1 files changed, 527 insertions, 0 deletions

diff --git a/net/tipc/subscr.c b/net/tipc/subscr.c
new file mode 100644
index 000000000000..80e219ba527d
--- /dev/null
+++ b/net/tipc/subscr.c
@@ -0,0 +1,527 @@
+/*
+ * 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);
+}
+
+/**
+ * subscr_overlap - test for subscription overlap with the given values
+ *
+ * Returns 1 if there is overlap, otherwise 0.
+ */
+
+int 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;
+}
+
+/**
+ * subscr_report_overlap - issue event if there is subscription overlap
+ * 
+ * Protected by nameseq.lock in name_table.c
+ */
+
+void 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 (!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 *)ref_lock(subscriber_ref);
+        if (subscriber == NULL)
+                return;
+
+        /* Unlink subscription from name table */
+
+        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 */
+
+        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 */
+
+        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);
+                }
+                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;
+        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 = 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 = 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 = 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");
+                ref_discard(subscriber->ref);
+                kfree(subscriber);
+                return;
+        }
+        tipc_connect2port(subscriber->port_ref, orig);
+
+
+        /* Add subscriber to topology server's subscriber list */
+
+        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 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 = 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 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) {
+                        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(nametbl_translate(name->type, name->instance,&domain) != 0);
+}
+