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