1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. NET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * Definitions for the Ethernet handlers.
8 *
9 * Version: @(#)eth.h 1.0.4 05/13/93
10 *
11 * Authors: Ross Biro
12 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
13 *
14 * Relocated to include/linux where it belongs by Alan Cox
15 * <gw4pts@gw4pts.ampr.org>
16 */
17#ifndef _LINUX_ETHERDEVICE_H
18#define _LINUX_ETHERDEVICE_H
19
20#include <linux/if_ether.h>
21#include <linux/netdevice.h>
22#include <linux/random.h>
23#include <linux/crc32.h>
24#include <asm/unaligned.h>
25#include <asm/bitsperlong.h>
26
27#ifdef __KERNEL__
28struct device;
29struct fwnode_handle;
30
31int eth_platform_get_mac_address(struct device *dev, u8 *mac_addr);
32int platform_get_ethdev_address(struct device *dev, struct net_device *netdev);
33unsigned char *arch_get_platform_mac_address(void);
34int nvmem_get_mac_address(struct device *dev, void *addrbuf);
35int device_get_mac_address(struct device *dev, char *addr);
36int device_get_ethdev_address(struct device *dev, struct net_device *netdev);
37int fwnode_get_mac_address(struct fwnode_handle *fwnode, char *addr);
38
39u32 eth_get_headlen(const struct net_device *dev, const void *data, u32 len);
40__be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev);
41extern const struct header_ops eth_header_ops;
42
43int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
44 const void *daddr, const void *saddr, unsigned len);
45int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
46int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh,
47 __be16 type);
48void eth_header_cache_update(struct hh_cache *hh, const struct net_device *dev,
49 const unsigned char *haddr);
50__be16 eth_header_parse_protocol(const struct sk_buff *skb);
51int eth_prepare_mac_addr_change(struct net_device *dev, void *p);
52void eth_commit_mac_addr_change(struct net_device *dev, void *p);
53int eth_mac_addr(struct net_device *dev, void *p);
54int eth_validate_addr(struct net_device *dev);
55
56struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs,
57 unsigned int rxqs);
58#define alloc_etherdev(sizeof_priv) alloc_etherdev_mq(sizeof_priv, 1)
59#define alloc_etherdev_mq(sizeof_priv, count) alloc_etherdev_mqs(sizeof_priv, count, count)
60
61struct net_device *devm_alloc_etherdev_mqs(struct device *dev, int sizeof_priv,
62 unsigned int txqs,
63 unsigned int rxqs);
64#define devm_alloc_etherdev(dev, sizeof_priv) devm_alloc_etherdev_mqs(dev, sizeof_priv, 1, 1)
65
66struct sk_buff *eth_gro_receive(struct list_head *head, struct sk_buff *skb);
67int eth_gro_complete(struct sk_buff *skb, int nhoff);
68
69/* Reserved Ethernet Addresses per IEEE 802.1Q */
70static const u8 eth_reserved_addr_base[ETH_ALEN] __aligned(2) =
71{ 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
72#define eth_stp_addr eth_reserved_addr_base
73
74/**
75 * is_link_local_ether_addr - Determine if given Ethernet address is link-local
76 * @addr: Pointer to a six-byte array containing the Ethernet address
77 *
78 * Return true if address is link local reserved addr (01:80:c2:00:00:0X) per
79 * IEEE 802.1Q 8.6.3 Frame filtering.
80 *
81 * Please note: addr must be aligned to u16.
82 */
83static inline bool is_link_local_ether_addr(const u8 *addr)
84{
85 __be16 *a = (__be16 *)addr;
86 static const __be16 *b = (const __be16 *)eth_reserved_addr_base;
87 static const __be16 m = cpu_to_be16(0xfff0);
88
89#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
90 return (((*(const u32 *)addr) ^ (*(const u32 *)b)) |
91 (__force int)((a[2] ^ b[2]) & m)) == 0;
92#else
93 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0;
94#endif
95}
96
97/**
98 * is_zero_ether_addr - Determine if give Ethernet address is all zeros.
99 * @addr: Pointer to a six-byte array containing the Ethernet address
100 *
101 * Return true if the address is all zeroes.
102 *
103 * Please note: addr must be aligned to u16.
104 */
105static inline bool is_zero_ether_addr(const u8 *addr)
106{
107#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
108 return ((*(const u32 *)addr) | (*(const u16 *)(addr + 4))) == 0;
109#else
110 return (*(const u16 *)(addr + 0) |
111 *(const u16 *)(addr + 2) |
112 *(const u16 *)(addr + 4)) == 0;
113#endif
114}
115
116/**
117 * is_multicast_ether_addr - Determine if the Ethernet address is a multicast.
118 * @addr: Pointer to a six-byte array containing the Ethernet address
119 *
120 * Return true if the address is a multicast address.
121 * By definition the broadcast address is also a multicast address.
122 */
123static inline bool is_multicast_ether_addr(const u8 *addr)
124{
125#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
126 u32 a = *(const u32 *)addr;
127#else
128 u16 a = *(const u16 *)addr;
129#endif
130#ifdef __BIG_ENDIAN
131 return 0x01 & (a >> ((sizeof(a) * 8) - 8));
132#else
133 return 0x01 & a;
134#endif
135}
136
137static inline bool is_multicast_ether_addr_64bits(const u8 *addr)
138{
139#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
140#ifdef __BIG_ENDIAN
141 return 0x01 & ((*(const u64 *)addr) >> 56);
142#else
143 return 0x01 & (*(const u64 *)addr);
144#endif
145#else
146 return is_multicast_ether_addr(addr);
147#endif
148}
149
150/**
151 * is_local_ether_addr - Determine if the Ethernet address is locally-assigned one (IEEE 802).
152 * @addr: Pointer to a six-byte array containing the Ethernet address
153 *
154 * Return true if the address is a local address.
155 */
156static inline bool is_local_ether_addr(const u8 *addr)
157{
158 return 0x02 & addr[0];
159}
160
161/**
162 * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast
163 * @addr: Pointer to a six-byte array containing the Ethernet address
164 *
165 * Return true if the address is the broadcast address.
166 *
167 * Please note: addr must be aligned to u16.
168 */
169static inline bool is_broadcast_ether_addr(const u8 *addr)
170{
171 return (*(const u16 *)(addr + 0) &
172 *(const u16 *)(addr + 2) &
173 *(const u16 *)(addr + 4)) == 0xffff;
174}
175
176/**
177 * is_unicast_ether_addr - Determine if the Ethernet address is unicast
178 * @addr: Pointer to a six-byte array containing the Ethernet address
179 *
180 * Return true if the address is a unicast address.
181 */
182static inline bool is_unicast_ether_addr(const u8 *addr)
183{
184 return !is_multicast_ether_addr(addr);
185}
186
187/**
188 * is_valid_ether_addr - Determine if the given Ethernet address is valid
189 * @addr: Pointer to a six-byte array containing the Ethernet address
190 *
191 * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not
192 * a multicast address, and is not FF:FF:FF:FF:FF:FF.
193 *
194 * Return true if the address is valid.
195 *
196 * Please note: addr must be aligned to u16.
197 */
198static inline bool is_valid_ether_addr(const u8 *addr)
199{
200 /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to
201 * explicitly check for it here. */
202 return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr);
203}
204
205/**
206 * eth_proto_is_802_3 - Determine if a given Ethertype/length is a protocol
207 * @proto: Ethertype/length value to be tested
208 *
209 * Check that the value from the Ethertype/length field is a valid Ethertype.
210 *
211 * Return true if the valid is an 802.3 supported Ethertype.
212 */
213static inline bool eth_proto_is_802_3(__be16 proto)
214{
215#ifndef __BIG_ENDIAN
216 /* if CPU is little endian mask off bits representing LSB */
217 proto &= htons(0xFF00);
218#endif
219 /* cast both to u16 and compare since LSB can be ignored */
220 return (__force u16)proto >= (__force u16)htons(ETH_P_802_3_MIN);
221}
222
223/**
224 * eth_random_addr - Generate software assigned random Ethernet address
225 * @addr: Pointer to a six-byte array containing the Ethernet address
226 *
227 * Generate a random Ethernet address (MAC) that is not multicast
228 * and has the local assigned bit set.
229 */
230static inline void eth_random_addr(u8 *addr)
231{
232 get_random_bytes(addr, ETH_ALEN);
233 addr[0] &= 0xfe; /* clear multicast bit */
234 addr[0] |= 0x02; /* set local assignment bit (IEEE802) */
235}
236
237/**
238 * eth_broadcast_addr - Assign broadcast address
239 * @addr: Pointer to a six-byte array containing the Ethernet address
240 *
241 * Assign the broadcast address to the given address array.
242 */
243static inline void eth_broadcast_addr(u8 *addr)
244{
245 memset(addr, 0xff, ETH_ALEN);
246}
247
248/**
249 * eth_zero_addr - Assign zero address
250 * @addr: Pointer to a six-byte array containing the Ethernet address
251 *
252 * Assign the zero address to the given address array.
253 */
254static inline void eth_zero_addr(u8 *addr)
255{
256 memset(addr, 0x00, ETH_ALEN);
257}
258
259/**
260 * eth_hw_addr_random - Generate software assigned random Ethernet and
261 * set device flag
262 * @dev: pointer to net_device structure
263 *
264 * Generate a random Ethernet address (MAC) to be used by a net device
265 * and set addr_assign_type so the state can be read by sysfs and be
266 * used by userspace.
267 */
268static inline void eth_hw_addr_random(struct net_device *dev)
269{
270 u8 addr[ETH_ALEN];
271
272 eth_random_addr(addr);
273 __dev_addr_set(dev, addr, ETH_ALEN);
274 dev->addr_assign_type = NET_ADDR_RANDOM;
275}
276
277/**
278 * eth_hw_addr_crc - Calculate CRC from netdev_hw_addr
279 * @ha: pointer to hardware address
280 *
281 * Calculate CRC from a hardware address as basis for filter hashes.
282 */
283static inline u32 eth_hw_addr_crc(struct netdev_hw_addr *ha)
284{
285 return ether_crc(ETH_ALEN, ha->addr);
286}
287
288/**
289 * ether_addr_copy - Copy an Ethernet address
290 * @dst: Pointer to a six-byte array Ethernet address destination
291 * @src: Pointer to a six-byte array Ethernet address source
292 *
293 * Please note: dst & src must both be aligned to u16.
294 */
295static inline void ether_addr_copy(u8 *dst, const u8 *src)
296{
297#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
298 *(u32 *)dst = *(const u32 *)src;
299 *(u16 *)(dst + 4) = *(const u16 *)(src + 4);
300#else
301 u16 *a = (u16 *)dst;
302 const u16 *b = (const u16 *)src;
303
304 a[0] = b[0];
305 a[1] = b[1];
306 a[2] = b[2];
307#endif
308}
309
310/**
311 * eth_hw_addr_set - Assign Ethernet address to a net_device
312 * @dev: pointer to net_device structure
313 * @addr: address to assign
314 *
315 * Assign given address to the net_device, addr_assign_type is not changed.
316 */
317static inline void eth_hw_addr_set(struct net_device *dev, const u8 *addr)
318{
319 __dev_addr_set(dev, addr, ETH_ALEN);
320}
321
322/**
323 * eth_hw_addr_inherit - Copy dev_addr from another net_device
324 * @dst: pointer to net_device to copy dev_addr to
325 * @src: pointer to net_device to copy dev_addr from
326 *
327 * Copy the Ethernet address from one net_device to another along with
328 * the address attributes (addr_assign_type).
329 */
330static inline void eth_hw_addr_inherit(struct net_device *dst,
331 struct net_device *src)
332{
333 dst->addr_assign_type = src->addr_assign_type;
334 eth_hw_addr_set(dst, src->dev_addr);
335}
336
337/**
338 * ether_addr_equal - Compare two Ethernet addresses
339 * @addr1: Pointer to a six-byte array containing the Ethernet address
340 * @addr2: Pointer other six-byte array containing the Ethernet address
341 *
342 * Compare two Ethernet addresses, returns true if equal
343 *
344 * Please note: addr1 & addr2 must both be aligned to u16.
345 */
346static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2)
347{
348#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
349 u32 fold = ((*(const u32 *)addr1) ^ (*(const u32 *)addr2)) |
350 ((*(const u16 *)(addr1 + 4)) ^ (*(const u16 *)(addr2 + 4)));
351
352 return fold == 0;
353#else
354 const u16 *a = (const u16 *)addr1;
355 const u16 *b = (const u16 *)addr2;
356
357 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) == 0;
358#endif
359}
360
361/**
362 * ether_addr_equal_64bits - Compare two Ethernet addresses
363 * @addr1: Pointer to an array of 8 bytes
364 * @addr2: Pointer to an other array of 8 bytes
365 *
366 * Compare two Ethernet addresses, returns true if equal, false otherwise.
367 *
368 * The function doesn't need any conditional branches and possibly uses
369 * word memory accesses on CPU allowing cheap unaligned memory reads.
370 * arrays = { byte1, byte2, byte3, byte4, byte5, byte6, pad1, pad2 }
371 *
372 * Please note that alignment of addr1 & addr2 are only guaranteed to be 16 bits.
373 */
374
375static inline bool ether_addr_equal_64bits(const u8 *addr1, const u8 *addr2)
376{
377#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
378 u64 fold = (*(const u64 *)addr1) ^ (*(const u64 *)addr2);
379
380#ifdef __BIG_ENDIAN
381 return (fold >> 16) == 0;
382#else
383 return (fold << 16) == 0;
384#endif
385#else
386 return ether_addr_equal(addr1, addr2);
387#endif
388}
389
390/**
391 * ether_addr_equal_unaligned - Compare two not u16 aligned Ethernet addresses
392 * @addr1: Pointer to a six-byte array containing the Ethernet address
393 * @addr2: Pointer other six-byte array containing the Ethernet address
394 *
395 * Compare two Ethernet addresses, returns true if equal
396 *
397 * Please note: Use only when any Ethernet address may not be u16 aligned.
398 */
399static inline bool ether_addr_equal_unaligned(const u8 *addr1, const u8 *addr2)
400{
401#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
402 return ether_addr_equal(addr1, addr2);
403#else
404 return memcmp(addr1, addr2, ETH_ALEN) == 0;
405#endif
406}
407
408/**
409 * ether_addr_equal_masked - Compare two Ethernet addresses with a mask
410 * @addr1: Pointer to a six-byte array containing the 1st Ethernet address
411 * @addr2: Pointer to a six-byte array containing the 2nd Ethernet address
412 * @mask: Pointer to a six-byte array containing the Ethernet address bitmask
413 *
414 * Compare two Ethernet addresses with a mask, returns true if for every bit
415 * set in the bitmask the equivalent bits in the ethernet addresses are equal.
416 * Using a mask with all bits set is a slower ether_addr_equal.
417 */
418static inline bool ether_addr_equal_masked(const u8 *addr1, const u8 *addr2,
419 const u8 *mask)
420{
421 int i;
422
423 for (i = 0; i < ETH_ALEN; i++) {
424 if ((addr1[i] ^ addr2[i]) & mask[i])
425 return false;
426 }
427
428 return true;
429}
430
431/**
432 * ether_addr_to_u64 - Convert an Ethernet address into a u64 value.
433 * @addr: Pointer to a six-byte array containing the Ethernet address
434 *
435 * Return a u64 value of the address
436 */
437static inline u64 ether_addr_to_u64(const u8 *addr)
438{
439 u64 u = 0;
440 int i;
441
442 for (i = 0; i < ETH_ALEN; i++)
443 u = u << 8 | addr[i];
444
445 return u;
446}
447
448/**
449 * u64_to_ether_addr - Convert a u64 to an Ethernet address.
450 * @u: u64 to convert to an Ethernet MAC address
451 * @addr: Pointer to a six-byte array to contain the Ethernet address
452 */
453static inline void u64_to_ether_addr(u64 u, u8 *addr)
454{
455 int i;
456
457 for (i = ETH_ALEN - 1; i >= 0; i--) {
458 addr[i] = u & 0xff;
459 u = u >> 8;
460 }
461}
462
463/**
464 * eth_addr_dec - Decrement the given MAC address
465 *
466 * @addr: Pointer to a six-byte array containing Ethernet address to decrement
467 */
468static inline void eth_addr_dec(u8 *addr)
469{
470 u64 u = ether_addr_to_u64(addr);
471
472 u--;
473 u64_to_ether_addr(u, addr);
474}
475
476/**
477 * eth_addr_inc() - Increment the given MAC address.
478 * @addr: Pointer to a six-byte array containing Ethernet address to increment.
479 */
480static inline void eth_addr_inc(u8 *addr)
481{
482 u64 u = ether_addr_to_u64(addr);
483
484 u++;
485 u64_to_ether_addr(u, addr);
486}
487
488/**
489 * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
490 * @dev: Pointer to a device structure
491 * @addr: Pointer to a six-byte array containing the Ethernet address
492 *
493 * Compare passed address with all addresses of the device. Return true if the
494 * address if one of the device addresses.
495 *
496 * Note that this function calls ether_addr_equal_64bits() so take care of
497 * the right padding.
498 */
499static inline bool is_etherdev_addr(const struct net_device *dev,
500 const u8 addr[6 + 2])
501{
502 struct netdev_hw_addr *ha;
503 bool res = false;
504
505 rcu_read_lock();
506 for_each_dev_addr(dev, ha) {
507 res = ether_addr_equal_64bits(addr, ha->addr);
508 if (res)
509 break;
510 }
511 rcu_read_unlock();
512 return res;
513}
514#endif /* __KERNEL__ */
515
516/**
517 * compare_ether_header - Compare two Ethernet headers
518 * @a: Pointer to Ethernet header
519 * @b: Pointer to Ethernet header
520 *
521 * Compare two Ethernet headers, returns 0 if equal.
522 * This assumes that the network header (i.e., IP header) is 4-byte
523 * aligned OR the platform can handle unaligned access. This is the
524 * case for all packets coming into netif_receive_skb or similar
525 * entry points.
526 */
527
528static inline unsigned long compare_ether_header(const void *a, const void *b)
529{
530#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
531 unsigned long fold;
532
533 /*
534 * We want to compare 14 bytes:
535 * [a0 ... a13] ^ [b0 ... b13]
536 * Use two long XOR, ORed together, with an overlap of two bytes.
537 * [a0 a1 a2 a3 a4 a5 a6 a7 ] ^ [b0 b1 b2 b3 b4 b5 b6 b7 ] |
538 * [a6 a7 a8 a9 a10 a11 a12 a13] ^ [b6 b7 b8 b9 b10 b11 b12 b13]
539 * This means the [a6 a7] ^ [b6 b7] part is done two times.
540 */
541 fold = *(unsigned long *)a ^ *(unsigned long *)b;
542 fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6);
543 return fold;
544#else
545 u32 *a32 = (u32 *)((u8 *)a + 2);
546 u32 *b32 = (u32 *)((u8 *)b + 2);
547
548 return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) |
549 (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]);
550#endif
551}
552
553/**
554 * eth_hw_addr_gen - Generate and assign Ethernet address to a port
555 * @dev: pointer to port's net_device structure
556 * @base_addr: base Ethernet address
557 * @id: offset to add to the base address
558 *
559 * Generate a MAC address using a base address and an offset and assign it
560 * to a net_device. Commonly used by switch drivers which need to compute
561 * addresses for all their ports. addr_assign_type is not changed.
562 */
563static inline void eth_hw_addr_gen(struct net_device *dev, const u8 *base_addr,
564 unsigned int id)
565{
566 u64 u = ether_addr_to_u64(base_addr);
567 u8 addr[ETH_ALEN];
568
569 u += id;
570 u64_to_ether_addr(u, addr);
571 eth_hw_addr_set(dev, addr);
572}
573
574/**
575 * eth_skb_pad - Pad buffer to mininum number of octets for Ethernet frame
576 * @skb: Buffer to pad
577 *
578 * An Ethernet frame should have a minimum size of 60 bytes. This function
579 * takes short frames and pads them with zeros up to the 60 byte limit.
580 */
581static inline int eth_skb_pad(struct sk_buff *skb)
582{
583 return skb_put_padto(skb, ETH_ZLEN);
584}
585
586#endif /* _LINUX_ETHERDEVICE_H */
587

source code of linux/include/linux/etherdevice.h