| /* |
| * net/tipc/subscr.c: TIPC network topology service |
| * |
| * Copyright (c) 2000-2006, Ericsson AB |
| * Copyright (c) 2005-2007, 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 "port.h" |
| #include "subscr.h" |
| |
| /** |
| * struct subscriber - TIPC network topology subscriber |
| * @port_ref: object reference to server port connecting to subscriber |
| * @lock: pointer to spinlock controlling access to subscriber's server port |
| * @subscriber_list: adjacent subscribers in top. server's list of subscribers |
| * @subscription_list: list of subscription objects for this subscriber |
| */ |
| |
| struct subscriber { |
| u32 port_ref; |
| spinlock_t *lock; |
| struct list_head subscriber_list; |
| struct list_head subscription_list; |
| }; |
| |
| /** |
| * 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 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 u32 htohl(u32 in, int swap) |
| { |
| return swap ? swab32(in) : in; |
| } |
| |
| /** |
| * subscr_send_event - send a message containing a tipc_event to the subscriber |
| * |
| * Note: Must not hold subscriber's server port lock, since tipc_send() will |
| * try to take the lock if the message is rejected and returned! |
| */ |
| |
| 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->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_send(sub->server_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) |
| { |
| if (!tipc_subscr_overlap(sub, found_lower, found_upper)) |
| return; |
| if (!must && !(sub->filter & TIPC_SUB_PORTS)) |
| return; |
| |
| sub->event_cb(sub, found_lower, found_upper, event, port_ref, node); |
| } |
| |
| /** |
| * subscr_timeout - subscription timeout has occurred |
| */ |
| |
| static void subscr_timeout(struct subscription *sub) |
| { |
| struct port *server_port; |
| |
| /* Validate server port reference (in case subscriber is terminating) */ |
| |
| server_port = tipc_port_lock(sub->server_ref); |
| if (server_port == NULL) |
| return; |
| |
| /* Validate timeout (in case subscription is being cancelled) */ |
| |
| if (sub->timeout == TIPC_WAIT_FOREVER) { |
| tipc_port_unlock(server_port); |
| return; |
| } |
| |
| /* Unlink subscription from name table */ |
| |
| tipc_nametbl_unsubscribe(sub); |
| |
| /* Unlink subscription from subscriber */ |
| |
| list_del(&sub->subscription_list); |
| |
| /* Release subscriber's server port */ |
| |
| tipc_port_unlock(server_port); |
| |
| /* 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 */ |
| |
| k_term_timer(&sub->timer); |
| kfree(sub); |
| atomic_dec(&topsrv.subscription_count); |
| } |
| |
| /** |
| * subscr_del - delete a subscription within a subscription list |
| * |
| * Called with subscriber port locked. |
| */ |
| |
| static void subscr_del(struct subscription *sub) |
| { |
| tipc_nametbl_unsubscribe(sub); |
| list_del(&sub->subscription_list); |
| kfree(sub); |
| atomic_dec(&topsrv.subscription_count); |
| } |
| |
| /** |
| * subscr_terminate - terminate communication with a subscriber |
| * |
| * Called with subscriber port locked. Routine must temporarily release 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) |
| { |
| u32 port_ref; |
| struct subscription *sub; |
| struct subscription *sub_temp; |
| |
| /* Invalidate subscriber reference */ |
| |
| port_ref = subscriber->port_ref; |
| subscriber->port_ref = 0; |
| spin_unlock_bh(subscriber->lock); |
| |
| /* Sever connection to subscriber */ |
| |
| tipc_shutdown(port_ref); |
| tipc_deleteport(port_ref); |
| |
| /* 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); |
| } |
| subscr_del(sub); |
| } |
| |
| /* Remove subscriber from topology server's subscriber list */ |
| |
| spin_lock_bh(&topsrv.lock); |
| list_del(&subscriber->subscriber_list); |
| spin_unlock_bh(&topsrv.lock); |
| |
| /* Reclaim subscriber lock */ |
| |
| spin_lock_bh(subscriber->lock); |
| |
| /* Now destroy subscriber */ |
| |
| kfree(subscriber); |
| } |
| |
| /** |
| * subscr_cancel - handle subscription cancellation request |
| * |
| * Called with subscriber port locked. 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 subscriber *subscriber) |
| { |
| struct subscription *sub; |
| struct 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); |
| k_cancel_timer(&sub->timer); |
| k_term_timer(&sub->timer); |
| spin_lock_bh(subscriber->lock); |
| } |
| subscr_del(sub); |
| } |
| |
| /** |
| * subscr_subscribe - create subscription for subscriber |
| * |
| * Called with subscriber port locked. |
| */ |
| |
| static struct subscription *subscr_subscribe(struct tipc_subscr *s, |
| struct subscriber *subscriber) |
| { |
| struct 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 NULL; |
| } |
| |
| /* Refuse subscription if global limit exceeded */ |
| |
| if (atomic_read(&topsrv.subscription_count) >= tipc_max_subscriptions) { |
| warn("Subscription rejected, subscription limit reached (%u)\n", |
| tipc_max_subscriptions); |
| subscr_terminate(subscriber); |
| return NULL; |
| } |
| |
| /* Allocate subscription object */ |
| |
| sub = kmalloc(sizeof(*sub), GFP_ATOMIC); |
| if (!sub) { |
| warn("Subscription rejected, no memory\n"); |
| subscr_terminate(subscriber); |
| return NULL; |
| } |
| |
| /* Initialize subscription object */ |
| |
| 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 = 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)) { |
| warn("Subscription rejected, illegal request\n"); |
| kfree(sub); |
| subscr_terminate(subscriber); |
| return NULL; |
| } |
| sub->event_cb = subscr_send_event; |
| INIT_LIST_HEAD(&sub->nameseq_list); |
| list_add(&sub->subscription_list, &subscriber->subscription_list); |
| sub->server_ref = subscriber->port_ref; |
| sub->swap = swap; |
| memcpy(&sub->evt.s, s, sizeof(struct tipc_subscr)); |
| 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); |
| } |
| |
| return sub; |
| } |
| |
| /** |
| * subscr_conn_shutdown_event - handle termination request from subscriber |
| * |
| * Called with subscriber's server port unlocked. |
| */ |
| |
| static void subscr_conn_shutdown_event(void *usr_handle, |
| u32 port_ref, |
| struct sk_buff **buf, |
| unsigned char const *data, |
| unsigned int size, |
| int reason) |
| { |
| struct subscriber *subscriber = usr_handle; |
| spinlock_t *subscriber_lock; |
| |
| if (tipc_port_lock(port_ref) == NULL) |
| return; |
| |
| subscriber_lock = subscriber->lock; |
| subscr_terminate(subscriber); |
| spin_unlock_bh(subscriber_lock); |
| } |
| |
| /** |
| * subscr_conn_msg_event - handle new subscription request from subscriber |
| * |
| * Called with subscriber's server port unlocked. |
| */ |
| |
| static void subscr_conn_msg_event(void *usr_handle, |
| u32 port_ref, |
| struct sk_buff **buf, |
| const unchar *data, |
| u32 size) |
| { |
| struct subscriber *subscriber = usr_handle; |
| spinlock_t *subscriber_lock; |
| struct subscription *sub; |
| |
| /* |
| * Lock subscriber's server port (& make a local copy of lock pointer, |
| * in case subscriber is deleted while processing subscription request) |
| */ |
| |
| if (tipc_port_lock(port_ref) == NULL) |
| return; |
| |
| subscriber_lock = subscriber->lock; |
| |
| if (size != sizeof(struct tipc_subscr)) { |
| subscr_terminate(subscriber); |
| spin_unlock_bh(subscriber_lock); |
| } else { |
| sub = subscr_subscribe((struct tipc_subscr *)data, subscriber); |
| spin_unlock_bh(subscriber_lock); |
| if (sub != NULL) { |
| |
| /* |
| * We must release the server port lock before adding a |
| * subscription to the name table since TIPC needs to be |
| * able to (re)acquire the port lock if an event message |
| * issued by the subscription process is rejected and |
| * returned. The subscription cannot be deleted while |
| * it is being added to the name table because: |
| * a) the single-threading of the native API port code |
| * ensures the subscription cannot be cancelled and |
| * the subscriber connection cannot be broken, and |
| * b) the name table lock ensures the subscription |
| * timeout code cannot delete the subscription, |
| * so the subscription object is still protected. |
| */ |
| |
| tipc_nametbl_subscribe(sub); |
| } |
| } |
| } |
| |
| /** |
| * 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) |
| { |
| static struct iovec msg_sect = {NULL, 0}; |
| |
| struct subscriber *subscriber; |
| u32 server_port_ref; |
| |
| /* Create subscriber object */ |
| |
| subscriber = kzalloc(sizeof(struct subscriber), GFP_ATOMIC); |
| if (subscriber == NULL) { |
| warn("Subscriber rejected, no memory\n"); |
| return; |
| } |
| INIT_LIST_HEAD(&subscriber->subscription_list); |
| INIT_LIST_HEAD(&subscriber->subscriber_list); |
| |
| /* Create server port & establish connection to subscriber */ |
| |
| tipc_createport(subscriber, |
| importance, |
| NULL, |
| NULL, |
| subscr_conn_shutdown_event, |
| NULL, |
| NULL, |
| subscr_conn_msg_event, |
| NULL, |
| &subscriber->port_ref); |
| if (subscriber->port_ref == 0) { |
| warn("Subscriber rejected, unable to create port\n"); |
| kfree(subscriber); |
| return; |
| } |
| tipc_connect2port(subscriber->port_ref, orig); |
| |
| /* Lock server port (& save lock address for future use) */ |
| |
| subscriber->lock = tipc_port_lock(subscriber->port_ref)->publ.lock; |
| |
| /* Add subscriber to topology server's subscriber list */ |
| |
| spin_lock_bh(&topsrv.lock); |
| list_add(&subscriber->subscriber_list, &topsrv.subscriber_list); |
| spin_unlock_bh(&topsrv.lock); |
| |
| /* Unlock server port */ |
| |
| server_port_ref = subscriber->port_ref; |
| spin_unlock_bh(subscriber->lock); |
| |
| /* Send an ACK- to complete connection handshaking */ |
| |
| tipc_send(server_port_ref, 1, &msg_sect); |
| |
| /* Handle optional subscription request */ |
| |
| if (size != 0) { |
| subscr_conn_msg_event(subscriber, server_port_ref, |
| buf, data, size); |
| } |
| } |
| |
| int tipc_subscr_start(void) |
| { |
| struct tipc_name_seq seq = {TIPC_TOP_SRV, TIPC_TOP_SRV, TIPC_TOP_SRV}; |
| int res; |
| |
| memset(&topsrv, 0, sizeof(topsrv)); |
| spin_lock_init(&topsrv.lock); |
| INIT_LIST_HEAD(&topsrv.subscriber_list); |
| |
| spin_lock_bh(&topsrv.lock); |
| res = tipc_createport(NULL, |
| TIPC_CRITICAL_IMPORTANCE, |
| NULL, |
| NULL, |
| NULL, |
| NULL, |
| subscr_named_msg_event, |
| NULL, |
| NULL, |
| &topsrv.setup_port); |
| if (res) |
| goto failed; |
| |
| res = tipc_nametbl_publish_rsv(topsrv.setup_port, TIPC_NODE_SCOPE, &seq); |
| if (res) { |
| tipc_deleteport(topsrv.setup_port); |
| topsrv.setup_port = 0; |
| goto failed; |
| } |
| |
| spin_unlock_bh(&topsrv.lock); |
| return 0; |
| |
| failed: |
| err("Failed to create subscription service\n"); |
| 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.setup_port) { |
| tipc_deleteport(topsrv.setup_port); |
| topsrv.setup_port = 0; |
| |
| list_for_each_entry_safe(subscriber, subscriber_temp, |
| &topsrv.subscriber_list, |
| subscriber_list) { |
| subscriber_lock = subscriber->lock; |
| spin_lock_bh(subscriber_lock); |
| subscr_terminate(subscriber); |
| spin_unlock_bh(subscriber_lock); |
| } |
| } |
| } |