1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * VLAN An implementation of 802.1Q VLAN tagging. 4 * 5 * Authors: Ben Greear <greearb@candelatech.com> 6 */ 7 #ifndef _LINUX_IF_VLAN_H_ 8 #define _LINUX_IF_VLAN_H_ 9 10 #include <linux/netdevice.h> 11 #include <linux/etherdevice.h> 12 #include <linux/rtnetlink.h> 13 #include <linux/bug.h> 14 #include <uapi/linux/if_vlan.h> 15 16 #define VLAN_HLEN 4 /* The additional bytes required by VLAN 17 * (in addition to the Ethernet header) 18 */ 19 #define VLAN_ETH_HLEN 18 /* Total octets in header. */ 20 #define VLAN_ETH_ZLEN 64 /* Min. octets in frame sans FCS */ 21 22 /* 23 * According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan 24 */ 25 #define VLAN_ETH_DATA_LEN 1500 /* Max. octets in payload */ 26 #define VLAN_ETH_FRAME_LEN 1518 /* Max. octets in frame sans FCS */ 27 28 #define VLAN_MAX_DEPTH 8 /* Max. number of nested VLAN tags parsed */ 29 30 /* 31 * struct vlan_hdr - vlan header 32 * @h_vlan_TCI: priority and VLAN ID 33 * @h_vlan_encapsulated_proto: packet type ID or len 34 */ 35 struct vlan_hdr { 36 __be16 h_vlan_TCI; 37 __be16 h_vlan_encapsulated_proto; 38 }; 39 40 /** 41 * struct vlan_ethhdr - vlan ethernet header (ethhdr + vlan_hdr) 42 * @h_dest: destination ethernet address 43 * @h_source: source ethernet address 44 * @h_vlan_proto: ethernet protocol 45 * @h_vlan_TCI: priority and VLAN ID 46 * @h_vlan_encapsulated_proto: packet type ID or len 47 */ 48 struct vlan_ethhdr { 49 unsigned char h_dest[ETH_ALEN]; 50 unsigned char h_source[ETH_ALEN]; 51 __be16 h_vlan_proto; 52 __be16 h_vlan_TCI; 53 __be16 h_vlan_encapsulated_proto; 54 }; 55 56 #include <linux/skbuff.h> 57 58 static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb) 59 { 60 return (struct vlan_ethhdr *)skb_mac_header(skb); 61 } 62 63 #define VLAN_PRIO_MASK 0xe000 /* Priority Code Point */ 64 #define VLAN_PRIO_SHIFT 13 65 #define VLAN_CFI_MASK 0x1000 /* Canonical Format Indicator / Drop Eligible Indicator */ 66 #define VLAN_VID_MASK 0x0fff /* VLAN Identifier */ 67 #define VLAN_N_VID 4096 68 69 /* found in socket.c */ 70 extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *)); 71 72 static inline bool is_vlan_dev(const struct net_device *dev) 73 { 74 return dev->priv_flags & IFF_802_1Q_VLAN; 75 } 76 77 #define skb_vlan_tag_present(__skb) ((__skb)->vlan_present) 78 #define skb_vlan_tag_get(__skb) ((__skb)->vlan_tci) 79 #define skb_vlan_tag_get_id(__skb) ((__skb)->vlan_tci & VLAN_VID_MASK) 80 #define skb_vlan_tag_get_cfi(__skb) (!!((__skb)->vlan_tci & VLAN_CFI_MASK)) 81 #define skb_vlan_tag_get_prio(__skb) (((__skb)->vlan_tci & VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT) 82 83 static inline int vlan_get_rx_ctag_filter_info(struct net_device *dev) 84 { 85 ASSERT_RTNL(); 86 return notifier_to_errno(call_netdevice_notifiers(NETDEV_CVLAN_FILTER_PUSH_INFO, dev)); 87 } 88 89 static inline void vlan_drop_rx_ctag_filter_info(struct net_device *dev) 90 { 91 ASSERT_RTNL(); 92 call_netdevice_notifiers(NETDEV_CVLAN_FILTER_DROP_INFO, dev); 93 } 94 95 static inline int vlan_get_rx_stag_filter_info(struct net_device *dev) 96 { 97 ASSERT_RTNL(); 98 return notifier_to_errno(call_netdevice_notifiers(NETDEV_SVLAN_FILTER_PUSH_INFO, dev)); 99 } 100 101 static inline void vlan_drop_rx_stag_filter_info(struct net_device *dev) 102 { 103 ASSERT_RTNL(); 104 call_netdevice_notifiers(NETDEV_SVLAN_FILTER_DROP_INFO, dev); 105 } 106 107 /** 108 * struct vlan_pcpu_stats - VLAN percpu rx/tx stats 109 * @rx_packets: number of received packets 110 * @rx_bytes: number of received bytes 111 * @rx_multicast: number of received multicast packets 112 * @tx_packets: number of transmitted packets 113 * @tx_bytes: number of transmitted bytes 114 * @syncp: synchronization point for 64bit counters 115 * @rx_errors: number of rx errors 116 * @tx_dropped: number of tx drops 117 */ 118 struct vlan_pcpu_stats { 119 u64 rx_packets; 120 u64 rx_bytes; 121 u64 rx_multicast; 122 u64 tx_packets; 123 u64 tx_bytes; 124 struct u64_stats_sync syncp; 125 u32 rx_errors; 126 u32 tx_dropped; 127 }; 128 129 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE) 130 131 extern struct net_device *__vlan_find_dev_deep_rcu(struct net_device *real_dev, 132 __be16 vlan_proto, u16 vlan_id); 133 extern int vlan_for_each(struct net_device *dev, 134 int (*action)(struct net_device *dev, int vid, 135 void *arg), void *arg); 136 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev); 137 extern u16 vlan_dev_vlan_id(const struct net_device *dev); 138 extern __be16 vlan_dev_vlan_proto(const struct net_device *dev); 139 140 /** 141 * struct vlan_priority_tci_mapping - vlan egress priority mappings 142 * @priority: skb priority 143 * @vlan_qos: vlan priority: (skb->priority << 13) & 0xE000 144 * @next: pointer to next struct 145 */ 146 struct vlan_priority_tci_mapping { 147 u32 priority; 148 u16 vlan_qos; 149 struct vlan_priority_tci_mapping *next; 150 }; 151 152 struct proc_dir_entry; 153 struct netpoll; 154 155 /** 156 * struct vlan_dev_priv - VLAN private device data 157 * @nr_ingress_mappings: number of ingress priority mappings 158 * @ingress_priority_map: ingress priority mappings 159 * @nr_egress_mappings: number of egress priority mappings 160 * @egress_priority_map: hash of egress priority mappings 161 * @vlan_proto: VLAN encapsulation protocol 162 * @vlan_id: VLAN identifier 163 * @flags: device flags 164 * @real_dev: underlying netdevice 165 * @dev_tracker: refcount tracker for @real_dev reference 166 * @real_dev_addr: address of underlying netdevice 167 * @dent: proc dir entry 168 * @vlan_pcpu_stats: ptr to percpu rx stats 169 */ 170 struct vlan_dev_priv { 171 unsigned int nr_ingress_mappings; 172 u32 ingress_priority_map[8]; 173 unsigned int nr_egress_mappings; 174 struct vlan_priority_tci_mapping *egress_priority_map[16]; 175 176 __be16 vlan_proto; 177 u16 vlan_id; 178 u16 flags; 179 180 struct net_device *real_dev; 181 netdevice_tracker dev_tracker; 182 183 unsigned char real_dev_addr[ETH_ALEN]; 184 185 struct proc_dir_entry *dent; 186 struct vlan_pcpu_stats __percpu *vlan_pcpu_stats; 187 #ifdef CONFIG_NET_POLL_CONTROLLER 188 struct netpoll *netpoll; 189 #endif 190 }; 191 192 static inline struct vlan_dev_priv *vlan_dev_priv(const struct net_device *dev) 193 { 194 return netdev_priv(dev); 195 } 196 197 static inline u16 198 vlan_dev_get_egress_qos_mask(struct net_device *dev, u32 skprio) 199 { 200 struct vlan_priority_tci_mapping *mp; 201 202 smp_rmb(); /* coupled with smp_wmb() in vlan_dev_set_egress_priority() */ 203 204 mp = vlan_dev_priv(dev)->egress_priority_map[(skprio & 0xF)]; 205 while (mp) { 206 if (mp->priority == skprio) { 207 return mp->vlan_qos; /* This should already be shifted 208 * to mask correctly with the 209 * VLAN's TCI */ 210 } 211 mp = mp->next; 212 } 213 return 0; 214 } 215 216 extern bool vlan_do_receive(struct sk_buff **skb); 217 218 extern int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid); 219 extern void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid); 220 221 extern int vlan_vids_add_by_dev(struct net_device *dev, 222 const struct net_device *by_dev); 223 extern void vlan_vids_del_by_dev(struct net_device *dev, 224 const struct net_device *by_dev); 225 226 extern bool vlan_uses_dev(const struct net_device *dev); 227 228 #else 229 static inline struct net_device * 230 __vlan_find_dev_deep_rcu(struct net_device *real_dev, 231 __be16 vlan_proto, u16 vlan_id) 232 { 233 return NULL; 234 } 235 236 static inline int 237 vlan_for_each(struct net_device *dev, 238 int (*action)(struct net_device *dev, int vid, void *arg), 239 void *arg) 240 { 241 return 0; 242 } 243 244 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev) 245 { 246 BUG(); 247 return NULL; 248 } 249 250 static inline u16 vlan_dev_vlan_id(const struct net_device *dev) 251 { 252 BUG(); 253 return 0; 254 } 255 256 static inline __be16 vlan_dev_vlan_proto(const struct net_device *dev) 257 { 258 BUG(); 259 return 0; 260 } 261 262 static inline u16 vlan_dev_get_egress_qos_mask(struct net_device *dev, 263 u32 skprio) 264 { 265 return 0; 266 } 267 268 static inline bool vlan_do_receive(struct sk_buff **skb) 269 { 270 return false; 271 } 272 273 static inline int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid) 274 { 275 return 0; 276 } 277 278 static inline void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid) 279 { 280 } 281 282 static inline int vlan_vids_add_by_dev(struct net_device *dev, 283 const struct net_device *by_dev) 284 { 285 return 0; 286 } 287 288 static inline void vlan_vids_del_by_dev(struct net_device *dev, 289 const struct net_device *by_dev) 290 { 291 } 292 293 static inline bool vlan_uses_dev(const struct net_device *dev) 294 { 295 return false; 296 } 297 #endif 298 299 /** 300 * eth_type_vlan - check for valid vlan ether type. 301 * @ethertype: ether type to check 302 * 303 * Returns true if the ether type is a vlan ether type. 304 */ 305 static inline bool eth_type_vlan(__be16 ethertype) 306 { 307 switch (ethertype) { 308 case htons(ETH_P_8021Q): 309 case htons(ETH_P_8021AD): 310 return true; 311 default: 312 return false; 313 } 314 } 315 316 static inline bool vlan_hw_offload_capable(netdev_features_t features, 317 __be16 proto) 318 { 319 if (proto == htons(ETH_P_8021Q) && features & NETIF_F_HW_VLAN_CTAG_TX) 320 return true; 321 if (proto == htons(ETH_P_8021AD) && features & NETIF_F_HW_VLAN_STAG_TX) 322 return true; 323 return false; 324 } 325 326 /** 327 * __vlan_insert_inner_tag - inner VLAN tag inserting 328 * @skb: skbuff to tag 329 * @vlan_proto: VLAN encapsulation protocol 330 * @vlan_tci: VLAN TCI to insert 331 * @mac_len: MAC header length including outer vlan headers 332 * 333 * Inserts the VLAN tag into @skb as part of the payload at offset mac_len 334 * Returns error if skb_cow_head fails. 335 * 336 * Does not change skb->protocol so this function can be used during receive. 337 */ 338 static inline int __vlan_insert_inner_tag(struct sk_buff *skb, 339 __be16 vlan_proto, u16 vlan_tci, 340 unsigned int mac_len) 341 { 342 struct vlan_ethhdr *veth; 343 344 if (skb_cow_head(skb, VLAN_HLEN) < 0) 345 return -ENOMEM; 346 347 skb_push(skb, VLAN_HLEN); 348 349 /* Move the mac header sans proto to the beginning of the new header. */ 350 if (likely(mac_len > ETH_TLEN)) 351 memmove(skb->data, skb->data + VLAN_HLEN, mac_len - ETH_TLEN); 352 skb->mac_header -= VLAN_HLEN; 353 354 veth = (struct vlan_ethhdr *)(skb->data + mac_len - ETH_HLEN); 355 356 /* first, the ethernet type */ 357 if (likely(mac_len >= ETH_TLEN)) { 358 /* h_vlan_encapsulated_proto should already be populated, and 359 * skb->data has space for h_vlan_proto 360 */ 361 veth->h_vlan_proto = vlan_proto; 362 } else { 363 /* h_vlan_encapsulated_proto should not be populated, and 364 * skb->data has no space for h_vlan_proto 365 */ 366 veth->h_vlan_encapsulated_proto = skb->protocol; 367 } 368 369 /* now, the TCI */ 370 veth->h_vlan_TCI = htons(vlan_tci); 371 372 return 0; 373 } 374 375 /** 376 * __vlan_insert_tag - regular VLAN tag inserting 377 * @skb: skbuff to tag 378 * @vlan_proto: VLAN encapsulation protocol 379 * @vlan_tci: VLAN TCI to insert 380 * 381 * Inserts the VLAN tag into @skb as part of the payload 382 * Returns error if skb_cow_head fails. 383 * 384 * Does not change skb->protocol so this function can be used during receive. 385 */ 386 static inline int __vlan_insert_tag(struct sk_buff *skb, 387 __be16 vlan_proto, u16 vlan_tci) 388 { 389 return __vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, ETH_HLEN); 390 } 391 392 /** 393 * vlan_insert_inner_tag - inner VLAN tag inserting 394 * @skb: skbuff to tag 395 * @vlan_proto: VLAN encapsulation protocol 396 * @vlan_tci: VLAN TCI to insert 397 * @mac_len: MAC header length including outer vlan headers 398 * 399 * Inserts the VLAN tag into @skb as part of the payload at offset mac_len 400 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed. 401 * 402 * Following the skb_unshare() example, in case of error, the calling function 403 * doesn't have to worry about freeing the original skb. 404 * 405 * Does not change skb->protocol so this function can be used during receive. 406 */ 407 static inline struct sk_buff *vlan_insert_inner_tag(struct sk_buff *skb, 408 __be16 vlan_proto, 409 u16 vlan_tci, 410 unsigned int mac_len) 411 { 412 int err; 413 414 err = __vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, mac_len); 415 if (err) { 416 dev_kfree_skb_any(skb); 417 return NULL; 418 } 419 return skb; 420 } 421 422 /** 423 * vlan_insert_tag - regular VLAN tag inserting 424 * @skb: skbuff to tag 425 * @vlan_proto: VLAN encapsulation protocol 426 * @vlan_tci: VLAN TCI to insert 427 * 428 * Inserts the VLAN tag into @skb as part of the payload 429 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed. 430 * 431 * Following the skb_unshare() example, in case of error, the calling function 432 * doesn't have to worry about freeing the original skb. 433 * 434 * Does not change skb->protocol so this function can be used during receive. 435 */ 436 static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, 437 __be16 vlan_proto, u16 vlan_tci) 438 { 439 return vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, ETH_HLEN); 440 } 441 442 /** 443 * vlan_insert_tag_set_proto - regular VLAN tag inserting 444 * @skb: skbuff to tag 445 * @vlan_proto: VLAN encapsulation protocol 446 * @vlan_tci: VLAN TCI to insert 447 * 448 * Inserts the VLAN tag into @skb as part of the payload 449 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed. 450 * 451 * Following the skb_unshare() example, in case of error, the calling function 452 * doesn't have to worry about freeing the original skb. 453 */ 454 static inline struct sk_buff *vlan_insert_tag_set_proto(struct sk_buff *skb, 455 __be16 vlan_proto, 456 u16 vlan_tci) 457 { 458 skb = vlan_insert_tag(skb, vlan_proto, vlan_tci); 459 if (skb) 460 skb->protocol = vlan_proto; 461 return skb; 462 } 463 464 /** 465 * __vlan_hwaccel_clear_tag - clear hardware accelerated VLAN info 466 * @skb: skbuff to clear 467 * 468 * Clears the VLAN information from @skb 469 */ 470 static inline void __vlan_hwaccel_clear_tag(struct sk_buff *skb) 471 { 472 skb->vlan_present = 0; 473 } 474 475 /** 476 * __vlan_hwaccel_copy_tag - copy hardware accelerated VLAN info from another skb 477 * @dst: skbuff to copy to 478 * @src: skbuff to copy from 479 * 480 * Copies VLAN information from @src to @dst (for branchless code) 481 */ 482 static inline void __vlan_hwaccel_copy_tag(struct sk_buff *dst, const struct sk_buff *src) 483 { 484 dst->vlan_present = src->vlan_present; 485 dst->vlan_proto = src->vlan_proto; 486 dst->vlan_tci = src->vlan_tci; 487 } 488 489 /* 490 * __vlan_hwaccel_push_inside - pushes vlan tag to the payload 491 * @skb: skbuff to tag 492 * 493 * Pushes the VLAN tag from @skb->vlan_tci inside to the payload. 494 * 495 * Following the skb_unshare() example, in case of error, the calling function 496 * doesn't have to worry about freeing the original skb. 497 */ 498 static inline struct sk_buff *__vlan_hwaccel_push_inside(struct sk_buff *skb) 499 { 500 skb = vlan_insert_tag_set_proto(skb, skb->vlan_proto, 501 skb_vlan_tag_get(skb)); 502 if (likely(skb)) 503 __vlan_hwaccel_clear_tag(skb); 504 return skb; 505 } 506 507 /** 508 * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting 509 * @skb: skbuff to tag 510 * @vlan_proto: VLAN encapsulation protocol 511 * @vlan_tci: VLAN TCI to insert 512 * 513 * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest 514 */ 515 static inline void __vlan_hwaccel_put_tag(struct sk_buff *skb, 516 __be16 vlan_proto, u16 vlan_tci) 517 { 518 skb->vlan_proto = vlan_proto; 519 skb->vlan_tci = vlan_tci; 520 skb->vlan_present = 1; 521 } 522 523 /** 524 * __vlan_get_tag - get the VLAN ID that is part of the payload 525 * @skb: skbuff to query 526 * @vlan_tci: buffer to store value 527 * 528 * Returns error if the skb is not of VLAN type 529 */ 530 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci) 531 { 532 struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data; 533 534 if (!eth_type_vlan(veth->h_vlan_proto)) 535 return -EINVAL; 536 537 *vlan_tci = ntohs(veth->h_vlan_TCI); 538 return 0; 539 } 540 541 /** 542 * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[] 543 * @skb: skbuff to query 544 * @vlan_tci: buffer to store value 545 * 546 * Returns error if @skb->vlan_tci is not set correctly 547 */ 548 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb, 549 u16 *vlan_tci) 550 { 551 if (skb_vlan_tag_present(skb)) { 552 *vlan_tci = skb_vlan_tag_get(skb); 553 return 0; 554 } else { 555 *vlan_tci = 0; 556 return -EINVAL; 557 } 558 } 559 560 /** 561 * vlan_get_tag - get the VLAN ID from the skb 562 * @skb: skbuff to query 563 * @vlan_tci: buffer to store value 564 * 565 * Returns error if the skb is not VLAN tagged 566 */ 567 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci) 568 { 569 if (skb->dev->features & NETIF_F_HW_VLAN_CTAG_TX) { 570 return __vlan_hwaccel_get_tag(skb, vlan_tci); 571 } else { 572 return __vlan_get_tag(skb, vlan_tci); 573 } 574 } 575 576 /** 577 * vlan_get_protocol - get protocol EtherType. 578 * @skb: skbuff to query 579 * @type: first vlan protocol 580 * @depth: buffer to store length of eth and vlan tags in bytes 581 * 582 * Returns the EtherType of the packet, regardless of whether it is 583 * vlan encapsulated (normal or hardware accelerated) or not. 584 */ 585 static inline __be16 __vlan_get_protocol(const struct sk_buff *skb, __be16 type, 586 int *depth) 587 { 588 unsigned int vlan_depth = skb->mac_len, parse_depth = VLAN_MAX_DEPTH; 589 590 /* if type is 802.1Q/AD then the header should already be 591 * present at mac_len - VLAN_HLEN (if mac_len > 0), or at 592 * ETH_HLEN otherwise 593 */ 594 if (eth_type_vlan(type)) { 595 if (vlan_depth) { 596 if (WARN_ON(vlan_depth < VLAN_HLEN)) 597 return 0; 598 vlan_depth -= VLAN_HLEN; 599 } else { 600 vlan_depth = ETH_HLEN; 601 } 602 do { 603 struct vlan_hdr vhdr, *vh; 604 605 vh = skb_header_pointer(skb, vlan_depth, sizeof(vhdr), &vhdr); 606 if (unlikely(!vh || !--parse_depth)) 607 return 0; 608 609 type = vh->h_vlan_encapsulated_proto; 610 vlan_depth += VLAN_HLEN; 611 } while (eth_type_vlan(type)); 612 } 613 614 if (depth) 615 *depth = vlan_depth; 616 617 return type; 618 } 619 620 /** 621 * vlan_get_protocol - get protocol EtherType. 622 * @skb: skbuff to query 623 * 624 * Returns the EtherType of the packet, regardless of whether it is 625 * vlan encapsulated (normal or hardware accelerated) or not. 626 */ 627 static inline __be16 vlan_get_protocol(const struct sk_buff *skb) 628 { 629 return __vlan_get_protocol(skb, skb->protocol, NULL); 630 } 631 632 /* A getter for the SKB protocol field which will handle VLAN tags consistently 633 * whether VLAN acceleration is enabled or not. 634 */ 635 static inline __be16 skb_protocol(const struct sk_buff *skb, bool skip_vlan) 636 { 637 if (!skip_vlan) 638 /* VLAN acceleration strips the VLAN header from the skb and 639 * moves it to skb->vlan_proto 640 */ 641 return skb_vlan_tag_present(skb) ? skb->vlan_proto : skb->protocol; 642 643 return vlan_get_protocol(skb); 644 } 645 646 static inline void vlan_set_encap_proto(struct sk_buff *skb, 647 struct vlan_hdr *vhdr) 648 { 649 __be16 proto; 650 unsigned short *rawp; 651 652 /* 653 * Was a VLAN packet, grab the encapsulated protocol, which the layer 654 * three protocols care about. 655 */ 656 657 proto = vhdr->h_vlan_encapsulated_proto; 658 if (eth_proto_is_802_3(proto)) { 659 skb->protocol = proto; 660 return; 661 } 662 663 rawp = (unsigned short *)(vhdr + 1); 664 if (*rawp == 0xFFFF) 665 /* 666 * This is a magic hack to spot IPX packets. Older Novell 667 * breaks the protocol design and runs IPX over 802.3 without 668 * an 802.2 LLC layer. We look for FFFF which isn't a used 669 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware 670 * but does for the rest. 671 */ 672 skb->protocol = htons(ETH_P_802_3); 673 else 674 /* 675 * Real 802.2 LLC 676 */ 677 skb->protocol = htons(ETH_P_802_2); 678 } 679 680 /** 681 * skb_vlan_tagged - check if skb is vlan tagged. 682 * @skb: skbuff to query 683 * 684 * Returns true if the skb is tagged, regardless of whether it is hardware 685 * accelerated or not. 686 */ 687 static inline bool skb_vlan_tagged(const struct sk_buff *skb) 688 { 689 if (!skb_vlan_tag_present(skb) && 690 likely(!eth_type_vlan(skb->protocol))) 691 return false; 692 693 return true; 694 } 695 696 /** 697 * skb_vlan_tagged_multi - check if skb is vlan tagged with multiple headers. 698 * @skb: skbuff to query 699 * 700 * Returns true if the skb is tagged with multiple vlan headers, regardless 701 * of whether it is hardware accelerated or not. 702 */ 703 static inline bool skb_vlan_tagged_multi(struct sk_buff *skb) 704 { 705 __be16 protocol = skb->protocol; 706 707 if (!skb_vlan_tag_present(skb)) { 708 struct vlan_ethhdr *veh; 709 710 if (likely(!eth_type_vlan(protocol))) 711 return false; 712 713 if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN))) 714 return false; 715 716 veh = (struct vlan_ethhdr *)skb->data; 717 protocol = veh->h_vlan_encapsulated_proto; 718 } 719 720 if (!eth_type_vlan(protocol)) 721 return false; 722 723 return true; 724 } 725 726 /** 727 * vlan_features_check - drop unsafe features for skb with multiple tags. 728 * @skb: skbuff to query 729 * @features: features to be checked 730 * 731 * Returns features without unsafe ones if the skb has multiple tags. 732 */ 733 static inline netdev_features_t vlan_features_check(struct sk_buff *skb, 734 netdev_features_t features) 735 { 736 if (skb_vlan_tagged_multi(skb)) { 737 /* In the case of multi-tagged packets, use a direct mask 738 * instead of using netdev_interesect_features(), to make 739 * sure that only devices supporting NETIF_F_HW_CSUM will 740 * have checksum offloading support. 741 */ 742 features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_HW_CSUM | 743 NETIF_F_FRAGLIST | NETIF_F_HW_VLAN_CTAG_TX | 744 NETIF_F_HW_VLAN_STAG_TX; 745 } 746 747 return features; 748 } 749 750 /** 751 * compare_vlan_header - Compare two vlan headers 752 * @h1: Pointer to vlan header 753 * @h2: Pointer to vlan header 754 * 755 * Compare two vlan headers, returns 0 if equal. 756 * 757 * Please note that alignment of h1 & h2 are only guaranteed to be 16 bits. 758 */ 759 static inline unsigned long compare_vlan_header(const struct vlan_hdr *h1, 760 const struct vlan_hdr *h2) 761 { 762 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) 763 return *(u32 *)h1 ^ *(u32 *)h2; 764 #else 765 return ((__force u32)h1->h_vlan_TCI ^ (__force u32)h2->h_vlan_TCI) | 766 ((__force u32)h1->h_vlan_encapsulated_proto ^ 767 (__force u32)h2->h_vlan_encapsulated_proto); 768 #endif 769 } 770 #endif /* !(_LINUX_IF_VLAN_H_) */ 771