1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) 2 /* gw.c - CAN frame Gateway/Router/Bridge with netlink interface 3 * 4 * Copyright (c) 2019 Volkswagen Group Electronic Research 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of Volkswagen nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * Alternatively, provided that this notice is retained in full, this 20 * software may be distributed under the terms of the GNU General 21 * Public License ("GPL") version 2, in which case the provisions of the 22 * GPL apply INSTEAD OF those given above. 23 * 24 * The provided data structures and external interfaces from this code 25 * are not restricted to be used by modules with a GPL compatible license. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 38 * DAMAGE. 39 * 40 */ 41 42 #include <linux/module.h> 43 #include <linux/init.h> 44 #include <linux/types.h> 45 #include <linux/kernel.h> 46 #include <linux/list.h> 47 #include <linux/spinlock.h> 48 #include <linux/rcupdate.h> 49 #include <linux/rculist.h> 50 #include <linux/net.h> 51 #include <linux/netdevice.h> 52 #include <linux/if_arp.h> 53 #include <linux/skbuff.h> 54 #include <linux/can.h> 55 #include <linux/can/core.h> 56 #include <linux/can/skb.h> 57 #include <linux/can/gw.h> 58 #include <net/rtnetlink.h> 59 #include <net/net_namespace.h> 60 #include <net/sock.h> 61 62 #define CAN_GW_NAME "can-gw" 63 64 MODULE_DESCRIPTION("PF_CAN netlink gateway"); 65 MODULE_LICENSE("Dual BSD/GPL"); 66 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>"); 67 MODULE_ALIAS(CAN_GW_NAME); 68 69 #define CGW_MIN_HOPS 1 70 #define CGW_MAX_HOPS 6 71 #define CGW_DEFAULT_HOPS 1 72 73 static unsigned int max_hops __read_mostly = CGW_DEFAULT_HOPS; 74 module_param(max_hops, uint, 0444); 75 MODULE_PARM_DESC(max_hops, 76 "maximum " CAN_GW_NAME " routing hops for CAN frames " 77 "(valid values: " __stringify(CGW_MIN_HOPS) "-" 78 __stringify(CGW_MAX_HOPS) " hops, " 79 "default: " __stringify(CGW_DEFAULT_HOPS) ")"); 80 81 static struct notifier_block notifier; 82 static struct kmem_cache *cgw_cache __read_mostly; 83 84 /* structure that contains the (on-the-fly) CAN frame modifications */ 85 struct cf_mod { 86 struct { 87 struct canfd_frame and; 88 struct canfd_frame or; 89 struct canfd_frame xor; 90 struct canfd_frame set; 91 } modframe; 92 struct { 93 u8 and; 94 u8 or; 95 u8 xor; 96 u8 set; 97 } modtype; 98 void (*modfunc[MAX_MODFUNCTIONS])(struct canfd_frame *cf, 99 struct cf_mod *mod); 100 101 /* CAN frame checksum calculation after CAN frame modifications */ 102 struct { 103 struct cgw_csum_xor xor; 104 struct cgw_csum_crc8 crc8; 105 } csum; 106 struct { 107 void (*xor)(struct canfd_frame *cf, 108 struct cgw_csum_xor *xor); 109 void (*crc8)(struct canfd_frame *cf, 110 struct cgw_csum_crc8 *crc8); 111 } csumfunc; 112 u32 uid; 113 }; 114 115 /* So far we just support CAN -> CAN routing and frame modifications. 116 * 117 * The internal can_can_gw structure contains data and attributes for 118 * a CAN -> CAN gateway job. 119 */ 120 struct can_can_gw { 121 struct can_filter filter; 122 int src_idx; 123 int dst_idx; 124 }; 125 126 /* list entry for CAN gateways jobs */ 127 struct cgw_job { 128 struct hlist_node list; 129 struct rcu_head rcu; 130 u32 handled_frames; 131 u32 dropped_frames; 132 u32 deleted_frames; 133 struct cf_mod __rcu *cf_mod; 134 union { 135 /* CAN frame data source */ 136 struct net_device *dev; 137 } src; 138 union { 139 /* CAN frame data destination */ 140 struct net_device *dev; 141 } dst; 142 union { 143 struct can_can_gw ccgw; 144 /* tbc */ 145 }; 146 u8 gwtype; 147 u8 limit_hops; 148 u16 flags; 149 }; 150 151 /* modification functions that are invoked in the hot path in can_can_gw_rcv */ 152 153 #define MODFUNC(func, op) static void func(struct canfd_frame *cf, \ 154 struct cf_mod *mod) { op ; } 155 156 MODFUNC(mod_and_id, cf->can_id &= mod->modframe.and.can_id) 157 MODFUNC(mod_and_len, cf->len &= mod->modframe.and.len) 158 MODFUNC(mod_and_flags, cf->flags &= mod->modframe.and.flags) 159 MODFUNC(mod_and_data, *(u64 *)cf->data &= *(u64 *)mod->modframe.and.data) 160 MODFUNC(mod_or_id, cf->can_id |= mod->modframe.or.can_id) 161 MODFUNC(mod_or_len, cf->len |= mod->modframe.or.len) 162 MODFUNC(mod_or_flags, cf->flags |= mod->modframe.or.flags) 163 MODFUNC(mod_or_data, *(u64 *)cf->data |= *(u64 *)mod->modframe.or.data) 164 MODFUNC(mod_xor_id, cf->can_id ^= mod->modframe.xor.can_id) 165 MODFUNC(mod_xor_len, cf->len ^= mod->modframe.xor.len) 166 MODFUNC(mod_xor_flags, cf->flags ^= mod->modframe.xor.flags) 167 MODFUNC(mod_xor_data, *(u64 *)cf->data ^= *(u64 *)mod->modframe.xor.data) 168 MODFUNC(mod_set_id, cf->can_id = mod->modframe.set.can_id) 169 MODFUNC(mod_set_len, cf->len = mod->modframe.set.len) 170 MODFUNC(mod_set_flags, cf->flags = mod->modframe.set.flags) 171 MODFUNC(mod_set_data, *(u64 *)cf->data = *(u64 *)mod->modframe.set.data) 172 173 static void mod_and_fddata(struct canfd_frame *cf, struct cf_mod *mod) 174 { 175 int i; 176 177 for (i = 0; i < CANFD_MAX_DLEN; i += 8) 178 *(u64 *)(cf->data + i) &= *(u64 *)(mod->modframe.and.data + i); 179 } 180 181 static void mod_or_fddata(struct canfd_frame *cf, struct cf_mod *mod) 182 { 183 int i; 184 185 for (i = 0; i < CANFD_MAX_DLEN; i += 8) 186 *(u64 *)(cf->data + i) |= *(u64 *)(mod->modframe.or.data + i); 187 } 188 189 static void mod_xor_fddata(struct canfd_frame *cf, struct cf_mod *mod) 190 { 191 int i; 192 193 for (i = 0; i < CANFD_MAX_DLEN; i += 8) 194 *(u64 *)(cf->data + i) ^= *(u64 *)(mod->modframe.xor.data + i); 195 } 196 197 static void mod_set_fddata(struct canfd_frame *cf, struct cf_mod *mod) 198 { 199 memcpy(cf->data, mod->modframe.set.data, CANFD_MAX_DLEN); 200 } 201 202 /* retrieve valid CC DLC value and store it into 'len' */ 203 static void mod_retrieve_ccdlc(struct canfd_frame *cf) 204 { 205 struct can_frame *ccf = (struct can_frame *)cf; 206 207 /* len8_dlc is only valid if len == CAN_MAX_DLEN */ 208 if (ccf->len != CAN_MAX_DLEN) 209 return; 210 211 /* do we have a valid len8_dlc value from 9 .. 15 ? */ 212 if (ccf->len8_dlc > CAN_MAX_DLEN && ccf->len8_dlc <= CAN_MAX_RAW_DLC) 213 ccf->len = ccf->len8_dlc; 214 } 215 216 /* convert valid CC DLC value in 'len' into struct can_frame elements */ 217 static void mod_store_ccdlc(struct canfd_frame *cf) 218 { 219 struct can_frame *ccf = (struct can_frame *)cf; 220 221 /* clear potential leftovers */ 222 ccf->len8_dlc = 0; 223 224 /* plain data length 0 .. 8 - that was easy */ 225 if (ccf->len <= CAN_MAX_DLEN) 226 return; 227 228 /* potentially broken values are caught in can_can_gw_rcv() */ 229 if (ccf->len > CAN_MAX_RAW_DLC) 230 return; 231 232 /* we have a valid dlc value from 9 .. 15 in ccf->len */ 233 ccf->len8_dlc = ccf->len; 234 ccf->len = CAN_MAX_DLEN; 235 } 236 237 static void mod_and_ccdlc(struct canfd_frame *cf, struct cf_mod *mod) 238 { 239 mod_retrieve_ccdlc(cf); 240 mod_and_len(cf, mod); 241 mod_store_ccdlc(cf); 242 } 243 244 static void mod_or_ccdlc(struct canfd_frame *cf, struct cf_mod *mod) 245 { 246 mod_retrieve_ccdlc(cf); 247 mod_or_len(cf, mod); 248 mod_store_ccdlc(cf); 249 } 250 251 static void mod_xor_ccdlc(struct canfd_frame *cf, struct cf_mod *mod) 252 { 253 mod_retrieve_ccdlc(cf); 254 mod_xor_len(cf, mod); 255 mod_store_ccdlc(cf); 256 } 257 258 static void mod_set_ccdlc(struct canfd_frame *cf, struct cf_mod *mod) 259 { 260 mod_set_len(cf, mod); 261 mod_store_ccdlc(cf); 262 } 263 264 static void canframecpy(struct canfd_frame *dst, struct can_frame *src) 265 { 266 /* Copy the struct members separately to ensure that no uninitialized 267 * data are copied in the 3 bytes hole of the struct. This is needed 268 * to make easy compares of the data in the struct cf_mod. 269 */ 270 271 dst->can_id = src->can_id; 272 dst->len = src->len; 273 *(u64 *)dst->data = *(u64 *)src->data; 274 } 275 276 static void canfdframecpy(struct canfd_frame *dst, struct canfd_frame *src) 277 { 278 /* Copy the struct members separately to ensure that no uninitialized 279 * data are copied in the 2 bytes hole of the struct. This is needed 280 * to make easy compares of the data in the struct cf_mod. 281 */ 282 283 dst->can_id = src->can_id; 284 dst->flags = src->flags; 285 dst->len = src->len; 286 memcpy(dst->data, src->data, CANFD_MAX_DLEN); 287 } 288 289 static int cgw_chk_csum_parms(s8 fr, s8 to, s8 re, struct rtcanmsg *r) 290 { 291 s8 dlen = CAN_MAX_DLEN; 292 293 if (r->flags & CGW_FLAGS_CAN_FD) 294 dlen = CANFD_MAX_DLEN; 295 296 /* absolute dlc values 0 .. 7 => 0 .. 7, e.g. data [0] 297 * relative to received dlc -1 .. -8 : 298 * e.g. for received dlc = 8 299 * -1 => index = 7 (data[7]) 300 * -3 => index = 5 (data[5]) 301 * -8 => index = 0 (data[0]) 302 */ 303 304 if (fr >= -dlen && fr < dlen && 305 to >= -dlen && to < dlen && 306 re >= -dlen && re < dlen) 307 return 0; 308 else 309 return -EINVAL; 310 } 311 312 static inline int calc_idx(int idx, int rx_len) 313 { 314 if (idx < 0) 315 return rx_len + idx; 316 else 317 return idx; 318 } 319 320 static void cgw_csum_xor_rel(struct canfd_frame *cf, struct cgw_csum_xor *xor) 321 { 322 int from = calc_idx(xor->from_idx, cf->len); 323 int to = calc_idx(xor->to_idx, cf->len); 324 int res = calc_idx(xor->result_idx, cf->len); 325 u8 val = xor->init_xor_val; 326 int i; 327 328 if (from < 0 || to < 0 || res < 0) 329 return; 330 331 if (from <= to) { 332 for (i = from; i <= to; i++) 333 val ^= cf->data[i]; 334 } else { 335 for (i = from; i >= to; i--) 336 val ^= cf->data[i]; 337 } 338 339 cf->data[res] = val; 340 } 341 342 static void cgw_csum_xor_pos(struct canfd_frame *cf, struct cgw_csum_xor *xor) 343 { 344 u8 val = xor->init_xor_val; 345 int i; 346 347 for (i = xor->from_idx; i <= xor->to_idx; i++) 348 val ^= cf->data[i]; 349 350 cf->data[xor->result_idx] = val; 351 } 352 353 static void cgw_csum_xor_neg(struct canfd_frame *cf, struct cgw_csum_xor *xor) 354 { 355 u8 val = xor->init_xor_val; 356 int i; 357 358 for (i = xor->from_idx; i >= xor->to_idx; i--) 359 val ^= cf->data[i]; 360 361 cf->data[xor->result_idx] = val; 362 } 363 364 static void cgw_csum_crc8_rel(struct canfd_frame *cf, 365 struct cgw_csum_crc8 *crc8) 366 { 367 int from = calc_idx(crc8->from_idx, cf->len); 368 int to = calc_idx(crc8->to_idx, cf->len); 369 int res = calc_idx(crc8->result_idx, cf->len); 370 u8 crc = crc8->init_crc_val; 371 int i; 372 373 if (from < 0 || to < 0 || res < 0) 374 return; 375 376 if (from <= to) { 377 for (i = crc8->from_idx; i <= crc8->to_idx; i++) 378 crc = crc8->crctab[crc ^ cf->data[i]]; 379 } else { 380 for (i = crc8->from_idx; i >= crc8->to_idx; i--) 381 crc = crc8->crctab[crc ^ cf->data[i]]; 382 } 383 384 switch (crc8->profile) { 385 case CGW_CRC8PRF_1U8: 386 crc = crc8->crctab[crc ^ crc8->profile_data[0]]; 387 break; 388 389 case CGW_CRC8PRF_16U8: 390 crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]]; 391 break; 392 393 case CGW_CRC8PRF_SFFID_XOR: 394 crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^ 395 (cf->can_id >> 8 & 0xFF)]; 396 break; 397 } 398 399 cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val; 400 } 401 402 static void cgw_csum_crc8_pos(struct canfd_frame *cf, 403 struct cgw_csum_crc8 *crc8) 404 { 405 u8 crc = crc8->init_crc_val; 406 int i; 407 408 for (i = crc8->from_idx; i <= crc8->to_idx; i++) 409 crc = crc8->crctab[crc ^ cf->data[i]]; 410 411 switch (crc8->profile) { 412 case CGW_CRC8PRF_1U8: 413 crc = crc8->crctab[crc ^ crc8->profile_data[0]]; 414 break; 415 416 case CGW_CRC8PRF_16U8: 417 crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]]; 418 break; 419 420 case CGW_CRC8PRF_SFFID_XOR: 421 crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^ 422 (cf->can_id >> 8 & 0xFF)]; 423 break; 424 } 425 426 cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val; 427 } 428 429 static void cgw_csum_crc8_neg(struct canfd_frame *cf, 430 struct cgw_csum_crc8 *crc8) 431 { 432 u8 crc = crc8->init_crc_val; 433 int i; 434 435 for (i = crc8->from_idx; i >= crc8->to_idx; i--) 436 crc = crc8->crctab[crc ^ cf->data[i]]; 437 438 switch (crc8->profile) { 439 case CGW_CRC8PRF_1U8: 440 crc = crc8->crctab[crc ^ crc8->profile_data[0]]; 441 break; 442 443 case CGW_CRC8PRF_16U8: 444 crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]]; 445 break; 446 447 case CGW_CRC8PRF_SFFID_XOR: 448 crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^ 449 (cf->can_id >> 8 & 0xFF)]; 450 break; 451 } 452 453 cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val; 454 } 455 456 /* the receive & process & send function */ 457 static void can_can_gw_rcv(struct sk_buff *skb, void *data) 458 { 459 struct cgw_job *gwj = (struct cgw_job *)data; 460 struct canfd_frame *cf; 461 struct sk_buff *nskb; 462 struct cf_mod *mod; 463 int modidx = 0; 464 465 /* process strictly Classic CAN or CAN FD frames */ 466 if (gwj->flags & CGW_FLAGS_CAN_FD) { 467 if (!can_is_canfd_skb(skb)) 468 return; 469 } else { 470 if (!can_is_can_skb(skb)) 471 return; 472 } 473 474 /* Do not handle CAN frames routed more than 'max_hops' times. 475 * In general we should never catch this delimiter which is intended 476 * to cover a misconfiguration protection (e.g. circular CAN routes). 477 * 478 * The Controller Area Network controllers only accept CAN frames with 479 * correct CRCs - which are not visible in the controller registers. 480 * According to skbuff.h documentation the csum_start element for IP 481 * checksums is undefined/unused when ip_summed == CHECKSUM_UNNECESSARY. 482 * Only CAN skbs can be processed here which already have this property. 483 */ 484 485 #define cgw_hops(skb) ((skb)->csum_start) 486 487 BUG_ON(skb->ip_summed != CHECKSUM_UNNECESSARY); 488 489 if (cgw_hops(skb) >= max_hops) { 490 /* indicate deleted frames due to misconfiguration */ 491 gwj->deleted_frames++; 492 return; 493 } 494 495 if (!(gwj->dst.dev->flags & IFF_UP)) { 496 gwj->dropped_frames++; 497 return; 498 } 499 500 /* is sending the skb back to the incoming interface not allowed? */ 501 if (!(gwj->flags & CGW_FLAGS_CAN_IIF_TX_OK) && 502 can_skb_prv(skb)->ifindex == gwj->dst.dev->ifindex) 503 return; 504 505 /* clone the given skb, which has not been done in can_rcv() 506 * 507 * When there is at least one modification function activated, 508 * we need to copy the skb as we want to modify skb->data. 509 */ 510 mod = rcu_dereference(gwj->cf_mod); 511 if (mod->modfunc[0]) 512 nskb = skb_copy(skb, GFP_ATOMIC); 513 else 514 nskb = skb_clone(skb, GFP_ATOMIC); 515 516 if (!nskb) { 517 gwj->dropped_frames++; 518 return; 519 } 520 521 /* put the incremented hop counter in the cloned skb */ 522 cgw_hops(nskb) = cgw_hops(skb) + 1; 523 524 /* first processing of this CAN frame -> adjust to private hop limit */ 525 if (gwj->limit_hops && cgw_hops(nskb) == 1) 526 cgw_hops(nskb) = max_hops - gwj->limit_hops + 1; 527 528 nskb->dev = gwj->dst.dev; 529 530 /* pointer to modifiable CAN frame */ 531 cf = (struct canfd_frame *)nskb->data; 532 533 /* perform preprocessed modification functions if there are any */ 534 while (modidx < MAX_MODFUNCTIONS && mod->modfunc[modidx]) 535 (*mod->modfunc[modidx++])(cf, mod); 536 537 /* Has the CAN frame been modified? */ 538 if (modidx) { 539 /* get available space for the processed CAN frame type */ 540 int max_len = nskb->len - offsetof(struct canfd_frame, data); 541 542 /* dlc may have changed, make sure it fits to the CAN frame */ 543 if (cf->len > max_len) { 544 /* delete frame due to misconfiguration */ 545 gwj->deleted_frames++; 546 kfree_skb(nskb); 547 return; 548 } 549 550 /* check for checksum updates */ 551 if (mod->csumfunc.crc8) 552 (*mod->csumfunc.crc8)(cf, &mod->csum.crc8); 553 554 if (mod->csumfunc.xor) 555 (*mod->csumfunc.xor)(cf, &mod->csum.xor); 556 } 557 558 /* clear the skb timestamp if not configured the other way */ 559 if (!(gwj->flags & CGW_FLAGS_CAN_SRC_TSTAMP)) 560 nskb->tstamp = 0; 561 562 /* send to netdevice */ 563 if (can_send(nskb, gwj->flags & CGW_FLAGS_CAN_ECHO)) 564 gwj->dropped_frames++; 565 else 566 gwj->handled_frames++; 567 } 568 569 static inline int cgw_register_filter(struct net *net, struct cgw_job *gwj) 570 { 571 return can_rx_register(net, gwj->src.dev, gwj->ccgw.filter.can_id, 572 gwj->ccgw.filter.can_mask, can_can_gw_rcv, 573 gwj, "gw", NULL); 574 } 575 576 static inline void cgw_unregister_filter(struct net *net, struct cgw_job *gwj) 577 { 578 can_rx_unregister(net, gwj->src.dev, gwj->ccgw.filter.can_id, 579 gwj->ccgw.filter.can_mask, can_can_gw_rcv, gwj); 580 } 581 582 static void cgw_job_free_rcu(struct rcu_head *rcu_head) 583 { 584 struct cgw_job *gwj = container_of(rcu_head, struct cgw_job, rcu); 585 586 /* cgw_job::cf_mod is always accessed from the same cgw_job object within 587 * the same RCU read section. Once cgw_job is scheduled for removal, 588 * cf_mod can also be removed without mandating an additional grace period. 589 */ 590 kfree(rcu_access_pointer(gwj->cf_mod)); 591 kmem_cache_free(cgw_cache, gwj); 592 } 593 594 /* Return cgw_job::cf_mod with RTNL protected section */ 595 static struct cf_mod *cgw_job_cf_mod(struct cgw_job *gwj) 596 { 597 return rcu_dereference_protected(gwj->cf_mod, rtnl_is_locked()); 598 } 599 600 static int cgw_notifier(struct notifier_block *nb, 601 unsigned long msg, void *ptr) 602 { 603 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 604 struct net *net = dev_net(dev); 605 606 if (dev->type != ARPHRD_CAN) 607 return NOTIFY_DONE; 608 609 if (msg == NETDEV_UNREGISTER) { 610 struct cgw_job *gwj = NULL; 611 struct hlist_node *nx; 612 613 ASSERT_RTNL(); 614 615 hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) { 616 if (gwj->src.dev == dev || gwj->dst.dev == dev) { 617 hlist_del(&gwj->list); 618 cgw_unregister_filter(net, gwj); 619 call_rcu(&gwj->rcu, cgw_job_free_rcu); 620 } 621 } 622 } 623 624 return NOTIFY_DONE; 625 } 626 627 static int cgw_put_job(struct sk_buff *skb, struct cgw_job *gwj, int type, 628 u32 pid, u32 seq, int flags) 629 { 630 struct rtcanmsg *rtcan; 631 struct nlmsghdr *nlh; 632 struct cf_mod *mod; 633 634 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*rtcan), flags); 635 if (!nlh) 636 return -EMSGSIZE; 637 638 rtcan = nlmsg_data(nlh); 639 rtcan->can_family = AF_CAN; 640 rtcan->gwtype = gwj->gwtype; 641 rtcan->flags = gwj->flags; 642 643 /* add statistics if available */ 644 645 if (gwj->handled_frames) { 646 if (nla_put_u32(skb, CGW_HANDLED, gwj->handled_frames) < 0) 647 goto cancel; 648 } 649 650 if (gwj->dropped_frames) { 651 if (nla_put_u32(skb, CGW_DROPPED, gwj->dropped_frames) < 0) 652 goto cancel; 653 } 654 655 if (gwj->deleted_frames) { 656 if (nla_put_u32(skb, CGW_DELETED, gwj->deleted_frames) < 0) 657 goto cancel; 658 } 659 660 /* check non default settings of attributes */ 661 662 if (gwj->limit_hops) { 663 if (nla_put_u8(skb, CGW_LIM_HOPS, gwj->limit_hops) < 0) 664 goto cancel; 665 } 666 667 mod = cgw_job_cf_mod(gwj); 668 if (gwj->flags & CGW_FLAGS_CAN_FD) { 669 struct cgw_fdframe_mod mb; 670 671 if (mod->modtype.and) { 672 memcpy(&mb.cf, &mod->modframe.and, sizeof(mb.cf)); 673 mb.modtype = mod->modtype.and; 674 if (nla_put(skb, CGW_FDMOD_AND, sizeof(mb), &mb) < 0) 675 goto cancel; 676 } 677 678 if (mod->modtype.or) { 679 memcpy(&mb.cf, &mod->modframe.or, sizeof(mb.cf)); 680 mb.modtype = mod->modtype.or; 681 if (nla_put(skb, CGW_FDMOD_OR, sizeof(mb), &mb) < 0) 682 goto cancel; 683 } 684 685 if (mod->modtype.xor) { 686 memcpy(&mb.cf, &mod->modframe.xor, sizeof(mb.cf)); 687 mb.modtype = mod->modtype.xor; 688 if (nla_put(skb, CGW_FDMOD_XOR, sizeof(mb), &mb) < 0) 689 goto cancel; 690 } 691 692 if (mod->modtype.set) { 693 memcpy(&mb.cf, &mod->modframe.set, sizeof(mb.cf)); 694 mb.modtype = mod->modtype.set; 695 if (nla_put(skb, CGW_FDMOD_SET, sizeof(mb), &mb) < 0) 696 goto cancel; 697 } 698 } else { 699 struct cgw_frame_mod mb; 700 701 if (mod->modtype.and) { 702 memcpy(&mb.cf, &mod->modframe.and, sizeof(mb.cf)); 703 mb.modtype = mod->modtype.and; 704 if (nla_put(skb, CGW_MOD_AND, sizeof(mb), &mb) < 0) 705 goto cancel; 706 } 707 708 if (mod->modtype.or) { 709 memcpy(&mb.cf, &mod->modframe.or, sizeof(mb.cf)); 710 mb.modtype = mod->modtype.or; 711 if (nla_put(skb, CGW_MOD_OR, sizeof(mb), &mb) < 0) 712 goto cancel; 713 } 714 715 if (mod->modtype.xor) { 716 memcpy(&mb.cf, &mod->modframe.xor, sizeof(mb.cf)); 717 mb.modtype = mod->modtype.xor; 718 if (nla_put(skb, CGW_MOD_XOR, sizeof(mb), &mb) < 0) 719 goto cancel; 720 } 721 722 if (mod->modtype.set) { 723 memcpy(&mb.cf, &mod->modframe.set, sizeof(mb.cf)); 724 mb.modtype = mod->modtype.set; 725 if (nla_put(skb, CGW_MOD_SET, sizeof(mb), &mb) < 0) 726 goto cancel; 727 } 728 } 729 730 if (mod->uid) { 731 if (nla_put_u32(skb, CGW_MOD_UID, mod->uid) < 0) 732 goto cancel; 733 } 734 735 if (mod->csumfunc.crc8) { 736 if (nla_put(skb, CGW_CS_CRC8, CGW_CS_CRC8_LEN, 737 &mod->csum.crc8) < 0) 738 goto cancel; 739 } 740 741 if (mod->csumfunc.xor) { 742 if (nla_put(skb, CGW_CS_XOR, CGW_CS_XOR_LEN, 743 &mod->csum.xor) < 0) 744 goto cancel; 745 } 746 747 if (gwj->gwtype == CGW_TYPE_CAN_CAN) { 748 if (gwj->ccgw.filter.can_id || gwj->ccgw.filter.can_mask) { 749 if (nla_put(skb, CGW_FILTER, sizeof(struct can_filter), 750 &gwj->ccgw.filter) < 0) 751 goto cancel; 752 } 753 754 if (nla_put_u32(skb, CGW_SRC_IF, gwj->ccgw.src_idx) < 0) 755 goto cancel; 756 757 if (nla_put_u32(skb, CGW_DST_IF, gwj->ccgw.dst_idx) < 0) 758 goto cancel; 759 } 760 761 nlmsg_end(skb, nlh); 762 return 0; 763 764 cancel: 765 nlmsg_cancel(skb, nlh); 766 return -EMSGSIZE; 767 } 768 769 /* Dump information about all CAN gateway jobs, in response to RTM_GETROUTE */ 770 static int cgw_dump_jobs(struct sk_buff *skb, struct netlink_callback *cb) 771 { 772 struct net *net = sock_net(skb->sk); 773 struct cgw_job *gwj = NULL; 774 int idx = 0; 775 int s_idx = cb->args[0]; 776 777 rcu_read_lock(); 778 hlist_for_each_entry_rcu(gwj, &net->can.cgw_list, list) { 779 if (idx < s_idx) 780 goto cont; 781 782 if (cgw_put_job(skb, gwj, RTM_NEWROUTE, 783 NETLINK_CB(cb->skb).portid, 784 cb->nlh->nlmsg_seq, NLM_F_MULTI) < 0) 785 break; 786 cont: 787 idx++; 788 } 789 rcu_read_unlock(); 790 791 cb->args[0] = idx; 792 793 return skb->len; 794 } 795 796 static const struct nla_policy cgw_policy[CGW_MAX + 1] = { 797 [CGW_MOD_AND] = { .len = sizeof(struct cgw_frame_mod) }, 798 [CGW_MOD_OR] = { .len = sizeof(struct cgw_frame_mod) }, 799 [CGW_MOD_XOR] = { .len = sizeof(struct cgw_frame_mod) }, 800 [CGW_MOD_SET] = { .len = sizeof(struct cgw_frame_mod) }, 801 [CGW_CS_XOR] = { .len = sizeof(struct cgw_csum_xor) }, 802 [CGW_CS_CRC8] = { .len = sizeof(struct cgw_csum_crc8) }, 803 [CGW_SRC_IF] = { .type = NLA_U32 }, 804 [CGW_DST_IF] = { .type = NLA_U32 }, 805 [CGW_FILTER] = { .len = sizeof(struct can_filter) }, 806 [CGW_LIM_HOPS] = { .type = NLA_U8 }, 807 [CGW_MOD_UID] = { .type = NLA_U32 }, 808 [CGW_FDMOD_AND] = { .len = sizeof(struct cgw_fdframe_mod) }, 809 [CGW_FDMOD_OR] = { .len = sizeof(struct cgw_fdframe_mod) }, 810 [CGW_FDMOD_XOR] = { .len = sizeof(struct cgw_fdframe_mod) }, 811 [CGW_FDMOD_SET] = { .len = sizeof(struct cgw_fdframe_mod) }, 812 }; 813 814 /* check for common and gwtype specific attributes */ 815 static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod, 816 u8 gwtype, void *gwtypeattr, u8 *limhops) 817 { 818 struct nlattr *tb[CGW_MAX + 1]; 819 struct rtcanmsg *r = nlmsg_data(nlh); 820 int modidx = 0; 821 int err = 0; 822 823 /* initialize modification & checksum data space */ 824 memset(mod, 0, sizeof(*mod)); 825 826 err = nlmsg_parse_deprecated(nlh, sizeof(struct rtcanmsg), tb, 827 CGW_MAX, cgw_policy, NULL); 828 if (err < 0) 829 return err; 830 831 if (tb[CGW_LIM_HOPS]) { 832 *limhops = nla_get_u8(tb[CGW_LIM_HOPS]); 833 834 if (*limhops < 1 || *limhops > max_hops) 835 return -EINVAL; 836 } 837 838 /* check for AND/OR/XOR/SET modifications */ 839 if (r->flags & CGW_FLAGS_CAN_FD) { 840 struct cgw_fdframe_mod mb; 841 842 if (tb[CGW_FDMOD_AND]) { 843 nla_memcpy(&mb, tb[CGW_FDMOD_AND], CGW_FDMODATTR_LEN); 844 845 canfdframecpy(&mod->modframe.and, &mb.cf); 846 mod->modtype.and = mb.modtype; 847 848 if (mb.modtype & CGW_MOD_ID) 849 mod->modfunc[modidx++] = mod_and_id; 850 851 if (mb.modtype & CGW_MOD_LEN) 852 mod->modfunc[modidx++] = mod_and_len; 853 854 if (mb.modtype & CGW_MOD_FLAGS) 855 mod->modfunc[modidx++] = mod_and_flags; 856 857 if (mb.modtype & CGW_MOD_DATA) 858 mod->modfunc[modidx++] = mod_and_fddata; 859 } 860 861 if (tb[CGW_FDMOD_OR]) { 862 nla_memcpy(&mb, tb[CGW_FDMOD_OR], CGW_FDMODATTR_LEN); 863 864 canfdframecpy(&mod->modframe.or, &mb.cf); 865 mod->modtype.or = mb.modtype; 866 867 if (mb.modtype & CGW_MOD_ID) 868 mod->modfunc[modidx++] = mod_or_id; 869 870 if (mb.modtype & CGW_MOD_LEN) 871 mod->modfunc[modidx++] = mod_or_len; 872 873 if (mb.modtype & CGW_MOD_FLAGS) 874 mod->modfunc[modidx++] = mod_or_flags; 875 876 if (mb.modtype & CGW_MOD_DATA) 877 mod->modfunc[modidx++] = mod_or_fddata; 878 } 879 880 if (tb[CGW_FDMOD_XOR]) { 881 nla_memcpy(&mb, tb[CGW_FDMOD_XOR], CGW_FDMODATTR_LEN); 882 883 canfdframecpy(&mod->modframe.xor, &mb.cf); 884 mod->modtype.xor = mb.modtype; 885 886 if (mb.modtype & CGW_MOD_ID) 887 mod->modfunc[modidx++] = mod_xor_id; 888 889 if (mb.modtype & CGW_MOD_LEN) 890 mod->modfunc[modidx++] = mod_xor_len; 891 892 if (mb.modtype & CGW_MOD_FLAGS) 893 mod->modfunc[modidx++] = mod_xor_flags; 894 895 if (mb.modtype & CGW_MOD_DATA) 896 mod->modfunc[modidx++] = mod_xor_fddata; 897 } 898 899 if (tb[CGW_FDMOD_SET]) { 900 nla_memcpy(&mb, tb[CGW_FDMOD_SET], CGW_FDMODATTR_LEN); 901 902 canfdframecpy(&mod->modframe.set, &mb.cf); 903 mod->modtype.set = mb.modtype; 904 905 if (mb.modtype & CGW_MOD_ID) 906 mod->modfunc[modidx++] = mod_set_id; 907 908 if (mb.modtype & CGW_MOD_LEN) 909 mod->modfunc[modidx++] = mod_set_len; 910 911 if (mb.modtype & CGW_MOD_FLAGS) 912 mod->modfunc[modidx++] = mod_set_flags; 913 914 if (mb.modtype & CGW_MOD_DATA) 915 mod->modfunc[modidx++] = mod_set_fddata; 916 } 917 } else { 918 struct cgw_frame_mod mb; 919 920 if (tb[CGW_MOD_AND]) { 921 nla_memcpy(&mb, tb[CGW_MOD_AND], CGW_MODATTR_LEN); 922 923 canframecpy(&mod->modframe.and, &mb.cf); 924 mod->modtype.and = mb.modtype; 925 926 if (mb.modtype & CGW_MOD_ID) 927 mod->modfunc[modidx++] = mod_and_id; 928 929 if (mb.modtype & CGW_MOD_DLC) 930 mod->modfunc[modidx++] = mod_and_ccdlc; 931 932 if (mb.modtype & CGW_MOD_DATA) 933 mod->modfunc[modidx++] = mod_and_data; 934 } 935 936 if (tb[CGW_MOD_OR]) { 937 nla_memcpy(&mb, tb[CGW_MOD_OR], CGW_MODATTR_LEN); 938 939 canframecpy(&mod->modframe.or, &mb.cf); 940 mod->modtype.or = mb.modtype; 941 942 if (mb.modtype & CGW_MOD_ID) 943 mod->modfunc[modidx++] = mod_or_id; 944 945 if (mb.modtype & CGW_MOD_DLC) 946 mod->modfunc[modidx++] = mod_or_ccdlc; 947 948 if (mb.modtype & CGW_MOD_DATA) 949 mod->modfunc[modidx++] = mod_or_data; 950 } 951 952 if (tb[CGW_MOD_XOR]) { 953 nla_memcpy(&mb, tb[CGW_MOD_XOR], CGW_MODATTR_LEN); 954 955 canframecpy(&mod->modframe.xor, &mb.cf); 956 mod->modtype.xor = mb.modtype; 957 958 if (mb.modtype & CGW_MOD_ID) 959 mod->modfunc[modidx++] = mod_xor_id; 960 961 if (mb.modtype & CGW_MOD_DLC) 962 mod->modfunc[modidx++] = mod_xor_ccdlc; 963 964 if (mb.modtype & CGW_MOD_DATA) 965 mod->modfunc[modidx++] = mod_xor_data; 966 } 967 968 if (tb[CGW_MOD_SET]) { 969 nla_memcpy(&mb, tb[CGW_MOD_SET], CGW_MODATTR_LEN); 970 971 canframecpy(&mod->modframe.set, &mb.cf); 972 mod->modtype.set = mb.modtype; 973 974 if (mb.modtype & CGW_MOD_ID) 975 mod->modfunc[modidx++] = mod_set_id; 976 977 if (mb.modtype & CGW_MOD_DLC) 978 mod->modfunc[modidx++] = mod_set_ccdlc; 979 980 if (mb.modtype & CGW_MOD_DATA) 981 mod->modfunc[modidx++] = mod_set_data; 982 } 983 } 984 985 /* check for checksum operations after CAN frame modifications */ 986 if (modidx) { 987 if (tb[CGW_CS_CRC8]) { 988 struct cgw_csum_crc8 *c = nla_data(tb[CGW_CS_CRC8]); 989 990 err = cgw_chk_csum_parms(c->from_idx, c->to_idx, 991 c->result_idx, r); 992 if (err) 993 return err; 994 995 nla_memcpy(&mod->csum.crc8, tb[CGW_CS_CRC8], 996 CGW_CS_CRC8_LEN); 997 998 /* select dedicated processing function to reduce 999 * runtime operations in receive hot path. 1000 */ 1001 if (c->from_idx < 0 || c->to_idx < 0 || 1002 c->result_idx < 0) 1003 mod->csumfunc.crc8 = cgw_csum_crc8_rel; 1004 else if (c->from_idx <= c->to_idx) 1005 mod->csumfunc.crc8 = cgw_csum_crc8_pos; 1006 else 1007 mod->csumfunc.crc8 = cgw_csum_crc8_neg; 1008 } 1009 1010 if (tb[CGW_CS_XOR]) { 1011 struct cgw_csum_xor *c = nla_data(tb[CGW_CS_XOR]); 1012 1013 err = cgw_chk_csum_parms(c->from_idx, c->to_idx, 1014 c->result_idx, r); 1015 if (err) 1016 return err; 1017 1018 nla_memcpy(&mod->csum.xor, tb[CGW_CS_XOR], 1019 CGW_CS_XOR_LEN); 1020 1021 /* select dedicated processing function to reduce 1022 * runtime operations in receive hot path. 1023 */ 1024 if (c->from_idx < 0 || c->to_idx < 0 || 1025 c->result_idx < 0) 1026 mod->csumfunc.xor = cgw_csum_xor_rel; 1027 else if (c->from_idx <= c->to_idx) 1028 mod->csumfunc.xor = cgw_csum_xor_pos; 1029 else 1030 mod->csumfunc.xor = cgw_csum_xor_neg; 1031 } 1032 1033 if (tb[CGW_MOD_UID]) 1034 nla_memcpy(&mod->uid, tb[CGW_MOD_UID], sizeof(u32)); 1035 } 1036 1037 if (gwtype == CGW_TYPE_CAN_CAN) { 1038 /* check CGW_TYPE_CAN_CAN specific attributes */ 1039 struct can_can_gw *ccgw = (struct can_can_gw *)gwtypeattr; 1040 1041 memset(ccgw, 0, sizeof(*ccgw)); 1042 1043 /* check for can_filter in attributes */ 1044 if (tb[CGW_FILTER]) 1045 nla_memcpy(&ccgw->filter, tb[CGW_FILTER], 1046 sizeof(struct can_filter)); 1047 1048 err = -ENODEV; 1049 1050 /* specifying two interfaces is mandatory */ 1051 if (!tb[CGW_SRC_IF] || !tb[CGW_DST_IF]) 1052 return err; 1053 1054 ccgw->src_idx = nla_get_u32(tb[CGW_SRC_IF]); 1055 ccgw->dst_idx = nla_get_u32(tb[CGW_DST_IF]); 1056 1057 /* both indices set to 0 for flushing all routing entries */ 1058 if (!ccgw->src_idx && !ccgw->dst_idx) 1059 return 0; 1060 1061 /* only one index set to 0 is an error */ 1062 if (!ccgw->src_idx || !ccgw->dst_idx) 1063 return err; 1064 } 1065 1066 /* add the checks for other gwtypes here */ 1067 1068 return 0; 1069 } 1070 1071 static int cgw_create_job(struct sk_buff *skb, struct nlmsghdr *nlh, 1072 struct netlink_ext_ack *extack) 1073 { 1074 struct net *net = sock_net(skb->sk); 1075 struct rtcanmsg *r; 1076 struct cgw_job *gwj; 1077 struct cf_mod *mod; 1078 struct can_can_gw ccgw; 1079 u8 limhops = 0; 1080 int err = 0; 1081 1082 if (!netlink_capable(skb, CAP_NET_ADMIN)) 1083 return -EPERM; 1084 1085 if (nlmsg_len(nlh) < sizeof(*r)) 1086 return -EINVAL; 1087 1088 r = nlmsg_data(nlh); 1089 if (r->can_family != AF_CAN) 1090 return -EPFNOSUPPORT; 1091 1092 /* so far we only support CAN -> CAN routings */ 1093 if (r->gwtype != CGW_TYPE_CAN_CAN) 1094 return -EINVAL; 1095 1096 mod = kmalloc(sizeof(*mod), GFP_KERNEL); 1097 if (!mod) 1098 return -ENOMEM; 1099 1100 err = cgw_parse_attr(nlh, mod, CGW_TYPE_CAN_CAN, &ccgw, &limhops); 1101 if (err < 0) 1102 goto out_free_cf; 1103 1104 if (mod->uid) { 1105 ASSERT_RTNL(); 1106 1107 /* check for updating an existing job with identical uid */ 1108 hlist_for_each_entry(gwj, &net->can.cgw_list, list) { 1109 struct cf_mod *old_cf; 1110 1111 old_cf = cgw_job_cf_mod(gwj); 1112 if (old_cf->uid != mod->uid) 1113 continue; 1114 1115 /* interfaces & filters must be identical */ 1116 if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw))) { 1117 err = -EINVAL; 1118 goto out_free_cf; 1119 } 1120 1121 rcu_assign_pointer(gwj->cf_mod, mod); 1122 kfree_rcu_mightsleep(old_cf); 1123 return 0; 1124 } 1125 } 1126 1127 /* ifindex == 0 is not allowed for job creation */ 1128 if (!ccgw.src_idx || !ccgw.dst_idx) { 1129 err = -ENODEV; 1130 goto out_free_cf; 1131 } 1132 1133 gwj = kmem_cache_alloc(cgw_cache, GFP_KERNEL); 1134 if (!gwj) { 1135 err = -ENOMEM; 1136 goto out_free_cf; 1137 } 1138 1139 gwj->handled_frames = 0; 1140 gwj->dropped_frames = 0; 1141 gwj->deleted_frames = 0; 1142 gwj->flags = r->flags; 1143 gwj->gwtype = r->gwtype; 1144 gwj->limit_hops = limhops; 1145 1146 /* insert already parsed information */ 1147 RCU_INIT_POINTER(gwj->cf_mod, mod); 1148 memcpy(&gwj->ccgw, &ccgw, sizeof(ccgw)); 1149 1150 err = -ENODEV; 1151 1152 gwj->src.dev = __dev_get_by_index(net, gwj->ccgw.src_idx); 1153 1154 if (!gwj->src.dev) 1155 goto out; 1156 1157 if (gwj->src.dev->type != ARPHRD_CAN) 1158 goto out; 1159 1160 gwj->dst.dev = __dev_get_by_index(net, gwj->ccgw.dst_idx); 1161 1162 if (!gwj->dst.dev) 1163 goto out; 1164 1165 if (gwj->dst.dev->type != ARPHRD_CAN) 1166 goto out; 1167 1168 /* is sending the skb back to the incoming interface intended? */ 1169 if (gwj->src.dev == gwj->dst.dev && 1170 !(gwj->flags & CGW_FLAGS_CAN_IIF_TX_OK)) { 1171 err = -EINVAL; 1172 goto out; 1173 } 1174 1175 ASSERT_RTNL(); 1176 1177 err = cgw_register_filter(net, gwj); 1178 if (!err) 1179 hlist_add_head_rcu(&gwj->list, &net->can.cgw_list); 1180 out: 1181 if (err) { 1182 kmem_cache_free(cgw_cache, gwj); 1183 out_free_cf: 1184 kfree(mod); 1185 } 1186 return err; 1187 } 1188 1189 static void cgw_remove_all_jobs(struct net *net) 1190 { 1191 struct cgw_job *gwj = NULL; 1192 struct hlist_node *nx; 1193 1194 ASSERT_RTNL(); 1195 1196 hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) { 1197 hlist_del(&gwj->list); 1198 cgw_unregister_filter(net, gwj); 1199 call_rcu(&gwj->rcu, cgw_job_free_rcu); 1200 } 1201 } 1202 1203 static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh, 1204 struct netlink_ext_ack *extack) 1205 { 1206 struct net *net = sock_net(skb->sk); 1207 struct cgw_job *gwj = NULL; 1208 struct hlist_node *nx; 1209 struct rtcanmsg *r; 1210 struct cf_mod mod; 1211 struct can_can_gw ccgw; 1212 u8 limhops = 0; 1213 int err = 0; 1214 1215 if (!netlink_capable(skb, CAP_NET_ADMIN)) 1216 return -EPERM; 1217 1218 if (nlmsg_len(nlh) < sizeof(*r)) 1219 return -EINVAL; 1220 1221 r = nlmsg_data(nlh); 1222 if (r->can_family != AF_CAN) 1223 return -EPFNOSUPPORT; 1224 1225 /* so far we only support CAN -> CAN routings */ 1226 if (r->gwtype != CGW_TYPE_CAN_CAN) 1227 return -EINVAL; 1228 1229 err = cgw_parse_attr(nlh, &mod, CGW_TYPE_CAN_CAN, &ccgw, &limhops); 1230 if (err < 0) 1231 return err; 1232 1233 /* two interface indices both set to 0 => remove all entries */ 1234 if (!ccgw.src_idx && !ccgw.dst_idx) { 1235 cgw_remove_all_jobs(net); 1236 return 0; 1237 } 1238 1239 err = -EINVAL; 1240 1241 ASSERT_RTNL(); 1242 1243 /* remove only the first matching entry */ 1244 hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) { 1245 struct cf_mod *cf_mod; 1246 1247 if (gwj->flags != r->flags) 1248 continue; 1249 1250 if (gwj->limit_hops != limhops) 1251 continue; 1252 1253 cf_mod = cgw_job_cf_mod(gwj); 1254 /* we have a match when uid is enabled and identical */ 1255 if (cf_mod->uid || mod.uid) { 1256 if (cf_mod->uid != mod.uid) 1257 continue; 1258 } else { 1259 /* no uid => check for identical modifications */ 1260 if (memcmp(cf_mod, &mod, sizeof(mod))) 1261 continue; 1262 } 1263 1264 /* if (r->gwtype == CGW_TYPE_CAN_CAN) - is made sure here */ 1265 if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw))) 1266 continue; 1267 1268 hlist_del(&gwj->list); 1269 cgw_unregister_filter(net, gwj); 1270 call_rcu(&gwj->rcu, cgw_job_free_rcu); 1271 err = 0; 1272 break; 1273 } 1274 1275 return err; 1276 } 1277 1278 static int __net_init cangw_pernet_init(struct net *net) 1279 { 1280 INIT_HLIST_HEAD(&net->can.cgw_list); 1281 return 0; 1282 } 1283 1284 static void __net_exit cangw_pernet_exit_batch(struct list_head *net_list) 1285 { 1286 struct net *net; 1287 1288 rtnl_lock(); 1289 list_for_each_entry(net, net_list, exit_list) 1290 cgw_remove_all_jobs(net); 1291 rtnl_unlock(); 1292 } 1293 1294 static struct pernet_operations cangw_pernet_ops = { 1295 .init = cangw_pernet_init, 1296 .exit_batch = cangw_pernet_exit_batch, 1297 }; 1298 1299 static const struct rtnl_msg_handler cgw_rtnl_msg_handlers[] __initconst_or_module = { 1300 {.owner = THIS_MODULE, .protocol = PF_CAN, .msgtype = RTM_NEWROUTE, 1301 .doit = cgw_create_job}, 1302 {.owner = THIS_MODULE, .protocol = PF_CAN, .msgtype = RTM_DELROUTE, 1303 .doit = cgw_remove_job}, 1304 {.owner = THIS_MODULE, .protocol = PF_CAN, .msgtype = RTM_GETROUTE, 1305 .dumpit = cgw_dump_jobs}, 1306 }; 1307 1308 static __init int cgw_module_init(void) 1309 { 1310 int ret; 1311 1312 /* sanitize given module parameter */ 1313 max_hops = clamp_t(unsigned int, max_hops, CGW_MIN_HOPS, CGW_MAX_HOPS); 1314 1315 pr_info("can: netlink gateway - max_hops=%d\n", max_hops); 1316 1317 ret = register_pernet_subsys(&cangw_pernet_ops); 1318 if (ret) 1319 return ret; 1320 1321 ret = -ENOMEM; 1322 cgw_cache = kmem_cache_create("can_gw", sizeof(struct cgw_job), 1323 0, 0, NULL); 1324 if (!cgw_cache) 1325 goto out_cache_create; 1326 1327 /* set notifier */ 1328 notifier.notifier_call = cgw_notifier; 1329 ret = register_netdevice_notifier(¬ifier); 1330 if (ret) 1331 goto out_register_notifier; 1332 1333 ret = rtnl_register_many(cgw_rtnl_msg_handlers); 1334 if (ret) 1335 goto out_rtnl_register; 1336 1337 return 0; 1338 1339 out_rtnl_register: 1340 unregister_netdevice_notifier(¬ifier); 1341 out_register_notifier: 1342 kmem_cache_destroy(cgw_cache); 1343 out_cache_create: 1344 unregister_pernet_subsys(&cangw_pernet_ops); 1345 1346 return ret; 1347 } 1348 1349 static __exit void cgw_module_exit(void) 1350 { 1351 rtnl_unregister_all(PF_CAN); 1352 1353 unregister_netdevice_notifier(¬ifier); 1354 1355 unregister_pernet_subsys(&cangw_pernet_ops); 1356 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 1357 1358 kmem_cache_destroy(cgw_cache); 1359 } 1360 1361 module_init(cgw_module_init); 1362 module_exit(cgw_module_exit); 1363