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; 144 145 /* Notify subscriber of timeout */ 146 tipc_subscrp_send_event(sub, sub->evt.s.seq.lower, sub->evt.s.seq.upper, 147 TIPC_SUBSCR_TIMEOUT, 0, 0); 148 149 tipc_subscrp_put(sub); 150 } 151 152 static void tipc_subscrb_kref_release(struct kref *kref) 153 { 154 kfree(container_of(kref,struct tipc_subscriber, kref)); 155 } 156 157 static void tipc_subscrb_put(struct tipc_subscriber *subscriber) 158 { 159 kref_put(&subscriber->kref, tipc_subscrb_kref_release); 160 } 161 162 static void tipc_subscrb_get(struct tipc_subscriber *subscriber) 163 { 164 kref_get(&subscriber->kref); 165 } 166 167 static void tipc_subscrp_kref_release(struct kref *kref) 168 { 169 struct tipc_subscription *sub = container_of(kref, 170 struct tipc_subscription, 171 kref); 172 struct tipc_net *tn = net_generic(sub->net, tipc_net_id); 173 struct tipc_subscriber *subscriber = sub->subscriber; 174 175 spin_lock_bh(&subscriber->lock); 176 tipc_nametbl_unsubscribe(sub); 177 list_del(&sub->subscrp_list); 178 atomic_dec(&tn->subscription_count); 179 spin_unlock_bh(&subscriber->lock); 180 kfree(sub); 181 tipc_subscrb_put(subscriber); 182 } 183 184 static void tipc_subscrp_put(struct tipc_subscription *subscription) 185 { 186 kref_put(&subscription->kref, tipc_subscrp_kref_release); 187 } 188 189 static void tipc_subscrp_get(struct tipc_subscription *subscription) 190 { 191 kref_get(&subscription->kref); 192 } 193 194 /* tipc_subscrb_subscrp_delete - delete a specific subscription or all 195 * subscriptions for a given subscriber. 196 */ 197 static void tipc_subscrb_subscrp_delete(struct tipc_subscriber *subscriber, 198 struct tipc_subscr *s) 199 { 200 struct list_head *subscription_list = &subscriber->subscrp_list; 201 struct tipc_subscription *sub, *temp; 202 203 spin_lock_bh(&subscriber->lock); 204 list_for_each_entry_safe(sub, temp, subscription_list, subscrp_list) { 205 if (s && memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr))) 206 continue; 207 208 tipc_subscrp_get(sub); 209 spin_unlock_bh(&subscriber->lock); 210 tipc_subscrp_delete(sub); 211 tipc_subscrp_put(sub); 212 spin_lock_bh(&subscriber->lock); 213 214 if (s) 215 break; 216 } 217 spin_unlock_bh(&subscriber->lock); 218 } 219 220 static struct tipc_subscriber *tipc_subscrb_create(int conid) 221 { 222 struct tipc_subscriber *subscriber; 223 224 subscriber = kzalloc(sizeof(*subscriber), GFP_ATOMIC); 225 if (!subscriber) { 226 pr_warn("Subscriber rejected, no memory\n"); 227 return NULL; 228 } 229 INIT_LIST_HEAD(&subscriber->subscrp_list); 230 kref_init(&subscriber->kref); 231 subscriber->conid = conid; 232 spin_lock_init(&subscriber->lock); 233 234 return subscriber; 235 } 236 237 static void tipc_subscrb_delete(struct tipc_subscriber *subscriber) 238 { 239 tipc_subscrb_subscrp_delete(subscriber, NULL); 240 tipc_subscrb_put(subscriber); 241 } 242 243 static void tipc_subscrp_delete(struct tipc_subscription *sub) 244 { 245 u32 timeout = htohl(sub->evt.s.timeout, sub->swap); 246 247 if (timeout == TIPC_WAIT_FOREVER || del_timer(&sub->timer)) 248 tipc_subscrp_put(sub); 249 } 250 251 static void tipc_subscrp_cancel(struct tipc_subscr *s, 252 struct tipc_subscriber *subscriber) 253 { 254 tipc_subscrb_subscrp_delete(subscriber, s); 255 } 256 257 static struct tipc_subscription *tipc_subscrp_create(struct net *net, 258 struct tipc_subscr *s, 259 int swap) 260 { 261 struct tipc_net *tn = net_generic(net, tipc_net_id); 262 struct tipc_subscription *sub; 263 u32 filter = htohl(s->filter, swap); 264 265 /* Refuse subscription if global limit exceeded */ 266 if (atomic_read(&tn->subscription_count) >= TIPC_MAX_SUBSCRIPTIONS) { 267 pr_warn("Subscription rejected, limit reached (%u)\n", 268 TIPC_MAX_SUBSCRIPTIONS); 269 return NULL; 270 } 271 272 /* Allocate subscription object */ 273 sub = kmalloc(sizeof(*sub), GFP_ATOMIC); 274 if (!sub) { 275 pr_warn("Subscription rejected, no memory\n"); 276 return NULL; 277 } 278 279 /* Initialize subscription object */ 280 sub->net = net; 281 if (((filter & TIPC_SUB_PORTS) && (filter & TIPC_SUB_SERVICE)) || 282 (htohl(s->seq.lower, swap) > htohl(s->seq.upper, swap))) { 283 pr_warn("Subscription rejected, illegal request\n"); 284 kfree(sub); 285 return NULL; 286 } 287 288 sub->swap = swap; 289 memcpy(&sub->evt.s, s, sizeof(*s)); 290 atomic_inc(&tn->subscription_count); 291 kref_init(&sub->kref); 292 return sub; 293 } 294 295 static void tipc_subscrp_subscribe(struct net *net, struct tipc_subscr *s, 296 struct tipc_subscriber *subscriber, int swap) 297 { 298 struct tipc_net *tn = net_generic(net, tipc_net_id); 299 struct tipc_subscription *sub = NULL; 300 u32 timeout; 301 302 sub = tipc_subscrp_create(net, s, swap); 303 if (!sub) 304 return tipc_conn_terminate(tn->topsrv, subscriber->conid); 305 306 spin_lock_bh(&subscriber->lock); 307 list_add(&sub->subscrp_list, &subscriber->subscrp_list); 308 sub->subscriber = subscriber; 309 tipc_nametbl_subscribe(sub); 310 tipc_subscrb_get(subscriber); 311 spin_unlock_bh(&subscriber->lock); 312 313 setup_timer(&sub->timer, tipc_subscrp_timeout, (unsigned long)sub); 314 timeout = htohl(sub->evt.s.timeout, swap); 315 316 if (timeout != TIPC_WAIT_FOREVER) 317 mod_timer(&sub->timer, jiffies + msecs_to_jiffies(timeout)); 318 } 319 320 /* Handle one termination request for the subscriber */ 321 static void tipc_subscrb_release_cb(int conid, void *usr_data) 322 { 323 tipc_subscrb_delete((struct tipc_subscriber *)usr_data); 324 } 325 326 /* Handle one request to create a new subscription for the subscriber */ 327 static void tipc_subscrb_rcv_cb(struct net *net, int conid, 328 struct sockaddr_tipc *addr, void *usr_data, 329 void *buf, size_t len) 330 { 331 struct tipc_subscriber *subscriber = usr_data; 332 struct tipc_subscr *s = (struct tipc_subscr *)buf; 333 int swap; 334 335 /* Determine subscriber's endianness */ 336 swap = !(s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE | 337 TIPC_SUB_CANCEL)); 338 339 /* Detect & process a subscription cancellation request */ 340 if (s->filter & htohl(TIPC_SUB_CANCEL, swap)) { 341 s->filter &= ~htohl(TIPC_SUB_CANCEL, swap); 342 return tipc_subscrp_cancel(s, subscriber); 343 } 344 345 tipc_subscrp_subscribe(net, s, subscriber, swap); 346 } 347 348 /* Handle one request to establish a new subscriber */ 349 static void *tipc_subscrb_connect_cb(int conid) 350 { 351 return (void *)tipc_subscrb_create(conid); 352 } 353 354 int tipc_topsrv_start(struct net *net) 355 { 356 struct tipc_net *tn = net_generic(net, tipc_net_id); 357 const char name[] = "topology_server"; 358 struct tipc_server *topsrv; 359 struct sockaddr_tipc *saddr; 360 361 saddr = kzalloc(sizeof(*saddr), GFP_ATOMIC); 362 if (!saddr) 363 return -ENOMEM; 364 saddr->family = AF_TIPC; 365 saddr->addrtype = TIPC_ADDR_NAMESEQ; 366 saddr->addr.nameseq.type = TIPC_TOP_SRV; 367 saddr->addr.nameseq.lower = TIPC_TOP_SRV; 368 saddr->addr.nameseq.upper = TIPC_TOP_SRV; 369 saddr->scope = TIPC_NODE_SCOPE; 370 371 topsrv = kzalloc(sizeof(*topsrv), GFP_ATOMIC); 372 if (!topsrv) { 373 kfree(saddr); 374 return -ENOMEM; 375 } 376 topsrv->net = net; 377 topsrv->saddr = saddr; 378 topsrv->imp = TIPC_CRITICAL_IMPORTANCE; 379 topsrv->type = SOCK_SEQPACKET; 380 topsrv->max_rcvbuf_size = sizeof(struct tipc_subscr); 381 topsrv->tipc_conn_recvmsg = tipc_subscrb_rcv_cb; 382 topsrv->tipc_conn_new = tipc_subscrb_connect_cb; 383 topsrv->tipc_conn_release = tipc_subscrb_release_cb; 384 385 strncpy(topsrv->name, name, strlen(name) + 1); 386 tn->topsrv = topsrv; 387 atomic_set(&tn->subscription_count, 0); 388 389 return tipc_server_start(topsrv); 390 } 391 392 void tipc_topsrv_stop(struct net *net) 393 { 394 struct tipc_net *tn = net_generic(net, tipc_net_id); 395 struct tipc_server *topsrv = tn->topsrv; 396 397 tipc_server_stop(topsrv); 398 kfree(topsrv->saddr); 399 kfree(topsrv); 400 } 401