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.
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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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_subscription *sub, u32 found_lower,
98 if (found_lower < sub->seq.lower)
99 found_lower = sub->seq.lower;
100 if (found_upper > sub->seq.upper)
101 found_upper = sub->seq.upper;
102 if (found_lower > found_upper)
107 void tipc_subscrp_report_overlap(struct tipc_subscription *sub, u32 found_lower,
108 u32 found_upper, u32 event, u32 port_ref,
111 if (!tipc_subscrp_check_overlap(sub, found_lower, found_upper))
113 if (!must && !(sub->filter & TIPC_SUB_PORTS))
116 tipc_subscrp_send_event(sub, found_lower, found_upper, event, port_ref,
120 static void tipc_subscrp_timeout(unsigned long data)
122 struct tipc_subscription *sub = (struct tipc_subscription *)data;
123 struct tipc_subscriber *subscriber = sub->subscriber;
125 /* Notify subscriber of timeout */
126 tipc_subscrp_send_event(sub, sub->evt.s.seq.lower, sub->evt.s.seq.upper,
127 TIPC_SUBSCR_TIMEOUT, 0, 0);
129 spin_lock_bh(&subscriber->lock);
130 tipc_subscrp_delete(sub);
131 spin_unlock_bh(&subscriber->lock);
133 tipc_subscrb_put(subscriber);
136 static void tipc_subscrb_kref_release(struct kref *kref)
138 struct tipc_subscriber *subcriber = container_of(kref,
139 struct tipc_subscriber, kref);
144 static void tipc_subscrb_put(struct tipc_subscriber *subscriber)
146 kref_put(&subscriber->kref, tipc_subscrb_kref_release);
149 static void tipc_subscrb_get(struct tipc_subscriber *subscriber)
151 kref_get(&subscriber->kref);
154 static struct tipc_subscriber *tipc_subscrb_create(int conid)
156 struct tipc_subscriber *subscriber;
158 subscriber = kzalloc(sizeof(*subscriber), GFP_ATOMIC);
160 pr_warn("Subscriber rejected, no memory\n");
163 kref_init(&subscriber->kref);
164 INIT_LIST_HEAD(&subscriber->subscrp_list);
165 subscriber->conid = conid;
166 spin_lock_init(&subscriber->lock);
171 static void tipc_subscrb_delete(struct tipc_subscriber *subscriber)
173 struct tipc_subscription *sub, *temp;
175 spin_lock_bh(&subscriber->lock);
176 /* Destroy any existing subscriptions for subscriber */
177 list_for_each_entry_safe(sub, temp, &subscriber->subscrp_list,
179 if (del_timer(&sub->timer)) {
180 tipc_subscrp_delete(sub);
181 tipc_subscrb_put(subscriber);
184 spin_unlock_bh(&subscriber->lock);
186 tipc_subscrb_put(subscriber);
189 static void tipc_subscrp_delete(struct tipc_subscription *sub)
191 struct tipc_net *tn = net_generic(sub->net, tipc_net_id);
193 tipc_nametbl_unsubscribe(sub);
194 list_del(&sub->subscrp_list);
196 atomic_dec(&tn->subscription_count);
199 static void tipc_subscrp_cancel(struct tipc_subscr *s,
200 struct tipc_subscriber *subscriber)
202 struct tipc_subscription *sub, *temp;
204 /* Find first matching subscription, exit if not found */
205 list_for_each_entry_safe(sub, temp, &subscriber->subscrp_list,
207 if (!memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr))) {
208 if (del_timer(&sub->timer)) {
209 tipc_subscrp_delete(sub);
210 tipc_subscrb_put(subscriber);
217 static int tipc_subscrp_create(struct net *net, struct tipc_subscr *s,
218 struct tipc_subscriber *subscriber,
219 struct tipc_subscription **sub_p)
221 struct tipc_net *tn = net_generic(net, tipc_net_id);
222 struct tipc_subscription *sub;
225 /* Determine subscriber's endianness */
226 swap = !(s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE));
228 /* Detect & process a subscription cancellation request */
229 if (s->filter & htohl(TIPC_SUB_CANCEL, swap)) {
230 s->filter &= ~htohl(TIPC_SUB_CANCEL, swap);
231 tipc_subscrp_cancel(s, subscriber);
235 /* Refuse subscription if global limit exceeded */
236 if (atomic_read(&tn->subscription_count) >= TIPC_MAX_SUBSCRIPTIONS) {
237 pr_warn("Subscription rejected, limit reached (%u)\n",
238 TIPC_MAX_SUBSCRIPTIONS);
242 /* Allocate subscription object */
243 sub = kmalloc(sizeof(*sub), GFP_ATOMIC);
245 pr_warn("Subscription rejected, no memory\n");
249 /* Initialize subscription object */
251 sub->seq.type = htohl(s->seq.type, swap);
252 sub->seq.lower = htohl(s->seq.lower, swap);
253 sub->seq.upper = htohl(s->seq.upper, swap);
254 sub->timeout = msecs_to_jiffies(htohl(s->timeout, swap));
255 sub->filter = htohl(s->filter, swap);
256 if ((!(sub->filter & TIPC_SUB_PORTS) ==
257 !(sub->filter & TIPC_SUB_SERVICE)) ||
258 (sub->seq.lower > sub->seq.upper)) {
259 pr_warn("Subscription rejected, illegal request\n");
263 list_add(&sub->subscrp_list, &subscriber->subscrp_list);
264 sub->subscriber = subscriber;
266 memcpy(&sub->evt.s, s, sizeof(*s));
267 atomic_inc(&tn->subscription_count);
268 setup_timer(&sub->timer, tipc_subscrp_timeout, (unsigned long)sub);
269 if (sub->timeout != TIPC_WAIT_FOREVER)
270 sub->timeout += jiffies;
271 if (!mod_timer(&sub->timer, sub->timeout))
272 tipc_subscrb_get(subscriber);
277 /* Handle one termination request for the subscriber */
278 static void tipc_subscrb_shutdown_cb(int conid, void *usr_data)
280 tipc_subscrb_delete((struct tipc_subscriber *)usr_data);
283 /* Handle one request to create a new subscription for the subscriber */
284 static void tipc_subscrb_rcv_cb(struct net *net, int conid,
285 struct sockaddr_tipc *addr, void *usr_data,
286 void *buf, size_t len)
288 struct tipc_subscriber *subscriber = usr_data;
289 struct tipc_subscription *sub = NULL;
290 struct tipc_net *tn = net_generic(net, tipc_net_id);
292 spin_lock_bh(&subscriber->lock);
293 tipc_subscrp_create(net, (struct tipc_subscr *)buf, subscriber, &sub);
295 tipc_nametbl_subscribe(sub);
297 tipc_conn_terminate(tn->topsrv, subscriber->conid);
298 spin_unlock_bh(&subscriber->lock);
301 /* Handle one request to establish a new subscriber */
302 static void *tipc_subscrb_connect_cb(int conid)
304 return (void *)tipc_subscrb_create(conid);
307 int tipc_topsrv_start(struct net *net)
309 struct tipc_net *tn = net_generic(net, tipc_net_id);
310 const char name[] = "topology_server";
311 struct tipc_server *topsrv;
312 struct sockaddr_tipc *saddr;
314 saddr = kzalloc(sizeof(*saddr), GFP_ATOMIC);
317 saddr->family = AF_TIPC;
318 saddr->addrtype = TIPC_ADDR_NAMESEQ;
319 saddr->addr.nameseq.type = TIPC_TOP_SRV;
320 saddr->addr.nameseq.lower = TIPC_TOP_SRV;
321 saddr->addr.nameseq.upper = TIPC_TOP_SRV;
322 saddr->scope = TIPC_NODE_SCOPE;
324 topsrv = kzalloc(sizeof(*topsrv), GFP_ATOMIC);
330 topsrv->saddr = saddr;
331 topsrv->imp = TIPC_CRITICAL_IMPORTANCE;
332 topsrv->type = SOCK_SEQPACKET;
333 topsrv->max_rcvbuf_size = sizeof(struct tipc_subscr);
334 topsrv->tipc_conn_recvmsg = tipc_subscrb_rcv_cb;
335 topsrv->tipc_conn_new = tipc_subscrb_connect_cb;
336 topsrv->tipc_conn_shutdown = tipc_subscrb_shutdown_cb;
338 strncpy(topsrv->name, name, strlen(name) + 1);
340 atomic_set(&tn->subscription_count, 0);
342 return tipc_server_start(topsrv);
345 void tipc_topsrv_stop(struct net *net)
347 struct tipc_net *tn = net_generic(net, tipc_net_id);
348 struct tipc_server *topsrv = tn->topsrv;
350 tipc_server_stop(topsrv);
351 kfree(topsrv->saddr);