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-rw-r--r--net/tipc/subscr.c527
1 files changed, 527 insertions, 0 deletions
diff --git a/net/tipc/subscr.c b/net/tipc/subscr.c
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+++ b/net/tipc/subscr.c
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+/*
+ * net/tipc/subscr.c: TIPC subscription service
+ *
+ * Copyright (c) 2000-2006, Ericsson AB
+ * Copyright (c) 2005, 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 "dbg.h"
+#include "subscr.h"
+#include "name_table.h"
+#include "ref.h"
+
+/**
+ * struct subscriber - TIPC network topology subscriber
+ * @ref: object reference to subscriber object itself
+ * @lock: pointer to spinlock controlling access to subscriber object
+ * @subscriber_list: adjacent subscribers in top. server's list of subscribers
+ * @subscription_list: list of subscription objects for this subscriber
+ * @port_ref: object reference to port used to communicate with subscriber
+ * @swap: indicates if subscriber uses opposite endianness in its messages
+ */
+
+struct subscriber {
+ u32 ref;
+ spinlock_t *lock;
+ struct list_head subscriber_list;
+ struct list_head subscription_list;
+ u32 port_ref;
+ int swap;
+};
+
+/**
+ * struct top_srv - TIPC network topology subscription service
+ * @user_ref: TIPC userid of subscription service
+ * @setup_port: reference to TIPC port that handles subscription requests
+ * @subscription_count: number of active subscriptions (not subscribers!)
+ * @subscriber_list: list of ports subscribing to service
+ * @lock: spinlock govering access to subscriber list
+ */
+
+struct top_srv {
+ u32 user_ref;
+ u32 setup_port;
+ atomic_t subscription_count;
+ struct list_head subscriber_list;
+ spinlock_t lock;
+};
+
+static struct top_srv topsrv = { 0 };
+
+/**
+ * htohl - convert value to endianness used by destination
+ * @in: value to convert
+ * @swap: non-zero if endianness must be reversed
+ *
+ * Returns converted value
+ */
+
+static inline u32 htohl(u32 in, int swap)
+{
+ char *c = (char *)∈
+
+ return swap ? ((c[3] << 3) + (c[2] << 2) + (c[1] << 1) + c[0]) : in;
+}
+
+/**
+ * subscr_send_event - send a message containing a tipc_event to the subscriber
+ */
+
+static void subscr_send_event(struct subscription *sub,
+ u32 found_lower,
+ u32 found_upper,
+ u32 event,
+ u32 port_ref,
+ u32 node)
+{
+ struct iovec msg_sect;
+
+ msg_sect.iov_base = (void *)&sub->evt;
+ msg_sect.iov_len = sizeof(struct tipc_event);
+
+ sub->evt.event = htohl(event, sub->owner->swap);
+ sub->evt.found_lower = htohl(found_lower, sub->owner->swap);
+ sub->evt.found_upper = htohl(found_upper, sub->owner->swap);
+ sub->evt.port.ref = htohl(port_ref, sub->owner->swap);
+ sub->evt.port.node = htohl(node, sub->owner->swap);
+ tipc_send(sub->owner->port_ref, 1, &msg_sect);
+}
+
+/**
+ * tipc_subscr_overlap - test for subscription overlap with the given values
+ *
+ * Returns 1 if there is overlap, otherwise 0.
+ */
+
+int tipc_subscr_overlap(struct 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 subscription *sub,
+ u32 found_lower,
+ u32 found_upper,
+ u32 event,
+ u32 port_ref,
+ u32 node,
+ int must)
+{
+ dbg("Rep overlap %u:%u,%u<->%u,%u\n", sub->seq.type, sub->seq.lower,
+ sub->seq.upper, found_lower, found_upper);
+ 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);
+}
+
+/**
+ * subscr_timeout - subscription timeout has occurred
+ */
+
+static void subscr_timeout(struct subscription *sub)
+{
+ struct subscriber *subscriber;
+ u32 subscriber_ref;
+
+ /* Validate subscriber reference (in case subscriber is terminating) */
+
+ subscriber_ref = sub->owner->ref;
+ subscriber = (struct subscriber *)tipc_ref_lock(subscriber_ref);
+ if (subscriber == NULL)
+ return;
+
+ /* Unlink subscription from name table */
+
+ tipc_nametbl_unsubscribe(sub);
+
+ /* Notify subscriber of timeout, then unlink subscription */
+
+ subscr_send_event(sub,
+ sub->evt.s.seq.lower,
+ sub->evt.s.seq.upper,
+ TIPC_SUBSCR_TIMEOUT,
+ 0,
+ 0);
+ list_del(&sub->subscription_list);
+
+ /* Now destroy subscription */
+
+ tipc_ref_unlock(subscriber_ref);
+ k_term_timer(&sub->timer);
+ kfree(sub);
+ atomic_dec(&topsrv.subscription_count);
+}
+
+/**
+ * subscr_terminate - terminate communication with a subscriber
+ *
+ * Called with subscriber locked. Routine must temporarily release this lock
+ * to enable subscription timeout routine(s) to finish without deadlocking;
+ * the lock is then reclaimed to allow caller to release it upon return.
+ * (This should work even in the unlikely event some other thread creates
+ * a new object reference in the interim that uses this lock; this routine will
+ * simply wait for it to be released, then claim it.)
+ */
+
+static void subscr_terminate(struct subscriber *subscriber)
+{
+ struct subscription *sub;
+ struct subscription *sub_temp;
+
+ /* Invalidate subscriber reference */
+
+ tipc_ref_discard(subscriber->ref);
+ spin_unlock_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) {
+ k_cancel_timer(&sub->timer);
+ k_term_timer(&sub->timer);
+ }
+ tipc_nametbl_unsubscribe(sub);
+ list_del(&sub->subscription_list);
+ dbg("Term: Removed sub %u,%u,%u from subscriber %x list\n",
+ sub->seq.type, sub->seq.lower, sub->seq.upper, subscriber);
+ kfree(sub);
+ atomic_dec(&topsrv.subscription_count);
+ }
+
+ /* Sever connection to subscriber */
+
+ tipc_shutdown(subscriber->port_ref);
+ tipc_deleteport(subscriber->port_ref);
+
+ /* Remove subscriber from topology server's subscriber list */
+
+ spin_lock_bh(&topsrv.lock);
+ list_del(&subscriber->subscriber_list);
+ spin_unlock_bh(&topsrv.lock);
+
+ /* Now destroy subscriber */
+
+ spin_lock_bh(subscriber->lock);
+ kfree(subscriber);
+}
+
+/**
+ * subscr_subscribe - create subscription for subscriber
+ *
+ * Called with subscriber locked
+ */
+
+static void subscr_subscribe(struct tipc_subscr *s,
+ struct subscriber *subscriber)
+{
+ struct subscription *sub;
+
+ /* Refuse subscription if global limit exceeded */
+
+ if (atomic_read(&topsrv.subscription_count) >= tipc_max_subscriptions) {
+ warn("Failed: max %u subscriptions\n", tipc_max_subscriptions);
+ subscr_terminate(subscriber);
+ return;
+ }
+
+ /* Allocate subscription object */
+
+ sub = kmalloc(sizeof(*sub), GFP_ATOMIC);
+ if (sub == NULL) {
+ warn("Memory squeeze; ignoring subscription\n");
+ subscr_terminate(subscriber);
+ return;
+ }
+
+ /* Determine/update subscriber's endianness */
+
+ if ((s->filter == TIPC_SUB_PORTS) || (s->filter == TIPC_SUB_SERVICE))
+ subscriber->swap = 0;
+ else
+ subscriber->swap = 1;
+
+ /* Initialize subscription object */
+
+ memset(sub, 0, sizeof(*sub));
+ sub->seq.type = htohl(s->seq.type, subscriber->swap);
+ sub->seq.lower = htohl(s->seq.lower, subscriber->swap);
+ sub->seq.upper = htohl(s->seq.upper, subscriber->swap);
+ sub->timeout = htohl(s->timeout, subscriber->swap);
+ sub->filter = htohl(s->filter, subscriber->swap);
+ if ((((sub->filter != TIPC_SUB_PORTS)
+ && (sub->filter != TIPC_SUB_SERVICE)))
+ || (sub->seq.lower > sub->seq.upper)) {
+ warn("Rejecting illegal subscription %u,%u,%u\n",
+ sub->seq.type, sub->seq.lower, sub->seq.upper);
+ kfree(sub);
+ subscr_terminate(subscriber);
+ return;
+ }
+ memcpy(&sub->evt.s, s, sizeof(struct tipc_subscr));
+ INIT_LIST_HEAD(&sub->subscription_list);
+ INIT_LIST_HEAD(&sub->nameseq_list);
+ list_add(&sub->subscription_list, &subscriber->subscription_list);
+ atomic_inc(&topsrv.subscription_count);
+ if (sub->timeout != TIPC_WAIT_FOREVER) {
+ k_init_timer(&sub->timer,
+ (Handler)subscr_timeout, (unsigned long)sub);
+ k_start_timer(&sub->timer, sub->timeout);
+ }
+ sub->owner = subscriber;
+ tipc_nametbl_subscribe(sub);
+}
+
+/**
+ * subscr_conn_shutdown_event - handle termination request from subscriber
+ */
+
+static void subscr_conn_shutdown_event(void *usr_handle,
+ u32 portref,
+ struct sk_buff **buf,
+ unsigned char const *data,
+ unsigned int size,
+ int reason)
+{
+ struct subscriber *subscriber;
+ spinlock_t *subscriber_lock;
+
+ subscriber = tipc_ref_lock((u32)(unsigned long)usr_handle);
+ if (subscriber == NULL)
+ return;
+
+ subscriber_lock = subscriber->lock;
+ subscr_terminate(subscriber);
+ spin_unlock_bh(subscriber_lock);
+}
+
+/**
+ * subscr_conn_msg_event - handle new subscription request from subscriber
+ */
+
+static void subscr_conn_msg_event(void *usr_handle,
+ u32 port_ref,
+ struct sk_buff **buf,
+ const unchar *data,
+ u32 size)
+{
+ struct subscriber *subscriber;
+ spinlock_t *subscriber_lock;
+
+ subscriber = tipc_ref_lock((u32)(unsigned long)usr_handle);
+ if (subscriber == NULL)
+ return;
+
+ subscriber_lock = subscriber->lock;
+ if (size != sizeof(struct tipc_subscr))
+ subscr_terminate(subscriber);
+ else
+ subscr_subscribe((struct tipc_subscr *)data, subscriber);
+
+ spin_unlock_bh(subscriber_lock);
+}
+
+/**
+ * subscr_named_msg_event - handle request to establish a new subscriber
+ */
+
+static void subscr_named_msg_event(void *usr_handle,
+ u32 port_ref,
+ struct sk_buff **buf,
+ const unchar *data,
+ u32 size,
+ u32 importance,
+ struct tipc_portid const *orig,
+ struct tipc_name_seq const *dest)
+{
+ struct subscriber *subscriber;
+ struct iovec msg_sect = {0, 0};
+ spinlock_t *subscriber_lock;
+
+ dbg("subscr_named_msg_event: orig = %x own = %x,\n",
+ orig->node, tipc_own_addr);
+ if (size && (size != sizeof(struct tipc_subscr))) {
+ warn("Received tipc_subscr of invalid size\n");
+ return;
+ }
+
+ /* Create subscriber object */
+
+ subscriber = kmalloc(sizeof(struct subscriber), GFP_ATOMIC);
+ if (subscriber == NULL) {
+ warn("Memory squeeze; ignoring subscriber setup\n");
+ return;
+ }
+ memset(subscriber, 0, sizeof(struct subscriber));
+ INIT_LIST_HEAD(&subscriber->subscription_list);
+ INIT_LIST_HEAD(&subscriber->subscriber_list);
+ subscriber->ref = tipc_ref_acquire(subscriber, &subscriber->lock);
+ if (subscriber->ref == 0) {
+ warn("Failed to acquire subscriber reference\n");
+ kfree(subscriber);
+ return;
+ }
+
+ /* Establish a connection to subscriber */
+
+ tipc_createport(topsrv.user_ref,
+ (void *)(unsigned long)subscriber->ref,
+ importance,
+ 0,
+ 0,
+ subscr_conn_shutdown_event,
+ 0,
+ 0,
+ subscr_conn_msg_event,
+ 0,
+ &subscriber->port_ref);
+ if (subscriber->port_ref == 0) {
+ warn("Memory squeeze; failed to create subscription port\n");
+ tipc_ref_discard(subscriber->ref);
+ kfree(subscriber);
+ return;
+ }
+ tipc_connect2port(subscriber->port_ref, orig);
+
+
+ /* Add subscriber to topology server's subscriber list */
+
+ tipc_ref_lock(subscriber->ref);
+ spin_lock_bh(&topsrv.lock);
+ list_add(&subscriber->subscriber_list, &topsrv.subscriber_list);
+ spin_unlock_bh(&topsrv.lock);
+
+ /*
+ * Subscribe now if message contains a subscription,
+ * otherwise send an empty response to complete connection handshaking
+ */
+
+ subscriber_lock = subscriber->lock;
+ if (size)
+ subscr_subscribe((struct tipc_subscr *)data, subscriber);
+ else
+ tipc_send(subscriber->port_ref, 1, &msg_sect);
+
+ spin_unlock_bh(subscriber_lock);
+}
+
+int tipc_subscr_start(void)
+{
+ struct tipc_name_seq seq = {TIPC_TOP_SRV, TIPC_TOP_SRV, TIPC_TOP_SRV};
+ int res = -1;
+
+ memset(&topsrv, 0, sizeof (topsrv));
+ topsrv.lock = SPIN_LOCK_UNLOCKED;
+ INIT_LIST_HEAD(&topsrv.subscriber_list);
+
+ spin_lock_bh(&topsrv.lock);
+ res = tipc_attach(&topsrv.user_ref, 0, 0);
+ if (res) {
+ spin_unlock_bh(&topsrv.lock);
+ return res;
+ }
+
+ res = tipc_createport(topsrv.user_ref,
+ 0,
+ TIPC_CRITICAL_IMPORTANCE,
+ 0,
+ 0,
+ 0,
+ 0,
+ subscr_named_msg_event,
+ 0,
+ 0,
+ &topsrv.setup_port);
+ if (res)
+ goto failed;
+
+ res = tipc_nametbl_publish_rsv(topsrv.setup_port, TIPC_NODE_SCOPE, &seq);
+ if (res)
+ goto failed;
+
+ spin_unlock_bh(&topsrv.lock);
+ return 0;
+
+failed:
+ err("Failed to create subscription service\n");
+ tipc_detach(topsrv.user_ref);
+ topsrv.user_ref = 0;
+ spin_unlock_bh(&topsrv.lock);
+ return res;
+}
+
+void tipc_subscr_stop(void)
+{
+ struct subscriber *subscriber;
+ struct subscriber *subscriber_temp;
+ spinlock_t *subscriber_lock;
+
+ if (topsrv.user_ref) {
+ tipc_deleteport(topsrv.setup_port);
+ list_for_each_entry_safe(subscriber, subscriber_temp,
+ &topsrv.subscriber_list,
+ subscriber_list) {
+ tipc_ref_lock(subscriber->ref);
+ subscriber_lock = subscriber->lock;
+ subscr_terminate(subscriber);
+ spin_unlock_bh(subscriber_lock);
+ }
+ tipc_detach(topsrv.user_ref);
+ topsrv.user_ref = 0;
+ }
+}
+
+
+int tipc_ispublished(struct tipc_name const *name)
+{
+ u32 domain = 0;
+
+ return(tipc_nametbl_translate(name->type, name->instance,&domain) != 0);
+}
+
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