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