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, u32 scope, int must) 122 { 123 u32 filter = htohl(sub->evt.s.filter, sub->swap); 124 struct tipc_name_seq seq; 125 126 tipc_subscrp_convert_seq(&sub->evt.s.seq, sub->swap, &seq); 127 if (!tipc_subscrp_check_overlap(&seq, found_lower, found_upper)) 128 return; 129 if (!must && !(filter & TIPC_SUB_PORTS)) 130 return; 131 if (filter & TIPC_SUB_CLUSTER_SCOPE && scope == TIPC_NODE_SCOPE) 132 return; 133 if (filter & TIPC_SUB_NODE_SCOPE && scope != TIPC_NODE_SCOPE) 134 return; 135 136 tipc_subscrp_send_event(sub, found_lower, found_upper, event, port_ref, 137 node); 138 } 139 140 static void tipc_subscrp_timeout(struct timer_list *t) 141 { 142 struct tipc_subscription *sub = from_timer(sub, t, timer); 143 struct tipc_subscriber *subscriber = sub->subscriber; 144 145 spin_lock_bh(&subscriber->lock); 146 tipc_nametbl_unsubscribe(sub); 147 list_del(&sub->subscrp_list); 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 atomic_dec(&tn->subscription_count); 181 kfree(sub); 182 tipc_subscrb_put(subscriber); 183 } 184 185 void tipc_subscrp_put(struct tipc_subscription *subscription) 186 { 187 kref_put(&subscription->kref, tipc_subscrp_kref_release); 188 } 189 190 void tipc_subscrp_get(struct tipc_subscription *subscription) 191 { 192 kref_get(&subscription->kref); 193 } 194 195 /* tipc_subscrb_subscrp_delete - delete a specific subscription or all 196 * subscriptions for a given subscriber. 197 */ 198 static void tipc_subscrb_subscrp_delete(struct tipc_subscriber *subscriber, 199 struct tipc_subscr *s) 200 { 201 struct list_head *subscription_list = &subscriber->subscrp_list; 202 struct tipc_subscription *sub, *temp; 203 u32 timeout; 204 205 spin_lock_bh(&subscriber->lock); 206 list_for_each_entry_safe(sub, temp, subscription_list, subscrp_list) { 207 if (s && memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr))) 208 continue; 209 210 timeout = htohl(sub->evt.s.timeout, sub->swap); 211 if (timeout == TIPC_WAIT_FOREVER || del_timer(&sub->timer)) { 212 tipc_nametbl_unsubscribe(sub); 213 list_del(&sub->subscrp_list); 214 tipc_subscrp_put(sub); 215 } 216 217 if (s) 218 break; 219 } 220 spin_unlock_bh(&subscriber->lock); 221 } 222 223 static struct tipc_subscriber *tipc_subscrb_create(int conid) 224 { 225 struct tipc_subscriber *subscriber; 226 227 subscriber = kzalloc(sizeof(*subscriber), GFP_ATOMIC); 228 if (!subscriber) { 229 pr_warn("Subscriber rejected, no memory\n"); 230 return NULL; 231 } 232 INIT_LIST_HEAD(&subscriber->subscrp_list); 233 kref_init(&subscriber->kref); 234 subscriber->conid = conid; 235 spin_lock_init(&subscriber->lock); 236 237 return subscriber; 238 } 239 240 static void tipc_subscrb_delete(struct tipc_subscriber *subscriber) 241 { 242 tipc_subscrb_subscrp_delete(subscriber, NULL); 243 tipc_subscrb_put(subscriber); 244 } 245 246 static void tipc_subscrp_cancel(struct tipc_subscr *s, 247 struct tipc_subscriber *subscriber) 248 { 249 tipc_subscrb_get(subscriber); 250 tipc_subscrb_subscrp_delete(subscriber, s); 251 tipc_subscrb_put(subscriber); 252 } 253 254 static struct tipc_subscription *tipc_subscrp_create(struct net *net, 255 struct tipc_subscr *s, 256 int swap) 257 { 258 struct tipc_net *tn = net_generic(net, tipc_net_id); 259 struct tipc_subscription *sub; 260 u32 filter = htohl(s->filter, swap); 261 262 /* Refuse subscription if global limit exceeded */ 263 if (atomic_read(&tn->subscription_count) >= TIPC_MAX_SUBSCRIPTIONS) { 264 pr_warn("Subscription rejected, limit reached (%u)\n", 265 TIPC_MAX_SUBSCRIPTIONS); 266 return NULL; 267 } 268 269 /* Allocate subscription object */ 270 sub = kmalloc(sizeof(*sub), GFP_ATOMIC); 271 if (!sub) { 272 pr_warn("Subscription rejected, no memory\n"); 273 return NULL; 274 } 275 276 /* Initialize subscription object */ 277 sub->net = net; 278 if (((filter & TIPC_SUB_PORTS) && (filter & TIPC_SUB_SERVICE)) || 279 (htohl(s->seq.lower, swap) > htohl(s->seq.upper, swap))) { 280 pr_warn("Subscription rejected, illegal request\n"); 281 kfree(sub); 282 return NULL; 283 } 284 285 sub->swap = swap; 286 memcpy(&sub->evt.s, s, sizeof(*s)); 287 atomic_inc(&tn->subscription_count); 288 kref_init(&sub->kref); 289 return sub; 290 } 291 292 static int tipc_subscrp_subscribe(struct net *net, struct tipc_subscr *s, 293 struct tipc_subscriber *subscriber, int swap, 294 bool status) 295 { 296 struct tipc_subscription *sub = NULL; 297 u32 timeout; 298 299 sub = tipc_subscrp_create(net, s, swap); 300 if (!sub) 301 return -1; 302 303 spin_lock_bh(&subscriber->lock); 304 list_add(&sub->subscrp_list, &subscriber->subscrp_list); 305 sub->subscriber = subscriber; 306 tipc_nametbl_subscribe(sub, status); 307 tipc_subscrb_get(subscriber); 308 spin_unlock_bh(&subscriber->lock); 309 310 timer_setup(&sub->timer, tipc_subscrp_timeout, 0); 311 timeout = htohl(sub->evt.s.timeout, swap); 312 313 if (timeout != TIPC_WAIT_FOREVER) 314 mod_timer(&sub->timer, jiffies + msecs_to_jiffies(timeout)); 315 return 0; 316 } 317 318 /* Handle one termination request for the subscriber */ 319 static void tipc_subscrb_release_cb(int conid, void *usr_data) 320 { 321 tipc_subscrb_delete((struct tipc_subscriber *)usr_data); 322 } 323 324 /* Handle one request to create a new subscription for the subscriber */ 325 static int tipc_subscrb_rcv_cb(struct net *net, int conid, 326 struct sockaddr_tipc *addr, void *usr_data, 327 void *buf, size_t len) 328 { 329 struct tipc_subscriber *subscriber = usr_data; 330 struct tipc_subscr *s = (struct tipc_subscr *)buf; 331 bool status; 332 int swap; 333 334 /* Determine subscriber's endianness */ 335 swap = !(s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE | 336 TIPC_SUB_CANCEL)); 337 338 /* Detect & process a subscription cancellation request */ 339 if (s->filter & htohl(TIPC_SUB_CANCEL, swap)) { 340 s->filter &= ~htohl(TIPC_SUB_CANCEL, swap); 341 tipc_subscrp_cancel(s, subscriber); 342 return 0; 343 } 344 status = !(s->filter & htohl(TIPC_SUB_NO_STATUS, swap)); 345 return tipc_subscrp_subscribe(net, s, subscriber, swap, status); 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