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