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 58 /** 59 * htohl - convert value to endianness used by destination 60 * @in: value to convert 61 * @swap: non-zero if endianness must be reversed 62 * 63 * Returns converted value 64 */ 65 static u32 htohl(u32 in, int swap) 66 { 67 return swap ? swab32(in) : in; 68 } 69 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) 73 { 74 struct tipc_net *tn = net_generic(sub->net, tipc_net_id); 75 struct tipc_subscriber *subscriber = sub->subscriber; 76 struct kvec msg_sect; 77 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); 87 } 88 89 /** 90 * tipc_subscrp_check_overlap - test for subscription overlap with the 91 * given values 92 * 93 * Returns 1 if there is overlap, otherwise 0. 94 */ 95 int tipc_subscrp_check_overlap(struct tipc_name_seq *seq, u32 found_lower, 96 u32 found_upper) 97 { 98 if (found_lower < seq->lower) 99 found_lower = seq->lower; 100 if (found_upper > seq->upper) 101 found_upper = seq->upper; 102 if (found_lower > found_upper) 103 return 0; 104 return 1; 105 } 106 107 u32 tipc_subscrp_convert_seq_type(u32 type, int swap) 108 { 109 return htohl(type, swap); 110 } 111 112 void tipc_subscrp_convert_seq(struct tipc_name_seq *in, int swap, 113 struct tipc_name_seq *out) 114 { 115 out->type = htohl(in->type, swap); 116 out->lower = htohl(in->lower, swap); 117 out->upper = htohl(in->upper, swap); 118 } 119 120 void tipc_subscrp_report_overlap(struct tipc_subscription *sub, u32 found_lower, 121 u32 found_upper, u32 event, u32 port_ref, 122 u32 node, int must) 123 { 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 && 130 !(htohl(sub->evt.s.filter, sub->swap) & TIPC_SUB_PORTS)) 131 return; 132 133 tipc_subscrp_send_event(sub, found_lower, found_upper, event, port_ref, 134 node); 135 } 136 137 static void tipc_subscrp_timeout(unsigned long data) 138 { 139 struct tipc_subscription *sub = (struct tipc_subscription *)data; 140 struct tipc_subscriber *subscriber = sub->subscriber; 141 142 /* Notify subscriber of timeout */ 143 tipc_subscrp_send_event(sub, sub->evt.s.seq.lower, sub->evt.s.seq.upper, 144 TIPC_SUBSCR_TIMEOUT, 0, 0); 145 146 spin_lock_bh(&subscriber->lock); 147 tipc_subscrp_delete(sub); 148 spin_unlock_bh(&subscriber->lock); 149 150 tipc_subscrb_put(subscriber); 151 } 152 153 static void tipc_subscrb_kref_release(struct kref *kref) 154 { 155 struct tipc_subscriber *subcriber = container_of(kref, 156 struct tipc_subscriber, kref); 157 158 kfree(subcriber); 159 } 160 161 static void tipc_subscrb_put(struct tipc_subscriber *subscriber) 162 { 163 kref_put(&subscriber->kref, tipc_subscrb_kref_release); 164 } 165 166 static void tipc_subscrb_get(struct tipc_subscriber *subscriber) 167 { 168 kref_get(&subscriber->kref); 169 } 170 171 static struct tipc_subscriber *tipc_subscrb_create(int conid) 172 { 173 struct tipc_subscriber *subscriber; 174 175 subscriber = kzalloc(sizeof(*subscriber), GFP_ATOMIC); 176 if (!subscriber) { 177 pr_warn("Subscriber rejected, no memory\n"); 178 return NULL; 179 } 180 kref_init(&subscriber->kref); 181 INIT_LIST_HEAD(&subscriber->subscrp_list); 182 subscriber->conid = conid; 183 spin_lock_init(&subscriber->lock); 184 185 return subscriber; 186 } 187 188 static void tipc_subscrb_delete(struct tipc_subscriber *subscriber) 189 { 190 struct tipc_subscription *sub, *temp; 191 u32 timeout; 192 193 spin_lock_bh(&subscriber->lock); 194 /* Destroy any existing subscriptions for subscriber */ 195 list_for_each_entry_safe(sub, temp, &subscriber->subscrp_list, 196 subscrp_list) { 197 timeout = htohl(sub->evt.s.timeout, sub->swap); 198 if ((timeout == TIPC_WAIT_FOREVER) || del_timer(&sub->timer)) { 199 tipc_subscrp_delete(sub); 200 tipc_subscrb_put(subscriber); 201 } 202 } 203 spin_unlock_bh(&subscriber->lock); 204 205 tipc_subscrb_put(subscriber); 206 } 207 208 static void tipc_subscrp_delete(struct tipc_subscription *sub) 209 { 210 struct tipc_net *tn = net_generic(sub->net, tipc_net_id); 211 212 tipc_nametbl_unsubscribe(sub); 213 list_del(&sub->subscrp_list); 214 kfree(sub); 215 atomic_dec(&tn->subscription_count); 216 } 217 218 static void tipc_subscrp_cancel(struct tipc_subscr *s, 219 struct tipc_subscriber *subscriber) 220 { 221 struct tipc_subscription *sub, *temp; 222 u32 timeout; 223 224 spin_lock_bh(&subscriber->lock); 225 /* Find first matching subscription, exit if not found */ 226 list_for_each_entry_safe(sub, temp, &subscriber->subscrp_list, 227 subscrp_list) { 228 if (!memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr))) { 229 timeout = htohl(sub->evt.s.timeout, sub->swap); 230 if ((timeout == TIPC_WAIT_FOREVER) || 231 del_timer(&sub->timer)) { 232 tipc_subscrp_delete(sub); 233 tipc_subscrb_put(subscriber); 234 } 235 break; 236 } 237 } 238 spin_unlock_bh(&subscriber->lock); 239 } 240 241 static struct tipc_subscription *tipc_subscrp_create(struct net *net, 242 struct tipc_subscr *s, 243 int swap) 244 { 245 struct tipc_net *tn = net_generic(net, tipc_net_id); 246 struct tipc_subscription *sub; 247 u32 filter = htohl(s->filter, swap); 248 249 /* Refuse subscription if global limit exceeded */ 250 if (atomic_read(&tn->subscription_count) >= TIPC_MAX_SUBSCRIPTIONS) { 251 pr_warn("Subscription rejected, limit reached (%u)\n", 252 TIPC_MAX_SUBSCRIPTIONS); 253 return NULL; 254 } 255 256 /* Allocate subscription object */ 257 sub = kmalloc(sizeof(*sub), GFP_ATOMIC); 258 if (!sub) { 259 pr_warn("Subscription rejected, no memory\n"); 260 return NULL; 261 } 262 263 /* Initialize subscription object */ 264 sub->net = net; 265 if (((filter & TIPC_SUB_PORTS) && (filter & TIPC_SUB_SERVICE)) || 266 (htohl(s->seq.lower, swap) > htohl(s->seq.upper, swap))) { 267 pr_warn("Subscription rejected, illegal request\n"); 268 kfree(sub); 269 return NULL; 270 } 271 272 sub->swap = swap; 273 memcpy(&sub->evt.s, s, sizeof(*s)); 274 atomic_inc(&tn->subscription_count); 275 return sub; 276 } 277 278 static void tipc_subscrp_subscribe(struct net *net, struct tipc_subscr *s, 279 struct tipc_subscriber *subscriber, int swap) 280 { 281 struct tipc_net *tn = net_generic(net, tipc_net_id); 282 struct tipc_subscription *sub = NULL; 283 u32 timeout; 284 285 sub = tipc_subscrp_create(net, s, swap); 286 if (!sub) 287 return tipc_conn_terminate(tn->topsrv, subscriber->conid); 288 289 spin_lock_bh(&subscriber->lock); 290 list_add(&sub->subscrp_list, &subscriber->subscrp_list); 291 tipc_subscrb_get(subscriber); 292 sub->subscriber = subscriber; 293 tipc_nametbl_subscribe(sub); 294 spin_unlock_bh(&subscriber->lock); 295 296 timeout = htohl(sub->evt.s.timeout, swap); 297 if (timeout == TIPC_WAIT_FOREVER) 298 return; 299 300 setup_timer(&sub->timer, tipc_subscrp_timeout, (unsigned long)sub); 301 mod_timer(&sub->timer, jiffies + msecs_to_jiffies(timeout)); 302 } 303 304 /* Handle one termination request for the subscriber */ 305 static void tipc_subscrb_shutdown_cb(int conid, void *usr_data) 306 { 307 tipc_subscrb_delete((struct tipc_subscriber *)usr_data); 308 } 309 310 /* Handle one request to create a new subscription for the subscriber */ 311 static void tipc_subscrb_rcv_cb(struct net *net, int conid, 312 struct sockaddr_tipc *addr, void *usr_data, 313 void *buf, size_t len) 314 { 315 struct tipc_subscriber *subscriber = usr_data; 316 struct tipc_subscr *s = (struct tipc_subscr *)buf; 317 int swap; 318 319 /* Determine subscriber's endianness */ 320 swap = !(s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE | 321 TIPC_SUB_CANCEL)); 322 323 /* Detect & process a subscription cancellation request */ 324 if (s->filter & htohl(TIPC_SUB_CANCEL, swap)) { 325 s->filter &= ~htohl(TIPC_SUB_CANCEL, swap); 326 return tipc_subscrp_cancel(s, subscriber); 327 } 328 329 if (s) 330 tipc_subscrp_subscribe(net, s, subscriber, swap); 331 } 332 333 /* Handle one request to establish a new subscriber */ 334 static void *tipc_subscrb_connect_cb(int conid) 335 { 336 return (void *)tipc_subscrb_create(conid); 337 } 338 339 int tipc_topsrv_start(struct net *net) 340 { 341 struct tipc_net *tn = net_generic(net, tipc_net_id); 342 const char name[] = "topology_server"; 343 struct tipc_server *topsrv; 344 struct sockaddr_tipc *saddr; 345 346 saddr = kzalloc(sizeof(*saddr), GFP_ATOMIC); 347 if (!saddr) 348 return -ENOMEM; 349 saddr->family = AF_TIPC; 350 saddr->addrtype = TIPC_ADDR_NAMESEQ; 351 saddr->addr.nameseq.type = TIPC_TOP_SRV; 352 saddr->addr.nameseq.lower = TIPC_TOP_SRV; 353 saddr->addr.nameseq.upper = TIPC_TOP_SRV; 354 saddr->scope = TIPC_NODE_SCOPE; 355 356 topsrv = kzalloc(sizeof(*topsrv), GFP_ATOMIC); 357 if (!topsrv) { 358 kfree(saddr); 359 return -ENOMEM; 360 } 361 topsrv->net = net; 362 topsrv->saddr = saddr; 363 topsrv->imp = TIPC_CRITICAL_IMPORTANCE; 364 topsrv->type = SOCK_SEQPACKET; 365 topsrv->max_rcvbuf_size = sizeof(struct tipc_subscr); 366 topsrv->tipc_conn_recvmsg = tipc_subscrb_rcv_cb; 367 topsrv->tipc_conn_new = tipc_subscrb_connect_cb; 368 topsrv->tipc_conn_shutdown = tipc_subscrb_shutdown_cb; 369 370 strncpy(topsrv->name, name, strlen(name) + 1); 371 tn->topsrv = topsrv; 372 atomic_set(&tn->subscription_count, 0); 373 374 return tipc_server_start(topsrv); 375 } 376 377 void tipc_topsrv_stop(struct net *net) 378 { 379 struct tipc_net *tn = net_generic(net, tipc_net_id); 380 struct tipc_server *topsrv = tn->topsrv; 381 382 tipc_server_stop(topsrv); 383 kfree(topsrv->saddr); 384 kfree(topsrv); 385 } 386