/*
- * Copyright (c) 2008, 2009 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010 Nicira Networks.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include <config.h>
#include "csum.h"
+#include "unaligned.h"
/* Returns the IP checksum of the 'n' bytes in 'data'.
*
{
const uint16_t *data = data_;
- for (; n > 1; n -= 2) {
- partial = csum_add16(partial, *data++);
+ for (; n > 1; n -= 2, data++) {
+ partial = csum_add16(partial, get_unaligned_u16(data));
}
if (n) {
partial += *(uint8_t *) data;
uint16_t
csum_finish(uint32_t partial)
{
- return ~((partial & 0xffff) + (partial >> 16));
+ while (partial >> 16) {
+ partial = (partial & 0xffff) + (partial >> 16);
+ }
+ return ~partial;
}
/* Returns the new checksum for a packet in which the checksum field previously
uint16_t m_complement = ~old_u16;
uint16_t m_prime = new_u16;
uint32_t sum = hc_complement + m_complement + m_prime;
- uint16_t hc_prime_complement = sum + (sum >> 16);
- return ~hc_prime_complement;
+ return csum_finish(sum);
}
/* Returns the new checksum for a packet in which the checksum field previously