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_subscrb_put(struct tipc_subscriber *subscriber); 56 57 /** 58 * htohl - convert value to endianness used by destination 59 * @in: value to convert 60 * @swap: non-zero if endianness must be reversed 61 * 62 * Returns converted value 63 */ 64 static u32 htohl(u32 in, int swap) 65 { 66 return swap ? swab32(in) : in; 67 } 68 69 static void tipc_subscrp_send_event(struct tipc_subscription *sub, 70 u32 found_lower, u32 found_upper, 71 u32 event, u32 port_ref, u32 node) 72 { 73 struct tipc_net *tn = net_generic(sub->net, tipc_net_id); 74 struct tipc_subscriber *subscriber = sub->subscriber; 75 struct kvec msg_sect; 76 77 msg_sect.iov_base = (void *)&sub->evt; 78 msg_sect.iov_len = sizeof(struct tipc_event); 79 sub->evt.event = htohl(event, sub->swap); 80 sub->evt.found_lower = htohl(found_lower, sub->swap); 81 sub->evt.found_upper = htohl(found_upper, sub->swap); 82 sub->evt.port.ref = htohl(port_ref, sub->swap); 83 sub->evt.port.node = htohl(node, sub->swap); 84 tipc_conn_sendmsg(tn->topsrv, subscriber->conid, NULL, 85 msg_sect.iov_base, msg_sect.iov_len); 86 } 87 88 /** 89 * tipc_subscrp_check_overlap - test for subscription overlap with the 90 * given values 91 * 92 * Returns 1 if there is overlap, otherwise 0. 93 */ 94 int tipc_subscrp_check_overlap(struct tipc_name_seq *seq, u32 found_lower, 95 u32 found_upper) 96 { 97 if (found_lower < seq->lower) 98 found_lower = seq->lower; 99 if (found_upper > seq->upper) 100 found_upper = seq->upper; 101 if (found_lower > found_upper) 102 return 0; 103 return 1; 104 } 105 106 u32 tipc_subscrp_convert_seq_type(u32 type, int swap) 107 { 108 return htohl(type, swap); 109 } 110 111 void tipc_subscrp_convert_seq(struct tipc_name_seq *in, int swap, 112 struct tipc_name_seq *out) 113 { 114 out->type = htohl(in->type, swap); 115 out->lower = htohl(in->lower, swap); 116 out->upper = htohl(in->upper, swap); 117 } 118 119 void tipc_subscrp_report_overlap(struct tipc_subscription *sub, u32 found_lower, 120 u32 found_upper, u32 event, u32 port_ref, 121 u32 node, int must) 122 { 123 struct tipc_name_seq seq; 124 125 tipc_subscrp_convert_seq(&sub->evt.s.seq, sub->swap, &seq); 126 if (!tipc_subscrp_check_overlap(&seq, found_lower, found_upper)) 127 return; 128 if (!must && 129 !(htohl(sub->evt.s.filter, sub->swap) & TIPC_SUB_PORTS)) 130 return; 131 132 tipc_subscrp_send_event(sub, found_lower, found_upper, event, port_ref, 133 node); 134 } 135 136 static void tipc_subscrp_timeout(unsigned long data) 137 { 138 struct tipc_subscription *sub = (struct tipc_subscription *)data; 139 struct tipc_subscriber *subscriber = sub->subscriber; 140 141 spin_lock_bh(&subscriber->lock); 142 tipc_nametbl_unsubscribe(sub); 143 list_del(&sub->subscrp_list); 144 spin_unlock_bh(&subscriber->lock); 145 146 /* Notify subscriber of timeout */ 147 tipc_subscrp_send_event(sub, sub->evt.s.seq.lower, sub->evt.s.seq.upper, 148 TIPC_SUBSCR_TIMEOUT, 0, 0); 149 150 tipc_subscrp_put(sub); 151 } 152 153 static void tipc_subscrb_kref_release(struct kref *kref) 154 { 155 kfree(container_of(kref,struct tipc_subscriber, kref)); 156 } 157 158 static void tipc_subscrb_put(struct tipc_subscriber *subscriber) 159 { 160 kref_put(&subscriber->kref, tipc_subscrb_kref_release); 161 } 162 163 static void tipc_subscrb_get(struct tipc_subscriber *subscriber) 164 { 165 kref_get(&subscriber->kref); 166 } 167 168 static void tipc_subscrp_kref_release(struct kref *kref) 169 { 170 struct tipc_subscription *sub = container_of(kref, 171 struct tipc_subscription, 172 kref); 173 struct tipc_net *tn = net_generic(sub->net, tipc_net_id); 174 struct tipc_subscriber *subscriber = sub->subscriber; 175 176 atomic_dec(&tn->subscription_count); 177 kfree(sub); 178 tipc_subscrb_put(subscriber); 179 } 180 181 void tipc_subscrp_put(struct tipc_subscription *subscription) 182 { 183 kref_put(&subscription->kref, tipc_subscrp_kref_release); 184 } 185 186 void tipc_subscrp_get(struct tipc_subscription *subscription) 187 { 188 kref_get(&subscription->kref); 189 } 190 191 /* tipc_subscrb_subscrp_delete - delete a specific subscription or all 192 * subscriptions for a given subscriber. 193 */ 194 static void tipc_subscrb_subscrp_delete(struct tipc_subscriber *subscriber, 195 struct tipc_subscr *s) 196 { 197 struct list_head *subscription_list = &subscriber->subscrp_list; 198 struct tipc_subscription *sub, *temp; 199 u32 timeout; 200 201 spin_lock_bh(&subscriber->lock); 202 list_for_each_entry_safe(sub, temp, subscription_list, subscrp_list) { 203 if (s && memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr))) 204 continue; 205 206 timeout = htohl(sub->evt.s.timeout, sub->swap); 207 if (timeout == TIPC_WAIT_FOREVER || del_timer(&sub->timer)) { 208 tipc_nametbl_unsubscribe(sub); 209 list_del(&sub->subscrp_list); 210 tipc_subscrp_put(sub); 211 } 212 213 if (s) 214 break; 215 } 216 spin_unlock_bh(&subscriber->lock); 217 } 218 219 static struct tipc_subscriber *tipc_subscrb_create(int conid) 220 { 221 struct tipc_subscriber *subscriber; 222 223 subscriber = kzalloc(sizeof(*subscriber), GFP_ATOMIC); 224 if (!subscriber) { 225 pr_warn("Subscriber rejected, no memory\n"); 226 return NULL; 227 } 228 INIT_LIST_HEAD(&subscriber->subscrp_list); 229 kref_init(&subscriber->kref); 230 subscriber->conid = conid; 231 spin_lock_init(&subscriber->lock); 232 233 return subscriber; 234 } 235 236 static void tipc_subscrb_delete(struct tipc_subscriber *subscriber) 237 { 238 tipc_subscrb_subscrp_delete(subscriber, NULL); 239 tipc_subscrb_put(subscriber); 240 } 241 242 static void tipc_subscrp_cancel(struct tipc_subscr *s, 243 struct tipc_subscriber *subscriber) 244 { 245 tipc_subscrb_get(subscriber); 246 tipc_subscrb_subscrp_delete(subscriber, s); 247 tipc_subscrb_put(subscriber); 248 } 249 250 static struct tipc_subscription *tipc_subscrp_create(struct net *net, 251 struct tipc_subscr *s, 252 int swap) 253 { 254 struct tipc_net *tn = net_generic(net, tipc_net_id); 255 struct tipc_subscription *sub; 256 u32 filter = htohl(s->filter, swap); 257 258 /* Refuse subscription if global limit exceeded */ 259 if (atomic_read(&tn->subscription_count) >= TIPC_MAX_SUBSCRIPTIONS) { 260 pr_warn("Subscription rejected, limit reached (%u)\n", 261 TIPC_MAX_SUBSCRIPTIONS); 262 return NULL; 263 } 264 265 /* Allocate subscription object */ 266 sub = kmalloc(sizeof(*sub), GFP_ATOMIC); 267 if (!sub) { 268 pr_warn("Subscription rejected, no memory\n"); 269 return NULL; 270 } 271 272 /* Initialize subscription object */ 273 sub->net = net; 274 if (((filter & TIPC_SUB_PORTS) && (filter & TIPC_SUB_SERVICE)) || 275 (htohl(s->seq.lower, swap) > htohl(s->seq.upper, swap))) { 276 pr_warn("Subscription rejected, illegal request\n"); 277 kfree(sub); 278 return NULL; 279 } 280 281 sub->swap = swap; 282 memcpy(&sub->evt.s, s, sizeof(*s)); 283 atomic_inc(&tn->subscription_count); 284 kref_init(&sub->kref); 285 return sub; 286 } 287 288 static void tipc_subscrp_subscribe(struct net *net, struct tipc_subscr *s, 289 struct tipc_subscriber *subscriber, int swap) 290 { 291 struct tipc_net *tn = net_generic(net, tipc_net_id); 292 struct tipc_subscription *sub = NULL; 293 u32 timeout; 294 295 sub = tipc_subscrp_create(net, s, swap); 296 if (!sub) 297 return tipc_conn_terminate(tn->topsrv, subscriber->conid); 298 299 spin_lock_bh(&subscriber->lock); 300 list_add(&sub->subscrp_list, &subscriber->subscrp_list); 301 sub->subscriber = subscriber; 302 tipc_nametbl_subscribe(sub); 303 tipc_subscrb_get(subscriber); 304 spin_unlock_bh(&subscriber->lock); 305 306 setup_timer(&sub->timer, tipc_subscrp_timeout, (unsigned long)sub); 307 timeout = htohl(sub->evt.s.timeout, swap); 308 309 if (timeout != TIPC_WAIT_FOREVER) 310 mod_timer(&sub->timer, jiffies + msecs_to_jiffies(timeout)); 311 } 312 313 /* Handle one termination request for the subscriber */ 314 static void tipc_subscrb_release_cb(int conid, void *usr_data) 315 { 316 tipc_subscrb_delete((struct tipc_subscriber *)usr_data); 317 } 318 319 /* Handle one request to create a new subscription for the subscriber */ 320 static void tipc_subscrb_rcv_cb(struct net *net, int conid, 321 struct sockaddr_tipc *addr, void *usr_data, 322 void *buf, size_t len) 323 { 324 struct tipc_subscriber *subscriber = usr_data; 325 struct tipc_subscr *s = (struct tipc_subscr *)buf; 326 int swap; 327 328 /* Determine subscriber's endianness */ 329 swap = !(s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE | 330 TIPC_SUB_CANCEL)); 331 332 /* Detect & process a subscription cancellation request */ 333 if (s->filter & htohl(TIPC_SUB_CANCEL, swap)) { 334 s->filter &= ~htohl(TIPC_SUB_CANCEL, swap); 335 return tipc_subscrp_cancel(s, subscriber); 336 } 337 338 tipc_subscrp_subscribe(net, s, subscriber, swap); 339 } 340 341 /* Handle one request to establish a new subscriber */ 342 static void *tipc_subscrb_connect_cb(int conid) 343 { 344 return (void *)tipc_subscrb_create(conid); 345 } 346 347 int tipc_topsrv_start(struct net *net) 348 { 349 struct tipc_net *tn = net_generic(net, tipc_net_id); 350 const char name[] = "topology_server"; 351 struct tipc_server *topsrv; 352 struct sockaddr_tipc *saddr; 353 354 saddr = kzalloc(sizeof(*saddr), GFP_ATOMIC); 355 if (!saddr) 356 return -ENOMEM; 357 saddr->family = AF_TIPC; 358 saddr->addrtype = TIPC_ADDR_NAMESEQ; 359 saddr->addr.nameseq.type = TIPC_TOP_SRV; 360 saddr->addr.nameseq.lower = TIPC_TOP_SRV; 361 saddr->addr.nameseq.upper = TIPC_TOP_SRV; 362 saddr->scope = TIPC_NODE_SCOPE; 363 364 topsrv = kzalloc(sizeof(*topsrv), GFP_ATOMIC); 365 if (!topsrv) { 366 kfree(saddr); 367 return -ENOMEM; 368 } 369 topsrv->net = net; 370 topsrv->saddr = saddr; 371 topsrv->imp = TIPC_CRITICAL_IMPORTANCE; 372 topsrv->type = SOCK_SEQPACKET; 373 topsrv->max_rcvbuf_size = sizeof(struct tipc_subscr); 374 topsrv->tipc_conn_recvmsg = tipc_subscrb_rcv_cb; 375 topsrv->tipc_conn_new = tipc_subscrb_connect_cb; 376 topsrv->tipc_conn_release = tipc_subscrb_release_cb; 377 378 strncpy(topsrv->name, name, strlen(name) + 1); 379 tn->topsrv = topsrv; 380 atomic_set(&tn->subscription_count, 0); 381 382 return tipc_server_start(topsrv); 383 } 384 385 void tipc_topsrv_stop(struct net *net) 386 { 387 struct tipc_net *tn = net_generic(net, tipc_net_id); 388 struct tipc_server *topsrv = tn->topsrv; 389 390 tipc_server_stop(topsrv); 391 kfree(topsrv->saddr); 392 kfree(topsrv); 393 } 394