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 * @kref: reference counter to tipc_subscription object
44 * @conid: connection identifier to server connecting to subscriber
45 * @lock: control access to subscriber
46 * @subscrp_list: list of subscription objects for this subscriber
48 struct tipc_subscriber {
52 struct list_head subscrp_list;
55 static void tipc_subscrp_delete(struct tipc_subscription *sub);
56 static void tipc_subscrb_put(struct tipc_subscriber *subscriber);
59 * htohl - convert value to endianness used by destination
60 * @in: value to convert
61 * @swap: non-zero if endianness must be reversed
63 * Returns converted value
65 static u32 htohl(u32 in, int swap)
67 return swap ? swab32(in) : in;
70 static void tipc_subscrp_send_event(struct tipc_subscription *sub,
71 u32 found_lower, u32 found_upper,
72 u32 event, u32 port_ref, u32 node)
74 struct tipc_net *tn = net_generic(sub->net, tipc_net_id);
75 struct tipc_subscriber *subscriber = sub->subscriber;
78 msg_sect.iov_base = (void *)&sub->evt;
79 msg_sect.iov_len = sizeof(struct tipc_event);
80 sub->evt.event = htohl(event, sub->swap);
81 sub->evt.found_lower = htohl(found_lower, sub->swap);
82 sub->evt.found_upper = htohl(found_upper, sub->swap);
83 sub->evt.port.ref = htohl(port_ref, sub->swap);
84 sub->evt.port.node = htohl(node, sub->swap);
85 tipc_conn_sendmsg(tn->topsrv, subscriber->conid, NULL,
86 msg_sect.iov_base, msg_sect.iov_len);
90 * tipc_subscrp_check_overlap - test for subscription overlap with the
93 * Returns 1 if there is overlap, otherwise 0.
95 int tipc_subscrp_check_overlap(struct tipc_name_seq *seq, u32 found_lower,
98 if (found_lower < seq->lower)
99 found_lower = seq->lower;
100 if (found_upper > seq->upper)
101 found_upper = seq->upper;
102 if (found_lower > found_upper)
107 u32 tipc_subscrp_convert_seq_type(u32 type, int swap)
109 return htohl(type, swap);
112 void tipc_subscrp_convert_seq(struct tipc_name_seq *in, int swap,
113 struct tipc_name_seq *out)
115 out->type = htohl(in->type, swap);
116 out->lower = htohl(in->lower, swap);
117 out->upper = htohl(in->upper, swap);
120 void tipc_subscrp_report_overlap(struct tipc_subscription *sub, u32 found_lower,
121 u32 found_upper, u32 event, u32 port_ref,
124 struct tipc_name_seq seq;
126 tipc_subscrp_convert_seq(&sub->evt.s.seq, sub->swap, &seq);
127 if (!tipc_subscrp_check_overlap(&seq, found_lower, found_upper))
130 !(htohl(sub->evt.s.filter, sub->swap) & TIPC_SUB_PORTS))
133 tipc_subscrp_send_event(sub, found_lower, found_upper, event, port_ref,
137 static void tipc_subscrp_timeout(unsigned long data)
139 struct tipc_subscription *sub = (struct tipc_subscription *)data;
140 struct tipc_subscriber *subscriber = sub->subscriber;
142 /* Notify subscriber of timeout */
143 tipc_subscrp_send_event(sub, sub->evt.s.seq.lower, sub->evt.s.seq.upper,
144 TIPC_SUBSCR_TIMEOUT, 0, 0);
146 spin_lock_bh(&subscriber->lock);
147 tipc_subscrp_delete(sub);
148 spin_unlock_bh(&subscriber->lock);
150 tipc_subscrb_put(subscriber);
153 static void tipc_subscrb_kref_release(struct kref *kref)
155 struct tipc_subscriber *subcriber = container_of(kref,
156 struct tipc_subscriber, kref);
161 static void tipc_subscrb_put(struct tipc_subscriber *subscriber)
163 kref_put(&subscriber->kref, tipc_subscrb_kref_release);
166 static void tipc_subscrb_get(struct tipc_subscriber *subscriber)
168 kref_get(&subscriber->kref);
171 static struct tipc_subscriber *tipc_subscrb_create(int conid)
173 struct tipc_subscriber *subscriber;
175 subscriber = kzalloc(sizeof(*subscriber), GFP_ATOMIC);
177 pr_warn("Subscriber rejected, no memory\n");
180 kref_init(&subscriber->kref);
181 INIT_LIST_HEAD(&subscriber->subscrp_list);
182 subscriber->conid = conid;
183 spin_lock_init(&subscriber->lock);
188 static void tipc_subscrb_delete(struct tipc_subscriber *subscriber)
190 struct tipc_subscription *sub, *temp;
192 spin_lock_bh(&subscriber->lock);
193 /* Destroy any existing subscriptions for subscriber */
194 list_for_each_entry_safe(sub, temp, &subscriber->subscrp_list,
196 if (del_timer(&sub->timer)) {
197 tipc_subscrp_delete(sub);
198 tipc_subscrb_put(subscriber);
201 spin_unlock_bh(&subscriber->lock);
203 tipc_subscrb_put(subscriber);
206 static void tipc_subscrp_delete(struct tipc_subscription *sub)
208 struct tipc_net *tn = net_generic(sub->net, tipc_net_id);
210 tipc_nametbl_unsubscribe(sub);
211 list_del(&sub->subscrp_list);
213 atomic_dec(&tn->subscription_count);
216 static void tipc_subscrp_cancel(struct tipc_subscr *s,
217 struct tipc_subscriber *subscriber)
219 struct tipc_subscription *sub, *temp;
221 spin_lock_bh(&subscriber->lock);
222 /* Find first matching subscription, exit if not found */
223 list_for_each_entry_safe(sub, temp, &subscriber->subscrp_list,
225 if (!memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr))) {
226 if (del_timer(&sub->timer)) {
227 tipc_subscrp_delete(sub);
228 tipc_subscrb_put(subscriber);
233 spin_unlock_bh(&subscriber->lock);
236 static int tipc_subscrp_create(struct net *net, struct tipc_subscr *s,
237 struct tipc_subscriber *subscriber,
238 struct tipc_subscription **sub_p)
240 struct tipc_net *tn = net_generic(net, tipc_net_id);
241 struct tipc_subscription *sub;
245 /* Determine subscriber's endianness */
246 swap = !(s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE));
248 /* Detect & process a subscription cancellation request */
249 if (s->filter & htohl(TIPC_SUB_CANCEL, swap)) {
250 s->filter &= ~htohl(TIPC_SUB_CANCEL, swap);
251 tipc_subscrp_cancel(s, subscriber);
255 /* Refuse subscription if global limit exceeded */
256 if (atomic_read(&tn->subscription_count) >= TIPC_MAX_SUBSCRIPTIONS) {
257 pr_warn("Subscription rejected, limit reached (%u)\n",
258 TIPC_MAX_SUBSCRIPTIONS);
262 /* Allocate subscription object */
263 sub = kmalloc(sizeof(*sub), GFP_ATOMIC);
265 pr_warn("Subscription rejected, no memory\n");
269 /* Initialize subscription object */
271 filter = htohl(s->filter, swap);
272 if (((filter & TIPC_SUB_PORTS) && (filter & TIPC_SUB_SERVICE)) ||
273 (htohl(s->seq.lower, swap) > htohl(s->seq.upper, swap))) {
274 pr_warn("Subscription rejected, illegal request\n");
278 spin_lock_bh(&subscriber->lock);
279 list_add(&sub->subscrp_list, &subscriber->subscrp_list);
280 spin_unlock_bh(&subscriber->lock);
282 sub->subscriber = subscriber;
284 memcpy(&sub->evt.s, s, sizeof(*s));
285 atomic_inc(&tn->subscription_count);
286 setup_timer(&sub->timer, tipc_subscrp_timeout, (unsigned long)sub);
287 timeout = htohl(sub->evt.s.timeout, swap);
288 if (!mod_timer(&sub->timer, jiffies + msecs_to_jiffies(timeout)))
289 tipc_subscrb_get(subscriber);
294 /* Handle one termination request for the subscriber */
295 static void tipc_subscrb_shutdown_cb(int conid, void *usr_data)
297 tipc_subscrb_delete((struct tipc_subscriber *)usr_data);
300 /* Handle one request to create a new subscription for the subscriber */
301 static void tipc_subscrb_rcv_cb(struct net *net, int conid,
302 struct sockaddr_tipc *addr, void *usr_data,
303 void *buf, size_t len)
305 struct tipc_subscriber *subscrb = usr_data;
306 struct tipc_subscription *sub = NULL;
307 struct tipc_net *tn = net_generic(net, tipc_net_id);
309 if (tipc_subscrp_create(net, (struct tipc_subscr *)buf, subscrb, &sub))
310 return tipc_conn_terminate(tn->topsrv, subscrb->conid);
312 tipc_nametbl_subscribe(sub);
315 /* Handle one request to establish a new subscriber */
316 static void *tipc_subscrb_connect_cb(int conid)
318 return (void *)tipc_subscrb_create(conid);
321 int tipc_topsrv_start(struct net *net)
323 struct tipc_net *tn = net_generic(net, tipc_net_id);
324 const char name[] = "topology_server";
325 struct tipc_server *topsrv;
326 struct sockaddr_tipc *saddr;
328 saddr = kzalloc(sizeof(*saddr), GFP_ATOMIC);
331 saddr->family = AF_TIPC;
332 saddr->addrtype = TIPC_ADDR_NAMESEQ;
333 saddr->addr.nameseq.type = TIPC_TOP_SRV;
334 saddr->addr.nameseq.lower = TIPC_TOP_SRV;
335 saddr->addr.nameseq.upper = TIPC_TOP_SRV;
336 saddr->scope = TIPC_NODE_SCOPE;
338 topsrv = kzalloc(sizeof(*topsrv), GFP_ATOMIC);
344 topsrv->saddr = saddr;
345 topsrv->imp = TIPC_CRITICAL_IMPORTANCE;
346 topsrv->type = SOCK_SEQPACKET;
347 topsrv->max_rcvbuf_size = sizeof(struct tipc_subscr);
348 topsrv->tipc_conn_recvmsg = tipc_subscrb_rcv_cb;
349 topsrv->tipc_conn_new = tipc_subscrb_connect_cb;
350 topsrv->tipc_conn_shutdown = tipc_subscrb_shutdown_cb;
352 strncpy(topsrv->name, name, strlen(name) + 1);
354 atomic_set(&tn->subscription_count, 0);
356 return tipc_server_start(topsrv);
359 void tipc_topsrv_stop(struct net *net)
361 struct tipc_net *tn = net_generic(net, tipc_net_id);
362 struct tipc_server *topsrv = tn->topsrv;
364 tipc_server_stop(topsrv);
365 kfree(topsrv->saddr);