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-rw-r--r--src/vnet/ip/ip_checksum.c228
1 files changed, 228 insertions, 0 deletions
diff --git a/src/vnet/ip/ip_checksum.c b/src/vnet/ip/ip_checksum.c
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+++ b/src/vnet/ip/ip_checksum.c
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+/*
+ * Copyright (c) 2015 Cisco and/or its affiliates.
+ * 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:
+ *
+ * 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.
+ */
+/*
+ * ip4/ip_checksum.c: ip/tcp/udp checksums
+ *
+ * Copyright (c) 2008 Eliot Dresselhaus
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <vnet/ip/ip.h>
+
+ip_csum_t
+ip_incremental_checksum (ip_csum_t sum, void *_data, uword n_bytes)
+{
+ uword data = pointer_to_uword (_data);
+ ip_csum_t sum0, sum1;
+
+ sum0 = 0;
+ sum1 = sum;
+
+ /* Align data pointer to 64 bits. */
+#define _(t) \
+do { \
+ if (n_bytes >= sizeof (t) \
+ && sizeof (t) < sizeof (ip_csum_t) \
+ && (data % (2 * sizeof (t))) != 0) \
+ { \
+ sum0 += * uword_to_pointer (data, t *); \
+ data += sizeof (t); \
+ n_bytes -= sizeof (t); \
+ } \
+} while (0)
+
+ _(u8);
+ _(u16);
+ if (BITS (ip_csum_t) > 32)
+ _(u32);
+
+#undef _
+
+ {
+ ip_csum_t *d = uword_to_pointer (data, ip_csum_t *);
+
+ while (n_bytes >= 2 * sizeof (d[0]))
+ {
+ sum0 = ip_csum_with_carry (sum0, d[0]);
+ sum1 = ip_csum_with_carry (sum1, d[1]);
+ d += 2;
+ n_bytes -= 2 * sizeof (d[0]);
+ }
+
+ data = pointer_to_uword (d);
+ }
+
+#define _(t) \
+do { \
+ if (n_bytes >= sizeof (t) && sizeof (t) <= sizeof (ip_csum_t)) \
+ { \
+ sum0 = ip_csum_with_carry (sum0, * uword_to_pointer (data, t *)); \
+ data += sizeof (t); \
+ n_bytes -= sizeof (t); \
+ } \
+} while (0)
+
+ if (BITS (ip_csum_t) > 32)
+ _(u64);
+ _(u32);
+ _(u16);
+ _(u8);
+
+#undef _
+
+ /* Combine even and odd sums. */
+ sum0 = ip_csum_with_carry (sum0, sum1);
+
+ return sum0;
+}
+
+ip_csum_t
+ip_csum_and_memcpy (ip_csum_t sum, void *dst, void *src, uword n_bytes)
+{
+ uword n_left;
+ ip_csum_t sum0 = sum, sum1;
+ n_left = n_bytes;
+
+ if (n_left && (pointer_to_uword (dst) & sizeof (u8)))
+ {
+ u8 *d8, val;
+
+ d8 = dst;
+ val = ((u8 *) src)[0];
+ d8[0] = val;
+ dst += 1;
+ src += 1;
+ n_left -= 1;
+ sum0 =
+ ip_csum_with_carry (sum0, val << (8 * CLIB_ARCH_IS_LITTLE_ENDIAN));
+ }
+
+ while ((n_left >= sizeof (u16))
+ && (pointer_to_uword (dst) & (sizeof (sum) - sizeof (u16))))
+ {
+ u16 *d16, *s16;
+
+ d16 = dst;
+ s16 = src;
+
+ d16[0] = clib_mem_unaligned (&s16[0], u16);
+
+ sum0 = ip_csum_with_carry (sum0, d16[0]);
+ dst += sizeof (u16);
+ src += sizeof (u16);
+ n_left -= sizeof (u16);
+ }
+
+ sum1 = 0;
+ while (n_left >= 2 * sizeof (sum))
+ {
+ ip_csum_t dst0, dst1;
+ ip_csum_t *dst_even, *src_even;
+
+ dst_even = dst;
+ src_even = src;
+ dst0 = clib_mem_unaligned (&src_even[0], ip_csum_t);
+ dst1 = clib_mem_unaligned (&src_even[1], ip_csum_t);
+
+ dst_even[0] = dst0;
+ dst_even[1] = dst1;
+
+ dst += 2 * sizeof (dst_even[0]);
+ src += 2 * sizeof (dst_even[0]);
+ n_left -= 2 * sizeof (dst_even[0]);
+
+ sum0 = ip_csum_with_carry (sum0, dst0);
+ sum1 = ip_csum_with_carry (sum1, dst1);
+ }
+
+ sum0 = ip_csum_with_carry (sum0, sum1);
+ while (n_left >= 1 * sizeof (sum))
+ {
+ ip_csum_t dst0, *dst_even, *src_even;
+
+ dst_even = dst;
+ src_even = src;
+
+ dst0 = clib_mem_unaligned (&src_even[0], ip_csum_t);
+
+ dst_even[0] = dst0;
+
+ dst += 1 * sizeof (sum);
+ src += 1 * sizeof (sum);
+ n_left -= 1 * sizeof (sum);
+
+ sum0 = ip_csum_with_carry (sum0, dst0);
+ }
+
+ while (n_left >= sizeof (u16))
+ {
+ u16 dst0, *dst_short, *src_short;
+
+ dst_short = dst;
+ src_short = src;
+
+ dst0 = clib_mem_unaligned (&src_short[0], u16);
+
+ dst_short[0] = dst0;
+
+ sum0 = ip_csum_with_carry (sum0, dst_short[0]);
+ dst += 1 * sizeof (dst0);
+ src += 1 * sizeof (dst0);
+ n_left -= 1 * sizeof (dst0);
+
+ }
+
+ if (n_left == 1)
+ {
+ u8 *d8, *s8, val;
+
+ d8 = dst;
+ s8 = src;
+
+ d8[0] = val = s8[0];
+ d8 += 1;
+ s8 += 1;
+ n_left -= 1;
+ sum0 = ip_csum_with_carry (sum0, val << (8 * CLIB_ARCH_IS_BIG_ENDIAN));
+ }
+
+ return sum0;
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */