1 /* 2 * net/tipc/subscr.c: TIPC network topology service 3 * 4 * Copyright (c) 2000-2006, Ericsson AB 5 * Copyright (c) 2005-2007, 2010-2013, Wind River Systems 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the names of the copyright holders nor the names of its 17 * contributors may be used to endorse or promote products derived from 18 * this software without specific prior written permission. 19 * 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. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 34 * POSSIBILITY OF SUCH DAMAGE. 35 */ 36 37 #include "core.h" 38 #include "name_table.h" 39 #include "subscr.h" 40 41 /** 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 47 */ 48 struct tipc_subscriber { 49 struct kref kref; 50 int conid; 51 spinlock_t lock; 52 struct list_head subscrp_list; 53 }; 54 55 static void tipc_subscrp_delete(struct tipc_subscription *sub); 56 static void tipc_subscrb_put(struct tipc_subscriber *subscriber); 57 static void tipc_subscrp_put(struct tipc_subscription *subscription); 58 static void tipc_subscrp_get(struct tipc_subscription *subscription); 59 60 /** 61 * htohl - convert value to endianness used by destination 62 * @in: value to convert 63 * @swap: non-zero if endianness must be reversed 64 * 65 * Returns converted value 66 */ 67 static u32 htohl(u32 in, int swap) 68 { 69 return swap ? swab32(in) : in; 70 } 71 72 static void tipc_subscrp_send_event(struct tipc_subscription *sub, 73 u32 found_lower, u32 found_upper, 74 u32 event, u32 port_ref, u32 node) 75 { 76 struct tipc_net *tn = net_generic(sub->net, tipc_net_id); 77 struct tipc_subscriber *subscriber = sub->subscriber; 78 struct kvec msg_sect; 79 80 msg_sect.iov_base = (void *)&sub->evt; 81 msg_sect.iov_len = sizeof(struct tipc_event); 82 sub->evt.event = htohl(event, sub->swap); 83 sub->evt.found_lower = htohl(found_lower, sub->swap); 84 sub->evt.found_upper = htohl(found_upper, sub->swap); 85 sub->evt.port.ref = htohl(port_ref, sub->swap); 86 sub->evt.port.node = htohl(node, sub->swap); 87 tipc_conn_sendmsg(tn->topsrv, subscriber->conid, NULL, 88 msg_sect.iov_base, msg_sect.iov_len); 89 } 90 91 /** 92 * tipc_subscrp_check_overlap - test for subscription overlap with the 93 * given values 94 * 95 * Returns 1 if there is overlap, otherwise 0. 96 */ 97 int tipc_subscrp_check_overlap(struct tipc_name_seq *seq, u32 found_lower, 98 u32 found_upper) 99 { 100 if (found_lower < seq->lower) 101 found_lower = seq->lower; 102 if (found_upper > seq->upper) 103 found_upper = seq->upper; 104 if (found_lower > found_upper) 105 return 0; 106 return 1; 107 } 108 109 u32 tipc_subscrp_convert_seq_type(u32 type, int swap) 110 { 111 return htohl(type, swap); 112 } 113 114 void tipc_subscrp_convert_seq(struct tipc_name_seq *in, int swap, 115 struct tipc_name_seq *out) 116 { 117 out->type = htohl(in->type, swap); 118 out->lower = htohl(in->lower, swap); 119 out->upper = htohl(in->upper, swap); 120 } 121 122 void tipc_subscrp_report_overlap(struct tipc_subscription *sub, u32 found_lower, 123 u32 found_upper, u32 event, u32 port_ref, 124 u32 node, int must) 125 { 126 struct tipc_name_seq seq; 127 128 tipc_subscrp_get(sub); 129 tipc_subscrp_convert_seq(&sub->evt.s.seq, sub->swap, &seq); 130 if (!tipc_subscrp_check_overlap(&seq, found_lower, found_upper)) 131 return; 132 if (!must && 133 !(htohl(sub->evt.s.filter, sub->swap) & TIPC_SUB_PORTS)) 134 return; 135 136 tipc_subscrp_send_event(sub, found_lower, found_upper, event, port_ref, 137 node); 138 tipc_subscrp_put(sub); 139 } 140 141 static void tipc_subscrp_timeout(unsigned long data) 142 { 143 struct tipc_subscription *sub = (struct tipc_subscription *)data; 144 struct tipc_subscriber *subscriber = sub->subscriber; 145 146 spin_lock_bh(&subscriber->lock); 147 tipc_nametbl_unsubscribe(sub); 148 spin_unlock_bh(&subscriber->lock); 149 150 /* Notify subscriber of timeout */ 151 tipc_subscrp_send_event(sub, sub->evt.s.seq.lower, sub->evt.s.seq.upper, 152 TIPC_SUBSCR_TIMEOUT, 0, 0); 153 154 tipc_subscrp_put(sub); 155 } 156 157 static void tipc_subscrb_kref_release(struct kref *kref) 158 { 159 kfree(container_of(kref,struct tipc_subscriber, kref)); 160 } 161 162 static void tipc_subscrb_put(struct tipc_subscriber *subscriber) 163 { 164 kref_put(&subscriber->kref, tipc_subscrb_kref_release); 165 } 166 167 static void tipc_subscrb_get(struct tipc_subscriber *subscriber) 168 { 169 kref_get(&subscriber->kref); 170 } 171 172 static void tipc_subscrp_kref_release(struct kref *kref) 173 { 174 struct tipc_subscription *sub = container_of(kref, 175 struct tipc_subscription, 176 kref); 177 struct tipc_net *tn = net_generic(sub->net, tipc_net_id); 178 struct tipc_subscriber *subscriber = sub->subscriber; 179 180 spin_lock_bh(&subscriber->lock); 181 list_del(&sub->subscrp_list); 182 atomic_dec(&tn->subscription_count); 183 spin_unlock_bh(&subscriber->lock); 184 kfree(sub); 185 tipc_subscrb_put(subscriber); 186 } 187 188 static void tipc_subscrp_put(struct tipc_subscription *subscription) 189 { 190 kref_put(&subscription->kref, tipc_subscrp_kref_release); 191 } 192 193 static void tipc_subscrp_get(struct tipc_subscription *subscription) 194 { 195 kref_get(&subscription->kref); 196 } 197 198 /* tipc_subscrb_subscrp_delete - delete a specific subscription or all 199 * subscriptions for a given subscriber. 200 */ 201 static void tipc_subscrb_subscrp_delete(struct tipc_subscriber *subscriber, 202 struct tipc_subscr *s) 203 { 204 struct list_head *subscription_list = &subscriber->subscrp_list; 205 struct tipc_subscription *sub, *temp; 206 207 spin_lock_bh(&subscriber->lock); 208 list_for_each_entry_safe(sub, temp, subscription_list, subscrp_list) { 209 if (s && memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr))) 210 continue; 211 212 tipc_nametbl_unsubscribe(sub); 213 tipc_subscrp_get(sub); 214 spin_unlock_bh(&subscriber->lock); 215 tipc_subscrp_delete(sub); 216 tipc_subscrp_put(sub); 217 spin_lock_bh(&subscriber->lock); 218 219 if (s) 220 break; 221 } 222 spin_unlock_bh(&subscriber->lock); 223 } 224 225 static struct tipc_subscriber *tipc_subscrb_create(int conid) 226 { 227 struct tipc_subscriber *subscriber; 228 229 subscriber = kzalloc(sizeof(*subscriber), GFP_ATOMIC); 230 if (!subscriber) { 231 pr_warn("Subscriber rejected, no memory\n"); 232 return NULL; 233 } 234 INIT_LIST_HEAD(&subscriber->subscrp_list); 235 kref_init(&subscriber->kref); 236 subscriber->conid = conid; 237 spin_lock_init(&subscriber->lock); 238 239 return subscriber; 240 } 241 242 static void tipc_subscrb_delete(struct tipc_subscriber *subscriber) 243 { 244 tipc_subscrb_subscrp_delete(subscriber, NULL); 245 tipc_subscrb_put(subscriber); 246 } 247 248 static void tipc_subscrp_delete(struct tipc_subscription *sub) 249 { 250 u32 timeout = htohl(sub->evt.s.timeout, sub->swap); 251 252 if (timeout == TIPC_WAIT_FOREVER || del_timer(&sub->timer)) 253 tipc_subscrp_put(sub); 254 } 255 256 static void tipc_subscrp_cancel(struct tipc_subscr *s, 257 struct tipc_subscriber *subscriber) 258 { 259 tipc_subscrb_subscrp_delete(subscriber, s); 260 } 261 262 static struct tipc_subscription *tipc_subscrp_create(struct net *net, 263 struct tipc_subscr *s, 264 int swap) 265 { 266 struct tipc_net *tn = net_generic(net, tipc_net_id); 267 struct tipc_subscription *sub; 268 u32 filter = htohl(s->filter, swap); 269 270 /* Refuse subscription if global limit exceeded */ 271 if (atomic_read(&tn->subscription_count) >= TIPC_MAX_SUBSCRIPTIONS) { 272 pr_warn("Subscription rejected, limit reached (%u)\n", 273 TIPC_MAX_SUBSCRIPTIONS); 274 return NULL; 275 } 276 277 /* Allocate subscription object */ 278 sub = kmalloc(sizeof(*sub), GFP_ATOMIC); 279 if (!sub) { 280 pr_warn("Subscription rejected, no memory\n"); 281 return NULL; 282 } 283 284 /* Initialize subscription object */ 285 sub->net = net; 286 if (((filter & TIPC_SUB_PORTS) && (filter & TIPC_SUB_SERVICE)) || 287 (htohl(s->seq.lower, swap) > htohl(s->seq.upper, swap))) { 288 pr_warn("Subscription rejected, illegal request\n"); 289 kfree(sub); 290 return NULL; 291 } 292 293 sub->swap = swap; 294 memcpy(&sub->evt.s, s, sizeof(*s)); 295 atomic_inc(&tn->subscription_count); 296 kref_init(&sub->kref); 297 return sub; 298 } 299 300 static void tipc_subscrp_subscribe(struct net *net, struct tipc_subscr *s, 301 struct tipc_subscriber *subscriber, int swap) 302 { 303 struct tipc_net *tn = net_generic(net, tipc_net_id); 304 struct tipc_subscription *sub = NULL; 305 u32 timeout; 306 307 sub = tipc_subscrp_create(net, s, swap); 308 if (!sub) 309 return tipc_conn_terminate(tn->topsrv, subscriber->conid); 310 311 spin_lock_bh(&subscriber->lock); 312 list_add(&sub->subscrp_list, &subscriber->subscrp_list); 313 sub->subscriber = subscriber; 314 tipc_nametbl_subscribe(sub); 315 tipc_subscrb_get(subscriber); 316 spin_unlock_bh(&subscriber->lock); 317 318 setup_timer(&sub->timer, tipc_subscrp_timeout, (unsigned long)sub); 319 timeout = htohl(sub->evt.s.timeout, swap); 320 321 if (timeout != TIPC_WAIT_FOREVER) 322 mod_timer(&sub->timer, jiffies + msecs_to_jiffies(timeout)); 323 } 324 325 /* Handle one termination request for the subscriber */ 326 static void tipc_subscrb_release_cb(int conid, void *usr_data) 327 { 328 tipc_subscrb_delete((struct tipc_subscriber *)usr_data); 329 } 330 331 /* Handle one request to create a new subscription for the subscriber */ 332 static void tipc_subscrb_rcv_cb(struct net *net, int conid, 333 struct sockaddr_tipc *addr, void *usr_data, 334 void *buf, size_t len) 335 { 336 struct tipc_subscriber *subscriber = usr_data; 337 struct tipc_subscr *s = (struct tipc_subscr *)buf; 338 int swap; 339 340 /* Determine subscriber's endianness */ 341 swap = !(s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE | 342 TIPC_SUB_CANCEL)); 343 344 /* Detect & process a subscription cancellation request */ 345 if (s->filter & htohl(TIPC_SUB_CANCEL, swap)) { 346 s->filter &= ~htohl(TIPC_SUB_CANCEL, swap); 347 return tipc_subscrp_cancel(s, subscriber); 348 } 349 350 tipc_subscrp_subscribe(net, s, subscriber, swap); 351 } 352 353 /* Handle one request to establish a new subscriber */ 354 static void *tipc_subscrb_connect_cb(int conid) 355 { 356 return (void *)tipc_subscrb_create(conid); 357 } 358 359 int tipc_topsrv_start(struct net *net) 360 { 361 struct tipc_net *tn = net_generic(net, tipc_net_id); 362 const char name[] = "topology_server"; 363 struct tipc_server *topsrv; 364 struct sockaddr_tipc *saddr; 365 366 saddr = kzalloc(sizeof(*saddr), GFP_ATOMIC); 367 if (!saddr) 368 return -ENOMEM; 369 saddr->family = AF_TIPC; 370 saddr->addrtype = TIPC_ADDR_NAMESEQ; 371 saddr->addr.nameseq.type = TIPC_TOP_SRV; 372 saddr->addr.nameseq.lower = TIPC_TOP_SRV; 373 saddr->addr.nameseq.upper = TIPC_TOP_SRV; 374 saddr->scope = TIPC_NODE_SCOPE; 375 376 topsrv = kzalloc(sizeof(*topsrv), GFP_ATOMIC); 377 if (!topsrv) { 378 kfree(saddr); 379 return -ENOMEM; 380 } 381 topsrv->net = net; 382 topsrv->saddr = saddr; 383 topsrv->imp = TIPC_CRITICAL_IMPORTANCE; 384 topsrv->type = SOCK_SEQPACKET; 385 topsrv->max_rcvbuf_size = sizeof(struct tipc_subscr); 386 topsrv->tipc_conn_recvmsg = tipc_subscrb_rcv_cb; 387 topsrv->tipc_conn_new = tipc_subscrb_connect_cb; 388 topsrv->tipc_conn_release = tipc_subscrb_release_cb; 389 390 strncpy(topsrv->name, name, strlen(name) + 1); 391 tn->topsrv = topsrv; 392 atomic_set(&tn->subscription_count, 0); 393 394 return tipc_server_start(topsrv); 395 } 396 397 void tipc_topsrv_stop(struct net *net) 398 { 399 struct tipc_net *tn = net_generic(net, tipc_net_id); 400 struct tipc_server *topsrv = tn->topsrv; 401 402 tipc_server_stop(topsrv); 403 kfree(topsrv->saddr); 404 kfree(topsrv); 405 } 406