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 /* 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 unsigned int nest_level; 186 }; 187 188 static inline struct vlan_dev_priv *vlan_dev_priv(const struct net_device *dev) 189 { 190 return netdev_priv(dev); 191 } 192 193 static inline u16 194 vlan_dev_get_egress_qos_mask(struct net_device *dev, u32 skprio) 195 { 196 struct vlan_priority_tci_mapping *mp; 197 198 smp_rmb(); /* coupled with smp_wmb() in vlan_dev_set_egress_priority() */ 199 200 mp = vlan_dev_priv(dev)->egress_priority_map[(skprio & 0xF)]; 201 while (mp) { 202 if (mp->priority == skprio) { 203 return mp->vlan_qos; /* This should already be shifted 204 * to mask correctly with the 205 * VLAN's TCI */ 206 } 207 mp = mp->next; 208 } 209 return 0; 210 } 211 212 extern bool vlan_do_receive(struct sk_buff **skb); 213 214 extern int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid); 215 extern void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid); 216 217 extern int vlan_vids_add_by_dev(struct net_device *dev, 218 const struct net_device *by_dev); 219 extern void vlan_vids_del_by_dev(struct net_device *dev, 220 const struct net_device *by_dev); 221 222 extern bool vlan_uses_dev(const struct net_device *dev); 223 224 static inline int vlan_get_encap_level(struct net_device *dev) 225 { 226 BUG_ON(!is_vlan_dev(dev)); 227 return vlan_dev_priv(dev)->nest_level; 228 } 229 #else 230 static inline struct net_device * 231 __vlan_find_dev_deep_rcu(struct net_device *real_dev, 232 __be16 vlan_proto, u16 vlan_id) 233 { 234 return NULL; 235 } 236 237 static inline int 238 vlan_for_each(struct net_device *dev, 239 int (*action)(struct net_device *dev, int vid, void *arg), 240 void *arg) 241 { 242 return 0; 243 } 244 245 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev) 246 { 247 BUG(); 248 return NULL; 249 } 250 251 static inline u16 vlan_dev_vlan_id(const struct net_device *dev) 252 { 253 BUG(); 254 return 0; 255 } 256 257 static inline __be16 vlan_dev_vlan_proto(const struct net_device *dev) 258 { 259 BUG(); 260 return 0; 261 } 262 263 static inline u16 vlan_dev_get_egress_qos_mask(struct net_device *dev, 264 u32 skprio) 265 { 266 return 0; 267 } 268 269 static inline bool vlan_do_receive(struct sk_buff **skb) 270 { 271 return false; 272 } 273 274 static inline int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid) 275 { 276 return 0; 277 } 278 279 static inline void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid) 280 { 281 } 282 283 static inline int vlan_vids_add_by_dev(struct net_device *dev, 284 const struct net_device *by_dev) 285 { 286 return 0; 287 } 288 289 static inline void vlan_vids_del_by_dev(struct net_device *dev, 290 const struct net_device *by_dev) 291 { 292 } 293 294 static inline bool vlan_uses_dev(const struct net_device *dev) 295 { 296 return false; 297 } 298 static inline int vlan_get_encap_level(struct net_device *dev) 299 { 300 BUG(); 301 return 0; 302 } 303 #endif 304 305 /** 306 * eth_type_vlan - check for valid vlan ether type. 307 * @ethertype: ether type to check 308 * 309 * Returns true if the ether type is a vlan ether type. 310 */ 311 static inline bool eth_type_vlan(__be16 ethertype) 312 { 313 switch (ethertype) { 314 case htons(ETH_P_8021Q): 315 case htons(ETH_P_8021AD): 316 return true; 317 default: 318 return false; 319 } 320 } 321 322 static inline bool vlan_hw_offload_capable(netdev_features_t features, 323 __be16 proto) 324 { 325 if (proto == htons(ETH_P_8021Q) && features & NETIF_F_HW_VLAN_CTAG_TX) 326 return true; 327 if (proto == htons(ETH_P_8021AD) && features & NETIF_F_HW_VLAN_STAG_TX) 328 return true; 329 return false; 330 } 331 332 /** 333 * __vlan_insert_inner_tag - inner VLAN tag inserting 334 * @skb: skbuff to tag 335 * @vlan_proto: VLAN encapsulation protocol 336 * @vlan_tci: VLAN TCI to insert 337 * @mac_len: MAC header length including outer vlan headers 338 * 339 * Inserts the VLAN tag into @skb as part of the payload at offset mac_len 340 * Returns error if skb_cow_head fails. 341 * 342 * Does not change skb->protocol so this function can be used during receive. 343 */ 344 static inline int __vlan_insert_inner_tag(struct sk_buff *skb, 345 __be16 vlan_proto, u16 vlan_tci, 346 unsigned int mac_len) 347 { 348 struct vlan_ethhdr *veth; 349 350 if (skb_cow_head(skb, VLAN_HLEN) < 0) 351 return -ENOMEM; 352 353 skb_push(skb, VLAN_HLEN); 354 355 /* Move the mac header sans proto to the beginning of the new header. */ 356 if (likely(mac_len > ETH_TLEN)) 357 memmove(skb->data, skb->data + VLAN_HLEN, mac_len - ETH_TLEN); 358 skb->mac_header -= VLAN_HLEN; 359 360 veth = (struct vlan_ethhdr *)(skb->data + mac_len - ETH_HLEN); 361 362 /* first, the ethernet type */ 363 if (likely(mac_len >= ETH_TLEN)) { 364 /* h_vlan_encapsulated_proto should already be populated, and 365 * skb->data has space for h_vlan_proto 366 */ 367 veth->h_vlan_proto = vlan_proto; 368 } else { 369 /* h_vlan_encapsulated_proto should not be populated, and 370 * skb->data has no space for h_vlan_proto 371 */ 372 veth->h_vlan_encapsulated_proto = skb->protocol; 373 } 374 375 /* now, the TCI */ 376 veth->h_vlan_TCI = htons(vlan_tci); 377 378 return 0; 379 } 380 381 /** 382 * __vlan_insert_tag - regular VLAN tag inserting 383 * @skb: skbuff to tag 384 * @vlan_proto: VLAN encapsulation protocol 385 * @vlan_tci: VLAN TCI to insert 386 * 387 * Inserts the VLAN tag into @skb as part of the payload 388 * Returns error if skb_cow_head fails. 389 * 390 * Does not change skb->protocol so this function can be used during receive. 391 */ 392 static inline int __vlan_insert_tag(struct sk_buff *skb, 393 __be16 vlan_proto, u16 vlan_tci) 394 { 395 return __vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, ETH_HLEN); 396 } 397 398 /** 399 * vlan_insert_inner_tag - inner VLAN tag inserting 400 * @skb: skbuff to tag 401 * @vlan_proto: VLAN encapsulation protocol 402 * @vlan_tci: VLAN TCI to insert 403 * @mac_len: MAC header length including outer vlan headers 404 * 405 * Inserts the VLAN tag into @skb as part of the payload at offset mac_len 406 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed. 407 * 408 * Following the skb_unshare() example, in case of error, the calling function 409 * doesn't have to worry about freeing the original skb. 410 * 411 * Does not change skb->protocol so this function can be used during receive. 412 */ 413 static inline struct sk_buff *vlan_insert_inner_tag(struct sk_buff *skb, 414 __be16 vlan_proto, 415 u16 vlan_tci, 416 unsigned int mac_len) 417 { 418 int err; 419 420 err = __vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, mac_len); 421 if (err) { 422 dev_kfree_skb_any(skb); 423 return NULL; 424 } 425 return skb; 426 } 427 428 /** 429 * vlan_insert_tag - regular VLAN tag inserting 430 * @skb: skbuff to tag 431 * @vlan_proto: VLAN encapsulation protocol 432 * @vlan_tci: VLAN TCI to insert 433 * 434 * Inserts the VLAN tag into @skb as part of the payload 435 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed. 436 * 437 * Following the skb_unshare() example, in case of error, the calling function 438 * doesn't have to worry about freeing the original skb. 439 * 440 * Does not change skb->protocol so this function can be used during receive. 441 */ 442 static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, 443 __be16 vlan_proto, u16 vlan_tci) 444 { 445 return vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, ETH_HLEN); 446 } 447 448 /** 449 * vlan_insert_tag_set_proto - regular VLAN tag inserting 450 * @skb: skbuff to tag 451 * @vlan_proto: VLAN encapsulation protocol 452 * @vlan_tci: VLAN TCI to insert 453 * 454 * Inserts the VLAN tag into @skb as part of the payload 455 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed. 456 * 457 * Following the skb_unshare() example, in case of error, the calling function 458 * doesn't have to worry about freeing the original skb. 459 */ 460 static inline struct sk_buff *vlan_insert_tag_set_proto(struct sk_buff *skb, 461 __be16 vlan_proto, 462 u16 vlan_tci) 463 { 464 skb = vlan_insert_tag(skb, vlan_proto, vlan_tci); 465 if (skb) 466 skb->protocol = vlan_proto; 467 return skb; 468 } 469 470 /** 471 * __vlan_hwaccel_clear_tag - clear hardware accelerated VLAN info 472 * @skb: skbuff to clear 473 * 474 * Clears the VLAN information from @skb 475 */ 476 static inline void __vlan_hwaccel_clear_tag(struct sk_buff *skb) 477 { 478 skb->vlan_present = 0; 479 } 480 481 /** 482 * __vlan_hwaccel_copy_tag - copy hardware accelerated VLAN info from another skb 483 * @dst: skbuff to copy to 484 * @src: skbuff to copy from 485 * 486 * Copies VLAN information from @src to @dst (for branchless code) 487 */ 488 static inline void __vlan_hwaccel_copy_tag(struct sk_buff *dst, const struct sk_buff *src) 489 { 490 dst->vlan_present = src->vlan_present; 491 dst->vlan_proto = src->vlan_proto; 492 dst->vlan_tci = src->vlan_tci; 493 } 494 495 /* 496 * __vlan_hwaccel_push_inside - pushes vlan tag to the payload 497 * @skb: skbuff to tag 498 * 499 * Pushes the VLAN tag from @skb->vlan_tci inside to the payload. 500 * 501 * Following the skb_unshare() example, in case of error, the calling function 502 * doesn't have to worry about freeing the original skb. 503 */ 504 static inline struct sk_buff *__vlan_hwaccel_push_inside(struct sk_buff *skb) 505 { 506 skb = vlan_insert_tag_set_proto(skb, skb->vlan_proto, 507 skb_vlan_tag_get(skb)); 508 if (likely(skb)) 509 __vlan_hwaccel_clear_tag(skb); 510 return skb; 511 } 512 513 /** 514 * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting 515 * @skb: skbuff to tag 516 * @vlan_proto: VLAN encapsulation protocol 517 * @vlan_tci: VLAN TCI to insert 518 * 519 * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest 520 */ 521 static inline void __vlan_hwaccel_put_tag(struct sk_buff *skb, 522 __be16 vlan_proto, u16 vlan_tci) 523 { 524 skb->vlan_proto = vlan_proto; 525 skb->vlan_tci = vlan_tci; 526 skb->vlan_present = 1; 527 } 528 529 /** 530 * __vlan_get_tag - get the VLAN ID that is part of the payload 531 * @skb: skbuff to query 532 * @vlan_tci: buffer to store value 533 * 534 * Returns error if the skb is not of VLAN type 535 */ 536 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci) 537 { 538 struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data; 539 540 if (!eth_type_vlan(veth->h_vlan_proto)) 541 return -EINVAL; 542 543 *vlan_tci = ntohs(veth->h_vlan_TCI); 544 return 0; 545 } 546 547 /** 548 * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[] 549 * @skb: skbuff to query 550 * @vlan_tci: buffer to store value 551 * 552 * Returns error if @skb->vlan_tci is not set correctly 553 */ 554 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb, 555 u16 *vlan_tci) 556 { 557 if (skb_vlan_tag_present(skb)) { 558 *vlan_tci = skb_vlan_tag_get(skb); 559 return 0; 560 } else { 561 *vlan_tci = 0; 562 return -EINVAL; 563 } 564 } 565 566 /** 567 * vlan_get_tag - get the VLAN ID from the skb 568 * @skb: skbuff to query 569 * @vlan_tci: buffer to store value 570 * 571 * Returns error if the skb is not VLAN tagged 572 */ 573 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci) 574 { 575 if (skb->dev->features & NETIF_F_HW_VLAN_CTAG_TX) { 576 return __vlan_hwaccel_get_tag(skb, vlan_tci); 577 } else { 578 return __vlan_get_tag(skb, vlan_tci); 579 } 580 } 581 582 /** 583 * vlan_get_protocol - get protocol EtherType. 584 * @skb: skbuff to query 585 * @type: first vlan protocol 586 * @depth: buffer to store length of eth and vlan tags in bytes 587 * 588 * Returns the EtherType of the packet, regardless of whether it is 589 * vlan encapsulated (normal or hardware accelerated) or not. 590 */ 591 static inline __be16 __vlan_get_protocol(struct sk_buff *skb, __be16 type, 592 int *depth) 593 { 594 unsigned int vlan_depth = skb->mac_len; 595 596 /* if type is 802.1Q/AD then the header should already be 597 * present at mac_len - VLAN_HLEN (if mac_len > 0), or at 598 * ETH_HLEN otherwise 599 */ 600 if (eth_type_vlan(type)) { 601 if (vlan_depth) { 602 if (WARN_ON(vlan_depth < VLAN_HLEN)) 603 return 0; 604 vlan_depth -= VLAN_HLEN; 605 } else { 606 vlan_depth = ETH_HLEN; 607 } 608 do { 609 struct vlan_hdr *vh; 610 611 if (unlikely(!pskb_may_pull(skb, 612 vlan_depth + VLAN_HLEN))) 613 return 0; 614 615 vh = (struct vlan_hdr *)(skb->data + vlan_depth); 616 type = vh->h_vlan_encapsulated_proto; 617 vlan_depth += VLAN_HLEN; 618 } while (eth_type_vlan(type)); 619 } 620 621 if (depth) 622 *depth = vlan_depth; 623 624 return type; 625 } 626 627 /** 628 * vlan_get_protocol - get protocol EtherType. 629 * @skb: skbuff to query 630 * 631 * Returns the EtherType of the packet, regardless of whether it is 632 * vlan encapsulated (normal or hardware accelerated) or not. 633 */ 634 static inline __be16 vlan_get_protocol(struct sk_buff *skb) 635 { 636 return __vlan_get_protocol(skb, skb->protocol, NULL); 637 } 638 639 static inline void vlan_set_encap_proto(struct sk_buff *skb, 640 struct vlan_hdr *vhdr) 641 { 642 __be16 proto; 643 unsigned short *rawp; 644 645 /* 646 * Was a VLAN packet, grab the encapsulated protocol, which the layer 647 * three protocols care about. 648 */ 649 650 proto = vhdr->h_vlan_encapsulated_proto; 651 if (eth_proto_is_802_3(proto)) { 652 skb->protocol = proto; 653 return; 654 } 655 656 rawp = (unsigned short *)(vhdr + 1); 657 if (*rawp == 0xFFFF) 658 /* 659 * This is a magic hack to spot IPX packets. Older Novell 660 * breaks the protocol design and runs IPX over 802.3 without 661 * an 802.2 LLC layer. We look for FFFF which isn't a used 662 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware 663 * but does for the rest. 664 */ 665 skb->protocol = htons(ETH_P_802_3); 666 else 667 /* 668 * Real 802.2 LLC 669 */ 670 skb->protocol = htons(ETH_P_802_2); 671 } 672 673 /** 674 * skb_vlan_tagged - check if skb is vlan tagged. 675 * @skb: skbuff to query 676 * 677 * Returns true if the skb is tagged, regardless of whether it is hardware 678 * accelerated or not. 679 */ 680 static inline bool skb_vlan_tagged(const struct sk_buff *skb) 681 { 682 if (!skb_vlan_tag_present(skb) && 683 likely(!eth_type_vlan(skb->protocol))) 684 return false; 685 686 return true; 687 } 688 689 /** 690 * skb_vlan_tagged_multi - check if skb is vlan tagged with multiple headers. 691 * @skb: skbuff to query 692 * 693 * Returns true if the skb is tagged with multiple vlan headers, regardless 694 * of whether it is hardware accelerated or not. 695 */ 696 static inline bool skb_vlan_tagged_multi(struct sk_buff *skb) 697 { 698 __be16 protocol = skb->protocol; 699 700 if (!skb_vlan_tag_present(skb)) { 701 struct vlan_ethhdr *veh; 702 703 if (likely(!eth_type_vlan(protocol))) 704 return false; 705 706 if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN))) 707 return false; 708 709 veh = (struct vlan_ethhdr *)skb->data; 710 protocol = veh->h_vlan_encapsulated_proto; 711 } 712 713 if (!eth_type_vlan(protocol)) 714 return false; 715 716 return true; 717 } 718 719 /** 720 * vlan_features_check - drop unsafe features for skb with multiple tags. 721 * @skb: skbuff to query 722 * @features: features to be checked 723 * 724 * Returns features without unsafe ones if the skb has multiple tags. 725 */ 726 static inline netdev_features_t vlan_features_check(struct sk_buff *skb, 727 netdev_features_t features) 728 { 729 if (skb_vlan_tagged_multi(skb)) { 730 /* In the case of multi-tagged packets, use a direct mask 731 * instead of using netdev_interesect_features(), to make 732 * sure that only devices supporting NETIF_F_HW_CSUM will 733 * have checksum offloading support. 734 */ 735 features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_HW_CSUM | 736 NETIF_F_FRAGLIST | NETIF_F_HW_VLAN_CTAG_TX | 737 NETIF_F_HW_VLAN_STAG_TX; 738 } 739 740 return features; 741 } 742 743 /** 744 * compare_vlan_header - Compare two vlan headers 745 * @h1: Pointer to vlan header 746 * @h2: Pointer to vlan header 747 * 748 * Compare two vlan headers, returns 0 if equal. 749 * 750 * Please note that alignment of h1 & h2 are only guaranteed to be 16 bits. 751 */ 752 static inline unsigned long compare_vlan_header(const struct vlan_hdr *h1, 753 const struct vlan_hdr *h2) 754 { 755 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) 756 return *(u32 *)h1 ^ *(u32 *)h2; 757 #else 758 return ((__force u32)h1->h_vlan_TCI ^ (__force u32)h2->h_vlan_TCI) | 759 ((__force u32)h1->h_vlan_encapsulated_proto ^ 760 (__force u32)h2->h_vlan_encapsulated_proto); 761 #endif 762 } 763 #endif /* !(_LINUX_IF_VLAN_H_) */ 764