net/can/gw.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
mod_and_fddata
mod_or_fddata
mod_xor_fddata
mod_set_fddata
canframecpy
canfdframecpy
cgw_chk_csum_parms
calc_idx
cgw_csum_xor_rel
cgw_csum_xor_pos
cgw_csum_xor_neg
cgw_csum_crc8_rel
cgw_csum_crc8_pos
cgw_csum_crc8_neg
can_can_gw_rcv
cgw_register_filter
cgw_unregister_filter
cgw_notifier
cgw_put_job
cgw_dump_jobs
cgw_parse_attr
cgw_create_job
cgw_remove_all_jobs
cgw_remove_job
cangw_pernet_init
cangw_pernet_exit
cgw_module_init
cgw_module_exit
   1 // SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) 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_VERSION "20190810"
  63 #define CAN_GW_NAME "can-gw"
  64 
  65 MODULE_DESCRIPTION("PF_CAN netlink gateway");
  66 MODULE_LICENSE("Dual BSD/GPL");
  67 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
  68 MODULE_ALIAS(CAN_GW_NAME);
  69 
  70 #define CGW_MIN_HOPS 1
  71 #define CGW_MAX_HOPS 6
  72 #define CGW_DEFAULT_HOPS 1
  73 
  74 static unsigned int max_hops __read_mostly = CGW_DEFAULT_HOPS;
  75 module_param(max_hops, uint, 0444);
  76 MODULE_PARM_DESC(max_hops,
  77                  "maximum " CAN_GW_NAME " routing hops for CAN frames "
  78                  "(valid values: " __stringify(CGW_MIN_HOPS) "-"
  79                  __stringify(CGW_MAX_HOPS) " hops, "
  80                  "default: " __stringify(CGW_DEFAULT_HOPS) ")");
  81 
  82 static struct notifier_block notifier;
  83 static struct kmem_cache *cgw_cache __read_mostly;
  84 
  85 /* structure that contains the (on-the-fly) CAN frame modifications */
  86 struct cf_mod {
  87         struct {
  88                 struct canfd_frame and;
  89                 struct canfd_frame or;
  90                 struct canfd_frame xor;
  91                 struct canfd_frame set;
  92         } modframe;
  93         struct {
  94                 u8 and;
  95                 u8 or;
  96                 u8 xor;
  97                 u8 set;
  98         } modtype;
  99         void (*modfunc[MAX_MODFUNCTIONS])(struct canfd_frame *cf,
 100                                           struct cf_mod *mod);
 101 
 102         /* CAN frame checksum calculation after CAN frame modifications */
 103         struct {
 104                 struct cgw_csum_xor xor;
 105                 struct cgw_csum_crc8 crc8;
 106         } csum;
 107         struct {
 108                 void (*xor)(struct canfd_frame *cf,
 109                             struct cgw_csum_xor *xor);
 110                 void (*crc8)(struct canfd_frame *cf,
 111                              struct cgw_csum_crc8 *crc8);
 112         } csumfunc;
 113         u32 uid;
 114 };
 115 
 116 /* So far we just support CAN -> CAN routing and frame modifications.
 117  *
 118  * The internal can_can_gw structure contains data and attributes for
 119  * a CAN -> CAN gateway job.
 120  */
 121 struct can_can_gw {
 122         struct can_filter filter;
 123         int src_idx;
 124         int dst_idx;
 125 };
 126 
 127 /* list entry for CAN gateways jobs */
 128 struct cgw_job {
 129         struct hlist_node list;
 130         struct rcu_head rcu;
 131         u32 handled_frames;
 132         u32 dropped_frames;
 133         u32 deleted_frames;
 134         struct cf_mod mod;
 135         union {
 136                 /* CAN frame data source */
 137                 struct net_device *dev;
 138         } src;
 139         union {
 140                 /* CAN frame data destination */
 141                 struct net_device *dev;
 142         } dst;
 143         union {
 144                 struct can_can_gw ccgw;
 145                 /* tbc */
 146         };
 147         u8 gwtype;
 148         u8 limit_hops;
 149         u16 flags;
 150 };
 151 
 152 /* modification functions that are invoked in the hot path in can_can_gw_rcv */
 153 
 154 #define MODFUNC(func, op) static void func(struct canfd_frame *cf, \
 155                                            struct cf_mod *mod) { op ; }
 156 
 157 MODFUNC(mod_and_id, cf->can_id &= mod->modframe.and.can_id)
 158 MODFUNC(mod_and_len, cf->len &= mod->modframe.and.len)
 159 MODFUNC(mod_and_flags, cf->flags &= mod->modframe.and.flags)
 160 MODFUNC(mod_and_data, *(u64 *)cf->data &= *(u64 *)mod->modframe.and.data)
 161 MODFUNC(mod_or_id, cf->can_id |= mod->modframe.or.can_id)
 162 MODFUNC(mod_or_len, cf->len |= mod->modframe.or.len)
 163 MODFUNC(mod_or_flags, cf->flags |= mod->modframe.or.flags)
 164 MODFUNC(mod_or_data, *(u64 *)cf->data |= *(u64 *)mod->modframe.or.data)
 165 MODFUNC(mod_xor_id, cf->can_id ^= mod->modframe.xor.can_id)
 166 MODFUNC(mod_xor_len, cf->len ^= mod->modframe.xor.len)
 167 MODFUNC(mod_xor_flags, cf->flags ^= mod->modframe.xor.flags)
 168 MODFUNC(mod_xor_data, *(u64 *)cf->data ^= *(u64 *)mod->modframe.xor.data)
 169 MODFUNC(mod_set_id, cf->can_id = mod->modframe.set.can_id)
 170 MODFUNC(mod_set_len, cf->len = mod->modframe.set.len)
 171 MODFUNC(mod_set_flags, cf->flags = mod->modframe.set.flags)
 172 MODFUNC(mod_set_data, *(u64 *)cf->data = *(u64 *)mod->modframe.set.data)
 173 
 174 static void mod_and_fddata(struct canfd_frame *cf, struct cf_mod *mod)
 175 {
 176         int i;
 177 
 178         for (i = 0; i < CANFD_MAX_DLEN; i += 8)
 179                 *(u64 *)(cf->data + i) &= *(u64 *)(mod->modframe.and.data + i);
 180 }
 181 
 182 static void mod_or_fddata(struct canfd_frame *cf, struct cf_mod *mod)
 183 {
 184         int i;
 185 
 186         for (i = 0; i < CANFD_MAX_DLEN; i += 8)
 187                 *(u64 *)(cf->data + i) |= *(u64 *)(mod->modframe.or.data + i);
 188 }
 189 
 190 static void mod_xor_fddata(struct canfd_frame *cf, struct cf_mod *mod)
 191 {
 192         int i;
 193 
 194         for (i = 0; i < CANFD_MAX_DLEN; i += 8)
 195                 *(u64 *)(cf->data + i) ^= *(u64 *)(mod->modframe.xor.data + i);
 196 }
 197 
 198 static void mod_set_fddata(struct canfd_frame *cf, struct cf_mod *mod)
 199 {
 200         memcpy(cf->data, mod->modframe.set.data, CANFD_MAX_DLEN);
 201 }
 202 
 203 static void canframecpy(struct canfd_frame *dst, struct can_frame *src)
 204 {
 205         /* Copy the struct members separately to ensure that no uninitialized
 206          * data are copied in the 3 bytes hole of the struct. This is needed
 207          * to make easy compares of the data in the struct cf_mod.
 208          */
 209 
 210         dst->can_id = src->can_id;
 211         dst->len = src->can_dlc;
 212         *(u64 *)dst->data = *(u64 *)src->data;
 213 }
 214 
 215 static void canfdframecpy(struct canfd_frame *dst, struct canfd_frame *src)
 216 {
 217         /* Copy the struct members separately to ensure that no uninitialized
 218          * data are copied in the 2 bytes hole of the struct. This is needed
 219          * to make easy compares of the data in the struct cf_mod.
 220          */
 221 
 222         dst->can_id = src->can_id;
 223         dst->flags = src->flags;
 224         dst->len = src->len;
 225         memcpy(dst->data, src->data, CANFD_MAX_DLEN);
 226 }
 227 
 228 static int cgw_chk_csum_parms(s8 fr, s8 to, s8 re, struct rtcanmsg *r)
 229 {
 230         s8 dlen = CAN_MAX_DLEN;
 231 
 232         if (r->flags & CGW_FLAGS_CAN_FD)
 233                 dlen = CANFD_MAX_DLEN;
 234 
 235         /* absolute dlc values 0 .. 7 => 0 .. 7, e.g. data [0]
 236          * relative to received dlc -1 .. -8 :
 237          * e.g. for received dlc = 8
 238          * -1 => index = 7 (data[7])
 239          * -3 => index = 5 (data[5])
 240          * -8 => index = 0 (data[0])
 241          */
 242 
 243         if (fr >= -dlen && fr < dlen &&
 244             to >= -dlen && to < dlen &&
 245             re >= -dlen && re < dlen)
 246                 return 0;
 247         else
 248                 return -EINVAL;
 249 }
 250 
 251 static inline int calc_idx(int idx, int rx_len)
 252 {
 253         if (idx < 0)
 254                 return rx_len + idx;
 255         else
 256                 return idx;
 257 }
 258 
 259 static void cgw_csum_xor_rel(struct canfd_frame *cf, struct cgw_csum_xor *xor)
 260 {
 261         int from = calc_idx(xor->from_idx, cf->len);
 262         int to = calc_idx(xor->to_idx, cf->len);
 263         int res = calc_idx(xor->result_idx, cf->len);
 264         u8 val = xor->init_xor_val;
 265         int i;
 266 
 267         if (from < 0 || to < 0 || res < 0)
 268                 return;
 269 
 270         if (from <= to) {
 271                 for (i = from; i <= to; i++)
 272                         val ^= cf->data[i];
 273         } else {
 274                 for (i = from; i >= to; i--)
 275                         val ^= cf->data[i];
 276         }
 277 
 278         cf->data[res] = val;
 279 }
 280 
 281 static void cgw_csum_xor_pos(struct canfd_frame *cf, struct cgw_csum_xor *xor)
 282 {
 283         u8 val = xor->init_xor_val;
 284         int i;
 285 
 286         for (i = xor->from_idx; i <= xor->to_idx; i++)
 287                 val ^= cf->data[i];
 288 
 289         cf->data[xor->result_idx] = val;
 290 }
 291 
 292 static void cgw_csum_xor_neg(struct canfd_frame *cf, struct cgw_csum_xor *xor)
 293 {
 294         u8 val = xor->init_xor_val;
 295         int i;
 296 
 297         for (i = xor->from_idx; i >= xor->to_idx; i--)
 298                 val ^= cf->data[i];
 299 
 300         cf->data[xor->result_idx] = val;
 301 }
 302 
 303 static void cgw_csum_crc8_rel(struct canfd_frame *cf,
 304                               struct cgw_csum_crc8 *crc8)
 305 {
 306         int from = calc_idx(crc8->from_idx, cf->len);
 307         int to = calc_idx(crc8->to_idx, cf->len);
 308         int res = calc_idx(crc8->result_idx, cf->len);
 309         u8 crc = crc8->init_crc_val;
 310         int i;
 311 
 312         if (from < 0 || to < 0 || res < 0)
 313                 return;
 314 
 315         if (from <= to) {
 316                 for (i = crc8->from_idx; i <= crc8->to_idx; i++)
 317                         crc = crc8->crctab[crc ^ cf->data[i]];
 318         } else {
 319                 for (i = crc8->from_idx; i >= crc8->to_idx; i--)
 320                         crc = crc8->crctab[crc ^ cf->data[i]];
 321         }
 322 
 323         switch (crc8->profile) {
 324         case CGW_CRC8PRF_1U8:
 325                 crc = crc8->crctab[crc ^ crc8->profile_data[0]];
 326                 break;
 327 
 328         case  CGW_CRC8PRF_16U8:
 329                 crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]];
 330                 break;
 331 
 332         case CGW_CRC8PRF_SFFID_XOR:
 333                 crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^
 334                                    (cf->can_id >> 8 & 0xFF)];
 335                 break;
 336         }
 337 
 338         cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val;
 339 }
 340 
 341 static void cgw_csum_crc8_pos(struct canfd_frame *cf,
 342                               struct cgw_csum_crc8 *crc8)
 343 {
 344         u8 crc = crc8->init_crc_val;
 345         int i;
 346 
 347         for (i = crc8->from_idx; i <= crc8->to_idx; i++)
 348                 crc = crc8->crctab[crc ^ cf->data[i]];
 349 
 350         switch (crc8->profile) {
 351         case CGW_CRC8PRF_1U8:
 352                 crc = crc8->crctab[crc ^ crc8->profile_data[0]];
 353                 break;
 354 
 355         case  CGW_CRC8PRF_16U8:
 356                 crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]];
 357                 break;
 358 
 359         case CGW_CRC8PRF_SFFID_XOR:
 360                 crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^
 361                                    (cf->can_id >> 8 & 0xFF)];
 362                 break;
 363         }
 364 
 365         cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val;
 366 }
 367 
 368 static void cgw_csum_crc8_neg(struct canfd_frame *cf,
 369                               struct cgw_csum_crc8 *crc8)
 370 {
 371         u8 crc = crc8->init_crc_val;
 372         int i;
 373 
 374         for (i = crc8->from_idx; i >= crc8->to_idx; i--)
 375                 crc = crc8->crctab[crc ^ cf->data[i]];
 376 
 377         switch (crc8->profile) {
 378         case CGW_CRC8PRF_1U8:
 379                 crc = crc8->crctab[crc ^ crc8->profile_data[0]];
 380                 break;
 381 
 382         case  CGW_CRC8PRF_16U8:
 383                 crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]];
 384                 break;
 385 
 386         case CGW_CRC8PRF_SFFID_XOR:
 387                 crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^
 388                                    (cf->can_id >> 8 & 0xFF)];
 389                 break;
 390         }
 391 
 392         cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val;
 393 }
 394 
 395 /* the receive & process & send function */
 396 static void can_can_gw_rcv(struct sk_buff *skb, void *data)
 397 {
 398         struct cgw_job *gwj = (struct cgw_job *)data;
 399         struct canfd_frame *cf;
 400         struct sk_buff *nskb;
 401         int modidx = 0;
 402 
 403         /* process strictly Classic CAN or CAN FD frames */
 404         if (gwj->flags & CGW_FLAGS_CAN_FD) {
 405                 if (skb->len != CANFD_MTU)
 406                         return;
 407         } else {
 408                 if (skb->len != CAN_MTU)
 409                         return;
 410         }
 411 
 412         /* Do not handle CAN frames routed more than 'max_hops' times.
 413          * In general we should never catch this delimiter which is intended
 414          * to cover a misconfiguration protection (e.g. circular CAN routes).
 415          *
 416          * The Controller Area Network controllers only accept CAN frames with
 417          * correct CRCs - which are not visible in the controller registers.
 418          * According to skbuff.h documentation the csum_start element for IP
 419          * checksums is undefined/unused when ip_summed == CHECKSUM_UNNECESSARY.
 420          * Only CAN skbs can be processed here which already have this property.
 421          */
 422 
 423 #define cgw_hops(skb) ((skb)->csum_start)
 424 
 425         BUG_ON(skb->ip_summed != CHECKSUM_UNNECESSARY);
 426 
 427         if (cgw_hops(skb) >= max_hops) {
 428                 /* indicate deleted frames due to misconfiguration */
 429                 gwj->deleted_frames++;
 430                 return;
 431         }
 432 
 433         if (!(gwj->dst.dev->flags & IFF_UP)) {
 434                 gwj->dropped_frames++;
 435                 return;
 436         }
 437 
 438         /* is sending the skb back to the incoming interface not allowed? */
 439         if (!(gwj->flags & CGW_FLAGS_CAN_IIF_TX_OK) &&
 440             can_skb_prv(skb)->ifindex == gwj->dst.dev->ifindex)
 441                 return;
 442 
 443         /* clone the given skb, which has not been done in can_rcv()
 444          *
 445          * When there is at least one modification function activated,
 446          * we need to copy the skb as we want to modify skb->data.
 447          */
 448         if (gwj->mod.modfunc[0])
 449                 nskb = skb_copy(skb, GFP_ATOMIC);
 450         else
 451                 nskb = skb_clone(skb, GFP_ATOMIC);
 452 
 453         if (!nskb) {
 454                 gwj->dropped_frames++;
 455                 return;
 456         }
 457 
 458         /* put the incremented hop counter in the cloned skb */
 459         cgw_hops(nskb) = cgw_hops(skb) + 1;
 460 
 461         /* first processing of this CAN frame -> adjust to private hop limit */
 462         if (gwj->limit_hops && cgw_hops(nskb) == 1)
 463                 cgw_hops(nskb) = max_hops - gwj->limit_hops + 1;
 464 
 465         nskb->dev = gwj->dst.dev;
 466 
 467         /* pointer to modifiable CAN frame */
 468         cf = (struct canfd_frame *)nskb->data;
 469 
 470         /* perform preprocessed modification functions if there are any */
 471         while (modidx < MAX_MODFUNCTIONS && gwj->mod.modfunc[modidx])
 472                 (*gwj->mod.modfunc[modidx++])(cf, &gwj->mod);
 473 
 474         /* Has the CAN frame been modified? */
 475         if (modidx) {
 476                 /* get available space for the processed CAN frame type */
 477                 int max_len = nskb->len - offsetof(struct canfd_frame, data);
 478 
 479                 /* dlc may have changed, make sure it fits to the CAN frame */
 480                 if (cf->len > max_len) {
 481                         /* delete frame due to misconfiguration */
 482                         gwj->deleted_frames++;
 483                         kfree_skb(nskb);
 484                         return;
 485                 }
 486 
 487                 /* check for checksum updates */
 488                 if (gwj->mod.csumfunc.crc8)
 489                         (*gwj->mod.csumfunc.crc8)(cf, &gwj->mod.csum.crc8);
 490 
 491                 if (gwj->mod.csumfunc.xor)
 492                         (*gwj->mod.csumfunc.xor)(cf, &gwj->mod.csum.xor);
 493         }
 494 
 495         /* clear the skb timestamp if not configured the other way */
 496         if (!(gwj->flags & CGW_FLAGS_CAN_SRC_TSTAMP))
 497                 nskb->tstamp = 0;
 498 
 499         /* send to netdevice */
 500         if (can_send(nskb, gwj->flags & CGW_FLAGS_CAN_ECHO))
 501                 gwj->dropped_frames++;
 502         else
 503                 gwj->handled_frames++;
 504 }
 505 
 506 static inline int cgw_register_filter(struct net *net, struct cgw_job *gwj)
 507 {
 508         return can_rx_register(net, gwj->src.dev, gwj->ccgw.filter.can_id,
 509                                gwj->ccgw.filter.can_mask, can_can_gw_rcv,
 510                                gwj, "gw", NULL);
 511 }
 512 
 513 static inline void cgw_unregister_filter(struct net *net, struct cgw_job *gwj)
 514 {
 515         can_rx_unregister(net, gwj->src.dev, gwj->ccgw.filter.can_id,
 516                           gwj->ccgw.filter.can_mask, can_can_gw_rcv, gwj);
 517 }
 518 
 519 static int cgw_notifier(struct notifier_block *nb,
 520                         unsigned long msg, void *ptr)
 521 {
 522         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 523         struct net *net = dev_net(dev);
 524 
 525         if (dev->type != ARPHRD_CAN)
 526                 return NOTIFY_DONE;
 527 
 528         if (msg == NETDEV_UNREGISTER) {
 529                 struct cgw_job *gwj = NULL;
 530                 struct hlist_node *nx;
 531 
 532                 ASSERT_RTNL();
 533 
 534                 hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
 535                         if (gwj->src.dev == dev || gwj->dst.dev == dev) {
 536                                 hlist_del(&gwj->list);
 537                                 cgw_unregister_filter(net, gwj);
 538                                 kmem_cache_free(cgw_cache, gwj);
 539                         }
 540                 }
 541         }
 542 
 543         return NOTIFY_DONE;
 544 }
 545 
 546 static int cgw_put_job(struct sk_buff *skb, struct cgw_job *gwj, int type,
 547                        u32 pid, u32 seq, int flags)
 548 {
 549         struct rtcanmsg *rtcan;
 550         struct nlmsghdr *nlh;
 551 
 552         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*rtcan), flags);
 553         if (!nlh)
 554                 return -EMSGSIZE;
 555 
 556         rtcan = nlmsg_data(nlh);
 557         rtcan->can_family = AF_CAN;
 558         rtcan->gwtype = gwj->gwtype;
 559         rtcan->flags = gwj->flags;
 560 
 561         /* add statistics if available */
 562 
 563         if (gwj->handled_frames) {
 564                 if (nla_put_u32(skb, CGW_HANDLED, gwj->handled_frames) < 0)
 565                         goto cancel;
 566         }
 567 
 568         if (gwj->dropped_frames) {
 569                 if (nla_put_u32(skb, CGW_DROPPED, gwj->dropped_frames) < 0)
 570                         goto cancel;
 571         }
 572 
 573         if (gwj->deleted_frames) {
 574                 if (nla_put_u32(skb, CGW_DELETED, gwj->deleted_frames) < 0)
 575                         goto cancel;
 576         }
 577 
 578         /* check non default settings of attributes */
 579 
 580         if (gwj->limit_hops) {
 581                 if (nla_put_u8(skb, CGW_LIM_HOPS, gwj->limit_hops) < 0)
 582                         goto cancel;
 583         }
 584 
 585         if (gwj->flags & CGW_FLAGS_CAN_FD) {
 586                 struct cgw_fdframe_mod mb;
 587 
 588                 if (gwj->mod.modtype.and) {
 589                         memcpy(&mb.cf, &gwj->mod.modframe.and, sizeof(mb.cf));
 590                         mb.modtype = gwj->mod.modtype.and;
 591                         if (nla_put(skb, CGW_FDMOD_AND, sizeof(mb), &mb) < 0)
 592                                 goto cancel;
 593                 }
 594 
 595                 if (gwj->mod.modtype.or) {
 596                         memcpy(&mb.cf, &gwj->mod.modframe.or, sizeof(mb.cf));
 597                         mb.modtype = gwj->mod.modtype.or;
 598                         if (nla_put(skb, CGW_FDMOD_OR, sizeof(mb), &mb) < 0)
 599                                 goto cancel;
 600                 }
 601 
 602                 if (gwj->mod.modtype.xor) {
 603                         memcpy(&mb.cf, &gwj->mod.modframe.xor, sizeof(mb.cf));
 604                         mb.modtype = gwj->mod.modtype.xor;
 605                         if (nla_put(skb, CGW_FDMOD_XOR, sizeof(mb), &mb) < 0)
 606                                 goto cancel;
 607                 }
 608 
 609                 if (gwj->mod.modtype.set) {
 610                         memcpy(&mb.cf, &gwj->mod.modframe.set, sizeof(mb.cf));
 611                         mb.modtype = gwj->mod.modtype.set;
 612                         if (nla_put(skb, CGW_FDMOD_SET, sizeof(mb), &mb) < 0)
 613                                 goto cancel;
 614                 }
 615         } else {
 616                 struct cgw_frame_mod mb;
 617 
 618                 if (gwj->mod.modtype.and) {
 619                         memcpy(&mb.cf, &gwj->mod.modframe.and, sizeof(mb.cf));
 620                         mb.modtype = gwj->mod.modtype.and;
 621                         if (nla_put(skb, CGW_MOD_AND, sizeof(mb), &mb) < 0)
 622                                 goto cancel;
 623                 }
 624 
 625                 if (gwj->mod.modtype.or) {
 626                         memcpy(&mb.cf, &gwj->mod.modframe.or, sizeof(mb.cf));
 627                         mb.modtype = gwj->mod.modtype.or;
 628                         if (nla_put(skb, CGW_MOD_OR, sizeof(mb), &mb) < 0)
 629                                 goto cancel;
 630                 }
 631 
 632                 if (gwj->mod.modtype.xor) {
 633                         memcpy(&mb.cf, &gwj->mod.modframe.xor, sizeof(mb.cf));
 634                         mb.modtype = gwj->mod.modtype.xor;
 635                         if (nla_put(skb, CGW_MOD_XOR, sizeof(mb), &mb) < 0)
 636                                 goto cancel;
 637                 }
 638 
 639                 if (gwj->mod.modtype.set) {
 640                         memcpy(&mb.cf, &gwj->mod.modframe.set, sizeof(mb.cf));
 641                         mb.modtype = gwj->mod.modtype.set;
 642                         if (nla_put(skb, CGW_MOD_SET, sizeof(mb), &mb) < 0)
 643                                 goto cancel;
 644                 }
 645         }
 646 
 647         if (gwj->mod.uid) {
 648                 if (nla_put_u32(skb, CGW_MOD_UID, gwj->mod.uid) < 0)
 649                         goto cancel;
 650         }
 651 
 652         if (gwj->mod.csumfunc.crc8) {
 653                 if (nla_put(skb, CGW_CS_CRC8, CGW_CS_CRC8_LEN,
 654                             &gwj->mod.csum.crc8) < 0)
 655                         goto cancel;
 656         }
 657 
 658         if (gwj->mod.csumfunc.xor) {
 659                 if (nla_put(skb, CGW_CS_XOR, CGW_CS_XOR_LEN,
 660                             &gwj->mod.csum.xor) < 0)
 661                         goto cancel;
 662         }
 663 
 664         if (gwj->gwtype == CGW_TYPE_CAN_CAN) {
 665                 if (gwj->ccgw.filter.can_id || gwj->ccgw.filter.can_mask) {
 666                         if (nla_put(skb, CGW_FILTER, sizeof(struct can_filter),
 667                                     &gwj->ccgw.filter) < 0)
 668                                 goto cancel;
 669                 }
 670 
 671                 if (nla_put_u32(skb, CGW_SRC_IF, gwj->ccgw.src_idx) < 0)
 672                         goto cancel;
 673 
 674                 if (nla_put_u32(skb, CGW_DST_IF, gwj->ccgw.dst_idx) < 0)
 675                         goto cancel;
 676         }
 677 
 678         nlmsg_end(skb, nlh);
 679         return 0;
 680 
 681 cancel:
 682         nlmsg_cancel(skb, nlh);
 683         return -EMSGSIZE;
 684 }
 685 
 686 /* Dump information about all CAN gateway jobs, in response to RTM_GETROUTE */
 687 static int cgw_dump_jobs(struct sk_buff *skb, struct netlink_callback *cb)
 688 {
 689         struct net *net = sock_net(skb->sk);
 690         struct cgw_job *gwj = NULL;
 691         int idx = 0;
 692         int s_idx = cb->args[0];
 693 
 694         rcu_read_lock();
 695         hlist_for_each_entry_rcu(gwj, &net->can.cgw_list, list) {
 696                 if (idx < s_idx)
 697                         goto cont;
 698 
 699                 if (cgw_put_job(skb, gwj, RTM_NEWROUTE,
 700                                 NETLINK_CB(cb->skb).portid,
 701                                 cb->nlh->nlmsg_seq, NLM_F_MULTI) < 0)
 702                         break;
 703 cont:
 704                 idx++;
 705         }
 706         rcu_read_unlock();
 707 
 708         cb->args[0] = idx;
 709 
 710         return skb->len;
 711 }
 712 
 713 static const struct nla_policy cgw_policy[CGW_MAX + 1] = {
 714         [CGW_MOD_AND]   = { .len = sizeof(struct cgw_frame_mod) },
 715         [CGW_MOD_OR]    = { .len = sizeof(struct cgw_frame_mod) },
 716         [CGW_MOD_XOR]   = { .len = sizeof(struct cgw_frame_mod) },
 717         [CGW_MOD_SET]   = { .len = sizeof(struct cgw_frame_mod) },
 718         [CGW_CS_XOR]    = { .len = sizeof(struct cgw_csum_xor) },
 719         [CGW_CS_CRC8]   = { .len = sizeof(struct cgw_csum_crc8) },
 720         [CGW_SRC_IF]    = { .type = NLA_U32 },
 721         [CGW_DST_IF]    = { .type = NLA_U32 },
 722         [CGW_FILTER]    = { .len = sizeof(struct can_filter) },
 723         [CGW_LIM_HOPS]  = { .type = NLA_U8 },
 724         [CGW_MOD_UID]   = { .type = NLA_U32 },
 725         [CGW_FDMOD_AND] = { .len = sizeof(struct cgw_fdframe_mod) },
 726         [CGW_FDMOD_OR]  = { .len = sizeof(struct cgw_fdframe_mod) },
 727         [CGW_FDMOD_XOR] = { .len = sizeof(struct cgw_fdframe_mod) },
 728         [CGW_FDMOD_SET] = { .len = sizeof(struct cgw_fdframe_mod) },
 729 };
 730 
 731 /* check for common and gwtype specific attributes */
 732 static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod,
 733                           u8 gwtype, void *gwtypeattr, u8 *limhops)
 734 {
 735         struct nlattr *tb[CGW_MAX + 1];
 736         struct rtcanmsg *r = nlmsg_data(nlh);
 737         int modidx = 0;
 738         int err = 0;
 739 
 740         /* initialize modification & checksum data space */
 741         memset(mod, 0, sizeof(*mod));
 742 
 743         err = nlmsg_parse_deprecated(nlh, sizeof(struct rtcanmsg), tb,
 744                                      CGW_MAX, cgw_policy, NULL);
 745         if (err < 0)
 746                 return err;
 747 
 748         if (tb[CGW_LIM_HOPS]) {
 749                 *limhops = nla_get_u8(tb[CGW_LIM_HOPS]);
 750 
 751                 if (*limhops < 1 || *limhops > max_hops)
 752                         return -EINVAL;
 753         }
 754 
 755         /* check for AND/OR/XOR/SET modifications */
 756         if (r->flags & CGW_FLAGS_CAN_FD) {
 757                 struct cgw_fdframe_mod mb;
 758 
 759                 if (tb[CGW_FDMOD_AND]) {
 760                         nla_memcpy(&mb, tb[CGW_FDMOD_AND], CGW_FDMODATTR_LEN);
 761 
 762                         canfdframecpy(&mod->modframe.and, &mb.cf);
 763                         mod->modtype.and = mb.modtype;
 764 
 765                         if (mb.modtype & CGW_MOD_ID)
 766                                 mod->modfunc[modidx++] = mod_and_id;
 767 
 768                         if (mb.modtype & CGW_MOD_LEN)
 769                                 mod->modfunc[modidx++] = mod_and_len;
 770 
 771                         if (mb.modtype & CGW_MOD_FLAGS)
 772                                 mod->modfunc[modidx++] = mod_and_flags;
 773 
 774                         if (mb.modtype & CGW_MOD_DATA)
 775                                 mod->modfunc[modidx++] = mod_and_fddata;
 776                 }
 777 
 778                 if (tb[CGW_FDMOD_OR]) {
 779                         nla_memcpy(&mb, tb[CGW_FDMOD_OR], CGW_FDMODATTR_LEN);
 780 
 781                         canfdframecpy(&mod->modframe.or, &mb.cf);
 782                         mod->modtype.or = mb.modtype;
 783 
 784                         if (mb.modtype & CGW_MOD_ID)
 785                                 mod->modfunc[modidx++] = mod_or_id;
 786 
 787                         if (mb.modtype & CGW_MOD_LEN)
 788                                 mod->modfunc[modidx++] = mod_or_len;
 789 
 790                         if (mb.modtype & CGW_MOD_FLAGS)
 791                                 mod->modfunc[modidx++] = mod_or_flags;
 792 
 793                         if (mb.modtype & CGW_MOD_DATA)
 794                                 mod->modfunc[modidx++] = mod_or_fddata;
 795                 }
 796 
 797                 if (tb[CGW_FDMOD_XOR]) {
 798                         nla_memcpy(&mb, tb[CGW_FDMOD_XOR], CGW_FDMODATTR_LEN);
 799 
 800                         canfdframecpy(&mod->modframe.xor, &mb.cf);
 801                         mod->modtype.xor = mb.modtype;
 802 
 803                         if (mb.modtype & CGW_MOD_ID)
 804                                 mod->modfunc[modidx++] = mod_xor_id;
 805 
 806                         if (mb.modtype & CGW_MOD_LEN)
 807                                 mod->modfunc[modidx++] = mod_xor_len;
 808 
 809                         if (mb.modtype & CGW_MOD_FLAGS)
 810                                 mod->modfunc[modidx++] = mod_xor_flags;
 811 
 812                         if (mb.modtype & CGW_MOD_DATA)
 813                                 mod->modfunc[modidx++] = mod_xor_fddata;
 814                 }
 815 
 816                 if (tb[CGW_FDMOD_SET]) {
 817                         nla_memcpy(&mb, tb[CGW_FDMOD_SET], CGW_FDMODATTR_LEN);
 818 
 819                         canfdframecpy(&mod->modframe.set, &mb.cf);
 820                         mod->modtype.set = mb.modtype;
 821 
 822                         if (mb.modtype & CGW_MOD_ID)
 823                                 mod->modfunc[modidx++] = mod_set_id;
 824 
 825                         if (mb.modtype & CGW_MOD_LEN)
 826                                 mod->modfunc[modidx++] = mod_set_len;
 827 
 828                         if (mb.modtype & CGW_MOD_FLAGS)
 829                                 mod->modfunc[modidx++] = mod_set_flags;
 830 
 831                         if (mb.modtype & CGW_MOD_DATA)
 832                                 mod->modfunc[modidx++] = mod_set_fddata;
 833                 }
 834         } else {
 835                 struct cgw_frame_mod mb;
 836 
 837                 if (tb[CGW_MOD_AND]) {
 838                         nla_memcpy(&mb, tb[CGW_MOD_AND], CGW_MODATTR_LEN);
 839 
 840                         canframecpy(&mod->modframe.and, &mb.cf);
 841                         mod->modtype.and = mb.modtype;
 842 
 843                         if (mb.modtype & CGW_MOD_ID)
 844                                 mod->modfunc[modidx++] = mod_and_id;
 845 
 846                         if (mb.modtype & CGW_MOD_LEN)
 847                                 mod->modfunc[modidx++] = mod_and_len;
 848 
 849                         if (mb.modtype & CGW_MOD_DATA)
 850                                 mod->modfunc[modidx++] = mod_and_data;
 851                 }
 852 
 853                 if (tb[CGW_MOD_OR]) {
 854                         nla_memcpy(&mb, tb[CGW_MOD_OR], CGW_MODATTR_LEN);
 855 
 856                         canframecpy(&mod->modframe.or, &mb.cf);
 857                         mod->modtype.or = mb.modtype;
 858 
 859                         if (mb.modtype & CGW_MOD_ID)
 860                                 mod->modfunc[modidx++] = mod_or_id;
 861 
 862                         if (mb.modtype & CGW_MOD_LEN)
 863                                 mod->modfunc[modidx++] = mod_or_len;
 864 
 865                         if (mb.modtype & CGW_MOD_DATA)
 866                                 mod->modfunc[modidx++] = mod_or_data;
 867                 }
 868 
 869                 if (tb[CGW_MOD_XOR]) {
 870                         nla_memcpy(&mb, tb[CGW_MOD_XOR], CGW_MODATTR_LEN);
 871 
 872                         canframecpy(&mod->modframe.xor, &mb.cf);
 873                         mod->modtype.xor = mb.modtype;
 874 
 875                         if (mb.modtype & CGW_MOD_ID)
 876                                 mod->modfunc[modidx++] = mod_xor_id;
 877 
 878                         if (mb.modtype & CGW_MOD_LEN)
 879                                 mod->modfunc[modidx++] = mod_xor_len;
 880 
 881                         if (mb.modtype & CGW_MOD_DATA)
 882                                 mod->modfunc[modidx++] = mod_xor_data;
 883                 }
 884 
 885                 if (tb[CGW_MOD_SET]) {
 886                         nla_memcpy(&mb, tb[CGW_MOD_SET], CGW_MODATTR_LEN);
 887 
 888                         canframecpy(&mod->modframe.set, &mb.cf);
 889                         mod->modtype.set = mb.modtype;
 890 
 891                         if (mb.modtype & CGW_MOD_ID)
 892                                 mod->modfunc[modidx++] = mod_set_id;
 893 
 894                         if (mb.modtype & CGW_MOD_LEN)
 895                                 mod->modfunc[modidx++] = mod_set_len;
 896 
 897                         if (mb.modtype & CGW_MOD_DATA)
 898                                 mod->modfunc[modidx++] = mod_set_data;
 899                 }
 900         }
 901 
 902         /* check for checksum operations after CAN frame modifications */
 903         if (modidx) {
 904                 if (tb[CGW_CS_CRC8]) {
 905                         struct cgw_csum_crc8 *c = nla_data(tb[CGW_CS_CRC8]);
 906 
 907                         err = cgw_chk_csum_parms(c->from_idx, c->to_idx,
 908                                                  c->result_idx, r);
 909                         if (err)
 910                                 return err;
 911 
 912                         nla_memcpy(&mod->csum.crc8, tb[CGW_CS_CRC8],
 913                                    CGW_CS_CRC8_LEN);
 914 
 915                         /* select dedicated processing function to reduce
 916                          * runtime operations in receive hot path.
 917                          */
 918                         if (c->from_idx < 0 || c->to_idx < 0 ||
 919                             c->result_idx < 0)
 920                                 mod->csumfunc.crc8 = cgw_csum_crc8_rel;
 921                         else if (c->from_idx <= c->to_idx)
 922                                 mod->csumfunc.crc8 = cgw_csum_crc8_pos;
 923                         else
 924                                 mod->csumfunc.crc8 = cgw_csum_crc8_neg;
 925                 }
 926 
 927                 if (tb[CGW_CS_XOR]) {
 928                         struct cgw_csum_xor *c = nla_data(tb[CGW_CS_XOR]);
 929 
 930                         err = cgw_chk_csum_parms(c->from_idx, c->to_idx,
 931                                                  c->result_idx, r);
 932                         if (err)
 933                                 return err;
 934 
 935                         nla_memcpy(&mod->csum.xor, tb[CGW_CS_XOR],
 936                                    CGW_CS_XOR_LEN);
 937 
 938                         /* select dedicated processing function to reduce
 939                          * runtime operations in receive hot path.
 940                          */
 941                         if (c->from_idx < 0 || c->to_idx < 0 ||
 942                             c->result_idx < 0)
 943                                 mod->csumfunc.xor = cgw_csum_xor_rel;
 944                         else if (c->from_idx <= c->to_idx)
 945                                 mod->csumfunc.xor = cgw_csum_xor_pos;
 946                         else
 947                                 mod->csumfunc.xor = cgw_csum_xor_neg;
 948                 }
 949 
 950                 if (tb[CGW_MOD_UID])
 951                         nla_memcpy(&mod->uid, tb[CGW_MOD_UID], sizeof(u32));
 952         }
 953 
 954         if (gwtype == CGW_TYPE_CAN_CAN) {
 955                 /* check CGW_TYPE_CAN_CAN specific attributes */
 956                 struct can_can_gw *ccgw = (struct can_can_gw *)gwtypeattr;
 957 
 958                 memset(ccgw, 0, sizeof(*ccgw));
 959 
 960                 /* check for can_filter in attributes */
 961                 if (tb[CGW_FILTER])
 962                         nla_memcpy(&ccgw->filter, tb[CGW_FILTER],
 963                                    sizeof(struct can_filter));
 964 
 965                 err = -ENODEV;
 966 
 967                 /* specifying two interfaces is mandatory */
 968                 if (!tb[CGW_SRC_IF] || !tb[CGW_DST_IF])
 969                         return err;
 970 
 971                 ccgw->src_idx = nla_get_u32(tb[CGW_SRC_IF]);
 972                 ccgw->dst_idx = nla_get_u32(tb[CGW_DST_IF]);
 973 
 974                 /* both indices set to 0 for flushing all routing entries */
 975                 if (!ccgw->src_idx && !ccgw->dst_idx)
 976                         return 0;
 977 
 978                 /* only one index set to 0 is an error */
 979                 if (!ccgw->src_idx || !ccgw->dst_idx)
 980                         return err;
 981         }
 982 
 983         /* add the checks for other gwtypes here */
 984 
 985         return 0;
 986 }
 987 
 988 static int cgw_create_job(struct sk_buff *skb,  struct nlmsghdr *nlh,
 989                           struct netlink_ext_ack *extack)
 990 {
 991         struct net *net = sock_net(skb->sk);
 992         struct rtcanmsg *r;
 993         struct cgw_job *gwj;
 994         struct cf_mod mod;
 995         struct can_can_gw ccgw;
 996         u8 limhops = 0;
 997         int err = 0;
 998 
 999         if (!netlink_capable(skb, CAP_NET_ADMIN))
1000                 return -EPERM;
1001 
1002         if (nlmsg_len(nlh) < sizeof(*r))
1003                 return -EINVAL;
1004 
1005         r = nlmsg_data(nlh);
1006         if (r->can_family != AF_CAN)
1007                 return -EPFNOSUPPORT;
1008 
1009         /* so far we only support CAN -> CAN routings */
1010         if (r->gwtype != CGW_TYPE_CAN_CAN)
1011                 return -EINVAL;
1012 
1013         err = cgw_parse_attr(nlh, &mod, CGW_TYPE_CAN_CAN, &ccgw, &limhops);
1014         if (err < 0)
1015                 return err;
1016 
1017         if (mod.uid) {
1018                 ASSERT_RTNL();
1019 
1020                 /* check for updating an existing job with identical uid */
1021                 hlist_for_each_entry(gwj, &net->can.cgw_list, list) {
1022                         if (gwj->mod.uid != mod.uid)
1023                                 continue;
1024 
1025                         /* interfaces & filters must be identical */
1026                         if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw)))
1027                                 return -EINVAL;
1028 
1029                         /* update modifications with disabled softirq & quit */
1030                         local_bh_disable();
1031                         memcpy(&gwj->mod, &mod, sizeof(mod));
1032                         local_bh_enable();
1033                         return 0;
1034                 }
1035         }
1036 
1037         /* ifindex == 0 is not allowed for job creation */
1038         if (!ccgw.src_idx || !ccgw.dst_idx)
1039                 return -ENODEV;
1040 
1041         gwj = kmem_cache_alloc(cgw_cache, GFP_KERNEL);
1042         if (!gwj)
1043                 return -ENOMEM;
1044 
1045         gwj->handled_frames = 0;
1046         gwj->dropped_frames = 0;
1047         gwj->deleted_frames = 0;
1048         gwj->flags = r->flags;
1049         gwj->gwtype = r->gwtype;
1050         gwj->limit_hops = limhops;
1051 
1052         /* insert already parsed information */
1053         memcpy(&gwj->mod, &mod, sizeof(mod));
1054         memcpy(&gwj->ccgw, &ccgw, sizeof(ccgw));
1055 
1056         err = -ENODEV;
1057 
1058         gwj->src.dev = __dev_get_by_index(net, gwj->ccgw.src_idx);
1059 
1060         if (!gwj->src.dev)
1061                 goto out;
1062 
1063         if (gwj->src.dev->type != ARPHRD_CAN)
1064                 goto out;
1065 
1066         gwj->dst.dev = __dev_get_by_index(net, gwj->ccgw.dst_idx);
1067 
1068         if (!gwj->dst.dev)
1069                 goto out;
1070 
1071         if (gwj->dst.dev->type != ARPHRD_CAN)
1072                 goto out;
1073 
1074         ASSERT_RTNL();
1075 
1076         err = cgw_register_filter(net, gwj);
1077         if (!err)
1078                 hlist_add_head_rcu(&gwj->list, &net->can.cgw_list);
1079 out:
1080         if (err)
1081                 kmem_cache_free(cgw_cache, gwj);
1082 
1083         return err;
1084 }
1085 
1086 static void cgw_remove_all_jobs(struct net *net)
1087 {
1088         struct cgw_job *gwj = NULL;
1089         struct hlist_node *nx;
1090 
1091         ASSERT_RTNL();
1092 
1093         hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
1094                 hlist_del(&gwj->list);
1095                 cgw_unregister_filter(net, gwj);
1096                 kmem_cache_free(cgw_cache, gwj);
1097         }
1098 }
1099 
1100 static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh,
1101                           struct netlink_ext_ack *extack)
1102 {
1103         struct net *net = sock_net(skb->sk);
1104         struct cgw_job *gwj = NULL;
1105         struct hlist_node *nx;
1106         struct rtcanmsg *r;
1107         struct cf_mod mod;
1108         struct can_can_gw ccgw;
1109         u8 limhops = 0;
1110         int err = 0;
1111 
1112         if (!netlink_capable(skb, CAP_NET_ADMIN))
1113                 return -EPERM;
1114 
1115         if (nlmsg_len(nlh) < sizeof(*r))
1116                 return -EINVAL;
1117 
1118         r = nlmsg_data(nlh);
1119         if (r->can_family != AF_CAN)
1120                 return -EPFNOSUPPORT;
1121 
1122         /* so far we only support CAN -> CAN routings */
1123         if (r->gwtype != CGW_TYPE_CAN_CAN)
1124                 return -EINVAL;
1125 
1126         err = cgw_parse_attr(nlh, &mod, CGW_TYPE_CAN_CAN, &ccgw, &limhops);
1127         if (err < 0)
1128                 return err;
1129 
1130         /* two interface indices both set to 0 => remove all entries */
1131         if (!ccgw.src_idx && !ccgw.dst_idx) {
1132                 cgw_remove_all_jobs(net);
1133                 return 0;
1134         }
1135 
1136         err = -EINVAL;
1137 
1138         ASSERT_RTNL();
1139 
1140         /* remove only the first matching entry */
1141         hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
1142                 if (gwj->flags != r->flags)
1143                         continue;
1144 
1145                 if (gwj->limit_hops != limhops)
1146                         continue;
1147 
1148                 /* we have a match when uid is enabled and identical */
1149                 if (gwj->mod.uid || mod.uid) {
1150                         if (gwj->mod.uid != mod.uid)
1151                                 continue;
1152                 } else {
1153                         /* no uid => check for identical modifications */
1154                         if (memcmp(&gwj->mod, &mod, sizeof(mod)))
1155                                 continue;
1156                 }
1157 
1158                 /* if (r->gwtype == CGW_TYPE_CAN_CAN) - is made sure here */
1159                 if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw)))
1160                         continue;
1161 
1162                 hlist_del(&gwj->list);
1163                 cgw_unregister_filter(net, gwj);
1164                 kmem_cache_free(cgw_cache, gwj);
1165                 err = 0;
1166                 break;
1167         }
1168 
1169         return err;
1170 }
1171 
1172 static int __net_init cangw_pernet_init(struct net *net)
1173 {
1174         INIT_HLIST_HEAD(&net->can.cgw_list);
1175         return 0;
1176 }
1177 
1178 static void __net_exit cangw_pernet_exit(struct net *net)
1179 {
1180         rtnl_lock();
1181         cgw_remove_all_jobs(net);
1182         rtnl_unlock();
1183 }
1184 
1185 static struct pernet_operations cangw_pernet_ops = {
1186         .init = cangw_pernet_init,
1187         .exit = cangw_pernet_exit,
1188 };
1189 
1190 static __init int cgw_module_init(void)
1191 {
1192         int ret;
1193 
1194         /* sanitize given module parameter */
1195         max_hops = clamp_t(unsigned int, max_hops, CGW_MIN_HOPS, CGW_MAX_HOPS);
1196 
1197         pr_info("can: netlink gateway (rev " CAN_GW_VERSION ") max_hops=%d\n",
1198                 max_hops);
1199 
1200         ret = register_pernet_subsys(&cangw_pernet_ops);
1201         if (ret)
1202                 return ret;
1203 
1204         ret = -ENOMEM;
1205         cgw_cache = kmem_cache_create("can_gw", sizeof(struct cgw_job),
1206                                       0, 0, NULL);
1207         if (!cgw_cache)
1208                 goto out_cache_create;
1209 
1210         /* set notifier */
1211         notifier.notifier_call = cgw_notifier;
1212         ret = register_netdevice_notifier(&notifier);
1213         if (ret)
1214                 goto out_register_notifier;
1215 
1216         ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_GETROUTE,
1217                                    NULL, cgw_dump_jobs, 0);
1218         if (ret)
1219                 goto out_rtnl_register1;
1220 
1221         ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_NEWROUTE,
1222                                    cgw_create_job, NULL, 0);
1223         if (ret)
1224                 goto out_rtnl_register2;
1225         ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_DELROUTE,
1226                                    cgw_remove_job, NULL, 0);
1227         if (ret)
1228                 goto out_rtnl_register3;
1229 
1230         return 0;
1231 
1232 out_rtnl_register3:
1233         rtnl_unregister(PF_CAN, RTM_NEWROUTE);
1234 out_rtnl_register2:
1235         rtnl_unregister(PF_CAN, RTM_GETROUTE);
1236 out_rtnl_register1:
1237         unregister_netdevice_notifier(&notifier);
1238 out_register_notifier:
1239         kmem_cache_destroy(cgw_cache);
1240 out_cache_create:
1241         unregister_pernet_subsys(&cangw_pernet_ops);
1242 
1243         return ret;
1244 }
1245 
1246 static __exit void cgw_module_exit(void)
1247 {
1248         rtnl_unregister_all(PF_CAN);
1249 
1250         unregister_netdevice_notifier(&notifier);
1251 
1252         unregister_pernet_subsys(&cangw_pernet_ops);
1253         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1254 
1255         kmem_cache_destroy(cgw_cache);
1256 }
1257 
1258 module_init(cgw_module_init);
1259 module_exit(cgw_module_exit);
/* [<][>][^][v][top][bottom][index][help] */
root/net/can/gw.c

DEFINITIONS
