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