xref: /linux/include/linux/etherdevice.h (revision 7ec462100ef9142344ddbf86f2c3008b97acddbe)
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 <linux/unaligned.h>
25 #include <asm/bitsperlong.h>
26 
27 #ifdef __KERNEL__
28 struct device;
29 struct fwnode_handle;
30 
31 int eth_platform_get_mac_address(struct device *dev, u8 *mac_addr);
32 int platform_get_ethdev_address(struct device *dev, struct net_device *netdev);
33 unsigned char *arch_get_platform_mac_address(void);
34 int nvmem_get_mac_address(struct device *dev, void *addrbuf);
35 int device_get_mac_address(struct device *dev, char *addr);
36 int device_get_ethdev_address(struct device *dev, struct net_device *netdev);
37 int fwnode_get_mac_address(struct fwnode_handle *fwnode, char *addr);
38 
39 u32 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);
41 extern const struct header_ops eth_header_ops;
42 
43 int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
44 	       const void *daddr, const void *saddr, unsigned len);
45 int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
46 int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh,
47 		     __be16 type);
48 void 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);
51 int eth_prepare_mac_addr_change(struct net_device *dev, void *p);
52 void eth_commit_mac_addr_change(struct net_device *dev, void *p);
53 int eth_mac_addr(struct net_device *dev, void *p);
54 int eth_validate_addr(struct net_device *dev);
55 
56 struct 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 
61 struct 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 
66 struct sk_buff *eth_gro_receive(struct list_head *head, struct sk_buff *skb);
67 int eth_gro_complete(struct sk_buff *skb, int nhoff);
68 
69 /* Reserved Ethernet Addresses per IEEE 802.1Q */
70 static 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 static const u8 eth_ipv4_mcast_addr_base[ETH_ALEN] __aligned(2) =
75 { 0x01, 0x00, 0x5e, 0x00, 0x00, 0x00 };
76 
77 static const u8 eth_ipv6_mcast_addr_base[ETH_ALEN] __aligned(2) =
78 { 0x33, 0x33, 0x00, 0x00, 0x00, 0x00 };
79 
80 /**
81  * is_link_local_ether_addr - Determine if given Ethernet address is link-local
82  * @addr: Pointer to a six-byte array containing the Ethernet address
83  *
84  * Return true if address is link local reserved addr (01:80:c2:00:00:0X) per
85  * IEEE 802.1Q 8.6.3 Frame filtering.
86  *
87  * Please note: addr must be aligned to u16.
88  */
is_link_local_ether_addr(const u8 * addr)89 static inline bool is_link_local_ether_addr(const u8 *addr)
90 {
91 	__be16 *a = (__be16 *)addr;
92 	static const __be16 *b = (const __be16 *)eth_reserved_addr_base;
93 	static const __be16 m = cpu_to_be16(0xfff0);
94 
95 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
96 	return (((*(const u32 *)addr) ^ (*(const u32 *)b)) |
97 		(__force int)((a[2] ^ b[2]) & m)) == 0;
98 #else
99 	return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0;
100 #endif
101 }
102 
103 /**
104  * is_zero_ether_addr - Determine if give Ethernet address is all zeros.
105  * @addr: Pointer to a six-byte array containing the Ethernet address
106  *
107  * Return true if the address is all zeroes.
108  *
109  * Please note: addr must be aligned to u16.
110  */
is_zero_ether_addr(const u8 * addr)111 static inline bool is_zero_ether_addr(const u8 *addr)
112 {
113 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
114 	return ((*(const u32 *)addr) | (*(const u16 *)(addr + 4))) == 0;
115 #else
116 	return (*(const u16 *)(addr + 0) |
117 		*(const u16 *)(addr + 2) |
118 		*(const u16 *)(addr + 4)) == 0;
119 #endif
120 }
121 
122 /**
123  * is_multicast_ether_addr - Determine if the Ethernet address is a multicast.
124  * @addr: Pointer to a six-byte array containing the Ethernet address
125  *
126  * Return true if the address is a multicast address.
127  * By definition the broadcast address is also a multicast address.
128  */
is_multicast_ether_addr(const u8 * addr)129 static inline bool is_multicast_ether_addr(const u8 *addr)
130 {
131 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
132 	u32 a = *(const u32 *)addr;
133 #else
134 	u16 a = *(const u16 *)addr;
135 #endif
136 #ifdef __BIG_ENDIAN
137 	return 0x01 & (a >> ((sizeof(a) * 8) - 8));
138 #else
139 	return 0x01 & a;
140 #endif
141 }
142 
is_multicast_ether_addr_64bits(const u8 * addr)143 static inline bool is_multicast_ether_addr_64bits(const u8 *addr)
144 {
145 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
146 #ifdef __BIG_ENDIAN
147 	return 0x01 & ((*(const u64 *)addr) >> 56);
148 #else
149 	return 0x01 & (*(const u64 *)addr);
150 #endif
151 #else
152 	return is_multicast_ether_addr(addr);
153 #endif
154 }
155 
156 /**
157  * is_local_ether_addr - Determine if the Ethernet address is locally-assigned one (IEEE 802).
158  * @addr: Pointer to a six-byte array containing the Ethernet address
159  *
160  * Return true if the address is a local address.
161  */
is_local_ether_addr(const u8 * addr)162 static inline bool is_local_ether_addr(const u8 *addr)
163 {
164 	return 0x02 & addr[0];
165 }
166 
167 /**
168  * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast
169  * @addr: Pointer to a six-byte array containing the Ethernet address
170  *
171  * Return true if the address is the broadcast address.
172  *
173  * Please note: addr must be aligned to u16.
174  */
is_broadcast_ether_addr(const u8 * addr)175 static inline bool is_broadcast_ether_addr(const u8 *addr)
176 {
177 	return (*(const u16 *)(addr + 0) &
178 		*(const u16 *)(addr + 2) &
179 		*(const u16 *)(addr + 4)) == 0xffff;
180 }
181 
182 /**
183  * is_unicast_ether_addr - Determine if the Ethernet address is unicast
184  * @addr: Pointer to a six-byte array containing the Ethernet address
185  *
186  * Return true if the address is a unicast address.
187  */
is_unicast_ether_addr(const u8 * addr)188 static inline bool is_unicast_ether_addr(const u8 *addr)
189 {
190 	return !is_multicast_ether_addr(addr);
191 }
192 
193 /**
194  * is_valid_ether_addr - Determine if the given Ethernet address is valid
195  * @addr: Pointer to a six-byte array containing the Ethernet address
196  *
197  * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not
198  * a multicast address, and is not FF:FF:FF:FF:FF:FF.
199  *
200  * Return true if the address is valid.
201  *
202  * Please note: addr must be aligned to u16.
203  */
is_valid_ether_addr(const u8 * addr)204 static inline bool is_valid_ether_addr(const u8 *addr)
205 {
206 	/* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to
207 	 * explicitly check for it here. */
208 	return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr);
209 }
210 
211 /**
212  * eth_proto_is_802_3 - Determine if a given Ethertype/length is a protocol
213  * @proto: Ethertype/length value to be tested
214  *
215  * Check that the value from the Ethertype/length field is a valid Ethertype.
216  *
217  * Return true if the valid is an 802.3 supported Ethertype.
218  */
eth_proto_is_802_3(__be16 proto)219 static inline bool eth_proto_is_802_3(__be16 proto)
220 {
221 #ifndef __BIG_ENDIAN
222 	/* if CPU is little endian mask off bits representing LSB */
223 	proto &= htons(0xFF00);
224 #endif
225 	/* cast both to u16 and compare since LSB can be ignored */
226 	return (__force u16)proto >= (__force u16)htons(ETH_P_802_3_MIN);
227 }
228 
229 /**
230  * eth_random_addr - Generate software assigned random Ethernet address
231  * @addr: Pointer to a six-byte array containing the Ethernet address
232  *
233  * Generate a random Ethernet address (MAC) that is not multicast
234  * and has the local assigned bit set.
235  */
eth_random_addr(u8 * addr)236 static inline void eth_random_addr(u8 *addr)
237 {
238 	get_random_bytes(addr, ETH_ALEN);
239 	addr[0] &= 0xfe;	/* clear multicast bit */
240 	addr[0] |= 0x02;	/* set local assignment bit (IEEE802) */
241 }
242 
243 /**
244  * eth_broadcast_addr - Assign broadcast address
245  * @addr: Pointer to a six-byte array containing the Ethernet address
246  *
247  * Assign the broadcast address to the given address array.
248  */
eth_broadcast_addr(u8 * addr)249 static inline void eth_broadcast_addr(u8 *addr)
250 {
251 	memset(addr, 0xff, ETH_ALEN);
252 }
253 
254 /**
255  * eth_zero_addr - Assign zero address
256  * @addr: Pointer to a six-byte array containing the Ethernet address
257  *
258  * Assign the zero address to the given address array.
259  */
eth_zero_addr(u8 * addr)260 static inline void eth_zero_addr(u8 *addr)
261 {
262 	memset(addr, 0x00, ETH_ALEN);
263 }
264 
265 /**
266  * eth_hw_addr_random - Generate software assigned random Ethernet and
267  * set device flag
268  * @dev: pointer to net_device structure
269  *
270  * Generate a random Ethernet address (MAC) to be used by a net device
271  * and set addr_assign_type so the state can be read by sysfs and be
272  * used by userspace.
273  */
eth_hw_addr_random(struct net_device * dev)274 static inline void eth_hw_addr_random(struct net_device *dev)
275 {
276 	u8 addr[ETH_ALEN];
277 
278 	eth_random_addr(addr);
279 	__dev_addr_set(dev, addr, ETH_ALEN);
280 	dev->addr_assign_type = NET_ADDR_RANDOM;
281 }
282 
283 /**
284  * eth_hw_addr_crc - Calculate CRC from netdev_hw_addr
285  * @ha: pointer to hardware address
286  *
287  * Calculate CRC from a hardware address as basis for filter hashes.
288  */
eth_hw_addr_crc(struct netdev_hw_addr * ha)289 static inline u32 eth_hw_addr_crc(struct netdev_hw_addr *ha)
290 {
291 	return ether_crc(ETH_ALEN, ha->addr);
292 }
293 
294 /**
295  * ether_addr_copy - Copy an Ethernet address
296  * @dst: Pointer to a six-byte array Ethernet address destination
297  * @src: Pointer to a six-byte array Ethernet address source
298  *
299  * Please note: dst & src must both be aligned to u16.
300  */
ether_addr_copy(u8 * dst,const u8 * src)301 static inline void ether_addr_copy(u8 *dst, const u8 *src)
302 {
303 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
304 	*(u32 *)dst = *(const u32 *)src;
305 	*(u16 *)(dst + 4) = *(const u16 *)(src + 4);
306 #else
307 	u16 *a = (u16 *)dst;
308 	const u16 *b = (const u16 *)src;
309 
310 	a[0] = b[0];
311 	a[1] = b[1];
312 	a[2] = b[2];
313 #endif
314 }
315 
316 /**
317  * eth_hw_addr_set - Assign Ethernet address to a net_device
318  * @dev: pointer to net_device structure
319  * @addr: address to assign
320  *
321  * Assign given address to the net_device, addr_assign_type is not changed.
322  */
eth_hw_addr_set(struct net_device * dev,const u8 * addr)323 static inline void eth_hw_addr_set(struct net_device *dev, const u8 *addr)
324 {
325 	__dev_addr_set(dev, addr, ETH_ALEN);
326 }
327 
328 /**
329  * eth_hw_addr_inherit - Copy dev_addr from another net_device
330  * @dst: pointer to net_device to copy dev_addr to
331  * @src: pointer to net_device to copy dev_addr from
332  *
333  * Copy the Ethernet address from one net_device to another along with
334  * the address attributes (addr_assign_type).
335  */
eth_hw_addr_inherit(struct net_device * dst,struct net_device * src)336 static inline void eth_hw_addr_inherit(struct net_device *dst,
337 				       struct net_device *src)
338 {
339 	dst->addr_assign_type = src->addr_assign_type;
340 	eth_hw_addr_set(dst, src->dev_addr);
341 }
342 
343 /**
344  * ether_addr_equal - Compare two Ethernet addresses
345  * @addr1: Pointer to a six-byte array containing the Ethernet address
346  * @addr2: Pointer other six-byte array containing the Ethernet address
347  *
348  * Compare two Ethernet addresses, returns true if equal
349  *
350  * Please note: addr1 & addr2 must both be aligned to u16.
351  */
ether_addr_equal(const u8 * addr1,const u8 * addr2)352 static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2)
353 {
354 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
355 	u32 fold = ((*(const u32 *)addr1) ^ (*(const u32 *)addr2)) |
356 		   ((*(const u16 *)(addr1 + 4)) ^ (*(const u16 *)(addr2 + 4)));
357 
358 	return fold == 0;
359 #else
360 	const u16 *a = (const u16 *)addr1;
361 	const u16 *b = (const u16 *)addr2;
362 
363 	return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) == 0;
364 #endif
365 }
366 
367 /**
368  * ether_addr_equal_64bits - Compare two Ethernet addresses
369  * @addr1: Pointer to an array of 8 bytes
370  * @addr2: Pointer to an other array of 8 bytes
371  *
372  * Compare two Ethernet addresses, returns true if equal, false otherwise.
373  *
374  * The function doesn't need any conditional branches and possibly uses
375  * word memory accesses on CPU allowing cheap unaligned memory reads.
376  * arrays = { byte1, byte2, byte3, byte4, byte5, byte6, pad1, pad2 }
377  *
378  * Please note that alignment of addr1 & addr2 are only guaranteed to be 16 bits.
379  */
380 
ether_addr_equal_64bits(const u8 * addr1,const u8 * addr2)381 static inline bool ether_addr_equal_64bits(const u8 *addr1, const u8 *addr2)
382 {
383 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
384 	u64 fold = (*(const u64 *)addr1) ^ (*(const u64 *)addr2);
385 
386 #ifdef __BIG_ENDIAN
387 	return (fold >> 16) == 0;
388 #else
389 	return (fold << 16) == 0;
390 #endif
391 #else
392 	return ether_addr_equal(addr1, addr2);
393 #endif
394 }
395 
396 /**
397  * ether_addr_equal_unaligned - Compare two not u16 aligned Ethernet addresses
398  * @addr1: Pointer to a six-byte array containing the Ethernet address
399  * @addr2: Pointer other six-byte array containing the Ethernet address
400  *
401  * Compare two Ethernet addresses, returns true if equal
402  *
403  * Please note: Use only when any Ethernet address may not be u16 aligned.
404  */
ether_addr_equal_unaligned(const u8 * addr1,const u8 * addr2)405 static inline bool ether_addr_equal_unaligned(const u8 *addr1, const u8 *addr2)
406 {
407 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
408 	return ether_addr_equal(addr1, addr2);
409 #else
410 	return memcmp(addr1, addr2, ETH_ALEN) == 0;
411 #endif
412 }
413 
414 /**
415  * ether_addr_equal_masked - Compare two Ethernet addresses with a mask
416  * @addr1: Pointer to a six-byte array containing the 1st Ethernet address
417  * @addr2: Pointer to a six-byte array containing the 2nd Ethernet address
418  * @mask: Pointer to a six-byte array containing the Ethernet address bitmask
419  *
420  * Compare two Ethernet addresses with a mask, returns true if for every bit
421  * set in the bitmask the equivalent bits in the ethernet addresses are equal.
422  * Using a mask with all bits set is a slower ether_addr_equal.
423  */
ether_addr_equal_masked(const u8 * addr1,const u8 * addr2,const u8 * mask)424 static inline bool ether_addr_equal_masked(const u8 *addr1, const u8 *addr2,
425 					   const u8 *mask)
426 {
427 	int i;
428 
429 	for (i = 0; i < ETH_ALEN; i++) {
430 		if ((addr1[i] ^ addr2[i]) & mask[i])
431 			return false;
432 	}
433 
434 	return true;
435 }
436 
ether_addr_is_ipv4_mcast(const u8 * addr)437 static inline bool ether_addr_is_ipv4_mcast(const u8 *addr)
438 {
439 	u8 mask[ETH_ALEN] = { 0xff, 0xff, 0xff, 0x80, 0x00, 0x00 };
440 
441 	return ether_addr_equal_masked(addr, eth_ipv4_mcast_addr_base, mask);
442 }
443 
ether_addr_is_ipv6_mcast(const u8 * addr)444 static inline bool ether_addr_is_ipv6_mcast(const u8 *addr)
445 {
446 	u8 mask[ETH_ALEN] = { 0xff, 0xff, 0x00, 0x00, 0x00, 0x00 };
447 
448 	return ether_addr_equal_masked(addr, eth_ipv6_mcast_addr_base, mask);
449 }
450 
ether_addr_is_ip_mcast(const u8 * addr)451 static inline bool ether_addr_is_ip_mcast(const u8 *addr)
452 {
453 	return ether_addr_is_ipv4_mcast(addr) ||
454 		ether_addr_is_ipv6_mcast(addr);
455 }
456 
457 /**
458  * ether_addr_to_u64 - Convert an Ethernet address into a u64 value.
459  * @addr: Pointer to a six-byte array containing the Ethernet address
460  *
461  * Return a u64 value of the address
462  */
ether_addr_to_u64(const u8 * addr)463 static inline u64 ether_addr_to_u64(const u8 *addr)
464 {
465 	u64 u = 0;
466 	int i;
467 
468 	for (i = 0; i < ETH_ALEN; i++)
469 		u = u << 8 | addr[i];
470 
471 	return u;
472 }
473 
474 /**
475  * u64_to_ether_addr - Convert a u64 to an Ethernet address.
476  * @u: u64 to convert to an Ethernet MAC address
477  * @addr: Pointer to a six-byte array to contain the Ethernet address
478  */
u64_to_ether_addr(u64 u,u8 * addr)479 static inline void u64_to_ether_addr(u64 u, u8 *addr)
480 {
481 	int i;
482 
483 	for (i = ETH_ALEN - 1; i >= 0; i--) {
484 		addr[i] = u & 0xff;
485 		u = u >> 8;
486 	}
487 }
488 
489 /**
490  * eth_addr_dec - Decrement the given MAC address
491  *
492  * @addr: Pointer to a six-byte array containing Ethernet address to decrement
493  */
eth_addr_dec(u8 * addr)494 static inline void eth_addr_dec(u8 *addr)
495 {
496 	u64 u = ether_addr_to_u64(addr);
497 
498 	u--;
499 	u64_to_ether_addr(u, addr);
500 }
501 
502 /**
503  * eth_addr_inc() - Increment the given MAC address.
504  * @addr: Pointer to a six-byte array containing Ethernet address to increment.
505  */
eth_addr_inc(u8 * addr)506 static inline void eth_addr_inc(u8 *addr)
507 {
508 	u64 u = ether_addr_to_u64(addr);
509 
510 	u++;
511 	u64_to_ether_addr(u, addr);
512 }
513 
514 /**
515  * eth_addr_add() - Add (or subtract) an offset to/from the given MAC address.
516  *
517  * @offset: Offset to add.
518  * @addr: Pointer to a six-byte array containing Ethernet address to increment.
519  */
eth_addr_add(u8 * addr,long offset)520 static inline void eth_addr_add(u8 *addr, long offset)
521 {
522 	u64 u = ether_addr_to_u64(addr);
523 
524 	u += offset;
525 	u64_to_ether_addr(u, addr);
526 }
527 
528 /**
529  * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
530  * @dev: Pointer to a device structure
531  * @addr: Pointer to a six-byte array containing the Ethernet address
532  *
533  * Compare passed address with all addresses of the device. Return true if the
534  * address if one of the device addresses.
535  *
536  * Note that this function calls ether_addr_equal_64bits() so take care of
537  * the right padding.
538  */
is_etherdev_addr(const struct net_device * dev,const u8 addr[6+2])539 static inline bool is_etherdev_addr(const struct net_device *dev,
540 				    const u8 addr[6 + 2])
541 {
542 	struct netdev_hw_addr *ha;
543 	bool res = false;
544 
545 	rcu_read_lock();
546 	for_each_dev_addr(dev, ha) {
547 		res = ether_addr_equal_64bits(addr, ha->addr);
548 		if (res)
549 			break;
550 	}
551 	rcu_read_unlock();
552 	return res;
553 }
554 #endif	/* __KERNEL__ */
555 
556 /**
557  * compare_ether_header - Compare two Ethernet headers
558  * @a: Pointer to Ethernet header
559  * @b: Pointer to Ethernet header
560  *
561  * Compare two Ethernet headers, returns 0 if equal.
562  * This assumes that the network header (i.e., IP header) is 4-byte
563  * aligned OR the platform can handle unaligned access.  This is the
564  * case for all packets coming into netif_receive_skb or similar
565  * entry points.
566  */
567 
compare_ether_header(const void * a,const void * b)568 static inline unsigned long compare_ether_header(const void *a, const void *b)
569 {
570 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
571 	unsigned long fold;
572 
573 	/*
574 	 * We want to compare 14 bytes:
575 	 *  [a0 ... a13] ^ [b0 ... b13]
576 	 * Use two long XOR, ORed together, with an overlap of two bytes.
577 	 *  [a0  a1  a2  a3  a4  a5  a6  a7 ] ^ [b0  b1  b2  b3  b4  b5  b6  b7 ] |
578 	 *  [a6  a7  a8  a9  a10 a11 a12 a13] ^ [b6  b7  b8  b9  b10 b11 b12 b13]
579 	 * This means the [a6 a7] ^ [b6 b7] part is done two times.
580 	*/
581 	fold = *(unsigned long *)a ^ *(unsigned long *)b;
582 	fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6);
583 	return fold;
584 #else
585 	u32 *a32 = (u32 *)((u8 *)a + 2);
586 	u32 *b32 = (u32 *)((u8 *)b + 2);
587 
588 	return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) |
589 	       (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]);
590 #endif
591 }
592 
593 /**
594  * eth_hw_addr_gen - Generate and assign Ethernet address to a port
595  * @dev: pointer to port's net_device structure
596  * @base_addr: base Ethernet address
597  * @id: offset to add to the base address
598  *
599  * Generate a MAC address using a base address and an offset and assign it
600  * to a net_device. Commonly used by switch drivers which need to compute
601  * addresses for all their ports. addr_assign_type is not changed.
602  */
eth_hw_addr_gen(struct net_device * dev,const u8 * base_addr,unsigned int id)603 static inline void eth_hw_addr_gen(struct net_device *dev, const u8 *base_addr,
604 				   unsigned int id)
605 {
606 	u64 u = ether_addr_to_u64(base_addr);
607 	u8 addr[ETH_ALEN];
608 
609 	u += id;
610 	u64_to_ether_addr(u, addr);
611 	eth_hw_addr_set(dev, addr);
612 }
613 
614 /**
615  * eth_skb_pkt_type - Assign packet type if destination address does not match
616  * @skb: Assigned a packet type if address does not match @dev address
617  * @dev: Network device used to compare packet address against
618  *
619  * If the destination MAC address of the packet does not match the network
620  * device address, assign an appropriate packet type.
621  */
eth_skb_pkt_type(struct sk_buff * skb,const struct net_device * dev)622 static inline void eth_skb_pkt_type(struct sk_buff *skb,
623 				    const struct net_device *dev)
624 {
625 	const struct ethhdr *eth = eth_hdr(skb);
626 
627 	if (unlikely(!ether_addr_equal_64bits(eth->h_dest, dev->dev_addr))) {
628 		if (unlikely(is_multicast_ether_addr_64bits(eth->h_dest))) {
629 			if (ether_addr_equal_64bits(eth->h_dest, dev->broadcast))
630 				skb->pkt_type = PACKET_BROADCAST;
631 			else
632 				skb->pkt_type = PACKET_MULTICAST;
633 		} else {
634 			skb->pkt_type = PACKET_OTHERHOST;
635 		}
636 	}
637 }
638 
eth_skb_pull_mac(struct sk_buff * skb)639 static inline struct ethhdr *eth_skb_pull_mac(struct sk_buff *skb)
640 {
641 	struct ethhdr *eth = (struct ethhdr *)skb->data;
642 
643 	skb_pull_inline(skb, ETH_HLEN);
644 	return eth;
645 }
646 
647 /**
648  * eth_skb_pad - Pad buffer to minimum number of octets for Ethernet frame
649  * @skb: Buffer to pad
650  *
651  * An Ethernet frame should have a minimum size of 60 bytes.  This function
652  * takes short frames and pads them with zeros up to the 60 byte limit.
653  */
eth_skb_pad(struct sk_buff * skb)654 static inline int eth_skb_pad(struct sk_buff *skb)
655 {
656 	return skb_put_padto(skb, ETH_ZLEN);
657 }
658 
659 #endif	/* _LINUX_ETHERDEVICE_H */
660