1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * IEEE 802.1D Generic Attribute Registration Protocol (GARP) 4 * 5 * Copyright (c) 2008 Patrick McHardy <kaber@trash.net> 6 */ 7 #include <linux/kernel.h> 8 #include <linux/timer.h> 9 #include <linux/skbuff.h> 10 #include <linux/netdevice.h> 11 #include <linux/etherdevice.h> 12 #include <linux/rtnetlink.h> 13 #include <linux/llc.h> 14 #include <linux/slab.h> 15 #include <linux/module.h> 16 #include <net/llc.h> 17 #include <net/llc_pdu.h> 18 #include <net/garp.h> 19 #include <asm/unaligned.h> 20 21 static unsigned int garp_join_time __read_mostly = 200; 22 module_param(garp_join_time, uint, 0644); 23 MODULE_PARM_DESC(garp_join_time, "Join time in ms (default 200ms)"); 24 MODULE_LICENSE("GPL"); 25 26 static const struct garp_state_trans { 27 u8 state; 28 u8 action; 29 } garp_applicant_state_table[GARP_APPLICANT_MAX + 1][GARP_EVENT_MAX + 1] = { 30 [GARP_APPLICANT_VA] = { 31 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_AA, 32 .action = GARP_ACTION_S_JOIN_IN }, 33 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_AA }, 34 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VA }, 35 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VA }, 36 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VA }, 37 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP }, 38 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID }, 39 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_LA }, 40 }, 41 [GARP_APPLICANT_AA] = { 42 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_QA, 43 .action = GARP_ACTION_S_JOIN_IN }, 44 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QA }, 45 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VA }, 46 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VA }, 47 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VA }, 48 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP }, 49 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID }, 50 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_LA }, 51 }, 52 [GARP_APPLICANT_QA] = { 53 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID }, 54 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QA }, 55 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VA }, 56 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VA }, 57 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VP }, 58 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP }, 59 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID }, 60 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_LA }, 61 }, 62 [GARP_APPLICANT_LA] = { 63 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_VO, 64 .action = GARP_ACTION_S_LEAVE_EMPTY }, 65 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_LA }, 66 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VO }, 67 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_LA }, 68 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_LA }, 69 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VO }, 70 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_VA }, 71 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_INVALID }, 72 }, 73 [GARP_APPLICANT_VP] = { 74 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_AA, 75 .action = GARP_ACTION_S_JOIN_IN }, 76 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_AP }, 77 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VP }, 78 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VP }, 79 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VP }, 80 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP }, 81 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID }, 82 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_VO }, 83 }, 84 [GARP_APPLICANT_AP] = { 85 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_QA, 86 .action = GARP_ACTION_S_JOIN_IN }, 87 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QP }, 88 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VP }, 89 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VP }, 90 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VP }, 91 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP }, 92 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID }, 93 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_AO }, 94 }, 95 [GARP_APPLICANT_QP] = { 96 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID }, 97 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QP }, 98 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VP }, 99 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VP }, 100 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VP }, 101 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP }, 102 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID }, 103 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_QO }, 104 }, 105 [GARP_APPLICANT_VO] = { 106 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID }, 107 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_AO }, 108 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VO }, 109 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VO }, 110 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VO }, 111 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VO }, 112 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_VP }, 113 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_INVALID }, 114 }, 115 [GARP_APPLICANT_AO] = { 116 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID }, 117 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QO }, 118 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VO }, 119 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VO }, 120 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VO }, 121 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VO }, 122 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_AP }, 123 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_INVALID }, 124 }, 125 [GARP_APPLICANT_QO] = { 126 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID }, 127 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QO }, 128 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VO }, 129 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VO }, 130 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VO }, 131 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VO }, 132 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_QP }, 133 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_INVALID }, 134 }, 135 }; 136 137 static int garp_attr_cmp(const struct garp_attr *attr, 138 const void *data, u8 len, u8 type) 139 { 140 if (attr->type != type) 141 return attr->type - type; 142 if (attr->dlen != len) 143 return attr->dlen - len; 144 return memcmp(attr->data, data, len); 145 } 146 147 static struct garp_attr *garp_attr_lookup(const struct garp_applicant *app, 148 const void *data, u8 len, u8 type) 149 { 150 struct rb_node *parent = app->gid.rb_node; 151 struct garp_attr *attr; 152 int d; 153 154 while (parent) { 155 attr = rb_entry(parent, struct garp_attr, node); 156 d = garp_attr_cmp(attr, data, len, type); 157 if (d > 0) 158 parent = parent->rb_left; 159 else if (d < 0) 160 parent = parent->rb_right; 161 else 162 return attr; 163 } 164 return NULL; 165 } 166 167 static struct garp_attr *garp_attr_create(struct garp_applicant *app, 168 const void *data, u8 len, u8 type) 169 { 170 struct rb_node *parent = NULL, **p = &app->gid.rb_node; 171 struct garp_attr *attr; 172 int d; 173 174 while (*p) { 175 parent = *p; 176 attr = rb_entry(parent, struct garp_attr, node); 177 d = garp_attr_cmp(attr, data, len, type); 178 if (d > 0) 179 p = &parent->rb_left; 180 else if (d < 0) 181 p = &parent->rb_right; 182 else { 183 /* The attribute already exists; re-use it. */ 184 return attr; 185 } 186 } 187 attr = kmalloc(sizeof(*attr) + len, GFP_ATOMIC); 188 if (!attr) 189 return attr; 190 attr->state = GARP_APPLICANT_VO; 191 attr->type = type; 192 attr->dlen = len; 193 memcpy(attr->data, data, len); 194 195 rb_link_node(&attr->node, parent, p); 196 rb_insert_color(&attr->node, &app->gid); 197 return attr; 198 } 199 200 static void garp_attr_destroy(struct garp_applicant *app, struct garp_attr *attr) 201 { 202 rb_erase(&attr->node, &app->gid); 203 kfree(attr); 204 } 205 206 static int garp_pdu_init(struct garp_applicant *app) 207 { 208 struct sk_buff *skb; 209 struct garp_pdu_hdr *gp; 210 211 #define LLC_RESERVE sizeof(struct llc_pdu_un) 212 skb = alloc_skb(app->dev->mtu + LL_RESERVED_SPACE(app->dev), 213 GFP_ATOMIC); 214 if (!skb) 215 return -ENOMEM; 216 217 skb->dev = app->dev; 218 skb->protocol = htons(ETH_P_802_2); 219 skb_reserve(skb, LL_RESERVED_SPACE(app->dev) + LLC_RESERVE); 220 221 gp = __skb_put(skb, sizeof(*gp)); 222 put_unaligned(htons(GARP_PROTOCOL_ID), &gp->protocol); 223 224 app->pdu = skb; 225 return 0; 226 } 227 228 static int garp_pdu_append_end_mark(struct garp_applicant *app) 229 { 230 if (skb_tailroom(app->pdu) < sizeof(u8)) 231 return -1; 232 __skb_put_u8(app->pdu, GARP_END_MARK); 233 return 0; 234 } 235 236 static void garp_pdu_queue(struct garp_applicant *app) 237 { 238 if (!app->pdu) 239 return; 240 241 garp_pdu_append_end_mark(app); 242 garp_pdu_append_end_mark(app); 243 244 llc_pdu_header_init(app->pdu, LLC_PDU_TYPE_U, LLC_SAP_BSPAN, 245 LLC_SAP_BSPAN, LLC_PDU_CMD); 246 llc_pdu_init_as_ui_cmd(app->pdu); 247 llc_mac_hdr_init(app->pdu, app->dev->dev_addr, 248 app->app->proto.group_address); 249 250 skb_queue_tail(&app->queue, app->pdu); 251 app->pdu = NULL; 252 } 253 254 static void garp_queue_xmit(struct garp_applicant *app) 255 { 256 struct sk_buff *skb; 257 258 while ((skb = skb_dequeue(&app->queue))) 259 dev_queue_xmit(skb); 260 } 261 262 static int garp_pdu_append_msg(struct garp_applicant *app, u8 attrtype) 263 { 264 struct garp_msg_hdr *gm; 265 266 if (skb_tailroom(app->pdu) < sizeof(*gm)) 267 return -1; 268 gm = __skb_put(app->pdu, sizeof(*gm)); 269 gm->attrtype = attrtype; 270 garp_cb(app->pdu)->cur_type = attrtype; 271 return 0; 272 } 273 274 static int garp_pdu_append_attr(struct garp_applicant *app, 275 const struct garp_attr *attr, 276 enum garp_attr_event event) 277 { 278 struct garp_attr_hdr *ga; 279 unsigned int len; 280 int err; 281 again: 282 if (!app->pdu) { 283 err = garp_pdu_init(app); 284 if (err < 0) 285 return err; 286 } 287 288 if (garp_cb(app->pdu)->cur_type != attr->type) { 289 if (garp_cb(app->pdu)->cur_type && 290 garp_pdu_append_end_mark(app) < 0) 291 goto queue; 292 if (garp_pdu_append_msg(app, attr->type) < 0) 293 goto queue; 294 } 295 296 len = sizeof(*ga) + attr->dlen; 297 if (skb_tailroom(app->pdu) < len) 298 goto queue; 299 ga = __skb_put(app->pdu, len); 300 ga->len = len; 301 ga->event = event; 302 memcpy(ga->data, attr->data, attr->dlen); 303 return 0; 304 305 queue: 306 garp_pdu_queue(app); 307 goto again; 308 } 309 310 static void garp_attr_event(struct garp_applicant *app, 311 struct garp_attr *attr, enum garp_event event) 312 { 313 enum garp_applicant_state state; 314 315 state = garp_applicant_state_table[attr->state][event].state; 316 if (state == GARP_APPLICANT_INVALID) 317 return; 318 319 switch (garp_applicant_state_table[attr->state][event].action) { 320 case GARP_ACTION_NONE: 321 break; 322 case GARP_ACTION_S_JOIN_IN: 323 /* When appending the attribute fails, don't update state in 324 * order to retry on next TRANSMIT_PDU event. */ 325 if (garp_pdu_append_attr(app, attr, GARP_JOIN_IN) < 0) 326 return; 327 break; 328 case GARP_ACTION_S_LEAVE_EMPTY: 329 garp_pdu_append_attr(app, attr, GARP_LEAVE_EMPTY); 330 /* As a pure applicant, sending a leave message implies that 331 * the attribute was unregistered and can be destroyed. */ 332 garp_attr_destroy(app, attr); 333 return; 334 default: 335 WARN_ON(1); 336 } 337 338 attr->state = state; 339 } 340 341 int garp_request_join(const struct net_device *dev, 342 const struct garp_application *appl, 343 const void *data, u8 len, u8 type) 344 { 345 struct garp_port *port = rtnl_dereference(dev->garp_port); 346 struct garp_applicant *app = rtnl_dereference(port->applicants[appl->type]); 347 struct garp_attr *attr; 348 349 spin_lock_bh(&app->lock); 350 attr = garp_attr_create(app, data, len, type); 351 if (!attr) { 352 spin_unlock_bh(&app->lock); 353 return -ENOMEM; 354 } 355 garp_attr_event(app, attr, GARP_EVENT_REQ_JOIN); 356 spin_unlock_bh(&app->lock); 357 return 0; 358 } 359 EXPORT_SYMBOL_GPL(garp_request_join); 360 361 void garp_request_leave(const struct net_device *dev, 362 const struct garp_application *appl, 363 const void *data, u8 len, u8 type) 364 { 365 struct garp_port *port = rtnl_dereference(dev->garp_port); 366 struct garp_applicant *app = rtnl_dereference(port->applicants[appl->type]); 367 struct garp_attr *attr; 368 369 spin_lock_bh(&app->lock); 370 attr = garp_attr_lookup(app, data, len, type); 371 if (!attr) { 372 spin_unlock_bh(&app->lock); 373 return; 374 } 375 garp_attr_event(app, attr, GARP_EVENT_REQ_LEAVE); 376 spin_unlock_bh(&app->lock); 377 } 378 EXPORT_SYMBOL_GPL(garp_request_leave); 379 380 static void garp_gid_event(struct garp_applicant *app, enum garp_event event) 381 { 382 struct rb_node *node, *next; 383 struct garp_attr *attr; 384 385 for (node = rb_first(&app->gid); 386 next = node ? rb_next(node) : NULL, node != NULL; 387 node = next) { 388 attr = rb_entry(node, struct garp_attr, node); 389 garp_attr_event(app, attr, event); 390 } 391 } 392 393 static void garp_join_timer_arm(struct garp_applicant *app) 394 { 395 unsigned long delay; 396 397 delay = (u64)msecs_to_jiffies(garp_join_time) * prandom_u32() >> 32; 398 mod_timer(&app->join_timer, jiffies + delay); 399 } 400 401 static void garp_join_timer(struct timer_list *t) 402 { 403 struct garp_applicant *app = from_timer(app, t, join_timer); 404 405 spin_lock(&app->lock); 406 garp_gid_event(app, GARP_EVENT_TRANSMIT_PDU); 407 garp_pdu_queue(app); 408 spin_unlock(&app->lock); 409 410 garp_queue_xmit(app); 411 garp_join_timer_arm(app); 412 } 413 414 static int garp_pdu_parse_end_mark(struct sk_buff *skb) 415 { 416 if (!pskb_may_pull(skb, sizeof(u8))) 417 return -1; 418 if (*skb->data == GARP_END_MARK) { 419 skb_pull(skb, sizeof(u8)); 420 return -1; 421 } 422 return 0; 423 } 424 425 static int garp_pdu_parse_attr(struct garp_applicant *app, struct sk_buff *skb, 426 u8 attrtype) 427 { 428 const struct garp_attr_hdr *ga; 429 struct garp_attr *attr; 430 enum garp_event event; 431 unsigned int dlen; 432 433 if (!pskb_may_pull(skb, sizeof(*ga))) 434 return -1; 435 ga = (struct garp_attr_hdr *)skb->data; 436 if (ga->len < sizeof(*ga)) 437 return -1; 438 439 if (!pskb_may_pull(skb, ga->len)) 440 return -1; 441 skb_pull(skb, ga->len); 442 dlen = sizeof(*ga) - ga->len; 443 444 if (attrtype > app->app->maxattr) 445 return 0; 446 447 switch (ga->event) { 448 case GARP_LEAVE_ALL: 449 if (dlen != 0) 450 return -1; 451 garp_gid_event(app, GARP_EVENT_R_LEAVE_EMPTY); 452 return 0; 453 case GARP_JOIN_EMPTY: 454 event = GARP_EVENT_R_JOIN_EMPTY; 455 break; 456 case GARP_JOIN_IN: 457 event = GARP_EVENT_R_JOIN_IN; 458 break; 459 case GARP_LEAVE_EMPTY: 460 event = GARP_EVENT_R_LEAVE_EMPTY; 461 break; 462 case GARP_EMPTY: 463 event = GARP_EVENT_R_EMPTY; 464 break; 465 default: 466 return 0; 467 } 468 469 if (dlen == 0) 470 return -1; 471 attr = garp_attr_lookup(app, ga->data, dlen, attrtype); 472 if (attr == NULL) 473 return 0; 474 garp_attr_event(app, attr, event); 475 return 0; 476 } 477 478 static int garp_pdu_parse_msg(struct garp_applicant *app, struct sk_buff *skb) 479 { 480 const struct garp_msg_hdr *gm; 481 482 if (!pskb_may_pull(skb, sizeof(*gm))) 483 return -1; 484 gm = (struct garp_msg_hdr *)skb->data; 485 if (gm->attrtype == 0) 486 return -1; 487 skb_pull(skb, sizeof(*gm)); 488 489 while (skb->len > 0) { 490 if (garp_pdu_parse_attr(app, skb, gm->attrtype) < 0) 491 return -1; 492 if (garp_pdu_parse_end_mark(skb) < 0) 493 break; 494 } 495 return 0; 496 } 497 498 static void garp_pdu_rcv(const struct stp_proto *proto, struct sk_buff *skb, 499 struct net_device *dev) 500 { 501 struct garp_application *appl = proto->data; 502 struct garp_port *port; 503 struct garp_applicant *app; 504 const struct garp_pdu_hdr *gp; 505 506 port = rcu_dereference(dev->garp_port); 507 if (!port) 508 goto err; 509 app = rcu_dereference(port->applicants[appl->type]); 510 if (!app) 511 goto err; 512 513 if (!pskb_may_pull(skb, sizeof(*gp))) 514 goto err; 515 gp = (struct garp_pdu_hdr *)skb->data; 516 if (get_unaligned(&gp->protocol) != htons(GARP_PROTOCOL_ID)) 517 goto err; 518 skb_pull(skb, sizeof(*gp)); 519 520 spin_lock(&app->lock); 521 while (skb->len > 0) { 522 if (garp_pdu_parse_msg(app, skb) < 0) 523 break; 524 if (garp_pdu_parse_end_mark(skb) < 0) 525 break; 526 } 527 spin_unlock(&app->lock); 528 err: 529 kfree_skb(skb); 530 } 531 532 static int garp_init_port(struct net_device *dev) 533 { 534 struct garp_port *port; 535 536 port = kzalloc(sizeof(*port), GFP_KERNEL); 537 if (!port) 538 return -ENOMEM; 539 rcu_assign_pointer(dev->garp_port, port); 540 return 0; 541 } 542 543 static void garp_release_port(struct net_device *dev) 544 { 545 struct garp_port *port = rtnl_dereference(dev->garp_port); 546 unsigned int i; 547 548 for (i = 0; i <= GARP_APPLICATION_MAX; i++) { 549 if (rtnl_dereference(port->applicants[i])) 550 return; 551 } 552 RCU_INIT_POINTER(dev->garp_port, NULL); 553 kfree_rcu(port, rcu); 554 } 555 556 int garp_init_applicant(struct net_device *dev, struct garp_application *appl) 557 { 558 struct garp_applicant *app; 559 int err; 560 561 ASSERT_RTNL(); 562 563 if (!rtnl_dereference(dev->garp_port)) { 564 err = garp_init_port(dev); 565 if (err < 0) 566 goto err1; 567 } 568 569 err = -ENOMEM; 570 app = kzalloc(sizeof(*app), GFP_KERNEL); 571 if (!app) 572 goto err2; 573 574 err = dev_mc_add(dev, appl->proto.group_address); 575 if (err < 0) 576 goto err3; 577 578 app->dev = dev; 579 app->app = appl; 580 app->gid = RB_ROOT; 581 spin_lock_init(&app->lock); 582 skb_queue_head_init(&app->queue); 583 rcu_assign_pointer(dev->garp_port->applicants[appl->type], app); 584 timer_setup(&app->join_timer, garp_join_timer, 0); 585 garp_join_timer_arm(app); 586 return 0; 587 588 err3: 589 kfree(app); 590 err2: 591 garp_release_port(dev); 592 err1: 593 return err; 594 } 595 EXPORT_SYMBOL_GPL(garp_init_applicant); 596 597 void garp_uninit_applicant(struct net_device *dev, struct garp_application *appl) 598 { 599 struct garp_port *port = rtnl_dereference(dev->garp_port); 600 struct garp_applicant *app = rtnl_dereference(port->applicants[appl->type]); 601 602 ASSERT_RTNL(); 603 604 RCU_INIT_POINTER(port->applicants[appl->type], NULL); 605 606 /* Delete timer and generate a final TRANSMIT_PDU event to flush out 607 * all pending messages before the applicant is gone. */ 608 del_timer_sync(&app->join_timer); 609 610 spin_lock_bh(&app->lock); 611 garp_gid_event(app, GARP_EVENT_TRANSMIT_PDU); 612 garp_pdu_queue(app); 613 spin_unlock_bh(&app->lock); 614 615 garp_queue_xmit(app); 616 617 dev_mc_del(dev, appl->proto.group_address); 618 kfree_rcu(app, rcu); 619 garp_release_port(dev); 620 } 621 EXPORT_SYMBOL_GPL(garp_uninit_applicant); 622 623 int garp_register_application(struct garp_application *appl) 624 { 625 appl->proto.rcv = garp_pdu_rcv; 626 appl->proto.data = appl; 627 return stp_proto_register(&appl->proto); 628 } 629 EXPORT_SYMBOL_GPL(garp_register_application); 630 631 void garp_unregister_application(struct garp_application *appl) 632 { 633 stp_proto_unregister(&appl->proto); 634 } 635 EXPORT_SYMBOL_GPL(garp_unregister_application); 636