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