etherdevice.h 9.1 KB

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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. #include <linux/if_ether.h>
  25. #include <linux/netdevice.h>
  26. #include <linux/random.h>
  27. #include <asm/unaligned.h>
  28. #ifdef __KERNEL__
  29. extern __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev);
  30. extern const struct header_ops eth_header_ops;
  31. extern int eth_header(struct sk_buff *skb, struct net_device *dev,
  32. unsigned short type,
  33. const void *daddr, const void *saddr, unsigned len);
  34. extern int eth_rebuild_header(struct sk_buff *skb);
  35. extern int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
  36. extern int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh, __be16 type);
  37. extern void eth_header_cache_update(struct hh_cache *hh,
  38. const struct net_device *dev,
  39. const unsigned char *haddr);
  40. extern int eth_mac_addr(struct net_device *dev, void *p);
  41. extern int eth_change_mtu(struct net_device *dev, int new_mtu);
  42. extern int eth_validate_addr(struct net_device *dev);
  43. extern struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs,
  44. unsigned int rxqs);
  45. #define alloc_etherdev(sizeof_priv) alloc_etherdev_mq(sizeof_priv, 1)
  46. #define alloc_etherdev_mq(sizeof_priv, count) alloc_etherdev_mqs(sizeof_priv, count, count)
  47. /**
  48. * is_zero_ether_addr - Determine if give Ethernet address is all zeros.
  49. * @addr: Pointer to a six-byte array containing the Ethernet address
  50. *
  51. * Return true if the address is all zeroes.
  52. */
  53. static inline bool is_zero_ether_addr(const u8 *addr)
  54. {
  55. return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]);
  56. }
  57. /**
  58. * is_multicast_ether_addr - Determine if the Ethernet address is a multicast.
  59. * @addr: Pointer to a six-byte array containing the Ethernet address
  60. *
  61. * Return true if the address is a multicast address.
  62. * By definition the broadcast address is also a multicast address.
  63. */
  64. static inline bool is_multicast_ether_addr(const u8 *addr)
  65. {
  66. return 0x01 & addr[0];
  67. }
  68. /**
  69. * is_local_ether_addr - Determine if the Ethernet address is locally-assigned one (IEEE 802).
  70. * @addr: Pointer to a six-byte array containing the Ethernet address
  71. *
  72. * Return true if the address is a local address.
  73. */
  74. static inline bool is_local_ether_addr(const u8 *addr)
  75. {
  76. return 0x02 & addr[0];
  77. }
  78. /**
  79. * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast
  80. * @addr: Pointer to a six-byte array containing the Ethernet address
  81. *
  82. * Return true if the address is the broadcast address.
  83. */
  84. static inline bool is_broadcast_ether_addr(const u8 *addr)
  85. {
  86. return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff;
  87. }
  88. /**
  89. * is_unicast_ether_addr - Determine if the Ethernet address is unicast
  90. * @addr: Pointer to a six-byte array containing the Ethernet address
  91. *
  92. * Return true if the address is a unicast address.
  93. */
  94. static inline bool is_unicast_ether_addr(const u8 *addr)
  95. {
  96. return !is_multicast_ether_addr(addr);
  97. }
  98. /**
  99. * is_valid_ether_addr - Determine if the given Ethernet address is valid
  100. * @addr: Pointer to a six-byte array containing the Ethernet address
  101. *
  102. * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not
  103. * a multicast address, and is not FF:FF:FF:FF:FF:FF.
  104. *
  105. * Return true if the address is valid.
  106. */
  107. static inline bool is_valid_ether_addr(const u8 *addr)
  108. {
  109. /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to
  110. * explicitly check for it here. */
  111. return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr);
  112. }
  113. /**
  114. * random_ether_addr - Generate software assigned random Ethernet address
  115. * @addr: Pointer to a six-byte array containing the Ethernet address
  116. *
  117. * Generate a random Ethernet address (MAC) that is not multicast
  118. * and has the local assigned bit set.
  119. */
  120. static inline void random_ether_addr(u8 *addr)
  121. {
  122. get_random_bytes (addr, ETH_ALEN);
  123. addr [0] &= 0xfe; /* clear multicast bit */
  124. addr [0] |= 0x02; /* set local assignment bit (IEEE802) */
  125. }
  126. /**
  127. * eth_hw_addr_random - Generate software assigned random Ethernet and
  128. * set device flag
  129. * @dev: pointer to net_device structure
  130. *
  131. * Generate a random Ethernet address (MAC) to be used by a net device
  132. * and set addr_assign_type so the state can be read by sysfs and be
  133. * used by userspace.
  134. */
  135. static inline void eth_hw_addr_random(struct net_device *dev)
  136. {
  137. dev->addr_assign_type |= NET_ADDR_RANDOM;
  138. random_ether_addr(dev->dev_addr);
  139. }
  140. /**
  141. * compare_ether_addr - Compare two Ethernet addresses
  142. * @addr1: Pointer to a six-byte array containing the Ethernet address
  143. * @addr2: Pointer other six-byte array containing the Ethernet address
  144. *
  145. * Compare two Ethernet addresses, returns 0 if equal, non-zero otherwise.
  146. * Unlike memcmp(), it doesn't return a value suitable for sorting.
  147. */
  148. static inline unsigned compare_ether_addr(const u8 *addr1, const u8 *addr2)
  149. {
  150. const u16 *a = (const u16 *) addr1;
  151. const u16 *b = (const u16 *) addr2;
  152. BUILD_BUG_ON(ETH_ALEN != 6);
  153. return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) != 0;
  154. }
  155. /**
  156. * ether_addr_equal - Compare two Ethernet addresses
  157. * @addr1: Pointer to a six-byte array containing the Ethernet address
  158. * @addr2: Pointer other six-byte array containing the Ethernet address
  159. *
  160. * Compare two Ethernet addresses, returns true if equal
  161. */
  162. static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2)
  163. {
  164. return !compare_ether_addr(addr1, addr2);
  165. }
  166. static inline unsigned long zap_last_2bytes(unsigned long value)
  167. {
  168. #ifdef __BIG_ENDIAN
  169. return value >> 16;
  170. #else
  171. return value << 16;
  172. #endif
  173. }
  174. /**
  175. * ether_addr_equal_64bits - Compare two Ethernet addresses
  176. * @addr1: Pointer to an array of 8 bytes
  177. * @addr2: Pointer to an other array of 8 bytes
  178. *
  179. * Compare two Ethernet addresses, returns true if equal, false otherwise.
  180. *
  181. * The function doesn't need any conditional branches and possibly uses
  182. * word memory accesses on CPU allowing cheap unaligned memory reads.
  183. * arrays = { byte1, byte2, byte3, byte4, byte5, byte6, pad1, pad2 }
  184. *
  185. * Please note that alignment of addr1 & addr2 are only guaranteed to be 16 bits.
  186. */
  187. static inline bool ether_addr_equal_64bits(const u8 addr1[6+2],
  188. const u8 addr2[6+2])
  189. {
  190. #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
  191. unsigned long fold = ((*(unsigned long *)addr1) ^
  192. (*(unsigned long *)addr2));
  193. if (sizeof(fold) == 8)
  194. return zap_last_2bytes(fold) == 0;
  195. fold |= zap_last_2bytes((*(unsigned long *)(addr1 + 4)) ^
  196. (*(unsigned long *)(addr2 + 4)));
  197. return fold == 0;
  198. #else
  199. return ether_addr_equal(addr1, addr2);
  200. #endif
  201. }
  202. /**
  203. * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
  204. * @dev: Pointer to a device structure
  205. * @addr: Pointer to a six-byte array containing the Ethernet address
  206. *
  207. * Compare passed address with all addresses of the device. Return true if the
  208. * address if one of the device addresses.
  209. *
  210. * Note that this function calls ether_addr_equal_64bits() so take care of
  211. * the right padding.
  212. */
  213. static inline bool is_etherdev_addr(const struct net_device *dev,
  214. const u8 addr[6 + 2])
  215. {
  216. struct netdev_hw_addr *ha;
  217. bool res = false;
  218. rcu_read_lock();
  219. for_each_dev_addr(dev, ha) {
  220. res = ether_addr_equal_64bits(addr, ha->addr);
  221. if (res)
  222. break;
  223. }
  224. rcu_read_unlock();
  225. return res;
  226. }
  227. #endif /* __KERNEL__ */
  228. /**
  229. * compare_ether_header - Compare two Ethernet headers
  230. * @a: Pointer to Ethernet header
  231. * @b: Pointer to Ethernet header
  232. *
  233. * Compare two Ethernet headers, returns 0 if equal.
  234. * This assumes that the network header (i.e., IP header) is 4-byte
  235. * aligned OR the platform can handle unaligned access. This is the
  236. * case for all packets coming into netif_receive_skb or similar
  237. * entry points.
  238. */
  239. static inline unsigned long compare_ether_header(const void *a, const void *b)
  240. {
  241. #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
  242. unsigned long fold;
  243. /*
  244. * We want to compare 14 bytes:
  245. * [a0 ... a13] ^ [b0 ... b13]
  246. * Use two long XOR, ORed together, with an overlap of two bytes.
  247. * [a0 a1 a2 a3 a4 a5 a6 a7 ] ^ [b0 b1 b2 b3 b4 b5 b6 b7 ] |
  248. * [a6 a7 a8 a9 a10 a11 a12 a13] ^ [b6 b7 b8 b9 b10 b11 b12 b13]
  249. * This means the [a6 a7] ^ [b6 b7] part is done two times.
  250. */
  251. fold = *(unsigned long *)a ^ *(unsigned long *)b;
  252. fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6);
  253. return fold;
  254. #else
  255. u32 *a32 = (u32 *)((u8 *)a + 2);
  256. u32 *b32 = (u32 *)((u8 *)b + 2);
  257. return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) |
  258. (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]);
  259. #endif
  260. }
  261. #endif /* _LINUX_ETHERDEVICE_H */