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 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 int modidx = 0; 463 464 /* process strictly Classic CAN or CAN FD frames */ 465 if (gwj->flags & CGW_FLAGS_CAN_FD) { 466 if (!can_is_canfd_skb(skb)) 467 return; 468 } else { 469 if (!can_is_can_skb(skb)) 470 return; 471 } 472 473 /* Do not handle CAN frames routed more than 'max_hops' times. 474 * In general we should never catch this delimiter which is intended 475 * to cover a misconfiguration protection (e.g. circular CAN routes). 476 * 477 * The Controller Area Network controllers only accept CAN frames with 478 * correct CRCs - which are not visible in the controller registers. 479 * According to skbuff.h documentation the csum_start element for IP 480 * checksums is undefined/unused when ip_summed == CHECKSUM_UNNECESSARY. 481 * Only CAN skbs can be processed here which already have this property. 482 */ 483 484 #define cgw_hops(skb) ((skb)->csum_start) 485 486 BUG_ON(skb->ip_summed != CHECKSUM_UNNECESSARY); 487 488 if (cgw_hops(skb) >= max_hops) { 489 /* indicate deleted frames due to misconfiguration */ 490 gwj->deleted_frames++; 491 return; 492 } 493 494 if (!(gwj->dst.dev->flags & IFF_UP)) { 495 gwj->dropped_frames++; 496 return; 497 } 498 499 /* is sending the skb back to the incoming interface not allowed? */ 500 if (!(gwj->flags & CGW_FLAGS_CAN_IIF_TX_OK) && 501 can_skb_prv(skb)->ifindex == gwj->dst.dev->ifindex) 502 return; 503 504 /* clone the given skb, which has not been done in can_rcv() 505 * 506 * When there is at least one modification function activated, 507 * we need to copy the skb as we want to modify skb->data. 508 */ 509 if (gwj->mod.modfunc[0]) 510 nskb = skb_copy(skb, GFP_ATOMIC); 511 else 512 nskb = skb_clone(skb, GFP_ATOMIC); 513 514 if (!nskb) { 515 gwj->dropped_frames++; 516 return; 517 } 518 519 /* put the incremented hop counter in the cloned skb */ 520 cgw_hops(nskb) = cgw_hops(skb) + 1; 521 522 /* first processing of this CAN frame -> adjust to private hop limit */ 523 if (gwj->limit_hops && cgw_hops(nskb) == 1) 524 cgw_hops(nskb) = max_hops - gwj->limit_hops + 1; 525 526 nskb->dev = gwj->dst.dev; 527 528 /* pointer to modifiable CAN frame */ 529 cf = (struct canfd_frame *)nskb->data; 530 531 /* perform preprocessed modification functions if there are any */ 532 while (modidx < MAX_MODFUNCTIONS && gwj->mod.modfunc[modidx]) 533 (*gwj->mod.modfunc[modidx++])(cf, &gwj->mod); 534 535 /* Has the CAN frame been modified? */ 536 if (modidx) { 537 /* get available space for the processed CAN frame type */ 538 int max_len = nskb->len - offsetof(struct canfd_frame, data); 539 540 /* dlc may have changed, make sure it fits to the CAN frame */ 541 if (cf->len > max_len) { 542 /* delete frame due to misconfiguration */ 543 gwj->deleted_frames++; 544 kfree_skb(nskb); 545 return; 546 } 547 548 /* check for checksum updates */ 549 if (gwj->mod.csumfunc.crc8) 550 (*gwj->mod.csumfunc.crc8)(cf, &gwj->mod.csum.crc8); 551 552 if (gwj->mod.csumfunc.xor) 553 (*gwj->mod.csumfunc.xor)(cf, &gwj->mod.csum.xor); 554 } 555 556 /* clear the skb timestamp if not configured the other way */ 557 if (!(gwj->flags & CGW_FLAGS_CAN_SRC_TSTAMP)) 558 nskb->tstamp = 0; 559 560 /* send to netdevice */ 561 if (can_send(nskb, gwj->flags & CGW_FLAGS_CAN_ECHO)) 562 gwj->dropped_frames++; 563 else 564 gwj->handled_frames++; 565 } 566 567 static inline int cgw_register_filter(struct net *net, struct cgw_job *gwj) 568 { 569 return can_rx_register(net, gwj->src.dev, gwj->ccgw.filter.can_id, 570 gwj->ccgw.filter.can_mask, can_can_gw_rcv, 571 gwj, "gw", NULL); 572 } 573 574 static inline void cgw_unregister_filter(struct net *net, struct cgw_job *gwj) 575 { 576 can_rx_unregister(net, gwj->src.dev, gwj->ccgw.filter.can_id, 577 gwj->ccgw.filter.can_mask, can_can_gw_rcv, gwj); 578 } 579 580 static void cgw_job_free_rcu(struct rcu_head *rcu_head) 581 { 582 struct cgw_job *gwj = container_of(rcu_head, struct cgw_job, rcu); 583 584 kmem_cache_free(cgw_cache, gwj); 585 } 586 587 static int cgw_notifier(struct notifier_block *nb, 588 unsigned long msg, void *ptr) 589 { 590 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 591 struct net *net = dev_net(dev); 592 593 if (dev->type != ARPHRD_CAN) 594 return NOTIFY_DONE; 595 596 if (msg == NETDEV_UNREGISTER) { 597 struct cgw_job *gwj = NULL; 598 struct hlist_node *nx; 599 600 ASSERT_RTNL(); 601 602 hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) { 603 if (gwj->src.dev == dev || gwj->dst.dev == dev) { 604 hlist_del(&gwj->list); 605 cgw_unregister_filter(net, gwj); 606 call_rcu(&gwj->rcu, cgw_job_free_rcu); 607 } 608 } 609 } 610 611 return NOTIFY_DONE; 612 } 613 614 static int cgw_put_job(struct sk_buff *skb, struct cgw_job *gwj, int type, 615 u32 pid, u32 seq, int flags) 616 { 617 struct rtcanmsg *rtcan; 618 struct nlmsghdr *nlh; 619 620 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*rtcan), flags); 621 if (!nlh) 622 return -EMSGSIZE; 623 624 rtcan = nlmsg_data(nlh); 625 rtcan->can_family = AF_CAN; 626 rtcan->gwtype = gwj->gwtype; 627 rtcan->flags = gwj->flags; 628 629 /* add statistics if available */ 630 631 if (gwj->handled_frames) { 632 if (nla_put_u32(skb, CGW_HANDLED, gwj->handled_frames) < 0) 633 goto cancel; 634 } 635 636 if (gwj->dropped_frames) { 637 if (nla_put_u32(skb, CGW_DROPPED, gwj->dropped_frames) < 0) 638 goto cancel; 639 } 640 641 if (gwj->deleted_frames) { 642 if (nla_put_u32(skb, CGW_DELETED, gwj->deleted_frames) < 0) 643 goto cancel; 644 } 645 646 /* check non default settings of attributes */ 647 648 if (gwj->limit_hops) { 649 if (nla_put_u8(skb, CGW_LIM_HOPS, gwj->limit_hops) < 0) 650 goto cancel; 651 } 652 653 if (gwj->flags & CGW_FLAGS_CAN_FD) { 654 struct cgw_fdframe_mod mb; 655 656 if (gwj->mod.modtype.and) { 657 memcpy(&mb.cf, &gwj->mod.modframe.and, sizeof(mb.cf)); 658 mb.modtype = gwj->mod.modtype.and; 659 if (nla_put(skb, CGW_FDMOD_AND, sizeof(mb), &mb) < 0) 660 goto cancel; 661 } 662 663 if (gwj->mod.modtype.or) { 664 memcpy(&mb.cf, &gwj->mod.modframe.or, sizeof(mb.cf)); 665 mb.modtype = gwj->mod.modtype.or; 666 if (nla_put(skb, CGW_FDMOD_OR, sizeof(mb), &mb) < 0) 667 goto cancel; 668 } 669 670 if (gwj->mod.modtype.xor) { 671 memcpy(&mb.cf, &gwj->mod.modframe.xor, sizeof(mb.cf)); 672 mb.modtype = gwj->mod.modtype.xor; 673 if (nla_put(skb, CGW_FDMOD_XOR, sizeof(mb), &mb) < 0) 674 goto cancel; 675 } 676 677 if (gwj->mod.modtype.set) { 678 memcpy(&mb.cf, &gwj->mod.modframe.set, sizeof(mb.cf)); 679 mb.modtype = gwj->mod.modtype.set; 680 if (nla_put(skb, CGW_FDMOD_SET, sizeof(mb), &mb) < 0) 681 goto cancel; 682 } 683 } else { 684 struct cgw_frame_mod mb; 685 686 if (gwj->mod.modtype.and) { 687 memcpy(&mb.cf, &gwj->mod.modframe.and, sizeof(mb.cf)); 688 mb.modtype = gwj->mod.modtype.and; 689 if (nla_put(skb, CGW_MOD_AND, sizeof(mb), &mb) < 0) 690 goto cancel; 691 } 692 693 if (gwj->mod.modtype.or) { 694 memcpy(&mb.cf, &gwj->mod.modframe.or, sizeof(mb.cf)); 695 mb.modtype = gwj->mod.modtype.or; 696 if (nla_put(skb, CGW_MOD_OR, sizeof(mb), &mb) < 0) 697 goto cancel; 698 } 699 700 if (gwj->mod.modtype.xor) { 701 memcpy(&mb.cf, &gwj->mod.modframe.xor, sizeof(mb.cf)); 702 mb.modtype = gwj->mod.modtype.xor; 703 if (nla_put(skb, CGW_MOD_XOR, sizeof(mb), &mb) < 0) 704 goto cancel; 705 } 706 707 if (gwj->mod.modtype.set) { 708 memcpy(&mb.cf, &gwj->mod.modframe.set, sizeof(mb.cf)); 709 mb.modtype = gwj->mod.modtype.set; 710 if (nla_put(skb, CGW_MOD_SET, sizeof(mb), &mb) < 0) 711 goto cancel; 712 } 713 } 714 715 if (gwj->mod.uid) { 716 if (nla_put_u32(skb, CGW_MOD_UID, gwj->mod.uid) < 0) 717 goto cancel; 718 } 719 720 if (gwj->mod.csumfunc.crc8) { 721 if (nla_put(skb, CGW_CS_CRC8, CGW_CS_CRC8_LEN, 722 &gwj->mod.csum.crc8) < 0) 723 goto cancel; 724 } 725 726 if (gwj->mod.csumfunc.xor) { 727 if (nla_put(skb, CGW_CS_XOR, CGW_CS_XOR_LEN, 728 &gwj->mod.csum.xor) < 0) 729 goto cancel; 730 } 731 732 if (gwj->gwtype == CGW_TYPE_CAN_CAN) { 733 if (gwj->ccgw.filter.can_id || gwj->ccgw.filter.can_mask) { 734 if (nla_put(skb, CGW_FILTER, sizeof(struct can_filter), 735 &gwj->ccgw.filter) < 0) 736 goto cancel; 737 } 738 739 if (nla_put_u32(skb, CGW_SRC_IF, gwj->ccgw.src_idx) < 0) 740 goto cancel; 741 742 if (nla_put_u32(skb, CGW_DST_IF, gwj->ccgw.dst_idx) < 0) 743 goto cancel; 744 } 745 746 nlmsg_end(skb, nlh); 747 return 0; 748 749 cancel: 750 nlmsg_cancel(skb, nlh); 751 return -EMSGSIZE; 752 } 753 754 /* Dump information about all CAN gateway jobs, in response to RTM_GETROUTE */ 755 static int cgw_dump_jobs(struct sk_buff *skb, struct netlink_callback *cb) 756 { 757 struct net *net = sock_net(skb->sk); 758 struct cgw_job *gwj = NULL; 759 int idx = 0; 760 int s_idx = cb->args[0]; 761 762 rcu_read_lock(); 763 hlist_for_each_entry_rcu(gwj, &net->can.cgw_list, list) { 764 if (idx < s_idx) 765 goto cont; 766 767 if (cgw_put_job(skb, gwj, RTM_NEWROUTE, 768 NETLINK_CB(cb->skb).portid, 769 cb->nlh->nlmsg_seq, NLM_F_MULTI) < 0) 770 break; 771 cont: 772 idx++; 773 } 774 rcu_read_unlock(); 775 776 cb->args[0] = idx; 777 778 return skb->len; 779 } 780 781 static const struct nla_policy cgw_policy[CGW_MAX + 1] = { 782 [CGW_MOD_AND] = { .len = sizeof(struct cgw_frame_mod) }, 783 [CGW_MOD_OR] = { .len = sizeof(struct cgw_frame_mod) }, 784 [CGW_MOD_XOR] = { .len = sizeof(struct cgw_frame_mod) }, 785 [CGW_MOD_SET] = { .len = sizeof(struct cgw_frame_mod) }, 786 [CGW_CS_XOR] = { .len = sizeof(struct cgw_csum_xor) }, 787 [CGW_CS_CRC8] = { .len = sizeof(struct cgw_csum_crc8) }, 788 [CGW_SRC_IF] = { .type = NLA_U32 }, 789 [CGW_DST_IF] = { .type = NLA_U32 }, 790 [CGW_FILTER] = { .len = sizeof(struct can_filter) }, 791 [CGW_LIM_HOPS] = { .type = NLA_U8 }, 792 [CGW_MOD_UID] = { .type = NLA_U32 }, 793 [CGW_FDMOD_AND] = { .len = sizeof(struct cgw_fdframe_mod) }, 794 [CGW_FDMOD_OR] = { .len = sizeof(struct cgw_fdframe_mod) }, 795 [CGW_FDMOD_XOR] = { .len = sizeof(struct cgw_fdframe_mod) }, 796 [CGW_FDMOD_SET] = { .len = sizeof(struct cgw_fdframe_mod) }, 797 }; 798 799 /* check for common and gwtype specific attributes */ 800 static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod, 801 u8 gwtype, void *gwtypeattr, u8 *limhops) 802 { 803 struct nlattr *tb[CGW_MAX + 1]; 804 struct rtcanmsg *r = nlmsg_data(nlh); 805 int modidx = 0; 806 int err = 0; 807 808 /* initialize modification & checksum data space */ 809 memset(mod, 0, sizeof(*mod)); 810 811 err = nlmsg_parse_deprecated(nlh, sizeof(struct rtcanmsg), tb, 812 CGW_MAX, cgw_policy, NULL); 813 if (err < 0) 814 return err; 815 816 if (tb[CGW_LIM_HOPS]) { 817 *limhops = nla_get_u8(tb[CGW_LIM_HOPS]); 818 819 if (*limhops < 1 || *limhops > max_hops) 820 return -EINVAL; 821 } 822 823 /* check for AND/OR/XOR/SET modifications */ 824 if (r->flags & CGW_FLAGS_CAN_FD) { 825 struct cgw_fdframe_mod mb; 826 827 if (tb[CGW_FDMOD_AND]) { 828 nla_memcpy(&mb, tb[CGW_FDMOD_AND], CGW_FDMODATTR_LEN); 829 830 canfdframecpy(&mod->modframe.and, &mb.cf); 831 mod->modtype.and = mb.modtype; 832 833 if (mb.modtype & CGW_MOD_ID) 834 mod->modfunc[modidx++] = mod_and_id; 835 836 if (mb.modtype & CGW_MOD_LEN) 837 mod->modfunc[modidx++] = mod_and_len; 838 839 if (mb.modtype & CGW_MOD_FLAGS) 840 mod->modfunc[modidx++] = mod_and_flags; 841 842 if (mb.modtype & CGW_MOD_DATA) 843 mod->modfunc[modidx++] = mod_and_fddata; 844 } 845 846 if (tb[CGW_FDMOD_OR]) { 847 nla_memcpy(&mb, tb[CGW_FDMOD_OR], CGW_FDMODATTR_LEN); 848 849 canfdframecpy(&mod->modframe.or, &mb.cf); 850 mod->modtype.or = mb.modtype; 851 852 if (mb.modtype & CGW_MOD_ID) 853 mod->modfunc[modidx++] = mod_or_id; 854 855 if (mb.modtype & CGW_MOD_LEN) 856 mod->modfunc[modidx++] = mod_or_len; 857 858 if (mb.modtype & CGW_MOD_FLAGS) 859 mod->modfunc[modidx++] = mod_or_flags; 860 861 if (mb.modtype & CGW_MOD_DATA) 862 mod->modfunc[modidx++] = mod_or_fddata; 863 } 864 865 if (tb[CGW_FDMOD_XOR]) { 866 nla_memcpy(&mb, tb[CGW_FDMOD_XOR], CGW_FDMODATTR_LEN); 867 868 canfdframecpy(&mod->modframe.xor, &mb.cf); 869 mod->modtype.xor = mb.modtype; 870 871 if (mb.modtype & CGW_MOD_ID) 872 mod->modfunc[modidx++] = mod_xor_id; 873 874 if (mb.modtype & CGW_MOD_LEN) 875 mod->modfunc[modidx++] = mod_xor_len; 876 877 if (mb.modtype & CGW_MOD_FLAGS) 878 mod->modfunc[modidx++] = mod_xor_flags; 879 880 if (mb.modtype & CGW_MOD_DATA) 881 mod->modfunc[modidx++] = mod_xor_fddata; 882 } 883 884 if (tb[CGW_FDMOD_SET]) { 885 nla_memcpy(&mb, tb[CGW_FDMOD_SET], CGW_FDMODATTR_LEN); 886 887 canfdframecpy(&mod->modframe.set, &mb.cf); 888 mod->modtype.set = mb.modtype; 889 890 if (mb.modtype & CGW_MOD_ID) 891 mod->modfunc[modidx++] = mod_set_id; 892 893 if (mb.modtype & CGW_MOD_LEN) 894 mod->modfunc[modidx++] = mod_set_len; 895 896 if (mb.modtype & CGW_MOD_FLAGS) 897 mod->modfunc[modidx++] = mod_set_flags; 898 899 if (mb.modtype & CGW_MOD_DATA) 900 mod->modfunc[modidx++] = mod_set_fddata; 901 } 902 } else { 903 struct cgw_frame_mod mb; 904 905 if (tb[CGW_MOD_AND]) { 906 nla_memcpy(&mb, tb[CGW_MOD_AND], CGW_MODATTR_LEN); 907 908 canframecpy(&mod->modframe.and, &mb.cf); 909 mod->modtype.and = mb.modtype; 910 911 if (mb.modtype & CGW_MOD_ID) 912 mod->modfunc[modidx++] = mod_and_id; 913 914 if (mb.modtype & CGW_MOD_DLC) 915 mod->modfunc[modidx++] = mod_and_ccdlc; 916 917 if (mb.modtype & CGW_MOD_DATA) 918 mod->modfunc[modidx++] = mod_and_data; 919 } 920 921 if (tb[CGW_MOD_OR]) { 922 nla_memcpy(&mb, tb[CGW_MOD_OR], CGW_MODATTR_LEN); 923 924 canframecpy(&mod->modframe.or, &mb.cf); 925 mod->modtype.or = mb.modtype; 926 927 if (mb.modtype & CGW_MOD_ID) 928 mod->modfunc[modidx++] = mod_or_id; 929 930 if (mb.modtype & CGW_MOD_DLC) 931 mod->modfunc[modidx++] = mod_or_ccdlc; 932 933 if (mb.modtype & CGW_MOD_DATA) 934 mod->modfunc[modidx++] = mod_or_data; 935 } 936 937 if (tb[CGW_MOD_XOR]) { 938 nla_memcpy(&mb, tb[CGW_MOD_XOR], CGW_MODATTR_LEN); 939 940 canframecpy(&mod->modframe.xor, &mb.cf); 941 mod->modtype.xor = mb.modtype; 942 943 if (mb.modtype & CGW_MOD_ID) 944 mod->modfunc[modidx++] = mod_xor_id; 945 946 if (mb.modtype & CGW_MOD_DLC) 947 mod->modfunc[modidx++] = mod_xor_ccdlc; 948 949 if (mb.modtype & CGW_MOD_DATA) 950 mod->modfunc[modidx++] = mod_xor_data; 951 } 952 953 if (tb[CGW_MOD_SET]) { 954 nla_memcpy(&mb, tb[CGW_MOD_SET], CGW_MODATTR_LEN); 955 956 canframecpy(&mod->modframe.set, &mb.cf); 957 mod->modtype.set = mb.modtype; 958 959 if (mb.modtype & CGW_MOD_ID) 960 mod->modfunc[modidx++] = mod_set_id; 961 962 if (mb.modtype & CGW_MOD_DLC) 963 mod->modfunc[modidx++] = mod_set_ccdlc; 964 965 if (mb.modtype & CGW_MOD_DATA) 966 mod->modfunc[modidx++] = mod_set_data; 967 } 968 } 969 970 /* check for checksum operations after CAN frame modifications */ 971 if (modidx) { 972 if (tb[CGW_CS_CRC8]) { 973 struct cgw_csum_crc8 *c = nla_data(tb[CGW_CS_CRC8]); 974 975 err = cgw_chk_csum_parms(c->from_idx, c->to_idx, 976 c->result_idx, r); 977 if (err) 978 return err; 979 980 nla_memcpy(&mod->csum.crc8, tb[CGW_CS_CRC8], 981 CGW_CS_CRC8_LEN); 982 983 /* select dedicated processing function to reduce 984 * runtime operations in receive hot path. 985 */ 986 if (c->from_idx < 0 || c->to_idx < 0 || 987 c->result_idx < 0) 988 mod->csumfunc.crc8 = cgw_csum_crc8_rel; 989 else if (c->from_idx <= c->to_idx) 990 mod->csumfunc.crc8 = cgw_csum_crc8_pos; 991 else 992 mod->csumfunc.crc8 = cgw_csum_crc8_neg; 993 } 994 995 if (tb[CGW_CS_XOR]) { 996 struct cgw_csum_xor *c = nla_data(tb[CGW_CS_XOR]); 997 998 err = cgw_chk_csum_parms(c->from_idx, c->to_idx, 999 c->result_idx, r); 1000 if (err) 1001 return err; 1002 1003 nla_memcpy(&mod->csum.xor, tb[CGW_CS_XOR], 1004 CGW_CS_XOR_LEN); 1005 1006 /* select dedicated processing function to reduce 1007 * runtime operations in receive hot path. 1008 */ 1009 if (c->from_idx < 0 || c->to_idx < 0 || 1010 c->result_idx < 0) 1011 mod->csumfunc.xor = cgw_csum_xor_rel; 1012 else if (c->from_idx <= c->to_idx) 1013 mod->csumfunc.xor = cgw_csum_xor_pos; 1014 else 1015 mod->csumfunc.xor = cgw_csum_xor_neg; 1016 } 1017 1018 if (tb[CGW_MOD_UID]) 1019 nla_memcpy(&mod->uid, tb[CGW_MOD_UID], sizeof(u32)); 1020 } 1021 1022 if (gwtype == CGW_TYPE_CAN_CAN) { 1023 /* check CGW_TYPE_CAN_CAN specific attributes */ 1024 struct can_can_gw *ccgw = (struct can_can_gw *)gwtypeattr; 1025 1026 memset(ccgw, 0, sizeof(*ccgw)); 1027 1028 /* check for can_filter in attributes */ 1029 if (tb[CGW_FILTER]) 1030 nla_memcpy(&ccgw->filter, tb[CGW_FILTER], 1031 sizeof(struct can_filter)); 1032 1033 err = -ENODEV; 1034 1035 /* specifying two interfaces is mandatory */ 1036 if (!tb[CGW_SRC_IF] || !tb[CGW_DST_IF]) 1037 return err; 1038 1039 ccgw->src_idx = nla_get_u32(tb[CGW_SRC_IF]); 1040 ccgw->dst_idx = nla_get_u32(tb[CGW_DST_IF]); 1041 1042 /* both indices set to 0 for flushing all routing entries */ 1043 if (!ccgw->src_idx && !ccgw->dst_idx) 1044 return 0; 1045 1046 /* only one index set to 0 is an error */ 1047 if (!ccgw->src_idx || !ccgw->dst_idx) 1048 return err; 1049 } 1050 1051 /* add the checks for other gwtypes here */ 1052 1053 return 0; 1054 } 1055 1056 static int cgw_create_job(struct sk_buff *skb, struct nlmsghdr *nlh, 1057 struct netlink_ext_ack *extack) 1058 { 1059 struct net *net = sock_net(skb->sk); 1060 struct rtcanmsg *r; 1061 struct cgw_job *gwj; 1062 struct cf_mod mod; 1063 struct can_can_gw ccgw; 1064 u8 limhops = 0; 1065 int err = 0; 1066 1067 if (!netlink_capable(skb, CAP_NET_ADMIN)) 1068 return -EPERM; 1069 1070 if (nlmsg_len(nlh) < sizeof(*r)) 1071 return -EINVAL; 1072 1073 r = nlmsg_data(nlh); 1074 if (r->can_family != AF_CAN) 1075 return -EPFNOSUPPORT; 1076 1077 /* so far we only support CAN -> CAN routings */ 1078 if (r->gwtype != CGW_TYPE_CAN_CAN) 1079 return -EINVAL; 1080 1081 err = cgw_parse_attr(nlh, &mod, CGW_TYPE_CAN_CAN, &ccgw, &limhops); 1082 if (err < 0) 1083 return err; 1084 1085 if (mod.uid) { 1086 ASSERT_RTNL(); 1087 1088 /* check for updating an existing job with identical uid */ 1089 hlist_for_each_entry(gwj, &net->can.cgw_list, list) { 1090 if (gwj->mod.uid != mod.uid) 1091 continue; 1092 1093 /* interfaces & filters must be identical */ 1094 if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw))) 1095 return -EINVAL; 1096 1097 /* update modifications with disabled softirq & quit */ 1098 local_bh_disable(); 1099 memcpy(&gwj->mod, &mod, sizeof(mod)); 1100 local_bh_enable(); 1101 return 0; 1102 } 1103 } 1104 1105 /* ifindex == 0 is not allowed for job creation */ 1106 if (!ccgw.src_idx || !ccgw.dst_idx) 1107 return -ENODEV; 1108 1109 gwj = kmem_cache_alloc(cgw_cache, GFP_KERNEL); 1110 if (!gwj) 1111 return -ENOMEM; 1112 1113 gwj->handled_frames = 0; 1114 gwj->dropped_frames = 0; 1115 gwj->deleted_frames = 0; 1116 gwj->flags = r->flags; 1117 gwj->gwtype = r->gwtype; 1118 gwj->limit_hops = limhops; 1119 1120 /* insert already parsed information */ 1121 memcpy(&gwj->mod, &mod, sizeof(mod)); 1122 memcpy(&gwj->ccgw, &ccgw, sizeof(ccgw)); 1123 1124 err = -ENODEV; 1125 1126 gwj->src.dev = __dev_get_by_index(net, gwj->ccgw.src_idx); 1127 1128 if (!gwj->src.dev) 1129 goto out; 1130 1131 if (gwj->src.dev->type != ARPHRD_CAN) 1132 goto out; 1133 1134 gwj->dst.dev = __dev_get_by_index(net, gwj->ccgw.dst_idx); 1135 1136 if (!gwj->dst.dev) 1137 goto out; 1138 1139 if (gwj->dst.dev->type != ARPHRD_CAN) 1140 goto out; 1141 1142 ASSERT_RTNL(); 1143 1144 err = cgw_register_filter(net, gwj); 1145 if (!err) 1146 hlist_add_head_rcu(&gwj->list, &net->can.cgw_list); 1147 out: 1148 if (err) 1149 kmem_cache_free(cgw_cache, gwj); 1150 1151 return err; 1152 } 1153 1154 static void cgw_remove_all_jobs(struct net *net) 1155 { 1156 struct cgw_job *gwj = NULL; 1157 struct hlist_node *nx; 1158 1159 ASSERT_RTNL(); 1160 1161 hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) { 1162 hlist_del(&gwj->list); 1163 cgw_unregister_filter(net, gwj); 1164 call_rcu(&gwj->rcu, cgw_job_free_rcu); 1165 } 1166 } 1167 1168 static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh, 1169 struct netlink_ext_ack *extack) 1170 { 1171 struct net *net = sock_net(skb->sk); 1172 struct cgw_job *gwj = NULL; 1173 struct hlist_node *nx; 1174 struct rtcanmsg *r; 1175 struct cf_mod mod; 1176 struct can_can_gw ccgw; 1177 u8 limhops = 0; 1178 int err = 0; 1179 1180 if (!netlink_capable(skb, CAP_NET_ADMIN)) 1181 return -EPERM; 1182 1183 if (nlmsg_len(nlh) < sizeof(*r)) 1184 return -EINVAL; 1185 1186 r = nlmsg_data(nlh); 1187 if (r->can_family != AF_CAN) 1188 return -EPFNOSUPPORT; 1189 1190 /* so far we only support CAN -> CAN routings */ 1191 if (r->gwtype != CGW_TYPE_CAN_CAN) 1192 return -EINVAL; 1193 1194 err = cgw_parse_attr(nlh, &mod, CGW_TYPE_CAN_CAN, &ccgw, &limhops); 1195 if (err < 0) 1196 return err; 1197 1198 /* two interface indices both set to 0 => remove all entries */ 1199 if (!ccgw.src_idx && !ccgw.dst_idx) { 1200 cgw_remove_all_jobs(net); 1201 return 0; 1202 } 1203 1204 err = -EINVAL; 1205 1206 ASSERT_RTNL(); 1207 1208 /* remove only the first matching entry */ 1209 hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) { 1210 if (gwj->flags != r->flags) 1211 continue; 1212 1213 if (gwj->limit_hops != limhops) 1214 continue; 1215 1216 /* we have a match when uid is enabled and identical */ 1217 if (gwj->mod.uid || mod.uid) { 1218 if (gwj->mod.uid != mod.uid) 1219 continue; 1220 } else { 1221 /* no uid => check for identical modifications */ 1222 if (memcmp(&gwj->mod, &mod, sizeof(mod))) 1223 continue; 1224 } 1225 1226 /* if (r->gwtype == CGW_TYPE_CAN_CAN) - is made sure here */ 1227 if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw))) 1228 continue; 1229 1230 hlist_del(&gwj->list); 1231 cgw_unregister_filter(net, gwj); 1232 call_rcu(&gwj->rcu, cgw_job_free_rcu); 1233 err = 0; 1234 break; 1235 } 1236 1237 return err; 1238 } 1239 1240 static int __net_init cangw_pernet_init(struct net *net) 1241 { 1242 INIT_HLIST_HEAD(&net->can.cgw_list); 1243 return 0; 1244 } 1245 1246 static void __net_exit cangw_pernet_exit_batch(struct list_head *net_list) 1247 { 1248 struct net *net; 1249 1250 rtnl_lock(); 1251 list_for_each_entry(net, net_list, exit_list) 1252 cgw_remove_all_jobs(net); 1253 rtnl_unlock(); 1254 } 1255 1256 static struct pernet_operations cangw_pernet_ops = { 1257 .init = cangw_pernet_init, 1258 .exit_batch = cangw_pernet_exit_batch, 1259 }; 1260 1261 static __init int cgw_module_init(void) 1262 { 1263 int ret; 1264 1265 /* sanitize given module parameter */ 1266 max_hops = clamp_t(unsigned int, max_hops, CGW_MIN_HOPS, CGW_MAX_HOPS); 1267 1268 pr_info("can: netlink gateway - max_hops=%d\n", max_hops); 1269 1270 ret = register_pernet_subsys(&cangw_pernet_ops); 1271 if (ret) 1272 return ret; 1273 1274 ret = -ENOMEM; 1275 cgw_cache = kmem_cache_create("can_gw", sizeof(struct cgw_job), 1276 0, 0, NULL); 1277 if (!cgw_cache) 1278 goto out_cache_create; 1279 1280 /* set notifier */ 1281 notifier.notifier_call = cgw_notifier; 1282 ret = register_netdevice_notifier(¬ifier); 1283 if (ret) 1284 goto out_register_notifier; 1285 1286 ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_GETROUTE, 1287 NULL, cgw_dump_jobs, 0); 1288 if (ret) 1289 goto out_rtnl_register1; 1290 1291 ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_NEWROUTE, 1292 cgw_create_job, NULL, 0); 1293 if (ret) 1294 goto out_rtnl_register2; 1295 ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_DELROUTE, 1296 cgw_remove_job, NULL, 0); 1297 if (ret) 1298 goto out_rtnl_register3; 1299 1300 return 0; 1301 1302 out_rtnl_register3: 1303 rtnl_unregister(PF_CAN, RTM_NEWROUTE); 1304 out_rtnl_register2: 1305 rtnl_unregister(PF_CAN, RTM_GETROUTE); 1306 out_rtnl_register1: 1307 unregister_netdevice_notifier(¬ifier); 1308 out_register_notifier: 1309 kmem_cache_destroy(cgw_cache); 1310 out_cache_create: 1311 unregister_pernet_subsys(&cangw_pernet_ops); 1312 1313 return ret; 1314 } 1315 1316 static __exit void cgw_module_exit(void) 1317 { 1318 rtnl_unregister_all(PF_CAN); 1319 1320 unregister_netdevice_notifier(¬ifier); 1321 1322 unregister_pernet_subsys(&cangw_pernet_ops); 1323 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 1324 1325 kmem_cache_destroy(cgw_cache); 1326 } 1327 1328 module_init(cgw_module_init); 1329 module_exit(cgw_module_exit); 1330