *topsrv;
+ struct sockaddr_tipc *saddr;
+
+ saddr = kzalloc(sizeof(*saddr), GFP_ATOMIC);
+ if (!saddr)
+ return -ENOMEM;
+ saddr->family = AF_TIPC;
+ saddr->addrtype = TIPC_ADDR_NAMESEQ;
+ saddr->addr.nameseq.type = TIPC_TOP_SRV;
+ saddr->addr.nameseq.lower = TIPC_TOP_SRV;
+ saddr->addr.nameseq.upper = TIPC_TOP_SRV;
+ saddr->scope = TIPC_NODE_SCOPE;
+
+ topsrv = kzalloc(sizeof(*topsrv), GFP_ATOMIC);
+ if (!topsrv) {
+ kfree(saddr);
+ return -ENOMEM;
+ }
+ topsrv->net = net;
+ topsrv->saddr = saddr;
+ topsrv->imp = TIPC_CRITICAL_IMPORTANCE;
+ topsrv->type = SOCK_SEQPACKET;
+ topsrv->max_rcvbuf_size = sizeof(struct tipc_subscr);
+ topsrv->tipc_conn_recvmsg = subscr_conn_msg_event;
+ topsrv->tipc_conn_new = subscr_named_msg_event;
+ topsrv->tipc_conn_shutdown = subscr_conn_shutdown_event;
+
+ strncpy(topsrv->name, name, strlen(name) + 1);
+ tn->topsrv = topsrv;
+ atomic_set(&tn->subscription_count, 0);
+
+ return tipc_server_start(topsrv);
+}
+
+void tipc_subscr_stop(struct net *net)
+{
+ struct tipc_net *tn = net_generic(net, tipc_net_id);
+ struct tipc_server *topsrv = tn->topsrv;
+
+ tipc_server_stop(topsrv);
+ kfree(topsrv->saddr);
+ kfree(topsrv);
+}