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_subscription *sub, u32 found_lower, 96 u32 found_upper) 97 { 98 if (found_lower < sub->seq.lower) 99 found_lower = sub->seq.lower; 100 if (found_upper > sub->seq.upper) 101 found_upper = sub->seq.upper; 102 if (found_lower > found_upper) 103 return 0; 104 return 1; 105 } 106 107 void tipc_subscrp_report_overlap(struct tipc_subscription *sub, u32 found_lower, 108 u32 found_upper, u32 event, u32 port_ref, 109 u32 node, int must) 110 { 111 if (!tipc_subscrp_check_overlap(sub, found_lower, found_upper)) 112 return; 113 if (!must && !(sub->filter & TIPC_SUB_PORTS)) 114 return; 115 116 tipc_subscrp_send_event(sub, found_lower, found_upper, event, port_ref, 117 node); 118 } 119 120 static void tipc_subscrp_timeout(unsigned long data) 121 { 122 struct tipc_subscription *sub = (struct tipc_subscription *)data; 123 struct tipc_subscriber *subscriber = sub->subscriber; 124 125 /* Notify subscriber of timeout */ 126 tipc_subscrp_send_event(sub, sub->evt.s.seq.lower, sub->evt.s.seq.upper, 127 TIPC_SUBSCR_TIMEOUT, 0, 0); 128 129 spin_lock_bh(&subscriber->lock); 130 tipc_subscrp_delete(sub); 131 spin_unlock_bh(&subscriber->lock); 132 133 tipc_subscrb_put(subscriber); 134 } 135 136 static void tipc_subscrb_kref_release(struct kref *kref) 137 { 138 struct tipc_subscriber *subcriber = container_of(kref, 139 struct tipc_subscriber, kref); 140 141 kfree(subcriber); 142 } 143 144 static void tipc_subscrb_put(struct tipc_subscriber *subscriber) 145 { 146 kref_put(&subscriber->kref, tipc_subscrb_kref_release); 147 } 148 149 static void tipc_subscrb_get(struct tipc_subscriber *subscriber) 150 { 151 kref_get(&subscriber->kref); 152 } 153 154 static struct tipc_subscriber *tipc_subscrb_create(int conid) 155 { 156 struct tipc_subscriber *subscriber; 157 158 subscriber = kzalloc(sizeof(*subscriber), GFP_ATOMIC); 159 if (!subscriber) { 160 pr_warn("Subscriber rejected, no memory\n"); 161 return NULL; 162 } 163 kref_init(&subscriber->kref); 164 INIT_LIST_HEAD(&subscriber->subscrp_list); 165 subscriber->conid = conid; 166 spin_lock_init(&subscriber->lock); 167 168 return subscriber; 169 } 170 171 static void tipc_subscrb_delete(struct tipc_subscriber *subscriber) 172 { 173 struct tipc_subscription *sub, *temp; 174 175 spin_lock_bh(&subscriber->lock); 176 /* Destroy any existing subscriptions for subscriber */ 177 list_for_each_entry_safe(sub, temp, &subscriber->subscrp_list, 178 subscrp_list) { 179 if (del_timer(&sub->timer)) { 180 tipc_subscrp_delete(sub); 181 tipc_subscrb_put(subscriber); 182 } 183 } 184 spin_unlock_bh(&subscriber->lock); 185 186 tipc_subscrb_put(subscriber); 187 } 188 189 static void tipc_subscrp_delete(struct tipc_subscription *sub) 190 { 191 struct tipc_net *tn = net_generic(sub->net, tipc_net_id); 192 193 tipc_nametbl_unsubscribe(sub); 194 list_del(&sub->subscrp_list); 195 kfree(sub); 196 atomic_dec(&tn->subscription_count); 197 } 198 199 static void tipc_subscrp_cancel(struct tipc_subscr *s, 200 struct tipc_subscriber *subscriber) 201 { 202 struct tipc_subscription *sub, *temp; 203 204 spin_lock_bh(&subscriber->lock); 205 /* Find first matching subscription, exit if not found */ 206 list_for_each_entry_safe(sub, temp, &subscriber->subscrp_list, 207 subscrp_list) { 208 if (!memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr))) { 209 if (del_timer(&sub->timer)) { 210 tipc_subscrp_delete(sub); 211 tipc_subscrb_put(subscriber); 212 } 213 break; 214 } 215 } 216 spin_unlock_bh(&subscriber->lock); 217 } 218 219 static int tipc_subscrp_create(struct net *net, struct tipc_subscr *s, 220 struct tipc_subscriber *subscriber, 221 struct tipc_subscription **sub_p) 222 { 223 struct tipc_net *tn = net_generic(net, tipc_net_id); 224 struct tipc_subscription *sub; 225 int swap; 226 227 /* Determine subscriber's endianness */ 228 swap = !(s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE)); 229 230 /* Detect & process a subscription cancellation request */ 231 if (s->filter & htohl(TIPC_SUB_CANCEL, swap)) { 232 s->filter &= ~htohl(TIPC_SUB_CANCEL, swap); 233 tipc_subscrp_cancel(s, subscriber); 234 return 0; 235 } 236 237 /* Refuse subscription if global limit exceeded */ 238 if (atomic_read(&tn->subscription_count) >= TIPC_MAX_SUBSCRIPTIONS) { 239 pr_warn("Subscription rejected, limit reached (%u)\n", 240 TIPC_MAX_SUBSCRIPTIONS); 241 return -EINVAL; 242 } 243 244 /* Allocate subscription object */ 245 sub = kmalloc(sizeof(*sub), GFP_ATOMIC); 246 if (!sub) { 247 pr_warn("Subscription rejected, no memory\n"); 248 return -ENOMEM; 249 } 250 251 /* Initialize subscription object */ 252 sub->net = net; 253 sub->seq.type = htohl(s->seq.type, swap); 254 sub->seq.lower = htohl(s->seq.lower, swap); 255 sub->seq.upper = htohl(s->seq.upper, swap); 256 sub->timeout = msecs_to_jiffies(htohl(s->timeout, swap)); 257 sub->filter = htohl(s->filter, swap); 258 if ((!(sub->filter & TIPC_SUB_PORTS) == 259 !(sub->filter & TIPC_SUB_SERVICE)) || 260 (sub->seq.lower > sub->seq.upper)) { 261 pr_warn("Subscription rejected, illegal request\n"); 262 kfree(sub); 263 return -EINVAL; 264 } 265 spin_lock_bh(&subscriber->lock); 266 list_add(&sub->subscrp_list, &subscriber->subscrp_list); 267 spin_unlock_bh(&subscriber->lock); 268 sub->subscriber = subscriber; 269 sub->swap = swap; 270 memcpy(&sub->evt.s, s, sizeof(*s)); 271 atomic_inc(&tn->subscription_count); 272 setup_timer(&sub->timer, tipc_subscrp_timeout, (unsigned long)sub); 273 if (sub->timeout != TIPC_WAIT_FOREVER) 274 sub->timeout += jiffies; 275 if (!mod_timer(&sub->timer, sub->timeout)) 276 tipc_subscrb_get(subscriber); 277 *sub_p = sub; 278 return 0; 279 } 280 281 /* Handle one termination request for the subscriber */ 282 static void tipc_subscrb_shutdown_cb(int conid, void *usr_data) 283 { 284 tipc_subscrb_delete((struct tipc_subscriber *)usr_data); 285 } 286 287 /* Handle one request to create a new subscription for the subscriber */ 288 static void tipc_subscrb_rcv_cb(struct net *net, int conid, 289 struct sockaddr_tipc *addr, void *usr_data, 290 void *buf, size_t len) 291 { 292 struct tipc_subscriber *subscriber = usr_data; 293 struct tipc_subscription *sub = NULL; 294 struct tipc_net *tn = net_generic(net, tipc_net_id); 295 296 tipc_subscrp_create(net, (struct tipc_subscr *)buf, subscriber, &sub); 297 if (sub) 298 tipc_nametbl_subscribe(sub); 299 else 300 tipc_conn_terminate(tn->topsrv, subscriber->conid); 301 } 302 303 /* Handle one request to establish a new subscriber */ 304 static void *tipc_subscrb_connect_cb(int conid) 305 { 306 return (void *)tipc_subscrb_create(conid); 307 } 308 309 int tipc_topsrv_start(struct net *net) 310 { 311 struct tipc_net *tn = net_generic(net, tipc_net_id); 312 const char name[] = "topology_server"; 313 struct tipc_server *topsrv; 314 struct sockaddr_tipc *saddr; 315 316 saddr = kzalloc(sizeof(*saddr), GFP_ATOMIC); 317 if (!saddr) 318 return -ENOMEM; 319 saddr->family = AF_TIPC; 320 saddr->addrtype = TIPC_ADDR_NAMESEQ; 321 saddr->addr.nameseq.type = TIPC_TOP_SRV; 322 saddr->addr.nameseq.lower = TIPC_TOP_SRV; 323 saddr->addr.nameseq.upper = TIPC_TOP_SRV; 324 saddr->scope = TIPC_NODE_SCOPE; 325 326 topsrv = kzalloc(sizeof(*topsrv), GFP_ATOMIC); 327 if (!topsrv) { 328 kfree(saddr); 329 return -ENOMEM; 330 } 331 topsrv->net = net; 332 topsrv->saddr = saddr; 333 topsrv->imp = TIPC_CRITICAL_IMPORTANCE; 334 topsrv->type = SOCK_SEQPACKET; 335 topsrv->max_rcvbuf_size = sizeof(struct tipc_subscr); 336 topsrv->tipc_conn_recvmsg = tipc_subscrb_rcv_cb; 337 topsrv->tipc_conn_new = tipc_subscrb_connect_cb; 338 topsrv->tipc_conn_shutdown = tipc_subscrb_shutdown_cb; 339 340 strncpy(topsrv->name, name, strlen(name) + 1); 341 tn->topsrv = topsrv; 342 atomic_set(&tn->subscription_count, 0); 343 344 return tipc_server_start(topsrv); 345 } 346 347 void tipc_topsrv_stop(struct net *net) 348 { 349 struct tipc_net *tn = net_generic(net, tipc_net_id); 350 struct tipc_server *topsrv = tn->topsrv; 351 352 tipc_server_stop(topsrv); 353 kfree(topsrv->saddr); 354 kfree(topsrv); 355 } 356