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);
52 * Align pointer to 64 bits. The ip checksum is a 16-bit
53 * one's complememt sum. It's impractical to optimize
54 * the calculation if the incoming address is odd.
58 if (n_bytes >= sizeof (t) \
59 && sizeof (t) < sizeof (ip_csum_t) \
60 && (data % (2 * sizeof (t))) != 0) \
62 sum0 += * uword_to_pointer (data, t *); \
64 n_bytes -= sizeof (t); \
68 if (PREDICT_TRUE ((data & 1) == 0))
71 if (BITS (ip_csum_t) > 32)
77 ip_csum_t *d = uword_to_pointer (data, ip_csum_t *);
79 while (n_bytes >= 2 * sizeof (d[0]))
81 sum0 = ip_csum_with_carry (sum0, d[0]);
82 sum1 = ip_csum_with_carry (sum1, d[1]);
84 n_bytes -= 2 * sizeof (d[0]);
87 data = pointer_to_uword (d);
92 if (n_bytes >= sizeof (t) && sizeof (t) <= sizeof (ip_csum_t)) \
94 sum0 = ip_csum_with_carry (sum0, * uword_to_pointer (data, t *)); \
96 n_bytes -= sizeof (t); \
100 if (BITS (ip_csum_t) > 32)
108 /* Combine even and odd sums. */
109 sum0 = ip_csum_with_carry (sum0, sum1);
115 * Note: the tcp / udp checksum calculation is performance critical
116 * [e.g. when NIC h/w offload is not available],
117 * so it's worth producing architecture-dependent code.
119 * ip_incremental_checksum() is an always-inlined static
120 * function which uses the function pointer we set up in
121 * ip_checksum_init().
124 ip_csum_t (*vnet_incremental_checksum_fp) (ip_csum_t, void *, uword);
127 ip_checksum_init (vlib_main_t *vm)
129 vnet_incremental_checksum_fp = _ip_incremental_checksum;
133 VLIB_INIT_FUNCTION (ip_checksum_init);
137 static const char test_pkt[] = {
138 0x45, 0x00, 0x00, 0x3c, 0x5d, 0x6f, 0x40, 0x00,
139 0x40, 0x06, 0x3f, 0x6b, 0x0a, 0x76, 0x72, 0x44,
140 0x0a, 0x56, 0x16, 0xd2,
143 static clib_error_t *
144 test_ip_checksum_fn (vlib_main_t * vm,
145 unformat_input_t * input, vlib_cli_command_t * cmd)
152 vec_validate (align_test, ARRAY_LEN (test_pkt) + 7);
154 for (offset = 0; offset < 8; offset++)
156 memcpy (align_test + offset, test_pkt, ARRAY_LEN (test_pkt));
158 hp = (ip4_header_t *) (align_test + offset);
159 csum = ip4_header_checksum (hp);
161 vlib_cli_output (vm, "offset %d checksum %u expected result 27455",
169 VLIB_CLI_COMMAND (test_checksum, static) =
171 .path = "test ip checksum",
172 .short_help = "test ip checksum",
173 .function = test_ip_checksum_fn,
177 #endif /* CLIB_DEBUG */
180 * fd.io coding-style-patch-verification: ON
183 * eval: (c-set-style "gnu")