etherdevice.h 8.7 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. * WARNING: This move may well be temporary. This file will get merged with others RSN.
  22. *
  23. */
  24. #ifndef _LINUX_ETHERDEVICE_H
  25. #define _LINUX_ETHERDEVICE_H
  26. #include <linux/if_ether.h>
  27. #include <linux/netdevice.h>
  28. #include <linux/random.h>
  29. #include <asm/unaligned.h>
  30. #ifdef __KERNEL__
  31. extern __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev);
  32. extern const struct header_ops eth_header_ops;
  33. extern int eth_header(struct sk_buff *skb, struct net_device *dev,
  34. unsigned short type,
  35. const void *daddr, const void *saddr, unsigned len);
  36. extern int eth_rebuild_header(struct sk_buff *skb);
  37. extern int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
  38. extern int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh, __be16 type);
  39. extern void eth_header_cache_update(struct hh_cache *hh,
  40. const struct net_device *dev,
  41. const unsigned char *haddr);
  42. extern int eth_mac_addr(struct net_device *dev, void *p);
  43. extern int eth_change_mtu(struct net_device *dev, int new_mtu);
  44. extern int eth_validate_addr(struct net_device *dev);
  45. extern struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs,
  46. unsigned int rxqs);
  47. #define alloc_etherdev(sizeof_priv) alloc_etherdev_mq(sizeof_priv, 1)
  48. #define alloc_etherdev_mq(sizeof_priv, count) alloc_etherdev_mqs(sizeof_priv, count, count)
  49. /**
  50. * is_zero_ether_addr - Determine if give Ethernet address is all zeros.
  51. * @addr: Pointer to a six-byte array containing the Ethernet address
  52. *
  53. * Return true if the address is all zeroes.
  54. */
  55. static inline int is_zero_ether_addr(const u8 *addr)
  56. {
  57. return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]);
  58. }
  59. /**
  60. * is_multicast_ether_addr - Determine if the Ethernet address is a multicast.
  61. * @addr: Pointer to a six-byte array containing the Ethernet address
  62. *
  63. * Return true if the address is a multicast address.
  64. * By definition the broadcast address is also a multicast address.
  65. */
  66. static inline int is_multicast_ether_addr(const u8 *addr)
  67. {
  68. return 0x01 & addr[0];
  69. }
  70. /**
  71. * is_local_ether_addr - Determine if the Ethernet address is locally-assigned one (IEEE 802).
  72. * @addr: Pointer to a six-byte array containing the Ethernet address
  73. *
  74. * Return true if the address is a local address.
  75. */
  76. static inline int is_local_ether_addr(const u8 *addr)
  77. {
  78. return 0x02 & addr[0];
  79. }
  80. /**
  81. * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast
  82. * @addr: Pointer to a six-byte array containing the Ethernet address
  83. *
  84. * Return true if the address is the broadcast address.
  85. */
  86. static inline int is_broadcast_ether_addr(const u8 *addr)
  87. {
  88. return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff;
  89. }
  90. /**
  91. * is_unicast_ether_addr - Determine if the Ethernet address is unicast
  92. * @addr: Pointer to a six-byte array containing the Ethernet address
  93. *
  94. * Return true if the address is a unicast address.
  95. */
  96. static inline int is_unicast_ether_addr(const u8 *addr)
  97. {
  98. return !is_multicast_ether_addr(addr);
  99. }
  100. /**
  101. * is_valid_ether_addr - Determine if the given Ethernet address is valid
  102. * @addr: Pointer to a six-byte array containing the Ethernet address
  103. *
  104. * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not
  105. * a multicast address, and is not FF:FF:FF:FF:FF:FF.
  106. *
  107. * Return true if the address is valid.
  108. */
  109. static inline int is_valid_ether_addr(const u8 *addr)
  110. {
  111. /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to
  112. * explicitly check for it here. */
  113. return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr);
  114. }
  115. /**
  116. * random_ether_addr - Generate software assigned random Ethernet address
  117. * @addr: Pointer to a six-byte array containing the Ethernet address
  118. *
  119. * Generate a random Ethernet address (MAC) that is not multicast
  120. * and has the local assigned bit set.
  121. */
  122. static inline void random_ether_addr(u8 *addr)
  123. {
  124. get_random_bytes (addr, ETH_ALEN);
  125. addr [0] &= 0xfe; /* clear multicast bit */
  126. addr [0] |= 0x02; /* set local assignment bit (IEEE802) */
  127. }
  128. /**
  129. * eth_hw_addr_random - Generate software assigned random Ethernet and
  130. * set device flag
  131. * @dev: pointer to net_device structure
  132. *
  133. * Generate a random Ethernet address (MAC) to be used by a net device
  134. * and set addr_assign_type so the state can be read by sysfs and be
  135. * used by userspace.
  136. */
  137. static inline void eth_hw_addr_random(struct net_device *dev)
  138. {
  139. dev->addr_assign_type |= NET_ADDR_RANDOM;
  140. random_ether_addr(dev->dev_addr);
  141. }
  142. /**
  143. * compare_ether_addr - Compare two Ethernet addresses
  144. * @addr1: Pointer to a six-byte array containing the Ethernet address
  145. * @addr2: Pointer other six-byte array containing the Ethernet address
  146. *
  147. * Compare two ethernet addresses, returns 0 if equal
  148. */
  149. static inline unsigned compare_ether_addr(const u8 *addr1, const u8 *addr2)
  150. {
  151. const u16 *a = (const u16 *) addr1;
  152. const u16 *b = (const u16 *) addr2;
  153. BUILD_BUG_ON(ETH_ALEN != 6);
  154. return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) != 0;
  155. }
  156. static inline unsigned long zap_last_2bytes(unsigned long value)
  157. {
  158. #ifdef __BIG_ENDIAN
  159. return value >> 16;
  160. #else
  161. return value << 16;
  162. #endif
  163. }
  164. /**
  165. * compare_ether_addr_64bits - Compare two Ethernet addresses
  166. * @addr1: Pointer to an array of 8 bytes
  167. * @addr2: Pointer to an other array of 8 bytes
  168. *
  169. * Compare two ethernet addresses, returns 0 if equal.
  170. * Same result than "memcmp(addr1, addr2, ETH_ALEN)" but without conditional
  171. * branches, and possibly long word memory accesses on CPU allowing cheap
  172. * unaligned memory reads.
  173. * arrays = { byte1, byte2, byte3, byte4, byte6, byte7, pad1, pad2}
  174. *
  175. * Please note that alignment of addr1 & addr2 is only guaranted to be 16 bits.
  176. */
  177. static inline unsigned compare_ether_addr_64bits(const u8 addr1[6+2],
  178. const u8 addr2[6+2])
  179. {
  180. #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
  181. unsigned long fold = ((*(unsigned long *)addr1) ^
  182. (*(unsigned long *)addr2));
  183. if (sizeof(fold) == 8)
  184. return zap_last_2bytes(fold) != 0;
  185. fold |= zap_last_2bytes((*(unsigned long *)(addr1 + 4)) ^
  186. (*(unsigned long *)(addr2 + 4)));
  187. return fold != 0;
  188. #else
  189. return compare_ether_addr(addr1, addr2);
  190. #endif
  191. }
  192. /**
  193. * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
  194. * @dev: Pointer to a device structure
  195. * @addr: Pointer to a six-byte array containing the Ethernet address
  196. *
  197. * Compare passed address with all addresses of the device. Return true if the
  198. * address if one of the device addresses.
  199. *
  200. * Note that this function calls compare_ether_addr_64bits() so take care of
  201. * the right padding.
  202. */
  203. static inline bool is_etherdev_addr(const struct net_device *dev,
  204. const u8 addr[6 + 2])
  205. {
  206. struct netdev_hw_addr *ha;
  207. int res = 1;
  208. rcu_read_lock();
  209. for_each_dev_addr(dev, ha) {
  210. res = compare_ether_addr_64bits(addr, ha->addr);
  211. if (!res)
  212. break;
  213. }
  214. rcu_read_unlock();
  215. return !res;
  216. }
  217. #endif /* __KERNEL__ */
  218. /**
  219. * compare_ether_header - Compare two Ethernet headers
  220. * @a: Pointer to Ethernet header
  221. * @b: Pointer to Ethernet header
  222. *
  223. * Compare two ethernet headers, returns 0 if equal.
  224. * This assumes that the network header (i.e., IP header) is 4-byte
  225. * aligned OR the platform can handle unaligned access. This is the
  226. * case for all packets coming into netif_receive_skb or similar
  227. * entry points.
  228. */
  229. static inline unsigned long compare_ether_header(const void *a, const void *b)
  230. {
  231. #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
  232. unsigned long fold;
  233. /*
  234. * We want to compare 14 bytes:
  235. * [a0 ... a13] ^ [b0 ... b13]
  236. * Use two long XOR, ORed together, with an overlap of two bytes.
  237. * [a0 a1 a2 a3 a4 a5 a6 a7 ] ^ [b0 b1 b2 b3 b4 b5 b6 b7 ] |
  238. * [a6 a7 a8 a9 a10 a11 a12 a13] ^ [b6 b7 b8 b9 b10 b11 b12 b13]
  239. * This means the [a6 a7] ^ [b6 b7] part is done two times.
  240. */
  241. fold = *(unsigned long *)a ^ *(unsigned long *)b;
  242. fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6);
  243. return fold;
  244. #else
  245. u32 *a32 = (u32 *)((u8 *)a + 2);
  246. u32 *b32 = (u32 *)((u8 *)b + 2);
  247. return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) |
  248. (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]);
  249. #endif
  250. }
  251. #endif /* _LINUX_ETHERDEVICE_H */