diff options
Diffstat (limited to 'vnet/vnet/ip/ip_checksum.c')
| -rw-r--r-- | vnet/vnet/ip/ip_checksum.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/vnet/vnet/ip/ip_checksum.c b/vnet/vnet/ip/ip_checksum.c new file mode 100644 index 00000000000..23e7889bc7e --- /dev/null +++ b/vnet/vnet/ip/ip_checksum.c @@ -0,0 +1,184 @@ +/* + * 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, n_left_odd; + ip_csum_t * dst_even, * src_even; + ip_csum_t sum0 = sum, sum1; + + dst_even = uword_to_pointer + (pointer_to_uword (dst) &~ (sizeof (sum) - 1), + ip_csum_t *); + src_even = src; + + n_left = n_bytes; + if ((n_left_odd = dst - (void *) dst_even)) + { + u8 * d8 = dst, * s8 = src; + uword i, n_copy_odd; + + n_copy_odd = clib_min (n_left, n_left_odd); + + for (i = 0; i < n_copy_odd; i++) + d8[i] = s8[i]; + + if (n_copy_odd != n_left_odd) + return sum0; + + sum0 = ip_csum_with_carry (sum0, dst_even[0]); + dst_even += 1; + src_even = (void *) (src + n_copy_odd); + n_left -= n_left_odd; + } + + sum1 = 0; + while (n_left >= 2 * sizeof (dst_even[0])) + { + ip_csum_t dst0, dst1; + + 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_even += 2; + src_even += 2; + n_left -= 2 * sizeof (dst_even[0]); + + sum0 = ip_csum_with_carry (sum0, dst0); + sum1 = ip_csum_with_carry (sum1, dst1); + } + + if (n_left >= 1 * sizeof (dst_even[0])) + { + ip_csum_t dst0; + + dst0 = clib_mem_unaligned (&src_even[0], ip_csum_t); + + dst_even[0] = dst0; + + dst_even += 1; + src_even += 1; + n_left -= 1 * sizeof (dst_even[0]); + + sum0 = ip_csum_with_carry (sum0, dst0); + } + + if (n_left > 0) + { + u8 * d8 = dst, * s8 = src; + uword i; + for (i = 0; i < n_left; i++) + d8[i] = s8[i]; + } + + return ip_csum_with_carry (sum0, sum1); +} |