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 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 /**
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  */
is_link_local_ether_addr(const u8 * addr)83 static 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  */
is_zero_ether_addr(const u8 * addr)105 static 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  */
is_multicast_ether_addr(const u8 * addr)123 static 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 
is_multicast_ether_addr_64bits(const u8 addr[6+2])137 static inline bool is_multicast_ether_addr_64bits(const u8 addr[6+2])
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  */
is_local_ether_addr(const u8 * addr)156 static 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  */
is_broadcast_ether_addr(const u8 * addr)169 static 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  */
is_unicast_ether_addr(const u8 * addr)182 static 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  */
is_valid_ether_addr(const u8 * addr)198 static 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  */
eth_proto_is_802_3(__be16 proto)213 static 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  */
eth_random_addr(u8 * addr)230 static 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  */
eth_broadcast_addr(u8 * addr)243 static 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  */
eth_zero_addr(u8 * addr)254 static 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  */
eth_hw_addr_random(struct net_device * dev)268 static 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  */
eth_hw_addr_crc(struct netdev_hw_addr * ha)283 static 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  */
ether_addr_copy(u8 * dst,const u8 * src)295 static 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  */
eth_hw_addr_set(struct net_device * dev,const u8 * addr)317 static 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  */
eth_hw_addr_inherit(struct net_device * dst,struct net_device * src)330 static 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  */
ether_addr_equal(const u8 * addr1,const u8 * addr2)346 static 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 
ether_addr_equal_64bits(const u8 addr1[6+2],const u8 addr2[6+2])375 static inline bool ether_addr_equal_64bits(const u8 addr1[6+2],
376 					   const u8 addr2[6+2])
377 {
378 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
379 	u64 fold = (*(const u64 *)addr1) ^ (*(const u64 *)addr2);
380 
381 #ifdef __BIG_ENDIAN
382 	return (fold >> 16) == 0;
383 #else
384 	return (fold << 16) == 0;
385 #endif
386 #else
387 	return ether_addr_equal(addr1, addr2);
388 #endif
389 }
390 
391 /**
392  * ether_addr_equal_unaligned - Compare two not u16 aligned Ethernet addresses
393  * @addr1: Pointer to a six-byte array containing the Ethernet address
394  * @addr2: Pointer other six-byte array containing the Ethernet address
395  *
396  * Compare two Ethernet addresses, returns true if equal
397  *
398  * Please note: Use only when any Ethernet address may not be u16 aligned.
399  */
ether_addr_equal_unaligned(const u8 * addr1,const u8 * addr2)400 static inline bool ether_addr_equal_unaligned(const u8 *addr1, const u8 *addr2)
401 {
402 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
403 	return ether_addr_equal(addr1, addr2);
404 #else
405 	return memcmp(addr1, addr2, ETH_ALEN) == 0;
406 #endif
407 }
408 
409 /**
410  * ether_addr_equal_masked - Compare two Ethernet addresses with a mask
411  * @addr1: Pointer to a six-byte array containing the 1st Ethernet address
412  * @addr2: Pointer to a six-byte array containing the 2nd Ethernet address
413  * @mask: Pointer to a six-byte array containing the Ethernet address bitmask
414  *
415  * Compare two Ethernet addresses with a mask, returns true if for every bit
416  * set in the bitmask the equivalent bits in the ethernet addresses are equal.
417  * Using a mask with all bits set is a slower ether_addr_equal.
418  */
ether_addr_equal_masked(const u8 * addr1,const u8 * addr2,const u8 * mask)419 static inline bool ether_addr_equal_masked(const u8 *addr1, const u8 *addr2,
420 					   const u8 *mask)
421 {
422 	int i;
423 
424 	for (i = 0; i < ETH_ALEN; i++) {
425 		if ((addr1[i] ^ addr2[i]) & mask[i])
426 			return false;
427 	}
428 
429 	return true;
430 }
431 
432 /**
433  * ether_addr_to_u64 - Convert an Ethernet address into a u64 value.
434  * @addr: Pointer to a six-byte array containing the Ethernet address
435  *
436  * Return a u64 value of the address
437  */
ether_addr_to_u64(const u8 * addr)438 static inline u64 ether_addr_to_u64(const u8 *addr)
439 {
440 	u64 u = 0;
441 	int i;
442 
443 	for (i = 0; i < ETH_ALEN; i++)
444 		u = u << 8 | addr[i];
445 
446 	return u;
447 }
448 
449 /**
450  * u64_to_ether_addr - Convert a u64 to an Ethernet address.
451  * @u: u64 to convert to an Ethernet MAC address
452  * @addr: Pointer to a six-byte array to contain the Ethernet address
453  */
u64_to_ether_addr(u64 u,u8 * addr)454 static inline void u64_to_ether_addr(u64 u, u8 *addr)
455 {
456 	int i;
457 
458 	for (i = ETH_ALEN - 1; i >= 0; i--) {
459 		addr[i] = u & 0xff;
460 		u = u >> 8;
461 	}
462 }
463 
464 /**
465  * eth_addr_dec - Decrement the given MAC address
466  *
467  * @addr: Pointer to a six-byte array containing Ethernet address to decrement
468  */
eth_addr_dec(u8 * addr)469 static inline void eth_addr_dec(u8 *addr)
470 {
471 	u64 u = ether_addr_to_u64(addr);
472 
473 	u--;
474 	u64_to_ether_addr(u, addr);
475 }
476 
477 /**
478  * eth_addr_inc() - Increment the given MAC address.
479  * @addr: Pointer to a six-byte array containing Ethernet address to increment.
480  */
eth_addr_inc(u8 * addr)481 static inline void eth_addr_inc(u8 *addr)
482 {
483 	u64 u = ether_addr_to_u64(addr);
484 
485 	u++;
486 	u64_to_ether_addr(u, addr);
487 }
488 
489 /**
490  * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
491  * @dev: Pointer to a device structure
492  * @addr: Pointer to a six-byte array containing the Ethernet address
493  *
494  * Compare passed address with all addresses of the device. Return true if the
495  * address if one of the device addresses.
496  *
497  * Note that this function calls ether_addr_equal_64bits() so take care of
498  * the right padding.
499  */
is_etherdev_addr(const struct net_device * dev,const u8 addr[6+2])500 static inline bool is_etherdev_addr(const struct net_device *dev,
501 				    const u8 addr[6 + 2])
502 {
503 	struct netdev_hw_addr *ha;
504 	bool res = false;
505 
506 	rcu_read_lock();
507 	for_each_dev_addr(dev, ha) {
508 		res = ether_addr_equal_64bits(addr, ha->addr);
509 		if (res)
510 			break;
511 	}
512 	rcu_read_unlock();
513 	return res;
514 }
515 #endif	/* __KERNEL__ */
516 
517 /**
518  * compare_ether_header - Compare two Ethernet headers
519  * @a: Pointer to Ethernet header
520  * @b: Pointer to Ethernet header
521  *
522  * Compare two Ethernet headers, returns 0 if equal.
523  * This assumes that the network header (i.e., IP header) is 4-byte
524  * aligned OR the platform can handle unaligned access.  This is the
525  * case for all packets coming into netif_receive_skb or similar
526  * entry points.
527  */
528 
compare_ether_header(const void * a,const void * b)529 static inline unsigned long compare_ether_header(const void *a, const void *b)
530 {
531 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
532 	unsigned long fold;
533 
534 	/*
535 	 * We want to compare 14 bytes:
536 	 *  [a0 ... a13] ^ [b0 ... b13]
537 	 * Use two long XOR, ORed together, with an overlap of two bytes.
538 	 *  [a0  a1  a2  a3  a4  a5  a6  a7 ] ^ [b0  b1  b2  b3  b4  b5  b6  b7 ] |
539 	 *  [a6  a7  a8  a9  a10 a11 a12 a13] ^ [b6  b7  b8  b9  b10 b11 b12 b13]
540 	 * This means the [a6 a7] ^ [b6 b7] part is done two times.
541 	*/
542 	fold = *(unsigned long *)a ^ *(unsigned long *)b;
543 	fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6);
544 	return fold;
545 #else
546 	u32 *a32 = (u32 *)((u8 *)a + 2);
547 	u32 *b32 = (u32 *)((u8 *)b + 2);
548 
549 	return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) |
550 	       (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]);
551 #endif
552 }
553 
554 /**
555  * eth_hw_addr_gen - Generate and assign Ethernet address to a port
556  * @dev: pointer to port's net_device structure
557  * @base_addr: base Ethernet address
558  * @id: offset to add to the base address
559  *
560  * Generate a MAC address using a base address and an offset and assign it
561  * to a net_device. Commonly used by switch drivers which need to compute
562  * addresses for all their ports. addr_assign_type is not changed.
563  */
eth_hw_addr_gen(struct net_device * dev,const u8 * base_addr,unsigned int id)564 static inline void eth_hw_addr_gen(struct net_device *dev, const u8 *base_addr,
565 				   unsigned int id)
566 {
567 	u64 u = ether_addr_to_u64(base_addr);
568 	u8 addr[ETH_ALEN];
569 
570 	u += id;
571 	u64_to_ether_addr(u, addr);
572 	eth_hw_addr_set(dev, addr);
573 }
574 
575 /**
576  * eth_skb_pad - Pad buffer to mininum number of octets for Ethernet frame
577  * @skb: Buffer to pad
578  *
579  * An Ethernet frame should have a minimum size of 60 bytes.  This function
580  * takes short frames and pads them with zeros up to the 60 byte limit.
581  */
eth_skb_pad(struct sk_buff * skb)582 static inline int eth_skb_pad(struct sk_buff *skb)
583 {
584 	return skb_put_padto(skb, ETH_ZLEN);
585 }
586 
587 #endif	/* _LINUX_ETHERDEVICE_H */
588