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