1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * VLAN An implementation of 802.1Q VLAN tagging. 4 * 5 * Authors: Ben Greear <[email protected]> 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 /* 29 * struct vlan_hdr - vlan header 30 * @h_vlan_TCI: priority and VLAN ID 31 * @h_vlan_encapsulated_proto: packet type ID or len 32 */ 33 struct vlan_hdr { 34 __be16 h_vlan_TCI; 35 __be16 h_vlan_encapsulated_proto; 36 }; 37 38 /** 39 * struct vlan_ethhdr - vlan ethernet header (ethhdr + vlan_hdr) 40 * @h_dest: destination ethernet address 41 * @h_source: source ethernet address 42 * @h_vlan_proto: ethernet protocol 43 * @h_vlan_TCI: priority and VLAN ID 44 * @h_vlan_encapsulated_proto: packet type ID or len 45 */ 46 struct vlan_ethhdr { 47 unsigned char h_dest[ETH_ALEN]; 48 unsigned char h_source[ETH_ALEN]; 49 __be16 h_vlan_proto; 50 __be16 h_vlan_TCI; 51 __be16 h_vlan_encapsulated_proto; 52 }; 53 54 #include <linux/skbuff.h> 55 56 static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb) 57 { 58 return (struct vlan_ethhdr *)skb_mac_header(skb); 59 } 60 61 #define VLAN_PRIO_MASK 0xe000 /* Priority Code Point */ 62 #define VLAN_PRIO_SHIFT 13 63 #define VLAN_CFI_MASK 0x1000 /* Canonical Format Indicator / Drop Eligible Indicator */ 64 #define VLAN_VID_MASK 0x0fff /* VLAN Identifier */ 65 #define VLAN_N_VID 4096 66 67 /* found in socket.c */ 68 extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *)); 69 70 static inline bool is_vlan_dev(const struct net_device *dev) 71 { 72 return dev->priv_flags & IFF_802_1Q_VLAN; 73 } 74 75 #define skb_vlan_tag_present(__skb) ((__skb)->vlan_present) 76 #define skb_vlan_tag_get(__skb) ((__skb)->vlan_tci) 77 #define skb_vlan_tag_get_id(__skb) ((__skb)->vlan_tci & VLAN_VID_MASK) 78 #define skb_vlan_tag_get_cfi(__skb) (!!((__skb)->vlan_tci & VLAN_CFI_MASK)) 79 #define skb_vlan_tag_get_prio(__skb) (((__skb)->vlan_tci & VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT) 80 81 static inline int vlan_get_rx_ctag_filter_info(struct net_device *dev) 82 { 83 ASSERT_RTNL(); 84 return notifier_to_errno(call_netdevice_notifiers(NETDEV_CVLAN_FILTER_PUSH_INFO, dev)); 85 } 86 87 static inline void vlan_drop_rx_ctag_filter_info(struct net_device *dev) 88 { 89 ASSERT_RTNL(); 90 call_netdevice_notifiers(NETDEV_CVLAN_FILTER_DROP_INFO, dev); 91 } 92 93 static inline int vlan_get_rx_stag_filter_info(struct net_device *dev) 94 { 95 ASSERT_RTNL(); 96 return notifier_to_errno(call_netdevice_notifiers(NETDEV_SVLAN_FILTER_PUSH_INFO, dev)); 97 } 98 99 static inline void vlan_drop_rx_stag_filter_info(struct net_device *dev) 100 { 101 ASSERT_RTNL(); 102 call_netdevice_notifiers(NETDEV_SVLAN_FILTER_DROP_INFO, dev); 103 } 104 105 /** 106 * struct vlan_pcpu_stats - VLAN percpu rx/tx stats 107 * @rx_packets: number of received packets 108 * @rx_bytes: number of received bytes 109 * @rx_multicast: number of received multicast packets 110 * @tx_packets: number of transmitted packets 111 * @tx_bytes: number of transmitted bytes 112 * @syncp: synchronization point for 64bit counters 113 * @rx_errors: number of rx errors 114 * @tx_dropped: number of tx drops 115 */ 116 struct vlan_pcpu_stats { 117 u64 rx_packets; 118 u64 rx_bytes; 119 u64 rx_multicast; 120 u64 tx_packets; 121 u64 tx_bytes; 122 struct u64_stats_sync syncp; 123 u32 rx_errors; 124 u32 tx_dropped; 125 }; 126 127 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE) 128 129 extern struct net_device *__vlan_find_dev_deep_rcu(struct net_device *real_dev, 130 __be16 vlan_proto, u16 vlan_id); 131 extern int vlan_for_each(struct net_device *dev, 132 int (*action)(struct net_device *dev, int vid, 133 void *arg), void *arg); 134 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev); 135 extern u16 vlan_dev_vlan_id(const struct net_device *dev); 136 extern __be16 vlan_dev_vlan_proto(const struct net_device *dev); 137 138 /** 139 * struct vlan_priority_tci_mapping - vlan egress priority mappings 140 * @priority: skb priority 141 * @vlan_qos: vlan priority: (skb->priority << 13) & 0xE000 142 * @next: pointer to next struct 143 */ 144 struct vlan_priority_tci_mapping { 145 u32 priority; 146 u16 vlan_qos; 147 struct vlan_priority_tci_mapping *next; 148 }; 149 150 struct proc_dir_entry; 151 struct netpoll; 152 153 /** 154 * struct vlan_dev_priv - VLAN private device data 155 * @nr_ingress_mappings: number of ingress priority mappings 156 * @ingress_priority_map: ingress priority mappings 157 * @nr_egress_mappings: number of egress priority mappings 158 * @egress_priority_map: hash of egress priority mappings 159 * @vlan_proto: VLAN encapsulation protocol 160 * @vlan_id: VLAN identifier 161 * @flags: device flags 162 * @real_dev: underlying netdevice 163 * @real_dev_addr: address of underlying netdevice 164 * @dent: proc dir entry 165 * @vlan_pcpu_stats: ptr to percpu rx stats 166 */ 167 struct vlan_dev_priv { 168 unsigned int nr_ingress_mappings; 169 u32 ingress_priority_map[8]; 170 unsigned int nr_egress_mappings; 171 struct vlan_priority_tci_mapping *egress_priority_map[16]; 172 173 __be16 vlan_proto; 174 u16 vlan_id; 175 u16 flags; 176 177 struct net_device *real_dev; 178 unsigned char real_dev_addr[ETH_ALEN]; 179 180 struct proc_dir_entry *dent; 181 struct vlan_pcpu_stats __percpu *vlan_pcpu_stats; 182 #ifdef CONFIG_NET_POLL_CONTROLLER 183 struct netpoll *netpoll; 184 #endif 185 }; 186 187 static inline struct vlan_dev_priv *vlan_dev_priv(const struct net_device *dev) 188 { 189 return netdev_priv(dev); 190 } 191 192 static inline u16 193 vlan_dev_get_egress_qos_mask(struct net_device *dev, u32 skprio) 194 { 195 struct vlan_priority_tci_mapping *mp; 196 197 smp_rmb(); /* coupled with smp_wmb() in vlan_dev_set_egress_priority() */ 198 199 mp = vlan_dev_priv(dev)->egress_priority_map[(skprio & 0xF)]; 200 while (mp) { 201 if (mp->priority == skprio) { 202 return mp->vlan_qos; /* This should already be shifted 203 * to mask correctly with the 204 * VLAN's TCI */ 205 } 206 mp = mp->next; 207 } 208 return 0; 209 } 210 211 extern bool vlan_do_receive(struct sk_buff **skb); 212 213 extern int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid); 214 extern void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid); 215 216 extern int vlan_vids_add_by_dev(struct net_device *dev, 217 const struct net_device *by_dev); 218 extern void vlan_vids_del_by_dev(struct net_device *dev, 219 const struct net_device *by_dev); 220 221 extern bool vlan_uses_dev(const struct net_device *dev); 222 223 #else 224 static inline struct net_device * 225 __vlan_find_dev_deep_rcu(struct net_device *real_dev, 226 __be16 vlan_proto, u16 vlan_id) 227 { 228 return NULL; 229 } 230 231 static inline int 232 vlan_for_each(struct net_device *dev, 233 int (*action)(struct net_device *dev, int vid, void *arg), 234 void *arg) 235 { 236 return 0; 237 } 238 239 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev) 240 { 241 BUG(); 242 return NULL; 243 } 244 245 static inline u16 vlan_dev_vlan_id(const struct net_device *dev) 246 { 247 BUG(); 248 return 0; 249 } 250 251 static inline __be16 vlan_dev_vlan_proto(const struct net_device *dev) 252 { 253 BUG(); 254 return 0; 255 } 256 257 static inline u16 vlan_dev_get_egress_qos_mask(struct net_device *dev, 258 u32 skprio) 259 { 260 return 0; 261 } 262 263 static inline bool vlan_do_receive(struct sk_buff **skb) 264 { 265 return false; 266 } 267 268 static inline int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid) 269 { 270 return 0; 271 } 272 273 static inline void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid) 274 { 275 } 276 277 static inline int vlan_vids_add_by_dev(struct net_device *dev, 278 const struct net_device *by_dev) 279 { 280 return 0; 281 } 282 283 static inline void vlan_vids_del_by_dev(struct net_device *dev, 284 const struct net_device *by_dev) 285 { 286 } 287 288 static inline bool vlan_uses_dev(const struct net_device *dev) 289 { 290 return false; 291 } 292 #endif 293 294 /** 295 * eth_type_vlan - check for valid vlan ether type. 296 * @ethertype: ether type to check 297 * 298 * Returns true if the ether type is a vlan ether type. 299 */ 300 static inline bool eth_type_vlan(__be16 ethertype) 301 { 302 switch (ethertype) { 303 case htons(ETH_P_8021Q): 304 case htons(ETH_P_8021AD): 305 return true; 306 default: 307 return false; 308 } 309 } 310 311 /* A getter for the SKB protocol field which will handle VLAN tags consistently 312 * whether VLAN acceleration is enabled or not. 313 */ 314 static inline __be16 skb_protocol(const struct sk_buff *skb, bool skip_vlan) 315 { 316 unsigned int offset = skb_mac_offset(skb) + sizeof(struct ethhdr); 317 __be16 proto = skb->protocol; 318 319 if (!skip_vlan) 320 /* VLAN acceleration strips the VLAN header from the skb and 321 * moves it to skb->vlan_proto 322 */ 323 return skb_vlan_tag_present(skb) ? skb->vlan_proto : proto; 324 325 while (eth_type_vlan(proto)) { 326 struct vlan_hdr vhdr, *vh; 327 328 vh = skb_header_pointer(skb, offset, sizeof(vhdr), &vhdr); 329 if (!vh) 330 break; 331 332 proto = vh->h_vlan_encapsulated_proto; 333 offset += sizeof(vhdr); 334 } 335 336 return proto; 337 } 338 339 static inline bool vlan_hw_offload_capable(netdev_features_t features, 340 __be16 proto) 341 { 342 if (proto == htons(ETH_P_8021Q) && features & NETIF_F_HW_VLAN_CTAG_TX) 343 return true; 344 if (proto == htons(ETH_P_8021AD) && features & NETIF_F_HW_VLAN_STAG_TX) 345 return true; 346 return false; 347 } 348 349 /** 350 * __vlan_insert_inner_tag - inner VLAN tag inserting 351 * @skb: skbuff to tag 352 * @vlan_proto: VLAN encapsulation protocol 353 * @vlan_tci: VLAN TCI to insert 354 * @mac_len: MAC header length including outer vlan headers 355 * 356 * Inserts the VLAN tag into @skb as part of the payload at offset mac_len 357 * Returns error if skb_cow_head fails. 358 * 359 * Does not change skb->protocol so this function can be used during receive. 360 */ 361 static inline int __vlan_insert_inner_tag(struct sk_buff *skb, 362 __be16 vlan_proto, u16 vlan_tci, 363 unsigned int mac_len) 364 { 365 struct vlan_ethhdr *veth; 366 367 if (skb_cow_head(skb, VLAN_HLEN) < 0) 368 return -ENOMEM; 369 370 skb_push(skb, VLAN_HLEN); 371 372 /* Move the mac header sans proto to the beginning of the new header. */ 373 if (likely(mac_len > ETH_TLEN)) 374 memmove(skb->data, skb->data + VLAN_HLEN, mac_len - ETH_TLEN); 375 skb->mac_header -= VLAN_HLEN; 376 377 veth = (struct vlan_ethhdr *)(skb->data + mac_len - ETH_HLEN); 378 379 /* first, the ethernet type */ 380 if (likely(mac_len >= ETH_TLEN)) { 381 /* h_vlan_encapsulated_proto should already be populated, and 382 * skb->data has space for h_vlan_proto 383 */ 384 veth->h_vlan_proto = vlan_proto; 385 } else { 386 /* h_vlan_encapsulated_proto should not be populated, and 387 * skb->data has no space for h_vlan_proto 388 */ 389 veth->h_vlan_encapsulated_proto = skb->protocol; 390 } 391 392 /* now, the TCI */ 393 veth->h_vlan_TCI = htons(vlan_tci); 394 395 return 0; 396 } 397 398 /** 399 * __vlan_insert_tag - regular VLAN tag inserting 400 * @skb: skbuff to tag 401 * @vlan_proto: VLAN encapsulation protocol 402 * @vlan_tci: VLAN TCI to insert 403 * 404 * Inserts the VLAN tag into @skb as part of the payload 405 * Returns error if skb_cow_head fails. 406 * 407 * Does not change skb->protocol so this function can be used during receive. 408 */ 409 static inline int __vlan_insert_tag(struct sk_buff *skb, 410 __be16 vlan_proto, u16 vlan_tci) 411 { 412 return __vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, ETH_HLEN); 413 } 414 415 /** 416 * vlan_insert_inner_tag - inner VLAN tag inserting 417 * @skb: skbuff to tag 418 * @vlan_proto: VLAN encapsulation protocol 419 * @vlan_tci: VLAN TCI to insert 420 * @mac_len: MAC header length including outer vlan headers 421 * 422 * Inserts the VLAN tag into @skb as part of the payload at offset mac_len 423 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed. 424 * 425 * Following the skb_unshare() example, in case of error, the calling function 426 * doesn't have to worry about freeing the original skb. 427 * 428 * Does not change skb->protocol so this function can be used during receive. 429 */ 430 static inline struct sk_buff *vlan_insert_inner_tag(struct sk_buff *skb, 431 __be16 vlan_proto, 432 u16 vlan_tci, 433 unsigned int mac_len) 434 { 435 int err; 436 437 err = __vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, mac_len); 438 if (err) { 439 dev_kfree_skb_any(skb); 440 return NULL; 441 } 442 return skb; 443 } 444 445 /** 446 * vlan_insert_tag - regular VLAN tag inserting 447 * @skb: skbuff to tag 448 * @vlan_proto: VLAN encapsulation protocol 449 * @vlan_tci: VLAN TCI to insert 450 * 451 * Inserts the VLAN tag into @skb as part of the payload 452 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed. 453 * 454 * Following the skb_unshare() example, in case of error, the calling function 455 * doesn't have to worry about freeing the original skb. 456 * 457 * Does not change skb->protocol so this function can be used during receive. 458 */ 459 static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, 460 __be16 vlan_proto, u16 vlan_tci) 461 { 462 return vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, ETH_HLEN); 463 } 464 465 /** 466 * vlan_insert_tag_set_proto - regular VLAN tag inserting 467 * @skb: skbuff to tag 468 * @vlan_proto: VLAN encapsulation protocol 469 * @vlan_tci: VLAN TCI to insert 470 * 471 * Inserts the VLAN tag into @skb as part of the payload 472 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed. 473 * 474 * Following the skb_unshare() example, in case of error, the calling function 475 * doesn't have to worry about freeing the original skb. 476 */ 477 static inline struct sk_buff *vlan_insert_tag_set_proto(struct sk_buff *skb, 478 __be16 vlan_proto, 479 u16 vlan_tci) 480 { 481 skb = vlan_insert_tag(skb, vlan_proto, vlan_tci); 482 if (skb) 483 skb->protocol = vlan_proto; 484 return skb; 485 } 486 487 /** 488 * __vlan_hwaccel_clear_tag - clear hardware accelerated VLAN info 489 * @skb: skbuff to clear 490 * 491 * Clears the VLAN information from @skb 492 */ 493 static inline void __vlan_hwaccel_clear_tag(struct sk_buff *skb) 494 { 495 skb->vlan_present = 0; 496 } 497 498 /** 499 * __vlan_hwaccel_copy_tag - copy hardware accelerated VLAN info from another skb 500 * @dst: skbuff to copy to 501 * @src: skbuff to copy from 502 * 503 * Copies VLAN information from @src to @dst (for branchless code) 504 */ 505 static inline void __vlan_hwaccel_copy_tag(struct sk_buff *dst, const struct sk_buff *src) 506 { 507 dst->vlan_present = src->vlan_present; 508 dst->vlan_proto = src->vlan_proto; 509 dst->vlan_tci = src->vlan_tci; 510 } 511 512 /* 513 * __vlan_hwaccel_push_inside - pushes vlan tag to the payload 514 * @skb: skbuff to tag 515 * 516 * Pushes the VLAN tag from @skb->vlan_tci inside to the payload. 517 * 518 * Following the skb_unshare() example, in case of error, the calling function 519 * doesn't have to worry about freeing the original skb. 520 */ 521 static inline struct sk_buff *__vlan_hwaccel_push_inside(struct sk_buff *skb) 522 { 523 skb = vlan_insert_tag_set_proto(skb, skb->vlan_proto, 524 skb_vlan_tag_get(skb)); 525 if (likely(skb)) 526 __vlan_hwaccel_clear_tag(skb); 527 return skb; 528 } 529 530 /** 531 * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting 532 * @skb: skbuff to tag 533 * @vlan_proto: VLAN encapsulation protocol 534 * @vlan_tci: VLAN TCI to insert 535 * 536 * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest 537 */ 538 static inline void __vlan_hwaccel_put_tag(struct sk_buff *skb, 539 __be16 vlan_proto, u16 vlan_tci) 540 { 541 skb->vlan_proto = vlan_proto; 542 skb->vlan_tci = vlan_tci; 543 skb->vlan_present = 1; 544 } 545 546 /** 547 * __vlan_get_tag - get the VLAN ID that is part of the payload 548 * @skb: skbuff to query 549 * @vlan_tci: buffer to store value 550 * 551 * Returns error if the skb is not of VLAN type 552 */ 553 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci) 554 { 555 struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data; 556 557 if (!eth_type_vlan(veth->h_vlan_proto)) 558 return -EINVAL; 559 560 *vlan_tci = ntohs(veth->h_vlan_TCI); 561 return 0; 562 } 563 564 /** 565 * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[] 566 * @skb: skbuff to query 567 * @vlan_tci: buffer to store value 568 * 569 * Returns error if @skb->vlan_tci is not set correctly 570 */ 571 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb, 572 u16 *vlan_tci) 573 { 574 if (skb_vlan_tag_present(skb)) { 575 *vlan_tci = skb_vlan_tag_get(skb); 576 return 0; 577 } else { 578 *vlan_tci = 0; 579 return -EINVAL; 580 } 581 } 582 583 /** 584 * vlan_get_tag - get the VLAN ID from the skb 585 * @skb: skbuff to query 586 * @vlan_tci: buffer to store value 587 * 588 * Returns error if the skb is not VLAN tagged 589 */ 590 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci) 591 { 592 if (skb->dev->features & NETIF_F_HW_VLAN_CTAG_TX) { 593 return __vlan_hwaccel_get_tag(skb, vlan_tci); 594 } else { 595 return __vlan_get_tag(skb, vlan_tci); 596 } 597 } 598 599 /** 600 * vlan_get_protocol - get protocol EtherType. 601 * @skb: skbuff to query 602 * @type: first vlan protocol 603 * @depth: buffer to store length of eth and vlan tags in bytes 604 * 605 * Returns the EtherType of the packet, regardless of whether it is 606 * vlan encapsulated (normal or hardware accelerated) or not. 607 */ 608 static inline __be16 __vlan_get_protocol(struct sk_buff *skb, __be16 type, 609 int *depth) 610 { 611 unsigned int vlan_depth = skb->mac_len; 612 613 /* if type is 802.1Q/AD then the header should already be 614 * present at mac_len - VLAN_HLEN (if mac_len > 0), or at 615 * ETH_HLEN otherwise 616 */ 617 if (eth_type_vlan(type)) { 618 if (vlan_depth) { 619 if (WARN_ON(vlan_depth < VLAN_HLEN)) 620 return 0; 621 vlan_depth -= VLAN_HLEN; 622 } else { 623 vlan_depth = ETH_HLEN; 624 } 625 do { 626 struct vlan_hdr *vh; 627 628 if (unlikely(!pskb_may_pull(skb, 629 vlan_depth + VLAN_HLEN))) 630 return 0; 631 632 vh = (struct vlan_hdr *)(skb->data + vlan_depth); 633 type = vh->h_vlan_encapsulated_proto; 634 vlan_depth += VLAN_HLEN; 635 } while (eth_type_vlan(type)); 636 } 637 638 if (depth) 639 *depth = vlan_depth; 640 641 return type; 642 } 643 644 /** 645 * vlan_get_protocol - get protocol EtherType. 646 * @skb: skbuff to query 647 * 648 * Returns the EtherType of the packet, regardless of whether it is 649 * vlan encapsulated (normal or hardware accelerated) or not. 650 */ 651 static inline __be16 vlan_get_protocol(struct sk_buff *skb) 652 { 653 return __vlan_get_protocol(skb, skb->protocol, NULL); 654 } 655 656 static inline void vlan_set_encap_proto(struct sk_buff *skb, 657 struct vlan_hdr *vhdr) 658 { 659 __be16 proto; 660 unsigned short *rawp; 661 662 /* 663 * Was a VLAN packet, grab the encapsulated protocol, which the layer 664 * three protocols care about. 665 */ 666 667 proto = vhdr->h_vlan_encapsulated_proto; 668 if (eth_proto_is_802_3(proto)) { 669 skb->protocol = proto; 670 return; 671 } 672 673 rawp = (unsigned short *)(vhdr + 1); 674 if (*rawp == 0xFFFF) 675 /* 676 * This is a magic hack to spot IPX packets. Older Novell 677 * breaks the protocol design and runs IPX over 802.3 without 678 * an 802.2 LLC layer. We look for FFFF which isn't a used 679 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware 680 * but does for the rest. 681 */ 682 skb->protocol = htons(ETH_P_802_3); 683 else 684 /* 685 * Real 802.2 LLC 686 */ 687 skb->protocol = htons(ETH_P_802_2); 688 } 689 690 /** 691 * skb_vlan_tagged - check if skb is vlan tagged. 692 * @skb: skbuff to query 693 * 694 * Returns true if the skb is tagged, regardless of whether it is hardware 695 * accelerated or not. 696 */ 697 static inline bool skb_vlan_tagged(const struct sk_buff *skb) 698 { 699 if (!skb_vlan_tag_present(skb) && 700 likely(!eth_type_vlan(skb->protocol))) 701 return false; 702 703 return true; 704 } 705 706 /** 707 * skb_vlan_tagged_multi - check if skb is vlan tagged with multiple headers. 708 * @skb: skbuff to query 709 * 710 * Returns true if the skb is tagged with multiple vlan headers, regardless 711 * of whether it is hardware accelerated or not. 712 */ 713 static inline bool skb_vlan_tagged_multi(struct sk_buff *skb) 714 { 715 __be16 protocol = skb->protocol; 716 717 if (!skb_vlan_tag_present(skb)) { 718 struct vlan_ethhdr *veh; 719 720 if (likely(!eth_type_vlan(protocol))) 721 return false; 722 723 if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN))) 724 return false; 725 726 veh = (struct vlan_ethhdr *)skb->data; 727 protocol = veh->h_vlan_encapsulated_proto; 728 } 729 730 if (!eth_type_vlan(protocol)) 731 return false; 732 733 return true; 734 } 735 736 /** 737 * vlan_features_check - drop unsafe features for skb with multiple tags. 738 * @skb: skbuff to query 739 * @features: features to be checked 740 * 741 * Returns features without unsafe ones if the skb has multiple tags. 742 */ 743 static inline netdev_features_t vlan_features_check(struct sk_buff *skb, 744 netdev_features_t features) 745 { 746 if (skb_vlan_tagged_multi(skb)) { 747 /* In the case of multi-tagged packets, use a direct mask 748 * instead of using netdev_interesect_features(), to make 749 * sure that only devices supporting NETIF_F_HW_CSUM will 750 * have checksum offloading support. 751 */ 752 features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_HW_CSUM | 753 NETIF_F_FRAGLIST | NETIF_F_HW_VLAN_CTAG_TX | 754 NETIF_F_HW_VLAN_STAG_TX; 755 } 756 757 return features; 758 } 759 760 /** 761 * compare_vlan_header - Compare two vlan headers 762 * @h1: Pointer to vlan header 763 * @h2: Pointer to vlan header 764 * 765 * Compare two vlan headers, returns 0 if equal. 766 * 767 * Please note that alignment of h1 & h2 are only guaranteed to be 16 bits. 768 */ 769 static inline unsigned long compare_vlan_header(const struct vlan_hdr *h1, 770 const struct vlan_hdr *h2) 771 { 772 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) 773 return *(u32 *)h1 ^ *(u32 *)h2; 774 #else 775 return ((__force u32)h1->h_vlan_TCI ^ (__force u32)h2->h_vlan_TCI) | 776 ((__force u32)h1->h_vlan_encapsulated_proto ^ 777 (__force u32)h2->h_vlan_encapsulated_proto); 778 #endif 779 } 780 #endif /* !(_LINUX_IF_VLAN_H_) */ 781