2 * Copyright (c) 2015 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 * ip4/ip_checksum.c: ip/tcp/udp checksums
18 * Copyright (c) 2008 Eliot Dresselhaus
20 * Permission is hereby granted, free of charge, to any person obtaining
21 * a copy of this software and associated documentation files (the
22 * "Software"), to deal in the Software without restriction, including
23 * without limitation the rights to use, copy, modify, merge, publish,
24 * distribute, sublicense, and/or sell copies of the Software, and to
25 * permit persons to whom the Software is furnished to do so, subject to
26 * the following conditions:
28 * The above copyright notice and this permission notice shall be
29 * included in all copies or substantial portions of the Software.
31 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
32 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
33 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
34 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
35 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
36 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
37 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
40 #include <vnet/ip/ip.h>
43 ip_incremental_checksum (ip_csum_t sum, void * _data, uword n_bytes)
45 uword data = pointer_to_uword (_data);
51 /* Align data pointer to 64 bits. */
54 if (n_bytes >= sizeof (t) \
55 && sizeof (t) < sizeof (ip_csum_t) \
56 && (data % (2 * sizeof (t))) != 0) \
58 sum0 += * uword_to_pointer (data, t *); \
60 n_bytes -= sizeof (t); \
66 if (BITS (ip_csum_t) > 32)
72 ip_csum_t * d = uword_to_pointer (data, ip_csum_t *);
74 while (n_bytes >= 2 * sizeof (d[0]))
76 sum0 = ip_csum_with_carry (sum0, d[0]);
77 sum1 = ip_csum_with_carry (sum1, d[1]);
79 n_bytes -= 2 * sizeof (d[0]);
82 data = pointer_to_uword (d);
87 if (n_bytes >= sizeof (t) && sizeof (t) <= sizeof (ip_csum_t)) \
89 sum0 = ip_csum_with_carry (sum0, * uword_to_pointer (data, t *)); \
91 n_bytes -= sizeof (t); \
95 if (BITS (ip_csum_t) > 32)
103 /* Combine even and odd sums. */
104 sum0 = ip_csum_with_carry (sum0, sum1);
110 ip_csum_and_memcpy (ip_csum_t sum, void * dst, void * src, uword n_bytes)
112 uword n_left, n_left_odd;
113 ip_csum_t * dst_even, * src_even;
114 ip_csum_t sum0 = sum, sum1;
116 dst_even = uword_to_pointer
117 (pointer_to_uword (dst) &~ (sizeof (sum) - 1),
122 if ((n_left_odd = dst - (void *) dst_even))
124 u8 * d8 = dst, * s8 = src;
127 n_copy_odd = clib_min (n_left, n_left_odd);
129 for (i = 0; i < n_copy_odd; i++)
132 if (n_copy_odd != n_left_odd)
135 sum0 = ip_csum_with_carry (sum0, dst_even[0]);
137 src_even = (void *) (src + n_copy_odd);
138 n_left -= n_left_odd;
142 while (n_left >= 2 * sizeof (dst_even[0]))
144 ip_csum_t dst0, dst1;
146 dst0 = clib_mem_unaligned (&src_even[0], ip_csum_t);
147 dst1 = clib_mem_unaligned (&src_even[1], ip_csum_t);
154 n_left -= 2 * sizeof (dst_even[0]);
156 sum0 = ip_csum_with_carry (sum0, dst0);
157 sum1 = ip_csum_with_carry (sum1, dst1);
160 if (n_left >= 1 * sizeof (dst_even[0]))
164 dst0 = clib_mem_unaligned (&src_even[0], ip_csum_t);
170 n_left -= 1 * sizeof (dst_even[0]);
172 sum0 = ip_csum_with_carry (sum0, dst0);
177 u8 * d8 = dst, * s8 = src;
179 for (i = 0; i < n_left; i++)
183 return ip_csum_with_carry (sum0, sum1);