/*
- * Copyright (c) 2008 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2013, 2015 Nicira, Inc.
*
- * Permission to use, copy, modify, and/or distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
*
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
*/
#include <config.h>
#include "csum.h"
+#include "unaligned.h"
-/* Returns the IP checksum of the 'n' bytes in 'data'. */
-uint16_t
+#ifndef __CHECKER__
+/* Returns the IP checksum of the 'n' bytes in 'data'.
+ *
+ * The return value has the same endianness as the data. That is, if 'data'
+ * consists of a packet in network byte order, then the return value is a value
+ * in network byte order, and if 'data' consists of a data structure in host
+ * byte order, then the return value is in host byte order. */
+ovs_be16
csum(const void *data, size_t n)
{
return csum_finish(csum_continue(0, data, n));
}
-/* Adds the 16 bits in 'new' to the partial IP checksum 'partial' and returns
- * the updated checksum. (To start a new checksum, pass 0 for 'partial'. To
- * obtain the finished checksum, pass the return value to csum_finish().) */
-uint32_t
-csum_add16(uint32_t partial, uint16_t new)
-{
- return partial + new;
-}
-
-/* Adds the 32 bits in 'new' to the partial IP checksum 'partial' and returns
- * the updated checksum. (To start a new checksum, pass 0 for 'partial'. To
- * obtain the finished checksum, pass the return value to csum_finish().) */
-uint32_t
-csum_add32(uint32_t partial, uint32_t new)
-{
- return partial + (new >> 16) + (new & 0xffff);
-}
-
-
/* Adds the 'n' bytes in 'data' to the partial IP checksum 'partial' and
* returns the updated checksum. (To start a new checksum, pass 0 for
* 'partial'. To obtain the finished checksum, pass the return value to
uint32_t
csum_continue(uint32_t partial, const void *data_, size_t n)
{
- const uint16_t *data = data_;
+ const ovs_be16 *data = data_;
- for (; n > 1; n -= 2) {
- partial = csum_add16(partial, *data++);
+ for (; n > 1; n -= 2, data++) {
+ partial = csum_add16(partial, get_unaligned_be16(data));
}
if (n) {
partial += *(uint8_t *) data;
}
/* Returns the IP checksum corresponding to 'partial', which is a value updated
- * by some combination of csum_add16(), csum_add32(), and csum_continue(). */
-uint16_t
+ * by some combination of csum_add16(), csum_add32(), and csum_continue().
+ *
+ * The return value has the same endianness as the checksummed data. That is,
+ * if the data consist of a packet in network byte order, then the return value
+ * is a value in network byte order, and if the data are a data structure in
+ * host byte order, then the return value is in host byte order. */
+ovs_be16
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
* contained 'old_csum' and in which a field that contained 'old_u16' was
* changed to contain 'new_u16'. */
-uint16_t
-recalc_csum16(uint16_t old_csum, uint16_t old_u16, uint16_t new_u16)
+ovs_be16
+recalc_csum16(ovs_be16 old_csum, ovs_be16 old_u16, ovs_be16 new_u16)
{
/* Ones-complement arithmetic is endian-independent, so this code does not
* use htons() or ntohs().
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
* contained 'old_csum' and in which a field that contained 'old_u32' was
* changed to contain 'new_u32'. */
-uint16_t
-recalc_csum32(uint16_t old_csum, uint32_t old_u32, uint32_t new_u32)
+ovs_be16
+recalc_csum32(ovs_be16 old_csum, ovs_be32 old_u32, ovs_be32 new_u32)
{
return recalc_csum16(recalc_csum16(old_csum, old_u32, new_u32),
old_u32 >> 16, new_u32 >> 16);
}
+
+/* Returns the new checksum for a packet in which the checksum field previously
+ * contained 'old_csum' and in which a field that contained the 6 bytes at
+ * 'old_mac' was changed to contain the 6 bytes at 'new_mac'. */
+ovs_be16
+recalc_csum48(ovs_be16 old_csum, const struct eth_addr old_mac,
+ const struct eth_addr new_mac)
+{
+ ovs_be16 new_csum = old_csum;
+
+ for (int i = 0; i < 3; ++i) {
+ new_csum = recalc_csum16(new_csum, old_mac.be16[i], new_mac.be16[i]);
+ }
+
+ return new_csum;
+}
+
+/* Returns the new checksum for a packet in which the checksum field previously
+ * contained 'old_csum' and in which a field that contained 'old_u32[4]' was
+ * changed to contain 'new_u32[4]'. */
+ovs_be16
+recalc_csum128(ovs_be16 old_csum, ovs_16aligned_be32 old_u32[4],
+ const ovs_be32 new_u32[4])
+{
+ ovs_be16 new_csum = old_csum;
+ int i;
+
+ for (i = 0; i < 4; ++i) {
+ new_csum = recalc_csum32(new_csum,
+ get_16aligned_be32(&old_u32[i]), new_u32[i]);
+ }
+ return new_csum;
+}
+#else /* __CHECKER__ */
+/* Making sparse happy with these functions also makes them unreadable, so
+ * don't bother to show it their implementations. */
+#endif
projects / cascardo / ovs.git / blobdiff