Changeset fcae007 in mainline for uspace/lib/nic/src/nic_rx_control.c
- Timestamp:
- 2012-01-22T13:23:21Z (13 years ago)
- Branches:
- lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export
- Children:
- 08cc26b
- Parents:
- d9bbe45 (diff), 10a5479d (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
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- 1 edited
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uspace/lib/nic/src/nic_rx_control.c
rd9bbe45 rfcae007 40 40 #include <bool.h> 41 41 #include <errno.h> 42 #include <net/device.h> 43 #include <net_checksum.h> 44 #include <packet_client.h> 42 #include <mem.h> 43 #include <nic/nic.h> 45 44 #include "nic_rx_control.h" 46 45 … … 488 487 } 489 488 489 /** Polynomial used in multicast address hashing */ 490 #define CRC_MCAST_POLYNOMIAL 0x04c11db6 491 492 /** Compute the standard hash from MAC 493 * 494 * Hashing MAC into 64 possible values and using the value as index to 495 * 64bit number. 496 * 497 * The code is copied from qemu-0.13's implementation of ne2000 and rt8139 498 * drivers, but according to documentation there it originates in FreeBSD. 499 * 500 * @param[in] addr The 6-byte MAC address to be hashed 501 * 502 * @return 64-bit number with only single bit set to 1 503 * 504 */ 505 static uint64_t multicast_hash(const uint8_t addr[6]) 506 { 507 uint32_t crc; 508 int carry, i, j; 509 uint8_t b; 510 511 crc = 0xffffffff; 512 for (i = 0; i < 6; i++) { 513 b = addr[i]; 514 for (j = 0; j < 8; j++) { 515 carry = ((crc & 0x80000000L) ? 1 : 0) ^ (b & 0x01); 516 crc <<= 1; 517 b >>= 1; 518 if (carry) 519 crc = ((crc ^ CRC_MCAST_POLYNOMIAL) | carry); 520 } 521 } 522 523 uint64_t one64 = 1; 524 return one64 << (crc >> 26); 525 } 526 527 490 528 /** 491 529 * Computes hash for the address list based on standard multicast address
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