2 * net/tipc/subscr.c: TIPC network topology service
4 * Copyright (c) 2000-2006, Ericsson AB
5 * Copyright (c) 2005-2007, 2010-2013, Wind River Systems
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9 * modification, are permitted provided that the following conditions are met:
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18 * this software without specific prior written permission.
20 * Alternatively, this software may be distributed under the terms of the
21 * GNU General Public License ("GPL") version 2 as published by the Free
22 * Software Foundation.
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38 #include "name_table.h"
42 * struct tipc_subscriber - TIPC network topology subscriber
43 * @conid: connection identifier to server connecting to subscriber
44 * @lock: control access to subscriber
45 * @subscrp_list: list of subscription objects for this subscriber
47 struct tipc_subscriber {
50 struct list_head subscrp_list;
54 * htohl - convert value to endianness used by destination
55 * @in: value to convert
56 * @swap: non-zero if endianness must be reversed
58 * Returns converted value
60 static u32 htohl(u32 in, int swap)
62 return swap ? swab32(in) : in;
65 static void tipc_subscrp_send_event(struct tipc_subscription *sub,
66 u32 found_lower, u32 found_upper,
67 u32 event, u32 port_ref, u32 node)
69 struct tipc_net *tn = net_generic(sub->net, tipc_net_id);
70 struct tipc_subscriber *subscriber = sub->subscriber;
73 msg_sect.iov_base = (void *)&sub->evt;
74 msg_sect.iov_len = sizeof(struct tipc_event);
75 sub->evt.event = htohl(event, sub->swap);
76 sub->evt.found_lower = htohl(found_lower, sub->swap);
77 sub->evt.found_upper = htohl(found_upper, sub->swap);
78 sub->evt.port.ref = htohl(port_ref, sub->swap);
79 sub->evt.port.node = htohl(node, sub->swap);
80 tipc_conn_sendmsg(tn->topsrv, subscriber->conid, NULL,
81 msg_sect.iov_base, msg_sect.iov_len);
85 * tipc_subscrp_check_overlap - test for subscription overlap with the
88 * Returns 1 if there is overlap, otherwise 0.
90 int tipc_subscrp_check_overlap(struct tipc_subscription *sub, u32 found_lower,
93 if (found_lower < sub->seq.lower)
94 found_lower = sub->seq.lower;
95 if (found_upper > sub->seq.upper)
96 found_upper = sub->seq.upper;
97 if (found_lower > found_upper)
102 void tipc_subscrp_report_overlap(struct tipc_subscription *sub, u32 found_lower,
103 u32 found_upper, u32 event, u32 port_ref,
106 if (!tipc_subscrp_check_overlap(sub, found_lower, found_upper))
108 if (!must && !(sub->filter & TIPC_SUB_PORTS))
111 tipc_subscrp_send_event(sub, found_lower, found_upper, event, port_ref,
115 static void tipc_subscrp_timeout(unsigned long data)
117 struct tipc_subscription *sub = (struct tipc_subscription *)data;
118 struct tipc_subscriber *subscriber = sub->subscriber;
119 struct tipc_net *tn = net_generic(sub->net, tipc_net_id);
121 /* The spin lock per subscriber is used to protect its members */
122 spin_lock_bh(&subscriber->lock);
124 /* Validate timeout (in case subscription is being cancelled) */
125 if (sub->timeout == TIPC_WAIT_FOREVER) {
126 spin_unlock_bh(&subscriber->lock);
130 /* Unlink subscription from name table */
131 tipc_nametbl_unsubscribe(sub);
133 /* Unlink subscription from subscriber */
134 list_del(&sub->subscrp_list);
136 spin_unlock_bh(&subscriber->lock);
138 /* Notify subscriber of timeout */
139 tipc_subscrp_send_event(sub, sub->evt.s.seq.lower, sub->evt.s.seq.upper,
140 TIPC_SUBSCR_TIMEOUT, 0, 0);
142 /* Now destroy subscription */
144 atomic_dec(&tn->subscription_count);
147 static void tipc_subscrp_delete(struct tipc_subscription *sub)
149 struct tipc_net *tn = net_generic(sub->net, tipc_net_id);
151 tipc_nametbl_unsubscribe(sub);
152 list_del(&sub->subscrp_list);
154 atomic_dec(&tn->subscription_count);
157 static struct tipc_subscriber *tipc_subscrb_create(int conid)
159 struct tipc_subscriber *subscriber;
161 subscriber = kzalloc(sizeof(*subscriber), GFP_ATOMIC);
163 pr_warn("Subscriber rejected, no memory\n");
166 INIT_LIST_HEAD(&subscriber->subscrp_list);
167 subscriber->conid = conid;
168 spin_lock_init(&subscriber->lock);
173 static void tipc_subscrb_delete(struct tipc_subscriber *subscriber)
175 struct tipc_subscription *sub;
176 struct tipc_subscription *sub_temp;
178 spin_lock_bh(&subscriber->lock);
180 /* Destroy any existing subscriptions for subscriber */
181 list_for_each_entry_safe(sub, sub_temp, &subscriber->subscrp_list,
183 if (sub->timeout != TIPC_WAIT_FOREVER) {
184 spin_unlock_bh(&subscriber->lock);
185 del_timer_sync(&sub->timer);
186 spin_lock_bh(&subscriber->lock);
188 tipc_subscrp_delete(sub);
190 spin_unlock_bh(&subscriber->lock);
192 /* Now destroy subscriber */
197 * tipc_subscrp_cancel - handle subscription cancellation request
199 * Called with subscriber lock held. Routine must temporarily release lock
200 * to enable the subscription timeout routine to finish without deadlocking;
201 * the lock is then reclaimed to allow caller to release it upon return.
203 * Note that fields of 's' use subscriber's endianness!
205 static void tipc_subscrp_cancel(struct tipc_subscr *s,
206 struct tipc_subscriber *subscriber)
208 struct tipc_subscription *sub;
209 struct tipc_subscription *sub_temp;
212 /* Find first matching subscription, exit if not found */
213 list_for_each_entry_safe(sub, sub_temp, &subscriber->subscrp_list,
215 if (!memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr))) {
223 /* Cancel subscription timer (if used), then delete subscription */
224 if (sub->timeout != TIPC_WAIT_FOREVER) {
225 sub->timeout = TIPC_WAIT_FOREVER;
226 spin_unlock_bh(&subscriber->lock);
227 del_timer_sync(&sub->timer);
228 spin_lock_bh(&subscriber->lock);
230 tipc_subscrp_delete(sub);
233 static int tipc_subscrp_create(struct net *net, struct tipc_subscr *s,
234 struct tipc_subscriber *subscriber,
235 struct tipc_subscription **sub_p)
237 struct tipc_net *tn = net_generic(net, tipc_net_id);
238 struct tipc_subscription *sub;
241 /* Determine subscriber's endianness */
242 swap = !(s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE));
244 /* Detect & process a subscription cancellation request */
245 if (s->filter & htohl(TIPC_SUB_CANCEL, swap)) {
246 s->filter &= ~htohl(TIPC_SUB_CANCEL, swap);
247 tipc_subscrp_cancel(s, subscriber);
251 /* Refuse subscription if global limit exceeded */
252 if (atomic_read(&tn->subscription_count) >= TIPC_MAX_SUBSCRIPTIONS) {
253 pr_warn("Subscription rejected, limit reached (%u)\n",
254 TIPC_MAX_SUBSCRIPTIONS);
258 /* Allocate subscription object */
259 sub = kmalloc(sizeof(*sub), GFP_ATOMIC);
261 pr_warn("Subscription rejected, no memory\n");
265 /* Initialize subscription object */
267 sub->seq.type = htohl(s->seq.type, swap);
268 sub->seq.lower = htohl(s->seq.lower, swap);
269 sub->seq.upper = htohl(s->seq.upper, swap);
270 sub->timeout = msecs_to_jiffies(htohl(s->timeout, swap));
271 sub->filter = htohl(s->filter, swap);
272 if ((!(sub->filter & TIPC_SUB_PORTS) ==
273 !(sub->filter & TIPC_SUB_SERVICE)) ||
274 (sub->seq.lower > sub->seq.upper)) {
275 pr_warn("Subscription rejected, illegal request\n");
279 list_add(&sub->subscrp_list, &subscriber->subscrp_list);
280 sub->subscriber = subscriber;
282 memcpy(&sub->evt.s, s, sizeof(*s));
283 atomic_inc(&tn->subscription_count);
284 if (sub->timeout != TIPC_WAIT_FOREVER) {
285 setup_timer(&sub->timer, tipc_subscrp_timeout,
287 mod_timer(&sub->timer, jiffies + sub->timeout);
293 /* Handle one termination request for the subscriber */
294 static void tipc_subscrb_shutdown_cb(int conid, void *usr_data)
296 tipc_subscrb_delete((struct tipc_subscriber *)usr_data);
299 /* Handle one request to create a new subscription for the subscriber */
300 static void tipc_subscrb_rcv_cb(struct net *net, int conid,
301 struct sockaddr_tipc *addr, void *usr_data,
302 void *buf, size_t len)
304 struct tipc_subscriber *subscriber = usr_data;
305 struct tipc_subscription *sub = NULL;
306 struct tipc_net *tn = net_generic(net, tipc_net_id);
308 spin_lock_bh(&subscriber->lock);
309 tipc_subscrp_create(net, (struct tipc_subscr *)buf, subscriber, &sub);
311 tipc_nametbl_subscribe(sub);
313 tipc_conn_terminate(tn->topsrv, subscriber->conid);
314 spin_unlock_bh(&subscriber->lock);
317 /* Handle one request to establish a new subscriber */
318 static void *tipc_subscrb_connect_cb(int conid)
320 return (void *)tipc_subscrb_create(conid);
323 int tipc_topsrv_start(struct net *net)
325 struct tipc_net *tn = net_generic(net, tipc_net_id);
326 const char name[] = "topology_server";
327 struct tipc_server *topsrv;
328 struct sockaddr_tipc *saddr;
330 saddr = kzalloc(sizeof(*saddr), GFP_ATOMIC);
333 saddr->family = AF_TIPC;
334 saddr->addrtype = TIPC_ADDR_NAMESEQ;
335 saddr->addr.nameseq.type = TIPC_TOP_SRV;
336 saddr->addr.nameseq.lower = TIPC_TOP_SRV;
337 saddr->addr.nameseq.upper = TIPC_TOP_SRV;
338 saddr->scope = TIPC_NODE_SCOPE;
340 topsrv = kzalloc(sizeof(*topsrv), GFP_ATOMIC);
346 topsrv->saddr = saddr;
347 topsrv->imp = TIPC_CRITICAL_IMPORTANCE;
348 topsrv->type = SOCK_SEQPACKET;
349 topsrv->max_rcvbuf_size = sizeof(struct tipc_subscr);
350 topsrv->tipc_conn_recvmsg = tipc_subscrb_rcv_cb;
351 topsrv->tipc_conn_new = tipc_subscrb_connect_cb;
352 topsrv->tipc_conn_shutdown = tipc_subscrb_shutdown_cb;
354 strncpy(topsrv->name, name, strlen(name) + 1);
356 atomic_set(&tn->subscription_count, 0);
358 return tipc_server_start(topsrv);
361 void tipc_topsrv_stop(struct net *net)
363 struct tipc_net *tn = net_generic(net, tipc_net_id);
364 struct tipc_server *topsrv = tn->topsrv;
366 tipc_server_stop(topsrv);
367 kfree(topsrv->saddr);