• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 <asm/unaligned.h>
24 #include <asm/bitsperlong.h>
25 
26 #ifdef __KERNEL__
27 struct device;
28 int eth_platform_get_mac_address(struct device *dev, u8 *mac_addr);
29 unsigned char *arch_get_platform_mac_address(void);
30 int nvmem_get_mac_address(struct device *dev, void *addrbuf);
31 u32 eth_get_headlen(const struct net_device *dev, void *data, unsigned int len);
32 __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev);
33 extern const struct header_ops eth_header_ops;
34 
35 int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
36 	       const void *daddr, const void *saddr, unsigned len);
37 int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
38 int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh,
39 		     __be16 type);
40 void eth_header_cache_update(struct hh_cache *hh, const struct net_device *dev,
41 			     const unsigned char *haddr);
42 __be16 eth_header_parse_protocol(const struct sk_buff *skb);
43 int eth_prepare_mac_addr_change(struct net_device *dev, void *p);
44 void eth_commit_mac_addr_change(struct net_device *dev, void *p);
45 int eth_mac_addr(struct net_device *dev, void *p);
46 int eth_change_mtu(struct net_device *dev, int new_mtu);
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[6+2])130 static inline bool is_multicast_ether_addr_64bits(const u8 addr[6+2])
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  * ether_addr_copy - Copy an Ethernet address
271  * @dst: Pointer to a six-byte array Ethernet address destination
272  * @src: Pointer to a six-byte array Ethernet address source
273  *
274  * Please note: dst & src must both be aligned to u16.
275  */
ether_addr_copy(u8 * dst,const u8 * src)276 static inline void ether_addr_copy(u8 *dst, const u8 *src)
277 {
278 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
279 	*(u32 *)dst = *(const u32 *)src;
280 	*(u16 *)(dst + 4) = *(const u16 *)(src + 4);
281 #else
282 	u16 *a = (u16 *)dst;
283 	const u16 *b = (const u16 *)src;
284 
285 	a[0] = b[0];
286 	a[1] = b[1];
287 	a[2] = b[2];
288 #endif
289 }
290 
291 /**
292  * eth_hw_addr_inherit - Copy dev_addr from another net_device
293  * @dst: pointer to net_device to copy dev_addr to
294  * @src: pointer to net_device to copy dev_addr from
295  *
296  * Copy the Ethernet address from one net_device to another along with
297  * the address attributes (addr_assign_type).
298  */
eth_hw_addr_inherit(struct net_device * dst,struct net_device * src)299 static inline void eth_hw_addr_inherit(struct net_device *dst,
300 				       struct net_device *src)
301 {
302 	dst->addr_assign_type = src->addr_assign_type;
303 	ether_addr_copy(dst->dev_addr, src->dev_addr);
304 }
305 
306 /**
307  * ether_addr_equal - Compare two Ethernet addresses
308  * @addr1: Pointer to a six-byte array containing the Ethernet address
309  * @addr2: Pointer other six-byte array containing the Ethernet address
310  *
311  * Compare two Ethernet addresses, returns true if equal
312  *
313  * Please note: addr1 & addr2 must both be aligned to u16.
314  */
ether_addr_equal(const u8 * addr1,const u8 * addr2)315 static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2)
316 {
317 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
318 	u32 fold = ((*(const u32 *)addr1) ^ (*(const u32 *)addr2)) |
319 		   ((*(const u16 *)(addr1 + 4)) ^ (*(const u16 *)(addr2 + 4)));
320 
321 	return fold == 0;
322 #else
323 	const u16 *a = (const u16 *)addr1;
324 	const u16 *b = (const u16 *)addr2;
325 
326 	return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) == 0;
327 #endif
328 }
329 
330 /**
331  * ether_addr_equal_64bits - Compare two Ethernet addresses
332  * @addr1: Pointer to an array of 8 bytes
333  * @addr2: Pointer to an other array of 8 bytes
334  *
335  * Compare two Ethernet addresses, returns true if equal, false otherwise.
336  *
337  * The function doesn't need any conditional branches and possibly uses
338  * word memory accesses on CPU allowing cheap unaligned memory reads.
339  * arrays = { byte1, byte2, byte3, byte4, byte5, byte6, pad1, pad2 }
340  *
341  * Please note that alignment of addr1 & addr2 are only guaranteed to be 16 bits.
342  */
343 
ether_addr_equal_64bits(const u8 addr1[6+2],const u8 addr2[6+2])344 static inline bool ether_addr_equal_64bits(const u8 addr1[6+2],
345 					   const u8 addr2[6+2])
346 {
347 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
348 	u64 fold = (*(const u64 *)addr1) ^ (*(const u64 *)addr2);
349 
350 #ifdef __BIG_ENDIAN
351 	return (fold >> 16) == 0;
352 #else
353 	return (fold << 16) == 0;
354 #endif
355 #else
356 	return ether_addr_equal(addr1, addr2);
357 #endif
358 }
359 
360 /**
361  * ether_addr_equal_unaligned - Compare two not u16 aligned Ethernet addresses
362  * @addr1: Pointer to a six-byte array containing the Ethernet address
363  * @addr2: Pointer other six-byte array containing the Ethernet address
364  *
365  * Compare two Ethernet addresses, returns true if equal
366  *
367  * Please note: Use only when any Ethernet address may not be u16 aligned.
368  */
ether_addr_equal_unaligned(const u8 * addr1,const u8 * addr2)369 static inline bool ether_addr_equal_unaligned(const u8 *addr1, const u8 *addr2)
370 {
371 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
372 	return ether_addr_equal(addr1, addr2);
373 #else
374 	return memcmp(addr1, addr2, ETH_ALEN) == 0;
375 #endif
376 }
377 
378 /**
379  * ether_addr_equal_masked - Compare two Ethernet addresses with a mask
380  * @addr1: Pointer to a six-byte array containing the 1st Ethernet address
381  * @addr2: Pointer to a six-byte array containing the 2nd Ethernet address
382  * @mask: Pointer to a six-byte array containing the Ethernet address bitmask
383  *
384  * Compare two Ethernet addresses with a mask, returns true if for every bit
385  * set in the bitmask the equivalent bits in the ethernet addresses are equal.
386  * Using a mask with all bits set is a slower ether_addr_equal.
387  */
ether_addr_equal_masked(const u8 * addr1,const u8 * addr2,const u8 * mask)388 static inline bool ether_addr_equal_masked(const u8 *addr1, const u8 *addr2,
389 					   const u8 *mask)
390 {
391 	int i;
392 
393 	for (i = 0; i < ETH_ALEN; i++) {
394 		if ((addr1[i] ^ addr2[i]) & mask[i])
395 			return false;
396 	}
397 
398 	return true;
399 }
400 
401 /**
402  * ether_addr_to_u64 - Convert an Ethernet address into a u64 value.
403  * @addr: Pointer to a six-byte array containing the Ethernet address
404  *
405  * Return a u64 value of the address
406  */
ether_addr_to_u64(const u8 * addr)407 static inline u64 ether_addr_to_u64(const u8 *addr)
408 {
409 	u64 u = 0;
410 	int i;
411 
412 	for (i = 0; i < ETH_ALEN; i++)
413 		u = u << 8 | addr[i];
414 
415 	return u;
416 }
417 
418 /**
419  * u64_to_ether_addr - Convert a u64 to an Ethernet address.
420  * @u: u64 to convert to an Ethernet MAC address
421  * @addr: Pointer to a six-byte array to contain the Ethernet address
422  */
u64_to_ether_addr(u64 u,u8 * addr)423 static inline void u64_to_ether_addr(u64 u, u8 *addr)
424 {
425 	int i;
426 
427 	for (i = ETH_ALEN - 1; i >= 0; i--) {
428 		addr[i] = u & 0xff;
429 		u = u >> 8;
430 	}
431 }
432 
433 /**
434  * eth_addr_dec - Decrement the given MAC address
435  *
436  * @addr: Pointer to a six-byte array containing Ethernet address to decrement
437  */
eth_addr_dec(u8 * addr)438 static inline void eth_addr_dec(u8 *addr)
439 {
440 	u64 u = ether_addr_to_u64(addr);
441 
442 	u--;
443 	u64_to_ether_addr(u, addr);
444 }
445 
446 /**
447  * eth_addr_inc() - Increment the given MAC address.
448  * @addr: Pointer to a six-byte array containing Ethernet address to increment.
449  */
eth_addr_inc(u8 * addr)450 static inline void eth_addr_inc(u8 *addr)
451 {
452 	u64 u = ether_addr_to_u64(addr);
453 
454 	u++;
455 	u64_to_ether_addr(u, addr);
456 }
457 
458 /**
459  * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
460  * @dev: Pointer to a device structure
461  * @addr: Pointer to a six-byte array containing the Ethernet address
462  *
463  * Compare passed address with all addresses of the device. Return true if the
464  * address if one of the device addresses.
465  *
466  * Note that this function calls ether_addr_equal_64bits() so take care of
467  * the right padding.
468  */
is_etherdev_addr(const struct net_device * dev,const u8 addr[6+2])469 static inline bool is_etherdev_addr(const struct net_device *dev,
470 				    const u8 addr[6 + 2])
471 {
472 	struct netdev_hw_addr *ha;
473 	bool res = false;
474 
475 	rcu_read_lock();
476 	for_each_dev_addr(dev, ha) {
477 		res = ether_addr_equal_64bits(addr, ha->addr);
478 		if (res)
479 			break;
480 	}
481 	rcu_read_unlock();
482 	return res;
483 }
484 #endif	/* __KERNEL__ */
485 
486 /**
487  * compare_ether_header - Compare two Ethernet headers
488  * @a: Pointer to Ethernet header
489  * @b: Pointer to Ethernet header
490  *
491  * Compare two Ethernet headers, returns 0 if equal.
492  * This assumes that the network header (i.e., IP header) is 4-byte
493  * aligned OR the platform can handle unaligned access.  This is the
494  * case for all packets coming into netif_receive_skb or similar
495  * entry points.
496  */
497 
compare_ether_header(const void * a,const void * b)498 static inline unsigned long compare_ether_header(const void *a, const void *b)
499 {
500 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
501 	unsigned long fold;
502 
503 	/*
504 	 * We want to compare 14 bytes:
505 	 *  [a0 ... a13] ^ [b0 ... b13]
506 	 * Use two long XOR, ORed together, with an overlap of two bytes.
507 	 *  [a0  a1  a2  a3  a4  a5  a6  a7 ] ^ [b0  b1  b2  b3  b4  b5  b6  b7 ] |
508 	 *  [a6  a7  a8  a9  a10 a11 a12 a13] ^ [b6  b7  b8  b9  b10 b11 b12 b13]
509 	 * This means the [a6 a7] ^ [b6 b7] part is done two times.
510 	*/
511 	fold = *(unsigned long *)a ^ *(unsigned long *)b;
512 	fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6);
513 	return fold;
514 #else
515 	u32 *a32 = (u32 *)((u8 *)a + 2);
516 	u32 *b32 = (u32 *)((u8 *)b + 2);
517 
518 	return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) |
519 	       (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]);
520 #endif
521 }
522 
523 /**
524  * eth_skb_pad - Pad buffer to mininum number of octets for Ethernet frame
525  * @skb: Buffer to pad
526  *
527  * An Ethernet frame should have a minimum size of 60 bytes.  This function
528  * takes short frames and pads them with zeros up to the 60 byte limit.
529  */
eth_skb_pad(struct sk_buff * skb)530 static inline int eth_skb_pad(struct sk_buff *skb)
531 {
532 	return skb_put_padto(skb, ETH_ZLEN);
533 }
534 
535 #endif	/* _LINUX_ETHERDEVICE_H */
536