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__
32 struct device;
33 int eth_platform_get_mac_address(struct device *dev, u8 *mac_addr);
34 unsigned char *arch_get_platform_mac_address(void);
35 u32 eth_get_headlen(void *data, unsigned int max_len);
36 __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev);
37 extern const struct header_ops eth_header_ops;
38
39 int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
40 const void *daddr, const void *saddr, unsigned len);
41 int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
42 int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh,
43 __be16 type);
44 void eth_header_cache_update(struct hh_cache *hh, const struct net_device *dev,
45 const unsigned char *haddr);
46 int eth_prepare_mac_addr_change(struct net_device *dev, void *p);
47 void eth_commit_mac_addr_change(struct net_device *dev, void *p);
48 int eth_mac_addr(struct net_device *dev, void *p);
49 int eth_change_mtu(struct net_device *dev, int new_mtu);
50 int eth_validate_addr(struct net_device *dev);
51
52 struct 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
57 struct 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
62 struct sk_buff *eth_gro_receive(struct list_head *head, struct sk_buff *skb);
63 int eth_gro_complete(struct sk_buff *skb, int nhoff);
64
65 /* Reserved Ethernet Addresses per IEEE 802.1Q */
66 static 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 */
is_link_local_ether_addr(const u8 * addr)79 static 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 */
is_zero_ether_addr(const u8 * addr)101 static 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 */
is_multicast_ether_addr(const u8 * addr)119 static 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
is_multicast_ether_addr_64bits(const u8 * addr)133 static inline bool is_multicast_ether_addr_64bits(const u8 *addr)
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 */
is_local_ether_addr(const u8 * addr)152 static 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 */
is_broadcast_ether_addr(const u8 * addr)165 static 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 */
is_unicast_ether_addr(const u8 * addr)178 static 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 */
is_valid_ether_addr(const u8 * addr)194 static 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 */
eth_proto_is_802_3(__be16 proto)209 static 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 */
eth_random_addr(u8 * addr)226 static 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 */
eth_broadcast_addr(u8 * addr)241 static 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 */
eth_zero_addr(u8 * addr)252 static 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 */
eth_hw_addr_random(struct net_device * dev)266 static 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 */
ether_addr_copy(u8 * dst,const u8 * src)279 static 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_set - Assign Ethernet address to a net_device
296 * @dev: pointer to net_device structure
297 * @addr: address to assign
298 *
299 * Assign given address to the net_device, addr_assign_type is not changed.
300 */
eth_hw_addr_set(struct net_device * dev,const u8 * addr)301 static inline void eth_hw_addr_set(struct net_device *dev, const u8 *addr)
302 {
303 ether_addr_copy(dev->dev_addr, addr);
304 }
305
306 /**
307 * eth_hw_addr_inherit - Copy dev_addr from another net_device
308 * @dst: pointer to net_device to copy dev_addr to
309 * @src: pointer to net_device to copy dev_addr from
310 *
311 * Copy the Ethernet address from one net_device to another along with
312 * the address attributes (addr_assign_type).
313 */
eth_hw_addr_inherit(struct net_device * dst,struct net_device * src)314 static inline void eth_hw_addr_inherit(struct net_device *dst,
315 struct net_device *src)
316 {
317 dst->addr_assign_type = src->addr_assign_type;
318 ether_addr_copy(dst->dev_addr, src->dev_addr);
319 }
320
321 /**
322 * ether_addr_equal - Compare two Ethernet addresses
323 * @addr1: Pointer to a six-byte array containing the Ethernet address
324 * @addr2: Pointer other six-byte array containing the Ethernet address
325 *
326 * Compare two Ethernet addresses, returns true if equal
327 *
328 * Please note: addr1 & addr2 must both be aligned to u16.
329 */
ether_addr_equal(const u8 * addr1,const u8 * addr2)330 static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2)
331 {
332 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
333 u32 fold = ((*(const u32 *)addr1) ^ (*(const u32 *)addr2)) |
334 ((*(const u16 *)(addr1 + 4)) ^ (*(const u16 *)(addr2 + 4)));
335
336 return fold == 0;
337 #else
338 const u16 *a = (const u16 *)addr1;
339 const u16 *b = (const u16 *)addr2;
340
341 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) == 0;
342 #endif
343 }
344
345 /**
346 * ether_addr_equal_64bits - Compare two Ethernet addresses
347 * @addr1: Pointer to an array of 8 bytes
348 * @addr2: Pointer to an other array of 8 bytes
349 *
350 * Compare two Ethernet addresses, returns true if equal, false otherwise.
351 *
352 * The function doesn't need any conditional branches and possibly uses
353 * word memory accesses on CPU allowing cheap unaligned memory reads.
354 * arrays = { byte1, byte2, byte3, byte4, byte5, byte6, pad1, pad2 }
355 *
356 * Please note that alignment of addr1 & addr2 are only guaranteed to be 16 bits.
357 */
358
ether_addr_equal_64bits(const u8 * addr1,const u8 * addr2)359 static inline bool ether_addr_equal_64bits(const u8 *addr1, const u8 *addr2)
360 {
361 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
362 u64 fold = (*(const u64 *)addr1) ^ (*(const u64 *)addr2);
363
364 #ifdef __BIG_ENDIAN
365 return (fold >> 16) == 0;
366 #else
367 return (fold << 16) == 0;
368 #endif
369 #else
370 return ether_addr_equal(addr1, addr2);
371 #endif
372 }
373
374 /**
375 * ether_addr_equal_unaligned - Compare two not u16 aligned Ethernet addresses
376 * @addr1: Pointer to a six-byte array containing the Ethernet address
377 * @addr2: Pointer other six-byte array containing the Ethernet address
378 *
379 * Compare two Ethernet addresses, returns true if equal
380 *
381 * Please note: Use only when any Ethernet address may not be u16 aligned.
382 */
ether_addr_equal_unaligned(const u8 * addr1,const u8 * addr2)383 static inline bool ether_addr_equal_unaligned(const u8 *addr1, const u8 *addr2)
384 {
385 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
386 return ether_addr_equal(addr1, addr2);
387 #else
388 return memcmp(addr1, addr2, ETH_ALEN) == 0;
389 #endif
390 }
391
392 /**
393 * ether_addr_equal_masked - Compare two Ethernet addresses with a mask
394 * @addr1: Pointer to a six-byte array containing the 1st Ethernet address
395 * @addr2: Pointer to a six-byte array containing the 2nd Ethernet address
396 * @mask: Pointer to a six-byte array containing the Ethernet address bitmask
397 *
398 * Compare two Ethernet addresses with a mask, returns true if for every bit
399 * set in the bitmask the equivalent bits in the ethernet addresses are equal.
400 * Using a mask with all bits set is a slower ether_addr_equal.
401 */
ether_addr_equal_masked(const u8 * addr1,const u8 * addr2,const u8 * mask)402 static inline bool ether_addr_equal_masked(const u8 *addr1, const u8 *addr2,
403 const u8 *mask)
404 {
405 int i;
406
407 for (i = 0; i < ETH_ALEN; i++) {
408 if ((addr1[i] ^ addr2[i]) & mask[i])
409 return false;
410 }
411
412 return true;
413 }
414
415 /**
416 * ether_addr_to_u64 - Convert an Ethernet address into a u64 value.
417 * @addr: Pointer to a six-byte array containing the Ethernet address
418 *
419 * Return a u64 value of the address
420 */
ether_addr_to_u64(const u8 * addr)421 static inline u64 ether_addr_to_u64(const u8 *addr)
422 {
423 u64 u = 0;
424 int i;
425
426 for (i = 0; i < ETH_ALEN; i++)
427 u = u << 8 | addr[i];
428
429 return u;
430 }
431
432 /**
433 * u64_to_ether_addr - Convert a u64 to an Ethernet address.
434 * @u: u64 to convert to an Ethernet MAC address
435 * @addr: Pointer to a six-byte array to contain the Ethernet address
436 */
u64_to_ether_addr(u64 u,u8 * addr)437 static inline void u64_to_ether_addr(u64 u, u8 *addr)
438 {
439 int i;
440
441 for (i = ETH_ALEN - 1; i >= 0; i--) {
442 addr[i] = u & 0xff;
443 u = u >> 8;
444 }
445 }
446
447 /**
448 * eth_addr_dec - Decrement the given MAC address
449 *
450 * @addr: Pointer to a six-byte array containing Ethernet address to decrement
451 */
eth_addr_dec(u8 * addr)452 static inline void eth_addr_dec(u8 *addr)
453 {
454 u64 u = ether_addr_to_u64(addr);
455
456 u--;
457 u64_to_ether_addr(u, addr);
458 }
459
460 /**
461 * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
462 * @dev: Pointer to a device structure
463 * @addr: Pointer to a six-byte array containing the Ethernet address
464 *
465 * Compare passed address with all addresses of the device. Return true if the
466 * address if one of the device addresses.
467 *
468 * Note that this function calls ether_addr_equal_64bits() so take care of
469 * the right padding.
470 */
is_etherdev_addr(const struct net_device * dev,const u8 addr[6+2])471 static inline bool is_etherdev_addr(const struct net_device *dev,
472 const u8 addr[6 + 2])
473 {
474 struct netdev_hw_addr *ha;
475 bool res = false;
476
477 rcu_read_lock();
478 for_each_dev_addr(dev, ha) {
479 res = ether_addr_equal_64bits(addr, ha->addr);
480 if (res)
481 break;
482 }
483 rcu_read_unlock();
484 return res;
485 }
486 #endif /* __KERNEL__ */
487
488 /**
489 * compare_ether_header - Compare two Ethernet headers
490 * @a: Pointer to Ethernet header
491 * @b: Pointer to Ethernet header
492 *
493 * Compare two Ethernet headers, returns 0 if equal.
494 * This assumes that the network header (i.e., IP header) is 4-byte
495 * aligned OR the platform can handle unaligned access. This is the
496 * case for all packets coming into netif_receive_skb or similar
497 * entry points.
498 */
499
compare_ether_header(const void * a,const void * b)500 static inline unsigned long compare_ether_header(const void *a, const void *b)
501 {
502 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
503 unsigned long fold;
504
505 /*
506 * We want to compare 14 bytes:
507 * [a0 ... a13] ^ [b0 ... b13]
508 * Use two long XOR, ORed together, with an overlap of two bytes.
509 * [a0 a1 a2 a3 a4 a5 a6 a7 ] ^ [b0 b1 b2 b3 b4 b5 b6 b7 ] |
510 * [a6 a7 a8 a9 a10 a11 a12 a13] ^ [b6 b7 b8 b9 b10 b11 b12 b13]
511 * This means the [a6 a7] ^ [b6 b7] part is done two times.
512 */
513 fold = *(unsigned long *)a ^ *(unsigned long *)b;
514 fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6);
515 return fold;
516 #else
517 u32 *a32 = (u32 *)((u8 *)a + 2);
518 u32 *b32 = (u32 *)((u8 *)b + 2);
519
520 return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) |
521 (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]);
522 #endif
523 }
524
525 /**
526 * eth_skb_pad - Pad buffer to mininum number of octets for Ethernet frame
527 * @skb: Buffer to pad
528 *
529 * An Ethernet frame should have a minimum size of 60 bytes. This function
530 * takes short frames and pads them with zeros up to the 60 byte limit.
531 */
eth_skb_pad(struct sk_buff * skb)532 static inline int eth_skb_pad(struct sk_buff *skb)
533 {
534 return skb_put_padto(skb, ETH_ZLEN);
535 }
536
537 #endif /* _LINUX_ETHERDEVICE_H */
538